diff.con commit Merge branch 'sg/wt-status-header-inclusion' (6525496)
   1/*
   2 * Copyright (C) 2005 Junio C Hamano
   3 */
   4#include "cache.h"
   5#include "tempfile.h"
   6#include "quote.h"
   7#include "diff.h"
   8#include "diffcore.h"
   9#include "delta.h"
  10#include "xdiff-interface.h"
  11#include "color.h"
  12#include "attr.h"
  13#include "run-command.h"
  14#include "utf8.h"
  15#include "userdiff.h"
  16#include "sigchain.h"
  17#include "submodule.h"
  18#include "ll-merge.h"
  19#include "string-list.h"
  20#include "argv-array.h"
  21
  22#ifdef NO_FAST_WORKING_DIRECTORY
  23#define FAST_WORKING_DIRECTORY 0
  24#else
  25#define FAST_WORKING_DIRECTORY 1
  26#endif
  27
  28static int diff_detect_rename_default;
  29static int diff_rename_limit_default = 400;
  30static int diff_suppress_blank_empty;
  31static int diff_use_color_default = -1;
  32static int diff_context_default = 3;
  33static const char *diff_word_regex_cfg;
  34static const char *external_diff_cmd_cfg;
  35static const char *diff_order_file_cfg;
  36int diff_auto_refresh_index = 1;
  37static int diff_mnemonic_prefix;
  38static int diff_no_prefix;
  39static int diff_stat_graph_width;
  40static int diff_dirstat_permille_default = 30;
  41static struct diff_options default_diff_options;
  42static long diff_algorithm;
  43
  44static char diff_colors[][COLOR_MAXLEN] = {
  45        GIT_COLOR_RESET,
  46        GIT_COLOR_NORMAL,       /* CONTEXT */
  47        GIT_COLOR_BOLD,         /* METAINFO */
  48        GIT_COLOR_CYAN,         /* FRAGINFO */
  49        GIT_COLOR_RED,          /* OLD */
  50        GIT_COLOR_GREEN,        /* NEW */
  51        GIT_COLOR_YELLOW,       /* COMMIT */
  52        GIT_COLOR_BG_RED,       /* WHITESPACE */
  53        GIT_COLOR_NORMAL,       /* FUNCINFO */
  54};
  55
  56static int parse_diff_color_slot(const char *var)
  57{
  58        if (!strcasecmp(var, "context") || !strcasecmp(var, "plain"))
  59                return DIFF_CONTEXT;
  60        if (!strcasecmp(var, "meta"))
  61                return DIFF_METAINFO;
  62        if (!strcasecmp(var, "frag"))
  63                return DIFF_FRAGINFO;
  64        if (!strcasecmp(var, "old"))
  65                return DIFF_FILE_OLD;
  66        if (!strcasecmp(var, "new"))
  67                return DIFF_FILE_NEW;
  68        if (!strcasecmp(var, "commit"))
  69                return DIFF_COMMIT;
  70        if (!strcasecmp(var, "whitespace"))
  71                return DIFF_WHITESPACE;
  72        if (!strcasecmp(var, "func"))
  73                return DIFF_FUNCINFO;
  74        return -1;
  75}
  76
  77static int parse_dirstat_params(struct diff_options *options, const char *params_string,
  78                                struct strbuf *errmsg)
  79{
  80        char *params_copy = xstrdup(params_string);
  81        struct string_list params = STRING_LIST_INIT_NODUP;
  82        int ret = 0;
  83        int i;
  84
  85        if (*params_copy)
  86                string_list_split_in_place(&params, params_copy, ',', -1);
  87        for (i = 0; i < params.nr; i++) {
  88                const char *p = params.items[i].string;
  89                if (!strcmp(p, "changes")) {
  90                        DIFF_OPT_CLR(options, DIRSTAT_BY_LINE);
  91                        DIFF_OPT_CLR(options, DIRSTAT_BY_FILE);
  92                } else if (!strcmp(p, "lines")) {
  93                        DIFF_OPT_SET(options, DIRSTAT_BY_LINE);
  94                        DIFF_OPT_CLR(options, DIRSTAT_BY_FILE);
  95                } else if (!strcmp(p, "files")) {
  96                        DIFF_OPT_CLR(options, DIRSTAT_BY_LINE);
  97                        DIFF_OPT_SET(options, DIRSTAT_BY_FILE);
  98                } else if (!strcmp(p, "noncumulative")) {
  99                        DIFF_OPT_CLR(options, DIRSTAT_CUMULATIVE);
 100                } else if (!strcmp(p, "cumulative")) {
 101                        DIFF_OPT_SET(options, DIRSTAT_CUMULATIVE);
 102                } else if (isdigit(*p)) {
 103                        char *end;
 104                        int permille = strtoul(p, &end, 10) * 10;
 105                        if (*end == '.' && isdigit(*++end)) {
 106                                /* only use first digit */
 107                                permille += *end - '0';
 108                                /* .. and ignore any further digits */
 109                                while (isdigit(*++end))
 110                                        ; /* nothing */
 111                        }
 112                        if (!*end)
 113                                options->dirstat_permille = permille;
 114                        else {
 115                                strbuf_addf(errmsg, _("  Failed to parse dirstat cut-off percentage '%s'\n"),
 116                                            p);
 117                                ret++;
 118                        }
 119                } else {
 120                        strbuf_addf(errmsg, _("  Unknown dirstat parameter '%s'\n"), p);
 121                        ret++;
 122                }
 123
 124        }
 125        string_list_clear(&params, 0);
 126        free(params_copy);
 127        return ret;
 128}
 129
 130static int parse_submodule_params(struct diff_options *options, const char *value)
 131{
 132        if (!strcmp(value, "log"))
 133                DIFF_OPT_SET(options, SUBMODULE_LOG);
 134        else if (!strcmp(value, "short"))
 135                DIFF_OPT_CLR(options, SUBMODULE_LOG);
 136        else
 137                return -1;
 138        return 0;
 139}
 140
 141static int git_config_rename(const char *var, const char *value)
 142{
 143        if (!value)
 144                return DIFF_DETECT_RENAME;
 145        if (!strcasecmp(value, "copies") || !strcasecmp(value, "copy"))
 146                return  DIFF_DETECT_COPY;
 147        return git_config_bool(var,value) ? DIFF_DETECT_RENAME : 0;
 148}
 149
 150long parse_algorithm_value(const char *value)
 151{
 152        if (!value)
 153                return -1;
 154        else if (!strcasecmp(value, "myers") || !strcasecmp(value, "default"))
 155                return 0;
 156        else if (!strcasecmp(value, "minimal"))
 157                return XDF_NEED_MINIMAL;
 158        else if (!strcasecmp(value, "patience"))
 159                return XDF_PATIENCE_DIFF;
 160        else if (!strcasecmp(value, "histogram"))
 161                return XDF_HISTOGRAM_DIFF;
 162        return -1;
 163}
 164
 165/*
 166 * These are to give UI layer defaults.
 167 * The core-level commands such as git-diff-files should
 168 * never be affected by the setting of diff.renames
 169 * the user happens to have in the configuration file.
 170 */
 171int git_diff_ui_config(const char *var, const char *value, void *cb)
 172{
 173        if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
 174                diff_use_color_default = git_config_colorbool(var, value);
 175                return 0;
 176        }
 177        if (!strcmp(var, "diff.context")) {
 178                diff_context_default = git_config_int(var, value);
 179                if (diff_context_default < 0)
 180                        return -1;
 181                return 0;
 182        }
 183        if (!strcmp(var, "diff.renames")) {
 184                diff_detect_rename_default = git_config_rename(var, value);
 185                return 0;
 186        }
 187        if (!strcmp(var, "diff.autorefreshindex")) {
 188                diff_auto_refresh_index = git_config_bool(var, value);
 189                return 0;
 190        }
 191        if (!strcmp(var, "diff.mnemonicprefix")) {
 192                diff_mnemonic_prefix = git_config_bool(var, value);
 193                return 0;
 194        }
 195        if (!strcmp(var, "diff.noprefix")) {
 196                diff_no_prefix = git_config_bool(var, value);
 197                return 0;
 198        }
 199        if (!strcmp(var, "diff.statgraphwidth")) {
 200                diff_stat_graph_width = git_config_int(var, value);
 201                return 0;
 202        }
 203        if (!strcmp(var, "diff.external"))
 204                return git_config_string(&external_diff_cmd_cfg, var, value);
 205        if (!strcmp(var, "diff.wordregex"))
 206                return git_config_string(&diff_word_regex_cfg, var, value);
 207        if (!strcmp(var, "diff.orderfile"))
 208                return git_config_pathname(&diff_order_file_cfg, var, value);
 209
 210        if (!strcmp(var, "diff.ignoresubmodules"))
 211                handle_ignore_submodules_arg(&default_diff_options, value);
 212
 213        if (!strcmp(var, "diff.submodule")) {
 214                if (parse_submodule_params(&default_diff_options, value))
 215                        warning(_("Unknown value for 'diff.submodule' config variable: '%s'"),
 216                                value);
 217                return 0;
 218        }
 219
 220        if (!strcmp(var, "diff.algorithm")) {
 221                diff_algorithm = parse_algorithm_value(value);
 222                if (diff_algorithm < 0)
 223                        return -1;
 224                return 0;
 225        }
 226
 227        if (git_color_config(var, value, cb) < 0)
 228                return -1;
 229
 230        return git_diff_basic_config(var, value, cb);
 231}
 232
 233int git_diff_basic_config(const char *var, const char *value, void *cb)
 234{
 235        const char *name;
 236
 237        if (!strcmp(var, "diff.renamelimit")) {
 238                diff_rename_limit_default = git_config_int(var, value);
 239                return 0;
 240        }
 241
 242        if (userdiff_config(var, value) < 0)
 243                return -1;
 244
 245        if (skip_prefix(var, "diff.color.", &name) ||
 246            skip_prefix(var, "color.diff.", &name)) {
 247                int slot = parse_diff_color_slot(name);
 248                if (slot < 0)
 249                        return 0;
 250                if (!value)
 251                        return config_error_nonbool(var);
 252                return color_parse(value, diff_colors[slot]);
 253        }
 254
 255        /* like GNU diff's --suppress-blank-empty option  */
 256        if (!strcmp(var, "diff.suppressblankempty") ||
 257                        /* for backwards compatibility */
 258                        !strcmp(var, "diff.suppress-blank-empty")) {
 259                diff_suppress_blank_empty = git_config_bool(var, value);
 260                return 0;
 261        }
 262
 263        if (!strcmp(var, "diff.dirstat")) {
 264                struct strbuf errmsg = STRBUF_INIT;
 265                default_diff_options.dirstat_permille = diff_dirstat_permille_default;
 266                if (parse_dirstat_params(&default_diff_options, value, &errmsg))
 267                        warning(_("Found errors in 'diff.dirstat' config variable:\n%s"),
 268                                errmsg.buf);
 269                strbuf_release(&errmsg);
 270                diff_dirstat_permille_default = default_diff_options.dirstat_permille;
 271                return 0;
 272        }
 273
 274        if (starts_with(var, "submodule."))
 275                return parse_submodule_config_option(var, value);
 276
 277        return git_default_config(var, value, cb);
 278}
 279
 280static char *quote_two(const char *one, const char *two)
 281{
 282        int need_one = quote_c_style(one, NULL, NULL, 1);
 283        int need_two = quote_c_style(two, NULL, NULL, 1);
 284        struct strbuf res = STRBUF_INIT;
 285
 286        if (need_one + need_two) {
 287                strbuf_addch(&res, '"');
 288                quote_c_style(one, &res, NULL, 1);
 289                quote_c_style(two, &res, NULL, 1);
 290                strbuf_addch(&res, '"');
 291        } else {
 292                strbuf_addstr(&res, one);
 293                strbuf_addstr(&res, two);
 294        }
 295        return strbuf_detach(&res, NULL);
 296}
 297
 298static const char *external_diff(void)
 299{
 300        static const char *external_diff_cmd = NULL;
 301        static int done_preparing = 0;
 302
 303        if (done_preparing)
 304                return external_diff_cmd;
 305        external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
 306        if (!external_diff_cmd)
 307                external_diff_cmd = external_diff_cmd_cfg;
 308        done_preparing = 1;
 309        return external_diff_cmd;
 310}
 311
 312/*
 313 * Keep track of files used for diffing. Sometimes such an entry
 314 * refers to a temporary file, sometimes to an existing file, and
 315 * sometimes to "/dev/null".
 316 */
 317static struct diff_tempfile {
 318        /*
 319         * filename external diff should read from, or NULL if this
 320         * entry is currently not in use:
 321         */
 322        const char *name;
 323
 324        char hex[41];
 325        char mode[10];
 326
 327        /*
 328         * If this diff_tempfile instance refers to a temporary file,
 329         * this tempfile object is used to manage its lifetime.
 330         */
 331        struct tempfile tempfile;
 332} diff_temp[2];
 333
 334typedef unsigned long (*sane_truncate_fn)(char *line, unsigned long len);
 335
 336struct emit_callback {
 337        int color_diff;
 338        unsigned ws_rule;
 339        int blank_at_eof_in_preimage;
 340        int blank_at_eof_in_postimage;
 341        int lno_in_preimage;
 342        int lno_in_postimage;
 343        sane_truncate_fn truncate;
 344        const char **label_path;
 345        struct diff_words_data *diff_words;
 346        struct diff_options *opt;
 347        int *found_changesp;
 348        struct strbuf *header;
 349};
 350
 351static int count_lines(const char *data, int size)
 352{
 353        int count, ch, completely_empty = 1, nl_just_seen = 0;
 354        count = 0;
 355        while (0 < size--) {
 356                ch = *data++;
 357                if (ch == '\n') {
 358                        count++;
 359                        nl_just_seen = 1;
 360                        completely_empty = 0;
 361                }
 362                else {
 363                        nl_just_seen = 0;
 364                        completely_empty = 0;
 365                }
 366        }
 367        if (completely_empty)
 368                return 0;
 369        if (!nl_just_seen)
 370                count++; /* no trailing newline */
 371        return count;
 372}
 373
 374static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
 375{
 376        if (!DIFF_FILE_VALID(one)) {
 377                mf->ptr = (char *)""; /* does not matter */
 378                mf->size = 0;
 379                return 0;
 380        }
 381        else if (diff_populate_filespec(one, 0))
 382                return -1;
 383
 384        mf->ptr = one->data;
 385        mf->size = one->size;
 386        return 0;
 387}
 388
 389/* like fill_mmfile, but only for size, so we can avoid retrieving blob */
 390static unsigned long diff_filespec_size(struct diff_filespec *one)
 391{
 392        if (!DIFF_FILE_VALID(one))
 393                return 0;
 394        diff_populate_filespec(one, CHECK_SIZE_ONLY);
 395        return one->size;
 396}
 397
 398static int count_trailing_blank(mmfile_t *mf, unsigned ws_rule)
 399{
 400        char *ptr = mf->ptr;
 401        long size = mf->size;
 402        int cnt = 0;
 403
 404        if (!size)
 405                return cnt;
 406        ptr += size - 1; /* pointing at the very end */
 407        if (*ptr != '\n')
 408                ; /* incomplete line */
 409        else
 410                ptr--; /* skip the last LF */
 411        while (mf->ptr < ptr) {
 412                char *prev_eol;
 413                for (prev_eol = ptr; mf->ptr <= prev_eol; prev_eol--)
 414                        if (*prev_eol == '\n')
 415                                break;
 416                if (!ws_blank_line(prev_eol + 1, ptr - prev_eol, ws_rule))
 417                        break;
 418                cnt++;
 419                ptr = prev_eol - 1;
 420        }
 421        return cnt;
 422}
 423
 424static void check_blank_at_eof(mmfile_t *mf1, mmfile_t *mf2,
 425                               struct emit_callback *ecbdata)
 426{
 427        int l1, l2, at;
 428        unsigned ws_rule = ecbdata->ws_rule;
 429        l1 = count_trailing_blank(mf1, ws_rule);
 430        l2 = count_trailing_blank(mf2, ws_rule);
 431        if (l2 <= l1) {
 432                ecbdata->blank_at_eof_in_preimage = 0;
 433                ecbdata->blank_at_eof_in_postimage = 0;
 434                return;
 435        }
 436        at = count_lines(mf1->ptr, mf1->size);
 437        ecbdata->blank_at_eof_in_preimage = (at - l1) + 1;
 438
 439        at = count_lines(mf2->ptr, mf2->size);
 440        ecbdata->blank_at_eof_in_postimage = (at - l2) + 1;
 441}
 442
 443static void emit_line_0(struct diff_options *o, const char *set, const char *reset,
 444                        int first, const char *line, int len)
 445{
 446        int has_trailing_newline, has_trailing_carriage_return;
 447        int nofirst;
 448        FILE *file = o->file;
 449
 450        fputs(diff_line_prefix(o), file);
 451
 452        if (len == 0) {
 453                has_trailing_newline = (first == '\n');
 454                has_trailing_carriage_return = (!has_trailing_newline &&
 455                                                (first == '\r'));
 456                nofirst = has_trailing_newline || has_trailing_carriage_return;
 457        } else {
 458                has_trailing_newline = (len > 0 && line[len-1] == '\n');
 459                if (has_trailing_newline)
 460                        len--;
 461                has_trailing_carriage_return = (len > 0 && line[len-1] == '\r');
 462                if (has_trailing_carriage_return)
 463                        len--;
 464                nofirst = 0;
 465        }
 466
 467        if (len || !nofirst) {
 468                fputs(set, file);
 469                if (!nofirst)
 470                        fputc(first, file);
 471                fwrite(line, len, 1, file);
 472                fputs(reset, file);
 473        }
 474        if (has_trailing_carriage_return)
 475                fputc('\r', file);
 476        if (has_trailing_newline)
 477                fputc('\n', file);
 478}
 479
 480static void emit_line(struct diff_options *o, const char *set, const char *reset,
 481                      const char *line, int len)
 482{
 483        emit_line_0(o, set, reset, line[0], line+1, len-1);
 484}
 485
 486static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line, int len)
 487{
 488        if (!((ecbdata->ws_rule & WS_BLANK_AT_EOF) &&
 489              ecbdata->blank_at_eof_in_preimage &&
 490              ecbdata->blank_at_eof_in_postimage &&
 491              ecbdata->blank_at_eof_in_preimage <= ecbdata->lno_in_preimage &&
 492              ecbdata->blank_at_eof_in_postimage <= ecbdata->lno_in_postimage))
 493                return 0;
 494        return ws_blank_line(line, len, ecbdata->ws_rule);
 495}
 496
 497static void emit_line_checked(const char *reset,
 498                              struct emit_callback *ecbdata,
 499                              const char *line, int len,
 500                              enum color_diff color,
 501                              unsigned ws_error_highlight,
 502                              char sign)
 503{
 504        const char *set = diff_get_color(ecbdata->color_diff, color);
 505        const char *ws = NULL;
 506
 507        if (ecbdata->opt->ws_error_highlight & ws_error_highlight) {
 508                ws = diff_get_color(ecbdata->color_diff, DIFF_WHITESPACE);
 509                if (!*ws)
 510                        ws = NULL;
 511        }
 512
 513        if (!ws)
 514                emit_line_0(ecbdata->opt, set, reset, sign, line, len);
 515        else if (sign == '+' && new_blank_line_at_eof(ecbdata, line, len))
 516                /* Blank line at EOF - paint '+' as well */
 517                emit_line_0(ecbdata->opt, ws, reset, sign, line, len);
 518        else {
 519                /* Emit just the prefix, then the rest. */
 520                emit_line_0(ecbdata->opt, set, reset, sign, "", 0);
 521                ws_check_emit(line, len, ecbdata->ws_rule,
 522                              ecbdata->opt->file, set, reset, ws);
 523        }
 524}
 525
 526static void emit_add_line(const char *reset,
 527                          struct emit_callback *ecbdata,
 528                          const char *line, int len)
 529{
 530        emit_line_checked(reset, ecbdata, line, len,
 531                          DIFF_FILE_NEW, WSEH_NEW, '+');
 532}
 533
 534static void emit_del_line(const char *reset,
 535                          struct emit_callback *ecbdata,
 536                          const char *line, int len)
 537{
 538        emit_line_checked(reset, ecbdata, line, len,
 539                          DIFF_FILE_OLD, WSEH_OLD, '-');
 540}
 541
 542static void emit_context_line(const char *reset,
 543                              struct emit_callback *ecbdata,
 544                              const char *line, int len)
 545{
 546        emit_line_checked(reset, ecbdata, line, len,
 547                          DIFF_CONTEXT, WSEH_CONTEXT, ' ');
 548}
 549
 550static void emit_hunk_header(struct emit_callback *ecbdata,
 551                             const char *line, int len)
 552{
 553        const char *context = diff_get_color(ecbdata->color_diff, DIFF_CONTEXT);
 554        const char *frag = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
 555        const char *func = diff_get_color(ecbdata->color_diff, DIFF_FUNCINFO);
 556        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
 557        static const char atat[2] = { '@', '@' };
 558        const char *cp, *ep;
 559        struct strbuf msgbuf = STRBUF_INIT;
 560        int org_len = len;
 561        int i = 1;
 562
 563        /*
 564         * As a hunk header must begin with "@@ -<old>, +<new> @@",
 565         * it always is at least 10 bytes long.
 566         */
 567        if (len < 10 ||
 568            memcmp(line, atat, 2) ||
 569            !(ep = memmem(line + 2, len - 2, atat, 2))) {
 570                emit_line(ecbdata->opt, context, reset, line, len);
 571                return;
 572        }
 573        ep += 2; /* skip over @@ */
 574
 575        /* The hunk header in fraginfo color */
 576        strbuf_addstr(&msgbuf, frag);
 577        strbuf_add(&msgbuf, line, ep - line);
 578        strbuf_addstr(&msgbuf, reset);
 579
 580        /*
 581         * trailing "\r\n"
 582         */
 583        for ( ; i < 3; i++)
 584                if (line[len - i] == '\r' || line[len - i] == '\n')
 585                        len--;
 586
 587        /* blank before the func header */
 588        for (cp = ep; ep - line < len; ep++)
 589                if (*ep != ' ' && *ep != '\t')
 590                        break;
 591        if (ep != cp) {
 592                strbuf_addstr(&msgbuf, context);
 593                strbuf_add(&msgbuf, cp, ep - cp);
 594                strbuf_addstr(&msgbuf, reset);
 595        }
 596
 597        if (ep < line + len) {
 598                strbuf_addstr(&msgbuf, func);
 599                strbuf_add(&msgbuf, ep, line + len - ep);
 600                strbuf_addstr(&msgbuf, reset);
 601        }
 602
 603        strbuf_add(&msgbuf, line + len, org_len - len);
 604        emit_line(ecbdata->opt, "", "", msgbuf.buf, msgbuf.len);
 605        strbuf_release(&msgbuf);
 606}
 607
 608static struct diff_tempfile *claim_diff_tempfile(void) {
 609        int i;
 610        for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
 611                if (!diff_temp[i].name)
 612                        return diff_temp + i;
 613        die("BUG: diff is failing to clean up its tempfiles");
 614}
 615
 616static void remove_tempfile(void)
 617{
 618        int i;
 619        for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
 620                if (is_tempfile_active(&diff_temp[i].tempfile))
 621                        delete_tempfile(&diff_temp[i].tempfile);
 622                diff_temp[i].name = NULL;
 623        }
 624}
 625
 626static void print_line_count(FILE *file, int count)
 627{
 628        switch (count) {
 629        case 0:
 630                fprintf(file, "0,0");
 631                break;
 632        case 1:
 633                fprintf(file, "1");
 634                break;
 635        default:
 636                fprintf(file, "1,%d", count);
 637                break;
 638        }
 639}
 640
 641static void emit_rewrite_lines(struct emit_callback *ecb,
 642                               int prefix, const char *data, int size)
 643{
 644        const char *endp = NULL;
 645        static const char *nneof = " No newline at end of file\n";
 646        const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
 647
 648        while (0 < size) {
 649                int len;
 650
 651                endp = memchr(data, '\n', size);
 652                len = endp ? (endp - data + 1) : size;
 653                if (prefix != '+') {
 654                        ecb->lno_in_preimage++;
 655                        emit_del_line(reset, ecb, data, len);
 656                } else {
 657                        ecb->lno_in_postimage++;
 658                        emit_add_line(reset, ecb, data, len);
 659                }
 660                size -= len;
 661                data += len;
 662        }
 663        if (!endp) {
 664                const char *context = diff_get_color(ecb->color_diff,
 665                                                     DIFF_CONTEXT);
 666                putc('\n', ecb->opt->file);
 667                emit_line_0(ecb->opt, context, reset, '\\',
 668                            nneof, strlen(nneof));
 669        }
 670}
 671
 672static void emit_rewrite_diff(const char *name_a,
 673                              const char *name_b,
 674                              struct diff_filespec *one,
 675                              struct diff_filespec *two,
 676                              struct userdiff_driver *textconv_one,
 677                              struct userdiff_driver *textconv_two,
 678                              struct diff_options *o)
 679{
 680        int lc_a, lc_b;
 681        const char *name_a_tab, *name_b_tab;
 682        const char *metainfo = diff_get_color(o->use_color, DIFF_METAINFO);
 683        const char *fraginfo = diff_get_color(o->use_color, DIFF_FRAGINFO);
 684        const char *reset = diff_get_color(o->use_color, DIFF_RESET);
 685        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
 686        const char *a_prefix, *b_prefix;
 687        char *data_one, *data_two;
 688        size_t size_one, size_two;
 689        struct emit_callback ecbdata;
 690        const char *line_prefix = diff_line_prefix(o);
 691
 692        if (diff_mnemonic_prefix && DIFF_OPT_TST(o, REVERSE_DIFF)) {
 693                a_prefix = o->b_prefix;
 694                b_prefix = o->a_prefix;
 695        } else {
 696                a_prefix = o->a_prefix;
 697                b_prefix = o->b_prefix;
 698        }
 699
 700        name_a += (*name_a == '/');
 701        name_b += (*name_b == '/');
 702        name_a_tab = strchr(name_a, ' ') ? "\t" : "";
 703        name_b_tab = strchr(name_b, ' ') ? "\t" : "";
 704
 705        strbuf_reset(&a_name);
 706        strbuf_reset(&b_name);
 707        quote_two_c_style(&a_name, a_prefix, name_a, 0);
 708        quote_two_c_style(&b_name, b_prefix, name_b, 0);
 709
 710        size_one = fill_textconv(textconv_one, one, &data_one);
 711        size_two = fill_textconv(textconv_two, two, &data_two);
 712
 713        memset(&ecbdata, 0, sizeof(ecbdata));
 714        ecbdata.color_diff = want_color(o->use_color);
 715        ecbdata.found_changesp = &o->found_changes;
 716        ecbdata.ws_rule = whitespace_rule(name_b);
 717        ecbdata.opt = o;
 718        if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
 719                mmfile_t mf1, mf2;
 720                mf1.ptr = (char *)data_one;
 721                mf2.ptr = (char *)data_two;
 722                mf1.size = size_one;
 723                mf2.size = size_two;
 724                check_blank_at_eof(&mf1, &mf2, &ecbdata);
 725        }
 726        ecbdata.lno_in_preimage = 1;
 727        ecbdata.lno_in_postimage = 1;
 728
 729        lc_a = count_lines(data_one, size_one);
 730        lc_b = count_lines(data_two, size_two);
 731        fprintf(o->file,
 732                "%s%s--- %s%s%s\n%s%s+++ %s%s%s\n%s%s@@ -",
 733                line_prefix, metainfo, a_name.buf, name_a_tab, reset,
 734                line_prefix, metainfo, b_name.buf, name_b_tab, reset,
 735                line_prefix, fraginfo);
 736        if (!o->irreversible_delete)
 737                print_line_count(o->file, lc_a);
 738        else
 739                fprintf(o->file, "?,?");
 740        fprintf(o->file, " +");
 741        print_line_count(o->file, lc_b);
 742        fprintf(o->file, " @@%s\n", reset);
 743        if (lc_a && !o->irreversible_delete)
 744                emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
 745        if (lc_b)
 746                emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
 747        if (textconv_one)
 748                free((char *)data_one);
 749        if (textconv_two)
 750                free((char *)data_two);
 751}
 752
 753struct diff_words_buffer {
 754        mmfile_t text;
 755        long alloc;
 756        struct diff_words_orig {
 757                const char *begin, *end;
 758        } *orig;
 759        int orig_nr, orig_alloc;
 760};
 761
 762static void diff_words_append(char *line, unsigned long len,
 763                struct diff_words_buffer *buffer)
 764{
 765        ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
 766        line++;
 767        len--;
 768        memcpy(buffer->text.ptr + buffer->text.size, line, len);
 769        buffer->text.size += len;
 770        buffer->text.ptr[buffer->text.size] = '\0';
 771}
 772
 773struct diff_words_style_elem {
 774        const char *prefix;
 775        const char *suffix;
 776        const char *color; /* NULL; filled in by the setup code if
 777                            * color is enabled */
 778};
 779
 780struct diff_words_style {
 781        enum diff_words_type type;
 782        struct diff_words_style_elem new, old, ctx;
 783        const char *newline;
 784};
 785
 786static struct diff_words_style diff_words_styles[] = {
 787        { DIFF_WORDS_PORCELAIN, {"+", "\n"}, {"-", "\n"}, {" ", "\n"}, "~\n" },
 788        { DIFF_WORDS_PLAIN, {"{+", "+}"}, {"[-", "-]"}, {"", ""}, "\n" },
 789        { DIFF_WORDS_COLOR, {"", ""}, {"", ""}, {"", ""}, "\n" }
 790};
 791
 792struct diff_words_data {
 793        struct diff_words_buffer minus, plus;
 794        const char *current_plus;
 795        int last_minus;
 796        struct diff_options *opt;
 797        regex_t *word_regex;
 798        enum diff_words_type type;
 799        struct diff_words_style *style;
 800};
 801
 802static int fn_out_diff_words_write_helper(FILE *fp,
 803                                          struct diff_words_style_elem *st_el,
 804                                          const char *newline,
 805                                          size_t count, const char *buf,
 806                                          const char *line_prefix)
 807{
 808        int print = 0;
 809
 810        while (count) {
 811                char *p = memchr(buf, '\n', count);
 812                if (print)
 813                        fputs(line_prefix, fp);
 814                if (p != buf) {
 815                        if (st_el->color && fputs(st_el->color, fp) < 0)
 816                                return -1;
 817                        if (fputs(st_el->prefix, fp) < 0 ||
 818                            fwrite(buf, p ? p - buf : count, 1, fp) != 1 ||
 819                            fputs(st_el->suffix, fp) < 0)
 820                                return -1;
 821                        if (st_el->color && *st_el->color
 822                            && fputs(GIT_COLOR_RESET, fp) < 0)
 823                                return -1;
 824                }
 825                if (!p)
 826                        return 0;
 827                if (fputs(newline, fp) < 0)
 828                        return -1;
 829                count -= p + 1 - buf;
 830                buf = p + 1;
 831                print = 1;
 832        }
 833        return 0;
 834}
 835
 836/*
 837 * '--color-words' algorithm can be described as:
 838 *
 839 *   1. collect a the minus/plus lines of a diff hunk, divided into
 840 *      minus-lines and plus-lines;
 841 *
 842 *   2. break both minus-lines and plus-lines into words and
 843 *      place them into two mmfile_t with one word for each line;
 844 *
 845 *   3. use xdiff to run diff on the two mmfile_t to get the words level diff;
 846 *
 847 * And for the common parts of the both file, we output the plus side text.
 848 * diff_words->current_plus is used to trace the current position of the plus file
 849 * which printed. diff_words->last_minus is used to trace the last minus word
 850 * printed.
 851 *
 852 * For '--graph' to work with '--color-words', we need to output the graph prefix
 853 * on each line of color words output. Generally, there are two conditions on
 854 * which we should output the prefix.
 855 *
 856 *   1. diff_words->last_minus == 0 &&
 857 *      diff_words->current_plus == diff_words->plus.text.ptr
 858 *
 859 *      that is: the plus text must start as a new line, and if there is no minus
 860 *      word printed, a graph prefix must be printed.
 861 *
 862 *   2. diff_words->current_plus > diff_words->plus.text.ptr &&
 863 *      *(diff_words->current_plus - 1) == '\n'
 864 *
 865 *      that is: a graph prefix must be printed following a '\n'
 866 */
 867static int color_words_output_graph_prefix(struct diff_words_data *diff_words)
 868{
 869        if ((diff_words->last_minus == 0 &&
 870                diff_words->current_plus == diff_words->plus.text.ptr) ||
 871                (diff_words->current_plus > diff_words->plus.text.ptr &&
 872                *(diff_words->current_plus - 1) == '\n')) {
 873                return 1;
 874        } else {
 875                return 0;
 876        }
 877}
 878
 879static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
 880{
 881        struct diff_words_data *diff_words = priv;
 882        struct diff_words_style *style = diff_words->style;
 883        int minus_first, minus_len, plus_first, plus_len;
 884        const char *minus_begin, *minus_end, *plus_begin, *plus_end;
 885        struct diff_options *opt = diff_words->opt;
 886        const char *line_prefix;
 887
 888        if (line[0] != '@' || parse_hunk_header(line, len,
 889                        &minus_first, &minus_len, &plus_first, &plus_len))
 890                return;
 891
 892        assert(opt);
 893        line_prefix = diff_line_prefix(opt);
 894
 895        /* POSIX requires that first be decremented by one if len == 0... */
 896        if (minus_len) {
 897                minus_begin = diff_words->minus.orig[minus_first].begin;
 898                minus_end =
 899                        diff_words->minus.orig[minus_first + minus_len - 1].end;
 900        } else
 901                minus_begin = minus_end =
 902                        diff_words->minus.orig[minus_first].end;
 903
 904        if (plus_len) {
 905                plus_begin = diff_words->plus.orig[plus_first].begin;
 906                plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
 907        } else
 908                plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
 909
 910        if (color_words_output_graph_prefix(diff_words)) {
 911                fputs(line_prefix, diff_words->opt->file);
 912        }
 913        if (diff_words->current_plus != plus_begin) {
 914                fn_out_diff_words_write_helper(diff_words->opt->file,
 915                                &style->ctx, style->newline,
 916                                plus_begin - diff_words->current_plus,
 917                                diff_words->current_plus, line_prefix);
 918                if (*(plus_begin - 1) == '\n')
 919                        fputs(line_prefix, diff_words->opt->file);
 920        }
 921        if (minus_begin != minus_end) {
 922                fn_out_diff_words_write_helper(diff_words->opt->file,
 923                                &style->old, style->newline,
 924                                minus_end - minus_begin, minus_begin,
 925                                line_prefix);
 926        }
 927        if (plus_begin != plus_end) {
 928                fn_out_diff_words_write_helper(diff_words->opt->file,
 929                                &style->new, style->newline,
 930                                plus_end - plus_begin, plus_begin,
 931                                line_prefix);
 932        }
 933
 934        diff_words->current_plus = plus_end;
 935        diff_words->last_minus = minus_first;
 936}
 937
 938/* This function starts looking at *begin, and returns 0 iff a word was found. */
 939static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
 940                int *begin, int *end)
 941{
 942        if (word_regex && *begin < buffer->size) {
 943                regmatch_t match[1];
 944                if (!regexec(word_regex, buffer->ptr + *begin, 1, match, 0)) {
 945                        char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
 946                                        '\n', match[0].rm_eo - match[0].rm_so);
 947                        *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
 948                        *begin += match[0].rm_so;
 949                        return *begin >= *end;
 950                }
 951                return -1;
 952        }
 953
 954        /* find the next word */
 955        while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
 956                (*begin)++;
 957        if (*begin >= buffer->size)
 958                return -1;
 959
 960        /* find the end of the word */
 961        *end = *begin + 1;
 962        while (*end < buffer->size && !isspace(buffer->ptr[*end]))
 963                (*end)++;
 964
 965        return 0;
 966}
 967
 968/*
 969 * This function splits the words in buffer->text, stores the list with
 970 * newline separator into out, and saves the offsets of the original words
 971 * in buffer->orig.
 972 */
 973static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
 974                regex_t *word_regex)
 975{
 976        int i, j;
 977        long alloc = 0;
 978
 979        out->size = 0;
 980        out->ptr = NULL;
 981
 982        /* fake an empty "0th" word */
 983        ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
 984        buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
 985        buffer->orig_nr = 1;
 986
 987        for (i = 0; i < buffer->text.size; i++) {
 988                if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
 989                        return;
 990
 991                /* store original boundaries */
 992                ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
 993                                buffer->orig_alloc);
 994                buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
 995                buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
 996                buffer->orig_nr++;
 997
 998                /* store one word */
 999                ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
1000                memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
1001                out->ptr[out->size + j - i] = '\n';
1002                out->size += j - i + 1;
1003
1004                i = j - 1;
1005        }
1006}
1007
1008/* this executes the word diff on the accumulated buffers */
1009static void diff_words_show(struct diff_words_data *diff_words)
1010{
1011        xpparam_t xpp;
1012        xdemitconf_t xecfg;
1013        mmfile_t minus, plus;
1014        struct diff_words_style *style = diff_words->style;
1015
1016        struct diff_options *opt = diff_words->opt;
1017        const char *line_prefix;
1018
1019        assert(opt);
1020        line_prefix = diff_line_prefix(opt);
1021
1022        /* special case: only removal */
1023        if (!diff_words->plus.text.size) {
1024                fputs(line_prefix, diff_words->opt->file);
1025                fn_out_diff_words_write_helper(diff_words->opt->file,
1026                        &style->old, style->newline,
1027                        diff_words->minus.text.size,
1028                        diff_words->minus.text.ptr, line_prefix);
1029                diff_words->minus.text.size = 0;
1030                return;
1031        }
1032
1033        diff_words->current_plus = diff_words->plus.text.ptr;
1034        diff_words->last_minus = 0;
1035
1036        memset(&xpp, 0, sizeof(xpp));
1037        memset(&xecfg, 0, sizeof(xecfg));
1038        diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
1039        diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
1040        xpp.flags = 0;
1041        /* as only the hunk header will be parsed, we need a 0-context */
1042        xecfg.ctxlen = 0;
1043        xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
1044                      &xpp, &xecfg);
1045        free(minus.ptr);
1046        free(plus.ptr);
1047        if (diff_words->current_plus != diff_words->plus.text.ptr +
1048                        diff_words->plus.text.size) {
1049                if (color_words_output_graph_prefix(diff_words))
1050                        fputs(line_prefix, diff_words->opt->file);
1051                fn_out_diff_words_write_helper(diff_words->opt->file,
1052                        &style->ctx, style->newline,
1053                        diff_words->plus.text.ptr + diff_words->plus.text.size
1054                        - diff_words->current_plus, diff_words->current_plus,
1055                        line_prefix);
1056        }
1057        diff_words->minus.text.size = diff_words->plus.text.size = 0;
1058}
1059
1060/* In "color-words" mode, show word-diff of words accumulated in the buffer */
1061static void diff_words_flush(struct emit_callback *ecbdata)
1062{
1063        if (ecbdata->diff_words->minus.text.size ||
1064            ecbdata->diff_words->plus.text.size)
1065                diff_words_show(ecbdata->diff_words);
1066}
1067
1068static void diff_filespec_load_driver(struct diff_filespec *one)
1069{
1070        /* Use already-loaded driver */
1071        if (one->driver)
1072                return;
1073
1074        if (S_ISREG(one->mode))
1075                one->driver = userdiff_find_by_path(one->path);
1076
1077        /* Fallback to default settings */
1078        if (!one->driver)
1079                one->driver = userdiff_find_by_name("default");
1080}
1081
1082static const char *userdiff_word_regex(struct diff_filespec *one)
1083{
1084        diff_filespec_load_driver(one);
1085        return one->driver->word_regex;
1086}
1087
1088static void init_diff_words_data(struct emit_callback *ecbdata,
1089                                 struct diff_options *orig_opts,
1090                                 struct diff_filespec *one,
1091                                 struct diff_filespec *two)
1092{
1093        int i;
1094        struct diff_options *o = xmalloc(sizeof(struct diff_options));
1095        memcpy(o, orig_opts, sizeof(struct diff_options));
1096
1097        ecbdata->diff_words =
1098                xcalloc(1, sizeof(struct diff_words_data));
1099        ecbdata->diff_words->type = o->word_diff;
1100        ecbdata->diff_words->opt = o;
1101        if (!o->word_regex)
1102                o->word_regex = userdiff_word_regex(one);
1103        if (!o->word_regex)
1104                o->word_regex = userdiff_word_regex(two);
1105        if (!o->word_regex)
1106                o->word_regex = diff_word_regex_cfg;
1107        if (o->word_regex) {
1108                ecbdata->diff_words->word_regex = (regex_t *)
1109                        xmalloc(sizeof(regex_t));
1110                if (regcomp(ecbdata->diff_words->word_regex,
1111                            o->word_regex,
1112                            REG_EXTENDED | REG_NEWLINE))
1113                        die ("Invalid regular expression: %s",
1114                             o->word_regex);
1115        }
1116        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
1117                if (o->word_diff == diff_words_styles[i].type) {
1118                        ecbdata->diff_words->style =
1119                                &diff_words_styles[i];
1120                        break;
1121                }
1122        }
1123        if (want_color(o->use_color)) {
1124                struct diff_words_style *st = ecbdata->diff_words->style;
1125                st->old.color = diff_get_color_opt(o, DIFF_FILE_OLD);
1126                st->new.color = diff_get_color_opt(o, DIFF_FILE_NEW);
1127                st->ctx.color = diff_get_color_opt(o, DIFF_CONTEXT);
1128        }
1129}
1130
1131static void free_diff_words_data(struct emit_callback *ecbdata)
1132{
1133        if (ecbdata->diff_words) {
1134                diff_words_flush(ecbdata);
1135                free (ecbdata->diff_words->opt);
1136                free (ecbdata->diff_words->minus.text.ptr);
1137                free (ecbdata->diff_words->minus.orig);
1138                free (ecbdata->diff_words->plus.text.ptr);
1139                free (ecbdata->diff_words->plus.orig);
1140                if (ecbdata->diff_words->word_regex) {
1141                        regfree(ecbdata->diff_words->word_regex);
1142                        free(ecbdata->diff_words->word_regex);
1143                }
1144                free(ecbdata->diff_words);
1145                ecbdata->diff_words = NULL;
1146        }
1147}
1148
1149const char *diff_get_color(int diff_use_color, enum color_diff ix)
1150{
1151        if (want_color(diff_use_color))
1152                return diff_colors[ix];
1153        return "";
1154}
1155
1156const char *diff_line_prefix(struct diff_options *opt)
1157{
1158        struct strbuf *msgbuf;
1159        if (!opt->output_prefix)
1160                return "";
1161
1162        msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
1163        return msgbuf->buf;
1164}
1165
1166static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
1167{
1168        const char *cp;
1169        unsigned long allot;
1170        size_t l = len;
1171
1172        if (ecb->truncate)
1173                return ecb->truncate(line, len);
1174        cp = line;
1175        allot = l;
1176        while (0 < l) {
1177                (void) utf8_width(&cp, &l);
1178                if (!cp)
1179                        break; /* truncated in the middle? */
1180        }
1181        return allot - l;
1182}
1183
1184static void find_lno(const char *line, struct emit_callback *ecbdata)
1185{
1186        const char *p;
1187        ecbdata->lno_in_preimage = 0;
1188        ecbdata->lno_in_postimage = 0;
1189        p = strchr(line, '-');
1190        if (!p)
1191                return; /* cannot happen */
1192        ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
1193        p = strchr(p, '+');
1194        if (!p)
1195                return; /* cannot happen */
1196        ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
1197}
1198
1199static void fn_out_consume(void *priv, char *line, unsigned long len)
1200{
1201        struct emit_callback *ecbdata = priv;
1202        const char *meta = diff_get_color(ecbdata->color_diff, DIFF_METAINFO);
1203        const char *context = diff_get_color(ecbdata->color_diff, DIFF_CONTEXT);
1204        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
1205        struct diff_options *o = ecbdata->opt;
1206        const char *line_prefix = diff_line_prefix(o);
1207
1208        if (ecbdata->header) {
1209                fprintf(ecbdata->opt->file, "%s", ecbdata->header->buf);
1210                strbuf_reset(ecbdata->header);
1211                ecbdata->header = NULL;
1212        }
1213        *(ecbdata->found_changesp) = 1;
1214
1215        if (ecbdata->label_path[0]) {
1216                const char *name_a_tab, *name_b_tab;
1217
1218                name_a_tab = strchr(ecbdata->label_path[0], ' ') ? "\t" : "";
1219                name_b_tab = strchr(ecbdata->label_path[1], ' ') ? "\t" : "";
1220
1221                fprintf(ecbdata->opt->file, "%s%s--- %s%s%s\n",
1222                        line_prefix, meta, ecbdata->label_path[0], reset, name_a_tab);
1223                fprintf(ecbdata->opt->file, "%s%s+++ %s%s%s\n",
1224                        line_prefix, meta, ecbdata->label_path[1], reset, name_b_tab);
1225                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
1226        }
1227
1228        if (diff_suppress_blank_empty
1229            && len == 2 && line[0] == ' ' && line[1] == '\n') {
1230                line[0] = '\n';
1231                len = 1;
1232        }
1233
1234        if (line[0] == '@') {
1235                if (ecbdata->diff_words)
1236                        diff_words_flush(ecbdata);
1237                len = sane_truncate_line(ecbdata, line, len);
1238                find_lno(line, ecbdata);
1239                emit_hunk_header(ecbdata, line, len);
1240                if (line[len-1] != '\n')
1241                        putc('\n', ecbdata->opt->file);
1242                return;
1243        }
1244
1245        if (len < 1) {
1246                emit_line(ecbdata->opt, reset, reset, line, len);
1247                if (ecbdata->diff_words
1248                    && ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN)
1249                        fputs("~\n", ecbdata->opt->file);
1250                return;
1251        }
1252
1253        if (ecbdata->diff_words) {
1254                if (line[0] == '-') {
1255                        diff_words_append(line, len,
1256                                          &ecbdata->diff_words->minus);
1257                        return;
1258                } else if (line[0] == '+') {
1259                        diff_words_append(line, len,
1260                                          &ecbdata->diff_words->plus);
1261                        return;
1262                } else if (starts_with(line, "\\ ")) {
1263                        /*
1264                         * Eat the "no newline at eof" marker as if we
1265                         * saw a "+" or "-" line with nothing on it,
1266                         * and return without diff_words_flush() to
1267                         * defer processing. If this is the end of
1268                         * preimage, more "+" lines may come after it.
1269                         */
1270                        return;
1271                }
1272                diff_words_flush(ecbdata);
1273                if (ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN) {
1274                        emit_line(ecbdata->opt, context, reset, line, len);
1275                        fputs("~\n", ecbdata->opt->file);
1276                } else {
1277                        /*
1278                         * Skip the prefix character, if any.  With
1279                         * diff_suppress_blank_empty, there may be
1280                         * none.
1281                         */
1282                        if (line[0] != '\n') {
1283                              line++;
1284                              len--;
1285                        }
1286                        emit_line(ecbdata->opt, context, reset, line, len);
1287                }
1288                return;
1289        }
1290
1291        switch (line[0]) {
1292        case '+':
1293                ecbdata->lno_in_postimage++;
1294                emit_add_line(reset, ecbdata, line + 1, len - 1);
1295                break;
1296        case '-':
1297                ecbdata->lno_in_preimage++;
1298                emit_del_line(reset, ecbdata, line + 1, len - 1);
1299                break;
1300        case ' ':
1301                ecbdata->lno_in_postimage++;
1302                ecbdata->lno_in_preimage++;
1303                emit_context_line(reset, ecbdata, line + 1, len - 1);
1304                break;
1305        default:
1306                /* incomplete line at the end */
1307                ecbdata->lno_in_preimage++;
1308                emit_line(ecbdata->opt,
1309                          diff_get_color(ecbdata->color_diff, DIFF_CONTEXT),
1310                          reset, line, len);
1311                break;
1312        }
1313}
1314
1315static char *pprint_rename(const char *a, const char *b)
1316{
1317        const char *old = a;
1318        const char *new = b;
1319        struct strbuf name = STRBUF_INIT;
1320        int pfx_length, sfx_length;
1321        int pfx_adjust_for_slash;
1322        int len_a = strlen(a);
1323        int len_b = strlen(b);
1324        int a_midlen, b_midlen;
1325        int qlen_a = quote_c_style(a, NULL, NULL, 0);
1326        int qlen_b = quote_c_style(b, NULL, NULL, 0);
1327
1328        if (qlen_a || qlen_b) {
1329                quote_c_style(a, &name, NULL, 0);
1330                strbuf_addstr(&name, " => ");
1331                quote_c_style(b, &name, NULL, 0);
1332                return strbuf_detach(&name, NULL);
1333        }
1334
1335        /* Find common prefix */
1336        pfx_length = 0;
1337        while (*old && *new && *old == *new) {
1338                if (*old == '/')
1339                        pfx_length = old - a + 1;
1340                old++;
1341                new++;
1342        }
1343
1344        /* Find common suffix */
1345        old = a + len_a;
1346        new = b + len_b;
1347        sfx_length = 0;
1348        /*
1349         * If there is a common prefix, it must end in a slash.  In
1350         * that case we let this loop run 1 into the prefix to see the
1351         * same slash.
1352         *
1353         * If there is no common prefix, we cannot do this as it would
1354         * underrun the input strings.
1355         */
1356        pfx_adjust_for_slash = (pfx_length ? 1 : 0);
1357        while (a + pfx_length - pfx_adjust_for_slash <= old &&
1358               b + pfx_length - pfx_adjust_for_slash <= new &&
1359               *old == *new) {
1360                if (*old == '/')
1361                        sfx_length = len_a - (old - a);
1362                old--;
1363                new--;
1364        }
1365
1366        /*
1367         * pfx{mid-a => mid-b}sfx
1368         * {pfx-a => pfx-b}sfx
1369         * pfx{sfx-a => sfx-b}
1370         * name-a => name-b
1371         */
1372        a_midlen = len_a - pfx_length - sfx_length;
1373        b_midlen = len_b - pfx_length - sfx_length;
1374        if (a_midlen < 0)
1375                a_midlen = 0;
1376        if (b_midlen < 0)
1377                b_midlen = 0;
1378
1379        strbuf_grow(&name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
1380        if (pfx_length + sfx_length) {
1381                strbuf_add(&name, a, pfx_length);
1382                strbuf_addch(&name, '{');
1383        }
1384        strbuf_add(&name, a + pfx_length, a_midlen);
1385        strbuf_addstr(&name, " => ");
1386        strbuf_add(&name, b + pfx_length, b_midlen);
1387        if (pfx_length + sfx_length) {
1388                strbuf_addch(&name, '}');
1389                strbuf_add(&name, a + len_a - sfx_length, sfx_length);
1390        }
1391        return strbuf_detach(&name, NULL);
1392}
1393
1394struct diffstat_t {
1395        int nr;
1396        int alloc;
1397        struct diffstat_file {
1398                char *from_name;
1399                char *name;
1400                char *print_name;
1401                unsigned is_unmerged:1;
1402                unsigned is_binary:1;
1403                unsigned is_renamed:1;
1404                unsigned is_interesting:1;
1405                uintmax_t added, deleted;
1406        } **files;
1407};
1408
1409static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
1410                                          const char *name_a,
1411                                          const char *name_b)
1412{
1413        struct diffstat_file *x;
1414        x = xcalloc(1, sizeof(*x));
1415        ALLOC_GROW(diffstat->files, diffstat->nr + 1, diffstat->alloc);
1416        diffstat->files[diffstat->nr++] = x;
1417        if (name_b) {
1418                x->from_name = xstrdup(name_a);
1419                x->name = xstrdup(name_b);
1420                x->is_renamed = 1;
1421        }
1422        else {
1423                x->from_name = NULL;
1424                x->name = xstrdup(name_a);
1425        }
1426        return x;
1427}
1428
1429static void diffstat_consume(void *priv, char *line, unsigned long len)
1430{
1431        struct diffstat_t *diffstat = priv;
1432        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
1433
1434        if (line[0] == '+')
1435                x->added++;
1436        else if (line[0] == '-')
1437                x->deleted++;
1438}
1439
1440const char mime_boundary_leader[] = "------------";
1441
1442static int scale_linear(int it, int width, int max_change)
1443{
1444        if (!it)
1445                return 0;
1446        /*
1447         * make sure that at least one '-' or '+' is printed if
1448         * there is any change to this path. The easiest way is to
1449         * scale linearly as if the alloted width is one column shorter
1450         * than it is, and then add 1 to the result.
1451         */
1452        return 1 + (it * (width - 1) / max_change);
1453}
1454
1455static void show_name(FILE *file,
1456                      const char *prefix, const char *name, int len)
1457{
1458        fprintf(file, " %s%-*s |", prefix, len, name);
1459}
1460
1461static void show_graph(FILE *file, char ch, int cnt, const char *set, const char *reset)
1462{
1463        if (cnt <= 0)
1464                return;
1465        fprintf(file, "%s", set);
1466        while (cnt--)
1467                putc(ch, file);
1468        fprintf(file, "%s", reset);
1469}
1470
1471static void fill_print_name(struct diffstat_file *file)
1472{
1473        char *pname;
1474
1475        if (file->print_name)
1476                return;
1477
1478        if (!file->is_renamed) {
1479                struct strbuf buf = STRBUF_INIT;
1480                if (quote_c_style(file->name, &buf, NULL, 0)) {
1481                        pname = strbuf_detach(&buf, NULL);
1482                } else {
1483                        pname = file->name;
1484                        strbuf_release(&buf);
1485                }
1486        } else {
1487                pname = pprint_rename(file->from_name, file->name);
1488        }
1489        file->print_name = pname;
1490}
1491
1492int print_stat_summary(FILE *fp, int files, int insertions, int deletions)
1493{
1494        struct strbuf sb = STRBUF_INIT;
1495        int ret;
1496
1497        if (!files) {
1498                assert(insertions == 0 && deletions == 0);
1499                return fprintf(fp, "%s\n", " 0 files changed");
1500        }
1501
1502        strbuf_addf(&sb,
1503                    (files == 1) ? " %d file changed" : " %d files changed",
1504                    files);
1505
1506        /*
1507         * For binary diff, the caller may want to print "x files
1508         * changed" with insertions == 0 && deletions == 0.
1509         *
1510         * Not omitting "0 insertions(+), 0 deletions(-)" in this case
1511         * is probably less confusing (i.e skip over "2 files changed
1512         * but nothing about added/removed lines? Is this a bug in Git?").
1513         */
1514        if (insertions || deletions == 0) {
1515                strbuf_addf(&sb,
1516                            (insertions == 1) ? ", %d insertion(+)" : ", %d insertions(+)",
1517                            insertions);
1518        }
1519
1520        if (deletions || insertions == 0) {
1521                strbuf_addf(&sb,
1522                            (deletions == 1) ? ", %d deletion(-)" : ", %d deletions(-)",
1523                            deletions);
1524        }
1525        strbuf_addch(&sb, '\n');
1526        ret = fputs(sb.buf, fp);
1527        strbuf_release(&sb);
1528        return ret;
1529}
1530
1531static void show_stats(struct diffstat_t *data, struct diff_options *options)
1532{
1533        int i, len, add, del, adds = 0, dels = 0;
1534        uintmax_t max_change = 0, max_len = 0;
1535        int total_files = data->nr, count;
1536        int width, name_width, graph_width, number_width = 0, bin_width = 0;
1537        const char *reset, *add_c, *del_c;
1538        const char *line_prefix = "";
1539        int extra_shown = 0;
1540
1541        if (data->nr == 0)
1542                return;
1543
1544        line_prefix = diff_line_prefix(options);
1545        count = options->stat_count ? options->stat_count : data->nr;
1546
1547        reset = diff_get_color_opt(options, DIFF_RESET);
1548        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
1549        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
1550
1551        /*
1552         * Find the longest filename and max number of changes
1553         */
1554        for (i = 0; (i < count) && (i < data->nr); i++) {
1555                struct diffstat_file *file = data->files[i];
1556                uintmax_t change = file->added + file->deleted;
1557
1558                if (!file->is_interesting && (change == 0)) {
1559                        count++; /* not shown == room for one more */
1560                        continue;
1561                }
1562                fill_print_name(file);
1563                len = strlen(file->print_name);
1564                if (max_len < len)
1565                        max_len = len;
1566
1567                if (file->is_unmerged) {
1568                        /* "Unmerged" is 8 characters */
1569                        bin_width = bin_width < 8 ? 8 : bin_width;
1570                        continue;
1571                }
1572                if (file->is_binary) {
1573                        /* "Bin XXX -> YYY bytes" */
1574                        int w = 14 + decimal_width(file->added)
1575                                + decimal_width(file->deleted);
1576                        bin_width = bin_width < w ? w : bin_width;
1577                        /* Display change counts aligned with "Bin" */
1578                        number_width = 3;
1579                        continue;
1580                }
1581
1582                if (max_change < change)
1583                        max_change = change;
1584        }
1585        count = i; /* where we can stop scanning in data->files[] */
1586
1587        /*
1588         * We have width = stat_width or term_columns() columns total.
1589         * We want a maximum of min(max_len, stat_name_width) for the name part.
1590         * We want a maximum of min(max_change, stat_graph_width) for the +- part.
1591         * We also need 1 for " " and 4 + decimal_width(max_change)
1592         * for " | NNNN " and one the empty column at the end, altogether
1593         * 6 + decimal_width(max_change).
1594         *
1595         * If there's not enough space, we will use the smaller of
1596         * stat_name_width (if set) and 5/8*width for the filename,
1597         * and the rest for constant elements + graph part, but no more
1598         * than stat_graph_width for the graph part.
1599         * (5/8 gives 50 for filename and 30 for the constant parts + graph
1600         * for the standard terminal size).
1601         *
1602         * In other words: stat_width limits the maximum width, and
1603         * stat_name_width fixes the maximum width of the filename,
1604         * and is also used to divide available columns if there
1605         * aren't enough.
1606         *
1607         * Binary files are displayed with "Bin XXX -> YYY bytes"
1608         * instead of the change count and graph. This part is treated
1609         * similarly to the graph part, except that it is not
1610         * "scaled". If total width is too small to accommodate the
1611         * guaranteed minimum width of the filename part and the
1612         * separators and this message, this message will "overflow"
1613         * making the line longer than the maximum width.
1614         */
1615
1616        if (options->stat_width == -1)
1617                width = term_columns() - options->output_prefix_length;
1618        else
1619                width = options->stat_width ? options->stat_width : 80;
1620        number_width = decimal_width(max_change) > number_width ?
1621                decimal_width(max_change) : number_width;
1622
1623        if (options->stat_graph_width == -1)
1624                options->stat_graph_width = diff_stat_graph_width;
1625
1626        /*
1627         * Guarantee 3/8*16==6 for the graph part
1628         * and 5/8*16==10 for the filename part
1629         */
1630        if (width < 16 + 6 + number_width)
1631                width = 16 + 6 + number_width;
1632
1633        /*
1634         * First assign sizes that are wanted, ignoring available width.
1635         * strlen("Bin XXX -> YYY bytes") == bin_width, and the part
1636         * starting from "XXX" should fit in graph_width.
1637         */
1638        graph_width = max_change + 4 > bin_width ? max_change : bin_width - 4;
1639        if (options->stat_graph_width &&
1640            options->stat_graph_width < graph_width)
1641                graph_width = options->stat_graph_width;
1642
1643        name_width = (options->stat_name_width > 0 &&
1644                      options->stat_name_width < max_len) ?
1645                options->stat_name_width : max_len;
1646
1647        /*
1648         * Adjust adjustable widths not to exceed maximum width
1649         */
1650        if (name_width + number_width + 6 + graph_width > width) {
1651                if (graph_width > width * 3/8 - number_width - 6) {
1652                        graph_width = width * 3/8 - number_width - 6;
1653                        if (graph_width < 6)
1654                                graph_width = 6;
1655                }
1656
1657                if (options->stat_graph_width &&
1658                    graph_width > options->stat_graph_width)
1659                        graph_width = options->stat_graph_width;
1660                if (name_width > width - number_width - 6 - graph_width)
1661                        name_width = width - number_width - 6 - graph_width;
1662                else
1663                        graph_width = width - number_width - 6 - name_width;
1664        }
1665
1666        /*
1667         * From here name_width is the width of the name area,
1668         * and graph_width is the width of the graph area.
1669         * max_change is used to scale graph properly.
1670         */
1671        for (i = 0; i < count; i++) {
1672                const char *prefix = "";
1673                struct diffstat_file *file = data->files[i];
1674                char *name = file->print_name;
1675                uintmax_t added = file->added;
1676                uintmax_t deleted = file->deleted;
1677                int name_len;
1678
1679                if (!file->is_interesting && (added + deleted == 0))
1680                        continue;
1681
1682                /*
1683                 * "scale" the filename
1684                 */
1685                len = name_width;
1686                name_len = strlen(name);
1687                if (name_width < name_len) {
1688                        char *slash;
1689                        prefix = "...";
1690                        len -= 3;
1691                        name += name_len - len;
1692                        slash = strchr(name, '/');
1693                        if (slash)
1694                                name = slash;
1695                }
1696
1697                if (file->is_binary) {
1698                        fprintf(options->file, "%s", line_prefix);
1699                        show_name(options->file, prefix, name, len);
1700                        fprintf(options->file, " %*s", number_width, "Bin");
1701                        if (!added && !deleted) {
1702                                putc('\n', options->file);
1703                                continue;
1704                        }
1705                        fprintf(options->file, " %s%"PRIuMAX"%s",
1706                                del_c, deleted, reset);
1707                        fprintf(options->file, " -> ");
1708                        fprintf(options->file, "%s%"PRIuMAX"%s",
1709                                add_c, added, reset);
1710                        fprintf(options->file, " bytes");
1711                        fprintf(options->file, "\n");
1712                        continue;
1713                }
1714                else if (file->is_unmerged) {
1715                        fprintf(options->file, "%s", line_prefix);
1716                        show_name(options->file, prefix, name, len);
1717                        fprintf(options->file, " Unmerged\n");
1718                        continue;
1719                }
1720
1721                /*
1722                 * scale the add/delete
1723                 */
1724                add = added;
1725                del = deleted;
1726
1727                if (graph_width <= max_change) {
1728                        int total = scale_linear(add + del, graph_width, max_change);
1729                        if (total < 2 && add && del)
1730                                /* width >= 2 due to the sanity check */
1731                                total = 2;
1732                        if (add < del) {
1733                                add = scale_linear(add, graph_width, max_change);
1734                                del = total - add;
1735                        } else {
1736                                del = scale_linear(del, graph_width, max_change);
1737                                add = total - del;
1738                        }
1739                }
1740                fprintf(options->file, "%s", line_prefix);
1741                show_name(options->file, prefix, name, len);
1742                fprintf(options->file, " %*"PRIuMAX"%s",
1743                        number_width, added + deleted,
1744                        added + deleted ? " " : "");
1745                show_graph(options->file, '+', add, add_c, reset);
1746                show_graph(options->file, '-', del, del_c, reset);
1747                fprintf(options->file, "\n");
1748        }
1749
1750        for (i = 0; i < data->nr; i++) {
1751                struct diffstat_file *file = data->files[i];
1752                uintmax_t added = file->added;
1753                uintmax_t deleted = file->deleted;
1754
1755                if (file->is_unmerged ||
1756                    (!file->is_interesting && (added + deleted == 0))) {
1757                        total_files--;
1758                        continue;
1759                }
1760
1761                if (!file->is_binary) {
1762                        adds += added;
1763                        dels += deleted;
1764                }
1765                if (i < count)
1766                        continue;
1767                if (!extra_shown)
1768                        fprintf(options->file, "%s ...\n", line_prefix);
1769                extra_shown = 1;
1770        }
1771        fprintf(options->file, "%s", line_prefix);
1772        print_stat_summary(options->file, total_files, adds, dels);
1773}
1774
1775static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
1776{
1777        int i, adds = 0, dels = 0, total_files = data->nr;
1778
1779        if (data->nr == 0)
1780                return;
1781
1782        for (i = 0; i < data->nr; i++) {
1783                int added = data->files[i]->added;
1784                int deleted= data->files[i]->deleted;
1785
1786                if (data->files[i]->is_unmerged ||
1787                    (!data->files[i]->is_interesting && (added + deleted == 0))) {
1788                        total_files--;
1789                } else if (!data->files[i]->is_binary) { /* don't count bytes */
1790                        adds += added;
1791                        dels += deleted;
1792                }
1793        }
1794        fprintf(options->file, "%s", diff_line_prefix(options));
1795        print_stat_summary(options->file, total_files, adds, dels);
1796}
1797
1798static void show_numstat(struct diffstat_t *data, struct diff_options *options)
1799{
1800        int i;
1801
1802        if (data->nr == 0)
1803                return;
1804
1805        for (i = 0; i < data->nr; i++) {
1806                struct diffstat_file *file = data->files[i];
1807
1808                fprintf(options->file, "%s", diff_line_prefix(options));
1809
1810                if (file->is_binary)
1811                        fprintf(options->file, "-\t-\t");
1812                else
1813                        fprintf(options->file,
1814                                "%"PRIuMAX"\t%"PRIuMAX"\t",
1815                                file->added, file->deleted);
1816                if (options->line_termination) {
1817                        fill_print_name(file);
1818                        if (!file->is_renamed)
1819                                write_name_quoted(file->name, options->file,
1820                                                  options->line_termination);
1821                        else {
1822                                fputs(file->print_name, options->file);
1823                                putc(options->line_termination, options->file);
1824                        }
1825                } else {
1826                        if (file->is_renamed) {
1827                                putc('\0', options->file);
1828                                write_name_quoted(file->from_name, options->file, '\0');
1829                        }
1830                        write_name_quoted(file->name, options->file, '\0');
1831                }
1832        }
1833}
1834
1835struct dirstat_file {
1836        const char *name;
1837        unsigned long changed;
1838};
1839
1840struct dirstat_dir {
1841        struct dirstat_file *files;
1842        int alloc, nr, permille, cumulative;
1843};
1844
1845static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
1846                unsigned long changed, const char *base, int baselen)
1847{
1848        unsigned long this_dir = 0;
1849        unsigned int sources = 0;
1850        const char *line_prefix = diff_line_prefix(opt);
1851
1852        while (dir->nr) {
1853                struct dirstat_file *f = dir->files;
1854                int namelen = strlen(f->name);
1855                unsigned long this;
1856                char *slash;
1857
1858                if (namelen < baselen)
1859                        break;
1860                if (memcmp(f->name, base, baselen))
1861                        break;
1862                slash = strchr(f->name + baselen, '/');
1863                if (slash) {
1864                        int newbaselen = slash + 1 - f->name;
1865                        this = gather_dirstat(opt, dir, changed, f->name, newbaselen);
1866                        sources++;
1867                } else {
1868                        this = f->changed;
1869                        dir->files++;
1870                        dir->nr--;
1871                        sources += 2;
1872                }
1873                this_dir += this;
1874        }
1875
1876        /*
1877         * We don't report dirstat's for
1878         *  - the top level
1879         *  - or cases where everything came from a single directory
1880         *    under this directory (sources == 1).
1881         */
1882        if (baselen && sources != 1) {
1883                if (this_dir) {
1884                        int permille = this_dir * 1000 / changed;
1885                        if (permille >= dir->permille) {
1886                                fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
1887                                        permille / 10, permille % 10, baselen, base);
1888                                if (!dir->cumulative)
1889                                        return 0;
1890                        }
1891                }
1892        }
1893        return this_dir;
1894}
1895
1896static int dirstat_compare(const void *_a, const void *_b)
1897{
1898        const struct dirstat_file *a = _a;
1899        const struct dirstat_file *b = _b;
1900        return strcmp(a->name, b->name);
1901}
1902
1903static void show_dirstat(struct diff_options *options)
1904{
1905        int i;
1906        unsigned long changed;
1907        struct dirstat_dir dir;
1908        struct diff_queue_struct *q = &diff_queued_diff;
1909
1910        dir.files = NULL;
1911        dir.alloc = 0;
1912        dir.nr = 0;
1913        dir.permille = options->dirstat_permille;
1914        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1915
1916        changed = 0;
1917        for (i = 0; i < q->nr; i++) {
1918                struct diff_filepair *p = q->queue[i];
1919                const char *name;
1920                unsigned long copied, added, damage;
1921                int content_changed;
1922
1923                name = p->two->path ? p->two->path : p->one->path;
1924
1925                if (p->one->sha1_valid && p->two->sha1_valid)
1926                        content_changed = hashcmp(p->one->sha1, p->two->sha1);
1927                else
1928                        content_changed = 1;
1929
1930                if (!content_changed) {
1931                        /*
1932                         * The SHA1 has not changed, so pre-/post-content is
1933                         * identical. We can therefore skip looking at the
1934                         * file contents altogether.
1935                         */
1936                        damage = 0;
1937                        goto found_damage;
1938                }
1939
1940                if (DIFF_OPT_TST(options, DIRSTAT_BY_FILE)) {
1941                        /*
1942                         * In --dirstat-by-file mode, we don't really need to
1943                         * look at the actual file contents at all.
1944                         * The fact that the SHA1 changed is enough for us to
1945                         * add this file to the list of results
1946                         * (with each file contributing equal damage).
1947                         */
1948                        damage = 1;
1949                        goto found_damage;
1950                }
1951
1952                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
1953                        diff_populate_filespec(p->one, 0);
1954                        diff_populate_filespec(p->two, 0);
1955                        diffcore_count_changes(p->one, p->two, NULL, NULL, 0,
1956                                               &copied, &added);
1957                        diff_free_filespec_data(p->one);
1958                        diff_free_filespec_data(p->two);
1959                } else if (DIFF_FILE_VALID(p->one)) {
1960                        diff_populate_filespec(p->one, CHECK_SIZE_ONLY);
1961                        copied = added = 0;
1962                        diff_free_filespec_data(p->one);
1963                } else if (DIFF_FILE_VALID(p->two)) {
1964                        diff_populate_filespec(p->two, CHECK_SIZE_ONLY);
1965                        copied = 0;
1966                        added = p->two->size;
1967                        diff_free_filespec_data(p->two);
1968                } else
1969                        continue;
1970
1971                /*
1972                 * Original minus copied is the removed material,
1973                 * added is the new material.  They are both damages
1974                 * made to the preimage.
1975                 * If the resulting damage is zero, we know that
1976                 * diffcore_count_changes() considers the two entries to
1977                 * be identical, but since content_changed is true, we
1978                 * know that there must have been _some_ kind of change,
1979                 * so we force all entries to have damage > 0.
1980                 */
1981                damage = (p->one->size - copied) + added;
1982                if (!damage)
1983                        damage = 1;
1984
1985found_damage:
1986                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1987                dir.files[dir.nr].name = name;
1988                dir.files[dir.nr].changed = damage;
1989                changed += damage;
1990                dir.nr++;
1991        }
1992
1993        /* This can happen even with many files, if everything was renames */
1994        if (!changed)
1995                return;
1996
1997        /* Show all directories with more than x% of the changes */
1998        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1999        gather_dirstat(options, &dir, changed, "", 0);
2000}
2001
2002static void show_dirstat_by_line(struct diffstat_t *data, struct diff_options *options)
2003{
2004        int i;
2005        unsigned long changed;
2006        struct dirstat_dir dir;
2007
2008        if (data->nr == 0)
2009                return;
2010
2011        dir.files = NULL;
2012        dir.alloc = 0;
2013        dir.nr = 0;
2014        dir.permille = options->dirstat_permille;
2015        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
2016
2017        changed = 0;
2018        for (i = 0; i < data->nr; i++) {
2019                struct diffstat_file *file = data->files[i];
2020                unsigned long damage = file->added + file->deleted;
2021                if (file->is_binary)
2022                        /*
2023                         * binary files counts bytes, not lines. Must find some
2024                         * way to normalize binary bytes vs. textual lines.
2025                         * The following heuristic assumes that there are 64
2026                         * bytes per "line".
2027                         * This is stupid and ugly, but very cheap...
2028                         */
2029                        damage = (damage + 63) / 64;
2030                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
2031                dir.files[dir.nr].name = file->name;
2032                dir.files[dir.nr].changed = damage;
2033                changed += damage;
2034                dir.nr++;
2035        }
2036
2037        /* This can happen even with many files, if everything was renames */
2038        if (!changed)
2039                return;
2040
2041        /* Show all directories with more than x% of the changes */
2042        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
2043        gather_dirstat(options, &dir, changed, "", 0);
2044}
2045
2046static void free_diffstat_info(struct diffstat_t *diffstat)
2047{
2048        int i;
2049        for (i = 0; i < diffstat->nr; i++) {
2050                struct diffstat_file *f = diffstat->files[i];
2051                if (f->name != f->print_name)
2052                        free(f->print_name);
2053                free(f->name);
2054                free(f->from_name);
2055                free(f);
2056        }
2057        free(diffstat->files);
2058}
2059
2060struct checkdiff_t {
2061        const char *filename;
2062        int lineno;
2063        int conflict_marker_size;
2064        struct diff_options *o;
2065        unsigned ws_rule;
2066        unsigned status;
2067};
2068
2069static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
2070{
2071        char firstchar;
2072        int cnt;
2073
2074        if (len < marker_size + 1)
2075                return 0;
2076        firstchar = line[0];
2077        switch (firstchar) {
2078        case '=': case '>': case '<': case '|':
2079                break;
2080        default:
2081                return 0;
2082        }
2083        for (cnt = 1; cnt < marker_size; cnt++)
2084                if (line[cnt] != firstchar)
2085                        return 0;
2086        /* line[1] thru line[marker_size-1] are same as firstchar */
2087        if (len < marker_size + 1 || !isspace(line[marker_size]))
2088                return 0;
2089        return 1;
2090}
2091
2092static void checkdiff_consume(void *priv, char *line, unsigned long len)
2093{
2094        struct checkdiff_t *data = priv;
2095        int marker_size = data->conflict_marker_size;
2096        const char *ws = diff_get_color(data->o->use_color, DIFF_WHITESPACE);
2097        const char *reset = diff_get_color(data->o->use_color, DIFF_RESET);
2098        const char *set = diff_get_color(data->o->use_color, DIFF_FILE_NEW);
2099        char *err;
2100        const char *line_prefix;
2101
2102        assert(data->o);
2103        line_prefix = diff_line_prefix(data->o);
2104
2105        if (line[0] == '+') {
2106                unsigned bad;
2107                data->lineno++;
2108                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
2109                        data->status |= 1;
2110                        fprintf(data->o->file,
2111                                "%s%s:%d: leftover conflict marker\n",
2112                                line_prefix, data->filename, data->lineno);
2113                }
2114                bad = ws_check(line + 1, len - 1, data->ws_rule);
2115                if (!bad)
2116                        return;
2117                data->status |= bad;
2118                err = whitespace_error_string(bad);
2119                fprintf(data->o->file, "%s%s:%d: %s.\n",
2120                        line_prefix, data->filename, data->lineno, err);
2121                free(err);
2122                emit_line(data->o, set, reset, line, 1);
2123                ws_check_emit(line + 1, len - 1, data->ws_rule,
2124                              data->o->file, set, reset, ws);
2125        } else if (line[0] == ' ') {
2126                data->lineno++;
2127        } else if (line[0] == '@') {
2128                char *plus = strchr(line, '+');
2129                if (plus)
2130                        data->lineno = strtol(plus, NULL, 10) - 1;
2131                else
2132                        die("invalid diff");
2133        }
2134}
2135
2136static unsigned char *deflate_it(char *data,
2137                                 unsigned long size,
2138                                 unsigned long *result_size)
2139{
2140        int bound;
2141        unsigned char *deflated;
2142        git_zstream stream;
2143
2144        git_deflate_init(&stream, zlib_compression_level);
2145        bound = git_deflate_bound(&stream, size);
2146        deflated = xmalloc(bound);
2147        stream.next_out = deflated;
2148        stream.avail_out = bound;
2149
2150        stream.next_in = (unsigned char *)data;
2151        stream.avail_in = size;
2152        while (git_deflate(&stream, Z_FINISH) == Z_OK)
2153                ; /* nothing */
2154        git_deflate_end(&stream);
2155        *result_size = stream.total_out;
2156        return deflated;
2157}
2158
2159static void emit_binary_diff_body(FILE *file, mmfile_t *one, mmfile_t *two,
2160                                  const char *prefix)
2161{
2162        void *cp;
2163        void *delta;
2164        void *deflated;
2165        void *data;
2166        unsigned long orig_size;
2167        unsigned long delta_size;
2168        unsigned long deflate_size;
2169        unsigned long data_size;
2170
2171        /* We could do deflated delta, or we could do just deflated two,
2172         * whichever is smaller.
2173         */
2174        delta = NULL;
2175        deflated = deflate_it(two->ptr, two->size, &deflate_size);
2176        if (one->size && two->size) {
2177                delta = diff_delta(one->ptr, one->size,
2178                                   two->ptr, two->size,
2179                                   &delta_size, deflate_size);
2180                if (delta) {
2181                        void *to_free = delta;
2182                        orig_size = delta_size;
2183                        delta = deflate_it(delta, delta_size, &delta_size);
2184                        free(to_free);
2185                }
2186        }
2187
2188        if (delta && delta_size < deflate_size) {
2189                fprintf(file, "%sdelta %lu\n", prefix, orig_size);
2190                free(deflated);
2191                data = delta;
2192                data_size = delta_size;
2193        }
2194        else {
2195                fprintf(file, "%sliteral %lu\n", prefix, two->size);
2196                free(delta);
2197                data = deflated;
2198                data_size = deflate_size;
2199        }
2200
2201        /* emit data encoded in base85 */
2202        cp = data;
2203        while (data_size) {
2204                int bytes = (52 < data_size) ? 52 : data_size;
2205                char line[70];
2206                data_size -= bytes;
2207                if (bytes <= 26)
2208                        line[0] = bytes + 'A' - 1;
2209                else
2210                        line[0] = bytes - 26 + 'a' - 1;
2211                encode_85(line + 1, cp, bytes);
2212                cp = (char *) cp + bytes;
2213                fprintf(file, "%s", prefix);
2214                fputs(line, file);
2215                fputc('\n', file);
2216        }
2217        fprintf(file, "%s\n", prefix);
2218        free(data);
2219}
2220
2221static void emit_binary_diff(FILE *file, mmfile_t *one, mmfile_t *two,
2222                             const char *prefix)
2223{
2224        fprintf(file, "%sGIT binary patch\n", prefix);
2225        emit_binary_diff_body(file, one, two, prefix);
2226        emit_binary_diff_body(file, two, one, prefix);
2227}
2228
2229int diff_filespec_is_binary(struct diff_filespec *one)
2230{
2231        if (one->is_binary == -1) {
2232                diff_filespec_load_driver(one);
2233                if (one->driver->binary != -1)
2234                        one->is_binary = one->driver->binary;
2235                else {
2236                        if (!one->data && DIFF_FILE_VALID(one))
2237                                diff_populate_filespec(one, CHECK_BINARY);
2238                        if (one->is_binary == -1 && one->data)
2239                                one->is_binary = buffer_is_binary(one->data,
2240                                                one->size);
2241                        if (one->is_binary == -1)
2242                                one->is_binary = 0;
2243                }
2244        }
2245        return one->is_binary;
2246}
2247
2248static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
2249{
2250        diff_filespec_load_driver(one);
2251        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
2252}
2253
2254void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
2255{
2256        if (!options->a_prefix)
2257                options->a_prefix = a;
2258        if (!options->b_prefix)
2259                options->b_prefix = b;
2260}
2261
2262struct userdiff_driver *get_textconv(struct diff_filespec *one)
2263{
2264        if (!DIFF_FILE_VALID(one))
2265                return NULL;
2266
2267        diff_filespec_load_driver(one);
2268        return userdiff_get_textconv(one->driver);
2269}
2270
2271static void builtin_diff(const char *name_a,
2272                         const char *name_b,
2273                         struct diff_filespec *one,
2274                         struct diff_filespec *two,
2275                         const char *xfrm_msg,
2276                         int must_show_header,
2277                         struct diff_options *o,
2278                         int complete_rewrite)
2279{
2280        mmfile_t mf1, mf2;
2281        const char *lbl[2];
2282        char *a_one, *b_two;
2283        const char *meta = diff_get_color_opt(o, DIFF_METAINFO);
2284        const char *reset = diff_get_color_opt(o, DIFF_RESET);
2285        const char *a_prefix, *b_prefix;
2286        struct userdiff_driver *textconv_one = NULL;
2287        struct userdiff_driver *textconv_two = NULL;
2288        struct strbuf header = STRBUF_INIT;
2289        const char *line_prefix = diff_line_prefix(o);
2290
2291        if (DIFF_OPT_TST(o, SUBMODULE_LOG) &&
2292                        (!one->mode || S_ISGITLINK(one->mode)) &&
2293                        (!two->mode || S_ISGITLINK(two->mode))) {
2294                const char *del = diff_get_color_opt(o, DIFF_FILE_OLD);
2295                const char *add = diff_get_color_opt(o, DIFF_FILE_NEW);
2296                show_submodule_summary(o->file, one->path ? one->path : two->path,
2297                                line_prefix,
2298                                one->sha1, two->sha1, two->dirty_submodule,
2299                                meta, del, add, reset);
2300                return;
2301        }
2302
2303        if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
2304                textconv_one = get_textconv(one);
2305                textconv_two = get_textconv(two);
2306        }
2307
2308        diff_set_mnemonic_prefix(o, "a/", "b/");
2309        if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
2310                a_prefix = o->b_prefix;
2311                b_prefix = o->a_prefix;
2312        } else {
2313                a_prefix = o->a_prefix;
2314                b_prefix = o->b_prefix;
2315        }
2316
2317        /* Never use a non-valid filename anywhere if at all possible */
2318        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
2319        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
2320
2321        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
2322        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
2323        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
2324        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
2325        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, meta, a_one, b_two, reset);
2326        if (lbl[0][0] == '/') {
2327                /* /dev/null */
2328                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, meta, two->mode, reset);
2329                if (xfrm_msg)
2330                        strbuf_addstr(&header, xfrm_msg);
2331                must_show_header = 1;
2332        }
2333        else if (lbl[1][0] == '/') {
2334                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, meta, one->mode, reset);
2335                if (xfrm_msg)
2336                        strbuf_addstr(&header, xfrm_msg);
2337                must_show_header = 1;
2338        }
2339        else {
2340                if (one->mode != two->mode) {
2341                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, meta, one->mode, reset);
2342                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, meta, two->mode, reset);
2343                        must_show_header = 1;
2344                }
2345                if (xfrm_msg)
2346                        strbuf_addstr(&header, xfrm_msg);
2347
2348                /*
2349                 * we do not run diff between different kind
2350                 * of objects.
2351                 */
2352                if ((one->mode ^ two->mode) & S_IFMT)
2353                        goto free_ab_and_return;
2354                if (complete_rewrite &&
2355                    (textconv_one || !diff_filespec_is_binary(one)) &&
2356                    (textconv_two || !diff_filespec_is_binary(two))) {
2357                        fprintf(o->file, "%s", header.buf);
2358                        strbuf_reset(&header);
2359                        emit_rewrite_diff(name_a, name_b, one, two,
2360                                                textconv_one, textconv_two, o);
2361                        o->found_changes = 1;
2362                        goto free_ab_and_return;
2363                }
2364        }
2365
2366        if (o->irreversible_delete && lbl[1][0] == '/') {
2367                fprintf(o->file, "%s", header.buf);
2368                strbuf_reset(&header);
2369                goto free_ab_and_return;
2370        } else if (!DIFF_OPT_TST(o, TEXT) &&
2371            ( (!textconv_one && diff_filespec_is_binary(one)) ||
2372              (!textconv_two && diff_filespec_is_binary(two)) )) {
2373                if (!one->data && !two->data &&
2374                    S_ISREG(one->mode) && S_ISREG(two->mode) &&
2375                    !DIFF_OPT_TST(o, BINARY)) {
2376                        if (!hashcmp(one->sha1, two->sha1)) {
2377                                if (must_show_header)
2378                                        fprintf(o->file, "%s", header.buf);
2379                                goto free_ab_and_return;
2380                        }
2381                        fprintf(o->file, "%s", header.buf);
2382                        fprintf(o->file, "%sBinary files %s and %s differ\n",
2383                                line_prefix, lbl[0], lbl[1]);
2384                        goto free_ab_and_return;
2385                }
2386                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2387                        die("unable to read files to diff");
2388                /* Quite common confusing case */
2389                if (mf1.size == mf2.size &&
2390                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
2391                        if (must_show_header)
2392                                fprintf(o->file, "%s", header.buf);
2393                        goto free_ab_and_return;
2394                }
2395                fprintf(o->file, "%s", header.buf);
2396                strbuf_reset(&header);
2397                if (DIFF_OPT_TST(o, BINARY))
2398                        emit_binary_diff(o->file, &mf1, &mf2, line_prefix);
2399                else
2400                        fprintf(o->file, "%sBinary files %s and %s differ\n",
2401                                line_prefix, lbl[0], lbl[1]);
2402                o->found_changes = 1;
2403        } else {
2404                /* Crazy xdl interfaces.. */
2405                const char *diffopts = getenv("GIT_DIFF_OPTS");
2406                const char *v;
2407                xpparam_t xpp;
2408                xdemitconf_t xecfg;
2409                struct emit_callback ecbdata;
2410                const struct userdiff_funcname *pe;
2411
2412                if (must_show_header) {
2413                        fprintf(o->file, "%s", header.buf);
2414                        strbuf_reset(&header);
2415                }
2416
2417                mf1.size = fill_textconv(textconv_one, one, &mf1.ptr);
2418                mf2.size = fill_textconv(textconv_two, two, &mf2.ptr);
2419
2420                pe = diff_funcname_pattern(one);
2421                if (!pe)
2422                        pe = diff_funcname_pattern(two);
2423
2424                memset(&xpp, 0, sizeof(xpp));
2425                memset(&xecfg, 0, sizeof(xecfg));
2426                memset(&ecbdata, 0, sizeof(ecbdata));
2427                ecbdata.label_path = lbl;
2428                ecbdata.color_diff = want_color(o->use_color);
2429                ecbdata.found_changesp = &o->found_changes;
2430                ecbdata.ws_rule = whitespace_rule(name_b);
2431                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
2432                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2433                ecbdata.opt = o;
2434                ecbdata.header = header.len ? &header : NULL;
2435                xpp.flags = o->xdl_opts;
2436                xecfg.ctxlen = o->context;
2437                xecfg.interhunkctxlen = o->interhunkcontext;
2438                xecfg.flags = XDL_EMIT_FUNCNAMES;
2439                if (DIFF_OPT_TST(o, FUNCCONTEXT))
2440                        xecfg.flags |= XDL_EMIT_FUNCCONTEXT;
2441                if (pe)
2442                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
2443                if (!diffopts)
2444                        ;
2445                else if (skip_prefix(diffopts, "--unified=", &v))
2446                        xecfg.ctxlen = strtoul(v, NULL, 10);
2447                else if (skip_prefix(diffopts, "-u", &v))
2448                        xecfg.ctxlen = strtoul(v, NULL, 10);
2449                if (o->word_diff)
2450                        init_diff_words_data(&ecbdata, o, one, two);
2451                xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
2452                              &xpp, &xecfg);
2453                if (o->word_diff)
2454                        free_diff_words_data(&ecbdata);
2455                if (textconv_one)
2456                        free(mf1.ptr);
2457                if (textconv_two)
2458                        free(mf2.ptr);
2459                xdiff_clear_find_func(&xecfg);
2460        }
2461
2462 free_ab_and_return:
2463        strbuf_release(&header);
2464        diff_free_filespec_data(one);
2465        diff_free_filespec_data(two);
2466        free(a_one);
2467        free(b_two);
2468        return;
2469}
2470
2471static void builtin_diffstat(const char *name_a, const char *name_b,
2472                             struct diff_filespec *one,
2473                             struct diff_filespec *two,
2474                             struct diffstat_t *diffstat,
2475                             struct diff_options *o,
2476                             struct diff_filepair *p)
2477{
2478        mmfile_t mf1, mf2;
2479        struct diffstat_file *data;
2480        int same_contents;
2481        int complete_rewrite = 0;
2482
2483        if (!DIFF_PAIR_UNMERGED(p)) {
2484                if (p->status == DIFF_STATUS_MODIFIED && p->score)
2485                        complete_rewrite = 1;
2486        }
2487
2488        data = diffstat_add(diffstat, name_a, name_b);
2489        data->is_interesting = p->status != DIFF_STATUS_UNKNOWN;
2490
2491        if (!one || !two) {
2492                data->is_unmerged = 1;
2493                return;
2494        }
2495
2496        same_contents = !hashcmp(one->sha1, two->sha1);
2497
2498        if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
2499                data->is_binary = 1;
2500                if (same_contents) {
2501                        data->added = 0;
2502                        data->deleted = 0;
2503                } else {
2504                        data->added = diff_filespec_size(two);
2505                        data->deleted = diff_filespec_size(one);
2506                }
2507        }
2508
2509        else if (complete_rewrite) {
2510                diff_populate_filespec(one, 0);
2511                diff_populate_filespec(two, 0);
2512                data->deleted = count_lines(one->data, one->size);
2513                data->added = count_lines(two->data, two->size);
2514        }
2515
2516        else if (!same_contents) {
2517                /* Crazy xdl interfaces.. */
2518                xpparam_t xpp;
2519                xdemitconf_t xecfg;
2520
2521                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2522                        die("unable to read files to diff");
2523
2524                memset(&xpp, 0, sizeof(xpp));
2525                memset(&xecfg, 0, sizeof(xecfg));
2526                xpp.flags = o->xdl_opts;
2527                xecfg.ctxlen = o->context;
2528                xecfg.interhunkctxlen = o->interhunkcontext;
2529                xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
2530                              &xpp, &xecfg);
2531        }
2532
2533        diff_free_filespec_data(one);
2534        diff_free_filespec_data(two);
2535}
2536
2537static void builtin_checkdiff(const char *name_a, const char *name_b,
2538                              const char *attr_path,
2539                              struct diff_filespec *one,
2540                              struct diff_filespec *two,
2541                              struct diff_options *o)
2542{
2543        mmfile_t mf1, mf2;
2544        struct checkdiff_t data;
2545
2546        if (!two)
2547                return;
2548
2549        memset(&data, 0, sizeof(data));
2550        data.filename = name_b ? name_b : name_a;
2551        data.lineno = 0;
2552        data.o = o;
2553        data.ws_rule = whitespace_rule(attr_path);
2554        data.conflict_marker_size = ll_merge_marker_size(attr_path);
2555
2556        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2557                die("unable to read files to diff");
2558
2559        /*
2560         * All the other codepaths check both sides, but not checking
2561         * the "old" side here is deliberate.  We are checking the newly
2562         * introduced changes, and as long as the "new" side is text, we
2563         * can and should check what it introduces.
2564         */
2565        if (diff_filespec_is_binary(two))
2566                goto free_and_return;
2567        else {
2568                /* Crazy xdl interfaces.. */
2569                xpparam_t xpp;
2570                xdemitconf_t xecfg;
2571
2572                memset(&xpp, 0, sizeof(xpp));
2573                memset(&xecfg, 0, sizeof(xecfg));
2574                xecfg.ctxlen = 1; /* at least one context line */
2575                xpp.flags = 0;
2576                xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
2577                              &xpp, &xecfg);
2578
2579                if (data.ws_rule & WS_BLANK_AT_EOF) {
2580                        struct emit_callback ecbdata;
2581                        int blank_at_eof;
2582
2583                        ecbdata.ws_rule = data.ws_rule;
2584                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2585                        blank_at_eof = ecbdata.blank_at_eof_in_postimage;
2586
2587                        if (blank_at_eof) {
2588                                static char *err;
2589                                if (!err)
2590                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
2591                                fprintf(o->file, "%s:%d: %s.\n",
2592                                        data.filename, blank_at_eof, err);
2593                                data.status = 1; /* report errors */
2594                        }
2595                }
2596        }
2597 free_and_return:
2598        diff_free_filespec_data(one);
2599        diff_free_filespec_data(two);
2600        if (data.status)
2601                DIFF_OPT_SET(o, CHECK_FAILED);
2602}
2603
2604struct diff_filespec *alloc_filespec(const char *path)
2605{
2606        int namelen = strlen(path);
2607        struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
2608
2609        memset(spec, 0, sizeof(*spec));
2610        spec->path = (char *)(spec + 1);
2611        memcpy(spec->path, path, namelen+1);
2612        spec->count = 1;
2613        spec->is_binary = -1;
2614        return spec;
2615}
2616
2617void free_filespec(struct diff_filespec *spec)
2618{
2619        if (!--spec->count) {
2620                diff_free_filespec_data(spec);
2621                free(spec);
2622        }
2623}
2624
2625void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
2626                   int sha1_valid, unsigned short mode)
2627{
2628        if (mode) {
2629                spec->mode = canon_mode(mode);
2630                hashcpy(spec->sha1, sha1);
2631                spec->sha1_valid = sha1_valid;
2632        }
2633}
2634
2635/*
2636 * Given a name and sha1 pair, if the index tells us the file in
2637 * the work tree has that object contents, return true, so that
2638 * prepare_temp_file() does not have to inflate and extract.
2639 */
2640static int reuse_worktree_file(const char *name, const unsigned char *sha1, int want_file)
2641{
2642        const struct cache_entry *ce;
2643        struct stat st;
2644        int pos, len;
2645
2646        /*
2647         * We do not read the cache ourselves here, because the
2648         * benchmark with my previous version that always reads cache
2649         * shows that it makes things worse for diff-tree comparing
2650         * two linux-2.6 kernel trees in an already checked out work
2651         * tree.  This is because most diff-tree comparisons deal with
2652         * only a small number of files, while reading the cache is
2653         * expensive for a large project, and its cost outweighs the
2654         * savings we get by not inflating the object to a temporary
2655         * file.  Practically, this code only helps when we are used
2656         * by diff-cache --cached, which does read the cache before
2657         * calling us.
2658         */
2659        if (!active_cache)
2660                return 0;
2661
2662        /* We want to avoid the working directory if our caller
2663         * doesn't need the data in a normal file, this system
2664         * is rather slow with its stat/open/mmap/close syscalls,
2665         * and the object is contained in a pack file.  The pack
2666         * is probably already open and will be faster to obtain
2667         * the data through than the working directory.  Loose
2668         * objects however would tend to be slower as they need
2669         * to be individually opened and inflated.
2670         */
2671        if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(sha1))
2672                return 0;
2673
2674        len = strlen(name);
2675        pos = cache_name_pos(name, len);
2676        if (pos < 0)
2677                return 0;
2678        ce = active_cache[pos];
2679
2680        /*
2681         * This is not the sha1 we are looking for, or
2682         * unreusable because it is not a regular file.
2683         */
2684        if (hashcmp(sha1, ce->sha1) || !S_ISREG(ce->ce_mode))
2685                return 0;
2686
2687        /*
2688         * If ce is marked as "assume unchanged", there is no
2689         * guarantee that work tree matches what we are looking for.
2690         */
2691        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
2692                return 0;
2693
2694        /*
2695         * If ce matches the file in the work tree, we can reuse it.
2696         */
2697        if (ce_uptodate(ce) ||
2698            (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
2699                return 1;
2700
2701        return 0;
2702}
2703
2704static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
2705{
2706        int len;
2707        char *data = xmalloc(100), *dirty = "";
2708
2709        /* Are we looking at the work tree? */
2710        if (s->dirty_submodule)
2711                dirty = "-dirty";
2712
2713        len = snprintf(data, 100,
2714                       "Subproject commit %s%s\n", sha1_to_hex(s->sha1), dirty);
2715        s->data = data;
2716        s->size = len;
2717        s->should_free = 1;
2718        if (size_only) {
2719                s->data = NULL;
2720                free(data);
2721        }
2722        return 0;
2723}
2724
2725/*
2726 * While doing rename detection and pickaxe operation, we may need to
2727 * grab the data for the blob (or file) for our own in-core comparison.
2728 * diff_filespec has data and size fields for this purpose.
2729 */
2730int diff_populate_filespec(struct diff_filespec *s, unsigned int flags)
2731{
2732        int size_only = flags & CHECK_SIZE_ONLY;
2733        int err = 0;
2734        /*
2735         * demote FAIL to WARN to allow inspecting the situation
2736         * instead of refusing.
2737         */
2738        enum safe_crlf crlf_warn = (safe_crlf == SAFE_CRLF_FAIL
2739                                    ? SAFE_CRLF_WARN
2740                                    : safe_crlf);
2741
2742        if (!DIFF_FILE_VALID(s))
2743                die("internal error: asking to populate invalid file.");
2744        if (S_ISDIR(s->mode))
2745                return -1;
2746
2747        if (s->data)
2748                return 0;
2749
2750        if (size_only && 0 < s->size)
2751                return 0;
2752
2753        if (S_ISGITLINK(s->mode))
2754                return diff_populate_gitlink(s, size_only);
2755
2756        if (!s->sha1_valid ||
2757            reuse_worktree_file(s->path, s->sha1, 0)) {
2758                struct strbuf buf = STRBUF_INIT;
2759                struct stat st;
2760                int fd;
2761
2762                if (lstat(s->path, &st) < 0) {
2763                        if (errno == ENOENT) {
2764                        err_empty:
2765                                err = -1;
2766                        empty:
2767                                s->data = (char *)"";
2768                                s->size = 0;
2769                                return err;
2770                        }
2771                }
2772                s->size = xsize_t(st.st_size);
2773                if (!s->size)
2774                        goto empty;
2775                if (S_ISLNK(st.st_mode)) {
2776                        struct strbuf sb = STRBUF_INIT;
2777
2778                        if (strbuf_readlink(&sb, s->path, s->size))
2779                                goto err_empty;
2780                        s->size = sb.len;
2781                        s->data = strbuf_detach(&sb, NULL);
2782                        s->should_free = 1;
2783                        return 0;
2784                }
2785                if (size_only)
2786                        return 0;
2787                if ((flags & CHECK_BINARY) &&
2788                    s->size > big_file_threshold && s->is_binary == -1) {
2789                        s->is_binary = 1;
2790                        return 0;
2791                }
2792                fd = open(s->path, O_RDONLY);
2793                if (fd < 0)
2794                        goto err_empty;
2795                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
2796                close(fd);
2797                s->should_munmap = 1;
2798
2799                /*
2800                 * Convert from working tree format to canonical git format
2801                 */
2802                if (convert_to_git(s->path, s->data, s->size, &buf, crlf_warn)) {
2803                        size_t size = 0;
2804                        munmap(s->data, s->size);
2805                        s->should_munmap = 0;
2806                        s->data = strbuf_detach(&buf, &size);
2807                        s->size = size;
2808                        s->should_free = 1;
2809                }
2810        }
2811        else {
2812                enum object_type type;
2813                if (size_only || (flags & CHECK_BINARY)) {
2814                        type = sha1_object_info(s->sha1, &s->size);
2815                        if (type < 0)
2816                                die("unable to read %s", sha1_to_hex(s->sha1));
2817                        if (size_only)
2818                                return 0;
2819                        if (s->size > big_file_threshold && s->is_binary == -1) {
2820                                s->is_binary = 1;
2821                                return 0;
2822                        }
2823                }
2824                s->data = read_sha1_file(s->sha1, &type, &s->size);
2825                if (!s->data)
2826                        die("unable to read %s", sha1_to_hex(s->sha1));
2827                s->should_free = 1;
2828        }
2829        return 0;
2830}
2831
2832void diff_free_filespec_blob(struct diff_filespec *s)
2833{
2834        if (s->should_free)
2835                free(s->data);
2836        else if (s->should_munmap)
2837                munmap(s->data, s->size);
2838
2839        if (s->should_free || s->should_munmap) {
2840                s->should_free = s->should_munmap = 0;
2841                s->data = NULL;
2842        }
2843}
2844
2845void diff_free_filespec_data(struct diff_filespec *s)
2846{
2847        diff_free_filespec_blob(s);
2848        free(s->cnt_data);
2849        s->cnt_data = NULL;
2850}
2851
2852static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
2853                           void *blob,
2854                           unsigned long size,
2855                           const unsigned char *sha1,
2856                           int mode)
2857{
2858        int fd;
2859        struct strbuf buf = STRBUF_INIT;
2860        struct strbuf template = STRBUF_INIT;
2861        char *path_dup = xstrdup(path);
2862        const char *base = basename(path_dup);
2863
2864        /* Generate "XXXXXX_basename.ext" */
2865        strbuf_addstr(&template, "XXXXXX_");
2866        strbuf_addstr(&template, base);
2867
2868        fd = mks_tempfile_ts(&temp->tempfile, template.buf, strlen(base) + 1);
2869        if (fd < 0)
2870                die_errno("unable to create temp-file");
2871        if (convert_to_working_tree(path,
2872                        (const char *)blob, (size_t)size, &buf)) {
2873                blob = buf.buf;
2874                size = buf.len;
2875        }
2876        if (write_in_full(fd, blob, size) != size)
2877                die_errno("unable to write temp-file");
2878        close_tempfile(&temp->tempfile);
2879        temp->name = get_tempfile_path(&temp->tempfile);
2880        strcpy(temp->hex, sha1_to_hex(sha1));
2881        temp->hex[40] = 0;
2882        sprintf(temp->mode, "%06o", mode);
2883        strbuf_release(&buf);
2884        strbuf_release(&template);
2885        free(path_dup);
2886}
2887
2888static struct diff_tempfile *prepare_temp_file(const char *name,
2889                struct diff_filespec *one)
2890{
2891        struct diff_tempfile *temp = claim_diff_tempfile();
2892
2893        if (!DIFF_FILE_VALID(one)) {
2894        not_a_valid_file:
2895                /* A '-' entry produces this for file-2, and
2896                 * a '+' entry produces this for file-1.
2897                 */
2898                temp->name = "/dev/null";
2899                strcpy(temp->hex, ".");
2900                strcpy(temp->mode, ".");
2901                return temp;
2902        }
2903
2904        if (!S_ISGITLINK(one->mode) &&
2905            (!one->sha1_valid ||
2906             reuse_worktree_file(name, one->sha1, 1))) {
2907                struct stat st;
2908                if (lstat(name, &st) < 0) {
2909                        if (errno == ENOENT)
2910                                goto not_a_valid_file;
2911                        die_errno("stat(%s)", name);
2912                }
2913                if (S_ISLNK(st.st_mode)) {
2914                        struct strbuf sb = STRBUF_INIT;
2915                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
2916                                die_errno("readlink(%s)", name);
2917                        prep_temp_blob(name, temp, sb.buf, sb.len,
2918                                       (one->sha1_valid ?
2919                                        one->sha1 : null_sha1),
2920                                       (one->sha1_valid ?
2921                                        one->mode : S_IFLNK));
2922                        strbuf_release(&sb);
2923                }
2924                else {
2925                        /* we can borrow from the file in the work tree */
2926                        temp->name = name;
2927                        if (!one->sha1_valid)
2928                                strcpy(temp->hex, sha1_to_hex(null_sha1));
2929                        else
2930                                strcpy(temp->hex, sha1_to_hex(one->sha1));
2931                        /* Even though we may sometimes borrow the
2932                         * contents from the work tree, we always want
2933                         * one->mode.  mode is trustworthy even when
2934                         * !(one->sha1_valid), as long as
2935                         * DIFF_FILE_VALID(one).
2936                         */
2937                        sprintf(temp->mode, "%06o", one->mode);
2938                }
2939                return temp;
2940        }
2941        else {
2942                if (diff_populate_filespec(one, 0))
2943                        die("cannot read data blob for %s", one->path);
2944                prep_temp_blob(name, temp, one->data, one->size,
2945                               one->sha1, one->mode);
2946        }
2947        return temp;
2948}
2949
2950static void add_external_diff_name(struct argv_array *argv,
2951                                   const char *name,
2952                                   struct diff_filespec *df)
2953{
2954        struct diff_tempfile *temp = prepare_temp_file(name, df);
2955        argv_array_push(argv, temp->name);
2956        argv_array_push(argv, temp->hex);
2957        argv_array_push(argv, temp->mode);
2958}
2959
2960/* An external diff command takes:
2961 *
2962 * diff-cmd name infile1 infile1-sha1 infile1-mode \
2963 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
2964 *
2965 */
2966static void run_external_diff(const char *pgm,
2967                              const char *name,
2968                              const char *other,
2969                              struct diff_filespec *one,
2970                              struct diff_filespec *two,
2971                              const char *xfrm_msg,
2972                              int complete_rewrite,
2973                              struct diff_options *o)
2974{
2975        struct argv_array argv = ARGV_ARRAY_INIT;
2976        struct argv_array env = ARGV_ARRAY_INIT;
2977        struct diff_queue_struct *q = &diff_queued_diff;
2978
2979        argv_array_push(&argv, pgm);
2980        argv_array_push(&argv, name);
2981
2982        if (one && two) {
2983                add_external_diff_name(&argv, name, one);
2984                if (!other)
2985                        add_external_diff_name(&argv, name, two);
2986                else {
2987                        add_external_diff_name(&argv, other, two);
2988                        argv_array_push(&argv, other);
2989                        argv_array_push(&argv, xfrm_msg);
2990                }
2991        }
2992
2993        argv_array_pushf(&env, "GIT_DIFF_PATH_COUNTER=%d", ++o->diff_path_counter);
2994        argv_array_pushf(&env, "GIT_DIFF_PATH_TOTAL=%d", q->nr);
2995
2996        if (run_command_v_opt_cd_env(argv.argv, RUN_USING_SHELL, NULL, env.argv))
2997                die(_("external diff died, stopping at %s"), name);
2998
2999        remove_tempfile();
3000        argv_array_clear(&argv);
3001        argv_array_clear(&env);
3002}
3003
3004static int similarity_index(struct diff_filepair *p)
3005{
3006        return p->score * 100 / MAX_SCORE;
3007}
3008
3009static void fill_metainfo(struct strbuf *msg,
3010                          const char *name,
3011                          const char *other,
3012                          struct diff_filespec *one,
3013                          struct diff_filespec *two,
3014                          struct diff_options *o,
3015                          struct diff_filepair *p,
3016                          int *must_show_header,
3017                          int use_color)
3018{
3019        const char *set = diff_get_color(use_color, DIFF_METAINFO);
3020        const char *reset = diff_get_color(use_color, DIFF_RESET);
3021        const char *line_prefix = diff_line_prefix(o);
3022
3023        *must_show_header = 1;
3024        strbuf_init(msg, PATH_MAX * 2 + 300);
3025        switch (p->status) {
3026        case DIFF_STATUS_COPIED:
3027                strbuf_addf(msg, "%s%ssimilarity index %d%%",
3028                            line_prefix, set, similarity_index(p));
3029                strbuf_addf(msg, "%s\n%s%scopy from ",
3030                            reset,  line_prefix, set);
3031                quote_c_style(name, msg, NULL, 0);
3032                strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
3033                quote_c_style(other, msg, NULL, 0);
3034                strbuf_addf(msg, "%s\n", reset);
3035                break;
3036        case DIFF_STATUS_RENAMED:
3037                strbuf_addf(msg, "%s%ssimilarity index %d%%",
3038                            line_prefix, set, similarity_index(p));
3039                strbuf_addf(msg, "%s\n%s%srename from ",
3040                            reset, line_prefix, set);
3041                quote_c_style(name, msg, NULL, 0);
3042                strbuf_addf(msg, "%s\n%s%srename to ",
3043                            reset, line_prefix, set);
3044                quote_c_style(other, msg, NULL, 0);
3045                strbuf_addf(msg, "%s\n", reset);
3046                break;
3047        case DIFF_STATUS_MODIFIED:
3048                if (p->score) {
3049                        strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
3050                                    line_prefix,
3051                                    set, similarity_index(p), reset);
3052                        break;
3053                }
3054                /* fallthru */
3055        default:
3056                *must_show_header = 0;
3057        }
3058        if (one && two && hashcmp(one->sha1, two->sha1)) {
3059                int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
3060
3061                if (DIFF_OPT_TST(o, BINARY)) {
3062                        mmfile_t mf;
3063                        if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
3064                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
3065                                abbrev = 40;
3066                }
3067                strbuf_addf(msg, "%s%sindex %s..", line_prefix, set,
3068                            find_unique_abbrev(one->sha1, abbrev));
3069                strbuf_addstr(msg, find_unique_abbrev(two->sha1, abbrev));
3070                if (one->mode == two->mode)
3071                        strbuf_addf(msg, " %06o", one->mode);
3072                strbuf_addf(msg, "%s\n", reset);
3073        }
3074}
3075
3076static void run_diff_cmd(const char *pgm,
3077                         const char *name,
3078                         const char *other,
3079                         const char *attr_path,
3080                         struct diff_filespec *one,
3081                         struct diff_filespec *two,
3082                         struct strbuf *msg,
3083                         struct diff_options *o,
3084                         struct diff_filepair *p)
3085{
3086        const char *xfrm_msg = NULL;
3087        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
3088        int must_show_header = 0;
3089
3090
3091        if (DIFF_OPT_TST(o, ALLOW_EXTERNAL)) {
3092                struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
3093                if (drv && drv->external)
3094                        pgm = drv->external;
3095        }
3096
3097        if (msg) {
3098                /*
3099                 * don't use colors when the header is intended for an
3100                 * external diff driver
3101                 */
3102                fill_metainfo(msg, name, other, one, two, o, p,
3103                              &must_show_header,
3104                              want_color(o->use_color) && !pgm);
3105                xfrm_msg = msg->len ? msg->buf : NULL;
3106        }
3107
3108        if (pgm) {
3109                run_external_diff(pgm, name, other, one, two, xfrm_msg,
3110                                  complete_rewrite, o);
3111                return;
3112        }
3113        if (one && two)
3114                builtin_diff(name, other ? other : name,
3115                             one, two, xfrm_msg, must_show_header,
3116                             o, complete_rewrite);
3117        else
3118                fprintf(o->file, "* Unmerged path %s\n", name);
3119}
3120
3121static void diff_fill_sha1_info(struct diff_filespec *one)
3122{
3123        if (DIFF_FILE_VALID(one)) {
3124                if (!one->sha1_valid) {
3125                        struct stat st;
3126                        if (one->is_stdin) {
3127                                hashcpy(one->sha1, null_sha1);
3128                                return;
3129                        }
3130                        if (lstat(one->path, &st) < 0)
3131                                die_errno("stat '%s'", one->path);
3132                        if (index_path(one->sha1, one->path, &st, 0))
3133                                die("cannot hash %s", one->path);
3134                }
3135        }
3136        else
3137                hashclr(one->sha1);
3138}
3139
3140static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
3141{
3142        /* Strip the prefix but do not molest /dev/null and absolute paths */
3143        if (*namep && **namep != '/') {
3144                *namep += prefix_length;
3145                if (**namep == '/')
3146                        ++*namep;
3147        }
3148        if (*otherp && **otherp != '/') {
3149                *otherp += prefix_length;
3150                if (**otherp == '/')
3151                        ++*otherp;
3152        }
3153}
3154
3155static void run_diff(struct diff_filepair *p, struct diff_options *o)
3156{
3157        const char *pgm = external_diff();
3158        struct strbuf msg;
3159        struct diff_filespec *one = p->one;
3160        struct diff_filespec *two = p->two;
3161        const char *name;
3162        const char *other;
3163        const char *attr_path;
3164
3165        name  = p->one->path;
3166        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3167        attr_path = name;
3168        if (o->prefix_length)
3169                strip_prefix(o->prefix_length, &name, &other);
3170
3171        if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
3172                pgm = NULL;
3173
3174        if (DIFF_PAIR_UNMERGED(p)) {
3175                run_diff_cmd(pgm, name, NULL, attr_path,
3176                             NULL, NULL, NULL, o, p);
3177                return;
3178        }
3179
3180        diff_fill_sha1_info(one);
3181        diff_fill_sha1_info(two);
3182
3183        if (!pgm &&
3184            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
3185            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
3186                /*
3187                 * a filepair that changes between file and symlink
3188                 * needs to be split into deletion and creation.
3189                 */
3190                struct diff_filespec *null = alloc_filespec(two->path);
3191                run_diff_cmd(NULL, name, other, attr_path,
3192                             one, null, &msg, o, p);
3193                free(null);
3194                strbuf_release(&msg);
3195
3196                null = alloc_filespec(one->path);
3197                run_diff_cmd(NULL, name, other, attr_path,
3198                             null, two, &msg, o, p);
3199                free(null);
3200        }
3201        else
3202                run_diff_cmd(pgm, name, other, attr_path,
3203                             one, two, &msg, o, p);
3204
3205        strbuf_release(&msg);
3206}
3207
3208static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
3209                         struct diffstat_t *diffstat)
3210{
3211        const char *name;
3212        const char *other;
3213
3214        if (DIFF_PAIR_UNMERGED(p)) {
3215                /* unmerged */
3216                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, p);
3217                return;
3218        }
3219
3220        name = p->one->path;
3221        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3222
3223        if (o->prefix_length)
3224                strip_prefix(o->prefix_length, &name, &other);
3225
3226        diff_fill_sha1_info(p->one);
3227        diff_fill_sha1_info(p->two);
3228
3229        builtin_diffstat(name, other, p->one, p->two, diffstat, o, p);
3230}
3231
3232static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
3233{
3234        const char *name;
3235        const char *other;
3236        const char *attr_path;
3237
3238        if (DIFF_PAIR_UNMERGED(p)) {
3239                /* unmerged */
3240                return;
3241        }
3242
3243        name = p->one->path;
3244        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3245        attr_path = other ? other : name;
3246
3247        if (o->prefix_length)
3248                strip_prefix(o->prefix_length, &name, &other);
3249
3250        diff_fill_sha1_info(p->one);
3251        diff_fill_sha1_info(p->two);
3252
3253        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
3254}
3255
3256void diff_setup(struct diff_options *options)
3257{
3258        memcpy(options, &default_diff_options, sizeof(*options));
3259
3260        options->file = stdout;
3261
3262        options->line_termination = '\n';
3263        options->break_opt = -1;
3264        options->rename_limit = -1;
3265        options->dirstat_permille = diff_dirstat_permille_default;
3266        options->context = diff_context_default;
3267        options->ws_error_highlight = WSEH_NEW;
3268        DIFF_OPT_SET(options, RENAME_EMPTY);
3269
3270        /* pathchange left =NULL by default */
3271        options->change = diff_change;
3272        options->add_remove = diff_addremove;
3273        options->use_color = diff_use_color_default;
3274        options->detect_rename = diff_detect_rename_default;
3275        options->xdl_opts |= diff_algorithm;
3276
3277        options->orderfile = diff_order_file_cfg;
3278
3279        if (diff_no_prefix) {
3280                options->a_prefix = options->b_prefix = "";
3281        } else if (!diff_mnemonic_prefix) {
3282                options->a_prefix = "a/";
3283                options->b_prefix = "b/";
3284        }
3285}
3286
3287void diff_setup_done(struct diff_options *options)
3288{
3289        int count = 0;
3290
3291        if (options->set_default)
3292                options->set_default(options);
3293
3294        if (options->output_format & DIFF_FORMAT_NAME)
3295                count++;
3296        if (options->output_format & DIFF_FORMAT_NAME_STATUS)
3297                count++;
3298        if (options->output_format & DIFF_FORMAT_CHECKDIFF)
3299                count++;
3300        if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
3301                count++;
3302        if (count > 1)
3303                die("--name-only, --name-status, --check and -s are mutually exclusive");
3304
3305        /*
3306         * Most of the time we can say "there are changes"
3307         * only by checking if there are changed paths, but
3308         * --ignore-whitespace* options force us to look
3309         * inside contents.
3310         */
3311
3312        if (DIFF_XDL_TST(options, IGNORE_WHITESPACE) ||
3313            DIFF_XDL_TST(options, IGNORE_WHITESPACE_CHANGE) ||
3314            DIFF_XDL_TST(options, IGNORE_WHITESPACE_AT_EOL))
3315                DIFF_OPT_SET(options, DIFF_FROM_CONTENTS);
3316        else
3317                DIFF_OPT_CLR(options, DIFF_FROM_CONTENTS);
3318
3319        if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
3320                options->detect_rename = DIFF_DETECT_COPY;
3321
3322        if (!DIFF_OPT_TST(options, RELATIVE_NAME))
3323                options->prefix = NULL;
3324        if (options->prefix)
3325                options->prefix_length = strlen(options->prefix);
3326        else
3327                options->prefix_length = 0;
3328
3329        if (options->output_format & (DIFF_FORMAT_NAME |
3330                                      DIFF_FORMAT_NAME_STATUS |
3331                                      DIFF_FORMAT_CHECKDIFF |
3332                                      DIFF_FORMAT_NO_OUTPUT))
3333                options->output_format &= ~(DIFF_FORMAT_RAW |
3334                                            DIFF_FORMAT_NUMSTAT |
3335                                            DIFF_FORMAT_DIFFSTAT |
3336                                            DIFF_FORMAT_SHORTSTAT |
3337                                            DIFF_FORMAT_DIRSTAT |
3338                                            DIFF_FORMAT_SUMMARY |
3339                                            DIFF_FORMAT_PATCH);
3340
3341        /*
3342         * These cases always need recursive; we do not drop caller-supplied
3343         * recursive bits for other formats here.
3344         */
3345        if (options->output_format & (DIFF_FORMAT_PATCH |
3346                                      DIFF_FORMAT_NUMSTAT |
3347                                      DIFF_FORMAT_DIFFSTAT |
3348                                      DIFF_FORMAT_SHORTSTAT |
3349                                      DIFF_FORMAT_DIRSTAT |
3350                                      DIFF_FORMAT_SUMMARY |
3351                                      DIFF_FORMAT_CHECKDIFF))
3352                DIFF_OPT_SET(options, RECURSIVE);
3353        /*
3354         * Also pickaxe would not work very well if you do not say recursive
3355         */
3356        if (options->pickaxe)
3357                DIFF_OPT_SET(options, RECURSIVE);
3358        /*
3359         * When patches are generated, submodules diffed against the work tree
3360         * must be checked for dirtiness too so it can be shown in the output
3361         */
3362        if (options->output_format & DIFF_FORMAT_PATCH)
3363                DIFF_OPT_SET(options, DIRTY_SUBMODULES);
3364
3365        if (options->detect_rename && options->rename_limit < 0)
3366                options->rename_limit = diff_rename_limit_default;
3367        if (options->setup & DIFF_SETUP_USE_CACHE) {
3368                if (!active_cache)
3369                        /* read-cache does not die even when it fails
3370                         * so it is safe for us to do this here.  Also
3371                         * it does not smudge active_cache or active_nr
3372                         * when it fails, so we do not have to worry about
3373                         * cleaning it up ourselves either.
3374                         */
3375                        read_cache();
3376        }
3377        if (options->abbrev <= 0 || 40 < options->abbrev)
3378                options->abbrev = 40; /* full */
3379
3380        /*
3381         * It does not make sense to show the first hit we happened
3382         * to have found.  It does not make sense not to return with
3383         * exit code in such a case either.
3384         */
3385        if (DIFF_OPT_TST(options, QUICK)) {
3386                options->output_format = DIFF_FORMAT_NO_OUTPUT;
3387                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3388        }
3389
3390        options->diff_path_counter = 0;
3391
3392        if (DIFF_OPT_TST(options, FOLLOW_RENAMES) && options->pathspec.nr != 1)
3393                die(_("--follow requires exactly one pathspec"));
3394}
3395
3396static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
3397{
3398        char c, *eq;
3399        int len;
3400
3401        if (*arg != '-')
3402                return 0;
3403        c = *++arg;
3404        if (!c)
3405                return 0;
3406        if (c == arg_short) {
3407                c = *++arg;
3408                if (!c)
3409                        return 1;
3410                if (val && isdigit(c)) {
3411                        char *end;
3412                        int n = strtoul(arg, &end, 10);
3413                        if (*end)
3414                                return 0;
3415                        *val = n;
3416                        return 1;
3417                }
3418                return 0;
3419        }
3420        if (c != '-')
3421                return 0;
3422        arg++;
3423        eq = strchrnul(arg, '=');
3424        len = eq - arg;
3425        if (!len || strncmp(arg, arg_long, len))
3426                return 0;
3427        if (*eq) {
3428                int n;
3429                char *end;
3430                if (!isdigit(*++eq))
3431                        return 0;
3432                n = strtoul(eq, &end, 10);
3433                if (*end)
3434                        return 0;
3435                *val = n;
3436        }
3437        return 1;
3438}
3439
3440static int diff_scoreopt_parse(const char *opt);
3441
3442static inline int short_opt(char opt, const char **argv,
3443                            const char **optarg)
3444{
3445        const char *arg = argv[0];
3446        if (arg[0] != '-' || arg[1] != opt)
3447                return 0;
3448        if (arg[2] != '\0') {
3449                *optarg = arg + 2;
3450                return 1;
3451        }
3452        if (!argv[1])
3453                die("Option '%c' requires a value", opt);
3454        *optarg = argv[1];
3455        return 2;
3456}
3457
3458int parse_long_opt(const char *opt, const char **argv,
3459                   const char **optarg)
3460{
3461        const char *arg = argv[0];
3462        if (!skip_prefix(arg, "--", &arg))
3463                return 0;
3464        if (!skip_prefix(arg, opt, &arg))
3465                return 0;
3466        if (*arg == '=') { /* stuck form: --option=value */
3467                *optarg = arg + 1;
3468                return 1;
3469        }
3470        if (*arg != '\0')
3471                return 0;
3472        /* separate form: --option value */
3473        if (!argv[1])
3474                die("Option '--%s' requires a value", opt);
3475        *optarg = argv[1];
3476        return 2;
3477}
3478
3479static int stat_opt(struct diff_options *options, const char **av)
3480{
3481        const char *arg = av[0];
3482        char *end;
3483        int width = options->stat_width;
3484        int name_width = options->stat_name_width;
3485        int graph_width = options->stat_graph_width;
3486        int count = options->stat_count;
3487        int argcount = 1;
3488
3489        if (!skip_prefix(arg, "--stat", &arg))
3490                die("BUG: stat option does not begin with --stat: %s", arg);
3491        end = (char *)arg;
3492
3493        switch (*arg) {
3494        case '-':
3495                if (skip_prefix(arg, "-width", &arg)) {
3496                        if (*arg == '=')
3497                                width = strtoul(arg + 1, &end, 10);
3498                        else if (!*arg && !av[1])
3499                                die("Option '--stat-width' requires a value");
3500                        else if (!*arg) {
3501                                width = strtoul(av[1], &end, 10);
3502                                argcount = 2;
3503                        }
3504                } else if (skip_prefix(arg, "-name-width", &arg)) {
3505                        if (*arg == '=')
3506                                name_width = strtoul(arg + 1, &end, 10);
3507                        else if (!*arg && !av[1])
3508                                die("Option '--stat-name-width' requires a value");
3509                        else if (!*arg) {
3510                                name_width = strtoul(av[1], &end, 10);
3511                                argcount = 2;
3512                        }
3513                } else if (skip_prefix(arg, "-graph-width", &arg)) {
3514                        if (*arg == '=')
3515                                graph_width = strtoul(arg + 1, &end, 10);
3516                        else if (!*arg && !av[1])
3517                                die("Option '--stat-graph-width' requires a value");
3518                        else if (!*arg) {
3519                                graph_width = strtoul(av[1], &end, 10);
3520                                argcount = 2;
3521                        }
3522                } else if (skip_prefix(arg, "-count", &arg)) {
3523                        if (*arg == '=')
3524                                count = strtoul(arg + 1, &end, 10);
3525                        else if (!*arg && !av[1])
3526                                die("Option '--stat-count' requires a value");
3527                        else if (!*arg) {
3528                                count = strtoul(av[1], &end, 10);
3529                                argcount = 2;
3530                        }
3531                }
3532                break;
3533        case '=':
3534                width = strtoul(arg+1, &end, 10);
3535                if (*end == ',')
3536                        name_width = strtoul(end+1, &end, 10);
3537                if (*end == ',')
3538                        count = strtoul(end+1, &end, 10);
3539        }
3540
3541        /* Important! This checks all the error cases! */
3542        if (*end)
3543                return 0;
3544        options->output_format |= DIFF_FORMAT_DIFFSTAT;
3545        options->stat_name_width = name_width;
3546        options->stat_graph_width = graph_width;
3547        options->stat_width = width;
3548        options->stat_count = count;
3549        return argcount;
3550}
3551
3552static int parse_dirstat_opt(struct diff_options *options, const char *params)
3553{
3554        struct strbuf errmsg = STRBUF_INIT;
3555        if (parse_dirstat_params(options, params, &errmsg))
3556                die(_("Failed to parse --dirstat/-X option parameter:\n%s"),
3557                    errmsg.buf);
3558        strbuf_release(&errmsg);
3559        /*
3560         * The caller knows a dirstat-related option is given from the command
3561         * line; allow it to say "return this_function();"
3562         */
3563        options->output_format |= DIFF_FORMAT_DIRSTAT;
3564        return 1;
3565}
3566
3567static int parse_submodule_opt(struct diff_options *options, const char *value)
3568{
3569        if (parse_submodule_params(options, value))
3570                die(_("Failed to parse --submodule option parameter: '%s'"),
3571                        value);
3572        return 1;
3573}
3574
3575static const char diff_status_letters[] = {
3576        DIFF_STATUS_ADDED,
3577        DIFF_STATUS_COPIED,
3578        DIFF_STATUS_DELETED,
3579        DIFF_STATUS_MODIFIED,
3580        DIFF_STATUS_RENAMED,
3581        DIFF_STATUS_TYPE_CHANGED,
3582        DIFF_STATUS_UNKNOWN,
3583        DIFF_STATUS_UNMERGED,
3584        DIFF_STATUS_FILTER_AON,
3585        DIFF_STATUS_FILTER_BROKEN,
3586        '\0',
3587};
3588
3589static unsigned int filter_bit['Z' + 1];
3590
3591static void prepare_filter_bits(void)
3592{
3593        int i;
3594
3595        if (!filter_bit[DIFF_STATUS_ADDED]) {
3596                for (i = 0; diff_status_letters[i]; i++)
3597                        filter_bit[(int) diff_status_letters[i]] = (1 << i);
3598        }
3599}
3600
3601static unsigned filter_bit_tst(char status, const struct diff_options *opt)
3602{
3603        return opt->filter & filter_bit[(int) status];
3604}
3605
3606static int parse_diff_filter_opt(const char *optarg, struct diff_options *opt)
3607{
3608        int i, optch;
3609
3610        prepare_filter_bits();
3611
3612        /*
3613         * If there is a negation e.g. 'd' in the input, and we haven't
3614         * initialized the filter field with another --diff-filter, start
3615         * from full set of bits, except for AON.
3616         */
3617        if (!opt->filter) {
3618                for (i = 0; (optch = optarg[i]) != '\0'; i++) {
3619                        if (optch < 'a' || 'z' < optch)
3620                                continue;
3621                        opt->filter = (1 << (ARRAY_SIZE(diff_status_letters) - 1)) - 1;
3622                        opt->filter &= ~filter_bit[DIFF_STATUS_FILTER_AON];
3623                        break;
3624                }
3625        }
3626
3627        for (i = 0; (optch = optarg[i]) != '\0'; i++) {
3628                unsigned int bit;
3629                int negate;
3630
3631                if ('a' <= optch && optch <= 'z') {
3632                        negate = 1;
3633                        optch = toupper(optch);
3634                } else {
3635                        negate = 0;
3636                }
3637
3638                bit = (0 <= optch && optch <= 'Z') ? filter_bit[optch] : 0;
3639                if (!bit)
3640                        return optarg[i];
3641                if (negate)
3642                        opt->filter &= ~bit;
3643                else
3644                        opt->filter |= bit;
3645        }
3646        return 0;
3647}
3648
3649static void enable_patch_output(int *fmt) {
3650        *fmt &= ~DIFF_FORMAT_NO_OUTPUT;
3651        *fmt |= DIFF_FORMAT_PATCH;
3652}
3653
3654static int parse_one_token(const char **arg, const char *token)
3655{
3656        const char *rest;
3657        if (skip_prefix(*arg, token, &rest) && (!*rest || *rest == ',')) {
3658                *arg = rest;
3659                return 1;
3660        }
3661        return 0;
3662}
3663
3664static int parse_ws_error_highlight(struct diff_options *opt, const char *arg)
3665{
3666        const char *orig_arg = arg;
3667        unsigned val = 0;
3668        while (*arg) {
3669                if (parse_one_token(&arg, "none"))
3670                        val = 0;
3671                else if (parse_one_token(&arg, "default"))
3672                        val = WSEH_NEW;
3673                else if (parse_one_token(&arg, "all"))
3674                        val = WSEH_NEW | WSEH_OLD | WSEH_CONTEXT;
3675                else if (parse_one_token(&arg, "new"))
3676                        val |= WSEH_NEW;
3677                else if (parse_one_token(&arg, "old"))
3678                        val |= WSEH_OLD;
3679                else if (parse_one_token(&arg, "context"))
3680                        val |= WSEH_CONTEXT;
3681                else {
3682                        error("unknown value after ws-error-highlight=%.*s",
3683                              (int)(arg - orig_arg), orig_arg);
3684                        return 0;
3685                }
3686                if (*arg)
3687                        arg++;
3688        }
3689        opt->ws_error_highlight = val;
3690        return 1;
3691}
3692
3693int diff_opt_parse(struct diff_options *options, const char **av, int ac)
3694{
3695        const char *arg = av[0];
3696        const char *optarg;
3697        int argcount;
3698
3699        /* Output format options */
3700        if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch")
3701            || opt_arg(arg, 'U', "unified", &options->context))
3702                enable_patch_output(&options->output_format);
3703        else if (!strcmp(arg, "--raw"))
3704                options->output_format |= DIFF_FORMAT_RAW;
3705        else if (!strcmp(arg, "--patch-with-raw")) {
3706                enable_patch_output(&options->output_format);
3707                options->output_format |= DIFF_FORMAT_RAW;
3708        } else if (!strcmp(arg, "--numstat"))
3709                options->output_format |= DIFF_FORMAT_NUMSTAT;
3710        else if (!strcmp(arg, "--shortstat"))
3711                options->output_format |= DIFF_FORMAT_SHORTSTAT;
3712        else if (!strcmp(arg, "-X") || !strcmp(arg, "--dirstat"))
3713                return parse_dirstat_opt(options, "");
3714        else if (skip_prefix(arg, "-X", &arg))
3715                return parse_dirstat_opt(options, arg);
3716        else if (skip_prefix(arg, "--dirstat=", &arg))
3717                return parse_dirstat_opt(options, arg);
3718        else if (!strcmp(arg, "--cumulative"))
3719                return parse_dirstat_opt(options, "cumulative");
3720        else if (!strcmp(arg, "--dirstat-by-file"))
3721                return parse_dirstat_opt(options, "files");
3722        else if (skip_prefix(arg, "--dirstat-by-file=", &arg)) {
3723                parse_dirstat_opt(options, "files");
3724                return parse_dirstat_opt(options, arg);
3725        }
3726        else if (!strcmp(arg, "--check"))
3727                options->output_format |= DIFF_FORMAT_CHECKDIFF;
3728        else if (!strcmp(arg, "--summary"))
3729                options->output_format |= DIFF_FORMAT_SUMMARY;
3730        else if (!strcmp(arg, "--patch-with-stat")) {
3731                enable_patch_output(&options->output_format);
3732                options->output_format |= DIFF_FORMAT_DIFFSTAT;
3733        } else if (!strcmp(arg, "--name-only"))
3734                options->output_format |= DIFF_FORMAT_NAME;
3735        else if (!strcmp(arg, "--name-status"))
3736                options->output_format |= DIFF_FORMAT_NAME_STATUS;
3737        else if (!strcmp(arg, "-s") || !strcmp(arg, "--no-patch"))
3738                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
3739        else if (starts_with(arg, "--stat"))
3740                /* --stat, --stat-width, --stat-name-width, or --stat-count */
3741                return stat_opt(options, av);
3742
3743        /* renames options */
3744        else if (starts_with(arg, "-B") || starts_with(arg, "--break-rewrites=") ||
3745                 !strcmp(arg, "--break-rewrites")) {
3746                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
3747                        return error("invalid argument to -B: %s", arg+2);
3748        }
3749        else if (starts_with(arg, "-M") || starts_with(arg, "--find-renames=") ||
3750                 !strcmp(arg, "--find-renames")) {
3751                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3752                        return error("invalid argument to -M: %s", arg+2);
3753                options->detect_rename = DIFF_DETECT_RENAME;
3754        }
3755        else if (!strcmp(arg, "-D") || !strcmp(arg, "--irreversible-delete")) {
3756                options->irreversible_delete = 1;
3757        }
3758        else if (starts_with(arg, "-C") || starts_with(arg, "--find-copies=") ||
3759                 !strcmp(arg, "--find-copies")) {
3760                if (options->detect_rename == DIFF_DETECT_COPY)
3761                        DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3762                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3763                        return error("invalid argument to -C: %s", arg+2);
3764                options->detect_rename = DIFF_DETECT_COPY;
3765        }
3766        else if (!strcmp(arg, "--no-renames"))
3767                options->detect_rename = 0;
3768        else if (!strcmp(arg, "--rename-empty"))
3769                DIFF_OPT_SET(options, RENAME_EMPTY);
3770        else if (!strcmp(arg, "--no-rename-empty"))
3771                DIFF_OPT_CLR(options, RENAME_EMPTY);
3772        else if (!strcmp(arg, "--relative"))
3773                DIFF_OPT_SET(options, RELATIVE_NAME);
3774        else if (skip_prefix(arg, "--relative=", &arg)) {
3775                DIFF_OPT_SET(options, RELATIVE_NAME);
3776                options->prefix = arg;
3777        }
3778
3779        /* xdiff options */
3780        else if (!strcmp(arg, "--minimal"))
3781                DIFF_XDL_SET(options, NEED_MINIMAL);
3782        else if (!strcmp(arg, "--no-minimal"))
3783                DIFF_XDL_CLR(options, NEED_MINIMAL);
3784        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
3785                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
3786        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
3787                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
3788        else if (!strcmp(arg, "--ignore-space-at-eol"))
3789                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
3790        else if (!strcmp(arg, "--ignore-blank-lines"))
3791                DIFF_XDL_SET(options, IGNORE_BLANK_LINES);
3792        else if (!strcmp(arg, "--patience"))
3793                options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
3794        else if (!strcmp(arg, "--histogram"))
3795                options->xdl_opts = DIFF_WITH_ALG(options, HISTOGRAM_DIFF);
3796        else if ((argcount = parse_long_opt("diff-algorithm", av, &optarg))) {
3797                long value = parse_algorithm_value(optarg);
3798                if (value < 0)
3799                        return error("option diff-algorithm accepts \"myers\", "
3800                                     "\"minimal\", \"patience\" and \"histogram\"");
3801                /* clear out previous settings */
3802                DIFF_XDL_CLR(options, NEED_MINIMAL);
3803                options->xdl_opts &= ~XDF_DIFF_ALGORITHM_MASK;
3804                options->xdl_opts |= value;
3805                return argcount;
3806        }
3807
3808        /* flags options */
3809        else if (!strcmp(arg, "--binary")) {
3810                enable_patch_output(&options->output_format);
3811                DIFF_OPT_SET(options, BINARY);
3812        }
3813        else if (!strcmp(arg, "--full-index"))
3814                DIFF_OPT_SET(options, FULL_INDEX);
3815        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
3816                DIFF_OPT_SET(options, TEXT);
3817        else if (!strcmp(arg, "-R"))
3818                DIFF_OPT_SET(options, REVERSE_DIFF);
3819        else if (!strcmp(arg, "--find-copies-harder"))
3820                DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3821        else if (!strcmp(arg, "--follow"))
3822                DIFF_OPT_SET(options, FOLLOW_RENAMES);
3823        else if (!strcmp(arg, "--no-follow")) {
3824                DIFF_OPT_CLR(options, FOLLOW_RENAMES);
3825                DIFF_OPT_CLR(options, DEFAULT_FOLLOW_RENAMES);
3826        } else if (!strcmp(arg, "--color"))
3827                options->use_color = 1;
3828        else if (skip_prefix(arg, "--color=", &arg)) {
3829                int value = git_config_colorbool(NULL, arg);
3830                if (value < 0)
3831                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
3832                options->use_color = value;
3833        }
3834        else if (!strcmp(arg, "--no-color"))
3835                options->use_color = 0;
3836        else if (!strcmp(arg, "--color-words")) {
3837                options->use_color = 1;
3838                options->word_diff = DIFF_WORDS_COLOR;
3839        }
3840        else if (skip_prefix(arg, "--color-words=", &arg)) {
3841                options->use_color = 1;
3842                options->word_diff = DIFF_WORDS_COLOR;
3843                options->word_regex = arg;
3844        }
3845        else if (!strcmp(arg, "--word-diff")) {
3846                if (options->word_diff == DIFF_WORDS_NONE)
3847                        options->word_diff = DIFF_WORDS_PLAIN;
3848        }
3849        else if (skip_prefix(arg, "--word-diff=", &arg)) {
3850                if (!strcmp(arg, "plain"))
3851                        options->word_diff = DIFF_WORDS_PLAIN;
3852                else if (!strcmp(arg, "color")) {
3853                        options->use_color = 1;
3854                        options->word_diff = DIFF_WORDS_COLOR;
3855                }
3856                else if (!strcmp(arg, "porcelain"))
3857                        options->word_diff = DIFF_WORDS_PORCELAIN;
3858                else if (!strcmp(arg, "none"))
3859                        options->word_diff = DIFF_WORDS_NONE;
3860                else
3861                        die("bad --word-diff argument: %s", arg);
3862        }
3863        else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
3864                if (options->word_diff == DIFF_WORDS_NONE)
3865                        options->word_diff = DIFF_WORDS_PLAIN;
3866                options->word_regex = optarg;
3867                return argcount;
3868        }
3869        else if (!strcmp(arg, "--exit-code"))
3870                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3871        else if (!strcmp(arg, "--quiet"))
3872                DIFF_OPT_SET(options, QUICK);
3873        else if (!strcmp(arg, "--ext-diff"))
3874                DIFF_OPT_SET(options, ALLOW_EXTERNAL);
3875        else if (!strcmp(arg, "--no-ext-diff"))
3876                DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
3877        else if (!strcmp(arg, "--textconv"))
3878                DIFF_OPT_SET(options, ALLOW_TEXTCONV);
3879        else if (!strcmp(arg, "--no-textconv"))
3880                DIFF_OPT_CLR(options, ALLOW_TEXTCONV);
3881        else if (!strcmp(arg, "--ignore-submodules")) {
3882                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3883                handle_ignore_submodules_arg(options, "all");
3884        } else if (skip_prefix(arg, "--ignore-submodules=", &arg)) {
3885                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3886                handle_ignore_submodules_arg(options, arg);
3887        } else if (!strcmp(arg, "--submodule"))
3888                DIFF_OPT_SET(options, SUBMODULE_LOG);
3889        else if (skip_prefix(arg, "--submodule=", &arg))
3890                return parse_submodule_opt(options, arg);
3891        else if (skip_prefix(arg, "--ws-error-highlight=", &arg))
3892                return parse_ws_error_highlight(options, arg);
3893
3894        /* misc options */
3895        else if (!strcmp(arg, "-z"))
3896                options->line_termination = 0;
3897        else if ((argcount = short_opt('l', av, &optarg))) {
3898                options->rename_limit = strtoul(optarg, NULL, 10);
3899                return argcount;
3900        }
3901        else if ((argcount = short_opt('S', av, &optarg))) {
3902                options->pickaxe = optarg;
3903                options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
3904                return argcount;
3905        } else if ((argcount = short_opt('G', av, &optarg))) {
3906                options->pickaxe = optarg;
3907                options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
3908                return argcount;
3909        }
3910        else if (!strcmp(arg, "--pickaxe-all"))
3911                options->pickaxe_opts |= DIFF_PICKAXE_ALL;
3912        else if (!strcmp(arg, "--pickaxe-regex"))
3913                options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
3914        else if ((argcount = short_opt('O', av, &optarg))) {
3915                options->orderfile = optarg;
3916                return argcount;
3917        }
3918        else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
3919                int offending = parse_diff_filter_opt(optarg, options);
3920                if (offending)
3921                        die("unknown change class '%c' in --diff-filter=%s",
3922                            offending, optarg);
3923                return argcount;
3924        }
3925        else if (!strcmp(arg, "--abbrev"))
3926                options->abbrev = DEFAULT_ABBREV;
3927        else if (skip_prefix(arg, "--abbrev=", &arg)) {
3928                options->abbrev = strtoul(arg, NULL, 10);
3929                if (options->abbrev < MINIMUM_ABBREV)
3930                        options->abbrev = MINIMUM_ABBREV;
3931                else if (40 < options->abbrev)
3932                        options->abbrev = 40;
3933        }
3934        else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
3935                options->a_prefix = optarg;
3936                return argcount;
3937        }
3938        else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
3939                options->b_prefix = optarg;
3940                return argcount;
3941        }
3942        else if (!strcmp(arg, "--no-prefix"))
3943                options->a_prefix = options->b_prefix = "";
3944        else if (opt_arg(arg, '\0', "inter-hunk-context",
3945                         &options->interhunkcontext))
3946                ;
3947        else if (!strcmp(arg, "-W"))
3948                DIFF_OPT_SET(options, FUNCCONTEXT);
3949        else if (!strcmp(arg, "--function-context"))
3950                DIFF_OPT_SET(options, FUNCCONTEXT);
3951        else if (!strcmp(arg, "--no-function-context"))
3952                DIFF_OPT_CLR(options, FUNCCONTEXT);
3953        else if ((argcount = parse_long_opt("output", av, &optarg))) {
3954                options->file = fopen(optarg, "w");
3955                if (!options->file)
3956                        die_errno("Could not open '%s'", optarg);
3957                options->close_file = 1;
3958                return argcount;
3959        } else
3960                return 0;
3961        return 1;
3962}
3963
3964int parse_rename_score(const char **cp_p)
3965{
3966        unsigned long num, scale;
3967        int ch, dot;
3968        const char *cp = *cp_p;
3969
3970        num = 0;
3971        scale = 1;
3972        dot = 0;
3973        for (;;) {
3974                ch = *cp;
3975                if ( !dot && ch == '.' ) {
3976                        scale = 1;
3977                        dot = 1;
3978                } else if ( ch == '%' ) {
3979                        scale = dot ? scale*100 : 100;
3980                        cp++;   /* % is always at the end */
3981                        break;
3982                } else if ( ch >= '0' && ch <= '9' ) {
3983                        if ( scale < 100000 ) {
3984                                scale *= 10;
3985                                num = (num*10) + (ch-'0');
3986                        }
3987                } else {
3988                        break;
3989                }
3990                cp++;
3991        }
3992        *cp_p = cp;
3993
3994        /* user says num divided by scale and we say internally that
3995         * is MAX_SCORE * num / scale.
3996         */
3997        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
3998}
3999
4000static int diff_scoreopt_parse(const char *opt)
4001{
4002        int opt1, opt2, cmd;
4003
4004        if (*opt++ != '-')
4005                return -1;
4006        cmd = *opt++;
4007        if (cmd == '-') {
4008                /* convert the long-form arguments into short-form versions */
4009                if (skip_prefix(opt, "break-rewrites", &opt)) {
4010                        if (*opt == 0 || *opt++ == '=')
4011                                cmd = 'B';
4012                } else if (skip_prefix(opt, "find-copies", &opt)) {
4013                        if (*opt == 0 || *opt++ == '=')
4014                                cmd = 'C';
4015                } else if (skip_prefix(opt, "find-renames", &opt)) {
4016                        if (*opt == 0 || *opt++ == '=')
4017                                cmd = 'M';
4018                }
4019        }
4020        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
4021                return -1; /* that is not a -M, -C, or -B option */
4022
4023        opt1 = parse_rename_score(&opt);
4024        if (cmd != 'B')
4025                opt2 = 0;
4026        else {
4027                if (*opt == 0)
4028                        opt2 = 0;
4029                else if (*opt != '/')
4030                        return -1; /* we expect -B80/99 or -B80 */
4031                else {
4032                        opt++;
4033                        opt2 = parse_rename_score(&opt);
4034                }
4035        }
4036        if (*opt != 0)
4037                return -1;
4038        return opt1 | (opt2 << 16);
4039}
4040
4041struct diff_queue_struct diff_queued_diff;
4042
4043void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
4044{
4045        ALLOC_GROW(queue->queue, queue->nr + 1, queue->alloc);
4046        queue->queue[queue->nr++] = dp;
4047}
4048
4049struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
4050                                 struct diff_filespec *one,
4051                                 struct diff_filespec *two)
4052{
4053        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
4054        dp->one = one;
4055        dp->two = two;
4056        if (queue)
4057                diff_q(queue, dp);
4058        return dp;
4059}
4060
4061void diff_free_filepair(struct diff_filepair *p)
4062{
4063        free_filespec(p->one);
4064        free_filespec(p->two);
4065        free(p);
4066}
4067
4068/* This is different from find_unique_abbrev() in that
4069 * it stuffs the result with dots for alignment.
4070 */
4071const char *diff_unique_abbrev(const unsigned char *sha1, int len)
4072{
4073        int abblen;
4074        const char *abbrev;
4075        if (len == 40)
4076                return sha1_to_hex(sha1);
4077
4078        abbrev = find_unique_abbrev(sha1, len);
4079        abblen = strlen(abbrev);
4080        if (abblen < 37) {
4081                static char hex[41];
4082                if (len < abblen && abblen <= len + 2)
4083                        sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
4084                else
4085                        sprintf(hex, "%s...", abbrev);
4086                return hex;
4087        }
4088        return sha1_to_hex(sha1);
4089}
4090
4091static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
4092{
4093        int line_termination = opt->line_termination;
4094        int inter_name_termination = line_termination ? '\t' : '\0';
4095
4096        fprintf(opt->file, "%s", diff_line_prefix(opt));
4097        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
4098                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
4099                        diff_unique_abbrev(p->one->sha1, opt->abbrev));
4100                fprintf(opt->file, "%s ", diff_unique_abbrev(p->two->sha1, opt->abbrev));
4101        }
4102        if (p->score) {
4103                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
4104                        inter_name_termination);
4105        } else {
4106                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
4107        }
4108
4109        if (p->status == DIFF_STATUS_COPIED ||
4110            p->status == DIFF_STATUS_RENAMED) {
4111                const char *name_a, *name_b;
4112                name_a = p->one->path;
4113                name_b = p->two->path;
4114                strip_prefix(opt->prefix_length, &name_a, &name_b);
4115                write_name_quoted(name_a, opt->file, inter_name_termination);
4116                write_name_quoted(name_b, opt->file, line_termination);
4117        } else {
4118                const char *name_a, *name_b;
4119                name_a = p->one->mode ? p->one->path : p->two->path;
4120                name_b = NULL;
4121                strip_prefix(opt->prefix_length, &name_a, &name_b);
4122                write_name_quoted(name_a, opt->file, line_termination);
4123        }
4124}
4125
4126int diff_unmodified_pair(struct diff_filepair *p)
4127{
4128        /* This function is written stricter than necessary to support
4129         * the currently implemented transformers, but the idea is to
4130         * let transformers to produce diff_filepairs any way they want,
4131         * and filter and clean them up here before producing the output.
4132         */
4133        struct diff_filespec *one = p->one, *two = p->two;
4134
4135        if (DIFF_PAIR_UNMERGED(p))
4136                return 0; /* unmerged is interesting */
4137
4138        /* deletion, addition, mode or type change
4139         * and rename are all interesting.
4140         */
4141        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
4142            DIFF_PAIR_MODE_CHANGED(p) ||
4143            strcmp(one->path, two->path))
4144                return 0;
4145
4146        /* both are valid and point at the same path.  that is, we are
4147         * dealing with a change.
4148         */
4149        if (one->sha1_valid && two->sha1_valid &&
4150            !hashcmp(one->sha1, two->sha1) &&
4151            !one->dirty_submodule && !two->dirty_submodule)
4152                return 1; /* no change */
4153        if (!one->sha1_valid && !two->sha1_valid)
4154                return 1; /* both look at the same file on the filesystem. */
4155        return 0;
4156}
4157
4158static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
4159{
4160        if (diff_unmodified_pair(p))
4161                return;
4162
4163        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4164            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4165                return; /* no tree diffs in patch format */
4166
4167        run_diff(p, o);
4168}
4169
4170static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
4171                            struct diffstat_t *diffstat)
4172{
4173        if (diff_unmodified_pair(p))
4174                return;
4175
4176        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4177            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4178                return; /* no useful stat for tree diffs */
4179
4180        run_diffstat(p, o, diffstat);
4181}
4182
4183static void diff_flush_checkdiff(struct diff_filepair *p,
4184                struct diff_options *o)
4185{
4186        if (diff_unmodified_pair(p))
4187                return;
4188
4189        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4190            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4191                return; /* nothing to check in tree diffs */
4192
4193        run_checkdiff(p, o);
4194}
4195
4196int diff_queue_is_empty(void)
4197{
4198        struct diff_queue_struct *q = &diff_queued_diff;
4199        int i;
4200        for (i = 0; i < q->nr; i++)
4201                if (!diff_unmodified_pair(q->queue[i]))
4202                        return 0;
4203        return 1;
4204}
4205
4206#if DIFF_DEBUG
4207void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
4208{
4209        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
4210                x, one ? one : "",
4211                s->path,
4212                DIFF_FILE_VALID(s) ? "valid" : "invalid",
4213                s->mode,
4214                s->sha1_valid ? sha1_to_hex(s->sha1) : "");
4215        fprintf(stderr, "queue[%d] %s size %lu\n",
4216                x, one ? one : "",
4217                s->size);
4218}
4219
4220void diff_debug_filepair(const struct diff_filepair *p, int i)
4221{
4222        diff_debug_filespec(p->one, i, "one");
4223        diff_debug_filespec(p->two, i, "two");
4224        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
4225                p->score, p->status ? p->status : '?',
4226                p->one->rename_used, p->broken_pair);
4227}
4228
4229void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
4230{
4231        int i;
4232        if (msg)
4233                fprintf(stderr, "%s\n", msg);
4234        fprintf(stderr, "q->nr = %d\n", q->nr);
4235        for (i = 0; i < q->nr; i++) {
4236                struct diff_filepair *p = q->queue[i];
4237                diff_debug_filepair(p, i);
4238        }
4239}
4240#endif
4241
4242static void diff_resolve_rename_copy(void)
4243{
4244        int i;
4245        struct diff_filepair *p;
4246        struct diff_queue_struct *q = &diff_queued_diff;
4247
4248        diff_debug_queue("resolve-rename-copy", q);
4249
4250        for (i = 0; i < q->nr; i++) {
4251                p = q->queue[i];
4252                p->status = 0; /* undecided */
4253                if (DIFF_PAIR_UNMERGED(p))
4254                        p->status = DIFF_STATUS_UNMERGED;
4255                else if (!DIFF_FILE_VALID(p->one))
4256                        p->status = DIFF_STATUS_ADDED;
4257                else if (!DIFF_FILE_VALID(p->two))
4258                        p->status = DIFF_STATUS_DELETED;
4259                else if (DIFF_PAIR_TYPE_CHANGED(p))
4260                        p->status = DIFF_STATUS_TYPE_CHANGED;
4261
4262                /* from this point on, we are dealing with a pair
4263                 * whose both sides are valid and of the same type, i.e.
4264                 * either in-place edit or rename/copy edit.
4265                 */
4266                else if (DIFF_PAIR_RENAME(p)) {
4267                        /*
4268                         * A rename might have re-connected a broken
4269                         * pair up, causing the pathnames to be the
4270                         * same again. If so, that's not a rename at
4271                         * all, just a modification..
4272                         *
4273                         * Otherwise, see if this source was used for
4274                         * multiple renames, in which case we decrement
4275                         * the count, and call it a copy.
4276                         */
4277                        if (!strcmp(p->one->path, p->two->path))
4278                                p->status = DIFF_STATUS_MODIFIED;
4279                        else if (--p->one->rename_used > 0)
4280                                p->status = DIFF_STATUS_COPIED;
4281                        else
4282                                p->status = DIFF_STATUS_RENAMED;
4283                }
4284                else if (hashcmp(p->one->sha1, p->two->sha1) ||
4285                         p->one->mode != p->two->mode ||
4286                         p->one->dirty_submodule ||
4287                         p->two->dirty_submodule ||
4288                         is_null_sha1(p->one->sha1))
4289                        p->status = DIFF_STATUS_MODIFIED;
4290                else {
4291                        /* This is a "no-change" entry and should not
4292                         * happen anymore, but prepare for broken callers.
4293                         */
4294                        error("feeding unmodified %s to diffcore",
4295                              p->one->path);
4296                        p->status = DIFF_STATUS_UNKNOWN;
4297                }
4298        }
4299        diff_debug_queue("resolve-rename-copy done", q);
4300}
4301
4302static int check_pair_status(struct diff_filepair *p)
4303{
4304        switch (p->status) {
4305        case DIFF_STATUS_UNKNOWN:
4306                return 0;
4307        case 0:
4308                die("internal error in diff-resolve-rename-copy");
4309        default:
4310                return 1;
4311        }
4312}
4313
4314static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
4315{
4316        int fmt = opt->output_format;
4317
4318        if (fmt & DIFF_FORMAT_CHECKDIFF)
4319                diff_flush_checkdiff(p, opt);
4320        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
4321                diff_flush_raw(p, opt);
4322        else if (fmt & DIFF_FORMAT_NAME) {
4323                const char *name_a, *name_b;
4324                name_a = p->two->path;
4325                name_b = NULL;
4326                strip_prefix(opt->prefix_length, &name_a, &name_b);
4327                write_name_quoted(name_a, opt->file, opt->line_termination);
4328        }
4329}
4330
4331static void show_file_mode_name(FILE *file, const char *newdelete, struct diff_filespec *fs)
4332{
4333        if (fs->mode)
4334                fprintf(file, " %s mode %06o ", newdelete, fs->mode);
4335        else
4336                fprintf(file, " %s ", newdelete);
4337        write_name_quoted(fs->path, file, '\n');
4338}
4339
4340
4341static void show_mode_change(FILE *file, struct diff_filepair *p, int show_name,
4342                const char *line_prefix)
4343{
4344        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
4345                fprintf(file, "%s mode change %06o => %06o%c", line_prefix, p->one->mode,
4346                        p->two->mode, show_name ? ' ' : '\n');
4347                if (show_name) {
4348                        write_name_quoted(p->two->path, file, '\n');
4349                }
4350        }
4351}
4352
4353static void show_rename_copy(FILE *file, const char *renamecopy, struct diff_filepair *p,
4354                        const char *line_prefix)
4355{
4356        char *names = pprint_rename(p->one->path, p->two->path);
4357
4358        fprintf(file, " %s %s (%d%%)\n", renamecopy, names, similarity_index(p));
4359        free(names);
4360        show_mode_change(file, p, 0, line_prefix);
4361}
4362
4363static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
4364{
4365        FILE *file = opt->file;
4366        const char *line_prefix = diff_line_prefix(opt);
4367
4368        switch(p->status) {
4369        case DIFF_STATUS_DELETED:
4370                fputs(line_prefix, file);
4371                show_file_mode_name(file, "delete", p->one);
4372                break;
4373        case DIFF_STATUS_ADDED:
4374                fputs(line_prefix, file);
4375                show_file_mode_name(file, "create", p->two);
4376                break;
4377        case DIFF_STATUS_COPIED:
4378                fputs(line_prefix, file);
4379                show_rename_copy(file, "copy", p, line_prefix);
4380                break;
4381        case DIFF_STATUS_RENAMED:
4382                fputs(line_prefix, file);
4383                show_rename_copy(file, "rename", p, line_prefix);
4384                break;
4385        default:
4386                if (p->score) {
4387                        fprintf(file, "%s rewrite ", line_prefix);
4388                        write_name_quoted(p->two->path, file, ' ');
4389                        fprintf(file, "(%d%%)\n", similarity_index(p));
4390                }
4391                show_mode_change(file, p, !p->score, line_prefix);
4392                break;
4393        }
4394}
4395
4396struct patch_id_t {
4397        git_SHA_CTX *ctx;
4398        int patchlen;
4399};
4400
4401static int remove_space(char *line, int len)
4402{
4403        int i;
4404        char *dst = line;
4405        unsigned char c;
4406
4407        for (i = 0; i < len; i++)
4408                if (!isspace((c = line[i])))
4409                        *dst++ = c;
4410
4411        return dst - line;
4412}
4413
4414static void patch_id_consume(void *priv, char *line, unsigned long len)
4415{
4416        struct patch_id_t *data = priv;
4417        int new_len;
4418
4419        /* Ignore line numbers when computing the SHA1 of the patch */
4420        if (starts_with(line, "@@ -"))
4421                return;
4422
4423        new_len = remove_space(line, len);
4424
4425        git_SHA1_Update(data->ctx, line, new_len);
4426        data->patchlen += new_len;
4427}
4428
4429/* returns 0 upon success, and writes result into sha1 */
4430static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
4431{
4432        struct diff_queue_struct *q = &diff_queued_diff;
4433        int i;
4434        git_SHA_CTX ctx;
4435        struct patch_id_t data;
4436        char buffer[PATH_MAX * 4 + 20];
4437
4438        git_SHA1_Init(&ctx);
4439        memset(&data, 0, sizeof(struct patch_id_t));
4440        data.ctx = &ctx;
4441
4442        for (i = 0; i < q->nr; i++) {
4443                xpparam_t xpp;
4444                xdemitconf_t xecfg;
4445                mmfile_t mf1, mf2;
4446                struct diff_filepair *p = q->queue[i];
4447                int len1, len2;
4448
4449                memset(&xpp, 0, sizeof(xpp));
4450                memset(&xecfg, 0, sizeof(xecfg));
4451                if (p->status == 0)
4452                        return error("internal diff status error");
4453                if (p->status == DIFF_STATUS_UNKNOWN)
4454                        continue;
4455                if (diff_unmodified_pair(p))
4456                        continue;
4457                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4458                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4459                        continue;
4460                if (DIFF_PAIR_UNMERGED(p))
4461                        continue;
4462
4463                diff_fill_sha1_info(p->one);
4464                diff_fill_sha1_info(p->two);
4465                if (fill_mmfile(&mf1, p->one) < 0 ||
4466                                fill_mmfile(&mf2, p->two) < 0)
4467                        return error("unable to read files to diff");
4468
4469                len1 = remove_space(p->one->path, strlen(p->one->path));
4470                len2 = remove_space(p->two->path, strlen(p->two->path));
4471                if (p->one->mode == 0)
4472                        len1 = snprintf(buffer, sizeof(buffer),
4473                                        "diff--gita/%.*sb/%.*s"
4474                                        "newfilemode%06o"
4475                                        "---/dev/null"
4476                                        "+++b/%.*s",
4477                                        len1, p->one->path,
4478                                        len2, p->two->path,
4479                                        p->two->mode,
4480                                        len2, p->two->path);
4481                else if (p->two->mode == 0)
4482                        len1 = snprintf(buffer, sizeof(buffer),
4483                                        "diff--gita/%.*sb/%.*s"
4484                                        "deletedfilemode%06o"
4485                                        "---a/%.*s"
4486                                        "+++/dev/null",
4487                                        len1, p->one->path,
4488                                        len2, p->two->path,
4489                                        p->one->mode,
4490                                        len1, p->one->path);
4491                else
4492                        len1 = snprintf(buffer, sizeof(buffer),
4493                                        "diff--gita/%.*sb/%.*s"
4494                                        "---a/%.*s"
4495                                        "+++b/%.*s",
4496                                        len1, p->one->path,
4497                                        len2, p->two->path,
4498                                        len1, p->one->path,
4499                                        len2, p->two->path);
4500                git_SHA1_Update(&ctx, buffer, len1);
4501
4502                if (diff_filespec_is_binary(p->one) ||
4503                    diff_filespec_is_binary(p->two)) {
4504                        git_SHA1_Update(&ctx, sha1_to_hex(p->one->sha1), 40);
4505                        git_SHA1_Update(&ctx, sha1_to_hex(p->two->sha1), 40);
4506                        continue;
4507                }
4508
4509                xpp.flags = 0;
4510                xecfg.ctxlen = 3;
4511                xecfg.flags = 0;
4512                xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
4513                              &xpp, &xecfg);
4514        }
4515
4516        git_SHA1_Final(sha1, &ctx);
4517        return 0;
4518}
4519
4520int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1)
4521{
4522        struct diff_queue_struct *q = &diff_queued_diff;
4523        int i;
4524        int result = diff_get_patch_id(options, sha1);
4525
4526        for (i = 0; i < q->nr; i++)
4527                diff_free_filepair(q->queue[i]);
4528
4529        free(q->queue);
4530        DIFF_QUEUE_CLEAR(q);
4531
4532        return result;
4533}
4534
4535static int is_summary_empty(const struct diff_queue_struct *q)
4536{
4537        int i;
4538
4539        for (i = 0; i < q->nr; i++) {
4540                const struct diff_filepair *p = q->queue[i];
4541
4542                switch (p->status) {
4543                case DIFF_STATUS_DELETED:
4544                case DIFF_STATUS_ADDED:
4545                case DIFF_STATUS_COPIED:
4546                case DIFF_STATUS_RENAMED:
4547                        return 0;
4548                default:
4549                        if (p->score)
4550                                return 0;
4551                        if (p->one->mode && p->two->mode &&
4552                            p->one->mode != p->two->mode)
4553                                return 0;
4554                        break;
4555                }
4556        }
4557        return 1;
4558}
4559
4560static const char rename_limit_warning[] =
4561"inexact rename detection was skipped due to too many files.";
4562
4563static const char degrade_cc_to_c_warning[] =
4564"only found copies from modified paths due to too many files.";
4565
4566static const char rename_limit_advice[] =
4567"you may want to set your %s variable to at least "
4568"%d and retry the command.";
4569
4570void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc)
4571{
4572        if (degraded_cc)
4573                warning(degrade_cc_to_c_warning);
4574        else if (needed)
4575                warning(rename_limit_warning);
4576        else
4577                return;
4578        if (0 < needed && needed < 32767)
4579                warning(rename_limit_advice, varname, needed);
4580}
4581
4582void diff_flush(struct diff_options *options)
4583{
4584        struct diff_queue_struct *q = &diff_queued_diff;
4585        int i, output_format = options->output_format;
4586        int separator = 0;
4587        int dirstat_by_line = 0;
4588
4589        /*
4590         * Order: raw, stat, summary, patch
4591         * or:    name/name-status/checkdiff (other bits clear)
4592         */
4593        if (!q->nr)
4594                goto free_queue;
4595
4596        if (output_format & (DIFF_FORMAT_RAW |
4597                             DIFF_FORMAT_NAME |
4598                             DIFF_FORMAT_NAME_STATUS |
4599                             DIFF_FORMAT_CHECKDIFF)) {
4600                for (i = 0; i < q->nr; i++) {
4601                        struct diff_filepair *p = q->queue[i];
4602                        if (check_pair_status(p))
4603                                flush_one_pair(p, options);
4604                }
4605                separator++;
4606        }
4607
4608        if (output_format & DIFF_FORMAT_DIRSTAT && DIFF_OPT_TST(options, DIRSTAT_BY_LINE))
4609                dirstat_by_line = 1;
4610
4611        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT) ||
4612            dirstat_by_line) {
4613                struct diffstat_t diffstat;
4614
4615                memset(&diffstat, 0, sizeof(struct diffstat_t));
4616                for (i = 0; i < q->nr; i++) {
4617                        struct diff_filepair *p = q->queue[i];
4618                        if (check_pair_status(p))
4619                                diff_flush_stat(p, options, &diffstat);
4620                }
4621                if (output_format & DIFF_FORMAT_NUMSTAT)
4622                        show_numstat(&diffstat, options);
4623                if (output_format & DIFF_FORMAT_DIFFSTAT)
4624                        show_stats(&diffstat, options);
4625                if (output_format & DIFF_FORMAT_SHORTSTAT)
4626                        show_shortstats(&diffstat, options);
4627                if (output_format & DIFF_FORMAT_DIRSTAT && dirstat_by_line)
4628                        show_dirstat_by_line(&diffstat, options);
4629                free_diffstat_info(&diffstat);
4630                separator++;
4631        }
4632        if ((output_format & DIFF_FORMAT_DIRSTAT) && !dirstat_by_line)
4633                show_dirstat(options);
4634
4635        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
4636                for (i = 0; i < q->nr; i++) {
4637                        diff_summary(options, q->queue[i]);
4638                }
4639                separator++;
4640        }
4641
4642        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
4643            DIFF_OPT_TST(options, EXIT_WITH_STATUS) &&
4644            DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4645                /*
4646                 * run diff_flush_patch for the exit status. setting
4647                 * options->file to /dev/null should be safe, because we
4648                 * aren't supposed to produce any output anyway.
4649                 */
4650                if (options->close_file)
4651                        fclose(options->file);
4652                options->file = fopen("/dev/null", "w");
4653                if (!options->file)
4654                        die_errno("Could not open /dev/null");
4655                options->close_file = 1;
4656                for (i = 0; i < q->nr; i++) {
4657                        struct diff_filepair *p = q->queue[i];
4658                        if (check_pair_status(p))
4659                                diff_flush_patch(p, options);
4660                        if (options->found_changes)
4661                                break;
4662                }
4663        }
4664
4665        if (output_format & DIFF_FORMAT_PATCH) {
4666                if (separator) {
4667                        fprintf(options->file, "%s%c",
4668                                diff_line_prefix(options),
4669                                options->line_termination);
4670                        if (options->stat_sep) {
4671                                /* attach patch instead of inline */
4672                                fputs(options->stat_sep, options->file);
4673                        }
4674                }
4675
4676                for (i = 0; i < q->nr; i++) {
4677                        struct diff_filepair *p = q->queue[i];
4678                        if (check_pair_status(p))
4679                                diff_flush_patch(p, options);
4680                }
4681        }
4682
4683        if (output_format & DIFF_FORMAT_CALLBACK)
4684                options->format_callback(q, options, options->format_callback_data);
4685
4686        for (i = 0; i < q->nr; i++)
4687                diff_free_filepair(q->queue[i]);
4688free_queue:
4689        free(q->queue);
4690        DIFF_QUEUE_CLEAR(q);
4691        if (options->close_file)
4692                fclose(options->file);
4693
4694        /*
4695         * Report the content-level differences with HAS_CHANGES;
4696         * diff_addremove/diff_change does not set the bit when
4697         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
4698         */
4699        if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4700                if (options->found_changes)
4701                        DIFF_OPT_SET(options, HAS_CHANGES);
4702                else
4703                        DIFF_OPT_CLR(options, HAS_CHANGES);
4704        }
4705}
4706
4707static int match_filter(const struct diff_options *options, const struct diff_filepair *p)
4708{
4709        return (((p->status == DIFF_STATUS_MODIFIED) &&
4710                 ((p->score &&
4711                   filter_bit_tst(DIFF_STATUS_FILTER_BROKEN, options)) ||
4712                  (!p->score &&
4713                   filter_bit_tst(DIFF_STATUS_MODIFIED, options)))) ||
4714                ((p->status != DIFF_STATUS_MODIFIED) &&
4715                 filter_bit_tst(p->status, options)));
4716}
4717
4718static void diffcore_apply_filter(struct diff_options *options)
4719{
4720        int i;
4721        struct diff_queue_struct *q = &diff_queued_diff;
4722        struct diff_queue_struct outq;
4723
4724        DIFF_QUEUE_CLEAR(&outq);
4725
4726        if (!options->filter)
4727                return;
4728
4729        if (filter_bit_tst(DIFF_STATUS_FILTER_AON, options)) {
4730                int found;
4731                for (i = found = 0; !found && i < q->nr; i++) {
4732                        if (match_filter(options, q->queue[i]))
4733                                found++;
4734                }
4735                if (found)
4736                        return;
4737
4738                /* otherwise we will clear the whole queue
4739                 * by copying the empty outq at the end of this
4740                 * function, but first clear the current entries
4741                 * in the queue.
4742                 */
4743                for (i = 0; i < q->nr; i++)
4744                        diff_free_filepair(q->queue[i]);
4745        }
4746        else {
4747                /* Only the matching ones */
4748                for (i = 0; i < q->nr; i++) {
4749                        struct diff_filepair *p = q->queue[i];
4750                        if (match_filter(options, p))
4751                                diff_q(&outq, p);
4752                        else
4753                                diff_free_filepair(p);
4754                }
4755        }
4756        free(q->queue);
4757        *q = outq;
4758}
4759
4760/* Check whether two filespecs with the same mode and size are identical */
4761static int diff_filespec_is_identical(struct diff_filespec *one,
4762                                      struct diff_filespec *two)
4763{
4764        if (S_ISGITLINK(one->mode))
4765                return 0;
4766        if (diff_populate_filespec(one, 0))
4767                return 0;
4768        if (diff_populate_filespec(two, 0))
4769                return 0;
4770        return !memcmp(one->data, two->data, one->size);
4771}
4772
4773static int diff_filespec_check_stat_unmatch(struct diff_filepair *p)
4774{
4775        if (p->done_skip_stat_unmatch)
4776                return p->skip_stat_unmatch_result;
4777
4778        p->done_skip_stat_unmatch = 1;
4779        p->skip_stat_unmatch_result = 0;
4780        /*
4781         * 1. Entries that come from stat info dirtiness
4782         *    always have both sides (iow, not create/delete),
4783         *    one side of the object name is unknown, with
4784         *    the same mode and size.  Keep the ones that
4785         *    do not match these criteria.  They have real
4786         *    differences.
4787         *
4788         * 2. At this point, the file is known to be modified,
4789         *    with the same mode and size, and the object
4790         *    name of one side is unknown.  Need to inspect
4791         *    the identical contents.
4792         */
4793        if (!DIFF_FILE_VALID(p->one) || /* (1) */
4794            !DIFF_FILE_VALID(p->two) ||
4795            (p->one->sha1_valid && p->two->sha1_valid) ||
4796            (p->one->mode != p->two->mode) ||
4797            diff_populate_filespec(p->one, CHECK_SIZE_ONLY) ||
4798            diff_populate_filespec(p->two, CHECK_SIZE_ONLY) ||
4799            (p->one->size != p->two->size) ||
4800            !diff_filespec_is_identical(p->one, p->two)) /* (2) */
4801                p->skip_stat_unmatch_result = 1;
4802        return p->skip_stat_unmatch_result;
4803}
4804
4805static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
4806{
4807        int i;
4808        struct diff_queue_struct *q = &diff_queued_diff;
4809        struct diff_queue_struct outq;
4810        DIFF_QUEUE_CLEAR(&outq);
4811
4812        for (i = 0; i < q->nr; i++) {
4813                struct diff_filepair *p = q->queue[i];
4814
4815                if (diff_filespec_check_stat_unmatch(p))
4816                        diff_q(&outq, p);
4817                else {
4818                        /*
4819                         * The caller can subtract 1 from skip_stat_unmatch
4820                         * to determine how many paths were dirty only
4821                         * due to stat info mismatch.
4822                         */
4823                        if (!DIFF_OPT_TST(diffopt, NO_INDEX))
4824                                diffopt->skip_stat_unmatch++;
4825                        diff_free_filepair(p);
4826                }
4827        }
4828        free(q->queue);
4829        *q = outq;
4830}
4831
4832static int diffnamecmp(const void *a_, const void *b_)
4833{
4834        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
4835        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
4836        const char *name_a, *name_b;
4837
4838        name_a = a->one ? a->one->path : a->two->path;
4839        name_b = b->one ? b->one->path : b->two->path;
4840        return strcmp(name_a, name_b);
4841}
4842
4843void diffcore_fix_diff_index(struct diff_options *options)
4844{
4845        struct diff_queue_struct *q = &diff_queued_diff;
4846        qsort(q->queue, q->nr, sizeof(q->queue[0]), diffnamecmp);
4847}
4848
4849void diffcore_std(struct diff_options *options)
4850{
4851        /* NOTE please keep the following in sync with diff_tree_combined() */
4852        if (options->skip_stat_unmatch)
4853                diffcore_skip_stat_unmatch(options);
4854        if (!options->found_follow) {
4855                /* See try_to_follow_renames() in tree-diff.c */
4856                if (options->break_opt != -1)
4857                        diffcore_break(options->break_opt);
4858                if (options->detect_rename)
4859                        diffcore_rename(options);
4860                if (options->break_opt != -1)
4861                        diffcore_merge_broken();
4862        }
4863        if (options->pickaxe)
4864                diffcore_pickaxe(options);
4865        if (options->orderfile)
4866                diffcore_order(options->orderfile);
4867        if (!options->found_follow)
4868                /* See try_to_follow_renames() in tree-diff.c */
4869                diff_resolve_rename_copy();
4870        diffcore_apply_filter(options);
4871
4872        if (diff_queued_diff.nr && !DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4873                DIFF_OPT_SET(options, HAS_CHANGES);
4874        else
4875                DIFF_OPT_CLR(options, HAS_CHANGES);
4876
4877        options->found_follow = 0;
4878}
4879
4880int diff_result_code(struct diff_options *opt, int status)
4881{
4882        int result = 0;
4883
4884        diff_warn_rename_limit("diff.renameLimit",
4885                               opt->needed_rename_limit,
4886                               opt->degraded_cc_to_c);
4887        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4888            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
4889                return status;
4890        if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4891            DIFF_OPT_TST(opt, HAS_CHANGES))
4892                result |= 01;
4893        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
4894            DIFF_OPT_TST(opt, CHECK_FAILED))
4895                result |= 02;
4896        return result;
4897}
4898
4899int diff_can_quit_early(struct diff_options *opt)
4900{
4901        return (DIFF_OPT_TST(opt, QUICK) &&
4902                !opt->filter &&
4903                DIFF_OPT_TST(opt, HAS_CHANGES));
4904}
4905
4906/*
4907 * Shall changes to this submodule be ignored?
4908 *
4909 * Submodule changes can be configured to be ignored separately for each path,
4910 * but that configuration can be overridden from the command line.
4911 */
4912static int is_submodule_ignored(const char *path, struct diff_options *options)
4913{
4914        int ignored = 0;
4915        unsigned orig_flags = options->flags;
4916        if (!DIFF_OPT_TST(options, OVERRIDE_SUBMODULE_CONFIG))
4917                set_diffopt_flags_from_submodule_config(options, path);
4918        if (DIFF_OPT_TST(options, IGNORE_SUBMODULES))
4919                ignored = 1;
4920        options->flags = orig_flags;
4921        return ignored;
4922}
4923
4924void diff_addremove(struct diff_options *options,
4925                    int addremove, unsigned mode,
4926                    const unsigned char *sha1,
4927                    int sha1_valid,
4928                    const char *concatpath, unsigned dirty_submodule)
4929{
4930        struct diff_filespec *one, *two;
4931
4932        if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
4933                return;
4934
4935        /* This may look odd, but it is a preparation for
4936         * feeding "there are unchanged files which should
4937         * not produce diffs, but when you are doing copy
4938         * detection you would need them, so here they are"
4939         * entries to the diff-core.  They will be prefixed
4940         * with something like '=' or '*' (I haven't decided
4941         * which but should not make any difference).
4942         * Feeding the same new and old to diff_change()
4943         * also has the same effect.
4944         * Before the final output happens, they are pruned after
4945         * merged into rename/copy pairs as appropriate.
4946         */
4947        if (DIFF_OPT_TST(options, REVERSE_DIFF))
4948                addremove = (addremove == '+' ? '-' :
4949                             addremove == '-' ? '+' : addremove);
4950
4951        if (options->prefix &&
4952            strncmp(concatpath, options->prefix, options->prefix_length))
4953                return;
4954
4955        one = alloc_filespec(concatpath);
4956        two = alloc_filespec(concatpath);
4957
4958        if (addremove != '+')
4959                fill_filespec(one, sha1, sha1_valid, mode);
4960        if (addremove != '-') {
4961                fill_filespec(two, sha1, sha1_valid, mode);
4962                two->dirty_submodule = dirty_submodule;
4963        }
4964
4965        diff_queue(&diff_queued_diff, one, two);
4966        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4967                DIFF_OPT_SET(options, HAS_CHANGES);
4968}
4969
4970void diff_change(struct diff_options *options,
4971                 unsigned old_mode, unsigned new_mode,
4972                 const unsigned char *old_sha1,
4973                 const unsigned char *new_sha1,
4974                 int old_sha1_valid, int new_sha1_valid,
4975                 const char *concatpath,
4976                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
4977{
4978        struct diff_filespec *one, *two;
4979        struct diff_filepair *p;
4980
4981        if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
4982            is_submodule_ignored(concatpath, options))
4983                return;
4984
4985        if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
4986                unsigned tmp;
4987                const unsigned char *tmp_c;
4988                tmp = old_mode; old_mode = new_mode; new_mode = tmp;
4989                tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
4990                tmp = old_sha1_valid; old_sha1_valid = new_sha1_valid;
4991                        new_sha1_valid = tmp;
4992                tmp = old_dirty_submodule; old_dirty_submodule = new_dirty_submodule;
4993                        new_dirty_submodule = tmp;
4994        }
4995
4996        if (options->prefix &&
4997            strncmp(concatpath, options->prefix, options->prefix_length))
4998                return;
4999
5000        one = alloc_filespec(concatpath);
5001        two = alloc_filespec(concatpath);
5002        fill_filespec(one, old_sha1, old_sha1_valid, old_mode);
5003        fill_filespec(two, new_sha1, new_sha1_valid, new_mode);
5004        one->dirty_submodule = old_dirty_submodule;
5005        two->dirty_submodule = new_dirty_submodule;
5006        p = diff_queue(&diff_queued_diff, one, two);
5007
5008        if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
5009                return;
5010
5011        if (DIFF_OPT_TST(options, QUICK) && options->skip_stat_unmatch &&
5012            !diff_filespec_check_stat_unmatch(p))
5013                return;
5014
5015        DIFF_OPT_SET(options, HAS_CHANGES);
5016}
5017
5018struct diff_filepair *diff_unmerge(struct diff_options *options, const char *path)
5019{
5020        struct diff_filepair *pair;
5021        struct diff_filespec *one, *two;
5022
5023        if (options->prefix &&
5024            strncmp(path, options->prefix, options->prefix_length))
5025                return NULL;
5026
5027        one = alloc_filespec(path);
5028        two = alloc_filespec(path);
5029        pair = diff_queue(&diff_queued_diff, one, two);
5030        pair->is_unmerged = 1;
5031        return pair;
5032}
5033
5034static char *run_textconv(const char *pgm, struct diff_filespec *spec,
5035                size_t *outsize)
5036{
5037        struct diff_tempfile *temp;
5038        const char *argv[3];
5039        const char **arg = argv;
5040        struct child_process child = CHILD_PROCESS_INIT;
5041        struct strbuf buf = STRBUF_INIT;
5042        int err = 0;
5043
5044        temp = prepare_temp_file(spec->path, spec);
5045        *arg++ = pgm;
5046        *arg++ = temp->name;
5047        *arg = NULL;
5048
5049        child.use_shell = 1;
5050        child.argv = argv;
5051        child.out = -1;
5052        if (start_command(&child)) {
5053                remove_tempfile();
5054                return NULL;
5055        }
5056
5057        if (strbuf_read(&buf, child.out, 0) < 0)
5058                err = error("error reading from textconv command '%s'", pgm);
5059        close(child.out);
5060
5061        if (finish_command(&child) || err) {
5062                strbuf_release(&buf);
5063                remove_tempfile();
5064                return NULL;
5065        }
5066        remove_tempfile();
5067
5068        return strbuf_detach(&buf, outsize);
5069}
5070
5071size_t fill_textconv(struct userdiff_driver *driver,
5072                     struct diff_filespec *df,
5073                     char **outbuf)
5074{
5075        size_t size;
5076
5077        if (!driver || !driver->textconv) {
5078                if (!DIFF_FILE_VALID(df)) {
5079                        *outbuf = "";
5080                        return 0;
5081                }
5082                if (diff_populate_filespec(df, 0))
5083                        die("unable to read files to diff");
5084                *outbuf = df->data;
5085                return df->size;
5086        }
5087
5088        if (driver->textconv_cache && df->sha1_valid) {
5089                *outbuf = notes_cache_get(driver->textconv_cache, df->sha1,
5090                                          &size);
5091                if (*outbuf)
5092                        return size;
5093        }
5094
5095        *outbuf = run_textconv(driver->textconv, df, &size);
5096        if (!*outbuf)
5097                die("unable to read files to diff");
5098
5099        if (driver->textconv_cache && df->sha1_valid) {
5100                /* ignore errors, as we might be in a readonly repository */
5101                notes_cache_put(driver->textconv_cache, df->sha1, *outbuf,
5102                                size);
5103                /*
5104                 * we could save up changes and flush them all at the end,
5105                 * but we would need an extra call after all diffing is done.
5106                 * Since generating a cache entry is the slow path anyway,
5107                 * this extra overhead probably isn't a big deal.
5108                 */
5109                notes_cache_write(driver->textconv_cache);
5110        }
5111
5112        return size;
5113}
5114
5115void setup_diff_pager(struct diff_options *opt)
5116{
5117        /*
5118         * If the user asked for our exit code, then either they want --quiet
5119         * or --exit-code. We should definitely not bother with a pager in the
5120         * former case, as we will generate no output. Since we still properly
5121         * report our exit code even when a pager is run, we _could_ run a
5122         * pager with --exit-code. But since we have not done so historically,
5123         * and because it is easy to find people oneline advising "git diff
5124         * --exit-code" in hooks and other scripts, we do not do so.
5125         */
5126        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
5127            check_pager_config("diff") != 0)
5128                setup_pager();
5129}