diff.con commit Merge branch 'bc/object-id' (37aac3e)
   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 "object-store.h"
  17#include "userdiff.h"
  18#include "submodule-config.h"
  19#include "submodule.h"
  20#include "hashmap.h"
  21#include "ll-merge.h"
  22#include "string-list.h"
  23#include "argv-array.h"
  24#include "graph.h"
  25#include "packfile.h"
  26#include "help.h"
  27
  28#ifdef NO_FAST_WORKING_DIRECTORY
  29#define FAST_WORKING_DIRECTORY 0
  30#else
  31#define FAST_WORKING_DIRECTORY 1
  32#endif
  33
  34static int diff_detect_rename_default;
  35static int diff_indent_heuristic = 1;
  36static int diff_rename_limit_default = 400;
  37static int diff_suppress_blank_empty;
  38static int diff_use_color_default = -1;
  39static int diff_color_moved_default;
  40static int diff_context_default = 3;
  41static int diff_interhunk_context_default;
  42static const char *diff_word_regex_cfg;
  43static const char *external_diff_cmd_cfg;
  44static const char *diff_order_file_cfg;
  45int diff_auto_refresh_index = 1;
  46static int diff_mnemonic_prefix;
  47static int diff_no_prefix;
  48static int diff_stat_graph_width;
  49static int diff_dirstat_permille_default = 30;
  50static struct diff_options default_diff_options;
  51static long diff_algorithm;
  52static unsigned ws_error_highlight_default = WSEH_NEW;
  53
  54static char diff_colors[][COLOR_MAXLEN] = {
  55        GIT_COLOR_RESET,
  56        GIT_COLOR_NORMAL,       /* CONTEXT */
  57        GIT_COLOR_BOLD,         /* METAINFO */
  58        GIT_COLOR_CYAN,         /* FRAGINFO */
  59        GIT_COLOR_RED,          /* OLD */
  60        GIT_COLOR_GREEN,        /* NEW */
  61        GIT_COLOR_YELLOW,       /* COMMIT */
  62        GIT_COLOR_BG_RED,       /* WHITESPACE */
  63        GIT_COLOR_NORMAL,       /* FUNCINFO */
  64        GIT_COLOR_BOLD_MAGENTA, /* OLD_MOVED */
  65        GIT_COLOR_BOLD_BLUE,    /* OLD_MOVED ALTERNATIVE */
  66        GIT_COLOR_FAINT,        /* OLD_MOVED_DIM */
  67        GIT_COLOR_FAINT_ITALIC, /* OLD_MOVED_ALTERNATIVE_DIM */
  68        GIT_COLOR_BOLD_CYAN,    /* NEW_MOVED */
  69        GIT_COLOR_BOLD_YELLOW,  /* NEW_MOVED ALTERNATIVE */
  70        GIT_COLOR_FAINT,        /* NEW_MOVED_DIM */
  71        GIT_COLOR_FAINT_ITALIC, /* NEW_MOVED_ALTERNATIVE_DIM */
  72};
  73
  74static const char *color_diff_slots[] = {
  75        [DIFF_CONTEXT]                = "context",
  76        [DIFF_METAINFO]               = "meta",
  77        [DIFF_FRAGINFO]               = "frag",
  78        [DIFF_FILE_OLD]               = "old",
  79        [DIFF_FILE_NEW]               = "new",
  80        [DIFF_COMMIT]                 = "commit",
  81        [DIFF_WHITESPACE]             = "whitespace",
  82        [DIFF_FUNCINFO]               = "func",
  83        [DIFF_FILE_OLD_MOVED]         = "oldMoved",
  84        [DIFF_FILE_OLD_MOVED_ALT]     = "oldMovedAlternative",
  85        [DIFF_FILE_OLD_MOVED_DIM]     = "oldMovedDimmed",
  86        [DIFF_FILE_OLD_MOVED_ALT_DIM] = "oldMovedAlternativeDimmed",
  87        [DIFF_FILE_NEW_MOVED]         = "newMoved",
  88        [DIFF_FILE_NEW_MOVED_ALT]     = "newMovedAlternative",
  89        [DIFF_FILE_NEW_MOVED_DIM]     = "newMovedDimmed",
  90        [DIFF_FILE_NEW_MOVED_ALT_DIM] = "newMovedAlternativeDimmed",
  91};
  92
  93static NORETURN void die_want_option(const char *option_name)
  94{
  95        die(_("option '%s' requires a value"), option_name);
  96}
  97
  98define_list_config_array_extra(color_diff_slots, {"plain"});
  99
 100static int parse_diff_color_slot(const char *var)
 101{
 102        if (!strcasecmp(var, "plain"))
 103                return DIFF_CONTEXT;
 104        return LOOKUP_CONFIG(color_diff_slots, var);
 105}
 106
 107static int parse_dirstat_params(struct diff_options *options, const char *params_string,
 108                                struct strbuf *errmsg)
 109{
 110        char *params_copy = xstrdup(params_string);
 111        struct string_list params = STRING_LIST_INIT_NODUP;
 112        int ret = 0;
 113        int i;
 114
 115        if (*params_copy)
 116                string_list_split_in_place(&params, params_copy, ',', -1);
 117        for (i = 0; i < params.nr; i++) {
 118                const char *p = params.items[i].string;
 119                if (!strcmp(p, "changes")) {
 120                        options->flags.dirstat_by_line = 0;
 121                        options->flags.dirstat_by_file = 0;
 122                } else if (!strcmp(p, "lines")) {
 123                        options->flags.dirstat_by_line = 1;
 124                        options->flags.dirstat_by_file = 0;
 125                } else if (!strcmp(p, "files")) {
 126                        options->flags.dirstat_by_line = 0;
 127                        options->flags.dirstat_by_file = 1;
 128                } else if (!strcmp(p, "noncumulative")) {
 129                        options->flags.dirstat_cumulative = 0;
 130                } else if (!strcmp(p, "cumulative")) {
 131                        options->flags.dirstat_cumulative = 1;
 132                } else if (isdigit(*p)) {
 133                        char *end;
 134                        int permille = strtoul(p, &end, 10) * 10;
 135                        if (*end == '.' && isdigit(*++end)) {
 136                                /* only use first digit */
 137                                permille += *end - '0';
 138                                /* .. and ignore any further digits */
 139                                while (isdigit(*++end))
 140                                        ; /* nothing */
 141                        }
 142                        if (!*end)
 143                                options->dirstat_permille = permille;
 144                        else {
 145                                strbuf_addf(errmsg, _("  Failed to parse dirstat cut-off percentage '%s'\n"),
 146                                            p);
 147                                ret++;
 148                        }
 149                } else {
 150                        strbuf_addf(errmsg, _("  Unknown dirstat parameter '%s'\n"), p);
 151                        ret++;
 152                }
 153
 154        }
 155        string_list_clear(&params, 0);
 156        free(params_copy);
 157        return ret;
 158}
 159
 160static int parse_submodule_params(struct diff_options *options, const char *value)
 161{
 162        if (!strcmp(value, "log"))
 163                options->submodule_format = DIFF_SUBMODULE_LOG;
 164        else if (!strcmp(value, "short"))
 165                options->submodule_format = DIFF_SUBMODULE_SHORT;
 166        else if (!strcmp(value, "diff"))
 167                options->submodule_format = DIFF_SUBMODULE_INLINE_DIFF;
 168        else
 169                return -1;
 170        return 0;
 171}
 172
 173int git_config_rename(const char *var, const char *value)
 174{
 175        if (!value)
 176                return DIFF_DETECT_RENAME;
 177        if (!strcasecmp(value, "copies") || !strcasecmp(value, "copy"))
 178                return  DIFF_DETECT_COPY;
 179        return git_config_bool(var,value) ? DIFF_DETECT_RENAME : 0;
 180}
 181
 182long parse_algorithm_value(const char *value)
 183{
 184        if (!value)
 185                return -1;
 186        else if (!strcasecmp(value, "myers") || !strcasecmp(value, "default"))
 187                return 0;
 188        else if (!strcasecmp(value, "minimal"))
 189                return XDF_NEED_MINIMAL;
 190        else if (!strcasecmp(value, "patience"))
 191                return XDF_PATIENCE_DIFF;
 192        else if (!strcasecmp(value, "histogram"))
 193                return XDF_HISTOGRAM_DIFF;
 194        return -1;
 195}
 196
 197static int parse_one_token(const char **arg, const char *token)
 198{
 199        const char *rest;
 200        if (skip_prefix(*arg, token, &rest) && (!*rest || *rest == ',')) {
 201                *arg = rest;
 202                return 1;
 203        }
 204        return 0;
 205}
 206
 207static int parse_ws_error_highlight(const char *arg)
 208{
 209        const char *orig_arg = arg;
 210        unsigned val = 0;
 211
 212        while (*arg) {
 213                if (parse_one_token(&arg, "none"))
 214                        val = 0;
 215                else if (parse_one_token(&arg, "default"))
 216                        val = WSEH_NEW;
 217                else if (parse_one_token(&arg, "all"))
 218                        val = WSEH_NEW | WSEH_OLD | WSEH_CONTEXT;
 219                else if (parse_one_token(&arg, "new"))
 220                        val |= WSEH_NEW;
 221                else if (parse_one_token(&arg, "old"))
 222                        val |= WSEH_OLD;
 223                else if (parse_one_token(&arg, "context"))
 224                        val |= WSEH_CONTEXT;
 225                else {
 226                        return -1 - (int)(arg - orig_arg);
 227                }
 228                if (*arg)
 229                        arg++;
 230        }
 231        return val;
 232}
 233
 234/*
 235 * These are to give UI layer defaults.
 236 * The core-level commands such as git-diff-files should
 237 * never be affected by the setting of diff.renames
 238 * the user happens to have in the configuration file.
 239 */
 240void init_diff_ui_defaults(void)
 241{
 242        diff_detect_rename_default = DIFF_DETECT_RENAME;
 243}
 244
 245int git_diff_heuristic_config(const char *var, const char *value, void *cb)
 246{
 247        if (!strcmp(var, "diff.indentheuristic"))
 248                diff_indent_heuristic = git_config_bool(var, value);
 249        return 0;
 250}
 251
 252static int parse_color_moved(const char *arg)
 253{
 254        switch (git_parse_maybe_bool(arg)) {
 255        case 0:
 256                return COLOR_MOVED_NO;
 257        case 1:
 258                return COLOR_MOVED_DEFAULT;
 259        default:
 260                break;
 261        }
 262
 263        if (!strcmp(arg, "no"))
 264                return COLOR_MOVED_NO;
 265        else if (!strcmp(arg, "plain"))
 266                return COLOR_MOVED_PLAIN;
 267        else if (!strcmp(arg, "zebra"))
 268                return COLOR_MOVED_ZEBRA;
 269        else if (!strcmp(arg, "default"))
 270                return COLOR_MOVED_DEFAULT;
 271        else if (!strcmp(arg, "dimmed_zebra"))
 272                return COLOR_MOVED_ZEBRA_DIM;
 273        else
 274                return error(_("color moved setting must be one of 'no', 'default', 'zebra', 'dimmed_zebra', 'plain'"));
 275}
 276
 277int git_diff_ui_config(const char *var, const char *value, void *cb)
 278{
 279        if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
 280                diff_use_color_default = git_config_colorbool(var, value);
 281                return 0;
 282        }
 283        if (!strcmp(var, "diff.colormoved")) {
 284                int cm = parse_color_moved(value);
 285                if (cm < 0)
 286                        return -1;
 287                diff_color_moved_default = cm;
 288                return 0;
 289        }
 290        if (!strcmp(var, "diff.context")) {
 291                diff_context_default = git_config_int(var, value);
 292                if (diff_context_default < 0)
 293                        return -1;
 294                return 0;
 295        }
 296        if (!strcmp(var, "diff.interhunkcontext")) {
 297                diff_interhunk_context_default = git_config_int(var, value);
 298                if (diff_interhunk_context_default < 0)
 299                        return -1;
 300                return 0;
 301        }
 302        if (!strcmp(var, "diff.renames")) {
 303                diff_detect_rename_default = git_config_rename(var, value);
 304                return 0;
 305        }
 306        if (!strcmp(var, "diff.autorefreshindex")) {
 307                diff_auto_refresh_index = git_config_bool(var, value);
 308                return 0;
 309        }
 310        if (!strcmp(var, "diff.mnemonicprefix")) {
 311                diff_mnemonic_prefix = git_config_bool(var, value);
 312                return 0;
 313        }
 314        if (!strcmp(var, "diff.noprefix")) {
 315                diff_no_prefix = git_config_bool(var, value);
 316                return 0;
 317        }
 318        if (!strcmp(var, "diff.statgraphwidth")) {
 319                diff_stat_graph_width = git_config_int(var, value);
 320                return 0;
 321        }
 322        if (!strcmp(var, "diff.external"))
 323                return git_config_string(&external_diff_cmd_cfg, var, value);
 324        if (!strcmp(var, "diff.wordregex"))
 325                return git_config_string(&diff_word_regex_cfg, var, value);
 326        if (!strcmp(var, "diff.orderfile"))
 327                return git_config_pathname(&diff_order_file_cfg, var, value);
 328
 329        if (!strcmp(var, "diff.ignoresubmodules"))
 330                handle_ignore_submodules_arg(&default_diff_options, value);
 331
 332        if (!strcmp(var, "diff.submodule")) {
 333                if (parse_submodule_params(&default_diff_options, value))
 334                        warning(_("Unknown value for 'diff.submodule' config variable: '%s'"),
 335                                value);
 336                return 0;
 337        }
 338
 339        if (!strcmp(var, "diff.algorithm")) {
 340                diff_algorithm = parse_algorithm_value(value);
 341                if (diff_algorithm < 0)
 342                        return -1;
 343                return 0;
 344        }
 345
 346        if (!strcmp(var, "diff.wserrorhighlight")) {
 347                int val = parse_ws_error_highlight(value);
 348                if (val < 0)
 349                        return -1;
 350                ws_error_highlight_default = val;
 351                return 0;
 352        }
 353
 354        if (git_color_config(var, value, cb) < 0)
 355                return -1;
 356
 357        return git_diff_basic_config(var, value, cb);
 358}
 359
 360int git_diff_basic_config(const char *var, const char *value, void *cb)
 361{
 362        const char *name;
 363
 364        if (!strcmp(var, "diff.renamelimit")) {
 365                diff_rename_limit_default = git_config_int(var, value);
 366                return 0;
 367        }
 368
 369        if (userdiff_config(var, value) < 0)
 370                return -1;
 371
 372        if (skip_prefix(var, "diff.color.", &name) ||
 373            skip_prefix(var, "color.diff.", &name)) {
 374                int slot = parse_diff_color_slot(name);
 375                if (slot < 0)
 376                        return 0;
 377                if (!value)
 378                        return config_error_nonbool(var);
 379                return color_parse(value, diff_colors[slot]);
 380        }
 381
 382        /* like GNU diff's --suppress-blank-empty option  */
 383        if (!strcmp(var, "diff.suppressblankempty") ||
 384                        /* for backwards compatibility */
 385                        !strcmp(var, "diff.suppress-blank-empty")) {
 386                diff_suppress_blank_empty = git_config_bool(var, value);
 387                return 0;
 388        }
 389
 390        if (!strcmp(var, "diff.dirstat")) {
 391                struct strbuf errmsg = STRBUF_INIT;
 392                default_diff_options.dirstat_permille = diff_dirstat_permille_default;
 393                if (parse_dirstat_params(&default_diff_options, value, &errmsg))
 394                        warning(_("Found errors in 'diff.dirstat' config variable:\n%s"),
 395                                errmsg.buf);
 396                strbuf_release(&errmsg);
 397                diff_dirstat_permille_default = default_diff_options.dirstat_permille;
 398                return 0;
 399        }
 400
 401        if (git_diff_heuristic_config(var, value, cb) < 0)
 402                return -1;
 403
 404        return git_default_config(var, value, cb);
 405}
 406
 407static char *quote_two(const char *one, const char *two)
 408{
 409        int need_one = quote_c_style(one, NULL, NULL, 1);
 410        int need_two = quote_c_style(two, NULL, NULL, 1);
 411        struct strbuf res = STRBUF_INIT;
 412
 413        if (need_one + need_two) {
 414                strbuf_addch(&res, '"');
 415                quote_c_style(one, &res, NULL, 1);
 416                quote_c_style(two, &res, NULL, 1);
 417                strbuf_addch(&res, '"');
 418        } else {
 419                strbuf_addstr(&res, one);
 420                strbuf_addstr(&res, two);
 421        }
 422        return strbuf_detach(&res, NULL);
 423}
 424
 425static const char *external_diff(void)
 426{
 427        static const char *external_diff_cmd = NULL;
 428        static int done_preparing = 0;
 429
 430        if (done_preparing)
 431                return external_diff_cmd;
 432        external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
 433        if (!external_diff_cmd)
 434                external_diff_cmd = external_diff_cmd_cfg;
 435        done_preparing = 1;
 436        return external_diff_cmd;
 437}
 438
 439/*
 440 * Keep track of files used for diffing. Sometimes such an entry
 441 * refers to a temporary file, sometimes to an existing file, and
 442 * sometimes to "/dev/null".
 443 */
 444static struct diff_tempfile {
 445        /*
 446         * filename external diff should read from, or NULL if this
 447         * entry is currently not in use:
 448         */
 449        const char *name;
 450
 451        char hex[GIT_MAX_HEXSZ + 1];
 452        char mode[10];
 453
 454        /*
 455         * If this diff_tempfile instance refers to a temporary file,
 456         * this tempfile object is used to manage its lifetime.
 457         */
 458        struct tempfile *tempfile;
 459} diff_temp[2];
 460
 461struct emit_callback {
 462        int color_diff;
 463        unsigned ws_rule;
 464        int blank_at_eof_in_preimage;
 465        int blank_at_eof_in_postimage;
 466        int lno_in_preimage;
 467        int lno_in_postimage;
 468        const char **label_path;
 469        struct diff_words_data *diff_words;
 470        struct diff_options *opt;
 471        struct strbuf *header;
 472};
 473
 474static int count_lines(const char *data, int size)
 475{
 476        int count, ch, completely_empty = 1, nl_just_seen = 0;
 477        count = 0;
 478        while (0 < size--) {
 479                ch = *data++;
 480                if (ch == '\n') {
 481                        count++;
 482                        nl_just_seen = 1;
 483                        completely_empty = 0;
 484                }
 485                else {
 486                        nl_just_seen = 0;
 487                        completely_empty = 0;
 488                }
 489        }
 490        if (completely_empty)
 491                return 0;
 492        if (!nl_just_seen)
 493                count++; /* no trailing newline */
 494        return count;
 495}
 496
 497static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
 498{
 499        if (!DIFF_FILE_VALID(one)) {
 500                mf->ptr = (char *)""; /* does not matter */
 501                mf->size = 0;
 502                return 0;
 503        }
 504        else if (diff_populate_filespec(one, 0))
 505                return -1;
 506
 507        mf->ptr = one->data;
 508        mf->size = one->size;
 509        return 0;
 510}
 511
 512/* like fill_mmfile, but only for size, so we can avoid retrieving blob */
 513static unsigned long diff_filespec_size(struct diff_filespec *one)
 514{
 515        if (!DIFF_FILE_VALID(one))
 516                return 0;
 517        diff_populate_filespec(one, CHECK_SIZE_ONLY);
 518        return one->size;
 519}
 520
 521static int count_trailing_blank(mmfile_t *mf, unsigned ws_rule)
 522{
 523        char *ptr = mf->ptr;
 524        long size = mf->size;
 525        int cnt = 0;
 526
 527        if (!size)
 528                return cnt;
 529        ptr += size - 1; /* pointing at the very end */
 530        if (*ptr != '\n')
 531                ; /* incomplete line */
 532        else
 533                ptr--; /* skip the last LF */
 534        while (mf->ptr < ptr) {
 535                char *prev_eol;
 536                for (prev_eol = ptr; mf->ptr <= prev_eol; prev_eol--)
 537                        if (*prev_eol == '\n')
 538                                break;
 539                if (!ws_blank_line(prev_eol + 1, ptr - prev_eol, ws_rule))
 540                        break;
 541                cnt++;
 542                ptr = prev_eol - 1;
 543        }
 544        return cnt;
 545}
 546
 547static void check_blank_at_eof(mmfile_t *mf1, mmfile_t *mf2,
 548                               struct emit_callback *ecbdata)
 549{
 550        int l1, l2, at;
 551        unsigned ws_rule = ecbdata->ws_rule;
 552        l1 = count_trailing_blank(mf1, ws_rule);
 553        l2 = count_trailing_blank(mf2, ws_rule);
 554        if (l2 <= l1) {
 555                ecbdata->blank_at_eof_in_preimage = 0;
 556                ecbdata->blank_at_eof_in_postimage = 0;
 557                return;
 558        }
 559        at = count_lines(mf1->ptr, mf1->size);
 560        ecbdata->blank_at_eof_in_preimage = (at - l1) + 1;
 561
 562        at = count_lines(mf2->ptr, mf2->size);
 563        ecbdata->blank_at_eof_in_postimage = (at - l2) + 1;
 564}
 565
 566static void emit_line_0(struct diff_options *o, const char *set, const char *reset,
 567                        int first, const char *line, int len)
 568{
 569        int has_trailing_newline, has_trailing_carriage_return;
 570        int nofirst;
 571        FILE *file = o->file;
 572
 573        fputs(diff_line_prefix(o), file);
 574
 575        if (len == 0) {
 576                has_trailing_newline = (first == '\n');
 577                has_trailing_carriage_return = (!has_trailing_newline &&
 578                                                (first == '\r'));
 579                nofirst = has_trailing_newline || has_trailing_carriage_return;
 580        } else {
 581                has_trailing_newline = (len > 0 && line[len-1] == '\n');
 582                if (has_trailing_newline)
 583                        len--;
 584                has_trailing_carriage_return = (len > 0 && line[len-1] == '\r');
 585                if (has_trailing_carriage_return)
 586                        len--;
 587                nofirst = 0;
 588        }
 589
 590        if (len || !nofirst) {
 591                fputs(set, file);
 592                if (!nofirst)
 593                        fputc(first, file);
 594                fwrite(line, len, 1, file);
 595                fputs(reset, file);
 596        }
 597        if (has_trailing_carriage_return)
 598                fputc('\r', file);
 599        if (has_trailing_newline)
 600                fputc('\n', file);
 601}
 602
 603static void emit_line(struct diff_options *o, const char *set, const char *reset,
 604                      const char *line, int len)
 605{
 606        emit_line_0(o, set, reset, line[0], line+1, len-1);
 607}
 608
 609enum diff_symbol {
 610        DIFF_SYMBOL_BINARY_DIFF_HEADER,
 611        DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA,
 612        DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL,
 613        DIFF_SYMBOL_BINARY_DIFF_BODY,
 614        DIFF_SYMBOL_BINARY_DIFF_FOOTER,
 615        DIFF_SYMBOL_STATS_SUMMARY_NO_FILES,
 616        DIFF_SYMBOL_STATS_SUMMARY_ABBREV,
 617        DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES,
 618        DIFF_SYMBOL_STATS_LINE,
 619        DIFF_SYMBOL_WORD_DIFF,
 620        DIFF_SYMBOL_STAT_SEP,
 621        DIFF_SYMBOL_SUMMARY,
 622        DIFF_SYMBOL_SUBMODULE_ADD,
 623        DIFF_SYMBOL_SUBMODULE_DEL,
 624        DIFF_SYMBOL_SUBMODULE_UNTRACKED,
 625        DIFF_SYMBOL_SUBMODULE_MODIFIED,
 626        DIFF_SYMBOL_SUBMODULE_HEADER,
 627        DIFF_SYMBOL_SUBMODULE_ERROR,
 628        DIFF_SYMBOL_SUBMODULE_PIPETHROUGH,
 629        DIFF_SYMBOL_REWRITE_DIFF,
 630        DIFF_SYMBOL_BINARY_FILES,
 631        DIFF_SYMBOL_HEADER,
 632        DIFF_SYMBOL_FILEPAIR_PLUS,
 633        DIFF_SYMBOL_FILEPAIR_MINUS,
 634        DIFF_SYMBOL_WORDS_PORCELAIN,
 635        DIFF_SYMBOL_WORDS,
 636        DIFF_SYMBOL_CONTEXT,
 637        DIFF_SYMBOL_CONTEXT_INCOMPLETE,
 638        DIFF_SYMBOL_PLUS,
 639        DIFF_SYMBOL_MINUS,
 640        DIFF_SYMBOL_NO_LF_EOF,
 641        DIFF_SYMBOL_CONTEXT_FRAGINFO,
 642        DIFF_SYMBOL_CONTEXT_MARKER,
 643        DIFF_SYMBOL_SEPARATOR
 644};
 645/*
 646 * Flags for content lines:
 647 * 0..12 are whitespace rules
 648 * 13-15 are WSEH_NEW | WSEH_OLD | WSEH_CONTEXT
 649 * 16 is marking if the line is blank at EOF
 650 */
 651#define DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF      (1<<16)
 652#define DIFF_SYMBOL_MOVED_LINE                  (1<<17)
 653#define DIFF_SYMBOL_MOVED_LINE_ALT              (1<<18)
 654#define DIFF_SYMBOL_MOVED_LINE_UNINTERESTING    (1<<19)
 655#define DIFF_SYMBOL_CONTENT_WS_MASK (WSEH_NEW | WSEH_OLD | WSEH_CONTEXT | WS_RULE_MASK)
 656
 657/*
 658 * This struct is used when we need to buffer the output of the diff output.
 659 *
 660 * NEEDSWORK: Instead of storing a copy of the line, add an offset pointer
 661 * into the pre/post image file. This pointer could be a union with the
 662 * line pointer. By storing an offset into the file instead of the literal line,
 663 * we can decrease the memory footprint for the buffered output. At first we
 664 * may want to only have indirection for the content lines, but we could also
 665 * enhance the state for emitting prefabricated lines, e.g. the similarity
 666 * score line or hunk/file headers would only need to store a number or path
 667 * and then the output can be constructed later on depending on state.
 668 */
 669struct emitted_diff_symbol {
 670        const char *line;
 671        int len;
 672        int flags;
 673        enum diff_symbol s;
 674};
 675#define EMITTED_DIFF_SYMBOL_INIT {NULL}
 676
 677struct emitted_diff_symbols {
 678        struct emitted_diff_symbol *buf;
 679        int nr, alloc;
 680};
 681#define EMITTED_DIFF_SYMBOLS_INIT {NULL, 0, 0}
 682
 683static void append_emitted_diff_symbol(struct diff_options *o,
 684                                       struct emitted_diff_symbol *e)
 685{
 686        struct emitted_diff_symbol *f;
 687
 688        ALLOC_GROW(o->emitted_symbols->buf,
 689                   o->emitted_symbols->nr + 1,
 690                   o->emitted_symbols->alloc);
 691        f = &o->emitted_symbols->buf[o->emitted_symbols->nr++];
 692
 693        memcpy(f, e, sizeof(struct emitted_diff_symbol));
 694        f->line = e->line ? xmemdupz(e->line, e->len) : NULL;
 695}
 696
 697struct moved_entry {
 698        struct hashmap_entry ent;
 699        const struct emitted_diff_symbol *es;
 700        struct moved_entry *next_line;
 701};
 702
 703static int moved_entry_cmp(const struct diff_options *diffopt,
 704                           const struct moved_entry *a,
 705                           const struct moved_entry *b,
 706                           const void *keydata)
 707{
 708        return !xdiff_compare_lines(a->es->line, a->es->len,
 709                                    b->es->line, b->es->len,
 710                                    diffopt->xdl_opts);
 711}
 712
 713static struct moved_entry *prepare_entry(struct diff_options *o,
 714                                         int line_no)
 715{
 716        struct moved_entry *ret = xmalloc(sizeof(*ret));
 717        struct emitted_diff_symbol *l = &o->emitted_symbols->buf[line_no];
 718
 719        ret->ent.hash = xdiff_hash_string(l->line, l->len, o->xdl_opts);
 720        ret->es = l;
 721        ret->next_line = NULL;
 722
 723        return ret;
 724}
 725
 726static void add_lines_to_move_detection(struct diff_options *o,
 727                                        struct hashmap *add_lines,
 728                                        struct hashmap *del_lines)
 729{
 730        struct moved_entry *prev_line = NULL;
 731
 732        int n;
 733        for (n = 0; n < o->emitted_symbols->nr; n++) {
 734                struct hashmap *hm;
 735                struct moved_entry *key;
 736
 737                switch (o->emitted_symbols->buf[n].s) {
 738                case DIFF_SYMBOL_PLUS:
 739                        hm = add_lines;
 740                        break;
 741                case DIFF_SYMBOL_MINUS:
 742                        hm = del_lines;
 743                        break;
 744                default:
 745                        prev_line = NULL;
 746                        continue;
 747                }
 748
 749                key = prepare_entry(o, n);
 750                if (prev_line && prev_line->es->s == o->emitted_symbols->buf[n].s)
 751                        prev_line->next_line = key;
 752
 753                hashmap_add(hm, key);
 754                prev_line = key;
 755        }
 756}
 757
 758static int shrink_potential_moved_blocks(struct moved_entry **pmb,
 759                                         int pmb_nr)
 760{
 761        int lp, rp;
 762
 763        /* Shrink the set of potential block to the remaining running */
 764        for (lp = 0, rp = pmb_nr - 1; lp <= rp;) {
 765                while (lp < pmb_nr && pmb[lp])
 766                        lp++;
 767                /* lp points at the first NULL now */
 768
 769                while (rp > -1 && !pmb[rp])
 770                        rp--;
 771                /* rp points at the last non-NULL */
 772
 773                if (lp < pmb_nr && rp > -1 && lp < rp) {
 774                        pmb[lp] = pmb[rp];
 775                        pmb[rp] = NULL;
 776                        rp--;
 777                        lp++;
 778                }
 779        }
 780
 781        /* Remember the number of running sets */
 782        return rp + 1;
 783}
 784
 785/*
 786 * If o->color_moved is COLOR_MOVED_PLAIN, this function does nothing.
 787 *
 788 * Otherwise, if the last block has fewer alphanumeric characters than
 789 * COLOR_MOVED_MIN_ALNUM_COUNT, unset DIFF_SYMBOL_MOVED_LINE on all lines in
 790 * that block.
 791 *
 792 * The last block consists of the (n - block_length)'th line up to but not
 793 * including the nth line.
 794 *
 795 * NEEDSWORK: This uses the same heuristic as blame_entry_score() in blame.c.
 796 * Think of a way to unify them.
 797 */
 798static void adjust_last_block(struct diff_options *o, int n, int block_length)
 799{
 800        int i, alnum_count = 0;
 801        if (o->color_moved == COLOR_MOVED_PLAIN)
 802                return;
 803        for (i = 1; i < block_length + 1; i++) {
 804                const char *c = o->emitted_symbols->buf[n - i].line;
 805                for (; *c; c++) {
 806                        if (!isalnum(*c))
 807                                continue;
 808                        alnum_count++;
 809                        if (alnum_count >= COLOR_MOVED_MIN_ALNUM_COUNT)
 810                                return;
 811                }
 812        }
 813        for (i = 1; i < block_length + 1; i++)
 814                o->emitted_symbols->buf[n - i].flags &= ~DIFF_SYMBOL_MOVED_LINE;
 815}
 816
 817/* Find blocks of moved code, delegate actual coloring decision to helper */
 818static void mark_color_as_moved(struct diff_options *o,
 819                                struct hashmap *add_lines,
 820                                struct hashmap *del_lines)
 821{
 822        struct moved_entry **pmb = NULL; /* potentially moved blocks */
 823        int pmb_nr = 0, pmb_alloc = 0;
 824        int n, flipped_block = 1, block_length = 0;
 825
 826
 827        for (n = 0; n < o->emitted_symbols->nr; n++) {
 828                struct hashmap *hm = NULL;
 829                struct moved_entry *key;
 830                struct moved_entry *match = NULL;
 831                struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
 832                int i;
 833
 834                switch (l->s) {
 835                case DIFF_SYMBOL_PLUS:
 836                        hm = del_lines;
 837                        key = prepare_entry(o, n);
 838                        match = hashmap_get(hm, key, o);
 839                        free(key);
 840                        break;
 841                case DIFF_SYMBOL_MINUS:
 842                        hm = add_lines;
 843                        key = prepare_entry(o, n);
 844                        match = hashmap_get(hm, key, o);
 845                        free(key);
 846                        break;
 847                default:
 848                        flipped_block = 1;
 849                }
 850
 851                if (!match) {
 852                        adjust_last_block(o, n, block_length);
 853                        pmb_nr = 0;
 854                        block_length = 0;
 855                        continue;
 856                }
 857
 858                l->flags |= DIFF_SYMBOL_MOVED_LINE;
 859
 860                if (o->color_moved == COLOR_MOVED_PLAIN)
 861                        continue;
 862
 863                /* Check any potential block runs, advance each or nullify */
 864                for (i = 0; i < pmb_nr; i++) {
 865                        struct moved_entry *p = pmb[i];
 866                        struct moved_entry *pnext = (p && p->next_line) ?
 867                                        p->next_line : NULL;
 868                        if (pnext && !hm->cmpfn(o, pnext, match, NULL)) {
 869                                pmb[i] = p->next_line;
 870                        } else {
 871                                pmb[i] = NULL;
 872                        }
 873                }
 874
 875                pmb_nr = shrink_potential_moved_blocks(pmb, pmb_nr);
 876
 877                if (pmb_nr == 0) {
 878                        /*
 879                         * The current line is the start of a new block.
 880                         * Setup the set of potential blocks.
 881                         */
 882                        for (; match; match = hashmap_get_next(hm, match)) {
 883                                ALLOC_GROW(pmb, pmb_nr + 1, pmb_alloc);
 884                                pmb[pmb_nr++] = match;
 885                        }
 886
 887                        flipped_block = (flipped_block + 1) % 2;
 888
 889                        adjust_last_block(o, n, block_length);
 890                        block_length = 0;
 891                }
 892
 893                block_length++;
 894
 895                if (flipped_block)
 896                        l->flags |= DIFF_SYMBOL_MOVED_LINE_ALT;
 897        }
 898        adjust_last_block(o, n, block_length);
 899
 900        free(pmb);
 901}
 902
 903#define DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK \
 904  (DIFF_SYMBOL_MOVED_LINE | DIFF_SYMBOL_MOVED_LINE_ALT)
 905static void dim_moved_lines(struct diff_options *o)
 906{
 907        int n;
 908        for (n = 0; n < o->emitted_symbols->nr; n++) {
 909                struct emitted_diff_symbol *prev = (n != 0) ?
 910                                &o->emitted_symbols->buf[n - 1] : NULL;
 911                struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
 912                struct emitted_diff_symbol *next =
 913                                (n < o->emitted_symbols->nr - 1) ?
 914                                &o->emitted_symbols->buf[n + 1] : NULL;
 915
 916                /* Not a plus or minus line? */
 917                if (l->s != DIFF_SYMBOL_PLUS && l->s != DIFF_SYMBOL_MINUS)
 918                        continue;
 919
 920                /* Not a moved line? */
 921                if (!(l->flags & DIFF_SYMBOL_MOVED_LINE))
 922                        continue;
 923
 924                /*
 925                 * If prev or next are not a plus or minus line,
 926                 * pretend they don't exist
 927                 */
 928                if (prev && prev->s != DIFF_SYMBOL_PLUS &&
 929                            prev->s != DIFF_SYMBOL_MINUS)
 930                        prev = NULL;
 931                if (next && next->s != DIFF_SYMBOL_PLUS &&
 932                            next->s != DIFF_SYMBOL_MINUS)
 933                        next = NULL;
 934
 935                /* Inside a block? */
 936                if ((prev &&
 937                    (prev->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK) ==
 938                    (l->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK)) &&
 939                    (next &&
 940                    (next->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK) ==
 941                    (l->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK))) {
 942                        l->flags |= DIFF_SYMBOL_MOVED_LINE_UNINTERESTING;
 943                        continue;
 944                }
 945
 946                /* Check if we are at an interesting bound: */
 947                if (prev && (prev->flags & DIFF_SYMBOL_MOVED_LINE) &&
 948                    (prev->flags & DIFF_SYMBOL_MOVED_LINE_ALT) !=
 949                       (l->flags & DIFF_SYMBOL_MOVED_LINE_ALT))
 950                        continue;
 951                if (next && (next->flags & DIFF_SYMBOL_MOVED_LINE) &&
 952                    (next->flags & DIFF_SYMBOL_MOVED_LINE_ALT) !=
 953                       (l->flags & DIFF_SYMBOL_MOVED_LINE_ALT))
 954                        continue;
 955
 956                /*
 957                 * The boundary to prev and next are not interesting,
 958                 * so this line is not interesting as a whole
 959                 */
 960                l->flags |= DIFF_SYMBOL_MOVED_LINE_UNINTERESTING;
 961        }
 962}
 963
 964static void emit_line_ws_markup(struct diff_options *o,
 965                                const char *set, const char *reset,
 966                                const char *line, int len, char sign,
 967                                unsigned ws_rule, int blank_at_eof)
 968{
 969        const char *ws = NULL;
 970
 971        if (o->ws_error_highlight & ws_rule) {
 972                ws = diff_get_color_opt(o, DIFF_WHITESPACE);
 973                if (!*ws)
 974                        ws = NULL;
 975        }
 976
 977        if (!ws)
 978                emit_line_0(o, set, reset, sign, line, len);
 979        else if (blank_at_eof)
 980                /* Blank line at EOF - paint '+' as well */
 981                emit_line_0(o, ws, reset, sign, line, len);
 982        else {
 983                /* Emit just the prefix, then the rest. */
 984                emit_line_0(o, set, reset, sign, "", 0);
 985                ws_check_emit(line, len, ws_rule,
 986                              o->file, set, reset, ws);
 987        }
 988}
 989
 990static void emit_diff_symbol_from_struct(struct diff_options *o,
 991                                         struct emitted_diff_symbol *eds)
 992{
 993        static const char *nneof = " No newline at end of file\n";
 994        const char *context, *reset, *set, *meta, *fraginfo;
 995        struct strbuf sb = STRBUF_INIT;
 996
 997        enum diff_symbol s = eds->s;
 998        const char *line = eds->line;
 999        int len = eds->len;
1000        unsigned flags = eds->flags;
1001
1002        switch (s) {
1003        case DIFF_SYMBOL_NO_LF_EOF:
1004                context = diff_get_color_opt(o, DIFF_CONTEXT);
1005                reset = diff_get_color_opt(o, DIFF_RESET);
1006                putc('\n', o->file);
1007                emit_line_0(o, context, reset, '\\',
1008                            nneof, strlen(nneof));
1009                break;
1010        case DIFF_SYMBOL_SUBMODULE_HEADER:
1011        case DIFF_SYMBOL_SUBMODULE_ERROR:
1012        case DIFF_SYMBOL_SUBMODULE_PIPETHROUGH:
1013        case DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES:
1014        case DIFF_SYMBOL_SUMMARY:
1015        case DIFF_SYMBOL_STATS_LINE:
1016        case DIFF_SYMBOL_BINARY_DIFF_BODY:
1017        case DIFF_SYMBOL_CONTEXT_FRAGINFO:
1018                emit_line(o, "", "", line, len);
1019                break;
1020        case DIFF_SYMBOL_CONTEXT_INCOMPLETE:
1021        case DIFF_SYMBOL_CONTEXT_MARKER:
1022                context = diff_get_color_opt(o, DIFF_CONTEXT);
1023                reset = diff_get_color_opt(o, DIFF_RESET);
1024                emit_line(o, context, reset, line, len);
1025                break;
1026        case DIFF_SYMBOL_SEPARATOR:
1027                fprintf(o->file, "%s%c",
1028                        diff_line_prefix(o),
1029                        o->line_termination);
1030                break;
1031        case DIFF_SYMBOL_CONTEXT:
1032                set = diff_get_color_opt(o, DIFF_CONTEXT);
1033                reset = diff_get_color_opt(o, DIFF_RESET);
1034                emit_line_ws_markup(o, set, reset, line, len, ' ',
1035                                    flags & (DIFF_SYMBOL_CONTENT_WS_MASK), 0);
1036                break;
1037        case DIFF_SYMBOL_PLUS:
1038                switch (flags & (DIFF_SYMBOL_MOVED_LINE |
1039                                 DIFF_SYMBOL_MOVED_LINE_ALT |
1040                                 DIFF_SYMBOL_MOVED_LINE_UNINTERESTING)) {
1041                case DIFF_SYMBOL_MOVED_LINE |
1042                     DIFF_SYMBOL_MOVED_LINE_ALT |
1043                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1044                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED_ALT_DIM);
1045                        break;
1046                case DIFF_SYMBOL_MOVED_LINE |
1047                     DIFF_SYMBOL_MOVED_LINE_ALT:
1048                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED_ALT);
1049                        break;
1050                case DIFF_SYMBOL_MOVED_LINE |
1051                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1052                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED_DIM);
1053                        break;
1054                case DIFF_SYMBOL_MOVED_LINE:
1055                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED);
1056                        break;
1057                default:
1058                        set = diff_get_color_opt(o, DIFF_FILE_NEW);
1059                }
1060                reset = diff_get_color_opt(o, DIFF_RESET);
1061                emit_line_ws_markup(o, set, reset, line, len, '+',
1062                                    flags & DIFF_SYMBOL_CONTENT_WS_MASK,
1063                                    flags & DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF);
1064                break;
1065        case DIFF_SYMBOL_MINUS:
1066                switch (flags & (DIFF_SYMBOL_MOVED_LINE |
1067                                 DIFF_SYMBOL_MOVED_LINE_ALT |
1068                                 DIFF_SYMBOL_MOVED_LINE_UNINTERESTING)) {
1069                case DIFF_SYMBOL_MOVED_LINE |
1070                     DIFF_SYMBOL_MOVED_LINE_ALT |
1071                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1072                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_ALT_DIM);
1073                        break;
1074                case DIFF_SYMBOL_MOVED_LINE |
1075                     DIFF_SYMBOL_MOVED_LINE_ALT:
1076                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_ALT);
1077                        break;
1078                case DIFF_SYMBOL_MOVED_LINE |
1079                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1080                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_DIM);
1081                        break;
1082                case DIFF_SYMBOL_MOVED_LINE:
1083                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED);
1084                        break;
1085                default:
1086                        set = diff_get_color_opt(o, DIFF_FILE_OLD);
1087                }
1088                reset = diff_get_color_opt(o, DIFF_RESET);
1089                emit_line_ws_markup(o, set, reset, line, len, '-',
1090                                    flags & DIFF_SYMBOL_CONTENT_WS_MASK, 0);
1091                break;
1092        case DIFF_SYMBOL_WORDS_PORCELAIN:
1093                context = diff_get_color_opt(o, DIFF_CONTEXT);
1094                reset = diff_get_color_opt(o, DIFF_RESET);
1095                emit_line(o, context, reset, line, len);
1096                fputs("~\n", o->file);
1097                break;
1098        case DIFF_SYMBOL_WORDS:
1099                context = diff_get_color_opt(o, DIFF_CONTEXT);
1100                reset = diff_get_color_opt(o, DIFF_RESET);
1101                /*
1102                 * Skip the prefix character, if any.  With
1103                 * diff_suppress_blank_empty, there may be
1104                 * none.
1105                 */
1106                if (line[0] != '\n') {
1107                        line++;
1108                        len--;
1109                }
1110                emit_line(o, context, reset, line, len);
1111                break;
1112        case DIFF_SYMBOL_FILEPAIR_PLUS:
1113                meta = diff_get_color_opt(o, DIFF_METAINFO);
1114                reset = diff_get_color_opt(o, DIFF_RESET);
1115                fprintf(o->file, "%s%s+++ %s%s%s\n", diff_line_prefix(o), meta,
1116                        line, reset,
1117                        strchr(line, ' ') ? "\t" : "");
1118                break;
1119        case DIFF_SYMBOL_FILEPAIR_MINUS:
1120                meta = diff_get_color_opt(o, DIFF_METAINFO);
1121                reset = diff_get_color_opt(o, DIFF_RESET);
1122                fprintf(o->file, "%s%s--- %s%s%s\n", diff_line_prefix(o), meta,
1123                        line, reset,
1124                        strchr(line, ' ') ? "\t" : "");
1125                break;
1126        case DIFF_SYMBOL_BINARY_FILES:
1127        case DIFF_SYMBOL_HEADER:
1128                fprintf(o->file, "%s", line);
1129                break;
1130        case DIFF_SYMBOL_BINARY_DIFF_HEADER:
1131                fprintf(o->file, "%sGIT binary patch\n", diff_line_prefix(o));
1132                break;
1133        case DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA:
1134                fprintf(o->file, "%sdelta %s\n", diff_line_prefix(o), line);
1135                break;
1136        case DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL:
1137                fprintf(o->file, "%sliteral %s\n", diff_line_prefix(o), line);
1138                break;
1139        case DIFF_SYMBOL_BINARY_DIFF_FOOTER:
1140                fputs(diff_line_prefix(o), o->file);
1141                fputc('\n', o->file);
1142                break;
1143        case DIFF_SYMBOL_REWRITE_DIFF:
1144                fraginfo = diff_get_color(o->use_color, DIFF_FRAGINFO);
1145                reset = diff_get_color_opt(o, DIFF_RESET);
1146                emit_line(o, fraginfo, reset, line, len);
1147                break;
1148        case DIFF_SYMBOL_SUBMODULE_ADD:
1149                set = diff_get_color_opt(o, DIFF_FILE_NEW);
1150                reset = diff_get_color_opt(o, DIFF_RESET);
1151                emit_line(o, set, reset, line, len);
1152                break;
1153        case DIFF_SYMBOL_SUBMODULE_DEL:
1154                set = diff_get_color_opt(o, DIFF_FILE_OLD);
1155                reset = diff_get_color_opt(o, DIFF_RESET);
1156                emit_line(o, set, reset, line, len);
1157                break;
1158        case DIFF_SYMBOL_SUBMODULE_UNTRACKED:
1159                fprintf(o->file, "%sSubmodule %s contains untracked content\n",
1160                        diff_line_prefix(o), line);
1161                break;
1162        case DIFF_SYMBOL_SUBMODULE_MODIFIED:
1163                fprintf(o->file, "%sSubmodule %s contains modified content\n",
1164                        diff_line_prefix(o), line);
1165                break;
1166        case DIFF_SYMBOL_STATS_SUMMARY_NO_FILES:
1167                emit_line(o, "", "", " 0 files changed\n",
1168                          strlen(" 0 files changed\n"));
1169                break;
1170        case DIFF_SYMBOL_STATS_SUMMARY_ABBREV:
1171                emit_line(o, "", "", " ...\n", strlen(" ...\n"));
1172                break;
1173        case DIFF_SYMBOL_WORD_DIFF:
1174                fprintf(o->file, "%.*s", len, line);
1175                break;
1176        case DIFF_SYMBOL_STAT_SEP:
1177                fputs(o->stat_sep, o->file);
1178                break;
1179        default:
1180                BUG("unknown diff symbol");
1181        }
1182        strbuf_release(&sb);
1183}
1184
1185static void emit_diff_symbol(struct diff_options *o, enum diff_symbol s,
1186                             const char *line, int len, unsigned flags)
1187{
1188        struct emitted_diff_symbol e = {line, len, flags, s};
1189
1190        if (o->emitted_symbols)
1191                append_emitted_diff_symbol(o, &e);
1192        else
1193                emit_diff_symbol_from_struct(o, &e);
1194}
1195
1196void diff_emit_submodule_del(struct diff_options *o, const char *line)
1197{
1198        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_DEL, line, strlen(line), 0);
1199}
1200
1201void diff_emit_submodule_add(struct diff_options *o, const char *line)
1202{
1203        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_ADD, line, strlen(line), 0);
1204}
1205
1206void diff_emit_submodule_untracked(struct diff_options *o, const char *path)
1207{
1208        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_UNTRACKED,
1209                         path, strlen(path), 0);
1210}
1211
1212void diff_emit_submodule_modified(struct diff_options *o, const char *path)
1213{
1214        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_MODIFIED,
1215                         path, strlen(path), 0);
1216}
1217
1218void diff_emit_submodule_header(struct diff_options *o, const char *header)
1219{
1220        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_HEADER,
1221                         header, strlen(header), 0);
1222}
1223
1224void diff_emit_submodule_error(struct diff_options *o, const char *err)
1225{
1226        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_ERROR, err, strlen(err), 0);
1227}
1228
1229void diff_emit_submodule_pipethrough(struct diff_options *o,
1230                                     const char *line, int len)
1231{
1232        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_PIPETHROUGH, line, len, 0);
1233}
1234
1235static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line, int len)
1236{
1237        if (!((ecbdata->ws_rule & WS_BLANK_AT_EOF) &&
1238              ecbdata->blank_at_eof_in_preimage &&
1239              ecbdata->blank_at_eof_in_postimage &&
1240              ecbdata->blank_at_eof_in_preimage <= ecbdata->lno_in_preimage &&
1241              ecbdata->blank_at_eof_in_postimage <= ecbdata->lno_in_postimage))
1242                return 0;
1243        return ws_blank_line(line, len, ecbdata->ws_rule);
1244}
1245
1246static void emit_add_line(const char *reset,
1247                          struct emit_callback *ecbdata,
1248                          const char *line, int len)
1249{
1250        unsigned flags = WSEH_NEW | ecbdata->ws_rule;
1251        if (new_blank_line_at_eof(ecbdata, line, len))
1252                flags |= DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF;
1253
1254        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_PLUS, line, len, flags);
1255}
1256
1257static void emit_del_line(const char *reset,
1258                          struct emit_callback *ecbdata,
1259                          const char *line, int len)
1260{
1261        unsigned flags = WSEH_OLD | ecbdata->ws_rule;
1262        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_MINUS, line, len, flags);
1263}
1264
1265static void emit_context_line(const char *reset,
1266                              struct emit_callback *ecbdata,
1267                              const char *line, int len)
1268{
1269        unsigned flags = WSEH_CONTEXT | ecbdata->ws_rule;
1270        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_CONTEXT, line, len, flags);
1271}
1272
1273static void emit_hunk_header(struct emit_callback *ecbdata,
1274                             const char *line, int len)
1275{
1276        const char *context = diff_get_color(ecbdata->color_diff, DIFF_CONTEXT);
1277        const char *frag = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
1278        const char *func = diff_get_color(ecbdata->color_diff, DIFF_FUNCINFO);
1279        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
1280        static const char atat[2] = { '@', '@' };
1281        const char *cp, *ep;
1282        struct strbuf msgbuf = STRBUF_INIT;
1283        int org_len = len;
1284        int i = 1;
1285
1286        /*
1287         * As a hunk header must begin with "@@ -<old>, +<new> @@",
1288         * it always is at least 10 bytes long.
1289         */
1290        if (len < 10 ||
1291            memcmp(line, atat, 2) ||
1292            !(ep = memmem(line + 2, len - 2, atat, 2))) {
1293                emit_diff_symbol(ecbdata->opt,
1294                                 DIFF_SYMBOL_CONTEXT_MARKER, line, len, 0);
1295                return;
1296        }
1297        ep += 2; /* skip over @@ */
1298
1299        /* The hunk header in fraginfo color */
1300        strbuf_addstr(&msgbuf, frag);
1301        strbuf_add(&msgbuf, line, ep - line);
1302        strbuf_addstr(&msgbuf, reset);
1303
1304        /*
1305         * trailing "\r\n"
1306         */
1307        for ( ; i < 3; i++)
1308                if (line[len - i] == '\r' || line[len - i] == '\n')
1309                        len--;
1310
1311        /* blank before the func header */
1312        for (cp = ep; ep - line < len; ep++)
1313                if (*ep != ' ' && *ep != '\t')
1314                        break;
1315        if (ep != cp) {
1316                strbuf_addstr(&msgbuf, context);
1317                strbuf_add(&msgbuf, cp, ep - cp);
1318                strbuf_addstr(&msgbuf, reset);
1319        }
1320
1321        if (ep < line + len) {
1322                strbuf_addstr(&msgbuf, func);
1323                strbuf_add(&msgbuf, ep, line + len - ep);
1324                strbuf_addstr(&msgbuf, reset);
1325        }
1326
1327        strbuf_add(&msgbuf, line + len, org_len - len);
1328        strbuf_complete_line(&msgbuf);
1329        emit_diff_symbol(ecbdata->opt,
1330                         DIFF_SYMBOL_CONTEXT_FRAGINFO, msgbuf.buf, msgbuf.len, 0);
1331        strbuf_release(&msgbuf);
1332}
1333
1334static struct diff_tempfile *claim_diff_tempfile(void) {
1335        int i;
1336        for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
1337                if (!diff_temp[i].name)
1338                        return diff_temp + i;
1339        BUG("diff is failing to clean up its tempfiles");
1340}
1341
1342static void remove_tempfile(void)
1343{
1344        int i;
1345        for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
1346                if (is_tempfile_active(diff_temp[i].tempfile))
1347                        delete_tempfile(&diff_temp[i].tempfile);
1348                diff_temp[i].name = NULL;
1349        }
1350}
1351
1352static void add_line_count(struct strbuf *out, int count)
1353{
1354        switch (count) {
1355        case 0:
1356                strbuf_addstr(out, "0,0");
1357                break;
1358        case 1:
1359                strbuf_addstr(out, "1");
1360                break;
1361        default:
1362                strbuf_addf(out, "1,%d", count);
1363                break;
1364        }
1365}
1366
1367static void emit_rewrite_lines(struct emit_callback *ecb,
1368                               int prefix, const char *data, int size)
1369{
1370        const char *endp = NULL;
1371        const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
1372
1373        while (0 < size) {
1374                int len;
1375
1376                endp = memchr(data, '\n', size);
1377                len = endp ? (endp - data + 1) : size;
1378                if (prefix != '+') {
1379                        ecb->lno_in_preimage++;
1380                        emit_del_line(reset, ecb, data, len);
1381                } else {
1382                        ecb->lno_in_postimage++;
1383                        emit_add_line(reset, ecb, data, len);
1384                }
1385                size -= len;
1386                data += len;
1387        }
1388        if (!endp)
1389                emit_diff_symbol(ecb->opt, DIFF_SYMBOL_NO_LF_EOF, NULL, 0, 0);
1390}
1391
1392static void emit_rewrite_diff(const char *name_a,
1393                              const char *name_b,
1394                              struct diff_filespec *one,
1395                              struct diff_filespec *two,
1396                              struct userdiff_driver *textconv_one,
1397                              struct userdiff_driver *textconv_two,
1398                              struct diff_options *o)
1399{
1400        int lc_a, lc_b;
1401        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
1402        const char *a_prefix, *b_prefix;
1403        char *data_one, *data_two;
1404        size_t size_one, size_two;
1405        struct emit_callback ecbdata;
1406        struct strbuf out = STRBUF_INIT;
1407
1408        if (diff_mnemonic_prefix && o->flags.reverse_diff) {
1409                a_prefix = o->b_prefix;
1410                b_prefix = o->a_prefix;
1411        } else {
1412                a_prefix = o->a_prefix;
1413                b_prefix = o->b_prefix;
1414        }
1415
1416        name_a += (*name_a == '/');
1417        name_b += (*name_b == '/');
1418
1419        strbuf_reset(&a_name);
1420        strbuf_reset(&b_name);
1421        quote_two_c_style(&a_name, a_prefix, name_a, 0);
1422        quote_two_c_style(&b_name, b_prefix, name_b, 0);
1423
1424        size_one = fill_textconv(textconv_one, one, &data_one);
1425        size_two = fill_textconv(textconv_two, two, &data_two);
1426
1427        memset(&ecbdata, 0, sizeof(ecbdata));
1428        ecbdata.color_diff = want_color(o->use_color);
1429        ecbdata.ws_rule = whitespace_rule(name_b);
1430        ecbdata.opt = o;
1431        if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
1432                mmfile_t mf1, mf2;
1433                mf1.ptr = (char *)data_one;
1434                mf2.ptr = (char *)data_two;
1435                mf1.size = size_one;
1436                mf2.size = size_two;
1437                check_blank_at_eof(&mf1, &mf2, &ecbdata);
1438        }
1439        ecbdata.lno_in_preimage = 1;
1440        ecbdata.lno_in_postimage = 1;
1441
1442        lc_a = count_lines(data_one, size_one);
1443        lc_b = count_lines(data_two, size_two);
1444
1445        emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_MINUS,
1446                         a_name.buf, a_name.len, 0);
1447        emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_PLUS,
1448                         b_name.buf, b_name.len, 0);
1449
1450        strbuf_addstr(&out, "@@ -");
1451        if (!o->irreversible_delete)
1452                add_line_count(&out, lc_a);
1453        else
1454                strbuf_addstr(&out, "?,?");
1455        strbuf_addstr(&out, " +");
1456        add_line_count(&out, lc_b);
1457        strbuf_addstr(&out, " @@\n");
1458        emit_diff_symbol(o, DIFF_SYMBOL_REWRITE_DIFF, out.buf, out.len, 0);
1459        strbuf_release(&out);
1460
1461        if (lc_a && !o->irreversible_delete)
1462                emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
1463        if (lc_b)
1464                emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
1465        if (textconv_one)
1466                free((char *)data_one);
1467        if (textconv_two)
1468                free((char *)data_two);
1469}
1470
1471struct diff_words_buffer {
1472        mmfile_t text;
1473        unsigned long alloc;
1474        struct diff_words_orig {
1475                const char *begin, *end;
1476        } *orig;
1477        int orig_nr, orig_alloc;
1478};
1479
1480static void diff_words_append(char *line, unsigned long len,
1481                struct diff_words_buffer *buffer)
1482{
1483        ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
1484        line++;
1485        len--;
1486        memcpy(buffer->text.ptr + buffer->text.size, line, len);
1487        buffer->text.size += len;
1488        buffer->text.ptr[buffer->text.size] = '\0';
1489}
1490
1491struct diff_words_style_elem {
1492        const char *prefix;
1493        const char *suffix;
1494        const char *color; /* NULL; filled in by the setup code if
1495                            * color is enabled */
1496};
1497
1498struct diff_words_style {
1499        enum diff_words_type type;
1500        struct diff_words_style_elem new_word, old_word, ctx;
1501        const char *newline;
1502};
1503
1504static struct diff_words_style diff_words_styles[] = {
1505        { DIFF_WORDS_PORCELAIN, {"+", "\n"}, {"-", "\n"}, {" ", "\n"}, "~\n" },
1506        { DIFF_WORDS_PLAIN, {"{+", "+}"}, {"[-", "-]"}, {"", ""}, "\n" },
1507        { DIFF_WORDS_COLOR, {"", ""}, {"", ""}, {"", ""}, "\n" }
1508};
1509
1510struct diff_words_data {
1511        struct diff_words_buffer minus, plus;
1512        const char *current_plus;
1513        int last_minus;
1514        struct diff_options *opt;
1515        regex_t *word_regex;
1516        enum diff_words_type type;
1517        struct diff_words_style *style;
1518};
1519
1520static int fn_out_diff_words_write_helper(struct diff_options *o,
1521                                          struct diff_words_style_elem *st_el,
1522                                          const char *newline,
1523                                          size_t count, const char *buf)
1524{
1525        int print = 0;
1526        struct strbuf sb = STRBUF_INIT;
1527
1528        while (count) {
1529                char *p = memchr(buf, '\n', count);
1530                if (print)
1531                        strbuf_addstr(&sb, diff_line_prefix(o));
1532
1533                if (p != buf) {
1534                        const char *reset = st_el->color && *st_el->color ?
1535                                            GIT_COLOR_RESET : NULL;
1536                        if (st_el->color && *st_el->color)
1537                                strbuf_addstr(&sb, st_el->color);
1538                        strbuf_addstr(&sb, st_el->prefix);
1539                        strbuf_add(&sb, buf, p ? p - buf : count);
1540                        strbuf_addstr(&sb, st_el->suffix);
1541                        if (reset)
1542                                strbuf_addstr(&sb, reset);
1543                }
1544                if (!p)
1545                        goto out;
1546
1547                strbuf_addstr(&sb, newline);
1548                count -= p + 1 - buf;
1549                buf = p + 1;
1550                print = 1;
1551                if (count) {
1552                        emit_diff_symbol(o, DIFF_SYMBOL_WORD_DIFF,
1553                                         sb.buf, sb.len, 0);
1554                        strbuf_reset(&sb);
1555                }
1556        }
1557
1558out:
1559        if (sb.len)
1560                emit_diff_symbol(o, DIFF_SYMBOL_WORD_DIFF,
1561                                 sb.buf, sb.len, 0);
1562        strbuf_release(&sb);
1563        return 0;
1564}
1565
1566/*
1567 * '--color-words' algorithm can be described as:
1568 *
1569 *   1. collect the minus/plus lines of a diff hunk, divided into
1570 *      minus-lines and plus-lines;
1571 *
1572 *   2. break both minus-lines and plus-lines into words and
1573 *      place them into two mmfile_t with one word for each line;
1574 *
1575 *   3. use xdiff to run diff on the two mmfile_t to get the words level diff;
1576 *
1577 * And for the common parts of the both file, we output the plus side text.
1578 * diff_words->current_plus is used to trace the current position of the plus file
1579 * which printed. diff_words->last_minus is used to trace the last minus word
1580 * printed.
1581 *
1582 * For '--graph' to work with '--color-words', we need to output the graph prefix
1583 * on each line of color words output. Generally, there are two conditions on
1584 * which we should output the prefix.
1585 *
1586 *   1. diff_words->last_minus == 0 &&
1587 *      diff_words->current_plus == diff_words->plus.text.ptr
1588 *
1589 *      that is: the plus text must start as a new line, and if there is no minus
1590 *      word printed, a graph prefix must be printed.
1591 *
1592 *   2. diff_words->current_plus > diff_words->plus.text.ptr &&
1593 *      *(diff_words->current_plus - 1) == '\n'
1594 *
1595 *      that is: a graph prefix must be printed following a '\n'
1596 */
1597static int color_words_output_graph_prefix(struct diff_words_data *diff_words)
1598{
1599        if ((diff_words->last_minus == 0 &&
1600                diff_words->current_plus == diff_words->plus.text.ptr) ||
1601                (diff_words->current_plus > diff_words->plus.text.ptr &&
1602                *(diff_words->current_plus - 1) == '\n')) {
1603                return 1;
1604        } else {
1605                return 0;
1606        }
1607}
1608
1609static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
1610{
1611        struct diff_words_data *diff_words = priv;
1612        struct diff_words_style *style = diff_words->style;
1613        int minus_first, minus_len, plus_first, plus_len;
1614        const char *minus_begin, *minus_end, *plus_begin, *plus_end;
1615        struct diff_options *opt = diff_words->opt;
1616        const char *line_prefix;
1617
1618        if (line[0] != '@' || parse_hunk_header(line, len,
1619                        &minus_first, &minus_len, &plus_first, &plus_len))
1620                return;
1621
1622        assert(opt);
1623        line_prefix = diff_line_prefix(opt);
1624
1625        /* POSIX requires that first be decremented by one if len == 0... */
1626        if (minus_len) {
1627                minus_begin = diff_words->minus.orig[minus_first].begin;
1628                minus_end =
1629                        diff_words->minus.orig[minus_first + minus_len - 1].end;
1630        } else
1631                minus_begin = minus_end =
1632                        diff_words->minus.orig[minus_first].end;
1633
1634        if (plus_len) {
1635                plus_begin = diff_words->plus.orig[plus_first].begin;
1636                plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
1637        } else
1638                plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
1639
1640        if (color_words_output_graph_prefix(diff_words)) {
1641                fputs(line_prefix, diff_words->opt->file);
1642        }
1643        if (diff_words->current_plus != plus_begin) {
1644                fn_out_diff_words_write_helper(diff_words->opt,
1645                                &style->ctx, style->newline,
1646                                plus_begin - diff_words->current_plus,
1647                                diff_words->current_plus);
1648        }
1649        if (minus_begin != minus_end) {
1650                fn_out_diff_words_write_helper(diff_words->opt,
1651                                &style->old_word, style->newline,
1652                                minus_end - minus_begin, minus_begin);
1653        }
1654        if (plus_begin != plus_end) {
1655                fn_out_diff_words_write_helper(diff_words->opt,
1656                                &style->new_word, style->newline,
1657                                plus_end - plus_begin, plus_begin);
1658        }
1659
1660        diff_words->current_plus = plus_end;
1661        diff_words->last_minus = minus_first;
1662}
1663
1664/* This function starts looking at *begin, and returns 0 iff a word was found. */
1665static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
1666                int *begin, int *end)
1667{
1668        if (word_regex && *begin < buffer->size) {
1669                regmatch_t match[1];
1670                if (!regexec_buf(word_regex, buffer->ptr + *begin,
1671                                 buffer->size - *begin, 1, match, 0)) {
1672                        char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
1673                                        '\n', match[0].rm_eo - match[0].rm_so);
1674                        *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
1675                        *begin += match[0].rm_so;
1676                        return *begin >= *end;
1677                }
1678                return -1;
1679        }
1680
1681        /* find the next word */
1682        while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
1683                (*begin)++;
1684        if (*begin >= buffer->size)
1685                return -1;
1686
1687        /* find the end of the word */
1688        *end = *begin + 1;
1689        while (*end < buffer->size && !isspace(buffer->ptr[*end]))
1690                (*end)++;
1691
1692        return 0;
1693}
1694
1695/*
1696 * This function splits the words in buffer->text, stores the list with
1697 * newline separator into out, and saves the offsets of the original words
1698 * in buffer->orig.
1699 */
1700static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
1701                regex_t *word_regex)
1702{
1703        int i, j;
1704        long alloc = 0;
1705
1706        out->size = 0;
1707        out->ptr = NULL;
1708
1709        /* fake an empty "0th" word */
1710        ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
1711        buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
1712        buffer->orig_nr = 1;
1713
1714        for (i = 0; i < buffer->text.size; i++) {
1715                if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
1716                        return;
1717
1718                /* store original boundaries */
1719                ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
1720                                buffer->orig_alloc);
1721                buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
1722                buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
1723                buffer->orig_nr++;
1724
1725                /* store one word */
1726                ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
1727                memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
1728                out->ptr[out->size + j - i] = '\n';
1729                out->size += j - i + 1;
1730
1731                i = j - 1;
1732        }
1733}
1734
1735/* this executes the word diff on the accumulated buffers */
1736static void diff_words_show(struct diff_words_data *diff_words)
1737{
1738        xpparam_t xpp;
1739        xdemitconf_t xecfg;
1740        mmfile_t minus, plus;
1741        struct diff_words_style *style = diff_words->style;
1742
1743        struct diff_options *opt = diff_words->opt;
1744        const char *line_prefix;
1745
1746        assert(opt);
1747        line_prefix = diff_line_prefix(opt);
1748
1749        /* special case: only removal */
1750        if (!diff_words->plus.text.size) {
1751                emit_diff_symbol(diff_words->opt, DIFF_SYMBOL_WORD_DIFF,
1752                                 line_prefix, strlen(line_prefix), 0);
1753                fn_out_diff_words_write_helper(diff_words->opt,
1754                        &style->old_word, style->newline,
1755                        diff_words->minus.text.size,
1756                        diff_words->minus.text.ptr);
1757                diff_words->minus.text.size = 0;
1758                return;
1759        }
1760
1761        diff_words->current_plus = diff_words->plus.text.ptr;
1762        diff_words->last_minus = 0;
1763
1764        memset(&xpp, 0, sizeof(xpp));
1765        memset(&xecfg, 0, sizeof(xecfg));
1766        diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
1767        diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
1768        xpp.flags = 0;
1769        /* as only the hunk header will be parsed, we need a 0-context */
1770        xecfg.ctxlen = 0;
1771        if (xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
1772                          &xpp, &xecfg))
1773                die("unable to generate word diff");
1774        free(minus.ptr);
1775        free(plus.ptr);
1776        if (diff_words->current_plus != diff_words->plus.text.ptr +
1777                        diff_words->plus.text.size) {
1778                if (color_words_output_graph_prefix(diff_words))
1779                        emit_diff_symbol(diff_words->opt, DIFF_SYMBOL_WORD_DIFF,
1780                                         line_prefix, strlen(line_prefix), 0);
1781                fn_out_diff_words_write_helper(diff_words->opt,
1782                        &style->ctx, style->newline,
1783                        diff_words->plus.text.ptr + diff_words->plus.text.size
1784                        - diff_words->current_plus, diff_words->current_plus);
1785        }
1786        diff_words->minus.text.size = diff_words->plus.text.size = 0;
1787}
1788
1789/* In "color-words" mode, show word-diff of words accumulated in the buffer */
1790static void diff_words_flush(struct emit_callback *ecbdata)
1791{
1792        struct diff_options *wo = ecbdata->diff_words->opt;
1793
1794        if (ecbdata->diff_words->minus.text.size ||
1795            ecbdata->diff_words->plus.text.size)
1796                diff_words_show(ecbdata->diff_words);
1797
1798        if (wo->emitted_symbols) {
1799                struct diff_options *o = ecbdata->opt;
1800                struct emitted_diff_symbols *wol = wo->emitted_symbols;
1801                int i;
1802
1803                /*
1804                 * NEEDSWORK:
1805                 * Instead of appending each, concat all words to a line?
1806                 */
1807                for (i = 0; i < wol->nr; i++)
1808                        append_emitted_diff_symbol(o, &wol->buf[i]);
1809
1810                for (i = 0; i < wol->nr; i++)
1811                        free((void *)wol->buf[i].line);
1812
1813                wol->nr = 0;
1814        }
1815}
1816
1817static void diff_filespec_load_driver(struct diff_filespec *one)
1818{
1819        /* Use already-loaded driver */
1820        if (one->driver)
1821                return;
1822
1823        if (S_ISREG(one->mode))
1824                one->driver = userdiff_find_by_path(one->path);
1825
1826        /* Fallback to default settings */
1827        if (!one->driver)
1828                one->driver = userdiff_find_by_name("default");
1829}
1830
1831static const char *userdiff_word_regex(struct diff_filespec *one)
1832{
1833        diff_filespec_load_driver(one);
1834        return one->driver->word_regex;
1835}
1836
1837static void init_diff_words_data(struct emit_callback *ecbdata,
1838                                 struct diff_options *orig_opts,
1839                                 struct diff_filespec *one,
1840                                 struct diff_filespec *two)
1841{
1842        int i;
1843        struct diff_options *o = xmalloc(sizeof(struct diff_options));
1844        memcpy(o, orig_opts, sizeof(struct diff_options));
1845
1846        ecbdata->diff_words =
1847                xcalloc(1, sizeof(struct diff_words_data));
1848        ecbdata->diff_words->type = o->word_diff;
1849        ecbdata->diff_words->opt = o;
1850
1851        if (orig_opts->emitted_symbols)
1852                o->emitted_symbols =
1853                        xcalloc(1, sizeof(struct emitted_diff_symbols));
1854
1855        if (!o->word_regex)
1856                o->word_regex = userdiff_word_regex(one);
1857        if (!o->word_regex)
1858                o->word_regex = userdiff_word_regex(two);
1859        if (!o->word_regex)
1860                o->word_regex = diff_word_regex_cfg;
1861        if (o->word_regex) {
1862                ecbdata->diff_words->word_regex = (regex_t *)
1863                        xmalloc(sizeof(regex_t));
1864                if (regcomp(ecbdata->diff_words->word_regex,
1865                            o->word_regex,
1866                            REG_EXTENDED | REG_NEWLINE))
1867                        die ("Invalid regular expression: %s",
1868                             o->word_regex);
1869        }
1870        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
1871                if (o->word_diff == diff_words_styles[i].type) {
1872                        ecbdata->diff_words->style =
1873                                &diff_words_styles[i];
1874                        break;
1875                }
1876        }
1877        if (want_color(o->use_color)) {
1878                struct diff_words_style *st = ecbdata->diff_words->style;
1879                st->old_word.color = diff_get_color_opt(o, DIFF_FILE_OLD);
1880                st->new_word.color = diff_get_color_opt(o, DIFF_FILE_NEW);
1881                st->ctx.color = diff_get_color_opt(o, DIFF_CONTEXT);
1882        }
1883}
1884
1885static void free_diff_words_data(struct emit_callback *ecbdata)
1886{
1887        if (ecbdata->diff_words) {
1888                diff_words_flush(ecbdata);
1889                free (ecbdata->diff_words->opt->emitted_symbols);
1890                free (ecbdata->diff_words->opt);
1891                free (ecbdata->diff_words->minus.text.ptr);
1892                free (ecbdata->diff_words->minus.orig);
1893                free (ecbdata->diff_words->plus.text.ptr);
1894                free (ecbdata->diff_words->plus.orig);
1895                if (ecbdata->diff_words->word_regex) {
1896                        regfree(ecbdata->diff_words->word_regex);
1897                        free(ecbdata->diff_words->word_regex);
1898                }
1899                FREE_AND_NULL(ecbdata->diff_words);
1900        }
1901}
1902
1903const char *diff_get_color(int diff_use_color, enum color_diff ix)
1904{
1905        if (want_color(diff_use_color))
1906                return diff_colors[ix];
1907        return "";
1908}
1909
1910const char *diff_line_prefix(struct diff_options *opt)
1911{
1912        struct strbuf *msgbuf;
1913        if (!opt->output_prefix)
1914                return "";
1915
1916        msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
1917        return msgbuf->buf;
1918}
1919
1920static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
1921{
1922        const char *cp;
1923        unsigned long allot;
1924        size_t l = len;
1925
1926        cp = line;
1927        allot = l;
1928        while (0 < l) {
1929                (void) utf8_width(&cp, &l);
1930                if (!cp)
1931                        break; /* truncated in the middle? */
1932        }
1933        return allot - l;
1934}
1935
1936static void find_lno(const char *line, struct emit_callback *ecbdata)
1937{
1938        const char *p;
1939        ecbdata->lno_in_preimage = 0;
1940        ecbdata->lno_in_postimage = 0;
1941        p = strchr(line, '-');
1942        if (!p)
1943                return; /* cannot happen */
1944        ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
1945        p = strchr(p, '+');
1946        if (!p)
1947                return; /* cannot happen */
1948        ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
1949}
1950
1951static void fn_out_consume(void *priv, char *line, unsigned long len)
1952{
1953        struct emit_callback *ecbdata = priv;
1954        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
1955        struct diff_options *o = ecbdata->opt;
1956
1957        o->found_changes = 1;
1958
1959        if (ecbdata->header) {
1960                emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
1961                                 ecbdata->header->buf, ecbdata->header->len, 0);
1962                strbuf_reset(ecbdata->header);
1963                ecbdata->header = NULL;
1964        }
1965
1966        if (ecbdata->label_path[0]) {
1967                emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_MINUS,
1968                                 ecbdata->label_path[0],
1969                                 strlen(ecbdata->label_path[0]), 0);
1970                emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_PLUS,
1971                                 ecbdata->label_path[1],
1972                                 strlen(ecbdata->label_path[1]), 0);
1973                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
1974        }
1975
1976        if (diff_suppress_blank_empty
1977            && len == 2 && line[0] == ' ' && line[1] == '\n') {
1978                line[0] = '\n';
1979                len = 1;
1980        }
1981
1982        if (line[0] == '@') {
1983                if (ecbdata->diff_words)
1984                        diff_words_flush(ecbdata);
1985                len = sane_truncate_line(ecbdata, line, len);
1986                find_lno(line, ecbdata);
1987                emit_hunk_header(ecbdata, line, len);
1988                return;
1989        }
1990
1991        if (ecbdata->diff_words) {
1992                enum diff_symbol s =
1993                        ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN ?
1994                        DIFF_SYMBOL_WORDS_PORCELAIN : DIFF_SYMBOL_WORDS;
1995                if (line[0] == '-') {
1996                        diff_words_append(line, len,
1997                                          &ecbdata->diff_words->minus);
1998                        return;
1999                } else if (line[0] == '+') {
2000                        diff_words_append(line, len,
2001                                          &ecbdata->diff_words->plus);
2002                        return;
2003                } else if (starts_with(line, "\\ ")) {
2004                        /*
2005                         * Eat the "no newline at eof" marker as if we
2006                         * saw a "+" or "-" line with nothing on it,
2007                         * and return without diff_words_flush() to
2008                         * defer processing. If this is the end of
2009                         * preimage, more "+" lines may come after it.
2010                         */
2011                        return;
2012                }
2013                diff_words_flush(ecbdata);
2014                emit_diff_symbol(o, s, line, len, 0);
2015                return;
2016        }
2017
2018        switch (line[0]) {
2019        case '+':
2020                ecbdata->lno_in_postimage++;
2021                emit_add_line(reset, ecbdata, line + 1, len - 1);
2022                break;
2023        case '-':
2024                ecbdata->lno_in_preimage++;
2025                emit_del_line(reset, ecbdata, line + 1, len - 1);
2026                break;
2027        case ' ':
2028                ecbdata->lno_in_postimage++;
2029                ecbdata->lno_in_preimage++;
2030                emit_context_line(reset, ecbdata, line + 1, len - 1);
2031                break;
2032        default:
2033                /* incomplete line at the end */
2034                ecbdata->lno_in_preimage++;
2035                emit_diff_symbol(o, DIFF_SYMBOL_CONTEXT_INCOMPLETE,
2036                                 line, len, 0);
2037                break;
2038        }
2039}
2040
2041static void pprint_rename(struct strbuf *name, const char *a, const char *b)
2042{
2043        const char *old_name = a;
2044        const char *new_name = b;
2045        int pfx_length, sfx_length;
2046        int pfx_adjust_for_slash;
2047        int len_a = strlen(a);
2048        int len_b = strlen(b);
2049        int a_midlen, b_midlen;
2050        int qlen_a = quote_c_style(a, NULL, NULL, 0);
2051        int qlen_b = quote_c_style(b, NULL, NULL, 0);
2052
2053        if (qlen_a || qlen_b) {
2054                quote_c_style(a, name, NULL, 0);
2055                strbuf_addstr(name, " => ");
2056                quote_c_style(b, name, NULL, 0);
2057                return;
2058        }
2059
2060        /* Find common prefix */
2061        pfx_length = 0;
2062        while (*old_name && *new_name && *old_name == *new_name) {
2063                if (*old_name == '/')
2064                        pfx_length = old_name - a + 1;
2065                old_name++;
2066                new_name++;
2067        }
2068
2069        /* Find common suffix */
2070        old_name = a + len_a;
2071        new_name = b + len_b;
2072        sfx_length = 0;
2073        /*
2074         * If there is a common prefix, it must end in a slash.  In
2075         * that case we let this loop run 1 into the prefix to see the
2076         * same slash.
2077         *
2078         * If there is no common prefix, we cannot do this as it would
2079         * underrun the input strings.
2080         */
2081        pfx_adjust_for_slash = (pfx_length ? 1 : 0);
2082        while (a + pfx_length - pfx_adjust_for_slash <= old_name &&
2083               b + pfx_length - pfx_adjust_for_slash <= new_name &&
2084               *old_name == *new_name) {
2085                if (*old_name == '/')
2086                        sfx_length = len_a - (old_name - a);
2087                old_name--;
2088                new_name--;
2089        }
2090
2091        /*
2092         * pfx{mid-a => mid-b}sfx
2093         * {pfx-a => pfx-b}sfx
2094         * pfx{sfx-a => sfx-b}
2095         * name-a => name-b
2096         */
2097        a_midlen = len_a - pfx_length - sfx_length;
2098        b_midlen = len_b - pfx_length - sfx_length;
2099        if (a_midlen < 0)
2100                a_midlen = 0;
2101        if (b_midlen < 0)
2102                b_midlen = 0;
2103
2104        strbuf_grow(name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
2105        if (pfx_length + sfx_length) {
2106                strbuf_add(name, a, pfx_length);
2107                strbuf_addch(name, '{');
2108        }
2109        strbuf_add(name, a + pfx_length, a_midlen);
2110        strbuf_addstr(name, " => ");
2111        strbuf_add(name, b + pfx_length, b_midlen);
2112        if (pfx_length + sfx_length) {
2113                strbuf_addch(name, '}');
2114                strbuf_add(name, a + len_a - sfx_length, sfx_length);
2115        }
2116}
2117
2118struct diffstat_t {
2119        int nr;
2120        int alloc;
2121        struct diffstat_file {
2122                char *from_name;
2123                char *name;
2124                char *print_name;
2125                const char *comments;
2126                unsigned is_unmerged:1;
2127                unsigned is_binary:1;
2128                unsigned is_renamed:1;
2129                unsigned is_interesting:1;
2130                uintmax_t added, deleted;
2131        } **files;
2132};
2133
2134static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
2135                                          const char *name_a,
2136                                          const char *name_b)
2137{
2138        struct diffstat_file *x;
2139        x = xcalloc(1, sizeof(*x));
2140        ALLOC_GROW(diffstat->files, diffstat->nr + 1, diffstat->alloc);
2141        diffstat->files[diffstat->nr++] = x;
2142        if (name_b) {
2143                x->from_name = xstrdup(name_a);
2144                x->name = xstrdup(name_b);
2145                x->is_renamed = 1;
2146        }
2147        else {
2148                x->from_name = NULL;
2149                x->name = xstrdup(name_a);
2150        }
2151        return x;
2152}
2153
2154static void diffstat_consume(void *priv, char *line, unsigned long len)
2155{
2156        struct diffstat_t *diffstat = priv;
2157        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
2158
2159        if (line[0] == '+')
2160                x->added++;
2161        else if (line[0] == '-')
2162                x->deleted++;
2163}
2164
2165const char mime_boundary_leader[] = "------------";
2166
2167static int scale_linear(int it, int width, int max_change)
2168{
2169        if (!it)
2170                return 0;
2171        /*
2172         * make sure that at least one '-' or '+' is printed if
2173         * there is any change to this path. The easiest way is to
2174         * scale linearly as if the alloted width is one column shorter
2175         * than it is, and then add 1 to the result.
2176         */
2177        return 1 + (it * (width - 1) / max_change);
2178}
2179
2180static void show_graph(struct strbuf *out, char ch, int cnt,
2181                       const char *set, const char *reset)
2182{
2183        if (cnt <= 0)
2184                return;
2185        strbuf_addstr(out, set);
2186        strbuf_addchars(out, ch, cnt);
2187        strbuf_addstr(out, reset);
2188}
2189
2190static void fill_print_name(struct diffstat_file *file)
2191{
2192        struct strbuf pname = STRBUF_INIT;
2193
2194        if (file->print_name)
2195                return;
2196
2197        if (file->is_renamed)
2198                pprint_rename(&pname, file->from_name, file->name);
2199        else
2200                quote_c_style(file->name, &pname, NULL, 0);
2201
2202        if (file->comments)
2203                strbuf_addf(&pname, " (%s)", file->comments);
2204
2205        file->print_name = strbuf_detach(&pname, NULL);
2206}
2207
2208static void print_stat_summary_inserts_deletes(struct diff_options *options,
2209                int files, int insertions, int deletions)
2210{
2211        struct strbuf sb = STRBUF_INIT;
2212
2213        if (!files) {
2214                assert(insertions == 0 && deletions == 0);
2215                emit_diff_symbol(options, DIFF_SYMBOL_STATS_SUMMARY_NO_FILES,
2216                                 NULL, 0, 0);
2217                return;
2218        }
2219
2220        strbuf_addf(&sb,
2221                    (files == 1) ? " %d file changed" : " %d files changed",
2222                    files);
2223
2224        /*
2225         * For binary diff, the caller may want to print "x files
2226         * changed" with insertions == 0 && deletions == 0.
2227         *
2228         * Not omitting "0 insertions(+), 0 deletions(-)" in this case
2229         * is probably less confusing (i.e skip over "2 files changed
2230         * but nothing about added/removed lines? Is this a bug in Git?").
2231         */
2232        if (insertions || deletions == 0) {
2233                strbuf_addf(&sb,
2234                            (insertions == 1) ? ", %d insertion(+)" : ", %d insertions(+)",
2235                            insertions);
2236        }
2237
2238        if (deletions || insertions == 0) {
2239                strbuf_addf(&sb,
2240                            (deletions == 1) ? ", %d deletion(-)" : ", %d deletions(-)",
2241                            deletions);
2242        }
2243        strbuf_addch(&sb, '\n');
2244        emit_diff_symbol(options, DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES,
2245                         sb.buf, sb.len, 0);
2246        strbuf_release(&sb);
2247}
2248
2249void print_stat_summary(FILE *fp, int files,
2250                        int insertions, int deletions)
2251{
2252        struct diff_options o;
2253        memset(&o, 0, sizeof(o));
2254        o.file = fp;
2255
2256        print_stat_summary_inserts_deletes(&o, files, insertions, deletions);
2257}
2258
2259static void show_stats(struct diffstat_t *data, struct diff_options *options)
2260{
2261        int i, len, add, del, adds = 0, dels = 0;
2262        uintmax_t max_change = 0, max_len = 0;
2263        int total_files = data->nr, count;
2264        int width, name_width, graph_width, number_width = 0, bin_width = 0;
2265        const char *reset, *add_c, *del_c;
2266        int extra_shown = 0;
2267        const char *line_prefix = diff_line_prefix(options);
2268        struct strbuf out = STRBUF_INIT;
2269
2270        if (data->nr == 0)
2271                return;
2272
2273        count = options->stat_count ? options->stat_count : data->nr;
2274
2275        reset = diff_get_color_opt(options, DIFF_RESET);
2276        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
2277        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
2278
2279        /*
2280         * Find the longest filename and max number of changes
2281         */
2282        for (i = 0; (i < count) && (i < data->nr); i++) {
2283                struct diffstat_file *file = data->files[i];
2284                uintmax_t change = file->added + file->deleted;
2285
2286                if (!file->is_interesting && (change == 0)) {
2287                        count++; /* not shown == room for one more */
2288                        continue;
2289                }
2290                fill_print_name(file);
2291                len = strlen(file->print_name);
2292                if (max_len < len)
2293                        max_len = len;
2294
2295                if (file->is_unmerged) {
2296                        /* "Unmerged" is 8 characters */
2297                        bin_width = bin_width < 8 ? 8 : bin_width;
2298                        continue;
2299                }
2300                if (file->is_binary) {
2301                        /* "Bin XXX -> YYY bytes" */
2302                        int w = 14 + decimal_width(file->added)
2303                                + decimal_width(file->deleted);
2304                        bin_width = bin_width < w ? w : bin_width;
2305                        /* Display change counts aligned with "Bin" */
2306                        number_width = 3;
2307                        continue;
2308                }
2309
2310                if (max_change < change)
2311                        max_change = change;
2312        }
2313        count = i; /* where we can stop scanning in data->files[] */
2314
2315        /*
2316         * We have width = stat_width or term_columns() columns total.
2317         * We want a maximum of min(max_len, stat_name_width) for the name part.
2318         * We want a maximum of min(max_change, stat_graph_width) for the +- part.
2319         * We also need 1 for " " and 4 + decimal_width(max_change)
2320         * for " | NNNN " and one the empty column at the end, altogether
2321         * 6 + decimal_width(max_change).
2322         *
2323         * If there's not enough space, we will use the smaller of
2324         * stat_name_width (if set) and 5/8*width for the filename,
2325         * and the rest for constant elements + graph part, but no more
2326         * than stat_graph_width for the graph part.
2327         * (5/8 gives 50 for filename and 30 for the constant parts + graph
2328         * for the standard terminal size).
2329         *
2330         * In other words: stat_width limits the maximum width, and
2331         * stat_name_width fixes the maximum width of the filename,
2332         * and is also used to divide available columns if there
2333         * aren't enough.
2334         *
2335         * Binary files are displayed with "Bin XXX -> YYY bytes"
2336         * instead of the change count and graph. This part is treated
2337         * similarly to the graph part, except that it is not
2338         * "scaled". If total width is too small to accommodate the
2339         * guaranteed minimum width of the filename part and the
2340         * separators and this message, this message will "overflow"
2341         * making the line longer than the maximum width.
2342         */
2343
2344        if (options->stat_width == -1)
2345                width = term_columns() - strlen(line_prefix);
2346        else
2347                width = options->stat_width ? options->stat_width : 80;
2348        number_width = decimal_width(max_change) > number_width ?
2349                decimal_width(max_change) : number_width;
2350
2351        if (options->stat_graph_width == -1)
2352                options->stat_graph_width = diff_stat_graph_width;
2353
2354        /*
2355         * Guarantee 3/8*16==6 for the graph part
2356         * and 5/8*16==10 for the filename part
2357         */
2358        if (width < 16 + 6 + number_width)
2359                width = 16 + 6 + number_width;
2360
2361        /*
2362         * First assign sizes that are wanted, ignoring available width.
2363         * strlen("Bin XXX -> YYY bytes") == bin_width, and the part
2364         * starting from "XXX" should fit in graph_width.
2365         */
2366        graph_width = max_change + 4 > bin_width ? max_change : bin_width - 4;
2367        if (options->stat_graph_width &&
2368            options->stat_graph_width < graph_width)
2369                graph_width = options->stat_graph_width;
2370
2371        name_width = (options->stat_name_width > 0 &&
2372                      options->stat_name_width < max_len) ?
2373                options->stat_name_width : max_len;
2374
2375        /*
2376         * Adjust adjustable widths not to exceed maximum width
2377         */
2378        if (name_width + number_width + 6 + graph_width > width) {
2379                if (graph_width > width * 3/8 - number_width - 6) {
2380                        graph_width = width * 3/8 - number_width - 6;
2381                        if (graph_width < 6)
2382                                graph_width = 6;
2383                }
2384
2385                if (options->stat_graph_width &&
2386                    graph_width > options->stat_graph_width)
2387                        graph_width = options->stat_graph_width;
2388                if (name_width > width - number_width - 6 - graph_width)
2389                        name_width = width - number_width - 6 - graph_width;
2390                else
2391                        graph_width = width - number_width - 6 - name_width;
2392        }
2393
2394        /*
2395         * From here name_width is the width of the name area,
2396         * and graph_width is the width of the graph area.
2397         * max_change is used to scale graph properly.
2398         */
2399        for (i = 0; i < count; i++) {
2400                const char *prefix = "";
2401                struct diffstat_file *file = data->files[i];
2402                char *name = file->print_name;
2403                uintmax_t added = file->added;
2404                uintmax_t deleted = file->deleted;
2405                int name_len;
2406
2407                if (!file->is_interesting && (added + deleted == 0))
2408                        continue;
2409
2410                /*
2411                 * "scale" the filename
2412                 */
2413                len = name_width;
2414                name_len = strlen(name);
2415                if (name_width < name_len) {
2416                        char *slash;
2417                        prefix = "...";
2418                        len -= 3;
2419                        name += name_len - len;
2420                        slash = strchr(name, '/');
2421                        if (slash)
2422                                name = slash;
2423                }
2424
2425                if (file->is_binary) {
2426                        strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2427                        strbuf_addf(&out, " %*s", number_width, "Bin");
2428                        if (!added && !deleted) {
2429                                strbuf_addch(&out, '\n');
2430                                emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2431                                                 out.buf, out.len, 0);
2432                                strbuf_reset(&out);
2433                                continue;
2434                        }
2435                        strbuf_addf(&out, " %s%"PRIuMAX"%s",
2436                                del_c, deleted, reset);
2437                        strbuf_addstr(&out, " -> ");
2438                        strbuf_addf(&out, "%s%"PRIuMAX"%s",
2439                                add_c, added, reset);
2440                        strbuf_addstr(&out, " bytes\n");
2441                        emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2442                                         out.buf, out.len, 0);
2443                        strbuf_reset(&out);
2444                        continue;
2445                }
2446                else if (file->is_unmerged) {
2447                        strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2448                        strbuf_addstr(&out, " Unmerged\n");
2449                        emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2450                                         out.buf, out.len, 0);
2451                        strbuf_reset(&out);
2452                        continue;
2453                }
2454
2455                /*
2456                 * scale the add/delete
2457                 */
2458                add = added;
2459                del = deleted;
2460
2461                if (graph_width <= max_change) {
2462                        int total = scale_linear(add + del, graph_width, max_change);
2463                        if (total < 2 && add && del)
2464                                /* width >= 2 due to the sanity check */
2465                                total = 2;
2466                        if (add < del) {
2467                                add = scale_linear(add, graph_width, max_change);
2468                                del = total - add;
2469                        } else {
2470                                del = scale_linear(del, graph_width, max_change);
2471                                add = total - del;
2472                        }
2473                }
2474                strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2475                strbuf_addf(&out, " %*"PRIuMAX"%s",
2476                        number_width, added + deleted,
2477                        added + deleted ? " " : "");
2478                show_graph(&out, '+', add, add_c, reset);
2479                show_graph(&out, '-', del, del_c, reset);
2480                strbuf_addch(&out, '\n');
2481                emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2482                                 out.buf, out.len, 0);
2483                strbuf_reset(&out);
2484        }
2485
2486        for (i = 0; i < data->nr; i++) {
2487                struct diffstat_file *file = data->files[i];
2488                uintmax_t added = file->added;
2489                uintmax_t deleted = file->deleted;
2490
2491                if (file->is_unmerged ||
2492                    (!file->is_interesting && (added + deleted == 0))) {
2493                        total_files--;
2494                        continue;
2495                }
2496
2497                if (!file->is_binary) {
2498                        adds += added;
2499                        dels += deleted;
2500                }
2501                if (i < count)
2502                        continue;
2503                if (!extra_shown)
2504                        emit_diff_symbol(options,
2505                                         DIFF_SYMBOL_STATS_SUMMARY_ABBREV,
2506                                         NULL, 0, 0);
2507                extra_shown = 1;
2508        }
2509
2510        print_stat_summary_inserts_deletes(options, total_files, adds, dels);
2511        strbuf_release(&out);
2512}
2513
2514static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
2515{
2516        int i, adds = 0, dels = 0, total_files = data->nr;
2517
2518        if (data->nr == 0)
2519                return;
2520
2521        for (i = 0; i < data->nr; i++) {
2522                int added = data->files[i]->added;
2523                int deleted = data->files[i]->deleted;
2524
2525                if (data->files[i]->is_unmerged ||
2526                    (!data->files[i]->is_interesting && (added + deleted == 0))) {
2527                        total_files--;
2528                } else if (!data->files[i]->is_binary) { /* don't count bytes */
2529                        adds += added;
2530                        dels += deleted;
2531                }
2532        }
2533        print_stat_summary_inserts_deletes(options, total_files, adds, dels);
2534}
2535
2536static void show_numstat(struct diffstat_t *data, struct diff_options *options)
2537{
2538        int i;
2539
2540        if (data->nr == 0)
2541                return;
2542
2543        for (i = 0; i < data->nr; i++) {
2544                struct diffstat_file *file = data->files[i];
2545
2546                fprintf(options->file, "%s", diff_line_prefix(options));
2547
2548                if (file->is_binary)
2549                        fprintf(options->file, "-\t-\t");
2550                else
2551                        fprintf(options->file,
2552                                "%"PRIuMAX"\t%"PRIuMAX"\t",
2553                                file->added, file->deleted);
2554                if (options->line_termination) {
2555                        fill_print_name(file);
2556                        if (!file->is_renamed)
2557                                write_name_quoted(file->name, options->file,
2558                                                  options->line_termination);
2559                        else {
2560                                fputs(file->print_name, options->file);
2561                                putc(options->line_termination, options->file);
2562                        }
2563                } else {
2564                        if (file->is_renamed) {
2565                                putc('\0', options->file);
2566                                write_name_quoted(file->from_name, options->file, '\0');
2567                        }
2568                        write_name_quoted(file->name, options->file, '\0');
2569                }
2570        }
2571}
2572
2573struct dirstat_file {
2574        const char *name;
2575        unsigned long changed;
2576};
2577
2578struct dirstat_dir {
2579        struct dirstat_file *files;
2580        int alloc, nr, permille, cumulative;
2581};
2582
2583static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
2584                unsigned long changed, const char *base, int baselen)
2585{
2586        unsigned long sum_changes = 0;
2587        unsigned int sources = 0;
2588        const char *line_prefix = diff_line_prefix(opt);
2589
2590        while (dir->nr) {
2591                struct dirstat_file *f = dir->files;
2592                int namelen = strlen(f->name);
2593                unsigned long changes;
2594                char *slash;
2595
2596                if (namelen < baselen)
2597                        break;
2598                if (memcmp(f->name, base, baselen))
2599                        break;
2600                slash = strchr(f->name + baselen, '/');
2601                if (slash) {
2602                        int newbaselen = slash + 1 - f->name;
2603                        changes = gather_dirstat(opt, dir, changed, f->name, newbaselen);
2604                        sources++;
2605                } else {
2606                        changes = f->changed;
2607                        dir->files++;
2608                        dir->nr--;
2609                        sources += 2;
2610                }
2611                sum_changes += changes;
2612        }
2613
2614        /*
2615         * We don't report dirstat's for
2616         *  - the top level
2617         *  - or cases where everything came from a single directory
2618         *    under this directory (sources == 1).
2619         */
2620        if (baselen && sources != 1) {
2621                if (sum_changes) {
2622                        int permille = sum_changes * 1000 / changed;
2623                        if (permille >= dir->permille) {
2624                                fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
2625                                        permille / 10, permille % 10, baselen, base);
2626                                if (!dir->cumulative)
2627                                        return 0;
2628                        }
2629                }
2630        }
2631        return sum_changes;
2632}
2633
2634static int dirstat_compare(const void *_a, const void *_b)
2635{
2636        const struct dirstat_file *a = _a;
2637        const struct dirstat_file *b = _b;
2638        return strcmp(a->name, b->name);
2639}
2640
2641static void show_dirstat(struct diff_options *options)
2642{
2643        int i;
2644        unsigned long changed;
2645        struct dirstat_dir dir;
2646        struct diff_queue_struct *q = &diff_queued_diff;
2647
2648        dir.files = NULL;
2649        dir.alloc = 0;
2650        dir.nr = 0;
2651        dir.permille = options->dirstat_permille;
2652        dir.cumulative = options->flags.dirstat_cumulative;
2653
2654        changed = 0;
2655        for (i = 0; i < q->nr; i++) {
2656                struct diff_filepair *p = q->queue[i];
2657                const char *name;
2658                unsigned long copied, added, damage;
2659                int content_changed;
2660
2661                name = p->two->path ? p->two->path : p->one->path;
2662
2663                if (p->one->oid_valid && p->two->oid_valid)
2664                        content_changed = oidcmp(&p->one->oid, &p->two->oid);
2665                else
2666                        content_changed = 1;
2667
2668                if (!content_changed) {
2669                        /*
2670                         * The SHA1 has not changed, so pre-/post-content is
2671                         * identical. We can therefore skip looking at the
2672                         * file contents altogether.
2673                         */
2674                        damage = 0;
2675                        goto found_damage;
2676                }
2677
2678                if (options->flags.dirstat_by_file) {
2679                        /*
2680                         * In --dirstat-by-file mode, we don't really need to
2681                         * look at the actual file contents at all.
2682                         * The fact that the SHA1 changed is enough for us to
2683                         * add this file to the list of results
2684                         * (with each file contributing equal damage).
2685                         */
2686                        damage = 1;
2687                        goto found_damage;
2688                }
2689
2690                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
2691                        diff_populate_filespec(p->one, 0);
2692                        diff_populate_filespec(p->two, 0);
2693                        diffcore_count_changes(p->one, p->two, NULL, NULL,
2694                                               &copied, &added);
2695                        diff_free_filespec_data(p->one);
2696                        diff_free_filespec_data(p->two);
2697                } else if (DIFF_FILE_VALID(p->one)) {
2698                        diff_populate_filespec(p->one, CHECK_SIZE_ONLY);
2699                        copied = added = 0;
2700                        diff_free_filespec_data(p->one);
2701                } else if (DIFF_FILE_VALID(p->two)) {
2702                        diff_populate_filespec(p->two, CHECK_SIZE_ONLY);
2703                        copied = 0;
2704                        added = p->two->size;
2705                        diff_free_filespec_data(p->two);
2706                } else
2707                        continue;
2708
2709                /*
2710                 * Original minus copied is the removed material,
2711                 * added is the new material.  They are both damages
2712                 * made to the preimage.
2713                 * If the resulting damage is zero, we know that
2714                 * diffcore_count_changes() considers the two entries to
2715                 * be identical, but since content_changed is true, we
2716                 * know that there must have been _some_ kind of change,
2717                 * so we force all entries to have damage > 0.
2718                 */
2719                damage = (p->one->size - copied) + added;
2720                if (!damage)
2721                        damage = 1;
2722
2723found_damage:
2724                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
2725                dir.files[dir.nr].name = name;
2726                dir.files[dir.nr].changed = damage;
2727                changed += damage;
2728                dir.nr++;
2729        }
2730
2731        /* This can happen even with many files, if everything was renames */
2732        if (!changed)
2733                return;
2734
2735        /* Show all directories with more than x% of the changes */
2736        QSORT(dir.files, dir.nr, dirstat_compare);
2737        gather_dirstat(options, &dir, changed, "", 0);
2738}
2739
2740static void show_dirstat_by_line(struct diffstat_t *data, struct diff_options *options)
2741{
2742        int i;
2743        unsigned long changed;
2744        struct dirstat_dir dir;
2745
2746        if (data->nr == 0)
2747                return;
2748
2749        dir.files = NULL;
2750        dir.alloc = 0;
2751        dir.nr = 0;
2752        dir.permille = options->dirstat_permille;
2753        dir.cumulative = options->flags.dirstat_cumulative;
2754
2755        changed = 0;
2756        for (i = 0; i < data->nr; i++) {
2757                struct diffstat_file *file = data->files[i];
2758                unsigned long damage = file->added + file->deleted;
2759                if (file->is_binary)
2760                        /*
2761                         * binary files counts bytes, not lines. Must find some
2762                         * way to normalize binary bytes vs. textual lines.
2763                         * The following heuristic assumes that there are 64
2764                         * bytes per "line".
2765                         * This is stupid and ugly, but very cheap...
2766                         */
2767                        damage = DIV_ROUND_UP(damage, 64);
2768                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
2769                dir.files[dir.nr].name = file->name;
2770                dir.files[dir.nr].changed = damage;
2771                changed += damage;
2772                dir.nr++;
2773        }
2774
2775        /* This can happen even with many files, if everything was renames */
2776        if (!changed)
2777                return;
2778
2779        /* Show all directories with more than x% of the changes */
2780        QSORT(dir.files, dir.nr, dirstat_compare);
2781        gather_dirstat(options, &dir, changed, "", 0);
2782}
2783
2784static void free_diffstat_info(struct diffstat_t *diffstat)
2785{
2786        int i;
2787        for (i = 0; i < diffstat->nr; i++) {
2788                struct diffstat_file *f = diffstat->files[i];
2789                free(f->print_name);
2790                free(f->name);
2791                free(f->from_name);
2792                free(f);
2793        }
2794        free(diffstat->files);
2795}
2796
2797struct checkdiff_t {
2798        const char *filename;
2799        int lineno;
2800        int conflict_marker_size;
2801        struct diff_options *o;
2802        unsigned ws_rule;
2803        unsigned status;
2804};
2805
2806static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
2807{
2808        char firstchar;
2809        int cnt;
2810
2811        if (len < marker_size + 1)
2812                return 0;
2813        firstchar = line[0];
2814        switch (firstchar) {
2815        case '=': case '>': case '<': case '|':
2816                break;
2817        default:
2818                return 0;
2819        }
2820        for (cnt = 1; cnt < marker_size; cnt++)
2821                if (line[cnt] != firstchar)
2822                        return 0;
2823        /* line[1] thru line[marker_size-1] are same as firstchar */
2824        if (len < marker_size + 1 || !isspace(line[marker_size]))
2825                return 0;
2826        return 1;
2827}
2828
2829static void checkdiff_consume(void *priv, char *line, unsigned long len)
2830{
2831        struct checkdiff_t *data = priv;
2832        int marker_size = data->conflict_marker_size;
2833        const char *ws = diff_get_color(data->o->use_color, DIFF_WHITESPACE);
2834        const char *reset = diff_get_color(data->o->use_color, DIFF_RESET);
2835        const char *set = diff_get_color(data->o->use_color, DIFF_FILE_NEW);
2836        char *err;
2837        const char *line_prefix;
2838
2839        assert(data->o);
2840        line_prefix = diff_line_prefix(data->o);
2841
2842        if (line[0] == '+') {
2843                unsigned bad;
2844                data->lineno++;
2845                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
2846                        data->status |= 1;
2847                        fprintf(data->o->file,
2848                                "%s%s:%d: leftover conflict marker\n",
2849                                line_prefix, data->filename, data->lineno);
2850                }
2851                bad = ws_check(line + 1, len - 1, data->ws_rule);
2852                if (!bad)
2853                        return;
2854                data->status |= bad;
2855                err = whitespace_error_string(bad);
2856                fprintf(data->o->file, "%s%s:%d: %s.\n",
2857                        line_prefix, data->filename, data->lineno, err);
2858                free(err);
2859                emit_line(data->o, set, reset, line, 1);
2860                ws_check_emit(line + 1, len - 1, data->ws_rule,
2861                              data->o->file, set, reset, ws);
2862        } else if (line[0] == ' ') {
2863                data->lineno++;
2864        } else if (line[0] == '@') {
2865                char *plus = strchr(line, '+');
2866                if (plus)
2867                        data->lineno = strtol(plus, NULL, 10) - 1;
2868                else
2869                        die("invalid diff");
2870        }
2871}
2872
2873static unsigned char *deflate_it(char *data,
2874                                 unsigned long size,
2875                                 unsigned long *result_size)
2876{
2877        int bound;
2878        unsigned char *deflated;
2879        git_zstream stream;
2880
2881        git_deflate_init(&stream, zlib_compression_level);
2882        bound = git_deflate_bound(&stream, size);
2883        deflated = xmalloc(bound);
2884        stream.next_out = deflated;
2885        stream.avail_out = bound;
2886
2887        stream.next_in = (unsigned char *)data;
2888        stream.avail_in = size;
2889        while (git_deflate(&stream, Z_FINISH) == Z_OK)
2890                ; /* nothing */
2891        git_deflate_end(&stream);
2892        *result_size = stream.total_out;
2893        return deflated;
2894}
2895
2896static void emit_binary_diff_body(struct diff_options *o,
2897                                  mmfile_t *one, mmfile_t *two)
2898{
2899        void *cp;
2900        void *delta;
2901        void *deflated;
2902        void *data;
2903        unsigned long orig_size;
2904        unsigned long delta_size;
2905        unsigned long deflate_size;
2906        unsigned long data_size;
2907
2908        /* We could do deflated delta, or we could do just deflated two,
2909         * whichever is smaller.
2910         */
2911        delta = NULL;
2912        deflated = deflate_it(two->ptr, two->size, &deflate_size);
2913        if (one->size && two->size) {
2914                delta = diff_delta(one->ptr, one->size,
2915                                   two->ptr, two->size,
2916                                   &delta_size, deflate_size);
2917                if (delta) {
2918                        void *to_free = delta;
2919                        orig_size = delta_size;
2920                        delta = deflate_it(delta, delta_size, &delta_size);
2921                        free(to_free);
2922                }
2923        }
2924
2925        if (delta && delta_size < deflate_size) {
2926                char *s = xstrfmt("%lu", orig_size);
2927                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA,
2928                                 s, strlen(s), 0);
2929                free(s);
2930                free(deflated);
2931                data = delta;
2932                data_size = delta_size;
2933        } else {
2934                char *s = xstrfmt("%lu", two->size);
2935                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL,
2936                                 s, strlen(s), 0);
2937                free(s);
2938                free(delta);
2939                data = deflated;
2940                data_size = deflate_size;
2941        }
2942
2943        /* emit data encoded in base85 */
2944        cp = data;
2945        while (data_size) {
2946                int len;
2947                int bytes = (52 < data_size) ? 52 : data_size;
2948                char line[71];
2949                data_size -= bytes;
2950                if (bytes <= 26)
2951                        line[0] = bytes + 'A' - 1;
2952                else
2953                        line[0] = bytes - 26 + 'a' - 1;
2954                encode_85(line + 1, cp, bytes);
2955                cp = (char *) cp + bytes;
2956
2957                len = strlen(line);
2958                line[len++] = '\n';
2959                line[len] = '\0';
2960
2961                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_BODY,
2962                                 line, len, 0);
2963        }
2964        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_FOOTER, NULL, 0, 0);
2965        free(data);
2966}
2967
2968static void emit_binary_diff(struct diff_options *o,
2969                             mmfile_t *one, mmfile_t *two)
2970{
2971        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER, NULL, 0, 0);
2972        emit_binary_diff_body(o, one, two);
2973        emit_binary_diff_body(o, two, one);
2974}
2975
2976int diff_filespec_is_binary(struct diff_filespec *one)
2977{
2978        if (one->is_binary == -1) {
2979                diff_filespec_load_driver(one);
2980                if (one->driver->binary != -1)
2981                        one->is_binary = one->driver->binary;
2982                else {
2983                        if (!one->data && DIFF_FILE_VALID(one))
2984                                diff_populate_filespec(one, CHECK_BINARY);
2985                        if (one->is_binary == -1 && one->data)
2986                                one->is_binary = buffer_is_binary(one->data,
2987                                                one->size);
2988                        if (one->is_binary == -1)
2989                                one->is_binary = 0;
2990                }
2991        }
2992        return one->is_binary;
2993}
2994
2995static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
2996{
2997        diff_filespec_load_driver(one);
2998        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
2999}
3000
3001void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
3002{
3003        if (!options->a_prefix)
3004                options->a_prefix = a;
3005        if (!options->b_prefix)
3006                options->b_prefix = b;
3007}
3008
3009struct userdiff_driver *get_textconv(struct diff_filespec *one)
3010{
3011        if (!DIFF_FILE_VALID(one))
3012                return NULL;
3013
3014        diff_filespec_load_driver(one);
3015        return userdiff_get_textconv(one->driver);
3016}
3017
3018static void builtin_diff(const char *name_a,
3019                         const char *name_b,
3020                         struct diff_filespec *one,
3021                         struct diff_filespec *two,
3022                         const char *xfrm_msg,
3023                         int must_show_header,
3024                         struct diff_options *o,
3025                         int complete_rewrite)
3026{
3027        mmfile_t mf1, mf2;
3028        const char *lbl[2];
3029        char *a_one, *b_two;
3030        const char *meta = diff_get_color_opt(o, DIFF_METAINFO);
3031        const char *reset = diff_get_color_opt(o, DIFF_RESET);
3032        const char *a_prefix, *b_prefix;
3033        struct userdiff_driver *textconv_one = NULL;
3034        struct userdiff_driver *textconv_two = NULL;
3035        struct strbuf header = STRBUF_INIT;
3036        const char *line_prefix = diff_line_prefix(o);
3037
3038        diff_set_mnemonic_prefix(o, "a/", "b/");
3039        if (o->flags.reverse_diff) {
3040                a_prefix = o->b_prefix;
3041                b_prefix = o->a_prefix;
3042        } else {
3043                a_prefix = o->a_prefix;
3044                b_prefix = o->b_prefix;
3045        }
3046
3047        if (o->submodule_format == DIFF_SUBMODULE_LOG &&
3048            (!one->mode || S_ISGITLINK(one->mode)) &&
3049            (!two->mode || S_ISGITLINK(two->mode))) {
3050                show_submodule_summary(o, one->path ? one->path : two->path,
3051                                &one->oid, &two->oid,
3052                                two->dirty_submodule);
3053                return;
3054        } else if (o->submodule_format == DIFF_SUBMODULE_INLINE_DIFF &&
3055                   (!one->mode || S_ISGITLINK(one->mode)) &&
3056                   (!two->mode || S_ISGITLINK(two->mode))) {
3057                show_submodule_inline_diff(o, one->path ? one->path : two->path,
3058                                &one->oid, &two->oid,
3059                                two->dirty_submodule);
3060                return;
3061        }
3062
3063        if (o->flags.allow_textconv) {
3064                textconv_one = get_textconv(one);
3065                textconv_two = get_textconv(two);
3066        }
3067
3068        /* Never use a non-valid filename anywhere if at all possible */
3069        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
3070        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
3071
3072        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
3073        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
3074        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
3075        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
3076        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, meta, a_one, b_two, reset);
3077        if (lbl[0][0] == '/') {
3078                /* /dev/null */
3079                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, meta, two->mode, reset);
3080                if (xfrm_msg)
3081                        strbuf_addstr(&header, xfrm_msg);
3082                must_show_header = 1;
3083        }
3084        else if (lbl[1][0] == '/') {
3085                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, meta, one->mode, reset);
3086                if (xfrm_msg)
3087                        strbuf_addstr(&header, xfrm_msg);
3088                must_show_header = 1;
3089        }
3090        else {
3091                if (one->mode != two->mode) {
3092                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, meta, one->mode, reset);
3093                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, meta, two->mode, reset);
3094                        must_show_header = 1;
3095                }
3096                if (xfrm_msg)
3097                        strbuf_addstr(&header, xfrm_msg);
3098
3099                /*
3100                 * we do not run diff between different kind
3101                 * of objects.
3102                 */
3103                if ((one->mode ^ two->mode) & S_IFMT)
3104                        goto free_ab_and_return;
3105                if (complete_rewrite &&
3106                    (textconv_one || !diff_filespec_is_binary(one)) &&
3107                    (textconv_two || !diff_filespec_is_binary(two))) {
3108                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3109                                         header.buf, header.len, 0);
3110                        strbuf_reset(&header);
3111                        emit_rewrite_diff(name_a, name_b, one, two,
3112                                                textconv_one, textconv_two, o);
3113                        o->found_changes = 1;
3114                        goto free_ab_and_return;
3115                }
3116        }
3117
3118        if (o->irreversible_delete && lbl[1][0] == '/') {
3119                emit_diff_symbol(o, DIFF_SYMBOL_HEADER, header.buf,
3120                                 header.len, 0);
3121                strbuf_reset(&header);
3122                goto free_ab_and_return;
3123        } else if (!o->flags.text &&
3124            ( (!textconv_one && diff_filespec_is_binary(one)) ||
3125              (!textconv_two && diff_filespec_is_binary(two)) )) {
3126                struct strbuf sb = STRBUF_INIT;
3127                if (!one->data && !two->data &&
3128                    S_ISREG(one->mode) && S_ISREG(two->mode) &&
3129                    !o->flags.binary) {
3130                        if (!oidcmp(&one->oid, &two->oid)) {
3131                                if (must_show_header)
3132                                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3133                                                         header.buf, header.len,
3134                                                         0);
3135                                goto free_ab_and_return;
3136                        }
3137                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3138                                         header.buf, header.len, 0);
3139                        strbuf_addf(&sb, "%sBinary files %s and %s differ\n",
3140                                    diff_line_prefix(o), lbl[0], lbl[1]);
3141                        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_FILES,
3142                                         sb.buf, sb.len, 0);
3143                        strbuf_release(&sb);
3144                        goto free_ab_and_return;
3145                }
3146                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
3147                        die("unable to read files to diff");
3148                /* Quite common confusing case */
3149                if (mf1.size == mf2.size &&
3150                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
3151                        if (must_show_header)
3152                                emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3153                                                 header.buf, header.len, 0);
3154                        goto free_ab_and_return;
3155                }
3156                emit_diff_symbol(o, DIFF_SYMBOL_HEADER, header.buf, header.len, 0);
3157                strbuf_reset(&header);
3158                if (o->flags.binary)
3159                        emit_binary_diff(o, &mf1, &mf2);
3160                else {
3161                        strbuf_addf(&sb, "%sBinary files %s and %s differ\n",
3162                                    diff_line_prefix(o), lbl[0], lbl[1]);
3163                        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_FILES,
3164                                         sb.buf, sb.len, 0);
3165                        strbuf_release(&sb);
3166                }
3167                o->found_changes = 1;
3168        } else {
3169                /* Crazy xdl interfaces.. */
3170                const char *diffopts = getenv("GIT_DIFF_OPTS");
3171                const char *v;
3172                xpparam_t xpp;
3173                xdemitconf_t xecfg;
3174                struct emit_callback ecbdata;
3175                const struct userdiff_funcname *pe;
3176
3177                if (must_show_header) {
3178                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3179                                         header.buf, header.len, 0);
3180                        strbuf_reset(&header);
3181                }
3182
3183                mf1.size = fill_textconv(textconv_one, one, &mf1.ptr);
3184                mf2.size = fill_textconv(textconv_two, two, &mf2.ptr);
3185
3186                pe = diff_funcname_pattern(one);
3187                if (!pe)
3188                        pe = diff_funcname_pattern(two);
3189
3190                memset(&xpp, 0, sizeof(xpp));
3191                memset(&xecfg, 0, sizeof(xecfg));
3192                memset(&ecbdata, 0, sizeof(ecbdata));
3193                ecbdata.label_path = lbl;
3194                ecbdata.color_diff = want_color(o->use_color);
3195                ecbdata.ws_rule = whitespace_rule(name_b);
3196                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
3197                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
3198                ecbdata.opt = o;
3199                ecbdata.header = header.len ? &header : NULL;
3200                xpp.flags = o->xdl_opts;
3201                xpp.anchors = o->anchors;
3202                xpp.anchors_nr = o->anchors_nr;
3203                xecfg.ctxlen = o->context;
3204                xecfg.interhunkctxlen = o->interhunkcontext;
3205                xecfg.flags = XDL_EMIT_FUNCNAMES;
3206                if (o->flags.funccontext)
3207                        xecfg.flags |= XDL_EMIT_FUNCCONTEXT;
3208                if (pe)
3209                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
3210                if (!diffopts)
3211                        ;
3212                else if (skip_prefix(diffopts, "--unified=", &v))
3213                        xecfg.ctxlen = strtoul(v, NULL, 10);
3214                else if (skip_prefix(diffopts, "-u", &v))
3215                        xecfg.ctxlen = strtoul(v, NULL, 10);
3216                if (o->word_diff)
3217                        init_diff_words_data(&ecbdata, o, one, two);
3218                if (xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
3219                                  &xpp, &xecfg))
3220                        die("unable to generate diff for %s", one->path);
3221                if (o->word_diff)
3222                        free_diff_words_data(&ecbdata);
3223                if (textconv_one)
3224                        free(mf1.ptr);
3225                if (textconv_two)
3226                        free(mf2.ptr);
3227                xdiff_clear_find_func(&xecfg);
3228        }
3229
3230 free_ab_and_return:
3231        strbuf_release(&header);
3232        diff_free_filespec_data(one);
3233        diff_free_filespec_data(two);
3234        free(a_one);
3235        free(b_two);
3236        return;
3237}
3238
3239static char *get_compact_summary(const struct diff_filepair *p, int is_renamed)
3240{
3241        if (!is_renamed) {
3242                if (p->status == DIFF_STATUS_ADDED) {
3243                        if (S_ISLNK(p->two->mode))
3244                                return "new +l";
3245                        else if ((p->two->mode & 0777) == 0755)
3246                                return "new +x";
3247                        else
3248                                return "new";
3249                } else if (p->status == DIFF_STATUS_DELETED)
3250                        return "gone";
3251        }
3252        if (S_ISLNK(p->one->mode) && !S_ISLNK(p->two->mode))
3253                return "mode -l";
3254        else if (!S_ISLNK(p->one->mode) && S_ISLNK(p->two->mode))
3255                return "mode +l";
3256        else if ((p->one->mode & 0777) == 0644 &&
3257                 (p->two->mode & 0777) == 0755)
3258                return "mode +x";
3259        else if ((p->one->mode & 0777) == 0755 &&
3260                 (p->two->mode & 0777) == 0644)
3261                return "mode -x";
3262        return NULL;
3263}
3264
3265static void builtin_diffstat(const char *name_a, const char *name_b,
3266                             struct diff_filespec *one,
3267                             struct diff_filespec *two,
3268                             struct diffstat_t *diffstat,
3269                             struct diff_options *o,
3270                             struct diff_filepair *p)
3271{
3272        mmfile_t mf1, mf2;
3273        struct diffstat_file *data;
3274        int same_contents;
3275        int complete_rewrite = 0;
3276
3277        if (!DIFF_PAIR_UNMERGED(p)) {
3278                if (p->status == DIFF_STATUS_MODIFIED && p->score)
3279                        complete_rewrite = 1;
3280        }
3281
3282        data = diffstat_add(diffstat, name_a, name_b);
3283        data->is_interesting = p->status != DIFF_STATUS_UNKNOWN;
3284        if (o->flags.stat_with_summary)
3285                data->comments = get_compact_summary(p, data->is_renamed);
3286
3287        if (!one || !two) {
3288                data->is_unmerged = 1;
3289                return;
3290        }
3291
3292        same_contents = !oidcmp(&one->oid, &two->oid);
3293
3294        if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
3295                data->is_binary = 1;
3296                if (same_contents) {
3297                        data->added = 0;
3298                        data->deleted = 0;
3299                } else {
3300                        data->added = diff_filespec_size(two);
3301                        data->deleted = diff_filespec_size(one);
3302                }
3303        }
3304
3305        else if (complete_rewrite) {
3306                diff_populate_filespec(one, 0);
3307                diff_populate_filespec(two, 0);
3308                data->deleted = count_lines(one->data, one->size);
3309                data->added = count_lines(two->data, two->size);
3310        }
3311
3312        else if (!same_contents) {
3313                /* Crazy xdl interfaces.. */
3314                xpparam_t xpp;
3315                xdemitconf_t xecfg;
3316
3317                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
3318                        die("unable to read files to diff");
3319
3320                memset(&xpp, 0, sizeof(xpp));
3321                memset(&xecfg, 0, sizeof(xecfg));
3322                xpp.flags = o->xdl_opts;
3323                xpp.anchors = o->anchors;
3324                xpp.anchors_nr = o->anchors_nr;
3325                xecfg.ctxlen = o->context;
3326                xecfg.interhunkctxlen = o->interhunkcontext;
3327                if (xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
3328                                  &xpp, &xecfg))
3329                        die("unable to generate diffstat for %s", one->path);
3330        }
3331
3332        diff_free_filespec_data(one);
3333        diff_free_filespec_data(two);
3334}
3335
3336static void builtin_checkdiff(const char *name_a, const char *name_b,
3337                              const char *attr_path,
3338                              struct diff_filespec *one,
3339                              struct diff_filespec *two,
3340                              struct diff_options *o)
3341{
3342        mmfile_t mf1, mf2;
3343        struct checkdiff_t data;
3344
3345        if (!two)
3346                return;
3347
3348        memset(&data, 0, sizeof(data));
3349        data.filename = name_b ? name_b : name_a;
3350        data.lineno = 0;
3351        data.o = o;
3352        data.ws_rule = whitespace_rule(attr_path);
3353        data.conflict_marker_size = ll_merge_marker_size(attr_path);
3354
3355        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
3356                die("unable to read files to diff");
3357
3358        /*
3359         * All the other codepaths check both sides, but not checking
3360         * the "old" side here is deliberate.  We are checking the newly
3361         * introduced changes, and as long as the "new" side is text, we
3362         * can and should check what it introduces.
3363         */
3364        if (diff_filespec_is_binary(two))
3365                goto free_and_return;
3366        else {
3367                /* Crazy xdl interfaces.. */
3368                xpparam_t xpp;
3369                xdemitconf_t xecfg;
3370
3371                memset(&xpp, 0, sizeof(xpp));
3372                memset(&xecfg, 0, sizeof(xecfg));
3373                xecfg.ctxlen = 1; /* at least one context line */
3374                xpp.flags = 0;
3375                if (xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
3376                                  &xpp, &xecfg))
3377                        die("unable to generate checkdiff for %s", one->path);
3378
3379                if (data.ws_rule & WS_BLANK_AT_EOF) {
3380                        struct emit_callback ecbdata;
3381                        int blank_at_eof;
3382
3383                        ecbdata.ws_rule = data.ws_rule;
3384                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
3385                        blank_at_eof = ecbdata.blank_at_eof_in_postimage;
3386
3387                        if (blank_at_eof) {
3388                                static char *err;
3389                                if (!err)
3390                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
3391                                fprintf(o->file, "%s:%d: %s.\n",
3392                                        data.filename, blank_at_eof, err);
3393                                data.status = 1; /* report errors */
3394                        }
3395                }
3396        }
3397 free_and_return:
3398        diff_free_filespec_data(one);
3399        diff_free_filespec_data(two);
3400        if (data.status)
3401                o->flags.check_failed = 1;
3402}
3403
3404struct diff_filespec *alloc_filespec(const char *path)
3405{
3406        struct diff_filespec *spec;
3407
3408        FLEXPTR_ALLOC_STR(spec, path, path);
3409        spec->count = 1;
3410        spec->is_binary = -1;
3411        return spec;
3412}
3413
3414void free_filespec(struct diff_filespec *spec)
3415{
3416        if (!--spec->count) {
3417                diff_free_filespec_data(spec);
3418                free(spec);
3419        }
3420}
3421
3422void fill_filespec(struct diff_filespec *spec, const struct object_id *oid,
3423                   int oid_valid, unsigned short mode)
3424{
3425        if (mode) {
3426                spec->mode = canon_mode(mode);
3427                oidcpy(&spec->oid, oid);
3428                spec->oid_valid = oid_valid;
3429        }
3430}
3431
3432/*
3433 * Given a name and sha1 pair, if the index tells us the file in
3434 * the work tree has that object contents, return true, so that
3435 * prepare_temp_file() does not have to inflate and extract.
3436 */
3437static int reuse_worktree_file(const char *name, const struct object_id *oid, int want_file)
3438{
3439        const struct cache_entry *ce;
3440        struct stat st;
3441        int pos, len;
3442
3443        /*
3444         * We do not read the cache ourselves here, because the
3445         * benchmark with my previous version that always reads cache
3446         * shows that it makes things worse for diff-tree comparing
3447         * two linux-2.6 kernel trees in an already checked out work
3448         * tree.  This is because most diff-tree comparisons deal with
3449         * only a small number of files, while reading the cache is
3450         * expensive for a large project, and its cost outweighs the
3451         * savings we get by not inflating the object to a temporary
3452         * file.  Practically, this code only helps when we are used
3453         * by diff-cache --cached, which does read the cache before
3454         * calling us.
3455         */
3456        if (!active_cache)
3457                return 0;
3458
3459        /* We want to avoid the working directory if our caller
3460         * doesn't need the data in a normal file, this system
3461         * is rather slow with its stat/open/mmap/close syscalls,
3462         * and the object is contained in a pack file.  The pack
3463         * is probably already open and will be faster to obtain
3464         * the data through than the working directory.  Loose
3465         * objects however would tend to be slower as they need
3466         * to be individually opened and inflated.
3467         */
3468        if (!FAST_WORKING_DIRECTORY && !want_file && has_object_pack(oid))
3469                return 0;
3470
3471        /*
3472         * Similarly, if we'd have to convert the file contents anyway, that
3473         * makes the optimization not worthwhile.
3474         */
3475        if (!want_file && would_convert_to_git(&the_index, name))
3476                return 0;
3477
3478        len = strlen(name);
3479        pos = cache_name_pos(name, len);
3480        if (pos < 0)
3481                return 0;
3482        ce = active_cache[pos];
3483
3484        /*
3485         * This is not the sha1 we are looking for, or
3486         * unreusable because it is not a regular file.
3487         */
3488        if (oidcmp(oid, &ce->oid) || !S_ISREG(ce->ce_mode))
3489                return 0;
3490
3491        /*
3492         * If ce is marked as "assume unchanged", there is no
3493         * guarantee that work tree matches what we are looking for.
3494         */
3495        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
3496                return 0;
3497
3498        /*
3499         * If ce matches the file in the work tree, we can reuse it.
3500         */
3501        if (ce_uptodate(ce) ||
3502            (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
3503                return 1;
3504
3505        return 0;
3506}
3507
3508static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
3509{
3510        struct strbuf buf = STRBUF_INIT;
3511        char *dirty = "";
3512
3513        /* Are we looking at the work tree? */
3514        if (s->dirty_submodule)
3515                dirty = "-dirty";
3516
3517        strbuf_addf(&buf, "Subproject commit %s%s\n",
3518                    oid_to_hex(&s->oid), dirty);
3519        s->size = buf.len;
3520        if (size_only) {
3521                s->data = NULL;
3522                strbuf_release(&buf);
3523        } else {
3524                s->data = strbuf_detach(&buf, NULL);
3525                s->should_free = 1;
3526        }
3527        return 0;
3528}
3529
3530/*
3531 * While doing rename detection and pickaxe operation, we may need to
3532 * grab the data for the blob (or file) for our own in-core comparison.
3533 * diff_filespec has data and size fields for this purpose.
3534 */
3535int diff_populate_filespec(struct diff_filespec *s, unsigned int flags)
3536{
3537        int size_only = flags & CHECK_SIZE_ONLY;
3538        int err = 0;
3539        int conv_flags = global_conv_flags_eol;
3540        /*
3541         * demote FAIL to WARN to allow inspecting the situation
3542         * instead of refusing.
3543         */
3544        if (conv_flags & CONV_EOL_RNDTRP_DIE)
3545                conv_flags = CONV_EOL_RNDTRP_WARN;
3546
3547        if (!DIFF_FILE_VALID(s))
3548                die("internal error: asking to populate invalid file.");
3549        if (S_ISDIR(s->mode))
3550                return -1;
3551
3552        if (s->data)
3553                return 0;
3554
3555        if (size_only && 0 < s->size)
3556                return 0;
3557
3558        if (S_ISGITLINK(s->mode))
3559                return diff_populate_gitlink(s, size_only);
3560
3561        if (!s->oid_valid ||
3562            reuse_worktree_file(s->path, &s->oid, 0)) {
3563                struct strbuf buf = STRBUF_INIT;
3564                struct stat st;
3565                int fd;
3566
3567                if (lstat(s->path, &st) < 0) {
3568                err_empty:
3569                        err = -1;
3570                empty:
3571                        s->data = (char *)"";
3572                        s->size = 0;
3573                        return err;
3574                }
3575                s->size = xsize_t(st.st_size);
3576                if (!s->size)
3577                        goto empty;
3578                if (S_ISLNK(st.st_mode)) {
3579                        struct strbuf sb = STRBUF_INIT;
3580
3581                        if (strbuf_readlink(&sb, s->path, s->size))
3582                                goto err_empty;
3583                        s->size = sb.len;
3584                        s->data = strbuf_detach(&sb, NULL);
3585                        s->should_free = 1;
3586                        return 0;
3587                }
3588
3589                /*
3590                 * Even if the caller would be happy with getting
3591                 * only the size, we cannot return early at this
3592                 * point if the path requires us to run the content
3593                 * conversion.
3594                 */
3595                if (size_only && !would_convert_to_git(&the_index, s->path))
3596                        return 0;
3597
3598                /*
3599                 * Note: this check uses xsize_t(st.st_size) that may
3600                 * not be the true size of the blob after it goes
3601                 * through convert_to_git().  This may not strictly be
3602                 * correct, but the whole point of big_file_threshold
3603                 * and is_binary check being that we want to avoid
3604                 * opening the file and inspecting the contents, this
3605                 * is probably fine.
3606                 */
3607                if ((flags & CHECK_BINARY) &&
3608                    s->size > big_file_threshold && s->is_binary == -1) {
3609                        s->is_binary = 1;
3610                        return 0;
3611                }
3612                fd = open(s->path, O_RDONLY);
3613                if (fd < 0)
3614                        goto err_empty;
3615                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
3616                close(fd);
3617                s->should_munmap = 1;
3618
3619                /*
3620                 * Convert from working tree format to canonical git format
3621                 */
3622                if (convert_to_git(&the_index, s->path, s->data, s->size, &buf, conv_flags)) {
3623                        size_t size = 0;
3624                        munmap(s->data, s->size);
3625                        s->should_munmap = 0;
3626                        s->data = strbuf_detach(&buf, &size);
3627                        s->size = size;
3628                        s->should_free = 1;
3629                }
3630        }
3631        else {
3632                enum object_type type;
3633                if (size_only || (flags & CHECK_BINARY)) {
3634                        type = oid_object_info(the_repository, &s->oid,
3635                                               &s->size);
3636                        if (type < 0)
3637                                die("unable to read %s",
3638                                    oid_to_hex(&s->oid));
3639                        if (size_only)
3640                                return 0;
3641                        if (s->size > big_file_threshold && s->is_binary == -1) {
3642                                s->is_binary = 1;
3643                                return 0;
3644                        }
3645                }
3646                s->data = read_object_file(&s->oid, &type, &s->size);
3647                if (!s->data)
3648                        die("unable to read %s", oid_to_hex(&s->oid));
3649                s->should_free = 1;
3650        }
3651        return 0;
3652}
3653
3654void diff_free_filespec_blob(struct diff_filespec *s)
3655{
3656        if (s->should_free)
3657                free(s->data);
3658        else if (s->should_munmap)
3659                munmap(s->data, s->size);
3660
3661        if (s->should_free || s->should_munmap) {
3662                s->should_free = s->should_munmap = 0;
3663                s->data = NULL;
3664        }
3665}
3666
3667void diff_free_filespec_data(struct diff_filespec *s)
3668{
3669        diff_free_filespec_blob(s);
3670        FREE_AND_NULL(s->cnt_data);
3671}
3672
3673static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
3674                           void *blob,
3675                           unsigned long size,
3676                           const struct object_id *oid,
3677                           int mode)
3678{
3679        struct strbuf buf = STRBUF_INIT;
3680        struct strbuf tempfile = STRBUF_INIT;
3681        char *path_dup = xstrdup(path);
3682        const char *base = basename(path_dup);
3683
3684        /* Generate "XXXXXX_basename.ext" */
3685        strbuf_addstr(&tempfile, "XXXXXX_");
3686        strbuf_addstr(&tempfile, base);
3687
3688        temp->tempfile = mks_tempfile_ts(tempfile.buf, strlen(base) + 1);
3689        if (!temp->tempfile)
3690                die_errno("unable to create temp-file");
3691        if (convert_to_working_tree(path,
3692                        (const char *)blob, (size_t)size, &buf)) {
3693                blob = buf.buf;
3694                size = buf.len;
3695        }
3696        if (write_in_full(temp->tempfile->fd, blob, size) < 0 ||
3697            close_tempfile_gently(temp->tempfile))
3698                die_errno("unable to write temp-file");
3699        temp->name = get_tempfile_path(temp->tempfile);
3700        oid_to_hex_r(temp->hex, oid);
3701        xsnprintf(temp->mode, sizeof(temp->mode), "%06o", mode);
3702        strbuf_release(&buf);
3703        strbuf_release(&tempfile);
3704        free(path_dup);
3705}
3706
3707static struct diff_tempfile *prepare_temp_file(const char *name,
3708                struct diff_filespec *one)
3709{
3710        struct diff_tempfile *temp = claim_diff_tempfile();
3711
3712        if (!DIFF_FILE_VALID(one)) {
3713        not_a_valid_file:
3714                /* A '-' entry produces this for file-2, and
3715                 * a '+' entry produces this for file-1.
3716                 */
3717                temp->name = "/dev/null";
3718                xsnprintf(temp->hex, sizeof(temp->hex), ".");
3719                xsnprintf(temp->mode, sizeof(temp->mode), ".");
3720                return temp;
3721        }
3722
3723        if (!S_ISGITLINK(one->mode) &&
3724            (!one->oid_valid ||
3725             reuse_worktree_file(name, &one->oid, 1))) {
3726                struct stat st;
3727                if (lstat(name, &st) < 0) {
3728                        if (errno == ENOENT)
3729                                goto not_a_valid_file;
3730                        die_errno("stat(%s)", name);
3731                }
3732                if (S_ISLNK(st.st_mode)) {
3733                        struct strbuf sb = STRBUF_INIT;
3734                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
3735                                die_errno("readlink(%s)", name);
3736                        prep_temp_blob(name, temp, sb.buf, sb.len,
3737                                       (one->oid_valid ?
3738                                        &one->oid : &null_oid),
3739                                       (one->oid_valid ?
3740                                        one->mode : S_IFLNK));
3741                        strbuf_release(&sb);
3742                }
3743                else {
3744                        /* we can borrow from the file in the work tree */
3745                        temp->name = name;
3746                        if (!one->oid_valid)
3747                                oid_to_hex_r(temp->hex, &null_oid);
3748                        else
3749                                oid_to_hex_r(temp->hex, &one->oid);
3750                        /* Even though we may sometimes borrow the
3751                         * contents from the work tree, we always want
3752                         * one->mode.  mode is trustworthy even when
3753                         * !(one->oid_valid), as long as
3754                         * DIFF_FILE_VALID(one).
3755                         */
3756                        xsnprintf(temp->mode, sizeof(temp->mode), "%06o", one->mode);
3757                }
3758                return temp;
3759        }
3760        else {
3761                if (diff_populate_filespec(one, 0))
3762                        die("cannot read data blob for %s", one->path);
3763                prep_temp_blob(name, temp, one->data, one->size,
3764                               &one->oid, one->mode);
3765        }
3766        return temp;
3767}
3768
3769static void add_external_diff_name(struct argv_array *argv,
3770                                   const char *name,
3771                                   struct diff_filespec *df)
3772{
3773        struct diff_tempfile *temp = prepare_temp_file(name, df);
3774        argv_array_push(argv, temp->name);
3775        argv_array_push(argv, temp->hex);
3776        argv_array_push(argv, temp->mode);
3777}
3778
3779/* An external diff command takes:
3780 *
3781 * diff-cmd name infile1 infile1-sha1 infile1-mode \
3782 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
3783 *
3784 */
3785static void run_external_diff(const char *pgm,
3786                              const char *name,
3787                              const char *other,
3788                              struct diff_filespec *one,
3789                              struct diff_filespec *two,
3790                              const char *xfrm_msg,
3791                              int complete_rewrite,
3792                              struct diff_options *o)
3793{
3794        struct argv_array argv = ARGV_ARRAY_INIT;
3795        struct argv_array env = ARGV_ARRAY_INIT;
3796        struct diff_queue_struct *q = &diff_queued_diff;
3797
3798        argv_array_push(&argv, pgm);
3799        argv_array_push(&argv, name);
3800
3801        if (one && two) {
3802                add_external_diff_name(&argv, name, one);
3803                if (!other)
3804                        add_external_diff_name(&argv, name, two);
3805                else {
3806                        add_external_diff_name(&argv, other, two);
3807                        argv_array_push(&argv, other);
3808                        argv_array_push(&argv, xfrm_msg);
3809                }
3810        }
3811
3812        argv_array_pushf(&env, "GIT_DIFF_PATH_COUNTER=%d", ++o->diff_path_counter);
3813        argv_array_pushf(&env, "GIT_DIFF_PATH_TOTAL=%d", q->nr);
3814
3815        if (run_command_v_opt_cd_env(argv.argv, RUN_USING_SHELL, NULL, env.argv))
3816                die(_("external diff died, stopping at %s"), name);
3817
3818        remove_tempfile();
3819        argv_array_clear(&argv);
3820        argv_array_clear(&env);
3821}
3822
3823static int similarity_index(struct diff_filepair *p)
3824{
3825        return p->score * 100 / MAX_SCORE;
3826}
3827
3828static const char *diff_abbrev_oid(const struct object_id *oid, int abbrev)
3829{
3830        if (startup_info->have_repository)
3831                return find_unique_abbrev(oid, abbrev);
3832        else {
3833                char *hex = oid_to_hex(oid);
3834                if (abbrev < 0)
3835                        abbrev = FALLBACK_DEFAULT_ABBREV;
3836                if (abbrev > the_hash_algo->hexsz)
3837                        BUG("oid abbreviation out of range: %d", abbrev);
3838                if (abbrev)
3839                        hex[abbrev] = '\0';
3840                return hex;
3841        }
3842}
3843
3844static void fill_metainfo(struct strbuf *msg,
3845                          const char *name,
3846                          const char *other,
3847                          struct diff_filespec *one,
3848                          struct diff_filespec *two,
3849                          struct diff_options *o,
3850                          struct diff_filepair *p,
3851                          int *must_show_header,
3852                          int use_color)
3853{
3854        const char *set = diff_get_color(use_color, DIFF_METAINFO);
3855        const char *reset = diff_get_color(use_color, DIFF_RESET);
3856        const char *line_prefix = diff_line_prefix(o);
3857
3858        *must_show_header = 1;
3859        strbuf_init(msg, PATH_MAX * 2 + 300);
3860        switch (p->status) {
3861        case DIFF_STATUS_COPIED:
3862                strbuf_addf(msg, "%s%ssimilarity index %d%%",
3863                            line_prefix, set, similarity_index(p));
3864                strbuf_addf(msg, "%s\n%s%scopy from ",
3865                            reset,  line_prefix, set);
3866                quote_c_style(name, msg, NULL, 0);
3867                strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
3868                quote_c_style(other, msg, NULL, 0);
3869                strbuf_addf(msg, "%s\n", reset);
3870                break;
3871        case DIFF_STATUS_RENAMED:
3872                strbuf_addf(msg, "%s%ssimilarity index %d%%",
3873                            line_prefix, set, similarity_index(p));
3874                strbuf_addf(msg, "%s\n%s%srename from ",
3875                            reset, line_prefix, set);
3876                quote_c_style(name, msg, NULL, 0);
3877                strbuf_addf(msg, "%s\n%s%srename to ",
3878                            reset, line_prefix, set);
3879                quote_c_style(other, msg, NULL, 0);
3880                strbuf_addf(msg, "%s\n", reset);
3881                break;
3882        case DIFF_STATUS_MODIFIED:
3883                if (p->score) {
3884                        strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
3885                                    line_prefix,
3886                                    set, similarity_index(p), reset);
3887                        break;
3888                }
3889                /* fallthru */
3890        default:
3891                *must_show_header = 0;
3892        }
3893        if (one && two && oidcmp(&one->oid, &two->oid)) {
3894                const unsigned hexsz = the_hash_algo->hexsz;
3895                int abbrev = o->flags.full_index ? hexsz : DEFAULT_ABBREV;
3896
3897                if (o->flags.binary) {
3898                        mmfile_t mf;
3899                        if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
3900                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
3901                                abbrev = hexsz;
3902                }
3903                strbuf_addf(msg, "%s%sindex %s..%s", line_prefix, set,
3904                            diff_abbrev_oid(&one->oid, abbrev),
3905                            diff_abbrev_oid(&two->oid, abbrev));
3906                if (one->mode == two->mode)
3907                        strbuf_addf(msg, " %06o", one->mode);
3908                strbuf_addf(msg, "%s\n", reset);
3909        }
3910}
3911
3912static void run_diff_cmd(const char *pgm,
3913                         const char *name,
3914                         const char *other,
3915                         const char *attr_path,
3916                         struct diff_filespec *one,
3917                         struct diff_filespec *two,
3918                         struct strbuf *msg,
3919                         struct diff_options *o,
3920                         struct diff_filepair *p)
3921{
3922        const char *xfrm_msg = NULL;
3923        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
3924        int must_show_header = 0;
3925
3926
3927        if (o->flags.allow_external) {
3928                struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
3929                if (drv && drv->external)
3930                        pgm = drv->external;
3931        }
3932
3933        if (msg) {
3934                /*
3935                 * don't use colors when the header is intended for an
3936                 * external diff driver
3937                 */
3938                fill_metainfo(msg, name, other, one, two, o, p,
3939                              &must_show_header,
3940                              want_color(o->use_color) && !pgm);
3941                xfrm_msg = msg->len ? msg->buf : NULL;
3942        }
3943
3944        if (pgm) {
3945                run_external_diff(pgm, name, other, one, two, xfrm_msg,
3946                                  complete_rewrite, o);
3947                return;
3948        }
3949        if (one && two)
3950                builtin_diff(name, other ? other : name,
3951                             one, two, xfrm_msg, must_show_header,
3952                             o, complete_rewrite);
3953        else
3954                fprintf(o->file, "* Unmerged path %s\n", name);
3955}
3956
3957static void diff_fill_oid_info(struct diff_filespec *one)
3958{
3959        if (DIFF_FILE_VALID(one)) {
3960                if (!one->oid_valid) {
3961                        struct stat st;
3962                        if (one->is_stdin) {
3963                                oidclr(&one->oid);
3964                                return;
3965                        }
3966                        if (lstat(one->path, &st) < 0)
3967                                die_errno("stat '%s'", one->path);
3968                        if (index_path(&one->oid, one->path, &st, 0))
3969                                die("cannot hash %s", one->path);
3970                }
3971        }
3972        else
3973                oidclr(&one->oid);
3974}
3975
3976static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
3977{
3978        /* Strip the prefix but do not molest /dev/null and absolute paths */
3979        if (*namep && **namep != '/') {
3980                *namep += prefix_length;
3981                if (**namep == '/')
3982                        ++*namep;
3983        }
3984        if (*otherp && **otherp != '/') {
3985                *otherp += prefix_length;
3986                if (**otherp == '/')
3987                        ++*otherp;
3988        }
3989}
3990
3991static void run_diff(struct diff_filepair *p, struct diff_options *o)
3992{
3993        const char *pgm = external_diff();
3994        struct strbuf msg;
3995        struct diff_filespec *one = p->one;
3996        struct diff_filespec *two = p->two;
3997        const char *name;
3998        const char *other;
3999        const char *attr_path;
4000
4001        name  = one->path;
4002        other = (strcmp(name, two->path) ? two->path : NULL);
4003        attr_path = name;
4004        if (o->prefix_length)
4005                strip_prefix(o->prefix_length, &name, &other);
4006
4007        if (!o->flags.allow_external)
4008                pgm = NULL;
4009
4010        if (DIFF_PAIR_UNMERGED(p)) {
4011                run_diff_cmd(pgm, name, NULL, attr_path,
4012                             NULL, NULL, NULL, o, p);
4013                return;
4014        }
4015
4016        diff_fill_oid_info(one);
4017        diff_fill_oid_info(two);
4018
4019        if (!pgm &&
4020            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
4021            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
4022                /*
4023                 * a filepair that changes between file and symlink
4024                 * needs to be split into deletion and creation.
4025                 */
4026                struct diff_filespec *null = alloc_filespec(two->path);
4027                run_diff_cmd(NULL, name, other, attr_path,
4028                             one, null, &msg, o, p);
4029                free(null);
4030                strbuf_release(&msg);
4031
4032                null = alloc_filespec(one->path);
4033                run_diff_cmd(NULL, name, other, attr_path,
4034                             null, two, &msg, o, p);
4035                free(null);
4036        }
4037        else
4038                run_diff_cmd(pgm, name, other, attr_path,
4039                             one, two, &msg, o, p);
4040
4041        strbuf_release(&msg);
4042}
4043
4044static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
4045                         struct diffstat_t *diffstat)
4046{
4047        const char *name;
4048        const char *other;
4049
4050        if (DIFF_PAIR_UNMERGED(p)) {
4051                /* unmerged */
4052                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, p);
4053                return;
4054        }
4055
4056        name = p->one->path;
4057        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
4058
4059        if (o->prefix_length)
4060                strip_prefix(o->prefix_length, &name, &other);
4061
4062        diff_fill_oid_info(p->one);
4063        diff_fill_oid_info(p->two);
4064
4065        builtin_diffstat(name, other, p->one, p->two, diffstat, o, p);
4066}
4067
4068static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
4069{
4070        const char *name;
4071        const char *other;
4072        const char *attr_path;
4073
4074        if (DIFF_PAIR_UNMERGED(p)) {
4075                /* unmerged */
4076                return;
4077        }
4078
4079        name = p->one->path;
4080        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
4081        attr_path = other ? other : name;
4082
4083        if (o->prefix_length)
4084                strip_prefix(o->prefix_length, &name, &other);
4085
4086        diff_fill_oid_info(p->one);
4087        diff_fill_oid_info(p->two);
4088
4089        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
4090}
4091
4092void diff_setup(struct diff_options *options)
4093{
4094        memcpy(options, &default_diff_options, sizeof(*options));
4095
4096        options->file = stdout;
4097
4098        options->abbrev = DEFAULT_ABBREV;
4099        options->line_termination = '\n';
4100        options->break_opt = -1;
4101        options->rename_limit = -1;
4102        options->dirstat_permille = diff_dirstat_permille_default;
4103        options->context = diff_context_default;
4104        options->interhunkcontext = diff_interhunk_context_default;
4105        options->ws_error_highlight = ws_error_highlight_default;
4106        options->flags.rename_empty = 1;
4107        options->objfind = NULL;
4108
4109        /* pathchange left =NULL by default */
4110        options->change = diff_change;
4111        options->add_remove = diff_addremove;
4112        options->use_color = diff_use_color_default;
4113        options->detect_rename = diff_detect_rename_default;
4114        options->xdl_opts |= diff_algorithm;
4115        if (diff_indent_heuristic)
4116                DIFF_XDL_SET(options, INDENT_HEURISTIC);
4117
4118        options->orderfile = diff_order_file_cfg;
4119
4120        if (diff_no_prefix) {
4121                options->a_prefix = options->b_prefix = "";
4122        } else if (!diff_mnemonic_prefix) {
4123                options->a_prefix = "a/";
4124                options->b_prefix = "b/";
4125        }
4126
4127        options->color_moved = diff_color_moved_default;
4128}
4129
4130void diff_setup_done(struct diff_options *options)
4131{
4132        unsigned check_mask = DIFF_FORMAT_NAME |
4133                              DIFF_FORMAT_NAME_STATUS |
4134                              DIFF_FORMAT_CHECKDIFF |
4135                              DIFF_FORMAT_NO_OUTPUT;
4136        /*
4137         * This must be signed because we're comparing against a potentially
4138         * negative value.
4139         */
4140        const int hexsz = the_hash_algo->hexsz;
4141
4142        if (options->set_default)
4143                options->set_default(options);
4144
4145        if (HAS_MULTI_BITS(options->output_format & check_mask))
4146                die(_("--name-only, --name-status, --check and -s are mutually exclusive"));
4147
4148        if (HAS_MULTI_BITS(options->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK))
4149                die(_("-G, -S and --find-object are mutually exclusive"));
4150
4151        /*
4152         * Most of the time we can say "there are changes"
4153         * only by checking if there are changed paths, but
4154         * --ignore-whitespace* options force us to look
4155         * inside contents.
4156         */
4157
4158        if ((options->xdl_opts & XDF_WHITESPACE_FLAGS))
4159                options->flags.diff_from_contents = 1;
4160        else
4161                options->flags.diff_from_contents = 0;
4162
4163        if (options->flags.find_copies_harder)
4164                options->detect_rename = DIFF_DETECT_COPY;
4165
4166        if (!options->flags.relative_name)
4167                options->prefix = NULL;
4168        if (options->prefix)
4169                options->prefix_length = strlen(options->prefix);
4170        else
4171                options->prefix_length = 0;
4172
4173        if (options->output_format & (DIFF_FORMAT_NAME |
4174                                      DIFF_FORMAT_NAME_STATUS |
4175                                      DIFF_FORMAT_CHECKDIFF |
4176                                      DIFF_FORMAT_NO_OUTPUT))
4177                options->output_format &= ~(DIFF_FORMAT_RAW |
4178                                            DIFF_FORMAT_NUMSTAT |
4179                                            DIFF_FORMAT_DIFFSTAT |
4180                                            DIFF_FORMAT_SHORTSTAT |
4181                                            DIFF_FORMAT_DIRSTAT |
4182                                            DIFF_FORMAT_SUMMARY |
4183                                            DIFF_FORMAT_PATCH);
4184
4185        /*
4186         * These cases always need recursive; we do not drop caller-supplied
4187         * recursive bits for other formats here.
4188         */
4189        if (options->output_format & (DIFF_FORMAT_PATCH |
4190                                      DIFF_FORMAT_NUMSTAT |
4191                                      DIFF_FORMAT_DIFFSTAT |
4192                                      DIFF_FORMAT_SHORTSTAT |
4193                                      DIFF_FORMAT_DIRSTAT |
4194                                      DIFF_FORMAT_SUMMARY |
4195                                      DIFF_FORMAT_CHECKDIFF))
4196                options->flags.recursive = 1;
4197        /*
4198         * Also pickaxe would not work very well if you do not say recursive
4199         */
4200        if (options->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK)
4201                options->flags.recursive = 1;
4202        /*
4203         * When patches are generated, submodules diffed against the work tree
4204         * must be checked for dirtiness too so it can be shown in the output
4205         */
4206        if (options->output_format & DIFF_FORMAT_PATCH)
4207                options->flags.dirty_submodules = 1;
4208
4209        if (options->detect_rename && options->rename_limit < 0)
4210                options->rename_limit = diff_rename_limit_default;
4211        if (options->setup & DIFF_SETUP_USE_CACHE) {
4212                if (!active_cache)
4213                        /* read-cache does not die even when it fails
4214                         * so it is safe for us to do this here.  Also
4215                         * it does not smudge active_cache or active_nr
4216                         * when it fails, so we do not have to worry about
4217                         * cleaning it up ourselves either.
4218                         */
4219                        read_cache();
4220        }
4221        if (hexsz < options->abbrev)
4222                options->abbrev = hexsz; /* full */
4223
4224        /*
4225         * It does not make sense to show the first hit we happened
4226         * to have found.  It does not make sense not to return with
4227         * exit code in such a case either.
4228         */
4229        if (options->flags.quick) {
4230                options->output_format = DIFF_FORMAT_NO_OUTPUT;
4231                options->flags.exit_with_status = 1;
4232        }
4233
4234        options->diff_path_counter = 0;
4235
4236        if (options->flags.follow_renames && options->pathspec.nr != 1)
4237                die(_("--follow requires exactly one pathspec"));
4238
4239        if (!options->use_color || external_diff())
4240                options->color_moved = 0;
4241}
4242
4243static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
4244{
4245        char c, *eq;
4246        int len;
4247
4248        if (*arg != '-')
4249                return 0;
4250        c = *++arg;
4251        if (!c)
4252                return 0;
4253        if (c == arg_short) {
4254                c = *++arg;
4255                if (!c)
4256                        return 1;
4257                if (val && isdigit(c)) {
4258                        char *end;
4259                        int n = strtoul(arg, &end, 10);
4260                        if (*end)
4261                                return 0;
4262                        *val = n;
4263                        return 1;
4264                }
4265                return 0;
4266        }
4267        if (c != '-')
4268                return 0;
4269        arg++;
4270        eq = strchrnul(arg, '=');
4271        len = eq - arg;
4272        if (!len || strncmp(arg, arg_long, len))
4273                return 0;
4274        if (*eq) {
4275                int n;
4276                char *end;
4277                if (!isdigit(*++eq))
4278                        return 0;
4279                n = strtoul(eq, &end, 10);
4280                if (*end)
4281                        return 0;
4282                *val = n;
4283        }
4284        return 1;
4285}
4286
4287static int diff_scoreopt_parse(const char *opt);
4288
4289static inline int short_opt(char opt, const char **argv,
4290                            const char **optarg)
4291{
4292        const char *arg = argv[0];
4293        if (arg[0] != '-' || arg[1] != opt)
4294                return 0;
4295        if (arg[2] != '\0') {
4296                *optarg = arg + 2;
4297                return 1;
4298        }
4299        if (!argv[1])
4300                die("Option '%c' requires a value", opt);
4301        *optarg = argv[1];
4302        return 2;
4303}
4304
4305int parse_long_opt(const char *opt, const char **argv,
4306                   const char **optarg)
4307{
4308        const char *arg = argv[0];
4309        if (!skip_prefix(arg, "--", &arg))
4310                return 0;
4311        if (!skip_prefix(arg, opt, &arg))
4312                return 0;
4313        if (*arg == '=') { /* stuck form: --option=value */
4314                *optarg = arg + 1;
4315                return 1;
4316        }
4317        if (*arg != '\0')
4318                return 0;
4319        /* separate form: --option value */
4320        if (!argv[1])
4321                die("Option '--%s' requires a value", opt);
4322        *optarg = argv[1];
4323        return 2;
4324}
4325
4326static int stat_opt(struct diff_options *options, const char **av)
4327{
4328        const char *arg = av[0];
4329        char *end;
4330        int width = options->stat_width;
4331        int name_width = options->stat_name_width;
4332        int graph_width = options->stat_graph_width;
4333        int count = options->stat_count;
4334        int argcount = 1;
4335
4336        if (!skip_prefix(arg, "--stat", &arg))
4337                BUG("stat option does not begin with --stat: %s", arg);
4338        end = (char *)arg;
4339
4340        switch (*arg) {
4341        case '-':
4342                if (skip_prefix(arg, "-width", &arg)) {
4343                        if (*arg == '=')
4344                                width = strtoul(arg + 1, &end, 10);
4345                        else if (!*arg && !av[1])
4346                                die_want_option("--stat-width");
4347                        else if (!*arg) {
4348                                width = strtoul(av[1], &end, 10);
4349                                argcount = 2;
4350                        }
4351                } else if (skip_prefix(arg, "-name-width", &arg)) {
4352                        if (*arg == '=')
4353                                name_width = strtoul(arg + 1, &end, 10);
4354                        else if (!*arg && !av[1])
4355                                die_want_option("--stat-name-width");
4356                        else if (!*arg) {
4357                                name_width = strtoul(av[1], &end, 10);
4358                                argcount = 2;
4359                        }
4360                } else if (skip_prefix(arg, "-graph-width", &arg)) {
4361                        if (*arg == '=')
4362                                graph_width = strtoul(arg + 1, &end, 10);
4363                        else if (!*arg && !av[1])
4364                                die_want_option("--stat-graph-width");
4365                        else if (!*arg) {
4366                                graph_width = strtoul(av[1], &end, 10);
4367                                argcount = 2;
4368                        }
4369                } else if (skip_prefix(arg, "-count", &arg)) {
4370                        if (*arg == '=')
4371                                count = strtoul(arg + 1, &end, 10);
4372                        else if (!*arg && !av[1])
4373                                die_want_option("--stat-count");
4374                        else if (!*arg) {
4375                                count = strtoul(av[1], &end, 10);
4376                                argcount = 2;
4377                        }
4378                }
4379                break;
4380        case '=':
4381                width = strtoul(arg+1, &end, 10);
4382                if (*end == ',')
4383                        name_width = strtoul(end+1, &end, 10);
4384                if (*end == ',')
4385                        count = strtoul(end+1, &end, 10);
4386        }
4387
4388        /* Important! This checks all the error cases! */
4389        if (*end)
4390                return 0;
4391        options->output_format |= DIFF_FORMAT_DIFFSTAT;
4392        options->stat_name_width = name_width;
4393        options->stat_graph_width = graph_width;
4394        options->stat_width = width;
4395        options->stat_count = count;
4396        return argcount;
4397}
4398
4399static int parse_dirstat_opt(struct diff_options *options, const char *params)
4400{
4401        struct strbuf errmsg = STRBUF_INIT;
4402        if (parse_dirstat_params(options, params, &errmsg))
4403                die(_("Failed to parse --dirstat/-X option parameter:\n%s"),
4404                    errmsg.buf);
4405        strbuf_release(&errmsg);
4406        /*
4407         * The caller knows a dirstat-related option is given from the command
4408         * line; allow it to say "return this_function();"
4409         */
4410        options->output_format |= DIFF_FORMAT_DIRSTAT;
4411        return 1;
4412}
4413
4414static int parse_submodule_opt(struct diff_options *options, const char *value)
4415{
4416        if (parse_submodule_params(options, value))
4417                die(_("Failed to parse --submodule option parameter: '%s'"),
4418                        value);
4419        return 1;
4420}
4421
4422static const char diff_status_letters[] = {
4423        DIFF_STATUS_ADDED,
4424        DIFF_STATUS_COPIED,
4425        DIFF_STATUS_DELETED,
4426        DIFF_STATUS_MODIFIED,
4427        DIFF_STATUS_RENAMED,
4428        DIFF_STATUS_TYPE_CHANGED,
4429        DIFF_STATUS_UNKNOWN,
4430        DIFF_STATUS_UNMERGED,
4431        DIFF_STATUS_FILTER_AON,
4432        DIFF_STATUS_FILTER_BROKEN,
4433        '\0',
4434};
4435
4436static unsigned int filter_bit['Z' + 1];
4437
4438static void prepare_filter_bits(void)
4439{
4440        int i;
4441
4442        if (!filter_bit[DIFF_STATUS_ADDED]) {
4443                for (i = 0; diff_status_letters[i]; i++)
4444                        filter_bit[(int) diff_status_letters[i]] = (1 << i);
4445        }
4446}
4447
4448static unsigned filter_bit_tst(char status, const struct diff_options *opt)
4449{
4450        return opt->filter & filter_bit[(int) status];
4451}
4452
4453static int parse_diff_filter_opt(const char *optarg, struct diff_options *opt)
4454{
4455        int i, optch;
4456
4457        prepare_filter_bits();
4458
4459        /*
4460         * If there is a negation e.g. 'd' in the input, and we haven't
4461         * initialized the filter field with another --diff-filter, start
4462         * from full set of bits, except for AON.
4463         */
4464        if (!opt->filter) {
4465                for (i = 0; (optch = optarg[i]) != '\0'; i++) {
4466                        if (optch < 'a' || 'z' < optch)
4467                                continue;
4468                        opt->filter = (1 << (ARRAY_SIZE(diff_status_letters) - 1)) - 1;
4469                        opt->filter &= ~filter_bit[DIFF_STATUS_FILTER_AON];
4470                        break;
4471                }
4472        }
4473
4474        for (i = 0; (optch = optarg[i]) != '\0'; i++) {
4475                unsigned int bit;
4476                int negate;
4477
4478                if ('a' <= optch && optch <= 'z') {
4479                        negate = 1;
4480                        optch = toupper(optch);
4481                } else {
4482                        negate = 0;
4483                }
4484
4485                bit = (0 <= optch && optch <= 'Z') ? filter_bit[optch] : 0;
4486                if (!bit)
4487                        return optarg[i];
4488                if (negate)
4489                        opt->filter &= ~bit;
4490                else
4491                        opt->filter |= bit;
4492        }
4493        return 0;
4494}
4495
4496static void enable_patch_output(int *fmt) {
4497        *fmt &= ~DIFF_FORMAT_NO_OUTPUT;
4498        *fmt |= DIFF_FORMAT_PATCH;
4499}
4500
4501static int parse_ws_error_highlight_opt(struct diff_options *opt, const char *arg)
4502{
4503        int val = parse_ws_error_highlight(arg);
4504
4505        if (val < 0) {
4506                error("unknown value after ws-error-highlight=%.*s",
4507                      -1 - val, arg);
4508                return 0;
4509        }
4510        opt->ws_error_highlight = val;
4511        return 1;
4512}
4513
4514static int parse_objfind_opt(struct diff_options *opt, const char *arg)
4515{
4516        struct object_id oid;
4517
4518        if (get_oid(arg, &oid))
4519                return error("unable to resolve '%s'", arg);
4520
4521        if (!opt->objfind)
4522                opt->objfind = xcalloc(1, sizeof(*opt->objfind));
4523
4524        opt->pickaxe_opts |= DIFF_PICKAXE_KIND_OBJFIND;
4525        opt->flags.recursive = 1;
4526        opt->flags.tree_in_recursive = 1;
4527        oidset_insert(opt->objfind, &oid);
4528        return 1;
4529}
4530
4531int diff_opt_parse(struct diff_options *options,
4532                   const char **av, int ac, const char *prefix)
4533{
4534        const char *arg = av[0];
4535        const char *optarg;
4536        int argcount;
4537
4538        if (!prefix)
4539                prefix = "";
4540
4541        /* Output format options */
4542        if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch")
4543            || opt_arg(arg, 'U', "unified", &options->context))
4544                enable_patch_output(&options->output_format);
4545        else if (!strcmp(arg, "--raw"))
4546                options->output_format |= DIFF_FORMAT_RAW;
4547        else if (!strcmp(arg, "--patch-with-raw")) {
4548                enable_patch_output(&options->output_format);
4549                options->output_format |= DIFF_FORMAT_RAW;
4550        } else if (!strcmp(arg, "--numstat"))
4551                options->output_format |= DIFF_FORMAT_NUMSTAT;
4552        else if (!strcmp(arg, "--shortstat"))
4553                options->output_format |= DIFF_FORMAT_SHORTSTAT;
4554        else if (skip_prefix(arg, "-X", &arg) ||
4555                 skip_to_optional_arg(arg, "--dirstat", &arg))
4556                return parse_dirstat_opt(options, arg);
4557        else if (!strcmp(arg, "--cumulative"))
4558                return parse_dirstat_opt(options, "cumulative");
4559        else if (skip_to_optional_arg(arg, "--dirstat-by-file", &arg)) {
4560                parse_dirstat_opt(options, "files");
4561                return parse_dirstat_opt(options, arg);
4562        }
4563        else if (!strcmp(arg, "--check"))
4564                options->output_format |= DIFF_FORMAT_CHECKDIFF;
4565        else if (!strcmp(arg, "--summary"))
4566                options->output_format |= DIFF_FORMAT_SUMMARY;
4567        else if (!strcmp(arg, "--patch-with-stat")) {
4568                enable_patch_output(&options->output_format);
4569                options->output_format |= DIFF_FORMAT_DIFFSTAT;
4570        } else if (!strcmp(arg, "--name-only"))
4571                options->output_format |= DIFF_FORMAT_NAME;
4572        else if (!strcmp(arg, "--name-status"))
4573                options->output_format |= DIFF_FORMAT_NAME_STATUS;
4574        else if (!strcmp(arg, "-s") || !strcmp(arg, "--no-patch"))
4575                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
4576        else if (starts_with(arg, "--stat"))
4577                /* --stat, --stat-width, --stat-name-width, or --stat-count */
4578                return stat_opt(options, av);
4579        else if (!strcmp(arg, "--compact-summary")) {
4580                 options->flags.stat_with_summary = 1;
4581                 options->output_format |= DIFF_FORMAT_DIFFSTAT;
4582        } else if (!strcmp(arg, "--no-compact-summary"))
4583                 options->flags.stat_with_summary = 0;
4584
4585        /* renames options */
4586        else if (starts_with(arg, "-B") ||
4587                 skip_to_optional_arg(arg, "--break-rewrites", NULL)) {
4588                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
4589                        return error("invalid argument to -B: %s", arg+2);
4590        }
4591        else if (starts_with(arg, "-M") ||
4592                 skip_to_optional_arg(arg, "--find-renames", NULL)) {
4593                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
4594                        return error("invalid argument to -M: %s", arg+2);
4595                options->detect_rename = DIFF_DETECT_RENAME;
4596        }
4597        else if (!strcmp(arg, "-D") || !strcmp(arg, "--irreversible-delete")) {
4598                options->irreversible_delete = 1;
4599        }
4600        else if (starts_with(arg, "-C") ||
4601                 skip_to_optional_arg(arg, "--find-copies", NULL)) {
4602                if (options->detect_rename == DIFF_DETECT_COPY)
4603                        options->flags.find_copies_harder = 1;
4604                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
4605                        return error("invalid argument to -C: %s", arg+2);
4606                options->detect_rename = DIFF_DETECT_COPY;
4607        }
4608        else if (!strcmp(arg, "--no-renames"))
4609                options->detect_rename = 0;
4610        else if (!strcmp(arg, "--rename-empty"))
4611                options->flags.rename_empty = 1;
4612        else if (!strcmp(arg, "--no-rename-empty"))
4613                options->flags.rename_empty = 0;
4614        else if (skip_to_optional_arg_default(arg, "--relative", &arg, NULL)) {
4615                options->flags.relative_name = 1;
4616                if (arg)
4617                        options->prefix = arg;
4618        }
4619
4620        /* xdiff options */
4621        else if (!strcmp(arg, "--minimal"))
4622                DIFF_XDL_SET(options, NEED_MINIMAL);
4623        else if (!strcmp(arg, "--no-minimal"))
4624                DIFF_XDL_CLR(options, NEED_MINIMAL);
4625        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
4626                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
4627        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
4628                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
4629        else if (!strcmp(arg, "--ignore-space-at-eol"))
4630                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
4631        else if (!strcmp(arg, "--ignore-cr-at-eol"))
4632                DIFF_XDL_SET(options, IGNORE_CR_AT_EOL);
4633        else if (!strcmp(arg, "--ignore-blank-lines"))
4634                DIFF_XDL_SET(options, IGNORE_BLANK_LINES);
4635        else if (!strcmp(arg, "--indent-heuristic"))
4636                DIFF_XDL_SET(options, INDENT_HEURISTIC);
4637        else if (!strcmp(arg, "--no-indent-heuristic"))
4638                DIFF_XDL_CLR(options, INDENT_HEURISTIC);
4639        else if (!strcmp(arg, "--patience")) {
4640                int i;
4641                options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
4642                /*
4643                 * Both --patience and --anchored use PATIENCE_DIFF
4644                 * internally, so remove any anchors previously
4645                 * specified.
4646                 */
4647                for (i = 0; i < options->anchors_nr; i++)
4648                        free(options->anchors[i]);
4649                options->anchors_nr = 0;
4650        } else if (!strcmp(arg, "--histogram"))
4651                options->xdl_opts = DIFF_WITH_ALG(options, HISTOGRAM_DIFF);
4652        else if ((argcount = parse_long_opt("diff-algorithm", av, &optarg))) {
4653                long value = parse_algorithm_value(optarg);
4654                if (value < 0)
4655                        return error("option diff-algorithm accepts \"myers\", "
4656                                     "\"minimal\", \"patience\" and \"histogram\"");
4657                /* clear out previous settings */
4658                DIFF_XDL_CLR(options, NEED_MINIMAL);
4659                options->xdl_opts &= ~XDF_DIFF_ALGORITHM_MASK;
4660                options->xdl_opts |= value;
4661                return argcount;
4662        } else if (skip_prefix(arg, "--anchored=", &arg)) {
4663                options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
4664                ALLOC_GROW(options->anchors, options->anchors_nr + 1,
4665                           options->anchors_alloc);
4666                options->anchors[options->anchors_nr++] = xstrdup(arg);
4667        }
4668
4669        /* flags options */
4670        else if (!strcmp(arg, "--binary")) {
4671                enable_patch_output(&options->output_format);
4672                options->flags.binary = 1;
4673        }
4674        else if (!strcmp(arg, "--full-index"))
4675                options->flags.full_index = 1;
4676        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
4677                options->flags.text = 1;
4678        else if (!strcmp(arg, "-R"))
4679                options->flags.reverse_diff = 1;
4680        else if (!strcmp(arg, "--find-copies-harder"))
4681                options->flags.find_copies_harder = 1;
4682        else if (!strcmp(arg, "--follow"))
4683                options->flags.follow_renames = 1;
4684        else if (!strcmp(arg, "--no-follow")) {
4685                options->flags.follow_renames = 0;
4686                options->flags.default_follow_renames = 0;
4687        } else if (skip_to_optional_arg_default(arg, "--color", &arg, "always")) {
4688                int value = git_config_colorbool(NULL, arg);
4689                if (value < 0)
4690                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
4691                options->use_color = value;
4692        }
4693        else if (!strcmp(arg, "--no-color"))
4694                options->use_color = 0;
4695        else if (!strcmp(arg, "--color-moved")) {
4696                if (diff_color_moved_default)
4697                        options->color_moved = diff_color_moved_default;
4698                if (options->color_moved == COLOR_MOVED_NO)
4699                        options->color_moved = COLOR_MOVED_DEFAULT;
4700        } else if (!strcmp(arg, "--no-color-moved"))
4701                options->color_moved = COLOR_MOVED_NO;
4702        else if (skip_prefix(arg, "--color-moved=", &arg)) {
4703                int cm = parse_color_moved(arg);
4704                if (cm < 0)
4705                        die("bad --color-moved argument: %s", arg);
4706                options->color_moved = cm;
4707        } else if (skip_to_optional_arg_default(arg, "--color-words", &options->word_regex, NULL)) {
4708                options->use_color = 1;
4709                options->word_diff = DIFF_WORDS_COLOR;
4710        }
4711        else if (!strcmp(arg, "--word-diff")) {
4712                if (options->word_diff == DIFF_WORDS_NONE)
4713                        options->word_diff = DIFF_WORDS_PLAIN;
4714        }
4715        else if (skip_prefix(arg, "--word-diff=", &arg)) {
4716                if (!strcmp(arg, "plain"))
4717                        options->word_diff = DIFF_WORDS_PLAIN;
4718                else if (!strcmp(arg, "color")) {
4719                        options->use_color = 1;
4720                        options->word_diff = DIFF_WORDS_COLOR;
4721                }
4722                else if (!strcmp(arg, "porcelain"))
4723                        options->word_diff = DIFF_WORDS_PORCELAIN;
4724                else if (!strcmp(arg, "none"))
4725                        options->word_diff = DIFF_WORDS_NONE;
4726                else
4727                        die("bad --word-diff argument: %s", arg);
4728        }
4729        else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
4730                if (options->word_diff == DIFF_WORDS_NONE)
4731                        options->word_diff = DIFF_WORDS_PLAIN;
4732                options->word_regex = optarg;
4733                return argcount;
4734        }
4735        else if (!strcmp(arg, "--exit-code"))
4736                options->flags.exit_with_status = 1;
4737        else if (!strcmp(arg, "--quiet"))
4738                options->flags.quick = 1;
4739        else if (!strcmp(arg, "--ext-diff"))
4740                options->flags.allow_external = 1;
4741        else if (!strcmp(arg, "--no-ext-diff"))
4742                options->flags.allow_external = 0;
4743        else if (!strcmp(arg, "--textconv")) {
4744                options->flags.allow_textconv = 1;
4745                options->flags.textconv_set_via_cmdline = 1;
4746        } else if (!strcmp(arg, "--no-textconv"))
4747                options->flags.allow_textconv = 0;
4748        else if (skip_to_optional_arg_default(arg, "--ignore-submodules", &arg, "all")) {
4749                options->flags.override_submodule_config = 1;
4750                handle_ignore_submodules_arg(options, arg);
4751        } else if (skip_to_optional_arg_default(arg, "--submodule", &arg, "log"))
4752                return parse_submodule_opt(options, arg);
4753        else if (skip_prefix(arg, "--ws-error-highlight=", &arg))
4754                return parse_ws_error_highlight_opt(options, arg);
4755        else if (!strcmp(arg, "--ita-invisible-in-index"))
4756                options->ita_invisible_in_index = 1;
4757        else if (!strcmp(arg, "--ita-visible-in-index"))
4758                options->ita_invisible_in_index = 0;
4759
4760        /* misc options */
4761        else if (!strcmp(arg, "-z"))
4762                options->line_termination = 0;
4763        else if ((argcount = short_opt('l', av, &optarg))) {
4764                options->rename_limit = strtoul(optarg, NULL, 10);
4765                return argcount;
4766        }
4767        else if ((argcount = short_opt('S', av, &optarg))) {
4768                options->pickaxe = optarg;
4769                options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
4770                return argcount;
4771        } else if ((argcount = short_opt('G', av, &optarg))) {
4772                options->pickaxe = optarg;
4773                options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
4774                return argcount;
4775        }
4776        else if (!strcmp(arg, "--pickaxe-all"))
4777                options->pickaxe_opts |= DIFF_PICKAXE_ALL;
4778        else if (!strcmp(arg, "--pickaxe-regex"))
4779                options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
4780        else if ((argcount = short_opt('O', av, &optarg))) {
4781                options->orderfile = prefix_filename(prefix, optarg);
4782                return argcount;
4783        } else if (skip_prefix(arg, "--find-object=", &arg))
4784                return parse_objfind_opt(options, arg);
4785        else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
4786                int offending = parse_diff_filter_opt(optarg, options);
4787                if (offending)
4788                        die("unknown change class '%c' in --diff-filter=%s",
4789                            offending, optarg);
4790                return argcount;
4791        }
4792        else if (!strcmp(arg, "--no-abbrev"))
4793                options->abbrev = 0;
4794        else if (!strcmp(arg, "--abbrev"))
4795                options->abbrev = DEFAULT_ABBREV;
4796        else if (skip_prefix(arg, "--abbrev=", &arg)) {
4797                options->abbrev = strtoul(arg, NULL, 10);
4798                if (options->abbrev < MINIMUM_ABBREV)
4799                        options->abbrev = MINIMUM_ABBREV;
4800                else if (the_hash_algo->hexsz < options->abbrev)
4801                        options->abbrev = the_hash_algo->hexsz;
4802        }
4803        else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
4804                options->a_prefix = optarg;
4805                return argcount;
4806        }
4807        else if ((argcount = parse_long_opt("line-prefix", av, &optarg))) {
4808                options->line_prefix = optarg;
4809                options->line_prefix_length = strlen(options->line_prefix);
4810                graph_setup_line_prefix(options);
4811                return argcount;
4812        }
4813        else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
4814                options->b_prefix = optarg;
4815                return argcount;
4816        }
4817        else if (!strcmp(arg, "--no-prefix"))
4818                options->a_prefix = options->b_prefix = "";
4819        else if (opt_arg(arg, '\0', "inter-hunk-context",
4820                         &options->interhunkcontext))
4821                ;
4822        else if (!strcmp(arg, "-W"))
4823                options->flags.funccontext = 1;
4824        else if (!strcmp(arg, "--function-context"))
4825                options->flags.funccontext = 1;
4826        else if (!strcmp(arg, "--no-function-context"))
4827                options->flags.funccontext = 0;
4828        else if ((argcount = parse_long_opt("output", av, &optarg))) {
4829                char *path = prefix_filename(prefix, optarg);
4830                options->file = xfopen(path, "w");
4831                options->close_file = 1;
4832                if (options->use_color != GIT_COLOR_ALWAYS)
4833                        options->use_color = GIT_COLOR_NEVER;
4834                free(path);
4835                return argcount;
4836        } else
4837                return 0;
4838        return 1;
4839}
4840
4841int parse_rename_score(const char **cp_p)
4842{
4843        unsigned long num, scale;
4844        int ch, dot;
4845        const char *cp = *cp_p;
4846
4847        num = 0;
4848        scale = 1;
4849        dot = 0;
4850        for (;;) {
4851                ch = *cp;
4852                if ( !dot && ch == '.' ) {
4853                        scale = 1;
4854                        dot = 1;
4855                } else if ( ch == '%' ) {
4856                        scale = dot ? scale*100 : 100;
4857                        cp++;   /* % is always at the end */
4858                        break;
4859                } else if ( ch >= '0' && ch <= '9' ) {
4860                        if ( scale < 100000 ) {
4861                                scale *= 10;
4862                                num = (num*10) + (ch-'0');
4863                        }
4864                } else {
4865                        break;
4866                }
4867                cp++;
4868        }
4869        *cp_p = cp;
4870
4871        /* user says num divided by scale and we say internally that
4872         * is MAX_SCORE * num / scale.
4873         */
4874        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
4875}
4876
4877static int diff_scoreopt_parse(const char *opt)
4878{
4879        int opt1, opt2, cmd;
4880
4881        if (*opt++ != '-')
4882                return -1;
4883        cmd = *opt++;
4884        if (cmd == '-') {
4885                /* convert the long-form arguments into short-form versions */
4886                if (skip_prefix(opt, "break-rewrites", &opt)) {
4887                        if (*opt == 0 || *opt++ == '=')
4888                                cmd = 'B';
4889                } else if (skip_prefix(opt, "find-copies", &opt)) {
4890                        if (*opt == 0 || *opt++ == '=')
4891                                cmd = 'C';
4892                } else if (skip_prefix(opt, "find-renames", &opt)) {
4893                        if (*opt == 0 || *opt++ == '=')
4894                                cmd = 'M';
4895                }
4896        }
4897        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
4898                return -1; /* that is not a -M, -C, or -B option */
4899
4900        opt1 = parse_rename_score(&opt);
4901        if (cmd != 'B')
4902                opt2 = 0;
4903        else {
4904                if (*opt == 0)
4905                        opt2 = 0;
4906                else if (*opt != '/')
4907                        return -1; /* we expect -B80/99 or -B80 */
4908                else {
4909                        opt++;
4910                        opt2 = parse_rename_score(&opt);
4911                }
4912        }
4913        if (*opt != 0)
4914                return -1;
4915        return opt1 | (opt2 << 16);
4916}
4917
4918struct diff_queue_struct diff_queued_diff;
4919
4920void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
4921{
4922        ALLOC_GROW(queue->queue, queue->nr + 1, queue->alloc);
4923        queue->queue[queue->nr++] = dp;
4924}
4925
4926struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
4927                                 struct diff_filespec *one,
4928                                 struct diff_filespec *two)
4929{
4930        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
4931        dp->one = one;
4932        dp->two = two;
4933        if (queue)
4934                diff_q(queue, dp);
4935        return dp;
4936}
4937
4938void diff_free_filepair(struct diff_filepair *p)
4939{
4940        free_filespec(p->one);
4941        free_filespec(p->two);
4942        free(p);
4943}
4944
4945const char *diff_aligned_abbrev(const struct object_id *oid, int len)
4946{
4947        int abblen;
4948        const char *abbrev;
4949
4950        /* Do we want all 40 hex characters? */
4951        if (len == the_hash_algo->hexsz)
4952                return oid_to_hex(oid);
4953
4954        /* An abbreviated value is fine, possibly followed by an ellipsis. */
4955        abbrev = diff_abbrev_oid(oid, len);
4956
4957        if (!print_sha1_ellipsis())
4958                return abbrev;
4959
4960        abblen = strlen(abbrev);
4961
4962        /*
4963         * In well-behaved cases, where the abbreviated result is the
4964         * same as the requested length, append three dots after the
4965         * abbreviation (hence the whole logic is limited to the case
4966         * where abblen < 37); when the actual abbreviated result is a
4967         * bit longer than the requested length, we reduce the number
4968         * of dots so that they match the well-behaved ones.  However,
4969         * if the actual abbreviation is longer than the requested
4970         * length by more than three, we give up on aligning, and add
4971         * three dots anyway, to indicate that the output is not the
4972         * full object name.  Yes, this may be suboptimal, but this
4973         * appears only in "diff --raw --abbrev" output and it is not
4974         * worth the effort to change it now.  Note that this would
4975         * likely to work fine when the automatic sizing of default
4976         * abbreviation length is used--we would be fed -1 in "len" in
4977         * that case, and will end up always appending three-dots, but
4978         * the automatic sizing is supposed to give abblen that ensures
4979         * uniqueness across all objects (statistically speaking).
4980         */
4981        if (abblen < the_hash_algo->hexsz - 3) {
4982                static char hex[GIT_MAX_HEXSZ + 1];
4983                if (len < abblen && abblen <= len + 2)
4984                        xsnprintf(hex, sizeof(hex), "%s%.*s", abbrev, len+3-abblen, "..");
4985                else
4986                        xsnprintf(hex, sizeof(hex), "%s...", abbrev);
4987                return hex;
4988        }
4989
4990        return oid_to_hex(oid);
4991}
4992
4993static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
4994{
4995        int line_termination = opt->line_termination;
4996        int inter_name_termination = line_termination ? '\t' : '\0';
4997
4998        fprintf(opt->file, "%s", diff_line_prefix(opt));
4999        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
5000                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
5001                        diff_aligned_abbrev(&p->one->oid, opt->abbrev));
5002                fprintf(opt->file, "%s ",
5003                        diff_aligned_abbrev(&p->two->oid, opt->abbrev));
5004        }
5005        if (p->score) {
5006                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
5007                        inter_name_termination);
5008        } else {
5009                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
5010        }
5011
5012        if (p->status == DIFF_STATUS_COPIED ||
5013            p->status == DIFF_STATUS_RENAMED) {
5014                const char *name_a, *name_b;
5015                name_a = p->one->path;
5016                name_b = p->two->path;
5017                strip_prefix(opt->prefix_length, &name_a, &name_b);
5018                write_name_quoted(name_a, opt->file, inter_name_termination);
5019                write_name_quoted(name_b, opt->file, line_termination);
5020        } else {
5021                const char *name_a, *name_b;
5022                name_a = p->one->mode ? p->one->path : p->two->path;
5023                name_b = NULL;
5024                strip_prefix(opt->prefix_length, &name_a, &name_b);
5025                write_name_quoted(name_a, opt->file, line_termination);
5026        }
5027}
5028
5029int diff_unmodified_pair(struct diff_filepair *p)
5030{
5031        /* This function is written stricter than necessary to support
5032         * the currently implemented transformers, but the idea is to
5033         * let transformers to produce diff_filepairs any way they want,
5034         * and filter and clean them up here before producing the output.
5035         */
5036        struct diff_filespec *one = p->one, *two = p->two;
5037
5038        if (DIFF_PAIR_UNMERGED(p))
5039                return 0; /* unmerged is interesting */
5040
5041        /* deletion, addition, mode or type change
5042         * and rename are all interesting.
5043         */
5044        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
5045            DIFF_PAIR_MODE_CHANGED(p) ||
5046            strcmp(one->path, two->path))
5047                return 0;
5048
5049        /* both are valid and point at the same path.  that is, we are
5050         * dealing with a change.
5051         */
5052        if (one->oid_valid && two->oid_valid &&
5053            !oidcmp(&one->oid, &two->oid) &&
5054            !one->dirty_submodule && !two->dirty_submodule)
5055                return 1; /* no change */
5056        if (!one->oid_valid && !two->oid_valid)
5057                return 1; /* both look at the same file on the filesystem. */
5058        return 0;
5059}
5060
5061static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
5062{
5063        if (diff_unmodified_pair(p))
5064                return;
5065
5066        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5067            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5068                return; /* no tree diffs in patch format */
5069
5070        run_diff(p, o);
5071}
5072
5073static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
5074                            struct diffstat_t *diffstat)
5075{
5076        if (diff_unmodified_pair(p))
5077                return;
5078
5079        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5080            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5081                return; /* no useful stat for tree diffs */
5082
5083        run_diffstat(p, o, diffstat);
5084}
5085
5086static void diff_flush_checkdiff(struct diff_filepair *p,
5087                struct diff_options *o)
5088{
5089        if (diff_unmodified_pair(p))
5090                return;
5091
5092        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5093            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5094                return; /* nothing to check in tree diffs */
5095
5096        run_checkdiff(p, o);
5097}
5098
5099int diff_queue_is_empty(void)
5100{
5101        struct diff_queue_struct *q = &diff_queued_diff;
5102        int i;
5103        for (i = 0; i < q->nr; i++)
5104                if (!diff_unmodified_pair(q->queue[i]))
5105                        return 0;
5106        return 1;
5107}
5108
5109#if DIFF_DEBUG
5110void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
5111{
5112        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
5113                x, one ? one : "",
5114                s->path,
5115                DIFF_FILE_VALID(s) ? "valid" : "invalid",
5116                s->mode,
5117                s->oid_valid ? oid_to_hex(&s->oid) : "");
5118        fprintf(stderr, "queue[%d] %s size %lu\n",
5119                x, one ? one : "",
5120                s->size);
5121}
5122
5123void diff_debug_filepair(const struct diff_filepair *p, int i)
5124{
5125        diff_debug_filespec(p->one, i, "one");
5126        diff_debug_filespec(p->two, i, "two");
5127        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
5128                p->score, p->status ? p->status : '?',
5129                p->one->rename_used, p->broken_pair);
5130}
5131
5132void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
5133{
5134        int i;
5135        if (msg)
5136                fprintf(stderr, "%s\n", msg);
5137        fprintf(stderr, "q->nr = %d\n", q->nr);
5138        for (i = 0; i < q->nr; i++) {
5139                struct diff_filepair *p = q->queue[i];
5140                diff_debug_filepair(p, i);
5141        }
5142}
5143#endif
5144
5145static void diff_resolve_rename_copy(void)
5146{
5147        int i;
5148        struct diff_filepair *p;
5149        struct diff_queue_struct *q = &diff_queued_diff;
5150
5151        diff_debug_queue("resolve-rename-copy", q);
5152
5153        for (i = 0; i < q->nr; i++) {
5154                p = q->queue[i];
5155                p->status = 0; /* undecided */
5156                if (DIFF_PAIR_UNMERGED(p))
5157                        p->status = DIFF_STATUS_UNMERGED;
5158                else if (!DIFF_FILE_VALID(p->one))
5159                        p->status = DIFF_STATUS_ADDED;
5160                else if (!DIFF_FILE_VALID(p->two))
5161                        p->status = DIFF_STATUS_DELETED;
5162                else if (DIFF_PAIR_TYPE_CHANGED(p))
5163                        p->status = DIFF_STATUS_TYPE_CHANGED;
5164
5165                /* from this point on, we are dealing with a pair
5166                 * whose both sides are valid and of the same type, i.e.
5167                 * either in-place edit or rename/copy edit.
5168                 */
5169                else if (DIFF_PAIR_RENAME(p)) {
5170                        /*
5171                         * A rename might have re-connected a broken
5172                         * pair up, causing the pathnames to be the
5173                         * same again. If so, that's not a rename at
5174                         * all, just a modification..
5175                         *
5176                         * Otherwise, see if this source was used for
5177                         * multiple renames, in which case we decrement
5178                         * the count, and call it a copy.
5179                         */
5180                        if (!strcmp(p->one->path, p->two->path))
5181                                p->status = DIFF_STATUS_MODIFIED;
5182                        else if (--p->one->rename_used > 0)
5183                                p->status = DIFF_STATUS_COPIED;
5184                        else
5185                                p->status = DIFF_STATUS_RENAMED;
5186                }
5187                else if (oidcmp(&p->one->oid, &p->two->oid) ||
5188                         p->one->mode != p->two->mode ||
5189                         p->one->dirty_submodule ||
5190                         p->two->dirty_submodule ||
5191                         is_null_oid(&p->one->oid))
5192                        p->status = DIFF_STATUS_MODIFIED;
5193                else {
5194                        /* This is a "no-change" entry and should not
5195                         * happen anymore, but prepare for broken callers.
5196                         */
5197                        error("feeding unmodified %s to diffcore",
5198                              p->one->path);
5199                        p->status = DIFF_STATUS_UNKNOWN;
5200                }
5201        }
5202        diff_debug_queue("resolve-rename-copy done", q);
5203}
5204
5205static int check_pair_status(struct diff_filepair *p)
5206{
5207        switch (p->status) {
5208        case DIFF_STATUS_UNKNOWN:
5209                return 0;
5210        case 0:
5211                die("internal error in diff-resolve-rename-copy");
5212        default:
5213                return 1;
5214        }
5215}
5216
5217static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
5218{
5219        int fmt = opt->output_format;
5220
5221        if (fmt & DIFF_FORMAT_CHECKDIFF)
5222                diff_flush_checkdiff(p, opt);
5223        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
5224                diff_flush_raw(p, opt);
5225        else if (fmt & DIFF_FORMAT_NAME) {
5226                const char *name_a, *name_b;
5227                name_a = p->two->path;
5228                name_b = NULL;
5229                strip_prefix(opt->prefix_length, &name_a, &name_b);
5230                fprintf(opt->file, "%s", diff_line_prefix(opt));
5231                write_name_quoted(name_a, opt->file, opt->line_termination);
5232        }
5233}
5234
5235static void show_file_mode_name(struct diff_options *opt, const char *newdelete, struct diff_filespec *fs)
5236{
5237        struct strbuf sb = STRBUF_INIT;
5238        if (fs->mode)
5239                strbuf_addf(&sb, " %s mode %06o ", newdelete, fs->mode);
5240        else
5241                strbuf_addf(&sb, " %s ", newdelete);
5242
5243        quote_c_style(fs->path, &sb, NULL, 0);
5244        strbuf_addch(&sb, '\n');
5245        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5246                         sb.buf, sb.len, 0);
5247        strbuf_release(&sb);
5248}
5249
5250static void show_mode_change(struct diff_options *opt, struct diff_filepair *p,
5251                int show_name)
5252{
5253        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
5254                struct strbuf sb = STRBUF_INIT;
5255                strbuf_addf(&sb, " mode change %06o => %06o",
5256                            p->one->mode, p->two->mode);
5257                if (show_name) {
5258                        strbuf_addch(&sb, ' ');
5259                        quote_c_style(p->two->path, &sb, NULL, 0);
5260                }
5261                strbuf_addch(&sb, '\n');
5262                emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5263                                 sb.buf, sb.len, 0);
5264                strbuf_release(&sb);
5265        }
5266}
5267
5268static void show_rename_copy(struct diff_options *opt, const char *renamecopy,
5269                struct diff_filepair *p)
5270{
5271        struct strbuf sb = STRBUF_INIT;
5272        struct strbuf names = STRBUF_INIT;
5273
5274        pprint_rename(&names, p->one->path, p->two->path);
5275        strbuf_addf(&sb, " %s %s (%d%%)\n",
5276                    renamecopy, names.buf, similarity_index(p));
5277        strbuf_release(&names);
5278        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5279                                 sb.buf, sb.len, 0);
5280        show_mode_change(opt, p, 0);
5281        strbuf_release(&sb);
5282}
5283
5284static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
5285{
5286        switch(p->status) {
5287        case DIFF_STATUS_DELETED:
5288                show_file_mode_name(opt, "delete", p->one);
5289                break;
5290        case DIFF_STATUS_ADDED:
5291                show_file_mode_name(opt, "create", p->two);
5292                break;
5293        case DIFF_STATUS_COPIED:
5294                show_rename_copy(opt, "copy", p);
5295                break;
5296        case DIFF_STATUS_RENAMED:
5297                show_rename_copy(opt, "rename", p);
5298                break;
5299        default:
5300                if (p->score) {
5301                        struct strbuf sb = STRBUF_INIT;
5302                        strbuf_addstr(&sb, " rewrite ");
5303                        quote_c_style(p->two->path, &sb, NULL, 0);
5304                        strbuf_addf(&sb, " (%d%%)\n", similarity_index(p));
5305                        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5306                                         sb.buf, sb.len, 0);
5307                        strbuf_release(&sb);
5308                }
5309                show_mode_change(opt, p, !p->score);
5310                break;
5311        }
5312}
5313
5314struct patch_id_t {
5315        git_SHA_CTX *ctx;
5316        int patchlen;
5317};
5318
5319static int remove_space(char *line, int len)
5320{
5321        int i;
5322        char *dst = line;
5323        unsigned char c;
5324
5325        for (i = 0; i < len; i++)
5326                if (!isspace((c = line[i])))
5327                        *dst++ = c;
5328
5329        return dst - line;
5330}
5331
5332static void patch_id_consume(void *priv, char *line, unsigned long len)
5333{
5334        struct patch_id_t *data = priv;
5335        int new_len;
5336
5337        /* Ignore line numbers when computing the SHA1 of the patch */
5338        if (starts_with(line, "@@ -"))
5339                return;
5340
5341        new_len = remove_space(line, len);
5342
5343        git_SHA1_Update(data->ctx, line, new_len);
5344        data->patchlen += new_len;
5345}
5346
5347static void patch_id_add_string(git_SHA_CTX *ctx, const char *str)
5348{
5349        git_SHA1_Update(ctx, str, strlen(str));
5350}
5351
5352static void patch_id_add_mode(git_SHA_CTX *ctx, unsigned mode)
5353{
5354        /* large enough for 2^32 in octal */
5355        char buf[12];
5356        int len = xsnprintf(buf, sizeof(buf), "%06o", mode);
5357        git_SHA1_Update(ctx, buf, len);
5358}
5359
5360/* returns 0 upon success, and writes result into sha1 */
5361static int diff_get_patch_id(struct diff_options *options, struct object_id *oid, int diff_header_only)
5362{
5363        struct diff_queue_struct *q = &diff_queued_diff;
5364        int i;
5365        git_SHA_CTX ctx;
5366        struct patch_id_t data;
5367
5368        git_SHA1_Init(&ctx);
5369        memset(&data, 0, sizeof(struct patch_id_t));
5370        data.ctx = &ctx;
5371
5372        for (i = 0; i < q->nr; i++) {
5373                xpparam_t xpp;
5374                xdemitconf_t xecfg;
5375                mmfile_t mf1, mf2;
5376                struct diff_filepair *p = q->queue[i];
5377                int len1, len2;
5378
5379                memset(&xpp, 0, sizeof(xpp));
5380                memset(&xecfg, 0, sizeof(xecfg));
5381                if (p->status == 0)
5382                        return error("internal diff status error");
5383                if (p->status == DIFF_STATUS_UNKNOWN)
5384                        continue;
5385                if (diff_unmodified_pair(p))
5386                        continue;
5387                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5388                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5389                        continue;
5390                if (DIFF_PAIR_UNMERGED(p))
5391                        continue;
5392
5393                diff_fill_oid_info(p->one);
5394                diff_fill_oid_info(p->two);
5395
5396                len1 = remove_space(p->one->path, strlen(p->one->path));
5397                len2 = remove_space(p->two->path, strlen(p->two->path));
5398                patch_id_add_string(&ctx, "diff--git");
5399                patch_id_add_string(&ctx, "a/");
5400                git_SHA1_Update(&ctx, p->one->path, len1);
5401                patch_id_add_string(&ctx, "b/");
5402                git_SHA1_Update(&ctx, p->two->path, len2);
5403
5404                if (p->one->mode == 0) {
5405                        patch_id_add_string(&ctx, "newfilemode");
5406                        patch_id_add_mode(&ctx, p->two->mode);
5407                        patch_id_add_string(&ctx, "---/dev/null");
5408                        patch_id_add_string(&ctx, "+++b/");
5409                        git_SHA1_Update(&ctx, p->two->path, len2);
5410                } else if (p->two->mode == 0) {
5411                        patch_id_add_string(&ctx, "deletedfilemode");
5412                        patch_id_add_mode(&ctx, p->one->mode);
5413                        patch_id_add_string(&ctx, "---a/");
5414                        git_SHA1_Update(&ctx, p->one->path, len1);
5415                        patch_id_add_string(&ctx, "+++/dev/null");
5416                } else {
5417                        patch_id_add_string(&ctx, "---a/");
5418                        git_SHA1_Update(&ctx, p->one->path, len1);
5419                        patch_id_add_string(&ctx, "+++b/");
5420                        git_SHA1_Update(&ctx, p->two->path, len2);
5421                }
5422
5423                if (diff_header_only)
5424                        continue;
5425
5426                if (fill_mmfile(&mf1, p->one) < 0 ||
5427                    fill_mmfile(&mf2, p->two) < 0)
5428                        return error("unable to read files to diff");
5429
5430                if (diff_filespec_is_binary(p->one) ||
5431                    diff_filespec_is_binary(p->two)) {
5432                        git_SHA1_Update(&ctx, oid_to_hex(&p->one->oid),
5433                                        GIT_SHA1_HEXSZ);
5434                        git_SHA1_Update(&ctx, oid_to_hex(&p->two->oid),
5435                                        GIT_SHA1_HEXSZ);
5436                        continue;
5437                }
5438
5439                xpp.flags = 0;
5440                xecfg.ctxlen = 3;
5441                xecfg.flags = 0;
5442                if (xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
5443                                  &xpp, &xecfg))
5444                        return error("unable to generate patch-id diff for %s",
5445                                     p->one->path);
5446        }
5447
5448        git_SHA1_Final(oid->hash, &ctx);
5449        return 0;
5450}
5451
5452int diff_flush_patch_id(struct diff_options *options, struct object_id *oid, int diff_header_only)
5453{
5454        struct diff_queue_struct *q = &diff_queued_diff;
5455        int i;
5456        int result = diff_get_patch_id(options, oid, diff_header_only);
5457
5458        for (i = 0; i < q->nr; i++)
5459                diff_free_filepair(q->queue[i]);
5460
5461        free(q->queue);
5462        DIFF_QUEUE_CLEAR(q);
5463
5464        return result;
5465}
5466
5467static int is_summary_empty(const struct diff_queue_struct *q)
5468{
5469        int i;
5470
5471        for (i = 0; i < q->nr; i++) {
5472                const struct diff_filepair *p = q->queue[i];
5473
5474                switch (p->status) {
5475                case DIFF_STATUS_DELETED:
5476                case DIFF_STATUS_ADDED:
5477                case DIFF_STATUS_COPIED:
5478                case DIFF_STATUS_RENAMED:
5479                        return 0;
5480                default:
5481                        if (p->score)
5482                                return 0;
5483                        if (p->one->mode && p->two->mode &&
5484                            p->one->mode != p->two->mode)
5485                                return 0;
5486                        break;
5487                }
5488        }
5489        return 1;
5490}
5491
5492static const char rename_limit_warning[] =
5493N_("inexact rename detection was skipped due to too many files.");
5494
5495static const char degrade_cc_to_c_warning[] =
5496N_("only found copies from modified paths due to too many files.");
5497
5498static const char rename_limit_advice[] =
5499N_("you may want to set your %s variable to at least "
5500   "%d and retry the command.");
5501
5502void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc)
5503{
5504        fflush(stdout);
5505        if (degraded_cc)
5506                warning(_(degrade_cc_to_c_warning));
5507        else if (needed)
5508                warning(_(rename_limit_warning));
5509        else
5510                return;
5511        if (0 < needed)
5512                warning(_(rename_limit_advice), varname, needed);
5513}
5514
5515static void diff_flush_patch_all_file_pairs(struct diff_options *o)
5516{
5517        int i;
5518        static struct emitted_diff_symbols esm = EMITTED_DIFF_SYMBOLS_INIT;
5519        struct diff_queue_struct *q = &diff_queued_diff;
5520
5521        if (WSEH_NEW & WS_RULE_MASK)
5522                BUG("WS rules bit mask overlaps with diff symbol flags");
5523
5524        if (o->color_moved)
5525                o->emitted_symbols = &esm;
5526
5527        for (i = 0; i < q->nr; i++) {
5528                struct diff_filepair *p = q->queue[i];
5529                if (check_pair_status(p))
5530                        diff_flush_patch(p, o);
5531        }
5532
5533        if (o->emitted_symbols) {
5534                if (o->color_moved) {
5535                        struct hashmap add_lines, del_lines;
5536
5537                        hashmap_init(&del_lines,
5538                                     (hashmap_cmp_fn)moved_entry_cmp, o, 0);
5539                        hashmap_init(&add_lines,
5540                                     (hashmap_cmp_fn)moved_entry_cmp, o, 0);
5541
5542                        add_lines_to_move_detection(o, &add_lines, &del_lines);
5543                        mark_color_as_moved(o, &add_lines, &del_lines);
5544                        if (o->color_moved == COLOR_MOVED_ZEBRA_DIM)
5545                                dim_moved_lines(o);
5546
5547                        hashmap_free(&add_lines, 0);
5548                        hashmap_free(&del_lines, 0);
5549                }
5550
5551                for (i = 0; i < esm.nr; i++)
5552                        emit_diff_symbol_from_struct(o, &esm.buf[i]);
5553
5554                for (i = 0; i < esm.nr; i++)
5555                        free((void *)esm.buf[i].line);
5556        }
5557        esm.nr = 0;
5558}
5559
5560void diff_flush(struct diff_options *options)
5561{
5562        struct diff_queue_struct *q = &diff_queued_diff;
5563        int i, output_format = options->output_format;
5564        int separator = 0;
5565        int dirstat_by_line = 0;
5566
5567        /*
5568         * Order: raw, stat, summary, patch
5569         * or:    name/name-status/checkdiff (other bits clear)
5570         */
5571        if (!q->nr)
5572                goto free_queue;
5573
5574        if (output_format & (DIFF_FORMAT_RAW |
5575                             DIFF_FORMAT_NAME |
5576                             DIFF_FORMAT_NAME_STATUS |
5577                             DIFF_FORMAT_CHECKDIFF)) {
5578                for (i = 0; i < q->nr; i++) {
5579                        struct diff_filepair *p = q->queue[i];
5580                        if (check_pair_status(p))
5581                                flush_one_pair(p, options);
5582                }
5583                separator++;
5584        }
5585
5586        if (output_format & DIFF_FORMAT_DIRSTAT && options->flags.dirstat_by_line)
5587                dirstat_by_line = 1;
5588
5589        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT) ||
5590            dirstat_by_line) {
5591                struct diffstat_t diffstat;
5592
5593                memset(&diffstat, 0, sizeof(struct diffstat_t));
5594                for (i = 0; i < q->nr; i++) {
5595                        struct diff_filepair *p = q->queue[i];
5596                        if (check_pair_status(p))
5597                                diff_flush_stat(p, options, &diffstat);
5598                }
5599                if (output_format & DIFF_FORMAT_NUMSTAT)
5600                        show_numstat(&diffstat, options);
5601                if (output_format & DIFF_FORMAT_DIFFSTAT)
5602                        show_stats(&diffstat, options);
5603                if (output_format & DIFF_FORMAT_SHORTSTAT)
5604                        show_shortstats(&diffstat, options);
5605                if (output_format & DIFF_FORMAT_DIRSTAT && dirstat_by_line)
5606                        show_dirstat_by_line(&diffstat, options);
5607                free_diffstat_info(&diffstat);
5608                separator++;
5609        }
5610        if ((output_format & DIFF_FORMAT_DIRSTAT) && !dirstat_by_line)
5611                show_dirstat(options);
5612
5613        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
5614                for (i = 0; i < q->nr; i++) {
5615                        diff_summary(options, q->queue[i]);
5616                }
5617                separator++;
5618        }
5619
5620        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
5621            options->flags.exit_with_status &&
5622            options->flags.diff_from_contents) {
5623                /*
5624                 * run diff_flush_patch for the exit status. setting
5625                 * options->file to /dev/null should be safe, because we
5626                 * aren't supposed to produce any output anyway.
5627                 */
5628                if (options->close_file)
5629                        fclose(options->file);
5630                options->file = xfopen("/dev/null", "w");
5631                options->close_file = 1;
5632                options->color_moved = 0;
5633                for (i = 0; i < q->nr; i++) {
5634                        struct diff_filepair *p = q->queue[i];
5635                        if (check_pair_status(p))
5636                                diff_flush_patch(p, options);
5637                        if (options->found_changes)
5638                                break;
5639                }
5640        }
5641
5642        if (output_format & DIFF_FORMAT_PATCH) {
5643                if (separator) {
5644                        emit_diff_symbol(options, DIFF_SYMBOL_SEPARATOR, NULL, 0, 0);
5645                        if (options->stat_sep)
5646                                /* attach patch instead of inline */
5647                                emit_diff_symbol(options, DIFF_SYMBOL_STAT_SEP,
5648                                                 NULL, 0, 0);
5649                }
5650
5651                diff_flush_patch_all_file_pairs(options);
5652        }
5653
5654        if (output_format & DIFF_FORMAT_CALLBACK)
5655                options->format_callback(q, options, options->format_callback_data);
5656
5657        for (i = 0; i < q->nr; i++)
5658                diff_free_filepair(q->queue[i]);
5659free_queue:
5660        free(q->queue);
5661        DIFF_QUEUE_CLEAR(q);
5662        if (options->close_file)
5663                fclose(options->file);
5664
5665        /*
5666         * Report the content-level differences with HAS_CHANGES;
5667         * diff_addremove/diff_change does not set the bit when
5668         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
5669         */
5670        if (options->flags.diff_from_contents) {
5671                if (options->found_changes)
5672                        options->flags.has_changes = 1;
5673                else
5674                        options->flags.has_changes = 0;
5675        }
5676}
5677
5678static int match_filter(const struct diff_options *options, const struct diff_filepair *p)
5679{
5680        return (((p->status == DIFF_STATUS_MODIFIED) &&
5681                 ((p->score &&
5682                   filter_bit_tst(DIFF_STATUS_FILTER_BROKEN, options)) ||
5683                  (!p->score &&
5684                   filter_bit_tst(DIFF_STATUS_MODIFIED, options)))) ||
5685                ((p->status != DIFF_STATUS_MODIFIED) &&
5686                 filter_bit_tst(p->status, options)));
5687}
5688
5689static void diffcore_apply_filter(struct diff_options *options)
5690{
5691        int i;
5692        struct diff_queue_struct *q = &diff_queued_diff;
5693        struct diff_queue_struct outq;
5694
5695        DIFF_QUEUE_CLEAR(&outq);
5696
5697        if (!options->filter)
5698                return;
5699
5700        if (filter_bit_tst(DIFF_STATUS_FILTER_AON, options)) {
5701                int found;
5702                for (i = found = 0; !found && i < q->nr; i++) {
5703                        if (match_filter(options, q->queue[i]))
5704                                found++;
5705                }
5706                if (found)
5707                        return;
5708
5709                /* otherwise we will clear the whole queue
5710                 * by copying the empty outq at the end of this
5711                 * function, but first clear the current entries
5712                 * in the queue.
5713                 */
5714                for (i = 0; i < q->nr; i++)
5715                        diff_free_filepair(q->queue[i]);
5716        }
5717        else {
5718                /* Only the matching ones */
5719                for (i = 0; i < q->nr; i++) {
5720                        struct diff_filepair *p = q->queue[i];
5721                        if (match_filter(options, p))
5722                                diff_q(&outq, p);
5723                        else
5724                                diff_free_filepair(p);
5725                }
5726        }
5727        free(q->queue);
5728        *q = outq;
5729}
5730
5731/* Check whether two filespecs with the same mode and size are identical */
5732static int diff_filespec_is_identical(struct diff_filespec *one,
5733                                      struct diff_filespec *two)
5734{
5735        if (S_ISGITLINK(one->mode))
5736                return 0;
5737        if (diff_populate_filespec(one, 0))
5738                return 0;
5739        if (diff_populate_filespec(two, 0))
5740                return 0;
5741        return !memcmp(one->data, two->data, one->size);
5742}
5743
5744static int diff_filespec_check_stat_unmatch(struct diff_filepair *p)
5745{
5746        if (p->done_skip_stat_unmatch)
5747                return p->skip_stat_unmatch_result;
5748
5749        p->done_skip_stat_unmatch = 1;
5750        p->skip_stat_unmatch_result = 0;
5751        /*
5752         * 1. Entries that come from stat info dirtiness
5753         *    always have both sides (iow, not create/delete),
5754         *    one side of the object name is unknown, with
5755         *    the same mode and size.  Keep the ones that
5756         *    do not match these criteria.  They have real
5757         *    differences.
5758         *
5759         * 2. At this point, the file is known to be modified,
5760         *    with the same mode and size, and the object
5761         *    name of one side is unknown.  Need to inspect
5762         *    the identical contents.
5763         */
5764        if (!DIFF_FILE_VALID(p->one) || /* (1) */
5765            !DIFF_FILE_VALID(p->two) ||
5766            (p->one->oid_valid && p->two->oid_valid) ||
5767            (p->one->mode != p->two->mode) ||
5768            diff_populate_filespec(p->one, CHECK_SIZE_ONLY) ||
5769            diff_populate_filespec(p->two, CHECK_SIZE_ONLY) ||
5770            (p->one->size != p->two->size) ||
5771            !diff_filespec_is_identical(p->one, p->two)) /* (2) */
5772                p->skip_stat_unmatch_result = 1;
5773        return p->skip_stat_unmatch_result;
5774}
5775
5776static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
5777{
5778        int i;
5779        struct diff_queue_struct *q = &diff_queued_diff;
5780        struct diff_queue_struct outq;
5781        DIFF_QUEUE_CLEAR(&outq);
5782
5783        for (i = 0; i < q->nr; i++) {
5784                struct diff_filepair *p = q->queue[i];
5785
5786                if (diff_filespec_check_stat_unmatch(p))
5787                        diff_q(&outq, p);
5788                else {
5789                        /*
5790                         * The caller can subtract 1 from skip_stat_unmatch
5791                         * to determine how many paths were dirty only
5792                         * due to stat info mismatch.
5793                         */
5794                        if (!diffopt->flags.no_index)
5795                                diffopt->skip_stat_unmatch++;
5796                        diff_free_filepair(p);
5797                }
5798        }
5799        free(q->queue);
5800        *q = outq;
5801}
5802
5803static int diffnamecmp(const void *a_, const void *b_)
5804{
5805        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
5806        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
5807        const char *name_a, *name_b;
5808
5809        name_a = a->one ? a->one->path : a->two->path;
5810        name_b = b->one ? b->one->path : b->two->path;
5811        return strcmp(name_a, name_b);
5812}
5813
5814void diffcore_fix_diff_index(struct diff_options *options)
5815{
5816        struct diff_queue_struct *q = &diff_queued_diff;
5817        QSORT(q->queue, q->nr, diffnamecmp);
5818}
5819
5820void diffcore_std(struct diff_options *options)
5821{
5822        /* NOTE please keep the following in sync with diff_tree_combined() */
5823        if (options->skip_stat_unmatch)
5824                diffcore_skip_stat_unmatch(options);
5825        if (!options->found_follow) {
5826                /* See try_to_follow_renames() in tree-diff.c */
5827                if (options->break_opt != -1)
5828                        diffcore_break(options->break_opt);
5829                if (options->detect_rename)
5830                        diffcore_rename(options);
5831                if (options->break_opt != -1)
5832                        diffcore_merge_broken();
5833        }
5834        if (options->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK)
5835                diffcore_pickaxe(options);
5836        if (options->orderfile)
5837                diffcore_order(options->orderfile);
5838        if (!options->found_follow)
5839                /* See try_to_follow_renames() in tree-diff.c */
5840                diff_resolve_rename_copy();
5841        diffcore_apply_filter(options);
5842
5843        if (diff_queued_diff.nr && !options->flags.diff_from_contents)
5844                options->flags.has_changes = 1;
5845        else
5846                options->flags.has_changes = 0;
5847
5848        options->found_follow = 0;
5849}
5850
5851int diff_result_code(struct diff_options *opt, int status)
5852{
5853        int result = 0;
5854
5855        diff_warn_rename_limit("diff.renameLimit",
5856                               opt->needed_rename_limit,
5857                               opt->degraded_cc_to_c);
5858        if (!opt->flags.exit_with_status &&
5859            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
5860                return status;
5861        if (opt->flags.exit_with_status &&
5862            opt->flags.has_changes)
5863                result |= 01;
5864        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
5865            opt->flags.check_failed)
5866                result |= 02;
5867        return result;
5868}
5869
5870int diff_can_quit_early(struct diff_options *opt)
5871{
5872        return (opt->flags.quick &&
5873                !opt->filter &&
5874                opt->flags.has_changes);
5875}
5876
5877/*
5878 * Shall changes to this submodule be ignored?
5879 *
5880 * Submodule changes can be configured to be ignored separately for each path,
5881 * but that configuration can be overridden from the command line.
5882 */
5883static int is_submodule_ignored(const char *path, struct diff_options *options)
5884{
5885        int ignored = 0;
5886        struct diff_flags orig_flags = options->flags;
5887        if (!options->flags.override_submodule_config)
5888                set_diffopt_flags_from_submodule_config(options, path);
5889        if (options->flags.ignore_submodules)
5890                ignored = 1;
5891        options->flags = orig_flags;
5892        return ignored;
5893}
5894
5895void diff_addremove(struct diff_options *options,
5896                    int addremove, unsigned mode,
5897                    const struct object_id *oid,
5898                    int oid_valid,
5899                    const char *concatpath, unsigned dirty_submodule)
5900{
5901        struct diff_filespec *one, *two;
5902
5903        if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
5904                return;
5905
5906        /* This may look odd, but it is a preparation for
5907         * feeding "there are unchanged files which should
5908         * not produce diffs, but when you are doing copy
5909         * detection you would need them, so here they are"
5910         * entries to the diff-core.  They will be prefixed
5911         * with something like '=' or '*' (I haven't decided
5912         * which but should not make any difference).
5913         * Feeding the same new and old to diff_change()
5914         * also has the same effect.
5915         * Before the final output happens, they are pruned after
5916         * merged into rename/copy pairs as appropriate.
5917         */
5918        if (options->flags.reverse_diff)
5919                addremove = (addremove == '+' ? '-' :
5920                             addremove == '-' ? '+' : addremove);
5921
5922        if (options->prefix &&
5923            strncmp(concatpath, options->prefix, options->prefix_length))
5924                return;
5925
5926        one = alloc_filespec(concatpath);
5927        two = alloc_filespec(concatpath);
5928
5929        if (addremove != '+')
5930                fill_filespec(one, oid, oid_valid, mode);
5931        if (addremove != '-') {
5932                fill_filespec(two, oid, oid_valid, mode);
5933                two->dirty_submodule = dirty_submodule;
5934        }
5935
5936        diff_queue(&diff_queued_diff, one, two);
5937        if (!options->flags.diff_from_contents)
5938                options->flags.has_changes = 1;
5939}
5940
5941void diff_change(struct diff_options *options,
5942                 unsigned old_mode, unsigned new_mode,
5943                 const struct object_id *old_oid,
5944                 const struct object_id *new_oid,
5945                 int old_oid_valid, int new_oid_valid,
5946                 const char *concatpath,
5947                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
5948{
5949        struct diff_filespec *one, *two;
5950        struct diff_filepair *p;
5951
5952        if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
5953            is_submodule_ignored(concatpath, options))
5954                return;
5955
5956        if (options->flags.reverse_diff) {
5957                SWAP(old_mode, new_mode);
5958                SWAP(old_oid, new_oid);
5959                SWAP(old_oid_valid, new_oid_valid);
5960                SWAP(old_dirty_submodule, new_dirty_submodule);
5961        }
5962
5963        if (options->prefix &&
5964            strncmp(concatpath, options->prefix, options->prefix_length))
5965                return;
5966
5967        one = alloc_filespec(concatpath);
5968        two = alloc_filespec(concatpath);
5969        fill_filespec(one, old_oid, old_oid_valid, old_mode);
5970        fill_filespec(two, new_oid, new_oid_valid, new_mode);
5971        one->dirty_submodule = old_dirty_submodule;
5972        two->dirty_submodule = new_dirty_submodule;
5973        p = diff_queue(&diff_queued_diff, one, two);
5974
5975        if (options->flags.diff_from_contents)
5976                return;
5977
5978        if (options->flags.quick && options->skip_stat_unmatch &&
5979            !diff_filespec_check_stat_unmatch(p))
5980                return;
5981
5982        options->flags.has_changes = 1;
5983}
5984
5985struct diff_filepair *diff_unmerge(struct diff_options *options, const char *path)
5986{
5987        struct diff_filepair *pair;
5988        struct diff_filespec *one, *two;
5989
5990        if (options->prefix &&
5991            strncmp(path, options->prefix, options->prefix_length))
5992                return NULL;
5993
5994        one = alloc_filespec(path);
5995        two = alloc_filespec(path);
5996        pair = diff_queue(&diff_queued_diff, one, two);
5997        pair->is_unmerged = 1;
5998        return pair;
5999}
6000
6001static char *run_textconv(const char *pgm, struct diff_filespec *spec,
6002                size_t *outsize)
6003{
6004        struct diff_tempfile *temp;
6005        const char *argv[3];
6006        const char **arg = argv;
6007        struct child_process child = CHILD_PROCESS_INIT;
6008        struct strbuf buf = STRBUF_INIT;
6009        int err = 0;
6010
6011        temp = prepare_temp_file(spec->path, spec);
6012        *arg++ = pgm;
6013        *arg++ = temp->name;
6014        *arg = NULL;
6015
6016        child.use_shell = 1;
6017        child.argv = argv;
6018        child.out = -1;
6019        if (start_command(&child)) {
6020                remove_tempfile();
6021                return NULL;
6022        }
6023
6024        if (strbuf_read(&buf, child.out, 0) < 0)
6025                err = error("error reading from textconv command '%s'", pgm);
6026        close(child.out);
6027
6028        if (finish_command(&child) || err) {
6029                strbuf_release(&buf);
6030                remove_tempfile();
6031                return NULL;
6032        }
6033        remove_tempfile();
6034
6035        return strbuf_detach(&buf, outsize);
6036}
6037
6038size_t fill_textconv(struct userdiff_driver *driver,
6039                     struct diff_filespec *df,
6040                     char **outbuf)
6041{
6042        size_t size;
6043
6044        if (!driver) {
6045                if (!DIFF_FILE_VALID(df)) {
6046                        *outbuf = "";
6047                        return 0;
6048                }
6049                if (diff_populate_filespec(df, 0))
6050                        die("unable to read files to diff");
6051                *outbuf = df->data;
6052                return df->size;
6053        }
6054
6055        if (!driver->textconv)
6056                BUG("fill_textconv called with non-textconv driver");
6057
6058        if (driver->textconv_cache && df->oid_valid) {
6059                *outbuf = notes_cache_get(driver->textconv_cache,
6060                                          &df->oid,
6061                                          &size);
6062                if (*outbuf)
6063                        return size;
6064        }
6065
6066        *outbuf = run_textconv(driver->textconv, df, &size);
6067        if (!*outbuf)
6068                die("unable to read files to diff");
6069
6070        if (driver->textconv_cache && df->oid_valid) {
6071                /* ignore errors, as we might be in a readonly repository */
6072                notes_cache_put(driver->textconv_cache, &df->oid, *outbuf,
6073                                size);
6074                /*
6075                 * we could save up changes and flush them all at the end,
6076                 * but we would need an extra call after all diffing is done.
6077                 * Since generating a cache entry is the slow path anyway,
6078                 * this extra overhead probably isn't a big deal.
6079                 */
6080                notes_cache_write(driver->textconv_cache);
6081        }
6082
6083        return size;
6084}
6085
6086int textconv_object(const char *path,
6087                    unsigned mode,
6088                    const struct object_id *oid,
6089                    int oid_valid,
6090                    char **buf,
6091                    unsigned long *buf_size)
6092{
6093        struct diff_filespec *df;
6094        struct userdiff_driver *textconv;
6095
6096        df = alloc_filespec(path);
6097        fill_filespec(df, oid, oid_valid, mode);
6098        textconv = get_textconv(df);
6099        if (!textconv) {
6100                free_filespec(df);
6101                return 0;
6102        }
6103
6104        *buf_size = fill_textconv(textconv, df, buf);
6105        free_filespec(df);
6106        return 1;
6107}
6108
6109void setup_diff_pager(struct diff_options *opt)
6110{
6111        /*
6112         * If the user asked for our exit code, then either they want --quiet
6113         * or --exit-code. We should definitely not bother with a pager in the
6114         * former case, as we will generate no output. Since we still properly
6115         * report our exit code even when a pager is run, we _could_ run a
6116         * pager with --exit-code. But since we have not done so historically,
6117         * and because it is easy to find people oneline advising "git diff
6118         * --exit-code" in hooks and other scripts, we do not do so.
6119         */
6120        if (!opt->flags.exit_with_status &&
6121            check_pager_config("diff") != 0)
6122                setup_pager();
6123}