diff.con commit Allow git commit --interactive with paths (e41fcfe)
   1/*
   2 * Copyright (C) 2005 Junio C Hamano
   3 */
   4#include "cache.h"
   5#include "quote.h"
   6#include "diff.h"
   7#include "diffcore.h"
   8#include "delta.h"
   9#include "xdiff-interface.h"
  10#include "color.h"
  11#include "attr.h"
  12#include "run-command.h"
  13#include "utf8.h"
  14#include "userdiff.h"
  15#include "sigchain.h"
  16#include "submodule.h"
  17#include "ll-merge.h"
  18
  19#ifdef NO_FAST_WORKING_DIRECTORY
  20#define FAST_WORKING_DIRECTORY 0
  21#else
  22#define FAST_WORKING_DIRECTORY 1
  23#endif
  24
  25static int diff_detect_rename_default;
  26static int diff_rename_limit_default = 400;
  27static int diff_suppress_blank_empty;
  28int diff_use_color_default = -1;
  29static const char *diff_word_regex_cfg;
  30static const char *external_diff_cmd_cfg;
  31int diff_auto_refresh_index = 1;
  32static int diff_mnemonic_prefix;
  33static int diff_no_prefix;
  34static struct diff_options default_diff_options;
  35
  36static char diff_colors[][COLOR_MAXLEN] = {
  37        GIT_COLOR_RESET,
  38        GIT_COLOR_NORMAL,       /* PLAIN */
  39        GIT_COLOR_BOLD,         /* METAINFO */
  40        GIT_COLOR_CYAN,         /* FRAGINFO */
  41        GIT_COLOR_RED,          /* OLD */
  42        GIT_COLOR_GREEN,        /* NEW */
  43        GIT_COLOR_YELLOW,       /* COMMIT */
  44        GIT_COLOR_BG_RED,       /* WHITESPACE */
  45        GIT_COLOR_NORMAL,       /* FUNCINFO */
  46};
  47
  48static int parse_diff_color_slot(const char *var, int ofs)
  49{
  50        if (!strcasecmp(var+ofs, "plain"))
  51                return DIFF_PLAIN;
  52        if (!strcasecmp(var+ofs, "meta"))
  53                return DIFF_METAINFO;
  54        if (!strcasecmp(var+ofs, "frag"))
  55                return DIFF_FRAGINFO;
  56        if (!strcasecmp(var+ofs, "old"))
  57                return DIFF_FILE_OLD;
  58        if (!strcasecmp(var+ofs, "new"))
  59                return DIFF_FILE_NEW;
  60        if (!strcasecmp(var+ofs, "commit"))
  61                return DIFF_COMMIT;
  62        if (!strcasecmp(var+ofs, "whitespace"))
  63                return DIFF_WHITESPACE;
  64        if (!strcasecmp(var+ofs, "func"))
  65                return DIFF_FUNCINFO;
  66        return -1;
  67}
  68
  69static int git_config_rename(const char *var, const char *value)
  70{
  71        if (!value)
  72                return DIFF_DETECT_RENAME;
  73        if (!strcasecmp(value, "copies") || !strcasecmp(value, "copy"))
  74                return  DIFF_DETECT_COPY;
  75        return git_config_bool(var,value) ? DIFF_DETECT_RENAME : 0;
  76}
  77
  78/*
  79 * These are to give UI layer defaults.
  80 * The core-level commands such as git-diff-files should
  81 * never be affected by the setting of diff.renames
  82 * the user happens to have in the configuration file.
  83 */
  84int git_diff_ui_config(const char *var, const char *value, void *cb)
  85{
  86        if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
  87                diff_use_color_default = git_config_colorbool(var, value, -1);
  88                return 0;
  89        }
  90        if (!strcmp(var, "diff.renames")) {
  91                diff_detect_rename_default = git_config_rename(var, value);
  92                return 0;
  93        }
  94        if (!strcmp(var, "diff.autorefreshindex")) {
  95                diff_auto_refresh_index = git_config_bool(var, value);
  96                return 0;
  97        }
  98        if (!strcmp(var, "diff.mnemonicprefix")) {
  99                diff_mnemonic_prefix = git_config_bool(var, value);
 100                return 0;
 101        }
 102        if (!strcmp(var, "diff.noprefix")) {
 103                diff_no_prefix = git_config_bool(var, value);
 104                return 0;
 105        }
 106        if (!strcmp(var, "diff.external"))
 107                return git_config_string(&external_diff_cmd_cfg, var, value);
 108        if (!strcmp(var, "diff.wordregex"))
 109                return git_config_string(&diff_word_regex_cfg, var, value);
 110
 111        if (!strcmp(var, "diff.ignoresubmodules"))
 112                handle_ignore_submodules_arg(&default_diff_options, value);
 113
 114        return git_diff_basic_config(var, value, cb);
 115}
 116
 117int git_diff_basic_config(const char *var, const char *value, void *cb)
 118{
 119        if (!strcmp(var, "diff.renamelimit")) {
 120                diff_rename_limit_default = git_config_int(var, value);
 121                return 0;
 122        }
 123
 124        switch (userdiff_config(var, value)) {
 125                case 0: break;
 126                case -1: return -1;
 127                default: return 0;
 128        }
 129
 130        if (!prefixcmp(var, "diff.color.") || !prefixcmp(var, "color.diff.")) {
 131                int slot = parse_diff_color_slot(var, 11);
 132                if (slot < 0)
 133                        return 0;
 134                if (!value)
 135                        return config_error_nonbool(var);
 136                color_parse(value, var, diff_colors[slot]);
 137                return 0;
 138        }
 139
 140        /* like GNU diff's --suppress-blank-empty option  */
 141        if (!strcmp(var, "diff.suppressblankempty") ||
 142                        /* for backwards compatibility */
 143                        !strcmp(var, "diff.suppress-blank-empty")) {
 144                diff_suppress_blank_empty = git_config_bool(var, value);
 145                return 0;
 146        }
 147
 148        if (!prefixcmp(var, "submodule."))
 149                return parse_submodule_config_option(var, value);
 150
 151        return git_color_default_config(var, value, cb);
 152}
 153
 154static char *quote_two(const char *one, const char *two)
 155{
 156        int need_one = quote_c_style(one, NULL, NULL, 1);
 157        int need_two = quote_c_style(two, NULL, NULL, 1);
 158        struct strbuf res = STRBUF_INIT;
 159
 160        if (need_one + need_two) {
 161                strbuf_addch(&res, '"');
 162                quote_c_style(one, &res, NULL, 1);
 163                quote_c_style(two, &res, NULL, 1);
 164                strbuf_addch(&res, '"');
 165        } else {
 166                strbuf_addstr(&res, one);
 167                strbuf_addstr(&res, two);
 168        }
 169        return strbuf_detach(&res, NULL);
 170}
 171
 172static const char *external_diff(void)
 173{
 174        static const char *external_diff_cmd = NULL;
 175        static int done_preparing = 0;
 176
 177        if (done_preparing)
 178                return external_diff_cmd;
 179        external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
 180        if (!external_diff_cmd)
 181                external_diff_cmd = external_diff_cmd_cfg;
 182        done_preparing = 1;
 183        return external_diff_cmd;
 184}
 185
 186static struct diff_tempfile {
 187        const char *name; /* filename external diff should read from */
 188        char hex[41];
 189        char mode[10];
 190        char tmp_path[PATH_MAX];
 191} diff_temp[2];
 192
 193typedef unsigned long (*sane_truncate_fn)(char *line, unsigned long len);
 194
 195struct emit_callback {
 196        int color_diff;
 197        unsigned ws_rule;
 198        int blank_at_eof_in_preimage;
 199        int blank_at_eof_in_postimage;
 200        int lno_in_preimage;
 201        int lno_in_postimage;
 202        sane_truncate_fn truncate;
 203        const char **label_path;
 204        struct diff_words_data *diff_words;
 205        struct diff_options *opt;
 206        int *found_changesp;
 207        struct strbuf *header;
 208};
 209
 210static int count_lines(const char *data, int size)
 211{
 212        int count, ch, completely_empty = 1, nl_just_seen = 0;
 213        count = 0;
 214        while (0 < size--) {
 215                ch = *data++;
 216                if (ch == '\n') {
 217                        count++;
 218                        nl_just_seen = 1;
 219                        completely_empty = 0;
 220                }
 221                else {
 222                        nl_just_seen = 0;
 223                        completely_empty = 0;
 224                }
 225        }
 226        if (completely_empty)
 227                return 0;
 228        if (!nl_just_seen)
 229                count++; /* no trailing newline */
 230        return count;
 231}
 232
 233static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
 234{
 235        if (!DIFF_FILE_VALID(one)) {
 236                mf->ptr = (char *)""; /* does not matter */
 237                mf->size = 0;
 238                return 0;
 239        }
 240        else if (diff_populate_filespec(one, 0))
 241                return -1;
 242
 243        mf->ptr = one->data;
 244        mf->size = one->size;
 245        return 0;
 246}
 247
 248/* like fill_mmfile, but only for size, so we can avoid retrieving blob */
 249static unsigned long diff_filespec_size(struct diff_filespec *one)
 250{
 251        if (!DIFF_FILE_VALID(one))
 252                return 0;
 253        diff_populate_filespec(one, 1);
 254        return one->size;
 255}
 256
 257static int count_trailing_blank(mmfile_t *mf, unsigned ws_rule)
 258{
 259        char *ptr = mf->ptr;
 260        long size = mf->size;
 261        int cnt = 0;
 262
 263        if (!size)
 264                return cnt;
 265        ptr += size - 1; /* pointing at the very end */
 266        if (*ptr != '\n')
 267                ; /* incomplete line */
 268        else
 269                ptr--; /* skip the last LF */
 270        while (mf->ptr < ptr) {
 271                char *prev_eol;
 272                for (prev_eol = ptr; mf->ptr <= prev_eol; prev_eol--)
 273                        if (*prev_eol == '\n')
 274                                break;
 275                if (!ws_blank_line(prev_eol + 1, ptr - prev_eol, ws_rule))
 276                        break;
 277                cnt++;
 278                ptr = prev_eol - 1;
 279        }
 280        return cnt;
 281}
 282
 283static void check_blank_at_eof(mmfile_t *mf1, mmfile_t *mf2,
 284                               struct emit_callback *ecbdata)
 285{
 286        int l1, l2, at;
 287        unsigned ws_rule = ecbdata->ws_rule;
 288        l1 = count_trailing_blank(mf1, ws_rule);
 289        l2 = count_trailing_blank(mf2, ws_rule);
 290        if (l2 <= l1) {
 291                ecbdata->blank_at_eof_in_preimage = 0;
 292                ecbdata->blank_at_eof_in_postimage = 0;
 293                return;
 294        }
 295        at = count_lines(mf1->ptr, mf1->size);
 296        ecbdata->blank_at_eof_in_preimage = (at - l1) + 1;
 297
 298        at = count_lines(mf2->ptr, mf2->size);
 299        ecbdata->blank_at_eof_in_postimage = (at - l2) + 1;
 300}
 301
 302static void emit_line_0(struct diff_options *o, const char *set, const char *reset,
 303                        int first, const char *line, int len)
 304{
 305        int has_trailing_newline, has_trailing_carriage_return;
 306        int nofirst;
 307        FILE *file = o->file;
 308
 309        if (o->output_prefix) {
 310                struct strbuf *msg = NULL;
 311                msg = o->output_prefix(o, o->output_prefix_data);
 312                assert(msg);
 313                fwrite(msg->buf, msg->len, 1, file);
 314        }
 315
 316        if (len == 0) {
 317                has_trailing_newline = (first == '\n');
 318                has_trailing_carriage_return = (!has_trailing_newline &&
 319                                                (first == '\r'));
 320                nofirst = has_trailing_newline || has_trailing_carriage_return;
 321        } else {
 322                has_trailing_newline = (len > 0 && line[len-1] == '\n');
 323                if (has_trailing_newline)
 324                        len--;
 325                has_trailing_carriage_return = (len > 0 && line[len-1] == '\r');
 326                if (has_trailing_carriage_return)
 327                        len--;
 328                nofirst = 0;
 329        }
 330
 331        if (len || !nofirst) {
 332                fputs(set, file);
 333                if (!nofirst)
 334                        fputc(first, file);
 335                fwrite(line, len, 1, file);
 336                fputs(reset, file);
 337        }
 338        if (has_trailing_carriage_return)
 339                fputc('\r', file);
 340        if (has_trailing_newline)
 341                fputc('\n', file);
 342}
 343
 344static void emit_line(struct diff_options *o, const char *set, const char *reset,
 345                      const char *line, int len)
 346{
 347        emit_line_0(o, set, reset, line[0], line+1, len-1);
 348}
 349
 350static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line, int len)
 351{
 352        if (!((ecbdata->ws_rule & WS_BLANK_AT_EOF) &&
 353              ecbdata->blank_at_eof_in_preimage &&
 354              ecbdata->blank_at_eof_in_postimage &&
 355              ecbdata->blank_at_eof_in_preimage <= ecbdata->lno_in_preimage &&
 356              ecbdata->blank_at_eof_in_postimage <= ecbdata->lno_in_postimage))
 357                return 0;
 358        return ws_blank_line(line, len, ecbdata->ws_rule);
 359}
 360
 361static void emit_add_line(const char *reset,
 362                          struct emit_callback *ecbdata,
 363                          const char *line, int len)
 364{
 365        const char *ws = diff_get_color(ecbdata->color_diff, DIFF_WHITESPACE);
 366        const char *set = diff_get_color(ecbdata->color_diff, DIFF_FILE_NEW);
 367
 368        if (!*ws)
 369                emit_line_0(ecbdata->opt, set, reset, '+', line, len);
 370        else if (new_blank_line_at_eof(ecbdata, line, len))
 371                /* Blank line at EOF - paint '+' as well */
 372                emit_line_0(ecbdata->opt, ws, reset, '+', line, len);
 373        else {
 374                /* Emit just the prefix, then the rest. */
 375                emit_line_0(ecbdata->opt, set, reset, '+', "", 0);
 376                ws_check_emit(line, len, ecbdata->ws_rule,
 377                              ecbdata->opt->file, set, reset, ws);
 378        }
 379}
 380
 381static void emit_hunk_header(struct emit_callback *ecbdata,
 382                             const char *line, int len)
 383{
 384        const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
 385        const char *frag = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
 386        const char *func = diff_get_color(ecbdata->color_diff, DIFF_FUNCINFO);
 387        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
 388        static const char atat[2] = { '@', '@' };
 389        const char *cp, *ep;
 390        struct strbuf msgbuf = STRBUF_INIT;
 391        int org_len = len;
 392        int i = 1;
 393
 394        /*
 395         * As a hunk header must begin with "@@ -<old>, +<new> @@",
 396         * it always is at least 10 bytes long.
 397         */
 398        if (len < 10 ||
 399            memcmp(line, atat, 2) ||
 400            !(ep = memmem(line + 2, len - 2, atat, 2))) {
 401                emit_line(ecbdata->opt, plain, reset, line, len);
 402                return;
 403        }
 404        ep += 2; /* skip over @@ */
 405
 406        /* The hunk header in fraginfo color */
 407        strbuf_add(&msgbuf, frag, strlen(frag));
 408        strbuf_add(&msgbuf, line, ep - line);
 409        strbuf_add(&msgbuf, reset, strlen(reset));
 410
 411        /*
 412         * trailing "\r\n"
 413         */
 414        for ( ; i < 3; i++)
 415                if (line[len - i] == '\r' || line[len - i] == '\n')
 416                        len--;
 417
 418        /* blank before the func header */
 419        for (cp = ep; ep - line < len; ep++)
 420                if (*ep != ' ' && *ep != '\t')
 421                        break;
 422        if (ep != cp) {
 423                strbuf_add(&msgbuf, plain, strlen(plain));
 424                strbuf_add(&msgbuf, cp, ep - cp);
 425                strbuf_add(&msgbuf, reset, strlen(reset));
 426        }
 427
 428        if (ep < line + len) {
 429                strbuf_add(&msgbuf, func, strlen(func));
 430                strbuf_add(&msgbuf, ep, line + len - ep);
 431                strbuf_add(&msgbuf, reset, strlen(reset));
 432        }
 433
 434        strbuf_add(&msgbuf, line + len, org_len - len);
 435        emit_line(ecbdata->opt, "", "", msgbuf.buf, msgbuf.len);
 436        strbuf_release(&msgbuf);
 437}
 438
 439static struct diff_tempfile *claim_diff_tempfile(void) {
 440        int i;
 441        for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
 442                if (!diff_temp[i].name)
 443                        return diff_temp + i;
 444        die("BUG: diff is failing to clean up its tempfiles");
 445}
 446
 447static int remove_tempfile_installed;
 448
 449static void remove_tempfile(void)
 450{
 451        int i;
 452        for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
 453                if (diff_temp[i].name == diff_temp[i].tmp_path)
 454                        unlink_or_warn(diff_temp[i].name);
 455                diff_temp[i].name = NULL;
 456        }
 457}
 458
 459static void remove_tempfile_on_signal(int signo)
 460{
 461        remove_tempfile();
 462        sigchain_pop(signo);
 463        raise(signo);
 464}
 465
 466static void print_line_count(FILE *file, int count)
 467{
 468        switch (count) {
 469        case 0:
 470                fprintf(file, "0,0");
 471                break;
 472        case 1:
 473                fprintf(file, "1");
 474                break;
 475        default:
 476                fprintf(file, "1,%d", count);
 477                break;
 478        }
 479}
 480
 481static void emit_rewrite_lines(struct emit_callback *ecb,
 482                               int prefix, const char *data, int size)
 483{
 484        const char *endp = NULL;
 485        static const char *nneof = " No newline at end of file\n";
 486        const char *old = diff_get_color(ecb->color_diff, DIFF_FILE_OLD);
 487        const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
 488
 489        while (0 < size) {
 490                int len;
 491
 492                endp = memchr(data, '\n', size);
 493                len = endp ? (endp - data + 1) : size;
 494                if (prefix != '+') {
 495                        ecb->lno_in_preimage++;
 496                        emit_line_0(ecb->opt, old, reset, '-',
 497                                    data, len);
 498                } else {
 499                        ecb->lno_in_postimage++;
 500                        emit_add_line(reset, ecb, data, len);
 501                }
 502                size -= len;
 503                data += len;
 504        }
 505        if (!endp) {
 506                const char *plain = diff_get_color(ecb->color_diff,
 507                                                   DIFF_PLAIN);
 508                emit_line_0(ecb->opt, plain, reset, '\\',
 509                            nneof, strlen(nneof));
 510        }
 511}
 512
 513static void emit_rewrite_diff(const char *name_a,
 514                              const char *name_b,
 515                              struct diff_filespec *one,
 516                              struct diff_filespec *two,
 517                              struct userdiff_driver *textconv_one,
 518                              struct userdiff_driver *textconv_two,
 519                              struct diff_options *o)
 520{
 521        int lc_a, lc_b;
 522        int color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
 523        const char *name_a_tab, *name_b_tab;
 524        const char *metainfo = diff_get_color(color_diff, DIFF_METAINFO);
 525        const char *fraginfo = diff_get_color(color_diff, DIFF_FRAGINFO);
 526        const char *reset = diff_get_color(color_diff, DIFF_RESET);
 527        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
 528        const char *a_prefix, *b_prefix;
 529        char *data_one, *data_two;
 530        size_t size_one, size_two;
 531        struct emit_callback ecbdata;
 532        char *line_prefix = "";
 533        struct strbuf *msgbuf;
 534
 535        if (o && o->output_prefix) {
 536                msgbuf = o->output_prefix(o, o->output_prefix_data);
 537                line_prefix = msgbuf->buf;
 538        }
 539
 540        if (diff_mnemonic_prefix && DIFF_OPT_TST(o, REVERSE_DIFF)) {
 541                a_prefix = o->b_prefix;
 542                b_prefix = o->a_prefix;
 543        } else {
 544                a_prefix = o->a_prefix;
 545                b_prefix = o->b_prefix;
 546        }
 547
 548        name_a += (*name_a == '/');
 549        name_b += (*name_b == '/');
 550        name_a_tab = strchr(name_a, ' ') ? "\t" : "";
 551        name_b_tab = strchr(name_b, ' ') ? "\t" : "";
 552
 553        strbuf_reset(&a_name);
 554        strbuf_reset(&b_name);
 555        quote_two_c_style(&a_name, a_prefix, name_a, 0);
 556        quote_two_c_style(&b_name, b_prefix, name_b, 0);
 557
 558        size_one = fill_textconv(textconv_one, one, &data_one);
 559        size_two = fill_textconv(textconv_two, two, &data_two);
 560
 561        memset(&ecbdata, 0, sizeof(ecbdata));
 562        ecbdata.color_diff = color_diff;
 563        ecbdata.found_changesp = &o->found_changes;
 564        ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
 565        ecbdata.opt = o;
 566        if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
 567                mmfile_t mf1, mf2;
 568                mf1.ptr = (char *)data_one;
 569                mf2.ptr = (char *)data_two;
 570                mf1.size = size_one;
 571                mf2.size = size_two;
 572                check_blank_at_eof(&mf1, &mf2, &ecbdata);
 573        }
 574        ecbdata.lno_in_preimage = 1;
 575        ecbdata.lno_in_postimage = 1;
 576
 577        lc_a = count_lines(data_one, size_one);
 578        lc_b = count_lines(data_two, size_two);
 579        fprintf(o->file,
 580                "%s%s--- %s%s%s\n%s%s+++ %s%s%s\n%s%s@@ -",
 581                line_prefix, metainfo, a_name.buf, name_a_tab, reset,
 582                line_prefix, metainfo, b_name.buf, name_b_tab, reset,
 583                line_prefix, fraginfo);
 584        print_line_count(o->file, lc_a);
 585        fprintf(o->file, " +");
 586        print_line_count(o->file, lc_b);
 587        fprintf(o->file, " @@%s\n", reset);
 588        if (lc_a)
 589                emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
 590        if (lc_b)
 591                emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
 592        if (textconv_one)
 593                free((char *)data_one);
 594        if (textconv_two)
 595                free((char *)data_two);
 596}
 597
 598struct diff_words_buffer {
 599        mmfile_t text;
 600        long alloc;
 601        struct diff_words_orig {
 602                const char *begin, *end;
 603        } *orig;
 604        int orig_nr, orig_alloc;
 605};
 606
 607static void diff_words_append(char *line, unsigned long len,
 608                struct diff_words_buffer *buffer)
 609{
 610        ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
 611        line++;
 612        len--;
 613        memcpy(buffer->text.ptr + buffer->text.size, line, len);
 614        buffer->text.size += len;
 615        buffer->text.ptr[buffer->text.size] = '\0';
 616}
 617
 618struct diff_words_style_elem {
 619        const char *prefix;
 620        const char *suffix;
 621        const char *color; /* NULL; filled in by the setup code if
 622                            * color is enabled */
 623};
 624
 625struct diff_words_style {
 626        enum diff_words_type type;
 627        struct diff_words_style_elem new, old, ctx;
 628        const char *newline;
 629};
 630
 631static struct diff_words_style diff_words_styles[] = {
 632        { DIFF_WORDS_PORCELAIN, {"+", "\n"}, {"-", "\n"}, {" ", "\n"}, "~\n" },
 633        { DIFF_WORDS_PLAIN, {"{+", "+}"}, {"[-", "-]"}, {"", ""}, "\n" },
 634        { DIFF_WORDS_COLOR, {"", ""}, {"", ""}, {"", ""}, "\n" }
 635};
 636
 637struct diff_words_data {
 638        struct diff_words_buffer minus, plus;
 639        const char *current_plus;
 640        int last_minus;
 641        struct diff_options *opt;
 642        regex_t *word_regex;
 643        enum diff_words_type type;
 644        struct diff_words_style *style;
 645};
 646
 647static int fn_out_diff_words_write_helper(FILE *fp,
 648                                          struct diff_words_style_elem *st_el,
 649                                          const char *newline,
 650                                          size_t count, const char *buf,
 651                                          const char *line_prefix)
 652{
 653        int print = 0;
 654
 655        while (count) {
 656                char *p = memchr(buf, '\n', count);
 657                if (print)
 658                        fputs(line_prefix, fp);
 659                if (p != buf) {
 660                        if (st_el->color && fputs(st_el->color, fp) < 0)
 661                                return -1;
 662                        if (fputs(st_el->prefix, fp) < 0 ||
 663                            fwrite(buf, p ? p - buf : count, 1, fp) != 1 ||
 664                            fputs(st_el->suffix, fp) < 0)
 665                                return -1;
 666                        if (st_el->color && *st_el->color
 667                            && fputs(GIT_COLOR_RESET, fp) < 0)
 668                                return -1;
 669                }
 670                if (!p)
 671                        return 0;
 672                if (fputs(newline, fp) < 0)
 673                        return -1;
 674                count -= p + 1 - buf;
 675                buf = p + 1;
 676                print = 1;
 677        }
 678        return 0;
 679}
 680
 681/*
 682 * '--color-words' algorithm can be described as:
 683 *
 684 *   1. collect a the minus/plus lines of a diff hunk, divided into
 685 *      minus-lines and plus-lines;
 686 *
 687 *   2. break both minus-lines and plus-lines into words and
 688 *      place them into two mmfile_t with one word for each line;
 689 *
 690 *   3. use xdiff to run diff on the two mmfile_t to get the words level diff;
 691 *
 692 * And for the common parts of the both file, we output the plus side text.
 693 * diff_words->current_plus is used to trace the current position of the plus file
 694 * which printed. diff_words->last_minus is used to trace the last minus word
 695 * printed.
 696 *
 697 * For '--graph' to work with '--color-words', we need to output the graph prefix
 698 * on each line of color words output. Generally, there are two conditions on
 699 * which we should output the prefix.
 700 *
 701 *   1. diff_words->last_minus == 0 &&
 702 *      diff_words->current_plus == diff_words->plus.text.ptr
 703 *
 704 *      that is: the plus text must start as a new line, and if there is no minus
 705 *      word printed, a graph prefix must be printed.
 706 *
 707 *   2. diff_words->current_plus > diff_words->plus.text.ptr &&
 708 *      *(diff_words->current_plus - 1) == '\n'
 709 *
 710 *      that is: a graph prefix must be printed following a '\n'
 711 */
 712static int color_words_output_graph_prefix(struct diff_words_data *diff_words)
 713{
 714        if ((diff_words->last_minus == 0 &&
 715                diff_words->current_plus == diff_words->plus.text.ptr) ||
 716                (diff_words->current_plus > diff_words->plus.text.ptr &&
 717                *(diff_words->current_plus - 1) == '\n')) {
 718                return 1;
 719        } else {
 720                return 0;
 721        }
 722}
 723
 724static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
 725{
 726        struct diff_words_data *diff_words = priv;
 727        struct diff_words_style *style = diff_words->style;
 728        int minus_first, minus_len, plus_first, plus_len;
 729        const char *minus_begin, *minus_end, *plus_begin, *plus_end;
 730        struct diff_options *opt = diff_words->opt;
 731        struct strbuf *msgbuf;
 732        char *line_prefix = "";
 733
 734        if (line[0] != '@' || parse_hunk_header(line, len,
 735                        &minus_first, &minus_len, &plus_first, &plus_len))
 736                return;
 737
 738        assert(opt);
 739        if (opt->output_prefix) {
 740                msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
 741                line_prefix = msgbuf->buf;
 742        }
 743
 744        /* POSIX requires that first be decremented by one if len == 0... */
 745        if (minus_len) {
 746                minus_begin = diff_words->minus.orig[minus_first].begin;
 747                minus_end =
 748                        diff_words->minus.orig[minus_first + minus_len - 1].end;
 749        } else
 750                minus_begin = minus_end =
 751                        diff_words->minus.orig[minus_first].end;
 752
 753        if (plus_len) {
 754                plus_begin = diff_words->plus.orig[plus_first].begin;
 755                plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
 756        } else
 757                plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
 758
 759        if (color_words_output_graph_prefix(diff_words)) {
 760                fputs(line_prefix, diff_words->opt->file);
 761        }
 762        if (diff_words->current_plus != plus_begin) {
 763                fn_out_diff_words_write_helper(diff_words->opt->file,
 764                                &style->ctx, style->newline,
 765                                plus_begin - diff_words->current_plus,
 766                                diff_words->current_plus, line_prefix);
 767                if (*(plus_begin - 1) == '\n')
 768                        fputs(line_prefix, diff_words->opt->file);
 769        }
 770        if (minus_begin != minus_end) {
 771                fn_out_diff_words_write_helper(diff_words->opt->file,
 772                                &style->old, style->newline,
 773                                minus_end - minus_begin, minus_begin,
 774                                line_prefix);
 775        }
 776        if (plus_begin != plus_end) {
 777                fn_out_diff_words_write_helper(diff_words->opt->file,
 778                                &style->new, style->newline,
 779                                plus_end - plus_begin, plus_begin,
 780                                line_prefix);
 781        }
 782
 783        diff_words->current_plus = plus_end;
 784        diff_words->last_minus = minus_first;
 785}
 786
 787/* This function starts looking at *begin, and returns 0 iff a word was found. */
 788static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
 789                int *begin, int *end)
 790{
 791        if (word_regex && *begin < buffer->size) {
 792                regmatch_t match[1];
 793                if (!regexec(word_regex, buffer->ptr + *begin, 1, match, 0)) {
 794                        char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
 795                                        '\n', match[0].rm_eo - match[0].rm_so);
 796                        *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
 797                        *begin += match[0].rm_so;
 798                        return *begin >= *end;
 799                }
 800                return -1;
 801        }
 802
 803        /* find the next word */
 804        while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
 805                (*begin)++;
 806        if (*begin >= buffer->size)
 807                return -1;
 808
 809        /* find the end of the word */
 810        *end = *begin + 1;
 811        while (*end < buffer->size && !isspace(buffer->ptr[*end]))
 812                (*end)++;
 813
 814        return 0;
 815}
 816
 817/*
 818 * This function splits the words in buffer->text, stores the list with
 819 * newline separator into out, and saves the offsets of the original words
 820 * in buffer->orig.
 821 */
 822static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
 823                regex_t *word_regex)
 824{
 825        int i, j;
 826        long alloc = 0;
 827
 828        out->size = 0;
 829        out->ptr = NULL;
 830
 831        /* fake an empty "0th" word */
 832        ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
 833        buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
 834        buffer->orig_nr = 1;
 835
 836        for (i = 0; i < buffer->text.size; i++) {
 837                if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
 838                        return;
 839
 840                /* store original boundaries */
 841                ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
 842                                buffer->orig_alloc);
 843                buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
 844                buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
 845                buffer->orig_nr++;
 846
 847                /* store one word */
 848                ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
 849                memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
 850                out->ptr[out->size + j - i] = '\n';
 851                out->size += j - i + 1;
 852
 853                i = j - 1;
 854        }
 855}
 856
 857/* this executes the word diff on the accumulated buffers */
 858static void diff_words_show(struct diff_words_data *diff_words)
 859{
 860        xpparam_t xpp;
 861        xdemitconf_t xecfg;
 862        mmfile_t minus, plus;
 863        struct diff_words_style *style = diff_words->style;
 864
 865        struct diff_options *opt = diff_words->opt;
 866        struct strbuf *msgbuf;
 867        char *line_prefix = "";
 868
 869        assert(opt);
 870        if (opt->output_prefix) {
 871                msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
 872                line_prefix = msgbuf->buf;
 873        }
 874
 875        /* special case: only removal */
 876        if (!diff_words->plus.text.size) {
 877                fputs(line_prefix, diff_words->opt->file);
 878                fn_out_diff_words_write_helper(diff_words->opt->file,
 879                        &style->old, style->newline,
 880                        diff_words->minus.text.size,
 881                        diff_words->minus.text.ptr, line_prefix);
 882                diff_words->minus.text.size = 0;
 883                return;
 884        }
 885
 886        diff_words->current_plus = diff_words->plus.text.ptr;
 887        diff_words->last_minus = 0;
 888
 889        memset(&xpp, 0, sizeof(xpp));
 890        memset(&xecfg, 0, sizeof(xecfg));
 891        diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
 892        diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
 893        xpp.flags = 0;
 894        /* as only the hunk header will be parsed, we need a 0-context */
 895        xecfg.ctxlen = 0;
 896        xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
 897                      &xpp, &xecfg);
 898        free(minus.ptr);
 899        free(plus.ptr);
 900        if (diff_words->current_plus != diff_words->plus.text.ptr +
 901                        diff_words->plus.text.size) {
 902                if (color_words_output_graph_prefix(diff_words))
 903                        fputs(line_prefix, diff_words->opt->file);
 904                fn_out_diff_words_write_helper(diff_words->opt->file,
 905                        &style->ctx, style->newline,
 906                        diff_words->plus.text.ptr + diff_words->plus.text.size
 907                        - diff_words->current_plus, diff_words->current_plus,
 908                        line_prefix);
 909        }
 910        diff_words->minus.text.size = diff_words->plus.text.size = 0;
 911}
 912
 913/* In "color-words" mode, show word-diff of words accumulated in the buffer */
 914static void diff_words_flush(struct emit_callback *ecbdata)
 915{
 916        if (ecbdata->diff_words->minus.text.size ||
 917            ecbdata->diff_words->plus.text.size)
 918                diff_words_show(ecbdata->diff_words);
 919}
 920
 921static void free_diff_words_data(struct emit_callback *ecbdata)
 922{
 923        if (ecbdata->diff_words) {
 924                diff_words_flush(ecbdata);
 925                free (ecbdata->diff_words->minus.text.ptr);
 926                free (ecbdata->diff_words->minus.orig);
 927                free (ecbdata->diff_words->plus.text.ptr);
 928                free (ecbdata->diff_words->plus.orig);
 929                if (ecbdata->diff_words->word_regex) {
 930                        regfree(ecbdata->diff_words->word_regex);
 931                        free(ecbdata->diff_words->word_regex);
 932                }
 933                free(ecbdata->diff_words);
 934                ecbdata->diff_words = NULL;
 935        }
 936}
 937
 938const char *diff_get_color(int diff_use_color, enum color_diff ix)
 939{
 940        if (diff_use_color)
 941                return diff_colors[ix];
 942        return "";
 943}
 944
 945static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
 946{
 947        const char *cp;
 948        unsigned long allot;
 949        size_t l = len;
 950
 951        if (ecb->truncate)
 952                return ecb->truncate(line, len);
 953        cp = line;
 954        allot = l;
 955        while (0 < l) {
 956                (void) utf8_width(&cp, &l);
 957                if (!cp)
 958                        break; /* truncated in the middle? */
 959        }
 960        return allot - l;
 961}
 962
 963static void find_lno(const char *line, struct emit_callback *ecbdata)
 964{
 965        const char *p;
 966        ecbdata->lno_in_preimage = 0;
 967        ecbdata->lno_in_postimage = 0;
 968        p = strchr(line, '-');
 969        if (!p)
 970                return; /* cannot happen */
 971        ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
 972        p = strchr(p, '+');
 973        if (!p)
 974                return; /* cannot happen */
 975        ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
 976}
 977
 978static void fn_out_consume(void *priv, char *line, unsigned long len)
 979{
 980        struct emit_callback *ecbdata = priv;
 981        const char *meta = diff_get_color(ecbdata->color_diff, DIFF_METAINFO);
 982        const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
 983        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
 984        struct diff_options *o = ecbdata->opt;
 985        char *line_prefix = "";
 986        struct strbuf *msgbuf;
 987
 988        if (o && o->output_prefix) {
 989                msgbuf = o->output_prefix(o, o->output_prefix_data);
 990                line_prefix = msgbuf->buf;
 991        }
 992
 993        if (ecbdata->header) {
 994                fprintf(ecbdata->opt->file, "%s", ecbdata->header->buf);
 995                strbuf_reset(ecbdata->header);
 996                ecbdata->header = NULL;
 997        }
 998        *(ecbdata->found_changesp) = 1;
 999
1000        if (ecbdata->label_path[0]) {
1001                const char *name_a_tab, *name_b_tab;
1002
1003                name_a_tab = strchr(ecbdata->label_path[0], ' ') ? "\t" : "";
1004                name_b_tab = strchr(ecbdata->label_path[1], ' ') ? "\t" : "";
1005
1006                fprintf(ecbdata->opt->file, "%s%s--- %s%s%s\n",
1007                        line_prefix, meta, ecbdata->label_path[0], reset, name_a_tab);
1008                fprintf(ecbdata->opt->file, "%s%s+++ %s%s%s\n",
1009                        line_prefix, meta, ecbdata->label_path[1], reset, name_b_tab);
1010                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
1011        }
1012
1013        if (diff_suppress_blank_empty
1014            && len == 2 && line[0] == ' ' && line[1] == '\n') {
1015                line[0] = '\n';
1016                len = 1;
1017        }
1018
1019        if (line[0] == '@') {
1020                if (ecbdata->diff_words)
1021                        diff_words_flush(ecbdata);
1022                len = sane_truncate_line(ecbdata, line, len);
1023                find_lno(line, ecbdata);
1024                emit_hunk_header(ecbdata, line, len);
1025                if (line[len-1] != '\n')
1026                        putc('\n', ecbdata->opt->file);
1027                return;
1028        }
1029
1030        if (len < 1) {
1031                emit_line(ecbdata->opt, reset, reset, line, len);
1032                if (ecbdata->diff_words
1033                    && ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN)
1034                        fputs("~\n", ecbdata->opt->file);
1035                return;
1036        }
1037
1038        if (ecbdata->diff_words) {
1039                if (line[0] == '-') {
1040                        diff_words_append(line, len,
1041                                          &ecbdata->diff_words->minus);
1042                        return;
1043                } else if (line[0] == '+') {
1044                        diff_words_append(line, len,
1045                                          &ecbdata->diff_words->plus);
1046                        return;
1047                }
1048                diff_words_flush(ecbdata);
1049                if (ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN) {
1050                        emit_line(ecbdata->opt, plain, reset, line, len);
1051                        fputs("~\n", ecbdata->opt->file);
1052                } else {
1053                        /* don't print the prefix character */
1054                        emit_line(ecbdata->opt, plain, reset, line+1, len-1);
1055                }
1056                return;
1057        }
1058
1059        if (line[0] != '+') {
1060                const char *color =
1061                        diff_get_color(ecbdata->color_diff,
1062                                       line[0] == '-' ? DIFF_FILE_OLD : DIFF_PLAIN);
1063                ecbdata->lno_in_preimage++;
1064                if (line[0] == ' ')
1065                        ecbdata->lno_in_postimage++;
1066                emit_line(ecbdata->opt, color, reset, line, len);
1067        } else {
1068                ecbdata->lno_in_postimage++;
1069                emit_add_line(reset, ecbdata, line + 1, len - 1);
1070        }
1071}
1072
1073static char *pprint_rename(const char *a, const char *b)
1074{
1075        const char *old = a;
1076        const char *new = b;
1077        struct strbuf name = STRBUF_INIT;
1078        int pfx_length, sfx_length;
1079        int len_a = strlen(a);
1080        int len_b = strlen(b);
1081        int a_midlen, b_midlen;
1082        int qlen_a = quote_c_style(a, NULL, NULL, 0);
1083        int qlen_b = quote_c_style(b, NULL, NULL, 0);
1084
1085        if (qlen_a || qlen_b) {
1086                quote_c_style(a, &name, NULL, 0);
1087                strbuf_addstr(&name, " => ");
1088                quote_c_style(b, &name, NULL, 0);
1089                return strbuf_detach(&name, NULL);
1090        }
1091
1092        /* Find common prefix */
1093        pfx_length = 0;
1094        while (*old && *new && *old == *new) {
1095                if (*old == '/')
1096                        pfx_length = old - a + 1;
1097                old++;
1098                new++;
1099        }
1100
1101        /* Find common suffix */
1102        old = a + len_a;
1103        new = b + len_b;
1104        sfx_length = 0;
1105        while (a <= old && b <= new && *old == *new) {
1106                if (*old == '/')
1107                        sfx_length = len_a - (old - a);
1108                old--;
1109                new--;
1110        }
1111
1112        /*
1113         * pfx{mid-a => mid-b}sfx
1114         * {pfx-a => pfx-b}sfx
1115         * pfx{sfx-a => sfx-b}
1116         * name-a => name-b
1117         */
1118        a_midlen = len_a - pfx_length - sfx_length;
1119        b_midlen = len_b - pfx_length - sfx_length;
1120        if (a_midlen < 0)
1121                a_midlen = 0;
1122        if (b_midlen < 0)
1123                b_midlen = 0;
1124
1125        strbuf_grow(&name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
1126        if (pfx_length + sfx_length) {
1127                strbuf_add(&name, a, pfx_length);
1128                strbuf_addch(&name, '{');
1129        }
1130        strbuf_add(&name, a + pfx_length, a_midlen);
1131        strbuf_addstr(&name, " => ");
1132        strbuf_add(&name, b + pfx_length, b_midlen);
1133        if (pfx_length + sfx_length) {
1134                strbuf_addch(&name, '}');
1135                strbuf_add(&name, a + len_a - sfx_length, sfx_length);
1136        }
1137        return strbuf_detach(&name, NULL);
1138}
1139
1140struct diffstat_t {
1141        int nr;
1142        int alloc;
1143        struct diffstat_file {
1144                char *from_name;
1145                char *name;
1146                char *print_name;
1147                unsigned is_unmerged:1;
1148                unsigned is_binary:1;
1149                unsigned is_renamed:1;
1150                uintmax_t added, deleted;
1151        } **files;
1152};
1153
1154static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
1155                                          const char *name_a,
1156                                          const char *name_b)
1157{
1158        struct diffstat_file *x;
1159        x = xcalloc(sizeof (*x), 1);
1160        if (diffstat->nr == diffstat->alloc) {
1161                diffstat->alloc = alloc_nr(diffstat->alloc);
1162                diffstat->files = xrealloc(diffstat->files,
1163                                diffstat->alloc * sizeof(x));
1164        }
1165        diffstat->files[diffstat->nr++] = x;
1166        if (name_b) {
1167                x->from_name = xstrdup(name_a);
1168                x->name = xstrdup(name_b);
1169                x->is_renamed = 1;
1170        }
1171        else {
1172                x->from_name = NULL;
1173                x->name = xstrdup(name_a);
1174        }
1175        return x;
1176}
1177
1178static void diffstat_consume(void *priv, char *line, unsigned long len)
1179{
1180        struct diffstat_t *diffstat = priv;
1181        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
1182
1183        if (line[0] == '+')
1184                x->added++;
1185        else if (line[0] == '-')
1186                x->deleted++;
1187}
1188
1189const char mime_boundary_leader[] = "------------";
1190
1191static int scale_linear(int it, int width, int max_change)
1192{
1193        /*
1194         * make sure that at least one '-' is printed if there were deletions,
1195         * and likewise for '+'.
1196         */
1197        if (max_change < 2)
1198                return it;
1199        return ((it - 1) * (width - 1) + max_change - 1) / (max_change - 1);
1200}
1201
1202static void show_name(FILE *file,
1203                      const char *prefix, const char *name, int len)
1204{
1205        fprintf(file, " %s%-*s |", prefix, len, name);
1206}
1207
1208static void show_graph(FILE *file, char ch, int cnt, const char *set, const char *reset)
1209{
1210        if (cnt <= 0)
1211                return;
1212        fprintf(file, "%s", set);
1213        while (cnt--)
1214                putc(ch, file);
1215        fprintf(file, "%s", reset);
1216}
1217
1218static void fill_print_name(struct diffstat_file *file)
1219{
1220        char *pname;
1221
1222        if (file->print_name)
1223                return;
1224
1225        if (!file->is_renamed) {
1226                struct strbuf buf = STRBUF_INIT;
1227                if (quote_c_style(file->name, &buf, NULL, 0)) {
1228                        pname = strbuf_detach(&buf, NULL);
1229                } else {
1230                        pname = file->name;
1231                        strbuf_release(&buf);
1232                }
1233        } else {
1234                pname = pprint_rename(file->from_name, file->name);
1235        }
1236        file->print_name = pname;
1237}
1238
1239static void show_stats(struct diffstat_t *data, struct diff_options *options)
1240{
1241        int i, len, add, del, adds = 0, dels = 0;
1242        uintmax_t max_change = 0, max_len = 0;
1243        int total_files = data->nr;
1244        int width, name_width;
1245        const char *reset, *add_c, *del_c;
1246        const char *line_prefix = "";
1247        struct strbuf *msg = NULL;
1248
1249        if (data->nr == 0)
1250                return;
1251
1252        if (options->output_prefix) {
1253                msg = options->output_prefix(options, options->output_prefix_data);
1254                line_prefix = msg->buf;
1255        }
1256
1257        width = options->stat_width ? options->stat_width : 80;
1258        name_width = options->stat_name_width ? options->stat_name_width : 50;
1259
1260        /* Sanity: give at least 5 columns to the graph,
1261         * but leave at least 10 columns for the name.
1262         */
1263        if (width < 25)
1264                width = 25;
1265        if (name_width < 10)
1266                name_width = 10;
1267        else if (width < name_width + 15)
1268                name_width = width - 15;
1269
1270        /* Find the longest filename and max number of changes */
1271        reset = diff_get_color_opt(options, DIFF_RESET);
1272        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
1273        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
1274
1275        for (i = 0; i < data->nr; i++) {
1276                struct diffstat_file *file = data->files[i];
1277                uintmax_t change = file->added + file->deleted;
1278                fill_print_name(file);
1279                len = strlen(file->print_name);
1280                if (max_len < len)
1281                        max_len = len;
1282
1283                if (file->is_binary || file->is_unmerged)
1284                        continue;
1285                if (max_change < change)
1286                        max_change = change;
1287        }
1288
1289        /* Compute the width of the graph part;
1290         * 10 is for one blank at the beginning of the line plus
1291         * " | count " between the name and the graph.
1292         *
1293         * From here on, name_width is the width of the name area,
1294         * and width is the width of the graph area.
1295         */
1296        name_width = (name_width < max_len) ? name_width : max_len;
1297        if (width < (name_width + 10) + max_change)
1298                width = width - (name_width + 10);
1299        else
1300                width = max_change;
1301
1302        for (i = 0; i < data->nr; i++) {
1303                const char *prefix = "";
1304                char *name = data->files[i]->print_name;
1305                uintmax_t added = data->files[i]->added;
1306                uintmax_t deleted = data->files[i]->deleted;
1307                int name_len;
1308
1309                /*
1310                 * "scale" the filename
1311                 */
1312                len = name_width;
1313                name_len = strlen(name);
1314                if (name_width < name_len) {
1315                        char *slash;
1316                        prefix = "...";
1317                        len -= 3;
1318                        name += name_len - len;
1319                        slash = strchr(name, '/');
1320                        if (slash)
1321                                name = slash;
1322                }
1323
1324                if (data->files[i]->is_binary) {
1325                        fprintf(options->file, "%s", line_prefix);
1326                        show_name(options->file, prefix, name, len);
1327                        fprintf(options->file, "  Bin ");
1328                        fprintf(options->file, "%s%"PRIuMAX"%s",
1329                                del_c, deleted, reset);
1330                        fprintf(options->file, " -> ");
1331                        fprintf(options->file, "%s%"PRIuMAX"%s",
1332                                add_c, added, reset);
1333                        fprintf(options->file, " bytes");
1334                        fprintf(options->file, "\n");
1335                        continue;
1336                }
1337                else if (data->files[i]->is_unmerged) {
1338                        fprintf(options->file, "%s", line_prefix);
1339                        show_name(options->file, prefix, name, len);
1340                        fprintf(options->file, "  Unmerged\n");
1341                        continue;
1342                }
1343                else if (!data->files[i]->is_renamed &&
1344                         (added + deleted == 0)) {
1345                        total_files--;
1346                        continue;
1347                }
1348
1349                /*
1350                 * scale the add/delete
1351                 */
1352                add = added;
1353                del = deleted;
1354                adds += add;
1355                dels += del;
1356
1357                if (width <= max_change) {
1358                        add = scale_linear(add, width, max_change);
1359                        del = scale_linear(del, width, max_change);
1360                }
1361                fprintf(options->file, "%s", line_prefix);
1362                show_name(options->file, prefix, name, len);
1363                fprintf(options->file, "%5"PRIuMAX"%s", added + deleted,
1364                                added + deleted ? " " : "");
1365                show_graph(options->file, '+', add, add_c, reset);
1366                show_graph(options->file, '-', del, del_c, reset);
1367                fprintf(options->file, "\n");
1368        }
1369        fprintf(options->file, "%s", line_prefix);
1370        fprintf(options->file,
1371               " %d files changed, %d insertions(+), %d deletions(-)\n",
1372               total_files, adds, dels);
1373}
1374
1375static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
1376{
1377        int i, adds = 0, dels = 0, total_files = data->nr;
1378
1379        if (data->nr == 0)
1380                return;
1381
1382        for (i = 0; i < data->nr; i++) {
1383                if (!data->files[i]->is_binary &&
1384                    !data->files[i]->is_unmerged) {
1385                        int added = data->files[i]->added;
1386                        int deleted= data->files[i]->deleted;
1387                        if (!data->files[i]->is_renamed &&
1388                            (added + deleted == 0)) {
1389                                total_files--;
1390                        } else {
1391                                adds += added;
1392                                dels += deleted;
1393                        }
1394                }
1395        }
1396        if (options->output_prefix) {
1397                struct strbuf *msg = NULL;
1398                msg = options->output_prefix(options,
1399                                options->output_prefix_data);
1400                fprintf(options->file, "%s", msg->buf);
1401        }
1402        fprintf(options->file, " %d files changed, %d insertions(+), %d deletions(-)\n",
1403               total_files, adds, dels);
1404}
1405
1406static void show_numstat(struct diffstat_t *data, struct diff_options *options)
1407{
1408        int i;
1409
1410        if (data->nr == 0)
1411                return;
1412
1413        for (i = 0; i < data->nr; i++) {
1414                struct diffstat_file *file = data->files[i];
1415
1416                if (options->output_prefix) {
1417                        struct strbuf *msg = NULL;
1418                        msg = options->output_prefix(options,
1419                                        options->output_prefix_data);
1420                        fprintf(options->file, "%s", msg->buf);
1421                }
1422
1423                if (file->is_binary)
1424                        fprintf(options->file, "-\t-\t");
1425                else
1426                        fprintf(options->file,
1427                                "%"PRIuMAX"\t%"PRIuMAX"\t",
1428                                file->added, file->deleted);
1429                if (options->line_termination) {
1430                        fill_print_name(file);
1431                        if (!file->is_renamed)
1432                                write_name_quoted(file->name, options->file,
1433                                                  options->line_termination);
1434                        else {
1435                                fputs(file->print_name, options->file);
1436                                putc(options->line_termination, options->file);
1437                        }
1438                } else {
1439                        if (file->is_renamed) {
1440                                putc('\0', options->file);
1441                                write_name_quoted(file->from_name, options->file, '\0');
1442                        }
1443                        write_name_quoted(file->name, options->file, '\0');
1444                }
1445        }
1446}
1447
1448struct dirstat_file {
1449        const char *name;
1450        unsigned long changed;
1451};
1452
1453struct dirstat_dir {
1454        struct dirstat_file *files;
1455        int alloc, nr, percent, cumulative;
1456};
1457
1458static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
1459                unsigned long changed, const char *base, int baselen)
1460{
1461        unsigned long this_dir = 0;
1462        unsigned int sources = 0;
1463        const char *line_prefix = "";
1464        struct strbuf *msg = NULL;
1465
1466        if (opt->output_prefix) {
1467                msg = opt->output_prefix(opt, opt->output_prefix_data);
1468                line_prefix = msg->buf;
1469        }
1470
1471        while (dir->nr) {
1472                struct dirstat_file *f = dir->files;
1473                int namelen = strlen(f->name);
1474                unsigned long this;
1475                char *slash;
1476
1477                if (namelen < baselen)
1478                        break;
1479                if (memcmp(f->name, base, baselen))
1480                        break;
1481                slash = strchr(f->name + baselen, '/');
1482                if (slash) {
1483                        int newbaselen = slash + 1 - f->name;
1484                        this = gather_dirstat(opt, dir, changed, f->name, newbaselen);
1485                        sources++;
1486                } else {
1487                        this = f->changed;
1488                        dir->files++;
1489                        dir->nr--;
1490                        sources += 2;
1491                }
1492                this_dir += this;
1493        }
1494
1495        /*
1496         * We don't report dirstat's for
1497         *  - the top level
1498         *  - or cases where everything came from a single directory
1499         *    under this directory (sources == 1).
1500         */
1501        if (baselen && sources != 1) {
1502                int permille = this_dir * 1000 / changed;
1503                if (permille) {
1504                        int percent = permille / 10;
1505                        if (percent >= dir->percent) {
1506                                fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
1507                                        percent, permille % 10, baselen, base);
1508                                if (!dir->cumulative)
1509                                        return 0;
1510                        }
1511                }
1512        }
1513        return this_dir;
1514}
1515
1516static int dirstat_compare(const void *_a, const void *_b)
1517{
1518        const struct dirstat_file *a = _a;
1519        const struct dirstat_file *b = _b;
1520        return strcmp(a->name, b->name);
1521}
1522
1523static void show_dirstat(struct diff_options *options)
1524{
1525        int i;
1526        unsigned long changed;
1527        struct dirstat_dir dir;
1528        struct diff_queue_struct *q = &diff_queued_diff;
1529
1530        dir.files = NULL;
1531        dir.alloc = 0;
1532        dir.nr = 0;
1533        dir.percent = options->dirstat_percent;
1534        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1535
1536        changed = 0;
1537        for (i = 0; i < q->nr; i++) {
1538                struct diff_filepair *p = q->queue[i];
1539                const char *name;
1540                unsigned long copied, added, damage;
1541
1542                name = p->one->path ? p->one->path : p->two->path;
1543
1544                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
1545                        diff_populate_filespec(p->one, 0);
1546                        diff_populate_filespec(p->two, 0);
1547                        diffcore_count_changes(p->one, p->two, NULL, NULL, 0,
1548                                               &copied, &added);
1549                        diff_free_filespec_data(p->one);
1550                        diff_free_filespec_data(p->two);
1551                } else if (DIFF_FILE_VALID(p->one)) {
1552                        diff_populate_filespec(p->one, 1);
1553                        copied = added = 0;
1554                        diff_free_filespec_data(p->one);
1555                } else if (DIFF_FILE_VALID(p->two)) {
1556                        diff_populate_filespec(p->two, 1);
1557                        copied = 0;
1558                        added = p->two->size;
1559                        diff_free_filespec_data(p->two);
1560                } else
1561                        continue;
1562
1563                /*
1564                 * Original minus copied is the removed material,
1565                 * added is the new material.  They are both damages
1566                 * made to the preimage. In --dirstat-by-file mode, count
1567                 * damaged files, not damaged lines. This is done by
1568                 * counting only a single damaged line per file.
1569                 */
1570                damage = (p->one->size - copied) + added;
1571                if (DIFF_OPT_TST(options, DIRSTAT_BY_FILE) && damage > 0)
1572                        damage = 1;
1573
1574                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1575                dir.files[dir.nr].name = name;
1576                dir.files[dir.nr].changed = damage;
1577                changed += damage;
1578                dir.nr++;
1579        }
1580
1581        /* This can happen even with many files, if everything was renames */
1582        if (!changed)
1583                return;
1584
1585        /* Show all directories with more than x% of the changes */
1586        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1587        gather_dirstat(options, &dir, changed, "", 0);
1588}
1589
1590static void free_diffstat_info(struct diffstat_t *diffstat)
1591{
1592        int i;
1593        for (i = 0; i < diffstat->nr; i++) {
1594                struct diffstat_file *f = diffstat->files[i];
1595                if (f->name != f->print_name)
1596                        free(f->print_name);
1597                free(f->name);
1598                free(f->from_name);
1599                free(f);
1600        }
1601        free(diffstat->files);
1602}
1603
1604struct checkdiff_t {
1605        const char *filename;
1606        int lineno;
1607        int conflict_marker_size;
1608        struct diff_options *o;
1609        unsigned ws_rule;
1610        unsigned status;
1611};
1612
1613static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
1614{
1615        char firstchar;
1616        int cnt;
1617
1618        if (len < marker_size + 1)
1619                return 0;
1620        firstchar = line[0];
1621        switch (firstchar) {
1622        case '=': case '>': case '<': case '|':
1623                break;
1624        default:
1625                return 0;
1626        }
1627        for (cnt = 1; cnt < marker_size; cnt++)
1628                if (line[cnt] != firstchar)
1629                        return 0;
1630        /* line[1] thru line[marker_size-1] are same as firstchar */
1631        if (len < marker_size + 1 || !isspace(line[marker_size]))
1632                return 0;
1633        return 1;
1634}
1635
1636static void checkdiff_consume(void *priv, char *line, unsigned long len)
1637{
1638        struct checkdiff_t *data = priv;
1639        int color_diff = DIFF_OPT_TST(data->o, COLOR_DIFF);
1640        int marker_size = data->conflict_marker_size;
1641        const char *ws = diff_get_color(color_diff, DIFF_WHITESPACE);
1642        const char *reset = diff_get_color(color_diff, DIFF_RESET);
1643        const char *set = diff_get_color(color_diff, DIFF_FILE_NEW);
1644        char *err;
1645        char *line_prefix = "";
1646        struct strbuf *msgbuf;
1647
1648        assert(data->o);
1649        if (data->o->output_prefix) {
1650                msgbuf = data->o->output_prefix(data->o,
1651                        data->o->output_prefix_data);
1652                line_prefix = msgbuf->buf;
1653        }
1654
1655        if (line[0] == '+') {
1656                unsigned bad;
1657                data->lineno++;
1658                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
1659                        data->status |= 1;
1660                        fprintf(data->o->file,
1661                                "%s%s:%d: leftover conflict marker\n",
1662                                line_prefix, data->filename, data->lineno);
1663                }
1664                bad = ws_check(line + 1, len - 1, data->ws_rule);
1665                if (!bad)
1666                        return;
1667                data->status |= bad;
1668                err = whitespace_error_string(bad);
1669                fprintf(data->o->file, "%s%s:%d: %s.\n",
1670                        line_prefix, data->filename, data->lineno, err);
1671                free(err);
1672                emit_line(data->o, set, reset, line, 1);
1673                ws_check_emit(line + 1, len - 1, data->ws_rule,
1674                              data->o->file, set, reset, ws);
1675        } else if (line[0] == ' ') {
1676                data->lineno++;
1677        } else if (line[0] == '@') {
1678                char *plus = strchr(line, '+');
1679                if (plus)
1680                        data->lineno = strtol(plus, NULL, 10) - 1;
1681                else
1682                        die("invalid diff");
1683        }
1684}
1685
1686static unsigned char *deflate_it(char *data,
1687                                 unsigned long size,
1688                                 unsigned long *result_size)
1689{
1690        int bound;
1691        unsigned char *deflated;
1692        z_stream stream;
1693
1694        memset(&stream, 0, sizeof(stream));
1695        deflateInit(&stream, zlib_compression_level);
1696        bound = deflateBound(&stream, size);
1697        deflated = xmalloc(bound);
1698        stream.next_out = deflated;
1699        stream.avail_out = bound;
1700
1701        stream.next_in = (unsigned char *)data;
1702        stream.avail_in = size;
1703        while (deflate(&stream, Z_FINISH) == Z_OK)
1704                ; /* nothing */
1705        deflateEnd(&stream);
1706        *result_size = stream.total_out;
1707        return deflated;
1708}
1709
1710static void emit_binary_diff_body(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
1711{
1712        void *cp;
1713        void *delta;
1714        void *deflated;
1715        void *data;
1716        unsigned long orig_size;
1717        unsigned long delta_size;
1718        unsigned long deflate_size;
1719        unsigned long data_size;
1720
1721        /* We could do deflated delta, or we could do just deflated two,
1722         * whichever is smaller.
1723         */
1724        delta = NULL;
1725        deflated = deflate_it(two->ptr, two->size, &deflate_size);
1726        if (one->size && two->size) {
1727                delta = diff_delta(one->ptr, one->size,
1728                                   two->ptr, two->size,
1729                                   &delta_size, deflate_size);
1730                if (delta) {
1731                        void *to_free = delta;
1732                        orig_size = delta_size;
1733                        delta = deflate_it(delta, delta_size, &delta_size);
1734                        free(to_free);
1735                }
1736        }
1737
1738        if (delta && delta_size < deflate_size) {
1739                fprintf(file, "%sdelta %lu\n", prefix, orig_size);
1740                free(deflated);
1741                data = delta;
1742                data_size = delta_size;
1743        }
1744        else {
1745                fprintf(file, "%sliteral %lu\n", prefix, two->size);
1746                free(delta);
1747                data = deflated;
1748                data_size = deflate_size;
1749        }
1750
1751        /* emit data encoded in base85 */
1752        cp = data;
1753        while (data_size) {
1754                int bytes = (52 < data_size) ? 52 : data_size;
1755                char line[70];
1756                data_size -= bytes;
1757                if (bytes <= 26)
1758                        line[0] = bytes + 'A' - 1;
1759                else
1760                        line[0] = bytes - 26 + 'a' - 1;
1761                encode_85(line + 1, cp, bytes);
1762                cp = (char *) cp + bytes;
1763                fprintf(file, "%s", prefix);
1764                fputs(line, file);
1765                fputc('\n', file);
1766        }
1767        fprintf(file, "%s\n", prefix);
1768        free(data);
1769}
1770
1771static void emit_binary_diff(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
1772{
1773        fprintf(file, "%sGIT binary patch\n", prefix);
1774        emit_binary_diff_body(file, one, two, prefix);
1775        emit_binary_diff_body(file, two, one, prefix);
1776}
1777
1778static void diff_filespec_load_driver(struct diff_filespec *one)
1779{
1780        /* Use already-loaded driver */
1781        if (one->driver)
1782                return;
1783
1784        if (S_ISREG(one->mode))
1785                one->driver = userdiff_find_by_path(one->path);
1786
1787        /* Fallback to default settings */
1788        if (!one->driver)
1789                one->driver = userdiff_find_by_name("default");
1790}
1791
1792int diff_filespec_is_binary(struct diff_filespec *one)
1793{
1794        if (one->is_binary == -1) {
1795                diff_filespec_load_driver(one);
1796                if (one->driver->binary != -1)
1797                        one->is_binary = one->driver->binary;
1798                else {
1799                        if (!one->data && DIFF_FILE_VALID(one))
1800                                diff_populate_filespec(one, 0);
1801                        if (one->data)
1802                                one->is_binary = buffer_is_binary(one->data,
1803                                                one->size);
1804                        if (one->is_binary == -1)
1805                                one->is_binary = 0;
1806                }
1807        }
1808        return one->is_binary;
1809}
1810
1811static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
1812{
1813        diff_filespec_load_driver(one);
1814        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
1815}
1816
1817static const char *userdiff_word_regex(struct diff_filespec *one)
1818{
1819        diff_filespec_load_driver(one);
1820        return one->driver->word_regex;
1821}
1822
1823void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
1824{
1825        if (!options->a_prefix)
1826                options->a_prefix = a;
1827        if (!options->b_prefix)
1828                options->b_prefix = b;
1829}
1830
1831struct userdiff_driver *get_textconv(struct diff_filespec *one)
1832{
1833        if (!DIFF_FILE_VALID(one))
1834                return NULL;
1835
1836        diff_filespec_load_driver(one);
1837        if (!one->driver->textconv)
1838                return NULL;
1839
1840        if (one->driver->textconv_want_cache && !one->driver->textconv_cache) {
1841                struct notes_cache *c = xmalloc(sizeof(*c));
1842                struct strbuf name = STRBUF_INIT;
1843
1844                strbuf_addf(&name, "textconv/%s", one->driver->name);
1845                notes_cache_init(c, name.buf, one->driver->textconv);
1846                one->driver->textconv_cache = c;
1847        }
1848
1849        return one->driver;
1850}
1851
1852static void builtin_diff(const char *name_a,
1853                         const char *name_b,
1854                         struct diff_filespec *one,
1855                         struct diff_filespec *two,
1856                         const char *xfrm_msg,
1857                         int must_show_header,
1858                         struct diff_options *o,
1859                         int complete_rewrite)
1860{
1861        mmfile_t mf1, mf2;
1862        const char *lbl[2];
1863        char *a_one, *b_two;
1864        const char *set = diff_get_color_opt(o, DIFF_METAINFO);
1865        const char *reset = diff_get_color_opt(o, DIFF_RESET);
1866        const char *a_prefix, *b_prefix;
1867        struct userdiff_driver *textconv_one = NULL;
1868        struct userdiff_driver *textconv_two = NULL;
1869        struct strbuf header = STRBUF_INIT;
1870        struct strbuf *msgbuf;
1871        char *line_prefix = "";
1872
1873        if (o->output_prefix) {
1874                msgbuf = o->output_prefix(o, o->output_prefix_data);
1875                line_prefix = msgbuf->buf;
1876        }
1877
1878        if (DIFF_OPT_TST(o, SUBMODULE_LOG) &&
1879                        (!one->mode || S_ISGITLINK(one->mode)) &&
1880                        (!two->mode || S_ISGITLINK(two->mode))) {
1881                const char *del = diff_get_color_opt(o, DIFF_FILE_OLD);
1882                const char *add = diff_get_color_opt(o, DIFF_FILE_NEW);
1883                show_submodule_summary(o->file, one ? one->path : two->path,
1884                                one->sha1, two->sha1, two->dirty_submodule,
1885                                del, add, reset);
1886                return;
1887        }
1888
1889        if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
1890                textconv_one = get_textconv(one);
1891                textconv_two = get_textconv(two);
1892        }
1893
1894        diff_set_mnemonic_prefix(o, "a/", "b/");
1895        if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
1896                a_prefix = o->b_prefix;
1897                b_prefix = o->a_prefix;
1898        } else {
1899                a_prefix = o->a_prefix;
1900                b_prefix = o->b_prefix;
1901        }
1902
1903        /* Never use a non-valid filename anywhere if at all possible */
1904        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
1905        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
1906
1907        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
1908        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
1909        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
1910        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
1911        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, set, a_one, b_two, reset);
1912        if (lbl[0][0] == '/') {
1913                /* /dev/null */
1914                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, set, two->mode, reset);
1915                if (xfrm_msg)
1916                        strbuf_addstr(&header, xfrm_msg);
1917                must_show_header = 1;
1918        }
1919        else if (lbl[1][0] == '/') {
1920                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, set, one->mode, reset);
1921                if (xfrm_msg)
1922                        strbuf_addstr(&header, xfrm_msg);
1923                must_show_header = 1;
1924        }
1925        else {
1926                if (one->mode != two->mode) {
1927                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, set, one->mode, reset);
1928                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, set, two->mode, reset);
1929                        must_show_header = 1;
1930                }
1931                if (xfrm_msg)
1932                        strbuf_addstr(&header, xfrm_msg);
1933
1934                /*
1935                 * we do not run diff between different kind
1936                 * of objects.
1937                 */
1938                if ((one->mode ^ two->mode) & S_IFMT)
1939                        goto free_ab_and_return;
1940                if (complete_rewrite &&
1941                    (textconv_one || !diff_filespec_is_binary(one)) &&
1942                    (textconv_two || !diff_filespec_is_binary(two))) {
1943                        fprintf(o->file, "%s", header.buf);
1944                        strbuf_reset(&header);
1945                        emit_rewrite_diff(name_a, name_b, one, two,
1946                                                textconv_one, textconv_two, o);
1947                        o->found_changes = 1;
1948                        goto free_ab_and_return;
1949                }
1950        }
1951
1952        if (!DIFF_OPT_TST(o, TEXT) &&
1953            ( (!textconv_one && diff_filespec_is_binary(one)) ||
1954              (!textconv_two && diff_filespec_is_binary(two)) )) {
1955                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1956                        die("unable to read files to diff");
1957                /* Quite common confusing case */
1958                if (mf1.size == mf2.size &&
1959                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
1960                        if (must_show_header)
1961                                fprintf(o->file, "%s", header.buf);
1962                        goto free_ab_and_return;
1963                }
1964                fprintf(o->file, "%s", header.buf);
1965                strbuf_reset(&header);
1966                if (DIFF_OPT_TST(o, BINARY))
1967                        emit_binary_diff(o->file, &mf1, &mf2, line_prefix);
1968                else
1969                        fprintf(o->file, "%sBinary files %s and %s differ\n",
1970                                line_prefix, lbl[0], lbl[1]);
1971                o->found_changes = 1;
1972        }
1973        else {
1974                /* Crazy xdl interfaces.. */
1975                const char *diffopts = getenv("GIT_DIFF_OPTS");
1976                xpparam_t xpp;
1977                xdemitconf_t xecfg;
1978                struct emit_callback ecbdata;
1979                const struct userdiff_funcname *pe;
1980
1981                if (!DIFF_XDL_TST(o, WHITESPACE_FLAGS) || must_show_header) {
1982                        fprintf(o->file, "%s", header.buf);
1983                        strbuf_reset(&header);
1984                }
1985
1986                mf1.size = fill_textconv(textconv_one, one, &mf1.ptr);
1987                mf2.size = fill_textconv(textconv_two, two, &mf2.ptr);
1988
1989                pe = diff_funcname_pattern(one);
1990                if (!pe)
1991                        pe = diff_funcname_pattern(two);
1992
1993                memset(&xpp, 0, sizeof(xpp));
1994                memset(&xecfg, 0, sizeof(xecfg));
1995                memset(&ecbdata, 0, sizeof(ecbdata));
1996                ecbdata.label_path = lbl;
1997                ecbdata.color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
1998                ecbdata.found_changesp = &o->found_changes;
1999                ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
2000                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
2001                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2002                ecbdata.opt = o;
2003                ecbdata.header = header.len ? &header : NULL;
2004                xpp.flags = o->xdl_opts;
2005                xecfg.ctxlen = o->context;
2006                xecfg.interhunkctxlen = o->interhunkcontext;
2007                xecfg.flags = XDL_EMIT_FUNCNAMES;
2008                if (pe)
2009                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
2010                if (!diffopts)
2011                        ;
2012                else if (!prefixcmp(diffopts, "--unified="))
2013                        xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
2014                else if (!prefixcmp(diffopts, "-u"))
2015                        xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
2016                if (o->word_diff) {
2017                        int i;
2018
2019                        ecbdata.diff_words =
2020                                xcalloc(1, sizeof(struct diff_words_data));
2021                        ecbdata.diff_words->type = o->word_diff;
2022                        ecbdata.diff_words->opt = o;
2023                        if (!o->word_regex)
2024                                o->word_regex = userdiff_word_regex(one);
2025                        if (!o->word_regex)
2026                                o->word_regex = userdiff_word_regex(two);
2027                        if (!o->word_regex)
2028                                o->word_regex = diff_word_regex_cfg;
2029                        if (o->word_regex) {
2030                                ecbdata.diff_words->word_regex = (regex_t *)
2031                                        xmalloc(sizeof(regex_t));
2032                                if (regcomp(ecbdata.diff_words->word_regex,
2033                                                o->word_regex,
2034                                                REG_EXTENDED | REG_NEWLINE))
2035                                        die ("Invalid regular expression: %s",
2036                                                        o->word_regex);
2037                        }
2038                        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
2039                                if (o->word_diff == diff_words_styles[i].type) {
2040                                        ecbdata.diff_words->style =
2041                                                &diff_words_styles[i];
2042                                        break;
2043                                }
2044                        }
2045                        if (DIFF_OPT_TST(o, COLOR_DIFF)) {
2046                                struct diff_words_style *st = ecbdata.diff_words->style;
2047                                st->old.color = diff_get_color_opt(o, DIFF_FILE_OLD);
2048                                st->new.color = diff_get_color_opt(o, DIFF_FILE_NEW);
2049                                st->ctx.color = diff_get_color_opt(o, DIFF_PLAIN);
2050                        }
2051                }
2052                xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
2053                              &xpp, &xecfg);
2054                if (o->word_diff)
2055                        free_diff_words_data(&ecbdata);
2056                if (textconv_one)
2057                        free(mf1.ptr);
2058                if (textconv_two)
2059                        free(mf2.ptr);
2060                xdiff_clear_find_func(&xecfg);
2061        }
2062
2063 free_ab_and_return:
2064        strbuf_release(&header);
2065        diff_free_filespec_data(one);
2066        diff_free_filespec_data(two);
2067        free(a_one);
2068        free(b_two);
2069        return;
2070}
2071
2072static void builtin_diffstat(const char *name_a, const char *name_b,
2073                             struct diff_filespec *one,
2074                             struct diff_filespec *two,
2075                             struct diffstat_t *diffstat,
2076                             struct diff_options *o,
2077                             int complete_rewrite)
2078{
2079        mmfile_t mf1, mf2;
2080        struct diffstat_file *data;
2081
2082        data = diffstat_add(diffstat, name_a, name_b);
2083
2084        if (!one || !two) {
2085                data->is_unmerged = 1;
2086                return;
2087        }
2088
2089        if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
2090                data->is_binary = 1;
2091                data->added = diff_filespec_size(two);
2092                data->deleted = diff_filespec_size(one);
2093        }
2094
2095        else if (complete_rewrite) {
2096                diff_populate_filespec(one, 0);
2097                diff_populate_filespec(two, 0);
2098                data->deleted = count_lines(one->data, one->size);
2099                data->added = count_lines(two->data, two->size);
2100        }
2101
2102        else {
2103                /* Crazy xdl interfaces.. */
2104                xpparam_t xpp;
2105                xdemitconf_t xecfg;
2106
2107                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2108                        die("unable to read files to diff");
2109
2110                memset(&xpp, 0, sizeof(xpp));
2111                memset(&xecfg, 0, sizeof(xecfg));
2112                xpp.flags = o->xdl_opts;
2113                xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
2114                              &xpp, &xecfg);
2115        }
2116
2117        diff_free_filespec_data(one);
2118        diff_free_filespec_data(two);
2119}
2120
2121static void builtin_checkdiff(const char *name_a, const char *name_b,
2122                              const char *attr_path,
2123                              struct diff_filespec *one,
2124                              struct diff_filespec *two,
2125                              struct diff_options *o)
2126{
2127        mmfile_t mf1, mf2;
2128        struct checkdiff_t data;
2129
2130        if (!two)
2131                return;
2132
2133        memset(&data, 0, sizeof(data));
2134        data.filename = name_b ? name_b : name_a;
2135        data.lineno = 0;
2136        data.o = o;
2137        data.ws_rule = whitespace_rule(attr_path);
2138        data.conflict_marker_size = ll_merge_marker_size(attr_path);
2139
2140        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2141                die("unable to read files to diff");
2142
2143        /*
2144         * All the other codepaths check both sides, but not checking
2145         * the "old" side here is deliberate.  We are checking the newly
2146         * introduced changes, and as long as the "new" side is text, we
2147         * can and should check what it introduces.
2148         */
2149        if (diff_filespec_is_binary(two))
2150                goto free_and_return;
2151        else {
2152                /* Crazy xdl interfaces.. */
2153                xpparam_t xpp;
2154                xdemitconf_t xecfg;
2155
2156                memset(&xpp, 0, sizeof(xpp));
2157                memset(&xecfg, 0, sizeof(xecfg));
2158                xecfg.ctxlen = 1; /* at least one context line */
2159                xpp.flags = 0;
2160                xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
2161                              &xpp, &xecfg);
2162
2163                if (data.ws_rule & WS_BLANK_AT_EOF) {
2164                        struct emit_callback ecbdata;
2165                        int blank_at_eof;
2166
2167                        ecbdata.ws_rule = data.ws_rule;
2168                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2169                        blank_at_eof = ecbdata.blank_at_eof_in_postimage;
2170
2171                        if (blank_at_eof) {
2172                                static char *err;
2173                                if (!err)
2174                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
2175                                fprintf(o->file, "%s:%d: %s.\n",
2176                                        data.filename, blank_at_eof, err);
2177                                data.status = 1; /* report errors */
2178                        }
2179                }
2180        }
2181 free_and_return:
2182        diff_free_filespec_data(one);
2183        diff_free_filespec_data(two);
2184        if (data.status)
2185                DIFF_OPT_SET(o, CHECK_FAILED);
2186}
2187
2188struct diff_filespec *alloc_filespec(const char *path)
2189{
2190        int namelen = strlen(path);
2191        struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
2192
2193        memset(spec, 0, sizeof(*spec));
2194        spec->path = (char *)(spec + 1);
2195        memcpy(spec->path, path, namelen+1);
2196        spec->count = 1;
2197        spec->is_binary = -1;
2198        return spec;
2199}
2200
2201void free_filespec(struct diff_filespec *spec)
2202{
2203        if (!--spec->count) {
2204                diff_free_filespec_data(spec);
2205                free(spec);
2206        }
2207}
2208
2209void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
2210                   unsigned short mode)
2211{
2212        if (mode) {
2213                spec->mode = canon_mode(mode);
2214                hashcpy(spec->sha1, sha1);
2215                spec->sha1_valid = !is_null_sha1(sha1);
2216        }
2217}
2218
2219/*
2220 * Given a name and sha1 pair, if the index tells us the file in
2221 * the work tree has that object contents, return true, so that
2222 * prepare_temp_file() does not have to inflate and extract.
2223 */
2224static int reuse_worktree_file(const char *name, const unsigned char *sha1, int want_file)
2225{
2226        struct cache_entry *ce;
2227        struct stat st;
2228        int pos, len;
2229
2230        /*
2231         * We do not read the cache ourselves here, because the
2232         * benchmark with my previous version that always reads cache
2233         * shows that it makes things worse for diff-tree comparing
2234         * two linux-2.6 kernel trees in an already checked out work
2235         * tree.  This is because most diff-tree comparisons deal with
2236         * only a small number of files, while reading the cache is
2237         * expensive for a large project, and its cost outweighs the
2238         * savings we get by not inflating the object to a temporary
2239         * file.  Practically, this code only helps when we are used
2240         * by diff-cache --cached, which does read the cache before
2241         * calling us.
2242         */
2243        if (!active_cache)
2244                return 0;
2245
2246        /* We want to avoid the working directory if our caller
2247         * doesn't need the data in a normal file, this system
2248         * is rather slow with its stat/open/mmap/close syscalls,
2249         * and the object is contained in a pack file.  The pack
2250         * is probably already open and will be faster to obtain
2251         * the data through than the working directory.  Loose
2252         * objects however would tend to be slower as they need
2253         * to be individually opened and inflated.
2254         */
2255        if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(sha1))
2256                return 0;
2257
2258        len = strlen(name);
2259        pos = cache_name_pos(name, len);
2260        if (pos < 0)
2261                return 0;
2262        ce = active_cache[pos];
2263
2264        /*
2265         * This is not the sha1 we are looking for, or
2266         * unreusable because it is not a regular file.
2267         */
2268        if (hashcmp(sha1, ce->sha1) || !S_ISREG(ce->ce_mode))
2269                return 0;
2270
2271        /*
2272         * If ce is marked as "assume unchanged", there is no
2273         * guarantee that work tree matches what we are looking for.
2274         */
2275        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
2276                return 0;
2277
2278        /*
2279         * If ce matches the file in the work tree, we can reuse it.
2280         */
2281        if (ce_uptodate(ce) ||
2282            (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
2283                return 1;
2284
2285        return 0;
2286}
2287
2288static int populate_from_stdin(struct diff_filespec *s)
2289{
2290        struct strbuf buf = STRBUF_INIT;
2291        size_t size = 0;
2292
2293        if (strbuf_read(&buf, 0, 0) < 0)
2294                return error("error while reading from stdin %s",
2295                                     strerror(errno));
2296
2297        s->should_munmap = 0;
2298        s->data = strbuf_detach(&buf, &size);
2299        s->size = size;
2300        s->should_free = 1;
2301        return 0;
2302}
2303
2304static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
2305{
2306        int len;
2307        char *data = xmalloc(100), *dirty = "";
2308
2309        /* Are we looking at the work tree? */
2310        if (s->dirty_submodule)
2311                dirty = "-dirty";
2312
2313        len = snprintf(data, 100,
2314                       "Subproject commit %s%s\n", sha1_to_hex(s->sha1), dirty);
2315        s->data = data;
2316        s->size = len;
2317        s->should_free = 1;
2318        if (size_only) {
2319                s->data = NULL;
2320                free(data);
2321        }
2322        return 0;
2323}
2324
2325/*
2326 * While doing rename detection and pickaxe operation, we may need to
2327 * grab the data for the blob (or file) for our own in-core comparison.
2328 * diff_filespec has data and size fields for this purpose.
2329 */
2330int diff_populate_filespec(struct diff_filespec *s, int size_only)
2331{
2332        int err = 0;
2333        if (!DIFF_FILE_VALID(s))
2334                die("internal error: asking to populate invalid file.");
2335        if (S_ISDIR(s->mode))
2336                return -1;
2337
2338        if (s->data)
2339                return 0;
2340
2341        if (size_only && 0 < s->size)
2342                return 0;
2343
2344        if (S_ISGITLINK(s->mode))
2345                return diff_populate_gitlink(s, size_only);
2346
2347        if (!s->sha1_valid ||
2348            reuse_worktree_file(s->path, s->sha1, 0)) {
2349                struct strbuf buf = STRBUF_INIT;
2350                struct stat st;
2351                int fd;
2352
2353                if (!strcmp(s->path, "-"))
2354                        return populate_from_stdin(s);
2355
2356                if (lstat(s->path, &st) < 0) {
2357                        if (errno == ENOENT) {
2358                        err_empty:
2359                                err = -1;
2360                        empty:
2361                                s->data = (char *)"";
2362                                s->size = 0;
2363                                return err;
2364                        }
2365                }
2366                s->size = xsize_t(st.st_size);
2367                if (!s->size)
2368                        goto empty;
2369                if (S_ISLNK(st.st_mode)) {
2370                        struct strbuf sb = STRBUF_INIT;
2371
2372                        if (strbuf_readlink(&sb, s->path, s->size))
2373                                goto err_empty;
2374                        s->size = sb.len;
2375                        s->data = strbuf_detach(&sb, NULL);
2376                        s->should_free = 1;
2377                        return 0;
2378                }
2379                if (size_only)
2380                        return 0;
2381                fd = open(s->path, O_RDONLY);
2382                if (fd < 0)
2383                        goto err_empty;
2384                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
2385                close(fd);
2386                s->should_munmap = 1;
2387
2388                /*
2389                 * Convert from working tree format to canonical git format
2390                 */
2391                if (convert_to_git(s->path, s->data, s->size, &buf, safe_crlf)) {
2392                        size_t size = 0;
2393                        munmap(s->data, s->size);
2394                        s->should_munmap = 0;
2395                        s->data = strbuf_detach(&buf, &size);
2396                        s->size = size;
2397                        s->should_free = 1;
2398                }
2399        }
2400        else {
2401                enum object_type type;
2402                if (size_only) {
2403                        type = sha1_object_info(s->sha1, &s->size);
2404                        if (type < 0)
2405                                die("unable to read %s", sha1_to_hex(s->sha1));
2406                } else {
2407                        s->data = read_sha1_file(s->sha1, &type, &s->size);
2408                        if (!s->data)
2409                                die("unable to read %s", sha1_to_hex(s->sha1));
2410                        s->should_free = 1;
2411                }
2412        }
2413        return 0;
2414}
2415
2416void diff_free_filespec_blob(struct diff_filespec *s)
2417{
2418        if (s->should_free)
2419                free(s->data);
2420        else if (s->should_munmap)
2421                munmap(s->data, s->size);
2422
2423        if (s->should_free || s->should_munmap) {
2424                s->should_free = s->should_munmap = 0;
2425                s->data = NULL;
2426        }
2427}
2428
2429void diff_free_filespec_data(struct diff_filespec *s)
2430{
2431        diff_free_filespec_blob(s);
2432        free(s->cnt_data);
2433        s->cnt_data = NULL;
2434}
2435
2436static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
2437                           void *blob,
2438                           unsigned long size,
2439                           const unsigned char *sha1,
2440                           int mode)
2441{
2442        int fd;
2443        struct strbuf buf = STRBUF_INIT;
2444        struct strbuf template = STRBUF_INIT;
2445        char *path_dup = xstrdup(path);
2446        const char *base = basename(path_dup);
2447
2448        /* Generate "XXXXXX_basename.ext" */
2449        strbuf_addstr(&template, "XXXXXX_");
2450        strbuf_addstr(&template, base);
2451
2452        fd = git_mkstemps(temp->tmp_path, PATH_MAX, template.buf,
2453                        strlen(base) + 1);
2454        if (fd < 0)
2455                die_errno("unable to create temp-file");
2456        if (convert_to_working_tree(path,
2457                        (const char *)blob, (size_t)size, &buf)) {
2458                blob = buf.buf;
2459                size = buf.len;
2460        }
2461        if (write_in_full(fd, blob, size) != size)
2462                die_errno("unable to write temp-file");
2463        close(fd);
2464        temp->name = temp->tmp_path;
2465        strcpy(temp->hex, sha1_to_hex(sha1));
2466        temp->hex[40] = 0;
2467        sprintf(temp->mode, "%06o", mode);
2468        strbuf_release(&buf);
2469        strbuf_release(&template);
2470        free(path_dup);
2471}
2472
2473static struct diff_tempfile *prepare_temp_file(const char *name,
2474                struct diff_filespec *one)
2475{
2476        struct diff_tempfile *temp = claim_diff_tempfile();
2477
2478        if (!DIFF_FILE_VALID(one)) {
2479        not_a_valid_file:
2480                /* A '-' entry produces this for file-2, and
2481                 * a '+' entry produces this for file-1.
2482                 */
2483                temp->name = "/dev/null";
2484                strcpy(temp->hex, ".");
2485                strcpy(temp->mode, ".");
2486                return temp;
2487        }
2488
2489        if (!remove_tempfile_installed) {
2490                atexit(remove_tempfile);
2491                sigchain_push_common(remove_tempfile_on_signal);
2492                remove_tempfile_installed = 1;
2493        }
2494
2495        if (!one->sha1_valid ||
2496            reuse_worktree_file(name, one->sha1, 1)) {
2497                struct stat st;
2498                if (lstat(name, &st) < 0) {
2499                        if (errno == ENOENT)
2500                                goto not_a_valid_file;
2501                        die_errno("stat(%s)", name);
2502                }
2503                if (S_ISLNK(st.st_mode)) {
2504                        struct strbuf sb = STRBUF_INIT;
2505                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
2506                                die_errno("readlink(%s)", name);
2507                        prep_temp_blob(name, temp, sb.buf, sb.len,
2508                                       (one->sha1_valid ?
2509                                        one->sha1 : null_sha1),
2510                                       (one->sha1_valid ?
2511                                        one->mode : S_IFLNK));
2512                        strbuf_release(&sb);
2513                }
2514                else {
2515                        /* we can borrow from the file in the work tree */
2516                        temp->name = name;
2517                        if (!one->sha1_valid)
2518                                strcpy(temp->hex, sha1_to_hex(null_sha1));
2519                        else
2520                                strcpy(temp->hex, sha1_to_hex(one->sha1));
2521                        /* Even though we may sometimes borrow the
2522                         * contents from the work tree, we always want
2523                         * one->mode.  mode is trustworthy even when
2524                         * !(one->sha1_valid), as long as
2525                         * DIFF_FILE_VALID(one).
2526                         */
2527                        sprintf(temp->mode, "%06o", one->mode);
2528                }
2529                return temp;
2530        }
2531        else {
2532                if (diff_populate_filespec(one, 0))
2533                        die("cannot read data blob for %s", one->path);
2534                prep_temp_blob(name, temp, one->data, one->size,
2535                               one->sha1, one->mode);
2536        }
2537        return temp;
2538}
2539
2540/* An external diff command takes:
2541 *
2542 * diff-cmd name infile1 infile1-sha1 infile1-mode \
2543 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
2544 *
2545 */
2546static void run_external_diff(const char *pgm,
2547                              const char *name,
2548                              const char *other,
2549                              struct diff_filespec *one,
2550                              struct diff_filespec *two,
2551                              const char *xfrm_msg,
2552                              int complete_rewrite)
2553{
2554        const char *spawn_arg[10];
2555        int retval;
2556        const char **arg = &spawn_arg[0];
2557
2558        if (one && two) {
2559                struct diff_tempfile *temp_one, *temp_two;
2560                const char *othername = (other ? other : name);
2561                temp_one = prepare_temp_file(name, one);
2562                temp_two = prepare_temp_file(othername, two);
2563                *arg++ = pgm;
2564                *arg++ = name;
2565                *arg++ = temp_one->name;
2566                *arg++ = temp_one->hex;
2567                *arg++ = temp_one->mode;
2568                *arg++ = temp_two->name;
2569                *arg++ = temp_two->hex;
2570                *arg++ = temp_two->mode;
2571                if (other) {
2572                        *arg++ = other;
2573                        *arg++ = xfrm_msg;
2574                }
2575        } else {
2576                *arg++ = pgm;
2577                *arg++ = name;
2578        }
2579        *arg = NULL;
2580        fflush(NULL);
2581        retval = run_command_v_opt(spawn_arg, RUN_USING_SHELL);
2582        remove_tempfile();
2583        if (retval) {
2584                fprintf(stderr, "external diff died, stopping at %s.\n", name);
2585                exit(1);
2586        }
2587}
2588
2589static int similarity_index(struct diff_filepair *p)
2590{
2591        return p->score * 100 / MAX_SCORE;
2592}
2593
2594static void fill_metainfo(struct strbuf *msg,
2595                          const char *name,
2596                          const char *other,
2597                          struct diff_filespec *one,
2598                          struct diff_filespec *two,
2599                          struct diff_options *o,
2600                          struct diff_filepair *p,
2601                          int *must_show_header,
2602                          int use_color)
2603{
2604        const char *set = diff_get_color(use_color, DIFF_METAINFO);
2605        const char *reset = diff_get_color(use_color, DIFF_RESET);
2606        struct strbuf *msgbuf;
2607        char *line_prefix = "";
2608
2609        *must_show_header = 1;
2610        if (o->output_prefix) {
2611                msgbuf = o->output_prefix(o, o->output_prefix_data);
2612                line_prefix = msgbuf->buf;
2613        }
2614        strbuf_init(msg, PATH_MAX * 2 + 300);
2615        switch (p->status) {
2616        case DIFF_STATUS_COPIED:
2617                strbuf_addf(msg, "%s%ssimilarity index %d%%",
2618                            line_prefix, set, similarity_index(p));
2619                strbuf_addf(msg, "%s\n%s%scopy from ",
2620                            reset,  line_prefix, set);
2621                quote_c_style(name, msg, NULL, 0);
2622                strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
2623                quote_c_style(other, msg, NULL, 0);
2624                strbuf_addf(msg, "%s\n", reset);
2625                break;
2626        case DIFF_STATUS_RENAMED:
2627                strbuf_addf(msg, "%s%ssimilarity index %d%%",
2628                            line_prefix, set, similarity_index(p));
2629                strbuf_addf(msg, "%s\n%s%srename from ",
2630                            reset, line_prefix, set);
2631                quote_c_style(name, msg, NULL, 0);
2632                strbuf_addf(msg, "%s\n%s%srename to ",
2633                            reset, line_prefix, set);
2634                quote_c_style(other, msg, NULL, 0);
2635                strbuf_addf(msg, "%s\n", reset);
2636                break;
2637        case DIFF_STATUS_MODIFIED:
2638                if (p->score) {
2639                        strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
2640                                    line_prefix,
2641                                    set, similarity_index(p), reset);
2642                        break;
2643                }
2644                /* fallthru */
2645        default:
2646                *must_show_header = 0;
2647        }
2648        if (one && two && hashcmp(one->sha1, two->sha1)) {
2649                int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
2650
2651                if (DIFF_OPT_TST(o, BINARY)) {
2652                        mmfile_t mf;
2653                        if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
2654                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
2655                                abbrev = 40;
2656                }
2657                strbuf_addf(msg, "%s%sindex %s..", line_prefix, set,
2658                            find_unique_abbrev(one->sha1, abbrev));
2659                strbuf_addstr(msg, find_unique_abbrev(two->sha1, abbrev));
2660                if (one->mode == two->mode)
2661                        strbuf_addf(msg, " %06o", one->mode);
2662                strbuf_addf(msg, "%s\n", reset);
2663        }
2664}
2665
2666static void run_diff_cmd(const char *pgm,
2667                         const char *name,
2668                         const char *other,
2669                         const char *attr_path,
2670                         struct diff_filespec *one,
2671                         struct diff_filespec *two,
2672                         struct strbuf *msg,
2673                         struct diff_options *o,
2674                         struct diff_filepair *p)
2675{
2676        const char *xfrm_msg = NULL;
2677        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
2678        int must_show_header = 0;
2679
2680        if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
2681                pgm = NULL;
2682        else {
2683                struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
2684                if (drv && drv->external)
2685                        pgm = drv->external;
2686        }
2687
2688        if (msg) {
2689                /*
2690                 * don't use colors when the header is intended for an
2691                 * external diff driver
2692                 */
2693                fill_metainfo(msg, name, other, one, two, o, p,
2694                              &must_show_header,
2695                              DIFF_OPT_TST(o, COLOR_DIFF) && !pgm);
2696                xfrm_msg = msg->len ? msg->buf : NULL;
2697        }
2698
2699        if (pgm) {
2700                run_external_diff(pgm, name, other, one, two, xfrm_msg,
2701                                  complete_rewrite);
2702                return;
2703        }
2704        if (one && two)
2705                builtin_diff(name, other ? other : name,
2706                             one, two, xfrm_msg, must_show_header,
2707                             o, complete_rewrite);
2708        else
2709                fprintf(o->file, "* Unmerged path %s\n", name);
2710}
2711
2712static void diff_fill_sha1_info(struct diff_filespec *one)
2713{
2714        if (DIFF_FILE_VALID(one)) {
2715                if (!one->sha1_valid) {
2716                        struct stat st;
2717                        if (!strcmp(one->path, "-")) {
2718                                hashcpy(one->sha1, null_sha1);
2719                                return;
2720                        }
2721                        if (lstat(one->path, &st) < 0)
2722                                die_errno("stat '%s'", one->path);
2723                        if (index_path(one->sha1, one->path, &st, 0))
2724                                die("cannot hash %s", one->path);
2725                }
2726        }
2727        else
2728                hashclr(one->sha1);
2729}
2730
2731static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
2732{
2733        /* Strip the prefix but do not molest /dev/null and absolute paths */
2734        if (*namep && **namep != '/') {
2735                *namep += prefix_length;
2736                if (**namep == '/')
2737                        ++*namep;
2738        }
2739        if (*otherp && **otherp != '/') {
2740                *otherp += prefix_length;
2741                if (**otherp == '/')
2742                        ++*otherp;
2743        }
2744}
2745
2746static void run_diff(struct diff_filepair *p, struct diff_options *o)
2747{
2748        const char *pgm = external_diff();
2749        struct strbuf msg;
2750        struct diff_filespec *one = p->one;
2751        struct diff_filespec *two = p->two;
2752        const char *name;
2753        const char *other;
2754        const char *attr_path;
2755
2756        name  = p->one->path;
2757        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2758        attr_path = name;
2759        if (o->prefix_length)
2760                strip_prefix(o->prefix_length, &name, &other);
2761
2762        if (DIFF_PAIR_UNMERGED(p)) {
2763                run_diff_cmd(pgm, name, NULL, attr_path,
2764                             NULL, NULL, NULL, o, p);
2765                return;
2766        }
2767
2768        diff_fill_sha1_info(one);
2769        diff_fill_sha1_info(two);
2770
2771        if (!pgm &&
2772            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
2773            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
2774                /*
2775                 * a filepair that changes between file and symlink
2776                 * needs to be split into deletion and creation.
2777                 */
2778                struct diff_filespec *null = alloc_filespec(two->path);
2779                run_diff_cmd(NULL, name, other, attr_path,
2780                             one, null, &msg, o, p);
2781                free(null);
2782                strbuf_release(&msg);
2783
2784                null = alloc_filespec(one->path);
2785                run_diff_cmd(NULL, name, other, attr_path,
2786                             null, two, &msg, o, p);
2787                free(null);
2788        }
2789        else
2790                run_diff_cmd(pgm, name, other, attr_path,
2791                             one, two, &msg, o, p);
2792
2793        strbuf_release(&msg);
2794}
2795
2796static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
2797                         struct diffstat_t *diffstat)
2798{
2799        const char *name;
2800        const char *other;
2801        int complete_rewrite = 0;
2802
2803        if (DIFF_PAIR_UNMERGED(p)) {
2804                /* unmerged */
2805                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, 0);
2806                return;
2807        }
2808
2809        name = p->one->path;
2810        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2811
2812        if (o->prefix_length)
2813                strip_prefix(o->prefix_length, &name, &other);
2814
2815        diff_fill_sha1_info(p->one);
2816        diff_fill_sha1_info(p->two);
2817
2818        if (p->status == DIFF_STATUS_MODIFIED && p->score)
2819                complete_rewrite = 1;
2820        builtin_diffstat(name, other, p->one, p->two, diffstat, o, complete_rewrite);
2821}
2822
2823static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
2824{
2825        const char *name;
2826        const char *other;
2827        const char *attr_path;
2828
2829        if (DIFF_PAIR_UNMERGED(p)) {
2830                /* unmerged */
2831                return;
2832        }
2833
2834        name = p->one->path;
2835        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2836        attr_path = other ? other : name;
2837
2838        if (o->prefix_length)
2839                strip_prefix(o->prefix_length, &name, &other);
2840
2841        diff_fill_sha1_info(p->one);
2842        diff_fill_sha1_info(p->two);
2843
2844        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
2845}
2846
2847void diff_setup(struct diff_options *options)
2848{
2849        memcpy(options, &default_diff_options, sizeof(*options));
2850
2851        options->file = stdout;
2852
2853        options->line_termination = '\n';
2854        options->break_opt = -1;
2855        options->rename_limit = -1;
2856        options->dirstat_percent = 3;
2857        options->context = 3;
2858
2859        options->change = diff_change;
2860        options->add_remove = diff_addremove;
2861        if (diff_use_color_default > 0)
2862                DIFF_OPT_SET(options, COLOR_DIFF);
2863        options->detect_rename = diff_detect_rename_default;
2864
2865        if (diff_no_prefix) {
2866                options->a_prefix = options->b_prefix = "";
2867        } else if (!diff_mnemonic_prefix) {
2868                options->a_prefix = "a/";
2869                options->b_prefix = "b/";
2870        }
2871}
2872
2873int diff_setup_done(struct diff_options *options)
2874{
2875        int count = 0;
2876
2877        if (options->output_format & DIFF_FORMAT_NAME)
2878                count++;
2879        if (options->output_format & DIFF_FORMAT_NAME_STATUS)
2880                count++;
2881        if (options->output_format & DIFF_FORMAT_CHECKDIFF)
2882                count++;
2883        if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
2884                count++;
2885        if (count > 1)
2886                die("--name-only, --name-status, --check and -s are mutually exclusive");
2887
2888        /*
2889         * Most of the time we can say "there are changes"
2890         * only by checking if there are changed paths, but
2891         * --ignore-whitespace* options force us to look
2892         * inside contents.
2893         */
2894
2895        if (DIFF_XDL_TST(options, IGNORE_WHITESPACE) ||
2896            DIFF_XDL_TST(options, IGNORE_WHITESPACE_CHANGE) ||
2897            DIFF_XDL_TST(options, IGNORE_WHITESPACE_AT_EOL))
2898                DIFF_OPT_SET(options, DIFF_FROM_CONTENTS);
2899        else
2900                DIFF_OPT_CLR(options, DIFF_FROM_CONTENTS);
2901
2902        if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
2903                options->detect_rename = DIFF_DETECT_COPY;
2904
2905        if (!DIFF_OPT_TST(options, RELATIVE_NAME))
2906                options->prefix = NULL;
2907        if (options->prefix)
2908                options->prefix_length = strlen(options->prefix);
2909        else
2910                options->prefix_length = 0;
2911
2912        if (options->output_format & (DIFF_FORMAT_NAME |
2913                                      DIFF_FORMAT_NAME_STATUS |
2914                                      DIFF_FORMAT_CHECKDIFF |
2915                                      DIFF_FORMAT_NO_OUTPUT))
2916                options->output_format &= ~(DIFF_FORMAT_RAW |
2917                                            DIFF_FORMAT_NUMSTAT |
2918                                            DIFF_FORMAT_DIFFSTAT |
2919                                            DIFF_FORMAT_SHORTSTAT |
2920                                            DIFF_FORMAT_DIRSTAT |
2921                                            DIFF_FORMAT_SUMMARY |
2922                                            DIFF_FORMAT_PATCH);
2923
2924        /*
2925         * These cases always need recursive; we do not drop caller-supplied
2926         * recursive bits for other formats here.
2927         */
2928        if (options->output_format & (DIFF_FORMAT_PATCH |
2929                                      DIFF_FORMAT_NUMSTAT |
2930                                      DIFF_FORMAT_DIFFSTAT |
2931                                      DIFF_FORMAT_SHORTSTAT |
2932                                      DIFF_FORMAT_DIRSTAT |
2933                                      DIFF_FORMAT_SUMMARY |
2934                                      DIFF_FORMAT_CHECKDIFF))
2935                DIFF_OPT_SET(options, RECURSIVE);
2936        /*
2937         * Also pickaxe would not work very well if you do not say recursive
2938         */
2939        if (options->pickaxe)
2940                DIFF_OPT_SET(options, RECURSIVE);
2941        /*
2942         * When patches are generated, submodules diffed against the work tree
2943         * must be checked for dirtiness too so it can be shown in the output
2944         */
2945        if (options->output_format & DIFF_FORMAT_PATCH)
2946                DIFF_OPT_SET(options, DIRTY_SUBMODULES);
2947
2948        if (options->detect_rename && options->rename_limit < 0)
2949                options->rename_limit = diff_rename_limit_default;
2950        if (options->setup & DIFF_SETUP_USE_CACHE) {
2951                if (!active_cache)
2952                        /* read-cache does not die even when it fails
2953                         * so it is safe for us to do this here.  Also
2954                         * it does not smudge active_cache or active_nr
2955                         * when it fails, so we do not have to worry about
2956                         * cleaning it up ourselves either.
2957                         */
2958                        read_cache();
2959        }
2960        if (options->abbrev <= 0 || 40 < options->abbrev)
2961                options->abbrev = 40; /* full */
2962
2963        /*
2964         * It does not make sense to show the first hit we happened
2965         * to have found.  It does not make sense not to return with
2966         * exit code in such a case either.
2967         */
2968        if (DIFF_OPT_TST(options, QUICK)) {
2969                options->output_format = DIFF_FORMAT_NO_OUTPUT;
2970                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
2971        }
2972
2973        return 0;
2974}
2975
2976static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
2977{
2978        char c, *eq;
2979        int len;
2980
2981        if (*arg != '-')
2982                return 0;
2983        c = *++arg;
2984        if (!c)
2985                return 0;
2986        if (c == arg_short) {
2987                c = *++arg;
2988                if (!c)
2989                        return 1;
2990                if (val && isdigit(c)) {
2991                        char *end;
2992                        int n = strtoul(arg, &end, 10);
2993                        if (*end)
2994                                return 0;
2995                        *val = n;
2996                        return 1;
2997                }
2998                return 0;
2999        }
3000        if (c != '-')
3001                return 0;
3002        arg++;
3003        eq = strchr(arg, '=');
3004        if (eq)
3005                len = eq - arg;
3006        else
3007                len = strlen(arg);
3008        if (!len || strncmp(arg, arg_long, len))
3009                return 0;
3010        if (eq) {
3011                int n;
3012                char *end;
3013                if (!isdigit(*++eq))
3014                        return 0;
3015                n = strtoul(eq, &end, 10);
3016                if (*end)
3017                        return 0;
3018                *val = n;
3019        }
3020        return 1;
3021}
3022
3023static int diff_scoreopt_parse(const char *opt);
3024
3025static inline int short_opt(char opt, const char **argv,
3026                            const char **optarg)
3027{
3028        const char *arg = argv[0];
3029        if (arg[0] != '-' || arg[1] != opt)
3030                return 0;
3031        if (arg[2] != '\0') {
3032                *optarg = arg + 2;
3033                return 1;
3034        }
3035        if (!argv[1])
3036                die("Option '%c' requires a value", opt);
3037        *optarg = argv[1];
3038        return 2;
3039}
3040
3041int parse_long_opt(const char *opt, const char **argv,
3042                   const char **optarg)
3043{
3044        const char *arg = argv[0];
3045        if (arg[0] != '-' || arg[1] != '-')
3046                return 0;
3047        arg += strlen("--");
3048        if (prefixcmp(arg, opt))
3049                return 0;
3050        arg += strlen(opt);
3051        if (*arg == '=') { /* sticked form: --option=value */
3052                *optarg = arg + 1;
3053                return 1;
3054        }
3055        if (*arg != '\0')
3056                return 0;
3057        /* separate form: --option value */
3058        if (!argv[1])
3059                die("Option '--%s' requires a value", opt);
3060        *optarg = argv[1];
3061        return 2;
3062}
3063
3064static int stat_opt(struct diff_options *options, const char **av)
3065{
3066        const char *arg = av[0];
3067        char *end;
3068        int width = options->stat_width;
3069        int name_width = options->stat_name_width;
3070        int argcount = 1;
3071
3072        arg += strlen("--stat");
3073        end = (char *)arg;
3074
3075        switch (*arg) {
3076        case '-':
3077                if (!prefixcmp(arg, "-width")) {
3078                        arg += strlen("-width");
3079                        if (*arg == '=')
3080                                width = strtoul(arg + 1, &end, 10);
3081                        else if (!*arg && !av[1])
3082                                die("Option '--stat-width' requires a value");
3083                        else if (!*arg) {
3084                                width = strtoul(av[1], &end, 10);
3085                                argcount = 2;
3086                        }
3087                } else if (!prefixcmp(arg, "-name-width")) {
3088                        arg += strlen("-name-width");
3089                        if (*arg == '=')
3090                                name_width = strtoul(arg + 1, &end, 10);
3091                        else if (!*arg && !av[1])
3092                                die("Option '--stat-name-width' requires a value");
3093                        else if (!*arg) {
3094                                name_width = strtoul(av[1], &end, 10);
3095                                argcount = 2;
3096                        }
3097                }
3098                break;
3099        case '=':
3100                width = strtoul(arg+1, &end, 10);
3101                if (*end == ',')
3102                        name_width = strtoul(end+1, &end, 10);
3103        }
3104
3105        /* Important! This checks all the error cases! */
3106        if (*end)
3107                return 0;
3108        options->output_format |= DIFF_FORMAT_DIFFSTAT;
3109        options->stat_name_width = name_width;
3110        options->stat_width = width;
3111        return argcount;
3112}
3113
3114int diff_opt_parse(struct diff_options *options, const char **av, int ac)
3115{
3116        const char *arg = av[0];
3117        const char *optarg;
3118        int argcount;
3119
3120        /* Output format options */
3121        if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch"))
3122                options->output_format |= DIFF_FORMAT_PATCH;
3123        else if (opt_arg(arg, 'U', "unified", &options->context))
3124                options->output_format |= DIFF_FORMAT_PATCH;
3125        else if (!strcmp(arg, "--raw"))
3126                options->output_format |= DIFF_FORMAT_RAW;
3127        else if (!strcmp(arg, "--patch-with-raw"))
3128                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_RAW;
3129        else if (!strcmp(arg, "--numstat"))
3130                options->output_format |= DIFF_FORMAT_NUMSTAT;
3131        else if (!strcmp(arg, "--shortstat"))
3132                options->output_format |= DIFF_FORMAT_SHORTSTAT;
3133        else if (opt_arg(arg, 'X', "dirstat", &options->dirstat_percent))
3134                options->output_format |= DIFF_FORMAT_DIRSTAT;
3135        else if (!strcmp(arg, "--cumulative")) {
3136                options->output_format |= DIFF_FORMAT_DIRSTAT;
3137                DIFF_OPT_SET(options, DIRSTAT_CUMULATIVE);
3138        } else if (opt_arg(arg, 0, "dirstat-by-file",
3139                           &options->dirstat_percent)) {
3140                options->output_format |= DIFF_FORMAT_DIRSTAT;
3141                DIFF_OPT_SET(options, DIRSTAT_BY_FILE);
3142        }
3143        else if (!strcmp(arg, "--check"))
3144                options->output_format |= DIFF_FORMAT_CHECKDIFF;
3145        else if (!strcmp(arg, "--summary"))
3146                options->output_format |= DIFF_FORMAT_SUMMARY;
3147        else if (!strcmp(arg, "--patch-with-stat"))
3148                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_DIFFSTAT;
3149        else if (!strcmp(arg, "--name-only"))
3150                options->output_format |= DIFF_FORMAT_NAME;
3151        else if (!strcmp(arg, "--name-status"))
3152                options->output_format |= DIFF_FORMAT_NAME_STATUS;
3153        else if (!strcmp(arg, "-s"))
3154                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
3155        else if (!prefixcmp(arg, "--stat"))
3156                /* --stat, --stat-width, or --stat-name-width */
3157                return stat_opt(options, av);
3158
3159        /* renames options */
3160        else if (!prefixcmp(arg, "-B") || !prefixcmp(arg, "--break-rewrites=") ||
3161                 !strcmp(arg, "--break-rewrites")) {
3162                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
3163                        return error("invalid argument to -B: %s", arg+2);
3164        }
3165        else if (!prefixcmp(arg, "-M") || !prefixcmp(arg, "--find-renames=") ||
3166                 !strcmp(arg, "--find-renames")) {
3167                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3168                        return error("invalid argument to -M: %s", arg+2);
3169                options->detect_rename = DIFF_DETECT_RENAME;
3170        }
3171        else if (!prefixcmp(arg, "-C") || !prefixcmp(arg, "--find-copies=") ||
3172                 !strcmp(arg, "--find-copies")) {
3173                if (options->detect_rename == DIFF_DETECT_COPY)
3174                        DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3175                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3176                        return error("invalid argument to -C: %s", arg+2);
3177                options->detect_rename = DIFF_DETECT_COPY;
3178        }
3179        else if (!strcmp(arg, "--no-renames"))
3180                options->detect_rename = 0;
3181        else if (!strcmp(arg, "--relative"))
3182                DIFF_OPT_SET(options, RELATIVE_NAME);
3183        else if (!prefixcmp(arg, "--relative=")) {
3184                DIFF_OPT_SET(options, RELATIVE_NAME);
3185                options->prefix = arg + 11;
3186        }
3187
3188        /* xdiff options */
3189        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
3190                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
3191        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
3192                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
3193        else if (!strcmp(arg, "--ignore-space-at-eol"))
3194                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
3195        else if (!strcmp(arg, "--patience"))
3196                DIFF_XDL_SET(options, PATIENCE_DIFF);
3197
3198        /* flags options */
3199        else if (!strcmp(arg, "--binary")) {
3200                options->output_format |= DIFF_FORMAT_PATCH;
3201                DIFF_OPT_SET(options, BINARY);
3202        }
3203        else if (!strcmp(arg, "--full-index"))
3204                DIFF_OPT_SET(options, FULL_INDEX);
3205        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
3206                DIFF_OPT_SET(options, TEXT);
3207        else if (!strcmp(arg, "-R"))
3208                DIFF_OPT_SET(options, REVERSE_DIFF);
3209        else if (!strcmp(arg, "--find-copies-harder"))
3210                DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3211        else if (!strcmp(arg, "--follow"))
3212                DIFF_OPT_SET(options, FOLLOW_RENAMES);
3213        else if (!strcmp(arg, "--color"))
3214                DIFF_OPT_SET(options, COLOR_DIFF);
3215        else if (!prefixcmp(arg, "--color=")) {
3216                int value = git_config_colorbool(NULL, arg+8, -1);
3217                if (value == 0)
3218                        DIFF_OPT_CLR(options, COLOR_DIFF);
3219                else if (value > 0)
3220                        DIFF_OPT_SET(options, COLOR_DIFF);
3221                else
3222                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
3223        }
3224        else if (!strcmp(arg, "--no-color"))
3225                DIFF_OPT_CLR(options, COLOR_DIFF);
3226        else if (!strcmp(arg, "--color-words")) {
3227                DIFF_OPT_SET(options, COLOR_DIFF);
3228                options->word_diff = DIFF_WORDS_COLOR;
3229        }
3230        else if (!prefixcmp(arg, "--color-words=")) {
3231                DIFF_OPT_SET(options, COLOR_DIFF);
3232                options->word_diff = DIFF_WORDS_COLOR;
3233                options->word_regex = arg + 14;
3234        }
3235        else if (!strcmp(arg, "--word-diff")) {
3236                if (options->word_diff == DIFF_WORDS_NONE)
3237                        options->word_diff = DIFF_WORDS_PLAIN;
3238        }
3239        else if (!prefixcmp(arg, "--word-diff=")) {
3240                const char *type = arg + 12;
3241                if (!strcmp(type, "plain"))
3242                        options->word_diff = DIFF_WORDS_PLAIN;
3243                else if (!strcmp(type, "color")) {
3244                        DIFF_OPT_SET(options, COLOR_DIFF);
3245                        options->word_diff = DIFF_WORDS_COLOR;
3246                }
3247                else if (!strcmp(type, "porcelain"))
3248                        options->word_diff = DIFF_WORDS_PORCELAIN;
3249                else if (!strcmp(type, "none"))
3250                        options->word_diff = DIFF_WORDS_NONE;
3251                else
3252                        die("bad --word-diff argument: %s", type);
3253        }
3254        else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
3255                if (options->word_diff == DIFF_WORDS_NONE)
3256                        options->word_diff = DIFF_WORDS_PLAIN;
3257                options->word_regex = optarg;
3258                return argcount;
3259        }
3260        else if (!strcmp(arg, "--exit-code"))
3261                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3262        else if (!strcmp(arg, "--quiet"))
3263                DIFF_OPT_SET(options, QUICK);
3264        else if (!strcmp(arg, "--ext-diff"))
3265                DIFF_OPT_SET(options, ALLOW_EXTERNAL);
3266        else if (!strcmp(arg, "--no-ext-diff"))
3267                DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
3268        else if (!strcmp(arg, "--textconv"))
3269                DIFF_OPT_SET(options, ALLOW_TEXTCONV);
3270        else if (!strcmp(arg, "--no-textconv"))
3271                DIFF_OPT_CLR(options, ALLOW_TEXTCONV);
3272        else if (!strcmp(arg, "--ignore-submodules")) {
3273                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3274                handle_ignore_submodules_arg(options, "all");
3275        } else if (!prefixcmp(arg, "--ignore-submodules=")) {
3276                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3277                handle_ignore_submodules_arg(options, arg + 20);
3278        } else if (!strcmp(arg, "--submodule"))
3279                DIFF_OPT_SET(options, SUBMODULE_LOG);
3280        else if (!prefixcmp(arg, "--submodule=")) {
3281                if (!strcmp(arg + 12, "log"))
3282                        DIFF_OPT_SET(options, SUBMODULE_LOG);
3283        }
3284
3285        /* misc options */
3286        else if (!strcmp(arg, "-z"))
3287                options->line_termination = 0;
3288        else if ((argcount = short_opt('l', av, &optarg))) {
3289                options->rename_limit = strtoul(optarg, NULL, 10);
3290                return argcount;
3291        }
3292        else if ((argcount = short_opt('S', av, &optarg))) {
3293                options->pickaxe = optarg;
3294                options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
3295                return argcount;
3296        } else if ((argcount = short_opt('G', av, &optarg))) {
3297                options->pickaxe = optarg;
3298                options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
3299                return argcount;
3300        }
3301        else if (!strcmp(arg, "--pickaxe-all"))
3302                options->pickaxe_opts |= DIFF_PICKAXE_ALL;
3303        else if (!strcmp(arg, "--pickaxe-regex"))
3304                options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
3305        else if ((argcount = short_opt('O', av, &optarg))) {
3306                options->orderfile = optarg;
3307                return argcount;
3308        }
3309        else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
3310                options->filter = optarg;
3311                return argcount;
3312        }
3313        else if (!strcmp(arg, "--abbrev"))
3314                options->abbrev = DEFAULT_ABBREV;
3315        else if (!prefixcmp(arg, "--abbrev=")) {
3316                options->abbrev = strtoul(arg + 9, NULL, 10);
3317                if (options->abbrev < MINIMUM_ABBREV)
3318                        options->abbrev = MINIMUM_ABBREV;
3319                else if (40 < options->abbrev)
3320                        options->abbrev = 40;
3321        }
3322        else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
3323                options->a_prefix = optarg;
3324                return argcount;
3325        }
3326        else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
3327                options->b_prefix = optarg;
3328                return argcount;
3329        }
3330        else if (!strcmp(arg, "--no-prefix"))
3331                options->a_prefix = options->b_prefix = "";
3332        else if (opt_arg(arg, '\0', "inter-hunk-context",
3333                         &options->interhunkcontext))
3334                ;
3335        else if ((argcount = parse_long_opt("output", av, &optarg))) {
3336                options->file = fopen(optarg, "w");
3337                if (!options->file)
3338                        die_errno("Could not open '%s'", optarg);
3339                options->close_file = 1;
3340                return argcount;
3341        } else
3342                return 0;
3343        return 1;
3344}
3345
3346int parse_rename_score(const char **cp_p)
3347{
3348        unsigned long num, scale;
3349        int ch, dot;
3350        const char *cp = *cp_p;
3351
3352        num = 0;
3353        scale = 1;
3354        dot = 0;
3355        for (;;) {
3356                ch = *cp;
3357                if ( !dot && ch == '.' ) {
3358                        scale = 1;
3359                        dot = 1;
3360                } else if ( ch == '%' ) {
3361                        scale = dot ? scale*100 : 100;
3362                        cp++;   /* % is always at the end */
3363                        break;
3364                } else if ( ch >= '0' && ch <= '9' ) {
3365                        if ( scale < 100000 ) {
3366                                scale *= 10;
3367                                num = (num*10) + (ch-'0');
3368                        }
3369                } else {
3370                        break;
3371                }
3372                cp++;
3373        }
3374        *cp_p = cp;
3375
3376        /* user says num divided by scale and we say internally that
3377         * is MAX_SCORE * num / scale.
3378         */
3379        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
3380}
3381
3382static int diff_scoreopt_parse(const char *opt)
3383{
3384        int opt1, opt2, cmd;
3385
3386        if (*opt++ != '-')
3387                return -1;
3388        cmd = *opt++;
3389        if (cmd == '-') {
3390                /* convert the long-form arguments into short-form versions */
3391                if (!prefixcmp(opt, "break-rewrites")) {
3392                        opt += strlen("break-rewrites");
3393                        if (*opt == 0 || *opt++ == '=')
3394                                cmd = 'B';
3395                } else if (!prefixcmp(opt, "find-copies")) {
3396                        opt += strlen("find-copies");
3397                        if (*opt == 0 || *opt++ == '=')
3398                                cmd = 'C';
3399                } else if (!prefixcmp(opt, "find-renames")) {
3400                        opt += strlen("find-renames");
3401                        if (*opt == 0 || *opt++ == '=')
3402                                cmd = 'M';
3403                }
3404        }
3405        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
3406                return -1; /* that is not a -M, -C nor -B option */
3407
3408        opt1 = parse_rename_score(&opt);
3409        if (cmd != 'B')
3410                opt2 = 0;
3411        else {
3412                if (*opt == 0)
3413                        opt2 = 0;
3414                else if (*opt != '/')
3415                        return -1; /* we expect -B80/99 or -B80 */
3416                else {
3417                        opt++;
3418                        opt2 = parse_rename_score(&opt);
3419                }
3420        }
3421        if (*opt != 0)
3422                return -1;
3423        return opt1 | (opt2 << 16);
3424}
3425
3426struct diff_queue_struct diff_queued_diff;
3427
3428void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
3429{
3430        if (queue->alloc <= queue->nr) {
3431                queue->alloc = alloc_nr(queue->alloc);
3432                queue->queue = xrealloc(queue->queue,
3433                                        sizeof(dp) * queue->alloc);
3434        }
3435        queue->queue[queue->nr++] = dp;
3436}
3437
3438struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
3439                                 struct diff_filespec *one,
3440                                 struct diff_filespec *two)
3441{
3442        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
3443        dp->one = one;
3444        dp->two = two;
3445        if (queue)
3446                diff_q(queue, dp);
3447        return dp;
3448}
3449
3450void diff_free_filepair(struct diff_filepair *p)
3451{
3452        free_filespec(p->one);
3453        free_filespec(p->two);
3454        free(p);
3455}
3456
3457/* This is different from find_unique_abbrev() in that
3458 * it stuffs the result with dots for alignment.
3459 */
3460const char *diff_unique_abbrev(const unsigned char *sha1, int len)
3461{
3462        int abblen;
3463        const char *abbrev;
3464        if (len == 40)
3465                return sha1_to_hex(sha1);
3466
3467        abbrev = find_unique_abbrev(sha1, len);
3468        abblen = strlen(abbrev);
3469        if (abblen < 37) {
3470                static char hex[41];
3471                if (len < abblen && abblen <= len + 2)
3472                        sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
3473                else
3474                        sprintf(hex, "%s...", abbrev);
3475                return hex;
3476        }
3477        return sha1_to_hex(sha1);
3478}
3479
3480static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
3481{
3482        int line_termination = opt->line_termination;
3483        int inter_name_termination = line_termination ? '\t' : '\0';
3484        if (opt->output_prefix) {
3485                struct strbuf *msg = NULL;
3486                msg = opt->output_prefix(opt, opt->output_prefix_data);
3487                fprintf(opt->file, "%s", msg->buf);
3488        }
3489
3490        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
3491                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
3492                        diff_unique_abbrev(p->one->sha1, opt->abbrev));
3493                fprintf(opt->file, "%s ", diff_unique_abbrev(p->two->sha1, opt->abbrev));
3494        }
3495        if (p->score) {
3496                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
3497                        inter_name_termination);
3498        } else {
3499                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
3500        }
3501
3502        if (p->status == DIFF_STATUS_COPIED ||
3503            p->status == DIFF_STATUS_RENAMED) {
3504                const char *name_a, *name_b;
3505                name_a = p->one->path;
3506                name_b = p->two->path;
3507                strip_prefix(opt->prefix_length, &name_a, &name_b);
3508                write_name_quoted(name_a, opt->file, inter_name_termination);
3509                write_name_quoted(name_b, opt->file, line_termination);
3510        } else {
3511                const char *name_a, *name_b;
3512                name_a = p->one->mode ? p->one->path : p->two->path;
3513                name_b = NULL;
3514                strip_prefix(opt->prefix_length, &name_a, &name_b);
3515                write_name_quoted(name_a, opt->file, line_termination);
3516        }
3517}
3518
3519int diff_unmodified_pair(struct diff_filepair *p)
3520{
3521        /* This function is written stricter than necessary to support
3522         * the currently implemented transformers, but the idea is to
3523         * let transformers to produce diff_filepairs any way they want,
3524         * and filter and clean them up here before producing the output.
3525         */
3526        struct diff_filespec *one = p->one, *two = p->two;
3527
3528        if (DIFF_PAIR_UNMERGED(p))
3529                return 0; /* unmerged is interesting */
3530
3531        /* deletion, addition, mode or type change
3532         * and rename are all interesting.
3533         */
3534        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
3535            DIFF_PAIR_MODE_CHANGED(p) ||
3536            strcmp(one->path, two->path))
3537                return 0;
3538
3539        /* both are valid and point at the same path.  that is, we are
3540         * dealing with a change.
3541         */
3542        if (one->sha1_valid && two->sha1_valid &&
3543            !hashcmp(one->sha1, two->sha1) &&
3544            !one->dirty_submodule && !two->dirty_submodule)
3545                return 1; /* no change */
3546        if (!one->sha1_valid && !two->sha1_valid)
3547                return 1; /* both look at the same file on the filesystem. */
3548        return 0;
3549}
3550
3551static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
3552{
3553        if (diff_unmodified_pair(p))
3554                return;
3555
3556        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3557            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3558                return; /* no tree diffs in patch format */
3559
3560        run_diff(p, o);
3561}
3562
3563static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
3564                            struct diffstat_t *diffstat)
3565{
3566        if (diff_unmodified_pair(p))
3567                return;
3568
3569        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3570            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3571                return; /* no useful stat for tree diffs */
3572
3573        run_diffstat(p, o, diffstat);
3574}
3575
3576static void diff_flush_checkdiff(struct diff_filepair *p,
3577                struct diff_options *o)
3578{
3579        if (diff_unmodified_pair(p))
3580                return;
3581
3582        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3583            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3584                return; /* nothing to check in tree diffs */
3585
3586        run_checkdiff(p, o);
3587}
3588
3589int diff_queue_is_empty(void)
3590{
3591        struct diff_queue_struct *q = &diff_queued_diff;
3592        int i;
3593        for (i = 0; i < q->nr; i++)
3594                if (!diff_unmodified_pair(q->queue[i]))
3595                        return 0;
3596        return 1;
3597}
3598
3599#if DIFF_DEBUG
3600void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
3601{
3602        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
3603                x, one ? one : "",
3604                s->path,
3605                DIFF_FILE_VALID(s) ? "valid" : "invalid",
3606                s->mode,
3607                s->sha1_valid ? sha1_to_hex(s->sha1) : "");
3608        fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
3609                x, one ? one : "",
3610                s->size, s->xfrm_flags);
3611}
3612
3613void diff_debug_filepair(const struct diff_filepair *p, int i)
3614{
3615        diff_debug_filespec(p->one, i, "one");
3616        diff_debug_filespec(p->two, i, "two");
3617        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
3618                p->score, p->status ? p->status : '?',
3619                p->one->rename_used, p->broken_pair);
3620}
3621
3622void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
3623{
3624        int i;
3625        if (msg)
3626                fprintf(stderr, "%s\n", msg);
3627        fprintf(stderr, "q->nr = %d\n", q->nr);
3628        for (i = 0; i < q->nr; i++) {
3629                struct diff_filepair *p = q->queue[i];
3630                diff_debug_filepair(p, i);
3631        }
3632}
3633#endif
3634
3635static void diff_resolve_rename_copy(void)
3636{
3637        int i;
3638        struct diff_filepair *p;
3639        struct diff_queue_struct *q = &diff_queued_diff;
3640
3641        diff_debug_queue("resolve-rename-copy", q);
3642
3643        for (i = 0; i < q->nr; i++) {
3644                p = q->queue[i];
3645                p->status = 0; /* undecided */
3646                if (DIFF_PAIR_UNMERGED(p))
3647                        p->status = DIFF_STATUS_UNMERGED;
3648                else if (!DIFF_FILE_VALID(p->one))
3649                        p->status = DIFF_STATUS_ADDED;
3650                else if (!DIFF_FILE_VALID(p->two))
3651                        p->status = DIFF_STATUS_DELETED;
3652                else if (DIFF_PAIR_TYPE_CHANGED(p))
3653                        p->status = DIFF_STATUS_TYPE_CHANGED;
3654
3655                /* from this point on, we are dealing with a pair
3656                 * whose both sides are valid and of the same type, i.e.
3657                 * either in-place edit or rename/copy edit.
3658                 */
3659                else if (DIFF_PAIR_RENAME(p)) {
3660                        /*
3661                         * A rename might have re-connected a broken
3662                         * pair up, causing the pathnames to be the
3663                         * same again. If so, that's not a rename at
3664                         * all, just a modification..
3665                         *
3666                         * Otherwise, see if this source was used for
3667                         * multiple renames, in which case we decrement
3668                         * the count, and call it a copy.
3669                         */
3670                        if (!strcmp(p->one->path, p->two->path))
3671                                p->status = DIFF_STATUS_MODIFIED;
3672                        else if (--p->one->rename_used > 0)
3673                                p->status = DIFF_STATUS_COPIED;
3674                        else
3675                                p->status = DIFF_STATUS_RENAMED;
3676                }
3677                else if (hashcmp(p->one->sha1, p->two->sha1) ||
3678                         p->one->mode != p->two->mode ||
3679                         p->one->dirty_submodule ||
3680                         p->two->dirty_submodule ||
3681                         is_null_sha1(p->one->sha1))
3682                        p->status = DIFF_STATUS_MODIFIED;
3683                else {
3684                        /* This is a "no-change" entry and should not
3685                         * happen anymore, but prepare for broken callers.
3686                         */
3687                        error("feeding unmodified %s to diffcore",
3688                              p->one->path);
3689                        p->status = DIFF_STATUS_UNKNOWN;
3690                }
3691        }
3692        diff_debug_queue("resolve-rename-copy done", q);
3693}
3694
3695static int check_pair_status(struct diff_filepair *p)
3696{
3697        switch (p->status) {
3698        case DIFF_STATUS_UNKNOWN:
3699                return 0;
3700        case 0:
3701                die("internal error in diff-resolve-rename-copy");
3702        default:
3703                return 1;
3704        }
3705}
3706
3707static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
3708{
3709        int fmt = opt->output_format;
3710
3711        if (fmt & DIFF_FORMAT_CHECKDIFF)
3712                diff_flush_checkdiff(p, opt);
3713        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
3714                diff_flush_raw(p, opt);
3715        else if (fmt & DIFF_FORMAT_NAME) {
3716                const char *name_a, *name_b;
3717                name_a = p->two->path;
3718                name_b = NULL;
3719                strip_prefix(opt->prefix_length, &name_a, &name_b);
3720                write_name_quoted(name_a, opt->file, opt->line_termination);
3721        }
3722}
3723
3724static void show_file_mode_name(FILE *file, const char *newdelete, struct diff_filespec *fs)
3725{
3726        if (fs->mode)
3727                fprintf(file, " %s mode %06o ", newdelete, fs->mode);
3728        else
3729                fprintf(file, " %s ", newdelete);
3730        write_name_quoted(fs->path, file, '\n');
3731}
3732
3733
3734static void show_mode_change(FILE *file, struct diff_filepair *p, int show_name,
3735                const char *line_prefix)
3736{
3737        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
3738                fprintf(file, "%s mode change %06o => %06o%c", line_prefix, p->one->mode,
3739                        p->two->mode, show_name ? ' ' : '\n');
3740                if (show_name) {
3741                        write_name_quoted(p->two->path, file, '\n');
3742                }
3743        }
3744}
3745
3746static void show_rename_copy(FILE *file, const char *renamecopy, struct diff_filepair *p,
3747                        const char *line_prefix)
3748{
3749        char *names = pprint_rename(p->one->path, p->two->path);
3750
3751        fprintf(file, " %s %s (%d%%)\n", renamecopy, names, similarity_index(p));
3752        free(names);
3753        show_mode_change(file, p, 0, line_prefix);
3754}
3755
3756static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
3757{
3758        FILE *file = opt->file;
3759        char *line_prefix = "";
3760
3761        if (opt->output_prefix) {
3762                struct strbuf *buf = opt->output_prefix(opt, opt->output_prefix_data);
3763                line_prefix = buf->buf;
3764        }
3765
3766        switch(p->status) {
3767        case DIFF_STATUS_DELETED:
3768                fputs(line_prefix, file);
3769                show_file_mode_name(file, "delete", p->one);
3770                break;
3771        case DIFF_STATUS_ADDED:
3772                fputs(line_prefix, file);
3773                show_file_mode_name(file, "create", p->two);
3774                break;
3775        case DIFF_STATUS_COPIED:
3776                fputs(line_prefix, file);
3777                show_rename_copy(file, "copy", p, line_prefix);
3778                break;
3779        case DIFF_STATUS_RENAMED:
3780                fputs(line_prefix, file);
3781                show_rename_copy(file, "rename", p, line_prefix);
3782                break;
3783        default:
3784                if (p->score) {
3785                        fprintf(file, "%s rewrite ", line_prefix);
3786                        write_name_quoted(p->two->path, file, ' ');
3787                        fprintf(file, "(%d%%)\n", similarity_index(p));
3788                }
3789                show_mode_change(file, p, !p->score, line_prefix);
3790                break;
3791        }
3792}
3793
3794struct patch_id_t {
3795        git_SHA_CTX *ctx;
3796        int patchlen;
3797};
3798
3799static int remove_space(char *line, int len)
3800{
3801        int i;
3802        char *dst = line;
3803        unsigned char c;
3804
3805        for (i = 0; i < len; i++)
3806                if (!isspace((c = line[i])))
3807                        *dst++ = c;
3808
3809        return dst - line;
3810}
3811
3812static void patch_id_consume(void *priv, char *line, unsigned long len)
3813{
3814        struct patch_id_t *data = priv;
3815        int new_len;
3816
3817        /* Ignore line numbers when computing the SHA1 of the patch */
3818        if (!prefixcmp(line, "@@ -"))
3819                return;
3820
3821        new_len = remove_space(line, len);
3822
3823        git_SHA1_Update(data->ctx, line, new_len);
3824        data->patchlen += new_len;
3825}
3826
3827/* returns 0 upon success, and writes result into sha1 */
3828static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
3829{
3830        struct diff_queue_struct *q = &diff_queued_diff;
3831        int i;
3832        git_SHA_CTX ctx;
3833        struct patch_id_t data;
3834        char buffer[PATH_MAX * 4 + 20];
3835
3836        git_SHA1_Init(&ctx);
3837        memset(&data, 0, sizeof(struct patch_id_t));
3838        data.ctx = &ctx;
3839
3840        for (i = 0; i < q->nr; i++) {
3841                xpparam_t xpp;
3842                xdemitconf_t xecfg;
3843                mmfile_t mf1, mf2;
3844                struct diff_filepair *p = q->queue[i];
3845                int len1, len2;
3846
3847                memset(&xpp, 0, sizeof(xpp));
3848                memset(&xecfg, 0, sizeof(xecfg));
3849                if (p->status == 0)
3850                        return error("internal diff status error");
3851                if (p->status == DIFF_STATUS_UNKNOWN)
3852                        continue;
3853                if (diff_unmodified_pair(p))
3854                        continue;
3855                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3856                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3857                        continue;
3858                if (DIFF_PAIR_UNMERGED(p))
3859                        continue;
3860
3861                diff_fill_sha1_info(p->one);
3862                diff_fill_sha1_info(p->two);
3863                if (fill_mmfile(&mf1, p->one) < 0 ||
3864                                fill_mmfile(&mf2, p->two) < 0)
3865                        return error("unable to read files to diff");
3866
3867                len1 = remove_space(p->one->path, strlen(p->one->path));
3868                len2 = remove_space(p->two->path, strlen(p->two->path));
3869                if (p->one->mode == 0)
3870                        len1 = snprintf(buffer, sizeof(buffer),
3871                                        "diff--gita/%.*sb/%.*s"
3872                                        "newfilemode%06o"
3873                                        "---/dev/null"
3874                                        "+++b/%.*s",
3875                                        len1, p->one->path,
3876                                        len2, p->two->path,
3877                                        p->two->mode,
3878                                        len2, p->two->path);
3879                else if (p->two->mode == 0)
3880                        len1 = snprintf(buffer, sizeof(buffer),
3881                                        "diff--gita/%.*sb/%.*s"
3882                                        "deletedfilemode%06o"
3883                                        "---a/%.*s"
3884                                        "+++/dev/null",
3885                                        len1, p->one->path,
3886                                        len2, p->two->path,
3887                                        p->one->mode,
3888                                        len1, p->one->path);
3889                else
3890                        len1 = snprintf(buffer, sizeof(buffer),
3891                                        "diff--gita/%.*sb/%.*s"
3892                                        "---a/%.*s"
3893                                        "+++b/%.*s",
3894                                        len1, p->one->path,
3895                                        len2, p->two->path,
3896                                        len1, p->one->path,
3897                                        len2, p->two->path);
3898                git_SHA1_Update(&ctx, buffer, len1);
3899
3900                if (diff_filespec_is_binary(p->one) ||
3901                    diff_filespec_is_binary(p->two)) {
3902                        git_SHA1_Update(&ctx, sha1_to_hex(p->one->sha1), 40);
3903                        git_SHA1_Update(&ctx, sha1_to_hex(p->two->sha1), 40);
3904                        continue;
3905                }
3906
3907                xpp.flags = 0;
3908                xecfg.ctxlen = 3;
3909                xecfg.flags = 0;
3910                xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
3911                              &xpp, &xecfg);
3912        }
3913
3914        git_SHA1_Final(sha1, &ctx);
3915        return 0;
3916}
3917
3918int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1)
3919{
3920        struct diff_queue_struct *q = &diff_queued_diff;
3921        int i;
3922        int result = diff_get_patch_id(options, sha1);
3923
3924        for (i = 0; i < q->nr; i++)
3925                diff_free_filepair(q->queue[i]);
3926
3927        free(q->queue);
3928        DIFF_QUEUE_CLEAR(q);
3929
3930        return result;
3931}
3932
3933static int is_summary_empty(const struct diff_queue_struct *q)
3934{
3935        int i;
3936
3937        for (i = 0; i < q->nr; i++) {
3938                const struct diff_filepair *p = q->queue[i];
3939
3940                switch (p->status) {
3941                case DIFF_STATUS_DELETED:
3942                case DIFF_STATUS_ADDED:
3943                case DIFF_STATUS_COPIED:
3944                case DIFF_STATUS_RENAMED:
3945                        return 0;
3946                default:
3947                        if (p->score)
3948                                return 0;
3949                        if (p->one->mode && p->two->mode &&
3950                            p->one->mode != p->two->mode)
3951                                return 0;
3952                        break;
3953                }
3954        }
3955        return 1;
3956}
3957
3958void diff_flush(struct diff_options *options)
3959{
3960        struct diff_queue_struct *q = &diff_queued_diff;
3961        int i, output_format = options->output_format;
3962        int separator = 0;
3963
3964        /*
3965         * Order: raw, stat, summary, patch
3966         * or:    name/name-status/checkdiff (other bits clear)
3967         */
3968        if (!q->nr)
3969                goto free_queue;
3970
3971        if (output_format & (DIFF_FORMAT_RAW |
3972                             DIFF_FORMAT_NAME |
3973                             DIFF_FORMAT_NAME_STATUS |
3974                             DIFF_FORMAT_CHECKDIFF)) {
3975                for (i = 0; i < q->nr; i++) {
3976                        struct diff_filepair *p = q->queue[i];
3977                        if (check_pair_status(p))
3978                                flush_one_pair(p, options);
3979                }
3980                separator++;
3981        }
3982
3983        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT)) {
3984                struct diffstat_t diffstat;
3985
3986                memset(&diffstat, 0, sizeof(struct diffstat_t));
3987                for (i = 0; i < q->nr; i++) {
3988                        struct diff_filepair *p = q->queue[i];
3989                        if (check_pair_status(p))
3990                                diff_flush_stat(p, options, &diffstat);
3991                }
3992                if (output_format & DIFF_FORMAT_NUMSTAT)
3993                        show_numstat(&diffstat, options);
3994                if (output_format & DIFF_FORMAT_DIFFSTAT)
3995                        show_stats(&diffstat, options);
3996                if (output_format & DIFF_FORMAT_SHORTSTAT)
3997                        show_shortstats(&diffstat, options);
3998                free_diffstat_info(&diffstat);
3999                separator++;
4000        }
4001        if (output_format & DIFF_FORMAT_DIRSTAT)
4002                show_dirstat(options);
4003
4004        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
4005                for (i = 0; i < q->nr; i++) {
4006                        diff_summary(options, q->queue[i]);
4007                }
4008                separator++;
4009        }
4010
4011        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
4012            DIFF_OPT_TST(options, EXIT_WITH_STATUS) &&
4013            DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4014                /*
4015                 * run diff_flush_patch for the exit status. setting
4016                 * options->file to /dev/null should be safe, becaue we
4017                 * aren't supposed to produce any output anyway.
4018                 */
4019                if (options->close_file)
4020                        fclose(options->file);
4021                options->file = fopen("/dev/null", "w");
4022                if (!options->file)
4023                        die_errno("Could not open /dev/null");
4024                options->close_file = 1;
4025                for (i = 0; i < q->nr; i++) {
4026                        struct diff_filepair *p = q->queue[i];
4027                        if (check_pair_status(p))
4028                                diff_flush_patch(p, options);
4029                        if (options->found_changes)
4030                                break;
4031                }
4032        }
4033
4034        if (output_format & DIFF_FORMAT_PATCH) {
4035                if (separator) {
4036                        putc(options->line_termination, options->file);
4037                        if (options->stat_sep) {
4038                                /* attach patch instead of inline */
4039                                fputs(options->stat_sep, options->file);
4040                        }
4041                }
4042
4043                for (i = 0; i < q->nr; i++) {
4044                        struct diff_filepair *p = q->queue[i];
4045                        if (check_pair_status(p))
4046                                diff_flush_patch(p, options);
4047                }
4048        }
4049
4050        if (output_format & DIFF_FORMAT_CALLBACK)
4051                options->format_callback(q, options, options->format_callback_data);
4052
4053        for (i = 0; i < q->nr; i++)
4054                diff_free_filepair(q->queue[i]);
4055free_queue:
4056        free(q->queue);
4057        DIFF_QUEUE_CLEAR(q);
4058        if (options->close_file)
4059                fclose(options->file);
4060
4061        /*
4062         * Report the content-level differences with HAS_CHANGES;
4063         * diff_addremove/diff_change does not set the bit when
4064         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
4065         */
4066        if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4067                if (options->found_changes)
4068                        DIFF_OPT_SET(options, HAS_CHANGES);
4069                else
4070                        DIFF_OPT_CLR(options, HAS_CHANGES);
4071        }
4072}
4073
4074static void diffcore_apply_filter(const char *filter)
4075{
4076        int i;
4077        struct diff_queue_struct *q = &diff_queued_diff;
4078        struct diff_queue_struct outq;
4079        DIFF_QUEUE_CLEAR(&outq);
4080
4081        if (!filter)
4082                return;
4083
4084        if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
4085                int found;
4086                for (i = found = 0; !found && i < q->nr; i++) {
4087                        struct diff_filepair *p = q->queue[i];
4088                        if (((p->status == DIFF_STATUS_MODIFIED) &&
4089                             ((p->score &&
4090                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
4091                              (!p->score &&
4092                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
4093                            ((p->status != DIFF_STATUS_MODIFIED) &&
4094                             strchr(filter, p->status)))
4095                                found++;
4096                }
4097                if (found)
4098                        return;
4099
4100                /* otherwise we will clear the whole queue
4101                 * by copying the empty outq at the end of this
4102                 * function, but first clear the current entries
4103                 * in the queue.
4104                 */
4105                for (i = 0; i < q->nr; i++)
4106                        diff_free_filepair(q->queue[i]);
4107        }
4108        else {
4109                /* Only the matching ones */
4110                for (i = 0; i < q->nr; i++) {
4111                        struct diff_filepair *p = q->queue[i];
4112
4113                        if (((p->status == DIFF_STATUS_MODIFIED) &&
4114                             ((p->score &&
4115                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
4116                              (!p->score &&
4117                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
4118                            ((p->status != DIFF_STATUS_MODIFIED) &&
4119                             strchr(filter, p->status)))
4120                                diff_q(&outq, p);
4121                        else
4122                                diff_free_filepair(p);
4123                }
4124        }
4125        free(q->queue);
4126        *q = outq;
4127}
4128
4129/* Check whether two filespecs with the same mode and size are identical */
4130static int diff_filespec_is_identical(struct diff_filespec *one,
4131                                      struct diff_filespec *two)
4132{
4133        if (S_ISGITLINK(one->mode))
4134                return 0;
4135        if (diff_populate_filespec(one, 0))
4136                return 0;
4137        if (diff_populate_filespec(two, 0))
4138                return 0;
4139        return !memcmp(one->data, two->data, one->size);
4140}
4141
4142static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
4143{
4144        int i;
4145        struct diff_queue_struct *q = &diff_queued_diff;
4146        struct diff_queue_struct outq;
4147        DIFF_QUEUE_CLEAR(&outq);
4148
4149        for (i = 0; i < q->nr; i++) {
4150                struct diff_filepair *p = q->queue[i];
4151
4152                /*
4153                 * 1. Entries that come from stat info dirtiness
4154                 *    always have both sides (iow, not create/delete),
4155                 *    one side of the object name is unknown, with
4156                 *    the same mode and size.  Keep the ones that
4157                 *    do not match these criteria.  They have real
4158                 *    differences.
4159                 *
4160                 * 2. At this point, the file is known to be modified,
4161                 *    with the same mode and size, and the object
4162                 *    name of one side is unknown.  Need to inspect
4163                 *    the identical contents.
4164                 */
4165                if (!DIFF_FILE_VALID(p->one) || /* (1) */
4166                    !DIFF_FILE_VALID(p->two) ||
4167                    (p->one->sha1_valid && p->two->sha1_valid) ||
4168                    (p->one->mode != p->two->mode) ||
4169                    diff_populate_filespec(p->one, 1) ||
4170                    diff_populate_filespec(p->two, 1) ||
4171                    (p->one->size != p->two->size) ||
4172                    !diff_filespec_is_identical(p->one, p->two)) /* (2) */
4173                        diff_q(&outq, p);
4174                else {
4175                        /*
4176                         * The caller can subtract 1 from skip_stat_unmatch
4177                         * to determine how many paths were dirty only
4178                         * due to stat info mismatch.
4179                         */
4180                        if (!DIFF_OPT_TST(diffopt, NO_INDEX))
4181                                diffopt->skip_stat_unmatch++;
4182                        diff_free_filepair(p);
4183                }
4184        }
4185        free(q->queue);
4186        *q = outq;
4187}
4188
4189static int diffnamecmp(const void *a_, const void *b_)
4190{
4191        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
4192        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
4193        const char *name_a, *name_b;
4194
4195        name_a = a->one ? a->one->path : a->two->path;
4196        name_b = b->one ? b->one->path : b->two->path;
4197        return strcmp(name_a, name_b);
4198}
4199
4200void diffcore_fix_diff_index(struct diff_options *options)
4201{
4202        struct diff_queue_struct *q = &diff_queued_diff;
4203        qsort(q->queue, q->nr, sizeof(q->queue[0]), diffnamecmp);
4204}
4205
4206void diffcore_std(struct diff_options *options)
4207{
4208        if (options->skip_stat_unmatch)
4209                diffcore_skip_stat_unmatch(options);
4210        if (!options->found_follow) {
4211                /* See try_to_follow_renames() in tree-diff.c */
4212                if (options->break_opt != -1)
4213                        diffcore_break(options->break_opt);
4214                if (options->detect_rename)
4215                        diffcore_rename(options);
4216                if (options->break_opt != -1)
4217                        diffcore_merge_broken();
4218        }
4219        if (options->pickaxe)
4220                diffcore_pickaxe(options);
4221        if (options->orderfile)
4222                diffcore_order(options->orderfile);
4223        if (!options->found_follow)
4224                /* See try_to_follow_renames() in tree-diff.c */
4225                diff_resolve_rename_copy();
4226        diffcore_apply_filter(options->filter);
4227
4228        if (diff_queued_diff.nr && !DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4229                DIFF_OPT_SET(options, HAS_CHANGES);
4230        else
4231                DIFF_OPT_CLR(options, HAS_CHANGES);
4232
4233        options->found_follow = 0;
4234}
4235
4236int diff_result_code(struct diff_options *opt, int status)
4237{
4238        int result = 0;
4239        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4240            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
4241                return status;
4242        if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4243            DIFF_OPT_TST(opt, HAS_CHANGES))
4244                result |= 01;
4245        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
4246            DIFF_OPT_TST(opt, CHECK_FAILED))
4247                result |= 02;
4248        return result;
4249}
4250
4251/*
4252 * Shall changes to this submodule be ignored?
4253 *
4254 * Submodule changes can be configured to be ignored separately for each path,
4255 * but that configuration can be overridden from the command line.
4256 */
4257static int is_submodule_ignored(const char *path, struct diff_options *options)
4258{
4259        int ignored = 0;
4260        unsigned orig_flags = options->flags;
4261        if (!DIFF_OPT_TST(options, OVERRIDE_SUBMODULE_CONFIG))
4262                set_diffopt_flags_from_submodule_config(options, path);
4263        if (DIFF_OPT_TST(options, IGNORE_SUBMODULES))
4264                ignored = 1;
4265        options->flags = orig_flags;
4266        return ignored;
4267}
4268
4269void diff_addremove(struct diff_options *options,
4270                    int addremove, unsigned mode,
4271                    const unsigned char *sha1,
4272                    const char *concatpath, unsigned dirty_submodule)
4273{
4274        struct diff_filespec *one, *two;
4275
4276        if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
4277                return;
4278
4279        /* This may look odd, but it is a preparation for
4280         * feeding "there are unchanged files which should
4281         * not produce diffs, but when you are doing copy
4282         * detection you would need them, so here they are"
4283         * entries to the diff-core.  They will be prefixed
4284         * with something like '=' or '*' (I haven't decided
4285         * which but should not make any difference).
4286         * Feeding the same new and old to diff_change()
4287         * also has the same effect.
4288         * Before the final output happens, they are pruned after
4289         * merged into rename/copy pairs as appropriate.
4290         */
4291        if (DIFF_OPT_TST(options, REVERSE_DIFF))
4292                addremove = (addremove == '+' ? '-' :
4293                             addremove == '-' ? '+' : addremove);
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
4302        if (addremove != '+')
4303                fill_filespec(one, sha1, mode);
4304        if (addremove != '-') {
4305                fill_filespec(two, sha1, mode);
4306                two->dirty_submodule = dirty_submodule;
4307        }
4308
4309        diff_queue(&diff_queued_diff, one, two);
4310        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4311                DIFF_OPT_SET(options, HAS_CHANGES);
4312}
4313
4314void diff_change(struct diff_options *options,
4315                 unsigned old_mode, unsigned new_mode,
4316                 const unsigned char *old_sha1,
4317                 const unsigned char *new_sha1,
4318                 const char *concatpath,
4319                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
4320{
4321        struct diff_filespec *one, *two;
4322
4323        if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
4324            is_submodule_ignored(concatpath, options))
4325                return;
4326
4327        if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
4328                unsigned tmp;
4329                const unsigned char *tmp_c;
4330                tmp = old_mode; old_mode = new_mode; new_mode = tmp;
4331                tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
4332                tmp = old_dirty_submodule; old_dirty_submodule = new_dirty_submodule;
4333                        new_dirty_submodule = tmp;
4334        }
4335
4336        if (options->prefix &&
4337            strncmp(concatpath, options->prefix, options->prefix_length))
4338                return;
4339
4340        one = alloc_filespec(concatpath);
4341        two = alloc_filespec(concatpath);
4342        fill_filespec(one, old_sha1, old_mode);
4343        fill_filespec(two, new_sha1, new_mode);
4344        one->dirty_submodule = old_dirty_submodule;
4345        two->dirty_submodule = new_dirty_submodule;
4346
4347        diff_queue(&diff_queued_diff, one, two);
4348        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4349                DIFF_OPT_SET(options, HAS_CHANGES);
4350}
4351
4352void diff_unmerge(struct diff_options *options,
4353                  const char *path,
4354                  unsigned mode, const unsigned char *sha1)
4355{
4356        struct diff_filespec *one, *two;
4357
4358        if (options->prefix &&
4359            strncmp(path, options->prefix, options->prefix_length))
4360                return;
4361
4362        one = alloc_filespec(path);
4363        two = alloc_filespec(path);
4364        fill_filespec(one, sha1, mode);
4365        diff_queue(&diff_queued_diff, one, two)->is_unmerged = 1;
4366}
4367
4368static char *run_textconv(const char *pgm, struct diff_filespec *spec,
4369                size_t *outsize)
4370{
4371        struct diff_tempfile *temp;
4372        const char *argv[3];
4373        const char **arg = argv;
4374        struct child_process child;
4375        struct strbuf buf = STRBUF_INIT;
4376        int err = 0;
4377
4378        temp = prepare_temp_file(spec->path, spec);
4379        *arg++ = pgm;
4380        *arg++ = temp->name;
4381        *arg = NULL;
4382
4383        memset(&child, 0, sizeof(child));
4384        child.use_shell = 1;
4385        child.argv = argv;
4386        child.out = -1;
4387        if (start_command(&child)) {
4388                remove_tempfile();
4389                return NULL;
4390        }
4391
4392        if (strbuf_read(&buf, child.out, 0) < 0)
4393                err = error("error reading from textconv command '%s'", pgm);
4394        close(child.out);
4395
4396        if (finish_command(&child) || err) {
4397                strbuf_release(&buf);
4398                remove_tempfile();
4399                return NULL;
4400        }
4401        remove_tempfile();
4402
4403        return strbuf_detach(&buf, outsize);
4404}
4405
4406size_t fill_textconv(struct userdiff_driver *driver,
4407                     struct diff_filespec *df,
4408                     char **outbuf)
4409{
4410        size_t size;
4411
4412        if (!driver || !driver->textconv) {
4413                if (!DIFF_FILE_VALID(df)) {
4414                        *outbuf = "";
4415                        return 0;
4416                }
4417                if (diff_populate_filespec(df, 0))
4418                        die("unable to read files to diff");
4419                *outbuf = df->data;
4420                return df->size;
4421        }
4422
4423        if (driver->textconv_cache && df->sha1_valid) {
4424                *outbuf = notes_cache_get(driver->textconv_cache, df->sha1,
4425                                          &size);
4426                if (*outbuf)
4427                        return size;
4428        }
4429
4430        *outbuf = run_textconv(driver->textconv, df, &size);
4431        if (!*outbuf)
4432                die("unable to read files to diff");
4433
4434        if (driver->textconv_cache && df->sha1_valid) {
4435                /* ignore errors, as we might be in a readonly repository */
4436                notes_cache_put(driver->textconv_cache, df->sha1, *outbuf,
4437                                size);
4438                /*
4439                 * we could save up changes and flush them all at the end,
4440                 * but we would need an extra call after all diffing is done.
4441                 * Since generating a cache entry is the slow path anyway,
4442                 * this extra overhead probably isn't a big deal.
4443                 */
4444                notes_cache_write(driver->textconv_cache);
4445        }
4446
4447        return size;
4448}