diff.con commit tag: recognize rfc1991 signatures (3d5854e)
   1/*
   2 * Copyright (C) 2005 Junio C Hamano
   3 */
   4#include "cache.h"
   5#include "quote.h"
   6#include "diff.h"
   7#include "diffcore.h"
   8#include "delta.h"
   9#include "xdiff-interface.h"
  10#include "color.h"
  11#include "attr.h"
  12#include "run-command.h"
  13#include "utf8.h"
  14#include "userdiff.h"
  15#include "sigchain.h"
  16#include "submodule.h"
  17#include "ll-merge.h"
  18
  19#ifdef NO_FAST_WORKING_DIRECTORY
  20#define FAST_WORKING_DIRECTORY 0
  21#else
  22#define FAST_WORKING_DIRECTORY 1
  23#endif
  24
  25static int diff_detect_rename_default;
  26static int diff_rename_limit_default = 200;
  27static int diff_suppress_blank_empty;
  28int diff_use_color_default = -1;
  29static const char *diff_word_regex_cfg;
  30static const char *external_diff_cmd_cfg;
  31int diff_auto_refresh_index = 1;
  32static int diff_mnemonic_prefix;
  33static int diff_no_prefix;
  34static struct diff_options default_diff_options;
  35
  36static char diff_colors[][COLOR_MAXLEN] = {
  37        GIT_COLOR_RESET,
  38        GIT_COLOR_NORMAL,       /* PLAIN */
  39        GIT_COLOR_BOLD,         /* METAINFO */
  40        GIT_COLOR_CYAN,         /* FRAGINFO */
  41        GIT_COLOR_RED,          /* OLD */
  42        GIT_COLOR_GREEN,        /* NEW */
  43        GIT_COLOR_YELLOW,       /* COMMIT */
  44        GIT_COLOR_BG_RED,       /* WHITESPACE */
  45        GIT_COLOR_NORMAL,       /* FUNCINFO */
  46};
  47
  48static int parse_diff_color_slot(const char *var, int ofs)
  49{
  50        if (!strcasecmp(var+ofs, "plain"))
  51                return DIFF_PLAIN;
  52        if (!strcasecmp(var+ofs, "meta"))
  53                return DIFF_METAINFO;
  54        if (!strcasecmp(var+ofs, "frag"))
  55                return DIFF_FRAGINFO;
  56        if (!strcasecmp(var+ofs, "old"))
  57                return DIFF_FILE_OLD;
  58        if (!strcasecmp(var+ofs, "new"))
  59                return DIFF_FILE_NEW;
  60        if (!strcasecmp(var+ofs, "commit"))
  61                return DIFF_COMMIT;
  62        if (!strcasecmp(var+ofs, "whitespace"))
  63                return DIFF_WHITESPACE;
  64        if (!strcasecmp(var+ofs, "func"))
  65                return DIFF_FUNCINFO;
  66        return -1;
  67}
  68
  69static int git_config_rename(const char *var, const char *value)
  70{
  71        if (!value)
  72                return DIFF_DETECT_RENAME;
  73        if (!strcasecmp(value, "copies") || !strcasecmp(value, "copy"))
  74                return  DIFF_DETECT_COPY;
  75        return git_config_bool(var,value) ? DIFF_DETECT_RENAME : 0;
  76}
  77
  78/*
  79 * These are to give UI layer defaults.
  80 * The core-level commands such as git-diff-files should
  81 * never be affected by the setting of diff.renames
  82 * the user happens to have in the configuration file.
  83 */
  84int git_diff_ui_config(const char *var, const char *value, void *cb)
  85{
  86        if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
  87                diff_use_color_default = git_config_colorbool(var, value, -1);
  88                return 0;
  89        }
  90        if (!strcmp(var, "diff.renames")) {
  91                diff_detect_rename_default = git_config_rename(var, value);
  92                return 0;
  93        }
  94        if (!strcmp(var, "diff.autorefreshindex")) {
  95                diff_auto_refresh_index = git_config_bool(var, value);
  96                return 0;
  97        }
  98        if (!strcmp(var, "diff.mnemonicprefix")) {
  99                diff_mnemonic_prefix = git_config_bool(var, value);
 100                return 0;
 101        }
 102        if (!strcmp(var, "diff.noprefix")) {
 103                diff_no_prefix = git_config_bool(var, value);
 104                return 0;
 105        }
 106        if (!strcmp(var, "diff.external"))
 107                return git_config_string(&external_diff_cmd_cfg, var, value);
 108        if (!strcmp(var, "diff.wordregex"))
 109                return git_config_string(&diff_word_regex_cfg, var, value);
 110
 111        if (!strcmp(var, "diff.ignoresubmodules"))
 112                handle_ignore_submodules_arg(&default_diff_options, value);
 113
 114        return git_diff_basic_config(var, value, cb);
 115}
 116
 117int git_diff_basic_config(const char *var, const char *value, void *cb)
 118{
 119        if (!strcmp(var, "diff.renamelimit")) {
 120                diff_rename_limit_default = git_config_int(var, value);
 121                return 0;
 122        }
 123
 124        switch (userdiff_config(var, value)) {
 125                case 0: break;
 126                case -1: return -1;
 127                default: return 0;
 128        }
 129
 130        if (!prefixcmp(var, "diff.color.") || !prefixcmp(var, "color.diff.")) {
 131                int slot = parse_diff_color_slot(var, 11);
 132                if (slot < 0)
 133                        return 0;
 134                if (!value)
 135                        return config_error_nonbool(var);
 136                color_parse(value, var, diff_colors[slot]);
 137                return 0;
 138        }
 139
 140        /* like GNU diff's --suppress-blank-empty option  */
 141        if (!strcmp(var, "diff.suppressblankempty") ||
 142                        /* for backwards compatibility */
 143                        !strcmp(var, "diff.suppress-blank-empty")) {
 144                diff_suppress_blank_empty = git_config_bool(var, value);
 145                return 0;
 146        }
 147
 148        if (!prefixcmp(var, "submodule."))
 149                return parse_submodule_config_option(var, value);
 150
 151        return git_color_default_config(var, value, cb);
 152}
 153
 154static char *quote_two(const char *one, const char *two)
 155{
 156        int need_one = quote_c_style(one, NULL, NULL, 1);
 157        int need_two = quote_c_style(two, NULL, NULL, 1);
 158        struct strbuf res = STRBUF_INIT;
 159
 160        if (need_one + need_two) {
 161                strbuf_addch(&res, '"');
 162                quote_c_style(one, &res, NULL, 1);
 163                quote_c_style(two, &res, NULL, 1);
 164                strbuf_addch(&res, '"');
 165        } else {
 166                strbuf_addstr(&res, one);
 167                strbuf_addstr(&res, two);
 168        }
 169        return strbuf_detach(&res, NULL);
 170}
 171
 172static const char *external_diff(void)
 173{
 174        static const char *external_diff_cmd = NULL;
 175        static int done_preparing = 0;
 176
 177        if (done_preparing)
 178                return external_diff_cmd;
 179        external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
 180        if (!external_diff_cmd)
 181                external_diff_cmd = external_diff_cmd_cfg;
 182        done_preparing = 1;
 183        return external_diff_cmd;
 184}
 185
 186static struct diff_tempfile {
 187        const char *name; /* filename external diff should read from */
 188        char hex[41];
 189        char mode[10];
 190        char tmp_path[PATH_MAX];
 191} diff_temp[2];
 192
 193typedef unsigned long (*sane_truncate_fn)(char *line, unsigned long len);
 194
 195struct emit_callback {
 196        int color_diff;
 197        unsigned ws_rule;
 198        int blank_at_eof_in_preimage;
 199        int blank_at_eof_in_postimage;
 200        int lno_in_preimage;
 201        int lno_in_postimage;
 202        sane_truncate_fn truncate;
 203        const char **label_path;
 204        struct diff_words_data *diff_words;
 205        struct diff_options *opt;
 206        int *found_changesp;
 207        struct strbuf *header;
 208};
 209
 210static int count_lines(const char *data, int size)
 211{
 212        int count, ch, completely_empty = 1, nl_just_seen = 0;
 213        count = 0;
 214        while (0 < size--) {
 215                ch = *data++;
 216                if (ch == '\n') {
 217                        count++;
 218                        nl_just_seen = 1;
 219                        completely_empty = 0;
 220                }
 221                else {
 222                        nl_just_seen = 0;
 223                        completely_empty = 0;
 224                }
 225        }
 226        if (completely_empty)
 227                return 0;
 228        if (!nl_just_seen)
 229                count++; /* no trailing newline */
 230        return count;
 231}
 232
 233static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
 234{
 235        if (!DIFF_FILE_VALID(one)) {
 236                mf->ptr = (char *)""; /* does not matter */
 237                mf->size = 0;
 238                return 0;
 239        }
 240        else if (diff_populate_filespec(one, 0))
 241                return -1;
 242
 243        mf->ptr = one->data;
 244        mf->size = one->size;
 245        return 0;
 246}
 247
 248static int count_trailing_blank(mmfile_t *mf, unsigned ws_rule)
 249{
 250        char *ptr = mf->ptr;
 251        long size = mf->size;
 252        int cnt = 0;
 253
 254        if (!size)
 255                return cnt;
 256        ptr += size - 1; /* pointing at the very end */
 257        if (*ptr != '\n')
 258                ; /* incomplete line */
 259        else
 260                ptr--; /* skip the last LF */
 261        while (mf->ptr < ptr) {
 262                char *prev_eol;
 263                for (prev_eol = ptr; mf->ptr <= prev_eol; prev_eol--)
 264                        if (*prev_eol == '\n')
 265                                break;
 266                if (!ws_blank_line(prev_eol + 1, ptr - prev_eol, ws_rule))
 267                        break;
 268                cnt++;
 269                ptr = prev_eol - 1;
 270        }
 271        return cnt;
 272}
 273
 274static void check_blank_at_eof(mmfile_t *mf1, mmfile_t *mf2,
 275                               struct emit_callback *ecbdata)
 276{
 277        int l1, l2, at;
 278        unsigned ws_rule = ecbdata->ws_rule;
 279        l1 = count_trailing_blank(mf1, ws_rule);
 280        l2 = count_trailing_blank(mf2, ws_rule);
 281        if (l2 <= l1) {
 282                ecbdata->blank_at_eof_in_preimage = 0;
 283                ecbdata->blank_at_eof_in_postimage = 0;
 284                return;
 285        }
 286        at = count_lines(mf1->ptr, mf1->size);
 287        ecbdata->blank_at_eof_in_preimage = (at - l1) + 1;
 288
 289        at = count_lines(mf2->ptr, mf2->size);
 290        ecbdata->blank_at_eof_in_postimage = (at - l2) + 1;
 291}
 292
 293static void emit_line_0(struct diff_options *o, const char *set, const char *reset,
 294                        int first, const char *line, int len)
 295{
 296        int has_trailing_newline, has_trailing_carriage_return;
 297        int nofirst;
 298        FILE *file = o->file;
 299
 300        if (o->output_prefix) {
 301                struct strbuf *msg = NULL;
 302                msg = o->output_prefix(o, o->output_prefix_data);
 303                assert(msg);
 304                fwrite(msg->buf, msg->len, 1, file);
 305        }
 306
 307        if (len == 0) {
 308                has_trailing_newline = (first == '\n');
 309                has_trailing_carriage_return = (!has_trailing_newline &&
 310                                                (first == '\r'));
 311                nofirst = has_trailing_newline || has_trailing_carriage_return;
 312        } else {
 313                has_trailing_newline = (len > 0 && line[len-1] == '\n');
 314                if (has_trailing_newline)
 315                        len--;
 316                has_trailing_carriage_return = (len > 0 && line[len-1] == '\r');
 317                if (has_trailing_carriage_return)
 318                        len--;
 319                nofirst = 0;
 320        }
 321
 322        if (len || !nofirst) {
 323                fputs(set, file);
 324                if (!nofirst)
 325                        fputc(first, file);
 326                fwrite(line, len, 1, file);
 327                fputs(reset, file);
 328        }
 329        if (has_trailing_carriage_return)
 330                fputc('\r', file);
 331        if (has_trailing_newline)
 332                fputc('\n', file);
 333}
 334
 335static void emit_line(struct diff_options *o, const char *set, const char *reset,
 336                      const char *line, int len)
 337{
 338        emit_line_0(o, set, reset, line[0], line+1, len-1);
 339}
 340
 341static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line, int len)
 342{
 343        if (!((ecbdata->ws_rule & WS_BLANK_AT_EOF) &&
 344              ecbdata->blank_at_eof_in_preimage &&
 345              ecbdata->blank_at_eof_in_postimage &&
 346              ecbdata->blank_at_eof_in_preimage <= ecbdata->lno_in_preimage &&
 347              ecbdata->blank_at_eof_in_postimage <= ecbdata->lno_in_postimage))
 348                return 0;
 349        return ws_blank_line(line, len, ecbdata->ws_rule);
 350}
 351
 352static void emit_add_line(const char *reset,
 353                          struct emit_callback *ecbdata,
 354                          const char *line, int len)
 355{
 356        const char *ws = diff_get_color(ecbdata->color_diff, DIFF_WHITESPACE);
 357        const char *set = diff_get_color(ecbdata->color_diff, DIFF_FILE_NEW);
 358
 359        if (!*ws)
 360                emit_line_0(ecbdata->opt, set, reset, '+', line, len);
 361        else if (new_blank_line_at_eof(ecbdata, line, len))
 362                /* Blank line at EOF - paint '+' as well */
 363                emit_line_0(ecbdata->opt, ws, reset, '+', line, len);
 364        else {
 365                /* Emit just the prefix, then the rest. */
 366                emit_line_0(ecbdata->opt, set, reset, '+', "", 0);
 367                ws_check_emit(line, len, ecbdata->ws_rule,
 368                              ecbdata->opt->file, set, reset, ws);
 369        }
 370}
 371
 372static void emit_hunk_header(struct emit_callback *ecbdata,
 373                             const char *line, int len)
 374{
 375        const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
 376        const char *frag = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
 377        const char *func = diff_get_color(ecbdata->color_diff, DIFF_FUNCINFO);
 378        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
 379        static const char atat[2] = { '@', '@' };
 380        const char *cp, *ep;
 381        struct strbuf msgbuf = STRBUF_INIT;
 382        int org_len = len;
 383        int i = 1;
 384
 385        /*
 386         * As a hunk header must begin with "@@ -<old>, +<new> @@",
 387         * it always is at least 10 bytes long.
 388         */
 389        if (len < 10 ||
 390            memcmp(line, atat, 2) ||
 391            !(ep = memmem(line + 2, len - 2, atat, 2))) {
 392                emit_line(ecbdata->opt, plain, reset, line, len);
 393                return;
 394        }
 395        ep += 2; /* skip over @@ */
 396
 397        /* The hunk header in fraginfo color */
 398        strbuf_add(&msgbuf, frag, strlen(frag));
 399        strbuf_add(&msgbuf, line, ep - line);
 400        strbuf_add(&msgbuf, reset, strlen(reset));
 401
 402        /*
 403         * trailing "\r\n"
 404         */
 405        for ( ; i < 3; i++)
 406                if (line[len - i] == '\r' || line[len - i] == '\n')
 407                        len--;
 408
 409        /* blank before the func header */
 410        for (cp = ep; ep - line < len; ep++)
 411                if (*ep != ' ' && *ep != '\t')
 412                        break;
 413        if (ep != cp) {
 414                strbuf_add(&msgbuf, plain, strlen(plain));
 415                strbuf_add(&msgbuf, cp, ep - cp);
 416                strbuf_add(&msgbuf, reset, strlen(reset));
 417        }
 418
 419        if (ep < line + len) {
 420                strbuf_add(&msgbuf, func, strlen(func));
 421                strbuf_add(&msgbuf, ep, line + len - ep);
 422                strbuf_add(&msgbuf, reset, strlen(reset));
 423        }
 424
 425        strbuf_add(&msgbuf, line + len, org_len - len);
 426        emit_line(ecbdata->opt, "", "", msgbuf.buf, msgbuf.len);
 427        strbuf_release(&msgbuf);
 428}
 429
 430static struct diff_tempfile *claim_diff_tempfile(void) {
 431        int i;
 432        for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
 433                if (!diff_temp[i].name)
 434                        return diff_temp + i;
 435        die("BUG: diff is failing to clean up its tempfiles");
 436}
 437
 438static int remove_tempfile_installed;
 439
 440static void remove_tempfile(void)
 441{
 442        int i;
 443        for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
 444                if (diff_temp[i].name == diff_temp[i].tmp_path)
 445                        unlink_or_warn(diff_temp[i].name);
 446                diff_temp[i].name = NULL;
 447        }
 448}
 449
 450static void remove_tempfile_on_signal(int signo)
 451{
 452        remove_tempfile();
 453        sigchain_pop(signo);
 454        raise(signo);
 455}
 456
 457static void print_line_count(FILE *file, int count)
 458{
 459        switch (count) {
 460        case 0:
 461                fprintf(file, "0,0");
 462                break;
 463        case 1:
 464                fprintf(file, "1");
 465                break;
 466        default:
 467                fprintf(file, "1,%d", count);
 468                break;
 469        }
 470}
 471
 472static void emit_rewrite_lines(struct emit_callback *ecb,
 473                               int prefix, const char *data, int size)
 474{
 475        const char *endp = NULL;
 476        static const char *nneof = " No newline at end of file\n";
 477        const char *old = diff_get_color(ecb->color_diff, DIFF_FILE_OLD);
 478        const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
 479
 480        while (0 < size) {
 481                int len;
 482
 483                endp = memchr(data, '\n', size);
 484                len = endp ? (endp - data + 1) : size;
 485                if (prefix != '+') {
 486                        ecb->lno_in_preimage++;
 487                        emit_line_0(ecb->opt, old, reset, '-',
 488                                    data, len);
 489                } else {
 490                        ecb->lno_in_postimage++;
 491                        emit_add_line(reset, ecb, data, len);
 492                }
 493                size -= len;
 494                data += len;
 495        }
 496        if (!endp) {
 497                const char *plain = diff_get_color(ecb->color_diff,
 498                                                   DIFF_PLAIN);
 499                emit_line_0(ecb->opt, plain, reset, '\\',
 500                            nneof, strlen(nneof));
 501        }
 502}
 503
 504static void emit_rewrite_diff(const char *name_a,
 505                              const char *name_b,
 506                              struct diff_filespec *one,
 507                              struct diff_filespec *two,
 508                              struct userdiff_driver *textconv_one,
 509                              struct userdiff_driver *textconv_two,
 510                              struct diff_options *o)
 511{
 512        int lc_a, lc_b;
 513        int color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
 514        const char *name_a_tab, *name_b_tab;
 515        const char *metainfo = diff_get_color(color_diff, DIFF_METAINFO);
 516        const char *fraginfo = diff_get_color(color_diff, DIFF_FRAGINFO);
 517        const char *reset = diff_get_color(color_diff, DIFF_RESET);
 518        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
 519        const char *a_prefix, *b_prefix;
 520        char *data_one, *data_two;
 521        size_t size_one, size_two;
 522        struct emit_callback ecbdata;
 523        char *line_prefix = "";
 524        struct strbuf *msgbuf;
 525
 526        if (o && o->output_prefix) {
 527                msgbuf = o->output_prefix(o, o->output_prefix_data);
 528                line_prefix = msgbuf->buf;
 529        }
 530
 531        if (diff_mnemonic_prefix && DIFF_OPT_TST(o, REVERSE_DIFF)) {
 532                a_prefix = o->b_prefix;
 533                b_prefix = o->a_prefix;
 534        } else {
 535                a_prefix = o->a_prefix;
 536                b_prefix = o->b_prefix;
 537        }
 538
 539        name_a += (*name_a == '/');
 540        name_b += (*name_b == '/');
 541        name_a_tab = strchr(name_a, ' ') ? "\t" : "";
 542        name_b_tab = strchr(name_b, ' ') ? "\t" : "";
 543
 544        strbuf_reset(&a_name);
 545        strbuf_reset(&b_name);
 546        quote_two_c_style(&a_name, a_prefix, name_a, 0);
 547        quote_two_c_style(&b_name, b_prefix, name_b, 0);
 548
 549        size_one = fill_textconv(textconv_one, one, &data_one);
 550        size_two = fill_textconv(textconv_two, two, &data_two);
 551
 552        memset(&ecbdata, 0, sizeof(ecbdata));
 553        ecbdata.color_diff = color_diff;
 554        ecbdata.found_changesp = &o->found_changes;
 555        ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
 556        ecbdata.opt = o;
 557        if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
 558                mmfile_t mf1, mf2;
 559                mf1.ptr = (char *)data_one;
 560                mf2.ptr = (char *)data_two;
 561                mf1.size = size_one;
 562                mf2.size = size_two;
 563                check_blank_at_eof(&mf1, &mf2, &ecbdata);
 564        }
 565        ecbdata.lno_in_preimage = 1;
 566        ecbdata.lno_in_postimage = 1;
 567
 568        lc_a = count_lines(data_one, size_one);
 569        lc_b = count_lines(data_two, size_two);
 570        fprintf(o->file,
 571                "%s%s--- %s%s%s\n%s%s+++ %s%s%s\n%s%s@@ -",
 572                line_prefix, metainfo, a_name.buf, name_a_tab, reset,
 573                line_prefix, metainfo, b_name.buf, name_b_tab, reset,
 574                line_prefix, fraginfo);
 575        print_line_count(o->file, lc_a);
 576        fprintf(o->file, " +");
 577        print_line_count(o->file, lc_b);
 578        fprintf(o->file, " @@%s\n", reset);
 579        if (lc_a)
 580                emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
 581        if (lc_b)
 582                emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
 583        if (textconv_one)
 584                free((char *)data_one);
 585        if (textconv_two)
 586                free((char *)data_two);
 587}
 588
 589struct diff_words_buffer {
 590        mmfile_t text;
 591        long alloc;
 592        struct diff_words_orig {
 593                const char *begin, *end;
 594        } *orig;
 595        int orig_nr, orig_alloc;
 596};
 597
 598static void diff_words_append(char *line, unsigned long len,
 599                struct diff_words_buffer *buffer)
 600{
 601        ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
 602        line++;
 603        len--;
 604        memcpy(buffer->text.ptr + buffer->text.size, line, len);
 605        buffer->text.size += len;
 606        buffer->text.ptr[buffer->text.size] = '\0';
 607}
 608
 609struct diff_words_style_elem
 610{
 611        const char *prefix;
 612        const char *suffix;
 613        const char *color; /* NULL; filled in by the setup code if
 614                            * color is enabled */
 615};
 616
 617struct diff_words_style
 618{
 619        enum diff_words_type type;
 620        struct diff_words_style_elem new, old, ctx;
 621        const char *newline;
 622};
 623
 624struct diff_words_style diff_words_styles[] = {
 625        { DIFF_WORDS_PORCELAIN, {"+", "\n"}, {"-", "\n"}, {" ", "\n"}, "~\n" },
 626        { DIFF_WORDS_PLAIN, {"{+", "+}"}, {"[-", "-]"}, {"", ""}, "\n" },
 627        { DIFF_WORDS_COLOR, {"", ""}, {"", ""}, {"", ""}, "\n" }
 628};
 629
 630struct diff_words_data {
 631        struct diff_words_buffer minus, plus;
 632        const char *current_plus;
 633        int last_minus;
 634        struct diff_options *opt;
 635        regex_t *word_regex;
 636        enum diff_words_type type;
 637        struct diff_words_style *style;
 638};
 639
 640static int fn_out_diff_words_write_helper(FILE *fp,
 641                                          struct diff_words_style_elem *st_el,
 642                                          const char *newline,
 643                                          size_t count, const char *buf,
 644                                          const char *line_prefix)
 645{
 646        int print = 0;
 647
 648        while (count) {
 649                char *p = memchr(buf, '\n', count);
 650                if (print)
 651                        fputs(line_prefix, fp);
 652                if (p != buf) {
 653                        if (st_el->color && fputs(st_el->color, fp) < 0)
 654                                return -1;
 655                        if (fputs(st_el->prefix, fp) < 0 ||
 656                            fwrite(buf, p ? p - buf : count, 1, fp) != 1 ||
 657                            fputs(st_el->suffix, fp) < 0)
 658                                return -1;
 659                        if (st_el->color && *st_el->color
 660                            && fputs(GIT_COLOR_RESET, fp) < 0)
 661                                return -1;
 662                }
 663                if (!p)
 664                        return 0;
 665                if (fputs(newline, fp) < 0)
 666                        return -1;
 667                count -= p + 1 - buf;
 668                buf = p + 1;
 669                print = 1;
 670        }
 671        return 0;
 672}
 673
 674/*
 675 * '--color-words' algorithm can be described as:
 676 *
 677 *   1. collect a the minus/plus lines of a diff hunk, divided into
 678 *      minus-lines and plus-lines;
 679 *
 680 *   2. break both minus-lines and plus-lines into words and
 681 *      place them into two mmfile_t with one word for each line;
 682 *
 683 *   3. use xdiff to run diff on the two mmfile_t to get the words level diff;
 684 *
 685 * And for the common parts of the both file, we output the plus side text.
 686 * diff_words->current_plus is used to trace the current position of the plus file
 687 * which printed. diff_words->last_minus is used to trace the last minus word
 688 * printed.
 689 *
 690 * For '--graph' to work with '--color-words', we need to output the graph prefix
 691 * on each line of color words output. Generally, there are two conditions on
 692 * which we should output the prefix.
 693 *
 694 *   1. diff_words->last_minus == 0 &&
 695 *      diff_words->current_plus == diff_words->plus.text.ptr
 696 *
 697 *      that is: the plus text must start as a new line, and if there is no minus
 698 *      word printed, a graph prefix must be printed.
 699 *
 700 *   2. diff_words->current_plus > diff_words->plus.text.ptr &&
 701 *      *(diff_words->current_plus - 1) == '\n'
 702 *
 703 *      that is: a graph prefix must be printed following a '\n'
 704 */
 705static int color_words_output_graph_prefix(struct diff_words_data *diff_words)
 706{
 707        if ((diff_words->last_minus == 0 &&
 708                diff_words->current_plus == diff_words->plus.text.ptr) ||
 709                (diff_words->current_plus > diff_words->plus.text.ptr &&
 710                *(diff_words->current_plus - 1) == '\n')) {
 711                return 1;
 712        } else {
 713                return 0;
 714        }
 715}
 716
 717static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
 718{
 719        struct diff_words_data *diff_words = priv;
 720        struct diff_words_style *style = diff_words->style;
 721        int minus_first, minus_len, plus_first, plus_len;
 722        const char *minus_begin, *minus_end, *plus_begin, *plus_end;
 723        struct diff_options *opt = diff_words->opt;
 724        struct strbuf *msgbuf;
 725        char *line_prefix = "";
 726
 727        if (line[0] != '@' || parse_hunk_header(line, len,
 728                        &minus_first, &minus_len, &plus_first, &plus_len))
 729                return;
 730
 731        assert(opt);
 732        if (opt->output_prefix) {
 733                msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
 734                line_prefix = msgbuf->buf;
 735        }
 736
 737        /* POSIX requires that first be decremented by one if len == 0... */
 738        if (minus_len) {
 739                minus_begin = diff_words->minus.orig[minus_first].begin;
 740                minus_end =
 741                        diff_words->minus.orig[minus_first + minus_len - 1].end;
 742        } else
 743                minus_begin = minus_end =
 744                        diff_words->minus.orig[minus_first].end;
 745
 746        if (plus_len) {
 747                plus_begin = diff_words->plus.orig[plus_first].begin;
 748                plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
 749        } else
 750                plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
 751
 752        if (color_words_output_graph_prefix(diff_words)) {
 753                fputs(line_prefix, diff_words->opt->file);
 754        }
 755        if (diff_words->current_plus != plus_begin) {
 756                fn_out_diff_words_write_helper(diff_words->opt->file,
 757                                &style->ctx, style->newline,
 758                                plus_begin - diff_words->current_plus,
 759                                diff_words->current_plus, line_prefix);
 760                if (*(plus_begin - 1) == '\n')
 761                        fputs(line_prefix, diff_words->opt->file);
 762        }
 763        if (minus_begin != minus_end) {
 764                fn_out_diff_words_write_helper(diff_words->opt->file,
 765                                &style->old, style->newline,
 766                                minus_end - minus_begin, minus_begin,
 767                                line_prefix);
 768        }
 769        if (plus_begin != plus_end) {
 770                fn_out_diff_words_write_helper(diff_words->opt->file,
 771                                &style->new, style->newline,
 772                                plus_end - plus_begin, plus_begin,
 773                                line_prefix);
 774        }
 775
 776        diff_words->current_plus = plus_end;
 777        diff_words->last_minus = minus_first;
 778}
 779
 780/* This function starts looking at *begin, and returns 0 iff a word was found. */
 781static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
 782                int *begin, int *end)
 783{
 784        if (word_regex && *begin < buffer->size) {
 785                regmatch_t match[1];
 786                if (!regexec(word_regex, buffer->ptr + *begin, 1, match, 0)) {
 787                        char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
 788                                        '\n', match[0].rm_eo - match[0].rm_so);
 789                        *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
 790                        *begin += match[0].rm_so;
 791                        return *begin >= *end;
 792                }
 793                return -1;
 794        }
 795
 796        /* find the next word */
 797        while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
 798                (*begin)++;
 799        if (*begin >= buffer->size)
 800                return -1;
 801
 802        /* find the end of the word */
 803        *end = *begin + 1;
 804        while (*end < buffer->size && !isspace(buffer->ptr[*end]))
 805                (*end)++;
 806
 807        return 0;
 808}
 809
 810/*
 811 * This function splits the words in buffer->text, stores the list with
 812 * newline separator into out, and saves the offsets of the original words
 813 * in buffer->orig.
 814 */
 815static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
 816                regex_t *word_regex)
 817{
 818        int i, j;
 819        long alloc = 0;
 820
 821        out->size = 0;
 822        out->ptr = NULL;
 823
 824        /* fake an empty "0th" word */
 825        ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
 826        buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
 827        buffer->orig_nr = 1;
 828
 829        for (i = 0; i < buffer->text.size; i++) {
 830                if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
 831                        return;
 832
 833                /* store original boundaries */
 834                ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
 835                                buffer->orig_alloc);
 836                buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
 837                buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
 838                buffer->orig_nr++;
 839
 840                /* store one word */
 841                ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
 842                memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
 843                out->ptr[out->size + j - i] = '\n';
 844                out->size += j - i + 1;
 845
 846                i = j - 1;
 847        }
 848}
 849
 850/* this executes the word diff on the accumulated buffers */
 851static void diff_words_show(struct diff_words_data *diff_words)
 852{
 853        xpparam_t xpp;
 854        xdemitconf_t xecfg;
 855        mmfile_t minus, plus;
 856        struct diff_words_style *style = diff_words->style;
 857
 858        struct diff_options *opt = diff_words->opt;
 859        struct strbuf *msgbuf;
 860        char *line_prefix = "";
 861
 862        assert(opt);
 863        if (opt->output_prefix) {
 864                msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
 865                line_prefix = msgbuf->buf;
 866        }
 867
 868        /* special case: only removal */
 869        if (!diff_words->plus.text.size) {
 870                fputs(line_prefix, diff_words->opt->file);
 871                fn_out_diff_words_write_helper(diff_words->opt->file,
 872                        &style->old, style->newline,
 873                        diff_words->minus.text.size,
 874                        diff_words->minus.text.ptr, line_prefix);
 875                diff_words->minus.text.size = 0;
 876                return;
 877        }
 878
 879        diff_words->current_plus = diff_words->plus.text.ptr;
 880        diff_words->last_minus = 0;
 881
 882        memset(&xpp, 0, sizeof(xpp));
 883        memset(&xecfg, 0, sizeof(xecfg));
 884        diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
 885        diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
 886        xpp.flags = 0;
 887        /* as only the hunk header will be parsed, we need a 0-context */
 888        xecfg.ctxlen = 0;
 889        xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
 890                      &xpp, &xecfg);
 891        free(minus.ptr);
 892        free(plus.ptr);
 893        if (diff_words->current_plus != diff_words->plus.text.ptr +
 894                        diff_words->plus.text.size) {
 895                if (color_words_output_graph_prefix(diff_words))
 896                        fputs(line_prefix, diff_words->opt->file);
 897                fn_out_diff_words_write_helper(diff_words->opt->file,
 898                        &style->ctx, style->newline,
 899                        diff_words->plus.text.ptr + diff_words->plus.text.size
 900                        - diff_words->current_plus, diff_words->current_plus,
 901                        line_prefix);
 902        }
 903        diff_words->minus.text.size = diff_words->plus.text.size = 0;
 904}
 905
 906/* In "color-words" mode, show word-diff of words accumulated in the buffer */
 907static void diff_words_flush(struct emit_callback *ecbdata)
 908{
 909        if (ecbdata->diff_words->minus.text.size ||
 910            ecbdata->diff_words->plus.text.size)
 911                diff_words_show(ecbdata->diff_words);
 912}
 913
 914static void free_diff_words_data(struct emit_callback *ecbdata)
 915{
 916        if (ecbdata->diff_words) {
 917                diff_words_flush(ecbdata);
 918                free (ecbdata->diff_words->minus.text.ptr);
 919                free (ecbdata->diff_words->minus.orig);
 920                free (ecbdata->diff_words->plus.text.ptr);
 921                free (ecbdata->diff_words->plus.orig);
 922                if (ecbdata->diff_words->word_regex) {
 923                        regfree(ecbdata->diff_words->word_regex);
 924                        free(ecbdata->diff_words->word_regex);
 925                }
 926                free(ecbdata->diff_words);
 927                ecbdata->diff_words = NULL;
 928        }
 929}
 930
 931const char *diff_get_color(int diff_use_color, enum color_diff ix)
 932{
 933        if (diff_use_color)
 934                return diff_colors[ix];
 935        return "";
 936}
 937
 938static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
 939{
 940        const char *cp;
 941        unsigned long allot;
 942        size_t l = len;
 943
 944        if (ecb->truncate)
 945                return ecb->truncate(line, len);
 946        cp = line;
 947        allot = l;
 948        while (0 < l) {
 949                (void) utf8_width(&cp, &l);
 950                if (!cp)
 951                        break; /* truncated in the middle? */
 952        }
 953        return allot - l;
 954}
 955
 956static void find_lno(const char *line, struct emit_callback *ecbdata)
 957{
 958        const char *p;
 959        ecbdata->lno_in_preimage = 0;
 960        ecbdata->lno_in_postimage = 0;
 961        p = strchr(line, '-');
 962        if (!p)
 963                return; /* cannot happen */
 964        ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
 965        p = strchr(p, '+');
 966        if (!p)
 967                return; /* cannot happen */
 968        ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
 969}
 970
 971static void fn_out_consume(void *priv, char *line, unsigned long len)
 972{
 973        struct emit_callback *ecbdata = priv;
 974        const char *meta = diff_get_color(ecbdata->color_diff, DIFF_METAINFO);
 975        const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
 976        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
 977        struct diff_options *o = ecbdata->opt;
 978        char *line_prefix = "";
 979        struct strbuf *msgbuf;
 980
 981        if (o && o->output_prefix) {
 982                msgbuf = o->output_prefix(o, o->output_prefix_data);
 983                line_prefix = msgbuf->buf;
 984        }
 985
 986        if (ecbdata->header) {
 987                fprintf(ecbdata->opt->file, "%s", ecbdata->header->buf);
 988                strbuf_reset(ecbdata->header);
 989                ecbdata->header = NULL;
 990        }
 991        *(ecbdata->found_changesp) = 1;
 992
 993        if (ecbdata->label_path[0]) {
 994                const char *name_a_tab, *name_b_tab;
 995
 996                name_a_tab = strchr(ecbdata->label_path[0], ' ') ? "\t" : "";
 997                name_b_tab = strchr(ecbdata->label_path[1], ' ') ? "\t" : "";
 998
 999                fprintf(ecbdata->opt->file, "%s%s--- %s%s%s\n",
1000                        line_prefix, meta, ecbdata->label_path[0], reset, name_a_tab);
1001                fprintf(ecbdata->opt->file, "%s%s+++ %s%s%s\n",
1002                        line_prefix, meta, ecbdata->label_path[1], reset, name_b_tab);
1003                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
1004        }
1005
1006        if (diff_suppress_blank_empty
1007            && len == 2 && line[0] == ' ' && line[1] == '\n') {
1008                line[0] = '\n';
1009                len = 1;
1010        }
1011
1012        if (line[0] == '@') {
1013                if (ecbdata->diff_words)
1014                        diff_words_flush(ecbdata);
1015                len = sane_truncate_line(ecbdata, line, len);
1016                find_lno(line, ecbdata);
1017                emit_hunk_header(ecbdata, line, len);
1018                if (line[len-1] != '\n')
1019                        putc('\n', ecbdata->opt->file);
1020                return;
1021        }
1022
1023        if (len < 1) {
1024                emit_line(ecbdata->opt, reset, reset, line, len);
1025                if (ecbdata->diff_words
1026                    && ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN)
1027                        fputs("~\n", ecbdata->opt->file);
1028                return;
1029        }
1030
1031        if (ecbdata->diff_words) {
1032                if (line[0] == '-') {
1033                        diff_words_append(line, len,
1034                                          &ecbdata->diff_words->minus);
1035                        return;
1036                } else if (line[0] == '+') {
1037                        diff_words_append(line, len,
1038                                          &ecbdata->diff_words->plus);
1039                        return;
1040                }
1041                diff_words_flush(ecbdata);
1042                if (ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN) {
1043                        emit_line(ecbdata->opt, plain, reset, line, len);
1044                        fputs("~\n", ecbdata->opt->file);
1045                } else {
1046                        /* don't print the prefix character */
1047                        emit_line(ecbdata->opt, plain, reset, line+1, len-1);
1048                }
1049                return;
1050        }
1051
1052        if (line[0] != '+') {
1053                const char *color =
1054                        diff_get_color(ecbdata->color_diff,
1055                                       line[0] == '-' ? DIFF_FILE_OLD : DIFF_PLAIN);
1056                ecbdata->lno_in_preimage++;
1057                if (line[0] == ' ')
1058                        ecbdata->lno_in_postimage++;
1059                emit_line(ecbdata->opt, color, reset, line, len);
1060        } else {
1061                ecbdata->lno_in_postimage++;
1062                emit_add_line(reset, ecbdata, line + 1, len - 1);
1063        }
1064}
1065
1066static char *pprint_rename(const char *a, const char *b)
1067{
1068        const char *old = a;
1069        const char *new = b;
1070        struct strbuf name = STRBUF_INIT;
1071        int pfx_length, sfx_length;
1072        int len_a = strlen(a);
1073        int len_b = strlen(b);
1074        int a_midlen, b_midlen;
1075        int qlen_a = quote_c_style(a, NULL, NULL, 0);
1076        int qlen_b = quote_c_style(b, NULL, NULL, 0);
1077
1078        if (qlen_a || qlen_b) {
1079                quote_c_style(a, &name, NULL, 0);
1080                strbuf_addstr(&name, " => ");
1081                quote_c_style(b, &name, NULL, 0);
1082                return strbuf_detach(&name, NULL);
1083        }
1084
1085        /* Find common prefix */
1086        pfx_length = 0;
1087        while (*old && *new && *old == *new) {
1088                if (*old == '/')
1089                        pfx_length = old - a + 1;
1090                old++;
1091                new++;
1092        }
1093
1094        /* Find common suffix */
1095        old = a + len_a;
1096        new = b + len_b;
1097        sfx_length = 0;
1098        while (a <= old && b <= new && *old == *new) {
1099                if (*old == '/')
1100                        sfx_length = len_a - (old - a);
1101                old--;
1102                new--;
1103        }
1104
1105        /*
1106         * pfx{mid-a => mid-b}sfx
1107         * {pfx-a => pfx-b}sfx
1108         * pfx{sfx-a => sfx-b}
1109         * name-a => name-b
1110         */
1111        a_midlen = len_a - pfx_length - sfx_length;
1112        b_midlen = len_b - pfx_length - sfx_length;
1113        if (a_midlen < 0)
1114                a_midlen = 0;
1115        if (b_midlen < 0)
1116                b_midlen = 0;
1117
1118        strbuf_grow(&name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
1119        if (pfx_length + sfx_length) {
1120                strbuf_add(&name, a, pfx_length);
1121                strbuf_addch(&name, '{');
1122        }
1123        strbuf_add(&name, a + pfx_length, a_midlen);
1124        strbuf_addstr(&name, " => ");
1125        strbuf_add(&name, b + pfx_length, b_midlen);
1126        if (pfx_length + sfx_length) {
1127                strbuf_addch(&name, '}');
1128                strbuf_add(&name, a + len_a - sfx_length, sfx_length);
1129        }
1130        return strbuf_detach(&name, NULL);
1131}
1132
1133struct diffstat_t {
1134        int nr;
1135        int alloc;
1136        struct diffstat_file {
1137                char *from_name;
1138                char *name;
1139                char *print_name;
1140                unsigned is_unmerged:1;
1141                unsigned is_binary:1;
1142                unsigned is_renamed:1;
1143                uintmax_t added, deleted;
1144        } **files;
1145};
1146
1147static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
1148                                          const char *name_a,
1149                                          const char *name_b)
1150{
1151        struct diffstat_file *x;
1152        x = xcalloc(sizeof (*x), 1);
1153        if (diffstat->nr == diffstat->alloc) {
1154                diffstat->alloc = alloc_nr(diffstat->alloc);
1155                diffstat->files = xrealloc(diffstat->files,
1156                                diffstat->alloc * sizeof(x));
1157        }
1158        diffstat->files[diffstat->nr++] = x;
1159        if (name_b) {
1160                x->from_name = xstrdup(name_a);
1161                x->name = xstrdup(name_b);
1162                x->is_renamed = 1;
1163        }
1164        else {
1165                x->from_name = NULL;
1166                x->name = xstrdup(name_a);
1167        }
1168        return x;
1169}
1170
1171static void diffstat_consume(void *priv, char *line, unsigned long len)
1172{
1173        struct diffstat_t *diffstat = priv;
1174        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
1175
1176        if (line[0] == '+')
1177                x->added++;
1178        else if (line[0] == '-')
1179                x->deleted++;
1180}
1181
1182const char mime_boundary_leader[] = "------------";
1183
1184static int scale_linear(int it, int width, int max_change)
1185{
1186        /*
1187         * make sure that at least one '-' is printed if there were deletions,
1188         * and likewise for '+'.
1189         */
1190        if (max_change < 2)
1191                return it;
1192        return ((it - 1) * (width - 1) + max_change - 1) / (max_change - 1);
1193}
1194
1195static void show_name(FILE *file,
1196                      const char *prefix, const char *name, int len)
1197{
1198        fprintf(file, " %s%-*s |", prefix, len, name);
1199}
1200
1201static void show_graph(FILE *file, char ch, int cnt, const char *set, const char *reset)
1202{
1203        if (cnt <= 0)
1204                return;
1205        fprintf(file, "%s", set);
1206        while (cnt--)
1207                putc(ch, file);
1208        fprintf(file, "%s", reset);
1209}
1210
1211static void fill_print_name(struct diffstat_file *file)
1212{
1213        char *pname;
1214
1215        if (file->print_name)
1216                return;
1217
1218        if (!file->is_renamed) {
1219                struct strbuf buf = STRBUF_INIT;
1220                if (quote_c_style(file->name, &buf, NULL, 0)) {
1221                        pname = strbuf_detach(&buf, NULL);
1222                } else {
1223                        pname = file->name;
1224                        strbuf_release(&buf);
1225                }
1226        } else {
1227                pname = pprint_rename(file->from_name, file->name);
1228        }
1229        file->print_name = pname;
1230}
1231
1232static void show_stats(struct diffstat_t *data, struct diff_options *options)
1233{
1234        int i, len, add, del, adds = 0, dels = 0;
1235        uintmax_t max_change = 0, max_len = 0;
1236        int total_files = data->nr;
1237        int width, name_width;
1238        const char *reset, *set, *add_c, *del_c;
1239        const char *line_prefix = "";
1240        struct strbuf *msg = NULL;
1241
1242        if (data->nr == 0)
1243                return;
1244
1245        if (options->output_prefix) {
1246                msg = options->output_prefix(options, options->output_prefix_data);
1247                line_prefix = msg->buf;
1248        }
1249
1250        width = options->stat_width ? options->stat_width : 80;
1251        name_width = options->stat_name_width ? options->stat_name_width : 50;
1252
1253        /* Sanity: give at least 5 columns to the graph,
1254         * but leave at least 10 columns for the name.
1255         */
1256        if (width < 25)
1257                width = 25;
1258        if (name_width < 10)
1259                name_width = 10;
1260        else if (width < name_width + 15)
1261                name_width = width - 15;
1262
1263        /* Find the longest filename and max number of changes */
1264        reset = diff_get_color_opt(options, DIFF_RESET);
1265        set   = diff_get_color_opt(options, DIFF_PLAIN);
1266        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
1267        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
1268
1269        for (i = 0; i < data->nr; i++) {
1270                struct diffstat_file *file = data->files[i];
1271                uintmax_t change = file->added + file->deleted;
1272                fill_print_name(file);
1273                len = strlen(file->print_name);
1274                if (max_len < len)
1275                        max_len = len;
1276
1277                if (file->is_binary || file->is_unmerged)
1278                        continue;
1279                if (max_change < change)
1280                        max_change = change;
1281        }
1282
1283        /* Compute the width of the graph part;
1284         * 10 is for one blank at the beginning of the line plus
1285         * " | count " between the name and the graph.
1286         *
1287         * From here on, name_width is the width of the name area,
1288         * and width is the width of the graph area.
1289         */
1290        name_width = (name_width < max_len) ? name_width : max_len;
1291        if (width < (name_width + 10) + max_change)
1292                width = width - (name_width + 10);
1293        else
1294                width = max_change;
1295
1296        for (i = 0; i < data->nr; i++) {
1297                const char *prefix = "";
1298                char *name = data->files[i]->print_name;
1299                uintmax_t added = data->files[i]->added;
1300                uintmax_t deleted = data->files[i]->deleted;
1301                int name_len;
1302
1303                /*
1304                 * "scale" the filename
1305                 */
1306                len = name_width;
1307                name_len = strlen(name);
1308                if (name_width < name_len) {
1309                        char *slash;
1310                        prefix = "...";
1311                        len -= 3;
1312                        name += name_len - len;
1313                        slash = strchr(name, '/');
1314                        if (slash)
1315                                name = slash;
1316                }
1317
1318                if (data->files[i]->is_binary) {
1319                        fprintf(options->file, "%s", line_prefix);
1320                        show_name(options->file, prefix, name, len);
1321                        fprintf(options->file, "  Bin ");
1322                        fprintf(options->file, "%s%"PRIuMAX"%s",
1323                                del_c, deleted, reset);
1324                        fprintf(options->file, " -> ");
1325                        fprintf(options->file, "%s%"PRIuMAX"%s",
1326                                add_c, added, reset);
1327                        fprintf(options->file, " bytes");
1328                        fprintf(options->file, "\n");
1329                        continue;
1330                }
1331                else if (data->files[i]->is_unmerged) {
1332                        fprintf(options->file, "%s", line_prefix);
1333                        show_name(options->file, prefix, name, len);
1334                        fprintf(options->file, "  Unmerged\n");
1335                        continue;
1336                }
1337                else if (!data->files[i]->is_renamed &&
1338                         (added + deleted == 0)) {
1339                        total_files--;
1340                        continue;
1341                }
1342
1343                /*
1344                 * scale the add/delete
1345                 */
1346                add = added;
1347                del = deleted;
1348                adds += add;
1349                dels += del;
1350
1351                if (width <= max_change) {
1352                        add = scale_linear(add, width, max_change);
1353                        del = scale_linear(del, width, max_change);
1354                }
1355                fprintf(options->file, "%s", line_prefix);
1356                show_name(options->file, prefix, name, len);
1357                fprintf(options->file, "%5"PRIuMAX"%s", added + deleted,
1358                                added + deleted ? " " : "");
1359                show_graph(options->file, '+', add, add_c, reset);
1360                show_graph(options->file, '-', del, del_c, reset);
1361                fprintf(options->file, "\n");
1362        }
1363        fprintf(options->file, "%s", line_prefix);
1364        fprintf(options->file,
1365               " %d files changed, %d insertions(+), %d deletions(-)\n",
1366               total_files, adds, dels);
1367}
1368
1369static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
1370{
1371        int i, adds = 0, dels = 0, total_files = data->nr;
1372
1373        if (data->nr == 0)
1374                return;
1375
1376        for (i = 0; i < data->nr; i++) {
1377                if (!data->files[i]->is_binary &&
1378                    !data->files[i]->is_unmerged) {
1379                        int added = data->files[i]->added;
1380                        int deleted= data->files[i]->deleted;
1381                        if (!data->files[i]->is_renamed &&
1382                            (added + deleted == 0)) {
1383                                total_files--;
1384                        } else {
1385                                adds += added;
1386                                dels += deleted;
1387                        }
1388                }
1389        }
1390        if (options->output_prefix) {
1391                struct strbuf *msg = NULL;
1392                msg = options->output_prefix(options,
1393                                options->output_prefix_data);
1394                fprintf(options->file, "%s", msg->buf);
1395        }
1396        fprintf(options->file, " %d files changed, %d insertions(+), %d deletions(-)\n",
1397               total_files, adds, dels);
1398}
1399
1400static void show_numstat(struct diffstat_t *data, struct diff_options *options)
1401{
1402        int i;
1403
1404        if (data->nr == 0)
1405                return;
1406
1407        for (i = 0; i < data->nr; i++) {
1408                struct diffstat_file *file = data->files[i];
1409
1410                if (options->output_prefix) {
1411                        struct strbuf *msg = NULL;
1412                        msg = options->output_prefix(options,
1413                                        options->output_prefix_data);
1414                        fprintf(options->file, "%s", msg->buf);
1415                }
1416
1417                if (file->is_binary)
1418                        fprintf(options->file, "-\t-\t");
1419                else
1420                        fprintf(options->file,
1421                                "%"PRIuMAX"\t%"PRIuMAX"\t",
1422                                file->added, file->deleted);
1423                if (options->line_termination) {
1424                        fill_print_name(file);
1425                        if (!file->is_renamed)
1426                                write_name_quoted(file->name, options->file,
1427                                                  options->line_termination);
1428                        else {
1429                                fputs(file->print_name, options->file);
1430                                putc(options->line_termination, options->file);
1431                        }
1432                } else {
1433                        if (file->is_renamed) {
1434                                putc('\0', options->file);
1435                                write_name_quoted(file->from_name, options->file, '\0');
1436                        }
1437                        write_name_quoted(file->name, options->file, '\0');
1438                }
1439        }
1440}
1441
1442struct dirstat_file {
1443        const char *name;
1444        unsigned long changed;
1445};
1446
1447struct dirstat_dir {
1448        struct dirstat_file *files;
1449        int alloc, nr, percent, cumulative;
1450};
1451
1452static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
1453                unsigned long changed, const char *base, int baselen)
1454{
1455        unsigned long this_dir = 0;
1456        unsigned int sources = 0;
1457        const char *line_prefix = "";
1458        struct strbuf *msg = NULL;
1459
1460        if (opt->output_prefix) {
1461                msg = opt->output_prefix(opt, opt->output_prefix_data);
1462                line_prefix = msg->buf;
1463        }
1464
1465        while (dir->nr) {
1466                struct dirstat_file *f = dir->files;
1467                int namelen = strlen(f->name);
1468                unsigned long this;
1469                char *slash;
1470
1471                if (namelen < baselen)
1472                        break;
1473                if (memcmp(f->name, base, baselen))
1474                        break;
1475                slash = strchr(f->name + baselen, '/');
1476                if (slash) {
1477                        int newbaselen = slash + 1 - f->name;
1478                        this = gather_dirstat(opt, dir, changed, f->name, newbaselen);
1479                        sources++;
1480                } else {
1481                        this = f->changed;
1482                        dir->files++;
1483                        dir->nr--;
1484                        sources += 2;
1485                }
1486                this_dir += this;
1487        }
1488
1489        /*
1490         * We don't report dirstat's for
1491         *  - the top level
1492         *  - or cases where everything came from a single directory
1493         *    under this directory (sources == 1).
1494         */
1495        if (baselen && sources != 1) {
1496                int permille = this_dir * 1000 / changed;
1497                if (permille) {
1498                        int percent = permille / 10;
1499                        if (percent >= dir->percent) {
1500                                fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
1501                                        percent, permille % 10, baselen, base);
1502                                if (!dir->cumulative)
1503                                        return 0;
1504                        }
1505                }
1506        }
1507        return this_dir;
1508}
1509
1510static int dirstat_compare(const void *_a, const void *_b)
1511{
1512        const struct dirstat_file *a = _a;
1513        const struct dirstat_file *b = _b;
1514        return strcmp(a->name, b->name);
1515}
1516
1517static void show_dirstat(struct diff_options *options)
1518{
1519        int i;
1520        unsigned long changed;
1521        struct dirstat_dir dir;
1522        struct diff_queue_struct *q = &diff_queued_diff;
1523
1524        dir.files = NULL;
1525        dir.alloc = 0;
1526        dir.nr = 0;
1527        dir.percent = options->dirstat_percent;
1528        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1529
1530        changed = 0;
1531        for (i = 0; i < q->nr; i++) {
1532                struct diff_filepair *p = q->queue[i];
1533                const char *name;
1534                unsigned long copied, added, damage;
1535
1536                name = p->one->path ? p->one->path : p->two->path;
1537
1538                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
1539                        diff_populate_filespec(p->one, 0);
1540                        diff_populate_filespec(p->two, 0);
1541                        diffcore_count_changes(p->one, p->two, NULL, NULL, 0,
1542                                               &copied, &added);
1543                        diff_free_filespec_data(p->one);
1544                        diff_free_filespec_data(p->two);
1545                } else if (DIFF_FILE_VALID(p->one)) {
1546                        diff_populate_filespec(p->one, 1);
1547                        copied = added = 0;
1548                        diff_free_filespec_data(p->one);
1549                } else if (DIFF_FILE_VALID(p->two)) {
1550                        diff_populate_filespec(p->two, 1);
1551                        copied = 0;
1552                        added = p->two->size;
1553                        diff_free_filespec_data(p->two);
1554                } else
1555                        continue;
1556
1557                /*
1558                 * Original minus copied is the removed material,
1559                 * added is the new material.  They are both damages
1560                 * made to the preimage. In --dirstat-by-file mode, count
1561                 * damaged files, not damaged lines. This is done by
1562                 * counting only a single damaged line per file.
1563                 */
1564                damage = (p->one->size - copied) + added;
1565                if (DIFF_OPT_TST(options, DIRSTAT_BY_FILE) && damage > 0)
1566                        damage = 1;
1567
1568                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1569                dir.files[dir.nr].name = name;
1570                dir.files[dir.nr].changed = damage;
1571                changed += damage;
1572                dir.nr++;
1573        }
1574
1575        /* This can happen even with many files, if everything was renames */
1576        if (!changed)
1577                return;
1578
1579        /* Show all directories with more than x% of the changes */
1580        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1581        gather_dirstat(options, &dir, changed, "", 0);
1582}
1583
1584static void free_diffstat_info(struct diffstat_t *diffstat)
1585{
1586        int i;
1587        for (i = 0; i < diffstat->nr; i++) {
1588                struct diffstat_file *f = diffstat->files[i];
1589                if (f->name != f->print_name)
1590                        free(f->print_name);
1591                free(f->name);
1592                free(f->from_name);
1593                free(f);
1594        }
1595        free(diffstat->files);
1596}
1597
1598struct checkdiff_t {
1599        const char *filename;
1600        int lineno;
1601        int conflict_marker_size;
1602        struct diff_options *o;
1603        unsigned ws_rule;
1604        unsigned status;
1605};
1606
1607static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
1608{
1609        char firstchar;
1610        int cnt;
1611
1612        if (len < marker_size + 1)
1613                return 0;
1614        firstchar = line[0];
1615        switch (firstchar) {
1616        case '=': case '>': case '<': case '|':
1617                break;
1618        default:
1619                return 0;
1620        }
1621        for (cnt = 1; cnt < marker_size; cnt++)
1622                if (line[cnt] != firstchar)
1623                        return 0;
1624        /* line[1] thru line[marker_size-1] are same as firstchar */
1625        if (len < marker_size + 1 || !isspace(line[marker_size]))
1626                return 0;
1627        return 1;
1628}
1629
1630static void checkdiff_consume(void *priv, char *line, unsigned long len)
1631{
1632        struct checkdiff_t *data = priv;
1633        int color_diff = DIFF_OPT_TST(data->o, COLOR_DIFF);
1634        int marker_size = data->conflict_marker_size;
1635        const char *ws = diff_get_color(color_diff, DIFF_WHITESPACE);
1636        const char *reset = diff_get_color(color_diff, DIFF_RESET);
1637        const char *set = diff_get_color(color_diff, DIFF_FILE_NEW);
1638        char *err;
1639        char *line_prefix = "";
1640        struct strbuf *msgbuf;
1641
1642        assert(data->o);
1643        if (data->o->output_prefix) {
1644                msgbuf = data->o->output_prefix(data->o,
1645                        data->o->output_prefix_data);
1646                line_prefix = msgbuf->buf;
1647        }
1648
1649        if (line[0] == '+') {
1650                unsigned bad;
1651                data->lineno++;
1652                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
1653                        data->status |= 1;
1654                        fprintf(data->o->file,
1655                                "%s%s:%d: leftover conflict marker\n",
1656                                line_prefix, data->filename, data->lineno);
1657                }
1658                bad = ws_check(line + 1, len - 1, data->ws_rule);
1659                if (!bad)
1660                        return;
1661                data->status |= bad;
1662                err = whitespace_error_string(bad);
1663                fprintf(data->o->file, "%s%s:%d: %s.\n",
1664                        line_prefix, data->filename, data->lineno, err);
1665                free(err);
1666                emit_line(data->o, set, reset, line, 1);
1667                ws_check_emit(line + 1, len - 1, data->ws_rule,
1668                              data->o->file, set, reset, ws);
1669        } else if (line[0] == ' ') {
1670                data->lineno++;
1671        } else if (line[0] == '@') {
1672                char *plus = strchr(line, '+');
1673                if (plus)
1674                        data->lineno = strtol(plus, NULL, 10) - 1;
1675                else
1676                        die("invalid diff");
1677        }
1678}
1679
1680static unsigned char *deflate_it(char *data,
1681                                 unsigned long size,
1682                                 unsigned long *result_size)
1683{
1684        int bound;
1685        unsigned char *deflated;
1686        z_stream stream;
1687
1688        memset(&stream, 0, sizeof(stream));
1689        deflateInit(&stream, zlib_compression_level);
1690        bound = deflateBound(&stream, size);
1691        deflated = xmalloc(bound);
1692        stream.next_out = deflated;
1693        stream.avail_out = bound;
1694
1695        stream.next_in = (unsigned char *)data;
1696        stream.avail_in = size;
1697        while (deflate(&stream, Z_FINISH) == Z_OK)
1698                ; /* nothing */
1699        deflateEnd(&stream);
1700        *result_size = stream.total_out;
1701        return deflated;
1702}
1703
1704static void emit_binary_diff_body(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
1705{
1706        void *cp;
1707        void *delta;
1708        void *deflated;
1709        void *data;
1710        unsigned long orig_size;
1711        unsigned long delta_size;
1712        unsigned long deflate_size;
1713        unsigned long data_size;
1714
1715        /* We could do deflated delta, or we could do just deflated two,
1716         * whichever is smaller.
1717         */
1718        delta = NULL;
1719        deflated = deflate_it(two->ptr, two->size, &deflate_size);
1720        if (one->size && two->size) {
1721                delta = diff_delta(one->ptr, one->size,
1722                                   two->ptr, two->size,
1723                                   &delta_size, deflate_size);
1724                if (delta) {
1725                        void *to_free = delta;
1726                        orig_size = delta_size;
1727                        delta = deflate_it(delta, delta_size, &delta_size);
1728                        free(to_free);
1729                }
1730        }
1731
1732        if (delta && delta_size < deflate_size) {
1733                fprintf(file, "%sdelta %lu\n", prefix, orig_size);
1734                free(deflated);
1735                data = delta;
1736                data_size = delta_size;
1737        }
1738        else {
1739                fprintf(file, "%sliteral %lu\n", prefix, two->size);
1740                free(delta);
1741                data = deflated;
1742                data_size = deflate_size;
1743        }
1744
1745        /* emit data encoded in base85 */
1746        cp = data;
1747        while (data_size) {
1748                int bytes = (52 < data_size) ? 52 : data_size;
1749                char line[70];
1750                data_size -= bytes;
1751                if (bytes <= 26)
1752                        line[0] = bytes + 'A' - 1;
1753                else
1754                        line[0] = bytes - 26 + 'a' - 1;
1755                encode_85(line + 1, cp, bytes);
1756                cp = (char *) cp + bytes;
1757                fprintf(file, "%s", prefix);
1758                fputs(line, file);
1759                fputc('\n', file);
1760        }
1761        fprintf(file, "%s\n", prefix);
1762        free(data);
1763}
1764
1765static void emit_binary_diff(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
1766{
1767        fprintf(file, "%sGIT binary patch\n", prefix);
1768        emit_binary_diff_body(file, one, two, prefix);
1769        emit_binary_diff_body(file, two, one, prefix);
1770}
1771
1772static void diff_filespec_load_driver(struct diff_filespec *one)
1773{
1774        if (!one->driver)
1775                one->driver = userdiff_find_by_path(one->path);
1776        if (!one->driver)
1777                one->driver = userdiff_find_by_name("default");
1778}
1779
1780int diff_filespec_is_binary(struct diff_filespec *one)
1781{
1782        if (one->is_binary == -1) {
1783                diff_filespec_load_driver(one);
1784                if (one->driver->binary != -1)
1785                        one->is_binary = one->driver->binary;
1786                else {
1787                        if (!one->data && DIFF_FILE_VALID(one))
1788                                diff_populate_filespec(one, 0);
1789                        if (one->data)
1790                                one->is_binary = buffer_is_binary(one->data,
1791                                                one->size);
1792                        if (one->is_binary == -1)
1793                                one->is_binary = 0;
1794                }
1795        }
1796        return one->is_binary;
1797}
1798
1799static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
1800{
1801        diff_filespec_load_driver(one);
1802        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
1803}
1804
1805static const char *userdiff_word_regex(struct diff_filespec *one)
1806{
1807        diff_filespec_load_driver(one);
1808        return one->driver->word_regex;
1809}
1810
1811void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
1812{
1813        if (!options->a_prefix)
1814                options->a_prefix = a;
1815        if (!options->b_prefix)
1816                options->b_prefix = b;
1817}
1818
1819struct userdiff_driver *get_textconv(struct diff_filespec *one)
1820{
1821        if (!DIFF_FILE_VALID(one))
1822                return NULL;
1823        if (!S_ISREG(one->mode))
1824                return NULL;
1825        diff_filespec_load_driver(one);
1826        if (!one->driver->textconv)
1827                return NULL;
1828
1829        if (one->driver->textconv_want_cache && !one->driver->textconv_cache) {
1830                struct notes_cache *c = xmalloc(sizeof(*c));
1831                struct strbuf name = STRBUF_INIT;
1832
1833                strbuf_addf(&name, "textconv/%s", one->driver->name);
1834                notes_cache_init(c, name.buf, one->driver->textconv);
1835                one->driver->textconv_cache = c;
1836        }
1837
1838        return one->driver;
1839}
1840
1841static void builtin_diff(const char *name_a,
1842                         const char *name_b,
1843                         struct diff_filespec *one,
1844                         struct diff_filespec *two,
1845                         const char *xfrm_msg,
1846                         int must_show_header,
1847                         struct diff_options *o,
1848                         int complete_rewrite)
1849{
1850        mmfile_t mf1, mf2;
1851        const char *lbl[2];
1852        char *a_one, *b_two;
1853        const char *set = diff_get_color_opt(o, DIFF_METAINFO);
1854        const char *reset = diff_get_color_opt(o, DIFF_RESET);
1855        const char *a_prefix, *b_prefix;
1856        struct userdiff_driver *textconv_one = NULL;
1857        struct userdiff_driver *textconv_two = NULL;
1858        struct strbuf header = STRBUF_INIT;
1859        struct strbuf *msgbuf;
1860        char *line_prefix = "";
1861
1862        if (o->output_prefix) {
1863                msgbuf = o->output_prefix(o, o->output_prefix_data);
1864                line_prefix = msgbuf->buf;
1865        }
1866
1867        if (DIFF_OPT_TST(o, SUBMODULE_LOG) &&
1868                        (!one->mode || S_ISGITLINK(one->mode)) &&
1869                        (!two->mode || S_ISGITLINK(two->mode))) {
1870                const char *del = diff_get_color_opt(o, DIFF_FILE_OLD);
1871                const char *add = diff_get_color_opt(o, DIFF_FILE_NEW);
1872                show_submodule_summary(o->file, one ? one->path : two->path,
1873                                one->sha1, two->sha1, two->dirty_submodule,
1874                                del, add, reset);
1875                return;
1876        }
1877
1878        if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
1879                textconv_one = get_textconv(one);
1880                textconv_two = get_textconv(two);
1881        }
1882
1883        diff_set_mnemonic_prefix(o, "a/", "b/");
1884        if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
1885                a_prefix = o->b_prefix;
1886                b_prefix = o->a_prefix;
1887        } else {
1888                a_prefix = o->a_prefix;
1889                b_prefix = o->b_prefix;
1890        }
1891
1892        /* Never use a non-valid filename anywhere if at all possible */
1893        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
1894        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
1895
1896        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
1897        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
1898        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
1899        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
1900        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, set, a_one, b_two, reset);
1901        if (lbl[0][0] == '/') {
1902                /* /dev/null */
1903                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, set, two->mode, reset);
1904                if (xfrm_msg)
1905                        strbuf_addstr(&header, xfrm_msg);
1906                must_show_header = 1;
1907        }
1908        else if (lbl[1][0] == '/') {
1909                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, set, one->mode, reset);
1910                if (xfrm_msg)
1911                        strbuf_addstr(&header, xfrm_msg);
1912                must_show_header = 1;
1913        }
1914        else {
1915                if (one->mode != two->mode) {
1916                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, set, one->mode, reset);
1917                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, set, two->mode, reset);
1918                        must_show_header = 1;
1919                }
1920                if (xfrm_msg)
1921                        strbuf_addstr(&header, xfrm_msg);
1922
1923                /*
1924                 * we do not run diff between different kind
1925                 * of objects.
1926                 */
1927                if ((one->mode ^ two->mode) & S_IFMT)
1928                        goto free_ab_and_return;
1929                if (complete_rewrite &&
1930                    (textconv_one || !diff_filespec_is_binary(one)) &&
1931                    (textconv_two || !diff_filespec_is_binary(two))) {
1932                        fprintf(o->file, "%s", header.buf);
1933                        strbuf_reset(&header);
1934                        emit_rewrite_diff(name_a, name_b, one, two,
1935                                                textconv_one, textconv_two, o);
1936                        o->found_changes = 1;
1937                        goto free_ab_and_return;
1938                }
1939        }
1940
1941        if (!DIFF_OPT_TST(o, TEXT) &&
1942            ( (!textconv_one && diff_filespec_is_binary(one)) ||
1943              (!textconv_two && diff_filespec_is_binary(two)) )) {
1944                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1945                        die("unable to read files to diff");
1946                /* Quite common confusing case */
1947                if (mf1.size == mf2.size &&
1948                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
1949                        if (must_show_header)
1950                                fprintf(o->file, "%s", header.buf);
1951                        goto free_ab_and_return;
1952                }
1953                fprintf(o->file, "%s", header.buf);
1954                strbuf_reset(&header);
1955                if (DIFF_OPT_TST(o, BINARY))
1956                        emit_binary_diff(o->file, &mf1, &mf2, line_prefix);
1957                else
1958                        fprintf(o->file, "%sBinary files %s and %s differ\n",
1959                                line_prefix, lbl[0], lbl[1]);
1960                o->found_changes = 1;
1961        }
1962        else {
1963                /* Crazy xdl interfaces.. */
1964                const char *diffopts = getenv("GIT_DIFF_OPTS");
1965                xpparam_t xpp;
1966                xdemitconf_t xecfg;
1967                struct emit_callback ecbdata;
1968                const struct userdiff_funcname *pe;
1969
1970                if (!DIFF_XDL_TST(o, WHITESPACE_FLAGS) || must_show_header) {
1971                        fprintf(o->file, "%s", header.buf);
1972                        strbuf_reset(&header);
1973                }
1974
1975                mf1.size = fill_textconv(textconv_one, one, &mf1.ptr);
1976                mf2.size = fill_textconv(textconv_two, two, &mf2.ptr);
1977
1978                pe = diff_funcname_pattern(one);
1979                if (!pe)
1980                        pe = diff_funcname_pattern(two);
1981
1982                memset(&xpp, 0, sizeof(xpp));
1983                memset(&xecfg, 0, sizeof(xecfg));
1984                memset(&ecbdata, 0, sizeof(ecbdata));
1985                ecbdata.label_path = lbl;
1986                ecbdata.color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
1987                ecbdata.found_changesp = &o->found_changes;
1988                ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
1989                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
1990                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
1991                ecbdata.opt = o;
1992                ecbdata.header = header.len ? &header : NULL;
1993                xpp.flags = o->xdl_opts;
1994                xecfg.ctxlen = o->context;
1995                xecfg.interhunkctxlen = o->interhunkcontext;
1996                xecfg.flags = XDL_EMIT_FUNCNAMES;
1997                if (pe)
1998                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
1999                if (!diffopts)
2000                        ;
2001                else if (!prefixcmp(diffopts, "--unified="))
2002                        xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
2003                else if (!prefixcmp(diffopts, "-u"))
2004                        xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
2005                if (o->word_diff) {
2006                        int i;
2007
2008                        ecbdata.diff_words =
2009                                xcalloc(1, sizeof(struct diff_words_data));
2010                        ecbdata.diff_words->type = o->word_diff;
2011                        ecbdata.diff_words->opt = o;
2012                        if (!o->word_regex)
2013                                o->word_regex = userdiff_word_regex(one);
2014                        if (!o->word_regex)
2015                                o->word_regex = userdiff_word_regex(two);
2016                        if (!o->word_regex)
2017                                o->word_regex = diff_word_regex_cfg;
2018                        if (o->word_regex) {
2019                                ecbdata.diff_words->word_regex = (regex_t *)
2020                                        xmalloc(sizeof(regex_t));
2021                                if (regcomp(ecbdata.diff_words->word_regex,
2022                                                o->word_regex,
2023                                                REG_EXTENDED | REG_NEWLINE))
2024                                        die ("Invalid regular expression: %s",
2025                                                        o->word_regex);
2026                        }
2027                        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
2028                                if (o->word_diff == diff_words_styles[i].type) {
2029                                        ecbdata.diff_words->style =
2030                                                &diff_words_styles[i];
2031                                        break;
2032                                }
2033                        }
2034                        if (DIFF_OPT_TST(o, COLOR_DIFF)) {
2035                                struct diff_words_style *st = ecbdata.diff_words->style;
2036                                st->old.color = diff_get_color_opt(o, DIFF_FILE_OLD);
2037                                st->new.color = diff_get_color_opt(o, DIFF_FILE_NEW);
2038                                st->ctx.color = diff_get_color_opt(o, DIFF_PLAIN);
2039                        }
2040                }
2041                xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
2042                              &xpp, &xecfg);
2043                if (o->word_diff)
2044                        free_diff_words_data(&ecbdata);
2045                if (textconv_one)
2046                        free(mf1.ptr);
2047                if (textconv_two)
2048                        free(mf2.ptr);
2049                xdiff_clear_find_func(&xecfg);
2050        }
2051
2052 free_ab_and_return:
2053        strbuf_release(&header);
2054        diff_free_filespec_data(one);
2055        diff_free_filespec_data(two);
2056        free(a_one);
2057        free(b_two);
2058        return;
2059}
2060
2061static void builtin_diffstat(const char *name_a, const char *name_b,
2062                             struct diff_filespec *one,
2063                             struct diff_filespec *two,
2064                             struct diffstat_t *diffstat,
2065                             struct diff_options *o,
2066                             int complete_rewrite)
2067{
2068        mmfile_t mf1, mf2;
2069        struct diffstat_file *data;
2070
2071        data = diffstat_add(diffstat, name_a, name_b);
2072
2073        if (!one || !two) {
2074                data->is_unmerged = 1;
2075                return;
2076        }
2077        if (complete_rewrite) {
2078                diff_populate_filespec(one, 0);
2079                diff_populate_filespec(two, 0);
2080                data->deleted = count_lines(one->data, one->size);
2081                data->added = count_lines(two->data, two->size);
2082                goto free_and_return;
2083        }
2084        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2085                die("unable to read files to diff");
2086
2087        if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
2088                data->is_binary = 1;
2089                data->added = mf2.size;
2090                data->deleted = mf1.size;
2091        } else {
2092                /* Crazy xdl interfaces.. */
2093                xpparam_t xpp;
2094                xdemitconf_t xecfg;
2095
2096                memset(&xpp, 0, sizeof(xpp));
2097                memset(&xecfg, 0, sizeof(xecfg));
2098                xpp.flags = o->xdl_opts;
2099                xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
2100                              &xpp, &xecfg);
2101        }
2102
2103 free_and_return:
2104        diff_free_filespec_data(one);
2105        diff_free_filespec_data(two);
2106}
2107
2108static void builtin_checkdiff(const char *name_a, const char *name_b,
2109                              const char *attr_path,
2110                              struct diff_filespec *one,
2111                              struct diff_filespec *two,
2112                              struct diff_options *o)
2113{
2114        mmfile_t mf1, mf2;
2115        struct checkdiff_t data;
2116
2117        if (!two)
2118                return;
2119
2120        memset(&data, 0, sizeof(data));
2121        data.filename = name_b ? name_b : name_a;
2122        data.lineno = 0;
2123        data.o = o;
2124        data.ws_rule = whitespace_rule(attr_path);
2125        data.conflict_marker_size = ll_merge_marker_size(attr_path);
2126
2127        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2128                die("unable to read files to diff");
2129
2130        /*
2131         * All the other codepaths check both sides, but not checking
2132         * the "old" side here is deliberate.  We are checking the newly
2133         * introduced changes, and as long as the "new" side is text, we
2134         * can and should check what it introduces.
2135         */
2136        if (diff_filespec_is_binary(two))
2137                goto free_and_return;
2138        else {
2139                /* Crazy xdl interfaces.. */
2140                xpparam_t xpp;
2141                xdemitconf_t xecfg;
2142
2143                memset(&xpp, 0, sizeof(xpp));
2144                memset(&xecfg, 0, sizeof(xecfg));
2145                xecfg.ctxlen = 1; /* at least one context line */
2146                xpp.flags = 0;
2147                xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
2148                              &xpp, &xecfg);
2149
2150                if (data.ws_rule & WS_BLANK_AT_EOF) {
2151                        struct emit_callback ecbdata;
2152                        int blank_at_eof;
2153
2154                        ecbdata.ws_rule = data.ws_rule;
2155                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2156                        blank_at_eof = ecbdata.blank_at_eof_in_preimage;
2157
2158                        if (blank_at_eof) {
2159                                static char *err;
2160                                if (!err)
2161                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
2162                                fprintf(o->file, "%s:%d: %s.\n",
2163                                        data.filename, blank_at_eof, err);
2164                                data.status = 1; /* report errors */
2165                        }
2166                }
2167        }
2168 free_and_return:
2169        diff_free_filespec_data(one);
2170        diff_free_filespec_data(two);
2171        if (data.status)
2172                DIFF_OPT_SET(o, CHECK_FAILED);
2173}
2174
2175struct diff_filespec *alloc_filespec(const char *path)
2176{
2177        int namelen = strlen(path);
2178        struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
2179
2180        memset(spec, 0, sizeof(*spec));
2181        spec->path = (char *)(spec + 1);
2182        memcpy(spec->path, path, namelen+1);
2183        spec->count = 1;
2184        spec->is_binary = -1;
2185        return spec;
2186}
2187
2188void free_filespec(struct diff_filespec *spec)
2189{
2190        if (!--spec->count) {
2191                diff_free_filespec_data(spec);
2192                free(spec);
2193        }
2194}
2195
2196void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
2197                   unsigned short mode)
2198{
2199        if (mode) {
2200                spec->mode = canon_mode(mode);
2201                hashcpy(spec->sha1, sha1);
2202                spec->sha1_valid = !is_null_sha1(sha1);
2203        }
2204}
2205
2206/*
2207 * Given a name and sha1 pair, if the index tells us the file in
2208 * the work tree has that object contents, return true, so that
2209 * prepare_temp_file() does not have to inflate and extract.
2210 */
2211static int reuse_worktree_file(const char *name, const unsigned char *sha1, int want_file)
2212{
2213        struct cache_entry *ce;
2214        struct stat st;
2215        int pos, len;
2216
2217        /*
2218         * We do not read the cache ourselves here, because the
2219         * benchmark with my previous version that always reads cache
2220         * shows that it makes things worse for diff-tree comparing
2221         * two linux-2.6 kernel trees in an already checked out work
2222         * tree.  This is because most diff-tree comparisons deal with
2223         * only a small number of files, while reading the cache is
2224         * expensive for a large project, and its cost outweighs the
2225         * savings we get by not inflating the object to a temporary
2226         * file.  Practically, this code only helps when we are used
2227         * by diff-cache --cached, which does read the cache before
2228         * calling us.
2229         */
2230        if (!active_cache)
2231                return 0;
2232
2233        /* We want to avoid the working directory if our caller
2234         * doesn't need the data in a normal file, this system
2235         * is rather slow with its stat/open/mmap/close syscalls,
2236         * and the object is contained in a pack file.  The pack
2237         * is probably already open and will be faster to obtain
2238         * the data through than the working directory.  Loose
2239         * objects however would tend to be slower as they need
2240         * to be individually opened and inflated.
2241         */
2242        if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(sha1))
2243                return 0;
2244
2245        len = strlen(name);
2246        pos = cache_name_pos(name, len);
2247        if (pos < 0)
2248                return 0;
2249        ce = active_cache[pos];
2250
2251        /*
2252         * This is not the sha1 we are looking for, or
2253         * unreusable because it is not a regular file.
2254         */
2255        if (hashcmp(sha1, ce->sha1) || !S_ISREG(ce->ce_mode))
2256                return 0;
2257
2258        /*
2259         * If ce is marked as "assume unchanged", there is no
2260         * guarantee that work tree matches what we are looking for.
2261         */
2262        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
2263                return 0;
2264
2265        /*
2266         * If ce matches the file in the work tree, we can reuse it.
2267         */
2268        if (ce_uptodate(ce) ||
2269            (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
2270                return 1;
2271
2272        return 0;
2273}
2274
2275static int populate_from_stdin(struct diff_filespec *s)
2276{
2277        struct strbuf buf = STRBUF_INIT;
2278        size_t size = 0;
2279
2280        if (strbuf_read(&buf, 0, 0) < 0)
2281                return error("error while reading from stdin %s",
2282                                     strerror(errno));
2283
2284        s->should_munmap = 0;
2285        s->data = strbuf_detach(&buf, &size);
2286        s->size = size;
2287        s->should_free = 1;
2288        return 0;
2289}
2290
2291static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
2292{
2293        int len;
2294        char *data = xmalloc(100), *dirty = "";
2295
2296        /* Are we looking at the work tree? */
2297        if (s->dirty_submodule)
2298                dirty = "-dirty";
2299
2300        len = snprintf(data, 100,
2301                       "Subproject commit %s%s\n", sha1_to_hex(s->sha1), dirty);
2302        s->data = data;
2303        s->size = len;
2304        s->should_free = 1;
2305        if (size_only) {
2306                s->data = NULL;
2307                free(data);
2308        }
2309        return 0;
2310}
2311
2312/*
2313 * While doing rename detection and pickaxe operation, we may need to
2314 * grab the data for the blob (or file) for our own in-core comparison.
2315 * diff_filespec has data and size fields for this purpose.
2316 */
2317int diff_populate_filespec(struct diff_filespec *s, int size_only)
2318{
2319        int err = 0;
2320        if (!DIFF_FILE_VALID(s))
2321                die("internal error: asking to populate invalid file.");
2322        if (S_ISDIR(s->mode))
2323                return -1;
2324
2325        if (s->data)
2326                return 0;
2327
2328        if (size_only && 0 < s->size)
2329                return 0;
2330
2331        if (S_ISGITLINK(s->mode))
2332                return diff_populate_gitlink(s, size_only);
2333
2334        if (!s->sha1_valid ||
2335            reuse_worktree_file(s->path, s->sha1, 0)) {
2336                struct strbuf buf = STRBUF_INIT;
2337                struct stat st;
2338                int fd;
2339
2340                if (!strcmp(s->path, "-"))
2341                        return populate_from_stdin(s);
2342
2343                if (lstat(s->path, &st) < 0) {
2344                        if (errno == ENOENT) {
2345                        err_empty:
2346                                err = -1;
2347                        empty:
2348                                s->data = (char *)"";
2349                                s->size = 0;
2350                                return err;
2351                        }
2352                }
2353                s->size = xsize_t(st.st_size);
2354                if (!s->size)
2355                        goto empty;
2356                if (S_ISLNK(st.st_mode)) {
2357                        struct strbuf sb = STRBUF_INIT;
2358
2359                        if (strbuf_readlink(&sb, s->path, s->size))
2360                                goto err_empty;
2361                        s->size = sb.len;
2362                        s->data = strbuf_detach(&sb, NULL);
2363                        s->should_free = 1;
2364                        return 0;
2365                }
2366                if (size_only)
2367                        return 0;
2368                fd = open(s->path, O_RDONLY);
2369                if (fd < 0)
2370                        goto err_empty;
2371                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
2372                close(fd);
2373                s->should_munmap = 1;
2374
2375                /*
2376                 * Convert from working tree format to canonical git format
2377                 */
2378                if (convert_to_git(s->path, s->data, s->size, &buf, safe_crlf)) {
2379                        size_t size = 0;
2380                        munmap(s->data, s->size);
2381                        s->should_munmap = 0;
2382                        s->data = strbuf_detach(&buf, &size);
2383                        s->size = size;
2384                        s->should_free = 1;
2385                }
2386        }
2387        else {
2388                enum object_type type;
2389                if (size_only)
2390                        type = sha1_object_info(s->sha1, &s->size);
2391                else {
2392                        s->data = read_sha1_file(s->sha1, &type, &s->size);
2393                        s->should_free = 1;
2394                }
2395        }
2396        return 0;
2397}
2398
2399void diff_free_filespec_blob(struct diff_filespec *s)
2400{
2401        if (s->should_free)
2402                free(s->data);
2403        else if (s->should_munmap)
2404                munmap(s->data, s->size);
2405
2406        if (s->should_free || s->should_munmap) {
2407                s->should_free = s->should_munmap = 0;
2408                s->data = NULL;
2409        }
2410}
2411
2412void diff_free_filespec_data(struct diff_filespec *s)
2413{
2414        diff_free_filespec_blob(s);
2415        free(s->cnt_data);
2416        s->cnt_data = NULL;
2417}
2418
2419static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
2420                           void *blob,
2421                           unsigned long size,
2422                           const unsigned char *sha1,
2423                           int mode)
2424{
2425        int fd;
2426        struct strbuf buf = STRBUF_INIT;
2427        struct strbuf template = STRBUF_INIT;
2428        char *path_dup = xstrdup(path);
2429        const char *base = basename(path_dup);
2430
2431        /* Generate "XXXXXX_basename.ext" */
2432        strbuf_addstr(&template, "XXXXXX_");
2433        strbuf_addstr(&template, base);
2434
2435        fd = git_mkstemps(temp->tmp_path, PATH_MAX, template.buf,
2436                        strlen(base) + 1);
2437        if (fd < 0)
2438                die_errno("unable to create temp-file");
2439        if (convert_to_working_tree(path,
2440                        (const char *)blob, (size_t)size, &buf)) {
2441                blob = buf.buf;
2442                size = buf.len;
2443        }
2444        if (write_in_full(fd, blob, size) != size)
2445                die_errno("unable to write temp-file");
2446        close(fd);
2447        temp->name = temp->tmp_path;
2448        strcpy(temp->hex, sha1_to_hex(sha1));
2449        temp->hex[40] = 0;
2450        sprintf(temp->mode, "%06o", mode);
2451        strbuf_release(&buf);
2452        strbuf_release(&template);
2453        free(path_dup);
2454}
2455
2456static struct diff_tempfile *prepare_temp_file(const char *name,
2457                struct diff_filespec *one)
2458{
2459        struct diff_tempfile *temp = claim_diff_tempfile();
2460
2461        if (!DIFF_FILE_VALID(one)) {
2462        not_a_valid_file:
2463                /* A '-' entry produces this for file-2, and
2464                 * a '+' entry produces this for file-1.
2465                 */
2466                temp->name = "/dev/null";
2467                strcpy(temp->hex, ".");
2468                strcpy(temp->mode, ".");
2469                return temp;
2470        }
2471
2472        if (!remove_tempfile_installed) {
2473                atexit(remove_tempfile);
2474                sigchain_push_common(remove_tempfile_on_signal);
2475                remove_tempfile_installed = 1;
2476        }
2477
2478        if (!one->sha1_valid ||
2479            reuse_worktree_file(name, one->sha1, 1)) {
2480                struct stat st;
2481                if (lstat(name, &st) < 0) {
2482                        if (errno == ENOENT)
2483                                goto not_a_valid_file;
2484                        die_errno("stat(%s)", name);
2485                }
2486                if (S_ISLNK(st.st_mode)) {
2487                        struct strbuf sb = STRBUF_INIT;
2488                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
2489                                die_errno("readlink(%s)", name);
2490                        prep_temp_blob(name, temp, sb.buf, sb.len,
2491                                       (one->sha1_valid ?
2492                                        one->sha1 : null_sha1),
2493                                       (one->sha1_valid ?
2494                                        one->mode : S_IFLNK));
2495                        strbuf_release(&sb);
2496                }
2497                else {
2498                        /* we can borrow from the file in the work tree */
2499                        temp->name = name;
2500                        if (!one->sha1_valid)
2501                                strcpy(temp->hex, sha1_to_hex(null_sha1));
2502                        else
2503                                strcpy(temp->hex, sha1_to_hex(one->sha1));
2504                        /* Even though we may sometimes borrow the
2505                         * contents from the work tree, we always want
2506                         * one->mode.  mode is trustworthy even when
2507                         * !(one->sha1_valid), as long as
2508                         * DIFF_FILE_VALID(one).
2509                         */
2510                        sprintf(temp->mode, "%06o", one->mode);
2511                }
2512                return temp;
2513        }
2514        else {
2515                if (diff_populate_filespec(one, 0))
2516                        die("cannot read data blob for %s", one->path);
2517                prep_temp_blob(name, temp, one->data, one->size,
2518                               one->sha1, one->mode);
2519        }
2520        return temp;
2521}
2522
2523/* An external diff command takes:
2524 *
2525 * diff-cmd name infile1 infile1-sha1 infile1-mode \
2526 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
2527 *
2528 */
2529static void run_external_diff(const char *pgm,
2530                              const char *name,
2531                              const char *other,
2532                              struct diff_filespec *one,
2533                              struct diff_filespec *two,
2534                              const char *xfrm_msg,
2535                              int complete_rewrite)
2536{
2537        const char *spawn_arg[10];
2538        int retval;
2539        const char **arg = &spawn_arg[0];
2540
2541        if (one && two) {
2542                struct diff_tempfile *temp_one, *temp_two;
2543                const char *othername = (other ? other : name);
2544                temp_one = prepare_temp_file(name, one);
2545                temp_two = prepare_temp_file(othername, two);
2546                *arg++ = pgm;
2547                *arg++ = name;
2548                *arg++ = temp_one->name;
2549                *arg++ = temp_one->hex;
2550                *arg++ = temp_one->mode;
2551                *arg++ = temp_two->name;
2552                *arg++ = temp_two->hex;
2553                *arg++ = temp_two->mode;
2554                if (other) {
2555                        *arg++ = other;
2556                        *arg++ = xfrm_msg;
2557                }
2558        } else {
2559                *arg++ = pgm;
2560                *arg++ = name;
2561        }
2562        *arg = NULL;
2563        fflush(NULL);
2564        retval = run_command_v_opt(spawn_arg, RUN_USING_SHELL);
2565        remove_tempfile();
2566        if (retval) {
2567                fprintf(stderr, "external diff died, stopping at %s.\n", name);
2568                exit(1);
2569        }
2570}
2571
2572static int similarity_index(struct diff_filepair *p)
2573{
2574        return p->score * 100 / MAX_SCORE;
2575}
2576
2577static void fill_metainfo(struct strbuf *msg,
2578                          const char *name,
2579                          const char *other,
2580                          struct diff_filespec *one,
2581                          struct diff_filespec *two,
2582                          struct diff_options *o,
2583                          struct diff_filepair *p,
2584                          int *must_show_header,
2585                          int use_color)
2586{
2587        const char *set = diff_get_color(use_color, DIFF_METAINFO);
2588        const char *reset = diff_get_color(use_color, DIFF_RESET);
2589        struct strbuf *msgbuf;
2590        char *line_prefix = "";
2591
2592        *must_show_header = 1;
2593        if (o->output_prefix) {
2594                msgbuf = o->output_prefix(o, o->output_prefix_data);
2595                line_prefix = msgbuf->buf;
2596        }
2597        strbuf_init(msg, PATH_MAX * 2 + 300);
2598        switch (p->status) {
2599        case DIFF_STATUS_COPIED:
2600                strbuf_addf(msg, "%s%ssimilarity index %d%%",
2601                            line_prefix, set, similarity_index(p));
2602                strbuf_addf(msg, "%s\n%s%scopy from ",
2603                            reset,  line_prefix, set);
2604                quote_c_style(name, msg, NULL, 0);
2605                strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
2606                quote_c_style(other, msg, NULL, 0);
2607                strbuf_addf(msg, "%s\n", reset);
2608                break;
2609        case DIFF_STATUS_RENAMED:
2610                strbuf_addf(msg, "%s%ssimilarity index %d%%",
2611                            line_prefix, set, similarity_index(p));
2612                strbuf_addf(msg, "%s\n%s%srename from ",
2613                            reset, line_prefix, set);
2614                quote_c_style(name, msg, NULL, 0);
2615                strbuf_addf(msg, "%s\n%s%srename to ",
2616                            reset, line_prefix, set);
2617                quote_c_style(other, msg, NULL, 0);
2618                strbuf_addf(msg, "%s\n", reset);
2619                break;
2620        case DIFF_STATUS_MODIFIED:
2621                if (p->score) {
2622                        strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
2623                                    line_prefix,
2624                                    set, similarity_index(p), reset);
2625                        break;
2626                }
2627                /* fallthru */
2628        default:
2629                *must_show_header = 0;
2630        }
2631        if (one && two && hashcmp(one->sha1, two->sha1)) {
2632                int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
2633
2634                if (DIFF_OPT_TST(o, BINARY)) {
2635                        mmfile_t mf;
2636                        if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
2637                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
2638                                abbrev = 40;
2639                }
2640                strbuf_addf(msg, "%s%sindex %s..", line_prefix, set,
2641                            find_unique_abbrev(one->sha1, abbrev));
2642                strbuf_addstr(msg, find_unique_abbrev(two->sha1, abbrev));
2643                if (one->mode == two->mode)
2644                        strbuf_addf(msg, " %06o", one->mode);
2645                strbuf_addf(msg, "%s\n", reset);
2646        }
2647}
2648
2649static void run_diff_cmd(const char *pgm,
2650                         const char *name,
2651                         const char *other,
2652                         const char *attr_path,
2653                         struct diff_filespec *one,
2654                         struct diff_filespec *two,
2655                         struct strbuf *msg,
2656                         struct diff_options *o,
2657                         struct diff_filepair *p)
2658{
2659        const char *xfrm_msg = NULL;
2660        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
2661        int must_show_header = 0;
2662
2663        if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
2664                pgm = NULL;
2665        else {
2666                struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
2667                if (drv && drv->external)
2668                        pgm = drv->external;
2669        }
2670
2671        if (msg) {
2672                /*
2673                 * don't use colors when the header is intended for an
2674                 * external diff driver
2675                 */
2676                fill_metainfo(msg, name, other, one, two, o, p,
2677                              &must_show_header,
2678                              DIFF_OPT_TST(o, COLOR_DIFF) && !pgm);
2679                xfrm_msg = msg->len ? msg->buf : NULL;
2680        }
2681
2682        if (pgm) {
2683                run_external_diff(pgm, name, other, one, two, xfrm_msg,
2684                                  complete_rewrite);
2685                return;
2686        }
2687        if (one && two)
2688                builtin_diff(name, other ? other : name,
2689                             one, two, xfrm_msg, must_show_header,
2690                             o, complete_rewrite);
2691        else
2692                fprintf(o->file, "* Unmerged path %s\n", name);
2693}
2694
2695static void diff_fill_sha1_info(struct diff_filespec *one)
2696{
2697        if (DIFF_FILE_VALID(one)) {
2698                if (!one->sha1_valid) {
2699                        struct stat st;
2700                        if (!strcmp(one->path, "-")) {
2701                                hashcpy(one->sha1, null_sha1);
2702                                return;
2703                        }
2704                        if (lstat(one->path, &st) < 0)
2705                                die_errno("stat '%s'", one->path);
2706                        if (index_path(one->sha1, one->path, &st, 0))
2707                                die("cannot hash %s", one->path);
2708                }
2709        }
2710        else
2711                hashclr(one->sha1);
2712}
2713
2714static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
2715{
2716        /* Strip the prefix but do not molest /dev/null and absolute paths */
2717        if (*namep && **namep != '/') {
2718                *namep += prefix_length;
2719                if (**namep == '/')
2720                        ++*namep;
2721        }
2722        if (*otherp && **otherp != '/') {
2723                *otherp += prefix_length;
2724                if (**otherp == '/')
2725                        ++*otherp;
2726        }
2727}
2728
2729static void run_diff(struct diff_filepair *p, struct diff_options *o)
2730{
2731        const char *pgm = external_diff();
2732        struct strbuf msg;
2733        struct diff_filespec *one = p->one;
2734        struct diff_filespec *two = p->two;
2735        const char *name;
2736        const char *other;
2737        const char *attr_path;
2738
2739        name  = p->one->path;
2740        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2741        attr_path = name;
2742        if (o->prefix_length)
2743                strip_prefix(o->prefix_length, &name, &other);
2744
2745        if (DIFF_PAIR_UNMERGED(p)) {
2746                run_diff_cmd(pgm, name, NULL, attr_path,
2747                             NULL, NULL, NULL, o, p);
2748                return;
2749        }
2750
2751        diff_fill_sha1_info(one);
2752        diff_fill_sha1_info(two);
2753
2754        if (!pgm &&
2755            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
2756            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
2757                /*
2758                 * a filepair that changes between file and symlink
2759                 * needs to be split into deletion and creation.
2760                 */
2761                struct diff_filespec *null = alloc_filespec(two->path);
2762                run_diff_cmd(NULL, name, other, attr_path,
2763                             one, null, &msg, o, p);
2764                free(null);
2765                strbuf_release(&msg);
2766
2767                null = alloc_filespec(one->path);
2768                run_diff_cmd(NULL, name, other, attr_path,
2769                             null, two, &msg, o, p);
2770                free(null);
2771        }
2772        else
2773                run_diff_cmd(pgm, name, other, attr_path,
2774                             one, two, &msg, o, p);
2775
2776        strbuf_release(&msg);
2777}
2778
2779static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
2780                         struct diffstat_t *diffstat)
2781{
2782        const char *name;
2783        const char *other;
2784        int complete_rewrite = 0;
2785
2786        if (DIFF_PAIR_UNMERGED(p)) {
2787                /* unmerged */
2788                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, 0);
2789                return;
2790        }
2791
2792        name = p->one->path;
2793        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2794
2795        if (o->prefix_length)
2796                strip_prefix(o->prefix_length, &name, &other);
2797
2798        diff_fill_sha1_info(p->one);
2799        diff_fill_sha1_info(p->two);
2800
2801        if (p->status == DIFF_STATUS_MODIFIED && p->score)
2802                complete_rewrite = 1;
2803        builtin_diffstat(name, other, p->one, p->two, diffstat, o, complete_rewrite);
2804}
2805
2806static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
2807{
2808        const char *name;
2809        const char *other;
2810        const char *attr_path;
2811
2812        if (DIFF_PAIR_UNMERGED(p)) {
2813                /* unmerged */
2814                return;
2815        }
2816
2817        name = p->one->path;
2818        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2819        attr_path = other ? other : name;
2820
2821        if (o->prefix_length)
2822                strip_prefix(o->prefix_length, &name, &other);
2823
2824        diff_fill_sha1_info(p->one);
2825        diff_fill_sha1_info(p->two);
2826
2827        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
2828}
2829
2830void diff_setup(struct diff_options *options)
2831{
2832        memcpy(options, &default_diff_options, sizeof(*options));
2833
2834        options->file = stdout;
2835
2836        options->line_termination = '\n';
2837        options->break_opt = -1;
2838        options->rename_limit = -1;
2839        options->dirstat_percent = 3;
2840        options->context = 3;
2841
2842        options->change = diff_change;
2843        options->add_remove = diff_addremove;
2844        if (diff_use_color_default > 0)
2845                DIFF_OPT_SET(options, COLOR_DIFF);
2846        options->detect_rename = diff_detect_rename_default;
2847
2848        if (diff_no_prefix) {
2849                options->a_prefix = options->b_prefix = "";
2850        } else if (!diff_mnemonic_prefix) {
2851                options->a_prefix = "a/";
2852                options->b_prefix = "b/";
2853        }
2854}
2855
2856int diff_setup_done(struct diff_options *options)
2857{
2858        int count = 0;
2859
2860        if (options->output_format & DIFF_FORMAT_NAME)
2861                count++;
2862        if (options->output_format & DIFF_FORMAT_NAME_STATUS)
2863                count++;
2864        if (options->output_format & DIFF_FORMAT_CHECKDIFF)
2865                count++;
2866        if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
2867                count++;
2868        if (count > 1)
2869                die("--name-only, --name-status, --check and -s are mutually exclusive");
2870
2871        /*
2872         * Most of the time we can say "there are changes"
2873         * only by checking if there are changed paths, but
2874         * --ignore-whitespace* options force us to look
2875         * inside contents.
2876         */
2877
2878        if (DIFF_XDL_TST(options, IGNORE_WHITESPACE) ||
2879            DIFF_XDL_TST(options, IGNORE_WHITESPACE_CHANGE) ||
2880            DIFF_XDL_TST(options, IGNORE_WHITESPACE_AT_EOL))
2881                DIFF_OPT_SET(options, DIFF_FROM_CONTENTS);
2882        else
2883                DIFF_OPT_CLR(options, DIFF_FROM_CONTENTS);
2884
2885        if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
2886                options->detect_rename = DIFF_DETECT_COPY;
2887
2888        if (!DIFF_OPT_TST(options, RELATIVE_NAME))
2889                options->prefix = NULL;
2890        if (options->prefix)
2891                options->prefix_length = strlen(options->prefix);
2892        else
2893                options->prefix_length = 0;
2894
2895        if (options->output_format & (DIFF_FORMAT_NAME |
2896                                      DIFF_FORMAT_NAME_STATUS |
2897                                      DIFF_FORMAT_CHECKDIFF |
2898                                      DIFF_FORMAT_NO_OUTPUT))
2899                options->output_format &= ~(DIFF_FORMAT_RAW |
2900                                            DIFF_FORMAT_NUMSTAT |
2901                                            DIFF_FORMAT_DIFFSTAT |
2902                                            DIFF_FORMAT_SHORTSTAT |
2903                                            DIFF_FORMAT_DIRSTAT |
2904                                            DIFF_FORMAT_SUMMARY |
2905                                            DIFF_FORMAT_PATCH);
2906
2907        /*
2908         * These cases always need recursive; we do not drop caller-supplied
2909         * recursive bits for other formats here.
2910         */
2911        if (options->output_format & (DIFF_FORMAT_PATCH |
2912                                      DIFF_FORMAT_NUMSTAT |
2913                                      DIFF_FORMAT_DIFFSTAT |
2914                                      DIFF_FORMAT_SHORTSTAT |
2915                                      DIFF_FORMAT_DIRSTAT |
2916                                      DIFF_FORMAT_SUMMARY |
2917                                      DIFF_FORMAT_CHECKDIFF))
2918                DIFF_OPT_SET(options, RECURSIVE);
2919        /*
2920         * Also pickaxe would not work very well if you do not say recursive
2921         */
2922        if (options->pickaxe)
2923                DIFF_OPT_SET(options, RECURSIVE);
2924        /*
2925         * When patches are generated, submodules diffed against the work tree
2926         * must be checked for dirtiness too so it can be shown in the output
2927         */
2928        if (options->output_format & DIFF_FORMAT_PATCH)
2929                DIFF_OPT_SET(options, DIRTY_SUBMODULES);
2930
2931        if (options->detect_rename && options->rename_limit < 0)
2932                options->rename_limit = diff_rename_limit_default;
2933        if (options->setup & DIFF_SETUP_USE_CACHE) {
2934                if (!active_cache)
2935                        /* read-cache does not die even when it fails
2936                         * so it is safe for us to do this here.  Also
2937                         * it does not smudge active_cache or active_nr
2938                         * when it fails, so we do not have to worry about
2939                         * cleaning it up ourselves either.
2940                         */
2941                        read_cache();
2942        }
2943        if (options->abbrev <= 0 || 40 < options->abbrev)
2944                options->abbrev = 40; /* full */
2945
2946        /*
2947         * It does not make sense to show the first hit we happened
2948         * to have found.  It does not make sense not to return with
2949         * exit code in such a case either.
2950         */
2951        if (DIFF_OPT_TST(options, QUICK)) {
2952                options->output_format = DIFF_FORMAT_NO_OUTPUT;
2953                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
2954        }
2955
2956        return 0;
2957}
2958
2959static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
2960{
2961        char c, *eq;
2962        int len;
2963
2964        if (*arg != '-')
2965                return 0;
2966        c = *++arg;
2967        if (!c)
2968                return 0;
2969        if (c == arg_short) {
2970                c = *++arg;
2971                if (!c)
2972                        return 1;
2973                if (val && isdigit(c)) {
2974                        char *end;
2975                        int n = strtoul(arg, &end, 10);
2976                        if (*end)
2977                                return 0;
2978                        *val = n;
2979                        return 1;
2980                }
2981                return 0;
2982        }
2983        if (c != '-')
2984                return 0;
2985        arg++;
2986        eq = strchr(arg, '=');
2987        if (eq)
2988                len = eq - arg;
2989        else
2990                len = strlen(arg);
2991        if (!len || strncmp(arg, arg_long, len))
2992                return 0;
2993        if (eq) {
2994                int n;
2995                char *end;
2996                if (!isdigit(*++eq))
2997                        return 0;
2998                n = strtoul(eq, &end, 10);
2999                if (*end)
3000                        return 0;
3001                *val = n;
3002        }
3003        return 1;
3004}
3005
3006static int diff_scoreopt_parse(const char *opt);
3007
3008static inline int short_opt(char opt, const char **argv,
3009                            const char **optarg)
3010{
3011        const char *arg = argv[0];
3012        if (arg[0] != '-' || arg[1] != opt)
3013                return 0;
3014        if (arg[2] != '\0') {
3015                *optarg = arg + 2;
3016                return 1;
3017        }
3018        if (!argv[1])
3019                die("Option '%c' requires a value", opt);
3020        *optarg = argv[1];
3021        return 2;
3022}
3023
3024int parse_long_opt(const char *opt, const char **argv,
3025                   const char **optarg)
3026{
3027        const char *arg = argv[0];
3028        if (arg[0] != '-' || arg[1] != '-')
3029                return 0;
3030        arg += strlen("--");
3031        if (prefixcmp(arg, opt))
3032                return 0;
3033        arg += strlen(opt);
3034        if (*arg == '=') { /* sticked form: --option=value */
3035                *optarg = arg + 1;
3036                return 1;
3037        }
3038        if (*arg != '\0')
3039                return 0;
3040        /* separate form: --option value */
3041        if (!argv[1])
3042                die("Option '--%s' requires a value", opt);
3043        *optarg = argv[1];
3044        return 2;
3045}
3046
3047static int stat_opt(struct diff_options *options, const char **av)
3048{
3049        const char *arg = av[0];
3050        char *end;
3051        int width = options->stat_width;
3052        int name_width = options->stat_name_width;
3053        int argcount = 1;
3054
3055        arg += strlen("--stat");
3056        end = (char *)arg;
3057
3058        switch (*arg) {
3059        case '-':
3060                if (!prefixcmp(arg, "-width")) {
3061                        arg += strlen("-width");
3062                        if (*arg == '=')
3063                                width = strtoul(arg + 1, &end, 10);
3064                        else if (!*arg && !av[1])
3065                                die("Option '--stat-width' requires a value");
3066                        else if (!*arg) {
3067                                width = strtoul(av[1], &end, 10);
3068                                argcount = 2;
3069                        }
3070                } else if (!prefixcmp(arg, "-name-width")) {
3071                        arg += strlen("-name-width");
3072                        if (*arg == '=')
3073                                name_width = strtoul(arg + 1, &end, 10);
3074                        else if (!*arg && !av[1])
3075                                die("Option '--stat-name-width' requires a value");
3076                        else if (!*arg) {
3077                                name_width = strtoul(av[1], &end, 10);
3078                                argcount = 2;
3079                        }
3080                }
3081                break;
3082        case '=':
3083                width = strtoul(arg+1, &end, 10);
3084                if (*end == ',')
3085                        name_width = strtoul(end+1, &end, 10);
3086        }
3087
3088        /* Important! This checks all the error cases! */
3089        if (*end)
3090                return 0;
3091        options->output_format |= DIFF_FORMAT_DIFFSTAT;
3092        options->stat_name_width = name_width;
3093        options->stat_width = width;
3094        return argcount;
3095}
3096
3097int diff_opt_parse(struct diff_options *options, const char **av, int ac)
3098{
3099        const char *arg = av[0];
3100        const char *optarg;
3101        int argcount;
3102
3103        /* Output format options */
3104        if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch"))
3105                options->output_format |= DIFF_FORMAT_PATCH;
3106        else if (opt_arg(arg, 'U', "unified", &options->context))
3107                options->output_format |= DIFF_FORMAT_PATCH;
3108        else if (!strcmp(arg, "--raw"))
3109                options->output_format |= DIFF_FORMAT_RAW;
3110        else if (!strcmp(arg, "--patch-with-raw"))
3111                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_RAW;
3112        else if (!strcmp(arg, "--numstat"))
3113                options->output_format |= DIFF_FORMAT_NUMSTAT;
3114        else if (!strcmp(arg, "--shortstat"))
3115                options->output_format |= DIFF_FORMAT_SHORTSTAT;
3116        else if (opt_arg(arg, 'X', "dirstat", &options->dirstat_percent))
3117                options->output_format |= DIFF_FORMAT_DIRSTAT;
3118        else if (!strcmp(arg, "--cumulative")) {
3119                options->output_format |= DIFF_FORMAT_DIRSTAT;
3120                DIFF_OPT_SET(options, DIRSTAT_CUMULATIVE);
3121        } else if (opt_arg(arg, 0, "dirstat-by-file",
3122                           &options->dirstat_percent)) {
3123                options->output_format |= DIFF_FORMAT_DIRSTAT;
3124                DIFF_OPT_SET(options, DIRSTAT_BY_FILE);
3125        }
3126        else if (!strcmp(arg, "--check"))
3127                options->output_format |= DIFF_FORMAT_CHECKDIFF;
3128        else if (!strcmp(arg, "--summary"))
3129                options->output_format |= DIFF_FORMAT_SUMMARY;
3130        else if (!strcmp(arg, "--patch-with-stat"))
3131                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_DIFFSTAT;
3132        else if (!strcmp(arg, "--name-only"))
3133                options->output_format |= DIFF_FORMAT_NAME;
3134        else if (!strcmp(arg, "--name-status"))
3135                options->output_format |= DIFF_FORMAT_NAME_STATUS;
3136        else if (!strcmp(arg, "-s"))
3137                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
3138        else if (!prefixcmp(arg, "--stat"))
3139                /* --stat, --stat-width, or --stat-name-width */
3140                return stat_opt(options, av);
3141
3142        /* renames options */
3143        else if (!prefixcmp(arg, "-B")) {
3144                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
3145                        return -1;
3146        }
3147        else if (!prefixcmp(arg, "-M")) {
3148                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3149                        return -1;
3150                options->detect_rename = DIFF_DETECT_RENAME;
3151        }
3152        else if (!prefixcmp(arg, "-C")) {
3153                if (options->detect_rename == DIFF_DETECT_COPY)
3154                        DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3155                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3156                        return -1;
3157                options->detect_rename = DIFF_DETECT_COPY;
3158        }
3159        else if (!strcmp(arg, "--no-renames"))
3160                options->detect_rename = 0;
3161        else if (!strcmp(arg, "--relative"))
3162                DIFF_OPT_SET(options, RELATIVE_NAME);
3163        else if (!prefixcmp(arg, "--relative=")) {
3164                DIFF_OPT_SET(options, RELATIVE_NAME);
3165                options->prefix = arg + 11;
3166        }
3167
3168        /* xdiff options */
3169        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
3170                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
3171        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
3172                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
3173        else if (!strcmp(arg, "--ignore-space-at-eol"))
3174                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
3175        else if (!strcmp(arg, "--patience"))
3176                DIFF_XDL_SET(options, PATIENCE_DIFF);
3177
3178        /* flags options */
3179        else if (!strcmp(arg, "--binary")) {
3180                options->output_format |= DIFF_FORMAT_PATCH;
3181                DIFF_OPT_SET(options, BINARY);
3182        }
3183        else if (!strcmp(arg, "--full-index"))
3184                DIFF_OPT_SET(options, FULL_INDEX);
3185        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
3186                DIFF_OPT_SET(options, TEXT);
3187        else if (!strcmp(arg, "-R"))
3188                DIFF_OPT_SET(options, REVERSE_DIFF);
3189        else if (!strcmp(arg, "--find-copies-harder"))
3190                DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3191        else if (!strcmp(arg, "--follow"))
3192                DIFF_OPT_SET(options, FOLLOW_RENAMES);
3193        else if (!strcmp(arg, "--color"))
3194                DIFF_OPT_SET(options, COLOR_DIFF);
3195        else if (!prefixcmp(arg, "--color=")) {
3196                int value = git_config_colorbool(NULL, arg+8, -1);
3197                if (value == 0)
3198                        DIFF_OPT_CLR(options, COLOR_DIFF);
3199                else if (value > 0)
3200                        DIFF_OPT_SET(options, COLOR_DIFF);
3201                else
3202                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
3203        }
3204        else if (!strcmp(arg, "--no-color"))
3205                DIFF_OPT_CLR(options, COLOR_DIFF);
3206        else if (!strcmp(arg, "--color-words")) {
3207                DIFF_OPT_SET(options, COLOR_DIFF);
3208                options->word_diff = DIFF_WORDS_COLOR;
3209        }
3210        else if (!prefixcmp(arg, "--color-words=")) {
3211                DIFF_OPT_SET(options, COLOR_DIFF);
3212                options->word_diff = DIFF_WORDS_COLOR;
3213                options->word_regex = arg + 14;
3214        }
3215        else if (!strcmp(arg, "--word-diff")) {
3216                if (options->word_diff == DIFF_WORDS_NONE)
3217                        options->word_diff = DIFF_WORDS_PLAIN;
3218        }
3219        else if (!prefixcmp(arg, "--word-diff=")) {
3220                const char *type = arg + 12;
3221                if (!strcmp(type, "plain"))
3222                        options->word_diff = DIFF_WORDS_PLAIN;
3223                else if (!strcmp(type, "color")) {
3224                        DIFF_OPT_SET(options, COLOR_DIFF);
3225                        options->word_diff = DIFF_WORDS_COLOR;
3226                }
3227                else if (!strcmp(type, "porcelain"))
3228                        options->word_diff = DIFF_WORDS_PORCELAIN;
3229                else if (!strcmp(type, "none"))
3230                        options->word_diff = DIFF_WORDS_NONE;
3231                else
3232                        die("bad --word-diff argument: %s", type);
3233        }
3234        else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
3235                if (options->word_diff == DIFF_WORDS_NONE)
3236                        options->word_diff = DIFF_WORDS_PLAIN;
3237                options->word_regex = optarg;
3238                return argcount;
3239        }
3240        else if (!strcmp(arg, "--exit-code"))
3241                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3242        else if (!strcmp(arg, "--quiet"))
3243                DIFF_OPT_SET(options, QUICK);
3244        else if (!strcmp(arg, "--ext-diff"))
3245                DIFF_OPT_SET(options, ALLOW_EXTERNAL);
3246        else if (!strcmp(arg, "--no-ext-diff"))
3247                DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
3248        else if (!strcmp(arg, "--textconv"))
3249                DIFF_OPT_SET(options, ALLOW_TEXTCONV);
3250        else if (!strcmp(arg, "--no-textconv"))
3251                DIFF_OPT_CLR(options, ALLOW_TEXTCONV);
3252        else if (!strcmp(arg, "--ignore-submodules")) {
3253                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3254                handle_ignore_submodules_arg(options, "all");
3255        } else if (!prefixcmp(arg, "--ignore-submodules=")) {
3256                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3257                handle_ignore_submodules_arg(options, arg + 20);
3258        } else if (!strcmp(arg, "--submodule"))
3259                DIFF_OPT_SET(options, SUBMODULE_LOG);
3260        else if (!prefixcmp(arg, "--submodule=")) {
3261                if (!strcmp(arg + 12, "log"))
3262                        DIFF_OPT_SET(options, SUBMODULE_LOG);
3263        }
3264
3265        /* misc options */
3266        else if (!strcmp(arg, "-z"))
3267                options->line_termination = 0;
3268        else if ((argcount = short_opt('l', av, &optarg))) {
3269                options->rename_limit = strtoul(optarg, NULL, 10);
3270                return argcount;
3271        }
3272        else if ((argcount = short_opt('S', av, &optarg))) {
3273                options->pickaxe = optarg;
3274                return argcount;
3275        }
3276        else if (!strcmp(arg, "--pickaxe-all"))
3277                options->pickaxe_opts = DIFF_PICKAXE_ALL;
3278        else if (!strcmp(arg, "--pickaxe-regex"))
3279                options->pickaxe_opts = DIFF_PICKAXE_REGEX;
3280        else if ((argcount = short_opt('O', av, &optarg))) {
3281                options->orderfile = optarg;
3282                return argcount;
3283        }
3284        else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
3285                options->filter = optarg;
3286                return argcount;
3287        }
3288        else if (!strcmp(arg, "--abbrev"))
3289                options->abbrev = DEFAULT_ABBREV;
3290        else if (!prefixcmp(arg, "--abbrev=")) {
3291                options->abbrev = strtoul(arg + 9, NULL, 10);
3292                if (options->abbrev < MINIMUM_ABBREV)
3293                        options->abbrev = MINIMUM_ABBREV;
3294                else if (40 < options->abbrev)
3295                        options->abbrev = 40;
3296        }
3297        else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
3298                options->a_prefix = optarg;
3299                return argcount;
3300        }
3301        else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
3302                options->b_prefix = optarg;
3303                return argcount;
3304        }
3305        else if (!strcmp(arg, "--no-prefix"))
3306                options->a_prefix = options->b_prefix = "";
3307        else if (opt_arg(arg, '\0', "inter-hunk-context",
3308                         &options->interhunkcontext))
3309                ;
3310        else if ((argcount = parse_long_opt("output", av, &optarg))) {
3311                options->file = fopen(optarg, "w");
3312                if (!options->file)
3313                        die_errno("Could not open '%s'", optarg);
3314                options->close_file = 1;
3315                return argcount;
3316        } else
3317                return 0;
3318        return 1;
3319}
3320
3321static int parse_num(const char **cp_p)
3322{
3323        unsigned long num, scale;
3324        int ch, dot;
3325        const char *cp = *cp_p;
3326
3327        num = 0;
3328        scale = 1;
3329        dot = 0;
3330        for (;;) {
3331                ch = *cp;
3332                if ( !dot && ch == '.' ) {
3333                        scale = 1;
3334                        dot = 1;
3335                } else if ( ch == '%' ) {
3336                        scale = dot ? scale*100 : 100;
3337                        cp++;   /* % is always at the end */
3338                        break;
3339                } else if ( ch >= '0' && ch <= '9' ) {
3340                        if ( scale < 100000 ) {
3341                                scale *= 10;
3342                                num = (num*10) + (ch-'0');
3343                        }
3344                } else {
3345                        break;
3346                }
3347                cp++;
3348        }
3349        *cp_p = cp;
3350
3351        /* user says num divided by scale and we say internally that
3352         * is MAX_SCORE * num / scale.
3353         */
3354        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
3355}
3356
3357static int diff_scoreopt_parse(const char *opt)
3358{
3359        int opt1, opt2, cmd;
3360
3361        if (*opt++ != '-')
3362                return -1;
3363        cmd = *opt++;
3364        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
3365                return -1; /* that is not a -M, -C nor -B option */
3366
3367        opt1 = parse_num(&opt);
3368        if (cmd != 'B')
3369                opt2 = 0;
3370        else {
3371                if (*opt == 0)
3372                        opt2 = 0;
3373                else if (*opt != '/')
3374                        return -1; /* we expect -B80/99 or -B80 */
3375                else {
3376                        opt++;
3377                        opt2 = parse_num(&opt);
3378                }
3379        }
3380        if (*opt != 0)
3381                return -1;
3382        return opt1 | (opt2 << 16);
3383}
3384
3385struct diff_queue_struct diff_queued_diff;
3386
3387void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
3388{
3389        if (queue->alloc <= queue->nr) {
3390                queue->alloc = alloc_nr(queue->alloc);
3391                queue->queue = xrealloc(queue->queue,
3392                                        sizeof(dp) * queue->alloc);
3393        }
3394        queue->queue[queue->nr++] = dp;
3395}
3396
3397struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
3398                                 struct diff_filespec *one,
3399                                 struct diff_filespec *two)
3400{
3401        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
3402        dp->one = one;
3403        dp->two = two;
3404        if (queue)
3405                diff_q(queue, dp);
3406        return dp;
3407}
3408
3409void diff_free_filepair(struct diff_filepair *p)
3410{
3411        free_filespec(p->one);
3412        free_filespec(p->two);
3413        free(p);
3414}
3415
3416/* This is different from find_unique_abbrev() in that
3417 * it stuffs the result with dots for alignment.
3418 */
3419const char *diff_unique_abbrev(const unsigned char *sha1, int len)
3420{
3421        int abblen;
3422        const char *abbrev;
3423        if (len == 40)
3424                return sha1_to_hex(sha1);
3425
3426        abbrev = find_unique_abbrev(sha1, len);
3427        abblen = strlen(abbrev);
3428        if (abblen < 37) {
3429                static char hex[41];
3430                if (len < abblen && abblen <= len + 2)
3431                        sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
3432                else
3433                        sprintf(hex, "%s...", abbrev);
3434                return hex;
3435        }
3436        return sha1_to_hex(sha1);
3437}
3438
3439static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
3440{
3441        int line_termination = opt->line_termination;
3442        int inter_name_termination = line_termination ? '\t' : '\0';
3443        if (opt->output_prefix) {
3444                struct strbuf *msg = NULL;
3445                msg = opt->output_prefix(opt, opt->output_prefix_data);
3446                fprintf(opt->file, "%s", msg->buf);
3447        }
3448
3449        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
3450                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
3451                        diff_unique_abbrev(p->one->sha1, opt->abbrev));
3452                fprintf(opt->file, "%s ", diff_unique_abbrev(p->two->sha1, opt->abbrev));
3453        }
3454        if (p->score) {
3455                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
3456                        inter_name_termination);
3457        } else {
3458                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
3459        }
3460
3461        if (p->status == DIFF_STATUS_COPIED ||
3462            p->status == DIFF_STATUS_RENAMED) {
3463                const char *name_a, *name_b;
3464                name_a = p->one->path;
3465                name_b = p->two->path;
3466                strip_prefix(opt->prefix_length, &name_a, &name_b);
3467                write_name_quoted(name_a, opt->file, inter_name_termination);
3468                write_name_quoted(name_b, opt->file, line_termination);
3469        } else {
3470                const char *name_a, *name_b;
3471                name_a = p->one->mode ? p->one->path : p->two->path;
3472                name_b = NULL;
3473                strip_prefix(opt->prefix_length, &name_a, &name_b);
3474                write_name_quoted(name_a, opt->file, line_termination);
3475        }
3476}
3477
3478int diff_unmodified_pair(struct diff_filepair *p)
3479{
3480        /* This function is written stricter than necessary to support
3481         * the currently implemented transformers, but the idea is to
3482         * let transformers to produce diff_filepairs any way they want,
3483         * and filter and clean them up here before producing the output.
3484         */
3485        struct diff_filespec *one = p->one, *two = p->two;
3486
3487        if (DIFF_PAIR_UNMERGED(p))
3488                return 0; /* unmerged is interesting */
3489
3490        /* deletion, addition, mode or type change
3491         * and rename are all interesting.
3492         */
3493        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
3494            DIFF_PAIR_MODE_CHANGED(p) ||
3495            strcmp(one->path, two->path))
3496                return 0;
3497
3498        /* both are valid and point at the same path.  that is, we are
3499         * dealing with a change.
3500         */
3501        if (one->sha1_valid && two->sha1_valid &&
3502            !hashcmp(one->sha1, two->sha1) &&
3503            !one->dirty_submodule && !two->dirty_submodule)
3504                return 1; /* no change */
3505        if (!one->sha1_valid && !two->sha1_valid)
3506                return 1; /* both look at the same file on the filesystem. */
3507        return 0;
3508}
3509
3510static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
3511{
3512        if (diff_unmodified_pair(p))
3513                return;
3514
3515        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3516            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3517                return; /* no tree diffs in patch format */
3518
3519        run_diff(p, o);
3520}
3521
3522static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
3523                            struct diffstat_t *diffstat)
3524{
3525        if (diff_unmodified_pair(p))
3526                return;
3527
3528        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3529            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3530                return; /* no useful stat for tree diffs */
3531
3532        run_diffstat(p, o, diffstat);
3533}
3534
3535static void diff_flush_checkdiff(struct diff_filepair *p,
3536                struct diff_options *o)
3537{
3538        if (diff_unmodified_pair(p))
3539                return;
3540
3541        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3542            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3543                return; /* nothing to check in tree diffs */
3544
3545        run_checkdiff(p, o);
3546}
3547
3548int diff_queue_is_empty(void)
3549{
3550        struct diff_queue_struct *q = &diff_queued_diff;
3551        int i;
3552        for (i = 0; i < q->nr; i++)
3553                if (!diff_unmodified_pair(q->queue[i]))
3554                        return 0;
3555        return 1;
3556}
3557
3558#if DIFF_DEBUG
3559void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
3560{
3561        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
3562                x, one ? one : "",
3563                s->path,
3564                DIFF_FILE_VALID(s) ? "valid" : "invalid",
3565                s->mode,
3566                s->sha1_valid ? sha1_to_hex(s->sha1) : "");
3567        fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
3568                x, one ? one : "",
3569                s->size, s->xfrm_flags);
3570}
3571
3572void diff_debug_filepair(const struct diff_filepair *p, int i)
3573{
3574        diff_debug_filespec(p->one, i, "one");
3575        diff_debug_filespec(p->two, i, "two");
3576        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
3577                p->score, p->status ? p->status : '?',
3578                p->one->rename_used, p->broken_pair);
3579}
3580
3581void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
3582{
3583        int i;
3584        if (msg)
3585                fprintf(stderr, "%s\n", msg);
3586        fprintf(stderr, "q->nr = %d\n", q->nr);
3587        for (i = 0; i < q->nr; i++) {
3588                struct diff_filepair *p = q->queue[i];
3589                diff_debug_filepair(p, i);
3590        }
3591}
3592#endif
3593
3594static void diff_resolve_rename_copy(void)
3595{
3596        int i;
3597        struct diff_filepair *p;
3598        struct diff_queue_struct *q = &diff_queued_diff;
3599
3600        diff_debug_queue("resolve-rename-copy", q);
3601
3602        for (i = 0; i < q->nr; i++) {
3603                p = q->queue[i];
3604                p->status = 0; /* undecided */
3605                if (DIFF_PAIR_UNMERGED(p))
3606                        p->status = DIFF_STATUS_UNMERGED;
3607                else if (!DIFF_FILE_VALID(p->one))
3608                        p->status = DIFF_STATUS_ADDED;
3609                else if (!DIFF_FILE_VALID(p->two))
3610                        p->status = DIFF_STATUS_DELETED;
3611                else if (DIFF_PAIR_TYPE_CHANGED(p))
3612                        p->status = DIFF_STATUS_TYPE_CHANGED;
3613
3614                /* from this point on, we are dealing with a pair
3615                 * whose both sides are valid and of the same type, i.e.
3616                 * either in-place edit or rename/copy edit.
3617                 */
3618                else if (DIFF_PAIR_RENAME(p)) {
3619                        /*
3620                         * A rename might have re-connected a broken
3621                         * pair up, causing the pathnames to be the
3622                         * same again. If so, that's not a rename at
3623                         * all, just a modification..
3624                         *
3625                         * Otherwise, see if this source was used for
3626                         * multiple renames, in which case we decrement
3627                         * the count, and call it a copy.
3628                         */
3629                        if (!strcmp(p->one->path, p->two->path))
3630                                p->status = DIFF_STATUS_MODIFIED;
3631                        else if (--p->one->rename_used > 0)
3632                                p->status = DIFF_STATUS_COPIED;
3633                        else
3634                                p->status = DIFF_STATUS_RENAMED;
3635                }
3636                else if (hashcmp(p->one->sha1, p->two->sha1) ||
3637                         p->one->mode != p->two->mode ||
3638                         p->one->dirty_submodule ||
3639                         p->two->dirty_submodule ||
3640                         is_null_sha1(p->one->sha1))
3641                        p->status = DIFF_STATUS_MODIFIED;
3642                else {
3643                        /* This is a "no-change" entry and should not
3644                         * happen anymore, but prepare for broken callers.
3645                         */
3646                        error("feeding unmodified %s to diffcore",
3647                              p->one->path);
3648                        p->status = DIFF_STATUS_UNKNOWN;
3649                }
3650        }
3651        diff_debug_queue("resolve-rename-copy done", q);
3652}
3653
3654static int check_pair_status(struct diff_filepair *p)
3655{
3656        switch (p->status) {
3657        case DIFF_STATUS_UNKNOWN:
3658                return 0;
3659        case 0:
3660                die("internal error in diff-resolve-rename-copy");
3661        default:
3662                return 1;
3663        }
3664}
3665
3666static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
3667{
3668        int fmt = opt->output_format;
3669
3670        if (fmt & DIFF_FORMAT_CHECKDIFF)
3671                diff_flush_checkdiff(p, opt);
3672        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
3673                diff_flush_raw(p, opt);
3674        else if (fmt & DIFF_FORMAT_NAME) {
3675                const char *name_a, *name_b;
3676                name_a = p->two->path;
3677                name_b = NULL;
3678                strip_prefix(opt->prefix_length, &name_a, &name_b);
3679                write_name_quoted(name_a, opt->file, opt->line_termination);
3680        }
3681}
3682
3683static void show_file_mode_name(FILE *file, const char *newdelete, struct diff_filespec *fs)
3684{
3685        if (fs->mode)
3686                fprintf(file, " %s mode %06o ", newdelete, fs->mode);
3687        else
3688                fprintf(file, " %s ", newdelete);
3689        write_name_quoted(fs->path, file, '\n');
3690}
3691
3692
3693static void show_mode_change(FILE *file, struct diff_filepair *p, int show_name,
3694                const char *line_prefix)
3695{
3696        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
3697                fprintf(file, "%s mode change %06o => %06o%c", line_prefix, p->one->mode,
3698                        p->two->mode, show_name ? ' ' : '\n');
3699                if (show_name) {
3700                        write_name_quoted(p->two->path, file, '\n');
3701                }
3702        }
3703}
3704
3705static void show_rename_copy(FILE *file, const char *renamecopy, struct diff_filepair *p,
3706                        const char *line_prefix)
3707{
3708        char *names = pprint_rename(p->one->path, p->two->path);
3709
3710        fprintf(file, " %s %s (%d%%)\n", renamecopy, names, similarity_index(p));
3711        free(names);
3712        show_mode_change(file, p, 0, line_prefix);
3713}
3714
3715static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
3716{
3717        FILE *file = opt->file;
3718        char *line_prefix = "";
3719
3720        if (opt->output_prefix) {
3721                struct strbuf *buf = opt->output_prefix(opt, opt->output_prefix_data);
3722                line_prefix = buf->buf;
3723        }
3724
3725        switch(p->status) {
3726        case DIFF_STATUS_DELETED:
3727                fputs(line_prefix, file);
3728                show_file_mode_name(file, "delete", p->one);
3729                break;
3730        case DIFF_STATUS_ADDED:
3731                fputs(line_prefix, file);
3732                show_file_mode_name(file, "create", p->two);
3733                break;
3734        case DIFF_STATUS_COPIED:
3735                fputs(line_prefix, file);
3736                show_rename_copy(file, "copy", p, line_prefix);
3737                break;
3738        case DIFF_STATUS_RENAMED:
3739                fputs(line_prefix, file);
3740                show_rename_copy(file, "rename", p, line_prefix);
3741                break;
3742        default:
3743                if (p->score) {
3744                        fprintf(file, "%s rewrite ", line_prefix);
3745                        write_name_quoted(p->two->path, file, ' ');
3746                        fprintf(file, "(%d%%)\n", similarity_index(p));
3747                }
3748                show_mode_change(file, p, !p->score, line_prefix);
3749                break;
3750        }
3751}
3752
3753struct patch_id_t {
3754        git_SHA_CTX *ctx;
3755        int patchlen;
3756};
3757
3758static int remove_space(char *line, int len)
3759{
3760        int i;
3761        char *dst = line;
3762        unsigned char c;
3763
3764        for (i = 0; i < len; i++)
3765                if (!isspace((c = line[i])))
3766                        *dst++ = c;
3767
3768        return dst - line;
3769}
3770
3771static void patch_id_consume(void *priv, char *line, unsigned long len)
3772{
3773        struct patch_id_t *data = priv;
3774        int new_len;
3775
3776        /* Ignore line numbers when computing the SHA1 of the patch */
3777        if (!prefixcmp(line, "@@ -"))
3778                return;
3779
3780        new_len = remove_space(line, len);
3781
3782        git_SHA1_Update(data->ctx, line, new_len);
3783        data->patchlen += new_len;
3784}
3785
3786/* returns 0 upon success, and writes result into sha1 */
3787static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
3788{
3789        struct diff_queue_struct *q = &diff_queued_diff;
3790        int i;
3791        git_SHA_CTX ctx;
3792        struct patch_id_t data;
3793        char buffer[PATH_MAX * 4 + 20];
3794
3795        git_SHA1_Init(&ctx);
3796        memset(&data, 0, sizeof(struct patch_id_t));
3797        data.ctx = &ctx;
3798
3799        for (i = 0; i < q->nr; i++) {
3800                xpparam_t xpp;
3801                xdemitconf_t xecfg;
3802                mmfile_t mf1, mf2;
3803                struct diff_filepair *p = q->queue[i];
3804                int len1, len2;
3805
3806                memset(&xpp, 0, sizeof(xpp));
3807                memset(&xecfg, 0, sizeof(xecfg));
3808                if (p->status == 0)
3809                        return error("internal diff status error");
3810                if (p->status == DIFF_STATUS_UNKNOWN)
3811                        continue;
3812                if (diff_unmodified_pair(p))
3813                        continue;
3814                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3815                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3816                        continue;
3817                if (DIFF_PAIR_UNMERGED(p))
3818                        continue;
3819
3820                diff_fill_sha1_info(p->one);
3821                diff_fill_sha1_info(p->two);
3822                if (fill_mmfile(&mf1, p->one) < 0 ||
3823                                fill_mmfile(&mf2, p->two) < 0)
3824                        return error("unable to read files to diff");
3825
3826                len1 = remove_space(p->one->path, strlen(p->one->path));
3827                len2 = remove_space(p->two->path, strlen(p->two->path));
3828                if (p->one->mode == 0)
3829                        len1 = snprintf(buffer, sizeof(buffer),
3830                                        "diff--gita/%.*sb/%.*s"
3831                                        "newfilemode%06o"
3832                                        "---/dev/null"
3833                                        "+++b/%.*s",
3834                                        len1, p->one->path,
3835                                        len2, p->two->path,
3836                                        p->two->mode,
3837                                        len2, p->two->path);
3838                else if (p->two->mode == 0)
3839                        len1 = snprintf(buffer, sizeof(buffer),
3840                                        "diff--gita/%.*sb/%.*s"
3841                                        "deletedfilemode%06o"
3842                                        "---a/%.*s"
3843                                        "+++/dev/null",
3844                                        len1, p->one->path,
3845                                        len2, p->two->path,
3846                                        p->one->mode,
3847                                        len1, p->one->path);
3848                else
3849                        len1 = snprintf(buffer, sizeof(buffer),
3850                                        "diff--gita/%.*sb/%.*s"
3851                                        "---a/%.*s"
3852                                        "+++b/%.*s",
3853                                        len1, p->one->path,
3854                                        len2, p->two->path,
3855                                        len1, p->one->path,
3856                                        len2, p->two->path);
3857                git_SHA1_Update(&ctx, buffer, len1);
3858
3859                if (diff_filespec_is_binary(p->one) ||
3860                    diff_filespec_is_binary(p->two)) {
3861                        git_SHA1_Update(&ctx, sha1_to_hex(p->one->sha1), 40);
3862                        git_SHA1_Update(&ctx, sha1_to_hex(p->two->sha1), 40);
3863                        continue;
3864                }
3865
3866                xpp.flags = 0;
3867                xecfg.ctxlen = 3;
3868                xecfg.flags = XDL_EMIT_FUNCNAMES;
3869                xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
3870                              &xpp, &xecfg);
3871        }
3872
3873        git_SHA1_Final(sha1, &ctx);
3874        return 0;
3875}
3876
3877int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1)
3878{
3879        struct diff_queue_struct *q = &diff_queued_diff;
3880        int i;
3881        int result = diff_get_patch_id(options, sha1);
3882
3883        for (i = 0; i < q->nr; i++)
3884                diff_free_filepair(q->queue[i]);
3885
3886        free(q->queue);
3887        DIFF_QUEUE_CLEAR(q);
3888
3889        return result;
3890}
3891
3892static int is_summary_empty(const struct diff_queue_struct *q)
3893{
3894        int i;
3895
3896        for (i = 0; i < q->nr; i++) {
3897                const struct diff_filepair *p = q->queue[i];
3898
3899                switch (p->status) {
3900                case DIFF_STATUS_DELETED:
3901                case DIFF_STATUS_ADDED:
3902                case DIFF_STATUS_COPIED:
3903                case DIFF_STATUS_RENAMED:
3904                        return 0;
3905                default:
3906                        if (p->score)
3907                                return 0;
3908                        if (p->one->mode && p->two->mode &&
3909                            p->one->mode != p->two->mode)
3910                                return 0;
3911                        break;
3912                }
3913        }
3914        return 1;
3915}
3916
3917void diff_flush(struct diff_options *options)
3918{
3919        struct diff_queue_struct *q = &diff_queued_diff;
3920        int i, output_format = options->output_format;
3921        int separator = 0;
3922
3923        /*
3924         * Order: raw, stat, summary, patch
3925         * or:    name/name-status/checkdiff (other bits clear)
3926         */
3927        if (!q->nr)
3928                goto free_queue;
3929
3930        if (output_format & (DIFF_FORMAT_RAW |
3931                             DIFF_FORMAT_NAME |
3932                             DIFF_FORMAT_NAME_STATUS |
3933                             DIFF_FORMAT_CHECKDIFF)) {
3934                for (i = 0; i < q->nr; i++) {
3935                        struct diff_filepair *p = q->queue[i];
3936                        if (check_pair_status(p))
3937                                flush_one_pair(p, options);
3938                }
3939                separator++;
3940        }
3941
3942        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT)) {
3943                struct diffstat_t diffstat;
3944
3945                memset(&diffstat, 0, sizeof(struct diffstat_t));
3946                for (i = 0; i < q->nr; i++) {
3947                        struct diff_filepair *p = q->queue[i];
3948                        if (check_pair_status(p))
3949                                diff_flush_stat(p, options, &diffstat);
3950                }
3951                if (output_format & DIFF_FORMAT_NUMSTAT)
3952                        show_numstat(&diffstat, options);
3953                if (output_format & DIFF_FORMAT_DIFFSTAT)
3954                        show_stats(&diffstat, options);
3955                if (output_format & DIFF_FORMAT_SHORTSTAT)
3956                        show_shortstats(&diffstat, options);
3957                free_diffstat_info(&diffstat);
3958                separator++;
3959        }
3960        if (output_format & DIFF_FORMAT_DIRSTAT)
3961                show_dirstat(options);
3962
3963        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
3964                for (i = 0; i < q->nr; i++) {
3965                        diff_summary(options, q->queue[i]);
3966                }
3967                separator++;
3968        }
3969
3970        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
3971            DIFF_OPT_TST(options, EXIT_WITH_STATUS) &&
3972            DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
3973                /*
3974                 * run diff_flush_patch for the exit status. setting
3975                 * options->file to /dev/null should be safe, becaue we
3976                 * aren't supposed to produce any output anyway.
3977                 */
3978                if (options->close_file)
3979                        fclose(options->file);
3980                options->file = fopen("/dev/null", "w");
3981                if (!options->file)
3982                        die_errno("Could not open /dev/null");
3983                options->close_file = 1;
3984                for (i = 0; i < q->nr; i++) {
3985                        struct diff_filepair *p = q->queue[i];
3986                        if (check_pair_status(p))
3987                                diff_flush_patch(p, options);
3988                        if (options->found_changes)
3989                                break;
3990                }
3991        }
3992
3993        if (output_format & DIFF_FORMAT_PATCH) {
3994                if (separator) {
3995                        putc(options->line_termination, options->file);
3996                        if (options->stat_sep) {
3997                                /* attach patch instead of inline */
3998                                fputs(options->stat_sep, options->file);
3999                        }
4000                }
4001
4002                for (i = 0; i < q->nr; i++) {
4003                        struct diff_filepair *p = q->queue[i];
4004                        if (check_pair_status(p))
4005                                diff_flush_patch(p, options);
4006                }
4007        }
4008
4009        if (output_format & DIFF_FORMAT_CALLBACK)
4010                options->format_callback(q, options, options->format_callback_data);
4011
4012        for (i = 0; i < q->nr; i++)
4013                diff_free_filepair(q->queue[i]);
4014free_queue:
4015        free(q->queue);
4016        DIFF_QUEUE_CLEAR(q);
4017        if (options->close_file)
4018                fclose(options->file);
4019
4020        /*
4021         * Report the content-level differences with HAS_CHANGES;
4022         * diff_addremove/diff_change does not set the bit when
4023         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
4024         */
4025        if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4026                if (options->found_changes)
4027                        DIFF_OPT_SET(options, HAS_CHANGES);
4028                else
4029                        DIFF_OPT_CLR(options, HAS_CHANGES);
4030        }
4031}
4032
4033static void diffcore_apply_filter(const char *filter)
4034{
4035        int i;
4036        struct diff_queue_struct *q = &diff_queued_diff;
4037        struct diff_queue_struct outq;
4038        DIFF_QUEUE_CLEAR(&outq);
4039
4040        if (!filter)
4041                return;
4042
4043        if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
4044                int found;
4045                for (i = found = 0; !found && i < q->nr; i++) {
4046                        struct diff_filepair *p = q->queue[i];
4047                        if (((p->status == DIFF_STATUS_MODIFIED) &&
4048                             ((p->score &&
4049                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
4050                              (!p->score &&
4051                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
4052                            ((p->status != DIFF_STATUS_MODIFIED) &&
4053                             strchr(filter, p->status)))
4054                                found++;
4055                }
4056                if (found)
4057                        return;
4058
4059                /* otherwise we will clear the whole queue
4060                 * by copying the empty outq at the end of this
4061                 * function, but first clear the current entries
4062                 * in the queue.
4063                 */
4064                for (i = 0; i < q->nr; i++)
4065                        diff_free_filepair(q->queue[i]);
4066        }
4067        else {
4068                /* Only the matching ones */
4069                for (i = 0; i < q->nr; i++) {
4070                        struct diff_filepair *p = q->queue[i];
4071
4072                        if (((p->status == DIFF_STATUS_MODIFIED) &&
4073                             ((p->score &&
4074                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
4075                              (!p->score &&
4076                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
4077                            ((p->status != DIFF_STATUS_MODIFIED) &&
4078                             strchr(filter, p->status)))
4079                                diff_q(&outq, p);
4080                        else
4081                                diff_free_filepair(p);
4082                }
4083        }
4084        free(q->queue);
4085        *q = outq;
4086}
4087
4088/* Check whether two filespecs with the same mode and size are identical */
4089static int diff_filespec_is_identical(struct diff_filespec *one,
4090                                      struct diff_filespec *two)
4091{
4092        if (S_ISGITLINK(one->mode))
4093                return 0;
4094        if (diff_populate_filespec(one, 0))
4095                return 0;
4096        if (diff_populate_filespec(two, 0))
4097                return 0;
4098        return !memcmp(one->data, two->data, one->size);
4099}
4100
4101static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
4102{
4103        int i;
4104        struct diff_queue_struct *q = &diff_queued_diff;
4105        struct diff_queue_struct outq;
4106        DIFF_QUEUE_CLEAR(&outq);
4107
4108        for (i = 0; i < q->nr; i++) {
4109                struct diff_filepair *p = q->queue[i];
4110
4111                /*
4112                 * 1. Entries that come from stat info dirtiness
4113                 *    always have both sides (iow, not create/delete),
4114                 *    one side of the object name is unknown, with
4115                 *    the same mode and size.  Keep the ones that
4116                 *    do not match these criteria.  They have real
4117                 *    differences.
4118                 *
4119                 * 2. At this point, the file is known to be modified,
4120                 *    with the same mode and size, and the object
4121                 *    name of one side is unknown.  Need to inspect
4122                 *    the identical contents.
4123                 */
4124                if (!DIFF_FILE_VALID(p->one) || /* (1) */
4125                    !DIFF_FILE_VALID(p->two) ||
4126                    (p->one->sha1_valid && p->two->sha1_valid) ||
4127                    (p->one->mode != p->two->mode) ||
4128                    diff_populate_filespec(p->one, 1) ||
4129                    diff_populate_filespec(p->two, 1) ||
4130                    (p->one->size != p->two->size) ||
4131                    !diff_filespec_is_identical(p->one, p->two)) /* (2) */
4132                        diff_q(&outq, p);
4133                else {
4134                        /*
4135                         * The caller can subtract 1 from skip_stat_unmatch
4136                         * to determine how many paths were dirty only
4137                         * due to stat info mismatch.
4138                         */
4139                        if (!DIFF_OPT_TST(diffopt, NO_INDEX))
4140                                diffopt->skip_stat_unmatch++;
4141                        diff_free_filepair(p);
4142                }
4143        }
4144        free(q->queue);
4145        *q = outq;
4146}
4147
4148static int diffnamecmp(const void *a_, const void *b_)
4149{
4150        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
4151        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
4152        const char *name_a, *name_b;
4153
4154        name_a = a->one ? a->one->path : a->two->path;
4155        name_b = b->one ? b->one->path : b->two->path;
4156        return strcmp(name_a, name_b);
4157}
4158
4159void diffcore_fix_diff_index(struct diff_options *options)
4160{
4161        struct diff_queue_struct *q = &diff_queued_diff;
4162        qsort(q->queue, q->nr, sizeof(q->queue[0]), diffnamecmp);
4163}
4164
4165void diffcore_std(struct diff_options *options)
4166{
4167        if (options->skip_stat_unmatch)
4168                diffcore_skip_stat_unmatch(options);
4169        if (!options->found_follow) {
4170                /* See try_to_follow_renames() in tree-diff.c */
4171                if (options->break_opt != -1)
4172                        diffcore_break(options->break_opt);
4173                if (options->detect_rename)
4174                        diffcore_rename(options);
4175                if (options->break_opt != -1)
4176                        diffcore_merge_broken();
4177        }
4178        if (options->pickaxe)
4179                diffcore_pickaxe(options->pickaxe, options->pickaxe_opts);
4180        if (options->orderfile)
4181                diffcore_order(options->orderfile);
4182        if (!options->found_follow)
4183                /* See try_to_follow_renames() in tree-diff.c */
4184                diff_resolve_rename_copy();
4185        diffcore_apply_filter(options->filter);
4186
4187        if (diff_queued_diff.nr && !DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4188                DIFF_OPT_SET(options, HAS_CHANGES);
4189        else
4190                DIFF_OPT_CLR(options, HAS_CHANGES);
4191
4192        options->found_follow = 0;
4193}
4194
4195int diff_result_code(struct diff_options *opt, int status)
4196{
4197        int result = 0;
4198        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4199            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
4200                return status;
4201        if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4202            DIFF_OPT_TST(opt, HAS_CHANGES))
4203                result |= 01;
4204        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
4205            DIFF_OPT_TST(opt, CHECK_FAILED))
4206                result |= 02;
4207        return result;
4208}
4209
4210/*
4211 * Shall changes to this submodule be ignored?
4212 *
4213 * Submodule changes can be configured to be ignored separately for each path,
4214 * but that configuration can be overridden from the command line.
4215 */
4216static int is_submodule_ignored(const char *path, struct diff_options *options)
4217{
4218        int ignored = 0;
4219        unsigned orig_flags = options->flags;
4220        if (!DIFF_OPT_TST(options, OVERRIDE_SUBMODULE_CONFIG))
4221                set_diffopt_flags_from_submodule_config(options, path);
4222        if (DIFF_OPT_TST(options, IGNORE_SUBMODULES))
4223                ignored = 1;
4224        options->flags = orig_flags;
4225        return ignored;
4226}
4227
4228void diff_addremove(struct diff_options *options,
4229                    int addremove, unsigned mode,
4230                    const unsigned char *sha1,
4231                    const char *concatpath, unsigned dirty_submodule)
4232{
4233        struct diff_filespec *one, *two;
4234
4235        if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
4236                return;
4237
4238        /* This may look odd, but it is a preparation for
4239         * feeding "there are unchanged files which should
4240         * not produce diffs, but when you are doing copy
4241         * detection you would need them, so here they are"
4242         * entries to the diff-core.  They will be prefixed
4243         * with something like '=' or '*' (I haven't decided
4244         * which but should not make any difference).
4245         * Feeding the same new and old to diff_change()
4246         * also has the same effect.
4247         * Before the final output happens, they are pruned after
4248         * merged into rename/copy pairs as appropriate.
4249         */
4250        if (DIFF_OPT_TST(options, REVERSE_DIFF))
4251                addremove = (addremove == '+' ? '-' :
4252                             addremove == '-' ? '+' : addremove);
4253
4254        if (options->prefix &&
4255            strncmp(concatpath, options->prefix, options->prefix_length))
4256                return;
4257
4258        one = alloc_filespec(concatpath);
4259        two = alloc_filespec(concatpath);
4260
4261        if (addremove != '+')
4262                fill_filespec(one, sha1, mode);
4263        if (addremove != '-') {
4264                fill_filespec(two, sha1, mode);
4265                two->dirty_submodule = dirty_submodule;
4266        }
4267
4268        diff_queue(&diff_queued_diff, one, two);
4269        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4270                DIFF_OPT_SET(options, HAS_CHANGES);
4271}
4272
4273void diff_change(struct diff_options *options,
4274                 unsigned old_mode, unsigned new_mode,
4275                 const unsigned char *old_sha1,
4276                 const unsigned char *new_sha1,
4277                 const char *concatpath,
4278                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
4279{
4280        struct diff_filespec *one, *two;
4281
4282        if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
4283            is_submodule_ignored(concatpath, options))
4284                return;
4285
4286        if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
4287                unsigned tmp;
4288                const unsigned char *tmp_c;
4289                tmp = old_mode; old_mode = new_mode; new_mode = tmp;
4290                tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
4291                tmp = old_dirty_submodule; old_dirty_submodule = new_dirty_submodule;
4292                        new_dirty_submodule = tmp;
4293        }
4294
4295        if (options->prefix &&
4296            strncmp(concatpath, options->prefix, options->prefix_length))
4297                return;
4298
4299        one = alloc_filespec(concatpath);
4300        two = alloc_filespec(concatpath);
4301        fill_filespec(one, old_sha1, old_mode);
4302        fill_filespec(two, new_sha1, new_mode);
4303        one->dirty_submodule = old_dirty_submodule;
4304        two->dirty_submodule = new_dirty_submodule;
4305
4306        diff_queue(&diff_queued_diff, one, two);
4307        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4308                DIFF_OPT_SET(options, HAS_CHANGES);
4309}
4310
4311void diff_unmerge(struct diff_options *options,
4312                  const char *path,
4313                  unsigned mode, const unsigned char *sha1)
4314{
4315        struct diff_filespec *one, *two;
4316
4317        if (options->prefix &&
4318            strncmp(path, options->prefix, options->prefix_length))
4319                return;
4320
4321        one = alloc_filespec(path);
4322        two = alloc_filespec(path);
4323        fill_filespec(one, sha1, mode);
4324        diff_queue(&diff_queued_diff, one, two)->is_unmerged = 1;
4325}
4326
4327static char *run_textconv(const char *pgm, struct diff_filespec *spec,
4328                size_t *outsize)
4329{
4330        struct diff_tempfile *temp;
4331        const char *argv[3];
4332        const char **arg = argv;
4333        struct child_process child;
4334        struct strbuf buf = STRBUF_INIT;
4335        int err = 0;
4336
4337        temp = prepare_temp_file(spec->path, spec);
4338        *arg++ = pgm;
4339        *arg++ = temp->name;
4340        *arg = NULL;
4341
4342        memset(&child, 0, sizeof(child));
4343        child.use_shell = 1;
4344        child.argv = argv;
4345        child.out = -1;
4346        if (start_command(&child)) {
4347                remove_tempfile();
4348                return NULL;
4349        }
4350
4351        if (strbuf_read(&buf, child.out, 0) < 0)
4352                err = error("error reading from textconv command '%s'", pgm);
4353        close(child.out);
4354
4355        if (finish_command(&child) || err) {
4356                strbuf_release(&buf);
4357                remove_tempfile();
4358                return NULL;
4359        }
4360        remove_tempfile();
4361
4362        return strbuf_detach(&buf, outsize);
4363}
4364
4365size_t fill_textconv(struct userdiff_driver *driver,
4366                     struct diff_filespec *df,
4367                     char **outbuf)
4368{
4369        size_t size;
4370
4371        if (!driver || !driver->textconv) {
4372                if (!DIFF_FILE_VALID(df)) {
4373                        *outbuf = "";
4374                        return 0;
4375                }
4376                if (diff_populate_filespec(df, 0))
4377                        die("unable to read files to diff");
4378                *outbuf = df->data;
4379                return df->size;
4380        }
4381
4382        if (driver->textconv_cache) {
4383                *outbuf = notes_cache_get(driver->textconv_cache, df->sha1,
4384                                          &size);
4385                if (*outbuf)
4386                        return size;
4387        }
4388
4389        *outbuf = run_textconv(driver->textconv, df, &size);
4390        if (!*outbuf)
4391                die("unable to read files to diff");
4392
4393        if (driver->textconv_cache) {
4394                /* ignore errors, as we might be in a readonly repository */
4395                notes_cache_put(driver->textconv_cache, df->sha1, *outbuf,
4396                                size);
4397                /*
4398                 * we could save up changes and flush them all at the end,
4399                 * but we would need an extra call after all diffing is done.
4400                 * Since generating a cache entry is the slow path anyway,
4401                 * this extra overhead probably isn't a big deal.
4402                 */
4403                notes_cache_write(driver->textconv_cache);
4404        }
4405
4406        return size;
4407}