05ca3ce08e21082f66ea9a8c6d0b51d1e56c6815
   1/*
   2 * Copyright (C) 2005 Junio C Hamano
   3 */
   4#include "cache.h"
   5#include "quote.h"
   6#include "diff.h"
   7#include "diffcore.h"
   8#include "delta.h"
   9#include "xdiff-interface.h"
  10#include "color.h"
  11#include "attr.h"
  12#include "run-command.h"
  13#include "utf8.h"
  14#include "userdiff.h"
  15#include "sigchain.h"
  16#include "submodule.h"
  17#include "ll-merge.h"
  18#include "string-list.h"
  19#include "argv-array.h"
  20
  21#ifdef NO_FAST_WORKING_DIRECTORY
  22#define FAST_WORKING_DIRECTORY 0
  23#else
  24#define FAST_WORKING_DIRECTORY 1
  25#endif
  26
  27static int diff_detect_rename_default;
  28static int diff_compaction_heuristic = 1;
  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.compactionheuristic")) {
 188                diff_compaction_heuristic = git_config_bool(var, value);
 189                return 0;
 190        }
 191        if (!strcmp(var, "diff.autorefreshindex")) {
 192                diff_auto_refresh_index = git_config_bool(var, value);
 193                return 0;
 194        }
 195        if (!strcmp(var, "diff.mnemonicprefix")) {
 196                diff_mnemonic_prefix = git_config_bool(var, value);
 197                return 0;
 198        }
 199        if (!strcmp(var, "diff.noprefix")) {
 200                diff_no_prefix = git_config_bool(var, value);
 201                return 0;
 202        }
 203        if (!strcmp(var, "diff.statgraphwidth")) {
 204                diff_stat_graph_width = git_config_int(var, value);
 205                return 0;
 206        }
 207        if (!strcmp(var, "diff.external"))
 208                return git_config_string(&external_diff_cmd_cfg, var, value);
 209        if (!strcmp(var, "diff.wordregex"))
 210                return git_config_string(&diff_word_regex_cfg, var, value);
 211        if (!strcmp(var, "diff.orderfile"))
 212                return git_config_pathname(&diff_order_file_cfg, var, value);
 213
 214        if (!strcmp(var, "diff.ignoresubmodules"))
 215                handle_ignore_submodules_arg(&default_diff_options, value);
 216
 217        if (!strcmp(var, "diff.submodule")) {
 218                if (parse_submodule_params(&default_diff_options, value))
 219                        warning(_("Unknown value for 'diff.submodule' config variable: '%s'"),
 220                                value);
 221                return 0;
 222        }
 223
 224        if (!strcmp(var, "diff.algorithm")) {
 225                diff_algorithm = parse_algorithm_value(value);
 226                if (diff_algorithm < 0)
 227                        return -1;
 228                return 0;
 229        }
 230
 231        if (git_color_config(var, value, cb) < 0)
 232                return -1;
 233
 234        return git_diff_basic_config(var, value, cb);
 235}
 236
 237int git_diff_basic_config(const char *var, const char *value, void *cb)
 238{
 239        const char *name;
 240
 241        if (!strcmp(var, "diff.renamelimit")) {
 242                diff_rename_limit_default = git_config_int(var, value);
 243                return 0;
 244        }
 245
 246        if (userdiff_config(var, value) < 0)
 247                return -1;
 248
 249        if (skip_prefix(var, "diff.color.", &name) ||
 250            skip_prefix(var, "color.diff.", &name)) {
 251                int slot = parse_diff_color_slot(name);
 252                if (slot < 0)
 253                        return 0;
 254                if (!value)
 255                        return config_error_nonbool(var);
 256                return color_parse(value, diff_colors[slot]);
 257        }
 258
 259        /* like GNU diff's --suppress-blank-empty option  */
 260        if (!strcmp(var, "diff.suppressblankempty") ||
 261                        /* for backwards compatibility */
 262                        !strcmp(var, "diff.suppress-blank-empty")) {
 263                diff_suppress_blank_empty = git_config_bool(var, value);
 264                return 0;
 265        }
 266
 267        if (!strcmp(var, "diff.dirstat")) {
 268                struct strbuf errmsg = STRBUF_INIT;
 269                default_diff_options.dirstat_permille = diff_dirstat_permille_default;
 270                if (parse_dirstat_params(&default_diff_options, value, &errmsg))
 271                        warning(_("Found errors in 'diff.dirstat' config variable:\n%s"),
 272                                errmsg.buf);
 273                strbuf_release(&errmsg);
 274                diff_dirstat_permille_default = default_diff_options.dirstat_permille;
 275                return 0;
 276        }
 277
 278        if (starts_with(var, "submodule."))
 279                return parse_submodule_config_option(var, value);
 280
 281        return git_default_config(var, value, cb);
 282}
 283
 284static char *quote_two(const char *one, const char *two)
 285{
 286        int need_one = quote_c_style(one, NULL, NULL, 1);
 287        int need_two = quote_c_style(two, NULL, NULL, 1);
 288        struct strbuf res = STRBUF_INIT;
 289
 290        if (need_one + need_two) {
 291                strbuf_addch(&res, '"');
 292                quote_c_style(one, &res, NULL, 1);
 293                quote_c_style(two, &res, NULL, 1);
 294                strbuf_addch(&res, '"');
 295        } else {
 296                strbuf_addstr(&res, one);
 297                strbuf_addstr(&res, two);
 298        }
 299        return strbuf_detach(&res, NULL);
 300}
 301
 302static const char *external_diff(void)
 303{
 304        static const char *external_diff_cmd = NULL;
 305        static int done_preparing = 0;
 306
 307        if (done_preparing)
 308                return external_diff_cmd;
 309        external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
 310        if (!external_diff_cmd)
 311                external_diff_cmd = external_diff_cmd_cfg;
 312        done_preparing = 1;
 313        return external_diff_cmd;
 314}
 315
 316static struct diff_tempfile {
 317        const char *name; /* filename external diff should read from */
 318        char hex[41];
 319        char mode[10];
 320        char tmp_path[PATH_MAX];
 321} diff_temp[2];
 322
 323typedef unsigned long (*sane_truncate_fn)(char *line, unsigned long len);
 324
 325struct emit_callback {
 326        int color_diff;
 327        unsigned ws_rule;
 328        int blank_at_eof_in_preimage;
 329        int blank_at_eof_in_postimage;
 330        int lno_in_preimage;
 331        int lno_in_postimage;
 332        sane_truncate_fn truncate;
 333        const char **label_path;
 334        struct diff_words_data *diff_words;
 335        struct diff_options *opt;
 336        int *found_changesp;
 337        struct strbuf *header;
 338};
 339
 340static int count_lines(const char *data, int size)
 341{
 342        int count, ch, completely_empty = 1, nl_just_seen = 0;
 343        count = 0;
 344        while (0 < size--) {
 345                ch = *data++;
 346                if (ch == '\n') {
 347                        count++;
 348                        nl_just_seen = 1;
 349                        completely_empty = 0;
 350                }
 351                else {
 352                        nl_just_seen = 0;
 353                        completely_empty = 0;
 354                }
 355        }
 356        if (completely_empty)
 357                return 0;
 358        if (!nl_just_seen)
 359                count++; /* no trailing newline */
 360        return count;
 361}
 362
 363static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
 364{
 365        if (!DIFF_FILE_VALID(one)) {
 366                mf->ptr = (char *)""; /* does not matter */
 367                mf->size = 0;
 368                return 0;
 369        }
 370        else if (diff_populate_filespec(one, 0))
 371                return -1;
 372
 373        mf->ptr = one->data;
 374        mf->size = one->size;
 375        return 0;
 376}
 377
 378/* like fill_mmfile, but only for size, so we can avoid retrieving blob */
 379static unsigned long diff_filespec_size(struct diff_filespec *one)
 380{
 381        if (!DIFF_FILE_VALID(one))
 382                return 0;
 383        diff_populate_filespec(one, CHECK_SIZE_ONLY);
 384        return one->size;
 385}
 386
 387static int count_trailing_blank(mmfile_t *mf, unsigned ws_rule)
 388{
 389        char *ptr = mf->ptr;
 390        long size = mf->size;
 391        int cnt = 0;
 392
 393        if (!size)
 394                return cnt;
 395        ptr += size - 1; /* pointing at the very end */
 396        if (*ptr != '\n')
 397                ; /* incomplete line */
 398        else
 399                ptr--; /* skip the last LF */
 400        while (mf->ptr < ptr) {
 401                char *prev_eol;
 402                for (prev_eol = ptr; mf->ptr <= prev_eol; prev_eol--)
 403                        if (*prev_eol == '\n')
 404                                break;
 405                if (!ws_blank_line(prev_eol + 1, ptr - prev_eol, ws_rule))
 406                        break;
 407                cnt++;
 408                ptr = prev_eol - 1;
 409        }
 410        return cnt;
 411}
 412
 413static void check_blank_at_eof(mmfile_t *mf1, mmfile_t *mf2,
 414                               struct emit_callback *ecbdata)
 415{
 416        int l1, l2, at;
 417        unsigned ws_rule = ecbdata->ws_rule;
 418        l1 = count_trailing_blank(mf1, ws_rule);
 419        l2 = count_trailing_blank(mf2, ws_rule);
 420        if (l2 <= l1) {
 421                ecbdata->blank_at_eof_in_preimage = 0;
 422                ecbdata->blank_at_eof_in_postimage = 0;
 423                return;
 424        }
 425        at = count_lines(mf1->ptr, mf1->size);
 426        ecbdata->blank_at_eof_in_preimage = (at - l1) + 1;
 427
 428        at = count_lines(mf2->ptr, mf2->size);
 429        ecbdata->blank_at_eof_in_postimage = (at - l2) + 1;
 430}
 431
 432static void emit_line_0(struct diff_options *o, const char *set, const char *reset,
 433                        int first, const char *line, int len)
 434{
 435        int has_trailing_newline, has_trailing_carriage_return;
 436        int nofirst;
 437        FILE *file = o->file;
 438
 439        fputs(diff_line_prefix(o), file);
 440
 441        if (len == 0) {
 442                has_trailing_newline = (first == '\n');
 443                has_trailing_carriage_return = (!has_trailing_newline &&
 444                                                (first == '\r'));
 445                nofirst = has_trailing_newline || has_trailing_carriage_return;
 446        } else {
 447                has_trailing_newline = (len > 0 && line[len-1] == '\n');
 448                if (has_trailing_newline)
 449                        len--;
 450                has_trailing_carriage_return = (len > 0 && line[len-1] == '\r');
 451                if (has_trailing_carriage_return)
 452                        len--;
 453                nofirst = 0;
 454        }
 455
 456        if (len || !nofirst) {
 457                fputs(set, file);
 458                if (!nofirst)
 459                        fputc(first, file);
 460                fwrite(line, len, 1, file);
 461                fputs(reset, file);
 462        }
 463        if (has_trailing_carriage_return)
 464                fputc('\r', file);
 465        if (has_trailing_newline)
 466                fputc('\n', file);
 467}
 468
 469static void emit_line(struct diff_options *o, const char *set, const char *reset,
 470                      const char *line, int len)
 471{
 472        emit_line_0(o, set, reset, line[0], line+1, len-1);
 473}
 474
 475static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line, int len)
 476{
 477        if (!((ecbdata->ws_rule & WS_BLANK_AT_EOF) &&
 478              ecbdata->blank_at_eof_in_preimage &&
 479              ecbdata->blank_at_eof_in_postimage &&
 480              ecbdata->blank_at_eof_in_preimage <= ecbdata->lno_in_preimage &&
 481              ecbdata->blank_at_eof_in_postimage <= ecbdata->lno_in_postimage))
 482                return 0;
 483        return ws_blank_line(line, len, ecbdata->ws_rule);
 484}
 485
 486static void emit_add_line(const char *reset,
 487                          struct emit_callback *ecbdata,
 488                          const char *line, int len)
 489{
 490        const char *ws = diff_get_color(ecbdata->color_diff, DIFF_WHITESPACE);
 491        const char *set = diff_get_color(ecbdata->color_diff, DIFF_FILE_NEW);
 492
 493        if (!*ws)
 494                emit_line_0(ecbdata->opt, set, reset, '+', line, len);
 495        else if (new_blank_line_at_eof(ecbdata, line, len))
 496                /* Blank line at EOF - paint '+' as well */
 497                emit_line_0(ecbdata->opt, ws, reset, '+', line, len);
 498        else {
 499                /* Emit just the prefix, then the rest. */
 500                emit_line_0(ecbdata->opt, set, reset, '+', "", 0);
 501                ws_check_emit(line, len, ecbdata->ws_rule,
 502                              ecbdata->opt->file, set, reset, ws);
 503        }
 504}
 505
 506static void emit_hunk_header(struct emit_callback *ecbdata,
 507                             const char *line, int len)
 508{
 509        const char *context = diff_get_color(ecbdata->color_diff, DIFF_CONTEXT);
 510        const char *frag = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
 511        const char *func = diff_get_color(ecbdata->color_diff, DIFF_FUNCINFO);
 512        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
 513        static const char atat[2] = { '@', '@' };
 514        const char *cp, *ep;
 515        struct strbuf msgbuf = STRBUF_INIT;
 516        int org_len = len;
 517        int i = 1;
 518
 519        /*
 520         * As a hunk header must begin with "@@ -<old>, +<new> @@",
 521         * it always is at least 10 bytes long.
 522         */
 523        if (len < 10 ||
 524            memcmp(line, atat, 2) ||
 525            !(ep = memmem(line + 2, len - 2, atat, 2))) {
 526                emit_line(ecbdata->opt, context, reset, line, len);
 527                return;
 528        }
 529        ep += 2; /* skip over @@ */
 530
 531        /* The hunk header in fraginfo color */
 532        strbuf_addstr(&msgbuf, frag);
 533        strbuf_add(&msgbuf, line, ep - line);
 534        strbuf_addstr(&msgbuf, reset);
 535
 536        /*
 537         * trailing "\r\n"
 538         */
 539        for ( ; i < 3; i++)
 540                if (line[len - i] == '\r' || line[len - i] == '\n')
 541                        len--;
 542
 543        /* blank before the func header */
 544        for (cp = ep; ep - line < len; ep++)
 545                if (*ep != ' ' && *ep != '\t')
 546                        break;
 547        if (ep != cp) {
 548                strbuf_addstr(&msgbuf, context);
 549                strbuf_add(&msgbuf, cp, ep - cp);
 550                strbuf_addstr(&msgbuf, reset);
 551        }
 552
 553        if (ep < line + len) {
 554                strbuf_addstr(&msgbuf, func);
 555                strbuf_add(&msgbuf, ep, line + len - ep);
 556                strbuf_addstr(&msgbuf, reset);
 557        }
 558
 559        strbuf_add(&msgbuf, line + len, org_len - len);
 560        emit_line(ecbdata->opt, "", "", msgbuf.buf, msgbuf.len);
 561        strbuf_release(&msgbuf);
 562}
 563
 564static struct diff_tempfile *claim_diff_tempfile(void) {
 565        int i;
 566        for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
 567                if (!diff_temp[i].name)
 568                        return diff_temp + i;
 569        die("BUG: diff is failing to clean up its tempfiles");
 570}
 571
 572static int remove_tempfile_installed;
 573
 574static void remove_tempfile(void)
 575{
 576        int i;
 577        for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
 578                if (diff_temp[i].name == diff_temp[i].tmp_path)
 579                        unlink_or_warn(diff_temp[i].name);
 580                diff_temp[i].name = NULL;
 581        }
 582}
 583
 584static void remove_tempfile_on_signal(int signo)
 585{
 586        remove_tempfile();
 587        sigchain_pop(signo);
 588        raise(signo);
 589}
 590
 591static void print_line_count(FILE *file, int count)
 592{
 593        switch (count) {
 594        case 0:
 595                fprintf(file, "0,0");
 596                break;
 597        case 1:
 598                fprintf(file, "1");
 599                break;
 600        default:
 601                fprintf(file, "1,%d", count);
 602                break;
 603        }
 604}
 605
 606static void emit_rewrite_lines(struct emit_callback *ecb,
 607                               int prefix, const char *data, int size)
 608{
 609        const char *endp = NULL;
 610        static const char *nneof = " No newline at end of file\n";
 611        const char *old = diff_get_color(ecb->color_diff, DIFF_FILE_OLD);
 612        const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
 613
 614        while (0 < size) {
 615                int len;
 616
 617                endp = memchr(data, '\n', size);
 618                len = endp ? (endp - data + 1) : size;
 619                if (prefix != '+') {
 620                        ecb->lno_in_preimage++;
 621                        emit_line_0(ecb->opt, old, reset, '-',
 622                                    data, len);
 623                } else {
 624                        ecb->lno_in_postimage++;
 625                        emit_add_line(reset, ecb, data, len);
 626                }
 627                size -= len;
 628                data += len;
 629        }
 630        if (!endp) {
 631                const char *context = diff_get_color(ecb->color_diff,
 632                                                     DIFF_CONTEXT);
 633                putc('\n', ecb->opt->file);
 634                emit_line_0(ecb->opt, context, reset, '\\',
 635                            nneof, strlen(nneof));
 636        }
 637}
 638
 639static void emit_rewrite_diff(const char *name_a,
 640                              const char *name_b,
 641                              struct diff_filespec *one,
 642                              struct diff_filespec *two,
 643                              struct userdiff_driver *textconv_one,
 644                              struct userdiff_driver *textconv_two,
 645                              struct diff_options *o)
 646{
 647        int lc_a, lc_b;
 648        const char *name_a_tab, *name_b_tab;
 649        const char *metainfo = diff_get_color(o->use_color, DIFF_METAINFO);
 650        const char *fraginfo = diff_get_color(o->use_color, DIFF_FRAGINFO);
 651        const char *reset = diff_get_color(o->use_color, DIFF_RESET);
 652        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
 653        const char *a_prefix, *b_prefix;
 654        char *data_one, *data_two;
 655        size_t size_one, size_two;
 656        struct emit_callback ecbdata;
 657        const char *line_prefix = diff_line_prefix(o);
 658
 659        if (diff_mnemonic_prefix && DIFF_OPT_TST(o, REVERSE_DIFF)) {
 660                a_prefix = o->b_prefix;
 661                b_prefix = o->a_prefix;
 662        } else {
 663                a_prefix = o->a_prefix;
 664                b_prefix = o->b_prefix;
 665        }
 666
 667        name_a += (*name_a == '/');
 668        name_b += (*name_b == '/');
 669        name_a_tab = strchr(name_a, ' ') ? "\t" : "";
 670        name_b_tab = strchr(name_b, ' ') ? "\t" : "";
 671
 672        strbuf_reset(&a_name);
 673        strbuf_reset(&b_name);
 674        quote_two_c_style(&a_name, a_prefix, name_a, 0);
 675        quote_two_c_style(&b_name, b_prefix, name_b, 0);
 676
 677        size_one = fill_textconv(textconv_one, one, &data_one);
 678        size_two = fill_textconv(textconv_two, two, &data_two);
 679
 680        memset(&ecbdata, 0, sizeof(ecbdata));
 681        ecbdata.color_diff = want_color(o->use_color);
 682        ecbdata.found_changesp = &o->found_changes;
 683        ecbdata.ws_rule = whitespace_rule(name_b);
 684        ecbdata.opt = o;
 685        if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
 686                mmfile_t mf1, mf2;
 687                mf1.ptr = (char *)data_one;
 688                mf2.ptr = (char *)data_two;
 689                mf1.size = size_one;
 690                mf2.size = size_two;
 691                check_blank_at_eof(&mf1, &mf2, &ecbdata);
 692        }
 693        ecbdata.lno_in_preimage = 1;
 694        ecbdata.lno_in_postimage = 1;
 695
 696        lc_a = count_lines(data_one, size_one);
 697        lc_b = count_lines(data_two, size_two);
 698        fprintf(o->file,
 699                "%s%s--- %s%s%s\n%s%s+++ %s%s%s\n%s%s@@ -",
 700                line_prefix, metainfo, a_name.buf, name_a_tab, reset,
 701                line_prefix, metainfo, b_name.buf, name_b_tab, reset,
 702                line_prefix, fraginfo);
 703        if (!o->irreversible_delete)
 704                print_line_count(o->file, lc_a);
 705        else
 706                fprintf(o->file, "?,?");
 707        fprintf(o->file, " +");
 708        print_line_count(o->file, lc_b);
 709        fprintf(o->file, " @@%s\n", reset);
 710        if (lc_a && !o->irreversible_delete)
 711                emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
 712        if (lc_b)
 713                emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
 714        if (textconv_one)
 715                free((char *)data_one);
 716        if (textconv_two)
 717                free((char *)data_two);
 718}
 719
 720struct diff_words_buffer {
 721        mmfile_t text;
 722        long alloc;
 723        struct diff_words_orig {
 724                const char *begin, *end;
 725        } *orig;
 726        int orig_nr, orig_alloc;
 727};
 728
 729static void diff_words_append(char *line, unsigned long len,
 730                struct diff_words_buffer *buffer)
 731{
 732        ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
 733        line++;
 734        len--;
 735        memcpy(buffer->text.ptr + buffer->text.size, line, len);
 736        buffer->text.size += len;
 737        buffer->text.ptr[buffer->text.size] = '\0';
 738}
 739
 740struct diff_words_style_elem {
 741        const char *prefix;
 742        const char *suffix;
 743        const char *color; /* NULL; filled in by the setup code if
 744                            * color is enabled */
 745};
 746
 747struct diff_words_style {
 748        enum diff_words_type type;
 749        struct diff_words_style_elem new, old, ctx;
 750        const char *newline;
 751};
 752
 753static struct diff_words_style diff_words_styles[] = {
 754        { DIFF_WORDS_PORCELAIN, {"+", "\n"}, {"-", "\n"}, {" ", "\n"}, "~\n" },
 755        { DIFF_WORDS_PLAIN, {"{+", "+}"}, {"[-", "-]"}, {"", ""}, "\n" },
 756        { DIFF_WORDS_COLOR, {"", ""}, {"", ""}, {"", ""}, "\n" }
 757};
 758
 759struct diff_words_data {
 760        struct diff_words_buffer minus, plus;
 761        const char *current_plus;
 762        int last_minus;
 763        struct diff_options *opt;
 764        regex_t *word_regex;
 765        enum diff_words_type type;
 766        struct diff_words_style *style;
 767};
 768
 769static int fn_out_diff_words_write_helper(FILE *fp,
 770                                          struct diff_words_style_elem *st_el,
 771                                          const char *newline,
 772                                          size_t count, const char *buf,
 773                                          const char *line_prefix)
 774{
 775        int print = 0;
 776
 777        while (count) {
 778                char *p = memchr(buf, '\n', count);
 779                if (print)
 780                        fputs(line_prefix, fp);
 781                if (p != buf) {
 782                        if (st_el->color && fputs(st_el->color, fp) < 0)
 783                                return -1;
 784                        if (fputs(st_el->prefix, fp) < 0 ||
 785                            fwrite(buf, p ? p - buf : count, 1, fp) != 1 ||
 786                            fputs(st_el->suffix, fp) < 0)
 787                                return -1;
 788                        if (st_el->color && *st_el->color
 789                            && fputs(GIT_COLOR_RESET, fp) < 0)
 790                                return -1;
 791                }
 792                if (!p)
 793                        return 0;
 794                if (fputs(newline, fp) < 0)
 795                        return -1;
 796                count -= p + 1 - buf;
 797                buf = p + 1;
 798                print = 1;
 799        }
 800        return 0;
 801}
 802
 803/*
 804 * '--color-words' algorithm can be described as:
 805 *
 806 *   1. collect a the minus/plus lines of a diff hunk, divided into
 807 *      minus-lines and plus-lines;
 808 *
 809 *   2. break both minus-lines and plus-lines into words and
 810 *      place them into two mmfile_t with one word for each line;
 811 *
 812 *   3. use xdiff to run diff on the two mmfile_t to get the words level diff;
 813 *
 814 * And for the common parts of the both file, we output the plus side text.
 815 * diff_words->current_plus is used to trace the current position of the plus file
 816 * which printed. diff_words->last_minus is used to trace the last minus word
 817 * printed.
 818 *
 819 * For '--graph' to work with '--color-words', we need to output the graph prefix
 820 * on each line of color words output. Generally, there are two conditions on
 821 * which we should output the prefix.
 822 *
 823 *   1. diff_words->last_minus == 0 &&
 824 *      diff_words->current_plus == diff_words->plus.text.ptr
 825 *
 826 *      that is: the plus text must start as a new line, and if there is no minus
 827 *      word printed, a graph prefix must be printed.
 828 *
 829 *   2. diff_words->current_plus > diff_words->plus.text.ptr &&
 830 *      *(diff_words->current_plus - 1) == '\n'
 831 *
 832 *      that is: a graph prefix must be printed following a '\n'
 833 */
 834static int color_words_output_graph_prefix(struct diff_words_data *diff_words)
 835{
 836        if ((diff_words->last_minus == 0 &&
 837                diff_words->current_plus == diff_words->plus.text.ptr) ||
 838                (diff_words->current_plus > diff_words->plus.text.ptr &&
 839                *(diff_words->current_plus - 1) == '\n')) {
 840                return 1;
 841        } else {
 842                return 0;
 843        }
 844}
 845
 846static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
 847{
 848        struct diff_words_data *diff_words = priv;
 849        struct diff_words_style *style = diff_words->style;
 850        int minus_first, minus_len, plus_first, plus_len;
 851        const char *minus_begin, *minus_end, *plus_begin, *plus_end;
 852        struct diff_options *opt = diff_words->opt;
 853        const char *line_prefix;
 854
 855        if (line[0] != '@' || parse_hunk_header(line, len,
 856                        &minus_first, &minus_len, &plus_first, &plus_len))
 857                return;
 858
 859        assert(opt);
 860        line_prefix = diff_line_prefix(opt);
 861
 862        /* POSIX requires that first be decremented by one if len == 0... */
 863        if (minus_len) {
 864                minus_begin = diff_words->minus.orig[minus_first].begin;
 865                minus_end =
 866                        diff_words->minus.orig[minus_first + minus_len - 1].end;
 867        } else
 868                minus_begin = minus_end =
 869                        diff_words->minus.orig[minus_first].end;
 870
 871        if (plus_len) {
 872                plus_begin = diff_words->plus.orig[plus_first].begin;
 873                plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
 874        } else
 875                plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
 876
 877        if (color_words_output_graph_prefix(diff_words)) {
 878                fputs(line_prefix, diff_words->opt->file);
 879        }
 880        if (diff_words->current_plus != plus_begin) {
 881                fn_out_diff_words_write_helper(diff_words->opt->file,
 882                                &style->ctx, style->newline,
 883                                plus_begin - diff_words->current_plus,
 884                                diff_words->current_plus, line_prefix);
 885                if (*(plus_begin - 1) == '\n')
 886                        fputs(line_prefix, diff_words->opt->file);
 887        }
 888        if (minus_begin != minus_end) {
 889                fn_out_diff_words_write_helper(diff_words->opt->file,
 890                                &style->old, style->newline,
 891                                minus_end - minus_begin, minus_begin,
 892                                line_prefix);
 893        }
 894        if (plus_begin != plus_end) {
 895                fn_out_diff_words_write_helper(diff_words->opt->file,
 896                                &style->new, style->newline,
 897                                plus_end - plus_begin, plus_begin,
 898                                line_prefix);
 899        }
 900
 901        diff_words->current_plus = plus_end;
 902        diff_words->last_minus = minus_first;
 903}
 904
 905/* This function starts looking at *begin, and returns 0 iff a word was found. */
 906static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
 907                int *begin, int *end)
 908{
 909        if (word_regex && *begin < buffer->size) {
 910                regmatch_t match[1];
 911                if (!regexec(word_regex, buffer->ptr + *begin, 1, match, 0)) {
 912                        char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
 913                                        '\n', match[0].rm_eo - match[0].rm_so);
 914                        *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
 915                        *begin += match[0].rm_so;
 916                        return *begin >= *end;
 917                }
 918                return -1;
 919        }
 920
 921        /* find the next word */
 922        while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
 923                (*begin)++;
 924        if (*begin >= buffer->size)
 925                return -1;
 926
 927        /* find the end of the word */
 928        *end = *begin + 1;
 929        while (*end < buffer->size && !isspace(buffer->ptr[*end]))
 930                (*end)++;
 931
 932        return 0;
 933}
 934
 935/*
 936 * This function splits the words in buffer->text, stores the list with
 937 * newline separator into out, and saves the offsets of the original words
 938 * in buffer->orig.
 939 */
 940static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
 941                regex_t *word_regex)
 942{
 943        int i, j;
 944        long alloc = 0;
 945
 946        out->size = 0;
 947        out->ptr = NULL;
 948
 949        /* fake an empty "0th" word */
 950        ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
 951        buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
 952        buffer->orig_nr = 1;
 953
 954        for (i = 0; i < buffer->text.size; i++) {
 955                if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
 956                        return;
 957
 958                /* store original boundaries */
 959                ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
 960                                buffer->orig_alloc);
 961                buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
 962                buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
 963                buffer->orig_nr++;
 964
 965                /* store one word */
 966                ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
 967                memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
 968                out->ptr[out->size + j - i] = '\n';
 969                out->size += j - i + 1;
 970
 971                i = j - 1;
 972        }
 973}
 974
 975/* this executes the word diff on the accumulated buffers */
 976static void diff_words_show(struct diff_words_data *diff_words)
 977{
 978        xpparam_t xpp;
 979        xdemitconf_t xecfg;
 980        mmfile_t minus, plus;
 981        struct diff_words_style *style = diff_words->style;
 982
 983        struct diff_options *opt = diff_words->opt;
 984        const char *line_prefix;
 985
 986        assert(opt);
 987        line_prefix = diff_line_prefix(opt);
 988
 989        /* special case: only removal */
 990        if (!diff_words->plus.text.size) {
 991                fputs(line_prefix, diff_words->opt->file);
 992                fn_out_diff_words_write_helper(diff_words->opt->file,
 993                        &style->old, style->newline,
 994                        diff_words->minus.text.size,
 995                        diff_words->minus.text.ptr, line_prefix);
 996                diff_words->minus.text.size = 0;
 997                return;
 998        }
 999
1000        diff_words->current_plus = diff_words->plus.text.ptr;
1001        diff_words->last_minus = 0;
1002
1003        memset(&xpp, 0, sizeof(xpp));
1004        memset(&xecfg, 0, sizeof(xecfg));
1005        diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
1006        diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
1007        xpp.flags = 0;
1008        /* as only the hunk header will be parsed, we need a 0-context */
1009        xecfg.ctxlen = 0;
1010        if (xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
1011                          &xpp, &xecfg))
1012                die("unable to generate word diff");
1013        free(minus.ptr);
1014        free(plus.ptr);
1015        if (diff_words->current_plus != diff_words->plus.text.ptr +
1016                        diff_words->plus.text.size) {
1017                if (color_words_output_graph_prefix(diff_words))
1018                        fputs(line_prefix, diff_words->opt->file);
1019                fn_out_diff_words_write_helper(diff_words->opt->file,
1020                        &style->ctx, style->newline,
1021                        diff_words->plus.text.ptr + diff_words->plus.text.size
1022                        - diff_words->current_plus, diff_words->current_plus,
1023                        line_prefix);
1024        }
1025        diff_words->minus.text.size = diff_words->plus.text.size = 0;
1026}
1027
1028/* In "color-words" mode, show word-diff of words accumulated in the buffer */
1029static void diff_words_flush(struct emit_callback *ecbdata)
1030{
1031        if (ecbdata->diff_words->minus.text.size ||
1032            ecbdata->diff_words->plus.text.size)
1033                diff_words_show(ecbdata->diff_words);
1034}
1035
1036static void diff_filespec_load_driver(struct diff_filespec *one)
1037{
1038        /* Use already-loaded driver */
1039        if (one->driver)
1040                return;
1041
1042        if (S_ISREG(one->mode))
1043                one->driver = userdiff_find_by_path(one->path);
1044
1045        /* Fallback to default settings */
1046        if (!one->driver)
1047                one->driver = userdiff_find_by_name("default");
1048}
1049
1050static const char *userdiff_word_regex(struct diff_filespec *one)
1051{
1052        diff_filespec_load_driver(one);
1053        return one->driver->word_regex;
1054}
1055
1056static void init_diff_words_data(struct emit_callback *ecbdata,
1057                                 struct diff_options *orig_opts,
1058                                 struct diff_filespec *one,
1059                                 struct diff_filespec *two)
1060{
1061        int i;
1062        struct diff_options *o = xmalloc(sizeof(struct diff_options));
1063        memcpy(o, orig_opts, sizeof(struct diff_options));
1064
1065        ecbdata->diff_words =
1066                xcalloc(1, sizeof(struct diff_words_data));
1067        ecbdata->diff_words->type = o->word_diff;
1068        ecbdata->diff_words->opt = o;
1069        if (!o->word_regex)
1070                o->word_regex = userdiff_word_regex(one);
1071        if (!o->word_regex)
1072                o->word_regex = userdiff_word_regex(two);
1073        if (!o->word_regex)
1074                o->word_regex = diff_word_regex_cfg;
1075        if (o->word_regex) {
1076                ecbdata->diff_words->word_regex = (regex_t *)
1077                        xmalloc(sizeof(regex_t));
1078                if (regcomp(ecbdata->diff_words->word_regex,
1079                            o->word_regex,
1080                            REG_EXTENDED | REG_NEWLINE))
1081                        die ("Invalid regular expression: %s",
1082                             o->word_regex);
1083        }
1084        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
1085                if (o->word_diff == diff_words_styles[i].type) {
1086                        ecbdata->diff_words->style =
1087                                &diff_words_styles[i];
1088                        break;
1089                }
1090        }
1091        if (want_color(o->use_color)) {
1092                struct diff_words_style *st = ecbdata->diff_words->style;
1093                st->old.color = diff_get_color_opt(o, DIFF_FILE_OLD);
1094                st->new.color = diff_get_color_opt(o, DIFF_FILE_NEW);
1095                st->ctx.color = diff_get_color_opt(o, DIFF_CONTEXT);
1096        }
1097}
1098
1099static void free_diff_words_data(struct emit_callback *ecbdata)
1100{
1101        if (ecbdata->diff_words) {
1102                diff_words_flush(ecbdata);
1103                free (ecbdata->diff_words->opt);
1104                free (ecbdata->diff_words->minus.text.ptr);
1105                free (ecbdata->diff_words->minus.orig);
1106                free (ecbdata->diff_words->plus.text.ptr);
1107                free (ecbdata->diff_words->plus.orig);
1108                if (ecbdata->diff_words->word_regex) {
1109                        regfree(ecbdata->diff_words->word_regex);
1110                        free(ecbdata->diff_words->word_regex);
1111                }
1112                free(ecbdata->diff_words);
1113                ecbdata->diff_words = NULL;
1114        }
1115}
1116
1117const char *diff_get_color(int diff_use_color, enum color_diff ix)
1118{
1119        if (want_color(diff_use_color))
1120                return diff_colors[ix];
1121        return "";
1122}
1123
1124const char *diff_line_prefix(struct diff_options *opt)
1125{
1126        struct strbuf *msgbuf;
1127        if (!opt->output_prefix)
1128                return "";
1129
1130        msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
1131        return msgbuf->buf;
1132}
1133
1134static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
1135{
1136        const char *cp;
1137        unsigned long allot;
1138        size_t l = len;
1139
1140        if (ecb->truncate)
1141                return ecb->truncate(line, len);
1142        cp = line;
1143        allot = l;
1144        while (0 < l) {
1145                (void) utf8_width(&cp, &l);
1146                if (!cp)
1147                        break; /* truncated in the middle? */
1148        }
1149        return allot - l;
1150}
1151
1152static void find_lno(const char *line, struct emit_callback *ecbdata)
1153{
1154        const char *p;
1155        ecbdata->lno_in_preimage = 0;
1156        ecbdata->lno_in_postimage = 0;
1157        p = strchr(line, '-');
1158        if (!p)
1159                return; /* cannot happen */
1160        ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
1161        p = strchr(p, '+');
1162        if (!p)
1163                return; /* cannot happen */
1164        ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
1165}
1166
1167static void fn_out_consume(void *priv, char *line, unsigned long len)
1168{
1169        struct emit_callback *ecbdata = priv;
1170        const char *meta = diff_get_color(ecbdata->color_diff, DIFF_METAINFO);
1171        const char *context = diff_get_color(ecbdata->color_diff, DIFF_CONTEXT);
1172        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
1173        struct diff_options *o = ecbdata->opt;
1174        const char *line_prefix = diff_line_prefix(o);
1175
1176        if (ecbdata->header) {
1177                fprintf(ecbdata->opt->file, "%s", ecbdata->header->buf);
1178                strbuf_reset(ecbdata->header);
1179                ecbdata->header = NULL;
1180        }
1181        *(ecbdata->found_changesp) = 1;
1182
1183        if (ecbdata->label_path[0]) {
1184                const char *name_a_tab, *name_b_tab;
1185
1186                name_a_tab = strchr(ecbdata->label_path[0], ' ') ? "\t" : "";
1187                name_b_tab = strchr(ecbdata->label_path[1], ' ') ? "\t" : "";
1188
1189                fprintf(ecbdata->opt->file, "%s%s--- %s%s%s\n",
1190                        line_prefix, meta, ecbdata->label_path[0], reset, name_a_tab);
1191                fprintf(ecbdata->opt->file, "%s%s+++ %s%s%s\n",
1192                        line_prefix, meta, ecbdata->label_path[1], reset, name_b_tab);
1193                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
1194        }
1195
1196        if (diff_suppress_blank_empty
1197            && len == 2 && line[0] == ' ' && line[1] == '\n') {
1198                line[0] = '\n';
1199                len = 1;
1200        }
1201
1202        if (line[0] == '@') {
1203                if (ecbdata->diff_words)
1204                        diff_words_flush(ecbdata);
1205                len = sane_truncate_line(ecbdata, line, len);
1206                find_lno(line, ecbdata);
1207                emit_hunk_header(ecbdata, line, len);
1208                if (line[len-1] != '\n')
1209                        putc('\n', ecbdata->opt->file);
1210                return;
1211        }
1212
1213        if (len < 1) {
1214                emit_line(ecbdata->opt, reset, reset, line, len);
1215                if (ecbdata->diff_words
1216                    && ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN)
1217                        fputs("~\n", ecbdata->opt->file);
1218                return;
1219        }
1220
1221        if (ecbdata->diff_words) {
1222                if (line[0] == '-') {
1223                        diff_words_append(line, len,
1224                                          &ecbdata->diff_words->minus);
1225                        return;
1226                } else if (line[0] == '+') {
1227                        diff_words_append(line, len,
1228                                          &ecbdata->diff_words->plus);
1229                        return;
1230                } else if (starts_with(line, "\\ ")) {
1231                        /*
1232                         * Eat the "no newline at eof" marker as if we
1233                         * saw a "+" or "-" line with nothing on it,
1234                         * and return without diff_words_flush() to
1235                         * defer processing. If this is the end of
1236                         * preimage, more "+" lines may come after it.
1237                         */
1238                        return;
1239                }
1240                diff_words_flush(ecbdata);
1241                if (ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN) {
1242                        emit_line(ecbdata->opt, context, reset, line, len);
1243                        fputs("~\n", ecbdata->opt->file);
1244                } else {
1245                        /*
1246                         * Skip the prefix character, if any.  With
1247                         * diff_suppress_blank_empty, there may be
1248                         * none.
1249                         */
1250                        if (line[0] != '\n') {
1251                              line++;
1252                              len--;
1253                        }
1254                        emit_line(ecbdata->opt, context, reset, line, len);
1255                }
1256                return;
1257        }
1258
1259        if (line[0] != '+') {
1260                const char *color =
1261                        diff_get_color(ecbdata->color_diff,
1262                                       line[0] == '-' ? DIFF_FILE_OLD : DIFF_CONTEXT);
1263                ecbdata->lno_in_preimage++;
1264                if (line[0] == ' ')
1265                        ecbdata->lno_in_postimage++;
1266                emit_line(ecbdata->opt, color, reset, line, len);
1267        } else {
1268                ecbdata->lno_in_postimage++;
1269                emit_add_line(reset, ecbdata, line + 1, len - 1);
1270        }
1271}
1272
1273static char *pprint_rename(const char *a, const char *b)
1274{
1275        const char *old = a;
1276        const char *new = b;
1277        struct strbuf name = STRBUF_INIT;
1278        int pfx_length, sfx_length;
1279        int pfx_adjust_for_slash;
1280        int len_a = strlen(a);
1281        int len_b = strlen(b);
1282        int a_midlen, b_midlen;
1283        int qlen_a = quote_c_style(a, NULL, NULL, 0);
1284        int qlen_b = quote_c_style(b, NULL, NULL, 0);
1285
1286        if (qlen_a || qlen_b) {
1287                quote_c_style(a, &name, NULL, 0);
1288                strbuf_addstr(&name, " => ");
1289                quote_c_style(b, &name, NULL, 0);
1290                return strbuf_detach(&name, NULL);
1291        }
1292
1293        /* Find common prefix */
1294        pfx_length = 0;
1295        while (*old && *new && *old == *new) {
1296                if (*old == '/')
1297                        pfx_length = old - a + 1;
1298                old++;
1299                new++;
1300        }
1301
1302        /* Find common suffix */
1303        old = a + len_a;
1304        new = b + len_b;
1305        sfx_length = 0;
1306        /*
1307         * If there is a common prefix, it must end in a slash.  In
1308         * that case we let this loop run 1 into the prefix to see the
1309         * same slash.
1310         *
1311         * If there is no common prefix, we cannot do this as it would
1312         * underrun the input strings.
1313         */
1314        pfx_adjust_for_slash = (pfx_length ? 1 : 0);
1315        while (a + pfx_length - pfx_adjust_for_slash <= old &&
1316               b + pfx_length - pfx_adjust_for_slash <= new &&
1317               *old == *new) {
1318                if (*old == '/')
1319                        sfx_length = len_a - (old - a);
1320                old--;
1321                new--;
1322        }
1323
1324        /*
1325         * pfx{mid-a => mid-b}sfx
1326         * {pfx-a => pfx-b}sfx
1327         * pfx{sfx-a => sfx-b}
1328         * name-a => name-b
1329         */
1330        a_midlen = len_a - pfx_length - sfx_length;
1331        b_midlen = len_b - pfx_length - sfx_length;
1332        if (a_midlen < 0)
1333                a_midlen = 0;
1334        if (b_midlen < 0)
1335                b_midlen = 0;
1336
1337        strbuf_grow(&name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
1338        if (pfx_length + sfx_length) {
1339                strbuf_add(&name, a, pfx_length);
1340                strbuf_addch(&name, '{');
1341        }
1342        strbuf_add(&name, a + pfx_length, a_midlen);
1343        strbuf_addstr(&name, " => ");
1344        strbuf_add(&name, b + pfx_length, b_midlen);
1345        if (pfx_length + sfx_length) {
1346                strbuf_addch(&name, '}');
1347                strbuf_add(&name, a + len_a - sfx_length, sfx_length);
1348        }
1349        return strbuf_detach(&name, NULL);
1350}
1351
1352struct diffstat_t {
1353        int nr;
1354        int alloc;
1355        struct diffstat_file {
1356                char *from_name;
1357                char *name;
1358                char *print_name;
1359                unsigned is_unmerged:1;
1360                unsigned is_binary:1;
1361                unsigned is_renamed:1;
1362                unsigned is_interesting:1;
1363                uintmax_t added, deleted;
1364        } **files;
1365};
1366
1367static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
1368                                          const char *name_a,
1369                                          const char *name_b)
1370{
1371        struct diffstat_file *x;
1372        x = xcalloc(1, sizeof(*x));
1373        ALLOC_GROW(diffstat->files, diffstat->nr + 1, diffstat->alloc);
1374        diffstat->files[diffstat->nr++] = x;
1375        if (name_b) {
1376                x->from_name = xstrdup(name_a);
1377                x->name = xstrdup(name_b);
1378                x->is_renamed = 1;
1379        }
1380        else {
1381                x->from_name = NULL;
1382                x->name = xstrdup(name_a);
1383        }
1384        return x;
1385}
1386
1387static void diffstat_consume(void *priv, char *line, unsigned long len)
1388{
1389        struct diffstat_t *diffstat = priv;
1390        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
1391
1392        if (line[0] == '+')
1393                x->added++;
1394        else if (line[0] == '-')
1395                x->deleted++;
1396}
1397
1398const char mime_boundary_leader[] = "------------";
1399
1400static int scale_linear(int it, int width, int max_change)
1401{
1402        if (!it)
1403                return 0;
1404        /*
1405         * make sure that at least one '-' or '+' is printed if
1406         * there is any change to this path. The easiest way is to
1407         * scale linearly as if the alloted width is one column shorter
1408         * than it is, and then add 1 to the result.
1409         */
1410        return 1 + (it * (width - 1) / max_change);
1411}
1412
1413static void show_name(FILE *file,
1414                      const char *prefix, const char *name, int len)
1415{
1416        fprintf(file, " %s%-*s |", prefix, len, name);
1417}
1418
1419static void show_graph(FILE *file, char ch, int cnt, const char *set, const char *reset)
1420{
1421        if (cnt <= 0)
1422                return;
1423        fprintf(file, "%s", set);
1424        while (cnt--)
1425                putc(ch, file);
1426        fprintf(file, "%s", reset);
1427}
1428
1429static void fill_print_name(struct diffstat_file *file)
1430{
1431        char *pname;
1432
1433        if (file->print_name)
1434                return;
1435
1436        if (!file->is_renamed) {
1437                struct strbuf buf = STRBUF_INIT;
1438                if (quote_c_style(file->name, &buf, NULL, 0)) {
1439                        pname = strbuf_detach(&buf, NULL);
1440                } else {
1441                        pname = file->name;
1442                        strbuf_release(&buf);
1443                }
1444        } else {
1445                pname = pprint_rename(file->from_name, file->name);
1446        }
1447        file->print_name = pname;
1448}
1449
1450int print_stat_summary(FILE *fp, int files, int insertions, int deletions)
1451{
1452        struct strbuf sb = STRBUF_INIT;
1453        int ret;
1454
1455        if (!files) {
1456                assert(insertions == 0 && deletions == 0);
1457                return fprintf(fp, "%s\n", " 0 files changed");
1458        }
1459
1460        strbuf_addf(&sb,
1461                    (files == 1) ? " %d file changed" : " %d files changed",
1462                    files);
1463
1464        /*
1465         * For binary diff, the caller may want to print "x files
1466         * changed" with insertions == 0 && deletions == 0.
1467         *
1468         * Not omitting "0 insertions(+), 0 deletions(-)" in this case
1469         * is probably less confusing (i.e skip over "2 files changed
1470         * but nothing about added/removed lines? Is this a bug in Git?").
1471         */
1472        if (insertions || deletions == 0) {
1473                strbuf_addf(&sb,
1474                            (insertions == 1) ? ", %d insertion(+)" : ", %d insertions(+)",
1475                            insertions);
1476        }
1477
1478        if (deletions || insertions == 0) {
1479                strbuf_addf(&sb,
1480                            (deletions == 1) ? ", %d deletion(-)" : ", %d deletions(-)",
1481                            deletions);
1482        }
1483        strbuf_addch(&sb, '\n');
1484        ret = fputs(sb.buf, fp);
1485        strbuf_release(&sb);
1486        return ret;
1487}
1488
1489static void show_stats(struct diffstat_t *data, struct diff_options *options)
1490{
1491        int i, len, add, del, adds = 0, dels = 0;
1492        uintmax_t max_change = 0, max_len = 0;
1493        int total_files = data->nr, count;
1494        int width, name_width, graph_width, number_width = 0, bin_width = 0;
1495        const char *reset, *add_c, *del_c;
1496        const char *line_prefix = "";
1497        int extra_shown = 0;
1498
1499        if (data->nr == 0)
1500                return;
1501
1502        line_prefix = diff_line_prefix(options);
1503        count = options->stat_count ? options->stat_count : data->nr;
1504
1505        reset = diff_get_color_opt(options, DIFF_RESET);
1506        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
1507        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
1508
1509        /*
1510         * Find the longest filename and max number of changes
1511         */
1512        for (i = 0; (i < count) && (i < data->nr); i++) {
1513                struct diffstat_file *file = data->files[i];
1514                uintmax_t change = file->added + file->deleted;
1515
1516                if (!file->is_interesting && (change == 0)) {
1517                        count++; /* not shown == room for one more */
1518                        continue;
1519                }
1520                fill_print_name(file);
1521                len = strlen(file->print_name);
1522                if (max_len < len)
1523                        max_len = len;
1524
1525                if (file->is_unmerged) {
1526                        /* "Unmerged" is 8 characters */
1527                        bin_width = bin_width < 8 ? 8 : bin_width;
1528                        continue;
1529                }
1530                if (file->is_binary) {
1531                        /* "Bin XXX -> YYY bytes" */
1532                        int w = 14 + decimal_width(file->added)
1533                                + decimal_width(file->deleted);
1534                        bin_width = bin_width < w ? w : bin_width;
1535                        /* Display change counts aligned with "Bin" */
1536                        number_width = 3;
1537                        continue;
1538                }
1539
1540                if (max_change < change)
1541                        max_change = change;
1542        }
1543        count = i; /* where we can stop scanning in data->files[] */
1544
1545        /*
1546         * We have width = stat_width or term_columns() columns total.
1547         * We want a maximum of min(max_len, stat_name_width) for the name part.
1548         * We want a maximum of min(max_change, stat_graph_width) for the +- part.
1549         * We also need 1 for " " and 4 + decimal_width(max_change)
1550         * for " | NNNN " and one the empty column at the end, altogether
1551         * 6 + decimal_width(max_change).
1552         *
1553         * If there's not enough space, we will use the smaller of
1554         * stat_name_width (if set) and 5/8*width for the filename,
1555         * and the rest for constant elements + graph part, but no more
1556         * than stat_graph_width for the graph part.
1557         * (5/8 gives 50 for filename and 30 for the constant parts + graph
1558         * for the standard terminal size).
1559         *
1560         * In other words: stat_width limits the maximum width, and
1561         * stat_name_width fixes the maximum width of the filename,
1562         * and is also used to divide available columns if there
1563         * aren't enough.
1564         *
1565         * Binary files are displayed with "Bin XXX -> YYY bytes"
1566         * instead of the change count and graph. This part is treated
1567         * similarly to the graph part, except that it is not
1568         * "scaled". If total width is too small to accommodate the
1569         * guaranteed minimum width of the filename part and the
1570         * separators and this message, this message will "overflow"
1571         * making the line longer than the maximum width.
1572         */
1573
1574        if (options->stat_width == -1)
1575                width = term_columns() - options->output_prefix_length;
1576        else
1577                width = options->stat_width ? options->stat_width : 80;
1578        number_width = decimal_width(max_change) > number_width ?
1579                decimal_width(max_change) : number_width;
1580
1581        if (options->stat_graph_width == -1)
1582                options->stat_graph_width = diff_stat_graph_width;
1583
1584        /*
1585         * Guarantee 3/8*16==6 for the graph part
1586         * and 5/8*16==10 for the filename part
1587         */
1588        if (width < 16 + 6 + number_width)
1589                width = 16 + 6 + number_width;
1590
1591        /*
1592         * First assign sizes that are wanted, ignoring available width.
1593         * strlen("Bin XXX -> YYY bytes") == bin_width, and the part
1594         * starting from "XXX" should fit in graph_width.
1595         */
1596        graph_width = max_change + 4 > bin_width ? max_change : bin_width - 4;
1597        if (options->stat_graph_width &&
1598            options->stat_graph_width < graph_width)
1599                graph_width = options->stat_graph_width;
1600
1601        name_width = (options->stat_name_width > 0 &&
1602                      options->stat_name_width < max_len) ?
1603                options->stat_name_width : max_len;
1604
1605        /*
1606         * Adjust adjustable widths not to exceed maximum width
1607         */
1608        if (name_width + number_width + 6 + graph_width > width) {
1609                if (graph_width > width * 3/8 - number_width - 6) {
1610                        graph_width = width * 3/8 - number_width - 6;
1611                        if (graph_width < 6)
1612                                graph_width = 6;
1613                }
1614
1615                if (options->stat_graph_width &&
1616                    graph_width > options->stat_graph_width)
1617                        graph_width = options->stat_graph_width;
1618                if (name_width > width - number_width - 6 - graph_width)
1619                        name_width = width - number_width - 6 - graph_width;
1620                else
1621                        graph_width = width - number_width - 6 - name_width;
1622        }
1623
1624        /*
1625         * From here name_width is the width of the name area,
1626         * and graph_width is the width of the graph area.
1627         * max_change is used to scale graph properly.
1628         */
1629        for (i = 0; i < count; i++) {
1630                const char *prefix = "";
1631                struct diffstat_file *file = data->files[i];
1632                char *name = file->print_name;
1633                uintmax_t added = file->added;
1634                uintmax_t deleted = file->deleted;
1635                int name_len;
1636
1637                if (!file->is_interesting && (added + deleted == 0))
1638                        continue;
1639
1640                /*
1641                 * "scale" the filename
1642                 */
1643                len = name_width;
1644                name_len = strlen(name);
1645                if (name_width < name_len) {
1646                        char *slash;
1647                        prefix = "...";
1648                        len -= 3;
1649                        name += name_len - len;
1650                        slash = strchr(name, '/');
1651                        if (slash)
1652                                name = slash;
1653                }
1654
1655                if (file->is_binary) {
1656                        fprintf(options->file, "%s", line_prefix);
1657                        show_name(options->file, prefix, name, len);
1658                        fprintf(options->file, " %*s", number_width, "Bin");
1659                        if (!added && !deleted) {
1660                                putc('\n', options->file);
1661                                continue;
1662                        }
1663                        fprintf(options->file, " %s%"PRIuMAX"%s",
1664                                del_c, deleted, reset);
1665                        fprintf(options->file, " -> ");
1666                        fprintf(options->file, "%s%"PRIuMAX"%s",
1667                                add_c, added, reset);
1668                        fprintf(options->file, " bytes");
1669                        fprintf(options->file, "\n");
1670                        continue;
1671                }
1672                else if (file->is_unmerged) {
1673                        fprintf(options->file, "%s", line_prefix);
1674                        show_name(options->file, prefix, name, len);
1675                        fprintf(options->file, " Unmerged\n");
1676                        continue;
1677                }
1678
1679                /*
1680                 * scale the add/delete
1681                 */
1682                add = added;
1683                del = deleted;
1684
1685                if (graph_width <= max_change) {
1686                        int total = scale_linear(add + del, graph_width, max_change);
1687                        if (total < 2 && add && del)
1688                                /* width >= 2 due to the sanity check */
1689                                total = 2;
1690                        if (add < del) {
1691                                add = scale_linear(add, graph_width, max_change);
1692                                del = total - add;
1693                        } else {
1694                                del = scale_linear(del, graph_width, max_change);
1695                                add = total - del;
1696                        }
1697                }
1698                fprintf(options->file, "%s", line_prefix);
1699                show_name(options->file, prefix, name, len);
1700                fprintf(options->file, " %*"PRIuMAX"%s",
1701                        number_width, added + deleted,
1702                        added + deleted ? " " : "");
1703                show_graph(options->file, '+', add, add_c, reset);
1704                show_graph(options->file, '-', del, del_c, reset);
1705                fprintf(options->file, "\n");
1706        }
1707
1708        for (i = 0; i < data->nr; i++) {
1709                struct diffstat_file *file = data->files[i];
1710                uintmax_t added = file->added;
1711                uintmax_t deleted = file->deleted;
1712
1713                if (file->is_unmerged ||
1714                    (!file->is_interesting && (added + deleted == 0))) {
1715                        total_files--;
1716                        continue;
1717                }
1718
1719                if (!file->is_binary) {
1720                        adds += added;
1721                        dels += deleted;
1722                }
1723                if (i < count)
1724                        continue;
1725                if (!extra_shown)
1726                        fprintf(options->file, "%s ...\n", line_prefix);
1727                extra_shown = 1;
1728        }
1729        fprintf(options->file, "%s", line_prefix);
1730        print_stat_summary(options->file, total_files, adds, dels);
1731}
1732
1733static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
1734{
1735        int i, adds = 0, dels = 0, total_files = data->nr;
1736
1737        if (data->nr == 0)
1738                return;
1739
1740        for (i = 0; i < data->nr; i++) {
1741                int added = data->files[i]->added;
1742                int deleted= data->files[i]->deleted;
1743
1744                if (data->files[i]->is_unmerged ||
1745                    (!data->files[i]->is_interesting && (added + deleted == 0))) {
1746                        total_files--;
1747                } else if (!data->files[i]->is_binary) { /* don't count bytes */
1748                        adds += added;
1749                        dels += deleted;
1750                }
1751        }
1752        fprintf(options->file, "%s", diff_line_prefix(options));
1753        print_stat_summary(options->file, total_files, adds, dels);
1754}
1755
1756static void show_numstat(struct diffstat_t *data, struct diff_options *options)
1757{
1758        int i;
1759
1760        if (data->nr == 0)
1761                return;
1762
1763        for (i = 0; i < data->nr; i++) {
1764                struct diffstat_file *file = data->files[i];
1765
1766                fprintf(options->file, "%s", diff_line_prefix(options));
1767
1768                if (file->is_binary)
1769                        fprintf(options->file, "-\t-\t");
1770                else
1771                        fprintf(options->file,
1772                                "%"PRIuMAX"\t%"PRIuMAX"\t",
1773                                file->added, file->deleted);
1774                if (options->line_termination) {
1775                        fill_print_name(file);
1776                        if (!file->is_renamed)
1777                                write_name_quoted(file->name, options->file,
1778                                                  options->line_termination);
1779                        else {
1780                                fputs(file->print_name, options->file);
1781                                putc(options->line_termination, options->file);
1782                        }
1783                } else {
1784                        if (file->is_renamed) {
1785                                putc('\0', options->file);
1786                                write_name_quoted(file->from_name, options->file, '\0');
1787                        }
1788                        write_name_quoted(file->name, options->file, '\0');
1789                }
1790        }
1791}
1792
1793struct dirstat_file {
1794        const char *name;
1795        unsigned long changed;
1796};
1797
1798struct dirstat_dir {
1799        struct dirstat_file *files;
1800        int alloc, nr, permille, cumulative;
1801};
1802
1803static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
1804                unsigned long changed, const char *base, int baselen)
1805{
1806        unsigned long this_dir = 0;
1807        unsigned int sources = 0;
1808        const char *line_prefix = diff_line_prefix(opt);
1809
1810        while (dir->nr) {
1811                struct dirstat_file *f = dir->files;
1812                int namelen = strlen(f->name);
1813                unsigned long this;
1814                char *slash;
1815
1816                if (namelen < baselen)
1817                        break;
1818                if (memcmp(f->name, base, baselen))
1819                        break;
1820                slash = strchr(f->name + baselen, '/');
1821                if (slash) {
1822                        int newbaselen = slash + 1 - f->name;
1823                        this = gather_dirstat(opt, dir, changed, f->name, newbaselen);
1824                        sources++;
1825                } else {
1826                        this = f->changed;
1827                        dir->files++;
1828                        dir->nr--;
1829                        sources += 2;
1830                }
1831                this_dir += this;
1832        }
1833
1834        /*
1835         * We don't report dirstat's for
1836         *  - the top level
1837         *  - or cases where everything came from a single directory
1838         *    under this directory (sources == 1).
1839         */
1840        if (baselen && sources != 1) {
1841                if (this_dir) {
1842                        int permille = this_dir * 1000 / changed;
1843                        if (permille >= dir->permille) {
1844                                fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
1845                                        permille / 10, permille % 10, baselen, base);
1846                                if (!dir->cumulative)
1847                                        return 0;
1848                        }
1849                }
1850        }
1851        return this_dir;
1852}
1853
1854static int dirstat_compare(const void *_a, const void *_b)
1855{
1856        const struct dirstat_file *a = _a;
1857        const struct dirstat_file *b = _b;
1858        return strcmp(a->name, b->name);
1859}
1860
1861static void show_dirstat(struct diff_options *options)
1862{
1863        int i;
1864        unsigned long changed;
1865        struct dirstat_dir dir;
1866        struct diff_queue_struct *q = &diff_queued_diff;
1867
1868        dir.files = NULL;
1869        dir.alloc = 0;
1870        dir.nr = 0;
1871        dir.permille = options->dirstat_permille;
1872        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1873
1874        changed = 0;
1875        for (i = 0; i < q->nr; i++) {
1876                struct diff_filepair *p = q->queue[i];
1877                const char *name;
1878                unsigned long copied, added, damage;
1879                int content_changed;
1880
1881                name = p->two->path ? p->two->path : p->one->path;
1882
1883                if (p->one->sha1_valid && p->two->sha1_valid)
1884                        content_changed = hashcmp(p->one->sha1, p->two->sha1);
1885                else
1886                        content_changed = 1;
1887
1888                if (!content_changed) {
1889                        /*
1890                         * The SHA1 has not changed, so pre-/post-content is
1891                         * identical. We can therefore skip looking at the
1892                         * file contents altogether.
1893                         */
1894                        damage = 0;
1895                        goto found_damage;
1896                }
1897
1898                if (DIFF_OPT_TST(options, DIRSTAT_BY_FILE)) {
1899                        /*
1900                         * In --dirstat-by-file mode, we don't really need to
1901                         * look at the actual file contents at all.
1902                         * The fact that the SHA1 changed is enough for us to
1903                         * add this file to the list of results
1904                         * (with each file contributing equal damage).
1905                         */
1906                        damage = 1;
1907                        goto found_damage;
1908                }
1909
1910                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
1911                        diff_populate_filespec(p->one, 0);
1912                        diff_populate_filespec(p->two, 0);
1913                        diffcore_count_changes(p->one, p->two, NULL, NULL, 0,
1914                                               &copied, &added);
1915                        diff_free_filespec_data(p->one);
1916                        diff_free_filespec_data(p->two);
1917                } else if (DIFF_FILE_VALID(p->one)) {
1918                        diff_populate_filespec(p->one, CHECK_SIZE_ONLY);
1919                        copied = added = 0;
1920                        diff_free_filespec_data(p->one);
1921                } else if (DIFF_FILE_VALID(p->two)) {
1922                        diff_populate_filespec(p->two, CHECK_SIZE_ONLY);
1923                        copied = 0;
1924                        added = p->two->size;
1925                        diff_free_filespec_data(p->two);
1926                } else
1927                        continue;
1928
1929                /*
1930                 * Original minus copied is the removed material,
1931                 * added is the new material.  They are both damages
1932                 * made to the preimage.
1933                 * If the resulting damage is zero, we know that
1934                 * diffcore_count_changes() considers the two entries to
1935                 * be identical, but since content_changed is true, we
1936                 * know that there must have been _some_ kind of change,
1937                 * so we force all entries to have damage > 0.
1938                 */
1939                damage = (p->one->size - copied) + added;
1940                if (!damage)
1941                        damage = 1;
1942
1943found_damage:
1944                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1945                dir.files[dir.nr].name = name;
1946                dir.files[dir.nr].changed = damage;
1947                changed += damage;
1948                dir.nr++;
1949        }
1950
1951        /* This can happen even with many files, if everything was renames */
1952        if (!changed)
1953                return;
1954
1955        /* Show all directories with more than x% of the changes */
1956        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1957        gather_dirstat(options, &dir, changed, "", 0);
1958}
1959
1960static void show_dirstat_by_line(struct diffstat_t *data, struct diff_options *options)
1961{
1962        int i;
1963        unsigned long changed;
1964        struct dirstat_dir dir;
1965
1966        if (data->nr == 0)
1967                return;
1968
1969        dir.files = NULL;
1970        dir.alloc = 0;
1971        dir.nr = 0;
1972        dir.permille = options->dirstat_permille;
1973        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1974
1975        changed = 0;
1976        for (i = 0; i < data->nr; i++) {
1977                struct diffstat_file *file = data->files[i];
1978                unsigned long damage = file->added + file->deleted;
1979                if (file->is_binary)
1980                        /*
1981                         * binary files counts bytes, not lines. Must find some
1982                         * way to normalize binary bytes vs. textual lines.
1983                         * The following heuristic assumes that there are 64
1984                         * bytes per "line".
1985                         * This is stupid and ugly, but very cheap...
1986                         */
1987                        damage = (damage + 63) / 64;
1988                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1989                dir.files[dir.nr].name = file->name;
1990                dir.files[dir.nr].changed = damage;
1991                changed += damage;
1992                dir.nr++;
1993        }
1994
1995        /* This can happen even with many files, if everything was renames */
1996        if (!changed)
1997                return;
1998
1999        /* Show all directories with more than x% of the changes */
2000        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
2001        gather_dirstat(options, &dir, changed, "", 0);
2002}
2003
2004static void free_diffstat_info(struct diffstat_t *diffstat)
2005{
2006        int i;
2007        for (i = 0; i < diffstat->nr; i++) {
2008                struct diffstat_file *f = diffstat->files[i];
2009                if (f->name != f->print_name)
2010                        free(f->print_name);
2011                free(f->name);
2012                free(f->from_name);
2013                free(f);
2014        }
2015        free(diffstat->files);
2016}
2017
2018struct checkdiff_t {
2019        const char *filename;
2020        int lineno;
2021        int conflict_marker_size;
2022        struct diff_options *o;
2023        unsigned ws_rule;
2024        unsigned status;
2025};
2026
2027static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
2028{
2029        char firstchar;
2030        int cnt;
2031
2032        if (len < marker_size + 1)
2033                return 0;
2034        firstchar = line[0];
2035        switch (firstchar) {
2036        case '=': case '>': case '<': case '|':
2037                break;
2038        default:
2039                return 0;
2040        }
2041        for (cnt = 1; cnt < marker_size; cnt++)
2042                if (line[cnt] != firstchar)
2043                        return 0;
2044        /* line[1] thru line[marker_size-1] are same as firstchar */
2045        if (len < marker_size + 1 || !isspace(line[marker_size]))
2046                return 0;
2047        return 1;
2048}
2049
2050static void checkdiff_consume(void *priv, char *line, unsigned long len)
2051{
2052        struct checkdiff_t *data = priv;
2053        int marker_size = data->conflict_marker_size;
2054        const char *ws = diff_get_color(data->o->use_color, DIFF_WHITESPACE);
2055        const char *reset = diff_get_color(data->o->use_color, DIFF_RESET);
2056        const char *set = diff_get_color(data->o->use_color, DIFF_FILE_NEW);
2057        char *err;
2058        const char *line_prefix;
2059
2060        assert(data->o);
2061        line_prefix = diff_line_prefix(data->o);
2062
2063        if (line[0] == '+') {
2064                unsigned bad;
2065                data->lineno++;
2066                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
2067                        data->status |= 1;
2068                        fprintf(data->o->file,
2069                                "%s%s:%d: leftover conflict marker\n",
2070                                line_prefix, data->filename, data->lineno);
2071                }
2072                bad = ws_check(line + 1, len - 1, data->ws_rule);
2073                if (!bad)
2074                        return;
2075                data->status |= bad;
2076                err = whitespace_error_string(bad);
2077                fprintf(data->o->file, "%s%s:%d: %s.\n",
2078                        line_prefix, data->filename, data->lineno, err);
2079                free(err);
2080                emit_line(data->o, set, reset, line, 1);
2081                ws_check_emit(line + 1, len - 1, data->ws_rule,
2082                              data->o->file, set, reset, ws);
2083        } else if (line[0] == ' ') {
2084                data->lineno++;
2085        } else if (line[0] == '@') {
2086                char *plus = strchr(line, '+');
2087                if (plus)
2088                        data->lineno = strtol(plus, NULL, 10) - 1;
2089                else
2090                        die("invalid diff");
2091        }
2092}
2093
2094static unsigned char *deflate_it(char *data,
2095                                 unsigned long size,
2096                                 unsigned long *result_size)
2097{
2098        int bound;
2099        unsigned char *deflated;
2100        git_zstream stream;
2101
2102        git_deflate_init(&stream, zlib_compression_level);
2103        bound = git_deflate_bound(&stream, size);
2104        deflated = xmalloc(bound);
2105        stream.next_out = deflated;
2106        stream.avail_out = bound;
2107
2108        stream.next_in = (unsigned char *)data;
2109        stream.avail_in = size;
2110        while (git_deflate(&stream, Z_FINISH) == Z_OK)
2111                ; /* nothing */
2112        git_deflate_end(&stream);
2113        *result_size = stream.total_out;
2114        return deflated;
2115}
2116
2117static void emit_binary_diff_body(FILE *file, mmfile_t *one, mmfile_t *two,
2118                                  const char *prefix)
2119{
2120        void *cp;
2121        void *delta;
2122        void *deflated;
2123        void *data;
2124        unsigned long orig_size;
2125        unsigned long delta_size;
2126        unsigned long deflate_size;
2127        unsigned long data_size;
2128
2129        /* We could do deflated delta, or we could do just deflated two,
2130         * whichever is smaller.
2131         */
2132        delta = NULL;
2133        deflated = deflate_it(two->ptr, two->size, &deflate_size);
2134        if (one->size && two->size) {
2135                delta = diff_delta(one->ptr, one->size,
2136                                   two->ptr, two->size,
2137                                   &delta_size, deflate_size);
2138                if (delta) {
2139                        void *to_free = delta;
2140                        orig_size = delta_size;
2141                        delta = deflate_it(delta, delta_size, &delta_size);
2142                        free(to_free);
2143                }
2144        }
2145
2146        if (delta && delta_size < deflate_size) {
2147                fprintf(file, "%sdelta %lu\n", prefix, orig_size);
2148                free(deflated);
2149                data = delta;
2150                data_size = delta_size;
2151        }
2152        else {
2153                fprintf(file, "%sliteral %lu\n", prefix, two->size);
2154                free(delta);
2155                data = deflated;
2156                data_size = deflate_size;
2157        }
2158
2159        /* emit data encoded in base85 */
2160        cp = data;
2161        while (data_size) {
2162                int bytes = (52 < data_size) ? 52 : data_size;
2163                char line[70];
2164                data_size -= bytes;
2165                if (bytes <= 26)
2166                        line[0] = bytes + 'A' - 1;
2167                else
2168                        line[0] = bytes - 26 + 'a' - 1;
2169                encode_85(line + 1, cp, bytes);
2170                cp = (char *) cp + bytes;
2171                fprintf(file, "%s", prefix);
2172                fputs(line, file);
2173                fputc('\n', file);
2174        }
2175        fprintf(file, "%s\n", prefix);
2176        free(data);
2177}
2178
2179static void emit_binary_diff(FILE *file, mmfile_t *one, mmfile_t *two,
2180                             const char *prefix)
2181{
2182        fprintf(file, "%sGIT binary patch\n", prefix);
2183        emit_binary_diff_body(file, one, two, prefix);
2184        emit_binary_diff_body(file, two, one, prefix);
2185}
2186
2187int diff_filespec_is_binary(struct diff_filespec *one)
2188{
2189        if (one->is_binary == -1) {
2190                diff_filespec_load_driver(one);
2191                if (one->driver->binary != -1)
2192                        one->is_binary = one->driver->binary;
2193                else {
2194                        if (!one->data && DIFF_FILE_VALID(one))
2195                                diff_populate_filespec(one, CHECK_BINARY);
2196                        if (one->is_binary == -1 && one->data)
2197                                one->is_binary = buffer_is_binary(one->data,
2198                                                one->size);
2199                        if (one->is_binary == -1)
2200                                one->is_binary = 0;
2201                }
2202        }
2203        return one->is_binary;
2204}
2205
2206static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
2207{
2208        diff_filespec_load_driver(one);
2209        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
2210}
2211
2212void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
2213{
2214        if (!options->a_prefix)
2215                options->a_prefix = a;
2216        if (!options->b_prefix)
2217                options->b_prefix = b;
2218}
2219
2220struct userdiff_driver *get_textconv(struct diff_filespec *one)
2221{
2222        if (!DIFF_FILE_VALID(one))
2223                return NULL;
2224
2225        diff_filespec_load_driver(one);
2226        return userdiff_get_textconv(one->driver);
2227}
2228
2229static void builtin_diff(const char *name_a,
2230                         const char *name_b,
2231                         struct diff_filespec *one,
2232                         struct diff_filespec *two,
2233                         const char *xfrm_msg,
2234                         int must_show_header,
2235                         struct diff_options *o,
2236                         int complete_rewrite)
2237{
2238        mmfile_t mf1, mf2;
2239        const char *lbl[2];
2240        char *a_one, *b_two;
2241        const char *meta = diff_get_color_opt(o, DIFF_METAINFO);
2242        const char *reset = diff_get_color_opt(o, DIFF_RESET);
2243        const char *a_prefix, *b_prefix;
2244        struct userdiff_driver *textconv_one = NULL;
2245        struct userdiff_driver *textconv_two = NULL;
2246        struct strbuf header = STRBUF_INIT;
2247        const char *line_prefix = diff_line_prefix(o);
2248
2249        if (DIFF_OPT_TST(o, SUBMODULE_LOG) &&
2250                        (!one->mode || S_ISGITLINK(one->mode)) &&
2251                        (!two->mode || S_ISGITLINK(two->mode))) {
2252                const char *del = diff_get_color_opt(o, DIFF_FILE_OLD);
2253                const char *add = diff_get_color_opt(o, DIFF_FILE_NEW);
2254                show_submodule_summary(o->file, one->path ? one->path : two->path,
2255                                line_prefix,
2256                                one->sha1, two->sha1, two->dirty_submodule,
2257                                meta, del, add, reset);
2258                return;
2259        }
2260
2261        if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
2262                textconv_one = get_textconv(one);
2263                textconv_two = get_textconv(two);
2264        }
2265
2266        diff_set_mnemonic_prefix(o, "a/", "b/");
2267        if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
2268                a_prefix = o->b_prefix;
2269                b_prefix = o->a_prefix;
2270        } else {
2271                a_prefix = o->a_prefix;
2272                b_prefix = o->b_prefix;
2273        }
2274
2275        /* Never use a non-valid filename anywhere if at all possible */
2276        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
2277        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
2278
2279        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
2280        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
2281        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
2282        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
2283        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, meta, a_one, b_two, reset);
2284        if (lbl[0][0] == '/') {
2285                /* /dev/null */
2286                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, meta, two->mode, reset);
2287                if (xfrm_msg)
2288                        strbuf_addstr(&header, xfrm_msg);
2289                must_show_header = 1;
2290        }
2291        else if (lbl[1][0] == '/') {
2292                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, meta, one->mode, reset);
2293                if (xfrm_msg)
2294                        strbuf_addstr(&header, xfrm_msg);
2295                must_show_header = 1;
2296        }
2297        else {
2298                if (one->mode != two->mode) {
2299                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, meta, one->mode, reset);
2300                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, meta, two->mode, reset);
2301                        must_show_header = 1;
2302                }
2303                if (xfrm_msg)
2304                        strbuf_addstr(&header, xfrm_msg);
2305
2306                /*
2307                 * we do not run diff between different kind
2308                 * of objects.
2309                 */
2310                if ((one->mode ^ two->mode) & S_IFMT)
2311                        goto free_ab_and_return;
2312                if (complete_rewrite &&
2313                    (textconv_one || !diff_filespec_is_binary(one)) &&
2314                    (textconv_two || !diff_filespec_is_binary(two))) {
2315                        fprintf(o->file, "%s", header.buf);
2316                        strbuf_reset(&header);
2317                        emit_rewrite_diff(name_a, name_b, one, two,
2318                                                textconv_one, textconv_two, o);
2319                        o->found_changes = 1;
2320                        goto free_ab_and_return;
2321                }
2322        }
2323
2324        if (o->irreversible_delete && lbl[1][0] == '/') {
2325                fprintf(o->file, "%s", header.buf);
2326                strbuf_reset(&header);
2327                goto free_ab_and_return;
2328        } else if (!DIFF_OPT_TST(o, TEXT) &&
2329            ( (!textconv_one && diff_filespec_is_binary(one)) ||
2330              (!textconv_two && diff_filespec_is_binary(two)) )) {
2331                if (!one->data && !two->data &&
2332                    S_ISREG(one->mode) && S_ISREG(two->mode) &&
2333                    !DIFF_OPT_TST(o, BINARY)) {
2334                        if (!hashcmp(one->sha1, two->sha1)) {
2335                                if (must_show_header)
2336                                        fprintf(o->file, "%s", header.buf);
2337                                goto free_ab_and_return;
2338                        }
2339                        fprintf(o->file, "%s", header.buf);
2340                        fprintf(o->file, "%sBinary files %s and %s differ\n",
2341                                line_prefix, lbl[0], lbl[1]);
2342                        goto free_ab_and_return;
2343                }
2344                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2345                        die("unable to read files to diff");
2346                /* Quite common confusing case */
2347                if (mf1.size == mf2.size &&
2348                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
2349                        if (must_show_header)
2350                                fprintf(o->file, "%s", header.buf);
2351                        goto free_ab_and_return;
2352                }
2353                fprintf(o->file, "%s", header.buf);
2354                strbuf_reset(&header);
2355                if (DIFF_OPT_TST(o, BINARY))
2356                        emit_binary_diff(o->file, &mf1, &mf2, line_prefix);
2357                else
2358                        fprintf(o->file, "%sBinary files %s and %s differ\n",
2359                                line_prefix, lbl[0], lbl[1]);
2360                o->found_changes = 1;
2361        } else {
2362                /* Crazy xdl interfaces.. */
2363                const char *diffopts = getenv("GIT_DIFF_OPTS");
2364                const char *v;
2365                xpparam_t xpp;
2366                xdemitconf_t xecfg;
2367                struct emit_callback ecbdata;
2368                const struct userdiff_funcname *pe;
2369
2370                if (must_show_header) {
2371                        fprintf(o->file, "%s", header.buf);
2372                        strbuf_reset(&header);
2373                }
2374
2375                mf1.size = fill_textconv(textconv_one, one, &mf1.ptr);
2376                mf2.size = fill_textconv(textconv_two, two, &mf2.ptr);
2377
2378                pe = diff_funcname_pattern(one);
2379                if (!pe)
2380                        pe = diff_funcname_pattern(two);
2381
2382                memset(&xpp, 0, sizeof(xpp));
2383                memset(&xecfg, 0, sizeof(xecfg));
2384                memset(&ecbdata, 0, sizeof(ecbdata));
2385                ecbdata.label_path = lbl;
2386                ecbdata.color_diff = want_color(o->use_color);
2387                ecbdata.found_changesp = &o->found_changes;
2388                ecbdata.ws_rule = whitespace_rule(name_b);
2389                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
2390                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2391                ecbdata.opt = o;
2392                ecbdata.header = header.len ? &header : NULL;
2393                xpp.flags = o->xdl_opts;
2394                xecfg.ctxlen = o->context;
2395                xecfg.interhunkctxlen = o->interhunkcontext;
2396                xecfg.flags = XDL_EMIT_FUNCNAMES;
2397                if (DIFF_OPT_TST(o, FUNCCONTEXT))
2398                        xecfg.flags |= XDL_EMIT_FUNCCONTEXT;
2399                if (pe)
2400                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
2401                if (!diffopts)
2402                        ;
2403                else if (skip_prefix(diffopts, "--unified=", &v))
2404                        xecfg.ctxlen = strtoul(v, NULL, 10);
2405                else if (skip_prefix(diffopts, "-u", &v))
2406                        xecfg.ctxlen = strtoul(v, NULL, 10);
2407                if (o->word_diff)
2408                        init_diff_words_data(&ecbdata, o, one, two);
2409                if (xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
2410                                  &xpp, &xecfg))
2411                        die("unable to generate diff for %s", one->path);
2412                if (o->word_diff)
2413                        free_diff_words_data(&ecbdata);
2414                if (textconv_one)
2415                        free(mf1.ptr);
2416                if (textconv_two)
2417                        free(mf2.ptr);
2418                xdiff_clear_find_func(&xecfg);
2419        }
2420
2421 free_ab_and_return:
2422        strbuf_release(&header);
2423        diff_free_filespec_data(one);
2424        diff_free_filespec_data(two);
2425        free(a_one);
2426        free(b_two);
2427        return;
2428}
2429
2430static void builtin_diffstat(const char *name_a, const char *name_b,
2431                             struct diff_filespec *one,
2432                             struct diff_filespec *two,
2433                             struct diffstat_t *diffstat,
2434                             struct diff_options *o,
2435                             struct diff_filepair *p)
2436{
2437        mmfile_t mf1, mf2;
2438        struct diffstat_file *data;
2439        int same_contents;
2440        int complete_rewrite = 0;
2441
2442        if (!DIFF_PAIR_UNMERGED(p)) {
2443                if (p->status == DIFF_STATUS_MODIFIED && p->score)
2444                        complete_rewrite = 1;
2445        }
2446
2447        data = diffstat_add(diffstat, name_a, name_b);
2448        data->is_interesting = p->status != DIFF_STATUS_UNKNOWN;
2449
2450        if (!one || !two) {
2451                data->is_unmerged = 1;
2452                return;
2453        }
2454
2455        same_contents = !hashcmp(one->sha1, two->sha1);
2456
2457        if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
2458                data->is_binary = 1;
2459                if (same_contents) {
2460                        data->added = 0;
2461                        data->deleted = 0;
2462                } else {
2463                        data->added = diff_filespec_size(two);
2464                        data->deleted = diff_filespec_size(one);
2465                }
2466        }
2467
2468        else if (complete_rewrite) {
2469                diff_populate_filespec(one, 0);
2470                diff_populate_filespec(two, 0);
2471                data->deleted = count_lines(one->data, one->size);
2472                data->added = count_lines(two->data, two->size);
2473        }
2474
2475        else if (!same_contents) {
2476                /* Crazy xdl interfaces.. */
2477                xpparam_t xpp;
2478                xdemitconf_t xecfg;
2479
2480                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2481                        die("unable to read files to diff");
2482
2483                memset(&xpp, 0, sizeof(xpp));
2484                memset(&xecfg, 0, sizeof(xecfg));
2485                xpp.flags = o->xdl_opts;
2486                xecfg.ctxlen = o->context;
2487                xecfg.interhunkctxlen = o->interhunkcontext;
2488                if (xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
2489                                  &xpp, &xecfg))
2490                        die("unable to generate diffstat for %s", one->path);
2491        }
2492
2493        diff_free_filespec_data(one);
2494        diff_free_filespec_data(two);
2495}
2496
2497static void builtin_checkdiff(const char *name_a, const char *name_b,
2498                              const char *attr_path,
2499                              struct diff_filespec *one,
2500                              struct diff_filespec *two,
2501                              struct diff_options *o)
2502{
2503        mmfile_t mf1, mf2;
2504        struct checkdiff_t data;
2505
2506        if (!two)
2507                return;
2508
2509        memset(&data, 0, sizeof(data));
2510        data.filename = name_b ? name_b : name_a;
2511        data.lineno = 0;
2512        data.o = o;
2513        data.ws_rule = whitespace_rule(attr_path);
2514        data.conflict_marker_size = ll_merge_marker_size(attr_path);
2515
2516        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2517                die("unable to read files to diff");
2518
2519        /*
2520         * All the other codepaths check both sides, but not checking
2521         * the "old" side here is deliberate.  We are checking the newly
2522         * introduced changes, and as long as the "new" side is text, we
2523         * can and should check what it introduces.
2524         */
2525        if (diff_filespec_is_binary(two))
2526                goto free_and_return;
2527        else {
2528                /* Crazy xdl interfaces.. */
2529                xpparam_t xpp;
2530                xdemitconf_t xecfg;
2531
2532                memset(&xpp, 0, sizeof(xpp));
2533                memset(&xecfg, 0, sizeof(xecfg));
2534                xecfg.ctxlen = 1; /* at least one context line */
2535                xpp.flags = 0;
2536                if (xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
2537                                  &xpp, &xecfg))
2538                        die("unable to generate checkdiff for %s", one->path);
2539
2540                if (data.ws_rule & WS_BLANK_AT_EOF) {
2541                        struct emit_callback ecbdata;
2542                        int blank_at_eof;
2543
2544                        ecbdata.ws_rule = data.ws_rule;
2545                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2546                        blank_at_eof = ecbdata.blank_at_eof_in_postimage;
2547
2548                        if (blank_at_eof) {
2549                                static char *err;
2550                                if (!err)
2551                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
2552                                fprintf(o->file, "%s:%d: %s.\n",
2553                                        data.filename, blank_at_eof, err);
2554                                data.status = 1; /* report errors */
2555                        }
2556                }
2557        }
2558 free_and_return:
2559        diff_free_filespec_data(one);
2560        diff_free_filespec_data(two);
2561        if (data.status)
2562                DIFF_OPT_SET(o, CHECK_FAILED);
2563}
2564
2565struct diff_filespec *alloc_filespec(const char *path)
2566{
2567        int namelen = strlen(path);
2568        struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
2569
2570        memset(spec, 0, sizeof(*spec));
2571        spec->path = (char *)(spec + 1);
2572        memcpy(spec->path, path, namelen+1);
2573        spec->count = 1;
2574        spec->is_binary = -1;
2575        return spec;
2576}
2577
2578void free_filespec(struct diff_filespec *spec)
2579{
2580        if (!--spec->count) {
2581                diff_free_filespec_data(spec);
2582                free(spec);
2583        }
2584}
2585
2586void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
2587                   int sha1_valid, unsigned short mode)
2588{
2589        if (mode) {
2590                spec->mode = canon_mode(mode);
2591                hashcpy(spec->sha1, sha1);
2592                spec->sha1_valid = sha1_valid;
2593        }
2594}
2595
2596/*
2597 * Given a name and sha1 pair, if the index tells us the file in
2598 * the work tree has that object contents, return true, so that
2599 * prepare_temp_file() does not have to inflate and extract.
2600 */
2601static int reuse_worktree_file(const char *name, const unsigned char *sha1, int want_file)
2602{
2603        const struct cache_entry *ce;
2604        struct stat st;
2605        int pos, len;
2606
2607        /*
2608         * We do not read the cache ourselves here, because the
2609         * benchmark with my previous version that always reads cache
2610         * shows that it makes things worse for diff-tree comparing
2611         * two linux-2.6 kernel trees in an already checked out work
2612         * tree.  This is because most diff-tree comparisons deal with
2613         * only a small number of files, while reading the cache is
2614         * expensive for a large project, and its cost outweighs the
2615         * savings we get by not inflating the object to a temporary
2616         * file.  Practically, this code only helps when we are used
2617         * by diff-cache --cached, which does read the cache before
2618         * calling us.
2619         */
2620        if (!active_cache)
2621                return 0;
2622
2623        /* We want to avoid the working directory if our caller
2624         * doesn't need the data in a normal file, this system
2625         * is rather slow with its stat/open/mmap/close syscalls,
2626         * and the object is contained in a pack file.  The pack
2627         * is probably already open and will be faster to obtain
2628         * the data through than the working directory.  Loose
2629         * objects however would tend to be slower as they need
2630         * to be individually opened and inflated.
2631         */
2632        if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(sha1))
2633                return 0;
2634
2635        len = strlen(name);
2636        pos = cache_name_pos(name, len);
2637        if (pos < 0)
2638                return 0;
2639        ce = active_cache[pos];
2640
2641        /*
2642         * This is not the sha1 we are looking for, or
2643         * unreusable because it is not a regular file.
2644         */
2645        if (hashcmp(sha1, ce->sha1) || !S_ISREG(ce->ce_mode))
2646                return 0;
2647
2648        /*
2649         * If ce is marked as "assume unchanged", there is no
2650         * guarantee that work tree matches what we are looking for.
2651         */
2652        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
2653                return 0;
2654
2655        /*
2656         * If ce matches the file in the work tree, we can reuse it.
2657         */
2658        if (ce_uptodate(ce) ||
2659            (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
2660                return 1;
2661
2662        return 0;
2663}
2664
2665static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
2666{
2667        int len;
2668        char *data = xmalloc(100), *dirty = "";
2669
2670        /* Are we looking at the work tree? */
2671        if (s->dirty_submodule)
2672                dirty = "-dirty";
2673
2674        len = snprintf(data, 100,
2675                       "Subproject commit %s%s\n", sha1_to_hex(s->sha1), dirty);
2676        s->data = data;
2677        s->size = len;
2678        s->should_free = 1;
2679        if (size_only) {
2680                s->data = NULL;
2681                free(data);
2682        }
2683        return 0;
2684}
2685
2686/*
2687 * While doing rename detection and pickaxe operation, we may need to
2688 * grab the data for the blob (or file) for our own in-core comparison.
2689 * diff_filespec has data and size fields for this purpose.
2690 */
2691int diff_populate_filespec(struct diff_filespec *s, unsigned int flags)
2692{
2693        int size_only = flags & CHECK_SIZE_ONLY;
2694        int err = 0;
2695        /*
2696         * demote FAIL to WARN to allow inspecting the situation
2697         * instead of refusing.
2698         */
2699        enum safe_crlf crlf_warn = (safe_crlf == SAFE_CRLF_FAIL
2700                                    ? SAFE_CRLF_WARN
2701                                    : safe_crlf);
2702
2703        if (!DIFF_FILE_VALID(s))
2704                die("internal error: asking to populate invalid file.");
2705        if (S_ISDIR(s->mode))
2706                return -1;
2707
2708        if (s->data)
2709                return 0;
2710
2711        if (size_only && 0 < s->size)
2712                return 0;
2713
2714        if (S_ISGITLINK(s->mode))
2715                return diff_populate_gitlink(s, size_only);
2716
2717        if (!s->sha1_valid ||
2718            reuse_worktree_file(s->path, s->sha1, 0)) {
2719                struct strbuf buf = STRBUF_INIT;
2720                struct stat st;
2721                int fd;
2722
2723                if (lstat(s->path, &st) < 0) {
2724                        if (errno == ENOENT) {
2725                        err_empty:
2726                                err = -1;
2727                        empty:
2728                                s->data = (char *)"";
2729                                s->size = 0;
2730                                return err;
2731                        }
2732                }
2733                s->size = xsize_t(st.st_size);
2734                if (!s->size)
2735                        goto empty;
2736                if (S_ISLNK(st.st_mode)) {
2737                        struct strbuf sb = STRBUF_INIT;
2738
2739                        if (strbuf_readlink(&sb, s->path, s->size))
2740                                goto err_empty;
2741                        s->size = sb.len;
2742                        s->data = strbuf_detach(&sb, NULL);
2743                        s->should_free = 1;
2744                        return 0;
2745                }
2746                if (size_only)
2747                        return 0;
2748                if ((flags & CHECK_BINARY) &&
2749                    s->size > big_file_threshold && s->is_binary == -1) {
2750                        s->is_binary = 1;
2751                        return 0;
2752                }
2753                fd = open(s->path, O_RDONLY);
2754                if (fd < 0)
2755                        goto err_empty;
2756                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
2757                close(fd);
2758                s->should_munmap = 1;
2759
2760                /*
2761                 * Convert from working tree format to canonical git format
2762                 */
2763                if (convert_to_git(s->path, s->data, s->size, &buf, crlf_warn)) {
2764                        size_t size = 0;
2765                        munmap(s->data, s->size);
2766                        s->should_munmap = 0;
2767                        s->data = strbuf_detach(&buf, &size);
2768                        s->size = size;
2769                        s->should_free = 1;
2770                }
2771        }
2772        else {
2773                enum object_type type;
2774                if (size_only || (flags & CHECK_BINARY)) {
2775                        type = sha1_object_info(s->sha1, &s->size);
2776                        if (type < 0)
2777                                die("unable to read %s", sha1_to_hex(s->sha1));
2778                        if (size_only)
2779                                return 0;
2780                        if (s->size > big_file_threshold && s->is_binary == -1) {
2781                                s->is_binary = 1;
2782                                return 0;
2783                        }
2784                }
2785                s->data = read_sha1_file(s->sha1, &type, &s->size);
2786                if (!s->data)
2787                        die("unable to read %s", sha1_to_hex(s->sha1));
2788                s->should_free = 1;
2789        }
2790        return 0;
2791}
2792
2793void diff_free_filespec_blob(struct diff_filespec *s)
2794{
2795        if (s->should_free)
2796                free(s->data);
2797        else if (s->should_munmap)
2798                munmap(s->data, s->size);
2799
2800        if (s->should_free || s->should_munmap) {
2801                s->should_free = s->should_munmap = 0;
2802                s->data = NULL;
2803        }
2804}
2805
2806void diff_free_filespec_data(struct diff_filespec *s)
2807{
2808        diff_free_filespec_blob(s);
2809        free(s->cnt_data);
2810        s->cnt_data = NULL;
2811}
2812
2813static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
2814                           void *blob,
2815                           unsigned long size,
2816                           const unsigned char *sha1,
2817                           int mode)
2818{
2819        int fd;
2820        struct strbuf buf = STRBUF_INIT;
2821        struct strbuf template = STRBUF_INIT;
2822        char *path_dup = xstrdup(path);
2823        const char *base = basename(path_dup);
2824
2825        /* Generate "XXXXXX_basename.ext" */
2826        strbuf_addstr(&template, "XXXXXX_");
2827        strbuf_addstr(&template, base);
2828
2829        fd = git_mkstemps(temp->tmp_path, PATH_MAX, template.buf,
2830                        strlen(base) + 1);
2831        if (fd < 0)
2832                die_errno("unable to create temp-file");
2833        if (convert_to_working_tree(path,
2834                        (const char *)blob, (size_t)size, &buf)) {
2835                blob = buf.buf;
2836                size = buf.len;
2837        }
2838        if (write_in_full(fd, blob, size) != size)
2839                die_errno("unable to write temp-file");
2840        close(fd);
2841        temp->name = temp->tmp_path;
2842        strcpy(temp->hex, sha1_to_hex(sha1));
2843        temp->hex[40] = 0;
2844        sprintf(temp->mode, "%06o", mode);
2845        strbuf_release(&buf);
2846        strbuf_release(&template);
2847        free(path_dup);
2848}
2849
2850static struct diff_tempfile *prepare_temp_file(const char *name,
2851                struct diff_filespec *one)
2852{
2853        struct diff_tempfile *temp = claim_diff_tempfile();
2854
2855        if (!DIFF_FILE_VALID(one)) {
2856        not_a_valid_file:
2857                /* A '-' entry produces this for file-2, and
2858                 * a '+' entry produces this for file-1.
2859                 */
2860                temp->name = "/dev/null";
2861                strcpy(temp->hex, ".");
2862                strcpy(temp->mode, ".");
2863                return temp;
2864        }
2865
2866        if (!remove_tempfile_installed) {
2867                atexit(remove_tempfile);
2868                sigchain_push_common(remove_tempfile_on_signal);
2869                remove_tempfile_installed = 1;
2870        }
2871
2872        if (!S_ISGITLINK(one->mode) &&
2873            (!one->sha1_valid ||
2874             reuse_worktree_file(name, one->sha1, 1))) {
2875                struct stat st;
2876                if (lstat(name, &st) < 0) {
2877                        if (errno == ENOENT)
2878                                goto not_a_valid_file;
2879                        die_errno("stat(%s)", name);
2880                }
2881                if (S_ISLNK(st.st_mode)) {
2882                        struct strbuf sb = STRBUF_INIT;
2883                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
2884                                die_errno("readlink(%s)", name);
2885                        prep_temp_blob(name, temp, sb.buf, sb.len,
2886                                       (one->sha1_valid ?
2887                                        one->sha1 : null_sha1),
2888                                       (one->sha1_valid ?
2889                                        one->mode : S_IFLNK));
2890                        strbuf_release(&sb);
2891                }
2892                else {
2893                        /* we can borrow from the file in the work tree */
2894                        temp->name = name;
2895                        if (!one->sha1_valid)
2896                                strcpy(temp->hex, sha1_to_hex(null_sha1));
2897                        else
2898                                strcpy(temp->hex, sha1_to_hex(one->sha1));
2899                        /* Even though we may sometimes borrow the
2900                         * contents from the work tree, we always want
2901                         * one->mode.  mode is trustworthy even when
2902                         * !(one->sha1_valid), as long as
2903                         * DIFF_FILE_VALID(one).
2904                         */
2905                        sprintf(temp->mode, "%06o", one->mode);
2906                }
2907                return temp;
2908        }
2909        else {
2910                if (diff_populate_filespec(one, 0))
2911                        die("cannot read data blob for %s", one->path);
2912                prep_temp_blob(name, temp, one->data, one->size,
2913                               one->sha1, one->mode);
2914        }
2915        return temp;
2916}
2917
2918static void add_external_diff_name(struct argv_array *argv,
2919                                   const char *name,
2920                                   struct diff_filespec *df)
2921{
2922        struct diff_tempfile *temp = prepare_temp_file(name, df);
2923        argv_array_push(argv, temp->name);
2924        argv_array_push(argv, temp->hex);
2925        argv_array_push(argv, temp->mode);
2926}
2927
2928/* An external diff command takes:
2929 *
2930 * diff-cmd name infile1 infile1-sha1 infile1-mode \
2931 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
2932 *
2933 */
2934static void run_external_diff(const char *pgm,
2935                              const char *name,
2936                              const char *other,
2937                              struct diff_filespec *one,
2938                              struct diff_filespec *two,
2939                              const char *xfrm_msg,
2940                              int complete_rewrite,
2941                              struct diff_options *o)
2942{
2943        struct argv_array argv = ARGV_ARRAY_INIT;
2944        struct argv_array env = ARGV_ARRAY_INIT;
2945        struct diff_queue_struct *q = &diff_queued_diff;
2946
2947        argv_array_push(&argv, pgm);
2948        argv_array_push(&argv, name);
2949
2950        if (one && two) {
2951                add_external_diff_name(&argv, name, one);
2952                if (!other)
2953                        add_external_diff_name(&argv, name, two);
2954                else {
2955                        add_external_diff_name(&argv, other, two);
2956                        argv_array_push(&argv, other);
2957                        argv_array_push(&argv, xfrm_msg);
2958                }
2959        }
2960
2961        argv_array_pushf(&env, "GIT_DIFF_PATH_COUNTER=%d", ++o->diff_path_counter);
2962        argv_array_pushf(&env, "GIT_DIFF_PATH_TOTAL=%d", q->nr);
2963
2964        if (run_command_v_opt_cd_env(argv.argv, RUN_USING_SHELL, NULL, env.argv))
2965                die(_("external diff died, stopping at %s"), name);
2966
2967        remove_tempfile();
2968        argv_array_clear(&argv);
2969        argv_array_clear(&env);
2970}
2971
2972static int similarity_index(struct diff_filepair *p)
2973{
2974        return p->score * 100 / MAX_SCORE;
2975}
2976
2977static void fill_metainfo(struct strbuf *msg,
2978                          const char *name,
2979                          const char *other,
2980                          struct diff_filespec *one,
2981                          struct diff_filespec *two,
2982                          struct diff_options *o,
2983                          struct diff_filepair *p,
2984                          int *must_show_header,
2985                          int use_color)
2986{
2987        const char *set = diff_get_color(use_color, DIFF_METAINFO);
2988        const char *reset = diff_get_color(use_color, DIFF_RESET);
2989        const char *line_prefix = diff_line_prefix(o);
2990
2991        *must_show_header = 1;
2992        strbuf_init(msg, PATH_MAX * 2 + 300);
2993        switch (p->status) {
2994        case DIFF_STATUS_COPIED:
2995                strbuf_addf(msg, "%s%ssimilarity index %d%%",
2996                            line_prefix, set, similarity_index(p));
2997                strbuf_addf(msg, "%s\n%s%scopy from ",
2998                            reset,  line_prefix, set);
2999                quote_c_style(name, msg, NULL, 0);
3000                strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
3001                quote_c_style(other, msg, NULL, 0);
3002                strbuf_addf(msg, "%s\n", reset);
3003                break;
3004        case DIFF_STATUS_RENAMED:
3005                strbuf_addf(msg, "%s%ssimilarity index %d%%",
3006                            line_prefix, set, similarity_index(p));
3007                strbuf_addf(msg, "%s\n%s%srename from ",
3008                            reset, line_prefix, set);
3009                quote_c_style(name, msg, NULL, 0);
3010                strbuf_addf(msg, "%s\n%s%srename to ",
3011                            reset, line_prefix, set);
3012                quote_c_style(other, msg, NULL, 0);
3013                strbuf_addf(msg, "%s\n", reset);
3014                break;
3015        case DIFF_STATUS_MODIFIED:
3016                if (p->score) {
3017                        strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
3018                                    line_prefix,
3019                                    set, similarity_index(p), reset);
3020                        break;
3021                }
3022                /* fallthru */
3023        default:
3024                *must_show_header = 0;
3025        }
3026        if (one && two && hashcmp(one->sha1, two->sha1)) {
3027                int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
3028
3029                if (DIFF_OPT_TST(o, BINARY)) {
3030                        mmfile_t mf;
3031                        if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
3032                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
3033                                abbrev = 40;
3034                }
3035                strbuf_addf(msg, "%s%sindex %s..", line_prefix, set,
3036                            find_unique_abbrev(one->sha1, abbrev));
3037                strbuf_addstr(msg, find_unique_abbrev(two->sha1, abbrev));
3038                if (one->mode == two->mode)
3039                        strbuf_addf(msg, " %06o", one->mode);
3040                strbuf_addf(msg, "%s\n", reset);
3041        }
3042}
3043
3044static void run_diff_cmd(const char *pgm,
3045                         const char *name,
3046                         const char *other,
3047                         const char *attr_path,
3048                         struct diff_filespec *one,
3049                         struct diff_filespec *two,
3050                         struct strbuf *msg,
3051                         struct diff_options *o,
3052                         struct diff_filepair *p)
3053{
3054        const char *xfrm_msg = NULL;
3055        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
3056        int must_show_header = 0;
3057
3058
3059        if (DIFF_OPT_TST(o, ALLOW_EXTERNAL)) {
3060                struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
3061                if (drv && drv->external)
3062                        pgm = drv->external;
3063        }
3064
3065        if (msg) {
3066                /*
3067                 * don't use colors when the header is intended for an
3068                 * external diff driver
3069                 */
3070                fill_metainfo(msg, name, other, one, two, o, p,
3071                              &must_show_header,
3072                              want_color(o->use_color) && !pgm);
3073                xfrm_msg = msg->len ? msg->buf : NULL;
3074        }
3075
3076        if (pgm) {
3077                run_external_diff(pgm, name, other, one, two, xfrm_msg,
3078                                  complete_rewrite, o);
3079                return;
3080        }
3081        if (one && two)
3082                builtin_diff(name, other ? other : name,
3083                             one, two, xfrm_msg, must_show_header,
3084                             o, complete_rewrite);
3085        else
3086                fprintf(o->file, "* Unmerged path %s\n", name);
3087}
3088
3089static void diff_fill_sha1_info(struct diff_filespec *one)
3090{
3091        if (DIFF_FILE_VALID(one)) {
3092                if (!one->sha1_valid) {
3093                        struct stat st;
3094                        if (one->is_stdin) {
3095                                hashcpy(one->sha1, null_sha1);
3096                                return;
3097                        }
3098                        if (lstat(one->path, &st) < 0)
3099                                die_errno("stat '%s'", one->path);
3100                        if (index_path(one->sha1, one->path, &st, 0))
3101                                die("cannot hash %s", one->path);
3102                }
3103        }
3104        else
3105                hashclr(one->sha1);
3106}
3107
3108static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
3109{
3110        /* Strip the prefix but do not molest /dev/null and absolute paths */
3111        if (*namep && **namep != '/') {
3112                *namep += prefix_length;
3113                if (**namep == '/')
3114                        ++*namep;
3115        }
3116        if (*otherp && **otherp != '/') {
3117                *otherp += prefix_length;
3118                if (**otherp == '/')
3119                        ++*otherp;
3120        }
3121}
3122
3123static void run_diff(struct diff_filepair *p, struct diff_options *o)
3124{
3125        const char *pgm = external_diff();
3126        struct strbuf msg;
3127        struct diff_filespec *one = p->one;
3128        struct diff_filespec *two = p->two;
3129        const char *name;
3130        const char *other;
3131        const char *attr_path;
3132
3133        name  = p->one->path;
3134        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3135        attr_path = name;
3136        if (o->prefix_length)
3137                strip_prefix(o->prefix_length, &name, &other);
3138
3139        if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
3140                pgm = NULL;
3141
3142        if (DIFF_PAIR_UNMERGED(p)) {
3143                run_diff_cmd(pgm, name, NULL, attr_path,
3144                             NULL, NULL, NULL, o, p);
3145                return;
3146        }
3147
3148        diff_fill_sha1_info(one);
3149        diff_fill_sha1_info(two);
3150
3151        if (!pgm &&
3152            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
3153            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
3154                /*
3155                 * a filepair that changes between file and symlink
3156                 * needs to be split into deletion and creation.
3157                 */
3158                struct diff_filespec *null = alloc_filespec(two->path);
3159                run_diff_cmd(NULL, name, other, attr_path,
3160                             one, null, &msg, o, p);
3161                free(null);
3162                strbuf_release(&msg);
3163
3164                null = alloc_filespec(one->path);
3165                run_diff_cmd(NULL, name, other, attr_path,
3166                             null, two, &msg, o, p);
3167                free(null);
3168        }
3169        else
3170                run_diff_cmd(pgm, name, other, attr_path,
3171                             one, two, &msg, o, p);
3172
3173        strbuf_release(&msg);
3174}
3175
3176static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
3177                         struct diffstat_t *diffstat)
3178{
3179        const char *name;
3180        const char *other;
3181
3182        if (DIFF_PAIR_UNMERGED(p)) {
3183                /* unmerged */
3184                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, p);
3185                return;
3186        }
3187
3188        name = p->one->path;
3189        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3190
3191        if (o->prefix_length)
3192                strip_prefix(o->prefix_length, &name, &other);
3193
3194        diff_fill_sha1_info(p->one);
3195        diff_fill_sha1_info(p->two);
3196
3197        builtin_diffstat(name, other, p->one, p->two, diffstat, o, p);
3198}
3199
3200static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
3201{
3202        const char *name;
3203        const char *other;
3204        const char *attr_path;
3205
3206        if (DIFF_PAIR_UNMERGED(p)) {
3207                /* unmerged */
3208                return;
3209        }
3210
3211        name = p->one->path;
3212        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3213        attr_path = other ? other : name;
3214
3215        if (o->prefix_length)
3216                strip_prefix(o->prefix_length, &name, &other);
3217
3218        diff_fill_sha1_info(p->one);
3219        diff_fill_sha1_info(p->two);
3220
3221        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
3222}
3223
3224void diff_setup(struct diff_options *options)
3225{
3226        memcpy(options, &default_diff_options, sizeof(*options));
3227
3228        options->file = stdout;
3229
3230        options->line_termination = '\n';
3231        options->break_opt = -1;
3232        options->rename_limit = -1;
3233        options->dirstat_permille = diff_dirstat_permille_default;
3234        options->context = diff_context_default;
3235        DIFF_OPT_SET(options, RENAME_EMPTY);
3236
3237        /* pathchange left =NULL by default */
3238        options->change = diff_change;
3239        options->add_remove = diff_addremove;
3240        options->use_color = diff_use_color_default;
3241        options->detect_rename = diff_detect_rename_default;
3242        options->xdl_opts |= diff_algorithm;
3243        if (diff_compaction_heuristic)
3244                DIFF_XDL_SET(options, COMPACTION_HEURISTIC);
3245
3246        options->orderfile = diff_order_file_cfg;
3247
3248        if (diff_no_prefix) {
3249                options->a_prefix = options->b_prefix = "";
3250        } else if (!diff_mnemonic_prefix) {
3251                options->a_prefix = "a/";
3252                options->b_prefix = "b/";
3253        }
3254}
3255
3256void diff_setup_done(struct diff_options *options)
3257{
3258        int count = 0;
3259
3260        if (options->set_default)
3261                options->set_default(options);
3262
3263        if (options->output_format & DIFF_FORMAT_NAME)
3264                count++;
3265        if (options->output_format & DIFF_FORMAT_NAME_STATUS)
3266                count++;
3267        if (options->output_format & DIFF_FORMAT_CHECKDIFF)
3268                count++;
3269        if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
3270                count++;
3271        if (count > 1)
3272                die("--name-only, --name-status, --check and -s are mutually exclusive");
3273
3274        /*
3275         * Most of the time we can say "there are changes"
3276         * only by checking if there are changed paths, but
3277         * --ignore-whitespace* options force us to look
3278         * inside contents.
3279         */
3280
3281        if (DIFF_XDL_TST(options, IGNORE_WHITESPACE) ||
3282            DIFF_XDL_TST(options, IGNORE_WHITESPACE_CHANGE) ||
3283            DIFF_XDL_TST(options, IGNORE_WHITESPACE_AT_EOL))
3284                DIFF_OPT_SET(options, DIFF_FROM_CONTENTS);
3285        else
3286                DIFF_OPT_CLR(options, DIFF_FROM_CONTENTS);
3287
3288        if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
3289                options->detect_rename = DIFF_DETECT_COPY;
3290
3291        if (!DIFF_OPT_TST(options, RELATIVE_NAME))
3292                options->prefix = NULL;
3293        if (options->prefix)
3294                options->prefix_length = strlen(options->prefix);
3295        else
3296                options->prefix_length = 0;
3297
3298        if (options->output_format & (DIFF_FORMAT_NAME |
3299                                      DIFF_FORMAT_NAME_STATUS |
3300                                      DIFF_FORMAT_CHECKDIFF |
3301                                      DIFF_FORMAT_NO_OUTPUT))
3302                options->output_format &= ~(DIFF_FORMAT_RAW |
3303                                            DIFF_FORMAT_NUMSTAT |
3304                                            DIFF_FORMAT_DIFFSTAT |
3305                                            DIFF_FORMAT_SHORTSTAT |
3306                                            DIFF_FORMAT_DIRSTAT |
3307                                            DIFF_FORMAT_SUMMARY |
3308                                            DIFF_FORMAT_PATCH);
3309
3310        /*
3311         * These cases always need recursive; we do not drop caller-supplied
3312         * recursive bits for other formats here.
3313         */
3314        if (options->output_format & (DIFF_FORMAT_PATCH |
3315                                      DIFF_FORMAT_NUMSTAT |
3316                                      DIFF_FORMAT_DIFFSTAT |
3317                                      DIFF_FORMAT_SHORTSTAT |
3318                                      DIFF_FORMAT_DIRSTAT |
3319                                      DIFF_FORMAT_SUMMARY |
3320                                      DIFF_FORMAT_CHECKDIFF))
3321                DIFF_OPT_SET(options, RECURSIVE);
3322        /*
3323         * Also pickaxe would not work very well if you do not say recursive
3324         */
3325        if (options->pickaxe)
3326                DIFF_OPT_SET(options, RECURSIVE);
3327        /*
3328         * When patches are generated, submodules diffed against the work tree
3329         * must be checked for dirtiness too so it can be shown in the output
3330         */
3331        if (options->output_format & DIFF_FORMAT_PATCH)
3332                DIFF_OPT_SET(options, DIRTY_SUBMODULES);
3333
3334        if (options->detect_rename && options->rename_limit < 0)
3335                options->rename_limit = diff_rename_limit_default;
3336        if (options->setup & DIFF_SETUP_USE_CACHE) {
3337                if (!active_cache)
3338                        /* read-cache does not die even when it fails
3339                         * so it is safe for us to do this here.  Also
3340                         * it does not smudge active_cache or active_nr
3341                         * when it fails, so we do not have to worry about
3342                         * cleaning it up ourselves either.
3343                         */
3344                        read_cache();
3345        }
3346        if (options->abbrev <= 0 || 40 < options->abbrev)
3347                options->abbrev = 40; /* full */
3348
3349        /*
3350         * It does not make sense to show the first hit we happened
3351         * to have found.  It does not make sense not to return with
3352         * exit code in such a case either.
3353         */
3354        if (DIFF_OPT_TST(options, QUICK)) {
3355                options->output_format = DIFF_FORMAT_NO_OUTPUT;
3356                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3357        }
3358
3359        options->diff_path_counter = 0;
3360
3361        if (DIFF_OPT_TST(options, FOLLOW_RENAMES) && options->pathspec.nr != 1)
3362                die(_("--follow requires exactly one pathspec"));
3363}
3364
3365static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
3366{
3367        char c, *eq;
3368        int len;
3369
3370        if (*arg != '-')
3371                return 0;
3372        c = *++arg;
3373        if (!c)
3374                return 0;
3375        if (c == arg_short) {
3376                c = *++arg;
3377                if (!c)
3378                        return 1;
3379                if (val && isdigit(c)) {
3380                        char *end;
3381                        int n = strtoul(arg, &end, 10);
3382                        if (*end)
3383                                return 0;
3384                        *val = n;
3385                        return 1;
3386                }
3387                return 0;
3388        }
3389        if (c != '-')
3390                return 0;
3391        arg++;
3392        eq = strchrnul(arg, '=');
3393        len = eq - arg;
3394        if (!len || strncmp(arg, arg_long, len))
3395                return 0;
3396        if (*eq) {
3397                int n;
3398                char *end;
3399                if (!isdigit(*++eq))
3400                        return 0;
3401                n = strtoul(eq, &end, 10);
3402                if (*end)
3403                        return 0;
3404                *val = n;
3405        }
3406        return 1;
3407}
3408
3409static int diff_scoreopt_parse(const char *opt);
3410
3411static inline int short_opt(char opt, const char **argv,
3412                            const char **optarg)
3413{
3414        const char *arg = argv[0];
3415        if (arg[0] != '-' || arg[1] != opt)
3416                return 0;
3417        if (arg[2] != '\0') {
3418                *optarg = arg + 2;
3419                return 1;
3420        }
3421        if (!argv[1])
3422                die("Option '%c' requires a value", opt);
3423        *optarg = argv[1];
3424        return 2;
3425}
3426
3427int parse_long_opt(const char *opt, const char **argv,
3428                   const char **optarg)
3429{
3430        const char *arg = argv[0];
3431        if (!skip_prefix(arg, "--", &arg))
3432                return 0;
3433        if (!skip_prefix(arg, opt, &arg))
3434                return 0;
3435        if (*arg == '=') { /* stuck form: --option=value */
3436                *optarg = arg + 1;
3437                return 1;
3438        }
3439        if (*arg != '\0')
3440                return 0;
3441        /* separate form: --option value */
3442        if (!argv[1])
3443                die("Option '--%s' requires a value", opt);
3444        *optarg = argv[1];
3445        return 2;
3446}
3447
3448static int stat_opt(struct diff_options *options, const char **av)
3449{
3450        const char *arg = av[0];
3451        char *end;
3452        int width = options->stat_width;
3453        int name_width = options->stat_name_width;
3454        int graph_width = options->stat_graph_width;
3455        int count = options->stat_count;
3456        int argcount = 1;
3457
3458        if (!skip_prefix(arg, "--stat", &arg))
3459                die("BUG: stat option does not begin with --stat: %s", arg);
3460        end = (char *)arg;
3461
3462        switch (*arg) {
3463        case '-':
3464                if (skip_prefix(arg, "-width", &arg)) {
3465                        if (*arg == '=')
3466                                width = strtoul(arg + 1, &end, 10);
3467                        else if (!*arg && !av[1])
3468                                die("Option '--stat-width' requires a value");
3469                        else if (!*arg) {
3470                                width = strtoul(av[1], &end, 10);
3471                                argcount = 2;
3472                        }
3473                } else if (skip_prefix(arg, "-name-width", &arg)) {
3474                        if (*arg == '=')
3475                                name_width = strtoul(arg + 1, &end, 10);
3476                        else if (!*arg && !av[1])
3477                                die("Option '--stat-name-width' requires a value");
3478                        else if (!*arg) {
3479                                name_width = strtoul(av[1], &end, 10);
3480                                argcount = 2;
3481                        }
3482                } else if (skip_prefix(arg, "-graph-width", &arg)) {
3483                        if (*arg == '=')
3484                                graph_width = strtoul(arg + 1, &end, 10);
3485                        else if (!*arg && !av[1])
3486                                die("Option '--stat-graph-width' requires a value");
3487                        else if (!*arg) {
3488                                graph_width = strtoul(av[1], &end, 10);
3489                                argcount = 2;
3490                        }
3491                } else if (skip_prefix(arg, "-count", &arg)) {
3492                        if (*arg == '=')
3493                                count = strtoul(arg + 1, &end, 10);
3494                        else if (!*arg && !av[1])
3495                                die("Option '--stat-count' requires a value");
3496                        else if (!*arg) {
3497                                count = strtoul(av[1], &end, 10);
3498                                argcount = 2;
3499                        }
3500                }
3501                break;
3502        case '=':
3503                width = strtoul(arg+1, &end, 10);
3504                if (*end == ',')
3505                        name_width = strtoul(end+1, &end, 10);
3506                if (*end == ',')
3507                        count = strtoul(end+1, &end, 10);
3508        }
3509
3510        /* Important! This checks all the error cases! */
3511        if (*end)
3512                return 0;
3513        options->output_format |= DIFF_FORMAT_DIFFSTAT;
3514        options->stat_name_width = name_width;
3515        options->stat_graph_width = graph_width;
3516        options->stat_width = width;
3517        options->stat_count = count;
3518        return argcount;
3519}
3520
3521static int parse_dirstat_opt(struct diff_options *options, const char *params)
3522{
3523        struct strbuf errmsg = STRBUF_INIT;
3524        if (parse_dirstat_params(options, params, &errmsg))
3525                die(_("Failed to parse --dirstat/-X option parameter:\n%s"),
3526                    errmsg.buf);
3527        strbuf_release(&errmsg);
3528        /*
3529         * The caller knows a dirstat-related option is given from the command
3530         * line; allow it to say "return this_function();"
3531         */
3532        options->output_format |= DIFF_FORMAT_DIRSTAT;
3533        return 1;
3534}
3535
3536static int parse_submodule_opt(struct diff_options *options, const char *value)
3537{
3538        if (parse_submodule_params(options, value))
3539                die(_("Failed to parse --submodule option parameter: '%s'"),
3540                        value);
3541        return 1;
3542}
3543
3544static const char diff_status_letters[] = {
3545        DIFF_STATUS_ADDED,
3546        DIFF_STATUS_COPIED,
3547        DIFF_STATUS_DELETED,
3548        DIFF_STATUS_MODIFIED,
3549        DIFF_STATUS_RENAMED,
3550        DIFF_STATUS_TYPE_CHANGED,
3551        DIFF_STATUS_UNKNOWN,
3552        DIFF_STATUS_UNMERGED,
3553        DIFF_STATUS_FILTER_AON,
3554        DIFF_STATUS_FILTER_BROKEN,
3555        '\0',
3556};
3557
3558static unsigned int filter_bit['Z' + 1];
3559
3560static void prepare_filter_bits(void)
3561{
3562        int i;
3563
3564        if (!filter_bit[DIFF_STATUS_ADDED]) {
3565                for (i = 0; diff_status_letters[i]; i++)
3566                        filter_bit[(int) diff_status_letters[i]] = (1 << i);
3567        }
3568}
3569
3570static unsigned filter_bit_tst(char status, const struct diff_options *opt)
3571{
3572        return opt->filter & filter_bit[(int) status];
3573}
3574
3575static int parse_diff_filter_opt(const char *optarg, struct diff_options *opt)
3576{
3577        int i, optch;
3578
3579        prepare_filter_bits();
3580
3581        /*
3582         * If there is a negation e.g. 'd' in the input, and we haven't
3583         * initialized the filter field with another --diff-filter, start
3584         * from full set of bits, except for AON.
3585         */
3586        if (!opt->filter) {
3587                for (i = 0; (optch = optarg[i]) != '\0'; i++) {
3588                        if (optch < 'a' || 'z' < optch)
3589                                continue;
3590                        opt->filter = (1 << (ARRAY_SIZE(diff_status_letters) - 1)) - 1;
3591                        opt->filter &= ~filter_bit[DIFF_STATUS_FILTER_AON];
3592                        break;
3593                }
3594        }
3595
3596        for (i = 0; (optch = optarg[i]) != '\0'; i++) {
3597                unsigned int bit;
3598                int negate;
3599
3600                if ('a' <= optch && optch <= 'z') {
3601                        negate = 1;
3602                        optch = toupper(optch);
3603                } else {
3604                        negate = 0;
3605                }
3606
3607                bit = (0 <= optch && optch <= 'Z') ? filter_bit[optch] : 0;
3608                if (!bit)
3609                        return optarg[i];
3610                if (negate)
3611                        opt->filter &= ~bit;
3612                else
3613                        opt->filter |= bit;
3614        }
3615        return 0;
3616}
3617
3618static void enable_patch_output(int *fmt) {
3619        *fmt &= ~DIFF_FORMAT_NO_OUTPUT;
3620        *fmt |= DIFF_FORMAT_PATCH;
3621}
3622
3623int diff_opt_parse(struct diff_options *options, const char **av, int ac)
3624{
3625        const char *arg = av[0];
3626        const char *optarg;
3627        int argcount;
3628
3629        /* Output format options */
3630        if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch")
3631            || opt_arg(arg, 'U', "unified", &options->context))
3632                enable_patch_output(&options->output_format);
3633        else if (!strcmp(arg, "--raw"))
3634                options->output_format |= DIFF_FORMAT_RAW;
3635        else if (!strcmp(arg, "--patch-with-raw")) {
3636                enable_patch_output(&options->output_format);
3637                options->output_format |= DIFF_FORMAT_RAW;
3638        } else if (!strcmp(arg, "--numstat"))
3639                options->output_format |= DIFF_FORMAT_NUMSTAT;
3640        else if (!strcmp(arg, "--shortstat"))
3641                options->output_format |= DIFF_FORMAT_SHORTSTAT;
3642        else if (!strcmp(arg, "-X") || !strcmp(arg, "--dirstat"))
3643                return parse_dirstat_opt(options, "");
3644        else if (skip_prefix(arg, "-X", &arg))
3645                return parse_dirstat_opt(options, arg);
3646        else if (skip_prefix(arg, "--dirstat=", &arg))
3647                return parse_dirstat_opt(options, arg);
3648        else if (!strcmp(arg, "--cumulative"))
3649                return parse_dirstat_opt(options, "cumulative");
3650        else if (!strcmp(arg, "--dirstat-by-file"))
3651                return parse_dirstat_opt(options, "files");
3652        else if (skip_prefix(arg, "--dirstat-by-file=", &arg)) {
3653                parse_dirstat_opt(options, "files");
3654                return parse_dirstat_opt(options, arg);
3655        }
3656        else if (!strcmp(arg, "--check"))
3657                options->output_format |= DIFF_FORMAT_CHECKDIFF;
3658        else if (!strcmp(arg, "--summary"))
3659                options->output_format |= DIFF_FORMAT_SUMMARY;
3660        else if (!strcmp(arg, "--patch-with-stat")) {
3661                enable_patch_output(&options->output_format);
3662                options->output_format |= DIFF_FORMAT_DIFFSTAT;
3663        } else if (!strcmp(arg, "--name-only"))
3664                options->output_format |= DIFF_FORMAT_NAME;
3665        else if (!strcmp(arg, "--name-status"))
3666                options->output_format |= DIFF_FORMAT_NAME_STATUS;
3667        else if (!strcmp(arg, "-s") || !strcmp(arg, "--no-patch"))
3668                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
3669        else if (starts_with(arg, "--stat"))
3670                /* --stat, --stat-width, --stat-name-width, or --stat-count */
3671                return stat_opt(options, av);
3672
3673        /* renames options */
3674        else if (starts_with(arg, "-B") || starts_with(arg, "--break-rewrites=") ||
3675                 !strcmp(arg, "--break-rewrites")) {
3676                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
3677                        return error("invalid argument to -B: %s", arg+2);
3678        }
3679        else if (starts_with(arg, "-M") || starts_with(arg, "--find-renames=") ||
3680                 !strcmp(arg, "--find-renames")) {
3681                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3682                        return error("invalid argument to -M: %s", arg+2);
3683                options->detect_rename = DIFF_DETECT_RENAME;
3684        }
3685        else if (!strcmp(arg, "-D") || !strcmp(arg, "--irreversible-delete")) {
3686                options->irreversible_delete = 1;
3687        }
3688        else if (starts_with(arg, "-C") || starts_with(arg, "--find-copies=") ||
3689                 !strcmp(arg, "--find-copies")) {
3690                if (options->detect_rename == DIFF_DETECT_COPY)
3691                        DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3692                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3693                        return error("invalid argument to -C: %s", arg+2);
3694                options->detect_rename = DIFF_DETECT_COPY;
3695        }
3696        else if (!strcmp(arg, "--no-renames"))
3697                options->detect_rename = 0;
3698        else if (!strcmp(arg, "--rename-empty"))
3699                DIFF_OPT_SET(options, RENAME_EMPTY);
3700        else if (!strcmp(arg, "--no-rename-empty"))
3701                DIFF_OPT_CLR(options, RENAME_EMPTY);
3702        else if (!strcmp(arg, "--relative"))
3703                DIFF_OPT_SET(options, RELATIVE_NAME);
3704        else if (skip_prefix(arg, "--relative=", &arg)) {
3705                DIFF_OPT_SET(options, RELATIVE_NAME);
3706                options->prefix = arg;
3707        }
3708
3709        /* xdiff options */
3710        else if (!strcmp(arg, "--minimal"))
3711                DIFF_XDL_SET(options, NEED_MINIMAL);
3712        else if (!strcmp(arg, "--no-minimal"))
3713                DIFF_XDL_CLR(options, NEED_MINIMAL);
3714        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
3715                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
3716        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
3717                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
3718        else if (!strcmp(arg, "--ignore-space-at-eol"))
3719                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
3720        else if (!strcmp(arg, "--ignore-blank-lines"))
3721                DIFF_XDL_SET(options, IGNORE_BLANK_LINES);
3722        else if (!strcmp(arg, "--compaction-heuristic"))
3723                DIFF_XDL_SET(options, COMPACTION_HEURISTIC);
3724        else if (!strcmp(arg, "--no-compaction-heuristic"))
3725                DIFF_XDL_CLR(options, COMPACTION_HEURISTIC);
3726        else if (!strcmp(arg, "--patience"))
3727                options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
3728        else if (!strcmp(arg, "--histogram"))
3729                options->xdl_opts = DIFF_WITH_ALG(options, HISTOGRAM_DIFF);
3730        else if ((argcount = parse_long_opt("diff-algorithm", av, &optarg))) {
3731                long value = parse_algorithm_value(optarg);
3732                if (value < 0)
3733                        return error("option diff-algorithm accepts \"myers\", "
3734                                     "\"minimal\", \"patience\" and \"histogram\"");
3735                /* clear out previous settings */
3736                DIFF_XDL_CLR(options, NEED_MINIMAL);
3737                options->xdl_opts &= ~XDF_DIFF_ALGORITHM_MASK;
3738                options->xdl_opts |= value;
3739                return argcount;
3740        }
3741
3742        /* flags options */
3743        else if (!strcmp(arg, "--binary")) {
3744                enable_patch_output(&options->output_format);
3745                DIFF_OPT_SET(options, BINARY);
3746        }
3747        else if (!strcmp(arg, "--full-index"))
3748                DIFF_OPT_SET(options, FULL_INDEX);
3749        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
3750                DIFF_OPT_SET(options, TEXT);
3751        else if (!strcmp(arg, "-R"))
3752                DIFF_OPT_SET(options, REVERSE_DIFF);
3753        else if (!strcmp(arg, "--find-copies-harder"))
3754                DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3755        else if (!strcmp(arg, "--follow"))
3756                DIFF_OPT_SET(options, FOLLOW_RENAMES);
3757        else if (!strcmp(arg, "--no-follow"))
3758                DIFF_OPT_CLR(options, FOLLOW_RENAMES);
3759        else if (!strcmp(arg, "--color"))
3760                options->use_color = 1;
3761        else if (skip_prefix(arg, "--color=", &arg)) {
3762                int value = git_config_colorbool(NULL, arg);
3763                if (value < 0)
3764                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
3765                options->use_color = value;
3766        }
3767        else if (!strcmp(arg, "--no-color"))
3768                options->use_color = 0;
3769        else if (!strcmp(arg, "--color-words")) {
3770                options->use_color = 1;
3771                options->word_diff = DIFF_WORDS_COLOR;
3772        }
3773        else if (skip_prefix(arg, "--color-words=", &arg)) {
3774                options->use_color = 1;
3775                options->word_diff = DIFF_WORDS_COLOR;
3776                options->word_regex = arg;
3777        }
3778        else if (!strcmp(arg, "--word-diff")) {
3779                if (options->word_diff == DIFF_WORDS_NONE)
3780                        options->word_diff = DIFF_WORDS_PLAIN;
3781        }
3782        else if (skip_prefix(arg, "--word-diff=", &arg)) {
3783                if (!strcmp(arg, "plain"))
3784                        options->word_diff = DIFF_WORDS_PLAIN;
3785                else if (!strcmp(arg, "color")) {
3786                        options->use_color = 1;
3787                        options->word_diff = DIFF_WORDS_COLOR;
3788                }
3789                else if (!strcmp(arg, "porcelain"))
3790                        options->word_diff = DIFF_WORDS_PORCELAIN;
3791                else if (!strcmp(arg, "none"))
3792                        options->word_diff = DIFF_WORDS_NONE;
3793                else
3794                        die("bad --word-diff argument: %s", arg);
3795        }
3796        else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
3797                if (options->word_diff == DIFF_WORDS_NONE)
3798                        options->word_diff = DIFF_WORDS_PLAIN;
3799                options->word_regex = optarg;
3800                return argcount;
3801        }
3802        else if (!strcmp(arg, "--exit-code"))
3803                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3804        else if (!strcmp(arg, "--quiet"))
3805                DIFF_OPT_SET(options, QUICK);
3806        else if (!strcmp(arg, "--ext-diff"))
3807                DIFF_OPT_SET(options, ALLOW_EXTERNAL);
3808        else if (!strcmp(arg, "--no-ext-diff"))
3809                DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
3810        else if (!strcmp(arg, "--textconv"))
3811                DIFF_OPT_SET(options, ALLOW_TEXTCONV);
3812        else if (!strcmp(arg, "--no-textconv"))
3813                DIFF_OPT_CLR(options, ALLOW_TEXTCONV);
3814        else if (!strcmp(arg, "--ignore-submodules")) {
3815                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3816                handle_ignore_submodules_arg(options, "all");
3817        } else if (skip_prefix(arg, "--ignore-submodules=", &arg)) {
3818                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3819                handle_ignore_submodules_arg(options, arg);
3820        } else if (!strcmp(arg, "--submodule"))
3821                DIFF_OPT_SET(options, SUBMODULE_LOG);
3822        else if (skip_prefix(arg, "--submodule=", &arg))
3823                return parse_submodule_opt(options, arg);
3824
3825        /* misc options */
3826        else if (!strcmp(arg, "-z"))
3827                options->line_termination = 0;
3828        else if ((argcount = short_opt('l', av, &optarg))) {
3829                options->rename_limit = strtoul(optarg, NULL, 10);
3830                return argcount;
3831        }
3832        else if ((argcount = short_opt('S', av, &optarg))) {
3833                options->pickaxe = optarg;
3834                options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
3835                return argcount;
3836        } else if ((argcount = short_opt('G', av, &optarg))) {
3837                options->pickaxe = optarg;
3838                options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
3839                return argcount;
3840        }
3841        else if (!strcmp(arg, "--pickaxe-all"))
3842                options->pickaxe_opts |= DIFF_PICKAXE_ALL;
3843        else if (!strcmp(arg, "--pickaxe-regex"))
3844                options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
3845        else if ((argcount = short_opt('O', av, &optarg))) {
3846                options->orderfile = optarg;
3847                return argcount;
3848        }
3849        else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
3850                int offending = parse_diff_filter_opt(optarg, options);
3851                if (offending)
3852                        die("unknown change class '%c' in --diff-filter=%s",
3853                            offending, optarg);
3854                return argcount;
3855        }
3856        else if (!strcmp(arg, "--abbrev"))
3857                options->abbrev = DEFAULT_ABBREV;
3858        else if (skip_prefix(arg, "--abbrev=", &arg)) {
3859                options->abbrev = strtoul(arg, NULL, 10);
3860                if (options->abbrev < MINIMUM_ABBREV)
3861                        options->abbrev = MINIMUM_ABBREV;
3862                else if (40 < options->abbrev)
3863                        options->abbrev = 40;
3864        }
3865        else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
3866                options->a_prefix = optarg;
3867                return argcount;
3868        }
3869        else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
3870                options->b_prefix = optarg;
3871                return argcount;
3872        }
3873        else if (!strcmp(arg, "--no-prefix"))
3874                options->a_prefix = options->b_prefix = "";
3875        else if (opt_arg(arg, '\0', "inter-hunk-context",
3876                         &options->interhunkcontext))
3877                ;
3878        else if (!strcmp(arg, "-W"))
3879                DIFF_OPT_SET(options, FUNCCONTEXT);
3880        else if (!strcmp(arg, "--function-context"))
3881                DIFF_OPT_SET(options, FUNCCONTEXT);
3882        else if (!strcmp(arg, "--no-function-context"))
3883                DIFF_OPT_CLR(options, FUNCCONTEXT);
3884        else if ((argcount = parse_long_opt("output", av, &optarg))) {
3885                options->file = fopen(optarg, "w");
3886                if (!options->file)
3887                        die_errno("Could not open '%s'", optarg);
3888                options->close_file = 1;
3889                return argcount;
3890        } else
3891                return 0;
3892        return 1;
3893}
3894
3895int parse_rename_score(const char **cp_p)
3896{
3897        unsigned long num, scale;
3898        int ch, dot;
3899        const char *cp = *cp_p;
3900
3901        num = 0;
3902        scale = 1;
3903        dot = 0;
3904        for (;;) {
3905                ch = *cp;
3906                if ( !dot && ch == '.' ) {
3907                        scale = 1;
3908                        dot = 1;
3909                } else if ( ch == '%' ) {
3910                        scale = dot ? scale*100 : 100;
3911                        cp++;   /* % is always at the end */
3912                        break;
3913                } else if ( ch >= '0' && ch <= '9' ) {
3914                        if ( scale < 100000 ) {
3915                                scale *= 10;
3916                                num = (num*10) + (ch-'0');
3917                        }
3918                } else {
3919                        break;
3920                }
3921                cp++;
3922        }
3923        *cp_p = cp;
3924
3925        /* user says num divided by scale and we say internally that
3926         * is MAX_SCORE * num / scale.
3927         */
3928        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
3929}
3930
3931static int diff_scoreopt_parse(const char *opt)
3932{
3933        int opt1, opt2, cmd;
3934
3935        if (*opt++ != '-')
3936                return -1;
3937        cmd = *opt++;
3938        if (cmd == '-') {
3939                /* convert the long-form arguments into short-form versions */
3940                if (skip_prefix(opt, "break-rewrites", &opt)) {
3941                        if (*opt == 0 || *opt++ == '=')
3942                                cmd = 'B';
3943                } else if (skip_prefix(opt, "find-copies", &opt)) {
3944                        if (*opt == 0 || *opt++ == '=')
3945                                cmd = 'C';
3946                } else if (skip_prefix(opt, "find-renames", &opt)) {
3947                        if (*opt == 0 || *opt++ == '=')
3948                                cmd = 'M';
3949                }
3950        }
3951        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
3952                return -1; /* that is not a -M, -C, or -B option */
3953
3954        opt1 = parse_rename_score(&opt);
3955        if (cmd != 'B')
3956                opt2 = 0;
3957        else {
3958                if (*opt == 0)
3959                        opt2 = 0;
3960                else if (*opt != '/')
3961                        return -1; /* we expect -B80/99 or -B80 */
3962                else {
3963                        opt++;
3964                        opt2 = parse_rename_score(&opt);
3965                }
3966        }
3967        if (*opt != 0)
3968                return -1;
3969        return opt1 | (opt2 << 16);
3970}
3971
3972struct diff_queue_struct diff_queued_diff;
3973
3974void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
3975{
3976        ALLOC_GROW(queue->queue, queue->nr + 1, queue->alloc);
3977        queue->queue[queue->nr++] = dp;
3978}
3979
3980struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
3981                                 struct diff_filespec *one,
3982                                 struct diff_filespec *two)
3983{
3984        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
3985        dp->one = one;
3986        dp->two = two;
3987        if (queue)
3988                diff_q(queue, dp);
3989        return dp;
3990}
3991
3992void diff_free_filepair(struct diff_filepair *p)
3993{
3994        free_filespec(p->one);
3995        free_filespec(p->two);
3996        free(p);
3997}
3998
3999/* This is different from find_unique_abbrev() in that
4000 * it stuffs the result with dots for alignment.
4001 */
4002const char *diff_unique_abbrev(const unsigned char *sha1, int len)
4003{
4004        int abblen;
4005        const char *abbrev;
4006        if (len == 40)
4007                return sha1_to_hex(sha1);
4008
4009        abbrev = find_unique_abbrev(sha1, len);
4010        abblen = strlen(abbrev);
4011        if (abblen < 37) {
4012                static char hex[41];
4013                if (len < abblen && abblen <= len + 2)
4014                        sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
4015                else
4016                        sprintf(hex, "%s...", abbrev);
4017                return hex;
4018        }
4019        return sha1_to_hex(sha1);
4020}
4021
4022static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
4023{
4024        int line_termination = opt->line_termination;
4025        int inter_name_termination = line_termination ? '\t' : '\0';
4026
4027        fprintf(opt->file, "%s", diff_line_prefix(opt));
4028        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
4029                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
4030                        diff_unique_abbrev(p->one->sha1, opt->abbrev));
4031                fprintf(opt->file, "%s ", diff_unique_abbrev(p->two->sha1, opt->abbrev));
4032        }
4033        if (p->score) {
4034                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
4035                        inter_name_termination);
4036        } else {
4037                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
4038        }
4039
4040        if (p->status == DIFF_STATUS_COPIED ||
4041            p->status == DIFF_STATUS_RENAMED) {
4042                const char *name_a, *name_b;
4043                name_a = p->one->path;
4044                name_b = p->two->path;
4045                strip_prefix(opt->prefix_length, &name_a, &name_b);
4046                write_name_quoted(name_a, opt->file, inter_name_termination);
4047                write_name_quoted(name_b, opt->file, line_termination);
4048        } else {
4049                const char *name_a, *name_b;
4050                name_a = p->one->mode ? p->one->path : p->two->path;
4051                name_b = NULL;
4052                strip_prefix(opt->prefix_length, &name_a, &name_b);
4053                write_name_quoted(name_a, opt->file, line_termination);
4054        }
4055}
4056
4057int diff_unmodified_pair(struct diff_filepair *p)
4058{
4059        /* This function is written stricter than necessary to support
4060         * the currently implemented transformers, but the idea is to
4061         * let transformers to produce diff_filepairs any way they want,
4062         * and filter and clean them up here before producing the output.
4063         */
4064        struct diff_filespec *one = p->one, *two = p->two;
4065
4066        if (DIFF_PAIR_UNMERGED(p))
4067                return 0; /* unmerged is interesting */
4068
4069        /* deletion, addition, mode or type change
4070         * and rename are all interesting.
4071         */
4072        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
4073            DIFF_PAIR_MODE_CHANGED(p) ||
4074            strcmp(one->path, two->path))
4075                return 0;
4076
4077        /* both are valid and point at the same path.  that is, we are
4078         * dealing with a change.
4079         */
4080        if (one->sha1_valid && two->sha1_valid &&
4081            !hashcmp(one->sha1, two->sha1) &&
4082            !one->dirty_submodule && !two->dirty_submodule)
4083                return 1; /* no change */
4084        if (!one->sha1_valid && !two->sha1_valid)
4085                return 1; /* both look at the same file on the filesystem. */
4086        return 0;
4087}
4088
4089static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
4090{
4091        if (diff_unmodified_pair(p))
4092                return;
4093
4094        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4095            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4096                return; /* no tree diffs in patch format */
4097
4098        run_diff(p, o);
4099}
4100
4101static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
4102                            struct diffstat_t *diffstat)
4103{
4104        if (diff_unmodified_pair(p))
4105                return;
4106
4107        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4108            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4109                return; /* no useful stat for tree diffs */
4110
4111        run_diffstat(p, o, diffstat);
4112}
4113
4114static void diff_flush_checkdiff(struct diff_filepair *p,
4115                struct diff_options *o)
4116{
4117        if (diff_unmodified_pair(p))
4118                return;
4119
4120        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4121            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4122                return; /* nothing to check in tree diffs */
4123
4124        run_checkdiff(p, o);
4125}
4126
4127int diff_queue_is_empty(void)
4128{
4129        struct diff_queue_struct *q = &diff_queued_diff;
4130        int i;
4131        for (i = 0; i < q->nr; i++)
4132                if (!diff_unmodified_pair(q->queue[i]))
4133                        return 0;
4134        return 1;
4135}
4136
4137#if DIFF_DEBUG
4138void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
4139{
4140        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
4141                x, one ? one : "",
4142                s->path,
4143                DIFF_FILE_VALID(s) ? "valid" : "invalid",
4144                s->mode,
4145                s->sha1_valid ? sha1_to_hex(s->sha1) : "");
4146        fprintf(stderr, "queue[%d] %s size %lu\n",
4147                x, one ? one : "",
4148                s->size);
4149}
4150
4151void diff_debug_filepair(const struct diff_filepair *p, int i)
4152{
4153        diff_debug_filespec(p->one, i, "one");
4154        diff_debug_filespec(p->two, i, "two");
4155        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
4156                p->score, p->status ? p->status : '?',
4157                p->one->rename_used, p->broken_pair);
4158}
4159
4160void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
4161{
4162        int i;
4163        if (msg)
4164                fprintf(stderr, "%s\n", msg);
4165        fprintf(stderr, "q->nr = %d\n", q->nr);
4166        for (i = 0; i < q->nr; i++) {
4167                struct diff_filepair *p = q->queue[i];
4168                diff_debug_filepair(p, i);
4169        }
4170}
4171#endif
4172
4173static void diff_resolve_rename_copy(void)
4174{
4175        int i;
4176        struct diff_filepair *p;
4177        struct diff_queue_struct *q = &diff_queued_diff;
4178
4179        diff_debug_queue("resolve-rename-copy", q);
4180
4181        for (i = 0; i < q->nr; i++) {
4182                p = q->queue[i];
4183                p->status = 0; /* undecided */
4184                if (DIFF_PAIR_UNMERGED(p))
4185                        p->status = DIFF_STATUS_UNMERGED;
4186                else if (!DIFF_FILE_VALID(p->one))
4187                        p->status = DIFF_STATUS_ADDED;
4188                else if (!DIFF_FILE_VALID(p->two))
4189                        p->status = DIFF_STATUS_DELETED;
4190                else if (DIFF_PAIR_TYPE_CHANGED(p))
4191                        p->status = DIFF_STATUS_TYPE_CHANGED;
4192
4193                /* from this point on, we are dealing with a pair
4194                 * whose both sides are valid and of the same type, i.e.
4195                 * either in-place edit or rename/copy edit.
4196                 */
4197                else if (DIFF_PAIR_RENAME(p)) {
4198                        /*
4199                         * A rename might have re-connected a broken
4200                         * pair up, causing the pathnames to be the
4201                         * same again. If so, that's not a rename at
4202                         * all, just a modification..
4203                         *
4204                         * Otherwise, see if this source was used for
4205                         * multiple renames, in which case we decrement
4206                         * the count, and call it a copy.
4207                         */
4208                        if (!strcmp(p->one->path, p->two->path))
4209                                p->status = DIFF_STATUS_MODIFIED;
4210                        else if (--p->one->rename_used > 0)
4211                                p->status = DIFF_STATUS_COPIED;
4212                        else
4213                                p->status = DIFF_STATUS_RENAMED;
4214                }
4215                else if (hashcmp(p->one->sha1, p->two->sha1) ||
4216                         p->one->mode != p->two->mode ||
4217                         p->one->dirty_submodule ||
4218                         p->two->dirty_submodule ||
4219                         is_null_sha1(p->one->sha1))
4220                        p->status = DIFF_STATUS_MODIFIED;
4221                else {
4222                        /* This is a "no-change" entry and should not
4223                         * happen anymore, but prepare for broken callers.
4224                         */
4225                        error("feeding unmodified %s to diffcore",
4226                              p->one->path);
4227                        p->status = DIFF_STATUS_UNKNOWN;
4228                }
4229        }
4230        diff_debug_queue("resolve-rename-copy done", q);
4231}
4232
4233static int check_pair_status(struct diff_filepair *p)
4234{
4235        switch (p->status) {
4236        case DIFF_STATUS_UNKNOWN:
4237                return 0;
4238        case 0:
4239                die("internal error in diff-resolve-rename-copy");
4240        default:
4241                return 1;
4242        }
4243}
4244
4245static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
4246{
4247        int fmt = opt->output_format;
4248
4249        if (fmt & DIFF_FORMAT_CHECKDIFF)
4250                diff_flush_checkdiff(p, opt);
4251        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
4252                diff_flush_raw(p, opt);
4253        else if (fmt & DIFF_FORMAT_NAME) {
4254                const char *name_a, *name_b;
4255                name_a = p->two->path;
4256                name_b = NULL;
4257                strip_prefix(opt->prefix_length, &name_a, &name_b);
4258                write_name_quoted(name_a, opt->file, opt->line_termination);
4259        }
4260}
4261
4262static void show_file_mode_name(FILE *file, const char *newdelete, struct diff_filespec *fs)
4263{
4264        if (fs->mode)
4265                fprintf(file, " %s mode %06o ", newdelete, fs->mode);
4266        else
4267                fprintf(file, " %s ", newdelete);
4268        write_name_quoted(fs->path, file, '\n');
4269}
4270
4271
4272static void show_mode_change(FILE *file, struct diff_filepair *p, int show_name,
4273                const char *line_prefix)
4274{
4275        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
4276                fprintf(file, "%s mode change %06o => %06o%c", line_prefix, p->one->mode,
4277                        p->two->mode, show_name ? ' ' : '\n');
4278                if (show_name) {
4279                        write_name_quoted(p->two->path, file, '\n');
4280                }
4281        }
4282}
4283
4284static void show_rename_copy(FILE *file, const char *renamecopy, struct diff_filepair *p,
4285                        const char *line_prefix)
4286{
4287        char *names = pprint_rename(p->one->path, p->two->path);
4288
4289        fprintf(file, " %s %s (%d%%)\n", renamecopy, names, similarity_index(p));
4290        free(names);
4291        show_mode_change(file, p, 0, line_prefix);
4292}
4293
4294static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
4295{
4296        FILE *file = opt->file;
4297        const char *line_prefix = diff_line_prefix(opt);
4298
4299        switch(p->status) {
4300        case DIFF_STATUS_DELETED:
4301                fputs(line_prefix, file);
4302                show_file_mode_name(file, "delete", p->one);
4303                break;
4304        case DIFF_STATUS_ADDED:
4305                fputs(line_prefix, file);
4306                show_file_mode_name(file, "create", p->two);
4307                break;
4308        case DIFF_STATUS_COPIED:
4309                fputs(line_prefix, file);
4310                show_rename_copy(file, "copy", p, line_prefix);
4311                break;
4312        case DIFF_STATUS_RENAMED:
4313                fputs(line_prefix, file);
4314                show_rename_copy(file, "rename", p, line_prefix);
4315                break;
4316        default:
4317                if (p->score) {
4318                        fprintf(file, "%s rewrite ", line_prefix);
4319                        write_name_quoted(p->two->path, file, ' ');
4320                        fprintf(file, "(%d%%)\n", similarity_index(p));
4321                }
4322                show_mode_change(file, p, !p->score, line_prefix);
4323                break;
4324        }
4325}
4326
4327struct patch_id_t {
4328        git_SHA_CTX *ctx;
4329        int patchlen;
4330};
4331
4332static int remove_space(char *line, int len)
4333{
4334        int i;
4335        char *dst = line;
4336        unsigned char c;
4337
4338        for (i = 0; i < len; i++)
4339                if (!isspace((c = line[i])))
4340                        *dst++ = c;
4341
4342        return dst - line;
4343}
4344
4345static void patch_id_consume(void *priv, char *line, unsigned long len)
4346{
4347        struct patch_id_t *data = priv;
4348        int new_len;
4349
4350        /* Ignore line numbers when computing the SHA1 of the patch */
4351        if (starts_with(line, "@@ -"))
4352                return;
4353
4354        new_len = remove_space(line, len);
4355
4356        git_SHA1_Update(data->ctx, line, new_len);
4357        data->patchlen += new_len;
4358}
4359
4360/* returns 0 upon success, and writes result into sha1 */
4361static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
4362{
4363        struct diff_queue_struct *q = &diff_queued_diff;
4364        int i;
4365        git_SHA_CTX ctx;
4366        struct patch_id_t data;
4367        char buffer[PATH_MAX * 4 + 20];
4368
4369        git_SHA1_Init(&ctx);
4370        memset(&data, 0, sizeof(struct patch_id_t));
4371        data.ctx = &ctx;
4372
4373        for (i = 0; i < q->nr; i++) {
4374                xpparam_t xpp;
4375                xdemitconf_t xecfg;
4376                mmfile_t mf1, mf2;
4377                struct diff_filepair *p = q->queue[i];
4378                int len1, len2;
4379
4380                memset(&xpp, 0, sizeof(xpp));
4381                memset(&xecfg, 0, sizeof(xecfg));
4382                if (p->status == 0)
4383                        return error("internal diff status error");
4384                if (p->status == DIFF_STATUS_UNKNOWN)
4385                        continue;
4386                if (diff_unmodified_pair(p))
4387                        continue;
4388                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4389                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4390                        continue;
4391                if (DIFF_PAIR_UNMERGED(p))
4392                        continue;
4393
4394                diff_fill_sha1_info(p->one);
4395                diff_fill_sha1_info(p->two);
4396                if (fill_mmfile(&mf1, p->one) < 0 ||
4397                                fill_mmfile(&mf2, p->two) < 0)
4398                        return error("unable to read files to diff");
4399
4400                len1 = remove_space(p->one->path, strlen(p->one->path));
4401                len2 = remove_space(p->two->path, strlen(p->two->path));
4402                if (p->one->mode == 0)
4403                        len1 = snprintf(buffer, sizeof(buffer),
4404                                        "diff--gita/%.*sb/%.*s"
4405                                        "newfilemode%06o"
4406                                        "---/dev/null"
4407                                        "+++b/%.*s",
4408                                        len1, p->one->path,
4409                                        len2, p->two->path,
4410                                        p->two->mode,
4411                                        len2, p->two->path);
4412                else if (p->two->mode == 0)
4413                        len1 = snprintf(buffer, sizeof(buffer),
4414                                        "diff--gita/%.*sb/%.*s"
4415                                        "deletedfilemode%06o"
4416                                        "---a/%.*s"
4417                                        "+++/dev/null",
4418                                        len1, p->one->path,
4419                                        len2, p->two->path,
4420                                        p->one->mode,
4421                                        len1, p->one->path);
4422                else
4423                        len1 = snprintf(buffer, sizeof(buffer),
4424                                        "diff--gita/%.*sb/%.*s"
4425                                        "---a/%.*s"
4426                                        "+++b/%.*s",
4427                                        len1, p->one->path,
4428                                        len2, p->two->path,
4429                                        len1, p->one->path,
4430                                        len2, p->two->path);
4431                git_SHA1_Update(&ctx, buffer, len1);
4432
4433                if (diff_filespec_is_binary(p->one) ||
4434                    diff_filespec_is_binary(p->two)) {
4435                        git_SHA1_Update(&ctx, sha1_to_hex(p->one->sha1), 40);
4436                        git_SHA1_Update(&ctx, sha1_to_hex(p->two->sha1), 40);
4437                        continue;
4438                }
4439
4440                xpp.flags = 0;
4441                xecfg.ctxlen = 3;
4442                xecfg.flags = 0;
4443                if (xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
4444                                  &xpp, &xecfg))
4445                        return error("unable to generate patch-id diff for %s",
4446                                     p->one->path);
4447        }
4448
4449        git_SHA1_Final(sha1, &ctx);
4450        return 0;
4451}
4452
4453int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1)
4454{
4455        struct diff_queue_struct *q = &diff_queued_diff;
4456        int i;
4457        int result = diff_get_patch_id(options, sha1);
4458
4459        for (i = 0; i < q->nr; i++)
4460                diff_free_filepair(q->queue[i]);
4461
4462        free(q->queue);
4463        DIFF_QUEUE_CLEAR(q);
4464
4465        return result;
4466}
4467
4468static int is_summary_empty(const struct diff_queue_struct *q)
4469{
4470        int i;
4471
4472        for (i = 0; i < q->nr; i++) {
4473                const struct diff_filepair *p = q->queue[i];
4474
4475                switch (p->status) {
4476                case DIFF_STATUS_DELETED:
4477                case DIFF_STATUS_ADDED:
4478                case DIFF_STATUS_COPIED:
4479                case DIFF_STATUS_RENAMED:
4480                        return 0;
4481                default:
4482                        if (p->score)
4483                                return 0;
4484                        if (p->one->mode && p->two->mode &&
4485                            p->one->mode != p->two->mode)
4486                                return 0;
4487                        break;
4488                }
4489        }
4490        return 1;
4491}
4492
4493static const char rename_limit_warning[] =
4494"inexact rename detection was skipped due to too many files.";
4495
4496static const char degrade_cc_to_c_warning[] =
4497"only found copies from modified paths due to too many files.";
4498
4499static const char rename_limit_advice[] =
4500"you may want to set your %s variable to at least "
4501"%d and retry the command.";
4502
4503void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc)
4504{
4505        if (degraded_cc)
4506                warning(degrade_cc_to_c_warning);
4507        else if (needed)
4508                warning(rename_limit_warning);
4509        else
4510                return;
4511        if (0 < needed && needed < 32767)
4512                warning(rename_limit_advice, varname, needed);
4513}
4514
4515void diff_flush(struct diff_options *options)
4516{
4517        struct diff_queue_struct *q = &diff_queued_diff;
4518        int i, output_format = options->output_format;
4519        int separator = 0;
4520        int dirstat_by_line = 0;
4521
4522        /*
4523         * Order: raw, stat, summary, patch
4524         * or:    name/name-status/checkdiff (other bits clear)
4525         */
4526        if (!q->nr)
4527                goto free_queue;
4528
4529        if (output_format & (DIFF_FORMAT_RAW |
4530                             DIFF_FORMAT_NAME |
4531                             DIFF_FORMAT_NAME_STATUS |
4532                             DIFF_FORMAT_CHECKDIFF)) {
4533                for (i = 0; i < q->nr; i++) {
4534                        struct diff_filepair *p = q->queue[i];
4535                        if (check_pair_status(p))
4536                                flush_one_pair(p, options);
4537                }
4538                separator++;
4539        }
4540
4541        if (output_format & DIFF_FORMAT_DIRSTAT && DIFF_OPT_TST(options, DIRSTAT_BY_LINE))
4542                dirstat_by_line = 1;
4543
4544        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT) ||
4545            dirstat_by_line) {
4546                struct diffstat_t diffstat;
4547
4548                memset(&diffstat, 0, sizeof(struct diffstat_t));
4549                for (i = 0; i < q->nr; i++) {
4550                        struct diff_filepair *p = q->queue[i];
4551                        if (check_pair_status(p))
4552                                diff_flush_stat(p, options, &diffstat);
4553                }
4554                if (output_format & DIFF_FORMAT_NUMSTAT)
4555                        show_numstat(&diffstat, options);
4556                if (output_format & DIFF_FORMAT_DIFFSTAT)
4557                        show_stats(&diffstat, options);
4558                if (output_format & DIFF_FORMAT_SHORTSTAT)
4559                        show_shortstats(&diffstat, options);
4560                if (output_format & DIFF_FORMAT_DIRSTAT && dirstat_by_line)
4561                        show_dirstat_by_line(&diffstat, options);
4562                free_diffstat_info(&diffstat);
4563                separator++;
4564        }
4565        if ((output_format & DIFF_FORMAT_DIRSTAT) && !dirstat_by_line)
4566                show_dirstat(options);
4567
4568        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
4569                for (i = 0; i < q->nr; i++) {
4570                        diff_summary(options, q->queue[i]);
4571                }
4572                separator++;
4573        }
4574
4575        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
4576            DIFF_OPT_TST(options, EXIT_WITH_STATUS) &&
4577            DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4578                /*
4579                 * run diff_flush_patch for the exit status. setting
4580                 * options->file to /dev/null should be safe, because we
4581                 * aren't supposed to produce any output anyway.
4582                 */
4583                if (options->close_file)
4584                        fclose(options->file);
4585                options->file = fopen("/dev/null", "w");
4586                if (!options->file)
4587                        die_errno("Could not open /dev/null");
4588                options->close_file = 1;
4589                for (i = 0; i < q->nr; i++) {
4590                        struct diff_filepair *p = q->queue[i];
4591                        if (check_pair_status(p))
4592                                diff_flush_patch(p, options);
4593                        if (options->found_changes)
4594                                break;
4595                }
4596        }
4597
4598        if (output_format & DIFF_FORMAT_PATCH) {
4599                if (separator) {
4600                        fprintf(options->file, "%s%c",
4601                                diff_line_prefix(options),
4602                                options->line_termination);
4603                        if (options->stat_sep) {
4604                                /* attach patch instead of inline */
4605                                fputs(options->stat_sep, options->file);
4606                        }
4607                }
4608
4609                for (i = 0; i < q->nr; i++) {
4610                        struct diff_filepair *p = q->queue[i];
4611                        if (check_pair_status(p))
4612                                diff_flush_patch(p, options);
4613                }
4614        }
4615
4616        if (output_format & DIFF_FORMAT_CALLBACK)
4617                options->format_callback(q, options, options->format_callback_data);
4618
4619        for (i = 0; i < q->nr; i++)
4620                diff_free_filepair(q->queue[i]);
4621free_queue:
4622        free(q->queue);
4623        DIFF_QUEUE_CLEAR(q);
4624        if (options->close_file)
4625                fclose(options->file);
4626
4627        /*
4628         * Report the content-level differences with HAS_CHANGES;
4629         * diff_addremove/diff_change does not set the bit when
4630         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
4631         */
4632        if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4633                if (options->found_changes)
4634                        DIFF_OPT_SET(options, HAS_CHANGES);
4635                else
4636                        DIFF_OPT_CLR(options, HAS_CHANGES);
4637        }
4638}
4639
4640static int match_filter(const struct diff_options *options, const struct diff_filepair *p)
4641{
4642        return (((p->status == DIFF_STATUS_MODIFIED) &&
4643                 ((p->score &&
4644                   filter_bit_tst(DIFF_STATUS_FILTER_BROKEN, options)) ||
4645                  (!p->score &&
4646                   filter_bit_tst(DIFF_STATUS_MODIFIED, options)))) ||
4647                ((p->status != DIFF_STATUS_MODIFIED) &&
4648                 filter_bit_tst(p->status, options)));
4649}
4650
4651static void diffcore_apply_filter(struct diff_options *options)
4652{
4653        int i;
4654        struct diff_queue_struct *q = &diff_queued_diff;
4655        struct diff_queue_struct outq;
4656
4657        DIFF_QUEUE_CLEAR(&outq);
4658
4659        if (!options->filter)
4660                return;
4661
4662        if (filter_bit_tst(DIFF_STATUS_FILTER_AON, options)) {
4663                int found;
4664                for (i = found = 0; !found && i < q->nr; i++) {
4665                        if (match_filter(options, q->queue[i]))
4666                                found++;
4667                }
4668                if (found)
4669                        return;
4670
4671                /* otherwise we will clear the whole queue
4672                 * by copying the empty outq at the end of this
4673                 * function, but first clear the current entries
4674                 * in the queue.
4675                 */
4676                for (i = 0; i < q->nr; i++)
4677                        diff_free_filepair(q->queue[i]);
4678        }
4679        else {
4680                /* Only the matching ones */
4681                for (i = 0; i < q->nr; i++) {
4682                        struct diff_filepair *p = q->queue[i];
4683                        if (match_filter(options, p))
4684                                diff_q(&outq, p);
4685                        else
4686                                diff_free_filepair(p);
4687                }
4688        }
4689        free(q->queue);
4690        *q = outq;
4691}
4692
4693/* Check whether two filespecs with the same mode and size are identical */
4694static int diff_filespec_is_identical(struct diff_filespec *one,
4695                                      struct diff_filespec *two)
4696{
4697        if (S_ISGITLINK(one->mode))
4698                return 0;
4699        if (diff_populate_filespec(one, 0))
4700                return 0;
4701        if (diff_populate_filespec(two, 0))
4702                return 0;
4703        return !memcmp(one->data, two->data, one->size);
4704}
4705
4706static int diff_filespec_check_stat_unmatch(struct diff_filepair *p)
4707{
4708        if (p->done_skip_stat_unmatch)
4709                return p->skip_stat_unmatch_result;
4710
4711        p->done_skip_stat_unmatch = 1;
4712        p->skip_stat_unmatch_result = 0;
4713        /*
4714         * 1. Entries that come from stat info dirtiness
4715         *    always have both sides (iow, not create/delete),
4716         *    one side of the object name is unknown, with
4717         *    the same mode and size.  Keep the ones that
4718         *    do not match these criteria.  They have real
4719         *    differences.
4720         *
4721         * 2. At this point, the file is known to be modified,
4722         *    with the same mode and size, and the object
4723         *    name of one side is unknown.  Need to inspect
4724         *    the identical contents.
4725         */
4726        if (!DIFF_FILE_VALID(p->one) || /* (1) */
4727            !DIFF_FILE_VALID(p->two) ||
4728            (p->one->sha1_valid && p->two->sha1_valid) ||
4729            (p->one->mode != p->two->mode) ||
4730            diff_populate_filespec(p->one, CHECK_SIZE_ONLY) ||
4731            diff_populate_filespec(p->two, CHECK_SIZE_ONLY) ||
4732            (p->one->size != p->two->size) ||
4733            !diff_filespec_is_identical(p->one, p->two)) /* (2) */
4734                p->skip_stat_unmatch_result = 1;
4735        return p->skip_stat_unmatch_result;
4736}
4737
4738static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
4739{
4740        int i;
4741        struct diff_queue_struct *q = &diff_queued_diff;
4742        struct diff_queue_struct outq;
4743        DIFF_QUEUE_CLEAR(&outq);
4744
4745        for (i = 0; i < q->nr; i++) {
4746                struct diff_filepair *p = q->queue[i];
4747
4748                if (diff_filespec_check_stat_unmatch(p))
4749                        diff_q(&outq, p);
4750                else {
4751                        /*
4752                         * The caller can subtract 1 from skip_stat_unmatch
4753                         * to determine how many paths were dirty only
4754                         * due to stat info mismatch.
4755                         */
4756                        if (!DIFF_OPT_TST(diffopt, NO_INDEX))
4757                                diffopt->skip_stat_unmatch++;
4758                        diff_free_filepair(p);
4759                }
4760        }
4761        free(q->queue);
4762        *q = outq;
4763}
4764
4765static int diffnamecmp(const void *a_, const void *b_)
4766{
4767        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
4768        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
4769        const char *name_a, *name_b;
4770
4771        name_a = a->one ? a->one->path : a->two->path;
4772        name_b = b->one ? b->one->path : b->two->path;
4773        return strcmp(name_a, name_b);
4774}
4775
4776void diffcore_fix_diff_index(struct diff_options *options)
4777{
4778        struct diff_queue_struct *q = &diff_queued_diff;
4779        qsort(q->queue, q->nr, sizeof(q->queue[0]), diffnamecmp);
4780}
4781
4782void diffcore_std(struct diff_options *options)
4783{
4784        /* NOTE please keep the following in sync with diff_tree_combined() */
4785        if (options->skip_stat_unmatch)
4786                diffcore_skip_stat_unmatch(options);
4787        if (!options->found_follow) {
4788                /* See try_to_follow_renames() in tree-diff.c */
4789                if (options->break_opt != -1)
4790                        diffcore_break(options->break_opt);
4791                if (options->detect_rename)
4792                        diffcore_rename(options);
4793                if (options->break_opt != -1)
4794                        diffcore_merge_broken();
4795        }
4796        if (options->pickaxe)
4797                diffcore_pickaxe(options);
4798        if (options->orderfile)
4799                diffcore_order(options->orderfile);
4800        if (!options->found_follow)
4801                /* See try_to_follow_renames() in tree-diff.c */
4802                diff_resolve_rename_copy();
4803        diffcore_apply_filter(options);
4804
4805        if (diff_queued_diff.nr && !DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4806                DIFF_OPT_SET(options, HAS_CHANGES);
4807        else
4808                DIFF_OPT_CLR(options, HAS_CHANGES);
4809
4810        options->found_follow = 0;
4811}
4812
4813int diff_result_code(struct diff_options *opt, int status)
4814{
4815        int result = 0;
4816
4817        diff_warn_rename_limit("diff.renameLimit",
4818                               opt->needed_rename_limit,
4819                               opt->degraded_cc_to_c);
4820        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4821            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
4822                return status;
4823        if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4824            DIFF_OPT_TST(opt, HAS_CHANGES))
4825                result |= 01;
4826        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
4827            DIFF_OPT_TST(opt, CHECK_FAILED))
4828                result |= 02;
4829        return result;
4830}
4831
4832int diff_can_quit_early(struct diff_options *opt)
4833{
4834        return (DIFF_OPT_TST(opt, QUICK) &&
4835                !opt->filter &&
4836                DIFF_OPT_TST(opt, HAS_CHANGES));
4837}
4838
4839/*
4840 * Shall changes to this submodule be ignored?
4841 *
4842 * Submodule changes can be configured to be ignored separately for each path,
4843 * but that configuration can be overridden from the command line.
4844 */
4845static int is_submodule_ignored(const char *path, struct diff_options *options)
4846{
4847        int ignored = 0;
4848        unsigned orig_flags = options->flags;
4849        if (!DIFF_OPT_TST(options, OVERRIDE_SUBMODULE_CONFIG))
4850                set_diffopt_flags_from_submodule_config(options, path);
4851        if (DIFF_OPT_TST(options, IGNORE_SUBMODULES))
4852                ignored = 1;
4853        options->flags = orig_flags;
4854        return ignored;
4855}
4856
4857void diff_addremove(struct diff_options *options,
4858                    int addremove, unsigned mode,
4859                    const unsigned char *sha1,
4860                    int sha1_valid,
4861                    const char *concatpath, unsigned dirty_submodule)
4862{
4863        struct diff_filespec *one, *two;
4864
4865        if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
4866                return;
4867
4868        /* This may look odd, but it is a preparation for
4869         * feeding "there are unchanged files which should
4870         * not produce diffs, but when you are doing copy
4871         * detection you would need them, so here they are"
4872         * entries to the diff-core.  They will be prefixed
4873         * with something like '=' or '*' (I haven't decided
4874         * which but should not make any difference).
4875         * Feeding the same new and old to diff_change()
4876         * also has the same effect.
4877         * Before the final output happens, they are pruned after
4878         * merged into rename/copy pairs as appropriate.
4879         */
4880        if (DIFF_OPT_TST(options, REVERSE_DIFF))
4881                addremove = (addremove == '+' ? '-' :
4882                             addremove == '-' ? '+' : addremove);
4883
4884        if (options->prefix &&
4885            strncmp(concatpath, options->prefix, options->prefix_length))
4886                return;
4887
4888        one = alloc_filespec(concatpath);
4889        two = alloc_filespec(concatpath);
4890
4891        if (addremove != '+')
4892                fill_filespec(one, sha1, sha1_valid, mode);
4893        if (addremove != '-') {
4894                fill_filespec(two, sha1, sha1_valid, mode);
4895                two->dirty_submodule = dirty_submodule;
4896        }
4897
4898        diff_queue(&diff_queued_diff, one, two);
4899        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4900                DIFF_OPT_SET(options, HAS_CHANGES);
4901}
4902
4903void diff_change(struct diff_options *options,
4904                 unsigned old_mode, unsigned new_mode,
4905                 const unsigned char *old_sha1,
4906                 const unsigned char *new_sha1,
4907                 int old_sha1_valid, int new_sha1_valid,
4908                 const char *concatpath,
4909                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
4910{
4911        struct diff_filespec *one, *two;
4912        struct diff_filepair *p;
4913
4914        if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
4915            is_submodule_ignored(concatpath, options))
4916                return;
4917
4918        if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
4919                unsigned tmp;
4920                const unsigned char *tmp_c;
4921                tmp = old_mode; old_mode = new_mode; new_mode = tmp;
4922                tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
4923                tmp = old_sha1_valid; old_sha1_valid = new_sha1_valid;
4924                        new_sha1_valid = tmp;
4925                tmp = old_dirty_submodule; old_dirty_submodule = new_dirty_submodule;
4926                        new_dirty_submodule = tmp;
4927        }
4928
4929        if (options->prefix &&
4930            strncmp(concatpath, options->prefix, options->prefix_length))
4931                return;
4932
4933        one = alloc_filespec(concatpath);
4934        two = alloc_filespec(concatpath);
4935        fill_filespec(one, old_sha1, old_sha1_valid, old_mode);
4936        fill_filespec(two, new_sha1, new_sha1_valid, new_mode);
4937        one->dirty_submodule = old_dirty_submodule;
4938        two->dirty_submodule = new_dirty_submodule;
4939        p = diff_queue(&diff_queued_diff, one, two);
4940
4941        if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4942                return;
4943
4944        if (DIFF_OPT_TST(options, QUICK) && options->skip_stat_unmatch &&
4945            !diff_filespec_check_stat_unmatch(p))
4946                return;
4947
4948        DIFF_OPT_SET(options, HAS_CHANGES);
4949}
4950
4951struct diff_filepair *diff_unmerge(struct diff_options *options, const char *path)
4952{
4953        struct diff_filepair *pair;
4954        struct diff_filespec *one, *two;
4955
4956        if (options->prefix &&
4957            strncmp(path, options->prefix, options->prefix_length))
4958                return NULL;
4959
4960        one = alloc_filespec(path);
4961        two = alloc_filespec(path);
4962        pair = diff_queue(&diff_queued_diff, one, two);
4963        pair->is_unmerged = 1;
4964        return pair;
4965}
4966
4967static char *run_textconv(const char *pgm, struct diff_filespec *spec,
4968                size_t *outsize)
4969{
4970        struct diff_tempfile *temp;
4971        const char *argv[3];
4972        const char **arg = argv;
4973        struct child_process child = CHILD_PROCESS_INIT;
4974        struct strbuf buf = STRBUF_INIT;
4975        int err = 0;
4976
4977        temp = prepare_temp_file(spec->path, spec);
4978        *arg++ = pgm;
4979        *arg++ = temp->name;
4980        *arg = NULL;
4981
4982        child.use_shell = 1;
4983        child.argv = argv;
4984        child.out = -1;
4985        if (start_command(&child)) {
4986                remove_tempfile();
4987                return NULL;
4988        }
4989
4990        if (strbuf_read(&buf, child.out, 0) < 0)
4991                err = error("error reading from textconv command '%s'", pgm);
4992        close(child.out);
4993
4994        if (finish_command(&child) || err) {
4995                strbuf_release(&buf);
4996                remove_tempfile();
4997                return NULL;
4998        }
4999        remove_tempfile();
5000
5001        return strbuf_detach(&buf, outsize);
5002}
5003
5004size_t fill_textconv(struct userdiff_driver *driver,
5005                     struct diff_filespec *df,
5006                     char **outbuf)
5007{
5008        size_t size;
5009
5010        if (!driver || !driver->textconv) {
5011                if (!DIFF_FILE_VALID(df)) {
5012                        *outbuf = "";
5013                        return 0;
5014                }
5015                if (diff_populate_filespec(df, 0))
5016                        die("unable to read files to diff");
5017                *outbuf = df->data;
5018                return df->size;
5019        }
5020
5021        if (driver->textconv_cache && df->sha1_valid) {
5022                *outbuf = notes_cache_get(driver->textconv_cache, df->sha1,
5023                                          &size);
5024                if (*outbuf)
5025                        return size;
5026        }
5027
5028        *outbuf = run_textconv(driver->textconv, df, &size);
5029        if (!*outbuf)
5030                die("unable to read files to diff");
5031
5032        if (driver->textconv_cache && df->sha1_valid) {
5033                /* ignore errors, as we might be in a readonly repository */
5034                notes_cache_put(driver->textconv_cache, df->sha1, *outbuf,
5035                                size);
5036                /*
5037                 * we could save up changes and flush them all at the end,
5038                 * but we would need an extra call after all diffing is done.
5039                 * Since generating a cache entry is the slow path anyway,
5040                 * this extra overhead probably isn't a big deal.
5041                 */
5042                notes_cache_write(driver->textconv_cache);
5043        }
5044
5045        return size;
5046}
5047
5048void setup_diff_pager(struct diff_options *opt)
5049{
5050        /*
5051         * If the user asked for our exit code, then either they want --quiet
5052         * or --exit-code. We should definitely not bother with a pager in the
5053         * former case, as we will generate no output. Since we still properly
5054         * report our exit code even when a pager is run, we _could_ run a
5055         * pager with --exit-code. But since we have not done so historically,
5056         * and because it is easy to find people oneline advising "git diff
5057         * --exit-code" in hooks and other scripts, we do not do so.
5058         */
5059        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
5060            check_pager_config("diff") != 0)
5061                setup_pager();
5062}