diff.con commit Merge branch 'js/maint-merge-use-prepare-commit-msg-hook' into maint (5b8aac3)
   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        const char *prefix;
 611        const char *suffix;
 612        const char *color; /* NULL; filled in by the setup code if
 613                            * color is enabled */
 614};
 615
 616struct diff_words_style {
 617        enum diff_words_type type;
 618        struct diff_words_style_elem new, old, ctx;
 619        const char *newline;
 620};
 621
 622struct diff_words_style diff_words_styles[] = {
 623        { DIFF_WORDS_PORCELAIN, {"+", "\n"}, {"-", "\n"}, {" ", "\n"}, "~\n" },
 624        { DIFF_WORDS_PLAIN, {"{+", "+}"}, {"[-", "-]"}, {"", ""}, "\n" },
 625        { DIFF_WORDS_COLOR, {"", ""}, {"", ""}, {"", ""}, "\n" }
 626};
 627
 628struct diff_words_data {
 629        struct diff_words_buffer minus, plus;
 630        const char *current_plus;
 631        int last_minus;
 632        struct diff_options *opt;
 633        regex_t *word_regex;
 634        enum diff_words_type type;
 635        struct diff_words_style *style;
 636};
 637
 638static int fn_out_diff_words_write_helper(FILE *fp,
 639                                          struct diff_words_style_elem *st_el,
 640                                          const char *newline,
 641                                          size_t count, const char *buf,
 642                                          const char *line_prefix)
 643{
 644        int print = 0;
 645
 646        while (count) {
 647                char *p = memchr(buf, '\n', count);
 648                if (print)
 649                        fputs(line_prefix, fp);
 650                if (p != buf) {
 651                        if (st_el->color && fputs(st_el->color, fp) < 0)
 652                                return -1;
 653                        if (fputs(st_el->prefix, fp) < 0 ||
 654                            fwrite(buf, p ? p - buf : count, 1, fp) != 1 ||
 655                            fputs(st_el->suffix, fp) < 0)
 656                                return -1;
 657                        if (st_el->color && *st_el->color
 658                            && fputs(GIT_COLOR_RESET, fp) < 0)
 659                                return -1;
 660                }
 661                if (!p)
 662                        return 0;
 663                if (fputs(newline, fp) < 0)
 664                        return -1;
 665                count -= p + 1 - buf;
 666                buf = p + 1;
 667                print = 1;
 668        }
 669        return 0;
 670}
 671
 672/*
 673 * '--color-words' algorithm can be described as:
 674 *
 675 *   1. collect a the minus/plus lines of a diff hunk, divided into
 676 *      minus-lines and plus-lines;
 677 *
 678 *   2. break both minus-lines and plus-lines into words and
 679 *      place them into two mmfile_t with one word for each line;
 680 *
 681 *   3. use xdiff to run diff on the two mmfile_t to get the words level diff;
 682 *
 683 * And for the common parts of the both file, we output the plus side text.
 684 * diff_words->current_plus is used to trace the current position of the plus file
 685 * which printed. diff_words->last_minus is used to trace the last minus word
 686 * printed.
 687 *
 688 * For '--graph' to work with '--color-words', we need to output the graph prefix
 689 * on each line of color words output. Generally, there are two conditions on
 690 * which we should output the prefix.
 691 *
 692 *   1. diff_words->last_minus == 0 &&
 693 *      diff_words->current_plus == diff_words->plus.text.ptr
 694 *
 695 *      that is: the plus text must start as a new line, and if there is no minus
 696 *      word printed, a graph prefix must be printed.
 697 *
 698 *   2. diff_words->current_plus > diff_words->plus.text.ptr &&
 699 *      *(diff_words->current_plus - 1) == '\n'
 700 *
 701 *      that is: a graph prefix must be printed following a '\n'
 702 */
 703static int color_words_output_graph_prefix(struct diff_words_data *diff_words)
 704{
 705        if ((diff_words->last_minus == 0 &&
 706                diff_words->current_plus == diff_words->plus.text.ptr) ||
 707                (diff_words->current_plus > diff_words->plus.text.ptr &&
 708                *(diff_words->current_plus - 1) == '\n')) {
 709                return 1;
 710        } else {
 711                return 0;
 712        }
 713}
 714
 715static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
 716{
 717        struct diff_words_data *diff_words = priv;
 718        struct diff_words_style *style = diff_words->style;
 719        int minus_first, minus_len, plus_first, plus_len;
 720        const char *minus_begin, *minus_end, *plus_begin, *plus_end;
 721        struct diff_options *opt = diff_words->opt;
 722        struct strbuf *msgbuf;
 723        char *line_prefix = "";
 724
 725        if (line[0] != '@' || parse_hunk_header(line, len,
 726                        &minus_first, &minus_len, &plus_first, &plus_len))
 727                return;
 728
 729        assert(opt);
 730        if (opt->output_prefix) {
 731                msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
 732                line_prefix = msgbuf->buf;
 733        }
 734
 735        /* POSIX requires that first be decremented by one if len == 0... */
 736        if (minus_len) {
 737                minus_begin = diff_words->minus.orig[minus_first].begin;
 738                minus_end =
 739                        diff_words->minus.orig[minus_first + minus_len - 1].end;
 740        } else
 741                minus_begin = minus_end =
 742                        diff_words->minus.orig[minus_first].end;
 743
 744        if (plus_len) {
 745                plus_begin = diff_words->plus.orig[plus_first].begin;
 746                plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
 747        } else
 748                plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
 749
 750        if (color_words_output_graph_prefix(diff_words)) {
 751                fputs(line_prefix, diff_words->opt->file);
 752        }
 753        if (diff_words->current_plus != plus_begin) {
 754                fn_out_diff_words_write_helper(diff_words->opt->file,
 755                                &style->ctx, style->newline,
 756                                plus_begin - diff_words->current_plus,
 757                                diff_words->current_plus, line_prefix);
 758                if (*(plus_begin - 1) == '\n')
 759                        fputs(line_prefix, diff_words->opt->file);
 760        }
 761        if (minus_begin != minus_end) {
 762                fn_out_diff_words_write_helper(diff_words->opt->file,
 763                                &style->old, style->newline,
 764                                minus_end - minus_begin, minus_begin,
 765                                line_prefix);
 766        }
 767        if (plus_begin != plus_end) {
 768                fn_out_diff_words_write_helper(diff_words->opt->file,
 769                                &style->new, style->newline,
 770                                plus_end - plus_begin, plus_begin,
 771                                line_prefix);
 772        }
 773
 774        diff_words->current_plus = plus_end;
 775        diff_words->last_minus = minus_first;
 776}
 777
 778/* This function starts looking at *begin, and returns 0 iff a word was found. */
 779static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
 780                int *begin, int *end)
 781{
 782        if (word_regex && *begin < buffer->size) {
 783                regmatch_t match[1];
 784                if (!regexec(word_regex, buffer->ptr + *begin, 1, match, 0)) {
 785                        char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
 786                                        '\n', match[0].rm_eo - match[0].rm_so);
 787                        *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
 788                        *begin += match[0].rm_so;
 789                        return *begin >= *end;
 790                }
 791                return -1;
 792        }
 793
 794        /* find the next word */
 795        while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
 796                (*begin)++;
 797        if (*begin >= buffer->size)
 798                return -1;
 799
 800        /* find the end of the word */
 801        *end = *begin + 1;
 802        while (*end < buffer->size && !isspace(buffer->ptr[*end]))
 803                (*end)++;
 804
 805        return 0;
 806}
 807
 808/*
 809 * This function splits the words in buffer->text, stores the list with
 810 * newline separator into out, and saves the offsets of the original words
 811 * in buffer->orig.
 812 */
 813static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
 814                regex_t *word_regex)
 815{
 816        int i, j;
 817        long alloc = 0;
 818
 819        out->size = 0;
 820        out->ptr = NULL;
 821
 822        /* fake an empty "0th" word */
 823        ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
 824        buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
 825        buffer->orig_nr = 1;
 826
 827        for (i = 0; i < buffer->text.size; i++) {
 828                if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
 829                        return;
 830
 831                /* store original boundaries */
 832                ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
 833                                buffer->orig_alloc);
 834                buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
 835                buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
 836                buffer->orig_nr++;
 837
 838                /* store one word */
 839                ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
 840                memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
 841                out->ptr[out->size + j - i] = '\n';
 842                out->size += j - i + 1;
 843
 844                i = j - 1;
 845        }
 846}
 847
 848/* this executes the word diff on the accumulated buffers */
 849static void diff_words_show(struct diff_words_data *diff_words)
 850{
 851        xpparam_t xpp;
 852        xdemitconf_t xecfg;
 853        mmfile_t minus, plus;
 854        struct diff_words_style *style = diff_words->style;
 855
 856        struct diff_options *opt = diff_words->opt;
 857        struct strbuf *msgbuf;
 858        char *line_prefix = "";
 859
 860        assert(opt);
 861        if (opt->output_prefix) {
 862                msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
 863                line_prefix = msgbuf->buf;
 864        }
 865
 866        /* special case: only removal */
 867        if (!diff_words->plus.text.size) {
 868                fputs(line_prefix, diff_words->opt->file);
 869                fn_out_diff_words_write_helper(diff_words->opt->file,
 870                        &style->old, style->newline,
 871                        diff_words->minus.text.size,
 872                        diff_words->minus.text.ptr, line_prefix);
 873                diff_words->minus.text.size = 0;
 874                return;
 875        }
 876
 877        diff_words->current_plus = diff_words->plus.text.ptr;
 878        diff_words->last_minus = 0;
 879
 880        memset(&xpp, 0, sizeof(xpp));
 881        memset(&xecfg, 0, sizeof(xecfg));
 882        diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
 883        diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
 884        xpp.flags = 0;
 885        /* as only the hunk header will be parsed, we need a 0-context */
 886        xecfg.ctxlen = 0;
 887        xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
 888                      &xpp, &xecfg);
 889        free(minus.ptr);
 890        free(plus.ptr);
 891        if (diff_words->current_plus != diff_words->plus.text.ptr +
 892                        diff_words->plus.text.size) {
 893                if (color_words_output_graph_prefix(diff_words))
 894                        fputs(line_prefix, diff_words->opt->file);
 895                fn_out_diff_words_write_helper(diff_words->opt->file,
 896                        &style->ctx, style->newline,
 897                        diff_words->plus.text.ptr + diff_words->plus.text.size
 898                        - diff_words->current_plus, diff_words->current_plus,
 899                        line_prefix);
 900        }
 901        diff_words->minus.text.size = diff_words->plus.text.size = 0;
 902}
 903
 904/* In "color-words" mode, show word-diff of words accumulated in the buffer */
 905static void diff_words_flush(struct emit_callback *ecbdata)
 906{
 907        if (ecbdata->diff_words->minus.text.size ||
 908            ecbdata->diff_words->plus.text.size)
 909                diff_words_show(ecbdata->diff_words);
 910}
 911
 912static void free_diff_words_data(struct emit_callback *ecbdata)
 913{
 914        if (ecbdata->diff_words) {
 915                diff_words_flush(ecbdata);
 916                free (ecbdata->diff_words->minus.text.ptr);
 917                free (ecbdata->diff_words->minus.orig);
 918                free (ecbdata->diff_words->plus.text.ptr);
 919                free (ecbdata->diff_words->plus.orig);
 920                if (ecbdata->diff_words->word_regex) {
 921                        regfree(ecbdata->diff_words->word_regex);
 922                        free(ecbdata->diff_words->word_regex);
 923                }
 924                free(ecbdata->diff_words);
 925                ecbdata->diff_words = NULL;
 926        }
 927}
 928
 929const char *diff_get_color(int diff_use_color, enum color_diff ix)
 930{
 931        if (diff_use_color)
 932                return diff_colors[ix];
 933        return "";
 934}
 935
 936static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
 937{
 938        const char *cp;
 939        unsigned long allot;
 940        size_t l = len;
 941
 942        if (ecb->truncate)
 943                return ecb->truncate(line, len);
 944        cp = line;
 945        allot = l;
 946        while (0 < l) {
 947                (void) utf8_width(&cp, &l);
 948                if (!cp)
 949                        break; /* truncated in the middle? */
 950        }
 951        return allot - l;
 952}
 953
 954static void find_lno(const char *line, struct emit_callback *ecbdata)
 955{
 956        const char *p;
 957        ecbdata->lno_in_preimage = 0;
 958        ecbdata->lno_in_postimage = 0;
 959        p = strchr(line, '-');
 960        if (!p)
 961                return; /* cannot happen */
 962        ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
 963        p = strchr(p, '+');
 964        if (!p)
 965                return; /* cannot happen */
 966        ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
 967}
 968
 969static void fn_out_consume(void *priv, char *line, unsigned long len)
 970{
 971        struct emit_callback *ecbdata = priv;
 972        const char *meta = diff_get_color(ecbdata->color_diff, DIFF_METAINFO);
 973        const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
 974        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
 975        struct diff_options *o = ecbdata->opt;
 976        char *line_prefix = "";
 977        struct strbuf *msgbuf;
 978
 979        if (o && o->output_prefix) {
 980                msgbuf = o->output_prefix(o, o->output_prefix_data);
 981                line_prefix = msgbuf->buf;
 982        }
 983
 984        if (ecbdata->header) {
 985                fprintf(ecbdata->opt->file, "%s", ecbdata->header->buf);
 986                strbuf_reset(ecbdata->header);
 987                ecbdata->header = NULL;
 988        }
 989        *(ecbdata->found_changesp) = 1;
 990
 991        if (ecbdata->label_path[0]) {
 992                const char *name_a_tab, *name_b_tab;
 993
 994                name_a_tab = strchr(ecbdata->label_path[0], ' ') ? "\t" : "";
 995                name_b_tab = strchr(ecbdata->label_path[1], ' ') ? "\t" : "";
 996
 997                fprintf(ecbdata->opt->file, "%s%s--- %s%s%s\n",
 998                        line_prefix, meta, ecbdata->label_path[0], reset, name_a_tab);
 999                fprintf(ecbdata->opt->file, "%s%s+++ %s%s%s\n",
1000                        line_prefix, meta, ecbdata->label_path[1], reset, name_b_tab);
1001                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
1002        }
1003
1004        if (diff_suppress_blank_empty
1005            && len == 2 && line[0] == ' ' && line[1] == '\n') {
1006                line[0] = '\n';
1007                len = 1;
1008        }
1009
1010        if (line[0] == '@') {
1011                if (ecbdata->diff_words)
1012                        diff_words_flush(ecbdata);
1013                len = sane_truncate_line(ecbdata, line, len);
1014                find_lno(line, ecbdata);
1015                emit_hunk_header(ecbdata, line, len);
1016                if (line[len-1] != '\n')
1017                        putc('\n', ecbdata->opt->file);
1018                return;
1019        }
1020
1021        if (len < 1) {
1022                emit_line(ecbdata->opt, reset, reset, line, len);
1023                if (ecbdata->diff_words
1024                    && ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN)
1025                        fputs("~\n", ecbdata->opt->file);
1026                return;
1027        }
1028
1029        if (ecbdata->diff_words) {
1030                if (line[0] == '-') {
1031                        diff_words_append(line, len,
1032                                          &ecbdata->diff_words->minus);
1033                        return;
1034                } else if (line[0] == '+') {
1035                        diff_words_append(line, len,
1036                                          &ecbdata->diff_words->plus);
1037                        return;
1038                }
1039                diff_words_flush(ecbdata);
1040                if (ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN) {
1041                        emit_line(ecbdata->opt, plain, reset, line, len);
1042                        fputs("~\n", ecbdata->opt->file);
1043                } else {
1044                        /* don't print the prefix character */
1045                        emit_line(ecbdata->opt, plain, reset, line+1, len-1);
1046                }
1047                return;
1048        }
1049
1050        if (line[0] != '+') {
1051                const char *color =
1052                        diff_get_color(ecbdata->color_diff,
1053                                       line[0] == '-' ? DIFF_FILE_OLD : DIFF_PLAIN);
1054                ecbdata->lno_in_preimage++;
1055                if (line[0] == ' ')
1056                        ecbdata->lno_in_postimage++;
1057                emit_line(ecbdata->opt, color, reset, line, len);
1058        } else {
1059                ecbdata->lno_in_postimage++;
1060                emit_add_line(reset, ecbdata, line + 1, len - 1);
1061        }
1062}
1063
1064static char *pprint_rename(const char *a, const char *b)
1065{
1066        const char *old = a;
1067        const char *new = b;
1068        struct strbuf name = STRBUF_INIT;
1069        int pfx_length, sfx_length;
1070        int len_a = strlen(a);
1071        int len_b = strlen(b);
1072        int a_midlen, b_midlen;
1073        int qlen_a = quote_c_style(a, NULL, NULL, 0);
1074        int qlen_b = quote_c_style(b, NULL, NULL, 0);
1075
1076        if (qlen_a || qlen_b) {
1077                quote_c_style(a, &name, NULL, 0);
1078                strbuf_addstr(&name, " => ");
1079                quote_c_style(b, &name, NULL, 0);
1080                return strbuf_detach(&name, NULL);
1081        }
1082
1083        /* Find common prefix */
1084        pfx_length = 0;
1085        while (*old && *new && *old == *new) {
1086                if (*old == '/')
1087                        pfx_length = old - a + 1;
1088                old++;
1089                new++;
1090        }
1091
1092        /* Find common suffix */
1093        old = a + len_a;
1094        new = b + len_b;
1095        sfx_length = 0;
1096        while (a <= old && b <= new && *old == *new) {
1097                if (*old == '/')
1098                        sfx_length = len_a - (old - a);
1099                old--;
1100                new--;
1101        }
1102
1103        /*
1104         * pfx{mid-a => mid-b}sfx
1105         * {pfx-a => pfx-b}sfx
1106         * pfx{sfx-a => sfx-b}
1107         * name-a => name-b
1108         */
1109        a_midlen = len_a - pfx_length - sfx_length;
1110        b_midlen = len_b - pfx_length - sfx_length;
1111        if (a_midlen < 0)
1112                a_midlen = 0;
1113        if (b_midlen < 0)
1114                b_midlen = 0;
1115
1116        strbuf_grow(&name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
1117        if (pfx_length + sfx_length) {
1118                strbuf_add(&name, a, pfx_length);
1119                strbuf_addch(&name, '{');
1120        }
1121        strbuf_add(&name, a + pfx_length, a_midlen);
1122        strbuf_addstr(&name, " => ");
1123        strbuf_add(&name, b + pfx_length, b_midlen);
1124        if (pfx_length + sfx_length) {
1125                strbuf_addch(&name, '}');
1126                strbuf_add(&name, a + len_a - sfx_length, sfx_length);
1127        }
1128        return strbuf_detach(&name, NULL);
1129}
1130
1131struct diffstat_t {
1132        int nr;
1133        int alloc;
1134        struct diffstat_file {
1135                char *from_name;
1136                char *name;
1137                char *print_name;
1138                unsigned is_unmerged:1;
1139                unsigned is_binary:1;
1140                unsigned is_renamed:1;
1141                uintmax_t added, deleted;
1142        } **files;
1143};
1144
1145static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
1146                                          const char *name_a,
1147                                          const char *name_b)
1148{
1149        struct diffstat_file *x;
1150        x = xcalloc(sizeof (*x), 1);
1151        if (diffstat->nr == diffstat->alloc) {
1152                diffstat->alloc = alloc_nr(diffstat->alloc);
1153                diffstat->files = xrealloc(diffstat->files,
1154                                diffstat->alloc * sizeof(x));
1155        }
1156        diffstat->files[diffstat->nr++] = x;
1157        if (name_b) {
1158                x->from_name = xstrdup(name_a);
1159                x->name = xstrdup(name_b);
1160                x->is_renamed = 1;
1161        }
1162        else {
1163                x->from_name = NULL;
1164                x->name = xstrdup(name_a);
1165        }
1166        return x;
1167}
1168
1169static void diffstat_consume(void *priv, char *line, unsigned long len)
1170{
1171        struct diffstat_t *diffstat = priv;
1172        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
1173
1174        if (line[0] == '+')
1175                x->added++;
1176        else if (line[0] == '-')
1177                x->deleted++;
1178}
1179
1180const char mime_boundary_leader[] = "------------";
1181
1182static int scale_linear(int it, int width, int max_change)
1183{
1184        /*
1185         * make sure that at least one '-' is printed if there were deletions,
1186         * and likewise for '+'.
1187         */
1188        if (max_change < 2)
1189                return it;
1190        return ((it - 1) * (width - 1) + max_change - 1) / (max_change - 1);
1191}
1192
1193static void show_name(FILE *file,
1194                      const char *prefix, const char *name, int len)
1195{
1196        fprintf(file, " %s%-*s |", prefix, len, name);
1197}
1198
1199static void show_graph(FILE *file, char ch, int cnt, const char *set, const char *reset)
1200{
1201        if (cnt <= 0)
1202                return;
1203        fprintf(file, "%s", set);
1204        while (cnt--)
1205                putc(ch, file);
1206        fprintf(file, "%s", reset);
1207}
1208
1209static void fill_print_name(struct diffstat_file *file)
1210{
1211        char *pname;
1212
1213        if (file->print_name)
1214                return;
1215
1216        if (!file->is_renamed) {
1217                struct strbuf buf = STRBUF_INIT;
1218                if (quote_c_style(file->name, &buf, NULL, 0)) {
1219                        pname = strbuf_detach(&buf, NULL);
1220                } else {
1221                        pname = file->name;
1222                        strbuf_release(&buf);
1223                }
1224        } else {
1225                pname = pprint_rename(file->from_name, file->name);
1226        }
1227        file->print_name = pname;
1228}
1229
1230static void show_stats(struct diffstat_t *data, struct diff_options *options)
1231{
1232        int i, len, add, del, adds = 0, dels = 0;
1233        uintmax_t max_change = 0, max_len = 0;
1234        int total_files = data->nr;
1235        int width, name_width;
1236        const char *reset, *set, *add_c, *del_c;
1237        const char *line_prefix = "";
1238        struct strbuf *msg = NULL;
1239
1240        if (data->nr == 0)
1241                return;
1242
1243        if (options->output_prefix) {
1244                msg = options->output_prefix(options, options->output_prefix_data);
1245                line_prefix = msg->buf;
1246        }
1247
1248        width = options->stat_width ? options->stat_width : 80;
1249        name_width = options->stat_name_width ? options->stat_name_width : 50;
1250
1251        /* Sanity: give at least 5 columns to the graph,
1252         * but leave at least 10 columns for the name.
1253         */
1254        if (width < 25)
1255                width = 25;
1256        if (name_width < 10)
1257                name_width = 10;
1258        else if (width < name_width + 15)
1259                name_width = width - 15;
1260
1261        /* Find the longest filename and max number of changes */
1262        reset = diff_get_color_opt(options, DIFF_RESET);
1263        set   = diff_get_color_opt(options, DIFF_PLAIN);
1264        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
1265        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
1266
1267        for (i = 0; i < data->nr; i++) {
1268                struct diffstat_file *file = data->files[i];
1269                uintmax_t change = file->added + file->deleted;
1270                fill_print_name(file);
1271                len = strlen(file->print_name);
1272                if (max_len < len)
1273                        max_len = len;
1274
1275                if (file->is_binary || file->is_unmerged)
1276                        continue;
1277                if (max_change < change)
1278                        max_change = change;
1279        }
1280
1281        /* Compute the width of the graph part;
1282         * 10 is for one blank at the beginning of the line plus
1283         * " | count " between the name and the graph.
1284         *
1285         * From here on, name_width is the width of the name area,
1286         * and width is the width of the graph area.
1287         */
1288        name_width = (name_width < max_len) ? name_width : max_len;
1289        if (width < (name_width + 10) + max_change)
1290                width = width - (name_width + 10);
1291        else
1292                width = max_change;
1293
1294        for (i = 0; i < data->nr; i++) {
1295                const char *prefix = "";
1296                char *name = data->files[i]->print_name;
1297                uintmax_t added = data->files[i]->added;
1298                uintmax_t deleted = data->files[i]->deleted;
1299                int name_len;
1300
1301                /*
1302                 * "scale" the filename
1303                 */
1304                len = name_width;
1305                name_len = strlen(name);
1306                if (name_width < name_len) {
1307                        char *slash;
1308                        prefix = "...";
1309                        len -= 3;
1310                        name += name_len - len;
1311                        slash = strchr(name, '/');
1312                        if (slash)
1313                                name = slash;
1314                }
1315
1316                if (data->files[i]->is_binary) {
1317                        fprintf(options->file, "%s", line_prefix);
1318                        show_name(options->file, prefix, name, len);
1319                        fprintf(options->file, "  Bin ");
1320                        fprintf(options->file, "%s%"PRIuMAX"%s",
1321                                del_c, deleted, reset);
1322                        fprintf(options->file, " -> ");
1323                        fprintf(options->file, "%s%"PRIuMAX"%s",
1324                                add_c, added, reset);
1325                        fprintf(options->file, " bytes");
1326                        fprintf(options->file, "\n");
1327                        continue;
1328                }
1329                else if (data->files[i]->is_unmerged) {
1330                        fprintf(options->file, "%s", line_prefix);
1331                        show_name(options->file, prefix, name, len);
1332                        fprintf(options->file, "  Unmerged\n");
1333                        continue;
1334                }
1335                else if (!data->files[i]->is_renamed &&
1336                         (added + deleted == 0)) {
1337                        total_files--;
1338                        continue;
1339                }
1340
1341                /*
1342                 * scale the add/delete
1343                 */
1344                add = added;
1345                del = deleted;
1346                adds += add;
1347                dels += del;
1348
1349                if (width <= max_change) {
1350                        add = scale_linear(add, width, max_change);
1351                        del = scale_linear(del, width, max_change);
1352                }
1353                fprintf(options->file, "%s", line_prefix);
1354                show_name(options->file, prefix, name, len);
1355                fprintf(options->file, "%5"PRIuMAX"%s", added + deleted,
1356                                added + deleted ? " " : "");
1357                show_graph(options->file, '+', add, add_c, reset);
1358                show_graph(options->file, '-', del, del_c, reset);
1359                fprintf(options->file, "\n");
1360        }
1361        fprintf(options->file, "%s", line_prefix);
1362        fprintf(options->file,
1363               " %d files changed, %d insertions(+), %d deletions(-)\n",
1364               total_files, adds, dels);
1365}
1366
1367static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
1368{
1369        int i, adds = 0, dels = 0, total_files = data->nr;
1370
1371        if (data->nr == 0)
1372                return;
1373
1374        for (i = 0; i < data->nr; i++) {
1375                if (!data->files[i]->is_binary &&
1376                    !data->files[i]->is_unmerged) {
1377                        int added = data->files[i]->added;
1378                        int deleted= data->files[i]->deleted;
1379                        if (!data->files[i]->is_renamed &&
1380                            (added + deleted == 0)) {
1381                                total_files--;
1382                        } else {
1383                                adds += added;
1384                                dels += deleted;
1385                        }
1386                }
1387        }
1388        if (options->output_prefix) {
1389                struct strbuf *msg = NULL;
1390                msg = options->output_prefix(options,
1391                                options->output_prefix_data);
1392                fprintf(options->file, "%s", msg->buf);
1393        }
1394        fprintf(options->file, " %d files changed, %d insertions(+), %d deletions(-)\n",
1395               total_files, adds, dels);
1396}
1397
1398static void show_numstat(struct diffstat_t *data, struct diff_options *options)
1399{
1400        int i;
1401
1402        if (data->nr == 0)
1403                return;
1404
1405        for (i = 0; i < data->nr; i++) {
1406                struct diffstat_file *file = data->files[i];
1407
1408                if (options->output_prefix) {
1409                        struct strbuf *msg = NULL;
1410                        msg = options->output_prefix(options,
1411                                        options->output_prefix_data);
1412                        fprintf(options->file, "%s", msg->buf);
1413                }
1414
1415                if (file->is_binary)
1416                        fprintf(options->file, "-\t-\t");
1417                else
1418                        fprintf(options->file,
1419                                "%"PRIuMAX"\t%"PRIuMAX"\t",
1420                                file->added, file->deleted);
1421                if (options->line_termination) {
1422                        fill_print_name(file);
1423                        if (!file->is_renamed)
1424                                write_name_quoted(file->name, options->file,
1425                                                  options->line_termination);
1426                        else {
1427                                fputs(file->print_name, options->file);
1428                                putc(options->line_termination, options->file);
1429                        }
1430                } else {
1431                        if (file->is_renamed) {
1432                                putc('\0', options->file);
1433                                write_name_quoted(file->from_name, options->file, '\0');
1434                        }
1435                        write_name_quoted(file->name, options->file, '\0');
1436                }
1437        }
1438}
1439
1440struct dirstat_file {
1441        const char *name;
1442        unsigned long changed;
1443};
1444
1445struct dirstat_dir {
1446        struct dirstat_file *files;
1447        int alloc, nr, percent, cumulative;
1448};
1449
1450static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
1451                unsigned long changed, const char *base, int baselen)
1452{
1453        unsigned long this_dir = 0;
1454        unsigned int sources = 0;
1455        const char *line_prefix = "";
1456        struct strbuf *msg = NULL;
1457
1458        if (opt->output_prefix) {
1459                msg = opt->output_prefix(opt, opt->output_prefix_data);
1460                line_prefix = msg->buf;
1461        }
1462
1463        while (dir->nr) {
1464                struct dirstat_file *f = dir->files;
1465                int namelen = strlen(f->name);
1466                unsigned long this;
1467                char *slash;
1468
1469                if (namelen < baselen)
1470                        break;
1471                if (memcmp(f->name, base, baselen))
1472                        break;
1473                slash = strchr(f->name + baselen, '/');
1474                if (slash) {
1475                        int newbaselen = slash + 1 - f->name;
1476                        this = gather_dirstat(opt, dir, changed, f->name, newbaselen);
1477                        sources++;
1478                } else {
1479                        this = f->changed;
1480                        dir->files++;
1481                        dir->nr--;
1482                        sources += 2;
1483                }
1484                this_dir += this;
1485        }
1486
1487        /*
1488         * We don't report dirstat's for
1489         *  - the top level
1490         *  - or cases where everything came from a single directory
1491         *    under this directory (sources == 1).
1492         */
1493        if (baselen && sources != 1) {
1494                int permille = this_dir * 1000 / changed;
1495                if (permille) {
1496                        int percent = permille / 10;
1497                        if (percent >= dir->percent) {
1498                                fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
1499                                        percent, permille % 10, baselen, base);
1500                                if (!dir->cumulative)
1501                                        return 0;
1502                        }
1503                }
1504        }
1505        return this_dir;
1506}
1507
1508static int dirstat_compare(const void *_a, const void *_b)
1509{
1510        const struct dirstat_file *a = _a;
1511        const struct dirstat_file *b = _b;
1512        return strcmp(a->name, b->name);
1513}
1514
1515static void show_dirstat(struct diff_options *options)
1516{
1517        int i;
1518        unsigned long changed;
1519        struct dirstat_dir dir;
1520        struct diff_queue_struct *q = &diff_queued_diff;
1521
1522        dir.files = NULL;
1523        dir.alloc = 0;
1524        dir.nr = 0;
1525        dir.percent = options->dirstat_percent;
1526        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1527
1528        changed = 0;
1529        for (i = 0; i < q->nr; i++) {
1530                struct diff_filepair *p = q->queue[i];
1531                const char *name;
1532                unsigned long copied, added, damage;
1533
1534                name = p->one->path ? p->one->path : p->two->path;
1535
1536                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
1537                        diff_populate_filespec(p->one, 0);
1538                        diff_populate_filespec(p->two, 0);
1539                        diffcore_count_changes(p->one, p->two, NULL, NULL, 0,
1540                                               &copied, &added);
1541                        diff_free_filespec_data(p->one);
1542                        diff_free_filespec_data(p->two);
1543                } else if (DIFF_FILE_VALID(p->one)) {
1544                        diff_populate_filespec(p->one, 1);
1545                        copied = added = 0;
1546                        diff_free_filespec_data(p->one);
1547                } else if (DIFF_FILE_VALID(p->two)) {
1548                        diff_populate_filespec(p->two, 1);
1549                        copied = 0;
1550                        added = p->two->size;
1551                        diff_free_filespec_data(p->two);
1552                } else
1553                        continue;
1554
1555                /*
1556                 * Original minus copied is the removed material,
1557                 * added is the new material.  They are both damages
1558                 * made to the preimage. In --dirstat-by-file mode, count
1559                 * damaged files, not damaged lines. This is done by
1560                 * counting only a single damaged line per file.
1561                 */
1562                damage = (p->one->size - copied) + added;
1563                if (DIFF_OPT_TST(options, DIRSTAT_BY_FILE) && damage > 0)
1564                        damage = 1;
1565
1566                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1567                dir.files[dir.nr].name = name;
1568                dir.files[dir.nr].changed = damage;
1569                changed += damage;
1570                dir.nr++;
1571        }
1572
1573        /* This can happen even with many files, if everything was renames */
1574        if (!changed)
1575                return;
1576
1577        /* Show all directories with more than x% of the changes */
1578        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1579        gather_dirstat(options, &dir, changed, "", 0);
1580}
1581
1582static void free_diffstat_info(struct diffstat_t *diffstat)
1583{
1584        int i;
1585        for (i = 0; i < diffstat->nr; i++) {
1586                struct diffstat_file *f = diffstat->files[i];
1587                if (f->name != f->print_name)
1588                        free(f->print_name);
1589                free(f->name);
1590                free(f->from_name);
1591                free(f);
1592        }
1593        free(diffstat->files);
1594}
1595
1596struct checkdiff_t {
1597        const char *filename;
1598        int lineno;
1599        int conflict_marker_size;
1600        struct diff_options *o;
1601        unsigned ws_rule;
1602        unsigned status;
1603};
1604
1605static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
1606{
1607        char firstchar;
1608        int cnt;
1609
1610        if (len < marker_size + 1)
1611                return 0;
1612        firstchar = line[0];
1613        switch (firstchar) {
1614        case '=': case '>': case '<': case '|':
1615                break;
1616        default:
1617                return 0;
1618        }
1619        for (cnt = 1; cnt < marker_size; cnt++)
1620                if (line[cnt] != firstchar)
1621                        return 0;
1622        /* line[1] thru line[marker_size-1] are same as firstchar */
1623        if (len < marker_size + 1 || !isspace(line[marker_size]))
1624                return 0;
1625        return 1;
1626}
1627
1628static void checkdiff_consume(void *priv, char *line, unsigned long len)
1629{
1630        struct checkdiff_t *data = priv;
1631        int color_diff = DIFF_OPT_TST(data->o, COLOR_DIFF);
1632        int marker_size = data->conflict_marker_size;
1633        const char *ws = diff_get_color(color_diff, DIFF_WHITESPACE);
1634        const char *reset = diff_get_color(color_diff, DIFF_RESET);
1635        const char *set = diff_get_color(color_diff, DIFF_FILE_NEW);
1636        char *err;
1637        char *line_prefix = "";
1638        struct strbuf *msgbuf;
1639
1640        assert(data->o);
1641        if (data->o->output_prefix) {
1642                msgbuf = data->o->output_prefix(data->o,
1643                        data->o->output_prefix_data);
1644                line_prefix = msgbuf->buf;
1645        }
1646
1647        if (line[0] == '+') {
1648                unsigned bad;
1649                data->lineno++;
1650                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
1651                        data->status |= 1;
1652                        fprintf(data->o->file,
1653                                "%s%s:%d: leftover conflict marker\n",
1654                                line_prefix, data->filename, data->lineno);
1655                }
1656                bad = ws_check(line + 1, len - 1, data->ws_rule);
1657                if (!bad)
1658                        return;
1659                data->status |= bad;
1660                err = whitespace_error_string(bad);
1661                fprintf(data->o->file, "%s%s:%d: %s.\n",
1662                        line_prefix, data->filename, data->lineno, err);
1663                free(err);
1664                emit_line(data->o, set, reset, line, 1);
1665                ws_check_emit(line + 1, len - 1, data->ws_rule,
1666                              data->o->file, set, reset, ws);
1667        } else if (line[0] == ' ') {
1668                data->lineno++;
1669        } else if (line[0] == '@') {
1670                char *plus = strchr(line, '+');
1671                if (plus)
1672                        data->lineno = strtol(plus, NULL, 10) - 1;
1673                else
1674                        die("invalid diff");
1675        }
1676}
1677
1678static unsigned char *deflate_it(char *data,
1679                                 unsigned long size,
1680                                 unsigned long *result_size)
1681{
1682        int bound;
1683        unsigned char *deflated;
1684        z_stream stream;
1685
1686        memset(&stream, 0, sizeof(stream));
1687        deflateInit(&stream, zlib_compression_level);
1688        bound = deflateBound(&stream, size);
1689        deflated = xmalloc(bound);
1690        stream.next_out = deflated;
1691        stream.avail_out = bound;
1692
1693        stream.next_in = (unsigned char *)data;
1694        stream.avail_in = size;
1695        while (deflate(&stream, Z_FINISH) == Z_OK)
1696                ; /* nothing */
1697        deflateEnd(&stream);
1698        *result_size = stream.total_out;
1699        return deflated;
1700}
1701
1702static void emit_binary_diff_body(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
1703{
1704        void *cp;
1705        void *delta;
1706        void *deflated;
1707        void *data;
1708        unsigned long orig_size;
1709        unsigned long delta_size;
1710        unsigned long deflate_size;
1711        unsigned long data_size;
1712
1713        /* We could do deflated delta, or we could do just deflated two,
1714         * whichever is smaller.
1715         */
1716        delta = NULL;
1717        deflated = deflate_it(two->ptr, two->size, &deflate_size);
1718        if (one->size && two->size) {
1719                delta = diff_delta(one->ptr, one->size,
1720                                   two->ptr, two->size,
1721                                   &delta_size, deflate_size);
1722                if (delta) {
1723                        void *to_free = delta;
1724                        orig_size = delta_size;
1725                        delta = deflate_it(delta, delta_size, &delta_size);
1726                        free(to_free);
1727                }
1728        }
1729
1730        if (delta && delta_size < deflate_size) {
1731                fprintf(file, "%sdelta %lu\n", prefix, orig_size);
1732                free(deflated);
1733                data = delta;
1734                data_size = delta_size;
1735        }
1736        else {
1737                fprintf(file, "%sliteral %lu\n", prefix, two->size);
1738                free(delta);
1739                data = deflated;
1740                data_size = deflate_size;
1741        }
1742
1743        /* emit data encoded in base85 */
1744        cp = data;
1745        while (data_size) {
1746                int bytes = (52 < data_size) ? 52 : data_size;
1747                char line[70];
1748                data_size -= bytes;
1749                if (bytes <= 26)
1750                        line[0] = bytes + 'A' - 1;
1751                else
1752                        line[0] = bytes - 26 + 'a' - 1;
1753                encode_85(line + 1, cp, bytes);
1754                cp = (char *) cp + bytes;
1755                fprintf(file, "%s", prefix);
1756                fputs(line, file);
1757                fputc('\n', file);
1758        }
1759        fprintf(file, "%s\n", prefix);
1760        free(data);
1761}
1762
1763static void emit_binary_diff(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
1764{
1765        fprintf(file, "%sGIT binary patch\n", prefix);
1766        emit_binary_diff_body(file, one, two, prefix);
1767        emit_binary_diff_body(file, two, one, prefix);
1768}
1769
1770static void diff_filespec_load_driver(struct diff_filespec *one)
1771{
1772        /* Use already-loaded driver */
1773        if (one->driver)
1774                return;
1775
1776        if (S_ISREG(one->mode))
1777                one->driver = userdiff_find_by_path(one->path);
1778
1779        /* Fallback to default settings */
1780        if (!one->driver)
1781                one->driver = userdiff_find_by_name("default");
1782}
1783
1784int diff_filespec_is_binary(struct diff_filespec *one)
1785{
1786        if (one->is_binary == -1) {
1787                diff_filespec_load_driver(one);
1788                if (one->driver->binary != -1)
1789                        one->is_binary = one->driver->binary;
1790                else {
1791                        if (!one->data && DIFF_FILE_VALID(one))
1792                                diff_populate_filespec(one, 0);
1793                        if (one->data)
1794                                one->is_binary = buffer_is_binary(one->data,
1795                                                one->size);
1796                        if (one->is_binary == -1)
1797                                one->is_binary = 0;
1798                }
1799        }
1800        return one->is_binary;
1801}
1802
1803static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
1804{
1805        diff_filespec_load_driver(one);
1806        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
1807}
1808
1809static const char *userdiff_word_regex(struct diff_filespec *one)
1810{
1811        diff_filespec_load_driver(one);
1812        return one->driver->word_regex;
1813}
1814
1815void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
1816{
1817        if (!options->a_prefix)
1818                options->a_prefix = a;
1819        if (!options->b_prefix)
1820                options->b_prefix = b;
1821}
1822
1823struct userdiff_driver *get_textconv(struct diff_filespec *one)
1824{
1825        if (!DIFF_FILE_VALID(one))
1826                return NULL;
1827
1828        diff_filespec_load_driver(one);
1829        if (!one->driver->textconv)
1830                return NULL;
1831
1832        if (one->driver->textconv_want_cache && !one->driver->textconv_cache) {
1833                struct notes_cache *c = xmalloc(sizeof(*c));
1834                struct strbuf name = STRBUF_INIT;
1835
1836                strbuf_addf(&name, "textconv/%s", one->driver->name);
1837                notes_cache_init(c, name.buf, one->driver->textconv);
1838                one->driver->textconv_cache = c;
1839        }
1840
1841        return one->driver;
1842}
1843
1844static void builtin_diff(const char *name_a,
1845                         const char *name_b,
1846                         struct diff_filespec *one,
1847                         struct diff_filespec *two,
1848                         const char *xfrm_msg,
1849                         int must_show_header,
1850                         struct diff_options *o,
1851                         int complete_rewrite)
1852{
1853        mmfile_t mf1, mf2;
1854        const char *lbl[2];
1855        char *a_one, *b_two;
1856        const char *set = diff_get_color_opt(o, DIFF_METAINFO);
1857        const char *reset = diff_get_color_opt(o, DIFF_RESET);
1858        const char *a_prefix, *b_prefix;
1859        struct userdiff_driver *textconv_one = NULL;
1860        struct userdiff_driver *textconv_two = NULL;
1861        struct strbuf header = STRBUF_INIT;
1862        struct strbuf *msgbuf;
1863        char *line_prefix = "";
1864
1865        if (o->output_prefix) {
1866                msgbuf = o->output_prefix(o, o->output_prefix_data);
1867                line_prefix = msgbuf->buf;
1868        }
1869
1870        if (DIFF_OPT_TST(o, SUBMODULE_LOG) &&
1871                        (!one->mode || S_ISGITLINK(one->mode)) &&
1872                        (!two->mode || S_ISGITLINK(two->mode))) {
1873                const char *del = diff_get_color_opt(o, DIFF_FILE_OLD);
1874                const char *add = diff_get_color_opt(o, DIFF_FILE_NEW);
1875                show_submodule_summary(o->file, one ? one->path : two->path,
1876                                one->sha1, two->sha1, two->dirty_submodule,
1877                                del, add, reset);
1878                return;
1879        }
1880
1881        if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
1882                textconv_one = get_textconv(one);
1883                textconv_two = get_textconv(two);
1884        }
1885
1886        diff_set_mnemonic_prefix(o, "a/", "b/");
1887        if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
1888                a_prefix = o->b_prefix;
1889                b_prefix = o->a_prefix;
1890        } else {
1891                a_prefix = o->a_prefix;
1892                b_prefix = o->b_prefix;
1893        }
1894
1895        /* Never use a non-valid filename anywhere if at all possible */
1896        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
1897        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
1898
1899        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
1900        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
1901        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
1902        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
1903        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, set, a_one, b_two, reset);
1904        if (lbl[0][0] == '/') {
1905                /* /dev/null */
1906                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, set, two->mode, reset);
1907                if (xfrm_msg)
1908                        strbuf_addstr(&header, xfrm_msg);
1909                must_show_header = 1;
1910        }
1911        else if (lbl[1][0] == '/') {
1912                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, set, one->mode, reset);
1913                if (xfrm_msg)
1914                        strbuf_addstr(&header, xfrm_msg);
1915                must_show_header = 1;
1916        }
1917        else {
1918                if (one->mode != two->mode) {
1919                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, set, one->mode, reset);
1920                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, set, two->mode, reset);
1921                        must_show_header = 1;
1922                }
1923                if (xfrm_msg)
1924                        strbuf_addstr(&header, xfrm_msg);
1925
1926                /*
1927                 * we do not run diff between different kind
1928                 * of objects.
1929                 */
1930                if ((one->mode ^ two->mode) & S_IFMT)
1931                        goto free_ab_and_return;
1932                if (complete_rewrite &&
1933                    (textconv_one || !diff_filespec_is_binary(one)) &&
1934                    (textconv_two || !diff_filespec_is_binary(two))) {
1935                        fprintf(o->file, "%s", header.buf);
1936                        strbuf_reset(&header);
1937                        emit_rewrite_diff(name_a, name_b, one, two,
1938                                                textconv_one, textconv_two, o);
1939                        o->found_changes = 1;
1940                        goto free_ab_and_return;
1941                }
1942        }
1943
1944        if (!DIFF_OPT_TST(o, TEXT) &&
1945            ( (!textconv_one && diff_filespec_is_binary(one)) ||
1946              (!textconv_two && diff_filespec_is_binary(two)) )) {
1947                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1948                        die("unable to read files to diff");
1949                /* Quite common confusing case */
1950                if (mf1.size == mf2.size &&
1951                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
1952                        if (must_show_header)
1953                                fprintf(o->file, "%s", header.buf);
1954                        goto free_ab_and_return;
1955                }
1956                fprintf(o->file, "%s", header.buf);
1957                strbuf_reset(&header);
1958                if (DIFF_OPT_TST(o, BINARY))
1959                        emit_binary_diff(o->file, &mf1, &mf2, line_prefix);
1960                else
1961                        fprintf(o->file, "%sBinary files %s and %s differ\n",
1962                                line_prefix, lbl[0], lbl[1]);
1963                o->found_changes = 1;
1964        }
1965        else {
1966                /* Crazy xdl interfaces.. */
1967                const char *diffopts = getenv("GIT_DIFF_OPTS");
1968                xpparam_t xpp;
1969                xdemitconf_t xecfg;
1970                struct emit_callback ecbdata;
1971                const struct userdiff_funcname *pe;
1972
1973                if (!DIFF_XDL_TST(o, WHITESPACE_FLAGS) || must_show_header) {
1974                        fprintf(o->file, "%s", header.buf);
1975                        strbuf_reset(&header);
1976                }
1977
1978                mf1.size = fill_textconv(textconv_one, one, &mf1.ptr);
1979                mf2.size = fill_textconv(textconv_two, two, &mf2.ptr);
1980
1981                pe = diff_funcname_pattern(one);
1982                if (!pe)
1983                        pe = diff_funcname_pattern(two);
1984
1985                memset(&xpp, 0, sizeof(xpp));
1986                memset(&xecfg, 0, sizeof(xecfg));
1987                memset(&ecbdata, 0, sizeof(ecbdata));
1988                ecbdata.label_path = lbl;
1989                ecbdata.color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
1990                ecbdata.found_changesp = &o->found_changes;
1991                ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
1992                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
1993                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
1994                ecbdata.opt = o;
1995                ecbdata.header = header.len ? &header : NULL;
1996                xpp.flags = o->xdl_opts;
1997                xecfg.ctxlen = o->context;
1998                xecfg.interhunkctxlen = o->interhunkcontext;
1999                xecfg.flags = XDL_EMIT_FUNCNAMES;
2000                if (pe)
2001                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
2002                if (!diffopts)
2003                        ;
2004                else if (!prefixcmp(diffopts, "--unified="))
2005                        xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
2006                else if (!prefixcmp(diffopts, "-u"))
2007                        xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
2008                if (o->word_diff) {
2009                        int i;
2010
2011                        ecbdata.diff_words =
2012                                xcalloc(1, sizeof(struct diff_words_data));
2013                        ecbdata.diff_words->type = o->word_diff;
2014                        ecbdata.diff_words->opt = o;
2015                        if (!o->word_regex)
2016                                o->word_regex = userdiff_word_regex(one);
2017                        if (!o->word_regex)
2018                                o->word_regex = userdiff_word_regex(two);
2019                        if (!o->word_regex)
2020                                o->word_regex = diff_word_regex_cfg;
2021                        if (o->word_regex) {
2022                                ecbdata.diff_words->word_regex = (regex_t *)
2023                                        xmalloc(sizeof(regex_t));
2024                                if (regcomp(ecbdata.diff_words->word_regex,
2025                                                o->word_regex,
2026                                                REG_EXTENDED | REG_NEWLINE))
2027                                        die ("Invalid regular expression: %s",
2028                                                        o->word_regex);
2029                        }
2030                        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
2031                                if (o->word_diff == diff_words_styles[i].type) {
2032                                        ecbdata.diff_words->style =
2033                                                &diff_words_styles[i];
2034                                        break;
2035                                }
2036                        }
2037                        if (DIFF_OPT_TST(o, COLOR_DIFF)) {
2038                                struct diff_words_style *st = ecbdata.diff_words->style;
2039                                st->old.color = diff_get_color_opt(o, DIFF_FILE_OLD);
2040                                st->new.color = diff_get_color_opt(o, DIFF_FILE_NEW);
2041                                st->ctx.color = diff_get_color_opt(o, DIFF_PLAIN);
2042                        }
2043                }
2044                xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
2045                              &xpp, &xecfg);
2046                if (o->word_diff)
2047                        free_diff_words_data(&ecbdata);
2048                if (textconv_one)
2049                        free(mf1.ptr);
2050                if (textconv_two)
2051                        free(mf2.ptr);
2052                xdiff_clear_find_func(&xecfg);
2053        }
2054
2055 free_ab_and_return:
2056        strbuf_release(&header);
2057        diff_free_filespec_data(one);
2058        diff_free_filespec_data(two);
2059        free(a_one);
2060        free(b_two);
2061        return;
2062}
2063
2064static void builtin_diffstat(const char *name_a, const char *name_b,
2065                             struct diff_filespec *one,
2066                             struct diff_filespec *two,
2067                             struct diffstat_t *diffstat,
2068                             struct diff_options *o,
2069                             int complete_rewrite)
2070{
2071        mmfile_t mf1, mf2;
2072        struct diffstat_file *data;
2073
2074        data = diffstat_add(diffstat, name_a, name_b);
2075
2076        if (!one || !two) {
2077                data->is_unmerged = 1;
2078                return;
2079        }
2080        if (complete_rewrite) {
2081                diff_populate_filespec(one, 0);
2082                diff_populate_filespec(two, 0);
2083                data->deleted = count_lines(one->data, one->size);
2084                data->added = count_lines(two->data, two->size);
2085                goto free_and_return;
2086        }
2087        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2088                die("unable to read files to diff");
2089
2090        if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
2091                data->is_binary = 1;
2092                data->added = mf2.size;
2093                data->deleted = mf1.size;
2094        } else {
2095                /* Crazy xdl interfaces.. */
2096                xpparam_t xpp;
2097                xdemitconf_t xecfg;
2098
2099                memset(&xpp, 0, sizeof(xpp));
2100                memset(&xecfg, 0, sizeof(xecfg));
2101                xpp.flags = o->xdl_opts;
2102                xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
2103                              &xpp, &xecfg);
2104        }
2105
2106 free_and_return:
2107        diff_free_filespec_data(one);
2108        diff_free_filespec_data(two);
2109}
2110
2111static void builtin_checkdiff(const char *name_a, const char *name_b,
2112                              const char *attr_path,
2113                              struct diff_filespec *one,
2114                              struct diff_filespec *two,
2115                              struct diff_options *o)
2116{
2117        mmfile_t mf1, mf2;
2118        struct checkdiff_t data;
2119
2120        if (!two)
2121                return;
2122
2123        memset(&data, 0, sizeof(data));
2124        data.filename = name_b ? name_b : name_a;
2125        data.lineno = 0;
2126        data.o = o;
2127        data.ws_rule = whitespace_rule(attr_path);
2128        data.conflict_marker_size = ll_merge_marker_size(attr_path);
2129
2130        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2131                die("unable to read files to diff");
2132
2133        /*
2134         * All the other codepaths check both sides, but not checking
2135         * the "old" side here is deliberate.  We are checking the newly
2136         * introduced changes, and as long as the "new" side is text, we
2137         * can and should check what it introduces.
2138         */
2139        if (diff_filespec_is_binary(two))
2140                goto free_and_return;
2141        else {
2142                /* Crazy xdl interfaces.. */
2143                xpparam_t xpp;
2144                xdemitconf_t xecfg;
2145
2146                memset(&xpp, 0, sizeof(xpp));
2147                memset(&xecfg, 0, sizeof(xecfg));
2148                xecfg.ctxlen = 1; /* at least one context line */
2149                xpp.flags = 0;
2150                xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
2151                              &xpp, &xecfg);
2152
2153                if (data.ws_rule & WS_BLANK_AT_EOF) {
2154                        struct emit_callback ecbdata;
2155                        int blank_at_eof;
2156
2157                        ecbdata.ws_rule = data.ws_rule;
2158                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2159                        blank_at_eof = ecbdata.blank_at_eof_in_postimage;
2160
2161                        if (blank_at_eof) {
2162                                static char *err;
2163                                if (!err)
2164                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
2165                                fprintf(o->file, "%s:%d: %s.\n",
2166                                        data.filename, blank_at_eof, err);
2167                                data.status = 1; /* report errors */
2168                        }
2169                }
2170        }
2171 free_and_return:
2172        diff_free_filespec_data(one);
2173        diff_free_filespec_data(two);
2174        if (data.status)
2175                DIFF_OPT_SET(o, CHECK_FAILED);
2176}
2177
2178struct diff_filespec *alloc_filespec(const char *path)
2179{
2180        int namelen = strlen(path);
2181        struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
2182
2183        memset(spec, 0, sizeof(*spec));
2184        spec->path = (char *)(spec + 1);
2185        memcpy(spec->path, path, namelen+1);
2186        spec->count = 1;
2187        spec->is_binary = -1;
2188        return spec;
2189}
2190
2191void free_filespec(struct diff_filespec *spec)
2192{
2193        if (!--spec->count) {
2194                diff_free_filespec_data(spec);
2195                free(spec);
2196        }
2197}
2198
2199void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
2200                   unsigned short mode)
2201{
2202        if (mode) {
2203                spec->mode = canon_mode(mode);
2204                hashcpy(spec->sha1, sha1);
2205                spec->sha1_valid = !is_null_sha1(sha1);
2206        }
2207}
2208
2209/*
2210 * Given a name and sha1 pair, if the index tells us the file in
2211 * the work tree has that object contents, return true, so that
2212 * prepare_temp_file() does not have to inflate and extract.
2213 */
2214static int reuse_worktree_file(const char *name, const unsigned char *sha1, int want_file)
2215{
2216        struct cache_entry *ce;
2217        struct stat st;
2218        int pos, len;
2219
2220        /*
2221         * We do not read the cache ourselves here, because the
2222         * benchmark with my previous version that always reads cache
2223         * shows that it makes things worse for diff-tree comparing
2224         * two linux-2.6 kernel trees in an already checked out work
2225         * tree.  This is because most diff-tree comparisons deal with
2226         * only a small number of files, while reading the cache is
2227         * expensive for a large project, and its cost outweighs the
2228         * savings we get by not inflating the object to a temporary
2229         * file.  Practically, this code only helps when we are used
2230         * by diff-cache --cached, which does read the cache before
2231         * calling us.
2232         */
2233        if (!active_cache)
2234                return 0;
2235
2236        /* We want to avoid the working directory if our caller
2237         * doesn't need the data in a normal file, this system
2238         * is rather slow with its stat/open/mmap/close syscalls,
2239         * and the object is contained in a pack file.  The pack
2240         * is probably already open and will be faster to obtain
2241         * the data through than the working directory.  Loose
2242         * objects however would tend to be slower as they need
2243         * to be individually opened and inflated.
2244         */
2245        if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(sha1))
2246                return 0;
2247
2248        len = strlen(name);
2249        pos = cache_name_pos(name, len);
2250        if (pos < 0)
2251                return 0;
2252        ce = active_cache[pos];
2253
2254        /*
2255         * This is not the sha1 we are looking for, or
2256         * unreusable because it is not a regular file.
2257         */
2258        if (hashcmp(sha1, ce->sha1) || !S_ISREG(ce->ce_mode))
2259                return 0;
2260
2261        /*
2262         * If ce is marked as "assume unchanged", there is no
2263         * guarantee that work tree matches what we are looking for.
2264         */
2265        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
2266                return 0;
2267
2268        /*
2269         * If ce matches the file in the work tree, we can reuse it.
2270         */
2271        if (ce_uptodate(ce) ||
2272            (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
2273                return 1;
2274
2275        return 0;
2276}
2277
2278static int populate_from_stdin(struct diff_filespec *s)
2279{
2280        struct strbuf buf = STRBUF_INIT;
2281        size_t size = 0;
2282
2283        if (strbuf_read(&buf, 0, 0) < 0)
2284                return error("error while reading from stdin %s",
2285                                     strerror(errno));
2286
2287        s->should_munmap = 0;
2288        s->data = strbuf_detach(&buf, &size);
2289        s->size = size;
2290        s->should_free = 1;
2291        return 0;
2292}
2293
2294static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
2295{
2296        int len;
2297        char *data = xmalloc(100), *dirty = "";
2298
2299        /* Are we looking at the work tree? */
2300        if (s->dirty_submodule)
2301                dirty = "-dirty";
2302
2303        len = snprintf(data, 100,
2304                       "Subproject commit %s%s\n", sha1_to_hex(s->sha1), dirty);
2305        s->data = data;
2306        s->size = len;
2307        s->should_free = 1;
2308        if (size_only) {
2309                s->data = NULL;
2310                free(data);
2311        }
2312        return 0;
2313}
2314
2315/*
2316 * While doing rename detection and pickaxe operation, we may need to
2317 * grab the data for the blob (or file) for our own in-core comparison.
2318 * diff_filespec has data and size fields for this purpose.
2319 */
2320int diff_populate_filespec(struct diff_filespec *s, int size_only)
2321{
2322        int err = 0;
2323        if (!DIFF_FILE_VALID(s))
2324                die("internal error: asking to populate invalid file.");
2325        if (S_ISDIR(s->mode))
2326                return -1;
2327
2328        if (s->data)
2329                return 0;
2330
2331        if (size_only && 0 < s->size)
2332                return 0;
2333
2334        if (S_ISGITLINK(s->mode))
2335                return diff_populate_gitlink(s, size_only);
2336
2337        if (!s->sha1_valid ||
2338            reuse_worktree_file(s->path, s->sha1, 0)) {
2339                struct strbuf buf = STRBUF_INIT;
2340                struct stat st;
2341                int fd;
2342
2343                if (!strcmp(s->path, "-"))
2344                        return populate_from_stdin(s);
2345
2346                if (lstat(s->path, &st) < 0) {
2347                        if (errno == ENOENT) {
2348                        err_empty:
2349                                err = -1;
2350                        empty:
2351                                s->data = (char *)"";
2352                                s->size = 0;
2353                                return err;
2354                        }
2355                }
2356                s->size = xsize_t(st.st_size);
2357                if (!s->size)
2358                        goto empty;
2359                if (S_ISLNK(st.st_mode)) {
2360                        struct strbuf sb = STRBUF_INIT;
2361
2362                        if (strbuf_readlink(&sb, s->path, s->size))
2363                                goto err_empty;
2364                        s->size = sb.len;
2365                        s->data = strbuf_detach(&sb, NULL);
2366                        s->should_free = 1;
2367                        return 0;
2368                }
2369                if (size_only)
2370                        return 0;
2371                fd = open(s->path, O_RDONLY);
2372                if (fd < 0)
2373                        goto err_empty;
2374                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
2375                close(fd);
2376                s->should_munmap = 1;
2377
2378                /*
2379                 * Convert from working tree format to canonical git format
2380                 */
2381                if (convert_to_git(s->path, s->data, s->size, &buf, safe_crlf)) {
2382                        size_t size = 0;
2383                        munmap(s->data, s->size);
2384                        s->should_munmap = 0;
2385                        s->data = strbuf_detach(&buf, &size);
2386                        s->size = size;
2387                        s->should_free = 1;
2388                }
2389        }
2390        else {
2391                enum object_type type;
2392                if (size_only) {
2393                        type = sha1_object_info(s->sha1, &s->size);
2394                        if (type < 0)
2395                                die("unable to read %s", sha1_to_hex(s->sha1));
2396                } else {
2397                        s->data = read_sha1_file(s->sha1, &type, &s->size);
2398                        if (!s->data)
2399                                die("unable to read %s", sha1_to_hex(s->sha1));
2400                        s->should_free = 1;
2401                }
2402        }
2403        return 0;
2404}
2405
2406void diff_free_filespec_blob(struct diff_filespec *s)
2407{
2408        if (s->should_free)
2409                free(s->data);
2410        else if (s->should_munmap)
2411                munmap(s->data, s->size);
2412
2413        if (s->should_free || s->should_munmap) {
2414                s->should_free = s->should_munmap = 0;
2415                s->data = NULL;
2416        }
2417}
2418
2419void diff_free_filespec_data(struct diff_filespec *s)
2420{
2421        diff_free_filespec_blob(s);
2422        free(s->cnt_data);
2423        s->cnt_data = NULL;
2424}
2425
2426static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
2427                           void *blob,
2428                           unsigned long size,
2429                           const unsigned char *sha1,
2430                           int mode)
2431{
2432        int fd;
2433        struct strbuf buf = STRBUF_INIT;
2434        struct strbuf template = STRBUF_INIT;
2435        char *path_dup = xstrdup(path);
2436        const char *base = basename(path_dup);
2437
2438        /* Generate "XXXXXX_basename.ext" */
2439        strbuf_addstr(&template, "XXXXXX_");
2440        strbuf_addstr(&template, base);
2441
2442        fd = git_mkstemps(temp->tmp_path, PATH_MAX, template.buf,
2443                        strlen(base) + 1);
2444        if (fd < 0)
2445                die_errno("unable to create temp-file");
2446        if (convert_to_working_tree(path,
2447                        (const char *)blob, (size_t)size, &buf)) {
2448                blob = buf.buf;
2449                size = buf.len;
2450        }
2451        if (write_in_full(fd, blob, size) != size)
2452                die_errno("unable to write temp-file");
2453        close(fd);
2454        temp->name = temp->tmp_path;
2455        strcpy(temp->hex, sha1_to_hex(sha1));
2456        temp->hex[40] = 0;
2457        sprintf(temp->mode, "%06o", mode);
2458        strbuf_release(&buf);
2459        strbuf_release(&template);
2460        free(path_dup);
2461}
2462
2463static struct diff_tempfile *prepare_temp_file(const char *name,
2464                struct diff_filespec *one)
2465{
2466        struct diff_tempfile *temp = claim_diff_tempfile();
2467
2468        if (!DIFF_FILE_VALID(one)) {
2469        not_a_valid_file:
2470                /* A '-' entry produces this for file-2, and
2471                 * a '+' entry produces this for file-1.
2472                 */
2473                temp->name = "/dev/null";
2474                strcpy(temp->hex, ".");
2475                strcpy(temp->mode, ".");
2476                return temp;
2477        }
2478
2479        if (!remove_tempfile_installed) {
2480                atexit(remove_tempfile);
2481                sigchain_push_common(remove_tempfile_on_signal);
2482                remove_tempfile_installed = 1;
2483        }
2484
2485        if (!one->sha1_valid ||
2486            reuse_worktree_file(name, one->sha1, 1)) {
2487                struct stat st;
2488                if (lstat(name, &st) < 0) {
2489                        if (errno == ENOENT)
2490                                goto not_a_valid_file;
2491                        die_errno("stat(%s)", name);
2492                }
2493                if (S_ISLNK(st.st_mode)) {
2494                        struct strbuf sb = STRBUF_INIT;
2495                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
2496                                die_errno("readlink(%s)", name);
2497                        prep_temp_blob(name, temp, sb.buf, sb.len,
2498                                       (one->sha1_valid ?
2499                                        one->sha1 : null_sha1),
2500                                       (one->sha1_valid ?
2501                                        one->mode : S_IFLNK));
2502                        strbuf_release(&sb);
2503                }
2504                else {
2505                        /* we can borrow from the file in the work tree */
2506                        temp->name = name;
2507                        if (!one->sha1_valid)
2508                                strcpy(temp->hex, sha1_to_hex(null_sha1));
2509                        else
2510                                strcpy(temp->hex, sha1_to_hex(one->sha1));
2511                        /* Even though we may sometimes borrow the
2512                         * contents from the work tree, we always want
2513                         * one->mode.  mode is trustworthy even when
2514                         * !(one->sha1_valid), as long as
2515                         * DIFF_FILE_VALID(one).
2516                         */
2517                        sprintf(temp->mode, "%06o", one->mode);
2518                }
2519                return temp;
2520        }
2521        else {
2522                if (diff_populate_filespec(one, 0))
2523                        die("cannot read data blob for %s", one->path);
2524                prep_temp_blob(name, temp, one->data, one->size,
2525                               one->sha1, one->mode);
2526        }
2527        return temp;
2528}
2529
2530/* An external diff command takes:
2531 *
2532 * diff-cmd name infile1 infile1-sha1 infile1-mode \
2533 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
2534 *
2535 */
2536static void run_external_diff(const char *pgm,
2537                              const char *name,
2538                              const char *other,
2539                              struct diff_filespec *one,
2540                              struct diff_filespec *two,
2541                              const char *xfrm_msg,
2542                              int complete_rewrite)
2543{
2544        const char *spawn_arg[10];
2545        int retval;
2546        const char **arg = &spawn_arg[0];
2547
2548        if (one && two) {
2549                struct diff_tempfile *temp_one, *temp_two;
2550                const char *othername = (other ? other : name);
2551                temp_one = prepare_temp_file(name, one);
2552                temp_two = prepare_temp_file(othername, two);
2553                *arg++ = pgm;
2554                *arg++ = name;
2555                *arg++ = temp_one->name;
2556                *arg++ = temp_one->hex;
2557                *arg++ = temp_one->mode;
2558                *arg++ = temp_two->name;
2559                *arg++ = temp_two->hex;
2560                *arg++ = temp_two->mode;
2561                if (other) {
2562                        *arg++ = other;
2563                        *arg++ = xfrm_msg;
2564                }
2565        } else {
2566                *arg++ = pgm;
2567                *arg++ = name;
2568        }
2569        *arg = NULL;
2570        fflush(NULL);
2571        retval = run_command_v_opt(spawn_arg, RUN_USING_SHELL);
2572        remove_tempfile();
2573        if (retval) {
2574                fprintf(stderr, "external diff died, stopping at %s.\n", name);
2575                exit(1);
2576        }
2577}
2578
2579static int similarity_index(struct diff_filepair *p)
2580{
2581        return p->score * 100 / MAX_SCORE;
2582}
2583
2584static void fill_metainfo(struct strbuf *msg,
2585                          const char *name,
2586                          const char *other,
2587                          struct diff_filespec *one,
2588                          struct diff_filespec *two,
2589                          struct diff_options *o,
2590                          struct diff_filepair *p,
2591                          int *must_show_header,
2592                          int use_color)
2593{
2594        const char *set = diff_get_color(use_color, DIFF_METAINFO);
2595        const char *reset = diff_get_color(use_color, DIFF_RESET);
2596        struct strbuf *msgbuf;
2597        char *line_prefix = "";
2598
2599        *must_show_header = 1;
2600        if (o->output_prefix) {
2601                msgbuf = o->output_prefix(o, o->output_prefix_data);
2602                line_prefix = msgbuf->buf;
2603        }
2604        strbuf_init(msg, PATH_MAX * 2 + 300);
2605        switch (p->status) {
2606        case DIFF_STATUS_COPIED:
2607                strbuf_addf(msg, "%s%ssimilarity index %d%%",
2608                            line_prefix, set, similarity_index(p));
2609                strbuf_addf(msg, "%s\n%s%scopy from ",
2610                            reset,  line_prefix, set);
2611                quote_c_style(name, msg, NULL, 0);
2612                strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
2613                quote_c_style(other, msg, NULL, 0);
2614                strbuf_addf(msg, "%s\n", reset);
2615                break;
2616        case DIFF_STATUS_RENAMED:
2617                strbuf_addf(msg, "%s%ssimilarity index %d%%",
2618                            line_prefix, set, similarity_index(p));
2619                strbuf_addf(msg, "%s\n%s%srename from ",
2620                            reset, line_prefix, set);
2621                quote_c_style(name, msg, NULL, 0);
2622                strbuf_addf(msg, "%s\n%s%srename to ",
2623                            reset, line_prefix, set);
2624                quote_c_style(other, msg, NULL, 0);
2625                strbuf_addf(msg, "%s\n", reset);
2626                break;
2627        case DIFF_STATUS_MODIFIED:
2628                if (p->score) {
2629                        strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
2630                                    line_prefix,
2631                                    set, similarity_index(p), reset);
2632                        break;
2633                }
2634                /* fallthru */
2635        default:
2636                *must_show_header = 0;
2637        }
2638        if (one && two && hashcmp(one->sha1, two->sha1)) {
2639                int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
2640
2641                if (DIFF_OPT_TST(o, BINARY)) {
2642                        mmfile_t mf;
2643                        if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
2644                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
2645                                abbrev = 40;
2646                }
2647                strbuf_addf(msg, "%s%sindex %s..", line_prefix, set,
2648                            find_unique_abbrev(one->sha1, abbrev));
2649                strbuf_addstr(msg, find_unique_abbrev(two->sha1, abbrev));
2650                if (one->mode == two->mode)
2651                        strbuf_addf(msg, " %06o", one->mode);
2652                strbuf_addf(msg, "%s\n", reset);
2653        }
2654}
2655
2656static void run_diff_cmd(const char *pgm,
2657                         const char *name,
2658                         const char *other,
2659                         const char *attr_path,
2660                         struct diff_filespec *one,
2661                         struct diff_filespec *two,
2662                         struct strbuf *msg,
2663                         struct diff_options *o,
2664                         struct diff_filepair *p)
2665{
2666        const char *xfrm_msg = NULL;
2667        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
2668        int must_show_header = 0;
2669
2670        if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
2671                pgm = NULL;
2672        else {
2673                struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
2674                if (drv && drv->external)
2675                        pgm = drv->external;
2676        }
2677
2678        if (msg) {
2679                /*
2680                 * don't use colors when the header is intended for an
2681                 * external diff driver
2682                 */
2683                fill_metainfo(msg, name, other, one, two, o, p,
2684                              &must_show_header,
2685                              DIFF_OPT_TST(o, COLOR_DIFF) && !pgm);
2686                xfrm_msg = msg->len ? msg->buf : NULL;
2687        }
2688
2689        if (pgm) {
2690                run_external_diff(pgm, name, other, one, two, xfrm_msg,
2691                                  complete_rewrite);
2692                return;
2693        }
2694        if (one && two)
2695                builtin_diff(name, other ? other : name,
2696                             one, two, xfrm_msg, must_show_header,
2697                             o, complete_rewrite);
2698        else
2699                fprintf(o->file, "* Unmerged path %s\n", name);
2700}
2701
2702static void diff_fill_sha1_info(struct diff_filespec *one)
2703{
2704        if (DIFF_FILE_VALID(one)) {
2705                if (!one->sha1_valid) {
2706                        struct stat st;
2707                        if (!strcmp(one->path, "-")) {
2708                                hashcpy(one->sha1, null_sha1);
2709                                return;
2710                        }
2711                        if (lstat(one->path, &st) < 0)
2712                                die_errno("stat '%s'", one->path);
2713                        if (index_path(one->sha1, one->path, &st, 0))
2714                                die("cannot hash %s", one->path);
2715                }
2716        }
2717        else
2718                hashclr(one->sha1);
2719}
2720
2721static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
2722{
2723        /* Strip the prefix but do not molest /dev/null and absolute paths */
2724        if (*namep && **namep != '/') {
2725                *namep += prefix_length;
2726                if (**namep == '/')
2727                        ++*namep;
2728        }
2729        if (*otherp && **otherp != '/') {
2730                *otherp += prefix_length;
2731                if (**otherp == '/')
2732                        ++*otherp;
2733        }
2734}
2735
2736static void run_diff(struct diff_filepair *p, struct diff_options *o)
2737{
2738        const char *pgm = external_diff();
2739        struct strbuf msg;
2740        struct diff_filespec *one = p->one;
2741        struct diff_filespec *two = p->two;
2742        const char *name;
2743        const char *other;
2744        const char *attr_path;
2745
2746        name  = p->one->path;
2747        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2748        attr_path = name;
2749        if (o->prefix_length)
2750                strip_prefix(o->prefix_length, &name, &other);
2751
2752        if (DIFF_PAIR_UNMERGED(p)) {
2753                run_diff_cmd(pgm, name, NULL, attr_path,
2754                             NULL, NULL, NULL, o, p);
2755                return;
2756        }
2757
2758        diff_fill_sha1_info(one);
2759        diff_fill_sha1_info(two);
2760
2761        if (!pgm &&
2762            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
2763            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
2764                /*
2765                 * a filepair that changes between file and symlink
2766                 * needs to be split into deletion and creation.
2767                 */
2768                struct diff_filespec *null = alloc_filespec(two->path);
2769                run_diff_cmd(NULL, name, other, attr_path,
2770                             one, null, &msg, o, p);
2771                free(null);
2772                strbuf_release(&msg);
2773
2774                null = alloc_filespec(one->path);
2775                run_diff_cmd(NULL, name, other, attr_path,
2776                             null, two, &msg, o, p);
2777                free(null);
2778        }
2779        else
2780                run_diff_cmd(pgm, name, other, attr_path,
2781                             one, two, &msg, o, p);
2782
2783        strbuf_release(&msg);
2784}
2785
2786static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
2787                         struct diffstat_t *diffstat)
2788{
2789        const char *name;
2790        const char *other;
2791        int complete_rewrite = 0;
2792
2793        if (DIFF_PAIR_UNMERGED(p)) {
2794                /* unmerged */
2795                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, 0);
2796                return;
2797        }
2798
2799        name = p->one->path;
2800        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2801
2802        if (o->prefix_length)
2803                strip_prefix(o->prefix_length, &name, &other);
2804
2805        diff_fill_sha1_info(p->one);
2806        diff_fill_sha1_info(p->two);
2807
2808        if (p->status == DIFF_STATUS_MODIFIED && p->score)
2809                complete_rewrite = 1;
2810        builtin_diffstat(name, other, p->one, p->two, diffstat, o, complete_rewrite);
2811}
2812
2813static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
2814{
2815        const char *name;
2816        const char *other;
2817        const char *attr_path;
2818
2819        if (DIFF_PAIR_UNMERGED(p)) {
2820                /* unmerged */
2821                return;
2822        }
2823
2824        name = p->one->path;
2825        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2826        attr_path = other ? other : name;
2827
2828        if (o->prefix_length)
2829                strip_prefix(o->prefix_length, &name, &other);
2830
2831        diff_fill_sha1_info(p->one);
2832        diff_fill_sha1_info(p->two);
2833
2834        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
2835}
2836
2837void diff_setup(struct diff_options *options)
2838{
2839        memcpy(options, &default_diff_options, sizeof(*options));
2840
2841        options->file = stdout;
2842
2843        options->line_termination = '\n';
2844        options->break_opt = -1;
2845        options->rename_limit = -1;
2846        options->dirstat_percent = 3;
2847        options->context = 3;
2848
2849        options->change = diff_change;
2850        options->add_remove = diff_addremove;
2851        if (diff_use_color_default > 0)
2852                DIFF_OPT_SET(options, COLOR_DIFF);
2853        options->detect_rename = diff_detect_rename_default;
2854
2855        if (diff_no_prefix) {
2856                options->a_prefix = options->b_prefix = "";
2857        } else if (!diff_mnemonic_prefix) {
2858                options->a_prefix = "a/";
2859                options->b_prefix = "b/";
2860        }
2861}
2862
2863int diff_setup_done(struct diff_options *options)
2864{
2865        int count = 0;
2866
2867        if (options->output_format & DIFF_FORMAT_NAME)
2868                count++;
2869        if (options->output_format & DIFF_FORMAT_NAME_STATUS)
2870                count++;
2871        if (options->output_format & DIFF_FORMAT_CHECKDIFF)
2872                count++;
2873        if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
2874                count++;
2875        if (count > 1)
2876                die("--name-only, --name-status, --check and -s are mutually exclusive");
2877
2878        /*
2879         * Most of the time we can say "there are changes"
2880         * only by checking if there are changed paths, but
2881         * --ignore-whitespace* options force us to look
2882         * inside contents.
2883         */
2884
2885        if (DIFF_XDL_TST(options, IGNORE_WHITESPACE) ||
2886            DIFF_XDL_TST(options, IGNORE_WHITESPACE_CHANGE) ||
2887            DIFF_XDL_TST(options, IGNORE_WHITESPACE_AT_EOL))
2888                DIFF_OPT_SET(options, DIFF_FROM_CONTENTS);
2889        else
2890                DIFF_OPT_CLR(options, DIFF_FROM_CONTENTS);
2891
2892        if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
2893                options->detect_rename = DIFF_DETECT_COPY;
2894
2895        if (!DIFF_OPT_TST(options, RELATIVE_NAME))
2896                options->prefix = NULL;
2897        if (options->prefix)
2898                options->prefix_length = strlen(options->prefix);
2899        else
2900                options->prefix_length = 0;
2901
2902        if (options->output_format & (DIFF_FORMAT_NAME |
2903                                      DIFF_FORMAT_NAME_STATUS |
2904                                      DIFF_FORMAT_CHECKDIFF |
2905                                      DIFF_FORMAT_NO_OUTPUT))
2906                options->output_format &= ~(DIFF_FORMAT_RAW |
2907                                            DIFF_FORMAT_NUMSTAT |
2908                                            DIFF_FORMAT_DIFFSTAT |
2909                                            DIFF_FORMAT_SHORTSTAT |
2910                                            DIFF_FORMAT_DIRSTAT |
2911                                            DIFF_FORMAT_SUMMARY |
2912                                            DIFF_FORMAT_PATCH);
2913
2914        /*
2915         * These cases always need recursive; we do not drop caller-supplied
2916         * recursive bits for other formats here.
2917         */
2918        if (options->output_format & (DIFF_FORMAT_PATCH |
2919                                      DIFF_FORMAT_NUMSTAT |
2920                                      DIFF_FORMAT_DIFFSTAT |
2921                                      DIFF_FORMAT_SHORTSTAT |
2922                                      DIFF_FORMAT_DIRSTAT |
2923                                      DIFF_FORMAT_SUMMARY |
2924                                      DIFF_FORMAT_CHECKDIFF))
2925                DIFF_OPT_SET(options, RECURSIVE);
2926        /*
2927         * Also pickaxe would not work very well if you do not say recursive
2928         */
2929        if (options->pickaxe)
2930                DIFF_OPT_SET(options, RECURSIVE);
2931        /*
2932         * When patches are generated, submodules diffed against the work tree
2933         * must be checked for dirtiness too so it can be shown in the output
2934         */
2935        if (options->output_format & DIFF_FORMAT_PATCH)
2936                DIFF_OPT_SET(options, DIRTY_SUBMODULES);
2937
2938        if (options->detect_rename && options->rename_limit < 0)
2939                options->rename_limit = diff_rename_limit_default;
2940        if (options->setup & DIFF_SETUP_USE_CACHE) {
2941                if (!active_cache)
2942                        /* read-cache does not die even when it fails
2943                         * so it is safe for us to do this here.  Also
2944                         * it does not smudge active_cache or active_nr
2945                         * when it fails, so we do not have to worry about
2946                         * cleaning it up ourselves either.
2947                         */
2948                        read_cache();
2949        }
2950        if (options->abbrev <= 0 || 40 < options->abbrev)
2951                options->abbrev = 40; /* full */
2952
2953        /*
2954         * It does not make sense to show the first hit we happened
2955         * to have found.  It does not make sense not to return with
2956         * exit code in such a case either.
2957         */
2958        if (DIFF_OPT_TST(options, QUICK)) {
2959                options->output_format = DIFF_FORMAT_NO_OUTPUT;
2960                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
2961        }
2962
2963        return 0;
2964}
2965
2966static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
2967{
2968        char c, *eq;
2969        int len;
2970
2971        if (*arg != '-')
2972                return 0;
2973        c = *++arg;
2974        if (!c)
2975                return 0;
2976        if (c == arg_short) {
2977                c = *++arg;
2978                if (!c)
2979                        return 1;
2980                if (val && isdigit(c)) {
2981                        char *end;
2982                        int n = strtoul(arg, &end, 10);
2983                        if (*end)
2984                                return 0;
2985                        *val = n;
2986                        return 1;
2987                }
2988                return 0;
2989        }
2990        if (c != '-')
2991                return 0;
2992        arg++;
2993        eq = strchr(arg, '=');
2994        if (eq)
2995                len = eq - arg;
2996        else
2997                len = strlen(arg);
2998        if (!len || strncmp(arg, arg_long, len))
2999                return 0;
3000        if (eq) {
3001                int n;
3002                char *end;
3003                if (!isdigit(*++eq))
3004                        return 0;
3005                n = strtoul(eq, &end, 10);
3006                if (*end)
3007                        return 0;
3008                *val = n;
3009        }
3010        return 1;
3011}
3012
3013static int diff_scoreopt_parse(const char *opt);
3014
3015static inline int short_opt(char opt, const char **argv,
3016                            const char **optarg)
3017{
3018        const char *arg = argv[0];
3019        if (arg[0] != '-' || arg[1] != opt)
3020                return 0;
3021        if (arg[2] != '\0') {
3022                *optarg = arg + 2;
3023                return 1;
3024        }
3025        if (!argv[1])
3026                die("Option '%c' requires a value", opt);
3027        *optarg = argv[1];
3028        return 2;
3029}
3030
3031int parse_long_opt(const char *opt, const char **argv,
3032                   const char **optarg)
3033{
3034        const char *arg = argv[0];
3035        if (arg[0] != '-' || arg[1] != '-')
3036                return 0;
3037        arg += strlen("--");
3038        if (prefixcmp(arg, opt))
3039                return 0;
3040        arg += strlen(opt);
3041        if (*arg == '=') { /* sticked form: --option=value */
3042                *optarg = arg + 1;
3043                return 1;
3044        }
3045        if (*arg != '\0')
3046                return 0;
3047        /* separate form: --option value */
3048        if (!argv[1])
3049                die("Option '--%s' requires a value", opt);
3050        *optarg = argv[1];
3051        return 2;
3052}
3053
3054static int stat_opt(struct diff_options *options, const char **av)
3055{
3056        const char *arg = av[0];
3057        char *end;
3058        int width = options->stat_width;
3059        int name_width = options->stat_name_width;
3060        int argcount = 1;
3061
3062        arg += strlen("--stat");
3063        end = (char *)arg;
3064
3065        switch (*arg) {
3066        case '-':
3067                if (!prefixcmp(arg, "-width")) {
3068                        arg += strlen("-width");
3069                        if (*arg == '=')
3070                                width = strtoul(arg + 1, &end, 10);
3071                        else if (!*arg && !av[1])
3072                                die("Option '--stat-width' requires a value");
3073                        else if (!*arg) {
3074                                width = strtoul(av[1], &end, 10);
3075                                argcount = 2;
3076                        }
3077                } else if (!prefixcmp(arg, "-name-width")) {
3078                        arg += strlen("-name-width");
3079                        if (*arg == '=')
3080                                name_width = strtoul(arg + 1, &end, 10);
3081                        else if (!*arg && !av[1])
3082                                die("Option '--stat-name-width' requires a value");
3083                        else if (!*arg) {
3084                                name_width = strtoul(av[1], &end, 10);
3085                                argcount = 2;
3086                        }
3087                }
3088                break;
3089        case '=':
3090                width = strtoul(arg+1, &end, 10);
3091                if (*end == ',')
3092                        name_width = strtoul(end+1, &end, 10);
3093        }
3094
3095        /* Important! This checks all the error cases! */
3096        if (*end)
3097                return 0;
3098        options->output_format |= DIFF_FORMAT_DIFFSTAT;
3099        options->stat_name_width = name_width;
3100        options->stat_width = width;
3101        return argcount;
3102}
3103
3104int diff_opt_parse(struct diff_options *options, const char **av, int ac)
3105{
3106        const char *arg = av[0];
3107        const char *optarg;
3108        int argcount;
3109
3110        /* Output format options */
3111        if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch"))
3112                options->output_format |= DIFF_FORMAT_PATCH;
3113        else if (opt_arg(arg, 'U', "unified", &options->context))
3114                options->output_format |= DIFF_FORMAT_PATCH;
3115        else if (!strcmp(arg, "--raw"))
3116                options->output_format |= DIFF_FORMAT_RAW;
3117        else if (!strcmp(arg, "--patch-with-raw"))
3118                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_RAW;
3119        else if (!strcmp(arg, "--numstat"))
3120                options->output_format |= DIFF_FORMAT_NUMSTAT;
3121        else if (!strcmp(arg, "--shortstat"))
3122                options->output_format |= DIFF_FORMAT_SHORTSTAT;
3123        else if (opt_arg(arg, 'X', "dirstat", &options->dirstat_percent))
3124                options->output_format |= DIFF_FORMAT_DIRSTAT;
3125        else if (!strcmp(arg, "--cumulative")) {
3126                options->output_format |= DIFF_FORMAT_DIRSTAT;
3127                DIFF_OPT_SET(options, DIRSTAT_CUMULATIVE);
3128        } else if (opt_arg(arg, 0, "dirstat-by-file",
3129                           &options->dirstat_percent)) {
3130                options->output_format |= DIFF_FORMAT_DIRSTAT;
3131                DIFF_OPT_SET(options, DIRSTAT_BY_FILE);
3132        }
3133        else if (!strcmp(arg, "--check"))
3134                options->output_format |= DIFF_FORMAT_CHECKDIFF;
3135        else if (!strcmp(arg, "--summary"))
3136                options->output_format |= DIFF_FORMAT_SUMMARY;
3137        else if (!strcmp(arg, "--patch-with-stat"))
3138                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_DIFFSTAT;
3139        else if (!strcmp(arg, "--name-only"))
3140                options->output_format |= DIFF_FORMAT_NAME;
3141        else if (!strcmp(arg, "--name-status"))
3142                options->output_format |= DIFF_FORMAT_NAME_STATUS;
3143        else if (!strcmp(arg, "-s"))
3144                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
3145        else if (!prefixcmp(arg, "--stat"))
3146                /* --stat, --stat-width, or --stat-name-width */
3147                return stat_opt(options, av);
3148
3149        /* renames options */
3150        else if (!prefixcmp(arg, "-B") || !prefixcmp(arg, "--break-rewrites=") ||
3151                 !strcmp(arg, "--break-rewrites")) {
3152                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
3153                        return error("invalid argument to -B: %s", arg+2);
3154        }
3155        else if (!prefixcmp(arg, "-M") || !prefixcmp(arg, "--find-renames=") ||
3156                 !strcmp(arg, "--find-renames")) {
3157                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3158                        return error("invalid argument to -M: %s", arg+2);
3159                options->detect_rename = DIFF_DETECT_RENAME;
3160        }
3161        else if (!prefixcmp(arg, "-C") || !prefixcmp(arg, "--find-copies=") ||
3162                 !strcmp(arg, "--find-copies")) {
3163                if (options->detect_rename == DIFF_DETECT_COPY)
3164                        DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3165                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3166                        return error("invalid argument to -C: %s", arg+2);
3167                options->detect_rename = DIFF_DETECT_COPY;
3168        }
3169        else if (!strcmp(arg, "--no-renames"))
3170                options->detect_rename = 0;
3171        else if (!strcmp(arg, "--relative"))
3172                DIFF_OPT_SET(options, RELATIVE_NAME);
3173        else if (!prefixcmp(arg, "--relative=")) {
3174                DIFF_OPT_SET(options, RELATIVE_NAME);
3175                options->prefix = arg + 11;
3176        }
3177
3178        /* xdiff options */
3179        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
3180                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
3181        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
3182                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
3183        else if (!strcmp(arg, "--ignore-space-at-eol"))
3184                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
3185        else if (!strcmp(arg, "--patience"))
3186                DIFF_XDL_SET(options, PATIENCE_DIFF);
3187
3188        /* flags options */
3189        else if (!strcmp(arg, "--binary")) {
3190                options->output_format |= DIFF_FORMAT_PATCH;
3191                DIFF_OPT_SET(options, BINARY);
3192        }
3193        else if (!strcmp(arg, "--full-index"))
3194                DIFF_OPT_SET(options, FULL_INDEX);
3195        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
3196                DIFF_OPT_SET(options, TEXT);
3197        else if (!strcmp(arg, "-R"))
3198                DIFF_OPT_SET(options, REVERSE_DIFF);
3199        else if (!strcmp(arg, "--find-copies-harder"))
3200                DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3201        else if (!strcmp(arg, "--follow"))
3202                DIFF_OPT_SET(options, FOLLOW_RENAMES);
3203        else if (!strcmp(arg, "--color"))
3204                DIFF_OPT_SET(options, COLOR_DIFF);
3205        else if (!prefixcmp(arg, "--color=")) {
3206                int value = git_config_colorbool(NULL, arg+8, -1);
3207                if (value == 0)
3208                        DIFF_OPT_CLR(options, COLOR_DIFF);
3209                else if (value > 0)
3210                        DIFF_OPT_SET(options, COLOR_DIFF);
3211                else
3212                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
3213        }
3214        else if (!strcmp(arg, "--no-color"))
3215                DIFF_OPT_CLR(options, COLOR_DIFF);
3216        else if (!strcmp(arg, "--color-words")) {
3217                DIFF_OPT_SET(options, COLOR_DIFF);
3218                options->word_diff = DIFF_WORDS_COLOR;
3219        }
3220        else if (!prefixcmp(arg, "--color-words=")) {
3221                DIFF_OPT_SET(options, COLOR_DIFF);
3222                options->word_diff = DIFF_WORDS_COLOR;
3223                options->word_regex = arg + 14;
3224        }
3225        else if (!strcmp(arg, "--word-diff")) {
3226                if (options->word_diff == DIFF_WORDS_NONE)
3227                        options->word_diff = DIFF_WORDS_PLAIN;
3228        }
3229        else if (!prefixcmp(arg, "--word-diff=")) {
3230                const char *type = arg + 12;
3231                if (!strcmp(type, "plain"))
3232                        options->word_diff = DIFF_WORDS_PLAIN;
3233                else if (!strcmp(type, "color")) {
3234                        DIFF_OPT_SET(options, COLOR_DIFF);
3235                        options->word_diff = DIFF_WORDS_COLOR;
3236                }
3237                else if (!strcmp(type, "porcelain"))
3238                        options->word_diff = DIFF_WORDS_PORCELAIN;
3239                else if (!strcmp(type, "none"))
3240                        options->word_diff = DIFF_WORDS_NONE;
3241                else
3242                        die("bad --word-diff argument: %s", type);
3243        }
3244        else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
3245                if (options->word_diff == DIFF_WORDS_NONE)
3246                        options->word_diff = DIFF_WORDS_PLAIN;
3247                options->word_regex = optarg;
3248                return argcount;
3249        }
3250        else if (!strcmp(arg, "--exit-code"))
3251                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3252        else if (!strcmp(arg, "--quiet"))
3253                DIFF_OPT_SET(options, QUICK);
3254        else if (!strcmp(arg, "--ext-diff"))
3255                DIFF_OPT_SET(options, ALLOW_EXTERNAL);
3256        else if (!strcmp(arg, "--no-ext-diff"))
3257                DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
3258        else if (!strcmp(arg, "--textconv"))
3259                DIFF_OPT_SET(options, ALLOW_TEXTCONV);
3260        else if (!strcmp(arg, "--no-textconv"))
3261                DIFF_OPT_CLR(options, ALLOW_TEXTCONV);
3262        else if (!strcmp(arg, "--ignore-submodules")) {
3263                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3264                handle_ignore_submodules_arg(options, "all");
3265        } else if (!prefixcmp(arg, "--ignore-submodules=")) {
3266                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3267                handle_ignore_submodules_arg(options, arg + 20);
3268        } else if (!strcmp(arg, "--submodule"))
3269                DIFF_OPT_SET(options, SUBMODULE_LOG);
3270        else if (!prefixcmp(arg, "--submodule=")) {
3271                if (!strcmp(arg + 12, "log"))
3272                        DIFF_OPT_SET(options, SUBMODULE_LOG);
3273        }
3274
3275        /* misc options */
3276        else if (!strcmp(arg, "-z"))
3277                options->line_termination = 0;
3278        else if ((argcount = short_opt('l', av, &optarg))) {
3279                options->rename_limit = strtoul(optarg, NULL, 10);
3280                return argcount;
3281        }
3282        else if ((argcount = short_opt('S', av, &optarg))) {
3283                options->pickaxe = optarg;
3284                options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
3285                return argcount;
3286        } else if ((argcount = short_opt('G', av, &optarg))) {
3287                options->pickaxe = optarg;
3288                options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
3289                return argcount;
3290        }
3291        else if (!strcmp(arg, "--pickaxe-all"))
3292                options->pickaxe_opts |= DIFF_PICKAXE_ALL;
3293        else if (!strcmp(arg, "--pickaxe-regex"))
3294                options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
3295        else if ((argcount = short_opt('O', av, &optarg))) {
3296                options->orderfile = optarg;
3297                return argcount;
3298        }
3299        else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
3300                options->filter = optarg;
3301                return argcount;
3302        }
3303        else if (!strcmp(arg, "--abbrev"))
3304                options->abbrev = DEFAULT_ABBREV;
3305        else if (!prefixcmp(arg, "--abbrev=")) {
3306                options->abbrev = strtoul(arg + 9, NULL, 10);
3307                if (options->abbrev < MINIMUM_ABBREV)
3308                        options->abbrev = MINIMUM_ABBREV;
3309                else if (40 < options->abbrev)
3310                        options->abbrev = 40;
3311        }
3312        else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
3313                options->a_prefix = optarg;
3314                return argcount;
3315        }
3316        else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
3317                options->b_prefix = optarg;
3318                return argcount;
3319        }
3320        else if (!strcmp(arg, "--no-prefix"))
3321                options->a_prefix = options->b_prefix = "";
3322        else if (opt_arg(arg, '\0', "inter-hunk-context",
3323                         &options->interhunkcontext))
3324                ;
3325        else if ((argcount = parse_long_opt("output", av, &optarg))) {
3326                options->file = fopen(optarg, "w");
3327                if (!options->file)
3328                        die_errno("Could not open '%s'", optarg);
3329                options->close_file = 1;
3330                return argcount;
3331        } else
3332                return 0;
3333        return 1;
3334}
3335
3336int parse_rename_score(const char **cp_p)
3337{
3338        unsigned long num, scale;
3339        int ch, dot;
3340        const char *cp = *cp_p;
3341
3342        num = 0;
3343        scale = 1;
3344        dot = 0;
3345        for (;;) {
3346                ch = *cp;
3347                if ( !dot && ch == '.' ) {
3348                        scale = 1;
3349                        dot = 1;
3350                } else if ( ch == '%' ) {
3351                        scale = dot ? scale*100 : 100;
3352                        cp++;   /* % is always at the end */
3353                        break;
3354                } else if ( ch >= '0' && ch <= '9' ) {
3355                        if ( scale < 100000 ) {
3356                                scale *= 10;
3357                                num = (num*10) + (ch-'0');
3358                        }
3359                } else {
3360                        break;
3361                }
3362                cp++;
3363        }
3364        *cp_p = cp;
3365
3366        /* user says num divided by scale and we say internally that
3367         * is MAX_SCORE * num / scale.
3368         */
3369        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
3370}
3371
3372static int diff_scoreopt_parse(const char *opt)
3373{
3374        int opt1, opt2, cmd;
3375
3376        if (*opt++ != '-')
3377                return -1;
3378        cmd = *opt++;
3379        if (cmd == '-') {
3380                /* convert the long-form arguments into short-form versions */
3381                if (!prefixcmp(opt, "break-rewrites")) {
3382                        opt += strlen("break-rewrites");
3383                        if (*opt == 0 || *opt++ == '=')
3384                                cmd = 'B';
3385                } else if (!prefixcmp(opt, "find-copies")) {
3386                        opt += strlen("find-copies");
3387                        if (*opt == 0 || *opt++ == '=')
3388                                cmd = 'C';
3389                } else if (!prefixcmp(opt, "find-renames")) {
3390                        opt += strlen("find-renames");
3391                        if (*opt == 0 || *opt++ == '=')
3392                                cmd = 'M';
3393                }
3394        }
3395        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
3396                return -1; /* that is not a -M, -C nor -B option */
3397
3398        opt1 = parse_rename_score(&opt);
3399        if (cmd != 'B')
3400                opt2 = 0;
3401        else {
3402                if (*opt == 0)
3403                        opt2 = 0;
3404                else if (*opt != '/')
3405                        return -1; /* we expect -B80/99 or -B80 */
3406                else {
3407                        opt++;
3408                        opt2 = parse_rename_score(&opt);
3409                }
3410        }
3411        if (*opt != 0)
3412                return -1;
3413        return opt1 | (opt2 << 16);
3414}
3415
3416struct diff_queue_struct diff_queued_diff;
3417
3418void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
3419{
3420        if (queue->alloc <= queue->nr) {
3421                queue->alloc = alloc_nr(queue->alloc);
3422                queue->queue = xrealloc(queue->queue,
3423                                        sizeof(dp) * queue->alloc);
3424        }
3425        queue->queue[queue->nr++] = dp;
3426}
3427
3428struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
3429                                 struct diff_filespec *one,
3430                                 struct diff_filespec *two)
3431{
3432        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
3433        dp->one = one;
3434        dp->two = two;
3435        if (queue)
3436                diff_q(queue, dp);
3437        return dp;
3438}
3439
3440void diff_free_filepair(struct diff_filepair *p)
3441{
3442        free_filespec(p->one);
3443        free_filespec(p->two);
3444        free(p);
3445}
3446
3447/* This is different from find_unique_abbrev() in that
3448 * it stuffs the result with dots for alignment.
3449 */
3450const char *diff_unique_abbrev(const unsigned char *sha1, int len)
3451{
3452        int abblen;
3453        const char *abbrev;
3454        if (len == 40)
3455                return sha1_to_hex(sha1);
3456
3457        abbrev = find_unique_abbrev(sha1, len);
3458        abblen = strlen(abbrev);
3459        if (abblen < 37) {
3460                static char hex[41];
3461                if (len < abblen && abblen <= len + 2)
3462                        sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
3463                else
3464                        sprintf(hex, "%s...", abbrev);
3465                return hex;
3466        }
3467        return sha1_to_hex(sha1);
3468}
3469
3470static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
3471{
3472        int line_termination = opt->line_termination;
3473        int inter_name_termination = line_termination ? '\t' : '\0';
3474        if (opt->output_prefix) {
3475                struct strbuf *msg = NULL;
3476                msg = opt->output_prefix(opt, opt->output_prefix_data);
3477                fprintf(opt->file, "%s", msg->buf);
3478        }
3479
3480        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
3481                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
3482                        diff_unique_abbrev(p->one->sha1, opt->abbrev));
3483                fprintf(opt->file, "%s ", diff_unique_abbrev(p->two->sha1, opt->abbrev));
3484        }
3485        if (p->score) {
3486                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
3487                        inter_name_termination);
3488        } else {
3489                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
3490        }
3491
3492        if (p->status == DIFF_STATUS_COPIED ||
3493            p->status == DIFF_STATUS_RENAMED) {
3494                const char *name_a, *name_b;
3495                name_a = p->one->path;
3496                name_b = p->two->path;
3497                strip_prefix(opt->prefix_length, &name_a, &name_b);
3498                write_name_quoted(name_a, opt->file, inter_name_termination);
3499                write_name_quoted(name_b, opt->file, line_termination);
3500        } else {
3501                const char *name_a, *name_b;
3502                name_a = p->one->mode ? p->one->path : p->two->path;
3503                name_b = NULL;
3504                strip_prefix(opt->prefix_length, &name_a, &name_b);
3505                write_name_quoted(name_a, opt->file, line_termination);
3506        }
3507}
3508
3509int diff_unmodified_pair(struct diff_filepair *p)
3510{
3511        /* This function is written stricter than necessary to support
3512         * the currently implemented transformers, but the idea is to
3513         * let transformers to produce diff_filepairs any way they want,
3514         * and filter and clean them up here before producing the output.
3515         */
3516        struct diff_filespec *one = p->one, *two = p->two;
3517
3518        if (DIFF_PAIR_UNMERGED(p))
3519                return 0; /* unmerged is interesting */
3520
3521        /* deletion, addition, mode or type change
3522         * and rename are all interesting.
3523         */
3524        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
3525            DIFF_PAIR_MODE_CHANGED(p) ||
3526            strcmp(one->path, two->path))
3527                return 0;
3528
3529        /* both are valid and point at the same path.  that is, we are
3530         * dealing with a change.
3531         */
3532        if (one->sha1_valid && two->sha1_valid &&
3533            !hashcmp(one->sha1, two->sha1) &&
3534            !one->dirty_submodule && !two->dirty_submodule)
3535                return 1; /* no change */
3536        if (!one->sha1_valid && !two->sha1_valid)
3537                return 1; /* both look at the same file on the filesystem. */
3538        return 0;
3539}
3540
3541static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
3542{
3543        if (diff_unmodified_pair(p))
3544                return;
3545
3546        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3547            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3548                return; /* no tree diffs in patch format */
3549
3550        run_diff(p, o);
3551}
3552
3553static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
3554                            struct diffstat_t *diffstat)
3555{
3556        if (diff_unmodified_pair(p))
3557                return;
3558
3559        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3560            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3561                return; /* no useful stat for tree diffs */
3562
3563        run_diffstat(p, o, diffstat);
3564}
3565
3566static void diff_flush_checkdiff(struct diff_filepair *p,
3567                struct diff_options *o)
3568{
3569        if (diff_unmodified_pair(p))
3570                return;
3571
3572        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3573            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3574                return; /* nothing to check in tree diffs */
3575
3576        run_checkdiff(p, o);
3577}
3578
3579int diff_queue_is_empty(void)
3580{
3581        struct diff_queue_struct *q = &diff_queued_diff;
3582        int i;
3583        for (i = 0; i < q->nr; i++)
3584                if (!diff_unmodified_pair(q->queue[i]))
3585                        return 0;
3586        return 1;
3587}
3588
3589#if DIFF_DEBUG
3590void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
3591{
3592        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
3593                x, one ? one : "",
3594                s->path,
3595                DIFF_FILE_VALID(s) ? "valid" : "invalid",
3596                s->mode,
3597                s->sha1_valid ? sha1_to_hex(s->sha1) : "");
3598        fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
3599                x, one ? one : "",
3600                s->size, s->xfrm_flags);
3601}
3602
3603void diff_debug_filepair(const struct diff_filepair *p, int i)
3604{
3605        diff_debug_filespec(p->one, i, "one");
3606        diff_debug_filespec(p->two, i, "two");
3607        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
3608                p->score, p->status ? p->status : '?',
3609                p->one->rename_used, p->broken_pair);
3610}
3611
3612void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
3613{
3614        int i;
3615        if (msg)
3616                fprintf(stderr, "%s\n", msg);
3617        fprintf(stderr, "q->nr = %d\n", q->nr);
3618        for (i = 0; i < q->nr; i++) {
3619                struct diff_filepair *p = q->queue[i];
3620                diff_debug_filepair(p, i);
3621        }
3622}
3623#endif
3624
3625static void diff_resolve_rename_copy(void)
3626{
3627        int i;
3628        struct diff_filepair *p;
3629        struct diff_queue_struct *q = &diff_queued_diff;
3630
3631        diff_debug_queue("resolve-rename-copy", q);
3632
3633        for (i = 0; i < q->nr; i++) {
3634                p = q->queue[i];
3635                p->status = 0; /* undecided */
3636                if (DIFF_PAIR_UNMERGED(p))
3637                        p->status = DIFF_STATUS_UNMERGED;
3638                else if (!DIFF_FILE_VALID(p->one))
3639                        p->status = DIFF_STATUS_ADDED;
3640                else if (!DIFF_FILE_VALID(p->two))
3641                        p->status = DIFF_STATUS_DELETED;
3642                else if (DIFF_PAIR_TYPE_CHANGED(p))
3643                        p->status = DIFF_STATUS_TYPE_CHANGED;
3644
3645                /* from this point on, we are dealing with a pair
3646                 * whose both sides are valid and of the same type, i.e.
3647                 * either in-place edit or rename/copy edit.
3648                 */
3649                else if (DIFF_PAIR_RENAME(p)) {
3650                        /*
3651                         * A rename might have re-connected a broken
3652                         * pair up, causing the pathnames to be the
3653                         * same again. If so, that's not a rename at
3654                         * all, just a modification..
3655                         *
3656                         * Otherwise, see if this source was used for
3657                         * multiple renames, in which case we decrement
3658                         * the count, and call it a copy.
3659                         */
3660                        if (!strcmp(p->one->path, p->two->path))
3661                                p->status = DIFF_STATUS_MODIFIED;
3662                        else if (--p->one->rename_used > 0)
3663                                p->status = DIFF_STATUS_COPIED;
3664                        else
3665                                p->status = DIFF_STATUS_RENAMED;
3666                }
3667                else if (hashcmp(p->one->sha1, p->two->sha1) ||
3668                         p->one->mode != p->two->mode ||
3669                         p->one->dirty_submodule ||
3670                         p->two->dirty_submodule ||
3671                         is_null_sha1(p->one->sha1))
3672                        p->status = DIFF_STATUS_MODIFIED;
3673                else {
3674                        /* This is a "no-change" entry and should not
3675                         * happen anymore, but prepare for broken callers.
3676                         */
3677                        error("feeding unmodified %s to diffcore",
3678                              p->one->path);
3679                        p->status = DIFF_STATUS_UNKNOWN;
3680                }
3681        }
3682        diff_debug_queue("resolve-rename-copy done", q);
3683}
3684
3685static int check_pair_status(struct diff_filepair *p)
3686{
3687        switch (p->status) {
3688        case DIFF_STATUS_UNKNOWN:
3689                return 0;
3690        case 0:
3691                die("internal error in diff-resolve-rename-copy");
3692        default:
3693                return 1;
3694        }
3695}
3696
3697static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
3698{
3699        int fmt = opt->output_format;
3700
3701        if (fmt & DIFF_FORMAT_CHECKDIFF)
3702                diff_flush_checkdiff(p, opt);
3703        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
3704                diff_flush_raw(p, opt);
3705        else if (fmt & DIFF_FORMAT_NAME) {
3706                const char *name_a, *name_b;
3707                name_a = p->two->path;
3708                name_b = NULL;
3709                strip_prefix(opt->prefix_length, &name_a, &name_b);
3710                write_name_quoted(name_a, opt->file, opt->line_termination);
3711        }
3712}
3713
3714static void show_file_mode_name(FILE *file, const char *newdelete, struct diff_filespec *fs)
3715{
3716        if (fs->mode)
3717                fprintf(file, " %s mode %06o ", newdelete, fs->mode);
3718        else
3719                fprintf(file, " %s ", newdelete);
3720        write_name_quoted(fs->path, file, '\n');
3721}
3722
3723
3724static void show_mode_change(FILE *file, struct diff_filepair *p, int show_name,
3725                const char *line_prefix)
3726{
3727        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
3728                fprintf(file, "%s mode change %06o => %06o%c", line_prefix, p->one->mode,
3729                        p->two->mode, show_name ? ' ' : '\n');
3730                if (show_name) {
3731                        write_name_quoted(p->two->path, file, '\n');
3732                }
3733        }
3734}
3735
3736static void show_rename_copy(FILE *file, const char *renamecopy, struct diff_filepair *p,
3737                        const char *line_prefix)
3738{
3739        char *names = pprint_rename(p->one->path, p->two->path);
3740
3741        fprintf(file, " %s %s (%d%%)\n", renamecopy, names, similarity_index(p));
3742        free(names);
3743        show_mode_change(file, p, 0, line_prefix);
3744}
3745
3746static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
3747{
3748        FILE *file = opt->file;
3749        char *line_prefix = "";
3750
3751        if (opt->output_prefix) {
3752                struct strbuf *buf = opt->output_prefix(opt, opt->output_prefix_data);
3753                line_prefix = buf->buf;
3754        }
3755
3756        switch(p->status) {
3757        case DIFF_STATUS_DELETED:
3758                fputs(line_prefix, file);
3759                show_file_mode_name(file, "delete", p->one);
3760                break;
3761        case DIFF_STATUS_ADDED:
3762                fputs(line_prefix, file);
3763                show_file_mode_name(file, "create", p->two);
3764                break;
3765        case DIFF_STATUS_COPIED:
3766                fputs(line_prefix, file);
3767                show_rename_copy(file, "copy", p, line_prefix);
3768                break;
3769        case DIFF_STATUS_RENAMED:
3770                fputs(line_prefix, file);
3771                show_rename_copy(file, "rename", p, line_prefix);
3772                break;
3773        default:
3774                if (p->score) {
3775                        fprintf(file, "%s rewrite ", line_prefix);
3776                        write_name_quoted(p->two->path, file, ' ');
3777                        fprintf(file, "(%d%%)\n", similarity_index(p));
3778                }
3779                show_mode_change(file, p, !p->score, line_prefix);
3780                break;
3781        }
3782}
3783
3784struct patch_id_t {
3785        git_SHA_CTX *ctx;
3786        int patchlen;
3787};
3788
3789static int remove_space(char *line, int len)
3790{
3791        int i;
3792        char *dst = line;
3793        unsigned char c;
3794
3795        for (i = 0; i < len; i++)
3796                if (!isspace((c = line[i])))
3797                        *dst++ = c;
3798
3799        return dst - line;
3800}
3801
3802static void patch_id_consume(void *priv, char *line, unsigned long len)
3803{
3804        struct patch_id_t *data = priv;
3805        int new_len;
3806
3807        /* Ignore line numbers when computing the SHA1 of the patch */
3808        if (!prefixcmp(line, "@@ -"))
3809                return;
3810
3811        new_len = remove_space(line, len);
3812
3813        git_SHA1_Update(data->ctx, line, new_len);
3814        data->patchlen += new_len;
3815}
3816
3817/* returns 0 upon success, and writes result into sha1 */
3818static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
3819{
3820        struct diff_queue_struct *q = &diff_queued_diff;
3821        int i;
3822        git_SHA_CTX ctx;
3823        struct patch_id_t data;
3824        char buffer[PATH_MAX * 4 + 20];
3825
3826        git_SHA1_Init(&ctx);
3827        memset(&data, 0, sizeof(struct patch_id_t));
3828        data.ctx = &ctx;
3829
3830        for (i = 0; i < q->nr; i++) {
3831                xpparam_t xpp;
3832                xdemitconf_t xecfg;
3833                mmfile_t mf1, mf2;
3834                struct diff_filepair *p = q->queue[i];
3835                int len1, len2;
3836
3837                memset(&xpp, 0, sizeof(xpp));
3838                memset(&xecfg, 0, sizeof(xecfg));
3839                if (p->status == 0)
3840                        return error("internal diff status error");
3841                if (p->status == DIFF_STATUS_UNKNOWN)
3842                        continue;
3843                if (diff_unmodified_pair(p))
3844                        continue;
3845                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3846                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3847                        continue;
3848                if (DIFF_PAIR_UNMERGED(p))
3849                        continue;
3850
3851                diff_fill_sha1_info(p->one);
3852                diff_fill_sha1_info(p->two);
3853                if (fill_mmfile(&mf1, p->one) < 0 ||
3854                                fill_mmfile(&mf2, p->two) < 0)
3855                        return error("unable to read files to diff");
3856
3857                len1 = remove_space(p->one->path, strlen(p->one->path));
3858                len2 = remove_space(p->two->path, strlen(p->two->path));
3859                if (p->one->mode == 0)
3860                        len1 = snprintf(buffer, sizeof(buffer),
3861                                        "diff--gita/%.*sb/%.*s"
3862                                        "newfilemode%06o"
3863                                        "---/dev/null"
3864                                        "+++b/%.*s",
3865                                        len1, p->one->path,
3866                                        len2, p->two->path,
3867                                        p->two->mode,
3868                                        len2, p->two->path);
3869                else if (p->two->mode == 0)
3870                        len1 = snprintf(buffer, sizeof(buffer),
3871                                        "diff--gita/%.*sb/%.*s"
3872                                        "deletedfilemode%06o"
3873                                        "---a/%.*s"
3874                                        "+++/dev/null",
3875                                        len1, p->one->path,
3876                                        len2, p->two->path,
3877                                        p->one->mode,
3878                                        len1, p->one->path);
3879                else
3880                        len1 = snprintf(buffer, sizeof(buffer),
3881                                        "diff--gita/%.*sb/%.*s"
3882                                        "---a/%.*s"
3883                                        "+++b/%.*s",
3884                                        len1, p->one->path,
3885                                        len2, p->two->path,
3886                                        len1, p->one->path,
3887                                        len2, p->two->path);
3888                git_SHA1_Update(&ctx, buffer, len1);
3889
3890                if (diff_filespec_is_binary(p->one) ||
3891                    diff_filespec_is_binary(p->two)) {
3892                        git_SHA1_Update(&ctx, sha1_to_hex(p->one->sha1), 40);
3893                        git_SHA1_Update(&ctx, sha1_to_hex(p->two->sha1), 40);
3894                        continue;
3895                }
3896
3897                xpp.flags = 0;
3898                xecfg.ctxlen = 3;
3899                xecfg.flags = 0;
3900                xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
3901                              &xpp, &xecfg);
3902        }
3903
3904        git_SHA1_Final(sha1, &ctx);
3905        return 0;
3906}
3907
3908int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1)
3909{
3910        struct diff_queue_struct *q = &diff_queued_diff;
3911        int i;
3912        int result = diff_get_patch_id(options, sha1);
3913
3914        for (i = 0; i < q->nr; i++)
3915                diff_free_filepair(q->queue[i]);
3916
3917        free(q->queue);
3918        DIFF_QUEUE_CLEAR(q);
3919
3920        return result;
3921}
3922
3923static int is_summary_empty(const struct diff_queue_struct *q)
3924{
3925        int i;
3926
3927        for (i = 0; i < q->nr; i++) {
3928                const struct diff_filepair *p = q->queue[i];
3929
3930                switch (p->status) {
3931                case DIFF_STATUS_DELETED:
3932                case DIFF_STATUS_ADDED:
3933                case DIFF_STATUS_COPIED:
3934                case DIFF_STATUS_RENAMED:
3935                        return 0;
3936                default:
3937                        if (p->score)
3938                                return 0;
3939                        if (p->one->mode && p->two->mode &&
3940                            p->one->mode != p->two->mode)
3941                                return 0;
3942                        break;
3943                }
3944        }
3945        return 1;
3946}
3947
3948void diff_flush(struct diff_options *options)
3949{
3950        struct diff_queue_struct *q = &diff_queued_diff;
3951        int i, output_format = options->output_format;
3952        int separator = 0;
3953
3954        /*
3955         * Order: raw, stat, summary, patch
3956         * or:    name/name-status/checkdiff (other bits clear)
3957         */
3958        if (!q->nr)
3959                goto free_queue;
3960
3961        if (output_format & (DIFF_FORMAT_RAW |
3962                             DIFF_FORMAT_NAME |
3963                             DIFF_FORMAT_NAME_STATUS |
3964                             DIFF_FORMAT_CHECKDIFF)) {
3965                for (i = 0; i < q->nr; i++) {
3966                        struct diff_filepair *p = q->queue[i];
3967                        if (check_pair_status(p))
3968                                flush_one_pair(p, options);
3969                }
3970                separator++;
3971        }
3972
3973        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT)) {
3974                struct diffstat_t diffstat;
3975
3976                memset(&diffstat, 0, sizeof(struct diffstat_t));
3977                for (i = 0; i < q->nr; i++) {
3978                        struct diff_filepair *p = q->queue[i];
3979                        if (check_pair_status(p))
3980                                diff_flush_stat(p, options, &diffstat);
3981                }
3982                if (output_format & DIFF_FORMAT_NUMSTAT)
3983                        show_numstat(&diffstat, options);
3984                if (output_format & DIFF_FORMAT_DIFFSTAT)
3985                        show_stats(&diffstat, options);
3986                if (output_format & DIFF_FORMAT_SHORTSTAT)
3987                        show_shortstats(&diffstat, options);
3988                free_diffstat_info(&diffstat);
3989                separator++;
3990        }
3991        if (output_format & DIFF_FORMAT_DIRSTAT)
3992                show_dirstat(options);
3993
3994        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
3995                for (i = 0; i < q->nr; i++) {
3996                        diff_summary(options, q->queue[i]);
3997                }
3998                separator++;
3999        }
4000
4001        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
4002            DIFF_OPT_TST(options, EXIT_WITH_STATUS) &&
4003            DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4004                /*
4005                 * run diff_flush_patch for the exit status. setting
4006                 * options->file to /dev/null should be safe, becaue we
4007                 * aren't supposed to produce any output anyway.
4008                 */
4009                if (options->close_file)
4010                        fclose(options->file);
4011                options->file = fopen("/dev/null", "w");
4012                if (!options->file)
4013                        die_errno("Could not open /dev/null");
4014                options->close_file = 1;
4015                for (i = 0; i < q->nr; i++) {
4016                        struct diff_filepair *p = q->queue[i];
4017                        if (check_pair_status(p))
4018                                diff_flush_patch(p, options);
4019                        if (options->found_changes)
4020                                break;
4021                }
4022        }
4023
4024        if (output_format & DIFF_FORMAT_PATCH) {
4025                if (separator) {
4026                        putc(options->line_termination, options->file);
4027                        if (options->stat_sep) {
4028                                /* attach patch instead of inline */
4029                                fputs(options->stat_sep, options->file);
4030                        }
4031                }
4032
4033                for (i = 0; i < q->nr; i++) {
4034                        struct diff_filepair *p = q->queue[i];
4035                        if (check_pair_status(p))
4036                                diff_flush_patch(p, options);
4037                }
4038        }
4039
4040        if (output_format & DIFF_FORMAT_CALLBACK)
4041                options->format_callback(q, options, options->format_callback_data);
4042
4043        for (i = 0; i < q->nr; i++)
4044                diff_free_filepair(q->queue[i]);
4045free_queue:
4046        free(q->queue);
4047        DIFF_QUEUE_CLEAR(q);
4048        if (options->close_file)
4049                fclose(options->file);
4050
4051        /*
4052         * Report the content-level differences with HAS_CHANGES;
4053         * diff_addremove/diff_change does not set the bit when
4054         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
4055         */
4056        if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4057                if (options->found_changes)
4058                        DIFF_OPT_SET(options, HAS_CHANGES);
4059                else
4060                        DIFF_OPT_CLR(options, HAS_CHANGES);
4061        }
4062}
4063
4064static void diffcore_apply_filter(const char *filter)
4065{
4066        int i;
4067        struct diff_queue_struct *q = &diff_queued_diff;
4068        struct diff_queue_struct outq;
4069        DIFF_QUEUE_CLEAR(&outq);
4070
4071        if (!filter)
4072                return;
4073
4074        if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
4075                int found;
4076                for (i = found = 0; !found && i < q->nr; i++) {
4077                        struct diff_filepair *p = q->queue[i];
4078                        if (((p->status == DIFF_STATUS_MODIFIED) &&
4079                             ((p->score &&
4080                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
4081                              (!p->score &&
4082                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
4083                            ((p->status != DIFF_STATUS_MODIFIED) &&
4084                             strchr(filter, p->status)))
4085                                found++;
4086                }
4087                if (found)
4088                        return;
4089
4090                /* otherwise we will clear the whole queue
4091                 * by copying the empty outq at the end of this
4092                 * function, but first clear the current entries
4093                 * in the queue.
4094                 */
4095                for (i = 0; i < q->nr; i++)
4096                        diff_free_filepair(q->queue[i]);
4097        }
4098        else {
4099                /* Only the matching ones */
4100                for (i = 0; i < q->nr; i++) {
4101                        struct diff_filepair *p = q->queue[i];
4102
4103                        if (((p->status == DIFF_STATUS_MODIFIED) &&
4104                             ((p->score &&
4105                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
4106                              (!p->score &&
4107                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
4108                            ((p->status != DIFF_STATUS_MODIFIED) &&
4109                             strchr(filter, p->status)))
4110                                diff_q(&outq, p);
4111                        else
4112                                diff_free_filepair(p);
4113                }
4114        }
4115        free(q->queue);
4116        *q = outq;
4117}
4118
4119/* Check whether two filespecs with the same mode and size are identical */
4120static int diff_filespec_is_identical(struct diff_filespec *one,
4121                                      struct diff_filespec *two)
4122{
4123        if (S_ISGITLINK(one->mode))
4124                return 0;
4125        if (diff_populate_filespec(one, 0))
4126                return 0;
4127        if (diff_populate_filespec(two, 0))
4128                return 0;
4129        return !memcmp(one->data, two->data, one->size);
4130}
4131
4132static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
4133{
4134        int i;
4135        struct diff_queue_struct *q = &diff_queued_diff;
4136        struct diff_queue_struct outq;
4137        DIFF_QUEUE_CLEAR(&outq);
4138
4139        for (i = 0; i < q->nr; i++) {
4140                struct diff_filepair *p = q->queue[i];
4141
4142                /*
4143                 * 1. Entries that come from stat info dirtiness
4144                 *    always have both sides (iow, not create/delete),
4145                 *    one side of the object name is unknown, with
4146                 *    the same mode and size.  Keep the ones that
4147                 *    do not match these criteria.  They have real
4148                 *    differences.
4149                 *
4150                 * 2. At this point, the file is known to be modified,
4151                 *    with the same mode and size, and the object
4152                 *    name of one side is unknown.  Need to inspect
4153                 *    the identical contents.
4154                 */
4155                if (!DIFF_FILE_VALID(p->one) || /* (1) */
4156                    !DIFF_FILE_VALID(p->two) ||
4157                    (p->one->sha1_valid && p->two->sha1_valid) ||
4158                    (p->one->mode != p->two->mode) ||
4159                    diff_populate_filespec(p->one, 1) ||
4160                    diff_populate_filespec(p->two, 1) ||
4161                    (p->one->size != p->two->size) ||
4162                    !diff_filespec_is_identical(p->one, p->two)) /* (2) */
4163                        diff_q(&outq, p);
4164                else {
4165                        /*
4166                         * The caller can subtract 1 from skip_stat_unmatch
4167                         * to determine how many paths were dirty only
4168                         * due to stat info mismatch.
4169                         */
4170                        if (!DIFF_OPT_TST(diffopt, NO_INDEX))
4171                                diffopt->skip_stat_unmatch++;
4172                        diff_free_filepair(p);
4173                }
4174        }
4175        free(q->queue);
4176        *q = outq;
4177}
4178
4179static int diffnamecmp(const void *a_, const void *b_)
4180{
4181        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
4182        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
4183        const char *name_a, *name_b;
4184
4185        name_a = a->one ? a->one->path : a->two->path;
4186        name_b = b->one ? b->one->path : b->two->path;
4187        return strcmp(name_a, name_b);
4188}
4189
4190void diffcore_fix_diff_index(struct diff_options *options)
4191{
4192        struct diff_queue_struct *q = &diff_queued_diff;
4193        qsort(q->queue, q->nr, sizeof(q->queue[0]), diffnamecmp);
4194}
4195
4196void diffcore_std(struct diff_options *options)
4197{
4198        if (options->skip_stat_unmatch)
4199                diffcore_skip_stat_unmatch(options);
4200        if (!options->found_follow) {
4201                /* See try_to_follow_renames() in tree-diff.c */
4202                if (options->break_opt != -1)
4203                        diffcore_break(options->break_opt);
4204                if (options->detect_rename)
4205                        diffcore_rename(options);
4206                if (options->break_opt != -1)
4207                        diffcore_merge_broken();
4208        }
4209        if (options->pickaxe)
4210                diffcore_pickaxe(options);
4211        if (options->orderfile)
4212                diffcore_order(options->orderfile);
4213        if (!options->found_follow)
4214                /* See try_to_follow_renames() in tree-diff.c */
4215                diff_resolve_rename_copy();
4216        diffcore_apply_filter(options->filter);
4217
4218        if (diff_queued_diff.nr && !DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4219                DIFF_OPT_SET(options, HAS_CHANGES);
4220        else
4221                DIFF_OPT_CLR(options, HAS_CHANGES);
4222
4223        options->found_follow = 0;
4224}
4225
4226int diff_result_code(struct diff_options *opt, int status)
4227{
4228        int result = 0;
4229        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4230            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
4231                return status;
4232        if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4233            DIFF_OPT_TST(opt, HAS_CHANGES))
4234                result |= 01;
4235        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
4236            DIFF_OPT_TST(opt, CHECK_FAILED))
4237                result |= 02;
4238        return result;
4239}
4240
4241/*
4242 * Shall changes to this submodule be ignored?
4243 *
4244 * Submodule changes can be configured to be ignored separately for each path,
4245 * but that configuration can be overridden from the command line.
4246 */
4247static int is_submodule_ignored(const char *path, struct diff_options *options)
4248{
4249        int ignored = 0;
4250        unsigned orig_flags = options->flags;
4251        if (!DIFF_OPT_TST(options, OVERRIDE_SUBMODULE_CONFIG))
4252                set_diffopt_flags_from_submodule_config(options, path);
4253        if (DIFF_OPT_TST(options, IGNORE_SUBMODULES))
4254                ignored = 1;
4255        options->flags = orig_flags;
4256        return ignored;
4257}
4258
4259void diff_addremove(struct diff_options *options,
4260                    int addremove, unsigned mode,
4261                    const unsigned char *sha1,
4262                    const char *concatpath, unsigned dirty_submodule)
4263{
4264        struct diff_filespec *one, *two;
4265
4266        if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
4267                return;
4268
4269        /* This may look odd, but it is a preparation for
4270         * feeding "there are unchanged files which should
4271         * not produce diffs, but when you are doing copy
4272         * detection you would need them, so here they are"
4273         * entries to the diff-core.  They will be prefixed
4274         * with something like '=' or '*' (I haven't decided
4275         * which but should not make any difference).
4276         * Feeding the same new and old to diff_change()
4277         * also has the same effect.
4278         * Before the final output happens, they are pruned after
4279         * merged into rename/copy pairs as appropriate.
4280         */
4281        if (DIFF_OPT_TST(options, REVERSE_DIFF))
4282                addremove = (addremove == '+' ? '-' :
4283                             addremove == '-' ? '+' : addremove);
4284
4285        if (options->prefix &&
4286            strncmp(concatpath, options->prefix, options->prefix_length))
4287                return;
4288
4289        one = alloc_filespec(concatpath);
4290        two = alloc_filespec(concatpath);
4291
4292        if (addremove != '+')
4293                fill_filespec(one, sha1, mode);
4294        if (addremove != '-') {
4295                fill_filespec(two, sha1, mode);
4296                two->dirty_submodule = dirty_submodule;
4297        }
4298
4299        diff_queue(&diff_queued_diff, one, two);
4300        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4301                DIFF_OPT_SET(options, HAS_CHANGES);
4302}
4303
4304void diff_change(struct diff_options *options,
4305                 unsigned old_mode, unsigned new_mode,
4306                 const unsigned char *old_sha1,
4307                 const unsigned char *new_sha1,
4308                 const char *concatpath,
4309                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
4310{
4311        struct diff_filespec *one, *two;
4312
4313        if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
4314            is_submodule_ignored(concatpath, options))
4315                return;
4316
4317        if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
4318                unsigned tmp;
4319                const unsigned char *tmp_c;
4320                tmp = old_mode; old_mode = new_mode; new_mode = tmp;
4321                tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
4322                tmp = old_dirty_submodule; old_dirty_submodule = new_dirty_submodule;
4323                        new_dirty_submodule = tmp;
4324        }
4325
4326        if (options->prefix &&
4327            strncmp(concatpath, options->prefix, options->prefix_length))
4328                return;
4329
4330        one = alloc_filespec(concatpath);
4331        two = alloc_filespec(concatpath);
4332        fill_filespec(one, old_sha1, old_mode);
4333        fill_filespec(two, new_sha1, new_mode);
4334        one->dirty_submodule = old_dirty_submodule;
4335        two->dirty_submodule = new_dirty_submodule;
4336
4337        diff_queue(&diff_queued_diff, one, two);
4338        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4339                DIFF_OPT_SET(options, HAS_CHANGES);
4340}
4341
4342void diff_unmerge(struct diff_options *options,
4343                  const char *path,
4344                  unsigned mode, const unsigned char *sha1)
4345{
4346        struct diff_filespec *one, *two;
4347
4348        if (options->prefix &&
4349            strncmp(path, options->prefix, options->prefix_length))
4350                return;
4351
4352        one = alloc_filespec(path);
4353        two = alloc_filespec(path);
4354        fill_filespec(one, sha1, mode);
4355        diff_queue(&diff_queued_diff, one, two)->is_unmerged = 1;
4356}
4357
4358static char *run_textconv(const char *pgm, struct diff_filespec *spec,
4359                size_t *outsize)
4360{
4361        struct diff_tempfile *temp;
4362        const char *argv[3];
4363        const char **arg = argv;
4364        struct child_process child;
4365        struct strbuf buf = STRBUF_INIT;
4366        int err = 0;
4367
4368        temp = prepare_temp_file(spec->path, spec);
4369        *arg++ = pgm;
4370        *arg++ = temp->name;
4371        *arg = NULL;
4372
4373        memset(&child, 0, sizeof(child));
4374        child.use_shell = 1;
4375        child.argv = argv;
4376        child.out = -1;
4377        if (start_command(&child)) {
4378                remove_tempfile();
4379                return NULL;
4380        }
4381
4382        if (strbuf_read(&buf, child.out, 0) < 0)
4383                err = error("error reading from textconv command '%s'", pgm);
4384        close(child.out);
4385
4386        if (finish_command(&child) || err) {
4387                strbuf_release(&buf);
4388                remove_tempfile();
4389                return NULL;
4390        }
4391        remove_tempfile();
4392
4393        return strbuf_detach(&buf, outsize);
4394}
4395
4396size_t fill_textconv(struct userdiff_driver *driver,
4397                     struct diff_filespec *df,
4398                     char **outbuf)
4399{
4400        size_t size;
4401
4402        if (!driver || !driver->textconv) {
4403                if (!DIFF_FILE_VALID(df)) {
4404                        *outbuf = "";
4405                        return 0;
4406                }
4407                if (diff_populate_filespec(df, 0))
4408                        die("unable to read files to diff");
4409                *outbuf = df->data;
4410                return df->size;
4411        }
4412
4413        if (driver->textconv_cache && df->sha1_valid) {
4414                *outbuf = notes_cache_get(driver->textconv_cache, df->sha1,
4415                                          &size);
4416                if (*outbuf)
4417                        return size;
4418        }
4419
4420        *outbuf = run_textconv(driver->textconv, df, &size);
4421        if (!*outbuf)
4422                die("unable to read files to diff");
4423
4424        if (driver->textconv_cache && df->sha1_valid) {
4425                /* ignore errors, as we might be in a readonly repository */
4426                notes_cache_put(driver->textconv_cache, df->sha1, *outbuf,
4427                                size);
4428                /*
4429                 * we could save up changes and flush them all at the end,
4430                 * but we would need an extra call after all diffing is done.
4431                 * Since generating a cache entry is the slow path anyway,
4432                 * this extra overhead probably isn't a big deal.
4433                 */
4434                notes_cache_write(driver->textconv_cache);
4435        }
4436
4437        return size;
4438}