diff.con commit Merge branch 'sb/plug-misc-leaks' (02f27d0)
   1/*
   2 * Copyright (C) 2005 Junio C Hamano
   3 */
   4#include "cache.h"
   5#include "config.h"
   6#include "tempfile.h"
   7#include "quote.h"
   8#include "diff.h"
   9#include "diffcore.h"
  10#include "delta.h"
  11#include "xdiff-interface.h"
  12#include "color.h"
  13#include "attr.h"
  14#include "run-command.h"
  15#include "utf8.h"
  16#include "userdiff.h"
  17#include "submodule-config.h"
  18#include "submodule.h"
  19#include "hashmap.h"
  20#include "ll-merge.h"
  21#include "string-list.h"
  22#include "argv-array.h"
  23#include "graph.h"
  24#include "packfile.h"
  25#include "help.h"
  26
  27#ifdef NO_FAST_WORKING_DIRECTORY
  28#define FAST_WORKING_DIRECTORY 0
  29#else
  30#define FAST_WORKING_DIRECTORY 1
  31#endif
  32
  33static int diff_detect_rename_default;
  34static int diff_indent_heuristic = 1;
  35static int diff_rename_limit_default = 400;
  36static int diff_suppress_blank_empty;
  37static int diff_use_color_default = -1;
  38static int diff_color_moved_default;
  39static int diff_context_default = 3;
  40static int diff_interhunk_context_default;
  41static const char *diff_word_regex_cfg;
  42static const char *external_diff_cmd_cfg;
  43static const char *diff_order_file_cfg;
  44int diff_auto_refresh_index = 1;
  45static int diff_mnemonic_prefix;
  46static int diff_no_prefix;
  47static int diff_stat_graph_width;
  48static int diff_dirstat_permille_default = 30;
  49static struct diff_options default_diff_options;
  50static long diff_algorithm;
  51static unsigned ws_error_highlight_default = WSEH_NEW;
  52
  53static char diff_colors[][COLOR_MAXLEN] = {
  54        GIT_COLOR_RESET,
  55        GIT_COLOR_NORMAL,       /* CONTEXT */
  56        GIT_COLOR_BOLD,         /* METAINFO */
  57        GIT_COLOR_CYAN,         /* FRAGINFO */
  58        GIT_COLOR_RED,          /* OLD */
  59        GIT_COLOR_GREEN,        /* NEW */
  60        GIT_COLOR_YELLOW,       /* COMMIT */
  61        GIT_COLOR_BG_RED,       /* WHITESPACE */
  62        GIT_COLOR_NORMAL,       /* FUNCINFO */
  63        GIT_COLOR_BOLD_MAGENTA, /* OLD_MOVED */
  64        GIT_COLOR_BOLD_BLUE,    /* OLD_MOVED ALTERNATIVE */
  65        GIT_COLOR_FAINT,        /* OLD_MOVED_DIM */
  66        GIT_COLOR_FAINT_ITALIC, /* OLD_MOVED_ALTERNATIVE_DIM */
  67        GIT_COLOR_BOLD_CYAN,    /* NEW_MOVED */
  68        GIT_COLOR_BOLD_YELLOW,  /* NEW_MOVED ALTERNATIVE */
  69        GIT_COLOR_FAINT,        /* NEW_MOVED_DIM */
  70        GIT_COLOR_FAINT_ITALIC, /* NEW_MOVED_ALTERNATIVE_DIM */
  71};
  72
  73static const char *color_diff_slots[] = {
  74        [DIFF_CONTEXT]                = "context",
  75        [DIFF_METAINFO]               = "meta",
  76        [DIFF_FRAGINFO]               = "frag",
  77        [DIFF_FILE_OLD]               = "old",
  78        [DIFF_FILE_NEW]               = "new",
  79        [DIFF_COMMIT]                 = "commit",
  80        [DIFF_WHITESPACE]             = "whitespace",
  81        [DIFF_FUNCINFO]               = "func",
  82        [DIFF_FILE_OLD_MOVED]         = "oldMoved",
  83        [DIFF_FILE_OLD_MOVED_ALT]     = "oldMovedAlternative",
  84        [DIFF_FILE_OLD_MOVED_DIM]     = "oldMovedDimmed",
  85        [DIFF_FILE_OLD_MOVED_ALT_DIM] = "oldMovedAlternativeDimmed",
  86        [DIFF_FILE_NEW_MOVED]         = "newMoved",
  87        [DIFF_FILE_NEW_MOVED_ALT]     = "newMovedAlternative",
  88        [DIFF_FILE_NEW_MOVED_DIM]     = "newMovedDimmed",
  89        [DIFF_FILE_NEW_MOVED_ALT_DIM] = "newMovedAlternativeDimmed",
  90};
  91
  92static NORETURN void die_want_option(const char *option_name)
  93{
  94        die(_("option '%s' requires a value"), option_name);
  95}
  96
  97define_list_config_array_extra(color_diff_slots, {"plain"});
  98
  99static int parse_diff_color_slot(const char *var)
 100{
 101        if (!strcasecmp(var, "plain"))
 102                return DIFF_CONTEXT;
 103        return LOOKUP_CONFIG(color_diff_slots, var);
 104}
 105
 106static int parse_dirstat_params(struct diff_options *options, const char *params_string,
 107                                struct strbuf *errmsg)
 108{
 109        char *params_copy = xstrdup(params_string);
 110        struct string_list params = STRING_LIST_INIT_NODUP;
 111        int ret = 0;
 112        int i;
 113
 114        if (*params_copy)
 115                string_list_split_in_place(&params, params_copy, ',', -1);
 116        for (i = 0; i < params.nr; i++) {
 117                const char *p = params.items[i].string;
 118                if (!strcmp(p, "changes")) {
 119                        options->flags.dirstat_by_line = 0;
 120                        options->flags.dirstat_by_file = 0;
 121                } else if (!strcmp(p, "lines")) {
 122                        options->flags.dirstat_by_line = 1;
 123                        options->flags.dirstat_by_file = 0;
 124                } else if (!strcmp(p, "files")) {
 125                        options->flags.dirstat_by_line = 0;
 126                        options->flags.dirstat_by_file = 1;
 127                } else if (!strcmp(p, "noncumulative")) {
 128                        options->flags.dirstat_cumulative = 0;
 129                } else if (!strcmp(p, "cumulative")) {
 130                        options->flags.dirstat_cumulative = 1;
 131                } else if (isdigit(*p)) {
 132                        char *end;
 133                        int permille = strtoul(p, &end, 10) * 10;
 134                        if (*end == '.' && isdigit(*++end)) {
 135                                /* only use first digit */
 136                                permille += *end - '0';
 137                                /* .. and ignore any further digits */
 138                                while (isdigit(*++end))
 139                                        ; /* nothing */
 140                        }
 141                        if (!*end)
 142                                options->dirstat_permille = permille;
 143                        else {
 144                                strbuf_addf(errmsg, _("  Failed to parse dirstat cut-off percentage '%s'\n"),
 145                                            p);
 146                                ret++;
 147                        }
 148                } else {
 149                        strbuf_addf(errmsg, _("  Unknown dirstat parameter '%s'\n"), p);
 150                        ret++;
 151                }
 152
 153        }
 154        string_list_clear(&params, 0);
 155        free(params_copy);
 156        return ret;
 157}
 158
 159static int parse_submodule_params(struct diff_options *options, const char *value)
 160{
 161        if (!strcmp(value, "log"))
 162                options->submodule_format = DIFF_SUBMODULE_LOG;
 163        else if (!strcmp(value, "short"))
 164                options->submodule_format = DIFF_SUBMODULE_SHORT;
 165        else if (!strcmp(value, "diff"))
 166                options->submodule_format = DIFF_SUBMODULE_INLINE_DIFF;
 167        else
 168                return -1;
 169        return 0;
 170}
 171
 172int git_config_rename(const char *var, const char *value)
 173{
 174        if (!value)
 175                return DIFF_DETECT_RENAME;
 176        if (!strcasecmp(value, "copies") || !strcasecmp(value, "copy"))
 177                return  DIFF_DETECT_COPY;
 178        return git_config_bool(var,value) ? DIFF_DETECT_RENAME : 0;
 179}
 180
 181long parse_algorithm_value(const char *value)
 182{
 183        if (!value)
 184                return -1;
 185        else if (!strcasecmp(value, "myers") || !strcasecmp(value, "default"))
 186                return 0;
 187        else if (!strcasecmp(value, "minimal"))
 188                return XDF_NEED_MINIMAL;
 189        else if (!strcasecmp(value, "patience"))
 190                return XDF_PATIENCE_DIFF;
 191        else if (!strcasecmp(value, "histogram"))
 192                return XDF_HISTOGRAM_DIFF;
 193        return -1;
 194}
 195
 196static int parse_one_token(const char **arg, const char *token)
 197{
 198        const char *rest;
 199        if (skip_prefix(*arg, token, &rest) && (!*rest || *rest == ',')) {
 200                *arg = rest;
 201                return 1;
 202        }
 203        return 0;
 204}
 205
 206static int parse_ws_error_highlight(const char *arg)
 207{
 208        const char *orig_arg = arg;
 209        unsigned val = 0;
 210
 211        while (*arg) {
 212                if (parse_one_token(&arg, "none"))
 213                        val = 0;
 214                else if (parse_one_token(&arg, "default"))
 215                        val = WSEH_NEW;
 216                else if (parse_one_token(&arg, "all"))
 217                        val = WSEH_NEW | WSEH_OLD | WSEH_CONTEXT;
 218                else if (parse_one_token(&arg, "new"))
 219                        val |= WSEH_NEW;
 220                else if (parse_one_token(&arg, "old"))
 221                        val |= WSEH_OLD;
 222                else if (parse_one_token(&arg, "context"))
 223                        val |= WSEH_CONTEXT;
 224                else {
 225                        return -1 - (int)(arg - orig_arg);
 226                }
 227                if (*arg)
 228                        arg++;
 229        }
 230        return val;
 231}
 232
 233/*
 234 * These are to give UI layer defaults.
 235 * The core-level commands such as git-diff-files should
 236 * never be affected by the setting of diff.renames
 237 * the user happens to have in the configuration file.
 238 */
 239void init_diff_ui_defaults(void)
 240{
 241        diff_detect_rename_default = DIFF_DETECT_RENAME;
 242}
 243
 244int git_diff_heuristic_config(const char *var, const char *value, void *cb)
 245{
 246        if (!strcmp(var, "diff.indentheuristic"))
 247                diff_indent_heuristic = git_config_bool(var, value);
 248        return 0;
 249}
 250
 251static int parse_color_moved(const char *arg)
 252{
 253        switch (git_parse_maybe_bool(arg)) {
 254        case 0:
 255                return COLOR_MOVED_NO;
 256        case 1:
 257                return COLOR_MOVED_DEFAULT;
 258        default:
 259                break;
 260        }
 261
 262        if (!strcmp(arg, "no"))
 263                return COLOR_MOVED_NO;
 264        else if (!strcmp(arg, "plain"))
 265                return COLOR_MOVED_PLAIN;
 266        else if (!strcmp(arg, "zebra"))
 267                return COLOR_MOVED_ZEBRA;
 268        else if (!strcmp(arg, "default"))
 269                return COLOR_MOVED_DEFAULT;
 270        else if (!strcmp(arg, "dimmed_zebra"))
 271                return COLOR_MOVED_ZEBRA_DIM;
 272        else
 273                return error(_("color moved setting must be one of 'no', 'default', 'zebra', 'dimmed_zebra', 'plain'"));
 274}
 275
 276int git_diff_ui_config(const char *var, const char *value, void *cb)
 277{
 278        if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
 279                diff_use_color_default = git_config_colorbool(var, value);
 280                return 0;
 281        }
 282        if (!strcmp(var, "diff.colormoved")) {
 283                int cm = parse_color_moved(value);
 284                if (cm < 0)
 285                        return -1;
 286                diff_color_moved_default = cm;
 287                return 0;
 288        }
 289        if (!strcmp(var, "diff.context")) {
 290                diff_context_default = git_config_int(var, value);
 291                if (diff_context_default < 0)
 292                        return -1;
 293                return 0;
 294        }
 295        if (!strcmp(var, "diff.interhunkcontext")) {
 296                diff_interhunk_context_default = git_config_int(var, value);
 297                if (diff_interhunk_context_default < 0)
 298                        return -1;
 299                return 0;
 300        }
 301        if (!strcmp(var, "diff.renames")) {
 302                diff_detect_rename_default = git_config_rename(var, value);
 303                return 0;
 304        }
 305        if (!strcmp(var, "diff.autorefreshindex")) {
 306                diff_auto_refresh_index = git_config_bool(var, value);
 307                return 0;
 308        }
 309        if (!strcmp(var, "diff.mnemonicprefix")) {
 310                diff_mnemonic_prefix = git_config_bool(var, value);
 311                return 0;
 312        }
 313        if (!strcmp(var, "diff.noprefix")) {
 314                diff_no_prefix = git_config_bool(var, value);
 315                return 0;
 316        }
 317        if (!strcmp(var, "diff.statgraphwidth")) {
 318                diff_stat_graph_width = git_config_int(var, value);
 319                return 0;
 320        }
 321        if (!strcmp(var, "diff.external"))
 322                return git_config_string(&external_diff_cmd_cfg, var, value);
 323        if (!strcmp(var, "diff.wordregex"))
 324                return git_config_string(&diff_word_regex_cfg, var, value);
 325        if (!strcmp(var, "diff.orderfile"))
 326                return git_config_pathname(&diff_order_file_cfg, var, value);
 327
 328        if (!strcmp(var, "diff.ignoresubmodules"))
 329                handle_ignore_submodules_arg(&default_diff_options, value);
 330
 331        if (!strcmp(var, "diff.submodule")) {
 332                if (parse_submodule_params(&default_diff_options, value))
 333                        warning(_("Unknown value for 'diff.submodule' config variable: '%s'"),
 334                                value);
 335                return 0;
 336        }
 337
 338        if (!strcmp(var, "diff.algorithm")) {
 339                diff_algorithm = parse_algorithm_value(value);
 340                if (diff_algorithm < 0)
 341                        return -1;
 342                return 0;
 343        }
 344
 345        if (!strcmp(var, "diff.wserrorhighlight")) {
 346                int val = parse_ws_error_highlight(value);
 347                if (val < 0)
 348                        return -1;
 349                ws_error_highlight_default = val;
 350                return 0;
 351        }
 352
 353        if (git_color_config(var, value, cb) < 0)
 354                return -1;
 355
 356        return git_diff_basic_config(var, value, cb);
 357}
 358
 359int git_diff_basic_config(const char *var, const char *value, void *cb)
 360{
 361        const char *name;
 362
 363        if (!strcmp(var, "diff.renamelimit")) {
 364                diff_rename_limit_default = git_config_int(var, value);
 365                return 0;
 366        }
 367
 368        if (userdiff_config(var, value) < 0)
 369                return -1;
 370
 371        if (skip_prefix(var, "diff.color.", &name) ||
 372            skip_prefix(var, "color.diff.", &name)) {
 373                int slot = parse_diff_color_slot(name);
 374                if (slot < 0)
 375                        return 0;
 376                if (!value)
 377                        return config_error_nonbool(var);
 378                return color_parse(value, diff_colors[slot]);
 379        }
 380
 381        /* like GNU diff's --suppress-blank-empty option  */
 382        if (!strcmp(var, "diff.suppressblankempty") ||
 383                        /* for backwards compatibility */
 384                        !strcmp(var, "diff.suppress-blank-empty")) {
 385                diff_suppress_blank_empty = git_config_bool(var, value);
 386                return 0;
 387        }
 388
 389        if (!strcmp(var, "diff.dirstat")) {
 390                struct strbuf errmsg = STRBUF_INIT;
 391                default_diff_options.dirstat_permille = diff_dirstat_permille_default;
 392                if (parse_dirstat_params(&default_diff_options, value, &errmsg))
 393                        warning(_("Found errors in 'diff.dirstat' config variable:\n%s"),
 394                                errmsg.buf);
 395                strbuf_release(&errmsg);
 396                diff_dirstat_permille_default = default_diff_options.dirstat_permille;
 397                return 0;
 398        }
 399
 400        if (git_diff_heuristic_config(var, value, cb) < 0)
 401                return -1;
 402
 403        return git_default_config(var, value, cb);
 404}
 405
 406static char *quote_two(const char *one, const char *two)
 407{
 408        int need_one = quote_c_style(one, NULL, NULL, 1);
 409        int need_two = quote_c_style(two, NULL, NULL, 1);
 410        struct strbuf res = STRBUF_INIT;
 411
 412        if (need_one + need_two) {
 413                strbuf_addch(&res, '"');
 414                quote_c_style(one, &res, NULL, 1);
 415                quote_c_style(two, &res, NULL, 1);
 416                strbuf_addch(&res, '"');
 417        } else {
 418                strbuf_addstr(&res, one);
 419                strbuf_addstr(&res, two);
 420        }
 421        return strbuf_detach(&res, NULL);
 422}
 423
 424static const char *external_diff(void)
 425{
 426        static const char *external_diff_cmd = NULL;
 427        static int done_preparing = 0;
 428
 429        if (done_preparing)
 430                return external_diff_cmd;
 431        external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
 432        if (!external_diff_cmd)
 433                external_diff_cmd = external_diff_cmd_cfg;
 434        done_preparing = 1;
 435        return external_diff_cmd;
 436}
 437
 438/*
 439 * Keep track of files used for diffing. Sometimes such an entry
 440 * refers to a temporary file, sometimes to an existing file, and
 441 * sometimes to "/dev/null".
 442 */
 443static struct diff_tempfile {
 444        /*
 445         * filename external diff should read from, or NULL if this
 446         * entry is currently not in use:
 447         */
 448        const char *name;
 449
 450        char hex[GIT_MAX_HEXSZ + 1];
 451        char mode[10];
 452
 453        /*
 454         * If this diff_tempfile instance refers to a temporary file,
 455         * this tempfile object is used to manage its lifetime.
 456         */
 457        struct tempfile *tempfile;
 458} diff_temp[2];
 459
 460struct emit_callback {
 461        int color_diff;
 462        unsigned ws_rule;
 463        int blank_at_eof_in_preimage;
 464        int blank_at_eof_in_postimage;
 465        int lno_in_preimage;
 466        int lno_in_postimage;
 467        const char **label_path;
 468        struct diff_words_data *diff_words;
 469        struct diff_options *opt;
 470        struct strbuf *header;
 471};
 472
 473static int count_lines(const char *data, int size)
 474{
 475        int count, ch, completely_empty = 1, nl_just_seen = 0;
 476        count = 0;
 477        while (0 < size--) {
 478                ch = *data++;
 479                if (ch == '\n') {
 480                        count++;
 481                        nl_just_seen = 1;
 482                        completely_empty = 0;
 483                }
 484                else {
 485                        nl_just_seen = 0;
 486                        completely_empty = 0;
 487                }
 488        }
 489        if (completely_empty)
 490                return 0;
 491        if (!nl_just_seen)
 492                count++; /* no trailing newline */
 493        return count;
 494}
 495
 496static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
 497{
 498        if (!DIFF_FILE_VALID(one)) {
 499                mf->ptr = (char *)""; /* does not matter */
 500                mf->size = 0;
 501                return 0;
 502        }
 503        else if (diff_populate_filespec(one, 0))
 504                return -1;
 505
 506        mf->ptr = one->data;
 507        mf->size = one->size;
 508        return 0;
 509}
 510
 511/* like fill_mmfile, but only for size, so we can avoid retrieving blob */
 512static unsigned long diff_filespec_size(struct diff_filespec *one)
 513{
 514        if (!DIFF_FILE_VALID(one))
 515                return 0;
 516        diff_populate_filespec(one, CHECK_SIZE_ONLY);
 517        return one->size;
 518}
 519
 520static int count_trailing_blank(mmfile_t *mf, unsigned ws_rule)
 521{
 522        char *ptr = mf->ptr;
 523        long size = mf->size;
 524        int cnt = 0;
 525
 526        if (!size)
 527                return cnt;
 528        ptr += size - 1; /* pointing at the very end */
 529        if (*ptr != '\n')
 530                ; /* incomplete line */
 531        else
 532                ptr--; /* skip the last LF */
 533        while (mf->ptr < ptr) {
 534                char *prev_eol;
 535                for (prev_eol = ptr; mf->ptr <= prev_eol; prev_eol--)
 536                        if (*prev_eol == '\n')
 537                                break;
 538                if (!ws_blank_line(prev_eol + 1, ptr - prev_eol, ws_rule))
 539                        break;
 540                cnt++;
 541                ptr = prev_eol - 1;
 542        }
 543        return cnt;
 544}
 545
 546static void check_blank_at_eof(mmfile_t *mf1, mmfile_t *mf2,
 547                               struct emit_callback *ecbdata)
 548{
 549        int l1, l2, at;
 550        unsigned ws_rule = ecbdata->ws_rule;
 551        l1 = count_trailing_blank(mf1, ws_rule);
 552        l2 = count_trailing_blank(mf2, ws_rule);
 553        if (l2 <= l1) {
 554                ecbdata->blank_at_eof_in_preimage = 0;
 555                ecbdata->blank_at_eof_in_postimage = 0;
 556                return;
 557        }
 558        at = count_lines(mf1->ptr, mf1->size);
 559        ecbdata->blank_at_eof_in_preimage = (at - l1) + 1;
 560
 561        at = count_lines(mf2->ptr, mf2->size);
 562        ecbdata->blank_at_eof_in_postimage = (at - l2) + 1;
 563}
 564
 565static void emit_line_0(struct diff_options *o, const char *set, const char *reset,
 566                        int first, const char *line, int len)
 567{
 568        int has_trailing_newline, has_trailing_carriage_return;
 569        int nofirst;
 570        FILE *file = o->file;
 571
 572        fputs(diff_line_prefix(o), file);
 573
 574        if (len == 0) {
 575                has_trailing_newline = (first == '\n');
 576                has_trailing_carriage_return = (!has_trailing_newline &&
 577                                                (first == '\r'));
 578                nofirst = has_trailing_newline || has_trailing_carriage_return;
 579        } else {
 580                has_trailing_newline = (len > 0 && line[len-1] == '\n');
 581                if (has_trailing_newline)
 582                        len--;
 583                has_trailing_carriage_return = (len > 0 && line[len-1] == '\r');
 584                if (has_trailing_carriage_return)
 585                        len--;
 586                nofirst = 0;
 587        }
 588
 589        if (len || !nofirst) {
 590                fputs(set, file);
 591                if (!nofirst)
 592                        fputc(first, file);
 593                fwrite(line, len, 1, file);
 594                fputs(reset, file);
 595        }
 596        if (has_trailing_carriage_return)
 597                fputc('\r', file);
 598        if (has_trailing_newline)
 599                fputc('\n', file);
 600}
 601
 602static void emit_line(struct diff_options *o, const char *set, const char *reset,
 603                      const char *line, int len)
 604{
 605        emit_line_0(o, set, reset, line[0], line+1, len-1);
 606}
 607
 608enum diff_symbol {
 609        DIFF_SYMBOL_BINARY_DIFF_HEADER,
 610        DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA,
 611        DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL,
 612        DIFF_SYMBOL_BINARY_DIFF_BODY,
 613        DIFF_SYMBOL_BINARY_DIFF_FOOTER,
 614        DIFF_SYMBOL_STATS_SUMMARY_NO_FILES,
 615        DIFF_SYMBOL_STATS_SUMMARY_ABBREV,
 616        DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES,
 617        DIFF_SYMBOL_STATS_LINE,
 618        DIFF_SYMBOL_WORD_DIFF,
 619        DIFF_SYMBOL_STAT_SEP,
 620        DIFF_SYMBOL_SUMMARY,
 621        DIFF_SYMBOL_SUBMODULE_ADD,
 622        DIFF_SYMBOL_SUBMODULE_DEL,
 623        DIFF_SYMBOL_SUBMODULE_UNTRACKED,
 624        DIFF_SYMBOL_SUBMODULE_MODIFIED,
 625        DIFF_SYMBOL_SUBMODULE_HEADER,
 626        DIFF_SYMBOL_SUBMODULE_ERROR,
 627        DIFF_SYMBOL_SUBMODULE_PIPETHROUGH,
 628        DIFF_SYMBOL_REWRITE_DIFF,
 629        DIFF_SYMBOL_BINARY_FILES,
 630        DIFF_SYMBOL_HEADER,
 631        DIFF_SYMBOL_FILEPAIR_PLUS,
 632        DIFF_SYMBOL_FILEPAIR_MINUS,
 633        DIFF_SYMBOL_WORDS_PORCELAIN,
 634        DIFF_SYMBOL_WORDS,
 635        DIFF_SYMBOL_CONTEXT,
 636        DIFF_SYMBOL_CONTEXT_INCOMPLETE,
 637        DIFF_SYMBOL_PLUS,
 638        DIFF_SYMBOL_MINUS,
 639        DIFF_SYMBOL_NO_LF_EOF,
 640        DIFF_SYMBOL_CONTEXT_FRAGINFO,
 641        DIFF_SYMBOL_CONTEXT_MARKER,
 642        DIFF_SYMBOL_SEPARATOR
 643};
 644/*
 645 * Flags for content lines:
 646 * 0..12 are whitespace rules
 647 * 13-15 are WSEH_NEW | WSEH_OLD | WSEH_CONTEXT
 648 * 16 is marking if the line is blank at EOF
 649 */
 650#define DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF      (1<<16)
 651#define DIFF_SYMBOL_MOVED_LINE                  (1<<17)
 652#define DIFF_SYMBOL_MOVED_LINE_ALT              (1<<18)
 653#define DIFF_SYMBOL_MOVED_LINE_UNINTERESTING    (1<<19)
 654#define DIFF_SYMBOL_CONTENT_WS_MASK (WSEH_NEW | WSEH_OLD | WSEH_CONTEXT | WS_RULE_MASK)
 655
 656/*
 657 * This struct is used when we need to buffer the output of the diff output.
 658 *
 659 * NEEDSWORK: Instead of storing a copy of the line, add an offset pointer
 660 * into the pre/post image file. This pointer could be a union with the
 661 * line pointer. By storing an offset into the file instead of the literal line,
 662 * we can decrease the memory footprint for the buffered output. At first we
 663 * may want to only have indirection for the content lines, but we could also
 664 * enhance the state for emitting prefabricated lines, e.g. the similarity
 665 * score line or hunk/file headers would only need to store a number or path
 666 * and then the output can be constructed later on depending on state.
 667 */
 668struct emitted_diff_symbol {
 669        const char *line;
 670        int len;
 671        int flags;
 672        enum diff_symbol s;
 673};
 674#define EMITTED_DIFF_SYMBOL_INIT {NULL}
 675
 676struct emitted_diff_symbols {
 677        struct emitted_diff_symbol *buf;
 678        int nr, alloc;
 679};
 680#define EMITTED_DIFF_SYMBOLS_INIT {NULL, 0, 0}
 681
 682static void append_emitted_diff_symbol(struct diff_options *o,
 683                                       struct emitted_diff_symbol *e)
 684{
 685        struct emitted_diff_symbol *f;
 686
 687        ALLOC_GROW(o->emitted_symbols->buf,
 688                   o->emitted_symbols->nr + 1,
 689                   o->emitted_symbols->alloc);
 690        f = &o->emitted_symbols->buf[o->emitted_symbols->nr++];
 691
 692        memcpy(f, e, sizeof(struct emitted_diff_symbol));
 693        f->line = e->line ? xmemdupz(e->line, e->len) : NULL;
 694}
 695
 696struct moved_entry {
 697        struct hashmap_entry ent;
 698        const struct emitted_diff_symbol *es;
 699        struct moved_entry *next_line;
 700};
 701
 702static int moved_entry_cmp(const struct diff_options *diffopt,
 703                           const struct moved_entry *a,
 704                           const struct moved_entry *b,
 705                           const void *keydata)
 706{
 707        return !xdiff_compare_lines(a->es->line, a->es->len,
 708                                    b->es->line, b->es->len,
 709                                    diffopt->xdl_opts);
 710}
 711
 712static struct moved_entry *prepare_entry(struct diff_options *o,
 713                                         int line_no)
 714{
 715        struct moved_entry *ret = xmalloc(sizeof(*ret));
 716        struct emitted_diff_symbol *l = &o->emitted_symbols->buf[line_no];
 717
 718        ret->ent.hash = xdiff_hash_string(l->line, l->len, o->xdl_opts);
 719        ret->es = l;
 720        ret->next_line = NULL;
 721
 722        return ret;
 723}
 724
 725static void add_lines_to_move_detection(struct diff_options *o,
 726                                        struct hashmap *add_lines,
 727                                        struct hashmap *del_lines)
 728{
 729        struct moved_entry *prev_line = NULL;
 730
 731        int n;
 732        for (n = 0; n < o->emitted_symbols->nr; n++) {
 733                struct hashmap *hm;
 734                struct moved_entry *key;
 735
 736                switch (o->emitted_symbols->buf[n].s) {
 737                case DIFF_SYMBOL_PLUS:
 738                        hm = add_lines;
 739                        break;
 740                case DIFF_SYMBOL_MINUS:
 741                        hm = del_lines;
 742                        break;
 743                default:
 744                        prev_line = NULL;
 745                        continue;
 746                }
 747
 748                key = prepare_entry(o, n);
 749                if (prev_line && prev_line->es->s == o->emitted_symbols->buf[n].s)
 750                        prev_line->next_line = key;
 751
 752                hashmap_add(hm, key);
 753                prev_line = key;
 754        }
 755}
 756
 757static int shrink_potential_moved_blocks(struct moved_entry **pmb,
 758                                         int pmb_nr)
 759{
 760        int lp, rp;
 761
 762        /* Shrink the set of potential block to the remaining running */
 763        for (lp = 0, rp = pmb_nr - 1; lp <= rp;) {
 764                while (lp < pmb_nr && pmb[lp])
 765                        lp++;
 766                /* lp points at the first NULL now */
 767
 768                while (rp > -1 && !pmb[rp])
 769                        rp--;
 770                /* rp points at the last non-NULL */
 771
 772                if (lp < pmb_nr && rp > -1 && lp < rp) {
 773                        pmb[lp] = pmb[rp];
 774                        pmb[rp] = NULL;
 775                        rp--;
 776                        lp++;
 777                }
 778        }
 779
 780        /* Remember the number of running sets */
 781        return rp + 1;
 782}
 783
 784/*
 785 * If o->color_moved is COLOR_MOVED_PLAIN, this function does nothing.
 786 *
 787 * Otherwise, if the last block has fewer alphanumeric characters than
 788 * COLOR_MOVED_MIN_ALNUM_COUNT, unset DIFF_SYMBOL_MOVED_LINE on all lines in
 789 * that block.
 790 *
 791 * The last block consists of the (n - block_length)'th line up to but not
 792 * including the nth line.
 793 *
 794 * NEEDSWORK: This uses the same heuristic as blame_entry_score() in blame.c.
 795 * Think of a way to unify them.
 796 */
 797static void adjust_last_block(struct diff_options *o, int n, int block_length)
 798{
 799        int i, alnum_count = 0;
 800        if (o->color_moved == COLOR_MOVED_PLAIN)
 801                return;
 802        for (i = 1; i < block_length + 1; i++) {
 803                const char *c = o->emitted_symbols->buf[n - i].line;
 804                for (; *c; c++) {
 805                        if (!isalnum(*c))
 806                                continue;
 807                        alnum_count++;
 808                        if (alnum_count >= COLOR_MOVED_MIN_ALNUM_COUNT)
 809                                return;
 810                }
 811        }
 812        for (i = 1; i < block_length + 1; i++)
 813                o->emitted_symbols->buf[n - i].flags &= ~DIFF_SYMBOL_MOVED_LINE;
 814}
 815
 816/* Find blocks of moved code, delegate actual coloring decision to helper */
 817static void mark_color_as_moved(struct diff_options *o,
 818                                struct hashmap *add_lines,
 819                                struct hashmap *del_lines)
 820{
 821        struct moved_entry **pmb = NULL; /* potentially moved blocks */
 822        int pmb_nr = 0, pmb_alloc = 0;
 823        int n, flipped_block = 1, block_length = 0;
 824
 825
 826        for (n = 0; n < o->emitted_symbols->nr; n++) {
 827                struct hashmap *hm = NULL;
 828                struct moved_entry *key;
 829                struct moved_entry *match = NULL;
 830                struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
 831                int i;
 832
 833                switch (l->s) {
 834                case DIFF_SYMBOL_PLUS:
 835                        hm = del_lines;
 836                        key = prepare_entry(o, n);
 837                        match = hashmap_get(hm, key, o);
 838                        free(key);
 839                        break;
 840                case DIFF_SYMBOL_MINUS:
 841                        hm = add_lines;
 842                        key = prepare_entry(o, n);
 843                        match = hashmap_get(hm, key, o);
 844                        free(key);
 845                        break;
 846                default:
 847                        flipped_block = 1;
 848                }
 849
 850                if (!match) {
 851                        adjust_last_block(o, n, block_length);
 852                        pmb_nr = 0;
 853                        block_length = 0;
 854                        continue;
 855                }
 856
 857                l->flags |= DIFF_SYMBOL_MOVED_LINE;
 858
 859                if (o->color_moved == COLOR_MOVED_PLAIN)
 860                        continue;
 861
 862                /* Check any potential block runs, advance each or nullify */
 863                for (i = 0; i < pmb_nr; i++) {
 864                        struct moved_entry *p = pmb[i];
 865                        struct moved_entry *pnext = (p && p->next_line) ?
 866                                        p->next_line : NULL;
 867                        if (pnext && !hm->cmpfn(o, pnext, match, NULL)) {
 868                                pmb[i] = p->next_line;
 869                        } else {
 870                                pmb[i] = NULL;
 871                        }
 872                }
 873
 874                pmb_nr = shrink_potential_moved_blocks(pmb, pmb_nr);
 875
 876                if (pmb_nr == 0) {
 877                        /*
 878                         * The current line is the start of a new block.
 879                         * Setup the set of potential blocks.
 880                         */
 881                        for (; match; match = hashmap_get_next(hm, match)) {
 882                                ALLOC_GROW(pmb, pmb_nr + 1, pmb_alloc);
 883                                pmb[pmb_nr++] = match;
 884                        }
 885
 886                        flipped_block = (flipped_block + 1) % 2;
 887
 888                        adjust_last_block(o, n, block_length);
 889                        block_length = 0;
 890                }
 891
 892                block_length++;
 893
 894                if (flipped_block)
 895                        l->flags |= DIFF_SYMBOL_MOVED_LINE_ALT;
 896        }
 897        adjust_last_block(o, n, block_length);
 898
 899        free(pmb);
 900}
 901
 902#define DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK \
 903  (DIFF_SYMBOL_MOVED_LINE | DIFF_SYMBOL_MOVED_LINE_ALT)
 904static void dim_moved_lines(struct diff_options *o)
 905{
 906        int n;
 907        for (n = 0; n < o->emitted_symbols->nr; n++) {
 908                struct emitted_diff_symbol *prev = (n != 0) ?
 909                                &o->emitted_symbols->buf[n - 1] : NULL;
 910                struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
 911                struct emitted_diff_symbol *next =
 912                                (n < o->emitted_symbols->nr - 1) ?
 913                                &o->emitted_symbols->buf[n + 1] : NULL;
 914
 915                /* Not a plus or minus line? */
 916                if (l->s != DIFF_SYMBOL_PLUS && l->s != DIFF_SYMBOL_MINUS)
 917                        continue;
 918
 919                /* Not a moved line? */
 920                if (!(l->flags & DIFF_SYMBOL_MOVED_LINE))
 921                        continue;
 922
 923                /*
 924                 * If prev or next are not a plus or minus line,
 925                 * pretend they don't exist
 926                 */
 927                if (prev && prev->s != DIFF_SYMBOL_PLUS &&
 928                            prev->s != DIFF_SYMBOL_MINUS)
 929                        prev = NULL;
 930                if (next && next->s != DIFF_SYMBOL_PLUS &&
 931                            next->s != DIFF_SYMBOL_MINUS)
 932                        next = NULL;
 933
 934                /* Inside a block? */
 935                if ((prev &&
 936                    (prev->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK) ==
 937                    (l->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK)) &&
 938                    (next &&
 939                    (next->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK) ==
 940                    (l->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK))) {
 941                        l->flags |= DIFF_SYMBOL_MOVED_LINE_UNINTERESTING;
 942                        continue;
 943                }
 944
 945                /* Check if we are at an interesting bound: */
 946                if (prev && (prev->flags & DIFF_SYMBOL_MOVED_LINE) &&
 947                    (prev->flags & DIFF_SYMBOL_MOVED_LINE_ALT) !=
 948                       (l->flags & DIFF_SYMBOL_MOVED_LINE_ALT))
 949                        continue;
 950                if (next && (next->flags & DIFF_SYMBOL_MOVED_LINE) &&
 951                    (next->flags & DIFF_SYMBOL_MOVED_LINE_ALT) !=
 952                       (l->flags & DIFF_SYMBOL_MOVED_LINE_ALT))
 953                        continue;
 954
 955                /*
 956                 * The boundary to prev and next are not interesting,
 957                 * so this line is not interesting as a whole
 958                 */
 959                l->flags |= DIFF_SYMBOL_MOVED_LINE_UNINTERESTING;
 960        }
 961}
 962
 963static void emit_line_ws_markup(struct diff_options *o,
 964                                const char *set, const char *reset,
 965                                const char *line, int len, char sign,
 966                                unsigned ws_rule, int blank_at_eof)
 967{
 968        const char *ws = NULL;
 969
 970        if (o->ws_error_highlight & ws_rule) {
 971                ws = diff_get_color_opt(o, DIFF_WHITESPACE);
 972                if (!*ws)
 973                        ws = NULL;
 974        }
 975
 976        if (!ws)
 977                emit_line_0(o, set, reset, sign, line, len);
 978        else if (blank_at_eof)
 979                /* Blank line at EOF - paint '+' as well */
 980                emit_line_0(o, ws, reset, sign, line, len);
 981        else {
 982                /* Emit just the prefix, then the rest. */
 983                emit_line_0(o, set, reset, sign, "", 0);
 984                ws_check_emit(line, len, ws_rule,
 985                              o->file, set, reset, ws);
 986        }
 987}
 988
 989static void emit_diff_symbol_from_struct(struct diff_options *o,
 990                                         struct emitted_diff_symbol *eds)
 991{
 992        static const char *nneof = " No newline at end of file\n";
 993        const char *context, *reset, *set, *meta, *fraginfo;
 994        struct strbuf sb = STRBUF_INIT;
 995
 996        enum diff_symbol s = eds->s;
 997        const char *line = eds->line;
 998        int len = eds->len;
 999        unsigned flags = eds->flags;
1000
1001        switch (s) {
1002        case DIFF_SYMBOL_NO_LF_EOF:
1003                context = diff_get_color_opt(o, DIFF_CONTEXT);
1004                reset = diff_get_color_opt(o, DIFF_RESET);
1005                putc('\n', o->file);
1006                emit_line_0(o, context, reset, '\\',
1007                            nneof, strlen(nneof));
1008                break;
1009        case DIFF_SYMBOL_SUBMODULE_HEADER:
1010        case DIFF_SYMBOL_SUBMODULE_ERROR:
1011        case DIFF_SYMBOL_SUBMODULE_PIPETHROUGH:
1012        case DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES:
1013        case DIFF_SYMBOL_SUMMARY:
1014        case DIFF_SYMBOL_STATS_LINE:
1015        case DIFF_SYMBOL_BINARY_DIFF_BODY:
1016        case DIFF_SYMBOL_CONTEXT_FRAGINFO:
1017                emit_line(o, "", "", line, len);
1018                break;
1019        case DIFF_SYMBOL_CONTEXT_INCOMPLETE:
1020        case DIFF_SYMBOL_CONTEXT_MARKER:
1021                context = diff_get_color_opt(o, DIFF_CONTEXT);
1022                reset = diff_get_color_opt(o, DIFF_RESET);
1023                emit_line(o, context, reset, line, len);
1024                break;
1025        case DIFF_SYMBOL_SEPARATOR:
1026                fprintf(o->file, "%s%c",
1027                        diff_line_prefix(o),
1028                        o->line_termination);
1029                break;
1030        case DIFF_SYMBOL_CONTEXT:
1031                set = diff_get_color_opt(o, DIFF_CONTEXT);
1032                reset = diff_get_color_opt(o, DIFF_RESET);
1033                emit_line_ws_markup(o, set, reset, line, len, ' ',
1034                                    flags & (DIFF_SYMBOL_CONTENT_WS_MASK), 0);
1035                break;
1036        case DIFF_SYMBOL_PLUS:
1037                switch (flags & (DIFF_SYMBOL_MOVED_LINE |
1038                                 DIFF_SYMBOL_MOVED_LINE_ALT |
1039                                 DIFF_SYMBOL_MOVED_LINE_UNINTERESTING)) {
1040                case DIFF_SYMBOL_MOVED_LINE |
1041                     DIFF_SYMBOL_MOVED_LINE_ALT |
1042                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1043                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED_ALT_DIM);
1044                        break;
1045                case DIFF_SYMBOL_MOVED_LINE |
1046                     DIFF_SYMBOL_MOVED_LINE_ALT:
1047                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED_ALT);
1048                        break;
1049                case DIFF_SYMBOL_MOVED_LINE |
1050                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1051                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED_DIM);
1052                        break;
1053                case DIFF_SYMBOL_MOVED_LINE:
1054                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED);
1055                        break;
1056                default:
1057                        set = diff_get_color_opt(o, DIFF_FILE_NEW);
1058                }
1059                reset = diff_get_color_opt(o, DIFF_RESET);
1060                emit_line_ws_markup(o, set, reset, line, len, '+',
1061                                    flags & DIFF_SYMBOL_CONTENT_WS_MASK,
1062                                    flags & DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF);
1063                break;
1064        case DIFF_SYMBOL_MINUS:
1065                switch (flags & (DIFF_SYMBOL_MOVED_LINE |
1066                                 DIFF_SYMBOL_MOVED_LINE_ALT |
1067                                 DIFF_SYMBOL_MOVED_LINE_UNINTERESTING)) {
1068                case DIFF_SYMBOL_MOVED_LINE |
1069                     DIFF_SYMBOL_MOVED_LINE_ALT |
1070                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1071                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_ALT_DIM);
1072                        break;
1073                case DIFF_SYMBOL_MOVED_LINE |
1074                     DIFF_SYMBOL_MOVED_LINE_ALT:
1075                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_ALT);
1076                        break;
1077                case DIFF_SYMBOL_MOVED_LINE |
1078                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1079                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_DIM);
1080                        break;
1081                case DIFF_SYMBOL_MOVED_LINE:
1082                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED);
1083                        break;
1084                default:
1085                        set = diff_get_color_opt(o, DIFF_FILE_OLD);
1086                }
1087                reset = diff_get_color_opt(o, DIFF_RESET);
1088                emit_line_ws_markup(o, set, reset, line, len, '-',
1089                                    flags & DIFF_SYMBOL_CONTENT_WS_MASK, 0);
1090                break;
1091        case DIFF_SYMBOL_WORDS_PORCELAIN:
1092                context = diff_get_color_opt(o, DIFF_CONTEXT);
1093                reset = diff_get_color_opt(o, DIFF_RESET);
1094                emit_line(o, context, reset, line, len);
1095                fputs("~\n", o->file);
1096                break;
1097        case DIFF_SYMBOL_WORDS:
1098                context = diff_get_color_opt(o, DIFF_CONTEXT);
1099                reset = diff_get_color_opt(o, DIFF_RESET);
1100                /*
1101                 * Skip the prefix character, if any.  With
1102                 * diff_suppress_blank_empty, there may be
1103                 * none.
1104                 */
1105                if (line[0] != '\n') {
1106                        line++;
1107                        len--;
1108                }
1109                emit_line(o, context, reset, line, len);
1110                break;
1111        case DIFF_SYMBOL_FILEPAIR_PLUS:
1112                meta = diff_get_color_opt(o, DIFF_METAINFO);
1113                reset = diff_get_color_opt(o, DIFF_RESET);
1114                fprintf(o->file, "%s%s+++ %s%s%s\n", diff_line_prefix(o), meta,
1115                        line, reset,
1116                        strchr(line, ' ') ? "\t" : "");
1117                break;
1118        case DIFF_SYMBOL_FILEPAIR_MINUS:
1119                meta = diff_get_color_opt(o, DIFF_METAINFO);
1120                reset = diff_get_color_opt(o, DIFF_RESET);
1121                fprintf(o->file, "%s%s--- %s%s%s\n", diff_line_prefix(o), meta,
1122                        line, reset,
1123                        strchr(line, ' ') ? "\t" : "");
1124                break;
1125        case DIFF_SYMBOL_BINARY_FILES:
1126        case DIFF_SYMBOL_HEADER:
1127                fprintf(o->file, "%s", line);
1128                break;
1129        case DIFF_SYMBOL_BINARY_DIFF_HEADER:
1130                fprintf(o->file, "%sGIT binary patch\n", diff_line_prefix(o));
1131                break;
1132        case DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA:
1133                fprintf(o->file, "%sdelta %s\n", diff_line_prefix(o), line);
1134                break;
1135        case DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL:
1136                fprintf(o->file, "%sliteral %s\n", diff_line_prefix(o), line);
1137                break;
1138        case DIFF_SYMBOL_BINARY_DIFF_FOOTER:
1139                fputs(diff_line_prefix(o), o->file);
1140                fputc('\n', o->file);
1141                break;
1142        case DIFF_SYMBOL_REWRITE_DIFF:
1143                fraginfo = diff_get_color(o->use_color, DIFF_FRAGINFO);
1144                reset = diff_get_color_opt(o, DIFF_RESET);
1145                emit_line(o, fraginfo, reset, line, len);
1146                break;
1147        case DIFF_SYMBOL_SUBMODULE_ADD:
1148                set = diff_get_color_opt(o, DIFF_FILE_NEW);
1149                reset = diff_get_color_opt(o, DIFF_RESET);
1150                emit_line(o, set, reset, line, len);
1151                break;
1152        case DIFF_SYMBOL_SUBMODULE_DEL:
1153                set = diff_get_color_opt(o, DIFF_FILE_OLD);
1154                reset = diff_get_color_opt(o, DIFF_RESET);
1155                emit_line(o, set, reset, line, len);
1156                break;
1157        case DIFF_SYMBOL_SUBMODULE_UNTRACKED:
1158                fprintf(o->file, "%sSubmodule %s contains untracked content\n",
1159                        diff_line_prefix(o), line);
1160                break;
1161        case DIFF_SYMBOL_SUBMODULE_MODIFIED:
1162                fprintf(o->file, "%sSubmodule %s contains modified content\n",
1163                        diff_line_prefix(o), line);
1164                break;
1165        case DIFF_SYMBOL_STATS_SUMMARY_NO_FILES:
1166                emit_line(o, "", "", " 0 files changed\n",
1167                          strlen(" 0 files changed\n"));
1168                break;
1169        case DIFF_SYMBOL_STATS_SUMMARY_ABBREV:
1170                emit_line(o, "", "", " ...\n", strlen(" ...\n"));
1171                break;
1172        case DIFF_SYMBOL_WORD_DIFF:
1173                fprintf(o->file, "%.*s", len, line);
1174                break;
1175        case DIFF_SYMBOL_STAT_SEP:
1176                fputs(o->stat_sep, o->file);
1177                break;
1178        default:
1179                BUG("unknown diff symbol");
1180        }
1181        strbuf_release(&sb);
1182}
1183
1184static void emit_diff_symbol(struct diff_options *o, enum diff_symbol s,
1185                             const char *line, int len, unsigned flags)
1186{
1187        struct emitted_diff_symbol e = {line, len, flags, s};
1188
1189        if (o->emitted_symbols)
1190                append_emitted_diff_symbol(o, &e);
1191        else
1192                emit_diff_symbol_from_struct(o, &e);
1193}
1194
1195void diff_emit_submodule_del(struct diff_options *o, const char *line)
1196{
1197        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_DEL, line, strlen(line), 0);
1198}
1199
1200void diff_emit_submodule_add(struct diff_options *o, const char *line)
1201{
1202        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_ADD, line, strlen(line), 0);
1203}
1204
1205void diff_emit_submodule_untracked(struct diff_options *o, const char *path)
1206{
1207        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_UNTRACKED,
1208                         path, strlen(path), 0);
1209}
1210
1211void diff_emit_submodule_modified(struct diff_options *o, const char *path)
1212{
1213        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_MODIFIED,
1214                         path, strlen(path), 0);
1215}
1216
1217void diff_emit_submodule_header(struct diff_options *o, const char *header)
1218{
1219        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_HEADER,
1220                         header, strlen(header), 0);
1221}
1222
1223void diff_emit_submodule_error(struct diff_options *o, const char *err)
1224{
1225        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_ERROR, err, strlen(err), 0);
1226}
1227
1228void diff_emit_submodule_pipethrough(struct diff_options *o,
1229                                     const char *line, int len)
1230{
1231        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_PIPETHROUGH, line, len, 0);
1232}
1233
1234static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line, int len)
1235{
1236        if (!((ecbdata->ws_rule & WS_BLANK_AT_EOF) &&
1237              ecbdata->blank_at_eof_in_preimage &&
1238              ecbdata->blank_at_eof_in_postimage &&
1239              ecbdata->blank_at_eof_in_preimage <= ecbdata->lno_in_preimage &&
1240              ecbdata->blank_at_eof_in_postimage <= ecbdata->lno_in_postimage))
1241                return 0;
1242        return ws_blank_line(line, len, ecbdata->ws_rule);
1243}
1244
1245static void emit_add_line(const char *reset,
1246                          struct emit_callback *ecbdata,
1247                          const char *line, int len)
1248{
1249        unsigned flags = WSEH_NEW | ecbdata->ws_rule;
1250        if (new_blank_line_at_eof(ecbdata, line, len))
1251                flags |= DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF;
1252
1253        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_PLUS, line, len, flags);
1254}
1255
1256static void emit_del_line(const char *reset,
1257                          struct emit_callback *ecbdata,
1258                          const char *line, int len)
1259{
1260        unsigned flags = WSEH_OLD | ecbdata->ws_rule;
1261        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_MINUS, line, len, flags);
1262}
1263
1264static void emit_context_line(const char *reset,
1265                              struct emit_callback *ecbdata,
1266                              const char *line, int len)
1267{
1268        unsigned flags = WSEH_CONTEXT | ecbdata->ws_rule;
1269        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_CONTEXT, line, len, flags);
1270}
1271
1272static void emit_hunk_header(struct emit_callback *ecbdata,
1273                             const char *line, int len)
1274{
1275        const char *context = diff_get_color(ecbdata->color_diff, DIFF_CONTEXT);
1276        const char *frag = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
1277        const char *func = diff_get_color(ecbdata->color_diff, DIFF_FUNCINFO);
1278        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
1279        static const char atat[2] = { '@', '@' };
1280        const char *cp, *ep;
1281        struct strbuf msgbuf = STRBUF_INIT;
1282        int org_len = len;
1283        int i = 1;
1284
1285        /*
1286         * As a hunk header must begin with "@@ -<old>, +<new> @@",
1287         * it always is at least 10 bytes long.
1288         */
1289        if (len < 10 ||
1290            memcmp(line, atat, 2) ||
1291            !(ep = memmem(line + 2, len - 2, atat, 2))) {
1292                emit_diff_symbol(ecbdata->opt,
1293                                 DIFF_SYMBOL_CONTEXT_MARKER, line, len, 0);
1294                return;
1295        }
1296        ep += 2; /* skip over @@ */
1297
1298        /* The hunk header in fraginfo color */
1299        strbuf_addstr(&msgbuf, frag);
1300        strbuf_add(&msgbuf, line, ep - line);
1301        strbuf_addstr(&msgbuf, reset);
1302
1303        /*
1304         * trailing "\r\n"
1305         */
1306        for ( ; i < 3; i++)
1307                if (line[len - i] == '\r' || line[len - i] == '\n')
1308                        len--;
1309
1310        /* blank before the func header */
1311        for (cp = ep; ep - line < len; ep++)
1312                if (*ep != ' ' && *ep != '\t')
1313                        break;
1314        if (ep != cp) {
1315                strbuf_addstr(&msgbuf, context);
1316                strbuf_add(&msgbuf, cp, ep - cp);
1317                strbuf_addstr(&msgbuf, reset);
1318        }
1319
1320        if (ep < line + len) {
1321                strbuf_addstr(&msgbuf, func);
1322                strbuf_add(&msgbuf, ep, line + len - ep);
1323                strbuf_addstr(&msgbuf, reset);
1324        }
1325
1326        strbuf_add(&msgbuf, line + len, org_len - len);
1327        strbuf_complete_line(&msgbuf);
1328        emit_diff_symbol(ecbdata->opt,
1329                         DIFF_SYMBOL_CONTEXT_FRAGINFO, msgbuf.buf, msgbuf.len, 0);
1330        strbuf_release(&msgbuf);
1331}
1332
1333static struct diff_tempfile *claim_diff_tempfile(void) {
1334        int i;
1335        for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
1336                if (!diff_temp[i].name)
1337                        return diff_temp + i;
1338        BUG("diff is failing to clean up its tempfiles");
1339}
1340
1341static void remove_tempfile(void)
1342{
1343        int i;
1344        for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
1345                if (is_tempfile_active(diff_temp[i].tempfile))
1346                        delete_tempfile(&diff_temp[i].tempfile);
1347                diff_temp[i].name = NULL;
1348        }
1349}
1350
1351static void add_line_count(struct strbuf *out, int count)
1352{
1353        switch (count) {
1354        case 0:
1355                strbuf_addstr(out, "0,0");
1356                break;
1357        case 1:
1358                strbuf_addstr(out, "1");
1359                break;
1360        default:
1361                strbuf_addf(out, "1,%d", count);
1362                break;
1363        }
1364}
1365
1366static void emit_rewrite_lines(struct emit_callback *ecb,
1367                               int prefix, const char *data, int size)
1368{
1369        const char *endp = NULL;
1370        const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
1371
1372        while (0 < size) {
1373                int len;
1374
1375                endp = memchr(data, '\n', size);
1376                len = endp ? (endp - data + 1) : size;
1377                if (prefix != '+') {
1378                        ecb->lno_in_preimage++;
1379                        emit_del_line(reset, ecb, data, len);
1380                } else {
1381                        ecb->lno_in_postimage++;
1382                        emit_add_line(reset, ecb, data, len);
1383                }
1384                size -= len;
1385                data += len;
1386        }
1387        if (!endp)
1388                emit_diff_symbol(ecb->opt, DIFF_SYMBOL_NO_LF_EOF, NULL, 0, 0);
1389}
1390
1391static void emit_rewrite_diff(const char *name_a,
1392                              const char *name_b,
1393                              struct diff_filespec *one,
1394                              struct diff_filespec *two,
1395                              struct userdiff_driver *textconv_one,
1396                              struct userdiff_driver *textconv_two,
1397                              struct diff_options *o)
1398{
1399        int lc_a, lc_b;
1400        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
1401        const char *a_prefix, *b_prefix;
1402        char *data_one, *data_two;
1403        size_t size_one, size_two;
1404        struct emit_callback ecbdata;
1405        struct strbuf out = STRBUF_INIT;
1406
1407        if (diff_mnemonic_prefix && o->flags.reverse_diff) {
1408                a_prefix = o->b_prefix;
1409                b_prefix = o->a_prefix;
1410        } else {
1411                a_prefix = o->a_prefix;
1412                b_prefix = o->b_prefix;
1413        }
1414
1415        name_a += (*name_a == '/');
1416        name_b += (*name_b == '/');
1417
1418        strbuf_reset(&a_name);
1419        strbuf_reset(&b_name);
1420        quote_two_c_style(&a_name, a_prefix, name_a, 0);
1421        quote_two_c_style(&b_name, b_prefix, name_b, 0);
1422
1423        size_one = fill_textconv(textconv_one, one, &data_one);
1424        size_two = fill_textconv(textconv_two, two, &data_two);
1425
1426        memset(&ecbdata, 0, sizeof(ecbdata));
1427        ecbdata.color_diff = want_color(o->use_color);
1428        ecbdata.ws_rule = whitespace_rule(name_b);
1429        ecbdata.opt = o;
1430        if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
1431                mmfile_t mf1, mf2;
1432                mf1.ptr = (char *)data_one;
1433                mf2.ptr = (char *)data_two;
1434                mf1.size = size_one;
1435                mf2.size = size_two;
1436                check_blank_at_eof(&mf1, &mf2, &ecbdata);
1437        }
1438        ecbdata.lno_in_preimage = 1;
1439        ecbdata.lno_in_postimage = 1;
1440
1441        lc_a = count_lines(data_one, size_one);
1442        lc_b = count_lines(data_two, size_two);
1443
1444        emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_MINUS,
1445                         a_name.buf, a_name.len, 0);
1446        emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_PLUS,
1447                         b_name.buf, b_name.len, 0);
1448
1449        strbuf_addstr(&out, "@@ -");
1450        if (!o->irreversible_delete)
1451                add_line_count(&out, lc_a);
1452        else
1453                strbuf_addstr(&out, "?,?");
1454        strbuf_addstr(&out, " +");
1455        add_line_count(&out, lc_b);
1456        strbuf_addstr(&out, " @@\n");
1457        emit_diff_symbol(o, DIFF_SYMBOL_REWRITE_DIFF, out.buf, out.len, 0);
1458        strbuf_release(&out);
1459
1460        if (lc_a && !o->irreversible_delete)
1461                emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
1462        if (lc_b)
1463                emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
1464        if (textconv_one)
1465                free((char *)data_one);
1466        if (textconv_two)
1467                free((char *)data_two);
1468}
1469
1470struct diff_words_buffer {
1471        mmfile_t text;
1472        unsigned long alloc;
1473        struct diff_words_orig {
1474                const char *begin, *end;
1475        } *orig;
1476        int orig_nr, orig_alloc;
1477};
1478
1479static void diff_words_append(char *line, unsigned long len,
1480                struct diff_words_buffer *buffer)
1481{
1482        ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
1483        line++;
1484        len--;
1485        memcpy(buffer->text.ptr + buffer->text.size, line, len);
1486        buffer->text.size += len;
1487        buffer->text.ptr[buffer->text.size] = '\0';
1488}
1489
1490struct diff_words_style_elem {
1491        const char *prefix;
1492        const char *suffix;
1493        const char *color; /* NULL; filled in by the setup code if
1494                            * color is enabled */
1495};
1496
1497struct diff_words_style {
1498        enum diff_words_type type;
1499        struct diff_words_style_elem new_word, old_word, ctx;
1500        const char *newline;
1501};
1502
1503static struct diff_words_style diff_words_styles[] = {
1504        { DIFF_WORDS_PORCELAIN, {"+", "\n"}, {"-", "\n"}, {" ", "\n"}, "~\n" },
1505        { DIFF_WORDS_PLAIN, {"{+", "+}"}, {"[-", "-]"}, {"", ""}, "\n" },
1506        { DIFF_WORDS_COLOR, {"", ""}, {"", ""}, {"", ""}, "\n" }
1507};
1508
1509struct diff_words_data {
1510        struct diff_words_buffer minus, plus;
1511        const char *current_plus;
1512        int last_minus;
1513        struct diff_options *opt;
1514        regex_t *word_regex;
1515        enum diff_words_type type;
1516        struct diff_words_style *style;
1517};
1518
1519static int fn_out_diff_words_write_helper(struct diff_options *o,
1520                                          struct diff_words_style_elem *st_el,
1521                                          const char *newline,
1522                                          size_t count, const char *buf)
1523{
1524        int print = 0;
1525        struct strbuf sb = STRBUF_INIT;
1526
1527        while (count) {
1528                char *p = memchr(buf, '\n', count);
1529                if (print)
1530                        strbuf_addstr(&sb, diff_line_prefix(o));
1531
1532                if (p != buf) {
1533                        const char *reset = st_el->color && *st_el->color ?
1534                                            GIT_COLOR_RESET : NULL;
1535                        if (st_el->color && *st_el->color)
1536                                strbuf_addstr(&sb, st_el->color);
1537                        strbuf_addstr(&sb, st_el->prefix);
1538                        strbuf_add(&sb, buf, p ? p - buf : count);
1539                        strbuf_addstr(&sb, st_el->suffix);
1540                        if (reset)
1541                                strbuf_addstr(&sb, reset);
1542                }
1543                if (!p)
1544                        goto out;
1545
1546                strbuf_addstr(&sb, newline);
1547                count -= p + 1 - buf;
1548                buf = p + 1;
1549                print = 1;
1550                if (count) {
1551                        emit_diff_symbol(o, DIFF_SYMBOL_WORD_DIFF,
1552                                         sb.buf, sb.len, 0);
1553                        strbuf_reset(&sb);
1554                }
1555        }
1556
1557out:
1558        if (sb.len)
1559                emit_diff_symbol(o, DIFF_SYMBOL_WORD_DIFF,
1560                                 sb.buf, sb.len, 0);
1561        strbuf_release(&sb);
1562        return 0;
1563}
1564
1565/*
1566 * '--color-words' algorithm can be described as:
1567 *
1568 *   1. collect the minus/plus lines of a diff hunk, divided into
1569 *      minus-lines and plus-lines;
1570 *
1571 *   2. break both minus-lines and plus-lines into words and
1572 *      place them into two mmfile_t with one word for each line;
1573 *
1574 *   3. use xdiff to run diff on the two mmfile_t to get the words level diff;
1575 *
1576 * And for the common parts of the both file, we output the plus side text.
1577 * diff_words->current_plus is used to trace the current position of the plus file
1578 * which printed. diff_words->last_minus is used to trace the last minus word
1579 * printed.
1580 *
1581 * For '--graph' to work with '--color-words', we need to output the graph prefix
1582 * on each line of color words output. Generally, there are two conditions on
1583 * which we should output the prefix.
1584 *
1585 *   1. diff_words->last_minus == 0 &&
1586 *      diff_words->current_plus == diff_words->plus.text.ptr
1587 *
1588 *      that is: the plus text must start as a new line, and if there is no minus
1589 *      word printed, a graph prefix must be printed.
1590 *
1591 *   2. diff_words->current_plus > diff_words->plus.text.ptr &&
1592 *      *(diff_words->current_plus - 1) == '\n'
1593 *
1594 *      that is: a graph prefix must be printed following a '\n'
1595 */
1596static int color_words_output_graph_prefix(struct diff_words_data *diff_words)
1597{
1598        if ((diff_words->last_minus == 0 &&
1599                diff_words->current_plus == diff_words->plus.text.ptr) ||
1600                (diff_words->current_plus > diff_words->plus.text.ptr &&
1601                *(diff_words->current_plus - 1) == '\n')) {
1602                return 1;
1603        } else {
1604                return 0;
1605        }
1606}
1607
1608static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
1609{
1610        struct diff_words_data *diff_words = priv;
1611        struct diff_words_style *style = diff_words->style;
1612        int minus_first, minus_len, plus_first, plus_len;
1613        const char *minus_begin, *minus_end, *plus_begin, *plus_end;
1614        struct diff_options *opt = diff_words->opt;
1615        const char *line_prefix;
1616
1617        if (line[0] != '@' || parse_hunk_header(line, len,
1618                        &minus_first, &minus_len, &plus_first, &plus_len))
1619                return;
1620
1621        assert(opt);
1622        line_prefix = diff_line_prefix(opt);
1623
1624        /* POSIX requires that first be decremented by one if len == 0... */
1625        if (minus_len) {
1626                minus_begin = diff_words->minus.orig[minus_first].begin;
1627                minus_end =
1628                        diff_words->minus.orig[minus_first + minus_len - 1].end;
1629        } else
1630                minus_begin = minus_end =
1631                        diff_words->minus.orig[minus_first].end;
1632
1633        if (plus_len) {
1634                plus_begin = diff_words->plus.orig[plus_first].begin;
1635                plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
1636        } else
1637                plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
1638
1639        if (color_words_output_graph_prefix(diff_words)) {
1640                fputs(line_prefix, diff_words->opt->file);
1641        }
1642        if (diff_words->current_plus != plus_begin) {
1643                fn_out_diff_words_write_helper(diff_words->opt,
1644                                &style->ctx, style->newline,
1645                                plus_begin - diff_words->current_plus,
1646                                diff_words->current_plus);
1647        }
1648        if (minus_begin != minus_end) {
1649                fn_out_diff_words_write_helper(diff_words->opt,
1650                                &style->old_word, style->newline,
1651                                minus_end - minus_begin, minus_begin);
1652        }
1653        if (plus_begin != plus_end) {
1654                fn_out_diff_words_write_helper(diff_words->opt,
1655                                &style->new_word, style->newline,
1656                                plus_end - plus_begin, plus_begin);
1657        }
1658
1659        diff_words->current_plus = plus_end;
1660        diff_words->last_minus = minus_first;
1661}
1662
1663/* This function starts looking at *begin, and returns 0 iff a word was found. */
1664static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
1665                int *begin, int *end)
1666{
1667        if (word_regex && *begin < buffer->size) {
1668                regmatch_t match[1];
1669                if (!regexec_buf(word_regex, buffer->ptr + *begin,
1670                                 buffer->size - *begin, 1, match, 0)) {
1671                        char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
1672                                        '\n', match[0].rm_eo - match[0].rm_so);
1673                        *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
1674                        *begin += match[0].rm_so;
1675                        return *begin >= *end;
1676                }
1677                return -1;
1678        }
1679
1680        /* find the next word */
1681        while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
1682                (*begin)++;
1683        if (*begin >= buffer->size)
1684                return -1;
1685
1686        /* find the end of the word */
1687        *end = *begin + 1;
1688        while (*end < buffer->size && !isspace(buffer->ptr[*end]))
1689                (*end)++;
1690
1691        return 0;
1692}
1693
1694/*
1695 * This function splits the words in buffer->text, stores the list with
1696 * newline separator into out, and saves the offsets of the original words
1697 * in buffer->orig.
1698 */
1699static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
1700                regex_t *word_regex)
1701{
1702        int i, j;
1703        long alloc = 0;
1704
1705        out->size = 0;
1706        out->ptr = NULL;
1707
1708        /* fake an empty "0th" word */
1709        ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
1710        buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
1711        buffer->orig_nr = 1;
1712
1713        for (i = 0; i < buffer->text.size; i++) {
1714                if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
1715                        return;
1716
1717                /* store original boundaries */
1718                ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
1719                                buffer->orig_alloc);
1720                buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
1721                buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
1722                buffer->orig_nr++;
1723
1724                /* store one word */
1725                ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
1726                memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
1727                out->ptr[out->size + j - i] = '\n';
1728                out->size += j - i + 1;
1729
1730                i = j - 1;
1731        }
1732}
1733
1734/* this executes the word diff on the accumulated buffers */
1735static void diff_words_show(struct diff_words_data *diff_words)
1736{
1737        xpparam_t xpp;
1738        xdemitconf_t xecfg;
1739        mmfile_t minus, plus;
1740        struct diff_words_style *style = diff_words->style;
1741
1742        struct diff_options *opt = diff_words->opt;
1743        const char *line_prefix;
1744
1745        assert(opt);
1746        line_prefix = diff_line_prefix(opt);
1747
1748        /* special case: only removal */
1749        if (!diff_words->plus.text.size) {
1750                emit_diff_symbol(diff_words->opt, DIFF_SYMBOL_WORD_DIFF,
1751                                 line_prefix, strlen(line_prefix), 0);
1752                fn_out_diff_words_write_helper(diff_words->opt,
1753                        &style->old_word, style->newline,
1754                        diff_words->minus.text.size,
1755                        diff_words->minus.text.ptr);
1756                diff_words->minus.text.size = 0;
1757                return;
1758        }
1759
1760        diff_words->current_plus = diff_words->plus.text.ptr;
1761        diff_words->last_minus = 0;
1762
1763        memset(&xpp, 0, sizeof(xpp));
1764        memset(&xecfg, 0, sizeof(xecfg));
1765        diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
1766        diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
1767        xpp.flags = 0;
1768        /* as only the hunk header will be parsed, we need a 0-context */
1769        xecfg.ctxlen = 0;
1770        if (xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
1771                          &xpp, &xecfg))
1772                die("unable to generate word diff");
1773        free(minus.ptr);
1774        free(plus.ptr);
1775        if (diff_words->current_plus != diff_words->plus.text.ptr +
1776                        diff_words->plus.text.size) {
1777                if (color_words_output_graph_prefix(diff_words))
1778                        emit_diff_symbol(diff_words->opt, DIFF_SYMBOL_WORD_DIFF,
1779                                         line_prefix, strlen(line_prefix), 0);
1780                fn_out_diff_words_write_helper(diff_words->opt,
1781                        &style->ctx, style->newline,
1782                        diff_words->plus.text.ptr + diff_words->plus.text.size
1783                        - diff_words->current_plus, diff_words->current_plus);
1784        }
1785        diff_words->minus.text.size = diff_words->plus.text.size = 0;
1786}
1787
1788/* In "color-words" mode, show word-diff of words accumulated in the buffer */
1789static void diff_words_flush(struct emit_callback *ecbdata)
1790{
1791        struct diff_options *wo = ecbdata->diff_words->opt;
1792
1793        if (ecbdata->diff_words->minus.text.size ||
1794            ecbdata->diff_words->plus.text.size)
1795                diff_words_show(ecbdata->diff_words);
1796
1797        if (wo->emitted_symbols) {
1798                struct diff_options *o = ecbdata->opt;
1799                struct emitted_diff_symbols *wol = wo->emitted_symbols;
1800                int i;
1801
1802                /*
1803                 * NEEDSWORK:
1804                 * Instead of appending each, concat all words to a line?
1805                 */
1806                for (i = 0; i < wol->nr; i++)
1807                        append_emitted_diff_symbol(o, &wol->buf[i]);
1808
1809                for (i = 0; i < wol->nr; i++)
1810                        free((void *)wol->buf[i].line);
1811
1812                wol->nr = 0;
1813        }
1814}
1815
1816static void diff_filespec_load_driver(struct diff_filespec *one)
1817{
1818        /* Use already-loaded driver */
1819        if (one->driver)
1820                return;
1821
1822        if (S_ISREG(one->mode))
1823                one->driver = userdiff_find_by_path(one->path);
1824
1825        /* Fallback to default settings */
1826        if (!one->driver)
1827                one->driver = userdiff_find_by_name("default");
1828}
1829
1830static const char *userdiff_word_regex(struct diff_filespec *one)
1831{
1832        diff_filespec_load_driver(one);
1833        return one->driver->word_regex;
1834}
1835
1836static void init_diff_words_data(struct emit_callback *ecbdata,
1837                                 struct diff_options *orig_opts,
1838                                 struct diff_filespec *one,
1839                                 struct diff_filespec *two)
1840{
1841        int i;
1842        struct diff_options *o = xmalloc(sizeof(struct diff_options));
1843        memcpy(o, orig_opts, sizeof(struct diff_options));
1844
1845        ecbdata->diff_words =
1846                xcalloc(1, sizeof(struct diff_words_data));
1847        ecbdata->diff_words->type = o->word_diff;
1848        ecbdata->diff_words->opt = o;
1849
1850        if (orig_opts->emitted_symbols)
1851                o->emitted_symbols =
1852                        xcalloc(1, sizeof(struct emitted_diff_symbols));
1853
1854        if (!o->word_regex)
1855                o->word_regex = userdiff_word_regex(one);
1856        if (!o->word_regex)
1857                o->word_regex = userdiff_word_regex(two);
1858        if (!o->word_regex)
1859                o->word_regex = diff_word_regex_cfg;
1860        if (o->word_regex) {
1861                ecbdata->diff_words->word_regex = (regex_t *)
1862                        xmalloc(sizeof(regex_t));
1863                if (regcomp(ecbdata->diff_words->word_regex,
1864                            o->word_regex,
1865                            REG_EXTENDED | REG_NEWLINE))
1866                        die ("Invalid regular expression: %s",
1867                             o->word_regex);
1868        }
1869        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
1870                if (o->word_diff == diff_words_styles[i].type) {
1871                        ecbdata->diff_words->style =
1872                                &diff_words_styles[i];
1873                        break;
1874                }
1875        }
1876        if (want_color(o->use_color)) {
1877                struct diff_words_style *st = ecbdata->diff_words->style;
1878                st->old_word.color = diff_get_color_opt(o, DIFF_FILE_OLD);
1879                st->new_word.color = diff_get_color_opt(o, DIFF_FILE_NEW);
1880                st->ctx.color = diff_get_color_opt(o, DIFF_CONTEXT);
1881        }
1882}
1883
1884static void free_diff_words_data(struct emit_callback *ecbdata)
1885{
1886        if (ecbdata->diff_words) {
1887                diff_words_flush(ecbdata);
1888                free (ecbdata->diff_words->opt->emitted_symbols);
1889                free (ecbdata->diff_words->opt);
1890                free (ecbdata->diff_words->minus.text.ptr);
1891                free (ecbdata->diff_words->minus.orig);
1892                free (ecbdata->diff_words->plus.text.ptr);
1893                free (ecbdata->diff_words->plus.orig);
1894                if (ecbdata->diff_words->word_regex) {
1895                        regfree(ecbdata->diff_words->word_regex);
1896                        free(ecbdata->diff_words->word_regex);
1897                }
1898                FREE_AND_NULL(ecbdata->diff_words);
1899        }
1900}
1901
1902const char *diff_get_color(int diff_use_color, enum color_diff ix)
1903{
1904        if (want_color(diff_use_color))
1905                return diff_colors[ix];
1906        return "";
1907}
1908
1909const char *diff_line_prefix(struct diff_options *opt)
1910{
1911        struct strbuf *msgbuf;
1912        if (!opt->output_prefix)
1913                return "";
1914
1915        msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
1916        return msgbuf->buf;
1917}
1918
1919static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
1920{
1921        const char *cp;
1922        unsigned long allot;
1923        size_t l = len;
1924
1925        cp = line;
1926        allot = l;
1927        while (0 < l) {
1928                (void) utf8_width(&cp, &l);
1929                if (!cp)
1930                        break; /* truncated in the middle? */
1931        }
1932        return allot - l;
1933}
1934
1935static void find_lno(const char *line, struct emit_callback *ecbdata)
1936{
1937        const char *p;
1938        ecbdata->lno_in_preimage = 0;
1939        ecbdata->lno_in_postimage = 0;
1940        p = strchr(line, '-');
1941        if (!p)
1942                return; /* cannot happen */
1943        ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
1944        p = strchr(p, '+');
1945        if (!p)
1946                return; /* cannot happen */
1947        ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
1948}
1949
1950static void fn_out_consume(void *priv, char *line, unsigned long len)
1951{
1952        struct emit_callback *ecbdata = priv;
1953        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
1954        struct diff_options *o = ecbdata->opt;
1955
1956        o->found_changes = 1;
1957
1958        if (ecbdata->header) {
1959                emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
1960                                 ecbdata->header->buf, ecbdata->header->len, 0);
1961                strbuf_reset(ecbdata->header);
1962                ecbdata->header = NULL;
1963        }
1964
1965        if (ecbdata->label_path[0]) {
1966                emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_MINUS,
1967                                 ecbdata->label_path[0],
1968                                 strlen(ecbdata->label_path[0]), 0);
1969                emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_PLUS,
1970                                 ecbdata->label_path[1],
1971                                 strlen(ecbdata->label_path[1]), 0);
1972                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
1973        }
1974
1975        if (diff_suppress_blank_empty
1976            && len == 2 && line[0] == ' ' && line[1] == '\n') {
1977                line[0] = '\n';
1978                len = 1;
1979        }
1980
1981        if (line[0] == '@') {
1982                if (ecbdata->diff_words)
1983                        diff_words_flush(ecbdata);
1984                len = sane_truncate_line(ecbdata, line, len);
1985                find_lno(line, ecbdata);
1986                emit_hunk_header(ecbdata, line, len);
1987                return;
1988        }
1989
1990        if (ecbdata->diff_words) {
1991                enum diff_symbol s =
1992                        ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN ?
1993                        DIFF_SYMBOL_WORDS_PORCELAIN : DIFF_SYMBOL_WORDS;
1994                if (line[0] == '-') {
1995                        diff_words_append(line, len,
1996                                          &ecbdata->diff_words->minus);
1997                        return;
1998                } else if (line[0] == '+') {
1999                        diff_words_append(line, len,
2000                                          &ecbdata->diff_words->plus);
2001                        return;
2002                } else if (starts_with(line, "\\ ")) {
2003                        /*
2004                         * Eat the "no newline at eof" marker as if we
2005                         * saw a "+" or "-" line with nothing on it,
2006                         * and return without diff_words_flush() to
2007                         * defer processing. If this is the end of
2008                         * preimage, more "+" lines may come after it.
2009                         */
2010                        return;
2011                }
2012                diff_words_flush(ecbdata);
2013                emit_diff_symbol(o, s, line, len, 0);
2014                return;
2015        }
2016
2017        switch (line[0]) {
2018        case '+':
2019                ecbdata->lno_in_postimage++;
2020                emit_add_line(reset, ecbdata, line + 1, len - 1);
2021                break;
2022        case '-':
2023                ecbdata->lno_in_preimage++;
2024                emit_del_line(reset, ecbdata, line + 1, len - 1);
2025                break;
2026        case ' ':
2027                ecbdata->lno_in_postimage++;
2028                ecbdata->lno_in_preimage++;
2029                emit_context_line(reset, ecbdata, line + 1, len - 1);
2030                break;
2031        default:
2032                /* incomplete line at the end */
2033                ecbdata->lno_in_preimage++;
2034                emit_diff_symbol(o, DIFF_SYMBOL_CONTEXT_INCOMPLETE,
2035                                 line, len, 0);
2036                break;
2037        }
2038}
2039
2040static void pprint_rename(struct strbuf *name, const char *a, const char *b)
2041{
2042        const char *old_name = a;
2043        const char *new_name = b;
2044        int pfx_length, sfx_length;
2045        int pfx_adjust_for_slash;
2046        int len_a = strlen(a);
2047        int len_b = strlen(b);
2048        int a_midlen, b_midlen;
2049        int qlen_a = quote_c_style(a, NULL, NULL, 0);
2050        int qlen_b = quote_c_style(b, NULL, NULL, 0);
2051
2052        if (qlen_a || qlen_b) {
2053                quote_c_style(a, name, NULL, 0);
2054                strbuf_addstr(name, " => ");
2055                quote_c_style(b, name, NULL, 0);
2056                return;
2057        }
2058
2059        /* Find common prefix */
2060        pfx_length = 0;
2061        while (*old_name && *new_name && *old_name == *new_name) {
2062                if (*old_name == '/')
2063                        pfx_length = old_name - a + 1;
2064                old_name++;
2065                new_name++;
2066        }
2067
2068        /* Find common suffix */
2069        old_name = a + len_a;
2070        new_name = b + len_b;
2071        sfx_length = 0;
2072        /*
2073         * If there is a common prefix, it must end in a slash.  In
2074         * that case we let this loop run 1 into the prefix to see the
2075         * same slash.
2076         *
2077         * If there is no common prefix, we cannot do this as it would
2078         * underrun the input strings.
2079         */
2080        pfx_adjust_for_slash = (pfx_length ? 1 : 0);
2081        while (a + pfx_length - pfx_adjust_for_slash <= old_name &&
2082               b + pfx_length - pfx_adjust_for_slash <= new_name &&
2083               *old_name == *new_name) {
2084                if (*old_name == '/')
2085                        sfx_length = len_a - (old_name - a);
2086                old_name--;
2087                new_name--;
2088        }
2089
2090        /*
2091         * pfx{mid-a => mid-b}sfx
2092         * {pfx-a => pfx-b}sfx
2093         * pfx{sfx-a => sfx-b}
2094         * name-a => name-b
2095         */
2096        a_midlen = len_a - pfx_length - sfx_length;
2097        b_midlen = len_b - pfx_length - sfx_length;
2098        if (a_midlen < 0)
2099                a_midlen = 0;
2100        if (b_midlen < 0)
2101                b_midlen = 0;
2102
2103        strbuf_grow(name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
2104        if (pfx_length + sfx_length) {
2105                strbuf_add(name, a, pfx_length);
2106                strbuf_addch(name, '{');
2107        }
2108        strbuf_add(name, a + pfx_length, a_midlen);
2109        strbuf_addstr(name, " => ");
2110        strbuf_add(name, b + pfx_length, b_midlen);
2111        if (pfx_length + sfx_length) {
2112                strbuf_addch(name, '}');
2113                strbuf_add(name, a + len_a - sfx_length, sfx_length);
2114        }
2115}
2116
2117struct diffstat_t {
2118        int nr;
2119        int alloc;
2120        struct diffstat_file {
2121                char *from_name;
2122                char *name;
2123                char *print_name;
2124                const char *comments;
2125                unsigned is_unmerged:1;
2126                unsigned is_binary:1;
2127                unsigned is_renamed:1;
2128                unsigned is_interesting:1;
2129                uintmax_t added, deleted;
2130        } **files;
2131};
2132
2133static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
2134                                          const char *name_a,
2135                                          const char *name_b)
2136{
2137        struct diffstat_file *x;
2138        x = xcalloc(1, sizeof(*x));
2139        ALLOC_GROW(diffstat->files, diffstat->nr + 1, diffstat->alloc);
2140        diffstat->files[diffstat->nr++] = x;
2141        if (name_b) {
2142                x->from_name = xstrdup(name_a);
2143                x->name = xstrdup(name_b);
2144                x->is_renamed = 1;
2145        }
2146        else {
2147                x->from_name = NULL;
2148                x->name = xstrdup(name_a);
2149        }
2150        return x;
2151}
2152
2153static void diffstat_consume(void *priv, char *line, unsigned long len)
2154{
2155        struct diffstat_t *diffstat = priv;
2156        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
2157
2158        if (line[0] == '+')
2159                x->added++;
2160        else if (line[0] == '-')
2161                x->deleted++;
2162}
2163
2164const char mime_boundary_leader[] = "------------";
2165
2166static int scale_linear(int it, int width, int max_change)
2167{
2168        if (!it)
2169                return 0;
2170        /*
2171         * make sure that at least one '-' or '+' is printed if
2172         * there is any change to this path. The easiest way is to
2173         * scale linearly as if the alloted width is one column shorter
2174         * than it is, and then add 1 to the result.
2175         */
2176        return 1 + (it * (width - 1) / max_change);
2177}
2178
2179static void show_graph(struct strbuf *out, char ch, int cnt,
2180                       const char *set, const char *reset)
2181{
2182        if (cnt <= 0)
2183                return;
2184        strbuf_addstr(out, set);
2185        strbuf_addchars(out, ch, cnt);
2186        strbuf_addstr(out, reset);
2187}
2188
2189static void fill_print_name(struct diffstat_file *file)
2190{
2191        struct strbuf pname = STRBUF_INIT;
2192
2193        if (file->print_name)
2194                return;
2195
2196        if (file->is_renamed)
2197                pprint_rename(&pname, file->from_name, file->name);
2198        else
2199                quote_c_style(file->name, &pname, NULL, 0);
2200
2201        if (file->comments)
2202                strbuf_addf(&pname, " (%s)", file->comments);
2203
2204        file->print_name = strbuf_detach(&pname, NULL);
2205}
2206
2207static void print_stat_summary_inserts_deletes(struct diff_options *options,
2208                int files, int insertions, int deletions)
2209{
2210        struct strbuf sb = STRBUF_INIT;
2211
2212        if (!files) {
2213                assert(insertions == 0 && deletions == 0);
2214                emit_diff_symbol(options, DIFF_SYMBOL_STATS_SUMMARY_NO_FILES,
2215                                 NULL, 0, 0);
2216                return;
2217        }
2218
2219        strbuf_addf(&sb,
2220                    (files == 1) ? " %d file changed" : " %d files changed",
2221                    files);
2222
2223        /*
2224         * For binary diff, the caller may want to print "x files
2225         * changed" with insertions == 0 && deletions == 0.
2226         *
2227         * Not omitting "0 insertions(+), 0 deletions(-)" in this case
2228         * is probably less confusing (i.e skip over "2 files changed
2229         * but nothing about added/removed lines? Is this a bug in Git?").
2230         */
2231        if (insertions || deletions == 0) {
2232                strbuf_addf(&sb,
2233                            (insertions == 1) ? ", %d insertion(+)" : ", %d insertions(+)",
2234                            insertions);
2235        }
2236
2237        if (deletions || insertions == 0) {
2238                strbuf_addf(&sb,
2239                            (deletions == 1) ? ", %d deletion(-)" : ", %d deletions(-)",
2240                            deletions);
2241        }
2242        strbuf_addch(&sb, '\n');
2243        emit_diff_symbol(options, DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES,
2244                         sb.buf, sb.len, 0);
2245        strbuf_release(&sb);
2246}
2247
2248void print_stat_summary(FILE *fp, int files,
2249                        int insertions, int deletions)
2250{
2251        struct diff_options o;
2252        memset(&o, 0, sizeof(o));
2253        o.file = fp;
2254
2255        print_stat_summary_inserts_deletes(&o, files, insertions, deletions);
2256}
2257
2258static void show_stats(struct diffstat_t *data, struct diff_options *options)
2259{
2260        int i, len, add, del, adds = 0, dels = 0;
2261        uintmax_t max_change = 0, max_len = 0;
2262        int total_files = data->nr, count;
2263        int width, name_width, graph_width, number_width = 0, bin_width = 0;
2264        const char *reset, *add_c, *del_c;
2265        int extra_shown = 0;
2266        const char *line_prefix = diff_line_prefix(options);
2267        struct strbuf out = STRBUF_INIT;
2268
2269        if (data->nr == 0)
2270                return;
2271
2272        count = options->stat_count ? options->stat_count : data->nr;
2273
2274        reset = diff_get_color_opt(options, DIFF_RESET);
2275        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
2276        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
2277
2278        /*
2279         * Find the longest filename and max number of changes
2280         */
2281        for (i = 0; (i < count) && (i < data->nr); i++) {
2282                struct diffstat_file *file = data->files[i];
2283                uintmax_t change = file->added + file->deleted;
2284
2285                if (!file->is_interesting && (change == 0)) {
2286                        count++; /* not shown == room for one more */
2287                        continue;
2288                }
2289                fill_print_name(file);
2290                len = strlen(file->print_name);
2291                if (max_len < len)
2292                        max_len = len;
2293
2294                if (file->is_unmerged) {
2295                        /* "Unmerged" is 8 characters */
2296                        bin_width = bin_width < 8 ? 8 : bin_width;
2297                        continue;
2298                }
2299                if (file->is_binary) {
2300                        /* "Bin XXX -> YYY bytes" */
2301                        int w = 14 + decimal_width(file->added)
2302                                + decimal_width(file->deleted);
2303                        bin_width = bin_width < w ? w : bin_width;
2304                        /* Display change counts aligned with "Bin" */
2305                        number_width = 3;
2306                        continue;
2307                }
2308
2309                if (max_change < change)
2310                        max_change = change;
2311        }
2312        count = i; /* where we can stop scanning in data->files[] */
2313
2314        /*
2315         * We have width = stat_width or term_columns() columns total.
2316         * We want a maximum of min(max_len, stat_name_width) for the name part.
2317         * We want a maximum of min(max_change, stat_graph_width) for the +- part.
2318         * We also need 1 for " " and 4 + decimal_width(max_change)
2319         * for " | NNNN " and one the empty column at the end, altogether
2320         * 6 + decimal_width(max_change).
2321         *
2322         * If there's not enough space, we will use the smaller of
2323         * stat_name_width (if set) and 5/8*width for the filename,
2324         * and the rest for constant elements + graph part, but no more
2325         * than stat_graph_width for the graph part.
2326         * (5/8 gives 50 for filename and 30 for the constant parts + graph
2327         * for the standard terminal size).
2328         *
2329         * In other words: stat_width limits the maximum width, and
2330         * stat_name_width fixes the maximum width of the filename,
2331         * and is also used to divide available columns if there
2332         * aren't enough.
2333         *
2334         * Binary files are displayed with "Bin XXX -> YYY bytes"
2335         * instead of the change count and graph. This part is treated
2336         * similarly to the graph part, except that it is not
2337         * "scaled". If total width is too small to accommodate the
2338         * guaranteed minimum width of the filename part and the
2339         * separators and this message, this message will "overflow"
2340         * making the line longer than the maximum width.
2341         */
2342
2343        if (options->stat_width == -1)
2344                width = term_columns() - strlen(line_prefix);
2345        else
2346                width = options->stat_width ? options->stat_width : 80;
2347        number_width = decimal_width(max_change) > number_width ?
2348                decimal_width(max_change) : number_width;
2349
2350        if (options->stat_graph_width == -1)
2351                options->stat_graph_width = diff_stat_graph_width;
2352
2353        /*
2354         * Guarantee 3/8*16==6 for the graph part
2355         * and 5/8*16==10 for the filename part
2356         */
2357        if (width < 16 + 6 + number_width)
2358                width = 16 + 6 + number_width;
2359
2360        /*
2361         * First assign sizes that are wanted, ignoring available width.
2362         * strlen("Bin XXX -> YYY bytes") == bin_width, and the part
2363         * starting from "XXX" should fit in graph_width.
2364         */
2365        graph_width = max_change + 4 > bin_width ? max_change : bin_width - 4;
2366        if (options->stat_graph_width &&
2367            options->stat_graph_width < graph_width)
2368                graph_width = options->stat_graph_width;
2369
2370        name_width = (options->stat_name_width > 0 &&
2371                      options->stat_name_width < max_len) ?
2372                options->stat_name_width : max_len;
2373
2374        /*
2375         * Adjust adjustable widths not to exceed maximum width
2376         */
2377        if (name_width + number_width + 6 + graph_width > width) {
2378                if (graph_width > width * 3/8 - number_width - 6) {
2379                        graph_width = width * 3/8 - number_width - 6;
2380                        if (graph_width < 6)
2381                                graph_width = 6;
2382                }
2383
2384                if (options->stat_graph_width &&
2385                    graph_width > options->stat_graph_width)
2386                        graph_width = options->stat_graph_width;
2387                if (name_width > width - number_width - 6 - graph_width)
2388                        name_width = width - number_width - 6 - graph_width;
2389                else
2390                        graph_width = width - number_width - 6 - name_width;
2391        }
2392
2393        /*
2394         * From here name_width is the width of the name area,
2395         * and graph_width is the width of the graph area.
2396         * max_change is used to scale graph properly.
2397         */
2398        for (i = 0; i < count; i++) {
2399                const char *prefix = "";
2400                struct diffstat_file *file = data->files[i];
2401                char *name = file->print_name;
2402                uintmax_t added = file->added;
2403                uintmax_t deleted = file->deleted;
2404                int name_len;
2405
2406                if (!file->is_interesting && (added + deleted == 0))
2407                        continue;
2408
2409                /*
2410                 * "scale" the filename
2411                 */
2412                len = name_width;
2413                name_len = strlen(name);
2414                if (name_width < name_len) {
2415                        char *slash;
2416                        prefix = "...";
2417                        len -= 3;
2418                        name += name_len - len;
2419                        slash = strchr(name, '/');
2420                        if (slash)
2421                                name = slash;
2422                }
2423
2424                if (file->is_binary) {
2425                        strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2426                        strbuf_addf(&out, " %*s", number_width, "Bin");
2427                        if (!added && !deleted) {
2428                                strbuf_addch(&out, '\n');
2429                                emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2430                                                 out.buf, out.len, 0);
2431                                strbuf_reset(&out);
2432                                continue;
2433                        }
2434                        strbuf_addf(&out, " %s%"PRIuMAX"%s",
2435                                del_c, deleted, reset);
2436                        strbuf_addstr(&out, " -> ");
2437                        strbuf_addf(&out, "%s%"PRIuMAX"%s",
2438                                add_c, added, reset);
2439                        strbuf_addstr(&out, " bytes\n");
2440                        emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2441                                         out.buf, out.len, 0);
2442                        strbuf_reset(&out);
2443                        continue;
2444                }
2445                else if (file->is_unmerged) {
2446                        strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2447                        strbuf_addstr(&out, " Unmerged\n");
2448                        emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2449                                         out.buf, out.len, 0);
2450                        strbuf_reset(&out);
2451                        continue;
2452                }
2453
2454                /*
2455                 * scale the add/delete
2456                 */
2457                add = added;
2458                del = deleted;
2459
2460                if (graph_width <= max_change) {
2461                        int total = scale_linear(add + del, graph_width, max_change);
2462                        if (total < 2 && add && del)
2463                                /* width >= 2 due to the sanity check */
2464                                total = 2;
2465                        if (add < del) {
2466                                add = scale_linear(add, graph_width, max_change);
2467                                del = total - add;
2468                        } else {
2469                                del = scale_linear(del, graph_width, max_change);
2470                                add = total - del;
2471                        }
2472                }
2473                strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2474                strbuf_addf(&out, " %*"PRIuMAX"%s",
2475                        number_width, added + deleted,
2476                        added + deleted ? " " : "");
2477                show_graph(&out, '+', add, add_c, reset);
2478                show_graph(&out, '-', del, del_c, reset);
2479                strbuf_addch(&out, '\n');
2480                emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2481                                 out.buf, out.len, 0);
2482                strbuf_reset(&out);
2483        }
2484
2485        for (i = 0; i < data->nr; i++) {
2486                struct diffstat_file *file = data->files[i];
2487                uintmax_t added = file->added;
2488                uintmax_t deleted = file->deleted;
2489
2490                if (file->is_unmerged ||
2491                    (!file->is_interesting && (added + deleted == 0))) {
2492                        total_files--;
2493                        continue;
2494                }
2495
2496                if (!file->is_binary) {
2497                        adds += added;
2498                        dels += deleted;
2499                }
2500                if (i < count)
2501                        continue;
2502                if (!extra_shown)
2503                        emit_diff_symbol(options,
2504                                         DIFF_SYMBOL_STATS_SUMMARY_ABBREV,
2505                                         NULL, 0, 0);
2506                extra_shown = 1;
2507        }
2508
2509        print_stat_summary_inserts_deletes(options, total_files, adds, dels);
2510        strbuf_release(&out);
2511}
2512
2513static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
2514{
2515        int i, adds = 0, dels = 0, total_files = data->nr;
2516
2517        if (data->nr == 0)
2518                return;
2519
2520        for (i = 0; i < data->nr; i++) {
2521                int added = data->files[i]->added;
2522                int deleted = data->files[i]->deleted;
2523
2524                if (data->files[i]->is_unmerged ||
2525                    (!data->files[i]->is_interesting && (added + deleted == 0))) {
2526                        total_files--;
2527                } else if (!data->files[i]->is_binary) { /* don't count bytes */
2528                        adds += added;
2529                        dels += deleted;
2530                }
2531        }
2532        print_stat_summary_inserts_deletes(options, total_files, adds, dels);
2533}
2534
2535static void show_numstat(struct diffstat_t *data, struct diff_options *options)
2536{
2537        int i;
2538
2539        if (data->nr == 0)
2540                return;
2541
2542        for (i = 0; i < data->nr; i++) {
2543                struct diffstat_file *file = data->files[i];
2544
2545                fprintf(options->file, "%s", diff_line_prefix(options));
2546
2547                if (file->is_binary)
2548                        fprintf(options->file, "-\t-\t");
2549                else
2550                        fprintf(options->file,
2551                                "%"PRIuMAX"\t%"PRIuMAX"\t",
2552                                file->added, file->deleted);
2553                if (options->line_termination) {
2554                        fill_print_name(file);
2555                        if (!file->is_renamed)
2556                                write_name_quoted(file->name, options->file,
2557                                                  options->line_termination);
2558                        else {
2559                                fputs(file->print_name, options->file);
2560                                putc(options->line_termination, options->file);
2561                        }
2562                } else {
2563                        if (file->is_renamed) {
2564                                putc('\0', options->file);
2565                                write_name_quoted(file->from_name, options->file, '\0');
2566                        }
2567                        write_name_quoted(file->name, options->file, '\0');
2568                }
2569        }
2570}
2571
2572struct dirstat_file {
2573        const char *name;
2574        unsigned long changed;
2575};
2576
2577struct dirstat_dir {
2578        struct dirstat_file *files;
2579        int alloc, nr, permille, cumulative;
2580};
2581
2582static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
2583                unsigned long changed, const char *base, int baselen)
2584{
2585        unsigned long sum_changes = 0;
2586        unsigned int sources = 0;
2587        const char *line_prefix = diff_line_prefix(opt);
2588
2589        while (dir->nr) {
2590                struct dirstat_file *f = dir->files;
2591                int namelen = strlen(f->name);
2592                unsigned long changes;
2593                char *slash;
2594
2595                if (namelen < baselen)
2596                        break;
2597                if (memcmp(f->name, base, baselen))
2598                        break;
2599                slash = strchr(f->name + baselen, '/');
2600                if (slash) {
2601                        int newbaselen = slash + 1 - f->name;
2602                        changes = gather_dirstat(opt, dir, changed, f->name, newbaselen);
2603                        sources++;
2604                } else {
2605                        changes = f->changed;
2606                        dir->files++;
2607                        dir->nr--;
2608                        sources += 2;
2609                }
2610                sum_changes += changes;
2611        }
2612
2613        /*
2614         * We don't report dirstat's for
2615         *  - the top level
2616         *  - or cases where everything came from a single directory
2617         *    under this directory (sources == 1).
2618         */
2619        if (baselen && sources != 1) {
2620                if (sum_changes) {
2621                        int permille = sum_changes * 1000 / changed;
2622                        if (permille >= dir->permille) {
2623                                fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
2624                                        permille / 10, permille % 10, baselen, base);
2625                                if (!dir->cumulative)
2626                                        return 0;
2627                        }
2628                }
2629        }
2630        return sum_changes;
2631}
2632
2633static int dirstat_compare(const void *_a, const void *_b)
2634{
2635        const struct dirstat_file *a = _a;
2636        const struct dirstat_file *b = _b;
2637        return strcmp(a->name, b->name);
2638}
2639
2640static void show_dirstat(struct diff_options *options)
2641{
2642        int i;
2643        unsigned long changed;
2644        struct dirstat_dir dir;
2645        struct diff_queue_struct *q = &diff_queued_diff;
2646
2647        dir.files = NULL;
2648        dir.alloc = 0;
2649        dir.nr = 0;
2650        dir.permille = options->dirstat_permille;
2651        dir.cumulative = options->flags.dirstat_cumulative;
2652
2653        changed = 0;
2654        for (i = 0; i < q->nr; i++) {
2655                struct diff_filepair *p = q->queue[i];
2656                const char *name;
2657                unsigned long copied, added, damage;
2658                int content_changed;
2659
2660                name = p->two->path ? p->two->path : p->one->path;
2661
2662                if (p->one->oid_valid && p->two->oid_valid)
2663                        content_changed = oidcmp(&p->one->oid, &p->two->oid);
2664                else
2665                        content_changed = 1;
2666
2667                if (!content_changed) {
2668                        /*
2669                         * The SHA1 has not changed, so pre-/post-content is
2670                         * identical. We can therefore skip looking at the
2671                         * file contents altogether.
2672                         */
2673                        damage = 0;
2674                        goto found_damage;
2675                }
2676
2677                if (options->flags.dirstat_by_file) {
2678                        /*
2679                         * In --dirstat-by-file mode, we don't really need to
2680                         * look at the actual file contents at all.
2681                         * The fact that the SHA1 changed is enough for us to
2682                         * add this file to the list of results
2683                         * (with each file contributing equal damage).
2684                         */
2685                        damage = 1;
2686                        goto found_damage;
2687                }
2688
2689                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
2690                        diff_populate_filespec(p->one, 0);
2691                        diff_populate_filespec(p->two, 0);
2692                        diffcore_count_changes(p->one, p->two, NULL, NULL,
2693                                               &copied, &added);
2694                        diff_free_filespec_data(p->one);
2695                        diff_free_filespec_data(p->two);
2696                } else if (DIFF_FILE_VALID(p->one)) {
2697                        diff_populate_filespec(p->one, CHECK_SIZE_ONLY);
2698                        copied = added = 0;
2699                        diff_free_filespec_data(p->one);
2700                } else if (DIFF_FILE_VALID(p->two)) {
2701                        diff_populate_filespec(p->two, CHECK_SIZE_ONLY);
2702                        copied = 0;
2703                        added = p->two->size;
2704                        diff_free_filespec_data(p->two);
2705                } else
2706                        continue;
2707
2708                /*
2709                 * Original minus copied is the removed material,
2710                 * added is the new material.  They are both damages
2711                 * made to the preimage.
2712                 * If the resulting damage is zero, we know that
2713                 * diffcore_count_changes() considers the two entries to
2714                 * be identical, but since content_changed is true, we
2715                 * know that there must have been _some_ kind of change,
2716                 * so we force all entries to have damage > 0.
2717                 */
2718                damage = (p->one->size - copied) + added;
2719                if (!damage)
2720                        damage = 1;
2721
2722found_damage:
2723                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
2724                dir.files[dir.nr].name = name;
2725                dir.files[dir.nr].changed = damage;
2726                changed += damage;
2727                dir.nr++;
2728        }
2729
2730        /* This can happen even with many files, if everything was renames */
2731        if (!changed)
2732                return;
2733
2734        /* Show all directories with more than x% of the changes */
2735        QSORT(dir.files, dir.nr, dirstat_compare);
2736        gather_dirstat(options, &dir, changed, "", 0);
2737}
2738
2739static void show_dirstat_by_line(struct diffstat_t *data, struct diff_options *options)
2740{
2741        int i;
2742        unsigned long changed;
2743        struct dirstat_dir dir;
2744
2745        if (data->nr == 0)
2746                return;
2747
2748        dir.files = NULL;
2749        dir.alloc = 0;
2750        dir.nr = 0;
2751        dir.permille = options->dirstat_permille;
2752        dir.cumulative = options->flags.dirstat_cumulative;
2753
2754        changed = 0;
2755        for (i = 0; i < data->nr; i++) {
2756                struct diffstat_file *file = data->files[i];
2757                unsigned long damage = file->added + file->deleted;
2758                if (file->is_binary)
2759                        /*
2760                         * binary files counts bytes, not lines. Must find some
2761                         * way to normalize binary bytes vs. textual lines.
2762                         * The following heuristic assumes that there are 64
2763                         * bytes per "line".
2764                         * This is stupid and ugly, but very cheap...
2765                         */
2766                        damage = DIV_ROUND_UP(damage, 64);
2767                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
2768                dir.files[dir.nr].name = file->name;
2769                dir.files[dir.nr].changed = damage;
2770                changed += damage;
2771                dir.nr++;
2772        }
2773
2774        /* This can happen even with many files, if everything was renames */
2775        if (!changed)
2776                return;
2777
2778        /* Show all directories with more than x% of the changes */
2779        QSORT(dir.files, dir.nr, dirstat_compare);
2780        gather_dirstat(options, &dir, changed, "", 0);
2781}
2782
2783static void free_diffstat_info(struct diffstat_t *diffstat)
2784{
2785        int i;
2786        for (i = 0; i < diffstat->nr; i++) {
2787                struct diffstat_file *f = diffstat->files[i];
2788                free(f->print_name);
2789                free(f->name);
2790                free(f->from_name);
2791                free(f);
2792        }
2793        free(diffstat->files);
2794}
2795
2796struct checkdiff_t {
2797        const char *filename;
2798        int lineno;
2799        int conflict_marker_size;
2800        struct diff_options *o;
2801        unsigned ws_rule;
2802        unsigned status;
2803};
2804
2805static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
2806{
2807        char firstchar;
2808        int cnt;
2809
2810        if (len < marker_size + 1)
2811                return 0;
2812        firstchar = line[0];
2813        switch (firstchar) {
2814        case '=': case '>': case '<': case '|':
2815                break;
2816        default:
2817                return 0;
2818        }
2819        for (cnt = 1; cnt < marker_size; cnt++)
2820                if (line[cnt] != firstchar)
2821                        return 0;
2822        /* line[1] thru line[marker_size-1] are same as firstchar */
2823        if (len < marker_size + 1 || !isspace(line[marker_size]))
2824                return 0;
2825        return 1;
2826}
2827
2828static void checkdiff_consume(void *priv, char *line, unsigned long len)
2829{
2830        struct checkdiff_t *data = priv;
2831        int marker_size = data->conflict_marker_size;
2832        const char *ws = diff_get_color(data->o->use_color, DIFF_WHITESPACE);
2833        const char *reset = diff_get_color(data->o->use_color, DIFF_RESET);
2834        const char *set = diff_get_color(data->o->use_color, DIFF_FILE_NEW);
2835        char *err;
2836        const char *line_prefix;
2837
2838        assert(data->o);
2839        line_prefix = diff_line_prefix(data->o);
2840
2841        if (line[0] == '+') {
2842                unsigned bad;
2843                data->lineno++;
2844                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
2845                        data->status |= 1;
2846                        fprintf(data->o->file,
2847                                "%s%s:%d: leftover conflict marker\n",
2848                                line_prefix, data->filename, data->lineno);
2849                }
2850                bad = ws_check(line + 1, len - 1, data->ws_rule);
2851                if (!bad)
2852                        return;
2853                data->status |= bad;
2854                err = whitespace_error_string(bad);
2855                fprintf(data->o->file, "%s%s:%d: %s.\n",
2856                        line_prefix, data->filename, data->lineno, err);
2857                free(err);
2858                emit_line(data->o, set, reset, line, 1);
2859                ws_check_emit(line + 1, len - 1, data->ws_rule,
2860                              data->o->file, set, reset, ws);
2861        } else if (line[0] == ' ') {
2862                data->lineno++;
2863        } else if (line[0] == '@') {
2864                char *plus = strchr(line, '+');
2865                if (plus)
2866                        data->lineno = strtol(plus, NULL, 10) - 1;
2867                else
2868                        die("invalid diff");
2869        }
2870}
2871
2872static unsigned char *deflate_it(char *data,
2873                                 unsigned long size,
2874                                 unsigned long *result_size)
2875{
2876        int bound;
2877        unsigned char *deflated;
2878        git_zstream stream;
2879
2880        git_deflate_init(&stream, zlib_compression_level);
2881        bound = git_deflate_bound(&stream, size);
2882        deflated = xmalloc(bound);
2883        stream.next_out = deflated;
2884        stream.avail_out = bound;
2885
2886        stream.next_in = (unsigned char *)data;
2887        stream.avail_in = size;
2888        while (git_deflate(&stream, Z_FINISH) == Z_OK)
2889                ; /* nothing */
2890        git_deflate_end(&stream);
2891        *result_size = stream.total_out;
2892        return deflated;
2893}
2894
2895static void emit_binary_diff_body(struct diff_options *o,
2896                                  mmfile_t *one, mmfile_t *two)
2897{
2898        void *cp;
2899        void *delta;
2900        void *deflated;
2901        void *data;
2902        unsigned long orig_size;
2903        unsigned long delta_size;
2904        unsigned long deflate_size;
2905        unsigned long data_size;
2906
2907        /* We could do deflated delta, or we could do just deflated two,
2908         * whichever is smaller.
2909         */
2910        delta = NULL;
2911        deflated = deflate_it(two->ptr, two->size, &deflate_size);
2912        if (one->size && two->size) {
2913                delta = diff_delta(one->ptr, one->size,
2914                                   two->ptr, two->size,
2915                                   &delta_size, deflate_size);
2916                if (delta) {
2917                        void *to_free = delta;
2918                        orig_size = delta_size;
2919                        delta = deflate_it(delta, delta_size, &delta_size);
2920                        free(to_free);
2921                }
2922        }
2923
2924        if (delta && delta_size < deflate_size) {
2925                char *s = xstrfmt("%lu", orig_size);
2926                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA,
2927                                 s, strlen(s), 0);
2928                free(s);
2929                free(deflated);
2930                data = delta;
2931                data_size = delta_size;
2932        } else {
2933                char *s = xstrfmt("%lu", two->size);
2934                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL,
2935                                 s, strlen(s), 0);
2936                free(s);
2937                free(delta);
2938                data = deflated;
2939                data_size = deflate_size;
2940        }
2941
2942        /* emit data encoded in base85 */
2943        cp = data;
2944        while (data_size) {
2945                int len;
2946                int bytes = (52 < data_size) ? 52 : data_size;
2947                char line[71];
2948                data_size -= bytes;
2949                if (bytes <= 26)
2950                        line[0] = bytes + 'A' - 1;
2951                else
2952                        line[0] = bytes - 26 + 'a' - 1;
2953                encode_85(line + 1, cp, bytes);
2954                cp = (char *) cp + bytes;
2955
2956                len = strlen(line);
2957                line[len++] = '\n';
2958                line[len] = '\0';
2959
2960                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_BODY,
2961                                 line, len, 0);
2962        }
2963        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_FOOTER, NULL, 0, 0);
2964        free(data);
2965}
2966
2967static void emit_binary_diff(struct diff_options *o,
2968                             mmfile_t *one, mmfile_t *two)
2969{
2970        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER, NULL, 0, 0);
2971        emit_binary_diff_body(o, one, two);
2972        emit_binary_diff_body(o, two, one);
2973}
2974
2975int diff_filespec_is_binary(struct diff_filespec *one)
2976{
2977        if (one->is_binary == -1) {
2978                diff_filespec_load_driver(one);
2979                if (one->driver->binary != -1)
2980                        one->is_binary = one->driver->binary;
2981                else {
2982                        if (!one->data && DIFF_FILE_VALID(one))
2983                                diff_populate_filespec(one, CHECK_BINARY);
2984                        if (one->is_binary == -1 && one->data)
2985                                one->is_binary = buffer_is_binary(one->data,
2986                                                one->size);
2987                        if (one->is_binary == -1)
2988                                one->is_binary = 0;
2989                }
2990        }
2991        return one->is_binary;
2992}
2993
2994static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
2995{
2996        diff_filespec_load_driver(one);
2997        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
2998}
2999
3000void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
3001{
3002        if (!options->a_prefix)
3003                options->a_prefix = a;
3004        if (!options->b_prefix)
3005                options->b_prefix = b;
3006}
3007
3008struct userdiff_driver *get_textconv(struct diff_filespec *one)
3009{
3010        if (!DIFF_FILE_VALID(one))
3011                return NULL;
3012
3013        diff_filespec_load_driver(one);
3014        return userdiff_get_textconv(one->driver);
3015}
3016
3017static void builtin_diff(const char *name_a,
3018                         const char *name_b,
3019                         struct diff_filespec *one,
3020                         struct diff_filespec *two,
3021                         const char *xfrm_msg,
3022                         int must_show_header,
3023                         struct diff_options *o,
3024                         int complete_rewrite)
3025{
3026        mmfile_t mf1, mf2;
3027        const char *lbl[2];
3028        char *a_one, *b_two;
3029        const char *meta = diff_get_color_opt(o, DIFF_METAINFO);
3030        const char *reset = diff_get_color_opt(o, DIFF_RESET);
3031        const char *a_prefix, *b_prefix;
3032        struct userdiff_driver *textconv_one = NULL;
3033        struct userdiff_driver *textconv_two = NULL;
3034        struct strbuf header = STRBUF_INIT;
3035        const char *line_prefix = diff_line_prefix(o);
3036
3037        diff_set_mnemonic_prefix(o, "a/", "b/");
3038        if (o->flags.reverse_diff) {
3039                a_prefix = o->b_prefix;
3040                b_prefix = o->a_prefix;
3041        } else {
3042                a_prefix = o->a_prefix;
3043                b_prefix = o->b_prefix;
3044        }
3045
3046        if (o->submodule_format == DIFF_SUBMODULE_LOG &&
3047            (!one->mode || S_ISGITLINK(one->mode)) &&
3048            (!two->mode || S_ISGITLINK(two->mode))) {
3049                show_submodule_summary(o, one->path ? one->path : two->path,
3050                                &one->oid, &two->oid,
3051                                two->dirty_submodule);
3052                return;
3053        } else if (o->submodule_format == DIFF_SUBMODULE_INLINE_DIFF &&
3054                   (!one->mode || S_ISGITLINK(one->mode)) &&
3055                   (!two->mode || S_ISGITLINK(two->mode))) {
3056                show_submodule_inline_diff(o, one->path ? one->path : two->path,
3057                                &one->oid, &two->oid,
3058                                two->dirty_submodule);
3059                return;
3060        }
3061
3062        if (o->flags.allow_textconv) {
3063                textconv_one = get_textconv(one);
3064                textconv_two = get_textconv(two);
3065        }
3066
3067        /* Never use a non-valid filename anywhere if at all possible */
3068        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
3069        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
3070
3071        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
3072        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
3073        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
3074        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
3075        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, meta, a_one, b_two, reset);
3076        if (lbl[0][0] == '/') {
3077                /* /dev/null */
3078                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, meta, two->mode, reset);
3079                if (xfrm_msg)
3080                        strbuf_addstr(&header, xfrm_msg);
3081                must_show_header = 1;
3082        }
3083        else if (lbl[1][0] == '/') {
3084                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, meta, one->mode, reset);
3085                if (xfrm_msg)
3086                        strbuf_addstr(&header, xfrm_msg);
3087                must_show_header = 1;
3088        }
3089        else {
3090                if (one->mode != two->mode) {
3091                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, meta, one->mode, reset);
3092                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, meta, two->mode, reset);
3093                        must_show_header = 1;
3094                }
3095                if (xfrm_msg)
3096                        strbuf_addstr(&header, xfrm_msg);
3097
3098                /*
3099                 * we do not run diff between different kind
3100                 * of objects.
3101                 */
3102                if ((one->mode ^ two->mode) & S_IFMT)
3103                        goto free_ab_and_return;
3104                if (complete_rewrite &&
3105                    (textconv_one || !diff_filespec_is_binary(one)) &&
3106                    (textconv_two || !diff_filespec_is_binary(two))) {
3107                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3108                                         header.buf, header.len, 0);
3109                        strbuf_reset(&header);
3110                        emit_rewrite_diff(name_a, name_b, one, two,
3111                                                textconv_one, textconv_two, o);
3112                        o->found_changes = 1;
3113                        goto free_ab_and_return;
3114                }
3115        }
3116
3117        if (o->irreversible_delete && lbl[1][0] == '/') {
3118                emit_diff_symbol(o, DIFF_SYMBOL_HEADER, header.buf,
3119                                 header.len, 0);
3120                strbuf_reset(&header);
3121                goto free_ab_and_return;
3122        } else if (!o->flags.text &&
3123            ( (!textconv_one && diff_filespec_is_binary(one)) ||
3124              (!textconv_two && diff_filespec_is_binary(two)) )) {
3125                struct strbuf sb = STRBUF_INIT;
3126                if (!one->data && !two->data &&
3127                    S_ISREG(one->mode) && S_ISREG(two->mode) &&
3128                    !o->flags.binary) {
3129                        if (!oidcmp(&one->oid, &two->oid)) {
3130                                if (must_show_header)
3131                                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3132                                                         header.buf, header.len,
3133                                                         0);
3134                                goto free_ab_and_return;
3135                        }
3136                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3137                                         header.buf, header.len, 0);
3138                        strbuf_addf(&sb, "%sBinary files %s and %s differ\n",
3139                                    diff_line_prefix(o), lbl[0], lbl[1]);
3140                        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_FILES,
3141                                         sb.buf, sb.len, 0);
3142                        strbuf_release(&sb);
3143                        goto free_ab_and_return;
3144                }
3145                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
3146                        die("unable to read files to diff");
3147                /* Quite common confusing case */
3148                if (mf1.size == mf2.size &&
3149                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
3150                        if (must_show_header)
3151                                emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3152                                                 header.buf, header.len, 0);
3153                        goto free_ab_and_return;
3154                }
3155                emit_diff_symbol(o, DIFF_SYMBOL_HEADER, header.buf, header.len, 0);
3156                strbuf_reset(&header);
3157                if (o->flags.binary)
3158                        emit_binary_diff(o, &mf1, &mf2);
3159                else {
3160                        strbuf_addf(&sb, "%sBinary files %s and %s differ\n",
3161                                    diff_line_prefix(o), lbl[0], lbl[1]);
3162                        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_FILES,
3163                                         sb.buf, sb.len, 0);
3164                        strbuf_release(&sb);
3165                }
3166                o->found_changes = 1;
3167        } else {
3168                /* Crazy xdl interfaces.. */
3169                const char *diffopts = getenv("GIT_DIFF_OPTS");
3170                const char *v;
3171                xpparam_t xpp;
3172                xdemitconf_t xecfg;
3173                struct emit_callback ecbdata;
3174                const struct userdiff_funcname *pe;
3175
3176                if (must_show_header) {
3177                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3178                                         header.buf, header.len, 0);
3179                        strbuf_reset(&header);
3180                }
3181
3182                mf1.size = fill_textconv(textconv_one, one, &mf1.ptr);
3183                mf2.size = fill_textconv(textconv_two, two, &mf2.ptr);
3184
3185                pe = diff_funcname_pattern(one);
3186                if (!pe)
3187                        pe = diff_funcname_pattern(two);
3188
3189                memset(&xpp, 0, sizeof(xpp));
3190                memset(&xecfg, 0, sizeof(xecfg));
3191                memset(&ecbdata, 0, sizeof(ecbdata));
3192                ecbdata.label_path = lbl;
3193                ecbdata.color_diff = want_color(o->use_color);
3194                ecbdata.ws_rule = whitespace_rule(name_b);
3195                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
3196                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
3197                ecbdata.opt = o;
3198                ecbdata.header = header.len ? &header : NULL;
3199                xpp.flags = o->xdl_opts;
3200                xpp.anchors = o->anchors;
3201                xpp.anchors_nr = o->anchors_nr;
3202                xecfg.ctxlen = o->context;
3203                xecfg.interhunkctxlen = o->interhunkcontext;
3204                xecfg.flags = XDL_EMIT_FUNCNAMES;
3205                if (o->flags.funccontext)
3206                        xecfg.flags |= XDL_EMIT_FUNCCONTEXT;
3207                if (pe)
3208                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
3209                if (!diffopts)
3210                        ;
3211                else if (skip_prefix(diffopts, "--unified=", &v))
3212                        xecfg.ctxlen = strtoul(v, NULL, 10);
3213                else if (skip_prefix(diffopts, "-u", &v))
3214                        xecfg.ctxlen = strtoul(v, NULL, 10);
3215                if (o->word_diff)
3216                        init_diff_words_data(&ecbdata, o, one, two);
3217                if (xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
3218                                  &xpp, &xecfg))
3219                        die("unable to generate diff for %s", one->path);
3220                if (o->word_diff)
3221                        free_diff_words_data(&ecbdata);
3222                if (textconv_one)
3223                        free(mf1.ptr);
3224                if (textconv_two)
3225                        free(mf2.ptr);
3226                xdiff_clear_find_func(&xecfg);
3227        }
3228
3229 free_ab_and_return:
3230        strbuf_release(&header);
3231        diff_free_filespec_data(one);
3232        diff_free_filespec_data(two);
3233        free(a_one);
3234        free(b_two);
3235        return;
3236}
3237
3238static char *get_compact_summary(const struct diff_filepair *p, int is_renamed)
3239{
3240        if (!is_renamed) {
3241                if (p->status == DIFF_STATUS_ADDED) {
3242                        if (S_ISLNK(p->two->mode))
3243                                return "new +l";
3244                        else if ((p->two->mode & 0777) == 0755)
3245                                return "new +x";
3246                        else
3247                                return "new";
3248                } else if (p->status == DIFF_STATUS_DELETED)
3249                        return "gone";
3250        }
3251        if (S_ISLNK(p->one->mode) && !S_ISLNK(p->two->mode))
3252                return "mode -l";
3253        else if (!S_ISLNK(p->one->mode) && S_ISLNK(p->two->mode))
3254                return "mode +l";
3255        else if ((p->one->mode & 0777) == 0644 &&
3256                 (p->two->mode & 0777) == 0755)
3257                return "mode +x";
3258        else if ((p->one->mode & 0777) == 0755 &&
3259                 (p->two->mode & 0777) == 0644)
3260                return "mode -x";
3261        return NULL;
3262}
3263
3264static void builtin_diffstat(const char *name_a, const char *name_b,
3265                             struct diff_filespec *one,
3266                             struct diff_filespec *two,
3267                             struct diffstat_t *diffstat,
3268                             struct diff_options *o,
3269                             struct diff_filepair *p)
3270{
3271        mmfile_t mf1, mf2;
3272        struct diffstat_file *data;
3273        int same_contents;
3274        int complete_rewrite = 0;
3275
3276        if (!DIFF_PAIR_UNMERGED(p)) {
3277                if (p->status == DIFF_STATUS_MODIFIED && p->score)
3278                        complete_rewrite = 1;
3279        }
3280
3281        data = diffstat_add(diffstat, name_a, name_b);
3282        data->is_interesting = p->status != DIFF_STATUS_UNKNOWN;
3283        if (o->flags.stat_with_summary)
3284                data->comments = get_compact_summary(p, data->is_renamed);
3285
3286        if (!one || !two) {
3287                data->is_unmerged = 1;
3288                return;
3289        }
3290
3291        same_contents = !oidcmp(&one->oid, &two->oid);
3292
3293        if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
3294                data->is_binary = 1;
3295                if (same_contents) {
3296                        data->added = 0;
3297                        data->deleted = 0;
3298                } else {
3299                        data->added = diff_filespec_size(two);
3300                        data->deleted = diff_filespec_size(one);
3301                }
3302        }
3303
3304        else if (complete_rewrite) {
3305                diff_populate_filespec(one, 0);
3306                diff_populate_filespec(two, 0);
3307                data->deleted = count_lines(one->data, one->size);
3308                data->added = count_lines(two->data, two->size);
3309        }
3310
3311        else if (!same_contents) {
3312                /* Crazy xdl interfaces.. */
3313                xpparam_t xpp;
3314                xdemitconf_t xecfg;
3315
3316                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
3317                        die("unable to read files to diff");
3318
3319                memset(&xpp, 0, sizeof(xpp));
3320                memset(&xecfg, 0, sizeof(xecfg));
3321                xpp.flags = o->xdl_opts;
3322                xpp.anchors = o->anchors;
3323                xpp.anchors_nr = o->anchors_nr;
3324                xecfg.ctxlen = o->context;
3325                xecfg.interhunkctxlen = o->interhunkcontext;
3326                if (xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
3327                                  &xpp, &xecfg))
3328                        die("unable to generate diffstat for %s", one->path);
3329        }
3330
3331        diff_free_filespec_data(one);
3332        diff_free_filespec_data(two);
3333}
3334
3335static void builtin_checkdiff(const char *name_a, const char *name_b,
3336                              const char *attr_path,
3337                              struct diff_filespec *one,
3338                              struct diff_filespec *two,
3339                              struct diff_options *o)
3340{
3341        mmfile_t mf1, mf2;
3342        struct checkdiff_t data;
3343
3344        if (!two)
3345                return;
3346
3347        memset(&data, 0, sizeof(data));
3348        data.filename = name_b ? name_b : name_a;
3349        data.lineno = 0;
3350        data.o = o;
3351        data.ws_rule = whitespace_rule(attr_path);
3352        data.conflict_marker_size = ll_merge_marker_size(attr_path);
3353
3354        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
3355                die("unable to read files to diff");
3356
3357        /*
3358         * All the other codepaths check both sides, but not checking
3359         * the "old" side here is deliberate.  We are checking the newly
3360         * introduced changes, and as long as the "new" side is text, we
3361         * can and should check what it introduces.
3362         */
3363        if (diff_filespec_is_binary(two))
3364                goto free_and_return;
3365        else {
3366                /* Crazy xdl interfaces.. */
3367                xpparam_t xpp;
3368                xdemitconf_t xecfg;
3369
3370                memset(&xpp, 0, sizeof(xpp));
3371                memset(&xecfg, 0, sizeof(xecfg));
3372                xecfg.ctxlen = 1; /* at least one context line */
3373                xpp.flags = 0;
3374                if (xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
3375                                  &xpp, &xecfg))
3376                        die("unable to generate checkdiff for %s", one->path);
3377
3378                if (data.ws_rule & WS_BLANK_AT_EOF) {
3379                        struct emit_callback ecbdata;
3380                        int blank_at_eof;
3381
3382                        ecbdata.ws_rule = data.ws_rule;
3383                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
3384                        blank_at_eof = ecbdata.blank_at_eof_in_postimage;
3385
3386                        if (blank_at_eof) {
3387                                static char *err;
3388                                if (!err)
3389                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
3390                                fprintf(o->file, "%s:%d: %s.\n",
3391                                        data.filename, blank_at_eof, err);
3392                                data.status = 1; /* report errors */
3393                        }
3394                }
3395        }
3396 free_and_return:
3397        diff_free_filespec_data(one);
3398        diff_free_filespec_data(two);
3399        if (data.status)
3400                o->flags.check_failed = 1;
3401}
3402
3403struct diff_filespec *alloc_filespec(const char *path)
3404{
3405        struct diff_filespec *spec;
3406
3407        FLEXPTR_ALLOC_STR(spec, path, path);
3408        spec->count = 1;
3409        spec->is_binary = -1;
3410        return spec;
3411}
3412
3413void free_filespec(struct diff_filespec *spec)
3414{
3415        if (!--spec->count) {
3416                diff_free_filespec_data(spec);
3417                free(spec);
3418        }
3419}
3420
3421void fill_filespec(struct diff_filespec *spec, const struct object_id *oid,
3422                   int oid_valid, unsigned short mode)
3423{
3424        if (mode) {
3425                spec->mode = canon_mode(mode);
3426                oidcpy(&spec->oid, oid);
3427                spec->oid_valid = oid_valid;
3428        }
3429}
3430
3431/*
3432 * Given a name and sha1 pair, if the index tells us the file in
3433 * the work tree has that object contents, return true, so that
3434 * prepare_temp_file() does not have to inflate and extract.
3435 */
3436static int reuse_worktree_file(const char *name, const struct object_id *oid, int want_file)
3437{
3438        const struct cache_entry *ce;
3439        struct stat st;
3440        int pos, len;
3441
3442        /*
3443         * We do not read the cache ourselves here, because the
3444         * benchmark with my previous version that always reads cache
3445         * shows that it makes things worse for diff-tree comparing
3446         * two linux-2.6 kernel trees in an already checked out work
3447         * tree.  This is because most diff-tree comparisons deal with
3448         * only a small number of files, while reading the cache is
3449         * expensive for a large project, and its cost outweighs the
3450         * savings we get by not inflating the object to a temporary
3451         * file.  Practically, this code only helps when we are used
3452         * by diff-cache --cached, which does read the cache before
3453         * calling us.
3454         */
3455        if (!active_cache)
3456                return 0;
3457
3458        /* We want to avoid the working directory if our caller
3459         * doesn't need the data in a normal file, this system
3460         * is rather slow with its stat/open/mmap/close syscalls,
3461         * and the object is contained in a pack file.  The pack
3462         * is probably already open and will be faster to obtain
3463         * the data through than the working directory.  Loose
3464         * objects however would tend to be slower as they need
3465         * to be individually opened and inflated.
3466         */
3467        if (!FAST_WORKING_DIRECTORY && !want_file && has_object_pack(oid))
3468                return 0;
3469
3470        /*
3471         * Similarly, if we'd have to convert the file contents anyway, that
3472         * makes the optimization not worthwhile.
3473         */
3474        if (!want_file && would_convert_to_git(&the_index, name))
3475                return 0;
3476
3477        len = strlen(name);
3478        pos = cache_name_pos(name, len);
3479        if (pos < 0)
3480                return 0;
3481        ce = active_cache[pos];
3482
3483        /*
3484         * This is not the sha1 we are looking for, or
3485         * unreusable because it is not a regular file.
3486         */
3487        if (oidcmp(oid, &ce->oid) || !S_ISREG(ce->ce_mode))
3488                return 0;
3489
3490        /*
3491         * If ce is marked as "assume unchanged", there is no
3492         * guarantee that work tree matches what we are looking for.
3493         */
3494        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
3495                return 0;
3496
3497        /*
3498         * If ce matches the file in the work tree, we can reuse it.
3499         */
3500        if (ce_uptodate(ce) ||
3501            (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
3502                return 1;
3503
3504        return 0;
3505}
3506
3507static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
3508{
3509        struct strbuf buf = STRBUF_INIT;
3510        char *dirty = "";
3511
3512        /* Are we looking at the work tree? */
3513        if (s->dirty_submodule)
3514                dirty = "-dirty";
3515
3516        strbuf_addf(&buf, "Subproject commit %s%s\n",
3517                    oid_to_hex(&s->oid), dirty);
3518        s->size = buf.len;
3519        if (size_only) {
3520                s->data = NULL;
3521                strbuf_release(&buf);
3522        } else {
3523                s->data = strbuf_detach(&buf, NULL);
3524                s->should_free = 1;
3525        }
3526        return 0;
3527}
3528
3529/*
3530 * While doing rename detection and pickaxe operation, we may need to
3531 * grab the data for the blob (or file) for our own in-core comparison.
3532 * diff_filespec has data and size fields for this purpose.
3533 */
3534int diff_populate_filespec(struct diff_filespec *s, unsigned int flags)
3535{
3536        int size_only = flags & CHECK_SIZE_ONLY;
3537        int err = 0;
3538        int conv_flags = global_conv_flags_eol;
3539        /*
3540         * demote FAIL to WARN to allow inspecting the situation
3541         * instead of refusing.
3542         */
3543        if (conv_flags & CONV_EOL_RNDTRP_DIE)
3544                conv_flags = CONV_EOL_RNDTRP_WARN;
3545
3546        if (!DIFF_FILE_VALID(s))
3547                die("internal error: asking to populate invalid file.");
3548        if (S_ISDIR(s->mode))
3549                return -1;
3550
3551        if (s->data)
3552                return 0;
3553
3554        if (size_only && 0 < s->size)
3555                return 0;
3556
3557        if (S_ISGITLINK(s->mode))
3558                return diff_populate_gitlink(s, size_only);
3559
3560        if (!s->oid_valid ||
3561            reuse_worktree_file(s->path, &s->oid, 0)) {
3562                struct strbuf buf = STRBUF_INIT;
3563                struct stat st;
3564                int fd;
3565
3566                if (lstat(s->path, &st) < 0) {
3567                err_empty:
3568                        err = -1;
3569                empty:
3570                        s->data = (char *)"";
3571                        s->size = 0;
3572                        return err;
3573                }
3574                s->size = xsize_t(st.st_size);
3575                if (!s->size)
3576                        goto empty;
3577                if (S_ISLNK(st.st_mode)) {
3578                        struct strbuf sb = STRBUF_INIT;
3579
3580                        if (strbuf_readlink(&sb, s->path, s->size))
3581                                goto err_empty;
3582                        s->size = sb.len;
3583                        s->data = strbuf_detach(&sb, NULL);
3584                        s->should_free = 1;
3585                        return 0;
3586                }
3587
3588                /*
3589                 * Even if the caller would be happy with getting
3590                 * only the size, we cannot return early at this
3591                 * point if the path requires us to run the content
3592                 * conversion.
3593                 */
3594                if (size_only && !would_convert_to_git(&the_index, s->path))
3595                        return 0;
3596
3597                /*
3598                 * Note: this check uses xsize_t(st.st_size) that may
3599                 * not be the true size of the blob after it goes
3600                 * through convert_to_git().  This may not strictly be
3601                 * correct, but the whole point of big_file_threshold
3602                 * and is_binary check being that we want to avoid
3603                 * opening the file and inspecting the contents, this
3604                 * is probably fine.
3605                 */
3606                if ((flags & CHECK_BINARY) &&
3607                    s->size > big_file_threshold && s->is_binary == -1) {
3608                        s->is_binary = 1;
3609                        return 0;
3610                }
3611                fd = open(s->path, O_RDONLY);
3612                if (fd < 0)
3613                        goto err_empty;
3614                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
3615                close(fd);
3616                s->should_munmap = 1;
3617
3618                /*
3619                 * Convert from working tree format to canonical git format
3620                 */
3621                if (convert_to_git(&the_index, s->path, s->data, s->size, &buf, conv_flags)) {
3622                        size_t size = 0;
3623                        munmap(s->data, s->size);
3624                        s->should_munmap = 0;
3625                        s->data = strbuf_detach(&buf, &size);
3626                        s->size = size;
3627                        s->should_free = 1;
3628                }
3629        }
3630        else {
3631                enum object_type type;
3632                if (size_only || (flags & CHECK_BINARY)) {
3633                        type = oid_object_info(the_repository, &s->oid,
3634                                               &s->size);
3635                        if (type < 0)
3636                                die("unable to read %s",
3637                                    oid_to_hex(&s->oid));
3638                        if (size_only)
3639                                return 0;
3640                        if (s->size > big_file_threshold && s->is_binary == -1) {
3641                                s->is_binary = 1;
3642                                return 0;
3643                        }
3644                }
3645                s->data = read_object_file(&s->oid, &type, &s->size);
3646                if (!s->data)
3647                        die("unable to read %s", oid_to_hex(&s->oid));
3648                s->should_free = 1;
3649        }
3650        return 0;
3651}
3652
3653void diff_free_filespec_blob(struct diff_filespec *s)
3654{
3655        if (s->should_free)
3656                free(s->data);
3657        else if (s->should_munmap)
3658                munmap(s->data, s->size);
3659
3660        if (s->should_free || s->should_munmap) {
3661                s->should_free = s->should_munmap = 0;
3662                s->data = NULL;
3663        }
3664}
3665
3666void diff_free_filespec_data(struct diff_filespec *s)
3667{
3668        diff_free_filespec_blob(s);
3669        FREE_AND_NULL(s->cnt_data);
3670}
3671
3672static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
3673                           void *blob,
3674                           unsigned long size,
3675                           const struct object_id *oid,
3676                           int mode)
3677{
3678        struct strbuf buf = STRBUF_INIT;
3679        struct strbuf tempfile = STRBUF_INIT;
3680        char *path_dup = xstrdup(path);
3681        const char *base = basename(path_dup);
3682
3683        /* Generate "XXXXXX_basename.ext" */
3684        strbuf_addstr(&tempfile, "XXXXXX_");
3685        strbuf_addstr(&tempfile, base);
3686
3687        temp->tempfile = mks_tempfile_ts(tempfile.buf, strlen(base) + 1);
3688        if (!temp->tempfile)
3689                die_errno("unable to create temp-file");
3690        if (convert_to_working_tree(path,
3691                        (const char *)blob, (size_t)size, &buf)) {
3692                blob = buf.buf;
3693                size = buf.len;
3694        }
3695        if (write_in_full(temp->tempfile->fd, blob, size) < 0 ||
3696            close_tempfile_gently(temp->tempfile))
3697                die_errno("unable to write temp-file");
3698        temp->name = get_tempfile_path(temp->tempfile);
3699        oid_to_hex_r(temp->hex, oid);
3700        xsnprintf(temp->mode, sizeof(temp->mode), "%06o", mode);
3701        strbuf_release(&buf);
3702        strbuf_release(&tempfile);
3703        free(path_dup);
3704}
3705
3706static struct diff_tempfile *prepare_temp_file(const char *name,
3707                struct diff_filespec *one)
3708{
3709        struct diff_tempfile *temp = claim_diff_tempfile();
3710
3711        if (!DIFF_FILE_VALID(one)) {
3712        not_a_valid_file:
3713                /* A '-' entry produces this for file-2, and
3714                 * a '+' entry produces this for file-1.
3715                 */
3716                temp->name = "/dev/null";
3717                xsnprintf(temp->hex, sizeof(temp->hex), ".");
3718                xsnprintf(temp->mode, sizeof(temp->mode), ".");
3719                return temp;
3720        }
3721
3722        if (!S_ISGITLINK(one->mode) &&
3723            (!one->oid_valid ||
3724             reuse_worktree_file(name, &one->oid, 1))) {
3725                struct stat st;
3726                if (lstat(name, &st) < 0) {
3727                        if (errno == ENOENT)
3728                                goto not_a_valid_file;
3729                        die_errno("stat(%s)", name);
3730                }
3731                if (S_ISLNK(st.st_mode)) {
3732                        struct strbuf sb = STRBUF_INIT;
3733                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
3734                                die_errno("readlink(%s)", name);
3735                        prep_temp_blob(name, temp, sb.buf, sb.len,
3736                                       (one->oid_valid ?
3737                                        &one->oid : &null_oid),
3738                                       (one->oid_valid ?
3739                                        one->mode : S_IFLNK));
3740                        strbuf_release(&sb);
3741                }
3742                else {
3743                        /* we can borrow from the file in the work tree */
3744                        temp->name = name;
3745                        if (!one->oid_valid)
3746                                oid_to_hex_r(temp->hex, &null_oid);
3747                        else
3748                                oid_to_hex_r(temp->hex, &one->oid);
3749                        /* Even though we may sometimes borrow the
3750                         * contents from the work tree, we always want
3751                         * one->mode.  mode is trustworthy even when
3752                         * !(one->oid_valid), as long as
3753                         * DIFF_FILE_VALID(one).
3754                         */
3755                        xsnprintf(temp->mode, sizeof(temp->mode), "%06o", one->mode);
3756                }
3757                return temp;
3758        }
3759        else {
3760                if (diff_populate_filespec(one, 0))
3761                        die("cannot read data blob for %s", one->path);
3762                prep_temp_blob(name, temp, one->data, one->size,
3763                               &one->oid, one->mode);
3764        }
3765        return temp;
3766}
3767
3768static void add_external_diff_name(struct argv_array *argv,
3769                                   const char *name,
3770                                   struct diff_filespec *df)
3771{
3772        struct diff_tempfile *temp = prepare_temp_file(name, df);
3773        argv_array_push(argv, temp->name);
3774        argv_array_push(argv, temp->hex);
3775        argv_array_push(argv, temp->mode);
3776}
3777
3778/* An external diff command takes:
3779 *
3780 * diff-cmd name infile1 infile1-sha1 infile1-mode \
3781 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
3782 *
3783 */
3784static void run_external_diff(const char *pgm,
3785                              const char *name,
3786                              const char *other,
3787                              struct diff_filespec *one,
3788                              struct diff_filespec *two,
3789                              const char *xfrm_msg,
3790                              int complete_rewrite,
3791                              struct diff_options *o)
3792{
3793        struct argv_array argv = ARGV_ARRAY_INIT;
3794        struct argv_array env = ARGV_ARRAY_INIT;
3795        struct diff_queue_struct *q = &diff_queued_diff;
3796
3797        argv_array_push(&argv, pgm);
3798        argv_array_push(&argv, name);
3799
3800        if (one && two) {
3801                add_external_diff_name(&argv, name, one);
3802                if (!other)
3803                        add_external_diff_name(&argv, name, two);
3804                else {
3805                        add_external_diff_name(&argv, other, two);
3806                        argv_array_push(&argv, other);
3807                        argv_array_push(&argv, xfrm_msg);
3808                }
3809        }
3810
3811        argv_array_pushf(&env, "GIT_DIFF_PATH_COUNTER=%d", ++o->diff_path_counter);
3812        argv_array_pushf(&env, "GIT_DIFF_PATH_TOTAL=%d", q->nr);
3813
3814        if (run_command_v_opt_cd_env(argv.argv, RUN_USING_SHELL, NULL, env.argv))
3815                die(_("external diff died, stopping at %s"), name);
3816
3817        remove_tempfile();
3818        argv_array_clear(&argv);
3819        argv_array_clear(&env);
3820}
3821
3822static int similarity_index(struct diff_filepair *p)
3823{
3824        return p->score * 100 / MAX_SCORE;
3825}
3826
3827static const char *diff_abbrev_oid(const struct object_id *oid, int abbrev)
3828{
3829        if (startup_info->have_repository)
3830                return find_unique_abbrev(oid, abbrev);
3831        else {
3832                char *hex = oid_to_hex(oid);
3833                if (abbrev < 0)
3834                        abbrev = FALLBACK_DEFAULT_ABBREV;
3835                if (abbrev > GIT_SHA1_HEXSZ)
3836                        BUG("oid abbreviation out of range: %d", abbrev);
3837                if (abbrev)
3838                        hex[abbrev] = '\0';
3839                return hex;
3840        }
3841}
3842
3843static void fill_metainfo(struct strbuf *msg,
3844                          const char *name,
3845                          const char *other,
3846                          struct diff_filespec *one,
3847                          struct diff_filespec *two,
3848                          struct diff_options *o,
3849                          struct diff_filepair *p,
3850                          int *must_show_header,
3851                          int use_color)
3852{
3853        const char *set = diff_get_color(use_color, DIFF_METAINFO);
3854        const char *reset = diff_get_color(use_color, DIFF_RESET);
3855        const char *line_prefix = diff_line_prefix(o);
3856
3857        *must_show_header = 1;
3858        strbuf_init(msg, PATH_MAX * 2 + 300);
3859        switch (p->status) {
3860        case DIFF_STATUS_COPIED:
3861                strbuf_addf(msg, "%s%ssimilarity index %d%%",
3862                            line_prefix, set, similarity_index(p));
3863                strbuf_addf(msg, "%s\n%s%scopy from ",
3864                            reset,  line_prefix, set);
3865                quote_c_style(name, msg, NULL, 0);
3866                strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
3867                quote_c_style(other, msg, NULL, 0);
3868                strbuf_addf(msg, "%s\n", reset);
3869                break;
3870        case DIFF_STATUS_RENAMED:
3871                strbuf_addf(msg, "%s%ssimilarity index %d%%",
3872                            line_prefix, set, similarity_index(p));
3873                strbuf_addf(msg, "%s\n%s%srename from ",
3874                            reset, line_prefix, set);
3875                quote_c_style(name, msg, NULL, 0);
3876                strbuf_addf(msg, "%s\n%s%srename to ",
3877                            reset, line_prefix, set);
3878                quote_c_style(other, msg, NULL, 0);
3879                strbuf_addf(msg, "%s\n", reset);
3880                break;
3881        case DIFF_STATUS_MODIFIED:
3882                if (p->score) {
3883                        strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
3884                                    line_prefix,
3885                                    set, similarity_index(p), reset);
3886                        break;
3887                }
3888                /* fallthru */
3889        default:
3890                *must_show_header = 0;
3891        }
3892        if (one && two && oidcmp(&one->oid, &two->oid)) {
3893                const unsigned hexsz = the_hash_algo->hexsz;
3894                int abbrev = o->flags.full_index ? hexsz : DEFAULT_ABBREV;
3895
3896                if (o->flags.binary) {
3897                        mmfile_t mf;
3898                        if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
3899                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
3900                                abbrev = hexsz;
3901                }
3902                strbuf_addf(msg, "%s%sindex %s..%s", line_prefix, set,
3903                            diff_abbrev_oid(&one->oid, abbrev),
3904                            diff_abbrev_oid(&two->oid, abbrev));
3905                if (one->mode == two->mode)
3906                        strbuf_addf(msg, " %06o", one->mode);
3907                strbuf_addf(msg, "%s\n", reset);
3908        }
3909}
3910
3911static void run_diff_cmd(const char *pgm,
3912                         const char *name,
3913                         const char *other,
3914                         const char *attr_path,
3915                         struct diff_filespec *one,
3916                         struct diff_filespec *two,
3917                         struct strbuf *msg,
3918                         struct diff_options *o,
3919                         struct diff_filepair *p)
3920{
3921        const char *xfrm_msg = NULL;
3922        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
3923        int must_show_header = 0;
3924
3925
3926        if (o->flags.allow_external) {
3927                struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
3928                if (drv && drv->external)
3929                        pgm = drv->external;
3930        }
3931
3932        if (msg) {
3933                /*
3934                 * don't use colors when the header is intended for an
3935                 * external diff driver
3936                 */
3937                fill_metainfo(msg, name, other, one, two, o, p,
3938                              &must_show_header,
3939                              want_color(o->use_color) && !pgm);
3940                xfrm_msg = msg->len ? msg->buf : NULL;
3941        }
3942
3943        if (pgm) {
3944                run_external_diff(pgm, name, other, one, two, xfrm_msg,
3945                                  complete_rewrite, o);
3946                return;
3947        }
3948        if (one && two)
3949                builtin_diff(name, other ? other : name,
3950                             one, two, xfrm_msg, must_show_header,
3951                             o, complete_rewrite);
3952        else
3953                fprintf(o->file, "* Unmerged path %s\n", name);
3954}
3955
3956static void diff_fill_oid_info(struct diff_filespec *one)
3957{
3958        if (DIFF_FILE_VALID(one)) {
3959                if (!one->oid_valid) {
3960                        struct stat st;
3961                        if (one->is_stdin) {
3962                                oidclr(&one->oid);
3963                                return;
3964                        }
3965                        if (lstat(one->path, &st) < 0)
3966                                die_errno("stat '%s'", one->path);
3967                        if (index_path(&one->oid, one->path, &st, 0))
3968                                die("cannot hash %s", one->path);
3969                }
3970        }
3971        else
3972                oidclr(&one->oid);
3973}
3974
3975static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
3976{
3977        /* Strip the prefix but do not molest /dev/null and absolute paths */
3978        if (*namep && **namep != '/') {
3979                *namep += prefix_length;
3980                if (**namep == '/')
3981                        ++*namep;
3982        }
3983        if (*otherp && **otherp != '/') {
3984                *otherp += prefix_length;
3985                if (**otherp == '/')
3986                        ++*otherp;
3987        }
3988}
3989
3990static void run_diff(struct diff_filepair *p, struct diff_options *o)
3991{
3992        const char *pgm = external_diff();
3993        struct strbuf msg;
3994        struct diff_filespec *one = p->one;
3995        struct diff_filespec *two = p->two;
3996        const char *name;
3997        const char *other;
3998        const char *attr_path;
3999
4000        name  = one->path;
4001        other = (strcmp(name, two->path) ? two->path : NULL);
4002        attr_path = name;
4003        if (o->prefix_length)
4004                strip_prefix(o->prefix_length, &name, &other);
4005
4006        if (!o->flags.allow_external)
4007                pgm = NULL;
4008
4009        if (DIFF_PAIR_UNMERGED(p)) {
4010                run_diff_cmd(pgm, name, NULL, attr_path,
4011                             NULL, NULL, NULL, o, p);
4012                return;
4013        }
4014
4015        diff_fill_oid_info(one);
4016        diff_fill_oid_info(two);
4017
4018        if (!pgm &&
4019            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
4020            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
4021                /*
4022                 * a filepair that changes between file and symlink
4023                 * needs to be split into deletion and creation.
4024                 */
4025                struct diff_filespec *null = alloc_filespec(two->path);
4026                run_diff_cmd(NULL, name, other, attr_path,
4027                             one, null, &msg, o, p);
4028                free(null);
4029                strbuf_release(&msg);
4030
4031                null = alloc_filespec(one->path);
4032                run_diff_cmd(NULL, name, other, attr_path,
4033                             null, two, &msg, o, p);
4034                free(null);
4035        }
4036        else
4037                run_diff_cmd(pgm, name, other, attr_path,
4038                             one, two, &msg, o, p);
4039
4040        strbuf_release(&msg);
4041}
4042
4043static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
4044                         struct diffstat_t *diffstat)
4045{
4046        const char *name;
4047        const char *other;
4048
4049        if (DIFF_PAIR_UNMERGED(p)) {
4050                /* unmerged */
4051                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, p);
4052                return;
4053        }
4054
4055        name = p->one->path;
4056        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
4057
4058        if (o->prefix_length)
4059                strip_prefix(o->prefix_length, &name, &other);
4060
4061        diff_fill_oid_info(p->one);
4062        diff_fill_oid_info(p->two);
4063
4064        builtin_diffstat(name, other, p->one, p->two, diffstat, o, p);
4065}
4066
4067static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
4068{
4069        const char *name;
4070        const char *other;
4071        const char *attr_path;
4072
4073        if (DIFF_PAIR_UNMERGED(p)) {
4074                /* unmerged */
4075                return;
4076        }
4077
4078        name = p->one->path;
4079        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
4080        attr_path = other ? other : name;
4081
4082        if (o->prefix_length)
4083                strip_prefix(o->prefix_length, &name, &other);
4084
4085        diff_fill_oid_info(p->one);
4086        diff_fill_oid_info(p->two);
4087
4088        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
4089}
4090
4091void diff_setup(struct diff_options *options)
4092{
4093        memcpy(options, &default_diff_options, sizeof(*options));
4094
4095        options->file = stdout;
4096
4097        options->abbrev = DEFAULT_ABBREV;
4098        options->line_termination = '\n';
4099        options->break_opt = -1;
4100        options->rename_limit = -1;
4101        options->dirstat_permille = diff_dirstat_permille_default;
4102        options->context = diff_context_default;
4103        options->interhunkcontext = diff_interhunk_context_default;
4104        options->ws_error_highlight = ws_error_highlight_default;
4105        options->flags.rename_empty = 1;
4106        options->objfind = NULL;
4107
4108        /* pathchange left =NULL by default */
4109        options->change = diff_change;
4110        options->add_remove = diff_addremove;
4111        options->use_color = diff_use_color_default;
4112        options->detect_rename = diff_detect_rename_default;
4113        options->xdl_opts |= diff_algorithm;
4114        if (diff_indent_heuristic)
4115                DIFF_XDL_SET(options, INDENT_HEURISTIC);
4116
4117        options->orderfile = diff_order_file_cfg;
4118
4119        if (diff_no_prefix) {
4120                options->a_prefix = options->b_prefix = "";
4121        } else if (!diff_mnemonic_prefix) {
4122                options->a_prefix = "a/";
4123                options->b_prefix = "b/";
4124        }
4125
4126        options->color_moved = diff_color_moved_default;
4127}
4128
4129void diff_setup_done(struct diff_options *options)
4130{
4131        unsigned check_mask = DIFF_FORMAT_NAME |
4132                              DIFF_FORMAT_NAME_STATUS |
4133                              DIFF_FORMAT_CHECKDIFF |
4134                              DIFF_FORMAT_NO_OUTPUT;
4135        /*
4136         * This must be signed because we're comparing against a potentially
4137         * negative value.
4138         */
4139        const int hexsz = the_hash_algo->hexsz;
4140
4141        if (options->set_default)
4142                options->set_default(options);
4143
4144        if (HAS_MULTI_BITS(options->output_format & check_mask))
4145                die(_("--name-only, --name-status, --check and -s are mutually exclusive"));
4146
4147        if (HAS_MULTI_BITS(options->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK))
4148                die(_("-G, -S and --find-object are mutually exclusive"));
4149
4150        /*
4151         * Most of the time we can say "there are changes"
4152         * only by checking if there are changed paths, but
4153         * --ignore-whitespace* options force us to look
4154         * inside contents.
4155         */
4156
4157        if ((options->xdl_opts & XDF_WHITESPACE_FLAGS))
4158                options->flags.diff_from_contents = 1;
4159        else
4160                options->flags.diff_from_contents = 0;
4161
4162        if (options->flags.find_copies_harder)
4163                options->detect_rename = DIFF_DETECT_COPY;
4164
4165        if (!options->flags.relative_name)
4166                options->prefix = NULL;
4167        if (options->prefix)
4168                options->prefix_length = strlen(options->prefix);
4169        else
4170                options->prefix_length = 0;
4171
4172        if (options->output_format & (DIFF_FORMAT_NAME |
4173                                      DIFF_FORMAT_NAME_STATUS |
4174                                      DIFF_FORMAT_CHECKDIFF |
4175                                      DIFF_FORMAT_NO_OUTPUT))
4176                options->output_format &= ~(DIFF_FORMAT_RAW |
4177                                            DIFF_FORMAT_NUMSTAT |
4178                                            DIFF_FORMAT_DIFFSTAT |
4179                                            DIFF_FORMAT_SHORTSTAT |
4180                                            DIFF_FORMAT_DIRSTAT |
4181                                            DIFF_FORMAT_SUMMARY |
4182                                            DIFF_FORMAT_PATCH);
4183
4184        /*
4185         * These cases always need recursive; we do not drop caller-supplied
4186         * recursive bits for other formats here.
4187         */
4188        if (options->output_format & (DIFF_FORMAT_PATCH |
4189                                      DIFF_FORMAT_NUMSTAT |
4190                                      DIFF_FORMAT_DIFFSTAT |
4191                                      DIFF_FORMAT_SHORTSTAT |
4192                                      DIFF_FORMAT_DIRSTAT |
4193                                      DIFF_FORMAT_SUMMARY |
4194                                      DIFF_FORMAT_CHECKDIFF))
4195                options->flags.recursive = 1;
4196        /*
4197         * Also pickaxe would not work very well if you do not say recursive
4198         */
4199        if (options->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK)
4200                options->flags.recursive = 1;
4201        /*
4202         * When patches are generated, submodules diffed against the work tree
4203         * must be checked for dirtiness too so it can be shown in the output
4204         */
4205        if (options->output_format & DIFF_FORMAT_PATCH)
4206                options->flags.dirty_submodules = 1;
4207
4208        if (options->detect_rename && options->rename_limit < 0)
4209                options->rename_limit = diff_rename_limit_default;
4210        if (options->setup & DIFF_SETUP_USE_CACHE) {
4211                if (!active_cache)
4212                        /* read-cache does not die even when it fails
4213                         * so it is safe for us to do this here.  Also
4214                         * it does not smudge active_cache or active_nr
4215                         * when it fails, so we do not have to worry about
4216                         * cleaning it up ourselves either.
4217                         */
4218                        read_cache();
4219        }
4220        if (hexsz < options->abbrev)
4221                options->abbrev = hexsz; /* full */
4222
4223        /*
4224         * It does not make sense to show the first hit we happened
4225         * to have found.  It does not make sense not to return with
4226         * exit code in such a case either.
4227         */
4228        if (options->flags.quick) {
4229                options->output_format = DIFF_FORMAT_NO_OUTPUT;
4230                options->flags.exit_with_status = 1;
4231        }
4232
4233        options->diff_path_counter = 0;
4234
4235        if (options->flags.follow_renames && options->pathspec.nr != 1)
4236                die(_("--follow requires exactly one pathspec"));
4237
4238        if (!options->use_color || external_diff())
4239                options->color_moved = 0;
4240}
4241
4242static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
4243{
4244        char c, *eq;
4245        int len;
4246
4247        if (*arg != '-')
4248                return 0;
4249        c = *++arg;
4250        if (!c)
4251                return 0;
4252        if (c == arg_short) {
4253                c = *++arg;
4254                if (!c)
4255                        return 1;
4256                if (val && isdigit(c)) {
4257                        char *end;
4258                        int n = strtoul(arg, &end, 10);
4259                        if (*end)
4260                                return 0;
4261                        *val = n;
4262                        return 1;
4263                }
4264                return 0;
4265        }
4266        if (c != '-')
4267                return 0;
4268        arg++;
4269        eq = strchrnul(arg, '=');
4270        len = eq - arg;
4271        if (!len || strncmp(arg, arg_long, len))
4272                return 0;
4273        if (*eq) {
4274                int n;
4275                char *end;
4276                if (!isdigit(*++eq))
4277                        return 0;
4278                n = strtoul(eq, &end, 10);
4279                if (*end)
4280                        return 0;
4281                *val = n;
4282        }
4283        return 1;
4284}
4285
4286static int diff_scoreopt_parse(const char *opt);
4287
4288static inline int short_opt(char opt, const char **argv,
4289                            const char **optarg)
4290{
4291        const char *arg = argv[0];
4292        if (arg[0] != '-' || arg[1] != opt)
4293                return 0;
4294        if (arg[2] != '\0') {
4295                *optarg = arg + 2;
4296                return 1;
4297        }
4298        if (!argv[1])
4299                die("Option '%c' requires a value", opt);
4300        *optarg = argv[1];
4301        return 2;
4302}
4303
4304int parse_long_opt(const char *opt, const char **argv,
4305                   const char **optarg)
4306{
4307        const char *arg = argv[0];
4308        if (!skip_prefix(arg, "--", &arg))
4309                return 0;
4310        if (!skip_prefix(arg, opt, &arg))
4311                return 0;
4312        if (*arg == '=') { /* stuck form: --option=value */
4313                *optarg = arg + 1;
4314                return 1;
4315        }
4316        if (*arg != '\0')
4317                return 0;
4318        /* separate form: --option value */
4319        if (!argv[1])
4320                die("Option '--%s' requires a value", opt);
4321        *optarg = argv[1];
4322        return 2;
4323}
4324
4325static int stat_opt(struct diff_options *options, const char **av)
4326{
4327        const char *arg = av[0];
4328        char *end;
4329        int width = options->stat_width;
4330        int name_width = options->stat_name_width;
4331        int graph_width = options->stat_graph_width;
4332        int count = options->stat_count;
4333        int argcount = 1;
4334
4335        if (!skip_prefix(arg, "--stat", &arg))
4336                BUG("stat option does not begin with --stat: %s", arg);
4337        end = (char *)arg;
4338
4339        switch (*arg) {
4340        case '-':
4341                if (skip_prefix(arg, "-width", &arg)) {
4342                        if (*arg == '=')
4343                                width = strtoul(arg + 1, &end, 10);
4344                        else if (!*arg && !av[1])
4345                                die_want_option("--stat-width");
4346                        else if (!*arg) {
4347                                width = strtoul(av[1], &end, 10);
4348                                argcount = 2;
4349                        }
4350                } else if (skip_prefix(arg, "-name-width", &arg)) {
4351                        if (*arg == '=')
4352                                name_width = strtoul(arg + 1, &end, 10);
4353                        else if (!*arg && !av[1])
4354                                die_want_option("--stat-name-width");
4355                        else if (!*arg) {
4356                                name_width = strtoul(av[1], &end, 10);
4357                                argcount = 2;
4358                        }
4359                } else if (skip_prefix(arg, "-graph-width", &arg)) {
4360                        if (*arg == '=')
4361                                graph_width = strtoul(arg + 1, &end, 10);
4362                        else if (!*arg && !av[1])
4363                                die_want_option("--stat-graph-width");
4364                        else if (!*arg) {
4365                                graph_width = strtoul(av[1], &end, 10);
4366                                argcount = 2;
4367                        }
4368                } else if (skip_prefix(arg, "-count", &arg)) {
4369                        if (*arg == '=')
4370                                count = strtoul(arg + 1, &end, 10);
4371                        else if (!*arg && !av[1])
4372                                die_want_option("--stat-count");
4373                        else if (!*arg) {
4374                                count = strtoul(av[1], &end, 10);
4375                                argcount = 2;
4376                        }
4377                }
4378                break;
4379        case '=':
4380                width = strtoul(arg+1, &end, 10);
4381                if (*end == ',')
4382                        name_width = strtoul(end+1, &end, 10);
4383                if (*end == ',')
4384                        count = strtoul(end+1, &end, 10);
4385        }
4386
4387        /* Important! This checks all the error cases! */
4388        if (*end)
4389                return 0;
4390        options->output_format |= DIFF_FORMAT_DIFFSTAT;
4391        options->stat_name_width = name_width;
4392        options->stat_graph_width = graph_width;
4393        options->stat_width = width;
4394        options->stat_count = count;
4395        return argcount;
4396}
4397
4398static int parse_dirstat_opt(struct diff_options *options, const char *params)
4399{
4400        struct strbuf errmsg = STRBUF_INIT;
4401        if (parse_dirstat_params(options, params, &errmsg))
4402                die(_("Failed to parse --dirstat/-X option parameter:\n%s"),
4403                    errmsg.buf);
4404        strbuf_release(&errmsg);
4405        /*
4406         * The caller knows a dirstat-related option is given from the command
4407         * line; allow it to say "return this_function();"
4408         */
4409        options->output_format |= DIFF_FORMAT_DIRSTAT;
4410        return 1;
4411}
4412
4413static int parse_submodule_opt(struct diff_options *options, const char *value)
4414{
4415        if (parse_submodule_params(options, value))
4416                die(_("Failed to parse --submodule option parameter: '%s'"),
4417                        value);
4418        return 1;
4419}
4420
4421static const char diff_status_letters[] = {
4422        DIFF_STATUS_ADDED,
4423        DIFF_STATUS_COPIED,
4424        DIFF_STATUS_DELETED,
4425        DIFF_STATUS_MODIFIED,
4426        DIFF_STATUS_RENAMED,
4427        DIFF_STATUS_TYPE_CHANGED,
4428        DIFF_STATUS_UNKNOWN,
4429        DIFF_STATUS_UNMERGED,
4430        DIFF_STATUS_FILTER_AON,
4431        DIFF_STATUS_FILTER_BROKEN,
4432        '\0',
4433};
4434
4435static unsigned int filter_bit['Z' + 1];
4436
4437static void prepare_filter_bits(void)
4438{
4439        int i;
4440
4441        if (!filter_bit[DIFF_STATUS_ADDED]) {
4442                for (i = 0; diff_status_letters[i]; i++)
4443                        filter_bit[(int) diff_status_letters[i]] = (1 << i);
4444        }
4445}
4446
4447static unsigned filter_bit_tst(char status, const struct diff_options *opt)
4448{
4449        return opt->filter & filter_bit[(int) status];
4450}
4451
4452static int parse_diff_filter_opt(const char *optarg, struct diff_options *opt)
4453{
4454        int i, optch;
4455
4456        prepare_filter_bits();
4457
4458        /*
4459         * If there is a negation e.g. 'd' in the input, and we haven't
4460         * initialized the filter field with another --diff-filter, start
4461         * from full set of bits, except for AON.
4462         */
4463        if (!opt->filter) {
4464                for (i = 0; (optch = optarg[i]) != '\0'; i++) {
4465                        if (optch < 'a' || 'z' < optch)
4466                                continue;
4467                        opt->filter = (1 << (ARRAY_SIZE(diff_status_letters) - 1)) - 1;
4468                        opt->filter &= ~filter_bit[DIFF_STATUS_FILTER_AON];
4469                        break;
4470                }
4471        }
4472
4473        for (i = 0; (optch = optarg[i]) != '\0'; i++) {
4474                unsigned int bit;
4475                int negate;
4476
4477                if ('a' <= optch && optch <= 'z') {
4478                        negate = 1;
4479                        optch = toupper(optch);
4480                } else {
4481                        negate = 0;
4482                }
4483
4484                bit = (0 <= optch && optch <= 'Z') ? filter_bit[optch] : 0;
4485                if (!bit)
4486                        return optarg[i];
4487                if (negate)
4488                        opt->filter &= ~bit;
4489                else
4490                        opt->filter |= bit;
4491        }
4492        return 0;
4493}
4494
4495static void enable_patch_output(int *fmt) {
4496        *fmt &= ~DIFF_FORMAT_NO_OUTPUT;
4497        *fmt |= DIFF_FORMAT_PATCH;
4498}
4499
4500static int parse_ws_error_highlight_opt(struct diff_options *opt, const char *arg)
4501{
4502        int val = parse_ws_error_highlight(arg);
4503
4504        if (val < 0) {
4505                error("unknown value after ws-error-highlight=%.*s",
4506                      -1 - val, arg);
4507                return 0;
4508        }
4509        opt->ws_error_highlight = val;
4510        return 1;
4511}
4512
4513static int parse_objfind_opt(struct diff_options *opt, const char *arg)
4514{
4515        struct object_id oid;
4516
4517        if (get_oid(arg, &oid))
4518                return error("unable to resolve '%s'", arg);
4519
4520        if (!opt->objfind)
4521                opt->objfind = xcalloc(1, sizeof(*opt->objfind));
4522
4523        opt->pickaxe_opts |= DIFF_PICKAXE_KIND_OBJFIND;
4524        opt->flags.recursive = 1;
4525        opt->flags.tree_in_recursive = 1;
4526        oidset_insert(opt->objfind, &oid);
4527        return 1;
4528}
4529
4530int diff_opt_parse(struct diff_options *options,
4531                   const char **av, int ac, const char *prefix)
4532{
4533        const char *arg = av[0];
4534        const char *optarg;
4535        int argcount;
4536
4537        if (!prefix)
4538                prefix = "";
4539
4540        /* Output format options */
4541        if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch")
4542            || opt_arg(arg, 'U', "unified", &options->context))
4543                enable_patch_output(&options->output_format);
4544        else if (!strcmp(arg, "--raw"))
4545                options->output_format |= DIFF_FORMAT_RAW;
4546        else if (!strcmp(arg, "--patch-with-raw")) {
4547                enable_patch_output(&options->output_format);
4548                options->output_format |= DIFF_FORMAT_RAW;
4549        } else if (!strcmp(arg, "--numstat"))
4550                options->output_format |= DIFF_FORMAT_NUMSTAT;
4551        else if (!strcmp(arg, "--shortstat"))
4552                options->output_format |= DIFF_FORMAT_SHORTSTAT;
4553        else if (skip_prefix(arg, "-X", &arg) ||
4554                 skip_to_optional_arg(arg, "--dirstat", &arg))
4555                return parse_dirstat_opt(options, arg);
4556        else if (!strcmp(arg, "--cumulative"))
4557                return parse_dirstat_opt(options, "cumulative");
4558        else if (skip_to_optional_arg(arg, "--dirstat-by-file", &arg)) {
4559                parse_dirstat_opt(options, "files");
4560                return parse_dirstat_opt(options, arg);
4561        }
4562        else if (!strcmp(arg, "--check"))
4563                options->output_format |= DIFF_FORMAT_CHECKDIFF;
4564        else if (!strcmp(arg, "--summary"))
4565                options->output_format |= DIFF_FORMAT_SUMMARY;
4566        else if (!strcmp(arg, "--patch-with-stat")) {
4567                enable_patch_output(&options->output_format);
4568                options->output_format |= DIFF_FORMAT_DIFFSTAT;
4569        } else if (!strcmp(arg, "--name-only"))
4570                options->output_format |= DIFF_FORMAT_NAME;
4571        else if (!strcmp(arg, "--name-status"))
4572                options->output_format |= DIFF_FORMAT_NAME_STATUS;
4573        else if (!strcmp(arg, "-s") || !strcmp(arg, "--no-patch"))
4574                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
4575        else if (starts_with(arg, "--stat"))
4576                /* --stat, --stat-width, --stat-name-width, or --stat-count */
4577                return stat_opt(options, av);
4578        else if (!strcmp(arg, "--compact-summary")) {
4579                 options->flags.stat_with_summary = 1;
4580                 options->output_format |= DIFF_FORMAT_DIFFSTAT;
4581        } else if (!strcmp(arg, "--no-compact-summary"))
4582                 options->flags.stat_with_summary = 0;
4583
4584        /* renames options */
4585        else if (starts_with(arg, "-B") ||
4586                 skip_to_optional_arg(arg, "--break-rewrites", NULL)) {
4587                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
4588                        return error("invalid argument to -B: %s", arg+2);
4589        }
4590        else if (starts_with(arg, "-M") ||
4591                 skip_to_optional_arg(arg, "--find-renames", NULL)) {
4592                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
4593                        return error("invalid argument to -M: %s", arg+2);
4594                options->detect_rename = DIFF_DETECT_RENAME;
4595        }
4596        else if (!strcmp(arg, "-D") || !strcmp(arg, "--irreversible-delete")) {
4597                options->irreversible_delete = 1;
4598        }
4599        else if (starts_with(arg, "-C") ||
4600                 skip_to_optional_arg(arg, "--find-copies", NULL)) {
4601                if (options->detect_rename == DIFF_DETECT_COPY)
4602                        options->flags.find_copies_harder = 1;
4603                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
4604                        return error("invalid argument to -C: %s", arg+2);
4605                options->detect_rename = DIFF_DETECT_COPY;
4606        }
4607        else if (!strcmp(arg, "--no-renames"))
4608                options->detect_rename = 0;
4609        else if (!strcmp(arg, "--rename-empty"))
4610                options->flags.rename_empty = 1;
4611        else if (!strcmp(arg, "--no-rename-empty"))
4612                options->flags.rename_empty = 0;
4613        else if (skip_to_optional_arg_default(arg, "--relative", &arg, NULL)) {
4614                options->flags.relative_name = 1;
4615                if (arg)
4616                        options->prefix = arg;
4617        }
4618
4619        /* xdiff options */
4620        else if (!strcmp(arg, "--minimal"))
4621                DIFF_XDL_SET(options, NEED_MINIMAL);
4622        else if (!strcmp(arg, "--no-minimal"))
4623                DIFF_XDL_CLR(options, NEED_MINIMAL);
4624        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
4625                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
4626        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
4627                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
4628        else if (!strcmp(arg, "--ignore-space-at-eol"))
4629                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
4630        else if (!strcmp(arg, "--ignore-cr-at-eol"))
4631                DIFF_XDL_SET(options, IGNORE_CR_AT_EOL);
4632        else if (!strcmp(arg, "--ignore-blank-lines"))
4633                DIFF_XDL_SET(options, IGNORE_BLANK_LINES);
4634        else if (!strcmp(arg, "--indent-heuristic"))
4635                DIFF_XDL_SET(options, INDENT_HEURISTIC);
4636        else if (!strcmp(arg, "--no-indent-heuristic"))
4637                DIFF_XDL_CLR(options, INDENT_HEURISTIC);
4638        else if (!strcmp(arg, "--patience")) {
4639                int i;
4640                options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
4641                /*
4642                 * Both --patience and --anchored use PATIENCE_DIFF
4643                 * internally, so remove any anchors previously
4644                 * specified.
4645                 */
4646                for (i = 0; i < options->anchors_nr; i++)
4647                        free(options->anchors[i]);
4648                options->anchors_nr = 0;
4649        } else if (!strcmp(arg, "--histogram"))
4650                options->xdl_opts = DIFF_WITH_ALG(options, HISTOGRAM_DIFF);
4651        else if ((argcount = parse_long_opt("diff-algorithm", av, &optarg))) {
4652                long value = parse_algorithm_value(optarg);
4653                if (value < 0)
4654                        return error("option diff-algorithm accepts \"myers\", "
4655                                     "\"minimal\", \"patience\" and \"histogram\"");
4656                /* clear out previous settings */
4657                DIFF_XDL_CLR(options, NEED_MINIMAL);
4658                options->xdl_opts &= ~XDF_DIFF_ALGORITHM_MASK;
4659                options->xdl_opts |= value;
4660                return argcount;
4661        } else if (skip_prefix(arg, "--anchored=", &arg)) {
4662                options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
4663                ALLOC_GROW(options->anchors, options->anchors_nr + 1,
4664                           options->anchors_alloc);
4665                options->anchors[options->anchors_nr++] = xstrdup(arg);
4666        }
4667
4668        /* flags options */
4669        else if (!strcmp(arg, "--binary")) {
4670                enable_patch_output(&options->output_format);
4671                options->flags.binary = 1;
4672        }
4673        else if (!strcmp(arg, "--full-index"))
4674                options->flags.full_index = 1;
4675        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
4676                options->flags.text = 1;
4677        else if (!strcmp(arg, "-R"))
4678                options->flags.reverse_diff = 1;
4679        else if (!strcmp(arg, "--find-copies-harder"))
4680                options->flags.find_copies_harder = 1;
4681        else if (!strcmp(arg, "--follow"))
4682                options->flags.follow_renames = 1;
4683        else if (!strcmp(arg, "--no-follow")) {
4684                options->flags.follow_renames = 0;
4685                options->flags.default_follow_renames = 0;
4686        } else if (skip_to_optional_arg_default(arg, "--color", &arg, "always")) {
4687                int value = git_config_colorbool(NULL, arg);
4688                if (value < 0)
4689                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
4690                options->use_color = value;
4691        }
4692        else if (!strcmp(arg, "--no-color"))
4693                options->use_color = 0;
4694        else if (!strcmp(arg, "--color-moved")) {
4695                if (diff_color_moved_default)
4696                        options->color_moved = diff_color_moved_default;
4697                if (options->color_moved == COLOR_MOVED_NO)
4698                        options->color_moved = COLOR_MOVED_DEFAULT;
4699        } else if (!strcmp(arg, "--no-color-moved"))
4700                options->color_moved = COLOR_MOVED_NO;
4701        else if (skip_prefix(arg, "--color-moved=", &arg)) {
4702                int cm = parse_color_moved(arg);
4703                if (cm < 0)
4704                        die("bad --color-moved argument: %s", arg);
4705                options->color_moved = cm;
4706        } else if (skip_to_optional_arg_default(arg, "--color-words", &options->word_regex, NULL)) {
4707                options->use_color = 1;
4708                options->word_diff = DIFF_WORDS_COLOR;
4709        }
4710        else if (!strcmp(arg, "--word-diff")) {
4711                if (options->word_diff == DIFF_WORDS_NONE)
4712                        options->word_diff = DIFF_WORDS_PLAIN;
4713        }
4714        else if (skip_prefix(arg, "--word-diff=", &arg)) {
4715                if (!strcmp(arg, "plain"))
4716                        options->word_diff = DIFF_WORDS_PLAIN;
4717                else if (!strcmp(arg, "color")) {
4718                        options->use_color = 1;
4719                        options->word_diff = DIFF_WORDS_COLOR;
4720                }
4721                else if (!strcmp(arg, "porcelain"))
4722                        options->word_diff = DIFF_WORDS_PORCELAIN;
4723                else if (!strcmp(arg, "none"))
4724                        options->word_diff = DIFF_WORDS_NONE;
4725                else
4726                        die("bad --word-diff argument: %s", arg);
4727        }
4728        else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
4729                if (options->word_diff == DIFF_WORDS_NONE)
4730                        options->word_diff = DIFF_WORDS_PLAIN;
4731                options->word_regex = optarg;
4732                return argcount;
4733        }
4734        else if (!strcmp(arg, "--exit-code"))
4735                options->flags.exit_with_status = 1;
4736        else if (!strcmp(arg, "--quiet"))
4737                options->flags.quick = 1;
4738        else if (!strcmp(arg, "--ext-diff"))
4739                options->flags.allow_external = 1;
4740        else if (!strcmp(arg, "--no-ext-diff"))
4741                options->flags.allow_external = 0;
4742        else if (!strcmp(arg, "--textconv")) {
4743                options->flags.allow_textconv = 1;
4744                options->flags.textconv_set_via_cmdline = 1;
4745        } else if (!strcmp(arg, "--no-textconv"))
4746                options->flags.allow_textconv = 0;
4747        else if (skip_to_optional_arg_default(arg, "--ignore-submodules", &arg, "all")) {
4748                options->flags.override_submodule_config = 1;
4749                handle_ignore_submodules_arg(options, arg);
4750        } else if (skip_to_optional_arg_default(arg, "--submodule", &arg, "log"))
4751                return parse_submodule_opt(options, arg);
4752        else if (skip_prefix(arg, "--ws-error-highlight=", &arg))
4753                return parse_ws_error_highlight_opt(options, arg);
4754        else if (!strcmp(arg, "--ita-invisible-in-index"))
4755                options->ita_invisible_in_index = 1;
4756        else if (!strcmp(arg, "--ita-visible-in-index"))
4757                options->ita_invisible_in_index = 0;
4758
4759        /* misc options */
4760        else if (!strcmp(arg, "-z"))
4761                options->line_termination = 0;
4762        else if ((argcount = short_opt('l', av, &optarg))) {
4763                options->rename_limit = strtoul(optarg, NULL, 10);
4764                return argcount;
4765        }
4766        else if ((argcount = short_opt('S', av, &optarg))) {
4767                options->pickaxe = optarg;
4768                options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
4769                return argcount;
4770        } else if ((argcount = short_opt('G', av, &optarg))) {
4771                options->pickaxe = optarg;
4772                options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
4773                return argcount;
4774        }
4775        else if (!strcmp(arg, "--pickaxe-all"))
4776                options->pickaxe_opts |= DIFF_PICKAXE_ALL;
4777        else if (!strcmp(arg, "--pickaxe-regex"))
4778                options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
4779        else if ((argcount = short_opt('O', av, &optarg))) {
4780                options->orderfile = prefix_filename(prefix, optarg);
4781                return argcount;
4782        } else if (skip_prefix(arg, "--find-object=", &arg))
4783                return parse_objfind_opt(options, arg);
4784        else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
4785                int offending = parse_diff_filter_opt(optarg, options);
4786                if (offending)
4787                        die("unknown change class '%c' in --diff-filter=%s",
4788                            offending, optarg);
4789                return argcount;
4790        }
4791        else if (!strcmp(arg, "--no-abbrev"))
4792                options->abbrev = 0;
4793        else if (!strcmp(arg, "--abbrev"))
4794                options->abbrev = DEFAULT_ABBREV;
4795        else if (skip_prefix(arg, "--abbrev=", &arg)) {
4796                options->abbrev = strtoul(arg, NULL, 10);
4797                if (options->abbrev < MINIMUM_ABBREV)
4798                        options->abbrev = MINIMUM_ABBREV;
4799                else if (the_hash_algo->hexsz < options->abbrev)
4800                        options->abbrev = the_hash_algo->hexsz;
4801        }
4802        else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
4803                options->a_prefix = optarg;
4804                return argcount;
4805        }
4806        else if ((argcount = parse_long_opt("line-prefix", av, &optarg))) {
4807                options->line_prefix = optarg;
4808                options->line_prefix_length = strlen(options->line_prefix);
4809                graph_setup_line_prefix(options);
4810                return argcount;
4811        }
4812        else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
4813                options->b_prefix = optarg;
4814                return argcount;
4815        }
4816        else if (!strcmp(arg, "--no-prefix"))
4817                options->a_prefix = options->b_prefix = "";
4818        else if (opt_arg(arg, '\0', "inter-hunk-context",
4819                         &options->interhunkcontext))
4820                ;
4821        else if (!strcmp(arg, "-W"))
4822                options->flags.funccontext = 1;
4823        else if (!strcmp(arg, "--function-context"))
4824                options->flags.funccontext = 1;
4825        else if (!strcmp(arg, "--no-function-context"))
4826                options->flags.funccontext = 0;
4827        else if ((argcount = parse_long_opt("output", av, &optarg))) {
4828                char *path = prefix_filename(prefix, optarg);
4829                options->file = xfopen(path, "w");
4830                options->close_file = 1;
4831                if (options->use_color != GIT_COLOR_ALWAYS)
4832                        options->use_color = GIT_COLOR_NEVER;
4833                free(path);
4834                return argcount;
4835        } else
4836                return 0;
4837        return 1;
4838}
4839
4840int parse_rename_score(const char **cp_p)
4841{
4842        unsigned long num, scale;
4843        int ch, dot;
4844        const char *cp = *cp_p;
4845
4846        num = 0;
4847        scale = 1;
4848        dot = 0;
4849        for (;;) {
4850                ch = *cp;
4851                if ( !dot && ch == '.' ) {
4852                        scale = 1;
4853                        dot = 1;
4854                } else if ( ch == '%' ) {
4855                        scale = dot ? scale*100 : 100;
4856                        cp++;   /* % is always at the end */
4857                        break;
4858                } else if ( ch >= '0' && ch <= '9' ) {
4859                        if ( scale < 100000 ) {
4860                                scale *= 10;
4861                                num = (num*10) + (ch-'0');
4862                        }
4863                } else {
4864                        break;
4865                }
4866                cp++;
4867        }
4868        *cp_p = cp;
4869
4870        /* user says num divided by scale and we say internally that
4871         * is MAX_SCORE * num / scale.
4872         */
4873        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
4874}
4875
4876static int diff_scoreopt_parse(const char *opt)
4877{
4878        int opt1, opt2, cmd;
4879
4880        if (*opt++ != '-')
4881                return -1;
4882        cmd = *opt++;
4883        if (cmd == '-') {
4884                /* convert the long-form arguments into short-form versions */
4885                if (skip_prefix(opt, "break-rewrites", &opt)) {
4886                        if (*opt == 0 || *opt++ == '=')
4887                                cmd = 'B';
4888                } else if (skip_prefix(opt, "find-copies", &opt)) {
4889                        if (*opt == 0 || *opt++ == '=')
4890                                cmd = 'C';
4891                } else if (skip_prefix(opt, "find-renames", &opt)) {
4892                        if (*opt == 0 || *opt++ == '=')
4893                                cmd = 'M';
4894                }
4895        }
4896        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
4897                return -1; /* that is not a -M, -C, or -B option */
4898
4899        opt1 = parse_rename_score(&opt);
4900        if (cmd != 'B')
4901                opt2 = 0;
4902        else {
4903                if (*opt == 0)
4904                        opt2 = 0;
4905                else if (*opt != '/')
4906                        return -1; /* we expect -B80/99 or -B80 */
4907                else {
4908                        opt++;
4909                        opt2 = parse_rename_score(&opt);
4910                }
4911        }
4912        if (*opt != 0)
4913                return -1;
4914        return opt1 | (opt2 << 16);
4915}
4916
4917struct diff_queue_struct diff_queued_diff;
4918
4919void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
4920{
4921        ALLOC_GROW(queue->queue, queue->nr + 1, queue->alloc);
4922        queue->queue[queue->nr++] = dp;
4923}
4924
4925struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
4926                                 struct diff_filespec *one,
4927                                 struct diff_filespec *two)
4928{
4929        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
4930        dp->one = one;
4931        dp->two = two;
4932        if (queue)
4933                diff_q(queue, dp);
4934        return dp;
4935}
4936
4937void diff_free_filepair(struct diff_filepair *p)
4938{
4939        free_filespec(p->one);
4940        free_filespec(p->two);
4941        free(p);
4942}
4943
4944const char *diff_aligned_abbrev(const struct object_id *oid, int len)
4945{
4946        int abblen;
4947        const char *abbrev;
4948
4949        /* Do we want all 40 hex characters? */
4950        if (len == GIT_SHA1_HEXSZ)
4951                return oid_to_hex(oid);
4952
4953        /* An abbreviated value is fine, possibly followed by an ellipsis. */
4954        abbrev = diff_abbrev_oid(oid, len);
4955
4956        if (!print_sha1_ellipsis())
4957                return abbrev;
4958
4959        abblen = strlen(abbrev);
4960
4961        /*
4962         * In well-behaved cases, where the abbreviated result is the
4963         * same as the requested length, append three dots after the
4964         * abbreviation (hence the whole logic is limited to the case
4965         * where abblen < 37); when the actual abbreviated result is a
4966         * bit longer than the requested length, we reduce the number
4967         * of dots so that they match the well-behaved ones.  However,
4968         * if the actual abbreviation is longer than the requested
4969         * length by more than three, we give up on aligning, and add
4970         * three dots anyway, to indicate that the output is not the
4971         * full object name.  Yes, this may be suboptimal, but this
4972         * appears only in "diff --raw --abbrev" output and it is not
4973         * worth the effort to change it now.  Note that this would
4974         * likely to work fine when the automatic sizing of default
4975         * abbreviation length is used--we would be fed -1 in "len" in
4976         * that case, and will end up always appending three-dots, but
4977         * the automatic sizing is supposed to give abblen that ensures
4978         * uniqueness across all objects (statistically speaking).
4979         */
4980        if (abblen < GIT_SHA1_HEXSZ - 3) {
4981                static char hex[GIT_MAX_HEXSZ + 1];
4982                if (len < abblen && abblen <= len + 2)
4983                        xsnprintf(hex, sizeof(hex), "%s%.*s", abbrev, len+3-abblen, "..");
4984                else
4985                        xsnprintf(hex, sizeof(hex), "%s...", abbrev);
4986                return hex;
4987        }
4988
4989        return oid_to_hex(oid);
4990}
4991
4992static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
4993{
4994        int line_termination = opt->line_termination;
4995        int inter_name_termination = line_termination ? '\t' : '\0';
4996
4997        fprintf(opt->file, "%s", diff_line_prefix(opt));
4998        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
4999                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
5000                        diff_aligned_abbrev(&p->one->oid, opt->abbrev));
5001                fprintf(opt->file, "%s ",
5002                        diff_aligned_abbrev(&p->two->oid, opt->abbrev));
5003        }
5004        if (p->score) {
5005                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
5006                        inter_name_termination);
5007        } else {
5008                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
5009        }
5010
5011        if (p->status == DIFF_STATUS_COPIED ||
5012            p->status == DIFF_STATUS_RENAMED) {
5013                const char *name_a, *name_b;
5014                name_a = p->one->path;
5015                name_b = p->two->path;
5016                strip_prefix(opt->prefix_length, &name_a, &name_b);
5017                write_name_quoted(name_a, opt->file, inter_name_termination);
5018                write_name_quoted(name_b, opt->file, line_termination);
5019        } else {
5020                const char *name_a, *name_b;
5021                name_a = p->one->mode ? p->one->path : p->two->path;
5022                name_b = NULL;
5023                strip_prefix(opt->prefix_length, &name_a, &name_b);
5024                write_name_quoted(name_a, opt->file, line_termination);
5025        }
5026}
5027
5028int diff_unmodified_pair(struct diff_filepair *p)
5029{
5030        /* This function is written stricter than necessary to support
5031         * the currently implemented transformers, but the idea is to
5032         * let transformers to produce diff_filepairs any way they want,
5033         * and filter and clean them up here before producing the output.
5034         */
5035        struct diff_filespec *one = p->one, *two = p->two;
5036
5037        if (DIFF_PAIR_UNMERGED(p))
5038                return 0; /* unmerged is interesting */
5039
5040        /* deletion, addition, mode or type change
5041         * and rename are all interesting.
5042         */
5043        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
5044            DIFF_PAIR_MODE_CHANGED(p) ||
5045            strcmp(one->path, two->path))
5046                return 0;
5047
5048        /* both are valid and point at the same path.  that is, we are
5049         * dealing with a change.
5050         */
5051        if (one->oid_valid && two->oid_valid &&
5052            !oidcmp(&one->oid, &two->oid) &&
5053            !one->dirty_submodule && !two->dirty_submodule)
5054                return 1; /* no change */
5055        if (!one->oid_valid && !two->oid_valid)
5056                return 1; /* both look at the same file on the filesystem. */
5057        return 0;
5058}
5059
5060static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
5061{
5062        if (diff_unmodified_pair(p))
5063                return;
5064
5065        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5066            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5067                return; /* no tree diffs in patch format */
5068
5069        run_diff(p, o);
5070}
5071
5072static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
5073                            struct diffstat_t *diffstat)
5074{
5075        if (diff_unmodified_pair(p))
5076                return;
5077
5078        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5079            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5080                return; /* no useful stat for tree diffs */
5081
5082        run_diffstat(p, o, diffstat);
5083}
5084
5085static void diff_flush_checkdiff(struct diff_filepair *p,
5086                struct diff_options *o)
5087{
5088        if (diff_unmodified_pair(p))
5089                return;
5090
5091        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5092            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5093                return; /* nothing to check in tree diffs */
5094
5095        run_checkdiff(p, o);
5096}
5097
5098int diff_queue_is_empty(void)
5099{
5100        struct diff_queue_struct *q = &diff_queued_diff;
5101        int i;
5102        for (i = 0; i < q->nr; i++)
5103                if (!diff_unmodified_pair(q->queue[i]))
5104                        return 0;
5105        return 1;
5106}
5107
5108#if DIFF_DEBUG
5109void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
5110{
5111        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
5112                x, one ? one : "",
5113                s->path,
5114                DIFF_FILE_VALID(s) ? "valid" : "invalid",
5115                s->mode,
5116                s->oid_valid ? oid_to_hex(&s->oid) : "");
5117        fprintf(stderr, "queue[%d] %s size %lu\n",
5118                x, one ? one : "",
5119                s->size);
5120}
5121
5122void diff_debug_filepair(const struct diff_filepair *p, int i)
5123{
5124        diff_debug_filespec(p->one, i, "one");
5125        diff_debug_filespec(p->two, i, "two");
5126        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
5127                p->score, p->status ? p->status : '?',
5128                p->one->rename_used, p->broken_pair);
5129}
5130
5131void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
5132{
5133        int i;
5134        if (msg)
5135                fprintf(stderr, "%s\n", msg);
5136        fprintf(stderr, "q->nr = %d\n", q->nr);
5137        for (i = 0; i < q->nr; i++) {
5138                struct diff_filepair *p = q->queue[i];
5139                diff_debug_filepair(p, i);
5140        }
5141}
5142#endif
5143
5144static void diff_resolve_rename_copy(void)
5145{
5146        int i;
5147        struct diff_filepair *p;
5148        struct diff_queue_struct *q = &diff_queued_diff;
5149
5150        diff_debug_queue("resolve-rename-copy", q);
5151
5152        for (i = 0; i < q->nr; i++) {
5153                p = q->queue[i];
5154                p->status = 0; /* undecided */
5155                if (DIFF_PAIR_UNMERGED(p))
5156                        p->status = DIFF_STATUS_UNMERGED;
5157                else if (!DIFF_FILE_VALID(p->one))
5158                        p->status = DIFF_STATUS_ADDED;
5159                else if (!DIFF_FILE_VALID(p->two))
5160                        p->status = DIFF_STATUS_DELETED;
5161                else if (DIFF_PAIR_TYPE_CHANGED(p))
5162                        p->status = DIFF_STATUS_TYPE_CHANGED;
5163
5164                /* from this point on, we are dealing with a pair
5165                 * whose both sides are valid and of the same type, i.e.
5166                 * either in-place edit or rename/copy edit.
5167                 */
5168                else if (DIFF_PAIR_RENAME(p)) {
5169                        /*
5170                         * A rename might have re-connected a broken
5171                         * pair up, causing the pathnames to be the
5172                         * same again. If so, that's not a rename at
5173                         * all, just a modification..
5174                         *
5175                         * Otherwise, see if this source was used for
5176                         * multiple renames, in which case we decrement
5177                         * the count, and call it a copy.
5178                         */
5179                        if (!strcmp(p->one->path, p->two->path))
5180                                p->status = DIFF_STATUS_MODIFIED;
5181                        else if (--p->one->rename_used > 0)
5182                                p->status = DIFF_STATUS_COPIED;
5183                        else
5184                                p->status = DIFF_STATUS_RENAMED;
5185                }
5186                else if (oidcmp(&p->one->oid, &p->two->oid) ||
5187                         p->one->mode != p->two->mode ||
5188                         p->one->dirty_submodule ||
5189                         p->two->dirty_submodule ||
5190                         is_null_oid(&p->one->oid))
5191                        p->status = DIFF_STATUS_MODIFIED;
5192                else {
5193                        /* This is a "no-change" entry and should not
5194                         * happen anymore, but prepare for broken callers.
5195                         */
5196                        error("feeding unmodified %s to diffcore",
5197                              p->one->path);
5198                        p->status = DIFF_STATUS_UNKNOWN;
5199                }
5200        }
5201        diff_debug_queue("resolve-rename-copy done", q);
5202}
5203
5204static int check_pair_status(struct diff_filepair *p)
5205{
5206        switch (p->status) {
5207        case DIFF_STATUS_UNKNOWN:
5208                return 0;
5209        case 0:
5210                die("internal error in diff-resolve-rename-copy");
5211        default:
5212                return 1;
5213        }
5214}
5215
5216static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
5217{
5218        int fmt = opt->output_format;
5219
5220        if (fmt & DIFF_FORMAT_CHECKDIFF)
5221                diff_flush_checkdiff(p, opt);
5222        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
5223                diff_flush_raw(p, opt);
5224        else if (fmt & DIFF_FORMAT_NAME) {
5225                const char *name_a, *name_b;
5226                name_a = p->two->path;
5227                name_b = NULL;
5228                strip_prefix(opt->prefix_length, &name_a, &name_b);
5229                fprintf(opt->file, "%s", diff_line_prefix(opt));
5230                write_name_quoted(name_a, opt->file, opt->line_termination);
5231        }
5232}
5233
5234static void show_file_mode_name(struct diff_options *opt, const char *newdelete, struct diff_filespec *fs)
5235{
5236        struct strbuf sb = STRBUF_INIT;
5237        if (fs->mode)
5238                strbuf_addf(&sb, " %s mode %06o ", newdelete, fs->mode);
5239        else
5240                strbuf_addf(&sb, " %s ", newdelete);
5241
5242        quote_c_style(fs->path, &sb, NULL, 0);
5243        strbuf_addch(&sb, '\n');
5244        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5245                         sb.buf, sb.len, 0);
5246        strbuf_release(&sb);
5247}
5248
5249static void show_mode_change(struct diff_options *opt, struct diff_filepair *p,
5250                int show_name)
5251{
5252        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
5253                struct strbuf sb = STRBUF_INIT;
5254                strbuf_addf(&sb, " mode change %06o => %06o",
5255                            p->one->mode, p->two->mode);
5256                if (show_name) {
5257                        strbuf_addch(&sb, ' ');
5258                        quote_c_style(p->two->path, &sb, NULL, 0);
5259                }
5260                strbuf_addch(&sb, '\n');
5261                emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5262                                 sb.buf, sb.len, 0);
5263                strbuf_release(&sb);
5264        }
5265}
5266
5267static void show_rename_copy(struct diff_options *opt, const char *renamecopy,
5268                struct diff_filepair *p)
5269{
5270        struct strbuf sb = STRBUF_INIT;
5271        struct strbuf names = STRBUF_INIT;
5272
5273        pprint_rename(&names, p->one->path, p->two->path);
5274        strbuf_addf(&sb, " %s %s (%d%%)\n",
5275                    renamecopy, names.buf, similarity_index(p));
5276        strbuf_release(&names);
5277        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5278                                 sb.buf, sb.len, 0);
5279        show_mode_change(opt, p, 0);
5280        strbuf_release(&sb);
5281}
5282
5283static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
5284{
5285        switch(p->status) {
5286        case DIFF_STATUS_DELETED:
5287                show_file_mode_name(opt, "delete", p->one);
5288                break;
5289        case DIFF_STATUS_ADDED:
5290                show_file_mode_name(opt, "create", p->two);
5291                break;
5292        case DIFF_STATUS_COPIED:
5293                show_rename_copy(opt, "copy", p);
5294                break;
5295        case DIFF_STATUS_RENAMED:
5296                show_rename_copy(opt, "rename", p);
5297                break;
5298        default:
5299                if (p->score) {
5300                        struct strbuf sb = STRBUF_INIT;
5301                        strbuf_addstr(&sb, " rewrite ");
5302                        quote_c_style(p->two->path, &sb, NULL, 0);
5303                        strbuf_addf(&sb, " (%d%%)\n", similarity_index(p));
5304                        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5305                                         sb.buf, sb.len, 0);
5306                        strbuf_release(&sb);
5307                }
5308                show_mode_change(opt, p, !p->score);
5309                break;
5310        }
5311}
5312
5313struct patch_id_t {
5314        git_SHA_CTX *ctx;
5315        int patchlen;
5316};
5317
5318static int remove_space(char *line, int len)
5319{
5320        int i;
5321        char *dst = line;
5322        unsigned char c;
5323
5324        for (i = 0; i < len; i++)
5325                if (!isspace((c = line[i])))
5326                        *dst++ = c;
5327
5328        return dst - line;
5329}
5330
5331static void patch_id_consume(void *priv, char *line, unsigned long len)
5332{
5333        struct patch_id_t *data = priv;
5334        int new_len;
5335
5336        /* Ignore line numbers when computing the SHA1 of the patch */
5337        if (starts_with(line, "@@ -"))
5338                return;
5339
5340        new_len = remove_space(line, len);
5341
5342        git_SHA1_Update(data->ctx, line, new_len);
5343        data->patchlen += new_len;
5344}
5345
5346static void patch_id_add_string(git_SHA_CTX *ctx, const char *str)
5347{
5348        git_SHA1_Update(ctx, str, strlen(str));
5349}
5350
5351static void patch_id_add_mode(git_SHA_CTX *ctx, unsigned mode)
5352{
5353        /* large enough for 2^32 in octal */
5354        char buf[12];
5355        int len = xsnprintf(buf, sizeof(buf), "%06o", mode);
5356        git_SHA1_Update(ctx, buf, len);
5357}
5358
5359/* returns 0 upon success, and writes result into sha1 */
5360static int diff_get_patch_id(struct diff_options *options, struct object_id *oid, int diff_header_only)
5361{
5362        struct diff_queue_struct *q = &diff_queued_diff;
5363        int i;
5364        git_SHA_CTX ctx;
5365        struct patch_id_t data;
5366
5367        git_SHA1_Init(&ctx);
5368        memset(&data, 0, sizeof(struct patch_id_t));
5369        data.ctx = &ctx;
5370
5371        for (i = 0; i < q->nr; i++) {
5372                xpparam_t xpp;
5373                xdemitconf_t xecfg;
5374                mmfile_t mf1, mf2;
5375                struct diff_filepair *p = q->queue[i];
5376                int len1, len2;
5377
5378                memset(&xpp, 0, sizeof(xpp));
5379                memset(&xecfg, 0, sizeof(xecfg));
5380                if (p->status == 0)
5381                        return error("internal diff status error");
5382                if (p->status == DIFF_STATUS_UNKNOWN)
5383                        continue;
5384                if (diff_unmodified_pair(p))
5385                        continue;
5386                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5387                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5388                        continue;
5389                if (DIFF_PAIR_UNMERGED(p))
5390                        continue;
5391
5392                diff_fill_oid_info(p->one);
5393                diff_fill_oid_info(p->two);
5394
5395                len1 = remove_space(p->one->path, strlen(p->one->path));
5396                len2 = remove_space(p->two->path, strlen(p->two->path));
5397                patch_id_add_string(&ctx, "diff--git");
5398                patch_id_add_string(&ctx, "a/");
5399                git_SHA1_Update(&ctx, p->one->path, len1);
5400                patch_id_add_string(&ctx, "b/");
5401                git_SHA1_Update(&ctx, p->two->path, len2);
5402
5403                if (p->one->mode == 0) {
5404                        patch_id_add_string(&ctx, "newfilemode");
5405                        patch_id_add_mode(&ctx, p->two->mode);
5406                        patch_id_add_string(&ctx, "---/dev/null");
5407                        patch_id_add_string(&ctx, "+++b/");
5408                        git_SHA1_Update(&ctx, p->two->path, len2);
5409                } else if (p->two->mode == 0) {
5410                        patch_id_add_string(&ctx, "deletedfilemode");
5411                        patch_id_add_mode(&ctx, p->one->mode);
5412                        patch_id_add_string(&ctx, "---a/");
5413                        git_SHA1_Update(&ctx, p->one->path, len1);
5414                        patch_id_add_string(&ctx, "+++/dev/null");
5415                } else {
5416                        patch_id_add_string(&ctx, "---a/");
5417                        git_SHA1_Update(&ctx, p->one->path, len1);
5418                        patch_id_add_string(&ctx, "+++b/");
5419                        git_SHA1_Update(&ctx, p->two->path, len2);
5420                }
5421
5422                if (diff_header_only)
5423                        continue;
5424
5425                if (fill_mmfile(&mf1, p->one) < 0 ||
5426                    fill_mmfile(&mf2, p->two) < 0)
5427                        return error("unable to read files to diff");
5428
5429                if (diff_filespec_is_binary(p->one) ||
5430                    diff_filespec_is_binary(p->two)) {
5431                        git_SHA1_Update(&ctx, oid_to_hex(&p->one->oid),
5432                                        GIT_SHA1_HEXSZ);
5433                        git_SHA1_Update(&ctx, oid_to_hex(&p->two->oid),
5434                                        GIT_SHA1_HEXSZ);
5435                        continue;
5436                }
5437
5438                xpp.flags = 0;
5439                xecfg.ctxlen = 3;
5440                xecfg.flags = 0;
5441                if (xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
5442                                  &xpp, &xecfg))
5443                        return error("unable to generate patch-id diff for %s",
5444                                     p->one->path);
5445        }
5446
5447        git_SHA1_Final(oid->hash, &ctx);
5448        return 0;
5449}
5450
5451int diff_flush_patch_id(struct diff_options *options, struct object_id *oid, int diff_header_only)
5452{
5453        struct diff_queue_struct *q = &diff_queued_diff;
5454        int i;
5455        int result = diff_get_patch_id(options, oid, diff_header_only);
5456
5457        for (i = 0; i < q->nr; i++)
5458                diff_free_filepair(q->queue[i]);
5459
5460        free(q->queue);
5461        DIFF_QUEUE_CLEAR(q);
5462
5463        return result;
5464}
5465
5466static int is_summary_empty(const struct diff_queue_struct *q)
5467{
5468        int i;
5469
5470        for (i = 0; i < q->nr; i++) {
5471                const struct diff_filepair *p = q->queue[i];
5472
5473                switch (p->status) {
5474                case DIFF_STATUS_DELETED:
5475                case DIFF_STATUS_ADDED:
5476                case DIFF_STATUS_COPIED:
5477                case DIFF_STATUS_RENAMED:
5478                        return 0;
5479                default:
5480                        if (p->score)
5481                                return 0;
5482                        if (p->one->mode && p->two->mode &&
5483                            p->one->mode != p->two->mode)
5484                                return 0;
5485                        break;
5486                }
5487        }
5488        return 1;
5489}
5490
5491static const char rename_limit_warning[] =
5492N_("inexact rename detection was skipped due to too many files.");
5493
5494static const char degrade_cc_to_c_warning[] =
5495N_("only found copies from modified paths due to too many files.");
5496
5497static const char rename_limit_advice[] =
5498N_("you may want to set your %s variable to at least "
5499   "%d and retry the command.");
5500
5501void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc)
5502{
5503        fflush(stdout);
5504        if (degraded_cc)
5505                warning(_(degrade_cc_to_c_warning));
5506        else if (needed)
5507                warning(_(rename_limit_warning));
5508        else
5509                return;
5510        if (0 < needed)
5511                warning(_(rename_limit_advice), varname, needed);
5512}
5513
5514static void diff_flush_patch_all_file_pairs(struct diff_options *o)
5515{
5516        int i;
5517        static struct emitted_diff_symbols esm = EMITTED_DIFF_SYMBOLS_INIT;
5518        struct diff_queue_struct *q = &diff_queued_diff;
5519
5520        if (WSEH_NEW & WS_RULE_MASK)
5521                BUG("WS rules bit mask overlaps with diff symbol flags");
5522
5523        if (o->color_moved)
5524                o->emitted_symbols = &esm;
5525
5526        for (i = 0; i < q->nr; i++) {
5527                struct diff_filepair *p = q->queue[i];
5528                if (check_pair_status(p))
5529                        diff_flush_patch(p, o);
5530        }
5531
5532        if (o->emitted_symbols) {
5533                if (o->color_moved) {
5534                        struct hashmap add_lines, del_lines;
5535
5536                        hashmap_init(&del_lines,
5537                                     (hashmap_cmp_fn)moved_entry_cmp, o, 0);
5538                        hashmap_init(&add_lines,
5539                                     (hashmap_cmp_fn)moved_entry_cmp, o, 0);
5540
5541                        add_lines_to_move_detection(o, &add_lines, &del_lines);
5542                        mark_color_as_moved(o, &add_lines, &del_lines);
5543                        if (o->color_moved == COLOR_MOVED_ZEBRA_DIM)
5544                                dim_moved_lines(o);
5545
5546                        hashmap_free(&add_lines, 0);
5547                        hashmap_free(&del_lines, 0);
5548                }
5549
5550                for (i = 0; i < esm.nr; i++)
5551                        emit_diff_symbol_from_struct(o, &esm.buf[i]);
5552
5553                for (i = 0; i < esm.nr; i++)
5554                        free((void *)esm.buf[i].line);
5555        }
5556        esm.nr = 0;
5557}
5558
5559void diff_flush(struct diff_options *options)
5560{
5561        struct diff_queue_struct *q = &diff_queued_diff;
5562        int i, output_format = options->output_format;
5563        int separator = 0;
5564        int dirstat_by_line = 0;
5565
5566        /*
5567         * Order: raw, stat, summary, patch
5568         * or:    name/name-status/checkdiff (other bits clear)
5569         */
5570        if (!q->nr)
5571                goto free_queue;
5572
5573        if (output_format & (DIFF_FORMAT_RAW |
5574                             DIFF_FORMAT_NAME |
5575                             DIFF_FORMAT_NAME_STATUS |
5576                             DIFF_FORMAT_CHECKDIFF)) {
5577                for (i = 0; i < q->nr; i++) {
5578                        struct diff_filepair *p = q->queue[i];
5579                        if (check_pair_status(p))
5580                                flush_one_pair(p, options);
5581                }
5582                separator++;
5583        }
5584
5585        if (output_format & DIFF_FORMAT_DIRSTAT && options->flags.dirstat_by_line)
5586                dirstat_by_line = 1;
5587
5588        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT) ||
5589            dirstat_by_line) {
5590                struct diffstat_t diffstat;
5591
5592                memset(&diffstat, 0, sizeof(struct diffstat_t));
5593                for (i = 0; i < q->nr; i++) {
5594                        struct diff_filepair *p = q->queue[i];
5595                        if (check_pair_status(p))
5596                                diff_flush_stat(p, options, &diffstat);
5597                }
5598                if (output_format & DIFF_FORMAT_NUMSTAT)
5599                        show_numstat(&diffstat, options);
5600                if (output_format & DIFF_FORMAT_DIFFSTAT)
5601                        show_stats(&diffstat, options);
5602                if (output_format & DIFF_FORMAT_SHORTSTAT)
5603                        show_shortstats(&diffstat, options);
5604                if (output_format & DIFF_FORMAT_DIRSTAT && dirstat_by_line)
5605                        show_dirstat_by_line(&diffstat, options);
5606                free_diffstat_info(&diffstat);
5607                separator++;
5608        }
5609        if ((output_format & DIFF_FORMAT_DIRSTAT) && !dirstat_by_line)
5610                show_dirstat(options);
5611
5612        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
5613                for (i = 0; i < q->nr; i++) {
5614                        diff_summary(options, q->queue[i]);
5615                }
5616                separator++;
5617        }
5618
5619        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
5620            options->flags.exit_with_status &&
5621            options->flags.diff_from_contents) {
5622                /*
5623                 * run diff_flush_patch for the exit status. setting
5624                 * options->file to /dev/null should be safe, because we
5625                 * aren't supposed to produce any output anyway.
5626                 */
5627                if (options->close_file)
5628                        fclose(options->file);
5629                options->file = xfopen("/dev/null", "w");
5630                options->close_file = 1;
5631                options->color_moved = 0;
5632                for (i = 0; i < q->nr; i++) {
5633                        struct diff_filepair *p = q->queue[i];
5634                        if (check_pair_status(p))
5635                                diff_flush_patch(p, options);
5636                        if (options->found_changes)
5637                                break;
5638                }
5639        }
5640
5641        if (output_format & DIFF_FORMAT_PATCH) {
5642                if (separator) {
5643                        emit_diff_symbol(options, DIFF_SYMBOL_SEPARATOR, NULL, 0, 0);
5644                        if (options->stat_sep)
5645                                /* attach patch instead of inline */
5646                                emit_diff_symbol(options, DIFF_SYMBOL_STAT_SEP,
5647                                                 NULL, 0, 0);
5648                }
5649
5650                diff_flush_patch_all_file_pairs(options);
5651        }
5652
5653        if (output_format & DIFF_FORMAT_CALLBACK)
5654                options->format_callback(q, options, options->format_callback_data);
5655
5656        for (i = 0; i < q->nr; i++)
5657                diff_free_filepair(q->queue[i]);
5658free_queue:
5659        free(q->queue);
5660        DIFF_QUEUE_CLEAR(q);
5661        if (options->close_file)
5662                fclose(options->file);
5663
5664        /*
5665         * Report the content-level differences with HAS_CHANGES;
5666         * diff_addremove/diff_change does not set the bit when
5667         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
5668         */
5669        if (options->flags.diff_from_contents) {
5670                if (options->found_changes)
5671                        options->flags.has_changes = 1;
5672                else
5673                        options->flags.has_changes = 0;
5674        }
5675}
5676
5677static int match_filter(const struct diff_options *options, const struct diff_filepair *p)
5678{
5679        return (((p->status == DIFF_STATUS_MODIFIED) &&
5680                 ((p->score &&
5681                   filter_bit_tst(DIFF_STATUS_FILTER_BROKEN, options)) ||
5682                  (!p->score &&
5683                   filter_bit_tst(DIFF_STATUS_MODIFIED, options)))) ||
5684                ((p->status != DIFF_STATUS_MODIFIED) &&
5685                 filter_bit_tst(p->status, options)));
5686}
5687
5688static void diffcore_apply_filter(struct diff_options *options)
5689{
5690        int i;
5691        struct diff_queue_struct *q = &diff_queued_diff;
5692        struct diff_queue_struct outq;
5693
5694        DIFF_QUEUE_CLEAR(&outq);
5695
5696        if (!options->filter)
5697                return;
5698
5699        if (filter_bit_tst(DIFF_STATUS_FILTER_AON, options)) {
5700                int found;
5701                for (i = found = 0; !found && i < q->nr; i++) {
5702                        if (match_filter(options, q->queue[i]))
5703                                found++;
5704                }
5705                if (found)
5706                        return;
5707
5708                /* otherwise we will clear the whole queue
5709                 * by copying the empty outq at the end of this
5710                 * function, but first clear the current entries
5711                 * in the queue.
5712                 */
5713                for (i = 0; i < q->nr; i++)
5714                        diff_free_filepair(q->queue[i]);
5715        }
5716        else {
5717                /* Only the matching ones */
5718                for (i = 0; i < q->nr; i++) {
5719                        struct diff_filepair *p = q->queue[i];
5720                        if (match_filter(options, p))
5721                                diff_q(&outq, p);
5722                        else
5723                                diff_free_filepair(p);
5724                }
5725        }
5726        free(q->queue);
5727        *q = outq;
5728}
5729
5730/* Check whether two filespecs with the same mode and size are identical */
5731static int diff_filespec_is_identical(struct diff_filespec *one,
5732                                      struct diff_filespec *two)
5733{
5734        if (S_ISGITLINK(one->mode))
5735                return 0;
5736        if (diff_populate_filespec(one, 0))
5737                return 0;
5738        if (diff_populate_filespec(two, 0))
5739                return 0;
5740        return !memcmp(one->data, two->data, one->size);
5741}
5742
5743static int diff_filespec_check_stat_unmatch(struct diff_filepair *p)
5744{
5745        if (p->done_skip_stat_unmatch)
5746                return p->skip_stat_unmatch_result;
5747
5748        p->done_skip_stat_unmatch = 1;
5749        p->skip_stat_unmatch_result = 0;
5750        /*
5751         * 1. Entries that come from stat info dirtiness
5752         *    always have both sides (iow, not create/delete),
5753         *    one side of the object name is unknown, with
5754         *    the same mode and size.  Keep the ones that
5755         *    do not match these criteria.  They have real
5756         *    differences.
5757         *
5758         * 2. At this point, the file is known to be modified,
5759         *    with the same mode and size, and the object
5760         *    name of one side is unknown.  Need to inspect
5761         *    the identical contents.
5762         */
5763        if (!DIFF_FILE_VALID(p->one) || /* (1) */
5764            !DIFF_FILE_VALID(p->two) ||
5765            (p->one->oid_valid && p->two->oid_valid) ||
5766            (p->one->mode != p->two->mode) ||
5767            diff_populate_filespec(p->one, CHECK_SIZE_ONLY) ||
5768            diff_populate_filespec(p->two, CHECK_SIZE_ONLY) ||
5769            (p->one->size != p->two->size) ||
5770            !diff_filespec_is_identical(p->one, p->two)) /* (2) */
5771                p->skip_stat_unmatch_result = 1;
5772        return p->skip_stat_unmatch_result;
5773}
5774
5775static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
5776{
5777        int i;
5778        struct diff_queue_struct *q = &diff_queued_diff;
5779        struct diff_queue_struct outq;
5780        DIFF_QUEUE_CLEAR(&outq);
5781
5782        for (i = 0; i < q->nr; i++) {
5783                struct diff_filepair *p = q->queue[i];
5784
5785                if (diff_filespec_check_stat_unmatch(p))
5786                        diff_q(&outq, p);
5787                else {
5788                        /*
5789                         * The caller can subtract 1 from skip_stat_unmatch
5790                         * to determine how many paths were dirty only
5791                         * due to stat info mismatch.
5792                         */
5793                        if (!diffopt->flags.no_index)
5794                                diffopt->skip_stat_unmatch++;
5795                        diff_free_filepair(p);
5796                }
5797        }
5798        free(q->queue);
5799        *q = outq;
5800}
5801
5802static int diffnamecmp(const void *a_, const void *b_)
5803{
5804        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
5805        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
5806        const char *name_a, *name_b;
5807
5808        name_a = a->one ? a->one->path : a->two->path;
5809        name_b = b->one ? b->one->path : b->two->path;
5810        return strcmp(name_a, name_b);
5811}
5812
5813void diffcore_fix_diff_index(struct diff_options *options)
5814{
5815        struct diff_queue_struct *q = &diff_queued_diff;
5816        QSORT(q->queue, q->nr, diffnamecmp);
5817}
5818
5819void diffcore_std(struct diff_options *options)
5820{
5821        /* NOTE please keep the following in sync with diff_tree_combined() */
5822        if (options->skip_stat_unmatch)
5823                diffcore_skip_stat_unmatch(options);
5824        if (!options->found_follow) {
5825                /* See try_to_follow_renames() in tree-diff.c */
5826                if (options->break_opt != -1)
5827                        diffcore_break(options->break_opt);
5828                if (options->detect_rename)
5829                        diffcore_rename(options);
5830                if (options->break_opt != -1)
5831                        diffcore_merge_broken();
5832        }
5833        if (options->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK)
5834                diffcore_pickaxe(options);
5835        if (options->orderfile)
5836                diffcore_order(options->orderfile);
5837        if (!options->found_follow)
5838                /* See try_to_follow_renames() in tree-diff.c */
5839                diff_resolve_rename_copy();
5840        diffcore_apply_filter(options);
5841
5842        if (diff_queued_diff.nr && !options->flags.diff_from_contents)
5843                options->flags.has_changes = 1;
5844        else
5845                options->flags.has_changes = 0;
5846
5847        options->found_follow = 0;
5848}
5849
5850int diff_result_code(struct diff_options *opt, int status)
5851{
5852        int result = 0;
5853
5854        diff_warn_rename_limit("diff.renameLimit",
5855                               opt->needed_rename_limit,
5856                               opt->degraded_cc_to_c);
5857        if (!opt->flags.exit_with_status &&
5858            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
5859                return status;
5860        if (opt->flags.exit_with_status &&
5861            opt->flags.has_changes)
5862                result |= 01;
5863        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
5864            opt->flags.check_failed)
5865                result |= 02;
5866        return result;
5867}
5868
5869int diff_can_quit_early(struct diff_options *opt)
5870{
5871        return (opt->flags.quick &&
5872                !opt->filter &&
5873                opt->flags.has_changes);
5874}
5875
5876/*
5877 * Shall changes to this submodule be ignored?
5878 *
5879 * Submodule changes can be configured to be ignored separately for each path,
5880 * but that configuration can be overridden from the command line.
5881 */
5882static int is_submodule_ignored(const char *path, struct diff_options *options)
5883{
5884        int ignored = 0;
5885        struct diff_flags orig_flags = options->flags;
5886        if (!options->flags.override_submodule_config)
5887                set_diffopt_flags_from_submodule_config(options, path);
5888        if (options->flags.ignore_submodules)
5889                ignored = 1;
5890        options->flags = orig_flags;
5891        return ignored;
5892}
5893
5894void diff_addremove(struct diff_options *options,
5895                    int addremove, unsigned mode,
5896                    const struct object_id *oid,
5897                    int oid_valid,
5898                    const char *concatpath, unsigned dirty_submodule)
5899{
5900        struct diff_filespec *one, *two;
5901
5902        if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
5903                return;
5904
5905        /* This may look odd, but it is a preparation for
5906         * feeding "there are unchanged files which should
5907         * not produce diffs, but when you are doing copy
5908         * detection you would need them, so here they are"
5909         * entries to the diff-core.  They will be prefixed
5910         * with something like '=' or '*' (I haven't decided
5911         * which but should not make any difference).
5912         * Feeding the same new and old to diff_change()
5913         * also has the same effect.
5914         * Before the final output happens, they are pruned after
5915         * merged into rename/copy pairs as appropriate.
5916         */
5917        if (options->flags.reverse_diff)
5918                addremove = (addremove == '+' ? '-' :
5919                             addremove == '-' ? '+' : addremove);
5920
5921        if (options->prefix &&
5922            strncmp(concatpath, options->prefix, options->prefix_length))
5923                return;
5924
5925        one = alloc_filespec(concatpath);
5926        two = alloc_filespec(concatpath);
5927
5928        if (addremove != '+')
5929                fill_filespec(one, oid, oid_valid, mode);
5930        if (addremove != '-') {
5931                fill_filespec(two, oid, oid_valid, mode);
5932                two->dirty_submodule = dirty_submodule;
5933        }
5934
5935        diff_queue(&diff_queued_diff, one, two);
5936        if (!options->flags.diff_from_contents)
5937                options->flags.has_changes = 1;
5938}
5939
5940void diff_change(struct diff_options *options,
5941                 unsigned old_mode, unsigned new_mode,
5942                 const struct object_id *old_oid,
5943                 const struct object_id *new_oid,
5944                 int old_oid_valid, int new_oid_valid,
5945                 const char *concatpath,
5946                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
5947{
5948        struct diff_filespec *one, *two;
5949        struct diff_filepair *p;
5950
5951        if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
5952            is_submodule_ignored(concatpath, options))
5953                return;
5954
5955        if (options->flags.reverse_diff) {
5956                SWAP(old_mode, new_mode);
5957                SWAP(old_oid, new_oid);
5958                SWAP(old_oid_valid, new_oid_valid);
5959                SWAP(old_dirty_submodule, new_dirty_submodule);
5960        }
5961
5962        if (options->prefix &&
5963            strncmp(concatpath, options->prefix, options->prefix_length))
5964                return;
5965
5966        one = alloc_filespec(concatpath);
5967        two = alloc_filespec(concatpath);
5968        fill_filespec(one, old_oid, old_oid_valid, old_mode);
5969        fill_filespec(two, new_oid, new_oid_valid, new_mode);
5970        one->dirty_submodule = old_dirty_submodule;
5971        two->dirty_submodule = new_dirty_submodule;
5972        p = diff_queue(&diff_queued_diff, one, two);
5973
5974        if (options->flags.diff_from_contents)
5975                return;
5976
5977        if (options->flags.quick && options->skip_stat_unmatch &&
5978            !diff_filespec_check_stat_unmatch(p))
5979                return;
5980
5981        options->flags.has_changes = 1;
5982}
5983
5984struct diff_filepair *diff_unmerge(struct diff_options *options, const char *path)
5985{
5986        struct diff_filepair *pair;
5987        struct diff_filespec *one, *two;
5988
5989        if (options->prefix &&
5990            strncmp(path, options->prefix, options->prefix_length))
5991                return NULL;
5992
5993        one = alloc_filespec(path);
5994        two = alloc_filespec(path);
5995        pair = diff_queue(&diff_queued_diff, one, two);
5996        pair->is_unmerged = 1;
5997        return pair;
5998}
5999
6000static char *run_textconv(const char *pgm, struct diff_filespec *spec,
6001                size_t *outsize)
6002{
6003        struct diff_tempfile *temp;
6004        const char *argv[3];
6005        const char **arg = argv;
6006        struct child_process child = CHILD_PROCESS_INIT;
6007        struct strbuf buf = STRBUF_INIT;
6008        int err = 0;
6009
6010        temp = prepare_temp_file(spec->path, spec);
6011        *arg++ = pgm;
6012        *arg++ = temp->name;
6013        *arg = NULL;
6014
6015        child.use_shell = 1;
6016        child.argv = argv;
6017        child.out = -1;
6018        if (start_command(&child)) {
6019                remove_tempfile();
6020                return NULL;
6021        }
6022
6023        if (strbuf_read(&buf, child.out, 0) < 0)
6024                err = error("error reading from textconv command '%s'", pgm);
6025        close(child.out);
6026
6027        if (finish_command(&child) || err) {
6028                strbuf_release(&buf);
6029                remove_tempfile();
6030                return NULL;
6031        }
6032        remove_tempfile();
6033
6034        return strbuf_detach(&buf, outsize);
6035}
6036
6037size_t fill_textconv(struct userdiff_driver *driver,
6038                     struct diff_filespec *df,
6039                     char **outbuf)
6040{
6041        size_t size;
6042
6043        if (!driver) {
6044                if (!DIFF_FILE_VALID(df)) {
6045                        *outbuf = "";
6046                        return 0;
6047                }
6048                if (diff_populate_filespec(df, 0))
6049                        die("unable to read files to diff");
6050                *outbuf = df->data;
6051                return df->size;
6052        }
6053
6054        if (!driver->textconv)
6055                BUG("fill_textconv called with non-textconv driver");
6056
6057        if (driver->textconv_cache && df->oid_valid) {
6058                *outbuf = notes_cache_get(driver->textconv_cache,
6059                                          &df->oid,
6060                                          &size);
6061                if (*outbuf)
6062                        return size;
6063        }
6064
6065        *outbuf = run_textconv(driver->textconv, df, &size);
6066        if (!*outbuf)
6067                die("unable to read files to diff");
6068
6069        if (driver->textconv_cache && df->oid_valid) {
6070                /* ignore errors, as we might be in a readonly repository */
6071                notes_cache_put(driver->textconv_cache, &df->oid, *outbuf,
6072                                size);
6073                /*
6074                 * we could save up changes and flush them all at the end,
6075                 * but we would need an extra call after all diffing is done.
6076                 * Since generating a cache entry is the slow path anyway,
6077                 * this extra overhead probably isn't a big deal.
6078                 */
6079                notes_cache_write(driver->textconv_cache);
6080        }
6081
6082        return size;
6083}
6084
6085int textconv_object(const char *path,
6086                    unsigned mode,
6087                    const struct object_id *oid,
6088                    int oid_valid,
6089                    char **buf,
6090                    unsigned long *buf_size)
6091{
6092        struct diff_filespec *df;
6093        struct userdiff_driver *textconv;
6094
6095        df = alloc_filespec(path);
6096        fill_filespec(df, oid, oid_valid, mode);
6097        textconv = get_textconv(df);
6098        if (!textconv) {
6099                free_filespec(df);
6100                return 0;
6101        }
6102
6103        *buf_size = fill_textconv(textconv, df, buf);
6104        free_filespec(df);
6105        return 1;
6106}
6107
6108void setup_diff_pager(struct diff_options *opt)
6109{
6110        /*
6111         * If the user asked for our exit code, then either they want --quiet
6112         * or --exit-code. We should definitely not bother with a pager in the
6113         * former case, as we will generate no output. Since we still properly
6114         * report our exit code even when a pager is run, we _could_ run a
6115         * pager with --exit-code. But since we have not done so historically,
6116         * and because it is easy to find people oneline advising "git diff
6117         * --exit-code" in hooks and other scripts, we do not do so.
6118         */
6119        if (!opt->flags.exit_with_status &&
6120            check_pager_config("diff") != 0)
6121                setup_pager();
6122}