diff.con commit t6022: Add testcase for spurious "refusing to lose untracked" messages (3f680ff)
   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                        /*
1054                         * Skip the prefix character, if any.  With
1055                         * diff_suppress_blank_empty, there may be
1056                         * none.
1057                         */
1058                        if (line[0] != '\n') {
1059                              line++;
1060                              len--;
1061                        }
1062                        emit_line(ecbdata->opt, plain, reset, line, len);
1063                }
1064                return;
1065        }
1066
1067        if (line[0] != '+') {
1068                const char *color =
1069                        diff_get_color(ecbdata->color_diff,
1070                                       line[0] == '-' ? DIFF_FILE_OLD : DIFF_PLAIN);
1071                ecbdata->lno_in_preimage++;
1072                if (line[0] == ' ')
1073                        ecbdata->lno_in_postimage++;
1074                emit_line(ecbdata->opt, color, reset, line, len);
1075        } else {
1076                ecbdata->lno_in_postimage++;
1077                emit_add_line(reset, ecbdata, line + 1, len - 1);
1078        }
1079}
1080
1081static char *pprint_rename(const char *a, const char *b)
1082{
1083        const char *old = a;
1084        const char *new = b;
1085        struct strbuf name = STRBUF_INIT;
1086        int pfx_length, sfx_length;
1087        int len_a = strlen(a);
1088        int len_b = strlen(b);
1089        int a_midlen, b_midlen;
1090        int qlen_a = quote_c_style(a, NULL, NULL, 0);
1091        int qlen_b = quote_c_style(b, NULL, NULL, 0);
1092
1093        if (qlen_a || qlen_b) {
1094                quote_c_style(a, &name, NULL, 0);
1095                strbuf_addstr(&name, " => ");
1096                quote_c_style(b, &name, NULL, 0);
1097                return strbuf_detach(&name, NULL);
1098        }
1099
1100        /* Find common prefix */
1101        pfx_length = 0;
1102        while (*old && *new && *old == *new) {
1103                if (*old == '/')
1104                        pfx_length = old - a + 1;
1105                old++;
1106                new++;
1107        }
1108
1109        /* Find common suffix */
1110        old = a + len_a;
1111        new = b + len_b;
1112        sfx_length = 0;
1113        while (a <= old && b <= new && *old == *new) {
1114                if (*old == '/')
1115                        sfx_length = len_a - (old - a);
1116                old--;
1117                new--;
1118        }
1119
1120        /*
1121         * pfx{mid-a => mid-b}sfx
1122         * {pfx-a => pfx-b}sfx
1123         * pfx{sfx-a => sfx-b}
1124         * name-a => name-b
1125         */
1126        a_midlen = len_a - pfx_length - sfx_length;
1127        b_midlen = len_b - pfx_length - sfx_length;
1128        if (a_midlen < 0)
1129                a_midlen = 0;
1130        if (b_midlen < 0)
1131                b_midlen = 0;
1132
1133        strbuf_grow(&name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
1134        if (pfx_length + sfx_length) {
1135                strbuf_add(&name, a, pfx_length);
1136                strbuf_addch(&name, '{');
1137        }
1138        strbuf_add(&name, a + pfx_length, a_midlen);
1139        strbuf_addstr(&name, " => ");
1140        strbuf_add(&name, b + pfx_length, b_midlen);
1141        if (pfx_length + sfx_length) {
1142                strbuf_addch(&name, '}');
1143                strbuf_add(&name, a + len_a - sfx_length, sfx_length);
1144        }
1145        return strbuf_detach(&name, NULL);
1146}
1147
1148struct diffstat_t {
1149        int nr;
1150        int alloc;
1151        struct diffstat_file {
1152                char *from_name;
1153                char *name;
1154                char *print_name;
1155                unsigned is_unmerged:1;
1156                unsigned is_binary:1;
1157                unsigned is_renamed:1;
1158                uintmax_t added, deleted;
1159        } **files;
1160};
1161
1162static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
1163                                          const char *name_a,
1164                                          const char *name_b)
1165{
1166        struct diffstat_file *x;
1167        x = xcalloc(sizeof (*x), 1);
1168        if (diffstat->nr == diffstat->alloc) {
1169                diffstat->alloc = alloc_nr(diffstat->alloc);
1170                diffstat->files = xrealloc(diffstat->files,
1171                                diffstat->alloc * sizeof(x));
1172        }
1173        diffstat->files[diffstat->nr++] = x;
1174        if (name_b) {
1175                x->from_name = xstrdup(name_a);
1176                x->name = xstrdup(name_b);
1177                x->is_renamed = 1;
1178        }
1179        else {
1180                x->from_name = NULL;
1181                x->name = xstrdup(name_a);
1182        }
1183        return x;
1184}
1185
1186static void diffstat_consume(void *priv, char *line, unsigned long len)
1187{
1188        struct diffstat_t *diffstat = priv;
1189        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
1190
1191        if (line[0] == '+')
1192                x->added++;
1193        else if (line[0] == '-')
1194                x->deleted++;
1195}
1196
1197const char mime_boundary_leader[] = "------------";
1198
1199static int scale_linear(int it, int width, int max_change)
1200{
1201        /*
1202         * make sure that at least one '-' is printed if there were deletions,
1203         * and likewise for '+'.
1204         */
1205        if (max_change < 2)
1206                return it;
1207        return ((it - 1) * (width - 1) + max_change - 1) / (max_change - 1);
1208}
1209
1210static void show_name(FILE *file,
1211                      const char *prefix, const char *name, int len)
1212{
1213        fprintf(file, " %s%-*s |", prefix, len, name);
1214}
1215
1216static void show_graph(FILE *file, char ch, int cnt, const char *set, const char *reset)
1217{
1218        if (cnt <= 0)
1219                return;
1220        fprintf(file, "%s", set);
1221        while (cnt--)
1222                putc(ch, file);
1223        fprintf(file, "%s", reset);
1224}
1225
1226static void fill_print_name(struct diffstat_file *file)
1227{
1228        char *pname;
1229
1230        if (file->print_name)
1231                return;
1232
1233        if (!file->is_renamed) {
1234                struct strbuf buf = STRBUF_INIT;
1235                if (quote_c_style(file->name, &buf, NULL, 0)) {
1236                        pname = strbuf_detach(&buf, NULL);
1237                } else {
1238                        pname = file->name;
1239                        strbuf_release(&buf);
1240                }
1241        } else {
1242                pname = pprint_rename(file->from_name, file->name);
1243        }
1244        file->print_name = pname;
1245}
1246
1247static void show_stats(struct diffstat_t *data, struct diff_options *options)
1248{
1249        int i, len, add, del, adds = 0, dels = 0;
1250        uintmax_t max_change = 0, max_len = 0;
1251        int total_files = data->nr;
1252        int width, name_width;
1253        const char *reset, *add_c, *del_c;
1254        const char *line_prefix = "";
1255        struct strbuf *msg = NULL;
1256
1257        if (data->nr == 0)
1258                return;
1259
1260        if (options->output_prefix) {
1261                msg = options->output_prefix(options, options->output_prefix_data);
1262                line_prefix = msg->buf;
1263        }
1264
1265        width = options->stat_width ? options->stat_width : 80;
1266        name_width = options->stat_name_width ? options->stat_name_width : 50;
1267
1268        /* Sanity: give at least 5 columns to the graph,
1269         * but leave at least 10 columns for the name.
1270         */
1271        if (width < 25)
1272                width = 25;
1273        if (name_width < 10)
1274                name_width = 10;
1275        else if (width < name_width + 15)
1276                name_width = width - 15;
1277
1278        /* Find the longest filename and max number of changes */
1279        reset = diff_get_color_opt(options, DIFF_RESET);
1280        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
1281        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
1282
1283        for (i = 0; i < data->nr; i++) {
1284                struct diffstat_file *file = data->files[i];
1285                uintmax_t change = file->added + file->deleted;
1286                fill_print_name(file);
1287                len = strlen(file->print_name);
1288                if (max_len < len)
1289                        max_len = len;
1290
1291                if (file->is_binary || file->is_unmerged)
1292                        continue;
1293                if (max_change < change)
1294                        max_change = change;
1295        }
1296
1297        /* Compute the width of the graph part;
1298         * 10 is for one blank at the beginning of the line plus
1299         * " | count " between the name and the graph.
1300         *
1301         * From here on, name_width is the width of the name area,
1302         * and width is the width of the graph area.
1303         */
1304        name_width = (name_width < max_len) ? name_width : max_len;
1305        if (width < (name_width + 10) + max_change)
1306                width = width - (name_width + 10);
1307        else
1308                width = max_change;
1309
1310        for (i = 0; i < data->nr; i++) {
1311                const char *prefix = "";
1312                char *name = data->files[i]->print_name;
1313                uintmax_t added = data->files[i]->added;
1314                uintmax_t deleted = data->files[i]->deleted;
1315                int name_len;
1316
1317                /*
1318                 * "scale" the filename
1319                 */
1320                len = name_width;
1321                name_len = strlen(name);
1322                if (name_width < name_len) {
1323                        char *slash;
1324                        prefix = "...";
1325                        len -= 3;
1326                        name += name_len - len;
1327                        slash = strchr(name, '/');
1328                        if (slash)
1329                                name = slash;
1330                }
1331
1332                if (data->files[i]->is_binary) {
1333                        fprintf(options->file, "%s", line_prefix);
1334                        show_name(options->file, prefix, name, len);
1335                        fprintf(options->file, "  Bin ");
1336                        fprintf(options->file, "%s%"PRIuMAX"%s",
1337                                del_c, deleted, reset);
1338                        fprintf(options->file, " -> ");
1339                        fprintf(options->file, "%s%"PRIuMAX"%s",
1340                                add_c, added, reset);
1341                        fprintf(options->file, " bytes");
1342                        fprintf(options->file, "\n");
1343                        continue;
1344                }
1345                else if (data->files[i]->is_unmerged) {
1346                        fprintf(options->file, "%s", line_prefix);
1347                        show_name(options->file, prefix, name, len);
1348                        fprintf(options->file, "  Unmerged\n");
1349                        continue;
1350                }
1351                else if (!data->files[i]->is_renamed &&
1352                         (added + deleted == 0)) {
1353                        total_files--;
1354                        continue;
1355                }
1356
1357                /*
1358                 * scale the add/delete
1359                 */
1360                add = added;
1361                del = deleted;
1362                adds += add;
1363                dels += del;
1364
1365                if (width <= max_change) {
1366                        add = scale_linear(add, width, max_change);
1367                        del = scale_linear(del, width, max_change);
1368                }
1369                fprintf(options->file, "%s", line_prefix);
1370                show_name(options->file, prefix, name, len);
1371                fprintf(options->file, "%5"PRIuMAX"%s", added + deleted,
1372                                added + deleted ? " " : "");
1373                show_graph(options->file, '+', add, add_c, reset);
1374                show_graph(options->file, '-', del, del_c, reset);
1375                fprintf(options->file, "\n");
1376        }
1377        fprintf(options->file, "%s", line_prefix);
1378        fprintf(options->file,
1379               " %d files changed, %d insertions(+), %d deletions(-)\n",
1380               total_files, adds, dels);
1381}
1382
1383static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
1384{
1385        int i, adds = 0, dels = 0, total_files = data->nr;
1386
1387        if (data->nr == 0)
1388                return;
1389
1390        for (i = 0; i < data->nr; i++) {
1391                if (!data->files[i]->is_binary &&
1392                    !data->files[i]->is_unmerged) {
1393                        int added = data->files[i]->added;
1394                        int deleted= data->files[i]->deleted;
1395                        if (!data->files[i]->is_renamed &&
1396                            (added + deleted == 0)) {
1397                                total_files--;
1398                        } else {
1399                                adds += added;
1400                                dels += deleted;
1401                        }
1402                }
1403        }
1404        if (options->output_prefix) {
1405                struct strbuf *msg = NULL;
1406                msg = options->output_prefix(options,
1407                                options->output_prefix_data);
1408                fprintf(options->file, "%s", msg->buf);
1409        }
1410        fprintf(options->file, " %d files changed, %d insertions(+), %d deletions(-)\n",
1411               total_files, adds, dels);
1412}
1413
1414static void show_numstat(struct diffstat_t *data, struct diff_options *options)
1415{
1416        int i;
1417
1418        if (data->nr == 0)
1419                return;
1420
1421        for (i = 0; i < data->nr; i++) {
1422                struct diffstat_file *file = data->files[i];
1423
1424                if (options->output_prefix) {
1425                        struct strbuf *msg = NULL;
1426                        msg = options->output_prefix(options,
1427                                        options->output_prefix_data);
1428                        fprintf(options->file, "%s", msg->buf);
1429                }
1430
1431                if (file->is_binary)
1432                        fprintf(options->file, "-\t-\t");
1433                else
1434                        fprintf(options->file,
1435                                "%"PRIuMAX"\t%"PRIuMAX"\t",
1436                                file->added, file->deleted);
1437                if (options->line_termination) {
1438                        fill_print_name(file);
1439                        if (!file->is_renamed)
1440                                write_name_quoted(file->name, options->file,
1441                                                  options->line_termination);
1442                        else {
1443                                fputs(file->print_name, options->file);
1444                                putc(options->line_termination, options->file);
1445                        }
1446                } else {
1447                        if (file->is_renamed) {
1448                                putc('\0', options->file);
1449                                write_name_quoted(file->from_name, options->file, '\0');
1450                        }
1451                        write_name_quoted(file->name, options->file, '\0');
1452                }
1453        }
1454}
1455
1456struct dirstat_file {
1457        const char *name;
1458        unsigned long changed;
1459};
1460
1461struct dirstat_dir {
1462        struct dirstat_file *files;
1463        int alloc, nr, percent, cumulative;
1464};
1465
1466static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
1467                unsigned long changed, const char *base, int baselen)
1468{
1469        unsigned long this_dir = 0;
1470        unsigned int sources = 0;
1471        const char *line_prefix = "";
1472        struct strbuf *msg = NULL;
1473
1474        if (opt->output_prefix) {
1475                msg = opt->output_prefix(opt, opt->output_prefix_data);
1476                line_prefix = msg->buf;
1477        }
1478
1479        while (dir->nr) {
1480                struct dirstat_file *f = dir->files;
1481                int namelen = strlen(f->name);
1482                unsigned long this;
1483                char *slash;
1484
1485                if (namelen < baselen)
1486                        break;
1487                if (memcmp(f->name, base, baselen))
1488                        break;
1489                slash = strchr(f->name + baselen, '/');
1490                if (slash) {
1491                        int newbaselen = slash + 1 - f->name;
1492                        this = gather_dirstat(opt, dir, changed, f->name, newbaselen);
1493                        sources++;
1494                } else {
1495                        this = f->changed;
1496                        dir->files++;
1497                        dir->nr--;
1498                        sources += 2;
1499                }
1500                this_dir += this;
1501        }
1502
1503        /*
1504         * We don't report dirstat's for
1505         *  - the top level
1506         *  - or cases where everything came from a single directory
1507         *    under this directory (sources == 1).
1508         */
1509        if (baselen && sources != 1) {
1510                int permille = this_dir * 1000 / changed;
1511                if (permille) {
1512                        int percent = permille / 10;
1513                        if (percent >= dir->percent) {
1514                                fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
1515                                        percent, permille % 10, baselen, base);
1516                                if (!dir->cumulative)
1517                                        return 0;
1518                        }
1519                }
1520        }
1521        return this_dir;
1522}
1523
1524static int dirstat_compare(const void *_a, const void *_b)
1525{
1526        const struct dirstat_file *a = _a;
1527        const struct dirstat_file *b = _b;
1528        return strcmp(a->name, b->name);
1529}
1530
1531static void show_dirstat(struct diff_options *options)
1532{
1533        int i;
1534        unsigned long changed;
1535        struct dirstat_dir dir;
1536        struct diff_queue_struct *q = &diff_queued_diff;
1537
1538        dir.files = NULL;
1539        dir.alloc = 0;
1540        dir.nr = 0;
1541        dir.percent = options->dirstat_percent;
1542        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1543
1544        changed = 0;
1545        for (i = 0; i < q->nr; i++) {
1546                struct diff_filepair *p = q->queue[i];
1547                const char *name;
1548                unsigned long copied, added, damage;
1549                int content_changed;
1550
1551                name = p->two->path ? p->two->path : p->one->path;
1552
1553                if (p->one->sha1_valid && p->two->sha1_valid)
1554                        content_changed = hashcmp(p->one->sha1, p->two->sha1);
1555                else
1556                        content_changed = 1;
1557
1558                if (!content_changed) {
1559                        /*
1560                         * The SHA1 has not changed, so pre-/post-content is
1561                         * identical. We can therefore skip looking at the
1562                         * file contents altogether.
1563                         */
1564                        damage = 0;
1565                        goto found_damage;
1566                }
1567
1568                if (DIFF_OPT_TST(options, DIRSTAT_BY_FILE)) {
1569                        /*
1570                         * In --dirstat-by-file mode, we don't really need to
1571                         * look at the actual file contents at all.
1572                         * The fact that the SHA1 changed is enough for us to
1573                         * add this file to the list of results
1574                         * (with each file contributing equal damage).
1575                         */
1576                        damage = 1;
1577                        goto found_damage;
1578                }
1579
1580                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
1581                        diff_populate_filespec(p->one, 0);
1582                        diff_populate_filespec(p->two, 0);
1583                        diffcore_count_changes(p->one, p->two, NULL, NULL, 0,
1584                                               &copied, &added);
1585                        diff_free_filespec_data(p->one);
1586                        diff_free_filespec_data(p->two);
1587                } else if (DIFF_FILE_VALID(p->one)) {
1588                        diff_populate_filespec(p->one, 1);
1589                        copied = added = 0;
1590                        diff_free_filespec_data(p->one);
1591                } else if (DIFF_FILE_VALID(p->two)) {
1592                        diff_populate_filespec(p->two, 1);
1593                        copied = 0;
1594                        added = p->two->size;
1595                        diff_free_filespec_data(p->two);
1596                } else
1597                        continue;
1598
1599                /*
1600                 * Original minus copied is the removed material,
1601                 * added is the new material.  They are both damages
1602                 * made to the preimage.
1603                 * If the resulting damage is zero, we know that
1604                 * diffcore_count_changes() considers the two entries to
1605                 * be identical, but since content_changed is true, we
1606                 * know that there must have been _some_ kind of change,
1607                 * so we force all entries to have damage > 0.
1608                 */
1609                damage = (p->one->size - copied) + added;
1610                if (!damage)
1611                        damage = 1;
1612
1613found_damage:
1614                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1615                dir.files[dir.nr].name = name;
1616                dir.files[dir.nr].changed = damage;
1617                changed += damage;
1618                dir.nr++;
1619        }
1620
1621        /* This can happen even with many files, if everything was renames */
1622        if (!changed)
1623                return;
1624
1625        /* Show all directories with more than x% of the changes */
1626        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1627        gather_dirstat(options, &dir, changed, "", 0);
1628}
1629
1630static void free_diffstat_info(struct diffstat_t *diffstat)
1631{
1632        int i;
1633        for (i = 0; i < diffstat->nr; i++) {
1634                struct diffstat_file *f = diffstat->files[i];
1635                if (f->name != f->print_name)
1636                        free(f->print_name);
1637                free(f->name);
1638                free(f->from_name);
1639                free(f);
1640        }
1641        free(diffstat->files);
1642}
1643
1644struct checkdiff_t {
1645        const char *filename;
1646        int lineno;
1647        int conflict_marker_size;
1648        struct diff_options *o;
1649        unsigned ws_rule;
1650        unsigned status;
1651};
1652
1653static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
1654{
1655        char firstchar;
1656        int cnt;
1657
1658        if (len < marker_size + 1)
1659                return 0;
1660        firstchar = line[0];
1661        switch (firstchar) {
1662        case '=': case '>': case '<': case '|':
1663                break;
1664        default:
1665                return 0;
1666        }
1667        for (cnt = 1; cnt < marker_size; cnt++)
1668                if (line[cnt] != firstchar)
1669                        return 0;
1670        /* line[1] thru line[marker_size-1] are same as firstchar */
1671        if (len < marker_size + 1 || !isspace(line[marker_size]))
1672                return 0;
1673        return 1;
1674}
1675
1676static void checkdiff_consume(void *priv, char *line, unsigned long len)
1677{
1678        struct checkdiff_t *data = priv;
1679        int color_diff = DIFF_OPT_TST(data->o, COLOR_DIFF);
1680        int marker_size = data->conflict_marker_size;
1681        const char *ws = diff_get_color(color_diff, DIFF_WHITESPACE);
1682        const char *reset = diff_get_color(color_diff, DIFF_RESET);
1683        const char *set = diff_get_color(color_diff, DIFF_FILE_NEW);
1684        char *err;
1685        char *line_prefix = "";
1686        struct strbuf *msgbuf;
1687
1688        assert(data->o);
1689        if (data->o->output_prefix) {
1690                msgbuf = data->o->output_prefix(data->o,
1691                        data->o->output_prefix_data);
1692                line_prefix = msgbuf->buf;
1693        }
1694
1695        if (line[0] == '+') {
1696                unsigned bad;
1697                data->lineno++;
1698                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
1699                        data->status |= 1;
1700                        fprintf(data->o->file,
1701                                "%s%s:%d: leftover conflict marker\n",
1702                                line_prefix, data->filename, data->lineno);
1703                }
1704                bad = ws_check(line + 1, len - 1, data->ws_rule);
1705                if (!bad)
1706                        return;
1707                data->status |= bad;
1708                err = whitespace_error_string(bad);
1709                fprintf(data->o->file, "%s%s:%d: %s.\n",
1710                        line_prefix, data->filename, data->lineno, err);
1711                free(err);
1712                emit_line(data->o, set, reset, line, 1);
1713                ws_check_emit(line + 1, len - 1, data->ws_rule,
1714                              data->o->file, set, reset, ws);
1715        } else if (line[0] == ' ') {
1716                data->lineno++;
1717        } else if (line[0] == '@') {
1718                char *plus = strchr(line, '+');
1719                if (plus)
1720                        data->lineno = strtol(plus, NULL, 10) - 1;
1721                else
1722                        die("invalid diff");
1723        }
1724}
1725
1726static unsigned char *deflate_it(char *data,
1727                                 unsigned long size,
1728                                 unsigned long *result_size)
1729{
1730        int bound;
1731        unsigned char *deflated;
1732        z_stream stream;
1733
1734        memset(&stream, 0, sizeof(stream));
1735        deflateInit(&stream, zlib_compression_level);
1736        bound = deflateBound(&stream, size);
1737        deflated = xmalloc(bound);
1738        stream.next_out = deflated;
1739        stream.avail_out = bound;
1740
1741        stream.next_in = (unsigned char *)data;
1742        stream.avail_in = size;
1743        while (deflate(&stream, Z_FINISH) == Z_OK)
1744                ; /* nothing */
1745        deflateEnd(&stream);
1746        *result_size = stream.total_out;
1747        return deflated;
1748}
1749
1750static void emit_binary_diff_body(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
1751{
1752        void *cp;
1753        void *delta;
1754        void *deflated;
1755        void *data;
1756        unsigned long orig_size;
1757        unsigned long delta_size;
1758        unsigned long deflate_size;
1759        unsigned long data_size;
1760
1761        /* We could do deflated delta, or we could do just deflated two,
1762         * whichever is smaller.
1763         */
1764        delta = NULL;
1765        deflated = deflate_it(two->ptr, two->size, &deflate_size);
1766        if (one->size && two->size) {
1767                delta = diff_delta(one->ptr, one->size,
1768                                   two->ptr, two->size,
1769                                   &delta_size, deflate_size);
1770                if (delta) {
1771                        void *to_free = delta;
1772                        orig_size = delta_size;
1773                        delta = deflate_it(delta, delta_size, &delta_size);
1774                        free(to_free);
1775                }
1776        }
1777
1778        if (delta && delta_size < deflate_size) {
1779                fprintf(file, "%sdelta %lu\n", prefix, orig_size);
1780                free(deflated);
1781                data = delta;
1782                data_size = delta_size;
1783        }
1784        else {
1785                fprintf(file, "%sliteral %lu\n", prefix, two->size);
1786                free(delta);
1787                data = deflated;
1788                data_size = deflate_size;
1789        }
1790
1791        /* emit data encoded in base85 */
1792        cp = data;
1793        while (data_size) {
1794                int bytes = (52 < data_size) ? 52 : data_size;
1795                char line[70];
1796                data_size -= bytes;
1797                if (bytes <= 26)
1798                        line[0] = bytes + 'A' - 1;
1799                else
1800                        line[0] = bytes - 26 + 'a' - 1;
1801                encode_85(line + 1, cp, bytes);
1802                cp = (char *) cp + bytes;
1803                fprintf(file, "%s", prefix);
1804                fputs(line, file);
1805                fputc('\n', file);
1806        }
1807        fprintf(file, "%s\n", prefix);
1808        free(data);
1809}
1810
1811static void emit_binary_diff(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
1812{
1813        fprintf(file, "%sGIT binary patch\n", prefix);
1814        emit_binary_diff_body(file, one, two, prefix);
1815        emit_binary_diff_body(file, two, one, prefix);
1816}
1817
1818static void diff_filespec_load_driver(struct diff_filespec *one)
1819{
1820        /* Use already-loaded driver */
1821        if (one->driver)
1822                return;
1823
1824        if (S_ISREG(one->mode))
1825                one->driver = userdiff_find_by_path(one->path);
1826
1827        /* Fallback to default settings */
1828        if (!one->driver)
1829                one->driver = userdiff_find_by_name("default");
1830}
1831
1832int diff_filespec_is_binary(struct diff_filespec *one)
1833{
1834        if (one->is_binary == -1) {
1835                diff_filespec_load_driver(one);
1836                if (one->driver->binary != -1)
1837                        one->is_binary = one->driver->binary;
1838                else {
1839                        if (!one->data && DIFF_FILE_VALID(one))
1840                                diff_populate_filespec(one, 0);
1841                        if (one->data)
1842                                one->is_binary = buffer_is_binary(one->data,
1843                                                one->size);
1844                        if (one->is_binary == -1)
1845                                one->is_binary = 0;
1846                }
1847        }
1848        return one->is_binary;
1849}
1850
1851static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
1852{
1853        diff_filespec_load_driver(one);
1854        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
1855}
1856
1857static const char *userdiff_word_regex(struct diff_filespec *one)
1858{
1859        diff_filespec_load_driver(one);
1860        return one->driver->word_regex;
1861}
1862
1863void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
1864{
1865        if (!options->a_prefix)
1866                options->a_prefix = a;
1867        if (!options->b_prefix)
1868                options->b_prefix = b;
1869}
1870
1871struct userdiff_driver *get_textconv(struct diff_filespec *one)
1872{
1873        if (!DIFF_FILE_VALID(one))
1874                return NULL;
1875
1876        diff_filespec_load_driver(one);
1877        if (!one->driver->textconv)
1878                return NULL;
1879
1880        if (one->driver->textconv_want_cache && !one->driver->textconv_cache) {
1881                struct notes_cache *c = xmalloc(sizeof(*c));
1882                struct strbuf name = STRBUF_INIT;
1883
1884                strbuf_addf(&name, "textconv/%s", one->driver->name);
1885                notes_cache_init(c, name.buf, one->driver->textconv);
1886                one->driver->textconv_cache = c;
1887        }
1888
1889        return one->driver;
1890}
1891
1892static void builtin_diff(const char *name_a,
1893                         const char *name_b,
1894                         struct diff_filespec *one,
1895                         struct diff_filespec *two,
1896                         const char *xfrm_msg,
1897                         int must_show_header,
1898                         struct diff_options *o,
1899                         int complete_rewrite)
1900{
1901        mmfile_t mf1, mf2;
1902        const char *lbl[2];
1903        char *a_one, *b_two;
1904        const char *set = diff_get_color_opt(o, DIFF_METAINFO);
1905        const char *reset = diff_get_color_opt(o, DIFF_RESET);
1906        const char *a_prefix, *b_prefix;
1907        struct userdiff_driver *textconv_one = NULL;
1908        struct userdiff_driver *textconv_two = NULL;
1909        struct strbuf header = STRBUF_INIT;
1910        struct strbuf *msgbuf;
1911        char *line_prefix = "";
1912
1913        if (o->output_prefix) {
1914                msgbuf = o->output_prefix(o, o->output_prefix_data);
1915                line_prefix = msgbuf->buf;
1916        }
1917
1918        if (DIFF_OPT_TST(o, SUBMODULE_LOG) &&
1919                        (!one->mode || S_ISGITLINK(one->mode)) &&
1920                        (!two->mode || S_ISGITLINK(two->mode))) {
1921                const char *del = diff_get_color_opt(o, DIFF_FILE_OLD);
1922                const char *add = diff_get_color_opt(o, DIFF_FILE_NEW);
1923                show_submodule_summary(o->file, one ? one->path : two->path,
1924                                one->sha1, two->sha1, two->dirty_submodule,
1925                                del, add, reset);
1926                return;
1927        }
1928
1929        if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
1930                textconv_one = get_textconv(one);
1931                textconv_two = get_textconv(two);
1932        }
1933
1934        diff_set_mnemonic_prefix(o, "a/", "b/");
1935        if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
1936                a_prefix = o->b_prefix;
1937                b_prefix = o->a_prefix;
1938        } else {
1939                a_prefix = o->a_prefix;
1940                b_prefix = o->b_prefix;
1941        }
1942
1943        /* Never use a non-valid filename anywhere if at all possible */
1944        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
1945        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
1946
1947        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
1948        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
1949        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
1950        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
1951        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, set, a_one, b_two, reset);
1952        if (lbl[0][0] == '/') {
1953                /* /dev/null */
1954                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, set, two->mode, reset);
1955                if (xfrm_msg)
1956                        strbuf_addstr(&header, xfrm_msg);
1957                must_show_header = 1;
1958        }
1959        else if (lbl[1][0] == '/') {
1960                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, set, one->mode, reset);
1961                if (xfrm_msg)
1962                        strbuf_addstr(&header, xfrm_msg);
1963                must_show_header = 1;
1964        }
1965        else {
1966                if (one->mode != two->mode) {
1967                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, set, one->mode, reset);
1968                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, set, two->mode, reset);
1969                        must_show_header = 1;
1970                }
1971                if (xfrm_msg)
1972                        strbuf_addstr(&header, xfrm_msg);
1973
1974                /*
1975                 * we do not run diff between different kind
1976                 * of objects.
1977                 */
1978                if ((one->mode ^ two->mode) & S_IFMT)
1979                        goto free_ab_and_return;
1980                if (complete_rewrite &&
1981                    (textconv_one || !diff_filespec_is_binary(one)) &&
1982                    (textconv_two || !diff_filespec_is_binary(two))) {
1983                        fprintf(o->file, "%s", header.buf);
1984                        strbuf_reset(&header);
1985                        emit_rewrite_diff(name_a, name_b, one, two,
1986                                                textconv_one, textconv_two, o);
1987                        o->found_changes = 1;
1988                        goto free_ab_and_return;
1989                }
1990        }
1991
1992        if (!DIFF_OPT_TST(o, TEXT) &&
1993            ( (!textconv_one && diff_filespec_is_binary(one)) ||
1994              (!textconv_two && diff_filespec_is_binary(two)) )) {
1995                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1996                        die("unable to read files to diff");
1997                /* Quite common confusing case */
1998                if (mf1.size == mf2.size &&
1999                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
2000                        if (must_show_header)
2001                                fprintf(o->file, "%s", header.buf);
2002                        goto free_ab_and_return;
2003                }
2004                fprintf(o->file, "%s", header.buf);
2005                strbuf_reset(&header);
2006                if (DIFF_OPT_TST(o, BINARY))
2007                        emit_binary_diff(o->file, &mf1, &mf2, line_prefix);
2008                else
2009                        fprintf(o->file, "%sBinary files %s and %s differ\n",
2010                                line_prefix, lbl[0], lbl[1]);
2011                o->found_changes = 1;
2012        }
2013        else {
2014                /* Crazy xdl interfaces.. */
2015                const char *diffopts = getenv("GIT_DIFF_OPTS");
2016                xpparam_t xpp;
2017                xdemitconf_t xecfg;
2018                struct emit_callback ecbdata;
2019                const struct userdiff_funcname *pe;
2020
2021                if (!DIFF_XDL_TST(o, WHITESPACE_FLAGS) || must_show_header) {
2022                        fprintf(o->file, "%s", header.buf);
2023                        strbuf_reset(&header);
2024                }
2025
2026                mf1.size = fill_textconv(textconv_one, one, &mf1.ptr);
2027                mf2.size = fill_textconv(textconv_two, two, &mf2.ptr);
2028
2029                pe = diff_funcname_pattern(one);
2030                if (!pe)
2031                        pe = diff_funcname_pattern(two);
2032
2033                memset(&xpp, 0, sizeof(xpp));
2034                memset(&xecfg, 0, sizeof(xecfg));
2035                memset(&ecbdata, 0, sizeof(ecbdata));
2036                ecbdata.label_path = lbl;
2037                ecbdata.color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
2038                ecbdata.found_changesp = &o->found_changes;
2039                ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
2040                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
2041                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2042                ecbdata.opt = o;
2043                ecbdata.header = header.len ? &header : NULL;
2044                xpp.flags = o->xdl_opts;
2045                xecfg.ctxlen = o->context;
2046                xecfg.interhunkctxlen = o->interhunkcontext;
2047                xecfg.flags = XDL_EMIT_FUNCNAMES;
2048                if (pe)
2049                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
2050                if (!diffopts)
2051                        ;
2052                else if (!prefixcmp(diffopts, "--unified="))
2053                        xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
2054                else if (!prefixcmp(diffopts, "-u"))
2055                        xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
2056                if (o->word_diff) {
2057                        int i;
2058
2059                        ecbdata.diff_words =
2060                                xcalloc(1, sizeof(struct diff_words_data));
2061                        ecbdata.diff_words->type = o->word_diff;
2062                        ecbdata.diff_words->opt = o;
2063                        if (!o->word_regex)
2064                                o->word_regex = userdiff_word_regex(one);
2065                        if (!o->word_regex)
2066                                o->word_regex = userdiff_word_regex(two);
2067                        if (!o->word_regex)
2068                                o->word_regex = diff_word_regex_cfg;
2069                        if (o->word_regex) {
2070                                ecbdata.diff_words->word_regex = (regex_t *)
2071                                        xmalloc(sizeof(regex_t));
2072                                if (regcomp(ecbdata.diff_words->word_regex,
2073                                                o->word_regex,
2074                                                REG_EXTENDED | REG_NEWLINE))
2075                                        die ("Invalid regular expression: %s",
2076                                                        o->word_regex);
2077                        }
2078                        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
2079                                if (o->word_diff == diff_words_styles[i].type) {
2080                                        ecbdata.diff_words->style =
2081                                                &diff_words_styles[i];
2082                                        break;
2083                                }
2084                        }
2085                        if (DIFF_OPT_TST(o, COLOR_DIFF)) {
2086                                struct diff_words_style *st = ecbdata.diff_words->style;
2087                                st->old.color = diff_get_color_opt(o, DIFF_FILE_OLD);
2088                                st->new.color = diff_get_color_opt(o, DIFF_FILE_NEW);
2089                                st->ctx.color = diff_get_color_opt(o, DIFF_PLAIN);
2090                        }
2091                }
2092                xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
2093                              &xpp, &xecfg);
2094                if (o->word_diff)
2095                        free_diff_words_data(&ecbdata);
2096                if (textconv_one)
2097                        free(mf1.ptr);
2098                if (textconv_two)
2099                        free(mf2.ptr);
2100                xdiff_clear_find_func(&xecfg);
2101        }
2102
2103 free_ab_and_return:
2104        strbuf_release(&header);
2105        diff_free_filespec_data(one);
2106        diff_free_filespec_data(two);
2107        free(a_one);
2108        free(b_two);
2109        return;
2110}
2111
2112static void builtin_diffstat(const char *name_a, const char *name_b,
2113                             struct diff_filespec *one,
2114                             struct diff_filespec *two,
2115                             struct diffstat_t *diffstat,
2116                             struct diff_options *o,
2117                             int complete_rewrite)
2118{
2119        mmfile_t mf1, mf2;
2120        struct diffstat_file *data;
2121
2122        data = diffstat_add(diffstat, name_a, name_b);
2123
2124        if (!one || !two) {
2125                data->is_unmerged = 1;
2126                return;
2127        }
2128
2129        if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
2130                data->is_binary = 1;
2131                data->added = diff_filespec_size(two);
2132                data->deleted = diff_filespec_size(one);
2133        }
2134
2135        else if (complete_rewrite) {
2136                diff_populate_filespec(one, 0);
2137                diff_populate_filespec(two, 0);
2138                data->deleted = count_lines(one->data, one->size);
2139                data->added = count_lines(two->data, two->size);
2140        }
2141
2142        else {
2143                /* Crazy xdl interfaces.. */
2144                xpparam_t xpp;
2145                xdemitconf_t xecfg;
2146
2147                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2148                        die("unable to read files to diff");
2149
2150                memset(&xpp, 0, sizeof(xpp));
2151                memset(&xecfg, 0, sizeof(xecfg));
2152                xpp.flags = o->xdl_opts;
2153                xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
2154                              &xpp, &xecfg);
2155        }
2156
2157        diff_free_filespec_data(one);
2158        diff_free_filespec_data(two);
2159}
2160
2161static void builtin_checkdiff(const char *name_a, const char *name_b,
2162                              const char *attr_path,
2163                              struct diff_filespec *one,
2164                              struct diff_filespec *two,
2165                              struct diff_options *o)
2166{
2167        mmfile_t mf1, mf2;
2168        struct checkdiff_t data;
2169
2170        if (!two)
2171                return;
2172
2173        memset(&data, 0, sizeof(data));
2174        data.filename = name_b ? name_b : name_a;
2175        data.lineno = 0;
2176        data.o = o;
2177        data.ws_rule = whitespace_rule(attr_path);
2178        data.conflict_marker_size = ll_merge_marker_size(attr_path);
2179
2180        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2181                die("unable to read files to diff");
2182
2183        /*
2184         * All the other codepaths check both sides, but not checking
2185         * the "old" side here is deliberate.  We are checking the newly
2186         * introduced changes, and as long as the "new" side is text, we
2187         * can and should check what it introduces.
2188         */
2189        if (diff_filespec_is_binary(two))
2190                goto free_and_return;
2191        else {
2192                /* Crazy xdl interfaces.. */
2193                xpparam_t xpp;
2194                xdemitconf_t xecfg;
2195
2196                memset(&xpp, 0, sizeof(xpp));
2197                memset(&xecfg, 0, sizeof(xecfg));
2198                xecfg.ctxlen = 1; /* at least one context line */
2199                xpp.flags = 0;
2200                xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
2201                              &xpp, &xecfg);
2202
2203                if (data.ws_rule & WS_BLANK_AT_EOF) {
2204                        struct emit_callback ecbdata;
2205                        int blank_at_eof;
2206
2207                        ecbdata.ws_rule = data.ws_rule;
2208                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2209                        blank_at_eof = ecbdata.blank_at_eof_in_postimage;
2210
2211                        if (blank_at_eof) {
2212                                static char *err;
2213                                if (!err)
2214                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
2215                                fprintf(o->file, "%s:%d: %s.\n",
2216                                        data.filename, blank_at_eof, err);
2217                                data.status = 1; /* report errors */
2218                        }
2219                }
2220        }
2221 free_and_return:
2222        diff_free_filespec_data(one);
2223        diff_free_filespec_data(two);
2224        if (data.status)
2225                DIFF_OPT_SET(o, CHECK_FAILED);
2226}
2227
2228struct diff_filespec *alloc_filespec(const char *path)
2229{
2230        int namelen = strlen(path);
2231        struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
2232
2233        memset(spec, 0, sizeof(*spec));
2234        spec->path = (char *)(spec + 1);
2235        memcpy(spec->path, path, namelen+1);
2236        spec->count = 1;
2237        spec->is_binary = -1;
2238        return spec;
2239}
2240
2241void free_filespec(struct diff_filespec *spec)
2242{
2243        if (!--spec->count) {
2244                diff_free_filespec_data(spec);
2245                free(spec);
2246        }
2247}
2248
2249void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
2250                   unsigned short mode)
2251{
2252        if (mode) {
2253                spec->mode = canon_mode(mode);
2254                hashcpy(spec->sha1, sha1);
2255                spec->sha1_valid = !is_null_sha1(sha1);
2256        }
2257}
2258
2259/*
2260 * Given a name and sha1 pair, if the index tells us the file in
2261 * the work tree has that object contents, return true, so that
2262 * prepare_temp_file() does not have to inflate and extract.
2263 */
2264static int reuse_worktree_file(const char *name, const unsigned char *sha1, int want_file)
2265{
2266        struct cache_entry *ce;
2267        struct stat st;
2268        int pos, len;
2269
2270        /*
2271         * We do not read the cache ourselves here, because the
2272         * benchmark with my previous version that always reads cache
2273         * shows that it makes things worse for diff-tree comparing
2274         * two linux-2.6 kernel trees in an already checked out work
2275         * tree.  This is because most diff-tree comparisons deal with
2276         * only a small number of files, while reading the cache is
2277         * expensive for a large project, and its cost outweighs the
2278         * savings we get by not inflating the object to a temporary
2279         * file.  Practically, this code only helps when we are used
2280         * by diff-cache --cached, which does read the cache before
2281         * calling us.
2282         */
2283        if (!active_cache)
2284                return 0;
2285
2286        /* We want to avoid the working directory if our caller
2287         * doesn't need the data in a normal file, this system
2288         * is rather slow with its stat/open/mmap/close syscalls,
2289         * and the object is contained in a pack file.  The pack
2290         * is probably already open and will be faster to obtain
2291         * the data through than the working directory.  Loose
2292         * objects however would tend to be slower as they need
2293         * to be individually opened and inflated.
2294         */
2295        if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(sha1))
2296                return 0;
2297
2298        len = strlen(name);
2299        pos = cache_name_pos(name, len);
2300        if (pos < 0)
2301                return 0;
2302        ce = active_cache[pos];
2303
2304        /*
2305         * This is not the sha1 we are looking for, or
2306         * unreusable because it is not a regular file.
2307         */
2308        if (hashcmp(sha1, ce->sha1) || !S_ISREG(ce->ce_mode))
2309                return 0;
2310
2311        /*
2312         * If ce is marked as "assume unchanged", there is no
2313         * guarantee that work tree matches what we are looking for.
2314         */
2315        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
2316                return 0;
2317
2318        /*
2319         * If ce matches the file in the work tree, we can reuse it.
2320         */
2321        if (ce_uptodate(ce) ||
2322            (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
2323                return 1;
2324
2325        return 0;
2326}
2327
2328static int populate_from_stdin(struct diff_filespec *s)
2329{
2330        struct strbuf buf = STRBUF_INIT;
2331        size_t size = 0;
2332
2333        if (strbuf_read(&buf, 0, 0) < 0)
2334                return error("error while reading from stdin %s",
2335                                     strerror(errno));
2336
2337        s->should_munmap = 0;
2338        s->data = strbuf_detach(&buf, &size);
2339        s->size = size;
2340        s->should_free = 1;
2341        return 0;
2342}
2343
2344static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
2345{
2346        int len;
2347        char *data = xmalloc(100), *dirty = "";
2348
2349        /* Are we looking at the work tree? */
2350        if (s->dirty_submodule)
2351                dirty = "-dirty";
2352
2353        len = snprintf(data, 100,
2354                       "Subproject commit %s%s\n", sha1_to_hex(s->sha1), dirty);
2355        s->data = data;
2356        s->size = len;
2357        s->should_free = 1;
2358        if (size_only) {
2359                s->data = NULL;
2360                free(data);
2361        }
2362        return 0;
2363}
2364
2365/*
2366 * While doing rename detection and pickaxe operation, we may need to
2367 * grab the data for the blob (or file) for our own in-core comparison.
2368 * diff_filespec has data and size fields for this purpose.
2369 */
2370int diff_populate_filespec(struct diff_filespec *s, int size_only)
2371{
2372        int err = 0;
2373        if (!DIFF_FILE_VALID(s))
2374                die("internal error: asking to populate invalid file.");
2375        if (S_ISDIR(s->mode))
2376                return -1;
2377
2378        if (s->data)
2379                return 0;
2380
2381        if (size_only && 0 < s->size)
2382                return 0;
2383
2384        if (S_ISGITLINK(s->mode))
2385                return diff_populate_gitlink(s, size_only);
2386
2387        if (!s->sha1_valid ||
2388            reuse_worktree_file(s->path, s->sha1, 0)) {
2389                struct strbuf buf = STRBUF_INIT;
2390                struct stat st;
2391                int fd;
2392
2393                if (!strcmp(s->path, "-"))
2394                        return populate_from_stdin(s);
2395
2396                if (lstat(s->path, &st) < 0) {
2397                        if (errno == ENOENT) {
2398                        err_empty:
2399                                err = -1;
2400                        empty:
2401                                s->data = (char *)"";
2402                                s->size = 0;
2403                                return err;
2404                        }
2405                }
2406                s->size = xsize_t(st.st_size);
2407                if (!s->size)
2408                        goto empty;
2409                if (S_ISLNK(st.st_mode)) {
2410                        struct strbuf sb = STRBUF_INIT;
2411
2412                        if (strbuf_readlink(&sb, s->path, s->size))
2413                                goto err_empty;
2414                        s->size = sb.len;
2415                        s->data = strbuf_detach(&sb, NULL);
2416                        s->should_free = 1;
2417                        return 0;
2418                }
2419                if (size_only)
2420                        return 0;
2421                fd = open(s->path, O_RDONLY);
2422                if (fd < 0)
2423                        goto err_empty;
2424                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
2425                close(fd);
2426                s->should_munmap = 1;
2427
2428                /*
2429                 * Convert from working tree format to canonical git format
2430                 */
2431                if (convert_to_git(s->path, s->data, s->size, &buf, safe_crlf)) {
2432                        size_t size = 0;
2433                        munmap(s->data, s->size);
2434                        s->should_munmap = 0;
2435                        s->data = strbuf_detach(&buf, &size);
2436                        s->size = size;
2437                        s->should_free = 1;
2438                }
2439        }
2440        else {
2441                enum object_type type;
2442                if (size_only) {
2443                        type = sha1_object_info(s->sha1, &s->size);
2444                        if (type < 0)
2445                                die("unable to read %s", sha1_to_hex(s->sha1));
2446                } else {
2447                        s->data = read_sha1_file(s->sha1, &type, &s->size);
2448                        if (!s->data)
2449                                die("unable to read %s", sha1_to_hex(s->sha1));
2450                        s->should_free = 1;
2451                }
2452        }
2453        return 0;
2454}
2455
2456void diff_free_filespec_blob(struct diff_filespec *s)
2457{
2458        if (s->should_free)
2459                free(s->data);
2460        else if (s->should_munmap)
2461                munmap(s->data, s->size);
2462
2463        if (s->should_free || s->should_munmap) {
2464                s->should_free = s->should_munmap = 0;
2465                s->data = NULL;
2466        }
2467}
2468
2469void diff_free_filespec_data(struct diff_filespec *s)
2470{
2471        diff_free_filespec_blob(s);
2472        free(s->cnt_data);
2473        s->cnt_data = NULL;
2474}
2475
2476static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
2477                           void *blob,
2478                           unsigned long size,
2479                           const unsigned char *sha1,
2480                           int mode)
2481{
2482        int fd;
2483        struct strbuf buf = STRBUF_INIT;
2484        struct strbuf template = STRBUF_INIT;
2485        char *path_dup = xstrdup(path);
2486        const char *base = basename(path_dup);
2487
2488        /* Generate "XXXXXX_basename.ext" */
2489        strbuf_addstr(&template, "XXXXXX_");
2490        strbuf_addstr(&template, base);
2491
2492        fd = git_mkstemps(temp->tmp_path, PATH_MAX, template.buf,
2493                        strlen(base) + 1);
2494        if (fd < 0)
2495                die_errno("unable to create temp-file");
2496        if (convert_to_working_tree(path,
2497                        (const char *)blob, (size_t)size, &buf)) {
2498                blob = buf.buf;
2499                size = buf.len;
2500        }
2501        if (write_in_full(fd, blob, size) != size)
2502                die_errno("unable to write temp-file");
2503        close(fd);
2504        temp->name = temp->tmp_path;
2505        strcpy(temp->hex, sha1_to_hex(sha1));
2506        temp->hex[40] = 0;
2507        sprintf(temp->mode, "%06o", mode);
2508        strbuf_release(&buf);
2509        strbuf_release(&template);
2510        free(path_dup);
2511}
2512
2513static struct diff_tempfile *prepare_temp_file(const char *name,
2514                struct diff_filespec *one)
2515{
2516        struct diff_tempfile *temp = claim_diff_tempfile();
2517
2518        if (!DIFF_FILE_VALID(one)) {
2519        not_a_valid_file:
2520                /* A '-' entry produces this for file-2, and
2521                 * a '+' entry produces this for file-1.
2522                 */
2523                temp->name = "/dev/null";
2524                strcpy(temp->hex, ".");
2525                strcpy(temp->mode, ".");
2526                return temp;
2527        }
2528
2529        if (!remove_tempfile_installed) {
2530                atexit(remove_tempfile);
2531                sigchain_push_common(remove_tempfile_on_signal);
2532                remove_tempfile_installed = 1;
2533        }
2534
2535        if (!one->sha1_valid ||
2536            reuse_worktree_file(name, one->sha1, 1)) {
2537                struct stat st;
2538                if (lstat(name, &st) < 0) {
2539                        if (errno == ENOENT)
2540                                goto not_a_valid_file;
2541                        die_errno("stat(%s)", name);
2542                }
2543                if (S_ISLNK(st.st_mode)) {
2544                        struct strbuf sb = STRBUF_INIT;
2545                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
2546                                die_errno("readlink(%s)", name);
2547                        prep_temp_blob(name, temp, sb.buf, sb.len,
2548                                       (one->sha1_valid ?
2549                                        one->sha1 : null_sha1),
2550                                       (one->sha1_valid ?
2551                                        one->mode : S_IFLNK));
2552                        strbuf_release(&sb);
2553                }
2554                else {
2555                        /* we can borrow from the file in the work tree */
2556                        temp->name = name;
2557                        if (!one->sha1_valid)
2558                                strcpy(temp->hex, sha1_to_hex(null_sha1));
2559                        else
2560                                strcpy(temp->hex, sha1_to_hex(one->sha1));
2561                        /* Even though we may sometimes borrow the
2562                         * contents from the work tree, we always want
2563                         * one->mode.  mode is trustworthy even when
2564                         * !(one->sha1_valid), as long as
2565                         * DIFF_FILE_VALID(one).
2566                         */
2567                        sprintf(temp->mode, "%06o", one->mode);
2568                }
2569                return temp;
2570        }
2571        else {
2572                if (diff_populate_filespec(one, 0))
2573                        die("cannot read data blob for %s", one->path);
2574                prep_temp_blob(name, temp, one->data, one->size,
2575                               one->sha1, one->mode);
2576        }
2577        return temp;
2578}
2579
2580/* An external diff command takes:
2581 *
2582 * diff-cmd name infile1 infile1-sha1 infile1-mode \
2583 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
2584 *
2585 */
2586static void run_external_diff(const char *pgm,
2587                              const char *name,
2588                              const char *other,
2589                              struct diff_filespec *one,
2590                              struct diff_filespec *two,
2591                              const char *xfrm_msg,
2592                              int complete_rewrite)
2593{
2594        const char *spawn_arg[10];
2595        int retval;
2596        const char **arg = &spawn_arg[0];
2597
2598        if (one && two) {
2599                struct diff_tempfile *temp_one, *temp_two;
2600                const char *othername = (other ? other : name);
2601                temp_one = prepare_temp_file(name, one);
2602                temp_two = prepare_temp_file(othername, two);
2603                *arg++ = pgm;
2604                *arg++ = name;
2605                *arg++ = temp_one->name;
2606                *arg++ = temp_one->hex;
2607                *arg++ = temp_one->mode;
2608                *arg++ = temp_two->name;
2609                *arg++ = temp_two->hex;
2610                *arg++ = temp_two->mode;
2611                if (other) {
2612                        *arg++ = other;
2613                        *arg++ = xfrm_msg;
2614                }
2615        } else {
2616                *arg++ = pgm;
2617                *arg++ = name;
2618        }
2619        *arg = NULL;
2620        fflush(NULL);
2621        retval = run_command_v_opt(spawn_arg, RUN_USING_SHELL);
2622        remove_tempfile();
2623        if (retval) {
2624                fprintf(stderr, "external diff died, stopping at %s.\n", name);
2625                exit(1);
2626        }
2627}
2628
2629static int similarity_index(struct diff_filepair *p)
2630{
2631        return p->score * 100 / MAX_SCORE;
2632}
2633
2634static void fill_metainfo(struct strbuf *msg,
2635                          const char *name,
2636                          const char *other,
2637                          struct diff_filespec *one,
2638                          struct diff_filespec *two,
2639                          struct diff_options *o,
2640                          struct diff_filepair *p,
2641                          int *must_show_header,
2642                          int use_color)
2643{
2644        const char *set = diff_get_color(use_color, DIFF_METAINFO);
2645        const char *reset = diff_get_color(use_color, DIFF_RESET);
2646        struct strbuf *msgbuf;
2647        char *line_prefix = "";
2648
2649        *must_show_header = 1;
2650        if (o->output_prefix) {
2651                msgbuf = o->output_prefix(o, o->output_prefix_data);
2652                line_prefix = msgbuf->buf;
2653        }
2654        strbuf_init(msg, PATH_MAX * 2 + 300);
2655        switch (p->status) {
2656        case DIFF_STATUS_COPIED:
2657                strbuf_addf(msg, "%s%ssimilarity index %d%%",
2658                            line_prefix, set, similarity_index(p));
2659                strbuf_addf(msg, "%s\n%s%scopy from ",
2660                            reset,  line_prefix, set);
2661                quote_c_style(name, msg, NULL, 0);
2662                strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
2663                quote_c_style(other, msg, NULL, 0);
2664                strbuf_addf(msg, "%s\n", reset);
2665                break;
2666        case DIFF_STATUS_RENAMED:
2667                strbuf_addf(msg, "%s%ssimilarity index %d%%",
2668                            line_prefix, set, similarity_index(p));
2669                strbuf_addf(msg, "%s\n%s%srename from ",
2670                            reset, line_prefix, set);
2671                quote_c_style(name, msg, NULL, 0);
2672                strbuf_addf(msg, "%s\n%s%srename to ",
2673                            reset, line_prefix, set);
2674                quote_c_style(other, msg, NULL, 0);
2675                strbuf_addf(msg, "%s\n", reset);
2676                break;
2677        case DIFF_STATUS_MODIFIED:
2678                if (p->score) {
2679                        strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
2680                                    line_prefix,
2681                                    set, similarity_index(p), reset);
2682                        break;
2683                }
2684                /* fallthru */
2685        default:
2686                *must_show_header = 0;
2687        }
2688        if (one && two && hashcmp(one->sha1, two->sha1)) {
2689                int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
2690
2691                if (DIFF_OPT_TST(o, BINARY)) {
2692                        mmfile_t mf;
2693                        if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
2694                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
2695                                abbrev = 40;
2696                }
2697                strbuf_addf(msg, "%s%sindex %s..", line_prefix, set,
2698                            find_unique_abbrev(one->sha1, abbrev));
2699                strbuf_addstr(msg, find_unique_abbrev(two->sha1, abbrev));
2700                if (one->mode == two->mode)
2701                        strbuf_addf(msg, " %06o", one->mode);
2702                strbuf_addf(msg, "%s\n", reset);
2703        }
2704}
2705
2706static void run_diff_cmd(const char *pgm,
2707                         const char *name,
2708                         const char *other,
2709                         const char *attr_path,
2710                         struct diff_filespec *one,
2711                         struct diff_filespec *two,
2712                         struct strbuf *msg,
2713                         struct diff_options *o,
2714                         struct diff_filepair *p)
2715{
2716        const char *xfrm_msg = NULL;
2717        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
2718        int must_show_header = 0;
2719
2720        if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
2721                pgm = NULL;
2722        else {
2723                struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
2724                if (drv && drv->external)
2725                        pgm = drv->external;
2726        }
2727
2728        if (msg) {
2729                /*
2730                 * don't use colors when the header is intended for an
2731                 * external diff driver
2732                 */
2733                fill_metainfo(msg, name, other, one, two, o, p,
2734                              &must_show_header,
2735                              DIFF_OPT_TST(o, COLOR_DIFF) && !pgm);
2736                xfrm_msg = msg->len ? msg->buf : NULL;
2737        }
2738
2739        if (pgm) {
2740                run_external_diff(pgm, name, other, one, two, xfrm_msg,
2741                                  complete_rewrite);
2742                return;
2743        }
2744        if (one && two)
2745                builtin_diff(name, other ? other : name,
2746                             one, two, xfrm_msg, must_show_header,
2747                             o, complete_rewrite);
2748        else
2749                fprintf(o->file, "* Unmerged path %s\n", name);
2750}
2751
2752static void diff_fill_sha1_info(struct diff_filespec *one)
2753{
2754        if (DIFF_FILE_VALID(one)) {
2755                if (!one->sha1_valid) {
2756                        struct stat st;
2757                        if (!strcmp(one->path, "-")) {
2758                                hashcpy(one->sha1, null_sha1);
2759                                return;
2760                        }
2761                        if (lstat(one->path, &st) < 0)
2762                                die_errno("stat '%s'", one->path);
2763                        if (index_path(one->sha1, one->path, &st, 0))
2764                                die("cannot hash %s", one->path);
2765                }
2766        }
2767        else
2768                hashclr(one->sha1);
2769}
2770
2771static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
2772{
2773        /* Strip the prefix but do not molest /dev/null and absolute paths */
2774        if (*namep && **namep != '/') {
2775                *namep += prefix_length;
2776                if (**namep == '/')
2777                        ++*namep;
2778        }
2779        if (*otherp && **otherp != '/') {
2780                *otherp += prefix_length;
2781                if (**otherp == '/')
2782                        ++*otherp;
2783        }
2784}
2785
2786static void run_diff(struct diff_filepair *p, struct diff_options *o)
2787{
2788        const char *pgm = external_diff();
2789        struct strbuf msg;
2790        struct diff_filespec *one = p->one;
2791        struct diff_filespec *two = p->two;
2792        const char *name;
2793        const char *other;
2794        const char *attr_path;
2795
2796        name  = p->one->path;
2797        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2798        attr_path = name;
2799        if (o->prefix_length)
2800                strip_prefix(o->prefix_length, &name, &other);
2801
2802        if (DIFF_PAIR_UNMERGED(p)) {
2803                run_diff_cmd(pgm, name, NULL, attr_path,
2804                             NULL, NULL, NULL, o, p);
2805                return;
2806        }
2807
2808        diff_fill_sha1_info(one);
2809        diff_fill_sha1_info(two);
2810
2811        if (!pgm &&
2812            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
2813            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
2814                /*
2815                 * a filepair that changes between file and symlink
2816                 * needs to be split into deletion and creation.
2817                 */
2818                struct diff_filespec *null = alloc_filespec(two->path);
2819                run_diff_cmd(NULL, name, other, attr_path,
2820                             one, null, &msg, o, p);
2821                free(null);
2822                strbuf_release(&msg);
2823
2824                null = alloc_filespec(one->path);
2825                run_diff_cmd(NULL, name, other, attr_path,
2826                             null, two, &msg, o, p);
2827                free(null);
2828        }
2829        else
2830                run_diff_cmd(pgm, name, other, attr_path,
2831                             one, two, &msg, o, p);
2832
2833        strbuf_release(&msg);
2834}
2835
2836static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
2837                         struct diffstat_t *diffstat)
2838{
2839        const char *name;
2840        const char *other;
2841        int complete_rewrite = 0;
2842
2843        if (DIFF_PAIR_UNMERGED(p)) {
2844                /* unmerged */
2845                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, 0);
2846                return;
2847        }
2848
2849        name = p->one->path;
2850        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2851
2852        if (o->prefix_length)
2853                strip_prefix(o->prefix_length, &name, &other);
2854
2855        diff_fill_sha1_info(p->one);
2856        diff_fill_sha1_info(p->two);
2857
2858        if (p->status == DIFF_STATUS_MODIFIED && p->score)
2859                complete_rewrite = 1;
2860        builtin_diffstat(name, other, p->one, p->two, diffstat, o, complete_rewrite);
2861}
2862
2863static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
2864{
2865        const char *name;
2866        const char *other;
2867        const char *attr_path;
2868
2869        if (DIFF_PAIR_UNMERGED(p)) {
2870                /* unmerged */
2871                return;
2872        }
2873
2874        name = p->one->path;
2875        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2876        attr_path = other ? other : name;
2877
2878        if (o->prefix_length)
2879                strip_prefix(o->prefix_length, &name, &other);
2880
2881        diff_fill_sha1_info(p->one);
2882        diff_fill_sha1_info(p->two);
2883
2884        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
2885}
2886
2887void diff_setup(struct diff_options *options)
2888{
2889        memcpy(options, &default_diff_options, sizeof(*options));
2890
2891        options->file = stdout;
2892
2893        options->line_termination = '\n';
2894        options->break_opt = -1;
2895        options->rename_limit = -1;
2896        options->dirstat_percent = 3;
2897        options->context = 3;
2898
2899        options->change = diff_change;
2900        options->add_remove = diff_addremove;
2901        if (diff_use_color_default > 0)
2902                DIFF_OPT_SET(options, COLOR_DIFF);
2903        options->detect_rename = diff_detect_rename_default;
2904
2905        if (diff_no_prefix) {
2906                options->a_prefix = options->b_prefix = "";
2907        } else if (!diff_mnemonic_prefix) {
2908                options->a_prefix = "a/";
2909                options->b_prefix = "b/";
2910        }
2911}
2912
2913int diff_setup_done(struct diff_options *options)
2914{
2915        int count = 0;
2916
2917        if (options->output_format & DIFF_FORMAT_NAME)
2918                count++;
2919        if (options->output_format & DIFF_FORMAT_NAME_STATUS)
2920                count++;
2921        if (options->output_format & DIFF_FORMAT_CHECKDIFF)
2922                count++;
2923        if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
2924                count++;
2925        if (count > 1)
2926                die("--name-only, --name-status, --check and -s are mutually exclusive");
2927
2928        /*
2929         * Most of the time we can say "there are changes"
2930         * only by checking if there are changed paths, but
2931         * --ignore-whitespace* options force us to look
2932         * inside contents.
2933         */
2934
2935        if (DIFF_XDL_TST(options, IGNORE_WHITESPACE) ||
2936            DIFF_XDL_TST(options, IGNORE_WHITESPACE_CHANGE) ||
2937            DIFF_XDL_TST(options, IGNORE_WHITESPACE_AT_EOL))
2938                DIFF_OPT_SET(options, DIFF_FROM_CONTENTS);
2939        else
2940                DIFF_OPT_CLR(options, DIFF_FROM_CONTENTS);
2941
2942        if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
2943                options->detect_rename = DIFF_DETECT_COPY;
2944
2945        if (!DIFF_OPT_TST(options, RELATIVE_NAME))
2946                options->prefix = NULL;
2947        if (options->prefix)
2948                options->prefix_length = strlen(options->prefix);
2949        else
2950                options->prefix_length = 0;
2951
2952        if (options->output_format & (DIFF_FORMAT_NAME |
2953                                      DIFF_FORMAT_NAME_STATUS |
2954                                      DIFF_FORMAT_CHECKDIFF |
2955                                      DIFF_FORMAT_NO_OUTPUT))
2956                options->output_format &= ~(DIFF_FORMAT_RAW |
2957                                            DIFF_FORMAT_NUMSTAT |
2958                                            DIFF_FORMAT_DIFFSTAT |
2959                                            DIFF_FORMAT_SHORTSTAT |
2960                                            DIFF_FORMAT_DIRSTAT |
2961                                            DIFF_FORMAT_SUMMARY |
2962                                            DIFF_FORMAT_PATCH);
2963
2964        /*
2965         * These cases always need recursive; we do not drop caller-supplied
2966         * recursive bits for other formats here.
2967         */
2968        if (options->output_format & (DIFF_FORMAT_PATCH |
2969                                      DIFF_FORMAT_NUMSTAT |
2970                                      DIFF_FORMAT_DIFFSTAT |
2971                                      DIFF_FORMAT_SHORTSTAT |
2972                                      DIFF_FORMAT_DIRSTAT |
2973                                      DIFF_FORMAT_SUMMARY |
2974                                      DIFF_FORMAT_CHECKDIFF))
2975                DIFF_OPT_SET(options, RECURSIVE);
2976        /*
2977         * Also pickaxe would not work very well if you do not say recursive
2978         */
2979        if (options->pickaxe)
2980                DIFF_OPT_SET(options, RECURSIVE);
2981        /*
2982         * When patches are generated, submodules diffed against the work tree
2983         * must be checked for dirtiness too so it can be shown in the output
2984         */
2985        if (options->output_format & DIFF_FORMAT_PATCH)
2986                DIFF_OPT_SET(options, DIRTY_SUBMODULES);
2987
2988        if (options->detect_rename && options->rename_limit < 0)
2989                options->rename_limit = diff_rename_limit_default;
2990        if (options->setup & DIFF_SETUP_USE_CACHE) {
2991                if (!active_cache)
2992                        /* read-cache does not die even when it fails
2993                         * so it is safe for us to do this here.  Also
2994                         * it does not smudge active_cache or active_nr
2995                         * when it fails, so we do not have to worry about
2996                         * cleaning it up ourselves either.
2997                         */
2998                        read_cache();
2999        }
3000        if (options->abbrev <= 0 || 40 < options->abbrev)
3001                options->abbrev = 40; /* full */
3002
3003        /*
3004         * It does not make sense to show the first hit we happened
3005         * to have found.  It does not make sense not to return with
3006         * exit code in such a case either.
3007         */
3008        if (DIFF_OPT_TST(options, QUICK)) {
3009                options->output_format = DIFF_FORMAT_NO_OUTPUT;
3010                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3011        }
3012
3013        return 0;
3014}
3015
3016static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
3017{
3018        char c, *eq;
3019        int len;
3020
3021        if (*arg != '-')
3022                return 0;
3023        c = *++arg;
3024        if (!c)
3025                return 0;
3026        if (c == arg_short) {
3027                c = *++arg;
3028                if (!c)
3029                        return 1;
3030                if (val && isdigit(c)) {
3031                        char *end;
3032                        int n = strtoul(arg, &end, 10);
3033                        if (*end)
3034                                return 0;
3035                        *val = n;
3036                        return 1;
3037                }
3038                return 0;
3039        }
3040        if (c != '-')
3041                return 0;
3042        arg++;
3043        eq = strchr(arg, '=');
3044        if (eq)
3045                len = eq - arg;
3046        else
3047                len = strlen(arg);
3048        if (!len || strncmp(arg, arg_long, len))
3049                return 0;
3050        if (eq) {
3051                int n;
3052                char *end;
3053                if (!isdigit(*++eq))
3054                        return 0;
3055                n = strtoul(eq, &end, 10);
3056                if (*end)
3057                        return 0;
3058                *val = n;
3059        }
3060        return 1;
3061}
3062
3063static int diff_scoreopt_parse(const char *opt);
3064
3065static inline int short_opt(char opt, const char **argv,
3066                            const char **optarg)
3067{
3068        const char *arg = argv[0];
3069        if (arg[0] != '-' || arg[1] != opt)
3070                return 0;
3071        if (arg[2] != '\0') {
3072                *optarg = arg + 2;
3073                return 1;
3074        }
3075        if (!argv[1])
3076                die("Option '%c' requires a value", opt);
3077        *optarg = argv[1];
3078        return 2;
3079}
3080
3081int parse_long_opt(const char *opt, const char **argv,
3082                   const char **optarg)
3083{
3084        const char *arg = argv[0];
3085        if (arg[0] != '-' || arg[1] != '-')
3086                return 0;
3087        arg += strlen("--");
3088        if (prefixcmp(arg, opt))
3089                return 0;
3090        arg += strlen(opt);
3091        if (*arg == '=') { /* sticked form: --option=value */
3092                *optarg = arg + 1;
3093                return 1;
3094        }
3095        if (*arg != '\0')
3096                return 0;
3097        /* separate form: --option value */
3098        if (!argv[1])
3099                die("Option '--%s' requires a value", opt);
3100        *optarg = argv[1];
3101        return 2;
3102}
3103
3104static int stat_opt(struct diff_options *options, const char **av)
3105{
3106        const char *arg = av[0];
3107        char *end;
3108        int width = options->stat_width;
3109        int name_width = options->stat_name_width;
3110        int argcount = 1;
3111
3112        arg += strlen("--stat");
3113        end = (char *)arg;
3114
3115        switch (*arg) {
3116        case '-':
3117                if (!prefixcmp(arg, "-width")) {
3118                        arg += strlen("-width");
3119                        if (*arg == '=')
3120                                width = strtoul(arg + 1, &end, 10);
3121                        else if (!*arg && !av[1])
3122                                die("Option '--stat-width' requires a value");
3123                        else if (!*arg) {
3124                                width = strtoul(av[1], &end, 10);
3125                                argcount = 2;
3126                        }
3127                } else if (!prefixcmp(arg, "-name-width")) {
3128                        arg += strlen("-name-width");
3129                        if (*arg == '=')
3130                                name_width = strtoul(arg + 1, &end, 10);
3131                        else if (!*arg && !av[1])
3132                                die("Option '--stat-name-width' requires a value");
3133                        else if (!*arg) {
3134                                name_width = strtoul(av[1], &end, 10);
3135                                argcount = 2;
3136                        }
3137                }
3138                break;
3139        case '=':
3140                width = strtoul(arg+1, &end, 10);
3141                if (*end == ',')
3142                        name_width = strtoul(end+1, &end, 10);
3143        }
3144
3145        /* Important! This checks all the error cases! */
3146        if (*end)
3147                return 0;
3148        options->output_format |= DIFF_FORMAT_DIFFSTAT;
3149        options->stat_name_width = name_width;
3150        options->stat_width = width;
3151        return argcount;
3152}
3153
3154int diff_opt_parse(struct diff_options *options, const char **av, int ac)
3155{
3156        const char *arg = av[0];
3157        const char *optarg;
3158        int argcount;
3159
3160        /* Output format options */
3161        if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch"))
3162                options->output_format |= DIFF_FORMAT_PATCH;
3163        else if (opt_arg(arg, 'U', "unified", &options->context))
3164                options->output_format |= DIFF_FORMAT_PATCH;
3165        else if (!strcmp(arg, "--raw"))
3166                options->output_format |= DIFF_FORMAT_RAW;
3167        else if (!strcmp(arg, "--patch-with-raw"))
3168                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_RAW;
3169        else if (!strcmp(arg, "--numstat"))
3170                options->output_format |= DIFF_FORMAT_NUMSTAT;
3171        else if (!strcmp(arg, "--shortstat"))
3172                options->output_format |= DIFF_FORMAT_SHORTSTAT;
3173        else if (opt_arg(arg, 'X', "dirstat", &options->dirstat_percent))
3174                options->output_format |= DIFF_FORMAT_DIRSTAT;
3175        else if (!strcmp(arg, "--cumulative")) {
3176                options->output_format |= DIFF_FORMAT_DIRSTAT;
3177                DIFF_OPT_SET(options, DIRSTAT_CUMULATIVE);
3178        } else if (opt_arg(arg, 0, "dirstat-by-file",
3179                           &options->dirstat_percent)) {
3180                options->output_format |= DIFF_FORMAT_DIRSTAT;
3181                DIFF_OPT_SET(options, DIRSTAT_BY_FILE);
3182        }
3183        else if (!strcmp(arg, "--check"))
3184                options->output_format |= DIFF_FORMAT_CHECKDIFF;
3185        else if (!strcmp(arg, "--summary"))
3186                options->output_format |= DIFF_FORMAT_SUMMARY;
3187        else if (!strcmp(arg, "--patch-with-stat"))
3188                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_DIFFSTAT;
3189        else if (!strcmp(arg, "--name-only"))
3190                options->output_format |= DIFF_FORMAT_NAME;
3191        else if (!strcmp(arg, "--name-status"))
3192                options->output_format |= DIFF_FORMAT_NAME_STATUS;
3193        else if (!strcmp(arg, "-s"))
3194                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
3195        else if (!prefixcmp(arg, "--stat"))
3196                /* --stat, --stat-width, or --stat-name-width */
3197                return stat_opt(options, av);
3198
3199        /* renames options */
3200        else if (!prefixcmp(arg, "-B") || !prefixcmp(arg, "--break-rewrites=") ||
3201                 !strcmp(arg, "--break-rewrites")) {
3202                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
3203                        return error("invalid argument to -B: %s", arg+2);
3204        }
3205        else if (!prefixcmp(arg, "-M") || !prefixcmp(arg, "--find-renames=") ||
3206                 !strcmp(arg, "--find-renames")) {
3207                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3208                        return error("invalid argument to -M: %s", arg+2);
3209                options->detect_rename = DIFF_DETECT_RENAME;
3210        }
3211        else if (!prefixcmp(arg, "-C") || !prefixcmp(arg, "--find-copies=") ||
3212                 !strcmp(arg, "--find-copies")) {
3213                if (options->detect_rename == DIFF_DETECT_COPY)
3214                        DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3215                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3216                        return error("invalid argument to -C: %s", arg+2);
3217                options->detect_rename = DIFF_DETECT_COPY;
3218        }
3219        else if (!strcmp(arg, "--no-renames"))
3220                options->detect_rename = 0;
3221        else if (!strcmp(arg, "--relative"))
3222                DIFF_OPT_SET(options, RELATIVE_NAME);
3223        else if (!prefixcmp(arg, "--relative=")) {
3224                DIFF_OPT_SET(options, RELATIVE_NAME);
3225                options->prefix = arg + 11;
3226        }
3227
3228        /* xdiff options */
3229        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
3230                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
3231        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
3232                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
3233        else if (!strcmp(arg, "--ignore-space-at-eol"))
3234                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
3235        else if (!strcmp(arg, "--patience"))
3236                DIFF_XDL_SET(options, PATIENCE_DIFF);
3237
3238        /* flags options */
3239        else if (!strcmp(arg, "--binary")) {
3240                options->output_format |= DIFF_FORMAT_PATCH;
3241                DIFF_OPT_SET(options, BINARY);
3242        }
3243        else if (!strcmp(arg, "--full-index"))
3244                DIFF_OPT_SET(options, FULL_INDEX);
3245        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
3246                DIFF_OPT_SET(options, TEXT);
3247        else if (!strcmp(arg, "-R"))
3248                DIFF_OPT_SET(options, REVERSE_DIFF);
3249        else if (!strcmp(arg, "--find-copies-harder"))
3250                DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3251        else if (!strcmp(arg, "--follow"))
3252                DIFF_OPT_SET(options, FOLLOW_RENAMES);
3253        else if (!strcmp(arg, "--color"))
3254                DIFF_OPT_SET(options, COLOR_DIFF);
3255        else if (!prefixcmp(arg, "--color=")) {
3256                int value = git_config_colorbool(NULL, arg+8, -1);
3257                if (value == 0)
3258                        DIFF_OPT_CLR(options, COLOR_DIFF);
3259                else if (value > 0)
3260                        DIFF_OPT_SET(options, COLOR_DIFF);
3261                else
3262                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
3263        }
3264        else if (!strcmp(arg, "--no-color"))
3265                DIFF_OPT_CLR(options, COLOR_DIFF);
3266        else if (!strcmp(arg, "--color-words")) {
3267                DIFF_OPT_SET(options, COLOR_DIFF);
3268                options->word_diff = DIFF_WORDS_COLOR;
3269        }
3270        else if (!prefixcmp(arg, "--color-words=")) {
3271                DIFF_OPT_SET(options, COLOR_DIFF);
3272                options->word_diff = DIFF_WORDS_COLOR;
3273                options->word_regex = arg + 14;
3274        }
3275        else if (!strcmp(arg, "--word-diff")) {
3276                if (options->word_diff == DIFF_WORDS_NONE)
3277                        options->word_diff = DIFF_WORDS_PLAIN;
3278        }
3279        else if (!prefixcmp(arg, "--word-diff=")) {
3280                const char *type = arg + 12;
3281                if (!strcmp(type, "plain"))
3282                        options->word_diff = DIFF_WORDS_PLAIN;
3283                else if (!strcmp(type, "color")) {
3284                        DIFF_OPT_SET(options, COLOR_DIFF);
3285                        options->word_diff = DIFF_WORDS_COLOR;
3286                }
3287                else if (!strcmp(type, "porcelain"))
3288                        options->word_diff = DIFF_WORDS_PORCELAIN;
3289                else if (!strcmp(type, "none"))
3290                        options->word_diff = DIFF_WORDS_NONE;
3291                else
3292                        die("bad --word-diff argument: %s", type);
3293        }
3294        else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
3295                if (options->word_diff == DIFF_WORDS_NONE)
3296                        options->word_diff = DIFF_WORDS_PLAIN;
3297                options->word_regex = optarg;
3298                return argcount;
3299        }
3300        else if (!strcmp(arg, "--exit-code"))
3301                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3302        else if (!strcmp(arg, "--quiet"))
3303                DIFF_OPT_SET(options, QUICK);
3304        else if (!strcmp(arg, "--ext-diff"))
3305                DIFF_OPT_SET(options, ALLOW_EXTERNAL);
3306        else if (!strcmp(arg, "--no-ext-diff"))
3307                DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
3308        else if (!strcmp(arg, "--textconv"))
3309                DIFF_OPT_SET(options, ALLOW_TEXTCONV);
3310        else if (!strcmp(arg, "--no-textconv"))
3311                DIFF_OPT_CLR(options, ALLOW_TEXTCONV);
3312        else if (!strcmp(arg, "--ignore-submodules")) {
3313                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3314                handle_ignore_submodules_arg(options, "all");
3315        } else if (!prefixcmp(arg, "--ignore-submodules=")) {
3316                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3317                handle_ignore_submodules_arg(options, arg + 20);
3318        } else if (!strcmp(arg, "--submodule"))
3319                DIFF_OPT_SET(options, SUBMODULE_LOG);
3320        else if (!prefixcmp(arg, "--submodule=")) {
3321                if (!strcmp(arg + 12, "log"))
3322                        DIFF_OPT_SET(options, SUBMODULE_LOG);
3323        }
3324
3325        /* misc options */
3326        else if (!strcmp(arg, "-z"))
3327                options->line_termination = 0;
3328        else if ((argcount = short_opt('l', av, &optarg))) {
3329                options->rename_limit = strtoul(optarg, NULL, 10);
3330                return argcount;
3331        }
3332        else if ((argcount = short_opt('S', av, &optarg))) {
3333                options->pickaxe = optarg;
3334                options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
3335                return argcount;
3336        } else if ((argcount = short_opt('G', av, &optarg))) {
3337                options->pickaxe = optarg;
3338                options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
3339                return argcount;
3340        }
3341        else if (!strcmp(arg, "--pickaxe-all"))
3342                options->pickaxe_opts |= DIFF_PICKAXE_ALL;
3343        else if (!strcmp(arg, "--pickaxe-regex"))
3344                options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
3345        else if ((argcount = short_opt('O', av, &optarg))) {
3346                options->orderfile = optarg;
3347                return argcount;
3348        }
3349        else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
3350                options->filter = optarg;
3351                return argcount;
3352        }
3353        else if (!strcmp(arg, "--abbrev"))
3354                options->abbrev = DEFAULT_ABBREV;
3355        else if (!prefixcmp(arg, "--abbrev=")) {
3356                options->abbrev = strtoul(arg + 9, NULL, 10);
3357                if (options->abbrev < MINIMUM_ABBREV)
3358                        options->abbrev = MINIMUM_ABBREV;
3359                else if (40 < options->abbrev)
3360                        options->abbrev = 40;
3361        }
3362        else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
3363                options->a_prefix = optarg;
3364                return argcount;
3365        }
3366        else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
3367                options->b_prefix = optarg;
3368                return argcount;
3369        }
3370        else if (!strcmp(arg, "--no-prefix"))
3371                options->a_prefix = options->b_prefix = "";
3372        else if (opt_arg(arg, '\0', "inter-hunk-context",
3373                         &options->interhunkcontext))
3374                ;
3375        else if ((argcount = parse_long_opt("output", av, &optarg))) {
3376                options->file = fopen(optarg, "w");
3377                if (!options->file)
3378                        die_errno("Could not open '%s'", optarg);
3379                options->close_file = 1;
3380                return argcount;
3381        } else
3382                return 0;
3383        return 1;
3384}
3385
3386int parse_rename_score(const char **cp_p)
3387{
3388        unsigned long num, scale;
3389        int ch, dot;
3390        const char *cp = *cp_p;
3391
3392        num = 0;
3393        scale = 1;
3394        dot = 0;
3395        for (;;) {
3396                ch = *cp;
3397                if ( !dot && ch == '.' ) {
3398                        scale = 1;
3399                        dot = 1;
3400                } else if ( ch == '%' ) {
3401                        scale = dot ? scale*100 : 100;
3402                        cp++;   /* % is always at the end */
3403                        break;
3404                } else if ( ch >= '0' && ch <= '9' ) {
3405                        if ( scale < 100000 ) {
3406                                scale *= 10;
3407                                num = (num*10) + (ch-'0');
3408                        }
3409                } else {
3410                        break;
3411                }
3412                cp++;
3413        }
3414        *cp_p = cp;
3415
3416        /* user says num divided by scale and we say internally that
3417         * is MAX_SCORE * num / scale.
3418         */
3419        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
3420}
3421
3422static int diff_scoreopt_parse(const char *opt)
3423{
3424        int opt1, opt2, cmd;
3425
3426        if (*opt++ != '-')
3427                return -1;
3428        cmd = *opt++;
3429        if (cmd == '-') {
3430                /* convert the long-form arguments into short-form versions */
3431                if (!prefixcmp(opt, "break-rewrites")) {
3432                        opt += strlen("break-rewrites");
3433                        if (*opt == 0 || *opt++ == '=')
3434                                cmd = 'B';
3435                } else if (!prefixcmp(opt, "find-copies")) {
3436                        opt += strlen("find-copies");
3437                        if (*opt == 0 || *opt++ == '=')
3438                                cmd = 'C';
3439                } else if (!prefixcmp(opt, "find-renames")) {
3440                        opt += strlen("find-renames");
3441                        if (*opt == 0 || *opt++ == '=')
3442                                cmd = 'M';
3443                }
3444        }
3445        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
3446                return -1; /* that is not a -M, -C nor -B option */
3447
3448        opt1 = parse_rename_score(&opt);
3449        if (cmd != 'B')
3450                opt2 = 0;
3451        else {
3452                if (*opt == 0)
3453                        opt2 = 0;
3454                else if (*opt != '/')
3455                        return -1; /* we expect -B80/99 or -B80 */
3456                else {
3457                        opt++;
3458                        opt2 = parse_rename_score(&opt);
3459                }
3460        }
3461        if (*opt != 0)
3462                return -1;
3463        return opt1 | (opt2 << 16);
3464}
3465
3466struct diff_queue_struct diff_queued_diff;
3467
3468void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
3469{
3470        if (queue->alloc <= queue->nr) {
3471                queue->alloc = alloc_nr(queue->alloc);
3472                queue->queue = xrealloc(queue->queue,
3473                                        sizeof(dp) * queue->alloc);
3474        }
3475        queue->queue[queue->nr++] = dp;
3476}
3477
3478struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
3479                                 struct diff_filespec *one,
3480                                 struct diff_filespec *two)
3481{
3482        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
3483        dp->one = one;
3484        dp->two = two;
3485        if (queue)
3486                diff_q(queue, dp);
3487        return dp;
3488}
3489
3490void diff_free_filepair(struct diff_filepair *p)
3491{
3492        free_filespec(p->one);
3493        free_filespec(p->two);
3494        free(p);
3495}
3496
3497/* This is different from find_unique_abbrev() in that
3498 * it stuffs the result with dots for alignment.
3499 */
3500const char *diff_unique_abbrev(const unsigned char *sha1, int len)
3501{
3502        int abblen;
3503        const char *abbrev;
3504        if (len == 40)
3505                return sha1_to_hex(sha1);
3506
3507        abbrev = find_unique_abbrev(sha1, len);
3508        abblen = strlen(abbrev);
3509        if (abblen < 37) {
3510                static char hex[41];
3511                if (len < abblen && abblen <= len + 2)
3512                        sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
3513                else
3514                        sprintf(hex, "%s...", abbrev);
3515                return hex;
3516        }
3517        return sha1_to_hex(sha1);
3518}
3519
3520static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
3521{
3522        int line_termination = opt->line_termination;
3523        int inter_name_termination = line_termination ? '\t' : '\0';
3524        if (opt->output_prefix) {
3525                struct strbuf *msg = NULL;
3526                msg = opt->output_prefix(opt, opt->output_prefix_data);
3527                fprintf(opt->file, "%s", msg->buf);
3528        }
3529
3530        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
3531                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
3532                        diff_unique_abbrev(p->one->sha1, opt->abbrev));
3533                fprintf(opt->file, "%s ", diff_unique_abbrev(p->two->sha1, opt->abbrev));
3534        }
3535        if (p->score) {
3536                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
3537                        inter_name_termination);
3538        } else {
3539                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
3540        }
3541
3542        if (p->status == DIFF_STATUS_COPIED ||
3543            p->status == DIFF_STATUS_RENAMED) {
3544                const char *name_a, *name_b;
3545                name_a = p->one->path;
3546                name_b = p->two->path;
3547                strip_prefix(opt->prefix_length, &name_a, &name_b);
3548                write_name_quoted(name_a, opt->file, inter_name_termination);
3549                write_name_quoted(name_b, opt->file, line_termination);
3550        } else {
3551                const char *name_a, *name_b;
3552                name_a = p->one->mode ? p->one->path : p->two->path;
3553                name_b = NULL;
3554                strip_prefix(opt->prefix_length, &name_a, &name_b);
3555                write_name_quoted(name_a, opt->file, line_termination);
3556        }
3557}
3558
3559int diff_unmodified_pair(struct diff_filepair *p)
3560{
3561        /* This function is written stricter than necessary to support
3562         * the currently implemented transformers, but the idea is to
3563         * let transformers to produce diff_filepairs any way they want,
3564         * and filter and clean them up here before producing the output.
3565         */
3566        struct diff_filespec *one = p->one, *two = p->two;
3567
3568        if (DIFF_PAIR_UNMERGED(p))
3569                return 0; /* unmerged is interesting */
3570
3571        /* deletion, addition, mode or type change
3572         * and rename are all interesting.
3573         */
3574        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
3575            DIFF_PAIR_MODE_CHANGED(p) ||
3576            strcmp(one->path, two->path))
3577                return 0;
3578
3579        /* both are valid and point at the same path.  that is, we are
3580         * dealing with a change.
3581         */
3582        if (one->sha1_valid && two->sha1_valid &&
3583            !hashcmp(one->sha1, two->sha1) &&
3584            !one->dirty_submodule && !two->dirty_submodule)
3585                return 1; /* no change */
3586        if (!one->sha1_valid && !two->sha1_valid)
3587                return 1; /* both look at the same file on the filesystem. */
3588        return 0;
3589}
3590
3591static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
3592{
3593        if (diff_unmodified_pair(p))
3594                return;
3595
3596        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3597            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3598                return; /* no tree diffs in patch format */
3599
3600        run_diff(p, o);
3601}
3602
3603static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
3604                            struct diffstat_t *diffstat)
3605{
3606        if (diff_unmodified_pair(p))
3607                return;
3608
3609        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3610            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3611                return; /* no useful stat for tree diffs */
3612
3613        run_diffstat(p, o, diffstat);
3614}
3615
3616static void diff_flush_checkdiff(struct diff_filepair *p,
3617                struct diff_options *o)
3618{
3619        if (diff_unmodified_pair(p))
3620                return;
3621
3622        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3623            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3624                return; /* nothing to check in tree diffs */
3625
3626        run_checkdiff(p, o);
3627}
3628
3629int diff_queue_is_empty(void)
3630{
3631        struct diff_queue_struct *q = &diff_queued_diff;
3632        int i;
3633        for (i = 0; i < q->nr; i++)
3634                if (!diff_unmodified_pair(q->queue[i]))
3635                        return 0;
3636        return 1;
3637}
3638
3639#if DIFF_DEBUG
3640void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
3641{
3642        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
3643                x, one ? one : "",
3644                s->path,
3645                DIFF_FILE_VALID(s) ? "valid" : "invalid",
3646                s->mode,
3647                s->sha1_valid ? sha1_to_hex(s->sha1) : "");
3648        fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
3649                x, one ? one : "",
3650                s->size, s->xfrm_flags);
3651}
3652
3653void diff_debug_filepair(const struct diff_filepair *p, int i)
3654{
3655        diff_debug_filespec(p->one, i, "one");
3656        diff_debug_filespec(p->two, i, "two");
3657        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
3658                p->score, p->status ? p->status : '?',
3659                p->one->rename_used, p->broken_pair);
3660}
3661
3662void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
3663{
3664        int i;
3665        if (msg)
3666                fprintf(stderr, "%s\n", msg);
3667        fprintf(stderr, "q->nr = %d\n", q->nr);
3668        for (i = 0; i < q->nr; i++) {
3669                struct diff_filepair *p = q->queue[i];
3670                diff_debug_filepair(p, i);
3671        }
3672}
3673#endif
3674
3675static void diff_resolve_rename_copy(void)
3676{
3677        int i;
3678        struct diff_filepair *p;
3679        struct diff_queue_struct *q = &diff_queued_diff;
3680
3681        diff_debug_queue("resolve-rename-copy", q);
3682
3683        for (i = 0; i < q->nr; i++) {
3684                p = q->queue[i];
3685                p->status = 0; /* undecided */
3686                if (DIFF_PAIR_UNMERGED(p))
3687                        p->status = DIFF_STATUS_UNMERGED;
3688                else if (!DIFF_FILE_VALID(p->one))
3689                        p->status = DIFF_STATUS_ADDED;
3690                else if (!DIFF_FILE_VALID(p->two))
3691                        p->status = DIFF_STATUS_DELETED;
3692                else if (DIFF_PAIR_TYPE_CHANGED(p))
3693                        p->status = DIFF_STATUS_TYPE_CHANGED;
3694
3695                /* from this point on, we are dealing with a pair
3696                 * whose both sides are valid and of the same type, i.e.
3697                 * either in-place edit or rename/copy edit.
3698                 */
3699                else if (DIFF_PAIR_RENAME(p)) {
3700                        /*
3701                         * A rename might have re-connected a broken
3702                         * pair up, causing the pathnames to be the
3703                         * same again. If so, that's not a rename at
3704                         * all, just a modification..
3705                         *
3706                         * Otherwise, see if this source was used for
3707                         * multiple renames, in which case we decrement
3708                         * the count, and call it a copy.
3709                         */
3710                        if (!strcmp(p->one->path, p->two->path))
3711                                p->status = DIFF_STATUS_MODIFIED;
3712                        else if (--p->one->rename_used > 0)
3713                                p->status = DIFF_STATUS_COPIED;
3714                        else
3715                                p->status = DIFF_STATUS_RENAMED;
3716                }
3717                else if (hashcmp(p->one->sha1, p->two->sha1) ||
3718                         p->one->mode != p->two->mode ||
3719                         p->one->dirty_submodule ||
3720                         p->two->dirty_submodule ||
3721                         is_null_sha1(p->one->sha1))
3722                        p->status = DIFF_STATUS_MODIFIED;
3723                else {
3724                        /* This is a "no-change" entry and should not
3725                         * happen anymore, but prepare for broken callers.
3726                         */
3727                        error("feeding unmodified %s to diffcore",
3728                              p->one->path);
3729                        p->status = DIFF_STATUS_UNKNOWN;
3730                }
3731        }
3732        diff_debug_queue("resolve-rename-copy done", q);
3733}
3734
3735static int check_pair_status(struct diff_filepair *p)
3736{
3737        switch (p->status) {
3738        case DIFF_STATUS_UNKNOWN:
3739                return 0;
3740        case 0:
3741                die("internal error in diff-resolve-rename-copy");
3742        default:
3743                return 1;
3744        }
3745}
3746
3747static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
3748{
3749        int fmt = opt->output_format;
3750
3751        if (fmt & DIFF_FORMAT_CHECKDIFF)
3752                diff_flush_checkdiff(p, opt);
3753        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
3754                diff_flush_raw(p, opt);
3755        else if (fmt & DIFF_FORMAT_NAME) {
3756                const char *name_a, *name_b;
3757                name_a = p->two->path;
3758                name_b = NULL;
3759                strip_prefix(opt->prefix_length, &name_a, &name_b);
3760                write_name_quoted(name_a, opt->file, opt->line_termination);
3761        }
3762}
3763
3764static void show_file_mode_name(FILE *file, const char *newdelete, struct diff_filespec *fs)
3765{
3766        if (fs->mode)
3767                fprintf(file, " %s mode %06o ", newdelete, fs->mode);
3768        else
3769                fprintf(file, " %s ", newdelete);
3770        write_name_quoted(fs->path, file, '\n');
3771}
3772
3773
3774static void show_mode_change(FILE *file, struct diff_filepair *p, int show_name,
3775                const char *line_prefix)
3776{
3777        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
3778                fprintf(file, "%s mode change %06o => %06o%c", line_prefix, p->one->mode,
3779                        p->two->mode, show_name ? ' ' : '\n');
3780                if (show_name) {
3781                        write_name_quoted(p->two->path, file, '\n');
3782                }
3783        }
3784}
3785
3786static void show_rename_copy(FILE *file, const char *renamecopy, struct diff_filepair *p,
3787                        const char *line_prefix)
3788{
3789        char *names = pprint_rename(p->one->path, p->two->path);
3790
3791        fprintf(file, " %s %s (%d%%)\n", renamecopy, names, similarity_index(p));
3792        free(names);
3793        show_mode_change(file, p, 0, line_prefix);
3794}
3795
3796static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
3797{
3798        FILE *file = opt->file;
3799        char *line_prefix = "";
3800
3801        if (opt->output_prefix) {
3802                struct strbuf *buf = opt->output_prefix(opt, opt->output_prefix_data);
3803                line_prefix = buf->buf;
3804        }
3805
3806        switch(p->status) {
3807        case DIFF_STATUS_DELETED:
3808                fputs(line_prefix, file);
3809                show_file_mode_name(file, "delete", p->one);
3810                break;
3811        case DIFF_STATUS_ADDED:
3812                fputs(line_prefix, file);
3813                show_file_mode_name(file, "create", p->two);
3814                break;
3815        case DIFF_STATUS_COPIED:
3816                fputs(line_prefix, file);
3817                show_rename_copy(file, "copy", p, line_prefix);
3818                break;
3819        case DIFF_STATUS_RENAMED:
3820                fputs(line_prefix, file);
3821                show_rename_copy(file, "rename", p, line_prefix);
3822                break;
3823        default:
3824                if (p->score) {
3825                        fprintf(file, "%s rewrite ", line_prefix);
3826                        write_name_quoted(p->two->path, file, ' ');
3827                        fprintf(file, "(%d%%)\n", similarity_index(p));
3828                }
3829                show_mode_change(file, p, !p->score, line_prefix);
3830                break;
3831        }
3832}
3833
3834struct patch_id_t {
3835        git_SHA_CTX *ctx;
3836        int patchlen;
3837};
3838
3839static int remove_space(char *line, int len)
3840{
3841        int i;
3842        char *dst = line;
3843        unsigned char c;
3844
3845        for (i = 0; i < len; i++)
3846                if (!isspace((c = line[i])))
3847                        *dst++ = c;
3848
3849        return dst - line;
3850}
3851
3852static void patch_id_consume(void *priv, char *line, unsigned long len)
3853{
3854        struct patch_id_t *data = priv;
3855        int new_len;
3856
3857        /* Ignore line numbers when computing the SHA1 of the patch */
3858        if (!prefixcmp(line, "@@ -"))
3859                return;
3860
3861        new_len = remove_space(line, len);
3862
3863        git_SHA1_Update(data->ctx, line, new_len);
3864        data->patchlen += new_len;
3865}
3866
3867/* returns 0 upon success, and writes result into sha1 */
3868static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
3869{
3870        struct diff_queue_struct *q = &diff_queued_diff;
3871        int i;
3872        git_SHA_CTX ctx;
3873        struct patch_id_t data;
3874        char buffer[PATH_MAX * 4 + 20];
3875
3876        git_SHA1_Init(&ctx);
3877        memset(&data, 0, sizeof(struct patch_id_t));
3878        data.ctx = &ctx;
3879
3880        for (i = 0; i < q->nr; i++) {
3881                xpparam_t xpp;
3882                xdemitconf_t xecfg;
3883                mmfile_t mf1, mf2;
3884                struct diff_filepair *p = q->queue[i];
3885                int len1, len2;
3886
3887                memset(&xpp, 0, sizeof(xpp));
3888                memset(&xecfg, 0, sizeof(xecfg));
3889                if (p->status == 0)
3890                        return error("internal diff status error");
3891                if (p->status == DIFF_STATUS_UNKNOWN)
3892                        continue;
3893                if (diff_unmodified_pair(p))
3894                        continue;
3895                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3896                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3897                        continue;
3898                if (DIFF_PAIR_UNMERGED(p))
3899                        continue;
3900
3901                diff_fill_sha1_info(p->one);
3902                diff_fill_sha1_info(p->two);
3903                if (fill_mmfile(&mf1, p->one) < 0 ||
3904                                fill_mmfile(&mf2, p->two) < 0)
3905                        return error("unable to read files to diff");
3906
3907                len1 = remove_space(p->one->path, strlen(p->one->path));
3908                len2 = remove_space(p->two->path, strlen(p->two->path));
3909                if (p->one->mode == 0)
3910                        len1 = snprintf(buffer, sizeof(buffer),
3911                                        "diff--gita/%.*sb/%.*s"
3912                                        "newfilemode%06o"
3913                                        "---/dev/null"
3914                                        "+++b/%.*s",
3915                                        len1, p->one->path,
3916                                        len2, p->two->path,
3917                                        p->two->mode,
3918                                        len2, p->two->path);
3919                else if (p->two->mode == 0)
3920                        len1 = snprintf(buffer, sizeof(buffer),
3921                                        "diff--gita/%.*sb/%.*s"
3922                                        "deletedfilemode%06o"
3923                                        "---a/%.*s"
3924                                        "+++/dev/null",
3925                                        len1, p->one->path,
3926                                        len2, p->two->path,
3927                                        p->one->mode,
3928                                        len1, p->one->path);
3929                else
3930                        len1 = snprintf(buffer, sizeof(buffer),
3931                                        "diff--gita/%.*sb/%.*s"
3932                                        "---a/%.*s"
3933                                        "+++b/%.*s",
3934                                        len1, p->one->path,
3935                                        len2, p->two->path,
3936                                        len1, p->one->path,
3937                                        len2, p->two->path);
3938                git_SHA1_Update(&ctx, buffer, len1);
3939
3940                if (diff_filespec_is_binary(p->one) ||
3941                    diff_filespec_is_binary(p->two)) {
3942                        git_SHA1_Update(&ctx, sha1_to_hex(p->one->sha1), 40);
3943                        git_SHA1_Update(&ctx, sha1_to_hex(p->two->sha1), 40);
3944                        continue;
3945                }
3946
3947                xpp.flags = 0;
3948                xecfg.ctxlen = 3;
3949                xecfg.flags = 0;
3950                xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
3951                              &xpp, &xecfg);
3952        }
3953
3954        git_SHA1_Final(sha1, &ctx);
3955        return 0;
3956}
3957
3958int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1)
3959{
3960        struct diff_queue_struct *q = &diff_queued_diff;
3961        int i;
3962        int result = diff_get_patch_id(options, sha1);
3963
3964        for (i = 0; i < q->nr; i++)
3965                diff_free_filepair(q->queue[i]);
3966
3967        free(q->queue);
3968        DIFF_QUEUE_CLEAR(q);
3969
3970        return result;
3971}
3972
3973static int is_summary_empty(const struct diff_queue_struct *q)
3974{
3975        int i;
3976
3977        for (i = 0; i < q->nr; i++) {
3978                const struct diff_filepair *p = q->queue[i];
3979
3980                switch (p->status) {
3981                case DIFF_STATUS_DELETED:
3982                case DIFF_STATUS_ADDED:
3983                case DIFF_STATUS_COPIED:
3984                case DIFF_STATUS_RENAMED:
3985                        return 0;
3986                default:
3987                        if (p->score)
3988                                return 0;
3989                        if (p->one->mode && p->two->mode &&
3990                            p->one->mode != p->two->mode)
3991                                return 0;
3992                        break;
3993                }
3994        }
3995        return 1;
3996}
3997
3998static const char rename_limit_warning[] =
3999"inexact rename detection was skipped due to too many files.";
4000
4001static const char degrade_cc_to_c_warning[] =
4002"only found copies from modified paths due to too many files.";
4003
4004static const char rename_limit_advice[] =
4005"you may want to set your %s variable to at least "
4006"%d and retry the command.";
4007
4008void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc)
4009{
4010        if (degraded_cc)
4011                warning(degrade_cc_to_c_warning);
4012        else if (needed)
4013                warning(rename_limit_warning);
4014        else
4015                return;
4016        if (0 < needed && needed < 32767)
4017                warning(rename_limit_advice, varname, needed);
4018}
4019
4020void diff_flush(struct diff_options *options)
4021{
4022        struct diff_queue_struct *q = &diff_queued_diff;
4023        int i, output_format = options->output_format;
4024        int separator = 0;
4025
4026        /*
4027         * Order: raw, stat, summary, patch
4028         * or:    name/name-status/checkdiff (other bits clear)
4029         */
4030        if (!q->nr)
4031                goto free_queue;
4032
4033        if (output_format & (DIFF_FORMAT_RAW |
4034                             DIFF_FORMAT_NAME |
4035                             DIFF_FORMAT_NAME_STATUS |
4036                             DIFF_FORMAT_CHECKDIFF)) {
4037                for (i = 0; i < q->nr; i++) {
4038                        struct diff_filepair *p = q->queue[i];
4039                        if (check_pair_status(p))
4040                                flush_one_pair(p, options);
4041                }
4042                separator++;
4043        }
4044
4045        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT)) {
4046                struct diffstat_t diffstat;
4047
4048                memset(&diffstat, 0, sizeof(struct diffstat_t));
4049                for (i = 0; i < q->nr; i++) {
4050                        struct diff_filepair *p = q->queue[i];
4051                        if (check_pair_status(p))
4052                                diff_flush_stat(p, options, &diffstat);
4053                }
4054                if (output_format & DIFF_FORMAT_NUMSTAT)
4055                        show_numstat(&diffstat, options);
4056                if (output_format & DIFF_FORMAT_DIFFSTAT)
4057                        show_stats(&diffstat, options);
4058                if (output_format & DIFF_FORMAT_SHORTSTAT)
4059                        show_shortstats(&diffstat, options);
4060                free_diffstat_info(&diffstat);
4061                separator++;
4062        }
4063        if (output_format & DIFF_FORMAT_DIRSTAT)
4064                show_dirstat(options);
4065
4066        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
4067                for (i = 0; i < q->nr; i++) {
4068                        diff_summary(options, q->queue[i]);
4069                }
4070                separator++;
4071        }
4072
4073        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
4074            DIFF_OPT_TST(options, EXIT_WITH_STATUS) &&
4075            DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4076                /*
4077                 * run diff_flush_patch for the exit status. setting
4078                 * options->file to /dev/null should be safe, becaue we
4079                 * aren't supposed to produce any output anyway.
4080                 */
4081                if (options->close_file)
4082                        fclose(options->file);
4083                options->file = fopen("/dev/null", "w");
4084                if (!options->file)
4085                        die_errno("Could not open /dev/null");
4086                options->close_file = 1;
4087                for (i = 0; i < q->nr; i++) {
4088                        struct diff_filepair *p = q->queue[i];
4089                        if (check_pair_status(p))
4090                                diff_flush_patch(p, options);
4091                        if (options->found_changes)
4092                                break;
4093                }
4094        }
4095
4096        if (output_format & DIFF_FORMAT_PATCH) {
4097                if (separator) {
4098                        putc(options->line_termination, options->file);
4099                        if (options->stat_sep) {
4100                                /* attach patch instead of inline */
4101                                fputs(options->stat_sep, options->file);
4102                        }
4103                }
4104
4105                for (i = 0; i < q->nr; i++) {
4106                        struct diff_filepair *p = q->queue[i];
4107                        if (check_pair_status(p))
4108                                diff_flush_patch(p, options);
4109                }
4110        }
4111
4112        if (output_format & DIFF_FORMAT_CALLBACK)
4113                options->format_callback(q, options, options->format_callback_data);
4114
4115        for (i = 0; i < q->nr; i++)
4116                diff_free_filepair(q->queue[i]);
4117free_queue:
4118        free(q->queue);
4119        DIFF_QUEUE_CLEAR(q);
4120        if (options->close_file)
4121                fclose(options->file);
4122
4123        /*
4124         * Report the content-level differences with HAS_CHANGES;
4125         * diff_addremove/diff_change does not set the bit when
4126         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
4127         */
4128        if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4129                if (options->found_changes)
4130                        DIFF_OPT_SET(options, HAS_CHANGES);
4131                else
4132                        DIFF_OPT_CLR(options, HAS_CHANGES);
4133        }
4134}
4135
4136static void diffcore_apply_filter(const char *filter)
4137{
4138        int i;
4139        struct diff_queue_struct *q = &diff_queued_diff;
4140        struct diff_queue_struct outq;
4141        DIFF_QUEUE_CLEAR(&outq);
4142
4143        if (!filter)
4144                return;
4145
4146        if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
4147                int found;
4148                for (i = found = 0; !found && i < q->nr; i++) {
4149                        struct diff_filepair *p = q->queue[i];
4150                        if (((p->status == DIFF_STATUS_MODIFIED) &&
4151                             ((p->score &&
4152                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
4153                              (!p->score &&
4154                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
4155                            ((p->status != DIFF_STATUS_MODIFIED) &&
4156                             strchr(filter, p->status)))
4157                                found++;
4158                }
4159                if (found)
4160                        return;
4161
4162                /* otherwise we will clear the whole queue
4163                 * by copying the empty outq at the end of this
4164                 * function, but first clear the current entries
4165                 * in the queue.
4166                 */
4167                for (i = 0; i < q->nr; i++)
4168                        diff_free_filepair(q->queue[i]);
4169        }
4170        else {
4171                /* Only the matching ones */
4172                for (i = 0; i < q->nr; i++) {
4173                        struct diff_filepair *p = q->queue[i];
4174
4175                        if (((p->status == DIFF_STATUS_MODIFIED) &&
4176                             ((p->score &&
4177                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
4178                              (!p->score &&
4179                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
4180                            ((p->status != DIFF_STATUS_MODIFIED) &&
4181                             strchr(filter, p->status)))
4182                                diff_q(&outq, p);
4183                        else
4184                                diff_free_filepair(p);
4185                }
4186        }
4187        free(q->queue);
4188        *q = outq;
4189}
4190
4191/* Check whether two filespecs with the same mode and size are identical */
4192static int diff_filespec_is_identical(struct diff_filespec *one,
4193                                      struct diff_filespec *two)
4194{
4195        if (S_ISGITLINK(one->mode))
4196                return 0;
4197        if (diff_populate_filespec(one, 0))
4198                return 0;
4199        if (diff_populate_filespec(two, 0))
4200                return 0;
4201        return !memcmp(one->data, two->data, one->size);
4202}
4203
4204static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
4205{
4206        int i;
4207        struct diff_queue_struct *q = &diff_queued_diff;
4208        struct diff_queue_struct outq;
4209        DIFF_QUEUE_CLEAR(&outq);
4210
4211        for (i = 0; i < q->nr; i++) {
4212                struct diff_filepair *p = q->queue[i];
4213
4214                /*
4215                 * 1. Entries that come from stat info dirtiness
4216                 *    always have both sides (iow, not create/delete),
4217                 *    one side of the object name is unknown, with
4218                 *    the same mode and size.  Keep the ones that
4219                 *    do not match these criteria.  They have real
4220                 *    differences.
4221                 *
4222                 * 2. At this point, the file is known to be modified,
4223                 *    with the same mode and size, and the object
4224                 *    name of one side is unknown.  Need to inspect
4225                 *    the identical contents.
4226                 */
4227                if (!DIFF_FILE_VALID(p->one) || /* (1) */
4228                    !DIFF_FILE_VALID(p->two) ||
4229                    (p->one->sha1_valid && p->two->sha1_valid) ||
4230                    (p->one->mode != p->two->mode) ||
4231                    diff_populate_filespec(p->one, 1) ||
4232                    diff_populate_filespec(p->two, 1) ||
4233                    (p->one->size != p->two->size) ||
4234                    !diff_filespec_is_identical(p->one, p->two)) /* (2) */
4235                        diff_q(&outq, p);
4236                else {
4237                        /*
4238                         * The caller can subtract 1 from skip_stat_unmatch
4239                         * to determine how many paths were dirty only
4240                         * due to stat info mismatch.
4241                         */
4242                        if (!DIFF_OPT_TST(diffopt, NO_INDEX))
4243                                diffopt->skip_stat_unmatch++;
4244                        diff_free_filepair(p);
4245                }
4246        }
4247        free(q->queue);
4248        *q = outq;
4249}
4250
4251static int diffnamecmp(const void *a_, const void *b_)
4252{
4253        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
4254        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
4255        const char *name_a, *name_b;
4256
4257        name_a = a->one ? a->one->path : a->two->path;
4258        name_b = b->one ? b->one->path : b->two->path;
4259        return strcmp(name_a, name_b);
4260}
4261
4262void diffcore_fix_diff_index(struct diff_options *options)
4263{
4264        struct diff_queue_struct *q = &diff_queued_diff;
4265        qsort(q->queue, q->nr, sizeof(q->queue[0]), diffnamecmp);
4266}
4267
4268void diffcore_std(struct diff_options *options)
4269{
4270        if (options->skip_stat_unmatch)
4271                diffcore_skip_stat_unmatch(options);
4272        if (!options->found_follow) {
4273                /* See try_to_follow_renames() in tree-diff.c */
4274                if (options->break_opt != -1)
4275                        diffcore_break(options->break_opt);
4276                if (options->detect_rename)
4277                        diffcore_rename(options);
4278                if (options->break_opt != -1)
4279                        diffcore_merge_broken();
4280        }
4281        if (options->pickaxe)
4282                diffcore_pickaxe(options);
4283        if (options->orderfile)
4284                diffcore_order(options->orderfile);
4285        if (!options->found_follow)
4286                /* See try_to_follow_renames() in tree-diff.c */
4287                diff_resolve_rename_copy();
4288        diffcore_apply_filter(options->filter);
4289
4290        if (diff_queued_diff.nr && !DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4291                DIFF_OPT_SET(options, HAS_CHANGES);
4292        else
4293                DIFF_OPT_CLR(options, HAS_CHANGES);
4294
4295        options->found_follow = 0;
4296}
4297
4298int diff_result_code(struct diff_options *opt, int status)
4299{
4300        int result = 0;
4301
4302        diff_warn_rename_limit("diff.renamelimit",
4303                               opt->needed_rename_limit,
4304                               opt->degraded_cc_to_c);
4305        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4306            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
4307                return status;
4308        if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4309            DIFF_OPT_TST(opt, HAS_CHANGES))
4310                result |= 01;
4311        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
4312            DIFF_OPT_TST(opt, CHECK_FAILED))
4313                result |= 02;
4314        return result;
4315}
4316
4317/*
4318 * Shall changes to this submodule be ignored?
4319 *
4320 * Submodule changes can be configured to be ignored separately for each path,
4321 * but that configuration can be overridden from the command line.
4322 */
4323static int is_submodule_ignored(const char *path, struct diff_options *options)
4324{
4325        int ignored = 0;
4326        unsigned orig_flags = options->flags;
4327        if (!DIFF_OPT_TST(options, OVERRIDE_SUBMODULE_CONFIG))
4328                set_diffopt_flags_from_submodule_config(options, path);
4329        if (DIFF_OPT_TST(options, IGNORE_SUBMODULES))
4330                ignored = 1;
4331        options->flags = orig_flags;
4332        return ignored;
4333}
4334
4335void diff_addremove(struct diff_options *options,
4336                    int addremove, unsigned mode,
4337                    const unsigned char *sha1,
4338                    const char *concatpath, unsigned dirty_submodule)
4339{
4340        struct diff_filespec *one, *two;
4341
4342        if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
4343                return;
4344
4345        /* This may look odd, but it is a preparation for
4346         * feeding "there are unchanged files which should
4347         * not produce diffs, but when you are doing copy
4348         * detection you would need them, so here they are"
4349         * entries to the diff-core.  They will be prefixed
4350         * with something like '=' or '*' (I haven't decided
4351         * which but should not make any difference).
4352         * Feeding the same new and old to diff_change()
4353         * also has the same effect.
4354         * Before the final output happens, they are pruned after
4355         * merged into rename/copy pairs as appropriate.
4356         */
4357        if (DIFF_OPT_TST(options, REVERSE_DIFF))
4358                addremove = (addremove == '+' ? '-' :
4359                             addremove == '-' ? '+' : addremove);
4360
4361        if (options->prefix &&
4362            strncmp(concatpath, options->prefix, options->prefix_length))
4363                return;
4364
4365        one = alloc_filespec(concatpath);
4366        two = alloc_filespec(concatpath);
4367
4368        if (addremove != '+')
4369                fill_filespec(one, sha1, mode);
4370        if (addremove != '-') {
4371                fill_filespec(two, sha1, mode);
4372                two->dirty_submodule = dirty_submodule;
4373        }
4374
4375        diff_queue(&diff_queued_diff, one, two);
4376        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4377                DIFF_OPT_SET(options, HAS_CHANGES);
4378}
4379
4380void diff_change(struct diff_options *options,
4381                 unsigned old_mode, unsigned new_mode,
4382                 const unsigned char *old_sha1,
4383                 const unsigned char *new_sha1,
4384                 const char *concatpath,
4385                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
4386{
4387        struct diff_filespec *one, *two;
4388
4389        if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
4390            is_submodule_ignored(concatpath, options))
4391                return;
4392
4393        if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
4394                unsigned tmp;
4395                const unsigned char *tmp_c;
4396                tmp = old_mode; old_mode = new_mode; new_mode = tmp;
4397                tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
4398                tmp = old_dirty_submodule; old_dirty_submodule = new_dirty_submodule;
4399                        new_dirty_submodule = tmp;
4400        }
4401
4402        if (options->prefix &&
4403            strncmp(concatpath, options->prefix, options->prefix_length))
4404                return;
4405
4406        one = alloc_filespec(concatpath);
4407        two = alloc_filespec(concatpath);
4408        fill_filespec(one, old_sha1, old_mode);
4409        fill_filespec(two, new_sha1, new_mode);
4410        one->dirty_submodule = old_dirty_submodule;
4411        two->dirty_submodule = new_dirty_submodule;
4412
4413        diff_queue(&diff_queued_diff, one, two);
4414        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4415                DIFF_OPT_SET(options, HAS_CHANGES);
4416}
4417
4418struct diff_filepair *diff_unmerge(struct diff_options *options, const char *path)
4419{
4420        struct diff_filepair *pair;
4421        struct diff_filespec *one, *two;
4422
4423        if (options->prefix &&
4424            strncmp(path, options->prefix, options->prefix_length))
4425                return NULL;
4426
4427        one = alloc_filespec(path);
4428        two = alloc_filespec(path);
4429        pair = diff_queue(&diff_queued_diff, one, two);
4430        pair->is_unmerged = 1;
4431        return pair;
4432}
4433
4434static char *run_textconv(const char *pgm, struct diff_filespec *spec,
4435                size_t *outsize)
4436{
4437        struct diff_tempfile *temp;
4438        const char *argv[3];
4439        const char **arg = argv;
4440        struct child_process child;
4441        struct strbuf buf = STRBUF_INIT;
4442        int err = 0;
4443
4444        temp = prepare_temp_file(spec->path, spec);
4445        *arg++ = pgm;
4446        *arg++ = temp->name;
4447        *arg = NULL;
4448
4449        memset(&child, 0, sizeof(child));
4450        child.use_shell = 1;
4451        child.argv = argv;
4452        child.out = -1;
4453        if (start_command(&child)) {
4454                remove_tempfile();
4455                return NULL;
4456        }
4457
4458        if (strbuf_read(&buf, child.out, 0) < 0)
4459                err = error("error reading from textconv command '%s'", pgm);
4460        close(child.out);
4461
4462        if (finish_command(&child) || err) {
4463                strbuf_release(&buf);
4464                remove_tempfile();
4465                return NULL;
4466        }
4467        remove_tempfile();
4468
4469        return strbuf_detach(&buf, outsize);
4470}
4471
4472size_t fill_textconv(struct userdiff_driver *driver,
4473                     struct diff_filespec *df,
4474                     char **outbuf)
4475{
4476        size_t size;
4477
4478        if (!driver || !driver->textconv) {
4479                if (!DIFF_FILE_VALID(df)) {
4480                        *outbuf = "";
4481                        return 0;
4482                }
4483                if (diff_populate_filespec(df, 0))
4484                        die("unable to read files to diff");
4485                *outbuf = df->data;
4486                return df->size;
4487        }
4488
4489        if (driver->textconv_cache && df->sha1_valid) {
4490                *outbuf = notes_cache_get(driver->textconv_cache, df->sha1,
4491                                          &size);
4492                if (*outbuf)
4493                        return size;
4494        }
4495
4496        *outbuf = run_textconv(driver->textconv, df, &size);
4497        if (!*outbuf)
4498                die("unable to read files to diff");
4499
4500        if (driver->textconv_cache && df->sha1_valid) {
4501                /* ignore errors, as we might be in a readonly repository */
4502                notes_cache_put(driver->textconv_cache, df->sha1, *outbuf,
4503                                size);
4504                /*
4505                 * we could save up changes and flush them all at the end,
4506                 * but we would need an extra call after all diffing is done.
4507                 * Since generating a cache entry is the slow path anyway,
4508                 * this extra overhead probably isn't a big deal.
4509                 */
4510                notes_cache_write(driver->textconv_cache);
4511        }
4512
4513        return size;
4514}