diff.con commit Merge branch 'maint' to sync with 1.7.2.2 (c11969d)
   1/*
   2 * Copyright (C) 2005 Junio C Hamano
   3 */
   4#include "cache.h"
   5#include "quote.h"
   6#include "diff.h"
   7#include "diffcore.h"
   8#include "delta.h"
   9#include "xdiff-interface.h"
  10#include "color.h"
  11#include "attr.h"
  12#include "run-command.h"
  13#include "utf8.h"
  14#include "userdiff.h"
  15#include "sigchain.h"
  16#include "submodule.h"
  17#include "ll-merge.h"
  18
  19#ifdef NO_FAST_WORKING_DIRECTORY
  20#define FAST_WORKING_DIRECTORY 0
  21#else
  22#define FAST_WORKING_DIRECTORY 1
  23#endif
  24
  25static int diff_detect_rename_default;
  26static int diff_rename_limit_default = 200;
  27static int diff_suppress_blank_empty;
  28int diff_use_color_default = -1;
  29static const char *diff_word_regex_cfg;
  30static const char *external_diff_cmd_cfg;
  31int diff_auto_refresh_index = 1;
  32static int diff_mnemonic_prefix;
  33static int diff_no_prefix;
  34static struct diff_options default_diff_options;
  35
  36static char diff_colors[][COLOR_MAXLEN] = {
  37        GIT_COLOR_RESET,
  38        GIT_COLOR_NORMAL,       /* PLAIN */
  39        GIT_COLOR_BOLD,         /* METAINFO */
  40        GIT_COLOR_CYAN,         /* FRAGINFO */
  41        GIT_COLOR_RED,          /* OLD */
  42        GIT_COLOR_GREEN,        /* NEW */
  43        GIT_COLOR_YELLOW,       /* COMMIT */
  44        GIT_COLOR_BG_RED,       /* WHITESPACE */
  45        GIT_COLOR_NORMAL,       /* FUNCINFO */
  46};
  47
  48static int parse_diff_color_slot(const char *var, int ofs)
  49{
  50        if (!strcasecmp(var+ofs, "plain"))
  51                return DIFF_PLAIN;
  52        if (!strcasecmp(var+ofs, "meta"))
  53                return DIFF_METAINFO;
  54        if (!strcasecmp(var+ofs, "frag"))
  55                return DIFF_FRAGINFO;
  56        if (!strcasecmp(var+ofs, "old"))
  57                return DIFF_FILE_OLD;
  58        if (!strcasecmp(var+ofs, "new"))
  59                return DIFF_FILE_NEW;
  60        if (!strcasecmp(var+ofs, "commit"))
  61                return DIFF_COMMIT;
  62        if (!strcasecmp(var+ofs, "whitespace"))
  63                return DIFF_WHITESPACE;
  64        if (!strcasecmp(var+ofs, "func"))
  65                return DIFF_FUNCINFO;
  66        return -1;
  67}
  68
  69static int git_config_rename(const char *var, const char *value)
  70{
  71        if (!value)
  72                return DIFF_DETECT_RENAME;
  73        if (!strcasecmp(value, "copies") || !strcasecmp(value, "copy"))
  74                return  DIFF_DETECT_COPY;
  75        return git_config_bool(var,value) ? DIFF_DETECT_RENAME : 0;
  76}
  77
  78/*
  79 * These are to give UI layer defaults.
  80 * The core-level commands such as git-diff-files should
  81 * never be affected by the setting of diff.renames
  82 * the user happens to have in the configuration file.
  83 */
  84int git_diff_ui_config(const char *var, const char *value, void *cb)
  85{
  86        if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
  87                diff_use_color_default = git_config_colorbool(var, value, -1);
  88                return 0;
  89        }
  90        if (!strcmp(var, "diff.renames")) {
  91                diff_detect_rename_default = git_config_rename(var, value);
  92                return 0;
  93        }
  94        if (!strcmp(var, "diff.autorefreshindex")) {
  95                diff_auto_refresh_index = git_config_bool(var, value);
  96                return 0;
  97        }
  98        if (!strcmp(var, "diff.mnemonicprefix")) {
  99                diff_mnemonic_prefix = git_config_bool(var, value);
 100                return 0;
 101        }
 102        if (!strcmp(var, "diff.noprefix")) {
 103                diff_no_prefix = git_config_bool(var, value);
 104                return 0;
 105        }
 106        if (!strcmp(var, "diff.external"))
 107                return git_config_string(&external_diff_cmd_cfg, var, value);
 108        if (!strcmp(var, "diff.wordregex"))
 109                return git_config_string(&diff_word_regex_cfg, var, value);
 110
 111        if (!strcmp(var, "diff.ignoresubmodules"))
 112                handle_ignore_submodules_arg(&default_diff_options, value);
 113
 114        return git_diff_basic_config(var, value, cb);
 115}
 116
 117int git_diff_basic_config(const char *var, const char *value, void *cb)
 118{
 119        if (!strcmp(var, "diff.renamelimit")) {
 120                diff_rename_limit_default = git_config_int(var, value);
 121                return 0;
 122        }
 123
 124        switch (userdiff_config(var, value)) {
 125                case 0: break;
 126                case -1: return -1;
 127                default: return 0;
 128        }
 129
 130        if (!prefixcmp(var, "diff.color.") || !prefixcmp(var, "color.diff.")) {
 131                int slot = parse_diff_color_slot(var, 11);
 132                if (slot < 0)
 133                        return 0;
 134                if (!value)
 135                        return config_error_nonbool(var);
 136                color_parse(value, var, diff_colors[slot]);
 137                return 0;
 138        }
 139
 140        /* like GNU diff's --suppress-blank-empty option  */
 141        if (!strcmp(var, "diff.suppressblankempty") ||
 142                        /* for backwards compatibility */
 143                        !strcmp(var, "diff.suppress-blank-empty")) {
 144                diff_suppress_blank_empty = git_config_bool(var, value);
 145                return 0;
 146        }
 147
 148        if (!prefixcmp(var, "submodule."))
 149                return parse_submodule_config_option(var, value);
 150
 151        return git_color_default_config(var, value, cb);
 152}
 153
 154static char *quote_two(const char *one, const char *two)
 155{
 156        int need_one = quote_c_style(one, NULL, NULL, 1);
 157        int need_two = quote_c_style(two, NULL, NULL, 1);
 158        struct strbuf res = STRBUF_INIT;
 159
 160        if (need_one + need_two) {
 161                strbuf_addch(&res, '"');
 162                quote_c_style(one, &res, NULL, 1);
 163                quote_c_style(two, &res, NULL, 1);
 164                strbuf_addch(&res, '"');
 165        } else {
 166                strbuf_addstr(&res, one);
 167                strbuf_addstr(&res, two);
 168        }
 169        return strbuf_detach(&res, NULL);
 170}
 171
 172static const char *external_diff(void)
 173{
 174        static const char *external_diff_cmd = NULL;
 175        static int done_preparing = 0;
 176
 177        if (done_preparing)
 178                return external_diff_cmd;
 179        external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
 180        if (!external_diff_cmd)
 181                external_diff_cmd = external_diff_cmd_cfg;
 182        done_preparing = 1;
 183        return external_diff_cmd;
 184}
 185
 186static struct diff_tempfile {
 187        const char *name; /* filename external diff should read from */
 188        char hex[41];
 189        char mode[10];
 190        char tmp_path[PATH_MAX];
 191} diff_temp[2];
 192
 193typedef unsigned long (*sane_truncate_fn)(char *line, unsigned long len);
 194
 195struct emit_callback {
 196        int color_diff;
 197        unsigned ws_rule;
 198        int blank_at_eof_in_preimage;
 199        int blank_at_eof_in_postimage;
 200        int lno_in_preimage;
 201        int lno_in_postimage;
 202        sane_truncate_fn truncate;
 203        const char **label_path;
 204        struct diff_words_data *diff_words;
 205        struct diff_options *opt;
 206        int *found_changesp;
 207        struct strbuf *header;
 208};
 209
 210static int count_lines(const char *data, int size)
 211{
 212        int count, ch, completely_empty = 1, nl_just_seen = 0;
 213        count = 0;
 214        while (0 < size--) {
 215                ch = *data++;
 216                if (ch == '\n') {
 217                        count++;
 218                        nl_just_seen = 1;
 219                        completely_empty = 0;
 220                }
 221                else {
 222                        nl_just_seen = 0;
 223                        completely_empty = 0;
 224                }
 225        }
 226        if (completely_empty)
 227                return 0;
 228        if (!nl_just_seen)
 229                count++; /* no trailing newline */
 230        return count;
 231}
 232
 233static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
 234{
 235        if (!DIFF_FILE_VALID(one)) {
 236                mf->ptr = (char *)""; /* does not matter */
 237                mf->size = 0;
 238                return 0;
 239        }
 240        else if (diff_populate_filespec(one, 0))
 241                return -1;
 242
 243        mf->ptr = one->data;
 244        mf->size = one->size;
 245        return 0;
 246}
 247
 248static int count_trailing_blank(mmfile_t *mf, unsigned ws_rule)
 249{
 250        char *ptr = mf->ptr;
 251        long size = mf->size;
 252        int cnt = 0;
 253
 254        if (!size)
 255                return cnt;
 256        ptr += size - 1; /* pointing at the very end */
 257        if (*ptr != '\n')
 258                ; /* incomplete line */
 259        else
 260                ptr--; /* skip the last LF */
 261        while (mf->ptr < ptr) {
 262                char *prev_eol;
 263                for (prev_eol = ptr; mf->ptr <= prev_eol; prev_eol--)
 264                        if (*prev_eol == '\n')
 265                                break;
 266                if (!ws_blank_line(prev_eol + 1, ptr - prev_eol, ws_rule))
 267                        break;
 268                cnt++;
 269                ptr = prev_eol - 1;
 270        }
 271        return cnt;
 272}
 273
 274static void check_blank_at_eof(mmfile_t *mf1, mmfile_t *mf2,
 275                               struct emit_callback *ecbdata)
 276{
 277        int l1, l2, at;
 278        unsigned ws_rule = ecbdata->ws_rule;
 279        l1 = count_trailing_blank(mf1, ws_rule);
 280        l2 = count_trailing_blank(mf2, ws_rule);
 281        if (l2 <= l1) {
 282                ecbdata->blank_at_eof_in_preimage = 0;
 283                ecbdata->blank_at_eof_in_postimage = 0;
 284                return;
 285        }
 286        at = count_lines(mf1->ptr, mf1->size);
 287        ecbdata->blank_at_eof_in_preimage = (at - l1) + 1;
 288
 289        at = count_lines(mf2->ptr, mf2->size);
 290        ecbdata->blank_at_eof_in_postimage = (at - l2) + 1;
 291}
 292
 293static void emit_line_0(struct diff_options *o, const char *set, const char *reset,
 294                        int first, const char *line, int len)
 295{
 296        int has_trailing_newline, has_trailing_carriage_return;
 297        int nofirst;
 298        FILE *file = o->file;
 299
 300        if (o->output_prefix) {
 301                struct strbuf *msg = NULL;
 302                msg = o->output_prefix(o, o->output_prefix_data);
 303                assert(msg);
 304                fwrite(msg->buf, msg->len, 1, file);
 305        }
 306
 307        if (len == 0) {
 308                has_trailing_newline = (first == '\n');
 309                has_trailing_carriage_return = (!has_trailing_newline &&
 310                                                (first == '\r'));
 311                nofirst = has_trailing_newline || has_trailing_carriage_return;
 312        } else {
 313                has_trailing_newline = (len > 0 && line[len-1] == '\n');
 314                if (has_trailing_newline)
 315                        len--;
 316                has_trailing_carriage_return = (len > 0 && line[len-1] == '\r');
 317                if (has_trailing_carriage_return)
 318                        len--;
 319                nofirst = 0;
 320        }
 321
 322        if (len || !nofirst) {
 323                fputs(set, file);
 324                if (!nofirst)
 325                        fputc(first, file);
 326                fwrite(line, len, 1, file);
 327                fputs(reset, file);
 328        }
 329        if (has_trailing_carriage_return)
 330                fputc('\r', file);
 331        if (has_trailing_newline)
 332                fputc('\n', file);
 333}
 334
 335static void emit_line(struct diff_options *o, const char *set, const char *reset,
 336                      const char *line, int len)
 337{
 338        emit_line_0(o, set, reset, line[0], line+1, len-1);
 339}
 340
 341static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line, int len)
 342{
 343        if (!((ecbdata->ws_rule & WS_BLANK_AT_EOF) &&
 344              ecbdata->blank_at_eof_in_preimage &&
 345              ecbdata->blank_at_eof_in_postimage &&
 346              ecbdata->blank_at_eof_in_preimage <= ecbdata->lno_in_preimage &&
 347              ecbdata->blank_at_eof_in_postimage <= ecbdata->lno_in_postimage))
 348                return 0;
 349        return ws_blank_line(line, len, ecbdata->ws_rule);
 350}
 351
 352static void emit_add_line(const char *reset,
 353                          struct emit_callback *ecbdata,
 354                          const char *line, int len)
 355{
 356        const char *ws = diff_get_color(ecbdata->color_diff, DIFF_WHITESPACE);
 357        const char *set = diff_get_color(ecbdata->color_diff, DIFF_FILE_NEW);
 358
 359        if (!*ws)
 360                emit_line_0(ecbdata->opt, set, reset, '+', line, len);
 361        else if (new_blank_line_at_eof(ecbdata, line, len))
 362                /* Blank line at EOF - paint '+' as well */
 363                emit_line_0(ecbdata->opt, ws, reset, '+', line, len);
 364        else {
 365                /* Emit just the prefix, then the rest. */
 366                emit_line_0(ecbdata->opt, set, reset, '+', "", 0);
 367                ws_check_emit(line, len, ecbdata->ws_rule,
 368                              ecbdata->opt->file, set, reset, ws);
 369        }
 370}
 371
 372static void emit_hunk_header(struct emit_callback *ecbdata,
 373                             const char *line, int len)
 374{
 375        const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
 376        const char *frag = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
 377        const char *func = diff_get_color(ecbdata->color_diff, DIFF_FUNCINFO);
 378        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
 379        static const char atat[2] = { '@', '@' };
 380        const char *cp, *ep;
 381        struct strbuf msgbuf = STRBUF_INIT;
 382        int org_len = len;
 383        int i = 1;
 384
 385        /*
 386         * As a hunk header must begin with "@@ -<old>, +<new> @@",
 387         * it always is at least 10 bytes long.
 388         */
 389        if (len < 10 ||
 390            memcmp(line, atat, 2) ||
 391            !(ep = memmem(line + 2, len - 2, atat, 2))) {
 392                emit_line(ecbdata->opt, plain, reset, line, len);
 393                return;
 394        }
 395        ep += 2; /* skip over @@ */
 396
 397        /* The hunk header in fraginfo color */
 398        strbuf_add(&msgbuf, frag, strlen(frag));
 399        strbuf_add(&msgbuf, line, ep - line);
 400        strbuf_add(&msgbuf, reset, strlen(reset));
 401
 402        /*
 403         * trailing "\r\n"
 404         */
 405        for ( ; i < 3; i++)
 406                if (line[len - i] == '\r' || line[len - i] == '\n')
 407                        len--;
 408
 409        /* blank before the func header */
 410        for (cp = ep; ep - line < len; ep++)
 411                if (*ep != ' ' && *ep != '\t')
 412                        break;
 413        if (ep != cp) {
 414                strbuf_add(&msgbuf, plain, strlen(plain));
 415                strbuf_add(&msgbuf, cp, ep - cp);
 416                strbuf_add(&msgbuf, reset, strlen(reset));
 417        }
 418
 419        if (ep < line + len) {
 420                strbuf_add(&msgbuf, func, strlen(func));
 421                strbuf_add(&msgbuf, ep, line + len - ep);
 422                strbuf_add(&msgbuf, reset, strlen(reset));
 423        }
 424
 425        strbuf_add(&msgbuf, line + len, org_len - len);
 426        emit_line(ecbdata->opt, "", "", msgbuf.buf, msgbuf.len);
 427        strbuf_release(&msgbuf);
 428}
 429
 430static struct diff_tempfile *claim_diff_tempfile(void) {
 431        int i;
 432        for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
 433                if (!diff_temp[i].name)
 434                        return diff_temp + i;
 435        die("BUG: diff is failing to clean up its tempfiles");
 436}
 437
 438static int remove_tempfile_installed;
 439
 440static void remove_tempfile(void)
 441{
 442        int i;
 443        for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
 444                if (diff_temp[i].name == diff_temp[i].tmp_path)
 445                        unlink_or_warn(diff_temp[i].name);
 446                diff_temp[i].name = NULL;
 447        }
 448}
 449
 450static void remove_tempfile_on_signal(int signo)
 451{
 452        remove_tempfile();
 453        sigchain_pop(signo);
 454        raise(signo);
 455}
 456
 457static void print_line_count(FILE *file, int count)
 458{
 459        switch (count) {
 460        case 0:
 461                fprintf(file, "0,0");
 462                break;
 463        case 1:
 464                fprintf(file, "1");
 465                break;
 466        default:
 467                fprintf(file, "1,%d", count);
 468                break;
 469        }
 470}
 471
 472static void emit_rewrite_lines(struct emit_callback *ecb,
 473                               int prefix, const char *data, int size)
 474{
 475        const char *endp = NULL;
 476        static const char *nneof = " No newline at end of file\n";
 477        const char *old = diff_get_color(ecb->color_diff, DIFF_FILE_OLD);
 478        const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
 479
 480        while (0 < size) {
 481                int len;
 482
 483                endp = memchr(data, '\n', size);
 484                len = endp ? (endp - data + 1) : size;
 485                if (prefix != '+') {
 486                        ecb->lno_in_preimage++;
 487                        emit_line_0(ecb->opt, old, reset, '-',
 488                                    data, len);
 489                } else {
 490                        ecb->lno_in_postimage++;
 491                        emit_add_line(reset, ecb, data, len);
 492                }
 493                size -= len;
 494                data += len;
 495        }
 496        if (!endp) {
 497                const char *plain = diff_get_color(ecb->color_diff,
 498                                                   DIFF_PLAIN);
 499                emit_line_0(ecb->opt, plain, reset, '\\',
 500                            nneof, strlen(nneof));
 501        }
 502}
 503
 504static void emit_rewrite_diff(const char *name_a,
 505                              const char *name_b,
 506                              struct diff_filespec *one,
 507                              struct diff_filespec *two,
 508                              struct userdiff_driver *textconv_one,
 509                              struct userdiff_driver *textconv_two,
 510                              struct diff_options *o)
 511{
 512        int lc_a, lc_b;
 513        int color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
 514        const char *name_a_tab, *name_b_tab;
 515        const char *metainfo = diff_get_color(color_diff, DIFF_METAINFO);
 516        const char *fraginfo = diff_get_color(color_diff, DIFF_FRAGINFO);
 517        const char *reset = diff_get_color(color_diff, DIFF_RESET);
 518        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
 519        const char *a_prefix, *b_prefix;
 520        char *data_one, *data_two;
 521        size_t size_one, size_two;
 522        struct emit_callback ecbdata;
 523        char *line_prefix = "";
 524        struct strbuf *msgbuf;
 525
 526        if (o && o->output_prefix) {
 527                msgbuf = o->output_prefix(o, o->output_prefix_data);
 528                line_prefix = msgbuf->buf;
 529        }
 530
 531        if (diff_mnemonic_prefix && DIFF_OPT_TST(o, REVERSE_DIFF)) {
 532                a_prefix = o->b_prefix;
 533                b_prefix = o->a_prefix;
 534        } else {
 535                a_prefix = o->a_prefix;
 536                b_prefix = o->b_prefix;
 537        }
 538
 539        name_a += (*name_a == '/');
 540        name_b += (*name_b == '/');
 541        name_a_tab = strchr(name_a, ' ') ? "\t" : "";
 542        name_b_tab = strchr(name_b, ' ') ? "\t" : "";
 543
 544        strbuf_reset(&a_name);
 545        strbuf_reset(&b_name);
 546        quote_two_c_style(&a_name, a_prefix, name_a, 0);
 547        quote_two_c_style(&b_name, b_prefix, name_b, 0);
 548
 549        size_one = fill_textconv(textconv_one, one, &data_one);
 550        size_two = fill_textconv(textconv_two, two, &data_two);
 551
 552        memset(&ecbdata, 0, sizeof(ecbdata));
 553        ecbdata.color_diff = color_diff;
 554        ecbdata.found_changesp = &o->found_changes;
 555        ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
 556        ecbdata.opt = o;
 557        if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
 558                mmfile_t mf1, mf2;
 559                mf1.ptr = (char *)data_one;
 560                mf2.ptr = (char *)data_two;
 561                mf1.size = size_one;
 562                mf2.size = size_two;
 563                check_blank_at_eof(&mf1, &mf2, &ecbdata);
 564        }
 565        ecbdata.lno_in_preimage = 1;
 566        ecbdata.lno_in_postimage = 1;
 567
 568        lc_a = count_lines(data_one, size_one);
 569        lc_b = count_lines(data_two, size_two);
 570        fprintf(o->file,
 571                "%s%s--- %s%s%s\n%s%s+++ %s%s%s\n%s%s@@ -",
 572                line_prefix, metainfo, a_name.buf, name_a_tab, reset,
 573                line_prefix, metainfo, b_name.buf, name_b_tab, reset,
 574                line_prefix, fraginfo);
 575        print_line_count(o->file, lc_a);
 576        fprintf(o->file, " +");
 577        print_line_count(o->file, lc_b);
 578        fprintf(o->file, " @@%s\n", reset);
 579        if (lc_a)
 580                emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
 581        if (lc_b)
 582                emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
 583        if (textconv_one)
 584                free((char *)data_one);
 585        if (textconv_two)
 586                free((char *)data_two);
 587}
 588
 589struct diff_words_buffer {
 590        mmfile_t text;
 591        long alloc;
 592        struct diff_words_orig {
 593                const char *begin, *end;
 594        } *orig;
 595        int orig_nr, orig_alloc;
 596};
 597
 598static void diff_words_append(char *line, unsigned long len,
 599                struct diff_words_buffer *buffer)
 600{
 601        ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
 602        line++;
 603        len--;
 604        memcpy(buffer->text.ptr + buffer->text.size, line, len);
 605        buffer->text.size += len;
 606        buffer->text.ptr[buffer->text.size] = '\0';
 607}
 608
 609struct diff_words_style_elem
 610{
 611        const char *prefix;
 612        const char *suffix;
 613        const char *color; /* NULL; filled in by the setup code if
 614                            * color is enabled */
 615};
 616
 617struct diff_words_style
 618{
 619        enum diff_words_type type;
 620        struct diff_words_style_elem new, old, ctx;
 621        const char *newline;
 622};
 623
 624struct diff_words_style diff_words_styles[] = {
 625        { DIFF_WORDS_PORCELAIN, {"+", "\n"}, {"-", "\n"}, {" ", "\n"}, "~\n" },
 626        { DIFF_WORDS_PLAIN, {"{+", "+}"}, {"[-", "-]"}, {"", ""}, "\n" },
 627        { DIFF_WORDS_COLOR, {"", ""}, {"", ""}, {"", ""}, "\n" }
 628};
 629
 630struct diff_words_data {
 631        struct diff_words_buffer minus, plus;
 632        const char *current_plus;
 633        int last_minus;
 634        struct diff_options *opt;
 635        regex_t *word_regex;
 636        enum diff_words_type type;
 637        struct diff_words_style *style;
 638};
 639
 640static int fn_out_diff_words_write_helper(FILE *fp,
 641                                          struct diff_words_style_elem *st_el,
 642                                          const char *newline,
 643                                          size_t count, const char *buf,
 644                                          const char *line_prefix)
 645{
 646        int print = 0;
 647
 648        while (count) {
 649                char *p = memchr(buf, '\n', count);
 650                if (print)
 651                        fputs(line_prefix, fp);
 652                if (p != buf) {
 653                        if (st_el->color && fputs(st_el->color, fp) < 0)
 654                                return -1;
 655                        if (fputs(st_el->prefix, fp) < 0 ||
 656                            fwrite(buf, p ? p - buf : count, 1, fp) != 1 ||
 657                            fputs(st_el->suffix, fp) < 0)
 658                                return -1;
 659                        if (st_el->color && *st_el->color
 660                            && fputs(GIT_COLOR_RESET, fp) < 0)
 661                                return -1;
 662                }
 663                if (!p)
 664                        return 0;
 665                if (fputs(newline, fp) < 0)
 666                        return -1;
 667                count -= p + 1 - buf;
 668                buf = p + 1;
 669                print = 1;
 670        }
 671        return 0;
 672}
 673
 674/*
 675 * '--color-words' algorithm can be described as:
 676 *
 677 *   1. collect a the minus/plus lines of a diff hunk, divided into
 678 *      minus-lines and plus-lines;
 679 *
 680 *   2. break both minus-lines and plus-lines into words and
 681 *      place them into two mmfile_t with one word for each line;
 682 *
 683 *   3. use xdiff to run diff on the two mmfile_t to get the words level diff;
 684 *
 685 * And for the common parts of the both file, we output the plus side text.
 686 * diff_words->current_plus is used to trace the current position of the plus file
 687 * which printed. diff_words->last_minus is used to trace the last minus word
 688 * printed.
 689 *
 690 * For '--graph' to work with '--color-words', we need to output the graph prefix
 691 * on each line of color words output. Generally, there are two conditions on
 692 * which we should output the prefix.
 693 *
 694 *   1. diff_words->last_minus == 0 &&
 695 *      diff_words->current_plus == diff_words->plus.text.ptr
 696 *
 697 *      that is: the plus text must start as a new line, and if there is no minus
 698 *      word printed, a graph prefix must be printed.
 699 *
 700 *   2. diff_words->current_plus > diff_words->plus.text.ptr &&
 701 *      *(diff_words->current_plus - 1) == '\n'
 702 *
 703 *      that is: a graph prefix must be printed following a '\n'
 704 */
 705static int color_words_output_graph_prefix(struct diff_words_data *diff_words)
 706{
 707        if ((diff_words->last_minus == 0 &&
 708                diff_words->current_plus == diff_words->plus.text.ptr) ||
 709                (diff_words->current_plus > diff_words->plus.text.ptr &&
 710                *(diff_words->current_plus - 1) == '\n')) {
 711                return 1;
 712        } else {
 713                return 0;
 714        }
 715}
 716
 717static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
 718{
 719        struct diff_words_data *diff_words = priv;
 720        struct diff_words_style *style = diff_words->style;
 721        int minus_first, minus_len, plus_first, plus_len;
 722        const char *minus_begin, *minus_end, *plus_begin, *plus_end;
 723        struct diff_options *opt = diff_words->opt;
 724        struct strbuf *msgbuf;
 725        char *line_prefix = "";
 726
 727        if (line[0] != '@' || parse_hunk_header(line, len,
 728                        &minus_first, &minus_len, &plus_first, &plus_len))
 729                return;
 730
 731        assert(opt);
 732        if (opt->output_prefix) {
 733                msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
 734                line_prefix = msgbuf->buf;
 735        }
 736
 737        /* POSIX requires that first be decremented by one if len == 0... */
 738        if (minus_len) {
 739                minus_begin = diff_words->minus.orig[minus_first].begin;
 740                minus_end =
 741                        diff_words->minus.orig[minus_first + minus_len - 1].end;
 742        } else
 743                minus_begin = minus_end =
 744                        diff_words->minus.orig[minus_first].end;
 745
 746        if (plus_len) {
 747                plus_begin = diff_words->plus.orig[plus_first].begin;
 748                plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
 749        } else
 750                plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
 751
 752        if (color_words_output_graph_prefix(diff_words)) {
 753                fputs(line_prefix, diff_words->opt->file);
 754        }
 755        if (diff_words->current_plus != plus_begin) {
 756                fn_out_diff_words_write_helper(diff_words->opt->file,
 757                                &style->ctx, style->newline,
 758                                plus_begin - diff_words->current_plus,
 759                                diff_words->current_plus, line_prefix);
 760                if (*(plus_begin - 1) == '\n')
 761                        fputs(line_prefix, diff_words->opt->file);
 762        }
 763        if (minus_begin != minus_end) {
 764                fn_out_diff_words_write_helper(diff_words->opt->file,
 765                                &style->old, style->newline,
 766                                minus_end - minus_begin, minus_begin,
 767                                line_prefix);
 768        }
 769        if (plus_begin != plus_end) {
 770                fn_out_diff_words_write_helper(diff_words->opt->file,
 771                                &style->new, style->newline,
 772                                plus_end - plus_begin, plus_begin,
 773                                line_prefix);
 774        }
 775
 776        diff_words->current_plus = plus_end;
 777        diff_words->last_minus = minus_first;
 778}
 779
 780/* This function starts looking at *begin, and returns 0 iff a word was found. */
 781static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
 782                int *begin, int *end)
 783{
 784        if (word_regex && *begin < buffer->size) {
 785                regmatch_t match[1];
 786                if (!regexec(word_regex, buffer->ptr + *begin, 1, match, 0)) {
 787                        char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
 788                                        '\n', match[0].rm_eo - match[0].rm_so);
 789                        *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
 790                        *begin += match[0].rm_so;
 791                        return *begin >= *end;
 792                }
 793                return -1;
 794        }
 795
 796        /* find the next word */
 797        while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
 798                (*begin)++;
 799        if (*begin >= buffer->size)
 800                return -1;
 801
 802        /* find the end of the word */
 803        *end = *begin + 1;
 804        while (*end < buffer->size && !isspace(buffer->ptr[*end]))
 805                (*end)++;
 806
 807        return 0;
 808}
 809
 810/*
 811 * This function splits the words in buffer->text, stores the list with
 812 * newline separator into out, and saves the offsets of the original words
 813 * in buffer->orig.
 814 */
 815static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
 816                regex_t *word_regex)
 817{
 818        int i, j;
 819        long alloc = 0;
 820
 821        out->size = 0;
 822        out->ptr = NULL;
 823
 824        /* fake an empty "0th" word */
 825        ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
 826        buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
 827        buffer->orig_nr = 1;
 828
 829        for (i = 0; i < buffer->text.size; i++) {
 830                if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
 831                        return;
 832
 833                /* store original boundaries */
 834                ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
 835                                buffer->orig_alloc);
 836                buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
 837                buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
 838                buffer->orig_nr++;
 839
 840                /* store one word */
 841                ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
 842                memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
 843                out->ptr[out->size + j - i] = '\n';
 844                out->size += j - i + 1;
 845
 846                i = j - 1;
 847        }
 848}
 849
 850/* this executes the word diff on the accumulated buffers */
 851static void diff_words_show(struct diff_words_data *diff_words)
 852{
 853        xpparam_t xpp;
 854        xdemitconf_t xecfg;
 855        mmfile_t minus, plus;
 856        struct diff_words_style *style = diff_words->style;
 857
 858        struct diff_options *opt = diff_words->opt;
 859        struct strbuf *msgbuf;
 860        char *line_prefix = "";
 861
 862        assert(opt);
 863        if (opt->output_prefix) {
 864                msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
 865                line_prefix = msgbuf->buf;
 866        }
 867
 868        /* special case: only removal */
 869        if (!diff_words->plus.text.size) {
 870                fputs(line_prefix, diff_words->opt->file);
 871                fn_out_diff_words_write_helper(diff_words->opt->file,
 872                        &style->old, style->newline,
 873                        diff_words->minus.text.size,
 874                        diff_words->minus.text.ptr, line_prefix);
 875                diff_words->minus.text.size = 0;
 876                return;
 877        }
 878
 879        diff_words->current_plus = diff_words->plus.text.ptr;
 880        diff_words->last_minus = 0;
 881
 882        memset(&xpp, 0, sizeof(xpp));
 883        memset(&xecfg, 0, sizeof(xecfg));
 884        diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
 885        diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
 886        xpp.flags = 0;
 887        /* as only the hunk header will be parsed, we need a 0-context */
 888        xecfg.ctxlen = 0;
 889        xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
 890                      &xpp, &xecfg);
 891        free(minus.ptr);
 892        free(plus.ptr);
 893        if (diff_words->current_plus != diff_words->plus.text.ptr +
 894                        diff_words->plus.text.size) {
 895                if (color_words_output_graph_prefix(diff_words))
 896                        fputs(line_prefix, diff_words->opt->file);
 897                fn_out_diff_words_write_helper(diff_words->opt->file,
 898                        &style->ctx, style->newline,
 899                        diff_words->plus.text.ptr + diff_words->plus.text.size
 900                        - diff_words->current_plus, diff_words->current_plus,
 901                        line_prefix);
 902        }
 903        diff_words->minus.text.size = diff_words->plus.text.size = 0;
 904}
 905
 906/* In "color-words" mode, show word-diff of words accumulated in the buffer */
 907static void diff_words_flush(struct emit_callback *ecbdata)
 908{
 909        if (ecbdata->diff_words->minus.text.size ||
 910            ecbdata->diff_words->plus.text.size)
 911                diff_words_show(ecbdata->diff_words);
 912}
 913
 914static void free_diff_words_data(struct emit_callback *ecbdata)
 915{
 916        if (ecbdata->diff_words) {
 917                diff_words_flush(ecbdata);
 918                free (ecbdata->diff_words->minus.text.ptr);
 919                free (ecbdata->diff_words->minus.orig);
 920                free (ecbdata->diff_words->plus.text.ptr);
 921                free (ecbdata->diff_words->plus.orig);
 922                free(ecbdata->diff_words->word_regex);
 923                free(ecbdata->diff_words);
 924                ecbdata->diff_words = NULL;
 925        }
 926}
 927
 928const char *diff_get_color(int diff_use_color, enum color_diff ix)
 929{
 930        if (diff_use_color)
 931                return diff_colors[ix];
 932        return "";
 933}
 934
 935static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
 936{
 937        const char *cp;
 938        unsigned long allot;
 939        size_t l = len;
 940
 941        if (ecb->truncate)
 942                return ecb->truncate(line, len);
 943        cp = line;
 944        allot = l;
 945        while (0 < l) {
 946                (void) utf8_width(&cp, &l);
 947                if (!cp)
 948                        break; /* truncated in the middle? */
 949        }
 950        return allot - l;
 951}
 952
 953static void find_lno(const char *line, struct emit_callback *ecbdata)
 954{
 955        const char *p;
 956        ecbdata->lno_in_preimage = 0;
 957        ecbdata->lno_in_postimage = 0;
 958        p = strchr(line, '-');
 959        if (!p)
 960                return; /* cannot happen */
 961        ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
 962        p = strchr(p, '+');
 963        if (!p)
 964                return; /* cannot happen */
 965        ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
 966}
 967
 968static void fn_out_consume(void *priv, char *line, unsigned long len)
 969{
 970        struct emit_callback *ecbdata = priv;
 971        const char *meta = diff_get_color(ecbdata->color_diff, DIFF_METAINFO);
 972        const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
 973        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
 974        struct diff_options *o = ecbdata->opt;
 975        char *line_prefix = "";
 976        struct strbuf *msgbuf;
 977
 978        if (o && o->output_prefix) {
 979                msgbuf = o->output_prefix(o, o->output_prefix_data);
 980                line_prefix = msgbuf->buf;
 981        }
 982
 983        if (ecbdata->header) {
 984                fprintf(ecbdata->opt->file, "%s", ecbdata->header->buf);
 985                strbuf_reset(ecbdata->header);
 986                ecbdata->header = NULL;
 987        }
 988        *(ecbdata->found_changesp) = 1;
 989
 990        if (ecbdata->label_path[0]) {
 991                const char *name_a_tab, *name_b_tab;
 992
 993                name_a_tab = strchr(ecbdata->label_path[0], ' ') ? "\t" : "";
 994                name_b_tab = strchr(ecbdata->label_path[1], ' ') ? "\t" : "";
 995
 996                fprintf(ecbdata->opt->file, "%s%s--- %s%s%s\n",
 997                        line_prefix, meta, ecbdata->label_path[0], reset, name_a_tab);
 998                fprintf(ecbdata->opt->file, "%s%s+++ %s%s%s\n",
 999                        line_prefix, meta, ecbdata->label_path[1], reset, name_b_tab);
1000                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
1001        }
1002
1003        if (diff_suppress_blank_empty
1004            && len == 2 && line[0] == ' ' && line[1] == '\n') {
1005                line[0] = '\n';
1006                len = 1;
1007        }
1008
1009        if (line[0] == '@') {
1010                if (ecbdata->diff_words)
1011                        diff_words_flush(ecbdata);
1012                len = sane_truncate_line(ecbdata, line, len);
1013                find_lno(line, ecbdata);
1014                emit_hunk_header(ecbdata, line, len);
1015                if (line[len-1] != '\n')
1016                        putc('\n', ecbdata->opt->file);
1017                return;
1018        }
1019
1020        if (len < 1) {
1021                emit_line(ecbdata->opt, reset, reset, line, len);
1022                if (ecbdata->diff_words
1023                    && ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN)
1024                        fputs("~\n", ecbdata->opt->file);
1025                return;
1026        }
1027
1028        if (ecbdata->diff_words) {
1029                if (line[0] == '-') {
1030                        diff_words_append(line, len,
1031                                          &ecbdata->diff_words->minus);
1032                        return;
1033                } else if (line[0] == '+') {
1034                        diff_words_append(line, len,
1035                                          &ecbdata->diff_words->plus);
1036                        return;
1037                }
1038                diff_words_flush(ecbdata);
1039                if (ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN) {
1040                        emit_line(ecbdata->opt, plain, reset, line, len);
1041                        fputs("~\n", ecbdata->opt->file);
1042                } else {
1043                        /* don't print the prefix character */
1044                        emit_line(ecbdata->opt, plain, reset, line+1, len-1);
1045                }
1046                return;
1047        }
1048
1049        if (line[0] != '+') {
1050                const char *color =
1051                        diff_get_color(ecbdata->color_diff,
1052                                       line[0] == '-' ? DIFF_FILE_OLD : DIFF_PLAIN);
1053                ecbdata->lno_in_preimage++;
1054                if (line[0] == ' ')
1055                        ecbdata->lno_in_postimage++;
1056                emit_line(ecbdata->opt, color, reset, line, len);
1057        } else {
1058                ecbdata->lno_in_postimage++;
1059                emit_add_line(reset, ecbdata, line + 1, len - 1);
1060        }
1061}
1062
1063static char *pprint_rename(const char *a, const char *b)
1064{
1065        const char *old = a;
1066        const char *new = b;
1067        struct strbuf name = STRBUF_INIT;
1068        int pfx_length, sfx_length;
1069        int len_a = strlen(a);
1070        int len_b = strlen(b);
1071        int a_midlen, b_midlen;
1072        int qlen_a = quote_c_style(a, NULL, NULL, 0);
1073        int qlen_b = quote_c_style(b, NULL, NULL, 0);
1074
1075        if (qlen_a || qlen_b) {
1076                quote_c_style(a, &name, NULL, 0);
1077                strbuf_addstr(&name, " => ");
1078                quote_c_style(b, &name, NULL, 0);
1079                return strbuf_detach(&name, NULL);
1080        }
1081
1082        /* Find common prefix */
1083        pfx_length = 0;
1084        while (*old && *new && *old == *new) {
1085                if (*old == '/')
1086                        pfx_length = old - a + 1;
1087                old++;
1088                new++;
1089        }
1090
1091        /* Find common suffix */
1092        old = a + len_a;
1093        new = b + len_b;
1094        sfx_length = 0;
1095        while (a <= old && b <= new && *old == *new) {
1096                if (*old == '/')
1097                        sfx_length = len_a - (old - a);
1098                old--;
1099                new--;
1100        }
1101
1102        /*
1103         * pfx{mid-a => mid-b}sfx
1104         * {pfx-a => pfx-b}sfx
1105         * pfx{sfx-a => sfx-b}
1106         * name-a => name-b
1107         */
1108        a_midlen = len_a - pfx_length - sfx_length;
1109        b_midlen = len_b - pfx_length - sfx_length;
1110        if (a_midlen < 0)
1111                a_midlen = 0;
1112        if (b_midlen < 0)
1113                b_midlen = 0;
1114
1115        strbuf_grow(&name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
1116        if (pfx_length + sfx_length) {
1117                strbuf_add(&name, a, pfx_length);
1118                strbuf_addch(&name, '{');
1119        }
1120        strbuf_add(&name, a + pfx_length, a_midlen);
1121        strbuf_addstr(&name, " => ");
1122        strbuf_add(&name, b + pfx_length, b_midlen);
1123        if (pfx_length + sfx_length) {
1124                strbuf_addch(&name, '}');
1125                strbuf_add(&name, a + len_a - sfx_length, sfx_length);
1126        }
1127        return strbuf_detach(&name, NULL);
1128}
1129
1130struct diffstat_t {
1131        int nr;
1132        int alloc;
1133        struct diffstat_file {
1134                char *from_name;
1135                char *name;
1136                char *print_name;
1137                unsigned is_unmerged:1;
1138                unsigned is_binary:1;
1139                unsigned is_renamed:1;
1140                uintmax_t added, deleted;
1141        } **files;
1142};
1143
1144static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
1145                                          const char *name_a,
1146                                          const char *name_b)
1147{
1148        struct diffstat_file *x;
1149        x = xcalloc(sizeof (*x), 1);
1150        if (diffstat->nr == diffstat->alloc) {
1151                diffstat->alloc = alloc_nr(diffstat->alloc);
1152                diffstat->files = xrealloc(diffstat->files,
1153                                diffstat->alloc * sizeof(x));
1154        }
1155        diffstat->files[diffstat->nr++] = x;
1156        if (name_b) {
1157                x->from_name = xstrdup(name_a);
1158                x->name = xstrdup(name_b);
1159                x->is_renamed = 1;
1160        }
1161        else {
1162                x->from_name = NULL;
1163                x->name = xstrdup(name_a);
1164        }
1165        return x;
1166}
1167
1168static void diffstat_consume(void *priv, char *line, unsigned long len)
1169{
1170        struct diffstat_t *diffstat = priv;
1171        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
1172
1173        if (line[0] == '+')
1174                x->added++;
1175        else if (line[0] == '-')
1176                x->deleted++;
1177}
1178
1179const char mime_boundary_leader[] = "------------";
1180
1181static int scale_linear(int it, int width, int max_change)
1182{
1183        /*
1184         * make sure that at least one '-' is printed if there were deletions,
1185         * and likewise for '+'.
1186         */
1187        if (max_change < 2)
1188                return it;
1189        return ((it - 1) * (width - 1) + max_change - 1) / (max_change - 1);
1190}
1191
1192static void show_name(FILE *file,
1193                      const char *prefix, const char *name, int len)
1194{
1195        fprintf(file, " %s%-*s |", prefix, len, name);
1196}
1197
1198static void show_graph(FILE *file, char ch, int cnt, const char *set, const char *reset)
1199{
1200        if (cnt <= 0)
1201                return;
1202        fprintf(file, "%s", set);
1203        while (cnt--)
1204                putc(ch, file);
1205        fprintf(file, "%s", reset);
1206}
1207
1208static void fill_print_name(struct diffstat_file *file)
1209{
1210        char *pname;
1211
1212        if (file->print_name)
1213                return;
1214
1215        if (!file->is_renamed) {
1216                struct strbuf buf = STRBUF_INIT;
1217                if (quote_c_style(file->name, &buf, NULL, 0)) {
1218                        pname = strbuf_detach(&buf, NULL);
1219                } else {
1220                        pname = file->name;
1221                        strbuf_release(&buf);
1222                }
1223        } else {
1224                pname = pprint_rename(file->from_name, file->name);
1225        }
1226        file->print_name = pname;
1227}
1228
1229static void show_stats(struct diffstat_t *data, struct diff_options *options)
1230{
1231        int i, len, add, del, adds = 0, dels = 0;
1232        uintmax_t max_change = 0, max_len = 0;
1233        int total_files = data->nr;
1234        int width, name_width;
1235        const char *reset, *set, *add_c, *del_c;
1236        const char *line_prefix = "";
1237        struct strbuf *msg = NULL;
1238
1239        if (data->nr == 0)
1240                return;
1241
1242        if (options->output_prefix) {
1243                msg = options->output_prefix(options, options->output_prefix_data);
1244                line_prefix = msg->buf;
1245        }
1246
1247        width = options->stat_width ? options->stat_width : 80;
1248        name_width = options->stat_name_width ? options->stat_name_width : 50;
1249
1250        /* Sanity: give at least 5 columns to the graph,
1251         * but leave at least 10 columns for the name.
1252         */
1253        if (width < 25)
1254                width = 25;
1255        if (name_width < 10)
1256                name_width = 10;
1257        else if (width < name_width + 15)
1258                name_width = width - 15;
1259
1260        /* Find the longest filename and max number of changes */
1261        reset = diff_get_color_opt(options, DIFF_RESET);
1262        set   = diff_get_color_opt(options, DIFF_PLAIN);
1263        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
1264        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
1265
1266        for (i = 0; i < data->nr; i++) {
1267                struct diffstat_file *file = data->files[i];
1268                uintmax_t change = file->added + file->deleted;
1269                fill_print_name(file);
1270                len = strlen(file->print_name);
1271                if (max_len < len)
1272                        max_len = len;
1273
1274                if (file->is_binary || file->is_unmerged)
1275                        continue;
1276                if (max_change < change)
1277                        max_change = change;
1278        }
1279
1280        /* Compute the width of the graph part;
1281         * 10 is for one blank at the beginning of the line plus
1282         * " | count " between the name and the graph.
1283         *
1284         * From here on, name_width is the width of the name area,
1285         * and width is the width of the graph area.
1286         */
1287        name_width = (name_width < max_len) ? name_width : max_len;
1288        if (width < (name_width + 10) + max_change)
1289                width = width - (name_width + 10);
1290        else
1291                width = max_change;
1292
1293        for (i = 0; i < data->nr; i++) {
1294                const char *prefix = "";
1295                char *name = data->files[i]->print_name;
1296                uintmax_t added = data->files[i]->added;
1297                uintmax_t deleted = data->files[i]->deleted;
1298                int name_len;
1299
1300                /*
1301                 * "scale" the filename
1302                 */
1303                len = name_width;
1304                name_len = strlen(name);
1305                if (name_width < name_len) {
1306                        char *slash;
1307                        prefix = "...";
1308                        len -= 3;
1309                        name += name_len - len;
1310                        slash = strchr(name, '/');
1311                        if (slash)
1312                                name = slash;
1313                }
1314
1315                if (data->files[i]->is_binary) {
1316                        fprintf(options->file, "%s", line_prefix);
1317                        show_name(options->file, prefix, name, len);
1318                        fprintf(options->file, "  Bin ");
1319                        fprintf(options->file, "%s%"PRIuMAX"%s",
1320                                del_c, deleted, reset);
1321                        fprintf(options->file, " -> ");
1322                        fprintf(options->file, "%s%"PRIuMAX"%s",
1323                                add_c, added, reset);
1324                        fprintf(options->file, " bytes");
1325                        fprintf(options->file, "\n");
1326                        continue;
1327                }
1328                else if (data->files[i]->is_unmerged) {
1329                        fprintf(options->file, "%s", line_prefix);
1330                        show_name(options->file, prefix, name, len);
1331                        fprintf(options->file, "  Unmerged\n");
1332                        continue;
1333                }
1334                else if (!data->files[i]->is_renamed &&
1335                         (added + deleted == 0)) {
1336                        total_files--;
1337                        continue;
1338                }
1339
1340                /*
1341                 * scale the add/delete
1342                 */
1343                add = added;
1344                del = deleted;
1345                adds += add;
1346                dels += del;
1347
1348                if (width <= max_change) {
1349                        add = scale_linear(add, width, max_change);
1350                        del = scale_linear(del, width, max_change);
1351                }
1352                fprintf(options->file, "%s", line_prefix);
1353                show_name(options->file, prefix, name, len);
1354                fprintf(options->file, "%5"PRIuMAX"%s", added + deleted,
1355                                added + deleted ? " " : "");
1356                show_graph(options->file, '+', add, add_c, reset);
1357                show_graph(options->file, '-', del, del_c, reset);
1358                fprintf(options->file, "\n");
1359        }
1360        fprintf(options->file, "%s", line_prefix);
1361        fprintf(options->file,
1362               " %d files changed, %d insertions(+), %d deletions(-)\n",
1363               total_files, adds, dels);
1364}
1365
1366static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
1367{
1368        int i, adds = 0, dels = 0, total_files = data->nr;
1369
1370        if (data->nr == 0)
1371                return;
1372
1373        for (i = 0; i < data->nr; i++) {
1374                if (!data->files[i]->is_binary &&
1375                    !data->files[i]->is_unmerged) {
1376                        int added = data->files[i]->added;
1377                        int deleted= data->files[i]->deleted;
1378                        if (!data->files[i]->is_renamed &&
1379                            (added + deleted == 0)) {
1380                                total_files--;
1381                        } else {
1382                                adds += added;
1383                                dels += deleted;
1384                        }
1385                }
1386        }
1387        if (options->output_prefix) {
1388                struct strbuf *msg = NULL;
1389                msg = options->output_prefix(options,
1390                                options->output_prefix_data);
1391                fprintf(options->file, "%s", msg->buf);
1392        }
1393        fprintf(options->file, " %d files changed, %d insertions(+), %d deletions(-)\n",
1394               total_files, adds, dels);
1395}
1396
1397static void show_numstat(struct diffstat_t *data, struct diff_options *options)
1398{
1399        int i;
1400
1401        if (data->nr == 0)
1402                return;
1403
1404        for (i = 0; i < data->nr; i++) {
1405                struct diffstat_file *file = data->files[i];
1406
1407                if (options->output_prefix) {
1408                        struct strbuf *msg = NULL;
1409                        msg = options->output_prefix(options,
1410                                        options->output_prefix_data);
1411                        fprintf(options->file, "%s", msg->buf);
1412                }
1413
1414                if (file->is_binary)
1415                        fprintf(options->file, "-\t-\t");
1416                else
1417                        fprintf(options->file,
1418                                "%"PRIuMAX"\t%"PRIuMAX"\t",
1419                                file->added, file->deleted);
1420                if (options->line_termination) {
1421                        fill_print_name(file);
1422                        if (!file->is_renamed)
1423                                write_name_quoted(file->name, options->file,
1424                                                  options->line_termination);
1425                        else {
1426                                fputs(file->print_name, options->file);
1427                                putc(options->line_termination, options->file);
1428                        }
1429                } else {
1430                        if (file->is_renamed) {
1431                                putc('\0', options->file);
1432                                write_name_quoted(file->from_name, options->file, '\0');
1433                        }
1434                        write_name_quoted(file->name, options->file, '\0');
1435                }
1436        }
1437}
1438
1439struct dirstat_file {
1440        const char *name;
1441        unsigned long changed;
1442};
1443
1444struct dirstat_dir {
1445        struct dirstat_file *files;
1446        int alloc, nr, percent, cumulative;
1447};
1448
1449static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
1450                unsigned long changed, const char *base, int baselen)
1451{
1452        unsigned long this_dir = 0;
1453        unsigned int sources = 0;
1454        const char *line_prefix = "";
1455        struct strbuf *msg = NULL;
1456
1457        if (opt->output_prefix) {
1458                msg = opt->output_prefix(opt, opt->output_prefix_data);
1459                line_prefix = msg->buf;
1460        }
1461
1462        while (dir->nr) {
1463                struct dirstat_file *f = dir->files;
1464                int namelen = strlen(f->name);
1465                unsigned long this;
1466                char *slash;
1467
1468                if (namelen < baselen)
1469                        break;
1470                if (memcmp(f->name, base, baselen))
1471                        break;
1472                slash = strchr(f->name + baselen, '/');
1473                if (slash) {
1474                        int newbaselen = slash + 1 - f->name;
1475                        this = gather_dirstat(opt, dir, changed, f->name, newbaselen);
1476                        sources++;
1477                } else {
1478                        this = f->changed;
1479                        dir->files++;
1480                        dir->nr--;
1481                        sources += 2;
1482                }
1483                this_dir += this;
1484        }
1485
1486        /*
1487         * We don't report dirstat's for
1488         *  - the top level
1489         *  - or cases where everything came from a single directory
1490         *    under this directory (sources == 1).
1491         */
1492        if (baselen && sources != 1) {
1493                int permille = this_dir * 1000 / changed;
1494                if (permille) {
1495                        int percent = permille / 10;
1496                        if (percent >= dir->percent) {
1497                                fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
1498                                        percent, permille % 10, baselen, base);
1499                                if (!dir->cumulative)
1500                                        return 0;
1501                        }
1502                }
1503        }
1504        return this_dir;
1505}
1506
1507static int dirstat_compare(const void *_a, const void *_b)
1508{
1509        const struct dirstat_file *a = _a;
1510        const struct dirstat_file *b = _b;
1511        return strcmp(a->name, b->name);
1512}
1513
1514static void show_dirstat(struct diff_options *options)
1515{
1516        int i;
1517        unsigned long changed;
1518        struct dirstat_dir dir;
1519        struct diff_queue_struct *q = &diff_queued_diff;
1520
1521        dir.files = NULL;
1522        dir.alloc = 0;
1523        dir.nr = 0;
1524        dir.percent = options->dirstat_percent;
1525        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1526
1527        changed = 0;
1528        for (i = 0; i < q->nr; i++) {
1529                struct diff_filepair *p = q->queue[i];
1530                const char *name;
1531                unsigned long copied, added, damage;
1532
1533                name = p->one->path ? p->one->path : p->two->path;
1534
1535                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
1536                        diff_populate_filespec(p->one, 0);
1537                        diff_populate_filespec(p->two, 0);
1538                        diffcore_count_changes(p->one, p->two, NULL, NULL, 0,
1539                                               &copied, &added);
1540                        diff_free_filespec_data(p->one);
1541                        diff_free_filespec_data(p->two);
1542                } else if (DIFF_FILE_VALID(p->one)) {
1543                        diff_populate_filespec(p->one, 1);
1544                        copied = added = 0;
1545                        diff_free_filespec_data(p->one);
1546                } else if (DIFF_FILE_VALID(p->two)) {
1547                        diff_populate_filespec(p->two, 1);
1548                        copied = 0;
1549                        added = p->two->size;
1550                        diff_free_filespec_data(p->two);
1551                } else
1552                        continue;
1553
1554                /*
1555                 * Original minus copied is the removed material,
1556                 * added is the new material.  They are both damages
1557                 * made to the preimage. In --dirstat-by-file mode, count
1558                 * damaged files, not damaged lines. This is done by
1559                 * counting only a single damaged line per file.
1560                 */
1561                damage = (p->one->size - copied) + added;
1562                if (DIFF_OPT_TST(options, DIRSTAT_BY_FILE) && damage > 0)
1563                        damage = 1;
1564
1565                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1566                dir.files[dir.nr].name = name;
1567                dir.files[dir.nr].changed = damage;
1568                changed += damage;
1569                dir.nr++;
1570        }
1571
1572        /* This can happen even with many files, if everything was renames */
1573        if (!changed)
1574                return;
1575
1576        /* Show all directories with more than x% of the changes */
1577        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1578        gather_dirstat(options, &dir, changed, "", 0);
1579}
1580
1581static void free_diffstat_info(struct diffstat_t *diffstat)
1582{
1583        int i;
1584        for (i = 0; i < diffstat->nr; i++) {
1585                struct diffstat_file *f = diffstat->files[i];
1586                if (f->name != f->print_name)
1587                        free(f->print_name);
1588                free(f->name);
1589                free(f->from_name);
1590                free(f);
1591        }
1592        free(diffstat->files);
1593}
1594
1595struct checkdiff_t {
1596        const char *filename;
1597        int lineno;
1598        int conflict_marker_size;
1599        struct diff_options *o;
1600        unsigned ws_rule;
1601        unsigned status;
1602};
1603
1604static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
1605{
1606        char firstchar;
1607        int cnt;
1608
1609        if (len < marker_size + 1)
1610                return 0;
1611        firstchar = line[0];
1612        switch (firstchar) {
1613        case '=': case '>': case '<': case '|':
1614                break;
1615        default:
1616                return 0;
1617        }
1618        for (cnt = 1; cnt < marker_size; cnt++)
1619                if (line[cnt] != firstchar)
1620                        return 0;
1621        /* line[1] thru line[marker_size-1] are same as firstchar */
1622        if (len < marker_size + 1 || !isspace(line[marker_size]))
1623                return 0;
1624        return 1;
1625}
1626
1627static void checkdiff_consume(void *priv, char *line, unsigned long len)
1628{
1629        struct checkdiff_t *data = priv;
1630        int color_diff = DIFF_OPT_TST(data->o, COLOR_DIFF);
1631        int marker_size = data->conflict_marker_size;
1632        const char *ws = diff_get_color(color_diff, DIFF_WHITESPACE);
1633        const char *reset = diff_get_color(color_diff, DIFF_RESET);
1634        const char *set = diff_get_color(color_diff, DIFF_FILE_NEW);
1635        char *err;
1636        char *line_prefix = "";
1637        struct strbuf *msgbuf;
1638
1639        assert(data->o);
1640        if (data->o->output_prefix) {
1641                msgbuf = data->o->output_prefix(data->o,
1642                        data->o->output_prefix_data);
1643                line_prefix = msgbuf->buf;
1644        }
1645
1646        if (line[0] == '+') {
1647                unsigned bad;
1648                data->lineno++;
1649                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
1650                        data->status |= 1;
1651                        fprintf(data->o->file,
1652                                "%s%s:%d: leftover conflict marker\n",
1653                                line_prefix, data->filename, data->lineno);
1654                }
1655                bad = ws_check(line + 1, len - 1, data->ws_rule);
1656                if (!bad)
1657                        return;
1658                data->status |= bad;
1659                err = whitespace_error_string(bad);
1660                fprintf(data->o->file, "%s%s:%d: %s.\n",
1661                        line_prefix, data->filename, data->lineno, err);
1662                free(err);
1663                emit_line(data->o, set, reset, line, 1);
1664                ws_check_emit(line + 1, len - 1, data->ws_rule,
1665                              data->o->file, set, reset, ws);
1666        } else if (line[0] == ' ') {
1667                data->lineno++;
1668        } else if (line[0] == '@') {
1669                char *plus = strchr(line, '+');
1670                if (plus)
1671                        data->lineno = strtol(plus, NULL, 10) - 1;
1672                else
1673                        die("invalid diff");
1674        }
1675}
1676
1677static unsigned char *deflate_it(char *data,
1678                                 unsigned long size,
1679                                 unsigned long *result_size)
1680{
1681        int bound;
1682        unsigned char *deflated;
1683        z_stream stream;
1684
1685        memset(&stream, 0, sizeof(stream));
1686        deflateInit(&stream, zlib_compression_level);
1687        bound = deflateBound(&stream, size);
1688        deflated = xmalloc(bound);
1689        stream.next_out = deflated;
1690        stream.avail_out = bound;
1691
1692        stream.next_in = (unsigned char *)data;
1693        stream.avail_in = size;
1694        while (deflate(&stream, Z_FINISH) == Z_OK)
1695                ; /* nothing */
1696        deflateEnd(&stream);
1697        *result_size = stream.total_out;
1698        return deflated;
1699}
1700
1701static void emit_binary_diff_body(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
1702{
1703        void *cp;
1704        void *delta;
1705        void *deflated;
1706        void *data;
1707        unsigned long orig_size;
1708        unsigned long delta_size;
1709        unsigned long deflate_size;
1710        unsigned long data_size;
1711
1712        /* We could do deflated delta, or we could do just deflated two,
1713         * whichever is smaller.
1714         */
1715        delta = NULL;
1716        deflated = deflate_it(two->ptr, two->size, &deflate_size);
1717        if (one->size && two->size) {
1718                delta = diff_delta(one->ptr, one->size,
1719                                   two->ptr, two->size,
1720                                   &delta_size, deflate_size);
1721                if (delta) {
1722                        void *to_free = delta;
1723                        orig_size = delta_size;
1724                        delta = deflate_it(delta, delta_size, &delta_size);
1725                        free(to_free);
1726                }
1727        }
1728
1729        if (delta && delta_size < deflate_size) {
1730                fprintf(file, "%sdelta %lu\n", prefix, orig_size);
1731                free(deflated);
1732                data = delta;
1733                data_size = delta_size;
1734        }
1735        else {
1736                fprintf(file, "%sliteral %lu\n", prefix, two->size);
1737                free(delta);
1738                data = deflated;
1739                data_size = deflate_size;
1740        }
1741
1742        /* emit data encoded in base85 */
1743        cp = data;
1744        while (data_size) {
1745                int bytes = (52 < data_size) ? 52 : data_size;
1746                char line[70];
1747                data_size -= bytes;
1748                if (bytes <= 26)
1749                        line[0] = bytes + 'A' - 1;
1750                else
1751                        line[0] = bytes - 26 + 'a' - 1;
1752                encode_85(line + 1, cp, bytes);
1753                cp = (char *) cp + bytes;
1754                fprintf(file, "%s", prefix);
1755                fputs(line, file);
1756                fputc('\n', file);
1757        }
1758        fprintf(file, "%s\n", prefix);
1759        free(data);
1760}
1761
1762static void emit_binary_diff(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
1763{
1764        fprintf(file, "%sGIT binary patch\n", prefix);
1765        emit_binary_diff_body(file, one, two, prefix);
1766        emit_binary_diff_body(file, two, one, prefix);
1767}
1768
1769static void diff_filespec_load_driver(struct diff_filespec *one)
1770{
1771        if (!one->driver)
1772                one->driver = userdiff_find_by_path(one->path);
1773        if (!one->driver)
1774                one->driver = userdiff_find_by_name("default");
1775}
1776
1777int diff_filespec_is_binary(struct diff_filespec *one)
1778{
1779        if (one->is_binary == -1) {
1780                diff_filespec_load_driver(one);
1781                if (one->driver->binary != -1)
1782                        one->is_binary = one->driver->binary;
1783                else {
1784                        if (!one->data && DIFF_FILE_VALID(one))
1785                                diff_populate_filespec(one, 0);
1786                        if (one->data)
1787                                one->is_binary = buffer_is_binary(one->data,
1788                                                one->size);
1789                        if (one->is_binary == -1)
1790                                one->is_binary = 0;
1791                }
1792        }
1793        return one->is_binary;
1794}
1795
1796static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
1797{
1798        diff_filespec_load_driver(one);
1799        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
1800}
1801
1802static const char *userdiff_word_regex(struct diff_filespec *one)
1803{
1804        diff_filespec_load_driver(one);
1805        return one->driver->word_regex;
1806}
1807
1808void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
1809{
1810        if (!options->a_prefix)
1811                options->a_prefix = a;
1812        if (!options->b_prefix)
1813                options->b_prefix = b;
1814}
1815
1816struct userdiff_driver *get_textconv(struct diff_filespec *one)
1817{
1818        if (!DIFF_FILE_VALID(one))
1819                return NULL;
1820        if (!S_ISREG(one->mode))
1821                return NULL;
1822        diff_filespec_load_driver(one);
1823        if (!one->driver->textconv)
1824                return NULL;
1825
1826        if (one->driver->textconv_want_cache && !one->driver->textconv_cache) {
1827                struct notes_cache *c = xmalloc(sizeof(*c));
1828                struct strbuf name = STRBUF_INIT;
1829
1830                strbuf_addf(&name, "textconv/%s", one->driver->name);
1831                notes_cache_init(c, name.buf, one->driver->textconv);
1832                one->driver->textconv_cache = c;
1833        }
1834
1835        return one->driver;
1836}
1837
1838static void builtin_diff(const char *name_a,
1839                         const char *name_b,
1840                         struct diff_filespec *one,
1841                         struct diff_filespec *two,
1842                         const char *xfrm_msg,
1843                         int must_show_header,
1844                         struct diff_options *o,
1845                         int complete_rewrite)
1846{
1847        mmfile_t mf1, mf2;
1848        const char *lbl[2];
1849        char *a_one, *b_two;
1850        const char *set = diff_get_color_opt(o, DIFF_METAINFO);
1851        const char *reset = diff_get_color_opt(o, DIFF_RESET);
1852        const char *a_prefix, *b_prefix;
1853        struct userdiff_driver *textconv_one = NULL;
1854        struct userdiff_driver *textconv_two = NULL;
1855        struct strbuf header = STRBUF_INIT;
1856        struct strbuf *msgbuf;
1857        char *line_prefix = "";
1858
1859        if (o->output_prefix) {
1860                msgbuf = o->output_prefix(o, o->output_prefix_data);
1861                line_prefix = msgbuf->buf;
1862        }
1863
1864        if (DIFF_OPT_TST(o, SUBMODULE_LOG) &&
1865                        (!one->mode || S_ISGITLINK(one->mode)) &&
1866                        (!two->mode || S_ISGITLINK(two->mode))) {
1867                const char *del = diff_get_color_opt(o, DIFF_FILE_OLD);
1868                const char *add = diff_get_color_opt(o, DIFF_FILE_NEW);
1869                show_submodule_summary(o->file, one ? one->path : two->path,
1870                                one->sha1, two->sha1, two->dirty_submodule,
1871                                del, add, reset);
1872                return;
1873        }
1874
1875        if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
1876                textconv_one = get_textconv(one);
1877                textconv_two = get_textconv(two);
1878        }
1879
1880        diff_set_mnemonic_prefix(o, "a/", "b/");
1881        if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
1882                a_prefix = o->b_prefix;
1883                b_prefix = o->a_prefix;
1884        } else {
1885                a_prefix = o->a_prefix;
1886                b_prefix = o->b_prefix;
1887        }
1888
1889        /* Never use a non-valid filename anywhere if at all possible */
1890        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
1891        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
1892
1893        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
1894        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
1895        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
1896        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
1897        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, set, a_one, b_two, reset);
1898        if (lbl[0][0] == '/') {
1899                /* /dev/null */
1900                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, set, two->mode, reset);
1901                if (xfrm_msg)
1902                        strbuf_addstr(&header, xfrm_msg);
1903                must_show_header = 1;
1904        }
1905        else if (lbl[1][0] == '/') {
1906                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, set, one->mode, reset);
1907                if (xfrm_msg)
1908                        strbuf_addstr(&header, xfrm_msg);
1909                must_show_header = 1;
1910        }
1911        else {
1912                if (one->mode != two->mode) {
1913                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, set, one->mode, reset);
1914                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, set, two->mode, reset);
1915                        must_show_header = 1;
1916                }
1917                if (xfrm_msg)
1918                        strbuf_addstr(&header, xfrm_msg);
1919
1920                /*
1921                 * we do not run diff between different kind
1922                 * of objects.
1923                 */
1924                if ((one->mode ^ two->mode) & S_IFMT)
1925                        goto free_ab_and_return;
1926                if (complete_rewrite &&
1927                    (textconv_one || !diff_filespec_is_binary(one)) &&
1928                    (textconv_two || !diff_filespec_is_binary(two))) {
1929                        fprintf(o->file, "%s", header.buf);
1930                        strbuf_reset(&header);
1931                        emit_rewrite_diff(name_a, name_b, one, two,
1932                                                textconv_one, textconv_two, o);
1933                        o->found_changes = 1;
1934                        goto free_ab_and_return;
1935                }
1936        }
1937
1938        if (!DIFF_OPT_TST(o, TEXT) &&
1939            ( (!textconv_one && diff_filespec_is_binary(one)) ||
1940              (!textconv_two && diff_filespec_is_binary(two)) )) {
1941                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1942                        die("unable to read files to diff");
1943                /* Quite common confusing case */
1944                if (mf1.size == mf2.size &&
1945                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
1946                        if (must_show_header)
1947                                fprintf(o->file, "%s", header.buf);
1948                        goto free_ab_and_return;
1949                }
1950                fprintf(o->file, "%s", header.buf);
1951                strbuf_reset(&header);
1952                if (DIFF_OPT_TST(o, BINARY))
1953                        emit_binary_diff(o->file, &mf1, &mf2, line_prefix);
1954                else
1955                        fprintf(o->file, "%sBinary files %s and %s differ\n",
1956                                line_prefix, lbl[0], lbl[1]);
1957                o->found_changes = 1;
1958        }
1959        else {
1960                /* Crazy xdl interfaces.. */
1961                const char *diffopts = getenv("GIT_DIFF_OPTS");
1962                xpparam_t xpp;
1963                xdemitconf_t xecfg;
1964                struct emit_callback ecbdata;
1965                const struct userdiff_funcname *pe;
1966
1967                if (!DIFF_XDL_TST(o, WHITESPACE_FLAGS) || must_show_header) {
1968                        fprintf(o->file, "%s", header.buf);
1969                        strbuf_reset(&header);
1970                }
1971
1972                mf1.size = fill_textconv(textconv_one, one, &mf1.ptr);
1973                mf2.size = fill_textconv(textconv_two, two, &mf2.ptr);
1974
1975                pe = diff_funcname_pattern(one);
1976                if (!pe)
1977                        pe = diff_funcname_pattern(two);
1978
1979                memset(&xpp, 0, sizeof(xpp));
1980                memset(&xecfg, 0, sizeof(xecfg));
1981                memset(&ecbdata, 0, sizeof(ecbdata));
1982                ecbdata.label_path = lbl;
1983                ecbdata.color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
1984                ecbdata.found_changesp = &o->found_changes;
1985                ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
1986                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
1987                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
1988                ecbdata.opt = o;
1989                ecbdata.header = header.len ? &header : NULL;
1990                xpp.flags = o->xdl_opts;
1991                xecfg.ctxlen = o->context;
1992                xecfg.interhunkctxlen = o->interhunkcontext;
1993                xecfg.flags = XDL_EMIT_FUNCNAMES;
1994                if (pe)
1995                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
1996                if (!diffopts)
1997                        ;
1998                else if (!prefixcmp(diffopts, "--unified="))
1999                        xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
2000                else if (!prefixcmp(diffopts, "-u"))
2001                        xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
2002                if (o->word_diff) {
2003                        int i;
2004
2005                        ecbdata.diff_words =
2006                                xcalloc(1, sizeof(struct diff_words_data));
2007                        ecbdata.diff_words->type = o->word_diff;
2008                        ecbdata.diff_words->opt = o;
2009                        if (!o->word_regex)
2010                                o->word_regex = userdiff_word_regex(one);
2011                        if (!o->word_regex)
2012                                o->word_regex = userdiff_word_regex(two);
2013                        if (!o->word_regex)
2014                                o->word_regex = diff_word_regex_cfg;
2015                        if (o->word_regex) {
2016                                ecbdata.diff_words->word_regex = (regex_t *)
2017                                        xmalloc(sizeof(regex_t));
2018                                if (regcomp(ecbdata.diff_words->word_regex,
2019                                                o->word_regex,
2020                                                REG_EXTENDED | REG_NEWLINE))
2021                                        die ("Invalid regular expression: %s",
2022                                                        o->word_regex);
2023                        }
2024                        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
2025                                if (o->word_diff == diff_words_styles[i].type) {
2026                                        ecbdata.diff_words->style =
2027                                                &diff_words_styles[i];
2028                                        break;
2029                                }
2030                        }
2031                        if (DIFF_OPT_TST(o, COLOR_DIFF)) {
2032                                struct diff_words_style *st = ecbdata.diff_words->style;
2033                                st->old.color = diff_get_color_opt(o, DIFF_FILE_OLD);
2034                                st->new.color = diff_get_color_opt(o, DIFF_FILE_NEW);
2035                                st->ctx.color = diff_get_color_opt(o, DIFF_PLAIN);
2036                        }
2037                }
2038                xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
2039                              &xpp, &xecfg);
2040                if (o->word_diff)
2041                        free_diff_words_data(&ecbdata);
2042                if (textconv_one)
2043                        free(mf1.ptr);
2044                if (textconv_two)
2045                        free(mf2.ptr);
2046                xdiff_clear_find_func(&xecfg);
2047        }
2048
2049 free_ab_and_return:
2050        strbuf_release(&header);
2051        diff_free_filespec_data(one);
2052        diff_free_filespec_data(two);
2053        free(a_one);
2054        free(b_two);
2055        return;
2056}
2057
2058static void builtin_diffstat(const char *name_a, const char *name_b,
2059                             struct diff_filespec *one,
2060                             struct diff_filespec *two,
2061                             struct diffstat_t *diffstat,
2062                             struct diff_options *o,
2063                             int complete_rewrite)
2064{
2065        mmfile_t mf1, mf2;
2066        struct diffstat_file *data;
2067
2068        data = diffstat_add(diffstat, name_a, name_b);
2069
2070        if (!one || !two) {
2071                data->is_unmerged = 1;
2072                return;
2073        }
2074        if (complete_rewrite) {
2075                diff_populate_filespec(one, 0);
2076                diff_populate_filespec(two, 0);
2077                data->deleted = count_lines(one->data, one->size);
2078                data->added = count_lines(two->data, two->size);
2079                goto free_and_return;
2080        }
2081        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2082                die("unable to read files to diff");
2083
2084        if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
2085                data->is_binary = 1;
2086                data->added = mf2.size;
2087                data->deleted = mf1.size;
2088        } else {
2089                /* Crazy xdl interfaces.. */
2090                xpparam_t xpp;
2091                xdemitconf_t xecfg;
2092
2093                memset(&xpp, 0, sizeof(xpp));
2094                memset(&xecfg, 0, sizeof(xecfg));
2095                xpp.flags = o->xdl_opts;
2096                xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
2097                              &xpp, &xecfg);
2098        }
2099
2100 free_and_return:
2101        diff_free_filespec_data(one);
2102        diff_free_filespec_data(two);
2103}
2104
2105static void builtin_checkdiff(const char *name_a, const char *name_b,
2106                              const char *attr_path,
2107                              struct diff_filespec *one,
2108                              struct diff_filespec *two,
2109                              struct diff_options *o)
2110{
2111        mmfile_t mf1, mf2;
2112        struct checkdiff_t data;
2113
2114        if (!two)
2115                return;
2116
2117        memset(&data, 0, sizeof(data));
2118        data.filename = name_b ? name_b : name_a;
2119        data.lineno = 0;
2120        data.o = o;
2121        data.ws_rule = whitespace_rule(attr_path);
2122        data.conflict_marker_size = ll_merge_marker_size(attr_path);
2123
2124        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2125                die("unable to read files to diff");
2126
2127        /*
2128         * All the other codepaths check both sides, but not checking
2129         * the "old" side here is deliberate.  We are checking the newly
2130         * introduced changes, and as long as the "new" side is text, we
2131         * can and should check what it introduces.
2132         */
2133        if (diff_filespec_is_binary(two))
2134                goto free_and_return;
2135        else {
2136                /* Crazy xdl interfaces.. */
2137                xpparam_t xpp;
2138                xdemitconf_t xecfg;
2139
2140                memset(&xpp, 0, sizeof(xpp));
2141                memset(&xecfg, 0, sizeof(xecfg));
2142                xecfg.ctxlen = 1; /* at least one context line */
2143                xpp.flags = 0;
2144                xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
2145                              &xpp, &xecfg);
2146
2147                if (data.ws_rule & WS_BLANK_AT_EOF) {
2148                        struct emit_callback ecbdata;
2149                        int blank_at_eof;
2150
2151                        ecbdata.ws_rule = data.ws_rule;
2152                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2153                        blank_at_eof = ecbdata.blank_at_eof_in_preimage;
2154
2155                        if (blank_at_eof) {
2156                                static char *err;
2157                                if (!err)
2158                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
2159                                fprintf(o->file, "%s:%d: %s.\n",
2160                                        data.filename, blank_at_eof, err);
2161                                data.status = 1; /* report errors */
2162                        }
2163                }
2164        }
2165 free_and_return:
2166        diff_free_filespec_data(one);
2167        diff_free_filespec_data(two);
2168        if (data.status)
2169                DIFF_OPT_SET(o, CHECK_FAILED);
2170}
2171
2172struct diff_filespec *alloc_filespec(const char *path)
2173{
2174        int namelen = strlen(path);
2175        struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
2176
2177        memset(spec, 0, sizeof(*spec));
2178        spec->path = (char *)(spec + 1);
2179        memcpy(spec->path, path, namelen+1);
2180        spec->count = 1;
2181        spec->is_binary = -1;
2182        return spec;
2183}
2184
2185void free_filespec(struct diff_filespec *spec)
2186{
2187        if (!--spec->count) {
2188                diff_free_filespec_data(spec);
2189                free(spec);
2190        }
2191}
2192
2193void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
2194                   unsigned short mode)
2195{
2196        if (mode) {
2197                spec->mode = canon_mode(mode);
2198                hashcpy(spec->sha1, sha1);
2199                spec->sha1_valid = !is_null_sha1(sha1);
2200        }
2201}
2202
2203/*
2204 * Given a name and sha1 pair, if the index tells us the file in
2205 * the work tree has that object contents, return true, so that
2206 * prepare_temp_file() does not have to inflate and extract.
2207 */
2208static int reuse_worktree_file(const char *name, const unsigned char *sha1, int want_file)
2209{
2210        struct cache_entry *ce;
2211        struct stat st;
2212        int pos, len;
2213
2214        /*
2215         * We do not read the cache ourselves here, because the
2216         * benchmark with my previous version that always reads cache
2217         * shows that it makes things worse for diff-tree comparing
2218         * two linux-2.6 kernel trees in an already checked out work
2219         * tree.  This is because most diff-tree comparisons deal with
2220         * only a small number of files, while reading the cache is
2221         * expensive for a large project, and its cost outweighs the
2222         * savings we get by not inflating the object to a temporary
2223         * file.  Practically, this code only helps when we are used
2224         * by diff-cache --cached, which does read the cache before
2225         * calling us.
2226         */
2227        if (!active_cache)
2228                return 0;
2229
2230        /* We want to avoid the working directory if our caller
2231         * doesn't need the data in a normal file, this system
2232         * is rather slow with its stat/open/mmap/close syscalls,
2233         * and the object is contained in a pack file.  The pack
2234         * is probably already open and will be faster to obtain
2235         * the data through than the working directory.  Loose
2236         * objects however would tend to be slower as they need
2237         * to be individually opened and inflated.
2238         */
2239        if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(sha1))
2240                return 0;
2241
2242        len = strlen(name);
2243        pos = cache_name_pos(name, len);
2244        if (pos < 0)
2245                return 0;
2246        ce = active_cache[pos];
2247
2248        /*
2249         * This is not the sha1 we are looking for, or
2250         * unreusable because it is not a regular file.
2251         */
2252        if (hashcmp(sha1, ce->sha1) || !S_ISREG(ce->ce_mode))
2253                return 0;
2254
2255        /*
2256         * If ce is marked as "assume unchanged", there is no
2257         * guarantee that work tree matches what we are looking for.
2258         */
2259        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
2260                return 0;
2261
2262        /*
2263         * If ce matches the file in the work tree, we can reuse it.
2264         */
2265        if (ce_uptodate(ce) ||
2266            (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
2267                return 1;
2268
2269        return 0;
2270}
2271
2272static int populate_from_stdin(struct diff_filespec *s)
2273{
2274        struct strbuf buf = STRBUF_INIT;
2275        size_t size = 0;
2276
2277        if (strbuf_read(&buf, 0, 0) < 0)
2278                return error("error while reading from stdin %s",
2279                                     strerror(errno));
2280
2281        s->should_munmap = 0;
2282        s->data = strbuf_detach(&buf, &size);
2283        s->size = size;
2284        s->should_free = 1;
2285        return 0;
2286}
2287
2288static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
2289{
2290        int len;
2291        char *data = xmalloc(100), *dirty = "";
2292
2293        /* Are we looking at the work tree? */
2294        if (s->dirty_submodule)
2295                dirty = "-dirty";
2296
2297        len = snprintf(data, 100,
2298                       "Subproject commit %s%s\n", sha1_to_hex(s->sha1), dirty);
2299        s->data = data;
2300        s->size = len;
2301        s->should_free = 1;
2302        if (size_only) {
2303                s->data = NULL;
2304                free(data);
2305        }
2306        return 0;
2307}
2308
2309/*
2310 * While doing rename detection and pickaxe operation, we may need to
2311 * grab the data for the blob (or file) for our own in-core comparison.
2312 * diff_filespec has data and size fields for this purpose.
2313 */
2314int diff_populate_filespec(struct diff_filespec *s, int size_only)
2315{
2316        int err = 0;
2317        if (!DIFF_FILE_VALID(s))
2318                die("internal error: asking to populate invalid file.");
2319        if (S_ISDIR(s->mode))
2320                return -1;
2321
2322        if (s->data)
2323                return 0;
2324
2325        if (size_only && 0 < s->size)
2326                return 0;
2327
2328        if (S_ISGITLINK(s->mode))
2329                return diff_populate_gitlink(s, size_only);
2330
2331        if (!s->sha1_valid ||
2332            reuse_worktree_file(s->path, s->sha1, 0)) {
2333                struct strbuf buf = STRBUF_INIT;
2334                struct stat st;
2335                int fd;
2336
2337                if (!strcmp(s->path, "-"))
2338                        return populate_from_stdin(s);
2339
2340                if (lstat(s->path, &st) < 0) {
2341                        if (errno == ENOENT) {
2342                        err_empty:
2343                                err = -1;
2344                        empty:
2345                                s->data = (char *)"";
2346                                s->size = 0;
2347                                return err;
2348                        }
2349                }
2350                s->size = xsize_t(st.st_size);
2351                if (!s->size)
2352                        goto empty;
2353                if (S_ISLNK(st.st_mode)) {
2354                        struct strbuf sb = STRBUF_INIT;
2355
2356                        if (strbuf_readlink(&sb, s->path, s->size))
2357                                goto err_empty;
2358                        s->size = sb.len;
2359                        s->data = strbuf_detach(&sb, NULL);
2360                        s->should_free = 1;
2361                        return 0;
2362                }
2363                if (size_only)
2364                        return 0;
2365                fd = open(s->path, O_RDONLY);
2366                if (fd < 0)
2367                        goto err_empty;
2368                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
2369                close(fd);
2370                s->should_munmap = 1;
2371
2372                /*
2373                 * Convert from working tree format to canonical git format
2374                 */
2375                if (convert_to_git(s->path, s->data, s->size, &buf, safe_crlf)) {
2376                        size_t size = 0;
2377                        munmap(s->data, s->size);
2378                        s->should_munmap = 0;
2379                        s->data = strbuf_detach(&buf, &size);
2380                        s->size = size;
2381                        s->should_free = 1;
2382                }
2383        }
2384        else {
2385                enum object_type type;
2386                if (size_only)
2387                        type = sha1_object_info(s->sha1, &s->size);
2388                else {
2389                        s->data = read_sha1_file(s->sha1, &type, &s->size);
2390                        s->should_free = 1;
2391                }
2392        }
2393        return 0;
2394}
2395
2396void diff_free_filespec_blob(struct diff_filespec *s)
2397{
2398        if (s->should_free)
2399                free(s->data);
2400        else if (s->should_munmap)
2401                munmap(s->data, s->size);
2402
2403        if (s->should_free || s->should_munmap) {
2404                s->should_free = s->should_munmap = 0;
2405                s->data = NULL;
2406        }
2407}
2408
2409void diff_free_filespec_data(struct diff_filespec *s)
2410{
2411        diff_free_filespec_blob(s);
2412        free(s->cnt_data);
2413        s->cnt_data = NULL;
2414}
2415
2416static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
2417                           void *blob,
2418                           unsigned long size,
2419                           const unsigned char *sha1,
2420                           int mode)
2421{
2422        int fd;
2423        struct strbuf buf = STRBUF_INIT;
2424        struct strbuf template = STRBUF_INIT;
2425        char *path_dup = xstrdup(path);
2426        const char *base = basename(path_dup);
2427
2428        /* Generate "XXXXXX_basename.ext" */
2429        strbuf_addstr(&template, "XXXXXX_");
2430        strbuf_addstr(&template, base);
2431
2432        fd = git_mkstemps(temp->tmp_path, PATH_MAX, template.buf,
2433                        strlen(base) + 1);
2434        if (fd < 0)
2435                die_errno("unable to create temp-file");
2436        if (convert_to_working_tree(path,
2437                        (const char *)blob, (size_t)size, &buf)) {
2438                blob = buf.buf;
2439                size = buf.len;
2440        }
2441        if (write_in_full(fd, blob, size) != size)
2442                die_errno("unable to write temp-file");
2443        close(fd);
2444        temp->name = temp->tmp_path;
2445        strcpy(temp->hex, sha1_to_hex(sha1));
2446        temp->hex[40] = 0;
2447        sprintf(temp->mode, "%06o", mode);
2448        strbuf_release(&buf);
2449        strbuf_release(&template);
2450        free(path_dup);
2451}
2452
2453static struct diff_tempfile *prepare_temp_file(const char *name,
2454                struct diff_filespec *one)
2455{
2456        struct diff_tempfile *temp = claim_diff_tempfile();
2457
2458        if (!DIFF_FILE_VALID(one)) {
2459        not_a_valid_file:
2460                /* A '-' entry produces this for file-2, and
2461                 * a '+' entry produces this for file-1.
2462                 */
2463                temp->name = "/dev/null";
2464                strcpy(temp->hex, ".");
2465                strcpy(temp->mode, ".");
2466                return temp;
2467        }
2468
2469        if (!remove_tempfile_installed) {
2470                atexit(remove_tempfile);
2471                sigchain_push_common(remove_tempfile_on_signal);
2472                remove_tempfile_installed = 1;
2473        }
2474
2475        if (!one->sha1_valid ||
2476            reuse_worktree_file(name, one->sha1, 1)) {
2477                struct stat st;
2478                if (lstat(name, &st) < 0) {
2479                        if (errno == ENOENT)
2480                                goto not_a_valid_file;
2481                        die_errno("stat(%s)", name);
2482                }
2483                if (S_ISLNK(st.st_mode)) {
2484                        struct strbuf sb = STRBUF_INIT;
2485                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
2486                                die_errno("readlink(%s)", name);
2487                        prep_temp_blob(name, temp, sb.buf, sb.len,
2488                                       (one->sha1_valid ?
2489                                        one->sha1 : null_sha1),
2490                                       (one->sha1_valid ?
2491                                        one->mode : S_IFLNK));
2492                        strbuf_release(&sb);
2493                }
2494                else {
2495                        /* we can borrow from the file in the work tree */
2496                        temp->name = name;
2497                        if (!one->sha1_valid)
2498                                strcpy(temp->hex, sha1_to_hex(null_sha1));
2499                        else
2500                                strcpy(temp->hex, sha1_to_hex(one->sha1));
2501                        /* Even though we may sometimes borrow the
2502                         * contents from the work tree, we always want
2503                         * one->mode.  mode is trustworthy even when
2504                         * !(one->sha1_valid), as long as
2505                         * DIFF_FILE_VALID(one).
2506                         */
2507                        sprintf(temp->mode, "%06o", one->mode);
2508                }
2509                return temp;
2510        }
2511        else {
2512                if (diff_populate_filespec(one, 0))
2513                        die("cannot read data blob for %s", one->path);
2514                prep_temp_blob(name, temp, one->data, one->size,
2515                               one->sha1, one->mode);
2516        }
2517        return temp;
2518}
2519
2520/* An external diff command takes:
2521 *
2522 * diff-cmd name infile1 infile1-sha1 infile1-mode \
2523 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
2524 *
2525 */
2526static void run_external_diff(const char *pgm,
2527                              const char *name,
2528                              const char *other,
2529                              struct diff_filespec *one,
2530                              struct diff_filespec *two,
2531                              const char *xfrm_msg,
2532                              int complete_rewrite)
2533{
2534        const char *spawn_arg[10];
2535        int retval;
2536        const char **arg = &spawn_arg[0];
2537
2538        if (one && two) {
2539                struct diff_tempfile *temp_one, *temp_two;
2540                const char *othername = (other ? other : name);
2541                temp_one = prepare_temp_file(name, one);
2542                temp_two = prepare_temp_file(othername, two);
2543                *arg++ = pgm;
2544                *arg++ = name;
2545                *arg++ = temp_one->name;
2546                *arg++ = temp_one->hex;
2547                *arg++ = temp_one->mode;
2548                *arg++ = temp_two->name;
2549                *arg++ = temp_two->hex;
2550                *arg++ = temp_two->mode;
2551                if (other) {
2552                        *arg++ = other;
2553                        *arg++ = xfrm_msg;
2554                }
2555        } else {
2556                *arg++ = pgm;
2557                *arg++ = name;
2558        }
2559        *arg = NULL;
2560        fflush(NULL);
2561        retval = run_command_v_opt(spawn_arg, RUN_USING_SHELL);
2562        remove_tempfile();
2563        if (retval) {
2564                fprintf(stderr, "external diff died, stopping at %s.\n", name);
2565                exit(1);
2566        }
2567}
2568
2569static int similarity_index(struct diff_filepair *p)
2570{
2571        return p->score * 100 / MAX_SCORE;
2572}
2573
2574static void fill_metainfo(struct strbuf *msg,
2575                          const char *name,
2576                          const char *other,
2577                          struct diff_filespec *one,
2578                          struct diff_filespec *two,
2579                          struct diff_options *o,
2580                          struct diff_filepair *p,
2581                          int *must_show_header,
2582                          int use_color)
2583{
2584        const char *set = diff_get_color(use_color, DIFF_METAINFO);
2585        const char *reset = diff_get_color(use_color, DIFF_RESET);
2586        struct strbuf *msgbuf;
2587        char *line_prefix = "";
2588
2589        *must_show_header = 1;
2590        if (o->output_prefix) {
2591                msgbuf = o->output_prefix(o, o->output_prefix_data);
2592                line_prefix = msgbuf->buf;
2593        }
2594        strbuf_init(msg, PATH_MAX * 2 + 300);
2595        switch (p->status) {
2596        case DIFF_STATUS_COPIED:
2597                strbuf_addf(msg, "%s%ssimilarity index %d%%",
2598                            line_prefix, set, similarity_index(p));
2599                strbuf_addf(msg, "%s\n%s%scopy from ",
2600                            reset,  line_prefix, set);
2601                quote_c_style(name, msg, NULL, 0);
2602                strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
2603                quote_c_style(other, msg, NULL, 0);
2604                strbuf_addf(msg, "%s\n", reset);
2605                break;
2606        case DIFF_STATUS_RENAMED:
2607                strbuf_addf(msg, "%s%ssimilarity index %d%%",
2608                            line_prefix, set, similarity_index(p));
2609                strbuf_addf(msg, "%s\n%s%srename from ",
2610                            reset, line_prefix, set);
2611                quote_c_style(name, msg, NULL, 0);
2612                strbuf_addf(msg, "%s\n%s%srename to ",
2613                            reset, line_prefix, set);
2614                quote_c_style(other, msg, NULL, 0);
2615                strbuf_addf(msg, "%s\n", reset);
2616                break;
2617        case DIFF_STATUS_MODIFIED:
2618                if (p->score) {
2619                        strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
2620                                    line_prefix,
2621                                    set, similarity_index(p), reset);
2622                        break;
2623                }
2624                /* fallthru */
2625        default:
2626                *must_show_header = 0;
2627        }
2628        if (one && two && hashcmp(one->sha1, two->sha1)) {
2629                int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
2630
2631                if (DIFF_OPT_TST(o, BINARY)) {
2632                        mmfile_t mf;
2633                        if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
2634                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
2635                                abbrev = 40;
2636                }
2637                strbuf_addf(msg, "%s%sindex %s..", line_prefix, set,
2638                            find_unique_abbrev(one->sha1, abbrev));
2639                strbuf_addstr(msg, find_unique_abbrev(two->sha1, abbrev));
2640                if (one->mode == two->mode)
2641                        strbuf_addf(msg, " %06o", one->mode);
2642                strbuf_addf(msg, "%s\n", reset);
2643        }
2644}
2645
2646static void run_diff_cmd(const char *pgm,
2647                         const char *name,
2648                         const char *other,
2649                         const char *attr_path,
2650                         struct diff_filespec *one,
2651                         struct diff_filespec *two,
2652                         struct strbuf *msg,
2653                         struct diff_options *o,
2654                         struct diff_filepair *p)
2655{
2656        const char *xfrm_msg = NULL;
2657        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
2658        int must_show_header = 0;
2659
2660        if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
2661                pgm = NULL;
2662        else {
2663                struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
2664                if (drv && drv->external)
2665                        pgm = drv->external;
2666        }
2667
2668        if (msg) {
2669                /*
2670                 * don't use colors when the header is intended for an
2671                 * external diff driver
2672                 */
2673                fill_metainfo(msg, name, other, one, two, o, p,
2674                              &must_show_header,
2675                              DIFF_OPT_TST(o, COLOR_DIFF) && !pgm);
2676                xfrm_msg = msg->len ? msg->buf : NULL;
2677        }
2678
2679        if (pgm) {
2680                run_external_diff(pgm, name, other, one, two, xfrm_msg,
2681                                  complete_rewrite);
2682                return;
2683        }
2684        if (one && two)
2685                builtin_diff(name, other ? other : name,
2686                             one, two, xfrm_msg, must_show_header,
2687                             o, complete_rewrite);
2688        else
2689                fprintf(o->file, "* Unmerged path %s\n", name);
2690}
2691
2692static void diff_fill_sha1_info(struct diff_filespec *one)
2693{
2694        if (DIFF_FILE_VALID(one)) {
2695                if (!one->sha1_valid) {
2696                        struct stat st;
2697                        if (!strcmp(one->path, "-")) {
2698                                hashcpy(one->sha1, null_sha1);
2699                                return;
2700                        }
2701                        if (lstat(one->path, &st) < 0)
2702                                die_errno("stat '%s'", one->path);
2703                        if (index_path(one->sha1, one->path, &st, 0))
2704                                die("cannot hash %s", one->path);
2705                }
2706        }
2707        else
2708                hashclr(one->sha1);
2709}
2710
2711static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
2712{
2713        /* Strip the prefix but do not molest /dev/null and absolute paths */
2714        if (*namep && **namep != '/') {
2715                *namep += prefix_length;
2716                if (**namep == '/')
2717                        ++*namep;
2718        }
2719        if (*otherp && **otherp != '/') {
2720                *otherp += prefix_length;
2721                if (**otherp == '/')
2722                        ++*otherp;
2723        }
2724}
2725
2726static void run_diff(struct diff_filepair *p, struct diff_options *o)
2727{
2728        const char *pgm = external_diff();
2729        struct strbuf msg;
2730        struct diff_filespec *one = p->one;
2731        struct diff_filespec *two = p->two;
2732        const char *name;
2733        const char *other;
2734        const char *attr_path;
2735
2736        name  = p->one->path;
2737        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2738        attr_path = name;
2739        if (o->prefix_length)
2740                strip_prefix(o->prefix_length, &name, &other);
2741
2742        if (DIFF_PAIR_UNMERGED(p)) {
2743                run_diff_cmd(pgm, name, NULL, attr_path,
2744                             NULL, NULL, NULL, o, p);
2745                return;
2746        }
2747
2748        diff_fill_sha1_info(one);
2749        diff_fill_sha1_info(two);
2750
2751        if (!pgm &&
2752            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
2753            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
2754                /*
2755                 * a filepair that changes between file and symlink
2756                 * needs to be split into deletion and creation.
2757                 */
2758                struct diff_filespec *null = alloc_filespec(two->path);
2759                run_diff_cmd(NULL, name, other, attr_path,
2760                             one, null, &msg, o, p);
2761                free(null);
2762                strbuf_release(&msg);
2763
2764                null = alloc_filespec(one->path);
2765                run_diff_cmd(NULL, name, other, attr_path,
2766                             null, two, &msg, o, p);
2767                free(null);
2768        }
2769        else
2770                run_diff_cmd(pgm, name, other, attr_path,
2771                             one, two, &msg, o, p);
2772
2773        strbuf_release(&msg);
2774}
2775
2776static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
2777                         struct diffstat_t *diffstat)
2778{
2779        const char *name;
2780        const char *other;
2781        int complete_rewrite = 0;
2782
2783        if (DIFF_PAIR_UNMERGED(p)) {
2784                /* unmerged */
2785                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, 0);
2786                return;
2787        }
2788
2789        name = p->one->path;
2790        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2791
2792        if (o->prefix_length)
2793                strip_prefix(o->prefix_length, &name, &other);
2794
2795        diff_fill_sha1_info(p->one);
2796        diff_fill_sha1_info(p->two);
2797
2798        if (p->status == DIFF_STATUS_MODIFIED && p->score)
2799                complete_rewrite = 1;
2800        builtin_diffstat(name, other, p->one, p->two, diffstat, o, complete_rewrite);
2801}
2802
2803static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
2804{
2805        const char *name;
2806        const char *other;
2807        const char *attr_path;
2808
2809        if (DIFF_PAIR_UNMERGED(p)) {
2810                /* unmerged */
2811                return;
2812        }
2813
2814        name = p->one->path;
2815        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2816        attr_path = other ? other : name;
2817
2818        if (o->prefix_length)
2819                strip_prefix(o->prefix_length, &name, &other);
2820
2821        diff_fill_sha1_info(p->one);
2822        diff_fill_sha1_info(p->two);
2823
2824        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
2825}
2826
2827void diff_setup(struct diff_options *options)
2828{
2829        memcpy(options, &default_diff_options, sizeof(*options));
2830
2831        options->file = stdout;
2832
2833        options->line_termination = '\n';
2834        options->break_opt = -1;
2835        options->rename_limit = -1;
2836        options->dirstat_percent = 3;
2837        options->context = 3;
2838
2839        options->change = diff_change;
2840        options->add_remove = diff_addremove;
2841        if (diff_use_color_default > 0)
2842                DIFF_OPT_SET(options, COLOR_DIFF);
2843        options->detect_rename = diff_detect_rename_default;
2844
2845        if (diff_no_prefix) {
2846                options->a_prefix = options->b_prefix = "";
2847        } else if (!diff_mnemonic_prefix) {
2848                options->a_prefix = "a/";
2849                options->b_prefix = "b/";
2850        }
2851}
2852
2853int diff_setup_done(struct diff_options *options)
2854{
2855        int count = 0;
2856
2857        if (options->output_format & DIFF_FORMAT_NAME)
2858                count++;
2859        if (options->output_format & DIFF_FORMAT_NAME_STATUS)
2860                count++;
2861        if (options->output_format & DIFF_FORMAT_CHECKDIFF)
2862                count++;
2863        if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
2864                count++;
2865        if (count > 1)
2866                die("--name-only, --name-status, --check and -s are mutually exclusive");
2867
2868        /*
2869         * Most of the time we can say "there are changes"
2870         * only by checking if there are changed paths, but
2871         * --ignore-whitespace* options force us to look
2872         * inside contents.
2873         */
2874
2875        if (DIFF_XDL_TST(options, IGNORE_WHITESPACE) ||
2876            DIFF_XDL_TST(options, IGNORE_WHITESPACE_CHANGE) ||
2877            DIFF_XDL_TST(options, IGNORE_WHITESPACE_AT_EOL))
2878                DIFF_OPT_SET(options, DIFF_FROM_CONTENTS);
2879        else
2880                DIFF_OPT_CLR(options, DIFF_FROM_CONTENTS);
2881
2882        if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
2883                options->detect_rename = DIFF_DETECT_COPY;
2884
2885        if (!DIFF_OPT_TST(options, RELATIVE_NAME))
2886                options->prefix = NULL;
2887        if (options->prefix)
2888                options->prefix_length = strlen(options->prefix);
2889        else
2890                options->prefix_length = 0;
2891
2892        if (options->output_format & (DIFF_FORMAT_NAME |
2893                                      DIFF_FORMAT_NAME_STATUS |
2894                                      DIFF_FORMAT_CHECKDIFF |
2895                                      DIFF_FORMAT_NO_OUTPUT))
2896                options->output_format &= ~(DIFF_FORMAT_RAW |
2897                                            DIFF_FORMAT_NUMSTAT |
2898                                            DIFF_FORMAT_DIFFSTAT |
2899                                            DIFF_FORMAT_SHORTSTAT |
2900                                            DIFF_FORMAT_DIRSTAT |
2901                                            DIFF_FORMAT_SUMMARY |
2902                                            DIFF_FORMAT_PATCH);
2903
2904        /*
2905         * These cases always need recursive; we do not drop caller-supplied
2906         * recursive bits for other formats here.
2907         */
2908        if (options->output_format & (DIFF_FORMAT_PATCH |
2909                                      DIFF_FORMAT_NUMSTAT |
2910                                      DIFF_FORMAT_DIFFSTAT |
2911                                      DIFF_FORMAT_SHORTSTAT |
2912                                      DIFF_FORMAT_DIRSTAT |
2913                                      DIFF_FORMAT_SUMMARY |
2914                                      DIFF_FORMAT_CHECKDIFF))
2915                DIFF_OPT_SET(options, RECURSIVE);
2916        /*
2917         * Also pickaxe would not work very well if you do not say recursive
2918         */
2919        if (options->pickaxe)
2920                DIFF_OPT_SET(options, RECURSIVE);
2921        /*
2922         * When patches are generated, submodules diffed against the work tree
2923         * must be checked for dirtiness too so it can be shown in the output
2924         */
2925        if (options->output_format & DIFF_FORMAT_PATCH)
2926                DIFF_OPT_SET(options, DIRTY_SUBMODULES);
2927
2928        if (options->detect_rename && options->rename_limit < 0)
2929                options->rename_limit = diff_rename_limit_default;
2930        if (options->setup & DIFF_SETUP_USE_CACHE) {
2931                if (!active_cache)
2932                        /* read-cache does not die even when it fails
2933                         * so it is safe for us to do this here.  Also
2934                         * it does not smudge active_cache or active_nr
2935                         * when it fails, so we do not have to worry about
2936                         * cleaning it up ourselves either.
2937                         */
2938                        read_cache();
2939        }
2940        if (options->abbrev <= 0 || 40 < options->abbrev)
2941                options->abbrev = 40; /* full */
2942
2943        /*
2944         * It does not make sense to show the first hit we happened
2945         * to have found.  It does not make sense not to return with
2946         * exit code in such a case either.
2947         */
2948        if (DIFF_OPT_TST(options, QUICK)) {
2949                options->output_format = DIFF_FORMAT_NO_OUTPUT;
2950                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
2951        }
2952
2953        return 0;
2954}
2955
2956static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
2957{
2958        char c, *eq;
2959        int len;
2960
2961        if (*arg != '-')
2962                return 0;
2963        c = *++arg;
2964        if (!c)
2965                return 0;
2966        if (c == arg_short) {
2967                c = *++arg;
2968                if (!c)
2969                        return 1;
2970                if (val && isdigit(c)) {
2971                        char *end;
2972                        int n = strtoul(arg, &end, 10);
2973                        if (*end)
2974                                return 0;
2975                        *val = n;
2976                        return 1;
2977                }
2978                return 0;
2979        }
2980        if (c != '-')
2981                return 0;
2982        arg++;
2983        eq = strchr(arg, '=');
2984        if (eq)
2985                len = eq - arg;
2986        else
2987                len = strlen(arg);
2988        if (!len || strncmp(arg, arg_long, len))
2989                return 0;
2990        if (eq) {
2991                int n;
2992                char *end;
2993                if (!isdigit(*++eq))
2994                        return 0;
2995                n = strtoul(eq, &end, 10);
2996                if (*end)
2997                        return 0;
2998                *val = n;
2999        }
3000        return 1;
3001}
3002
3003static int diff_scoreopt_parse(const char *opt);
3004
3005int diff_opt_parse(struct diff_options *options, const char **av, int ac)
3006{
3007        const char *arg = av[0];
3008
3009        /* Output format options */
3010        if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch"))
3011                options->output_format |= DIFF_FORMAT_PATCH;
3012        else if (opt_arg(arg, 'U', "unified", &options->context))
3013                options->output_format |= DIFF_FORMAT_PATCH;
3014        else if (!strcmp(arg, "--raw"))
3015                options->output_format |= DIFF_FORMAT_RAW;
3016        else if (!strcmp(arg, "--patch-with-raw"))
3017                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_RAW;
3018        else if (!strcmp(arg, "--numstat"))
3019                options->output_format |= DIFF_FORMAT_NUMSTAT;
3020        else if (!strcmp(arg, "--shortstat"))
3021                options->output_format |= DIFF_FORMAT_SHORTSTAT;
3022        else if (opt_arg(arg, 'X', "dirstat", &options->dirstat_percent))
3023                options->output_format |= DIFF_FORMAT_DIRSTAT;
3024        else if (!strcmp(arg, "--cumulative")) {
3025                options->output_format |= DIFF_FORMAT_DIRSTAT;
3026                DIFF_OPT_SET(options, DIRSTAT_CUMULATIVE);
3027        } else if (opt_arg(arg, 0, "dirstat-by-file",
3028                           &options->dirstat_percent)) {
3029                options->output_format |= DIFF_FORMAT_DIRSTAT;
3030                DIFF_OPT_SET(options, DIRSTAT_BY_FILE);
3031        }
3032        else if (!strcmp(arg, "--check"))
3033                options->output_format |= DIFF_FORMAT_CHECKDIFF;
3034        else if (!strcmp(arg, "--summary"))
3035                options->output_format |= DIFF_FORMAT_SUMMARY;
3036        else if (!strcmp(arg, "--patch-with-stat"))
3037                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_DIFFSTAT;
3038        else if (!strcmp(arg, "--name-only"))
3039                options->output_format |= DIFF_FORMAT_NAME;
3040        else if (!strcmp(arg, "--name-status"))
3041                options->output_format |= DIFF_FORMAT_NAME_STATUS;
3042        else if (!strcmp(arg, "-s"))
3043                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
3044        else if (!prefixcmp(arg, "--stat")) {
3045                char *end;
3046                int width = options->stat_width;
3047                int name_width = options->stat_name_width;
3048                arg += 6;
3049                end = (char *)arg;
3050
3051                switch (*arg) {
3052                case '-':
3053                        if (!prefixcmp(arg, "-width="))
3054                                width = strtoul(arg + 7, &end, 10);
3055                        else if (!prefixcmp(arg, "-name-width="))
3056                                name_width = strtoul(arg + 12, &end, 10);
3057                        break;
3058                case '=':
3059                        width = strtoul(arg+1, &end, 10);
3060                        if (*end == ',')
3061                                name_width = strtoul(end+1, &end, 10);
3062                }
3063
3064                /* Important! This checks all the error cases! */
3065                if (*end)
3066                        return 0;
3067                options->output_format |= DIFF_FORMAT_DIFFSTAT;
3068                options->stat_name_width = name_width;
3069                options->stat_width = width;
3070        }
3071
3072        /* renames options */
3073        else if (!prefixcmp(arg, "-B")) {
3074                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
3075                        return -1;
3076        }
3077        else if (!prefixcmp(arg, "-M")) {
3078                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3079                        return -1;
3080                options->detect_rename = DIFF_DETECT_RENAME;
3081        }
3082        else if (!prefixcmp(arg, "-C")) {
3083                if (options->detect_rename == DIFF_DETECT_COPY)
3084                        DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3085                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3086                        return -1;
3087                options->detect_rename = DIFF_DETECT_COPY;
3088        }
3089        else if (!strcmp(arg, "--no-renames"))
3090                options->detect_rename = 0;
3091        else if (!strcmp(arg, "--relative"))
3092                DIFF_OPT_SET(options, RELATIVE_NAME);
3093        else if (!prefixcmp(arg, "--relative=")) {
3094                DIFF_OPT_SET(options, RELATIVE_NAME);
3095                options->prefix = arg + 11;
3096        }
3097
3098        /* xdiff options */
3099        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
3100                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
3101        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
3102                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
3103        else if (!strcmp(arg, "--ignore-space-at-eol"))
3104                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
3105        else if (!strcmp(arg, "--patience"))
3106                DIFF_XDL_SET(options, PATIENCE_DIFF);
3107
3108        /* flags options */
3109        else if (!strcmp(arg, "--binary")) {
3110                options->output_format |= DIFF_FORMAT_PATCH;
3111                DIFF_OPT_SET(options, BINARY);
3112        }
3113        else if (!strcmp(arg, "--full-index"))
3114                DIFF_OPT_SET(options, FULL_INDEX);
3115        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
3116                DIFF_OPT_SET(options, TEXT);
3117        else if (!strcmp(arg, "-R"))
3118                DIFF_OPT_SET(options, REVERSE_DIFF);
3119        else if (!strcmp(arg, "--find-copies-harder"))
3120                DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3121        else if (!strcmp(arg, "--follow"))
3122                DIFF_OPT_SET(options, FOLLOW_RENAMES);
3123        else if (!strcmp(arg, "--color"))
3124                DIFF_OPT_SET(options, COLOR_DIFF);
3125        else if (!prefixcmp(arg, "--color=")) {
3126                int value = git_config_colorbool(NULL, arg+8, -1);
3127                if (value == 0)
3128                        DIFF_OPT_CLR(options, COLOR_DIFF);
3129                else if (value > 0)
3130                        DIFF_OPT_SET(options, COLOR_DIFF);
3131                else
3132                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
3133        }
3134        else if (!strcmp(arg, "--no-color"))
3135                DIFF_OPT_CLR(options, COLOR_DIFF);
3136        else if (!strcmp(arg, "--color-words")) {
3137                DIFF_OPT_SET(options, COLOR_DIFF);
3138                options->word_diff = DIFF_WORDS_COLOR;
3139        }
3140        else if (!prefixcmp(arg, "--color-words=")) {
3141                DIFF_OPT_SET(options, COLOR_DIFF);
3142                options->word_diff = DIFF_WORDS_COLOR;
3143                options->word_regex = arg + 14;
3144        }
3145        else if (!strcmp(arg, "--word-diff")) {
3146                if (options->word_diff == DIFF_WORDS_NONE)
3147                        options->word_diff = DIFF_WORDS_PLAIN;
3148        }
3149        else if (!prefixcmp(arg, "--word-diff=")) {
3150                const char *type = arg + 12;
3151                if (!strcmp(type, "plain"))
3152                        options->word_diff = DIFF_WORDS_PLAIN;
3153                else if (!strcmp(type, "color")) {
3154                        DIFF_OPT_SET(options, COLOR_DIFF);
3155                        options->word_diff = DIFF_WORDS_COLOR;
3156                }
3157                else if (!strcmp(type, "porcelain"))
3158                        options->word_diff = DIFF_WORDS_PORCELAIN;
3159                else if (!strcmp(type, "none"))
3160                        options->word_diff = DIFF_WORDS_NONE;
3161                else
3162                        die("bad --word-diff argument: %s", type);
3163        }
3164        else if (!prefixcmp(arg, "--word-diff-regex=")) {
3165                if (options->word_diff == DIFF_WORDS_NONE)
3166                        options->word_diff = DIFF_WORDS_PLAIN;
3167                options->word_regex = arg + 18;
3168        }
3169        else if (!strcmp(arg, "--exit-code"))
3170                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3171        else if (!strcmp(arg, "--quiet"))
3172                DIFF_OPT_SET(options, QUICK);
3173        else if (!strcmp(arg, "--ext-diff"))
3174                DIFF_OPT_SET(options, ALLOW_EXTERNAL);
3175        else if (!strcmp(arg, "--no-ext-diff"))
3176                DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
3177        else if (!strcmp(arg, "--textconv"))
3178                DIFF_OPT_SET(options, ALLOW_TEXTCONV);
3179        else if (!strcmp(arg, "--no-textconv"))
3180                DIFF_OPT_CLR(options, ALLOW_TEXTCONV);
3181        else if (!strcmp(arg, "--ignore-submodules")) {
3182                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3183                handle_ignore_submodules_arg(options, "all");
3184        } else if (!prefixcmp(arg, "--ignore-submodules=")) {
3185                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3186                handle_ignore_submodules_arg(options, arg + 20);
3187        } else if (!strcmp(arg, "--submodule"))
3188                DIFF_OPT_SET(options, SUBMODULE_LOG);
3189        else if (!prefixcmp(arg, "--submodule=")) {
3190                if (!strcmp(arg + 12, "log"))
3191                        DIFF_OPT_SET(options, SUBMODULE_LOG);
3192        }
3193
3194        /* misc options */
3195        else if (!strcmp(arg, "-z"))
3196                options->line_termination = 0;
3197        else if (!prefixcmp(arg, "-l"))
3198                options->rename_limit = strtoul(arg+2, NULL, 10);
3199        else if (!prefixcmp(arg, "-S"))
3200                options->pickaxe = arg + 2;
3201        else if (!strcmp(arg, "--pickaxe-all"))
3202                options->pickaxe_opts = DIFF_PICKAXE_ALL;
3203        else if (!strcmp(arg, "--pickaxe-regex"))
3204                options->pickaxe_opts = DIFF_PICKAXE_REGEX;
3205        else if (!prefixcmp(arg, "-O"))
3206                options->orderfile = arg + 2;
3207        else if (!prefixcmp(arg, "--diff-filter="))
3208                options->filter = arg + 14;
3209        else if (!strcmp(arg, "--abbrev"))
3210                options->abbrev = DEFAULT_ABBREV;
3211        else if (!prefixcmp(arg, "--abbrev=")) {
3212                options->abbrev = strtoul(arg + 9, NULL, 10);
3213                if (options->abbrev < MINIMUM_ABBREV)
3214                        options->abbrev = MINIMUM_ABBREV;
3215                else if (40 < options->abbrev)
3216                        options->abbrev = 40;
3217        }
3218        else if (!prefixcmp(arg, "--src-prefix="))
3219                options->a_prefix = arg + 13;
3220        else if (!prefixcmp(arg, "--dst-prefix="))
3221                options->b_prefix = arg + 13;
3222        else if (!strcmp(arg, "--no-prefix"))
3223                options->a_prefix = options->b_prefix = "";
3224        else if (opt_arg(arg, '\0', "inter-hunk-context",
3225                         &options->interhunkcontext))
3226                ;
3227        else if (!prefixcmp(arg, "--output=")) {
3228                options->file = fopen(arg + strlen("--output="), "w");
3229                if (!options->file)
3230                        die_errno("Could not open '%s'", arg + strlen("--output="));
3231                options->close_file = 1;
3232        } else
3233                return 0;
3234        return 1;
3235}
3236
3237static int parse_num(const char **cp_p)
3238{
3239        unsigned long num, scale;
3240        int ch, dot;
3241        const char *cp = *cp_p;
3242
3243        num = 0;
3244        scale = 1;
3245        dot = 0;
3246        for (;;) {
3247                ch = *cp;
3248                if ( !dot && ch == '.' ) {
3249                        scale = 1;
3250                        dot = 1;
3251                } else if ( ch == '%' ) {
3252                        scale = dot ? scale*100 : 100;
3253                        cp++;   /* % is always at the end */
3254                        break;
3255                } else if ( ch >= '0' && ch <= '9' ) {
3256                        if ( scale < 100000 ) {
3257                                scale *= 10;
3258                                num = (num*10) + (ch-'0');
3259                        }
3260                } else {
3261                        break;
3262                }
3263                cp++;
3264        }
3265        *cp_p = cp;
3266
3267        /* user says num divided by scale and we say internally that
3268         * is MAX_SCORE * num / scale.
3269         */
3270        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
3271}
3272
3273static int diff_scoreopt_parse(const char *opt)
3274{
3275        int opt1, opt2, cmd;
3276
3277        if (*opt++ != '-')
3278                return -1;
3279        cmd = *opt++;
3280        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
3281                return -1; /* that is not a -M, -C nor -B option */
3282
3283        opt1 = parse_num(&opt);
3284        if (cmd != 'B')
3285                opt2 = 0;
3286        else {
3287                if (*opt == 0)
3288                        opt2 = 0;
3289                else if (*opt != '/')
3290                        return -1; /* we expect -B80/99 or -B80 */
3291                else {
3292                        opt++;
3293                        opt2 = parse_num(&opt);
3294                }
3295        }
3296        if (*opt != 0)
3297                return -1;
3298        return opt1 | (opt2 << 16);
3299}
3300
3301struct diff_queue_struct diff_queued_diff;
3302
3303void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
3304{
3305        if (queue->alloc <= queue->nr) {
3306                queue->alloc = alloc_nr(queue->alloc);
3307                queue->queue = xrealloc(queue->queue,
3308                                        sizeof(dp) * queue->alloc);
3309        }
3310        queue->queue[queue->nr++] = dp;
3311}
3312
3313struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
3314                                 struct diff_filespec *one,
3315                                 struct diff_filespec *two)
3316{
3317        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
3318        dp->one = one;
3319        dp->two = two;
3320        if (queue)
3321                diff_q(queue, dp);
3322        return dp;
3323}
3324
3325void diff_free_filepair(struct diff_filepair *p)
3326{
3327        free_filespec(p->one);
3328        free_filespec(p->two);
3329        free(p);
3330}
3331
3332/* This is different from find_unique_abbrev() in that
3333 * it stuffs the result with dots for alignment.
3334 */
3335const char *diff_unique_abbrev(const unsigned char *sha1, int len)
3336{
3337        int abblen;
3338        const char *abbrev;
3339        if (len == 40)
3340                return sha1_to_hex(sha1);
3341
3342        abbrev = find_unique_abbrev(sha1, len);
3343        abblen = strlen(abbrev);
3344        if (abblen < 37) {
3345                static char hex[41];
3346                if (len < abblen && abblen <= len + 2)
3347                        sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
3348                else
3349                        sprintf(hex, "%s...", abbrev);
3350                return hex;
3351        }
3352        return sha1_to_hex(sha1);
3353}
3354
3355static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
3356{
3357        int line_termination = opt->line_termination;
3358        int inter_name_termination = line_termination ? '\t' : '\0';
3359        if (opt->output_prefix) {
3360                struct strbuf *msg = NULL;
3361                msg = opt->output_prefix(opt, opt->output_prefix_data);
3362                fprintf(opt->file, "%s", msg->buf);
3363        }
3364
3365        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
3366                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
3367                        diff_unique_abbrev(p->one->sha1, opt->abbrev));
3368                fprintf(opt->file, "%s ", diff_unique_abbrev(p->two->sha1, opt->abbrev));
3369        }
3370        if (p->score) {
3371                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
3372                        inter_name_termination);
3373        } else {
3374                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
3375        }
3376
3377        if (p->status == DIFF_STATUS_COPIED ||
3378            p->status == DIFF_STATUS_RENAMED) {
3379                const char *name_a, *name_b;
3380                name_a = p->one->path;
3381                name_b = p->two->path;
3382                strip_prefix(opt->prefix_length, &name_a, &name_b);
3383                write_name_quoted(name_a, opt->file, inter_name_termination);
3384                write_name_quoted(name_b, opt->file, line_termination);
3385        } else {
3386                const char *name_a, *name_b;
3387                name_a = p->one->mode ? p->one->path : p->two->path;
3388                name_b = NULL;
3389                strip_prefix(opt->prefix_length, &name_a, &name_b);
3390                write_name_quoted(name_a, opt->file, line_termination);
3391        }
3392}
3393
3394int diff_unmodified_pair(struct diff_filepair *p)
3395{
3396        /* This function is written stricter than necessary to support
3397         * the currently implemented transformers, but the idea is to
3398         * let transformers to produce diff_filepairs any way they want,
3399         * and filter and clean them up here before producing the output.
3400         */
3401        struct diff_filespec *one = p->one, *two = p->two;
3402
3403        if (DIFF_PAIR_UNMERGED(p))
3404                return 0; /* unmerged is interesting */
3405
3406        /* deletion, addition, mode or type change
3407         * and rename are all interesting.
3408         */
3409        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
3410            DIFF_PAIR_MODE_CHANGED(p) ||
3411            strcmp(one->path, two->path))
3412                return 0;
3413
3414        /* both are valid and point at the same path.  that is, we are
3415         * dealing with a change.
3416         */
3417        if (one->sha1_valid && two->sha1_valid &&
3418            !hashcmp(one->sha1, two->sha1) &&
3419            !one->dirty_submodule && !two->dirty_submodule)
3420                return 1; /* no change */
3421        if (!one->sha1_valid && !two->sha1_valid)
3422                return 1; /* both look at the same file on the filesystem. */
3423        return 0;
3424}
3425
3426static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
3427{
3428        if (diff_unmodified_pair(p))
3429                return;
3430
3431        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3432            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3433                return; /* no tree diffs in patch format */
3434
3435        run_diff(p, o);
3436}
3437
3438static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
3439                            struct diffstat_t *diffstat)
3440{
3441        if (diff_unmodified_pair(p))
3442                return;
3443
3444        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3445            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3446                return; /* no tree diffs in patch format */
3447
3448        run_diffstat(p, o, diffstat);
3449}
3450
3451static void diff_flush_checkdiff(struct diff_filepair *p,
3452                struct diff_options *o)
3453{
3454        if (diff_unmodified_pair(p))
3455                return;
3456
3457        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3458            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3459                return; /* no tree diffs in patch format */
3460
3461        run_checkdiff(p, o);
3462}
3463
3464int diff_queue_is_empty(void)
3465{
3466        struct diff_queue_struct *q = &diff_queued_diff;
3467        int i;
3468        for (i = 0; i < q->nr; i++)
3469                if (!diff_unmodified_pair(q->queue[i]))
3470                        return 0;
3471        return 1;
3472}
3473
3474#if DIFF_DEBUG
3475void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
3476{
3477        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
3478                x, one ? one : "",
3479                s->path,
3480                DIFF_FILE_VALID(s) ? "valid" : "invalid",
3481                s->mode,
3482                s->sha1_valid ? sha1_to_hex(s->sha1) : "");
3483        fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
3484                x, one ? one : "",
3485                s->size, s->xfrm_flags);
3486}
3487
3488void diff_debug_filepair(const struct diff_filepair *p, int i)
3489{
3490        diff_debug_filespec(p->one, i, "one");
3491        diff_debug_filespec(p->two, i, "two");
3492        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
3493                p->score, p->status ? p->status : '?',
3494                p->one->rename_used, p->broken_pair);
3495}
3496
3497void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
3498{
3499        int i;
3500        if (msg)
3501                fprintf(stderr, "%s\n", msg);
3502        fprintf(stderr, "q->nr = %d\n", q->nr);
3503        for (i = 0; i < q->nr; i++) {
3504                struct diff_filepair *p = q->queue[i];
3505                diff_debug_filepair(p, i);
3506        }
3507}
3508#endif
3509
3510static void diff_resolve_rename_copy(void)
3511{
3512        int i;
3513        struct diff_filepair *p;
3514        struct diff_queue_struct *q = &diff_queued_diff;
3515
3516        diff_debug_queue("resolve-rename-copy", q);
3517
3518        for (i = 0; i < q->nr; i++) {
3519                p = q->queue[i];
3520                p->status = 0; /* undecided */
3521                if (DIFF_PAIR_UNMERGED(p))
3522                        p->status = DIFF_STATUS_UNMERGED;
3523                else if (!DIFF_FILE_VALID(p->one))
3524                        p->status = DIFF_STATUS_ADDED;
3525                else if (!DIFF_FILE_VALID(p->two))
3526                        p->status = DIFF_STATUS_DELETED;
3527                else if (DIFF_PAIR_TYPE_CHANGED(p))
3528                        p->status = DIFF_STATUS_TYPE_CHANGED;
3529
3530                /* from this point on, we are dealing with a pair
3531                 * whose both sides are valid and of the same type, i.e.
3532                 * either in-place edit or rename/copy edit.
3533                 */
3534                else if (DIFF_PAIR_RENAME(p)) {
3535                        /*
3536                         * A rename might have re-connected a broken
3537                         * pair up, causing the pathnames to be the
3538                         * same again. If so, that's not a rename at
3539                         * all, just a modification..
3540                         *
3541                         * Otherwise, see if this source was used for
3542                         * multiple renames, in which case we decrement
3543                         * the count, and call it a copy.
3544                         */
3545                        if (!strcmp(p->one->path, p->two->path))
3546                                p->status = DIFF_STATUS_MODIFIED;
3547                        else if (--p->one->rename_used > 0)
3548                                p->status = DIFF_STATUS_COPIED;
3549                        else
3550                                p->status = DIFF_STATUS_RENAMED;
3551                }
3552                else if (hashcmp(p->one->sha1, p->two->sha1) ||
3553                         p->one->mode != p->two->mode ||
3554                         p->one->dirty_submodule ||
3555                         p->two->dirty_submodule ||
3556                         is_null_sha1(p->one->sha1))
3557                        p->status = DIFF_STATUS_MODIFIED;
3558                else {
3559                        /* This is a "no-change" entry and should not
3560                         * happen anymore, but prepare for broken callers.
3561                         */
3562                        error("feeding unmodified %s to diffcore",
3563                              p->one->path);
3564                        p->status = DIFF_STATUS_UNKNOWN;
3565                }
3566        }
3567        diff_debug_queue("resolve-rename-copy done", q);
3568}
3569
3570static int check_pair_status(struct diff_filepair *p)
3571{
3572        switch (p->status) {
3573        case DIFF_STATUS_UNKNOWN:
3574                return 0;
3575        case 0:
3576                die("internal error in diff-resolve-rename-copy");
3577        default:
3578                return 1;
3579        }
3580}
3581
3582static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
3583{
3584        int fmt = opt->output_format;
3585
3586        if (fmt & DIFF_FORMAT_CHECKDIFF)
3587                diff_flush_checkdiff(p, opt);
3588        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
3589                diff_flush_raw(p, opt);
3590        else if (fmt & DIFF_FORMAT_NAME) {
3591                const char *name_a, *name_b;
3592                name_a = p->two->path;
3593                name_b = NULL;
3594                strip_prefix(opt->prefix_length, &name_a, &name_b);
3595                write_name_quoted(name_a, opt->file, opt->line_termination);
3596        }
3597}
3598
3599static void show_file_mode_name(FILE *file, const char *newdelete, struct diff_filespec *fs)
3600{
3601        if (fs->mode)
3602                fprintf(file, " %s mode %06o ", newdelete, fs->mode);
3603        else
3604                fprintf(file, " %s ", newdelete);
3605        write_name_quoted(fs->path, file, '\n');
3606}
3607
3608
3609static void show_mode_change(FILE *file, struct diff_filepair *p, int show_name,
3610                const char *line_prefix)
3611{
3612        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
3613                fprintf(file, "%s mode change %06o => %06o%c", line_prefix, p->one->mode,
3614                        p->two->mode, show_name ? ' ' : '\n');
3615                if (show_name) {
3616                        write_name_quoted(p->two->path, file, '\n');
3617                }
3618        }
3619}
3620
3621static void show_rename_copy(FILE *file, const char *renamecopy, struct diff_filepair *p,
3622                        const char *line_prefix)
3623{
3624        char *names = pprint_rename(p->one->path, p->two->path);
3625
3626        fprintf(file, " %s %s (%d%%)\n", renamecopy, names, similarity_index(p));
3627        free(names);
3628        show_mode_change(file, p, 0, line_prefix);
3629}
3630
3631static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
3632{
3633        FILE *file = opt->file;
3634        char *line_prefix = "";
3635
3636        if (opt->output_prefix) {
3637                struct strbuf *buf = opt->output_prefix(opt, opt->output_prefix_data);
3638                line_prefix = buf->buf;
3639        }
3640
3641        switch(p->status) {
3642        case DIFF_STATUS_DELETED:
3643                fputs(line_prefix, file);
3644                show_file_mode_name(file, "delete", p->one);
3645                break;
3646        case DIFF_STATUS_ADDED:
3647                fputs(line_prefix, file);
3648                show_file_mode_name(file, "create", p->two);
3649                break;
3650        case DIFF_STATUS_COPIED:
3651                fputs(line_prefix, file);
3652                show_rename_copy(file, "copy", p, line_prefix);
3653                break;
3654        case DIFF_STATUS_RENAMED:
3655                fputs(line_prefix, file);
3656                show_rename_copy(file, "rename", p, line_prefix);
3657                break;
3658        default:
3659                if (p->score) {
3660                        fprintf(file, "%s rewrite ", line_prefix);
3661                        write_name_quoted(p->two->path, file, ' ');
3662                        fprintf(file, "(%d%%)\n", similarity_index(p));
3663                }
3664                show_mode_change(file, p, !p->score, line_prefix);
3665                break;
3666        }
3667}
3668
3669struct patch_id_t {
3670        git_SHA_CTX *ctx;
3671        int patchlen;
3672};
3673
3674static int remove_space(char *line, int len)
3675{
3676        int i;
3677        char *dst = line;
3678        unsigned char c;
3679
3680        for (i = 0; i < len; i++)
3681                if (!isspace((c = line[i])))
3682                        *dst++ = c;
3683
3684        return dst - line;
3685}
3686
3687static void patch_id_consume(void *priv, char *line, unsigned long len)
3688{
3689        struct patch_id_t *data = priv;
3690        int new_len;
3691
3692        /* Ignore line numbers when computing the SHA1 of the patch */
3693        if (!prefixcmp(line, "@@ -"))
3694                return;
3695
3696        new_len = remove_space(line, len);
3697
3698        git_SHA1_Update(data->ctx, line, new_len);
3699        data->patchlen += new_len;
3700}
3701
3702/* returns 0 upon success, and writes result into sha1 */
3703static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
3704{
3705        struct diff_queue_struct *q = &diff_queued_diff;
3706        int i;
3707        git_SHA_CTX ctx;
3708        struct patch_id_t data;
3709        char buffer[PATH_MAX * 4 + 20];
3710
3711        git_SHA1_Init(&ctx);
3712        memset(&data, 0, sizeof(struct patch_id_t));
3713        data.ctx = &ctx;
3714
3715        for (i = 0; i < q->nr; i++) {
3716                xpparam_t xpp;
3717                xdemitconf_t xecfg;
3718                mmfile_t mf1, mf2;
3719                struct diff_filepair *p = q->queue[i];
3720                int len1, len2;
3721
3722                memset(&xpp, 0, sizeof(xpp));
3723                memset(&xecfg, 0, sizeof(xecfg));
3724                if (p->status == 0)
3725                        return error("internal diff status error");
3726                if (p->status == DIFF_STATUS_UNKNOWN)
3727                        continue;
3728                if (diff_unmodified_pair(p))
3729                        continue;
3730                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3731                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3732                        continue;
3733                if (DIFF_PAIR_UNMERGED(p))
3734                        continue;
3735
3736                diff_fill_sha1_info(p->one);
3737                diff_fill_sha1_info(p->two);
3738                if (fill_mmfile(&mf1, p->one) < 0 ||
3739                                fill_mmfile(&mf2, p->two) < 0)
3740                        return error("unable to read files to diff");
3741
3742                len1 = remove_space(p->one->path, strlen(p->one->path));
3743                len2 = remove_space(p->two->path, strlen(p->two->path));
3744                if (p->one->mode == 0)
3745                        len1 = snprintf(buffer, sizeof(buffer),
3746                                        "diff--gita/%.*sb/%.*s"
3747                                        "newfilemode%06o"
3748                                        "---/dev/null"
3749                                        "+++b/%.*s",
3750                                        len1, p->one->path,
3751                                        len2, p->two->path,
3752                                        p->two->mode,
3753                                        len2, p->two->path);
3754                else if (p->two->mode == 0)
3755                        len1 = snprintf(buffer, sizeof(buffer),
3756                                        "diff--gita/%.*sb/%.*s"
3757                                        "deletedfilemode%06o"
3758                                        "---a/%.*s"
3759                                        "+++/dev/null",
3760                                        len1, p->one->path,
3761                                        len2, p->two->path,
3762                                        p->one->mode,
3763                                        len1, p->one->path);
3764                else
3765                        len1 = snprintf(buffer, sizeof(buffer),
3766                                        "diff--gita/%.*sb/%.*s"
3767                                        "---a/%.*s"
3768                                        "+++b/%.*s",
3769                                        len1, p->one->path,
3770                                        len2, p->two->path,
3771                                        len1, p->one->path,
3772                                        len2, p->two->path);
3773                git_SHA1_Update(&ctx, buffer, len1);
3774
3775                xpp.flags = 0;
3776                xecfg.ctxlen = 3;
3777                xecfg.flags = XDL_EMIT_FUNCNAMES;
3778                xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
3779                              &xpp, &xecfg);
3780        }
3781
3782        git_SHA1_Final(sha1, &ctx);
3783        return 0;
3784}
3785
3786int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1)
3787{
3788        struct diff_queue_struct *q = &diff_queued_diff;
3789        int i;
3790        int result = diff_get_patch_id(options, sha1);
3791
3792        for (i = 0; i < q->nr; i++)
3793                diff_free_filepair(q->queue[i]);
3794
3795        free(q->queue);
3796        DIFF_QUEUE_CLEAR(q);
3797
3798        return result;
3799}
3800
3801static int is_summary_empty(const struct diff_queue_struct *q)
3802{
3803        int i;
3804
3805        for (i = 0; i < q->nr; i++) {
3806                const struct diff_filepair *p = q->queue[i];
3807
3808                switch (p->status) {
3809                case DIFF_STATUS_DELETED:
3810                case DIFF_STATUS_ADDED:
3811                case DIFF_STATUS_COPIED:
3812                case DIFF_STATUS_RENAMED:
3813                        return 0;
3814                default:
3815                        if (p->score)
3816                                return 0;
3817                        if (p->one->mode && p->two->mode &&
3818                            p->one->mode != p->two->mode)
3819                                return 0;
3820                        break;
3821                }
3822        }
3823        return 1;
3824}
3825
3826void diff_flush(struct diff_options *options)
3827{
3828        struct diff_queue_struct *q = &diff_queued_diff;
3829        int i, output_format = options->output_format;
3830        int separator = 0;
3831
3832        /*
3833         * Order: raw, stat, summary, patch
3834         * or:    name/name-status/checkdiff (other bits clear)
3835         */
3836        if (!q->nr)
3837                goto free_queue;
3838
3839        if (output_format & (DIFF_FORMAT_RAW |
3840                             DIFF_FORMAT_NAME |
3841                             DIFF_FORMAT_NAME_STATUS |
3842                             DIFF_FORMAT_CHECKDIFF)) {
3843                for (i = 0; i < q->nr; i++) {
3844                        struct diff_filepair *p = q->queue[i];
3845                        if (check_pair_status(p))
3846                                flush_one_pair(p, options);
3847                }
3848                separator++;
3849        }
3850
3851        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT)) {
3852                struct diffstat_t diffstat;
3853
3854                memset(&diffstat, 0, sizeof(struct diffstat_t));
3855                for (i = 0; i < q->nr; i++) {
3856                        struct diff_filepair *p = q->queue[i];
3857                        if (check_pair_status(p))
3858                                diff_flush_stat(p, options, &diffstat);
3859                }
3860                if (output_format & DIFF_FORMAT_NUMSTAT)
3861                        show_numstat(&diffstat, options);
3862                if (output_format & DIFF_FORMAT_DIFFSTAT)
3863                        show_stats(&diffstat, options);
3864                if (output_format & DIFF_FORMAT_SHORTSTAT)
3865                        show_shortstats(&diffstat, options);
3866                free_diffstat_info(&diffstat);
3867                separator++;
3868        }
3869        if (output_format & DIFF_FORMAT_DIRSTAT)
3870                show_dirstat(options);
3871
3872        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
3873                for (i = 0; i < q->nr; i++) {
3874                        diff_summary(options, q->queue[i]);
3875                }
3876                separator++;
3877        }
3878
3879        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
3880            DIFF_OPT_TST(options, EXIT_WITH_STATUS) &&
3881            DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
3882                /*
3883                 * run diff_flush_patch for the exit status. setting
3884                 * options->file to /dev/null should be safe, becaue we
3885                 * aren't supposed to produce any output anyway.
3886                 */
3887                if (options->close_file)
3888                        fclose(options->file);
3889                options->file = fopen("/dev/null", "w");
3890                if (!options->file)
3891                        die_errno("Could not open /dev/null");
3892                options->close_file = 1;
3893                for (i = 0; i < q->nr; i++) {
3894                        struct diff_filepair *p = q->queue[i];
3895                        if (check_pair_status(p))
3896                                diff_flush_patch(p, options);
3897                        if (options->found_changes)
3898                                break;
3899                }
3900        }
3901
3902        if (output_format & DIFF_FORMAT_PATCH) {
3903                if (separator) {
3904                        putc(options->line_termination, options->file);
3905                        if (options->stat_sep) {
3906                                /* attach patch instead of inline */
3907                                fputs(options->stat_sep, options->file);
3908                        }
3909                }
3910
3911                for (i = 0; i < q->nr; i++) {
3912                        struct diff_filepair *p = q->queue[i];
3913                        if (check_pair_status(p))
3914                                diff_flush_patch(p, options);
3915                }
3916        }
3917
3918        if (output_format & DIFF_FORMAT_CALLBACK)
3919                options->format_callback(q, options, options->format_callback_data);
3920
3921        for (i = 0; i < q->nr; i++)
3922                diff_free_filepair(q->queue[i]);
3923free_queue:
3924        free(q->queue);
3925        DIFF_QUEUE_CLEAR(q);
3926        if (options->close_file)
3927                fclose(options->file);
3928
3929        /*
3930         * Report the content-level differences with HAS_CHANGES;
3931         * diff_addremove/diff_change does not set the bit when
3932         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
3933         */
3934        if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
3935                if (options->found_changes)
3936                        DIFF_OPT_SET(options, HAS_CHANGES);
3937                else
3938                        DIFF_OPT_CLR(options, HAS_CHANGES);
3939        }
3940}
3941
3942static void diffcore_apply_filter(const char *filter)
3943{
3944        int i;
3945        struct diff_queue_struct *q = &diff_queued_diff;
3946        struct diff_queue_struct outq;
3947        DIFF_QUEUE_CLEAR(&outq);
3948
3949        if (!filter)
3950                return;
3951
3952        if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
3953                int found;
3954                for (i = found = 0; !found && i < q->nr; i++) {
3955                        struct diff_filepair *p = q->queue[i];
3956                        if (((p->status == DIFF_STATUS_MODIFIED) &&
3957                             ((p->score &&
3958                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
3959                              (!p->score &&
3960                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
3961                            ((p->status != DIFF_STATUS_MODIFIED) &&
3962                             strchr(filter, p->status)))
3963                                found++;
3964                }
3965                if (found)
3966                        return;
3967
3968                /* otherwise we will clear the whole queue
3969                 * by copying the empty outq at the end of this
3970                 * function, but first clear the current entries
3971                 * in the queue.
3972                 */
3973                for (i = 0; i < q->nr; i++)
3974                        diff_free_filepair(q->queue[i]);
3975        }
3976        else {
3977                /* Only the matching ones */
3978                for (i = 0; i < q->nr; i++) {
3979                        struct diff_filepair *p = q->queue[i];
3980
3981                        if (((p->status == DIFF_STATUS_MODIFIED) &&
3982                             ((p->score &&
3983                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
3984                              (!p->score &&
3985                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
3986                            ((p->status != DIFF_STATUS_MODIFIED) &&
3987                             strchr(filter, p->status)))
3988                                diff_q(&outq, p);
3989                        else
3990                                diff_free_filepair(p);
3991                }
3992        }
3993        free(q->queue);
3994        *q = outq;
3995}
3996
3997/* Check whether two filespecs with the same mode and size are identical */
3998static int diff_filespec_is_identical(struct diff_filespec *one,
3999                                      struct diff_filespec *two)
4000{
4001        if (S_ISGITLINK(one->mode))
4002                return 0;
4003        if (diff_populate_filespec(one, 0))
4004                return 0;
4005        if (diff_populate_filespec(two, 0))
4006                return 0;
4007        return !memcmp(one->data, two->data, one->size);
4008}
4009
4010static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
4011{
4012        int i;
4013        struct diff_queue_struct *q = &diff_queued_diff;
4014        struct diff_queue_struct outq;
4015        DIFF_QUEUE_CLEAR(&outq);
4016
4017        for (i = 0; i < q->nr; i++) {
4018                struct diff_filepair *p = q->queue[i];
4019
4020                /*
4021                 * 1. Entries that come from stat info dirtiness
4022                 *    always have both sides (iow, not create/delete),
4023                 *    one side of the object name is unknown, with
4024                 *    the same mode and size.  Keep the ones that
4025                 *    do not match these criteria.  They have real
4026                 *    differences.
4027                 *
4028                 * 2. At this point, the file is known to be modified,
4029                 *    with the same mode and size, and the object
4030                 *    name of one side is unknown.  Need to inspect
4031                 *    the identical contents.
4032                 */
4033                if (!DIFF_FILE_VALID(p->one) || /* (1) */
4034                    !DIFF_FILE_VALID(p->two) ||
4035                    (p->one->sha1_valid && p->two->sha1_valid) ||
4036                    (p->one->mode != p->two->mode) ||
4037                    diff_populate_filespec(p->one, 1) ||
4038                    diff_populate_filespec(p->two, 1) ||
4039                    (p->one->size != p->two->size) ||
4040                    !diff_filespec_is_identical(p->one, p->two)) /* (2) */
4041                        diff_q(&outq, p);
4042                else {
4043                        /*
4044                         * The caller can subtract 1 from skip_stat_unmatch
4045                         * to determine how many paths were dirty only
4046                         * due to stat info mismatch.
4047                         */
4048                        if (!DIFF_OPT_TST(diffopt, NO_INDEX))
4049                                diffopt->skip_stat_unmatch++;
4050                        diff_free_filepair(p);
4051                }
4052        }
4053        free(q->queue);
4054        *q = outq;
4055}
4056
4057static int diffnamecmp(const void *a_, const void *b_)
4058{
4059        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
4060        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
4061        const char *name_a, *name_b;
4062
4063        name_a = a->one ? a->one->path : a->two->path;
4064        name_b = b->one ? b->one->path : b->two->path;
4065        return strcmp(name_a, name_b);
4066}
4067
4068void diffcore_fix_diff_index(struct diff_options *options)
4069{
4070        struct diff_queue_struct *q = &diff_queued_diff;
4071        qsort(q->queue, q->nr, sizeof(q->queue[0]), diffnamecmp);
4072}
4073
4074void diffcore_std(struct diff_options *options)
4075{
4076        if (options->skip_stat_unmatch)
4077                diffcore_skip_stat_unmatch(options);
4078        if (!options->found_follow) {
4079                /* See try_to_follow_renames() in tree-diff.c */
4080                if (options->break_opt != -1)
4081                        diffcore_break(options->break_opt);
4082                if (options->detect_rename)
4083                        diffcore_rename(options);
4084                if (options->break_opt != -1)
4085                        diffcore_merge_broken();
4086        }
4087        if (options->pickaxe)
4088                diffcore_pickaxe(options->pickaxe, options->pickaxe_opts);
4089        if (options->orderfile)
4090                diffcore_order(options->orderfile);
4091        if (!options->found_follow)
4092                /* See try_to_follow_renames() in tree-diff.c */
4093                diff_resolve_rename_copy();
4094        diffcore_apply_filter(options->filter);
4095
4096        if (diff_queued_diff.nr && !DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4097                DIFF_OPT_SET(options, HAS_CHANGES);
4098        else
4099                DIFF_OPT_CLR(options, HAS_CHANGES);
4100
4101        options->found_follow = 0;
4102}
4103
4104int diff_result_code(struct diff_options *opt, int status)
4105{
4106        int result = 0;
4107        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4108            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
4109                return status;
4110        if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4111            DIFF_OPT_TST(opt, HAS_CHANGES))
4112                result |= 01;
4113        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
4114            DIFF_OPT_TST(opt, CHECK_FAILED))
4115                result |= 02;
4116        return result;
4117}
4118
4119/*
4120 * Shall changes to this submodule be ignored?
4121 *
4122 * Submodule changes can be configured to be ignored separately for each path,
4123 * but that configuration can be overridden from the command line.
4124 */
4125static int is_submodule_ignored(const char *path, struct diff_options *options)
4126{
4127        int ignored = 0;
4128        unsigned orig_flags = options->flags;
4129        if (!DIFF_OPT_TST(options, OVERRIDE_SUBMODULE_CONFIG))
4130                set_diffopt_flags_from_submodule_config(options, path);
4131        if (DIFF_OPT_TST(options, IGNORE_SUBMODULES))
4132                ignored = 1;
4133        options->flags = orig_flags;
4134        return ignored;
4135}
4136
4137void diff_addremove(struct diff_options *options,
4138                    int addremove, unsigned mode,
4139                    const unsigned char *sha1,
4140                    const char *concatpath, unsigned dirty_submodule)
4141{
4142        struct diff_filespec *one, *two;
4143
4144        if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
4145                return;
4146
4147        /* This may look odd, but it is a preparation for
4148         * feeding "there are unchanged files which should
4149         * not produce diffs, but when you are doing copy
4150         * detection you would need them, so here they are"
4151         * entries to the diff-core.  They will be prefixed
4152         * with something like '=' or '*' (I haven't decided
4153         * which but should not make any difference).
4154         * Feeding the same new and old to diff_change()
4155         * also has the same effect.
4156         * Before the final output happens, they are pruned after
4157         * merged into rename/copy pairs as appropriate.
4158         */
4159        if (DIFF_OPT_TST(options, REVERSE_DIFF))
4160                addremove = (addremove == '+' ? '-' :
4161                             addremove == '-' ? '+' : addremove);
4162
4163        if (options->prefix &&
4164            strncmp(concatpath, options->prefix, options->prefix_length))
4165                return;
4166
4167        one = alloc_filespec(concatpath);
4168        two = alloc_filespec(concatpath);
4169
4170        if (addremove != '+')
4171                fill_filespec(one, sha1, mode);
4172        if (addremove != '-') {
4173                fill_filespec(two, sha1, mode);
4174                two->dirty_submodule = dirty_submodule;
4175        }
4176
4177        diff_queue(&diff_queued_diff, one, two);
4178        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4179                DIFF_OPT_SET(options, HAS_CHANGES);
4180}
4181
4182void diff_change(struct diff_options *options,
4183                 unsigned old_mode, unsigned new_mode,
4184                 const unsigned char *old_sha1,
4185                 const unsigned char *new_sha1,
4186                 const char *concatpath,
4187                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
4188{
4189        struct diff_filespec *one, *two;
4190
4191        if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
4192            is_submodule_ignored(concatpath, options))
4193                return;
4194
4195        if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
4196                unsigned tmp;
4197                const unsigned char *tmp_c;
4198                tmp = old_mode; old_mode = new_mode; new_mode = tmp;
4199                tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
4200                tmp = old_dirty_submodule; old_dirty_submodule = new_dirty_submodule;
4201                        new_dirty_submodule = tmp;
4202        }
4203
4204        if (options->prefix &&
4205            strncmp(concatpath, options->prefix, options->prefix_length))
4206                return;
4207
4208        one = alloc_filespec(concatpath);
4209        two = alloc_filespec(concatpath);
4210        fill_filespec(one, old_sha1, old_mode);
4211        fill_filespec(two, new_sha1, new_mode);
4212        one->dirty_submodule = old_dirty_submodule;
4213        two->dirty_submodule = new_dirty_submodule;
4214
4215        diff_queue(&diff_queued_diff, one, two);
4216        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4217                DIFF_OPT_SET(options, HAS_CHANGES);
4218}
4219
4220void diff_unmerge(struct diff_options *options,
4221                  const char *path,
4222                  unsigned mode, const unsigned char *sha1)
4223{
4224        struct diff_filespec *one, *two;
4225
4226        if (options->prefix &&
4227            strncmp(path, options->prefix, options->prefix_length))
4228                return;
4229
4230        one = alloc_filespec(path);
4231        two = alloc_filespec(path);
4232        fill_filespec(one, sha1, mode);
4233        diff_queue(&diff_queued_diff, one, two)->is_unmerged = 1;
4234}
4235
4236static char *run_textconv(const char *pgm, struct diff_filespec *spec,
4237                size_t *outsize)
4238{
4239        struct diff_tempfile *temp;
4240        const char *argv[3];
4241        const char **arg = argv;
4242        struct child_process child;
4243        struct strbuf buf = STRBUF_INIT;
4244        int err = 0;
4245
4246        temp = prepare_temp_file(spec->path, spec);
4247        *arg++ = pgm;
4248        *arg++ = temp->name;
4249        *arg = NULL;
4250
4251        memset(&child, 0, sizeof(child));
4252        child.use_shell = 1;
4253        child.argv = argv;
4254        child.out = -1;
4255        if (start_command(&child)) {
4256                remove_tempfile();
4257                return NULL;
4258        }
4259
4260        if (strbuf_read(&buf, child.out, 0) < 0)
4261                err = error("error reading from textconv command '%s'", pgm);
4262        close(child.out);
4263
4264        if (finish_command(&child) || err) {
4265                strbuf_release(&buf);
4266                remove_tempfile();
4267                return NULL;
4268        }
4269        remove_tempfile();
4270
4271        return strbuf_detach(&buf, outsize);
4272}
4273
4274size_t fill_textconv(struct userdiff_driver *driver,
4275                     struct diff_filespec *df,
4276                     char **outbuf)
4277{
4278        size_t size;
4279
4280        if (!driver || !driver->textconv) {
4281                if (!DIFF_FILE_VALID(df)) {
4282                        *outbuf = "";
4283                        return 0;
4284                }
4285                if (diff_populate_filespec(df, 0))
4286                        die("unable to read files to diff");
4287                *outbuf = df->data;
4288                return df->size;
4289        }
4290
4291        if (driver->textconv_cache) {
4292                *outbuf = notes_cache_get(driver->textconv_cache, df->sha1,
4293                                          &size);
4294                if (*outbuf)
4295                        return size;
4296        }
4297
4298        *outbuf = run_textconv(driver->textconv, df, &size);
4299        if (!*outbuf)
4300                die("unable to read files to diff");
4301
4302        if (driver->textconv_cache) {
4303                /* ignore errors, as we might be in a readonly repository */
4304                notes_cache_put(driver->textconv_cache, df->sha1, *outbuf,
4305                                size);
4306                /*
4307                 * we could save up changes and flush them all at the end,
4308                 * but we would need an extra call after all diffing is done.
4309                 * Since generating a cache entry is the slow path anyway,
4310                 * this extra overhead probably isn't a big deal.
4311                 */
4312                notes_cache_write(driver->textconv_cache);
4313        }
4314
4315        return size;
4316}