56d7bfded6a8cc06f635a50898f2747fe1eac9b1
   1/*
   2 * Copyright (C) 2005 Junio C Hamano
   3 */
   4#include "cache.h"
   5#include "config.h"
   6#include "tempfile.h"
   7#include "quote.h"
   8#include "diff.h"
   9#include "diffcore.h"
  10#include "delta.h"
  11#include "xdiff-interface.h"
  12#include "color.h"
  13#include "attr.h"
  14#include "run-command.h"
  15#include "utf8.h"
  16#include "userdiff.h"
  17#include "submodule-config.h"
  18#include "submodule.h"
  19#include "hashmap.h"
  20#include "ll-merge.h"
  21#include "string-list.h"
  22#include "argv-array.h"
  23#include "graph.h"
  24#include "packfile.h"
  25
  26#ifdef NO_FAST_WORKING_DIRECTORY
  27#define FAST_WORKING_DIRECTORY 0
  28#else
  29#define FAST_WORKING_DIRECTORY 1
  30#endif
  31
  32static int diff_detect_rename_default;
  33static int diff_indent_heuristic = 1;
  34static int diff_rename_limit_default = 400;
  35static int diff_suppress_blank_empty;
  36static int diff_use_color_default = -1;
  37static int diff_color_moved_default;
  38static int diff_context_default = 3;
  39static int diff_interhunk_context_default;
  40static const char *diff_word_regex_cfg;
  41static const char *external_diff_cmd_cfg;
  42static const char *diff_order_file_cfg;
  43int diff_auto_refresh_index = 1;
  44static int diff_mnemonic_prefix;
  45static int diff_no_prefix;
  46static int diff_stat_graph_width;
  47static int diff_dirstat_permille_default = 30;
  48static struct diff_options default_diff_options;
  49static long diff_algorithm;
  50static unsigned ws_error_highlight_default = WSEH_NEW;
  51
  52static char diff_colors[][COLOR_MAXLEN] = {
  53        GIT_COLOR_RESET,
  54        GIT_COLOR_NORMAL,       /* CONTEXT */
  55        GIT_COLOR_BOLD,         /* METAINFO */
  56        GIT_COLOR_CYAN,         /* FRAGINFO */
  57        GIT_COLOR_RED,          /* OLD */
  58        GIT_COLOR_GREEN,        /* NEW */
  59        GIT_COLOR_YELLOW,       /* COMMIT */
  60        GIT_COLOR_BG_RED,       /* WHITESPACE */
  61        GIT_COLOR_NORMAL,       /* FUNCINFO */
  62        GIT_COLOR_BOLD_MAGENTA, /* OLD_MOVED */
  63        GIT_COLOR_BOLD_BLUE,    /* OLD_MOVED ALTERNATIVE */
  64        GIT_COLOR_FAINT,        /* OLD_MOVED_DIM */
  65        GIT_COLOR_FAINT_ITALIC, /* OLD_MOVED_ALTERNATIVE_DIM */
  66        GIT_COLOR_BOLD_CYAN,    /* NEW_MOVED */
  67        GIT_COLOR_BOLD_YELLOW,  /* NEW_MOVED ALTERNATIVE */
  68        GIT_COLOR_FAINT,        /* NEW_MOVED_DIM */
  69        GIT_COLOR_FAINT_ITALIC, /* NEW_MOVED_ALTERNATIVE_DIM */
  70};
  71
  72static const char *color_diff_slots[] = {
  73        [DIFF_CONTEXT]                = "context",
  74        [DIFF_METAINFO]               = "meta",
  75        [DIFF_FRAGINFO]               = "frag",
  76        [DIFF_FILE_OLD]               = "old",
  77        [DIFF_FILE_NEW]               = "new",
  78        [DIFF_COMMIT]                 = "commit",
  79        [DIFF_WHITESPACE]             = "whitespace",
  80        [DIFF_FUNCINFO]               = "func",
  81        [DIFF_FILE_OLD_MOVED]         = "oldMoved",
  82        [DIFF_FILE_OLD_MOVED_ALT]     = "oldMovedAlternative",
  83        [DIFF_FILE_OLD_MOVED_DIM]     = "oldMovedDimmed",
  84        [DIFF_FILE_OLD_MOVED_ALT_DIM] = "oldMovedAlternativeDimmed",
  85        [DIFF_FILE_NEW_MOVED]         = "newMoved",
  86        [DIFF_FILE_NEW_MOVED_ALT]     = "newMovedAlternative",
  87        [DIFF_FILE_NEW_MOVED_DIM]     = "newMovedDimmed",
  88        [DIFF_FILE_NEW_MOVED_ALT_DIM] = "newMovedAlternativeDimmed",
  89};
  90
  91static NORETURN void die_want_option(const char *option_name)
  92{
  93        die(_("option '%s' requires a value"), option_name);
  94}
  95
  96static int parse_diff_color_slot(const char *var)
  97{
  98        if (!strcasecmp(var, "plain"))
  99                return DIFF_CONTEXT;
 100        return LOOKUP_CONFIG(color_diff_slots, var);
 101}
 102
 103static int parse_dirstat_params(struct diff_options *options, const char *params_string,
 104                                struct strbuf *errmsg)
 105{
 106        char *params_copy = xstrdup(params_string);
 107        struct string_list params = STRING_LIST_INIT_NODUP;
 108        int ret = 0;
 109        int i;
 110
 111        if (*params_copy)
 112                string_list_split_in_place(&params, params_copy, ',', -1);
 113        for (i = 0; i < params.nr; i++) {
 114                const char *p = params.items[i].string;
 115                if (!strcmp(p, "changes")) {
 116                        options->flags.dirstat_by_line = 0;
 117                        options->flags.dirstat_by_file = 0;
 118                } else if (!strcmp(p, "lines")) {
 119                        options->flags.dirstat_by_line = 1;
 120                        options->flags.dirstat_by_file = 0;
 121                } else if (!strcmp(p, "files")) {
 122                        options->flags.dirstat_by_line = 0;
 123                        options->flags.dirstat_by_file = 1;
 124                } else if (!strcmp(p, "noncumulative")) {
 125                        options->flags.dirstat_cumulative = 0;
 126                } else if (!strcmp(p, "cumulative")) {
 127                        options->flags.dirstat_cumulative = 1;
 128                } else if (isdigit(*p)) {
 129                        char *end;
 130                        int permille = strtoul(p, &end, 10) * 10;
 131                        if (*end == '.' && isdigit(*++end)) {
 132                                /* only use first digit */
 133                                permille += *end - '0';
 134                                /* .. and ignore any further digits */
 135                                while (isdigit(*++end))
 136                                        ; /* nothing */
 137                        }
 138                        if (!*end)
 139                                options->dirstat_permille = permille;
 140                        else {
 141                                strbuf_addf(errmsg, _("  Failed to parse dirstat cut-off percentage '%s'\n"),
 142                                            p);
 143                                ret++;
 144                        }
 145                } else {
 146                        strbuf_addf(errmsg, _("  Unknown dirstat parameter '%s'\n"), p);
 147                        ret++;
 148                }
 149
 150        }
 151        string_list_clear(&params, 0);
 152        free(params_copy);
 153        return ret;
 154}
 155
 156static int parse_submodule_params(struct diff_options *options, const char *value)
 157{
 158        if (!strcmp(value, "log"))
 159                options->submodule_format = DIFF_SUBMODULE_LOG;
 160        else if (!strcmp(value, "short"))
 161                options->submodule_format = DIFF_SUBMODULE_SHORT;
 162        else if (!strcmp(value, "diff"))
 163                options->submodule_format = DIFF_SUBMODULE_INLINE_DIFF;
 164        else
 165                return -1;
 166        return 0;
 167}
 168
 169static int git_config_rename(const char *var, const char *value)
 170{
 171        if (!value)
 172                return DIFF_DETECT_RENAME;
 173        if (!strcasecmp(value, "copies") || !strcasecmp(value, "copy"))
 174                return  DIFF_DETECT_COPY;
 175        return git_config_bool(var,value) ? DIFF_DETECT_RENAME : 0;
 176}
 177
 178long parse_algorithm_value(const char *value)
 179{
 180        if (!value)
 181                return -1;
 182        else if (!strcasecmp(value, "myers") || !strcasecmp(value, "default"))
 183                return 0;
 184        else if (!strcasecmp(value, "minimal"))
 185                return XDF_NEED_MINIMAL;
 186        else if (!strcasecmp(value, "patience"))
 187                return XDF_PATIENCE_DIFF;
 188        else if (!strcasecmp(value, "histogram"))
 189                return XDF_HISTOGRAM_DIFF;
 190        return -1;
 191}
 192
 193static int parse_one_token(const char **arg, const char *token)
 194{
 195        const char *rest;
 196        if (skip_prefix(*arg, token, &rest) && (!*rest || *rest == ',')) {
 197                *arg = rest;
 198                return 1;
 199        }
 200        return 0;
 201}
 202
 203static int parse_ws_error_highlight(const char *arg)
 204{
 205        const char *orig_arg = arg;
 206        unsigned val = 0;
 207
 208        while (*arg) {
 209                if (parse_one_token(&arg, "none"))
 210                        val = 0;
 211                else if (parse_one_token(&arg, "default"))
 212                        val = WSEH_NEW;
 213                else if (parse_one_token(&arg, "all"))
 214                        val = WSEH_NEW | WSEH_OLD | WSEH_CONTEXT;
 215                else if (parse_one_token(&arg, "new"))
 216                        val |= WSEH_NEW;
 217                else if (parse_one_token(&arg, "old"))
 218                        val |= WSEH_OLD;
 219                else if (parse_one_token(&arg, "context"))
 220                        val |= WSEH_CONTEXT;
 221                else {
 222                        return -1 - (int)(arg - orig_arg);
 223                }
 224                if (*arg)
 225                        arg++;
 226        }
 227        return val;
 228}
 229
 230/*
 231 * These are to give UI layer defaults.
 232 * The core-level commands such as git-diff-files should
 233 * never be affected by the setting of diff.renames
 234 * the user happens to have in the configuration file.
 235 */
 236void init_diff_ui_defaults(void)
 237{
 238        diff_detect_rename_default = DIFF_DETECT_RENAME;
 239}
 240
 241int git_diff_heuristic_config(const char *var, const char *value, void *cb)
 242{
 243        if (!strcmp(var, "diff.indentheuristic"))
 244                diff_indent_heuristic = git_config_bool(var, value);
 245        return 0;
 246}
 247
 248static int parse_color_moved(const char *arg)
 249{
 250        switch (git_parse_maybe_bool(arg)) {
 251        case 0:
 252                return COLOR_MOVED_NO;
 253        case 1:
 254                return COLOR_MOVED_DEFAULT;
 255        default:
 256                break;
 257        }
 258
 259        if (!strcmp(arg, "no"))
 260                return COLOR_MOVED_NO;
 261        else if (!strcmp(arg, "plain"))
 262                return COLOR_MOVED_PLAIN;
 263        else if (!strcmp(arg, "zebra"))
 264                return COLOR_MOVED_ZEBRA;
 265        else if (!strcmp(arg, "default"))
 266                return COLOR_MOVED_DEFAULT;
 267        else if (!strcmp(arg, "dimmed_zebra"))
 268                return COLOR_MOVED_ZEBRA_DIM;
 269        else
 270                return error(_("color moved setting must be one of 'no', 'default', 'zebra', 'dimmed_zebra', 'plain'"));
 271}
 272
 273int git_diff_ui_config(const char *var, const char *value, void *cb)
 274{
 275        if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
 276                diff_use_color_default = git_config_colorbool(var, value);
 277                return 0;
 278        }
 279        if (!strcmp(var, "diff.colormoved")) {
 280                int cm = parse_color_moved(value);
 281                if (cm < 0)
 282                        return -1;
 283                diff_color_moved_default = cm;
 284                return 0;
 285        }
 286        if (!strcmp(var, "diff.context")) {
 287                diff_context_default = git_config_int(var, value);
 288                if (diff_context_default < 0)
 289                        return -1;
 290                return 0;
 291        }
 292        if (!strcmp(var, "diff.interhunkcontext")) {
 293                diff_interhunk_context_default = git_config_int(var, value);
 294                if (diff_interhunk_context_default < 0)
 295                        return -1;
 296                return 0;
 297        }
 298        if (!strcmp(var, "diff.renames")) {
 299                diff_detect_rename_default = git_config_rename(var, value);
 300                return 0;
 301        }
 302        if (!strcmp(var, "diff.autorefreshindex")) {
 303                diff_auto_refresh_index = git_config_bool(var, value);
 304                return 0;
 305        }
 306        if (!strcmp(var, "diff.mnemonicprefix")) {
 307                diff_mnemonic_prefix = git_config_bool(var, value);
 308                return 0;
 309        }
 310        if (!strcmp(var, "diff.noprefix")) {
 311                diff_no_prefix = git_config_bool(var, value);
 312                return 0;
 313        }
 314        if (!strcmp(var, "diff.statgraphwidth")) {
 315                diff_stat_graph_width = git_config_int(var, value);
 316                return 0;
 317        }
 318        if (!strcmp(var, "diff.external"))
 319                return git_config_string(&external_diff_cmd_cfg, var, value);
 320        if (!strcmp(var, "diff.wordregex"))
 321                return git_config_string(&diff_word_regex_cfg, var, value);
 322        if (!strcmp(var, "diff.orderfile"))
 323                return git_config_pathname(&diff_order_file_cfg, var, value);
 324
 325        if (!strcmp(var, "diff.ignoresubmodules"))
 326                handle_ignore_submodules_arg(&default_diff_options, value);
 327
 328        if (!strcmp(var, "diff.submodule")) {
 329                if (parse_submodule_params(&default_diff_options, value))
 330                        warning(_("Unknown value for 'diff.submodule' config variable: '%s'"),
 331                                value);
 332                return 0;
 333        }
 334
 335        if (!strcmp(var, "diff.algorithm")) {
 336                diff_algorithm = parse_algorithm_value(value);
 337                if (diff_algorithm < 0)
 338                        return -1;
 339                return 0;
 340        }
 341
 342        if (!strcmp(var, "diff.wserrorhighlight")) {
 343                int val = parse_ws_error_highlight(value);
 344                if (val < 0)
 345                        return -1;
 346                ws_error_highlight_default = val;
 347                return 0;
 348        }
 349
 350        if (git_color_config(var, value, cb) < 0)
 351                return -1;
 352
 353        return git_diff_basic_config(var, value, cb);
 354}
 355
 356int git_diff_basic_config(const char *var, const char *value, void *cb)
 357{
 358        const char *name;
 359
 360        if (!strcmp(var, "diff.renamelimit")) {
 361                diff_rename_limit_default = git_config_int(var, value);
 362                return 0;
 363        }
 364
 365        if (userdiff_config(var, value) < 0)
 366                return -1;
 367
 368        if (skip_prefix(var, "diff.color.", &name) ||
 369            skip_prefix(var, "color.diff.", &name)) {
 370                int slot = parse_diff_color_slot(name);
 371                if (slot < 0)
 372                        return 0;
 373                if (!value)
 374                        return config_error_nonbool(var);
 375                return color_parse(value, diff_colors[slot]);
 376        }
 377
 378        /* like GNU diff's --suppress-blank-empty option  */
 379        if (!strcmp(var, "diff.suppressblankempty") ||
 380                        /* for backwards compatibility */
 381                        !strcmp(var, "diff.suppress-blank-empty")) {
 382                diff_suppress_blank_empty = git_config_bool(var, value);
 383                return 0;
 384        }
 385
 386        if (!strcmp(var, "diff.dirstat")) {
 387                struct strbuf errmsg = STRBUF_INIT;
 388                default_diff_options.dirstat_permille = diff_dirstat_permille_default;
 389                if (parse_dirstat_params(&default_diff_options, value, &errmsg))
 390                        warning(_("Found errors in 'diff.dirstat' config variable:\n%s"),
 391                                errmsg.buf);
 392                strbuf_release(&errmsg);
 393                diff_dirstat_permille_default = default_diff_options.dirstat_permille;
 394                return 0;
 395        }
 396
 397        if (git_diff_heuristic_config(var, value, cb) < 0)
 398                return -1;
 399
 400        return git_default_config(var, value, cb);
 401}
 402
 403static char *quote_two(const char *one, const char *two)
 404{
 405        int need_one = quote_c_style(one, NULL, NULL, 1);
 406        int need_two = quote_c_style(two, NULL, NULL, 1);
 407        struct strbuf res = STRBUF_INIT;
 408
 409        if (need_one + need_two) {
 410                strbuf_addch(&res, '"');
 411                quote_c_style(one, &res, NULL, 1);
 412                quote_c_style(two, &res, NULL, 1);
 413                strbuf_addch(&res, '"');
 414        } else {
 415                strbuf_addstr(&res, one);
 416                strbuf_addstr(&res, two);
 417        }
 418        return strbuf_detach(&res, NULL);
 419}
 420
 421static const char *external_diff(void)
 422{
 423        static const char *external_diff_cmd = NULL;
 424        static int done_preparing = 0;
 425
 426        if (done_preparing)
 427                return external_diff_cmd;
 428        external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
 429        if (!external_diff_cmd)
 430                external_diff_cmd = external_diff_cmd_cfg;
 431        done_preparing = 1;
 432        return external_diff_cmd;
 433}
 434
 435/*
 436 * Keep track of files used for diffing. Sometimes such an entry
 437 * refers to a temporary file, sometimes to an existing file, and
 438 * sometimes to "/dev/null".
 439 */
 440static struct diff_tempfile {
 441        /*
 442         * filename external diff should read from, or NULL if this
 443         * entry is currently not in use:
 444         */
 445        const char *name;
 446
 447        char hex[GIT_MAX_HEXSZ + 1];
 448        char mode[10];
 449
 450        /*
 451         * If this diff_tempfile instance refers to a temporary file,
 452         * this tempfile object is used to manage its lifetime.
 453         */
 454        struct tempfile *tempfile;
 455} diff_temp[2];
 456
 457struct emit_callback {
 458        int color_diff;
 459        unsigned ws_rule;
 460        int blank_at_eof_in_preimage;
 461        int blank_at_eof_in_postimage;
 462        int lno_in_preimage;
 463        int lno_in_postimage;
 464        const char **label_path;
 465        struct diff_words_data *diff_words;
 466        struct diff_options *opt;
 467        struct strbuf *header;
 468};
 469
 470static int count_lines(const char *data, int size)
 471{
 472        int count, ch, completely_empty = 1, nl_just_seen = 0;
 473        count = 0;
 474        while (0 < size--) {
 475                ch = *data++;
 476                if (ch == '\n') {
 477                        count++;
 478                        nl_just_seen = 1;
 479                        completely_empty = 0;
 480                }
 481                else {
 482                        nl_just_seen = 0;
 483                        completely_empty = 0;
 484                }
 485        }
 486        if (completely_empty)
 487                return 0;
 488        if (!nl_just_seen)
 489                count++; /* no trailing newline */
 490        return count;
 491}
 492
 493static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
 494{
 495        if (!DIFF_FILE_VALID(one)) {
 496                mf->ptr = (char *)""; /* does not matter */
 497                mf->size = 0;
 498                return 0;
 499        }
 500        else if (diff_populate_filespec(one, 0))
 501                return -1;
 502
 503        mf->ptr = one->data;
 504        mf->size = one->size;
 505        return 0;
 506}
 507
 508/* like fill_mmfile, but only for size, so we can avoid retrieving blob */
 509static unsigned long diff_filespec_size(struct diff_filespec *one)
 510{
 511        if (!DIFF_FILE_VALID(one))
 512                return 0;
 513        diff_populate_filespec(one, CHECK_SIZE_ONLY);
 514        return one->size;
 515}
 516
 517static int count_trailing_blank(mmfile_t *mf, unsigned ws_rule)
 518{
 519        char *ptr = mf->ptr;
 520        long size = mf->size;
 521        int cnt = 0;
 522
 523        if (!size)
 524                return cnt;
 525        ptr += size - 1; /* pointing at the very end */
 526        if (*ptr != '\n')
 527                ; /* incomplete line */
 528        else
 529                ptr--; /* skip the last LF */
 530        while (mf->ptr < ptr) {
 531                char *prev_eol;
 532                for (prev_eol = ptr; mf->ptr <= prev_eol; prev_eol--)
 533                        if (*prev_eol == '\n')
 534                                break;
 535                if (!ws_blank_line(prev_eol + 1, ptr - prev_eol, ws_rule))
 536                        break;
 537                cnt++;
 538                ptr = prev_eol - 1;
 539        }
 540        return cnt;
 541}
 542
 543static void check_blank_at_eof(mmfile_t *mf1, mmfile_t *mf2,
 544                               struct emit_callback *ecbdata)
 545{
 546        int l1, l2, at;
 547        unsigned ws_rule = ecbdata->ws_rule;
 548        l1 = count_trailing_blank(mf1, ws_rule);
 549        l2 = count_trailing_blank(mf2, ws_rule);
 550        if (l2 <= l1) {
 551                ecbdata->blank_at_eof_in_preimage = 0;
 552                ecbdata->blank_at_eof_in_postimage = 0;
 553                return;
 554        }
 555        at = count_lines(mf1->ptr, mf1->size);
 556        ecbdata->blank_at_eof_in_preimage = (at - l1) + 1;
 557
 558        at = count_lines(mf2->ptr, mf2->size);
 559        ecbdata->blank_at_eof_in_postimage = (at - l2) + 1;
 560}
 561
 562static void emit_line_0(struct diff_options *o, const char *set, const char *reset,
 563                        int first, const char *line, int len)
 564{
 565        int has_trailing_newline, has_trailing_carriage_return;
 566        int nofirst;
 567        FILE *file = o->file;
 568
 569        fputs(diff_line_prefix(o), file);
 570
 571        if (len == 0) {
 572                has_trailing_newline = (first == '\n');
 573                has_trailing_carriage_return = (!has_trailing_newline &&
 574                                                (first == '\r'));
 575                nofirst = has_trailing_newline || has_trailing_carriage_return;
 576        } else {
 577                has_trailing_newline = (len > 0 && line[len-1] == '\n');
 578                if (has_trailing_newline)
 579                        len--;
 580                has_trailing_carriage_return = (len > 0 && line[len-1] == '\r');
 581                if (has_trailing_carriage_return)
 582                        len--;
 583                nofirst = 0;
 584        }
 585
 586        if (len || !nofirst) {
 587                fputs(set, file);
 588                if (!nofirst)
 589                        fputc(first, file);
 590                fwrite(line, len, 1, file);
 591                fputs(reset, file);
 592        }
 593        if (has_trailing_carriage_return)
 594                fputc('\r', file);
 595        if (has_trailing_newline)
 596                fputc('\n', file);
 597}
 598
 599static void emit_line(struct diff_options *o, const char *set, const char *reset,
 600                      const char *line, int len)
 601{
 602        emit_line_0(o, set, reset, line[0], line+1, len-1);
 603}
 604
 605enum diff_symbol {
 606        DIFF_SYMBOL_BINARY_DIFF_HEADER,
 607        DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA,
 608        DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL,
 609        DIFF_SYMBOL_BINARY_DIFF_BODY,
 610        DIFF_SYMBOL_BINARY_DIFF_FOOTER,
 611        DIFF_SYMBOL_STATS_SUMMARY_NO_FILES,
 612        DIFF_SYMBOL_STATS_SUMMARY_ABBREV,
 613        DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES,
 614        DIFF_SYMBOL_STATS_LINE,
 615        DIFF_SYMBOL_WORD_DIFF,
 616        DIFF_SYMBOL_STAT_SEP,
 617        DIFF_SYMBOL_SUMMARY,
 618        DIFF_SYMBOL_SUBMODULE_ADD,
 619        DIFF_SYMBOL_SUBMODULE_DEL,
 620        DIFF_SYMBOL_SUBMODULE_UNTRACKED,
 621        DIFF_SYMBOL_SUBMODULE_MODIFIED,
 622        DIFF_SYMBOL_SUBMODULE_HEADER,
 623        DIFF_SYMBOL_SUBMODULE_ERROR,
 624        DIFF_SYMBOL_SUBMODULE_PIPETHROUGH,
 625        DIFF_SYMBOL_REWRITE_DIFF,
 626        DIFF_SYMBOL_BINARY_FILES,
 627        DIFF_SYMBOL_HEADER,
 628        DIFF_SYMBOL_FILEPAIR_PLUS,
 629        DIFF_SYMBOL_FILEPAIR_MINUS,
 630        DIFF_SYMBOL_WORDS_PORCELAIN,
 631        DIFF_SYMBOL_WORDS,
 632        DIFF_SYMBOL_CONTEXT,
 633        DIFF_SYMBOL_CONTEXT_INCOMPLETE,
 634        DIFF_SYMBOL_PLUS,
 635        DIFF_SYMBOL_MINUS,
 636        DIFF_SYMBOL_NO_LF_EOF,
 637        DIFF_SYMBOL_CONTEXT_FRAGINFO,
 638        DIFF_SYMBOL_CONTEXT_MARKER,
 639        DIFF_SYMBOL_SEPARATOR
 640};
 641/*
 642 * Flags for content lines:
 643 * 0..12 are whitespace rules
 644 * 13-15 are WSEH_NEW | WSEH_OLD | WSEH_CONTEXT
 645 * 16 is marking if the line is blank at EOF
 646 */
 647#define DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF      (1<<16)
 648#define DIFF_SYMBOL_MOVED_LINE                  (1<<17)
 649#define DIFF_SYMBOL_MOVED_LINE_ALT              (1<<18)
 650#define DIFF_SYMBOL_MOVED_LINE_UNINTERESTING    (1<<19)
 651#define DIFF_SYMBOL_CONTENT_WS_MASK (WSEH_NEW | WSEH_OLD | WSEH_CONTEXT | WS_RULE_MASK)
 652
 653/*
 654 * This struct is used when we need to buffer the output of the diff output.
 655 *
 656 * NEEDSWORK: Instead of storing a copy of the line, add an offset pointer
 657 * into the pre/post image file. This pointer could be a union with the
 658 * line pointer. By storing an offset into the file instead of the literal line,
 659 * we can decrease the memory footprint for the buffered output. At first we
 660 * may want to only have indirection for the content lines, but we could also
 661 * enhance the state for emitting prefabricated lines, e.g. the similarity
 662 * score line or hunk/file headers would only need to store a number or path
 663 * and then the output can be constructed later on depending on state.
 664 */
 665struct emitted_diff_symbol {
 666        const char *line;
 667        int len;
 668        int flags;
 669        enum diff_symbol s;
 670};
 671#define EMITTED_DIFF_SYMBOL_INIT {NULL}
 672
 673struct emitted_diff_symbols {
 674        struct emitted_diff_symbol *buf;
 675        int nr, alloc;
 676};
 677#define EMITTED_DIFF_SYMBOLS_INIT {NULL, 0, 0}
 678
 679static void append_emitted_diff_symbol(struct diff_options *o,
 680                                       struct emitted_diff_symbol *e)
 681{
 682        struct emitted_diff_symbol *f;
 683
 684        ALLOC_GROW(o->emitted_symbols->buf,
 685                   o->emitted_symbols->nr + 1,
 686                   o->emitted_symbols->alloc);
 687        f = &o->emitted_symbols->buf[o->emitted_symbols->nr++];
 688
 689        memcpy(f, e, sizeof(struct emitted_diff_symbol));
 690        f->line = e->line ? xmemdupz(e->line, e->len) : NULL;
 691}
 692
 693struct moved_entry {
 694        struct hashmap_entry ent;
 695        const struct emitted_diff_symbol *es;
 696        struct moved_entry *next_line;
 697};
 698
 699static int moved_entry_cmp(const struct diff_options *diffopt,
 700                           const struct moved_entry *a,
 701                           const struct moved_entry *b,
 702                           const void *keydata)
 703{
 704        return !xdiff_compare_lines(a->es->line, a->es->len,
 705                                    b->es->line, b->es->len,
 706                                    diffopt->xdl_opts);
 707}
 708
 709static struct moved_entry *prepare_entry(struct diff_options *o,
 710                                         int line_no)
 711{
 712        struct moved_entry *ret = xmalloc(sizeof(*ret));
 713        struct emitted_diff_symbol *l = &o->emitted_symbols->buf[line_no];
 714
 715        ret->ent.hash = xdiff_hash_string(l->line, l->len, o->xdl_opts);
 716        ret->es = l;
 717        ret->next_line = NULL;
 718
 719        return ret;
 720}
 721
 722static void add_lines_to_move_detection(struct diff_options *o,
 723                                        struct hashmap *add_lines,
 724                                        struct hashmap *del_lines)
 725{
 726        struct moved_entry *prev_line = NULL;
 727
 728        int n;
 729        for (n = 0; n < o->emitted_symbols->nr; n++) {
 730                struct hashmap *hm;
 731                struct moved_entry *key;
 732
 733                switch (o->emitted_symbols->buf[n].s) {
 734                case DIFF_SYMBOL_PLUS:
 735                        hm = add_lines;
 736                        break;
 737                case DIFF_SYMBOL_MINUS:
 738                        hm = del_lines;
 739                        break;
 740                default:
 741                        prev_line = NULL;
 742                        continue;
 743                }
 744
 745                key = prepare_entry(o, n);
 746                if (prev_line && prev_line->es->s == o->emitted_symbols->buf[n].s)
 747                        prev_line->next_line = key;
 748
 749                hashmap_add(hm, key);
 750                prev_line = key;
 751        }
 752}
 753
 754static int shrink_potential_moved_blocks(struct moved_entry **pmb,
 755                                         int pmb_nr)
 756{
 757        int lp, rp;
 758
 759        /* Shrink the set of potential block to the remaining running */
 760        for (lp = 0, rp = pmb_nr - 1; lp <= rp;) {
 761                while (lp < pmb_nr && pmb[lp])
 762                        lp++;
 763                /* lp points at the first NULL now */
 764
 765                while (rp > -1 && !pmb[rp])
 766                        rp--;
 767                /* rp points at the last non-NULL */
 768
 769                if (lp < pmb_nr && rp > -1 && lp < rp) {
 770                        pmb[lp] = pmb[rp];
 771                        pmb[rp] = NULL;
 772                        rp--;
 773                        lp++;
 774                }
 775        }
 776
 777        /* Remember the number of running sets */
 778        return rp + 1;
 779}
 780
 781/*
 782 * If o->color_moved is COLOR_MOVED_PLAIN, this function does nothing.
 783 *
 784 * Otherwise, if the last block has fewer alphanumeric characters than
 785 * COLOR_MOVED_MIN_ALNUM_COUNT, unset DIFF_SYMBOL_MOVED_LINE on all lines in
 786 * that block.
 787 *
 788 * The last block consists of the (n - block_length)'th line up to but not
 789 * including the nth line.
 790 *
 791 * NEEDSWORK: This uses the same heuristic as blame_entry_score() in blame.c.
 792 * Think of a way to unify them.
 793 */
 794static void adjust_last_block(struct diff_options *o, int n, int block_length)
 795{
 796        int i, alnum_count = 0;
 797        if (o->color_moved == COLOR_MOVED_PLAIN)
 798                return;
 799        for (i = 1; i < block_length + 1; i++) {
 800                const char *c = o->emitted_symbols->buf[n - i].line;
 801                for (; *c; c++) {
 802                        if (!isalnum(*c))
 803                                continue;
 804                        alnum_count++;
 805                        if (alnum_count >= COLOR_MOVED_MIN_ALNUM_COUNT)
 806                                return;
 807                }
 808        }
 809        for (i = 1; i < block_length + 1; i++)
 810                o->emitted_symbols->buf[n - i].flags &= ~DIFF_SYMBOL_MOVED_LINE;
 811}
 812
 813/* Find blocks of moved code, delegate actual coloring decision to helper */
 814static void mark_color_as_moved(struct diff_options *o,
 815                                struct hashmap *add_lines,
 816                                struct hashmap *del_lines)
 817{
 818        struct moved_entry **pmb = NULL; /* potentially moved blocks */
 819        int pmb_nr = 0, pmb_alloc = 0;
 820        int n, flipped_block = 1, block_length = 0;
 821
 822
 823        for (n = 0; n < o->emitted_symbols->nr; n++) {
 824                struct hashmap *hm = NULL;
 825                struct moved_entry *key;
 826                struct moved_entry *match = NULL;
 827                struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
 828                int i;
 829
 830                switch (l->s) {
 831                case DIFF_SYMBOL_PLUS:
 832                        hm = del_lines;
 833                        key = prepare_entry(o, n);
 834                        match = hashmap_get(hm, key, o);
 835                        free(key);
 836                        break;
 837                case DIFF_SYMBOL_MINUS:
 838                        hm = add_lines;
 839                        key = prepare_entry(o, n);
 840                        match = hashmap_get(hm, key, o);
 841                        free(key);
 842                        break;
 843                default:
 844                        flipped_block = 1;
 845                }
 846
 847                if (!match) {
 848                        adjust_last_block(o, n, block_length);
 849                        pmb_nr = 0;
 850                        block_length = 0;
 851                        continue;
 852                }
 853
 854                l->flags |= DIFF_SYMBOL_MOVED_LINE;
 855
 856                if (o->color_moved == COLOR_MOVED_PLAIN)
 857                        continue;
 858
 859                /* Check any potential block runs, advance each or nullify */
 860                for (i = 0; i < pmb_nr; i++) {
 861                        struct moved_entry *p = pmb[i];
 862                        struct moved_entry *pnext = (p && p->next_line) ?
 863                                        p->next_line : NULL;
 864                        if (pnext && !hm->cmpfn(o, pnext, match, NULL)) {
 865                                pmb[i] = p->next_line;
 866                        } else {
 867                                pmb[i] = NULL;
 868                        }
 869                }
 870
 871                pmb_nr = shrink_potential_moved_blocks(pmb, pmb_nr);
 872
 873                if (pmb_nr == 0) {
 874                        /*
 875                         * The current line is the start of a new block.
 876                         * Setup the set of potential blocks.
 877                         */
 878                        for (; match; match = hashmap_get_next(hm, match)) {
 879                                ALLOC_GROW(pmb, pmb_nr + 1, pmb_alloc);
 880                                pmb[pmb_nr++] = match;
 881                        }
 882
 883                        flipped_block = (flipped_block + 1) % 2;
 884
 885                        adjust_last_block(o, n, block_length);
 886                        block_length = 0;
 887                }
 888
 889                block_length++;
 890
 891                if (flipped_block)
 892                        l->flags |= DIFF_SYMBOL_MOVED_LINE_ALT;
 893        }
 894        adjust_last_block(o, n, block_length);
 895
 896        free(pmb);
 897}
 898
 899#define DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK \
 900  (DIFF_SYMBOL_MOVED_LINE | DIFF_SYMBOL_MOVED_LINE_ALT)
 901static void dim_moved_lines(struct diff_options *o)
 902{
 903        int n;
 904        for (n = 0; n < o->emitted_symbols->nr; n++) {
 905                struct emitted_diff_symbol *prev = (n != 0) ?
 906                                &o->emitted_symbols->buf[n - 1] : NULL;
 907                struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
 908                struct emitted_diff_symbol *next =
 909                                (n < o->emitted_symbols->nr - 1) ?
 910                                &o->emitted_symbols->buf[n + 1] : NULL;
 911
 912                /* Not a plus or minus line? */
 913                if (l->s != DIFF_SYMBOL_PLUS && l->s != DIFF_SYMBOL_MINUS)
 914                        continue;
 915
 916                /* Not a moved line? */
 917                if (!(l->flags & DIFF_SYMBOL_MOVED_LINE))
 918                        continue;
 919
 920                /*
 921                 * If prev or next are not a plus or minus line,
 922                 * pretend they don't exist
 923                 */
 924                if (prev && prev->s != DIFF_SYMBOL_PLUS &&
 925                            prev->s != DIFF_SYMBOL_MINUS)
 926                        prev = NULL;
 927                if (next && next->s != DIFF_SYMBOL_PLUS &&
 928                            next->s != DIFF_SYMBOL_MINUS)
 929                        next = NULL;
 930
 931                /* Inside a block? */
 932                if ((prev &&
 933                    (prev->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK) ==
 934                    (l->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK)) &&
 935                    (next &&
 936                    (next->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK) ==
 937                    (l->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK))) {
 938                        l->flags |= DIFF_SYMBOL_MOVED_LINE_UNINTERESTING;
 939                        continue;
 940                }
 941
 942                /* Check if we are at an interesting bound: */
 943                if (prev && (prev->flags & DIFF_SYMBOL_MOVED_LINE) &&
 944                    (prev->flags & DIFF_SYMBOL_MOVED_LINE_ALT) !=
 945                       (l->flags & DIFF_SYMBOL_MOVED_LINE_ALT))
 946                        continue;
 947                if (next && (next->flags & DIFF_SYMBOL_MOVED_LINE) &&
 948                    (next->flags & DIFF_SYMBOL_MOVED_LINE_ALT) !=
 949                       (l->flags & DIFF_SYMBOL_MOVED_LINE_ALT))
 950                        continue;
 951
 952                /*
 953                 * The boundary to prev and next are not interesting,
 954                 * so this line is not interesting as a whole
 955                 */
 956                l->flags |= DIFF_SYMBOL_MOVED_LINE_UNINTERESTING;
 957        }
 958}
 959
 960static void emit_line_ws_markup(struct diff_options *o,
 961                                const char *set, const char *reset,
 962                                const char *line, int len, char sign,
 963                                unsigned ws_rule, int blank_at_eof)
 964{
 965        const char *ws = NULL;
 966
 967        if (o->ws_error_highlight & ws_rule) {
 968                ws = diff_get_color_opt(o, DIFF_WHITESPACE);
 969                if (!*ws)
 970                        ws = NULL;
 971        }
 972
 973        if (!ws)
 974                emit_line_0(o, set, reset, sign, line, len);
 975        else if (blank_at_eof)
 976                /* Blank line at EOF - paint '+' as well */
 977                emit_line_0(o, ws, reset, sign, line, len);
 978        else {
 979                /* Emit just the prefix, then the rest. */
 980                emit_line_0(o, set, reset, sign, "", 0);
 981                ws_check_emit(line, len, ws_rule,
 982                              o->file, set, reset, ws);
 983        }
 984}
 985
 986static void emit_diff_symbol_from_struct(struct diff_options *o,
 987                                         struct emitted_diff_symbol *eds)
 988{
 989        static const char *nneof = " No newline at end of file\n";
 990        const char *context, *reset, *set, *meta, *fraginfo;
 991        struct strbuf sb = STRBUF_INIT;
 992
 993        enum diff_symbol s = eds->s;
 994        const char *line = eds->line;
 995        int len = eds->len;
 996        unsigned flags = eds->flags;
 997
 998        switch (s) {
 999        case DIFF_SYMBOL_NO_LF_EOF:
1000                context = diff_get_color_opt(o, DIFF_CONTEXT);
1001                reset = diff_get_color_opt(o, DIFF_RESET);
1002                putc('\n', o->file);
1003                emit_line_0(o, context, reset, '\\',
1004                            nneof, strlen(nneof));
1005                break;
1006        case DIFF_SYMBOL_SUBMODULE_HEADER:
1007        case DIFF_SYMBOL_SUBMODULE_ERROR:
1008        case DIFF_SYMBOL_SUBMODULE_PIPETHROUGH:
1009        case DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES:
1010        case DIFF_SYMBOL_SUMMARY:
1011        case DIFF_SYMBOL_STATS_LINE:
1012        case DIFF_SYMBOL_BINARY_DIFF_BODY:
1013        case DIFF_SYMBOL_CONTEXT_FRAGINFO:
1014                emit_line(o, "", "", line, len);
1015                break;
1016        case DIFF_SYMBOL_CONTEXT_INCOMPLETE:
1017        case DIFF_SYMBOL_CONTEXT_MARKER:
1018                context = diff_get_color_opt(o, DIFF_CONTEXT);
1019                reset = diff_get_color_opt(o, DIFF_RESET);
1020                emit_line(o, context, reset, line, len);
1021                break;
1022        case DIFF_SYMBOL_SEPARATOR:
1023                fprintf(o->file, "%s%c",
1024                        diff_line_prefix(o),
1025                        o->line_termination);
1026                break;
1027        case DIFF_SYMBOL_CONTEXT:
1028                set = diff_get_color_opt(o, DIFF_CONTEXT);
1029                reset = diff_get_color_opt(o, DIFF_RESET);
1030                emit_line_ws_markup(o, set, reset, line, len, ' ',
1031                                    flags & (DIFF_SYMBOL_CONTENT_WS_MASK), 0);
1032                break;
1033        case DIFF_SYMBOL_PLUS:
1034                switch (flags & (DIFF_SYMBOL_MOVED_LINE |
1035                                 DIFF_SYMBOL_MOVED_LINE_ALT |
1036                                 DIFF_SYMBOL_MOVED_LINE_UNINTERESTING)) {
1037                case DIFF_SYMBOL_MOVED_LINE |
1038                     DIFF_SYMBOL_MOVED_LINE_ALT |
1039                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1040                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED_ALT_DIM);
1041                        break;
1042                case DIFF_SYMBOL_MOVED_LINE |
1043                     DIFF_SYMBOL_MOVED_LINE_ALT:
1044                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED_ALT);
1045                        break;
1046                case DIFF_SYMBOL_MOVED_LINE |
1047                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1048                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED_DIM);
1049                        break;
1050                case DIFF_SYMBOL_MOVED_LINE:
1051                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED);
1052                        break;
1053                default:
1054                        set = diff_get_color_opt(o, DIFF_FILE_NEW);
1055                }
1056                reset = diff_get_color_opt(o, DIFF_RESET);
1057                emit_line_ws_markup(o, set, reset, line, len, '+',
1058                                    flags & DIFF_SYMBOL_CONTENT_WS_MASK,
1059                                    flags & DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF);
1060                break;
1061        case DIFF_SYMBOL_MINUS:
1062                switch (flags & (DIFF_SYMBOL_MOVED_LINE |
1063                                 DIFF_SYMBOL_MOVED_LINE_ALT |
1064                                 DIFF_SYMBOL_MOVED_LINE_UNINTERESTING)) {
1065                case DIFF_SYMBOL_MOVED_LINE |
1066                     DIFF_SYMBOL_MOVED_LINE_ALT |
1067                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1068                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_ALT_DIM);
1069                        break;
1070                case DIFF_SYMBOL_MOVED_LINE |
1071                     DIFF_SYMBOL_MOVED_LINE_ALT:
1072                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_ALT);
1073                        break;
1074                case DIFF_SYMBOL_MOVED_LINE |
1075                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1076                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_DIM);
1077                        break;
1078                case DIFF_SYMBOL_MOVED_LINE:
1079                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED);
1080                        break;
1081                default:
1082                        set = diff_get_color_opt(o, DIFF_FILE_OLD);
1083                }
1084                reset = diff_get_color_opt(o, DIFF_RESET);
1085                emit_line_ws_markup(o, set, reset, line, len, '-',
1086                                    flags & DIFF_SYMBOL_CONTENT_WS_MASK, 0);
1087                break;
1088        case DIFF_SYMBOL_WORDS_PORCELAIN:
1089                context = diff_get_color_opt(o, DIFF_CONTEXT);
1090                reset = diff_get_color_opt(o, DIFF_RESET);
1091                emit_line(o, context, reset, line, len);
1092                fputs("~\n", o->file);
1093                break;
1094        case DIFF_SYMBOL_WORDS:
1095                context = diff_get_color_opt(o, DIFF_CONTEXT);
1096                reset = diff_get_color_opt(o, DIFF_RESET);
1097                /*
1098                 * Skip the prefix character, if any.  With
1099                 * diff_suppress_blank_empty, there may be
1100                 * none.
1101                 */
1102                if (line[0] != '\n') {
1103                        line++;
1104                        len--;
1105                }
1106                emit_line(o, context, reset, line, len);
1107                break;
1108        case DIFF_SYMBOL_FILEPAIR_PLUS:
1109                meta = diff_get_color_opt(o, DIFF_METAINFO);
1110                reset = diff_get_color_opt(o, DIFF_RESET);
1111                fprintf(o->file, "%s%s+++ %s%s%s\n", diff_line_prefix(o), meta,
1112                        line, reset,
1113                        strchr(line, ' ') ? "\t" : "");
1114                break;
1115        case DIFF_SYMBOL_FILEPAIR_MINUS:
1116                meta = diff_get_color_opt(o, DIFF_METAINFO);
1117                reset = diff_get_color_opt(o, DIFF_RESET);
1118                fprintf(o->file, "%s%s--- %s%s%s\n", diff_line_prefix(o), meta,
1119                        line, reset,
1120                        strchr(line, ' ') ? "\t" : "");
1121                break;
1122        case DIFF_SYMBOL_BINARY_FILES:
1123        case DIFF_SYMBOL_HEADER:
1124                fprintf(o->file, "%s", line);
1125                break;
1126        case DIFF_SYMBOL_BINARY_DIFF_HEADER:
1127                fprintf(o->file, "%sGIT binary patch\n", diff_line_prefix(o));
1128                break;
1129        case DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA:
1130                fprintf(o->file, "%sdelta %s\n", diff_line_prefix(o), line);
1131                break;
1132        case DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL:
1133                fprintf(o->file, "%sliteral %s\n", diff_line_prefix(o), line);
1134                break;
1135        case DIFF_SYMBOL_BINARY_DIFF_FOOTER:
1136                fputs(diff_line_prefix(o), o->file);
1137                fputc('\n', o->file);
1138                break;
1139        case DIFF_SYMBOL_REWRITE_DIFF:
1140                fraginfo = diff_get_color(o->use_color, DIFF_FRAGINFO);
1141                reset = diff_get_color_opt(o, DIFF_RESET);
1142                emit_line(o, fraginfo, reset, line, len);
1143                break;
1144        case DIFF_SYMBOL_SUBMODULE_ADD:
1145                set = diff_get_color_opt(o, DIFF_FILE_NEW);
1146                reset = diff_get_color_opt(o, DIFF_RESET);
1147                emit_line(o, set, reset, line, len);
1148                break;
1149        case DIFF_SYMBOL_SUBMODULE_DEL:
1150                set = diff_get_color_opt(o, DIFF_FILE_OLD);
1151                reset = diff_get_color_opt(o, DIFF_RESET);
1152                emit_line(o, set, reset, line, len);
1153                break;
1154        case DIFF_SYMBOL_SUBMODULE_UNTRACKED:
1155                fprintf(o->file, "%sSubmodule %s contains untracked content\n",
1156                        diff_line_prefix(o), line);
1157                break;
1158        case DIFF_SYMBOL_SUBMODULE_MODIFIED:
1159                fprintf(o->file, "%sSubmodule %s contains modified content\n",
1160                        diff_line_prefix(o), line);
1161                break;
1162        case DIFF_SYMBOL_STATS_SUMMARY_NO_FILES:
1163                emit_line(o, "", "", " 0 files changed\n",
1164                          strlen(" 0 files changed\n"));
1165                break;
1166        case DIFF_SYMBOL_STATS_SUMMARY_ABBREV:
1167                emit_line(o, "", "", " ...\n", strlen(" ...\n"));
1168                break;
1169        case DIFF_SYMBOL_WORD_DIFF:
1170                fprintf(o->file, "%.*s", len, line);
1171                break;
1172        case DIFF_SYMBOL_STAT_SEP:
1173                fputs(o->stat_sep, o->file);
1174                break;
1175        default:
1176                die("BUG: unknown diff symbol");
1177        }
1178        strbuf_release(&sb);
1179}
1180
1181static void emit_diff_symbol(struct diff_options *o, enum diff_symbol s,
1182                             const char *line, int len, unsigned flags)
1183{
1184        struct emitted_diff_symbol e = {line, len, flags, s};
1185
1186        if (o->emitted_symbols)
1187                append_emitted_diff_symbol(o, &e);
1188        else
1189                emit_diff_symbol_from_struct(o, &e);
1190}
1191
1192void diff_emit_submodule_del(struct diff_options *o, const char *line)
1193{
1194        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_DEL, line, strlen(line), 0);
1195}
1196
1197void diff_emit_submodule_add(struct diff_options *o, const char *line)
1198{
1199        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_ADD, line, strlen(line), 0);
1200}
1201
1202void diff_emit_submodule_untracked(struct diff_options *o, const char *path)
1203{
1204        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_UNTRACKED,
1205                         path, strlen(path), 0);
1206}
1207
1208void diff_emit_submodule_modified(struct diff_options *o, const char *path)
1209{
1210        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_MODIFIED,
1211                         path, strlen(path), 0);
1212}
1213
1214void diff_emit_submodule_header(struct diff_options *o, const char *header)
1215{
1216        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_HEADER,
1217                         header, strlen(header), 0);
1218}
1219
1220void diff_emit_submodule_error(struct diff_options *o, const char *err)
1221{
1222        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_ERROR, err, strlen(err), 0);
1223}
1224
1225void diff_emit_submodule_pipethrough(struct diff_options *o,
1226                                     const char *line, int len)
1227{
1228        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_PIPETHROUGH, line, len, 0);
1229}
1230
1231static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line, int len)
1232{
1233        if (!((ecbdata->ws_rule & WS_BLANK_AT_EOF) &&
1234              ecbdata->blank_at_eof_in_preimage &&
1235              ecbdata->blank_at_eof_in_postimage &&
1236              ecbdata->blank_at_eof_in_preimage <= ecbdata->lno_in_preimage &&
1237              ecbdata->blank_at_eof_in_postimage <= ecbdata->lno_in_postimage))
1238                return 0;
1239        return ws_blank_line(line, len, ecbdata->ws_rule);
1240}
1241
1242static void emit_add_line(const char *reset,
1243                          struct emit_callback *ecbdata,
1244                          const char *line, int len)
1245{
1246        unsigned flags = WSEH_NEW | ecbdata->ws_rule;
1247        if (new_blank_line_at_eof(ecbdata, line, len))
1248                flags |= DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF;
1249
1250        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_PLUS, line, len, flags);
1251}
1252
1253static void emit_del_line(const char *reset,
1254                          struct emit_callback *ecbdata,
1255                          const char *line, int len)
1256{
1257        unsigned flags = WSEH_OLD | ecbdata->ws_rule;
1258        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_MINUS, line, len, flags);
1259}
1260
1261static void emit_context_line(const char *reset,
1262                              struct emit_callback *ecbdata,
1263                              const char *line, int len)
1264{
1265        unsigned flags = WSEH_CONTEXT | ecbdata->ws_rule;
1266        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_CONTEXT, line, len, flags);
1267}
1268
1269static void emit_hunk_header(struct emit_callback *ecbdata,
1270                             const char *line, int len)
1271{
1272        const char *context = diff_get_color(ecbdata->color_diff, DIFF_CONTEXT);
1273        const char *frag = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
1274        const char *func = diff_get_color(ecbdata->color_diff, DIFF_FUNCINFO);
1275        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
1276        static const char atat[2] = { '@', '@' };
1277        const char *cp, *ep;
1278        struct strbuf msgbuf = STRBUF_INIT;
1279        int org_len = len;
1280        int i = 1;
1281
1282        /*
1283         * As a hunk header must begin with "@@ -<old>, +<new> @@",
1284         * it always is at least 10 bytes long.
1285         */
1286        if (len < 10 ||
1287            memcmp(line, atat, 2) ||
1288            !(ep = memmem(line + 2, len - 2, atat, 2))) {
1289                emit_diff_symbol(ecbdata->opt,
1290                                 DIFF_SYMBOL_CONTEXT_MARKER, line, len, 0);
1291                return;
1292        }
1293        ep += 2; /* skip over @@ */
1294
1295        /* The hunk header in fraginfo color */
1296        strbuf_addstr(&msgbuf, frag);
1297        strbuf_add(&msgbuf, line, ep - line);
1298        strbuf_addstr(&msgbuf, reset);
1299
1300        /*
1301         * trailing "\r\n"
1302         */
1303        for ( ; i < 3; i++)
1304                if (line[len - i] == '\r' || line[len - i] == '\n')
1305                        len--;
1306
1307        /* blank before the func header */
1308        for (cp = ep; ep - line < len; ep++)
1309                if (*ep != ' ' && *ep != '\t')
1310                        break;
1311        if (ep != cp) {
1312                strbuf_addstr(&msgbuf, context);
1313                strbuf_add(&msgbuf, cp, ep - cp);
1314                strbuf_addstr(&msgbuf, reset);
1315        }
1316
1317        if (ep < line + len) {
1318                strbuf_addstr(&msgbuf, func);
1319                strbuf_add(&msgbuf, ep, line + len - ep);
1320                strbuf_addstr(&msgbuf, reset);
1321        }
1322
1323        strbuf_add(&msgbuf, line + len, org_len - len);
1324        strbuf_complete_line(&msgbuf);
1325        emit_diff_symbol(ecbdata->opt,
1326                         DIFF_SYMBOL_CONTEXT_FRAGINFO, msgbuf.buf, msgbuf.len, 0);
1327        strbuf_release(&msgbuf);
1328}
1329
1330static struct diff_tempfile *claim_diff_tempfile(void) {
1331        int i;
1332        for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
1333                if (!diff_temp[i].name)
1334                        return diff_temp + i;
1335        die("BUG: diff is failing to clean up its tempfiles");
1336}
1337
1338static void remove_tempfile(void)
1339{
1340        int i;
1341        for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
1342                if (is_tempfile_active(diff_temp[i].tempfile))
1343                        delete_tempfile(&diff_temp[i].tempfile);
1344                diff_temp[i].name = NULL;
1345        }
1346}
1347
1348static void add_line_count(struct strbuf *out, int count)
1349{
1350        switch (count) {
1351        case 0:
1352                strbuf_addstr(out, "0,0");
1353                break;
1354        case 1:
1355                strbuf_addstr(out, "1");
1356                break;
1357        default:
1358                strbuf_addf(out, "1,%d", count);
1359                break;
1360        }
1361}
1362
1363static void emit_rewrite_lines(struct emit_callback *ecb,
1364                               int prefix, const char *data, int size)
1365{
1366        const char *endp = NULL;
1367        const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
1368
1369        while (0 < size) {
1370                int len;
1371
1372                endp = memchr(data, '\n', size);
1373                len = endp ? (endp - data + 1) : size;
1374                if (prefix != '+') {
1375                        ecb->lno_in_preimage++;
1376                        emit_del_line(reset, ecb, data, len);
1377                } else {
1378                        ecb->lno_in_postimage++;
1379                        emit_add_line(reset, ecb, data, len);
1380                }
1381                size -= len;
1382                data += len;
1383        }
1384        if (!endp)
1385                emit_diff_symbol(ecb->opt, DIFF_SYMBOL_NO_LF_EOF, NULL, 0, 0);
1386}
1387
1388static void emit_rewrite_diff(const char *name_a,
1389                              const char *name_b,
1390                              struct diff_filespec *one,
1391                              struct diff_filespec *two,
1392                              struct userdiff_driver *textconv_one,
1393                              struct userdiff_driver *textconv_two,
1394                              struct diff_options *o)
1395{
1396        int lc_a, lc_b;
1397        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
1398        const char *a_prefix, *b_prefix;
1399        char *data_one, *data_two;
1400        size_t size_one, size_two;
1401        struct emit_callback ecbdata;
1402        struct strbuf out = STRBUF_INIT;
1403
1404        if (diff_mnemonic_prefix && o->flags.reverse_diff) {
1405                a_prefix = o->b_prefix;
1406                b_prefix = o->a_prefix;
1407        } else {
1408                a_prefix = o->a_prefix;
1409                b_prefix = o->b_prefix;
1410        }
1411
1412        name_a += (*name_a == '/');
1413        name_b += (*name_b == '/');
1414
1415        strbuf_reset(&a_name);
1416        strbuf_reset(&b_name);
1417        quote_two_c_style(&a_name, a_prefix, name_a, 0);
1418        quote_two_c_style(&b_name, b_prefix, name_b, 0);
1419
1420        size_one = fill_textconv(textconv_one, one, &data_one);
1421        size_two = fill_textconv(textconv_two, two, &data_two);
1422
1423        memset(&ecbdata, 0, sizeof(ecbdata));
1424        ecbdata.color_diff = want_color(o->use_color);
1425        ecbdata.ws_rule = whitespace_rule(name_b);
1426        ecbdata.opt = o;
1427        if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
1428                mmfile_t mf1, mf2;
1429                mf1.ptr = (char *)data_one;
1430                mf2.ptr = (char *)data_two;
1431                mf1.size = size_one;
1432                mf2.size = size_two;
1433                check_blank_at_eof(&mf1, &mf2, &ecbdata);
1434        }
1435        ecbdata.lno_in_preimage = 1;
1436        ecbdata.lno_in_postimage = 1;
1437
1438        lc_a = count_lines(data_one, size_one);
1439        lc_b = count_lines(data_two, size_two);
1440
1441        emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_MINUS,
1442                         a_name.buf, a_name.len, 0);
1443        emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_PLUS,
1444                         b_name.buf, b_name.len, 0);
1445
1446        strbuf_addstr(&out, "@@ -");
1447        if (!o->irreversible_delete)
1448                add_line_count(&out, lc_a);
1449        else
1450                strbuf_addstr(&out, "?,?");
1451        strbuf_addstr(&out, " +");
1452        add_line_count(&out, lc_b);
1453        strbuf_addstr(&out, " @@\n");
1454        emit_diff_symbol(o, DIFF_SYMBOL_REWRITE_DIFF, out.buf, out.len, 0);
1455        strbuf_release(&out);
1456
1457        if (lc_a && !o->irreversible_delete)
1458                emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
1459        if (lc_b)
1460                emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
1461        if (textconv_one)
1462                free((char *)data_one);
1463        if (textconv_two)
1464                free((char *)data_two);
1465}
1466
1467struct diff_words_buffer {
1468        mmfile_t text;
1469        unsigned long alloc;
1470        struct diff_words_orig {
1471                const char *begin, *end;
1472        } *orig;
1473        int orig_nr, orig_alloc;
1474};
1475
1476static void diff_words_append(char *line, unsigned long len,
1477                struct diff_words_buffer *buffer)
1478{
1479        ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
1480        line++;
1481        len--;
1482        memcpy(buffer->text.ptr + buffer->text.size, line, len);
1483        buffer->text.size += len;
1484        buffer->text.ptr[buffer->text.size] = '\0';
1485}
1486
1487struct diff_words_style_elem {
1488        const char *prefix;
1489        const char *suffix;
1490        const char *color; /* NULL; filled in by the setup code if
1491                            * color is enabled */
1492};
1493
1494struct diff_words_style {
1495        enum diff_words_type type;
1496        struct diff_words_style_elem new_word, old_word, ctx;
1497        const char *newline;
1498};
1499
1500static struct diff_words_style diff_words_styles[] = {
1501        { DIFF_WORDS_PORCELAIN, {"+", "\n"}, {"-", "\n"}, {" ", "\n"}, "~\n" },
1502        { DIFF_WORDS_PLAIN, {"{+", "+}"}, {"[-", "-]"}, {"", ""}, "\n" },
1503        { DIFF_WORDS_COLOR, {"", ""}, {"", ""}, {"", ""}, "\n" }
1504};
1505
1506struct diff_words_data {
1507        struct diff_words_buffer minus, plus;
1508        const char *current_plus;
1509        int last_minus;
1510        struct diff_options *opt;
1511        regex_t *word_regex;
1512        enum diff_words_type type;
1513        struct diff_words_style *style;
1514};
1515
1516static int fn_out_diff_words_write_helper(struct diff_options *o,
1517                                          struct diff_words_style_elem *st_el,
1518                                          const char *newline,
1519                                          size_t count, const char *buf)
1520{
1521        int print = 0;
1522        struct strbuf sb = STRBUF_INIT;
1523
1524        while (count) {
1525                char *p = memchr(buf, '\n', count);
1526                if (print)
1527                        strbuf_addstr(&sb, diff_line_prefix(o));
1528
1529                if (p != buf) {
1530                        const char *reset = st_el->color && *st_el->color ?
1531                                            GIT_COLOR_RESET : NULL;
1532                        if (st_el->color && *st_el->color)
1533                                strbuf_addstr(&sb, st_el->color);
1534                        strbuf_addstr(&sb, st_el->prefix);
1535                        strbuf_add(&sb, buf, p ? p - buf : count);
1536                        strbuf_addstr(&sb, st_el->suffix);
1537                        if (reset)
1538                                strbuf_addstr(&sb, reset);
1539                }
1540                if (!p)
1541                        goto out;
1542
1543                strbuf_addstr(&sb, newline);
1544                count -= p + 1 - buf;
1545                buf = p + 1;
1546                print = 1;
1547                if (count) {
1548                        emit_diff_symbol(o, DIFF_SYMBOL_WORD_DIFF,
1549                                         sb.buf, sb.len, 0);
1550                        strbuf_reset(&sb);
1551                }
1552        }
1553
1554out:
1555        if (sb.len)
1556                emit_diff_symbol(o, DIFF_SYMBOL_WORD_DIFF,
1557                                 sb.buf, sb.len, 0);
1558        strbuf_release(&sb);
1559        return 0;
1560}
1561
1562/*
1563 * '--color-words' algorithm can be described as:
1564 *
1565 *   1. collect the minus/plus lines of a diff hunk, divided into
1566 *      minus-lines and plus-lines;
1567 *
1568 *   2. break both minus-lines and plus-lines into words and
1569 *      place them into two mmfile_t with one word for each line;
1570 *
1571 *   3. use xdiff to run diff on the two mmfile_t to get the words level diff;
1572 *
1573 * And for the common parts of the both file, we output the plus side text.
1574 * diff_words->current_plus is used to trace the current position of the plus file
1575 * which printed. diff_words->last_minus is used to trace the last minus word
1576 * printed.
1577 *
1578 * For '--graph' to work with '--color-words', we need to output the graph prefix
1579 * on each line of color words output. Generally, there are two conditions on
1580 * which we should output the prefix.
1581 *
1582 *   1. diff_words->last_minus == 0 &&
1583 *      diff_words->current_plus == diff_words->plus.text.ptr
1584 *
1585 *      that is: the plus text must start as a new line, and if there is no minus
1586 *      word printed, a graph prefix must be printed.
1587 *
1588 *   2. diff_words->current_plus > diff_words->plus.text.ptr &&
1589 *      *(diff_words->current_plus - 1) == '\n'
1590 *
1591 *      that is: a graph prefix must be printed following a '\n'
1592 */
1593static int color_words_output_graph_prefix(struct diff_words_data *diff_words)
1594{
1595        if ((diff_words->last_minus == 0 &&
1596                diff_words->current_plus == diff_words->plus.text.ptr) ||
1597                (diff_words->current_plus > diff_words->plus.text.ptr &&
1598                *(diff_words->current_plus - 1) == '\n')) {
1599                return 1;
1600        } else {
1601                return 0;
1602        }
1603}
1604
1605static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
1606{
1607        struct diff_words_data *diff_words = priv;
1608        struct diff_words_style *style = diff_words->style;
1609        int minus_first, minus_len, plus_first, plus_len;
1610        const char *minus_begin, *minus_end, *plus_begin, *plus_end;
1611        struct diff_options *opt = diff_words->opt;
1612        const char *line_prefix;
1613
1614        if (line[0] != '@' || parse_hunk_header(line, len,
1615                        &minus_first, &minus_len, &plus_first, &plus_len))
1616                return;
1617
1618        assert(opt);
1619        line_prefix = diff_line_prefix(opt);
1620
1621        /* POSIX requires that first be decremented by one if len == 0... */
1622        if (minus_len) {
1623                minus_begin = diff_words->minus.orig[minus_first].begin;
1624                minus_end =
1625                        diff_words->minus.orig[minus_first + minus_len - 1].end;
1626        } else
1627                minus_begin = minus_end =
1628                        diff_words->minus.orig[minus_first].end;
1629
1630        if (plus_len) {
1631                plus_begin = diff_words->plus.orig[plus_first].begin;
1632                plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
1633        } else
1634                plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
1635
1636        if (color_words_output_graph_prefix(diff_words)) {
1637                fputs(line_prefix, diff_words->opt->file);
1638        }
1639        if (diff_words->current_plus != plus_begin) {
1640                fn_out_diff_words_write_helper(diff_words->opt,
1641                                &style->ctx, style->newline,
1642                                plus_begin - diff_words->current_plus,
1643                                diff_words->current_plus);
1644        }
1645        if (minus_begin != minus_end) {
1646                fn_out_diff_words_write_helper(diff_words->opt,
1647                                &style->old_word, style->newline,
1648                                minus_end - minus_begin, minus_begin);
1649        }
1650        if (plus_begin != plus_end) {
1651                fn_out_diff_words_write_helper(diff_words->opt,
1652                                &style->new_word, style->newline,
1653                                plus_end - plus_begin, plus_begin);
1654        }
1655
1656        diff_words->current_plus = plus_end;
1657        diff_words->last_minus = minus_first;
1658}
1659
1660/* This function starts looking at *begin, and returns 0 iff a word was found. */
1661static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
1662                int *begin, int *end)
1663{
1664        if (word_regex && *begin < buffer->size) {
1665                regmatch_t match[1];
1666                if (!regexec_buf(word_regex, buffer->ptr + *begin,
1667                                 buffer->size - *begin, 1, match, 0)) {
1668                        char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
1669                                        '\n', match[0].rm_eo - match[0].rm_so);
1670                        *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
1671                        *begin += match[0].rm_so;
1672                        return *begin >= *end;
1673                }
1674                return -1;
1675        }
1676
1677        /* find the next word */
1678        while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
1679                (*begin)++;
1680        if (*begin >= buffer->size)
1681                return -1;
1682
1683        /* find the end of the word */
1684        *end = *begin + 1;
1685        while (*end < buffer->size && !isspace(buffer->ptr[*end]))
1686                (*end)++;
1687
1688        return 0;
1689}
1690
1691/*
1692 * This function splits the words in buffer->text, stores the list with
1693 * newline separator into out, and saves the offsets of the original words
1694 * in buffer->orig.
1695 */
1696static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
1697                regex_t *word_regex)
1698{
1699        int i, j;
1700        long alloc = 0;
1701
1702        out->size = 0;
1703        out->ptr = NULL;
1704
1705        /* fake an empty "0th" word */
1706        ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
1707        buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
1708        buffer->orig_nr = 1;
1709
1710        for (i = 0; i < buffer->text.size; i++) {
1711                if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
1712                        return;
1713
1714                /* store original boundaries */
1715                ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
1716                                buffer->orig_alloc);
1717                buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
1718                buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
1719                buffer->orig_nr++;
1720
1721                /* store one word */
1722                ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
1723                memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
1724                out->ptr[out->size + j - i] = '\n';
1725                out->size += j - i + 1;
1726
1727                i = j - 1;
1728        }
1729}
1730
1731/* this executes the word diff on the accumulated buffers */
1732static void diff_words_show(struct diff_words_data *diff_words)
1733{
1734        xpparam_t xpp;
1735        xdemitconf_t xecfg;
1736        mmfile_t minus, plus;
1737        struct diff_words_style *style = diff_words->style;
1738
1739        struct diff_options *opt = diff_words->opt;
1740        const char *line_prefix;
1741
1742        assert(opt);
1743        line_prefix = diff_line_prefix(opt);
1744
1745        /* special case: only removal */
1746        if (!diff_words->plus.text.size) {
1747                emit_diff_symbol(diff_words->opt, DIFF_SYMBOL_WORD_DIFF,
1748                                 line_prefix, strlen(line_prefix), 0);
1749                fn_out_diff_words_write_helper(diff_words->opt,
1750                        &style->old_word, style->newline,
1751                        diff_words->minus.text.size,
1752                        diff_words->minus.text.ptr);
1753                diff_words->minus.text.size = 0;
1754                return;
1755        }
1756
1757        diff_words->current_plus = diff_words->plus.text.ptr;
1758        diff_words->last_minus = 0;
1759
1760        memset(&xpp, 0, sizeof(xpp));
1761        memset(&xecfg, 0, sizeof(xecfg));
1762        diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
1763        diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
1764        xpp.flags = 0;
1765        /* as only the hunk header will be parsed, we need a 0-context */
1766        xecfg.ctxlen = 0;
1767        if (xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
1768                          &xpp, &xecfg))
1769                die("unable to generate word diff");
1770        free(minus.ptr);
1771        free(plus.ptr);
1772        if (diff_words->current_plus != diff_words->plus.text.ptr +
1773                        diff_words->plus.text.size) {
1774                if (color_words_output_graph_prefix(diff_words))
1775                        emit_diff_symbol(diff_words->opt, DIFF_SYMBOL_WORD_DIFF,
1776                                         line_prefix, strlen(line_prefix), 0);
1777                fn_out_diff_words_write_helper(diff_words->opt,
1778                        &style->ctx, style->newline,
1779                        diff_words->plus.text.ptr + diff_words->plus.text.size
1780                        - diff_words->current_plus, diff_words->current_plus);
1781        }
1782        diff_words->minus.text.size = diff_words->plus.text.size = 0;
1783}
1784
1785/* In "color-words" mode, show word-diff of words accumulated in the buffer */
1786static void diff_words_flush(struct emit_callback *ecbdata)
1787{
1788        struct diff_options *wo = ecbdata->diff_words->opt;
1789
1790        if (ecbdata->diff_words->minus.text.size ||
1791            ecbdata->diff_words->plus.text.size)
1792                diff_words_show(ecbdata->diff_words);
1793
1794        if (wo->emitted_symbols) {
1795                struct diff_options *o = ecbdata->opt;
1796                struct emitted_diff_symbols *wol = wo->emitted_symbols;
1797                int i;
1798
1799                /*
1800                 * NEEDSWORK:
1801                 * Instead of appending each, concat all words to a line?
1802                 */
1803                for (i = 0; i < wol->nr; i++)
1804                        append_emitted_diff_symbol(o, &wol->buf[i]);
1805
1806                for (i = 0; i < wol->nr; i++)
1807                        free((void *)wol->buf[i].line);
1808
1809                wol->nr = 0;
1810        }
1811}
1812
1813static void diff_filespec_load_driver(struct diff_filespec *one)
1814{
1815        /* Use already-loaded driver */
1816        if (one->driver)
1817                return;
1818
1819        if (S_ISREG(one->mode))
1820                one->driver = userdiff_find_by_path(one->path);
1821
1822        /* Fallback to default settings */
1823        if (!one->driver)
1824                one->driver = userdiff_find_by_name("default");
1825}
1826
1827static const char *userdiff_word_regex(struct diff_filespec *one)
1828{
1829        diff_filespec_load_driver(one);
1830        return one->driver->word_regex;
1831}
1832
1833static void init_diff_words_data(struct emit_callback *ecbdata,
1834                                 struct diff_options *orig_opts,
1835                                 struct diff_filespec *one,
1836                                 struct diff_filespec *two)
1837{
1838        int i;
1839        struct diff_options *o = xmalloc(sizeof(struct diff_options));
1840        memcpy(o, orig_opts, sizeof(struct diff_options));
1841
1842        ecbdata->diff_words =
1843                xcalloc(1, sizeof(struct diff_words_data));
1844        ecbdata->diff_words->type = o->word_diff;
1845        ecbdata->diff_words->opt = o;
1846
1847        if (orig_opts->emitted_symbols)
1848                o->emitted_symbols =
1849                        xcalloc(1, sizeof(struct emitted_diff_symbols));
1850
1851        if (!o->word_regex)
1852                o->word_regex = userdiff_word_regex(one);
1853        if (!o->word_regex)
1854                o->word_regex = userdiff_word_regex(two);
1855        if (!o->word_regex)
1856                o->word_regex = diff_word_regex_cfg;
1857        if (o->word_regex) {
1858                ecbdata->diff_words->word_regex = (regex_t *)
1859                        xmalloc(sizeof(regex_t));
1860                if (regcomp(ecbdata->diff_words->word_regex,
1861                            o->word_regex,
1862                            REG_EXTENDED | REG_NEWLINE))
1863                        die ("Invalid regular expression: %s",
1864                             o->word_regex);
1865        }
1866        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
1867                if (o->word_diff == diff_words_styles[i].type) {
1868                        ecbdata->diff_words->style =
1869                                &diff_words_styles[i];
1870                        break;
1871                }
1872        }
1873        if (want_color(o->use_color)) {
1874                struct diff_words_style *st = ecbdata->diff_words->style;
1875                st->old_word.color = diff_get_color_opt(o, DIFF_FILE_OLD);
1876                st->new_word.color = diff_get_color_opt(o, DIFF_FILE_NEW);
1877                st->ctx.color = diff_get_color_opt(o, DIFF_CONTEXT);
1878        }
1879}
1880
1881static void free_diff_words_data(struct emit_callback *ecbdata)
1882{
1883        if (ecbdata->diff_words) {
1884                diff_words_flush(ecbdata);
1885                free (ecbdata->diff_words->opt->emitted_symbols);
1886                free (ecbdata->diff_words->opt);
1887                free (ecbdata->diff_words->minus.text.ptr);
1888                free (ecbdata->diff_words->minus.orig);
1889                free (ecbdata->diff_words->plus.text.ptr);
1890                free (ecbdata->diff_words->plus.orig);
1891                if (ecbdata->diff_words->word_regex) {
1892                        regfree(ecbdata->diff_words->word_regex);
1893                        free(ecbdata->diff_words->word_regex);
1894                }
1895                FREE_AND_NULL(ecbdata->diff_words);
1896        }
1897}
1898
1899const char *diff_get_color(int diff_use_color, enum color_diff ix)
1900{
1901        if (want_color(diff_use_color))
1902                return diff_colors[ix];
1903        return "";
1904}
1905
1906const char *diff_line_prefix(struct diff_options *opt)
1907{
1908        struct strbuf *msgbuf;
1909        if (!opt->output_prefix)
1910                return "";
1911
1912        msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
1913        return msgbuf->buf;
1914}
1915
1916static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
1917{
1918        const char *cp;
1919        unsigned long allot;
1920        size_t l = len;
1921
1922        cp = line;
1923        allot = l;
1924        while (0 < l) {
1925                (void) utf8_width(&cp, &l);
1926                if (!cp)
1927                        break; /* truncated in the middle? */
1928        }
1929        return allot - l;
1930}
1931
1932static void find_lno(const char *line, struct emit_callback *ecbdata)
1933{
1934        const char *p;
1935        ecbdata->lno_in_preimage = 0;
1936        ecbdata->lno_in_postimage = 0;
1937        p = strchr(line, '-');
1938        if (!p)
1939                return; /* cannot happen */
1940        ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
1941        p = strchr(p, '+');
1942        if (!p)
1943                return; /* cannot happen */
1944        ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
1945}
1946
1947static void fn_out_consume(void *priv, char *line, unsigned long len)
1948{
1949        struct emit_callback *ecbdata = priv;
1950        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
1951        struct diff_options *o = ecbdata->opt;
1952
1953        o->found_changes = 1;
1954
1955        if (ecbdata->header) {
1956                emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
1957                                 ecbdata->header->buf, ecbdata->header->len, 0);
1958                strbuf_reset(ecbdata->header);
1959                ecbdata->header = NULL;
1960        }
1961
1962        if (ecbdata->label_path[0]) {
1963                emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_MINUS,
1964                                 ecbdata->label_path[0],
1965                                 strlen(ecbdata->label_path[0]), 0);
1966                emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_PLUS,
1967                                 ecbdata->label_path[1],
1968                                 strlen(ecbdata->label_path[1]), 0);
1969                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
1970        }
1971
1972        if (diff_suppress_blank_empty
1973            && len == 2 && line[0] == ' ' && line[1] == '\n') {
1974                line[0] = '\n';
1975                len = 1;
1976        }
1977
1978        if (line[0] == '@') {
1979                if (ecbdata->diff_words)
1980                        diff_words_flush(ecbdata);
1981                len = sane_truncate_line(ecbdata, line, len);
1982                find_lno(line, ecbdata);
1983                emit_hunk_header(ecbdata, line, len);
1984                return;
1985        }
1986
1987        if (ecbdata->diff_words) {
1988                enum diff_symbol s =
1989                        ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN ?
1990                        DIFF_SYMBOL_WORDS_PORCELAIN : DIFF_SYMBOL_WORDS;
1991                if (line[0] == '-') {
1992                        diff_words_append(line, len,
1993                                          &ecbdata->diff_words->minus);
1994                        return;
1995                } else if (line[0] == '+') {
1996                        diff_words_append(line, len,
1997                                          &ecbdata->diff_words->plus);
1998                        return;
1999                } else if (starts_with(line, "\\ ")) {
2000                        /*
2001                         * Eat the "no newline at eof" marker as if we
2002                         * saw a "+" or "-" line with nothing on it,
2003                         * and return without diff_words_flush() to
2004                         * defer processing. If this is the end of
2005                         * preimage, more "+" lines may come after it.
2006                         */
2007                        return;
2008                }
2009                diff_words_flush(ecbdata);
2010                emit_diff_symbol(o, s, line, len, 0);
2011                return;
2012        }
2013
2014        switch (line[0]) {
2015        case '+':
2016                ecbdata->lno_in_postimage++;
2017                emit_add_line(reset, ecbdata, line + 1, len - 1);
2018                break;
2019        case '-':
2020                ecbdata->lno_in_preimage++;
2021                emit_del_line(reset, ecbdata, line + 1, len - 1);
2022                break;
2023        case ' ':
2024                ecbdata->lno_in_postimage++;
2025                ecbdata->lno_in_preimage++;
2026                emit_context_line(reset, ecbdata, line + 1, len - 1);
2027                break;
2028        default:
2029                /* incomplete line at the end */
2030                ecbdata->lno_in_preimage++;
2031                emit_diff_symbol(o, DIFF_SYMBOL_CONTEXT_INCOMPLETE,
2032                                 line, len, 0);
2033                break;
2034        }
2035}
2036
2037static void pprint_rename(struct strbuf *name, const char *a, const char *b)
2038{
2039        const char *old_name = a;
2040        const char *new_name = b;
2041        int pfx_length, sfx_length;
2042        int pfx_adjust_for_slash;
2043        int len_a = strlen(a);
2044        int len_b = strlen(b);
2045        int a_midlen, b_midlen;
2046        int qlen_a = quote_c_style(a, NULL, NULL, 0);
2047        int qlen_b = quote_c_style(b, NULL, NULL, 0);
2048
2049        if (qlen_a || qlen_b) {
2050                quote_c_style(a, name, NULL, 0);
2051                strbuf_addstr(name, " => ");
2052                quote_c_style(b, name, NULL, 0);
2053                return;
2054        }
2055
2056        /* Find common prefix */
2057        pfx_length = 0;
2058        while (*old_name && *new_name && *old_name == *new_name) {
2059                if (*old_name == '/')
2060                        pfx_length = old_name - a + 1;
2061                old_name++;
2062                new_name++;
2063        }
2064
2065        /* Find common suffix */
2066        old_name = a + len_a;
2067        new_name = b + len_b;
2068        sfx_length = 0;
2069        /*
2070         * If there is a common prefix, it must end in a slash.  In
2071         * that case we let this loop run 1 into the prefix to see the
2072         * same slash.
2073         *
2074         * If there is no common prefix, we cannot do this as it would
2075         * underrun the input strings.
2076         */
2077        pfx_adjust_for_slash = (pfx_length ? 1 : 0);
2078        while (a + pfx_length - pfx_adjust_for_slash <= old_name &&
2079               b + pfx_length - pfx_adjust_for_slash <= new_name &&
2080               *old_name == *new_name) {
2081                if (*old_name == '/')
2082                        sfx_length = len_a - (old_name - a);
2083                old_name--;
2084                new_name--;
2085        }
2086
2087        /*
2088         * pfx{mid-a => mid-b}sfx
2089         * {pfx-a => pfx-b}sfx
2090         * pfx{sfx-a => sfx-b}
2091         * name-a => name-b
2092         */
2093        a_midlen = len_a - pfx_length - sfx_length;
2094        b_midlen = len_b - pfx_length - sfx_length;
2095        if (a_midlen < 0)
2096                a_midlen = 0;
2097        if (b_midlen < 0)
2098                b_midlen = 0;
2099
2100        strbuf_grow(name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
2101        if (pfx_length + sfx_length) {
2102                strbuf_add(name, a, pfx_length);
2103                strbuf_addch(name, '{');
2104        }
2105        strbuf_add(name, a + pfx_length, a_midlen);
2106        strbuf_addstr(name, " => ");
2107        strbuf_add(name, b + pfx_length, b_midlen);
2108        if (pfx_length + sfx_length) {
2109                strbuf_addch(name, '}');
2110                strbuf_add(name, a + len_a - sfx_length, sfx_length);
2111        }
2112}
2113
2114struct diffstat_t {
2115        int nr;
2116        int alloc;
2117        struct diffstat_file {
2118                char *from_name;
2119                char *name;
2120                char *print_name;
2121                const char *comments;
2122                unsigned is_unmerged:1;
2123                unsigned is_binary:1;
2124                unsigned is_renamed:1;
2125                unsigned is_interesting:1;
2126                uintmax_t added, deleted;
2127        } **files;
2128};
2129
2130static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
2131                                          const char *name_a,
2132                                          const char *name_b)
2133{
2134        struct diffstat_file *x;
2135        x = xcalloc(1, sizeof(*x));
2136        ALLOC_GROW(diffstat->files, diffstat->nr + 1, diffstat->alloc);
2137        diffstat->files[diffstat->nr++] = x;
2138        if (name_b) {
2139                x->from_name = xstrdup(name_a);
2140                x->name = xstrdup(name_b);
2141                x->is_renamed = 1;
2142        }
2143        else {
2144                x->from_name = NULL;
2145                x->name = xstrdup(name_a);
2146        }
2147        return x;
2148}
2149
2150static void diffstat_consume(void *priv, char *line, unsigned long len)
2151{
2152        struct diffstat_t *diffstat = priv;
2153        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
2154
2155        if (line[0] == '+')
2156                x->added++;
2157        else if (line[0] == '-')
2158                x->deleted++;
2159}
2160
2161const char mime_boundary_leader[] = "------------";
2162
2163static int scale_linear(int it, int width, int max_change)
2164{
2165        if (!it)
2166                return 0;
2167        /*
2168         * make sure that at least one '-' or '+' is printed if
2169         * there is any change to this path. The easiest way is to
2170         * scale linearly as if the alloted width is one column shorter
2171         * than it is, and then add 1 to the result.
2172         */
2173        return 1 + (it * (width - 1) / max_change);
2174}
2175
2176static void show_graph(struct strbuf *out, char ch, int cnt,
2177                       const char *set, const char *reset)
2178{
2179        if (cnt <= 0)
2180                return;
2181        strbuf_addstr(out, set);
2182        strbuf_addchars(out, ch, cnt);
2183        strbuf_addstr(out, reset);
2184}
2185
2186static void fill_print_name(struct diffstat_file *file)
2187{
2188        struct strbuf pname = STRBUF_INIT;
2189
2190        if (file->print_name)
2191                return;
2192
2193        if (file->is_renamed)
2194                pprint_rename(&pname, file->from_name, file->name);
2195        else
2196                quote_c_style(file->name, &pname, NULL, 0);
2197
2198        if (file->comments)
2199                strbuf_addf(&pname, " (%s)", file->comments);
2200
2201        file->print_name = strbuf_detach(&pname, NULL);
2202}
2203
2204static void print_stat_summary_inserts_deletes(struct diff_options *options,
2205                int files, int insertions, int deletions)
2206{
2207        struct strbuf sb = STRBUF_INIT;
2208
2209        if (!files) {
2210                assert(insertions == 0 && deletions == 0);
2211                emit_diff_symbol(options, DIFF_SYMBOL_STATS_SUMMARY_NO_FILES,
2212                                 NULL, 0, 0);
2213                return;
2214        }
2215
2216        strbuf_addf(&sb,
2217                    (files == 1) ? " %d file changed" : " %d files changed",
2218                    files);
2219
2220        /*
2221         * For binary diff, the caller may want to print "x files
2222         * changed" with insertions == 0 && deletions == 0.
2223         *
2224         * Not omitting "0 insertions(+), 0 deletions(-)" in this case
2225         * is probably less confusing (i.e skip over "2 files changed
2226         * but nothing about added/removed lines? Is this a bug in Git?").
2227         */
2228        if (insertions || deletions == 0) {
2229                strbuf_addf(&sb,
2230                            (insertions == 1) ? ", %d insertion(+)" : ", %d insertions(+)",
2231                            insertions);
2232        }
2233
2234        if (deletions || insertions == 0) {
2235                strbuf_addf(&sb,
2236                            (deletions == 1) ? ", %d deletion(-)" : ", %d deletions(-)",
2237                            deletions);
2238        }
2239        strbuf_addch(&sb, '\n');
2240        emit_diff_symbol(options, DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES,
2241                         sb.buf, sb.len, 0);
2242        strbuf_release(&sb);
2243}
2244
2245void print_stat_summary(FILE *fp, int files,
2246                        int insertions, int deletions)
2247{
2248        struct diff_options o;
2249        memset(&o, 0, sizeof(o));
2250        o.file = fp;
2251
2252        print_stat_summary_inserts_deletes(&o, files, insertions, deletions);
2253}
2254
2255static void show_stats(struct diffstat_t *data, struct diff_options *options)
2256{
2257        int i, len, add, del, adds = 0, dels = 0;
2258        uintmax_t max_change = 0, max_len = 0;
2259        int total_files = data->nr, count;
2260        int width, name_width, graph_width, number_width = 0, bin_width = 0;
2261        const char *reset, *add_c, *del_c;
2262        int extra_shown = 0;
2263        const char *line_prefix = diff_line_prefix(options);
2264        struct strbuf out = STRBUF_INIT;
2265
2266        if (data->nr == 0)
2267                return;
2268
2269        count = options->stat_count ? options->stat_count : data->nr;
2270
2271        reset = diff_get_color_opt(options, DIFF_RESET);
2272        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
2273        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
2274
2275        /*
2276         * Find the longest filename and max number of changes
2277         */
2278        for (i = 0; (i < count) && (i < data->nr); i++) {
2279                struct diffstat_file *file = data->files[i];
2280                uintmax_t change = file->added + file->deleted;
2281
2282                if (!file->is_interesting && (change == 0)) {
2283                        count++; /* not shown == room for one more */
2284                        continue;
2285                }
2286                fill_print_name(file);
2287                len = strlen(file->print_name);
2288                if (max_len < len)
2289                        max_len = len;
2290
2291                if (file->is_unmerged) {
2292                        /* "Unmerged" is 8 characters */
2293                        bin_width = bin_width < 8 ? 8 : bin_width;
2294                        continue;
2295                }
2296                if (file->is_binary) {
2297                        /* "Bin XXX -> YYY bytes" */
2298                        int w = 14 + decimal_width(file->added)
2299                                + decimal_width(file->deleted);
2300                        bin_width = bin_width < w ? w : bin_width;
2301                        /* Display change counts aligned with "Bin" */
2302                        number_width = 3;
2303                        continue;
2304                }
2305
2306                if (max_change < change)
2307                        max_change = change;
2308        }
2309        count = i; /* where we can stop scanning in data->files[] */
2310
2311        /*
2312         * We have width = stat_width or term_columns() columns total.
2313         * We want a maximum of min(max_len, stat_name_width) for the name part.
2314         * We want a maximum of min(max_change, stat_graph_width) for the +- part.
2315         * We also need 1 for " " and 4 + decimal_width(max_change)
2316         * for " | NNNN " and one the empty column at the end, altogether
2317         * 6 + decimal_width(max_change).
2318         *
2319         * If there's not enough space, we will use the smaller of
2320         * stat_name_width (if set) and 5/8*width for the filename,
2321         * and the rest for constant elements + graph part, but no more
2322         * than stat_graph_width for the graph part.
2323         * (5/8 gives 50 for filename and 30 for the constant parts + graph
2324         * for the standard terminal size).
2325         *
2326         * In other words: stat_width limits the maximum width, and
2327         * stat_name_width fixes the maximum width of the filename,
2328         * and is also used to divide available columns if there
2329         * aren't enough.
2330         *
2331         * Binary files are displayed with "Bin XXX -> YYY bytes"
2332         * instead of the change count and graph. This part is treated
2333         * similarly to the graph part, except that it is not
2334         * "scaled". If total width is too small to accommodate the
2335         * guaranteed minimum width of the filename part and the
2336         * separators and this message, this message will "overflow"
2337         * making the line longer than the maximum width.
2338         */
2339
2340        if (options->stat_width == -1)
2341                width = term_columns() - strlen(line_prefix);
2342        else
2343                width = options->stat_width ? options->stat_width : 80;
2344        number_width = decimal_width(max_change) > number_width ?
2345                decimal_width(max_change) : number_width;
2346
2347        if (options->stat_graph_width == -1)
2348                options->stat_graph_width = diff_stat_graph_width;
2349
2350        /*
2351         * Guarantee 3/8*16==6 for the graph part
2352         * and 5/8*16==10 for the filename part
2353         */
2354        if (width < 16 + 6 + number_width)
2355                width = 16 + 6 + number_width;
2356
2357        /*
2358         * First assign sizes that are wanted, ignoring available width.
2359         * strlen("Bin XXX -> YYY bytes") == bin_width, and the part
2360         * starting from "XXX" should fit in graph_width.
2361         */
2362        graph_width = max_change + 4 > bin_width ? max_change : bin_width - 4;
2363        if (options->stat_graph_width &&
2364            options->stat_graph_width < graph_width)
2365                graph_width = options->stat_graph_width;
2366
2367        name_width = (options->stat_name_width > 0 &&
2368                      options->stat_name_width < max_len) ?
2369                options->stat_name_width : max_len;
2370
2371        /*
2372         * Adjust adjustable widths not to exceed maximum width
2373         */
2374        if (name_width + number_width + 6 + graph_width > width) {
2375                if (graph_width > width * 3/8 - number_width - 6) {
2376                        graph_width = width * 3/8 - number_width - 6;
2377                        if (graph_width < 6)
2378                                graph_width = 6;
2379                }
2380
2381                if (options->stat_graph_width &&
2382                    graph_width > options->stat_graph_width)
2383                        graph_width = options->stat_graph_width;
2384                if (name_width > width - number_width - 6 - graph_width)
2385                        name_width = width - number_width - 6 - graph_width;
2386                else
2387                        graph_width = width - number_width - 6 - name_width;
2388        }
2389
2390        /*
2391         * From here name_width is the width of the name area,
2392         * and graph_width is the width of the graph area.
2393         * max_change is used to scale graph properly.
2394         */
2395        for (i = 0; i < count; i++) {
2396                const char *prefix = "";
2397                struct diffstat_file *file = data->files[i];
2398                char *name = file->print_name;
2399                uintmax_t added = file->added;
2400                uintmax_t deleted = file->deleted;
2401                int name_len;
2402
2403                if (!file->is_interesting && (added + deleted == 0))
2404                        continue;
2405
2406                /*
2407                 * "scale" the filename
2408                 */
2409                len = name_width;
2410                name_len = strlen(name);
2411                if (name_width < name_len) {
2412                        char *slash;
2413                        prefix = "...";
2414                        len -= 3;
2415                        name += name_len - len;
2416                        slash = strchr(name, '/');
2417                        if (slash)
2418                                name = slash;
2419                }
2420
2421                if (file->is_binary) {
2422                        strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2423                        strbuf_addf(&out, " %*s", number_width, "Bin");
2424                        if (!added && !deleted) {
2425                                strbuf_addch(&out, '\n');
2426                                emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2427                                                 out.buf, out.len, 0);
2428                                strbuf_reset(&out);
2429                                continue;
2430                        }
2431                        strbuf_addf(&out, " %s%"PRIuMAX"%s",
2432                                del_c, deleted, reset);
2433                        strbuf_addstr(&out, " -> ");
2434                        strbuf_addf(&out, "%s%"PRIuMAX"%s",
2435                                add_c, added, reset);
2436                        strbuf_addstr(&out, " bytes\n");
2437                        emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2438                                         out.buf, out.len, 0);
2439                        strbuf_reset(&out);
2440                        continue;
2441                }
2442                else if (file->is_unmerged) {
2443                        strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2444                        strbuf_addstr(&out, " Unmerged\n");
2445                        emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2446                                         out.buf, out.len, 0);
2447                        strbuf_reset(&out);
2448                        continue;
2449                }
2450
2451                /*
2452                 * scale the add/delete
2453                 */
2454                add = added;
2455                del = deleted;
2456
2457                if (graph_width <= max_change) {
2458                        int total = scale_linear(add + del, graph_width, max_change);
2459                        if (total < 2 && add && del)
2460                                /* width >= 2 due to the sanity check */
2461                                total = 2;
2462                        if (add < del) {
2463                                add = scale_linear(add, graph_width, max_change);
2464                                del = total - add;
2465                        } else {
2466                                del = scale_linear(del, graph_width, max_change);
2467                                add = total - del;
2468                        }
2469                }
2470                strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2471                strbuf_addf(&out, " %*"PRIuMAX"%s",
2472                        number_width, added + deleted,
2473                        added + deleted ? " " : "");
2474                show_graph(&out, '+', add, add_c, reset);
2475                show_graph(&out, '-', del, del_c, reset);
2476                strbuf_addch(&out, '\n');
2477                emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2478                                 out.buf, out.len, 0);
2479                strbuf_reset(&out);
2480        }
2481
2482        for (i = 0; i < data->nr; i++) {
2483                struct diffstat_file *file = data->files[i];
2484                uintmax_t added = file->added;
2485                uintmax_t deleted = file->deleted;
2486
2487                if (file->is_unmerged ||
2488                    (!file->is_interesting && (added + deleted == 0))) {
2489                        total_files--;
2490                        continue;
2491                }
2492
2493                if (!file->is_binary) {
2494                        adds += added;
2495                        dels += deleted;
2496                }
2497                if (i < count)
2498                        continue;
2499                if (!extra_shown)
2500                        emit_diff_symbol(options,
2501                                         DIFF_SYMBOL_STATS_SUMMARY_ABBREV,
2502                                         NULL, 0, 0);
2503                extra_shown = 1;
2504        }
2505
2506        print_stat_summary_inserts_deletes(options, total_files, adds, dels);
2507        strbuf_release(&out);
2508}
2509
2510static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
2511{
2512        int i, adds = 0, dels = 0, total_files = data->nr;
2513
2514        if (data->nr == 0)
2515                return;
2516
2517        for (i = 0; i < data->nr; i++) {
2518                int added = data->files[i]->added;
2519                int deleted = data->files[i]->deleted;
2520
2521                if (data->files[i]->is_unmerged ||
2522                    (!data->files[i]->is_interesting && (added + deleted == 0))) {
2523                        total_files--;
2524                } else if (!data->files[i]->is_binary) { /* don't count bytes */
2525                        adds += added;
2526                        dels += deleted;
2527                }
2528        }
2529        print_stat_summary_inserts_deletes(options, total_files, adds, dels);
2530}
2531
2532static void show_numstat(struct diffstat_t *data, struct diff_options *options)
2533{
2534        int i;
2535
2536        if (data->nr == 0)
2537                return;
2538
2539        for (i = 0; i < data->nr; i++) {
2540                struct diffstat_file *file = data->files[i];
2541
2542                fprintf(options->file, "%s", diff_line_prefix(options));
2543
2544                if (file->is_binary)
2545                        fprintf(options->file, "-\t-\t");
2546                else
2547                        fprintf(options->file,
2548                                "%"PRIuMAX"\t%"PRIuMAX"\t",
2549                                file->added, file->deleted);
2550                if (options->line_termination) {
2551                        fill_print_name(file);
2552                        if (!file->is_renamed)
2553                                write_name_quoted(file->name, options->file,
2554                                                  options->line_termination);
2555                        else {
2556                                fputs(file->print_name, options->file);
2557                                putc(options->line_termination, options->file);
2558                        }
2559                } else {
2560                        if (file->is_renamed) {
2561                                putc('\0', options->file);
2562                                write_name_quoted(file->from_name, options->file, '\0');
2563                        }
2564                        write_name_quoted(file->name, options->file, '\0');
2565                }
2566        }
2567}
2568
2569struct dirstat_file {
2570        const char *name;
2571        unsigned long changed;
2572};
2573
2574struct dirstat_dir {
2575        struct dirstat_file *files;
2576        int alloc, nr, permille, cumulative;
2577};
2578
2579static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
2580                unsigned long changed, const char *base, int baselen)
2581{
2582        unsigned long sum_changes = 0;
2583        unsigned int sources = 0;
2584        const char *line_prefix = diff_line_prefix(opt);
2585
2586        while (dir->nr) {
2587                struct dirstat_file *f = dir->files;
2588                int namelen = strlen(f->name);
2589                unsigned long changes;
2590                char *slash;
2591
2592                if (namelen < baselen)
2593                        break;
2594                if (memcmp(f->name, base, baselen))
2595                        break;
2596                slash = strchr(f->name + baselen, '/');
2597                if (slash) {
2598                        int newbaselen = slash + 1 - f->name;
2599                        changes = gather_dirstat(opt, dir, changed, f->name, newbaselen);
2600                        sources++;
2601                } else {
2602                        changes = f->changed;
2603                        dir->files++;
2604                        dir->nr--;
2605                        sources += 2;
2606                }
2607                sum_changes += changes;
2608        }
2609
2610        /*
2611         * We don't report dirstat's for
2612         *  - the top level
2613         *  - or cases where everything came from a single directory
2614         *    under this directory (sources == 1).
2615         */
2616        if (baselen && sources != 1) {
2617                if (sum_changes) {
2618                        int permille = sum_changes * 1000 / changed;
2619                        if (permille >= dir->permille) {
2620                                fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
2621                                        permille / 10, permille % 10, baselen, base);
2622                                if (!dir->cumulative)
2623                                        return 0;
2624                        }
2625                }
2626        }
2627        return sum_changes;
2628}
2629
2630static int dirstat_compare(const void *_a, const void *_b)
2631{
2632        const struct dirstat_file *a = _a;
2633        const struct dirstat_file *b = _b;
2634        return strcmp(a->name, b->name);
2635}
2636
2637static void show_dirstat(struct diff_options *options)
2638{
2639        int i;
2640        unsigned long changed;
2641        struct dirstat_dir dir;
2642        struct diff_queue_struct *q = &diff_queued_diff;
2643
2644        dir.files = NULL;
2645        dir.alloc = 0;
2646        dir.nr = 0;
2647        dir.permille = options->dirstat_permille;
2648        dir.cumulative = options->flags.dirstat_cumulative;
2649
2650        changed = 0;
2651        for (i = 0; i < q->nr; i++) {
2652                struct diff_filepair *p = q->queue[i];
2653                const char *name;
2654                unsigned long copied, added, damage;
2655                int content_changed;
2656
2657                name = p->two->path ? p->two->path : p->one->path;
2658
2659                if (p->one->oid_valid && p->two->oid_valid)
2660                        content_changed = oidcmp(&p->one->oid, &p->two->oid);
2661                else
2662                        content_changed = 1;
2663
2664                if (!content_changed) {
2665                        /*
2666                         * The SHA1 has not changed, so pre-/post-content is
2667                         * identical. We can therefore skip looking at the
2668                         * file contents altogether.
2669                         */
2670                        damage = 0;
2671                        goto found_damage;
2672                }
2673
2674                if (options->flags.dirstat_by_file) {
2675                        /*
2676                         * In --dirstat-by-file mode, we don't really need to
2677                         * look at the actual file contents at all.
2678                         * The fact that the SHA1 changed is enough for us to
2679                         * add this file to the list of results
2680                         * (with each file contributing equal damage).
2681                         */
2682                        damage = 1;
2683                        goto found_damage;
2684                }
2685
2686                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
2687                        diff_populate_filespec(p->one, 0);
2688                        diff_populate_filespec(p->two, 0);
2689                        diffcore_count_changes(p->one, p->two, NULL, NULL,
2690                                               &copied, &added);
2691                        diff_free_filespec_data(p->one);
2692                        diff_free_filespec_data(p->two);
2693                } else if (DIFF_FILE_VALID(p->one)) {
2694                        diff_populate_filespec(p->one, CHECK_SIZE_ONLY);
2695                        copied = added = 0;
2696                        diff_free_filespec_data(p->one);
2697                } else if (DIFF_FILE_VALID(p->two)) {
2698                        diff_populate_filespec(p->two, CHECK_SIZE_ONLY);
2699                        copied = 0;
2700                        added = p->two->size;
2701                        diff_free_filespec_data(p->two);
2702                } else
2703                        continue;
2704
2705                /*
2706                 * Original minus copied is the removed material,
2707                 * added is the new material.  They are both damages
2708                 * made to the preimage.
2709                 * If the resulting damage is zero, we know that
2710                 * diffcore_count_changes() considers the two entries to
2711                 * be identical, but since content_changed is true, we
2712                 * know that there must have been _some_ kind of change,
2713                 * so we force all entries to have damage > 0.
2714                 */
2715                damage = (p->one->size - copied) + added;
2716                if (!damage)
2717                        damage = 1;
2718
2719found_damage:
2720                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
2721                dir.files[dir.nr].name = name;
2722                dir.files[dir.nr].changed = damage;
2723                changed += damage;
2724                dir.nr++;
2725        }
2726
2727        /* This can happen even with many files, if everything was renames */
2728        if (!changed)
2729                return;
2730
2731        /* Show all directories with more than x% of the changes */
2732        QSORT(dir.files, dir.nr, dirstat_compare);
2733        gather_dirstat(options, &dir, changed, "", 0);
2734}
2735
2736static void show_dirstat_by_line(struct diffstat_t *data, struct diff_options *options)
2737{
2738        int i;
2739        unsigned long changed;
2740        struct dirstat_dir dir;
2741
2742        if (data->nr == 0)
2743                return;
2744
2745        dir.files = NULL;
2746        dir.alloc = 0;
2747        dir.nr = 0;
2748        dir.permille = options->dirstat_permille;
2749        dir.cumulative = options->flags.dirstat_cumulative;
2750
2751        changed = 0;
2752        for (i = 0; i < data->nr; i++) {
2753                struct diffstat_file *file = data->files[i];
2754                unsigned long damage = file->added + file->deleted;
2755                if (file->is_binary)
2756                        /*
2757                         * binary files counts bytes, not lines. Must find some
2758                         * way to normalize binary bytes vs. textual lines.
2759                         * The following heuristic assumes that there are 64
2760                         * bytes per "line".
2761                         * This is stupid and ugly, but very cheap...
2762                         */
2763                        damage = DIV_ROUND_UP(damage, 64);
2764                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
2765                dir.files[dir.nr].name = file->name;
2766                dir.files[dir.nr].changed = damage;
2767                changed += damage;
2768                dir.nr++;
2769        }
2770
2771        /* This can happen even with many files, if everything was renames */
2772        if (!changed)
2773                return;
2774
2775        /* Show all directories with more than x% of the changes */
2776        QSORT(dir.files, dir.nr, dirstat_compare);
2777        gather_dirstat(options, &dir, changed, "", 0);
2778}
2779
2780static void free_diffstat_info(struct diffstat_t *diffstat)
2781{
2782        int i;
2783        for (i = 0; i < diffstat->nr; i++) {
2784                struct diffstat_file *f = diffstat->files[i];
2785                free(f->print_name);
2786                free(f->name);
2787                free(f->from_name);
2788                free(f);
2789        }
2790        free(diffstat->files);
2791}
2792
2793struct checkdiff_t {
2794        const char *filename;
2795        int lineno;
2796        int conflict_marker_size;
2797        struct diff_options *o;
2798        unsigned ws_rule;
2799        unsigned status;
2800};
2801
2802static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
2803{
2804        char firstchar;
2805        int cnt;
2806
2807        if (len < marker_size + 1)
2808                return 0;
2809        firstchar = line[0];
2810        switch (firstchar) {
2811        case '=': case '>': case '<': case '|':
2812                break;
2813        default:
2814                return 0;
2815        }
2816        for (cnt = 1; cnt < marker_size; cnt++)
2817                if (line[cnt] != firstchar)
2818                        return 0;
2819        /* line[1] thru line[marker_size-1] are same as firstchar */
2820        if (len < marker_size + 1 || !isspace(line[marker_size]))
2821                return 0;
2822        return 1;
2823}
2824
2825static void checkdiff_consume(void *priv, char *line, unsigned long len)
2826{
2827        struct checkdiff_t *data = priv;
2828        int marker_size = data->conflict_marker_size;
2829        const char *ws = diff_get_color(data->o->use_color, DIFF_WHITESPACE);
2830        const char *reset = diff_get_color(data->o->use_color, DIFF_RESET);
2831        const char *set = diff_get_color(data->o->use_color, DIFF_FILE_NEW);
2832        char *err;
2833        const char *line_prefix;
2834
2835        assert(data->o);
2836        line_prefix = diff_line_prefix(data->o);
2837
2838        if (line[0] == '+') {
2839                unsigned bad;
2840                data->lineno++;
2841                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
2842                        data->status |= 1;
2843                        fprintf(data->o->file,
2844                                "%s%s:%d: leftover conflict marker\n",
2845                                line_prefix, data->filename, data->lineno);
2846                }
2847                bad = ws_check(line + 1, len - 1, data->ws_rule);
2848                if (!bad)
2849                        return;
2850                data->status |= bad;
2851                err = whitespace_error_string(bad);
2852                fprintf(data->o->file, "%s%s:%d: %s.\n",
2853                        line_prefix, data->filename, data->lineno, err);
2854                free(err);
2855                emit_line(data->o, set, reset, line, 1);
2856                ws_check_emit(line + 1, len - 1, data->ws_rule,
2857                              data->o->file, set, reset, ws);
2858        } else if (line[0] == ' ') {
2859                data->lineno++;
2860        } else if (line[0] == '@') {
2861                char *plus = strchr(line, '+');
2862                if (plus)
2863                        data->lineno = strtol(plus, NULL, 10) - 1;
2864                else
2865                        die("invalid diff");
2866        }
2867}
2868
2869static unsigned char *deflate_it(char *data,
2870                                 unsigned long size,
2871                                 unsigned long *result_size)
2872{
2873        int bound;
2874        unsigned char *deflated;
2875        git_zstream stream;
2876
2877        git_deflate_init(&stream, zlib_compression_level);
2878        bound = git_deflate_bound(&stream, size);
2879        deflated = xmalloc(bound);
2880        stream.next_out = deflated;
2881        stream.avail_out = bound;
2882
2883        stream.next_in = (unsigned char *)data;
2884        stream.avail_in = size;
2885        while (git_deflate(&stream, Z_FINISH) == Z_OK)
2886                ; /* nothing */
2887        git_deflate_end(&stream);
2888        *result_size = stream.total_out;
2889        return deflated;
2890}
2891
2892static void emit_binary_diff_body(struct diff_options *o,
2893                                  mmfile_t *one, mmfile_t *two)
2894{
2895        void *cp;
2896        void *delta;
2897        void *deflated;
2898        void *data;
2899        unsigned long orig_size;
2900        unsigned long delta_size;
2901        unsigned long deflate_size;
2902        unsigned long data_size;
2903
2904        /* We could do deflated delta, or we could do just deflated two,
2905         * whichever is smaller.
2906         */
2907        delta = NULL;
2908        deflated = deflate_it(two->ptr, two->size, &deflate_size);
2909        if (one->size && two->size) {
2910                delta = diff_delta(one->ptr, one->size,
2911                                   two->ptr, two->size,
2912                                   &delta_size, deflate_size);
2913                if (delta) {
2914                        void *to_free = delta;
2915                        orig_size = delta_size;
2916                        delta = deflate_it(delta, delta_size, &delta_size);
2917                        free(to_free);
2918                }
2919        }
2920
2921        if (delta && delta_size < deflate_size) {
2922                char *s = xstrfmt("%lu", orig_size);
2923                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA,
2924                                 s, strlen(s), 0);
2925                free(s);
2926                free(deflated);
2927                data = delta;
2928                data_size = delta_size;
2929        } else {
2930                char *s = xstrfmt("%lu", two->size);
2931                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL,
2932                                 s, strlen(s), 0);
2933                free(s);
2934                free(delta);
2935                data = deflated;
2936                data_size = deflate_size;
2937        }
2938
2939        /* emit data encoded in base85 */
2940        cp = data;
2941        while (data_size) {
2942                int len;
2943                int bytes = (52 < data_size) ? 52 : data_size;
2944                char line[71];
2945                data_size -= bytes;
2946                if (bytes <= 26)
2947                        line[0] = bytes + 'A' - 1;
2948                else
2949                        line[0] = bytes - 26 + 'a' - 1;
2950                encode_85(line + 1, cp, bytes);
2951                cp = (char *) cp + bytes;
2952
2953                len = strlen(line);
2954                line[len++] = '\n';
2955                line[len] = '\0';
2956
2957                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_BODY,
2958                                 line, len, 0);
2959        }
2960        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_FOOTER, NULL, 0, 0);
2961        free(data);
2962}
2963
2964static void emit_binary_diff(struct diff_options *o,
2965                             mmfile_t *one, mmfile_t *two)
2966{
2967        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER, NULL, 0, 0);
2968        emit_binary_diff_body(o, one, two);
2969        emit_binary_diff_body(o, two, one);
2970}
2971
2972int diff_filespec_is_binary(struct diff_filespec *one)
2973{
2974        if (one->is_binary == -1) {
2975                diff_filespec_load_driver(one);
2976                if (one->driver->binary != -1)
2977                        one->is_binary = one->driver->binary;
2978                else {
2979                        if (!one->data && DIFF_FILE_VALID(one))
2980                                diff_populate_filespec(one, CHECK_BINARY);
2981                        if (one->is_binary == -1 && one->data)
2982                                one->is_binary = buffer_is_binary(one->data,
2983                                                one->size);
2984                        if (one->is_binary == -1)
2985                                one->is_binary = 0;
2986                }
2987        }
2988        return one->is_binary;
2989}
2990
2991static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
2992{
2993        diff_filespec_load_driver(one);
2994        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
2995}
2996
2997void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
2998{
2999        if (!options->a_prefix)
3000                options->a_prefix = a;
3001        if (!options->b_prefix)
3002                options->b_prefix = b;
3003}
3004
3005struct userdiff_driver *get_textconv(struct diff_filespec *one)
3006{
3007        if (!DIFF_FILE_VALID(one))
3008                return NULL;
3009
3010        diff_filespec_load_driver(one);
3011        return userdiff_get_textconv(one->driver);
3012}
3013
3014static void builtin_diff(const char *name_a,
3015                         const char *name_b,
3016                         struct diff_filespec *one,
3017                         struct diff_filespec *two,
3018                         const char *xfrm_msg,
3019                         int must_show_header,
3020                         struct diff_options *o,
3021                         int complete_rewrite)
3022{
3023        mmfile_t mf1, mf2;
3024        const char *lbl[2];
3025        char *a_one, *b_two;
3026        const char *meta = diff_get_color_opt(o, DIFF_METAINFO);
3027        const char *reset = diff_get_color_opt(o, DIFF_RESET);
3028        const char *a_prefix, *b_prefix;
3029        struct userdiff_driver *textconv_one = NULL;
3030        struct userdiff_driver *textconv_two = NULL;
3031        struct strbuf header = STRBUF_INIT;
3032        const char *line_prefix = diff_line_prefix(o);
3033
3034        diff_set_mnemonic_prefix(o, "a/", "b/");
3035        if (o->flags.reverse_diff) {
3036                a_prefix = o->b_prefix;
3037                b_prefix = o->a_prefix;
3038        } else {
3039                a_prefix = o->a_prefix;
3040                b_prefix = o->b_prefix;
3041        }
3042
3043        if (o->submodule_format == DIFF_SUBMODULE_LOG &&
3044            (!one->mode || S_ISGITLINK(one->mode)) &&
3045            (!two->mode || S_ISGITLINK(two->mode))) {
3046                show_submodule_summary(o, one->path ? one->path : two->path,
3047                                &one->oid, &two->oid,
3048                                two->dirty_submodule);
3049                return;
3050        } else if (o->submodule_format == DIFF_SUBMODULE_INLINE_DIFF &&
3051                   (!one->mode || S_ISGITLINK(one->mode)) &&
3052                   (!two->mode || S_ISGITLINK(two->mode))) {
3053                show_submodule_inline_diff(o, one->path ? one->path : two->path,
3054                                &one->oid, &two->oid,
3055                                two->dirty_submodule);
3056                return;
3057        }
3058
3059        if (o->flags.allow_textconv) {
3060                textconv_one = get_textconv(one);
3061                textconv_two = get_textconv(two);
3062        }
3063
3064        /* Never use a non-valid filename anywhere if at all possible */
3065        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
3066        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
3067
3068        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
3069        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
3070        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
3071        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
3072        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, meta, a_one, b_two, reset);
3073        if (lbl[0][0] == '/') {
3074                /* /dev/null */
3075                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, meta, two->mode, reset);
3076                if (xfrm_msg)
3077                        strbuf_addstr(&header, xfrm_msg);
3078                must_show_header = 1;
3079        }
3080        else if (lbl[1][0] == '/') {
3081                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, meta, one->mode, reset);
3082                if (xfrm_msg)
3083                        strbuf_addstr(&header, xfrm_msg);
3084                must_show_header = 1;
3085        }
3086        else {
3087                if (one->mode != two->mode) {
3088                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, meta, one->mode, reset);
3089                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, meta, two->mode, reset);
3090                        must_show_header = 1;
3091                }
3092                if (xfrm_msg)
3093                        strbuf_addstr(&header, xfrm_msg);
3094
3095                /*
3096                 * we do not run diff between different kind
3097                 * of objects.
3098                 */
3099                if ((one->mode ^ two->mode) & S_IFMT)
3100                        goto free_ab_and_return;
3101                if (complete_rewrite &&
3102                    (textconv_one || !diff_filespec_is_binary(one)) &&
3103                    (textconv_two || !diff_filespec_is_binary(two))) {
3104                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3105                                         header.buf, header.len, 0);
3106                        strbuf_reset(&header);
3107                        emit_rewrite_diff(name_a, name_b, one, two,
3108                                                textconv_one, textconv_two, o);
3109                        o->found_changes = 1;
3110                        goto free_ab_and_return;
3111                }
3112        }
3113
3114        if (o->irreversible_delete && lbl[1][0] == '/') {
3115                emit_diff_symbol(o, DIFF_SYMBOL_HEADER, header.buf,
3116                                 header.len, 0);
3117                strbuf_reset(&header);
3118                goto free_ab_and_return;
3119        } else if (!o->flags.text &&
3120            ( (!textconv_one && diff_filespec_is_binary(one)) ||
3121              (!textconv_two && diff_filespec_is_binary(two)) )) {
3122                struct strbuf sb = STRBUF_INIT;
3123                if (!one->data && !two->data &&
3124                    S_ISREG(one->mode) && S_ISREG(two->mode) &&
3125                    !o->flags.binary) {
3126                        if (!oidcmp(&one->oid, &two->oid)) {
3127                                if (must_show_header)
3128                                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3129                                                         header.buf, header.len,
3130                                                         0);
3131                                goto free_ab_and_return;
3132                        }
3133                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3134                                         header.buf, header.len, 0);
3135                        strbuf_addf(&sb, "%sBinary files %s and %s differ\n",
3136                                    diff_line_prefix(o), lbl[0], lbl[1]);
3137                        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_FILES,
3138                                         sb.buf, sb.len, 0);
3139                        strbuf_release(&sb);
3140                        goto free_ab_and_return;
3141                }
3142                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
3143                        die("unable to read files to diff");
3144                /* Quite common confusing case */
3145                if (mf1.size == mf2.size &&
3146                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
3147                        if (must_show_header)
3148                                emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3149                                                 header.buf, header.len, 0);
3150                        goto free_ab_and_return;
3151                }
3152                emit_diff_symbol(o, DIFF_SYMBOL_HEADER, header.buf, header.len, 0);
3153                strbuf_reset(&header);
3154                if (o->flags.binary)
3155                        emit_binary_diff(o, &mf1, &mf2);
3156                else {
3157                        strbuf_addf(&sb, "%sBinary files %s and %s differ\n",
3158                                    diff_line_prefix(o), lbl[0], lbl[1]);
3159                        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_FILES,
3160                                         sb.buf, sb.len, 0);
3161                        strbuf_release(&sb);
3162                }
3163                o->found_changes = 1;
3164        } else {
3165                /* Crazy xdl interfaces.. */
3166                const char *diffopts = getenv("GIT_DIFF_OPTS");
3167                const char *v;
3168                xpparam_t xpp;
3169                xdemitconf_t xecfg;
3170                struct emit_callback ecbdata;
3171                const struct userdiff_funcname *pe;
3172
3173                if (must_show_header) {
3174                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3175                                         header.buf, header.len, 0);
3176                        strbuf_reset(&header);
3177                }
3178
3179                mf1.size = fill_textconv(textconv_one, one, &mf1.ptr);
3180                mf2.size = fill_textconv(textconv_two, two, &mf2.ptr);
3181
3182                pe = diff_funcname_pattern(one);
3183                if (!pe)
3184                        pe = diff_funcname_pattern(two);
3185
3186                memset(&xpp, 0, sizeof(xpp));
3187                memset(&xecfg, 0, sizeof(xecfg));
3188                memset(&ecbdata, 0, sizeof(ecbdata));
3189                ecbdata.label_path = lbl;
3190                ecbdata.color_diff = want_color(o->use_color);
3191                ecbdata.ws_rule = whitespace_rule(name_b);
3192                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
3193                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
3194                ecbdata.opt = o;
3195                ecbdata.header = header.len ? &header : NULL;
3196                xpp.flags = o->xdl_opts;
3197                xpp.anchors = o->anchors;
3198                xpp.anchors_nr = o->anchors_nr;
3199                xecfg.ctxlen = o->context;
3200                xecfg.interhunkctxlen = o->interhunkcontext;
3201                xecfg.flags = XDL_EMIT_FUNCNAMES;
3202                if (o->flags.funccontext)
3203                        xecfg.flags |= XDL_EMIT_FUNCCONTEXT;
3204                if (pe)
3205                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
3206                if (!diffopts)
3207                        ;
3208                else if (skip_prefix(diffopts, "--unified=", &v))
3209                        xecfg.ctxlen = strtoul(v, NULL, 10);
3210                else if (skip_prefix(diffopts, "-u", &v))
3211                        xecfg.ctxlen = strtoul(v, NULL, 10);
3212                if (o->word_diff)
3213                        init_diff_words_data(&ecbdata, o, one, two);
3214                if (xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
3215                                  &xpp, &xecfg))
3216                        die("unable to generate diff for %s", one->path);
3217                if (o->word_diff)
3218                        free_diff_words_data(&ecbdata);
3219                if (textconv_one)
3220                        free(mf1.ptr);
3221                if (textconv_two)
3222                        free(mf2.ptr);
3223                xdiff_clear_find_func(&xecfg);
3224        }
3225
3226 free_ab_and_return:
3227        strbuf_release(&header);
3228        diff_free_filespec_data(one);
3229        diff_free_filespec_data(two);
3230        free(a_one);
3231        free(b_two);
3232        return;
3233}
3234
3235static char *get_compact_summary(const struct diff_filepair *p, int is_renamed)
3236{
3237        if (!is_renamed) {
3238                if (p->status == DIFF_STATUS_ADDED) {
3239                        if (S_ISLNK(p->two->mode))
3240                                return "new +l";
3241                        else if ((p->two->mode & 0777) == 0755)
3242                                return "new +x";
3243                        else
3244                                return "new";
3245                } else if (p->status == DIFF_STATUS_DELETED)
3246                        return "gone";
3247        }
3248        if (S_ISLNK(p->one->mode) && !S_ISLNK(p->two->mode))
3249                return "mode -l";
3250        else if (!S_ISLNK(p->one->mode) && S_ISLNK(p->two->mode))
3251                return "mode +l";
3252        else if ((p->one->mode & 0777) == 0644 &&
3253                 (p->two->mode & 0777) == 0755)
3254                return "mode +x";
3255        else if ((p->one->mode & 0777) == 0755 &&
3256                 (p->two->mode & 0777) == 0644)
3257                return "mode -x";
3258        return NULL;
3259}
3260
3261static void builtin_diffstat(const char *name_a, const char *name_b,
3262                             struct diff_filespec *one,
3263                             struct diff_filespec *two,
3264                             struct diffstat_t *diffstat,
3265                             struct diff_options *o,
3266                             struct diff_filepair *p)
3267{
3268        mmfile_t mf1, mf2;
3269        struct diffstat_file *data;
3270        int same_contents;
3271        int complete_rewrite = 0;
3272
3273        if (!DIFF_PAIR_UNMERGED(p)) {
3274                if (p->status == DIFF_STATUS_MODIFIED && p->score)
3275                        complete_rewrite = 1;
3276        }
3277
3278        data = diffstat_add(diffstat, name_a, name_b);
3279        data->is_interesting = p->status != DIFF_STATUS_UNKNOWN;
3280        if (o->flags.stat_with_summary)
3281                data->comments = get_compact_summary(p, data->is_renamed);
3282
3283        if (!one || !two) {
3284                data->is_unmerged = 1;
3285                return;
3286        }
3287
3288        same_contents = !oidcmp(&one->oid, &two->oid);
3289
3290        if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
3291                data->is_binary = 1;
3292                if (same_contents) {
3293                        data->added = 0;
3294                        data->deleted = 0;
3295                } else {
3296                        data->added = diff_filespec_size(two);
3297                        data->deleted = diff_filespec_size(one);
3298                }
3299        }
3300
3301        else if (complete_rewrite) {
3302                diff_populate_filespec(one, 0);
3303                diff_populate_filespec(two, 0);
3304                data->deleted = count_lines(one->data, one->size);
3305                data->added = count_lines(two->data, two->size);
3306        }
3307
3308        else if (!same_contents) {
3309                /* Crazy xdl interfaces.. */
3310                xpparam_t xpp;
3311                xdemitconf_t xecfg;
3312
3313                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
3314                        die("unable to read files to diff");
3315
3316                memset(&xpp, 0, sizeof(xpp));
3317                memset(&xecfg, 0, sizeof(xecfg));
3318                xpp.flags = o->xdl_opts;
3319                xpp.anchors = o->anchors;
3320                xpp.anchors_nr = o->anchors_nr;
3321                xecfg.ctxlen = o->context;
3322                xecfg.interhunkctxlen = o->interhunkcontext;
3323                if (xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
3324                                  &xpp, &xecfg))
3325                        die("unable to generate diffstat for %s", one->path);
3326        }
3327
3328        diff_free_filespec_data(one);
3329        diff_free_filespec_data(two);
3330}
3331
3332static void builtin_checkdiff(const char *name_a, const char *name_b,
3333                              const char *attr_path,
3334                              struct diff_filespec *one,
3335                              struct diff_filespec *two,
3336                              struct diff_options *o)
3337{
3338        mmfile_t mf1, mf2;
3339        struct checkdiff_t data;
3340
3341        if (!two)
3342                return;
3343
3344        memset(&data, 0, sizeof(data));
3345        data.filename = name_b ? name_b : name_a;
3346        data.lineno = 0;
3347        data.o = o;
3348        data.ws_rule = whitespace_rule(attr_path);
3349        data.conflict_marker_size = ll_merge_marker_size(attr_path);
3350
3351        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
3352                die("unable to read files to diff");
3353
3354        /*
3355         * All the other codepaths check both sides, but not checking
3356         * the "old" side here is deliberate.  We are checking the newly
3357         * introduced changes, and as long as the "new" side is text, we
3358         * can and should check what it introduces.
3359         */
3360        if (diff_filespec_is_binary(two))
3361                goto free_and_return;
3362        else {
3363                /* Crazy xdl interfaces.. */
3364                xpparam_t xpp;
3365                xdemitconf_t xecfg;
3366
3367                memset(&xpp, 0, sizeof(xpp));
3368                memset(&xecfg, 0, sizeof(xecfg));
3369                xecfg.ctxlen = 1; /* at least one context line */
3370                xpp.flags = 0;
3371                if (xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
3372                                  &xpp, &xecfg))
3373                        die("unable to generate checkdiff for %s", one->path);
3374
3375                if (data.ws_rule & WS_BLANK_AT_EOF) {
3376                        struct emit_callback ecbdata;
3377                        int blank_at_eof;
3378
3379                        ecbdata.ws_rule = data.ws_rule;
3380                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
3381                        blank_at_eof = ecbdata.blank_at_eof_in_postimage;
3382
3383                        if (blank_at_eof) {
3384                                static char *err;
3385                                if (!err)
3386                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
3387                                fprintf(o->file, "%s:%d: %s.\n",
3388                                        data.filename, blank_at_eof, err);
3389                                data.status = 1; /* report errors */
3390                        }
3391                }
3392        }
3393 free_and_return:
3394        diff_free_filespec_data(one);
3395        diff_free_filespec_data(two);
3396        if (data.status)
3397                o->flags.check_failed = 1;
3398}
3399
3400struct diff_filespec *alloc_filespec(const char *path)
3401{
3402        struct diff_filespec *spec;
3403
3404        FLEXPTR_ALLOC_STR(spec, path, path);
3405        spec->count = 1;
3406        spec->is_binary = -1;
3407        return spec;
3408}
3409
3410void free_filespec(struct diff_filespec *spec)
3411{
3412        if (!--spec->count) {
3413                diff_free_filespec_data(spec);
3414                free(spec);
3415        }
3416}
3417
3418void fill_filespec(struct diff_filespec *spec, const struct object_id *oid,
3419                   int oid_valid, unsigned short mode)
3420{
3421        if (mode) {
3422                spec->mode = canon_mode(mode);
3423                oidcpy(&spec->oid, oid);
3424                spec->oid_valid = oid_valid;
3425        }
3426}
3427
3428/*
3429 * Given a name and sha1 pair, if the index tells us the file in
3430 * the work tree has that object contents, return true, so that
3431 * prepare_temp_file() does not have to inflate and extract.
3432 */
3433static int reuse_worktree_file(const char *name, const struct object_id *oid, int want_file)
3434{
3435        const struct cache_entry *ce;
3436        struct stat st;
3437        int pos, len;
3438
3439        /*
3440         * We do not read the cache ourselves here, because the
3441         * benchmark with my previous version that always reads cache
3442         * shows that it makes things worse for diff-tree comparing
3443         * two linux-2.6 kernel trees in an already checked out work
3444         * tree.  This is because most diff-tree comparisons deal with
3445         * only a small number of files, while reading the cache is
3446         * expensive for a large project, and its cost outweighs the
3447         * savings we get by not inflating the object to a temporary
3448         * file.  Practically, this code only helps when we are used
3449         * by diff-cache --cached, which does read the cache before
3450         * calling us.
3451         */
3452        if (!active_cache)
3453                return 0;
3454
3455        /* We want to avoid the working directory if our caller
3456         * doesn't need the data in a normal file, this system
3457         * is rather slow with its stat/open/mmap/close syscalls,
3458         * and the object is contained in a pack file.  The pack
3459         * is probably already open and will be faster to obtain
3460         * the data through than the working directory.  Loose
3461         * objects however would tend to be slower as they need
3462         * to be individually opened and inflated.
3463         */
3464        if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(oid->hash))
3465                return 0;
3466
3467        /*
3468         * Similarly, if we'd have to convert the file contents anyway, that
3469         * makes the optimization not worthwhile.
3470         */
3471        if (!want_file && would_convert_to_git(&the_index, name))
3472                return 0;
3473
3474        len = strlen(name);
3475        pos = cache_name_pos(name, len);
3476        if (pos < 0)
3477                return 0;
3478        ce = active_cache[pos];
3479
3480        /*
3481         * This is not the sha1 we are looking for, or
3482         * unreusable because it is not a regular file.
3483         */
3484        if (oidcmp(oid, &ce->oid) || !S_ISREG(ce->ce_mode))
3485                return 0;
3486
3487        /*
3488         * If ce is marked as "assume unchanged", there is no
3489         * guarantee that work tree matches what we are looking for.
3490         */
3491        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
3492                return 0;
3493
3494        /*
3495         * If ce matches the file in the work tree, we can reuse it.
3496         */
3497        if (ce_uptodate(ce) ||
3498            (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
3499                return 1;
3500
3501        return 0;
3502}
3503
3504static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
3505{
3506        struct strbuf buf = STRBUF_INIT;
3507        char *dirty = "";
3508
3509        /* Are we looking at the work tree? */
3510        if (s->dirty_submodule)
3511                dirty = "-dirty";
3512
3513        strbuf_addf(&buf, "Subproject commit %s%s\n",
3514                    oid_to_hex(&s->oid), dirty);
3515        s->size = buf.len;
3516        if (size_only) {
3517                s->data = NULL;
3518                strbuf_release(&buf);
3519        } else {
3520                s->data = strbuf_detach(&buf, NULL);
3521                s->should_free = 1;
3522        }
3523        return 0;
3524}
3525
3526/*
3527 * While doing rename detection and pickaxe operation, we may need to
3528 * grab the data for the blob (or file) for our own in-core comparison.
3529 * diff_filespec has data and size fields for this purpose.
3530 */
3531int diff_populate_filespec(struct diff_filespec *s, unsigned int flags)
3532{
3533        int size_only = flags & CHECK_SIZE_ONLY;
3534        int err = 0;
3535        int conv_flags = global_conv_flags_eol;
3536        /*
3537         * demote FAIL to WARN to allow inspecting the situation
3538         * instead of refusing.
3539         */
3540        if (conv_flags & CONV_EOL_RNDTRP_DIE)
3541                conv_flags = CONV_EOL_RNDTRP_WARN;
3542
3543        if (!DIFF_FILE_VALID(s))
3544                die("internal error: asking to populate invalid file.");
3545        if (S_ISDIR(s->mode))
3546                return -1;
3547
3548        if (s->data)
3549                return 0;
3550
3551        if (size_only && 0 < s->size)
3552                return 0;
3553
3554        if (S_ISGITLINK(s->mode))
3555                return diff_populate_gitlink(s, size_only);
3556
3557        if (!s->oid_valid ||
3558            reuse_worktree_file(s->path, &s->oid, 0)) {
3559                struct strbuf buf = STRBUF_INIT;
3560                struct stat st;
3561                int fd;
3562
3563                if (lstat(s->path, &st) < 0) {
3564                err_empty:
3565                        err = -1;
3566                empty:
3567                        s->data = (char *)"";
3568                        s->size = 0;
3569                        return err;
3570                }
3571                s->size = xsize_t(st.st_size);
3572                if (!s->size)
3573                        goto empty;
3574                if (S_ISLNK(st.st_mode)) {
3575                        struct strbuf sb = STRBUF_INIT;
3576
3577                        if (strbuf_readlink(&sb, s->path, s->size))
3578                                goto err_empty;
3579                        s->size = sb.len;
3580                        s->data = strbuf_detach(&sb, NULL);
3581                        s->should_free = 1;
3582                        return 0;
3583                }
3584
3585                /*
3586                 * Even if the caller would be happy with getting
3587                 * only the size, we cannot return early at this
3588                 * point if the path requires us to run the content
3589                 * conversion.
3590                 */
3591                if (size_only && !would_convert_to_git(&the_index, s->path))
3592                        return 0;
3593
3594                /*
3595                 * Note: this check uses xsize_t(st.st_size) that may
3596                 * not be the true size of the blob after it goes
3597                 * through convert_to_git().  This may not strictly be
3598                 * correct, but the whole point of big_file_threshold
3599                 * and is_binary check being that we want to avoid
3600                 * opening the file and inspecting the contents, this
3601                 * is probably fine.
3602                 */
3603                if ((flags & CHECK_BINARY) &&
3604                    s->size > big_file_threshold && s->is_binary == -1) {
3605                        s->is_binary = 1;
3606                        return 0;
3607                }
3608                fd = open(s->path, O_RDONLY);
3609                if (fd < 0)
3610                        goto err_empty;
3611                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
3612                close(fd);
3613                s->should_munmap = 1;
3614
3615                /*
3616                 * Convert from working tree format to canonical git format
3617                 */
3618                if (convert_to_git(&the_index, s->path, s->data, s->size, &buf, conv_flags)) {
3619                        size_t size = 0;
3620                        munmap(s->data, s->size);
3621                        s->should_munmap = 0;
3622                        s->data = strbuf_detach(&buf, &size);
3623                        s->size = size;
3624                        s->should_free = 1;
3625                }
3626        }
3627        else {
3628                enum object_type type;
3629                if (size_only || (flags & CHECK_BINARY)) {
3630                        type = oid_object_info(the_repository, &s->oid,
3631                                               &s->size);
3632                        if (type < 0)
3633                                die("unable to read %s",
3634                                    oid_to_hex(&s->oid));
3635                        if (size_only)
3636                                return 0;
3637                        if (s->size > big_file_threshold && s->is_binary == -1) {
3638                                s->is_binary = 1;
3639                                return 0;
3640                        }
3641                }
3642                s->data = read_object_file(&s->oid, &type, &s->size);
3643                if (!s->data)
3644                        die("unable to read %s", oid_to_hex(&s->oid));
3645                s->should_free = 1;
3646        }
3647        return 0;
3648}
3649
3650void diff_free_filespec_blob(struct diff_filespec *s)
3651{
3652        if (s->should_free)
3653                free(s->data);
3654        else if (s->should_munmap)
3655                munmap(s->data, s->size);
3656
3657        if (s->should_free || s->should_munmap) {
3658                s->should_free = s->should_munmap = 0;
3659                s->data = NULL;
3660        }
3661}
3662
3663void diff_free_filespec_data(struct diff_filespec *s)
3664{
3665        diff_free_filespec_blob(s);
3666        FREE_AND_NULL(s->cnt_data);
3667}
3668
3669static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
3670                           void *blob,
3671                           unsigned long size,
3672                           const struct object_id *oid,
3673                           int mode)
3674{
3675        struct strbuf buf = STRBUF_INIT;
3676        struct strbuf tempfile = STRBUF_INIT;
3677        char *path_dup = xstrdup(path);
3678        const char *base = basename(path_dup);
3679
3680        /* Generate "XXXXXX_basename.ext" */
3681        strbuf_addstr(&tempfile, "XXXXXX_");
3682        strbuf_addstr(&tempfile, base);
3683
3684        temp->tempfile = mks_tempfile_ts(tempfile.buf, strlen(base) + 1);
3685        if (!temp->tempfile)
3686                die_errno("unable to create temp-file");
3687        if (convert_to_working_tree(path,
3688                        (const char *)blob, (size_t)size, &buf)) {
3689                blob = buf.buf;
3690                size = buf.len;
3691        }
3692        if (write_in_full(temp->tempfile->fd, blob, size) < 0 ||
3693            close_tempfile_gently(temp->tempfile))
3694                die_errno("unable to write temp-file");
3695        temp->name = get_tempfile_path(temp->tempfile);
3696        oid_to_hex_r(temp->hex, oid);
3697        xsnprintf(temp->mode, sizeof(temp->mode), "%06o", mode);
3698        strbuf_release(&buf);
3699        strbuf_release(&tempfile);
3700        free(path_dup);
3701}
3702
3703static struct diff_tempfile *prepare_temp_file(const char *name,
3704                struct diff_filespec *one)
3705{
3706        struct diff_tempfile *temp = claim_diff_tempfile();
3707
3708        if (!DIFF_FILE_VALID(one)) {
3709        not_a_valid_file:
3710                /* A '-' entry produces this for file-2, and
3711                 * a '+' entry produces this for file-1.
3712                 */
3713                temp->name = "/dev/null";
3714                xsnprintf(temp->hex, sizeof(temp->hex), ".");
3715                xsnprintf(temp->mode, sizeof(temp->mode), ".");
3716                return temp;
3717        }
3718
3719        if (!S_ISGITLINK(one->mode) &&
3720            (!one->oid_valid ||
3721             reuse_worktree_file(name, &one->oid, 1))) {
3722                struct stat st;
3723                if (lstat(name, &st) < 0) {
3724                        if (errno == ENOENT)
3725                                goto not_a_valid_file;
3726                        die_errno("stat(%s)", name);
3727                }
3728                if (S_ISLNK(st.st_mode)) {
3729                        struct strbuf sb = STRBUF_INIT;
3730                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
3731                                die_errno("readlink(%s)", name);
3732                        prep_temp_blob(name, temp, sb.buf, sb.len,
3733                                       (one->oid_valid ?
3734                                        &one->oid : &null_oid),
3735                                       (one->oid_valid ?
3736                                        one->mode : S_IFLNK));
3737                        strbuf_release(&sb);
3738                }
3739                else {
3740                        /* we can borrow from the file in the work tree */
3741                        temp->name = name;
3742                        if (!one->oid_valid)
3743                                oid_to_hex_r(temp->hex, &null_oid);
3744                        else
3745                                oid_to_hex_r(temp->hex, &one->oid);
3746                        /* Even though we may sometimes borrow the
3747                         * contents from the work tree, we always want
3748                         * one->mode.  mode is trustworthy even when
3749                         * !(one->oid_valid), as long as
3750                         * DIFF_FILE_VALID(one).
3751                         */
3752                        xsnprintf(temp->mode, sizeof(temp->mode), "%06o", one->mode);
3753                }
3754                return temp;
3755        }
3756        else {
3757                if (diff_populate_filespec(one, 0))
3758                        die("cannot read data blob for %s", one->path);
3759                prep_temp_blob(name, temp, one->data, one->size,
3760                               &one->oid, one->mode);
3761        }
3762        return temp;
3763}
3764
3765static void add_external_diff_name(struct argv_array *argv,
3766                                   const char *name,
3767                                   struct diff_filespec *df)
3768{
3769        struct diff_tempfile *temp = prepare_temp_file(name, df);
3770        argv_array_push(argv, temp->name);
3771        argv_array_push(argv, temp->hex);
3772        argv_array_push(argv, temp->mode);
3773}
3774
3775/* An external diff command takes:
3776 *
3777 * diff-cmd name infile1 infile1-sha1 infile1-mode \
3778 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
3779 *
3780 */
3781static void run_external_diff(const char *pgm,
3782                              const char *name,
3783                              const char *other,
3784                              struct diff_filespec *one,
3785                              struct diff_filespec *two,
3786                              const char *xfrm_msg,
3787                              int complete_rewrite,
3788                              struct diff_options *o)
3789{
3790        struct argv_array argv = ARGV_ARRAY_INIT;
3791        struct argv_array env = ARGV_ARRAY_INIT;
3792        struct diff_queue_struct *q = &diff_queued_diff;
3793
3794        argv_array_push(&argv, pgm);
3795        argv_array_push(&argv, name);
3796
3797        if (one && two) {
3798                add_external_diff_name(&argv, name, one);
3799                if (!other)
3800                        add_external_diff_name(&argv, name, two);
3801                else {
3802                        add_external_diff_name(&argv, other, two);
3803                        argv_array_push(&argv, other);
3804                        argv_array_push(&argv, xfrm_msg);
3805                }
3806        }
3807
3808        argv_array_pushf(&env, "GIT_DIFF_PATH_COUNTER=%d", ++o->diff_path_counter);
3809        argv_array_pushf(&env, "GIT_DIFF_PATH_TOTAL=%d", q->nr);
3810
3811        if (run_command_v_opt_cd_env(argv.argv, RUN_USING_SHELL, NULL, env.argv))
3812                die(_("external diff died, stopping at %s"), name);
3813
3814        remove_tempfile();
3815        argv_array_clear(&argv);
3816        argv_array_clear(&env);
3817}
3818
3819static int similarity_index(struct diff_filepair *p)
3820{
3821        return p->score * 100 / MAX_SCORE;
3822}
3823
3824static const char *diff_abbrev_oid(const struct object_id *oid, int abbrev)
3825{
3826        if (startup_info->have_repository)
3827                return find_unique_abbrev(oid, abbrev);
3828        else {
3829                char *hex = oid_to_hex(oid);
3830                if (abbrev < 0)
3831                        abbrev = FALLBACK_DEFAULT_ABBREV;
3832                if (abbrev > GIT_SHA1_HEXSZ)
3833                        die("BUG: oid abbreviation out of range: %d", abbrev);
3834                if (abbrev)
3835                        hex[abbrev] = '\0';
3836                return hex;
3837        }
3838}
3839
3840static void fill_metainfo(struct strbuf *msg,
3841                          const char *name,
3842                          const char *other,
3843                          struct diff_filespec *one,
3844                          struct diff_filespec *two,
3845                          struct diff_options *o,
3846                          struct diff_filepair *p,
3847                          int *must_show_header,
3848                          int use_color)
3849{
3850        const char *set = diff_get_color(use_color, DIFF_METAINFO);
3851        const char *reset = diff_get_color(use_color, DIFF_RESET);
3852        const char *line_prefix = diff_line_prefix(o);
3853
3854        *must_show_header = 1;
3855        strbuf_init(msg, PATH_MAX * 2 + 300);
3856        switch (p->status) {
3857        case DIFF_STATUS_COPIED:
3858                strbuf_addf(msg, "%s%ssimilarity index %d%%",
3859                            line_prefix, set, similarity_index(p));
3860                strbuf_addf(msg, "%s\n%s%scopy from ",
3861                            reset,  line_prefix, set);
3862                quote_c_style(name, msg, NULL, 0);
3863                strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
3864                quote_c_style(other, msg, NULL, 0);
3865                strbuf_addf(msg, "%s\n", reset);
3866                break;
3867        case DIFF_STATUS_RENAMED:
3868                strbuf_addf(msg, "%s%ssimilarity index %d%%",
3869                            line_prefix, set, similarity_index(p));
3870                strbuf_addf(msg, "%s\n%s%srename from ",
3871                            reset, line_prefix, set);
3872                quote_c_style(name, msg, NULL, 0);
3873                strbuf_addf(msg, "%s\n%s%srename to ",
3874                            reset, line_prefix, set);
3875                quote_c_style(other, msg, NULL, 0);
3876                strbuf_addf(msg, "%s\n", reset);
3877                break;
3878        case DIFF_STATUS_MODIFIED:
3879                if (p->score) {
3880                        strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
3881                                    line_prefix,
3882                                    set, similarity_index(p), reset);
3883                        break;
3884                }
3885                /* fallthru */
3886        default:
3887                *must_show_header = 0;
3888        }
3889        if (one && two && oidcmp(&one->oid, &two->oid)) {
3890                int abbrev = o->flags.full_index ? 40 : DEFAULT_ABBREV;
3891
3892                if (o->flags.binary) {
3893                        mmfile_t mf;
3894                        if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
3895                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
3896                                abbrev = 40;
3897                }
3898                strbuf_addf(msg, "%s%sindex %s..%s", line_prefix, set,
3899                            diff_abbrev_oid(&one->oid, abbrev),
3900                            diff_abbrev_oid(&two->oid, abbrev));
3901                if (one->mode == two->mode)
3902                        strbuf_addf(msg, " %06o", one->mode);
3903                strbuf_addf(msg, "%s\n", reset);
3904        }
3905}
3906
3907static void run_diff_cmd(const char *pgm,
3908                         const char *name,
3909                         const char *other,
3910                         const char *attr_path,
3911                         struct diff_filespec *one,
3912                         struct diff_filespec *two,
3913                         struct strbuf *msg,
3914                         struct diff_options *o,
3915                         struct diff_filepair *p)
3916{
3917        const char *xfrm_msg = NULL;
3918        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
3919        int must_show_header = 0;
3920
3921
3922        if (o->flags.allow_external) {
3923                struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
3924                if (drv && drv->external)
3925                        pgm = drv->external;
3926        }
3927
3928        if (msg) {
3929                /*
3930                 * don't use colors when the header is intended for an
3931                 * external diff driver
3932                 */
3933                fill_metainfo(msg, name, other, one, two, o, p,
3934                              &must_show_header,
3935                              want_color(o->use_color) && !pgm);
3936                xfrm_msg = msg->len ? msg->buf : NULL;
3937        }
3938
3939        if (pgm) {
3940                run_external_diff(pgm, name, other, one, two, xfrm_msg,
3941                                  complete_rewrite, o);
3942                return;
3943        }
3944        if (one && two)
3945                builtin_diff(name, other ? other : name,
3946                             one, two, xfrm_msg, must_show_header,
3947                             o, complete_rewrite);
3948        else
3949                fprintf(o->file, "* Unmerged path %s\n", name);
3950}
3951
3952static void diff_fill_oid_info(struct diff_filespec *one)
3953{
3954        if (DIFF_FILE_VALID(one)) {
3955                if (!one->oid_valid) {
3956                        struct stat st;
3957                        if (one->is_stdin) {
3958                                oidclr(&one->oid);
3959                                return;
3960                        }
3961                        if (lstat(one->path, &st) < 0)
3962                                die_errno("stat '%s'", one->path);
3963                        if (index_path(&one->oid, one->path, &st, 0))
3964                                die("cannot hash %s", one->path);
3965                }
3966        }
3967        else
3968                oidclr(&one->oid);
3969}
3970
3971static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
3972{
3973        /* Strip the prefix but do not molest /dev/null and absolute paths */
3974        if (*namep && **namep != '/') {
3975                *namep += prefix_length;
3976                if (**namep == '/')
3977                        ++*namep;
3978        }
3979        if (*otherp && **otherp != '/') {
3980                *otherp += prefix_length;
3981                if (**otherp == '/')
3982                        ++*otherp;
3983        }
3984}
3985
3986static void run_diff(struct diff_filepair *p, struct diff_options *o)
3987{
3988        const char *pgm = external_diff();
3989        struct strbuf msg;
3990        struct diff_filespec *one = p->one;
3991        struct diff_filespec *two = p->two;
3992        const char *name;
3993        const char *other;
3994        const char *attr_path;
3995
3996        name  = one->path;
3997        other = (strcmp(name, two->path) ? two->path : NULL);
3998        attr_path = name;
3999        if (o->prefix_length)
4000                strip_prefix(o->prefix_length, &name, &other);
4001
4002        if (!o->flags.allow_external)
4003                pgm = NULL;
4004
4005        if (DIFF_PAIR_UNMERGED(p)) {
4006                run_diff_cmd(pgm, name, NULL, attr_path,
4007                             NULL, NULL, NULL, o, p);
4008                return;
4009        }
4010
4011        diff_fill_oid_info(one);
4012        diff_fill_oid_info(two);
4013
4014        if (!pgm &&
4015            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
4016            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
4017                /*
4018                 * a filepair that changes between file and symlink
4019                 * needs to be split into deletion and creation.
4020                 */
4021                struct diff_filespec *null = alloc_filespec(two->path);
4022                run_diff_cmd(NULL, name, other, attr_path,
4023                             one, null, &msg, o, p);
4024                free(null);
4025                strbuf_release(&msg);
4026
4027                null = alloc_filespec(one->path);
4028                run_diff_cmd(NULL, name, other, attr_path,
4029                             null, two, &msg, o, p);
4030                free(null);
4031        }
4032        else
4033                run_diff_cmd(pgm, name, other, attr_path,
4034                             one, two, &msg, o, p);
4035
4036        strbuf_release(&msg);
4037}
4038
4039static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
4040                         struct diffstat_t *diffstat)
4041{
4042        const char *name;
4043        const char *other;
4044
4045        if (DIFF_PAIR_UNMERGED(p)) {
4046                /* unmerged */
4047                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, p);
4048                return;
4049        }
4050
4051        name = p->one->path;
4052        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
4053
4054        if (o->prefix_length)
4055                strip_prefix(o->prefix_length, &name, &other);
4056
4057        diff_fill_oid_info(p->one);
4058        diff_fill_oid_info(p->two);
4059
4060        builtin_diffstat(name, other, p->one, p->two, diffstat, o, p);
4061}
4062
4063static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
4064{
4065        const char *name;
4066        const char *other;
4067        const char *attr_path;
4068
4069        if (DIFF_PAIR_UNMERGED(p)) {
4070                /* unmerged */
4071                return;
4072        }
4073
4074        name = p->one->path;
4075        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
4076        attr_path = other ? other : name;
4077
4078        if (o->prefix_length)
4079                strip_prefix(o->prefix_length, &name, &other);
4080
4081        diff_fill_oid_info(p->one);
4082        diff_fill_oid_info(p->two);
4083
4084        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
4085}
4086
4087void diff_setup(struct diff_options *options)
4088{
4089        memcpy(options, &default_diff_options, sizeof(*options));
4090
4091        options->file = stdout;
4092
4093        options->abbrev = DEFAULT_ABBREV;
4094        options->line_termination = '\n';
4095        options->break_opt = -1;
4096        options->rename_limit = -1;
4097        options->dirstat_permille = diff_dirstat_permille_default;
4098        options->context = diff_context_default;
4099        options->interhunkcontext = diff_interhunk_context_default;
4100        options->ws_error_highlight = ws_error_highlight_default;
4101        options->flags.rename_empty = 1;
4102        options->objfind = NULL;
4103
4104        /* pathchange left =NULL by default */
4105        options->change = diff_change;
4106        options->add_remove = diff_addremove;
4107        options->use_color = diff_use_color_default;
4108        options->detect_rename = diff_detect_rename_default;
4109        options->xdl_opts |= diff_algorithm;
4110        if (diff_indent_heuristic)
4111                DIFF_XDL_SET(options, INDENT_HEURISTIC);
4112
4113        options->orderfile = diff_order_file_cfg;
4114
4115        if (diff_no_prefix) {
4116                options->a_prefix = options->b_prefix = "";
4117        } else if (!diff_mnemonic_prefix) {
4118                options->a_prefix = "a/";
4119                options->b_prefix = "b/";
4120        }
4121
4122        options->color_moved = diff_color_moved_default;
4123}
4124
4125void diff_setup_done(struct diff_options *options)
4126{
4127        unsigned check_mask = DIFF_FORMAT_NAME |
4128                              DIFF_FORMAT_NAME_STATUS |
4129                              DIFF_FORMAT_CHECKDIFF |
4130                              DIFF_FORMAT_NO_OUTPUT;
4131
4132        if (options->set_default)
4133                options->set_default(options);
4134
4135        if (HAS_MULTI_BITS(options->output_format & check_mask))
4136                die(_("--name-only, --name-status, --check and -s are mutually exclusive"));
4137
4138        if (HAS_MULTI_BITS(options->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK))
4139                die(_("-G, -S and --find-object are mutually exclusive"));
4140
4141        /*
4142         * Most of the time we can say "there are changes"
4143         * only by checking if there are changed paths, but
4144         * --ignore-whitespace* options force us to look
4145         * inside contents.
4146         */
4147
4148        if ((options->xdl_opts & XDF_WHITESPACE_FLAGS))
4149                options->flags.diff_from_contents = 1;
4150        else
4151                options->flags.diff_from_contents = 0;
4152
4153        if (options->flags.find_copies_harder)
4154                options->detect_rename = DIFF_DETECT_COPY;
4155
4156        if (!options->flags.relative_name)
4157                options->prefix = NULL;
4158        if (options->prefix)
4159                options->prefix_length = strlen(options->prefix);
4160        else
4161                options->prefix_length = 0;
4162
4163        if (options->output_format & (DIFF_FORMAT_NAME |
4164                                      DIFF_FORMAT_NAME_STATUS |
4165                                      DIFF_FORMAT_CHECKDIFF |
4166                                      DIFF_FORMAT_NO_OUTPUT))
4167                options->output_format &= ~(DIFF_FORMAT_RAW |
4168                                            DIFF_FORMAT_NUMSTAT |
4169                                            DIFF_FORMAT_DIFFSTAT |
4170                                            DIFF_FORMAT_SHORTSTAT |
4171                                            DIFF_FORMAT_DIRSTAT |
4172                                            DIFF_FORMAT_SUMMARY |
4173                                            DIFF_FORMAT_PATCH);
4174
4175        /*
4176         * These cases always need recursive; we do not drop caller-supplied
4177         * recursive bits for other formats here.
4178         */
4179        if (options->output_format & (DIFF_FORMAT_PATCH |
4180                                      DIFF_FORMAT_NUMSTAT |
4181                                      DIFF_FORMAT_DIFFSTAT |
4182                                      DIFF_FORMAT_SHORTSTAT |
4183                                      DIFF_FORMAT_DIRSTAT |
4184                                      DIFF_FORMAT_SUMMARY |
4185                                      DIFF_FORMAT_CHECKDIFF))
4186                options->flags.recursive = 1;
4187        /*
4188         * Also pickaxe would not work very well if you do not say recursive
4189         */
4190        if (options->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK)
4191                options->flags.recursive = 1;
4192        /*
4193         * When patches are generated, submodules diffed against the work tree
4194         * must be checked for dirtiness too so it can be shown in the output
4195         */
4196        if (options->output_format & DIFF_FORMAT_PATCH)
4197                options->flags.dirty_submodules = 1;
4198
4199        if (options->detect_rename && options->rename_limit < 0)
4200                options->rename_limit = diff_rename_limit_default;
4201        if (options->setup & DIFF_SETUP_USE_CACHE) {
4202                if (!active_cache)
4203                        /* read-cache does not die even when it fails
4204                         * so it is safe for us to do this here.  Also
4205                         * it does not smudge active_cache or active_nr
4206                         * when it fails, so we do not have to worry about
4207                         * cleaning it up ourselves either.
4208                         */
4209                        read_cache();
4210        }
4211        if (40 < options->abbrev)
4212                options->abbrev = 40; /* full */
4213
4214        /*
4215         * It does not make sense to show the first hit we happened
4216         * to have found.  It does not make sense not to return with
4217         * exit code in such a case either.
4218         */
4219        if (options->flags.quick) {
4220                options->output_format = DIFF_FORMAT_NO_OUTPUT;
4221                options->flags.exit_with_status = 1;
4222        }
4223
4224        options->diff_path_counter = 0;
4225
4226        if (options->flags.follow_renames && options->pathspec.nr != 1)
4227                die(_("--follow requires exactly one pathspec"));
4228
4229        if (!options->use_color || external_diff())
4230                options->color_moved = 0;
4231}
4232
4233static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
4234{
4235        char c, *eq;
4236        int len;
4237
4238        if (*arg != '-')
4239                return 0;
4240        c = *++arg;
4241        if (!c)
4242                return 0;
4243        if (c == arg_short) {
4244                c = *++arg;
4245                if (!c)
4246                        return 1;
4247                if (val && isdigit(c)) {
4248                        char *end;
4249                        int n = strtoul(arg, &end, 10);
4250                        if (*end)
4251                                return 0;
4252                        *val = n;
4253                        return 1;
4254                }
4255                return 0;
4256        }
4257        if (c != '-')
4258                return 0;
4259        arg++;
4260        eq = strchrnul(arg, '=');
4261        len = eq - arg;
4262        if (!len || strncmp(arg, arg_long, len))
4263                return 0;
4264        if (*eq) {
4265                int n;
4266                char *end;
4267                if (!isdigit(*++eq))
4268                        return 0;
4269                n = strtoul(eq, &end, 10);
4270                if (*end)
4271                        return 0;
4272                *val = n;
4273        }
4274        return 1;
4275}
4276
4277static int diff_scoreopt_parse(const char *opt);
4278
4279static inline int short_opt(char opt, const char **argv,
4280                            const char **optarg)
4281{
4282        const char *arg = argv[0];
4283        if (arg[0] != '-' || arg[1] != opt)
4284                return 0;
4285        if (arg[2] != '\0') {
4286                *optarg = arg + 2;
4287                return 1;
4288        }
4289        if (!argv[1])
4290                die("Option '%c' requires a value", opt);
4291        *optarg = argv[1];
4292        return 2;
4293}
4294
4295int parse_long_opt(const char *opt, const char **argv,
4296                   const char **optarg)
4297{
4298        const char *arg = argv[0];
4299        if (!skip_prefix(arg, "--", &arg))
4300                return 0;
4301        if (!skip_prefix(arg, opt, &arg))
4302                return 0;
4303        if (*arg == '=') { /* stuck form: --option=value */
4304                *optarg = arg + 1;
4305                return 1;
4306        }
4307        if (*arg != '\0')
4308                return 0;
4309        /* separate form: --option value */
4310        if (!argv[1])
4311                die("Option '--%s' requires a value", opt);
4312        *optarg = argv[1];
4313        return 2;
4314}
4315
4316static int stat_opt(struct diff_options *options, const char **av)
4317{
4318        const char *arg = av[0];
4319        char *end;
4320        int width = options->stat_width;
4321        int name_width = options->stat_name_width;
4322        int graph_width = options->stat_graph_width;
4323        int count = options->stat_count;
4324        int argcount = 1;
4325
4326        if (!skip_prefix(arg, "--stat", &arg))
4327                die("BUG: stat option does not begin with --stat: %s", arg);
4328        end = (char *)arg;
4329
4330        switch (*arg) {
4331        case '-':
4332                if (skip_prefix(arg, "-width", &arg)) {
4333                        if (*arg == '=')
4334                                width = strtoul(arg + 1, &end, 10);
4335                        else if (!*arg && !av[1])
4336                                die_want_option("--stat-width");
4337                        else if (!*arg) {
4338                                width = strtoul(av[1], &end, 10);
4339                                argcount = 2;
4340                        }
4341                } else if (skip_prefix(arg, "-name-width", &arg)) {
4342                        if (*arg == '=')
4343                                name_width = strtoul(arg + 1, &end, 10);
4344                        else if (!*arg && !av[1])
4345                                die_want_option("--stat-name-width");
4346                        else if (!*arg) {
4347                                name_width = strtoul(av[1], &end, 10);
4348                                argcount = 2;
4349                        }
4350                } else if (skip_prefix(arg, "-graph-width", &arg)) {
4351                        if (*arg == '=')
4352                                graph_width = strtoul(arg + 1, &end, 10);
4353                        else if (!*arg && !av[1])
4354                                die_want_option("--stat-graph-width");
4355                        else if (!*arg) {
4356                                graph_width = strtoul(av[1], &end, 10);
4357                                argcount = 2;
4358                        }
4359                } else if (skip_prefix(arg, "-count", &arg)) {
4360                        if (*arg == '=')
4361                                count = strtoul(arg + 1, &end, 10);
4362                        else if (!*arg && !av[1])
4363                                die_want_option("--stat-count");
4364                        else if (!*arg) {
4365                                count = strtoul(av[1], &end, 10);
4366                                argcount = 2;
4367                        }
4368                }
4369                break;
4370        case '=':
4371                width = strtoul(arg+1, &end, 10);
4372                if (*end == ',')
4373                        name_width = strtoul(end+1, &end, 10);
4374                if (*end == ',')
4375                        count = strtoul(end+1, &end, 10);
4376        }
4377
4378        /* Important! This checks all the error cases! */
4379        if (*end)
4380                return 0;
4381        options->output_format |= DIFF_FORMAT_DIFFSTAT;
4382        options->stat_name_width = name_width;
4383        options->stat_graph_width = graph_width;
4384        options->stat_width = width;
4385        options->stat_count = count;
4386        return argcount;
4387}
4388
4389static int parse_dirstat_opt(struct diff_options *options, const char *params)
4390{
4391        struct strbuf errmsg = STRBUF_INIT;
4392        if (parse_dirstat_params(options, params, &errmsg))
4393                die(_("Failed to parse --dirstat/-X option parameter:\n%s"),
4394                    errmsg.buf);
4395        strbuf_release(&errmsg);
4396        /*
4397         * The caller knows a dirstat-related option is given from the command
4398         * line; allow it to say "return this_function();"
4399         */
4400        options->output_format |= DIFF_FORMAT_DIRSTAT;
4401        return 1;
4402}
4403
4404static int parse_submodule_opt(struct diff_options *options, const char *value)
4405{
4406        if (parse_submodule_params(options, value))
4407                die(_("Failed to parse --submodule option parameter: '%s'"),
4408                        value);
4409        return 1;
4410}
4411
4412static const char diff_status_letters[] = {
4413        DIFF_STATUS_ADDED,
4414        DIFF_STATUS_COPIED,
4415        DIFF_STATUS_DELETED,
4416        DIFF_STATUS_MODIFIED,
4417        DIFF_STATUS_RENAMED,
4418        DIFF_STATUS_TYPE_CHANGED,
4419        DIFF_STATUS_UNKNOWN,
4420        DIFF_STATUS_UNMERGED,
4421        DIFF_STATUS_FILTER_AON,
4422        DIFF_STATUS_FILTER_BROKEN,
4423        '\0',
4424};
4425
4426static unsigned int filter_bit['Z' + 1];
4427
4428static void prepare_filter_bits(void)
4429{
4430        int i;
4431
4432        if (!filter_bit[DIFF_STATUS_ADDED]) {
4433                for (i = 0; diff_status_letters[i]; i++)
4434                        filter_bit[(int) diff_status_letters[i]] = (1 << i);
4435        }
4436}
4437
4438static unsigned filter_bit_tst(char status, const struct diff_options *opt)
4439{
4440        return opt->filter & filter_bit[(int) status];
4441}
4442
4443static int parse_diff_filter_opt(const char *optarg, struct diff_options *opt)
4444{
4445        int i, optch;
4446
4447        prepare_filter_bits();
4448
4449        /*
4450         * If there is a negation e.g. 'd' in the input, and we haven't
4451         * initialized the filter field with another --diff-filter, start
4452         * from full set of bits, except for AON.
4453         */
4454        if (!opt->filter) {
4455                for (i = 0; (optch = optarg[i]) != '\0'; i++) {
4456                        if (optch < 'a' || 'z' < optch)
4457                                continue;
4458                        opt->filter = (1 << (ARRAY_SIZE(diff_status_letters) - 1)) - 1;
4459                        opt->filter &= ~filter_bit[DIFF_STATUS_FILTER_AON];
4460                        break;
4461                }
4462        }
4463
4464        for (i = 0; (optch = optarg[i]) != '\0'; i++) {
4465                unsigned int bit;
4466                int negate;
4467
4468                if ('a' <= optch && optch <= 'z') {
4469                        negate = 1;
4470                        optch = toupper(optch);
4471                } else {
4472                        negate = 0;
4473                }
4474
4475                bit = (0 <= optch && optch <= 'Z') ? filter_bit[optch] : 0;
4476                if (!bit)
4477                        return optarg[i];
4478                if (negate)
4479                        opt->filter &= ~bit;
4480                else
4481                        opt->filter |= bit;
4482        }
4483        return 0;
4484}
4485
4486static void enable_patch_output(int *fmt) {
4487        *fmt &= ~DIFF_FORMAT_NO_OUTPUT;
4488        *fmt |= DIFF_FORMAT_PATCH;
4489}
4490
4491static int parse_ws_error_highlight_opt(struct diff_options *opt, const char *arg)
4492{
4493        int val = parse_ws_error_highlight(arg);
4494
4495        if (val < 0) {
4496                error("unknown value after ws-error-highlight=%.*s",
4497                      -1 - val, arg);
4498                return 0;
4499        }
4500        opt->ws_error_highlight = val;
4501        return 1;
4502}
4503
4504static int parse_objfind_opt(struct diff_options *opt, const char *arg)
4505{
4506        struct object_id oid;
4507
4508        if (get_oid(arg, &oid))
4509                return error("unable to resolve '%s'", arg);
4510
4511        if (!opt->objfind)
4512                opt->objfind = xcalloc(1, sizeof(*opt->objfind));
4513
4514        opt->pickaxe_opts |= DIFF_PICKAXE_KIND_OBJFIND;
4515        opt->flags.recursive = 1;
4516        opt->flags.tree_in_recursive = 1;
4517        oidset_insert(opt->objfind, &oid);
4518        return 1;
4519}
4520
4521int diff_opt_parse(struct diff_options *options,
4522                   const char **av, int ac, const char *prefix)
4523{
4524        const char *arg = av[0];
4525        const char *optarg;
4526        int argcount;
4527
4528        if (!prefix)
4529                prefix = "";
4530
4531        /* Output format options */
4532        if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch")
4533            || opt_arg(arg, 'U', "unified", &options->context))
4534                enable_patch_output(&options->output_format);
4535        else if (!strcmp(arg, "--raw"))
4536                options->output_format |= DIFF_FORMAT_RAW;
4537        else if (!strcmp(arg, "--patch-with-raw")) {
4538                enable_patch_output(&options->output_format);
4539                options->output_format |= DIFF_FORMAT_RAW;
4540        } else if (!strcmp(arg, "--numstat"))
4541                options->output_format |= DIFF_FORMAT_NUMSTAT;
4542        else if (!strcmp(arg, "--shortstat"))
4543                options->output_format |= DIFF_FORMAT_SHORTSTAT;
4544        else if (skip_prefix(arg, "-X", &arg) ||
4545                 skip_to_optional_arg(arg, "--dirstat", &arg))
4546                return parse_dirstat_opt(options, arg);
4547        else if (!strcmp(arg, "--cumulative"))
4548                return parse_dirstat_opt(options, "cumulative");
4549        else if (skip_to_optional_arg(arg, "--dirstat-by-file", &arg)) {
4550                parse_dirstat_opt(options, "files");
4551                return parse_dirstat_opt(options, arg);
4552        }
4553        else if (!strcmp(arg, "--check"))
4554                options->output_format |= DIFF_FORMAT_CHECKDIFF;
4555        else if (!strcmp(arg, "--summary"))
4556                options->output_format |= DIFF_FORMAT_SUMMARY;
4557        else if (!strcmp(arg, "--patch-with-stat")) {
4558                enable_patch_output(&options->output_format);
4559                options->output_format |= DIFF_FORMAT_DIFFSTAT;
4560        } else if (!strcmp(arg, "--name-only"))
4561                options->output_format |= DIFF_FORMAT_NAME;
4562        else if (!strcmp(arg, "--name-status"))
4563                options->output_format |= DIFF_FORMAT_NAME_STATUS;
4564        else if (!strcmp(arg, "-s") || !strcmp(arg, "--no-patch"))
4565                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
4566        else if (starts_with(arg, "--stat"))
4567                /* --stat, --stat-width, --stat-name-width, or --stat-count */
4568                return stat_opt(options, av);
4569        else if (!strcmp(arg, "--compact-summary")) {
4570                 options->flags.stat_with_summary = 1;
4571                 options->output_format |= DIFF_FORMAT_DIFFSTAT;
4572        } else if (!strcmp(arg, "--no-compact-summary"))
4573                 options->flags.stat_with_summary = 0;
4574
4575        /* renames options */
4576        else if (starts_with(arg, "-B") ||
4577                 skip_to_optional_arg(arg, "--break-rewrites", NULL)) {
4578                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
4579                        return error("invalid argument to -B: %s", arg+2);
4580        }
4581        else if (starts_with(arg, "-M") ||
4582                 skip_to_optional_arg(arg, "--find-renames", NULL)) {
4583                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
4584                        return error("invalid argument to -M: %s", arg+2);
4585                options->detect_rename = DIFF_DETECT_RENAME;
4586        }
4587        else if (!strcmp(arg, "-D") || !strcmp(arg, "--irreversible-delete")) {
4588                options->irreversible_delete = 1;
4589        }
4590        else if (starts_with(arg, "-C") ||
4591                 skip_to_optional_arg(arg, "--find-copies", NULL)) {
4592                if (options->detect_rename == DIFF_DETECT_COPY)
4593                        options->flags.find_copies_harder = 1;
4594                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
4595                        return error("invalid argument to -C: %s", arg+2);
4596                options->detect_rename = DIFF_DETECT_COPY;
4597        }
4598        else if (!strcmp(arg, "--no-renames"))
4599                options->detect_rename = 0;
4600        else if (!strcmp(arg, "--rename-empty"))
4601                options->flags.rename_empty = 1;
4602        else if (!strcmp(arg, "--no-rename-empty"))
4603                options->flags.rename_empty = 0;
4604        else if (skip_to_optional_arg_default(arg, "--relative", &arg, NULL)) {
4605                options->flags.relative_name = 1;
4606                if (arg)
4607                        options->prefix = arg;
4608        }
4609
4610        /* xdiff options */
4611        else if (!strcmp(arg, "--minimal"))
4612                DIFF_XDL_SET(options, NEED_MINIMAL);
4613        else if (!strcmp(arg, "--no-minimal"))
4614                DIFF_XDL_CLR(options, NEED_MINIMAL);
4615        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
4616                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
4617        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
4618                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
4619        else if (!strcmp(arg, "--ignore-space-at-eol"))
4620                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
4621        else if (!strcmp(arg, "--ignore-cr-at-eol"))
4622                DIFF_XDL_SET(options, IGNORE_CR_AT_EOL);
4623        else if (!strcmp(arg, "--ignore-blank-lines"))
4624                DIFF_XDL_SET(options, IGNORE_BLANK_LINES);
4625        else if (!strcmp(arg, "--indent-heuristic"))
4626                DIFF_XDL_SET(options, INDENT_HEURISTIC);
4627        else if (!strcmp(arg, "--no-indent-heuristic"))
4628                DIFF_XDL_CLR(options, INDENT_HEURISTIC);
4629        else if (!strcmp(arg, "--patience")) {
4630                int i;
4631                options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
4632                /*
4633                 * Both --patience and --anchored use PATIENCE_DIFF
4634                 * internally, so remove any anchors previously
4635                 * specified.
4636                 */
4637                for (i = 0; i < options->anchors_nr; i++)
4638                        free(options->anchors[i]);
4639                options->anchors_nr = 0;
4640        } else if (!strcmp(arg, "--histogram"))
4641                options->xdl_opts = DIFF_WITH_ALG(options, HISTOGRAM_DIFF);
4642        else if ((argcount = parse_long_opt("diff-algorithm", av, &optarg))) {
4643                long value = parse_algorithm_value(optarg);
4644                if (value < 0)
4645                        return error("option diff-algorithm accepts \"myers\", "
4646                                     "\"minimal\", \"patience\" and \"histogram\"");
4647                /* clear out previous settings */
4648                DIFF_XDL_CLR(options, NEED_MINIMAL);
4649                options->xdl_opts &= ~XDF_DIFF_ALGORITHM_MASK;
4650                options->xdl_opts |= value;
4651                return argcount;
4652        } else if (skip_prefix(arg, "--anchored=", &arg)) {
4653                options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
4654                ALLOC_GROW(options->anchors, options->anchors_nr + 1,
4655                           options->anchors_alloc);
4656                options->anchors[options->anchors_nr++] = xstrdup(arg);
4657        }
4658
4659        /* flags options */
4660        else if (!strcmp(arg, "--binary")) {
4661                enable_patch_output(&options->output_format);
4662                options->flags.binary = 1;
4663        }
4664        else if (!strcmp(arg, "--full-index"))
4665                options->flags.full_index = 1;
4666        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
4667                options->flags.text = 1;
4668        else if (!strcmp(arg, "-R"))
4669                options->flags.reverse_diff = 1;
4670        else if (!strcmp(arg, "--find-copies-harder"))
4671                options->flags.find_copies_harder = 1;
4672        else if (!strcmp(arg, "--follow"))
4673                options->flags.follow_renames = 1;
4674        else if (!strcmp(arg, "--no-follow")) {
4675                options->flags.follow_renames = 0;
4676                options->flags.default_follow_renames = 0;
4677        } else if (skip_to_optional_arg_default(arg, "--color", &arg, "always")) {
4678                int value = git_config_colorbool(NULL, arg);
4679                if (value < 0)
4680                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
4681                options->use_color = value;
4682        }
4683        else if (!strcmp(arg, "--no-color"))
4684                options->use_color = 0;
4685        else if (!strcmp(arg, "--color-moved")) {
4686                if (diff_color_moved_default)
4687                        options->color_moved = diff_color_moved_default;
4688                if (options->color_moved == COLOR_MOVED_NO)
4689                        options->color_moved = COLOR_MOVED_DEFAULT;
4690        } else if (!strcmp(arg, "--no-color-moved"))
4691                options->color_moved = COLOR_MOVED_NO;
4692        else if (skip_prefix(arg, "--color-moved=", &arg)) {
4693                int cm = parse_color_moved(arg);
4694                if (cm < 0)
4695                        die("bad --color-moved argument: %s", arg);
4696                options->color_moved = cm;
4697        } else if (skip_to_optional_arg_default(arg, "--color-words", &options->word_regex, NULL)) {
4698                options->use_color = 1;
4699                options->word_diff = DIFF_WORDS_COLOR;
4700        }
4701        else if (!strcmp(arg, "--word-diff")) {
4702                if (options->word_diff == DIFF_WORDS_NONE)
4703                        options->word_diff = DIFF_WORDS_PLAIN;
4704        }
4705        else if (skip_prefix(arg, "--word-diff=", &arg)) {
4706                if (!strcmp(arg, "plain"))
4707                        options->word_diff = DIFF_WORDS_PLAIN;
4708                else if (!strcmp(arg, "color")) {
4709                        options->use_color = 1;
4710                        options->word_diff = DIFF_WORDS_COLOR;
4711                }
4712                else if (!strcmp(arg, "porcelain"))
4713                        options->word_diff = DIFF_WORDS_PORCELAIN;
4714                else if (!strcmp(arg, "none"))
4715                        options->word_diff = DIFF_WORDS_NONE;
4716                else
4717                        die("bad --word-diff argument: %s", arg);
4718        }
4719        else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
4720                if (options->word_diff == DIFF_WORDS_NONE)
4721                        options->word_diff = DIFF_WORDS_PLAIN;
4722                options->word_regex = optarg;
4723                return argcount;
4724        }
4725        else if (!strcmp(arg, "--exit-code"))
4726                options->flags.exit_with_status = 1;
4727        else if (!strcmp(arg, "--quiet"))
4728                options->flags.quick = 1;
4729        else if (!strcmp(arg, "--ext-diff"))
4730                options->flags.allow_external = 1;
4731        else if (!strcmp(arg, "--no-ext-diff"))
4732                options->flags.allow_external = 0;
4733        else if (!strcmp(arg, "--textconv")) {
4734                options->flags.allow_textconv = 1;
4735                options->flags.textconv_set_via_cmdline = 1;
4736        } else if (!strcmp(arg, "--no-textconv"))
4737                options->flags.allow_textconv = 0;
4738        else if (skip_to_optional_arg_default(arg, "--ignore-submodules", &arg, "all")) {
4739                options->flags.override_submodule_config = 1;
4740                handle_ignore_submodules_arg(options, arg);
4741        } else if (skip_to_optional_arg_default(arg, "--submodule", &arg, "log"))
4742                return parse_submodule_opt(options, arg);
4743        else if (skip_prefix(arg, "--ws-error-highlight=", &arg))
4744                return parse_ws_error_highlight_opt(options, arg);
4745        else if (!strcmp(arg, "--ita-invisible-in-index"))
4746                options->ita_invisible_in_index = 1;
4747        else if (!strcmp(arg, "--ita-visible-in-index"))
4748                options->ita_invisible_in_index = 0;
4749
4750        /* misc options */
4751        else if (!strcmp(arg, "-z"))
4752                options->line_termination = 0;
4753        else if ((argcount = short_opt('l', av, &optarg))) {
4754                options->rename_limit = strtoul(optarg, NULL, 10);
4755                return argcount;
4756        }
4757        else if ((argcount = short_opt('S', av, &optarg))) {
4758                options->pickaxe = optarg;
4759                options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
4760                return argcount;
4761        } else if ((argcount = short_opt('G', av, &optarg))) {
4762                options->pickaxe = optarg;
4763                options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
4764                return argcount;
4765        }
4766        else if (!strcmp(arg, "--pickaxe-all"))
4767                options->pickaxe_opts |= DIFF_PICKAXE_ALL;
4768        else if (!strcmp(arg, "--pickaxe-regex"))
4769                options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
4770        else if ((argcount = short_opt('O', av, &optarg))) {
4771                options->orderfile = prefix_filename(prefix, optarg);
4772                return argcount;
4773        } else if (skip_prefix(arg, "--find-object=", &arg))
4774                return parse_objfind_opt(options, arg);
4775        else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
4776                int offending = parse_diff_filter_opt(optarg, options);
4777                if (offending)
4778                        die("unknown change class '%c' in --diff-filter=%s",
4779                            offending, optarg);
4780                return argcount;
4781        }
4782        else if (!strcmp(arg, "--no-abbrev"))
4783                options->abbrev = 0;
4784        else if (!strcmp(arg, "--abbrev"))
4785                options->abbrev = DEFAULT_ABBREV;
4786        else if (skip_prefix(arg, "--abbrev=", &arg)) {
4787                options->abbrev = strtoul(arg, NULL, 10);
4788                if (options->abbrev < MINIMUM_ABBREV)
4789                        options->abbrev = MINIMUM_ABBREV;
4790                else if (40 < options->abbrev)
4791                        options->abbrev = 40;
4792        }
4793        else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
4794                options->a_prefix = optarg;
4795                return argcount;
4796        }
4797        else if ((argcount = parse_long_opt("line-prefix", av, &optarg))) {
4798                options->line_prefix = optarg;
4799                options->line_prefix_length = strlen(options->line_prefix);
4800                graph_setup_line_prefix(options);
4801                return argcount;
4802        }
4803        else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
4804                options->b_prefix = optarg;
4805                return argcount;
4806        }
4807        else if (!strcmp(arg, "--no-prefix"))
4808                options->a_prefix = options->b_prefix = "";
4809        else if (opt_arg(arg, '\0', "inter-hunk-context",
4810                         &options->interhunkcontext))
4811                ;
4812        else if (!strcmp(arg, "-W"))
4813                options->flags.funccontext = 1;
4814        else if (!strcmp(arg, "--function-context"))
4815                options->flags.funccontext = 1;
4816        else if (!strcmp(arg, "--no-function-context"))
4817                options->flags.funccontext = 0;
4818        else if ((argcount = parse_long_opt("output", av, &optarg))) {
4819                char *path = prefix_filename(prefix, optarg);
4820                options->file = xfopen(path, "w");
4821                options->close_file = 1;
4822                if (options->use_color != GIT_COLOR_ALWAYS)
4823                        options->use_color = GIT_COLOR_NEVER;
4824                free(path);
4825                return argcount;
4826        } else
4827                return 0;
4828        return 1;
4829}
4830
4831int parse_rename_score(const char **cp_p)
4832{
4833        unsigned long num, scale;
4834        int ch, dot;
4835        const char *cp = *cp_p;
4836
4837        num = 0;
4838        scale = 1;
4839        dot = 0;
4840        for (;;) {
4841                ch = *cp;
4842                if ( !dot && ch == '.' ) {
4843                        scale = 1;
4844                        dot = 1;
4845                } else if ( ch == '%' ) {
4846                        scale = dot ? scale*100 : 100;
4847                        cp++;   /* % is always at the end */
4848                        break;
4849                } else if ( ch >= '0' && ch <= '9' ) {
4850                        if ( scale < 100000 ) {
4851                                scale *= 10;
4852                                num = (num*10) + (ch-'0');
4853                        }
4854                } else {
4855                        break;
4856                }
4857                cp++;
4858        }
4859        *cp_p = cp;
4860
4861        /* user says num divided by scale and we say internally that
4862         * is MAX_SCORE * num / scale.
4863         */
4864        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
4865}
4866
4867static int diff_scoreopt_parse(const char *opt)
4868{
4869        int opt1, opt2, cmd;
4870
4871        if (*opt++ != '-')
4872                return -1;
4873        cmd = *opt++;
4874        if (cmd == '-') {
4875                /* convert the long-form arguments into short-form versions */
4876                if (skip_prefix(opt, "break-rewrites", &opt)) {
4877                        if (*opt == 0 || *opt++ == '=')
4878                                cmd = 'B';
4879                } else if (skip_prefix(opt, "find-copies", &opt)) {
4880                        if (*opt == 0 || *opt++ == '=')
4881                                cmd = 'C';
4882                } else if (skip_prefix(opt, "find-renames", &opt)) {
4883                        if (*opt == 0 || *opt++ == '=')
4884                                cmd = 'M';
4885                }
4886        }
4887        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
4888                return -1; /* that is not a -M, -C, or -B option */
4889
4890        opt1 = parse_rename_score(&opt);
4891        if (cmd != 'B')
4892                opt2 = 0;
4893        else {
4894                if (*opt == 0)
4895                        opt2 = 0;
4896                else if (*opt != '/')
4897                        return -1; /* we expect -B80/99 or -B80 */
4898                else {
4899                        opt++;
4900                        opt2 = parse_rename_score(&opt);
4901                }
4902        }
4903        if (*opt != 0)
4904                return -1;
4905        return opt1 | (opt2 << 16);
4906}
4907
4908struct diff_queue_struct diff_queued_diff;
4909
4910void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
4911{
4912        ALLOC_GROW(queue->queue, queue->nr + 1, queue->alloc);
4913        queue->queue[queue->nr++] = dp;
4914}
4915
4916struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
4917                                 struct diff_filespec *one,
4918                                 struct diff_filespec *two)
4919{
4920        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
4921        dp->one = one;
4922        dp->two = two;
4923        if (queue)
4924                diff_q(queue, dp);
4925        return dp;
4926}
4927
4928void diff_free_filepair(struct diff_filepair *p)
4929{
4930        free_filespec(p->one);
4931        free_filespec(p->two);
4932        free(p);
4933}
4934
4935const char *diff_aligned_abbrev(const struct object_id *oid, int len)
4936{
4937        int abblen;
4938        const char *abbrev;
4939
4940        /* Do we want all 40 hex characters? */
4941        if (len == GIT_SHA1_HEXSZ)
4942                return oid_to_hex(oid);
4943
4944        /* An abbreviated value is fine, possibly followed by an ellipsis. */
4945        abbrev = diff_abbrev_oid(oid, len);
4946
4947        if (!print_sha1_ellipsis())
4948                return abbrev;
4949
4950        abblen = strlen(abbrev);
4951
4952        /*
4953         * In well-behaved cases, where the abbreviated result is the
4954         * same as the requested length, append three dots after the
4955         * abbreviation (hence the whole logic is limited to the case
4956         * where abblen < 37); when the actual abbreviated result is a
4957         * bit longer than the requested length, we reduce the number
4958         * of dots so that they match the well-behaved ones.  However,
4959         * if the actual abbreviation is longer than the requested
4960         * length by more than three, we give up on aligning, and add
4961         * three dots anyway, to indicate that the output is not the
4962         * full object name.  Yes, this may be suboptimal, but this
4963         * appears only in "diff --raw --abbrev" output and it is not
4964         * worth the effort to change it now.  Note that this would
4965         * likely to work fine when the automatic sizing of default
4966         * abbreviation length is used--we would be fed -1 in "len" in
4967         * that case, and will end up always appending three-dots, but
4968         * the automatic sizing is supposed to give abblen that ensures
4969         * uniqueness across all objects (statistically speaking).
4970         */
4971        if (abblen < GIT_SHA1_HEXSZ - 3) {
4972                static char hex[GIT_MAX_HEXSZ + 1];
4973                if (len < abblen && abblen <= len + 2)
4974                        xsnprintf(hex, sizeof(hex), "%s%.*s", abbrev, len+3-abblen, "..");
4975                else
4976                        xsnprintf(hex, sizeof(hex), "%s...", abbrev);
4977                return hex;
4978        }
4979
4980        return oid_to_hex(oid);
4981}
4982
4983static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
4984{
4985        int line_termination = opt->line_termination;
4986        int inter_name_termination = line_termination ? '\t' : '\0';
4987
4988        fprintf(opt->file, "%s", diff_line_prefix(opt));
4989        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
4990                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
4991                        diff_aligned_abbrev(&p->one->oid, opt->abbrev));
4992                fprintf(opt->file, "%s ",
4993                        diff_aligned_abbrev(&p->two->oid, opt->abbrev));
4994        }
4995        if (p->score) {
4996                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
4997                        inter_name_termination);
4998        } else {
4999                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
5000        }
5001
5002        if (p->status == DIFF_STATUS_COPIED ||
5003            p->status == DIFF_STATUS_RENAMED) {
5004                const char *name_a, *name_b;
5005                name_a = p->one->path;
5006                name_b = p->two->path;
5007                strip_prefix(opt->prefix_length, &name_a, &name_b);
5008                write_name_quoted(name_a, opt->file, inter_name_termination);
5009                write_name_quoted(name_b, opt->file, line_termination);
5010        } else {
5011                const char *name_a, *name_b;
5012                name_a = p->one->mode ? p->one->path : p->two->path;
5013                name_b = NULL;
5014                strip_prefix(opt->prefix_length, &name_a, &name_b);
5015                write_name_quoted(name_a, opt->file, line_termination);
5016        }
5017}
5018
5019int diff_unmodified_pair(struct diff_filepair *p)
5020{
5021        /* This function is written stricter than necessary to support
5022         * the currently implemented transformers, but the idea is to
5023         * let transformers to produce diff_filepairs any way they want,
5024         * and filter and clean them up here before producing the output.
5025         */
5026        struct diff_filespec *one = p->one, *two = p->two;
5027
5028        if (DIFF_PAIR_UNMERGED(p))
5029                return 0; /* unmerged is interesting */
5030
5031        /* deletion, addition, mode or type change
5032         * and rename are all interesting.
5033         */
5034        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
5035            DIFF_PAIR_MODE_CHANGED(p) ||
5036            strcmp(one->path, two->path))
5037                return 0;
5038
5039        /* both are valid and point at the same path.  that is, we are
5040         * dealing with a change.
5041         */
5042        if (one->oid_valid && two->oid_valid &&
5043            !oidcmp(&one->oid, &two->oid) &&
5044            !one->dirty_submodule && !two->dirty_submodule)
5045                return 1; /* no change */
5046        if (!one->oid_valid && !two->oid_valid)
5047                return 1; /* both look at the same file on the filesystem. */
5048        return 0;
5049}
5050
5051static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
5052{
5053        if (diff_unmodified_pair(p))
5054                return;
5055
5056        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5057            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5058                return; /* no tree diffs in patch format */
5059
5060        run_diff(p, o);
5061}
5062
5063static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
5064                            struct diffstat_t *diffstat)
5065{
5066        if (diff_unmodified_pair(p))
5067                return;
5068
5069        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5070            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5071                return; /* no useful stat for tree diffs */
5072
5073        run_diffstat(p, o, diffstat);
5074}
5075
5076static void diff_flush_checkdiff(struct diff_filepair *p,
5077                struct diff_options *o)
5078{
5079        if (diff_unmodified_pair(p))
5080                return;
5081
5082        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5083            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5084                return; /* nothing to check in tree diffs */
5085
5086        run_checkdiff(p, o);
5087}
5088
5089int diff_queue_is_empty(void)
5090{
5091        struct diff_queue_struct *q = &diff_queued_diff;
5092        int i;
5093        for (i = 0; i < q->nr; i++)
5094                if (!diff_unmodified_pair(q->queue[i]))
5095                        return 0;
5096        return 1;
5097}
5098
5099#if DIFF_DEBUG
5100void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
5101{
5102        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
5103                x, one ? one : "",
5104                s->path,
5105                DIFF_FILE_VALID(s) ? "valid" : "invalid",
5106                s->mode,
5107                s->oid_valid ? oid_to_hex(&s->oid) : "");
5108        fprintf(stderr, "queue[%d] %s size %lu\n",
5109                x, one ? one : "",
5110                s->size);
5111}
5112
5113void diff_debug_filepair(const struct diff_filepair *p, int i)
5114{
5115        diff_debug_filespec(p->one, i, "one");
5116        diff_debug_filespec(p->two, i, "two");
5117        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
5118                p->score, p->status ? p->status : '?',
5119                p->one->rename_used, p->broken_pair);
5120}
5121
5122void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
5123{
5124        int i;
5125        if (msg)
5126                fprintf(stderr, "%s\n", msg);
5127        fprintf(stderr, "q->nr = %d\n", q->nr);
5128        for (i = 0; i < q->nr; i++) {
5129                struct diff_filepair *p = q->queue[i];
5130                diff_debug_filepair(p, i);
5131        }
5132}
5133#endif
5134
5135static void diff_resolve_rename_copy(void)
5136{
5137        int i;
5138        struct diff_filepair *p;
5139        struct diff_queue_struct *q = &diff_queued_diff;
5140
5141        diff_debug_queue("resolve-rename-copy", q);
5142
5143        for (i = 0; i < q->nr; i++) {
5144                p = q->queue[i];
5145                p->status = 0; /* undecided */
5146                if (DIFF_PAIR_UNMERGED(p))
5147                        p->status = DIFF_STATUS_UNMERGED;
5148                else if (!DIFF_FILE_VALID(p->one))
5149                        p->status = DIFF_STATUS_ADDED;
5150                else if (!DIFF_FILE_VALID(p->two))
5151                        p->status = DIFF_STATUS_DELETED;
5152                else if (DIFF_PAIR_TYPE_CHANGED(p))
5153                        p->status = DIFF_STATUS_TYPE_CHANGED;
5154
5155                /* from this point on, we are dealing with a pair
5156                 * whose both sides are valid and of the same type, i.e.
5157                 * either in-place edit or rename/copy edit.
5158                 */
5159                else if (DIFF_PAIR_RENAME(p)) {
5160                        /*
5161                         * A rename might have re-connected a broken
5162                         * pair up, causing the pathnames to be the
5163                         * same again. If so, that's not a rename at
5164                         * all, just a modification..
5165                         *
5166                         * Otherwise, see if this source was used for
5167                         * multiple renames, in which case we decrement
5168                         * the count, and call it a copy.
5169                         */
5170                        if (!strcmp(p->one->path, p->two->path))
5171                                p->status = DIFF_STATUS_MODIFIED;
5172                        else if (--p->one->rename_used > 0)
5173                                p->status = DIFF_STATUS_COPIED;
5174                        else
5175                                p->status = DIFF_STATUS_RENAMED;
5176                }
5177                else if (oidcmp(&p->one->oid, &p->two->oid) ||
5178                         p->one->mode != p->two->mode ||
5179                         p->one->dirty_submodule ||
5180                         p->two->dirty_submodule ||
5181                         is_null_oid(&p->one->oid))
5182                        p->status = DIFF_STATUS_MODIFIED;
5183                else {
5184                        /* This is a "no-change" entry and should not
5185                         * happen anymore, but prepare for broken callers.
5186                         */
5187                        error("feeding unmodified %s to diffcore",
5188                              p->one->path);
5189                        p->status = DIFF_STATUS_UNKNOWN;
5190                }
5191        }
5192        diff_debug_queue("resolve-rename-copy done", q);
5193}
5194
5195static int check_pair_status(struct diff_filepair *p)
5196{
5197        switch (p->status) {
5198        case DIFF_STATUS_UNKNOWN:
5199                return 0;
5200        case 0:
5201                die("internal error in diff-resolve-rename-copy");
5202        default:
5203                return 1;
5204        }
5205}
5206
5207static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
5208{
5209        int fmt = opt->output_format;
5210
5211        if (fmt & DIFF_FORMAT_CHECKDIFF)
5212                diff_flush_checkdiff(p, opt);
5213        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
5214                diff_flush_raw(p, opt);
5215        else if (fmt & DIFF_FORMAT_NAME) {
5216                const char *name_a, *name_b;
5217                name_a = p->two->path;
5218                name_b = NULL;
5219                strip_prefix(opt->prefix_length, &name_a, &name_b);
5220                fprintf(opt->file, "%s", diff_line_prefix(opt));
5221                write_name_quoted(name_a, opt->file, opt->line_termination);
5222        }
5223}
5224
5225static void show_file_mode_name(struct diff_options *opt, const char *newdelete, struct diff_filespec *fs)
5226{
5227        struct strbuf sb = STRBUF_INIT;
5228        if (fs->mode)
5229                strbuf_addf(&sb, " %s mode %06o ", newdelete, fs->mode);
5230        else
5231                strbuf_addf(&sb, " %s ", newdelete);
5232
5233        quote_c_style(fs->path, &sb, NULL, 0);
5234        strbuf_addch(&sb, '\n');
5235        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5236                         sb.buf, sb.len, 0);
5237        strbuf_release(&sb);
5238}
5239
5240static void show_mode_change(struct diff_options *opt, struct diff_filepair *p,
5241                int show_name)
5242{
5243        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
5244                struct strbuf sb = STRBUF_INIT;
5245                strbuf_addf(&sb, " mode change %06o => %06o",
5246                            p->one->mode, p->two->mode);
5247                if (show_name) {
5248                        strbuf_addch(&sb, ' ');
5249                        quote_c_style(p->two->path, &sb, NULL, 0);
5250                }
5251                strbuf_addch(&sb, '\n');
5252                emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5253                                 sb.buf, sb.len, 0);
5254                strbuf_release(&sb);
5255        }
5256}
5257
5258static void show_rename_copy(struct diff_options *opt, const char *renamecopy,
5259                struct diff_filepair *p)
5260{
5261        struct strbuf sb = STRBUF_INIT;
5262        struct strbuf names = STRBUF_INIT;
5263
5264        pprint_rename(&names, p->one->path, p->two->path);
5265        strbuf_addf(&sb, " %s %s (%d%%)\n",
5266                    renamecopy, names.buf, similarity_index(p));
5267        strbuf_release(&names);
5268        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5269                                 sb.buf, sb.len, 0);
5270        show_mode_change(opt, p, 0);
5271        strbuf_release(&sb);
5272}
5273
5274static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
5275{
5276        switch(p->status) {
5277        case DIFF_STATUS_DELETED:
5278                show_file_mode_name(opt, "delete", p->one);
5279                break;
5280        case DIFF_STATUS_ADDED:
5281                show_file_mode_name(opt, "create", p->two);
5282                break;
5283        case DIFF_STATUS_COPIED:
5284                show_rename_copy(opt, "copy", p);
5285                break;
5286        case DIFF_STATUS_RENAMED:
5287                show_rename_copy(opt, "rename", p);
5288                break;
5289        default:
5290                if (p->score) {
5291                        struct strbuf sb = STRBUF_INIT;
5292                        strbuf_addstr(&sb, " rewrite ");
5293                        quote_c_style(p->two->path, &sb, NULL, 0);
5294                        strbuf_addf(&sb, " (%d%%)\n", similarity_index(p));
5295                        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5296                                         sb.buf, sb.len, 0);
5297                        strbuf_release(&sb);
5298                }
5299                show_mode_change(opt, p, !p->score);
5300                break;
5301        }
5302}
5303
5304struct patch_id_t {
5305        git_SHA_CTX *ctx;
5306        int patchlen;
5307};
5308
5309static int remove_space(char *line, int len)
5310{
5311        int i;
5312        char *dst = line;
5313        unsigned char c;
5314
5315        for (i = 0; i < len; i++)
5316                if (!isspace((c = line[i])))
5317                        *dst++ = c;
5318
5319        return dst - line;
5320}
5321
5322static void patch_id_consume(void *priv, char *line, unsigned long len)
5323{
5324        struct patch_id_t *data = priv;
5325        int new_len;
5326
5327        /* Ignore line numbers when computing the SHA1 of the patch */
5328        if (starts_with(line, "@@ -"))
5329                return;
5330
5331        new_len = remove_space(line, len);
5332
5333        git_SHA1_Update(data->ctx, line, new_len);
5334        data->patchlen += new_len;
5335}
5336
5337static void patch_id_add_string(git_SHA_CTX *ctx, const char *str)
5338{
5339        git_SHA1_Update(ctx, str, strlen(str));
5340}
5341
5342static void patch_id_add_mode(git_SHA_CTX *ctx, unsigned mode)
5343{
5344        /* large enough for 2^32 in octal */
5345        char buf[12];
5346        int len = xsnprintf(buf, sizeof(buf), "%06o", mode);
5347        git_SHA1_Update(ctx, buf, len);
5348}
5349
5350/* returns 0 upon success, and writes result into sha1 */
5351static int diff_get_patch_id(struct diff_options *options, struct object_id *oid, int diff_header_only)
5352{
5353        struct diff_queue_struct *q = &diff_queued_diff;
5354        int i;
5355        git_SHA_CTX ctx;
5356        struct patch_id_t data;
5357
5358        git_SHA1_Init(&ctx);
5359        memset(&data, 0, sizeof(struct patch_id_t));
5360        data.ctx = &ctx;
5361
5362        for (i = 0; i < q->nr; i++) {
5363                xpparam_t xpp;
5364                xdemitconf_t xecfg;
5365                mmfile_t mf1, mf2;
5366                struct diff_filepair *p = q->queue[i];
5367                int len1, len2;
5368
5369                memset(&xpp, 0, sizeof(xpp));
5370                memset(&xecfg, 0, sizeof(xecfg));
5371                if (p->status == 0)
5372                        return error("internal diff status error");
5373                if (p->status == DIFF_STATUS_UNKNOWN)
5374                        continue;
5375                if (diff_unmodified_pair(p))
5376                        continue;
5377                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5378                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5379                        continue;
5380                if (DIFF_PAIR_UNMERGED(p))
5381                        continue;
5382
5383                diff_fill_oid_info(p->one);
5384                diff_fill_oid_info(p->two);
5385
5386                len1 = remove_space(p->one->path, strlen(p->one->path));
5387                len2 = remove_space(p->two->path, strlen(p->two->path));
5388                patch_id_add_string(&ctx, "diff--git");
5389                patch_id_add_string(&ctx, "a/");
5390                git_SHA1_Update(&ctx, p->one->path, len1);
5391                patch_id_add_string(&ctx, "b/");
5392                git_SHA1_Update(&ctx, p->two->path, len2);
5393
5394                if (p->one->mode == 0) {
5395                        patch_id_add_string(&ctx, "newfilemode");
5396                        patch_id_add_mode(&ctx, p->two->mode);
5397                        patch_id_add_string(&ctx, "---/dev/null");
5398                        patch_id_add_string(&ctx, "+++b/");
5399                        git_SHA1_Update(&ctx, p->two->path, len2);
5400                } else if (p->two->mode == 0) {
5401                        patch_id_add_string(&ctx, "deletedfilemode");
5402                        patch_id_add_mode(&ctx, p->one->mode);
5403                        patch_id_add_string(&ctx, "---a/");
5404                        git_SHA1_Update(&ctx, p->one->path, len1);
5405                        patch_id_add_string(&ctx, "+++/dev/null");
5406                } else {
5407                        patch_id_add_string(&ctx, "---a/");
5408                        git_SHA1_Update(&ctx, p->one->path, len1);
5409                        patch_id_add_string(&ctx, "+++b/");
5410                        git_SHA1_Update(&ctx, p->two->path, len2);
5411                }
5412
5413                if (diff_header_only)
5414                        continue;
5415
5416                if (fill_mmfile(&mf1, p->one) < 0 ||
5417                    fill_mmfile(&mf2, p->two) < 0)
5418                        return error("unable to read files to diff");
5419
5420                if (diff_filespec_is_binary(p->one) ||
5421                    diff_filespec_is_binary(p->two)) {
5422                        git_SHA1_Update(&ctx, oid_to_hex(&p->one->oid),
5423                                        GIT_SHA1_HEXSZ);
5424                        git_SHA1_Update(&ctx, oid_to_hex(&p->two->oid),
5425                                        GIT_SHA1_HEXSZ);
5426                        continue;
5427                }
5428
5429                xpp.flags = 0;
5430                xecfg.ctxlen = 3;
5431                xecfg.flags = 0;
5432                if (xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
5433                                  &xpp, &xecfg))
5434                        return error("unable to generate patch-id diff for %s",
5435                                     p->one->path);
5436        }
5437
5438        git_SHA1_Final(oid->hash, &ctx);
5439        return 0;
5440}
5441
5442int diff_flush_patch_id(struct diff_options *options, struct object_id *oid, int diff_header_only)
5443{
5444        struct diff_queue_struct *q = &diff_queued_diff;
5445        int i;
5446        int result = diff_get_patch_id(options, oid, diff_header_only);
5447
5448        for (i = 0; i < q->nr; i++)
5449                diff_free_filepair(q->queue[i]);
5450
5451        free(q->queue);
5452        DIFF_QUEUE_CLEAR(q);
5453
5454        return result;
5455}
5456
5457static int is_summary_empty(const struct diff_queue_struct *q)
5458{
5459        int i;
5460
5461        for (i = 0; i < q->nr; i++) {
5462                const struct diff_filepair *p = q->queue[i];
5463
5464                switch (p->status) {
5465                case DIFF_STATUS_DELETED:
5466                case DIFF_STATUS_ADDED:
5467                case DIFF_STATUS_COPIED:
5468                case DIFF_STATUS_RENAMED:
5469                        return 0;
5470                default:
5471                        if (p->score)
5472                                return 0;
5473                        if (p->one->mode && p->two->mode &&
5474                            p->one->mode != p->two->mode)
5475                                return 0;
5476                        break;
5477                }
5478        }
5479        return 1;
5480}
5481
5482static const char rename_limit_warning[] =
5483N_("inexact rename detection was skipped due to too many files.");
5484
5485static const char degrade_cc_to_c_warning[] =
5486N_("only found copies from modified paths due to too many files.");
5487
5488static const char rename_limit_advice[] =
5489N_("you may want to set your %s variable to at least "
5490   "%d and retry the command.");
5491
5492void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc)
5493{
5494        fflush(stdout);
5495        if (degraded_cc)
5496                warning(_(degrade_cc_to_c_warning));
5497        else if (needed)
5498                warning(_(rename_limit_warning));
5499        else
5500                return;
5501        if (0 < needed)
5502                warning(_(rename_limit_advice), varname, needed);
5503}
5504
5505static void diff_flush_patch_all_file_pairs(struct diff_options *o)
5506{
5507        int i;
5508        static struct emitted_diff_symbols esm = EMITTED_DIFF_SYMBOLS_INIT;
5509        struct diff_queue_struct *q = &diff_queued_diff;
5510
5511        if (WSEH_NEW & WS_RULE_MASK)
5512                die("BUG: WS rules bit mask overlaps with diff symbol flags");
5513
5514        if (o->color_moved)
5515                o->emitted_symbols = &esm;
5516
5517        for (i = 0; i < q->nr; i++) {
5518                struct diff_filepair *p = q->queue[i];
5519                if (check_pair_status(p))
5520                        diff_flush_patch(p, o);
5521        }
5522
5523        if (o->emitted_symbols) {
5524                if (o->color_moved) {
5525                        struct hashmap add_lines, del_lines;
5526
5527                        hashmap_init(&del_lines,
5528                                     (hashmap_cmp_fn)moved_entry_cmp, o, 0);
5529                        hashmap_init(&add_lines,
5530                                     (hashmap_cmp_fn)moved_entry_cmp, o, 0);
5531
5532                        add_lines_to_move_detection(o, &add_lines, &del_lines);
5533                        mark_color_as_moved(o, &add_lines, &del_lines);
5534                        if (o->color_moved == COLOR_MOVED_ZEBRA_DIM)
5535                                dim_moved_lines(o);
5536
5537                        hashmap_free(&add_lines, 0);
5538                        hashmap_free(&del_lines, 0);
5539                }
5540
5541                for (i = 0; i < esm.nr; i++)
5542                        emit_diff_symbol_from_struct(o, &esm.buf[i]);
5543
5544                for (i = 0; i < esm.nr; i++)
5545                        free((void *)esm.buf[i].line);
5546        }
5547        esm.nr = 0;
5548}
5549
5550void diff_flush(struct diff_options *options)
5551{
5552        struct diff_queue_struct *q = &diff_queued_diff;
5553        int i, output_format = options->output_format;
5554        int separator = 0;
5555        int dirstat_by_line = 0;
5556
5557        /*
5558         * Order: raw, stat, summary, patch
5559         * or:    name/name-status/checkdiff (other bits clear)
5560         */
5561        if (!q->nr)
5562                goto free_queue;
5563
5564        if (output_format & (DIFF_FORMAT_RAW |
5565                             DIFF_FORMAT_NAME |
5566                             DIFF_FORMAT_NAME_STATUS |
5567                             DIFF_FORMAT_CHECKDIFF)) {
5568                for (i = 0; i < q->nr; i++) {
5569                        struct diff_filepair *p = q->queue[i];
5570                        if (check_pair_status(p))
5571                                flush_one_pair(p, options);
5572                }
5573                separator++;
5574        }
5575
5576        if (output_format & DIFF_FORMAT_DIRSTAT && options->flags.dirstat_by_line)
5577                dirstat_by_line = 1;
5578
5579        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT) ||
5580            dirstat_by_line) {
5581                struct diffstat_t diffstat;
5582
5583                memset(&diffstat, 0, sizeof(struct diffstat_t));
5584                for (i = 0; i < q->nr; i++) {
5585                        struct diff_filepair *p = q->queue[i];
5586                        if (check_pair_status(p))
5587                                diff_flush_stat(p, options, &diffstat);
5588                }
5589                if (output_format & DIFF_FORMAT_NUMSTAT)
5590                        show_numstat(&diffstat, options);
5591                if (output_format & DIFF_FORMAT_DIFFSTAT)
5592                        show_stats(&diffstat, options);
5593                if (output_format & DIFF_FORMAT_SHORTSTAT)
5594                        show_shortstats(&diffstat, options);
5595                if (output_format & DIFF_FORMAT_DIRSTAT && dirstat_by_line)
5596                        show_dirstat_by_line(&diffstat, options);
5597                free_diffstat_info(&diffstat);
5598                separator++;
5599        }
5600        if ((output_format & DIFF_FORMAT_DIRSTAT) && !dirstat_by_line)
5601                show_dirstat(options);
5602
5603        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
5604                for (i = 0; i < q->nr; i++) {
5605                        diff_summary(options, q->queue[i]);
5606                }
5607                separator++;
5608        }
5609
5610        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
5611            options->flags.exit_with_status &&
5612            options->flags.diff_from_contents) {
5613                /*
5614                 * run diff_flush_patch for the exit status. setting
5615                 * options->file to /dev/null should be safe, because we
5616                 * aren't supposed to produce any output anyway.
5617                 */
5618                if (options->close_file)
5619                        fclose(options->file);
5620                options->file = xfopen("/dev/null", "w");
5621                options->close_file = 1;
5622                options->color_moved = 0;
5623                for (i = 0; i < q->nr; i++) {
5624                        struct diff_filepair *p = q->queue[i];
5625                        if (check_pair_status(p))
5626                                diff_flush_patch(p, options);
5627                        if (options->found_changes)
5628                                break;
5629                }
5630        }
5631
5632        if (output_format & DIFF_FORMAT_PATCH) {
5633                if (separator) {
5634                        emit_diff_symbol(options, DIFF_SYMBOL_SEPARATOR, NULL, 0, 0);
5635                        if (options->stat_sep)
5636                                /* attach patch instead of inline */
5637                                emit_diff_symbol(options, DIFF_SYMBOL_STAT_SEP,
5638                                                 NULL, 0, 0);
5639                }
5640
5641                diff_flush_patch_all_file_pairs(options);
5642        }
5643
5644        if (output_format & DIFF_FORMAT_CALLBACK)
5645                options->format_callback(q, options, options->format_callback_data);
5646
5647        for (i = 0; i < q->nr; i++)
5648                diff_free_filepair(q->queue[i]);
5649free_queue:
5650        free(q->queue);
5651        DIFF_QUEUE_CLEAR(q);
5652        if (options->close_file)
5653                fclose(options->file);
5654
5655        /*
5656         * Report the content-level differences with HAS_CHANGES;
5657         * diff_addremove/diff_change does not set the bit when
5658         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
5659         */
5660        if (options->flags.diff_from_contents) {
5661                if (options->found_changes)
5662                        options->flags.has_changes = 1;
5663                else
5664                        options->flags.has_changes = 0;
5665        }
5666}
5667
5668static int match_filter(const struct diff_options *options, const struct diff_filepair *p)
5669{
5670        return (((p->status == DIFF_STATUS_MODIFIED) &&
5671                 ((p->score &&
5672                   filter_bit_tst(DIFF_STATUS_FILTER_BROKEN, options)) ||
5673                  (!p->score &&
5674                   filter_bit_tst(DIFF_STATUS_MODIFIED, options)))) ||
5675                ((p->status != DIFF_STATUS_MODIFIED) &&
5676                 filter_bit_tst(p->status, options)));
5677}
5678
5679static void diffcore_apply_filter(struct diff_options *options)
5680{
5681        int i;
5682        struct diff_queue_struct *q = &diff_queued_diff;
5683        struct diff_queue_struct outq;
5684
5685        DIFF_QUEUE_CLEAR(&outq);
5686
5687        if (!options->filter)
5688                return;
5689
5690        if (filter_bit_tst(DIFF_STATUS_FILTER_AON, options)) {
5691                int found;
5692                for (i = found = 0; !found && i < q->nr; i++) {
5693                        if (match_filter(options, q->queue[i]))
5694                                found++;
5695                }
5696                if (found)
5697                        return;
5698
5699                /* otherwise we will clear the whole queue
5700                 * by copying the empty outq at the end of this
5701                 * function, but first clear the current entries
5702                 * in the queue.
5703                 */
5704                for (i = 0; i < q->nr; i++)
5705                        diff_free_filepair(q->queue[i]);
5706        }
5707        else {
5708                /* Only the matching ones */
5709                for (i = 0; i < q->nr; i++) {
5710                        struct diff_filepair *p = q->queue[i];
5711                        if (match_filter(options, p))
5712                                diff_q(&outq, p);
5713                        else
5714                                diff_free_filepair(p);
5715                }
5716        }
5717        free(q->queue);
5718        *q = outq;
5719}
5720
5721/* Check whether two filespecs with the same mode and size are identical */
5722static int diff_filespec_is_identical(struct diff_filespec *one,
5723                                      struct diff_filespec *two)
5724{
5725        if (S_ISGITLINK(one->mode))
5726                return 0;
5727        if (diff_populate_filespec(one, 0))
5728                return 0;
5729        if (diff_populate_filespec(two, 0))
5730                return 0;
5731        return !memcmp(one->data, two->data, one->size);
5732}
5733
5734static int diff_filespec_check_stat_unmatch(struct diff_filepair *p)
5735{
5736        if (p->done_skip_stat_unmatch)
5737                return p->skip_stat_unmatch_result;
5738
5739        p->done_skip_stat_unmatch = 1;
5740        p->skip_stat_unmatch_result = 0;
5741        /*
5742         * 1. Entries that come from stat info dirtiness
5743         *    always have both sides (iow, not create/delete),
5744         *    one side of the object name is unknown, with
5745         *    the same mode and size.  Keep the ones that
5746         *    do not match these criteria.  They have real
5747         *    differences.
5748         *
5749         * 2. At this point, the file is known to be modified,
5750         *    with the same mode and size, and the object
5751         *    name of one side is unknown.  Need to inspect
5752         *    the identical contents.
5753         */
5754        if (!DIFF_FILE_VALID(p->one) || /* (1) */
5755            !DIFF_FILE_VALID(p->two) ||
5756            (p->one->oid_valid && p->two->oid_valid) ||
5757            (p->one->mode != p->two->mode) ||
5758            diff_populate_filespec(p->one, CHECK_SIZE_ONLY) ||
5759            diff_populate_filespec(p->two, CHECK_SIZE_ONLY) ||
5760            (p->one->size != p->two->size) ||
5761            !diff_filespec_is_identical(p->one, p->two)) /* (2) */
5762                p->skip_stat_unmatch_result = 1;
5763        return p->skip_stat_unmatch_result;
5764}
5765
5766static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
5767{
5768        int i;
5769        struct diff_queue_struct *q = &diff_queued_diff;
5770        struct diff_queue_struct outq;
5771        DIFF_QUEUE_CLEAR(&outq);
5772
5773        for (i = 0; i < q->nr; i++) {
5774                struct diff_filepair *p = q->queue[i];
5775
5776                if (diff_filespec_check_stat_unmatch(p))
5777                        diff_q(&outq, p);
5778                else {
5779                        /*
5780                         * The caller can subtract 1 from skip_stat_unmatch
5781                         * to determine how many paths were dirty only
5782                         * due to stat info mismatch.
5783                         */
5784                        if (!diffopt->flags.no_index)
5785                                diffopt->skip_stat_unmatch++;
5786                        diff_free_filepair(p);
5787                }
5788        }
5789        free(q->queue);
5790        *q = outq;
5791}
5792
5793static int diffnamecmp(const void *a_, const void *b_)
5794{
5795        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
5796        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
5797        const char *name_a, *name_b;
5798
5799        name_a = a->one ? a->one->path : a->two->path;
5800        name_b = b->one ? b->one->path : b->two->path;
5801        return strcmp(name_a, name_b);
5802}
5803
5804void diffcore_fix_diff_index(struct diff_options *options)
5805{
5806        struct diff_queue_struct *q = &diff_queued_diff;
5807        QSORT(q->queue, q->nr, diffnamecmp);
5808}
5809
5810void diffcore_std(struct diff_options *options)
5811{
5812        /* NOTE please keep the following in sync with diff_tree_combined() */
5813        if (options->skip_stat_unmatch)
5814                diffcore_skip_stat_unmatch(options);
5815        if (!options->found_follow) {
5816                /* See try_to_follow_renames() in tree-diff.c */
5817                if (options->break_opt != -1)
5818                        diffcore_break(options->break_opt);
5819                if (options->detect_rename)
5820                        diffcore_rename(options);
5821                if (options->break_opt != -1)
5822                        diffcore_merge_broken();
5823        }
5824        if (options->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK)
5825                diffcore_pickaxe(options);
5826        if (options->orderfile)
5827                diffcore_order(options->orderfile);
5828        if (!options->found_follow)
5829                /* See try_to_follow_renames() in tree-diff.c */
5830                diff_resolve_rename_copy();
5831        diffcore_apply_filter(options);
5832
5833        if (diff_queued_diff.nr && !options->flags.diff_from_contents)
5834                options->flags.has_changes = 1;
5835        else
5836                options->flags.has_changes = 0;
5837
5838        options->found_follow = 0;
5839}
5840
5841int diff_result_code(struct diff_options *opt, int status)
5842{
5843        int result = 0;
5844
5845        diff_warn_rename_limit("diff.renameLimit",
5846                               opt->needed_rename_limit,
5847                               opt->degraded_cc_to_c);
5848        if (!opt->flags.exit_with_status &&
5849            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
5850                return status;
5851        if (opt->flags.exit_with_status &&
5852            opt->flags.has_changes)
5853                result |= 01;
5854        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
5855            opt->flags.check_failed)
5856                result |= 02;
5857        return result;
5858}
5859
5860int diff_can_quit_early(struct diff_options *opt)
5861{
5862        return (opt->flags.quick &&
5863                !opt->filter &&
5864                opt->flags.has_changes);
5865}
5866
5867/*
5868 * Shall changes to this submodule be ignored?
5869 *
5870 * Submodule changes can be configured to be ignored separately for each path,
5871 * but that configuration can be overridden from the command line.
5872 */
5873static int is_submodule_ignored(const char *path, struct diff_options *options)
5874{
5875        int ignored = 0;
5876        struct diff_flags orig_flags = options->flags;
5877        if (!options->flags.override_submodule_config)
5878                set_diffopt_flags_from_submodule_config(options, path);
5879        if (options->flags.ignore_submodules)
5880                ignored = 1;
5881        options->flags = orig_flags;
5882        return ignored;
5883}
5884
5885void diff_addremove(struct diff_options *options,
5886                    int addremove, unsigned mode,
5887                    const struct object_id *oid,
5888                    int oid_valid,
5889                    const char *concatpath, unsigned dirty_submodule)
5890{
5891        struct diff_filespec *one, *two;
5892
5893        if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
5894                return;
5895
5896        /* This may look odd, but it is a preparation for
5897         * feeding "there are unchanged files which should
5898         * not produce diffs, but when you are doing copy
5899         * detection you would need them, so here they are"
5900         * entries to the diff-core.  They will be prefixed
5901         * with something like '=' or '*' (I haven't decided
5902         * which but should not make any difference).
5903         * Feeding the same new and old to diff_change()
5904         * also has the same effect.
5905         * Before the final output happens, they are pruned after
5906         * merged into rename/copy pairs as appropriate.
5907         */
5908        if (options->flags.reverse_diff)
5909                addremove = (addremove == '+' ? '-' :
5910                             addremove == '-' ? '+' : addremove);
5911
5912        if (options->prefix &&
5913            strncmp(concatpath, options->prefix, options->prefix_length))
5914                return;
5915
5916        one = alloc_filespec(concatpath);
5917        two = alloc_filespec(concatpath);
5918
5919        if (addremove != '+')
5920                fill_filespec(one, oid, oid_valid, mode);
5921        if (addremove != '-') {
5922                fill_filespec(two, oid, oid_valid, mode);
5923                two->dirty_submodule = dirty_submodule;
5924        }
5925
5926        diff_queue(&diff_queued_diff, one, two);
5927        if (!options->flags.diff_from_contents)
5928                options->flags.has_changes = 1;
5929}
5930
5931void diff_change(struct diff_options *options,
5932                 unsigned old_mode, unsigned new_mode,
5933                 const struct object_id *old_oid,
5934                 const struct object_id *new_oid,
5935                 int old_oid_valid, int new_oid_valid,
5936                 const char *concatpath,
5937                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
5938{
5939        struct diff_filespec *one, *two;
5940        struct diff_filepair *p;
5941
5942        if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
5943            is_submodule_ignored(concatpath, options))
5944                return;
5945
5946        if (options->flags.reverse_diff) {
5947                SWAP(old_mode, new_mode);
5948                SWAP(old_oid, new_oid);
5949                SWAP(old_oid_valid, new_oid_valid);
5950                SWAP(old_dirty_submodule, new_dirty_submodule);
5951        }
5952
5953        if (options->prefix &&
5954            strncmp(concatpath, options->prefix, options->prefix_length))
5955                return;
5956
5957        one = alloc_filespec(concatpath);
5958        two = alloc_filespec(concatpath);
5959        fill_filespec(one, old_oid, old_oid_valid, old_mode);
5960        fill_filespec(two, new_oid, new_oid_valid, new_mode);
5961        one->dirty_submodule = old_dirty_submodule;
5962        two->dirty_submodule = new_dirty_submodule;
5963        p = diff_queue(&diff_queued_diff, one, two);
5964
5965        if (options->flags.diff_from_contents)
5966                return;
5967
5968        if (options->flags.quick && options->skip_stat_unmatch &&
5969            !diff_filespec_check_stat_unmatch(p))
5970                return;
5971
5972        options->flags.has_changes = 1;
5973}
5974
5975struct diff_filepair *diff_unmerge(struct diff_options *options, const char *path)
5976{
5977        struct diff_filepair *pair;
5978        struct diff_filespec *one, *two;
5979
5980        if (options->prefix &&
5981            strncmp(path, options->prefix, options->prefix_length))
5982                return NULL;
5983
5984        one = alloc_filespec(path);
5985        two = alloc_filespec(path);
5986        pair = diff_queue(&diff_queued_diff, one, two);
5987        pair->is_unmerged = 1;
5988        return pair;
5989}
5990
5991static char *run_textconv(const char *pgm, struct diff_filespec *spec,
5992                size_t *outsize)
5993{
5994        struct diff_tempfile *temp;
5995        const char *argv[3];
5996        const char **arg = argv;
5997        struct child_process child = CHILD_PROCESS_INIT;
5998        struct strbuf buf = STRBUF_INIT;
5999        int err = 0;
6000
6001        temp = prepare_temp_file(spec->path, spec);
6002        *arg++ = pgm;
6003        *arg++ = temp->name;
6004        *arg = NULL;
6005
6006        child.use_shell = 1;
6007        child.argv = argv;
6008        child.out = -1;
6009        if (start_command(&child)) {
6010                remove_tempfile();
6011                return NULL;
6012        }
6013
6014        if (strbuf_read(&buf, child.out, 0) < 0)
6015                err = error("error reading from textconv command '%s'", pgm);
6016        close(child.out);
6017
6018        if (finish_command(&child) || err) {
6019                strbuf_release(&buf);
6020                remove_tempfile();
6021                return NULL;
6022        }
6023        remove_tempfile();
6024
6025        return strbuf_detach(&buf, outsize);
6026}
6027
6028size_t fill_textconv(struct userdiff_driver *driver,
6029                     struct diff_filespec *df,
6030                     char **outbuf)
6031{
6032        size_t size;
6033
6034        if (!driver) {
6035                if (!DIFF_FILE_VALID(df)) {
6036                        *outbuf = "";
6037                        return 0;
6038                }
6039                if (diff_populate_filespec(df, 0))
6040                        die("unable to read files to diff");
6041                *outbuf = df->data;
6042                return df->size;
6043        }
6044
6045        if (!driver->textconv)
6046                die("BUG: fill_textconv called with non-textconv driver");
6047
6048        if (driver->textconv_cache && df->oid_valid) {
6049                *outbuf = notes_cache_get(driver->textconv_cache,
6050                                          &df->oid,
6051                                          &size);
6052                if (*outbuf)
6053                        return size;
6054        }
6055
6056        *outbuf = run_textconv(driver->textconv, df, &size);
6057        if (!*outbuf)
6058                die("unable to read files to diff");
6059
6060        if (driver->textconv_cache && df->oid_valid) {
6061                /* ignore errors, as we might be in a readonly repository */
6062                notes_cache_put(driver->textconv_cache, &df->oid, *outbuf,
6063                                size);
6064                /*
6065                 * we could save up changes and flush them all at the end,
6066                 * but we would need an extra call after all diffing is done.
6067                 * Since generating a cache entry is the slow path anyway,
6068                 * this extra overhead probably isn't a big deal.
6069                 */
6070                notes_cache_write(driver->textconv_cache);
6071        }
6072
6073        return size;
6074}
6075
6076int textconv_object(const char *path,
6077                    unsigned mode,
6078                    const struct object_id *oid,
6079                    int oid_valid,
6080                    char **buf,
6081                    unsigned long *buf_size)
6082{
6083        struct diff_filespec *df;
6084        struct userdiff_driver *textconv;
6085
6086        df = alloc_filespec(path);
6087        fill_filespec(df, oid, oid_valid, mode);
6088        textconv = get_textconv(df);
6089        if (!textconv) {
6090                free_filespec(df);
6091                return 0;
6092        }
6093
6094        *buf_size = fill_textconv(textconv, df, buf);
6095        free_filespec(df);
6096        return 1;
6097}
6098
6099void setup_diff_pager(struct diff_options *opt)
6100{
6101        /*
6102         * If the user asked for our exit code, then either they want --quiet
6103         * or --exit-code. We should definitely not bother with a pager in the
6104         * former case, as we will generate no output. Since we still properly
6105         * report our exit code even when a pager is run, we _could_ run a
6106         * pager with --exit-code. But since we have not done so historically,
6107         * and because it is easy to find people oneline advising "git diff
6108         * --exit-code" in hooks and other scripts, we do not do so.
6109         */
6110        if (!opt->flags.exit_with_status &&
6111            check_pager_config("diff") != 0)
6112                setup_pager();
6113}