5180c2f5a96d977ea5250794e4201a252545201d
   1/*
   2 * Copyright (C) 2005 Junio C Hamano
   3 */
   4#include "cache.h"
   5#include "config.h"
   6#include "tempfile.h"
   7#include "quote.h"
   8#include "diff.h"
   9#include "diffcore.h"
  10#include "delta.h"
  11#include "xdiff-interface.h"
  12#include "color.h"
  13#include "attr.h"
  14#include "run-command.h"
  15#include "utf8.h"
  16#include "object-store.h"
  17#include "userdiff.h"
  18#include "submodule-config.h"
  19#include "submodule.h"
  20#include "hashmap.h"
  21#include "ll-merge.h"
  22#include "string-list.h"
  23#include "argv-array.h"
  24#include "graph.h"
  25#include "packfile.h"
  26#include "parse-options.h"
  27#include "help.h"
  28
  29#ifdef NO_FAST_WORKING_DIRECTORY
  30#define FAST_WORKING_DIRECTORY 0
  31#else
  32#define FAST_WORKING_DIRECTORY 1
  33#endif
  34
  35static int diff_detect_rename_default;
  36static int diff_indent_heuristic = 1;
  37static int diff_rename_limit_default = 400;
  38static int diff_suppress_blank_empty;
  39static int diff_use_color_default = -1;
  40static int diff_color_moved_default;
  41static int diff_color_moved_ws_default;
  42static int diff_context_default = 3;
  43static int diff_interhunk_context_default;
  44static const char *diff_word_regex_cfg;
  45static const char *external_diff_cmd_cfg;
  46static const char *diff_order_file_cfg;
  47int diff_auto_refresh_index = 1;
  48static int diff_mnemonic_prefix;
  49static int diff_no_prefix;
  50static int diff_stat_graph_width;
  51static int diff_dirstat_permille_default = 30;
  52static struct diff_options default_diff_options;
  53static long diff_algorithm;
  54static unsigned ws_error_highlight_default = WSEH_NEW;
  55
  56static char diff_colors[][COLOR_MAXLEN] = {
  57        GIT_COLOR_RESET,
  58        GIT_COLOR_NORMAL,       /* CONTEXT */
  59        GIT_COLOR_BOLD,         /* METAINFO */
  60        GIT_COLOR_CYAN,         /* FRAGINFO */
  61        GIT_COLOR_RED,          /* OLD */
  62        GIT_COLOR_GREEN,        /* NEW */
  63        GIT_COLOR_YELLOW,       /* COMMIT */
  64        GIT_COLOR_BG_RED,       /* WHITESPACE */
  65        GIT_COLOR_NORMAL,       /* FUNCINFO */
  66        GIT_COLOR_BOLD_MAGENTA, /* OLD_MOVED */
  67        GIT_COLOR_BOLD_BLUE,    /* OLD_MOVED ALTERNATIVE */
  68        GIT_COLOR_FAINT,        /* OLD_MOVED_DIM */
  69        GIT_COLOR_FAINT_ITALIC, /* OLD_MOVED_ALTERNATIVE_DIM */
  70        GIT_COLOR_BOLD_CYAN,    /* NEW_MOVED */
  71        GIT_COLOR_BOLD_YELLOW,  /* NEW_MOVED ALTERNATIVE */
  72        GIT_COLOR_FAINT,        /* NEW_MOVED_DIM */
  73        GIT_COLOR_FAINT_ITALIC, /* NEW_MOVED_ALTERNATIVE_DIM */
  74        GIT_COLOR_FAINT,        /* CONTEXT_DIM */
  75        GIT_COLOR_FAINT_RED,    /* OLD_DIM */
  76        GIT_COLOR_FAINT_GREEN,  /* NEW_DIM */
  77        GIT_COLOR_BOLD,         /* CONTEXT_BOLD */
  78        GIT_COLOR_BOLD_RED,     /* OLD_BOLD */
  79        GIT_COLOR_BOLD_GREEN,   /* NEW_BOLD */
  80};
  81
  82static const char *color_diff_slots[] = {
  83        [DIFF_CONTEXT]                = "context",
  84        [DIFF_METAINFO]               = "meta",
  85        [DIFF_FRAGINFO]               = "frag",
  86        [DIFF_FILE_OLD]               = "old",
  87        [DIFF_FILE_NEW]               = "new",
  88        [DIFF_COMMIT]                 = "commit",
  89        [DIFF_WHITESPACE]             = "whitespace",
  90        [DIFF_FUNCINFO]               = "func",
  91        [DIFF_FILE_OLD_MOVED]         = "oldMoved",
  92        [DIFF_FILE_OLD_MOVED_ALT]     = "oldMovedAlternative",
  93        [DIFF_FILE_OLD_MOVED_DIM]     = "oldMovedDimmed",
  94        [DIFF_FILE_OLD_MOVED_ALT_DIM] = "oldMovedAlternativeDimmed",
  95        [DIFF_FILE_NEW_MOVED]         = "newMoved",
  96        [DIFF_FILE_NEW_MOVED_ALT]     = "newMovedAlternative",
  97        [DIFF_FILE_NEW_MOVED_DIM]     = "newMovedDimmed",
  98        [DIFF_FILE_NEW_MOVED_ALT_DIM] = "newMovedAlternativeDimmed",
  99        [DIFF_CONTEXT_DIM]            = "contextDimmed",
 100        [DIFF_FILE_OLD_DIM]           = "oldDimmed",
 101        [DIFF_FILE_NEW_DIM]           = "newDimmed",
 102        [DIFF_CONTEXT_BOLD]           = "contextBold",
 103        [DIFF_FILE_OLD_BOLD]          = "oldBold",
 104        [DIFF_FILE_NEW_BOLD]          = "newBold",
 105};
 106
 107define_list_config_array_extra(color_diff_slots, {"plain"});
 108
 109static int parse_diff_color_slot(const char *var)
 110{
 111        if (!strcasecmp(var, "plain"))
 112                return DIFF_CONTEXT;
 113        return LOOKUP_CONFIG(color_diff_slots, var);
 114}
 115
 116static int parse_dirstat_params(struct diff_options *options, const char *params_string,
 117                                struct strbuf *errmsg)
 118{
 119        char *params_copy = xstrdup(params_string);
 120        struct string_list params = STRING_LIST_INIT_NODUP;
 121        int ret = 0;
 122        int i;
 123
 124        if (*params_copy)
 125                string_list_split_in_place(&params, params_copy, ',', -1);
 126        for (i = 0; i < params.nr; i++) {
 127                const char *p = params.items[i].string;
 128                if (!strcmp(p, "changes")) {
 129                        options->flags.dirstat_by_line = 0;
 130                        options->flags.dirstat_by_file = 0;
 131                } else if (!strcmp(p, "lines")) {
 132                        options->flags.dirstat_by_line = 1;
 133                        options->flags.dirstat_by_file = 0;
 134                } else if (!strcmp(p, "files")) {
 135                        options->flags.dirstat_by_line = 0;
 136                        options->flags.dirstat_by_file = 1;
 137                } else if (!strcmp(p, "noncumulative")) {
 138                        options->flags.dirstat_cumulative = 0;
 139                } else if (!strcmp(p, "cumulative")) {
 140                        options->flags.dirstat_cumulative = 1;
 141                } else if (isdigit(*p)) {
 142                        char *end;
 143                        int permille = strtoul(p, &end, 10) * 10;
 144                        if (*end == '.' && isdigit(*++end)) {
 145                                /* only use first digit */
 146                                permille += *end - '0';
 147                                /* .. and ignore any further digits */
 148                                while (isdigit(*++end))
 149                                        ; /* nothing */
 150                        }
 151                        if (!*end)
 152                                options->dirstat_permille = permille;
 153                        else {
 154                                strbuf_addf(errmsg, _("  Failed to parse dirstat cut-off percentage '%s'\n"),
 155                                            p);
 156                                ret++;
 157                        }
 158                } else {
 159                        strbuf_addf(errmsg, _("  Unknown dirstat parameter '%s'\n"), p);
 160                        ret++;
 161                }
 162
 163        }
 164        string_list_clear(&params, 0);
 165        free(params_copy);
 166        return ret;
 167}
 168
 169static int parse_submodule_params(struct diff_options *options, const char *value)
 170{
 171        if (!strcmp(value, "log"))
 172                options->submodule_format = DIFF_SUBMODULE_LOG;
 173        else if (!strcmp(value, "short"))
 174                options->submodule_format = DIFF_SUBMODULE_SHORT;
 175        else if (!strcmp(value, "diff"))
 176                options->submodule_format = DIFF_SUBMODULE_INLINE_DIFF;
 177        else
 178                return -1;
 179        return 0;
 180}
 181
 182int git_config_rename(const char *var, const char *value)
 183{
 184        if (!value)
 185                return DIFF_DETECT_RENAME;
 186        if (!strcasecmp(value, "copies") || !strcasecmp(value, "copy"))
 187                return  DIFF_DETECT_COPY;
 188        return git_config_bool(var,value) ? DIFF_DETECT_RENAME : 0;
 189}
 190
 191long parse_algorithm_value(const char *value)
 192{
 193        if (!value)
 194                return -1;
 195        else if (!strcasecmp(value, "myers") || !strcasecmp(value, "default"))
 196                return 0;
 197        else if (!strcasecmp(value, "minimal"))
 198                return XDF_NEED_MINIMAL;
 199        else if (!strcasecmp(value, "patience"))
 200                return XDF_PATIENCE_DIFF;
 201        else if (!strcasecmp(value, "histogram"))
 202                return XDF_HISTOGRAM_DIFF;
 203        return -1;
 204}
 205
 206static int parse_one_token(const char **arg, const char *token)
 207{
 208        const char *rest;
 209        if (skip_prefix(*arg, token, &rest) && (!*rest || *rest == ',')) {
 210                *arg = rest;
 211                return 1;
 212        }
 213        return 0;
 214}
 215
 216static int parse_ws_error_highlight(const char *arg)
 217{
 218        const char *orig_arg = arg;
 219        unsigned val = 0;
 220
 221        while (*arg) {
 222                if (parse_one_token(&arg, "none"))
 223                        val = 0;
 224                else if (parse_one_token(&arg, "default"))
 225                        val = WSEH_NEW;
 226                else if (parse_one_token(&arg, "all"))
 227                        val = WSEH_NEW | WSEH_OLD | WSEH_CONTEXT;
 228                else if (parse_one_token(&arg, "new"))
 229                        val |= WSEH_NEW;
 230                else if (parse_one_token(&arg, "old"))
 231                        val |= WSEH_OLD;
 232                else if (parse_one_token(&arg, "context"))
 233                        val |= WSEH_CONTEXT;
 234                else {
 235                        return -1 - (int)(arg - orig_arg);
 236                }
 237                if (*arg)
 238                        arg++;
 239        }
 240        return val;
 241}
 242
 243/*
 244 * These are to give UI layer defaults.
 245 * The core-level commands such as git-diff-files should
 246 * never be affected by the setting of diff.renames
 247 * the user happens to have in the configuration file.
 248 */
 249void init_diff_ui_defaults(void)
 250{
 251        diff_detect_rename_default = DIFF_DETECT_RENAME;
 252}
 253
 254int git_diff_heuristic_config(const char *var, const char *value, void *cb)
 255{
 256        if (!strcmp(var, "diff.indentheuristic"))
 257                diff_indent_heuristic = git_config_bool(var, value);
 258        return 0;
 259}
 260
 261static int parse_color_moved(const char *arg)
 262{
 263        switch (git_parse_maybe_bool(arg)) {
 264        case 0:
 265                return COLOR_MOVED_NO;
 266        case 1:
 267                return COLOR_MOVED_DEFAULT;
 268        default:
 269                break;
 270        }
 271
 272        if (!strcmp(arg, "no"))
 273                return COLOR_MOVED_NO;
 274        else if (!strcmp(arg, "plain"))
 275                return COLOR_MOVED_PLAIN;
 276        else if (!strcmp(arg, "blocks"))
 277                return COLOR_MOVED_BLOCKS;
 278        else if (!strcmp(arg, "zebra"))
 279                return COLOR_MOVED_ZEBRA;
 280        else if (!strcmp(arg, "default"))
 281                return COLOR_MOVED_DEFAULT;
 282        else if (!strcmp(arg, "dimmed-zebra"))
 283                return COLOR_MOVED_ZEBRA_DIM;
 284        else if (!strcmp(arg, "dimmed_zebra"))
 285                return COLOR_MOVED_ZEBRA_DIM;
 286        else
 287                return error(_("color moved setting must be one of 'no', 'default', 'blocks', 'zebra', 'dimmed-zebra', 'plain'"));
 288}
 289
 290static unsigned parse_color_moved_ws(const char *arg)
 291{
 292        int ret = 0;
 293        struct string_list l = STRING_LIST_INIT_DUP;
 294        struct string_list_item *i;
 295
 296        string_list_split(&l, arg, ',', -1);
 297
 298        for_each_string_list_item(i, &l) {
 299                struct strbuf sb = STRBUF_INIT;
 300                strbuf_addstr(&sb, i->string);
 301                strbuf_trim(&sb);
 302
 303                if (!strcmp(sb.buf, "ignore-space-change"))
 304                        ret |= XDF_IGNORE_WHITESPACE_CHANGE;
 305                else if (!strcmp(sb.buf, "ignore-space-at-eol"))
 306                        ret |= XDF_IGNORE_WHITESPACE_AT_EOL;
 307                else if (!strcmp(sb.buf, "ignore-all-space"))
 308                        ret |= XDF_IGNORE_WHITESPACE;
 309                else if (!strcmp(sb.buf, "allow-indentation-change"))
 310                        ret |= COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE;
 311                else {
 312                        ret |= COLOR_MOVED_WS_ERROR;
 313                        error(_("unknown color-moved-ws mode '%s', possible values are 'ignore-space-change', 'ignore-space-at-eol', 'ignore-all-space', 'allow-indentation-change'"), sb.buf);
 314                }
 315
 316                strbuf_release(&sb);
 317        }
 318
 319        if ((ret & COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE) &&
 320            (ret & XDF_WHITESPACE_FLAGS)) {
 321                error(_("color-moved-ws: allow-indentation-change cannot be combined with other white space modes"));
 322                ret |= COLOR_MOVED_WS_ERROR;
 323        }
 324
 325        string_list_clear(&l, 0);
 326
 327        return ret;
 328}
 329
 330int git_diff_ui_config(const char *var, const char *value, void *cb)
 331{
 332        if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
 333                diff_use_color_default = git_config_colorbool(var, value);
 334                return 0;
 335        }
 336        if (!strcmp(var, "diff.colormoved")) {
 337                int cm = parse_color_moved(value);
 338                if (cm < 0)
 339                        return -1;
 340                diff_color_moved_default = cm;
 341                return 0;
 342        }
 343        if (!strcmp(var, "diff.colormovedws")) {
 344                unsigned cm = parse_color_moved_ws(value);
 345                if (cm & COLOR_MOVED_WS_ERROR)
 346                        return -1;
 347                diff_color_moved_ws_default = cm;
 348                return 0;
 349        }
 350        if (!strcmp(var, "diff.context")) {
 351                diff_context_default = git_config_int(var, value);
 352                if (diff_context_default < 0)
 353                        return -1;
 354                return 0;
 355        }
 356        if (!strcmp(var, "diff.interhunkcontext")) {
 357                diff_interhunk_context_default = git_config_int(var, value);
 358                if (diff_interhunk_context_default < 0)
 359                        return -1;
 360                return 0;
 361        }
 362        if (!strcmp(var, "diff.renames")) {
 363                diff_detect_rename_default = git_config_rename(var, value);
 364                return 0;
 365        }
 366        if (!strcmp(var, "diff.autorefreshindex")) {
 367                diff_auto_refresh_index = git_config_bool(var, value);
 368                return 0;
 369        }
 370        if (!strcmp(var, "diff.mnemonicprefix")) {
 371                diff_mnemonic_prefix = git_config_bool(var, value);
 372                return 0;
 373        }
 374        if (!strcmp(var, "diff.noprefix")) {
 375                diff_no_prefix = git_config_bool(var, value);
 376                return 0;
 377        }
 378        if (!strcmp(var, "diff.statgraphwidth")) {
 379                diff_stat_graph_width = git_config_int(var, value);
 380                return 0;
 381        }
 382        if (!strcmp(var, "diff.external"))
 383                return git_config_string(&external_diff_cmd_cfg, var, value);
 384        if (!strcmp(var, "diff.wordregex"))
 385                return git_config_string(&diff_word_regex_cfg, var, value);
 386        if (!strcmp(var, "diff.orderfile"))
 387                return git_config_pathname(&diff_order_file_cfg, var, value);
 388
 389        if (!strcmp(var, "diff.ignoresubmodules"))
 390                handle_ignore_submodules_arg(&default_diff_options, value);
 391
 392        if (!strcmp(var, "diff.submodule")) {
 393                if (parse_submodule_params(&default_diff_options, value))
 394                        warning(_("Unknown value for 'diff.submodule' config variable: '%s'"),
 395                                value);
 396                return 0;
 397        }
 398
 399        if (!strcmp(var, "diff.algorithm")) {
 400                diff_algorithm = parse_algorithm_value(value);
 401                if (diff_algorithm < 0)
 402                        return -1;
 403                return 0;
 404        }
 405
 406        if (!strcmp(var, "diff.wserrorhighlight")) {
 407                int val = parse_ws_error_highlight(value);
 408                if (val < 0)
 409                        return -1;
 410                ws_error_highlight_default = val;
 411                return 0;
 412        }
 413
 414        if (git_color_config(var, value, cb) < 0)
 415                return -1;
 416
 417        return git_diff_basic_config(var, value, cb);
 418}
 419
 420int git_diff_basic_config(const char *var, const char *value, void *cb)
 421{
 422        const char *name;
 423
 424        if (!strcmp(var, "diff.renamelimit")) {
 425                diff_rename_limit_default = git_config_int(var, value);
 426                return 0;
 427        }
 428
 429        if (userdiff_config(var, value) < 0)
 430                return -1;
 431
 432        if (skip_prefix(var, "diff.color.", &name) ||
 433            skip_prefix(var, "color.diff.", &name)) {
 434                int slot = parse_diff_color_slot(name);
 435                if (slot < 0)
 436                        return 0;
 437                if (!value)
 438                        return config_error_nonbool(var);
 439                return color_parse(value, diff_colors[slot]);
 440        }
 441
 442        /* like GNU diff's --suppress-blank-empty option  */
 443        if (!strcmp(var, "diff.suppressblankempty") ||
 444                        /* for backwards compatibility */
 445                        !strcmp(var, "diff.suppress-blank-empty")) {
 446                diff_suppress_blank_empty = git_config_bool(var, value);
 447                return 0;
 448        }
 449
 450        if (!strcmp(var, "diff.dirstat")) {
 451                struct strbuf errmsg = STRBUF_INIT;
 452                default_diff_options.dirstat_permille = diff_dirstat_permille_default;
 453                if (parse_dirstat_params(&default_diff_options, value, &errmsg))
 454                        warning(_("Found errors in 'diff.dirstat' config variable:\n%s"),
 455                                errmsg.buf);
 456                strbuf_release(&errmsg);
 457                diff_dirstat_permille_default = default_diff_options.dirstat_permille;
 458                return 0;
 459        }
 460
 461        if (git_diff_heuristic_config(var, value, cb) < 0)
 462                return -1;
 463
 464        return git_default_config(var, value, cb);
 465}
 466
 467static char *quote_two(const char *one, const char *two)
 468{
 469        int need_one = quote_c_style(one, NULL, NULL, 1);
 470        int need_two = quote_c_style(two, NULL, NULL, 1);
 471        struct strbuf res = STRBUF_INIT;
 472
 473        if (need_one + need_two) {
 474                strbuf_addch(&res, '"');
 475                quote_c_style(one, &res, NULL, 1);
 476                quote_c_style(two, &res, NULL, 1);
 477                strbuf_addch(&res, '"');
 478        } else {
 479                strbuf_addstr(&res, one);
 480                strbuf_addstr(&res, two);
 481        }
 482        return strbuf_detach(&res, NULL);
 483}
 484
 485static const char *external_diff(void)
 486{
 487        static const char *external_diff_cmd = NULL;
 488        static int done_preparing = 0;
 489
 490        if (done_preparing)
 491                return external_diff_cmd;
 492        external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
 493        if (!external_diff_cmd)
 494                external_diff_cmd = external_diff_cmd_cfg;
 495        done_preparing = 1;
 496        return external_diff_cmd;
 497}
 498
 499/*
 500 * Keep track of files used for diffing. Sometimes such an entry
 501 * refers to a temporary file, sometimes to an existing file, and
 502 * sometimes to "/dev/null".
 503 */
 504static struct diff_tempfile {
 505        /*
 506         * filename external diff should read from, or NULL if this
 507         * entry is currently not in use:
 508         */
 509        const char *name;
 510
 511        char hex[GIT_MAX_HEXSZ + 1];
 512        char mode[10];
 513
 514        /*
 515         * If this diff_tempfile instance refers to a temporary file,
 516         * this tempfile object is used to manage its lifetime.
 517         */
 518        struct tempfile *tempfile;
 519} diff_temp[2];
 520
 521struct emit_callback {
 522        int color_diff;
 523        unsigned ws_rule;
 524        int blank_at_eof_in_preimage;
 525        int blank_at_eof_in_postimage;
 526        int lno_in_preimage;
 527        int lno_in_postimage;
 528        const char **label_path;
 529        struct diff_words_data *diff_words;
 530        struct diff_options *opt;
 531        struct strbuf *header;
 532};
 533
 534static int count_lines(const char *data, int size)
 535{
 536        int count, ch, completely_empty = 1, nl_just_seen = 0;
 537        count = 0;
 538        while (0 < size--) {
 539                ch = *data++;
 540                if (ch == '\n') {
 541                        count++;
 542                        nl_just_seen = 1;
 543                        completely_empty = 0;
 544                }
 545                else {
 546                        nl_just_seen = 0;
 547                        completely_empty = 0;
 548                }
 549        }
 550        if (completely_empty)
 551                return 0;
 552        if (!nl_just_seen)
 553                count++; /* no trailing newline */
 554        return count;
 555}
 556
 557static int fill_mmfile(struct repository *r, mmfile_t *mf,
 558                       struct diff_filespec *one)
 559{
 560        if (!DIFF_FILE_VALID(one)) {
 561                mf->ptr = (char *)""; /* does not matter */
 562                mf->size = 0;
 563                return 0;
 564        }
 565        else if (diff_populate_filespec(r, one, 0))
 566                return -1;
 567
 568        mf->ptr = one->data;
 569        mf->size = one->size;
 570        return 0;
 571}
 572
 573/* like fill_mmfile, but only for size, so we can avoid retrieving blob */
 574static unsigned long diff_filespec_size(struct repository *r,
 575                                        struct diff_filespec *one)
 576{
 577        if (!DIFF_FILE_VALID(one))
 578                return 0;
 579        diff_populate_filespec(r, one, CHECK_SIZE_ONLY);
 580        return one->size;
 581}
 582
 583static int count_trailing_blank(mmfile_t *mf, unsigned ws_rule)
 584{
 585        char *ptr = mf->ptr;
 586        long size = mf->size;
 587        int cnt = 0;
 588
 589        if (!size)
 590                return cnt;
 591        ptr += size - 1; /* pointing at the very end */
 592        if (*ptr != '\n')
 593                ; /* incomplete line */
 594        else
 595                ptr--; /* skip the last LF */
 596        while (mf->ptr < ptr) {
 597                char *prev_eol;
 598                for (prev_eol = ptr; mf->ptr <= prev_eol; prev_eol--)
 599                        if (*prev_eol == '\n')
 600                                break;
 601                if (!ws_blank_line(prev_eol + 1, ptr - prev_eol, ws_rule))
 602                        break;
 603                cnt++;
 604                ptr = prev_eol - 1;
 605        }
 606        return cnt;
 607}
 608
 609static void check_blank_at_eof(mmfile_t *mf1, mmfile_t *mf2,
 610                               struct emit_callback *ecbdata)
 611{
 612        int l1, l2, at;
 613        unsigned ws_rule = ecbdata->ws_rule;
 614        l1 = count_trailing_blank(mf1, ws_rule);
 615        l2 = count_trailing_blank(mf2, ws_rule);
 616        if (l2 <= l1) {
 617                ecbdata->blank_at_eof_in_preimage = 0;
 618                ecbdata->blank_at_eof_in_postimage = 0;
 619                return;
 620        }
 621        at = count_lines(mf1->ptr, mf1->size);
 622        ecbdata->blank_at_eof_in_preimage = (at - l1) + 1;
 623
 624        at = count_lines(mf2->ptr, mf2->size);
 625        ecbdata->blank_at_eof_in_postimage = (at - l2) + 1;
 626}
 627
 628static void emit_line_0(struct diff_options *o,
 629                        const char *set_sign, const char *set, unsigned reverse, const char *reset,
 630                        int first, const char *line, int len)
 631{
 632        int has_trailing_newline, has_trailing_carriage_return;
 633        int needs_reset = 0; /* at the end of the line */
 634        FILE *file = o->file;
 635
 636        fputs(diff_line_prefix(o), file);
 637
 638        has_trailing_newline = (len > 0 && line[len-1] == '\n');
 639        if (has_trailing_newline)
 640                len--;
 641
 642        has_trailing_carriage_return = (len > 0 && line[len-1] == '\r');
 643        if (has_trailing_carriage_return)
 644                len--;
 645
 646        if (!len && !first)
 647                goto end_of_line;
 648
 649        if (reverse && want_color(o->use_color)) {
 650                fputs(GIT_COLOR_REVERSE, file);
 651                needs_reset = 1;
 652        }
 653
 654        if (set_sign) {
 655                fputs(set_sign, file);
 656                needs_reset = 1;
 657        }
 658
 659        if (first)
 660                fputc(first, file);
 661
 662        if (!len)
 663                goto end_of_line;
 664
 665        if (set) {
 666                if (set_sign && set != set_sign)
 667                        fputs(reset, file);
 668                fputs(set, file);
 669                needs_reset = 1;
 670        }
 671        fwrite(line, len, 1, file);
 672        needs_reset = 1; /* 'line' may contain color codes. */
 673
 674end_of_line:
 675        if (needs_reset)
 676                fputs(reset, file);
 677        if (has_trailing_carriage_return)
 678                fputc('\r', file);
 679        if (has_trailing_newline)
 680                fputc('\n', file);
 681}
 682
 683static void emit_line(struct diff_options *o, const char *set, const char *reset,
 684                      const char *line, int len)
 685{
 686        emit_line_0(o, set, NULL, 0, reset, 0, line, len);
 687}
 688
 689enum diff_symbol {
 690        DIFF_SYMBOL_BINARY_DIFF_HEADER,
 691        DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA,
 692        DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL,
 693        DIFF_SYMBOL_BINARY_DIFF_BODY,
 694        DIFF_SYMBOL_BINARY_DIFF_FOOTER,
 695        DIFF_SYMBOL_STATS_SUMMARY_NO_FILES,
 696        DIFF_SYMBOL_STATS_SUMMARY_ABBREV,
 697        DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES,
 698        DIFF_SYMBOL_STATS_LINE,
 699        DIFF_SYMBOL_WORD_DIFF,
 700        DIFF_SYMBOL_STAT_SEP,
 701        DIFF_SYMBOL_SUMMARY,
 702        DIFF_SYMBOL_SUBMODULE_ADD,
 703        DIFF_SYMBOL_SUBMODULE_DEL,
 704        DIFF_SYMBOL_SUBMODULE_UNTRACKED,
 705        DIFF_SYMBOL_SUBMODULE_MODIFIED,
 706        DIFF_SYMBOL_SUBMODULE_HEADER,
 707        DIFF_SYMBOL_SUBMODULE_ERROR,
 708        DIFF_SYMBOL_SUBMODULE_PIPETHROUGH,
 709        DIFF_SYMBOL_REWRITE_DIFF,
 710        DIFF_SYMBOL_BINARY_FILES,
 711        DIFF_SYMBOL_HEADER,
 712        DIFF_SYMBOL_FILEPAIR_PLUS,
 713        DIFF_SYMBOL_FILEPAIR_MINUS,
 714        DIFF_SYMBOL_WORDS_PORCELAIN,
 715        DIFF_SYMBOL_WORDS,
 716        DIFF_SYMBOL_CONTEXT,
 717        DIFF_SYMBOL_CONTEXT_INCOMPLETE,
 718        DIFF_SYMBOL_PLUS,
 719        DIFF_SYMBOL_MINUS,
 720        DIFF_SYMBOL_NO_LF_EOF,
 721        DIFF_SYMBOL_CONTEXT_FRAGINFO,
 722        DIFF_SYMBOL_CONTEXT_MARKER,
 723        DIFF_SYMBOL_SEPARATOR
 724};
 725/*
 726 * Flags for content lines:
 727 * 0..12 are whitespace rules
 728 * 13-15 are WSEH_NEW | WSEH_OLD | WSEH_CONTEXT
 729 * 16 is marking if the line is blank at EOF
 730 */
 731#define DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF      (1<<16)
 732#define DIFF_SYMBOL_MOVED_LINE                  (1<<17)
 733#define DIFF_SYMBOL_MOVED_LINE_ALT              (1<<18)
 734#define DIFF_SYMBOL_MOVED_LINE_UNINTERESTING    (1<<19)
 735#define DIFF_SYMBOL_CONTENT_WS_MASK (WSEH_NEW | WSEH_OLD | WSEH_CONTEXT | WS_RULE_MASK)
 736
 737/*
 738 * This struct is used when we need to buffer the output of the diff output.
 739 *
 740 * NEEDSWORK: Instead of storing a copy of the line, add an offset pointer
 741 * into the pre/post image file. This pointer could be a union with the
 742 * line pointer. By storing an offset into the file instead of the literal line,
 743 * we can decrease the memory footprint for the buffered output. At first we
 744 * may want to only have indirection for the content lines, but we could also
 745 * enhance the state for emitting prefabricated lines, e.g. the similarity
 746 * score line or hunk/file headers would only need to store a number or path
 747 * and then the output can be constructed later on depending on state.
 748 */
 749struct emitted_diff_symbol {
 750        const char *line;
 751        int len;
 752        int flags;
 753        enum diff_symbol s;
 754};
 755#define EMITTED_DIFF_SYMBOL_INIT {NULL}
 756
 757struct emitted_diff_symbols {
 758        struct emitted_diff_symbol *buf;
 759        int nr, alloc;
 760};
 761#define EMITTED_DIFF_SYMBOLS_INIT {NULL, 0, 0}
 762
 763static void append_emitted_diff_symbol(struct diff_options *o,
 764                                       struct emitted_diff_symbol *e)
 765{
 766        struct emitted_diff_symbol *f;
 767
 768        ALLOC_GROW(o->emitted_symbols->buf,
 769                   o->emitted_symbols->nr + 1,
 770                   o->emitted_symbols->alloc);
 771        f = &o->emitted_symbols->buf[o->emitted_symbols->nr++];
 772
 773        memcpy(f, e, sizeof(struct emitted_diff_symbol));
 774        f->line = e->line ? xmemdupz(e->line, e->len) : NULL;
 775}
 776
 777struct moved_entry {
 778        struct hashmap_entry ent;
 779        const struct emitted_diff_symbol *es;
 780        struct moved_entry *next_line;
 781};
 782
 783/**
 784 * The struct ws_delta holds white space differences between moved lines, i.e.
 785 * between '+' and '-' lines that have been detected to be a move.
 786 * The string contains the difference in leading white spaces, before the
 787 * rest of the line is compared using the white space config for move
 788 * coloring. The current_longer indicates if the first string in the
 789 * comparision is longer than the second.
 790 */
 791struct ws_delta {
 792        char *string;
 793        unsigned int current_longer : 1;
 794};
 795#define WS_DELTA_INIT { NULL, 0 }
 796
 797struct moved_block {
 798        struct moved_entry *match;
 799        struct ws_delta wsd;
 800};
 801
 802static void moved_block_clear(struct moved_block *b)
 803{
 804        FREE_AND_NULL(b->wsd.string);
 805        b->match = NULL;
 806}
 807
 808static int compute_ws_delta(const struct emitted_diff_symbol *a,
 809                             const struct emitted_diff_symbol *b,
 810                             struct ws_delta *out)
 811{
 812        const struct emitted_diff_symbol *longer =  a->len > b->len ? a : b;
 813        const struct emitted_diff_symbol *shorter = a->len > b->len ? b : a;
 814        int d = longer->len - shorter->len;
 815
 816        if (strncmp(longer->line + d, shorter->line, shorter->len))
 817                return 0;
 818
 819        out->string = xmemdupz(longer->line, d);
 820        out->current_longer = (a == longer);
 821
 822        return 1;
 823}
 824
 825static int cmp_in_block_with_wsd(const struct diff_options *o,
 826                                 const struct moved_entry *cur,
 827                                 const struct moved_entry *match,
 828                                 struct moved_block *pmb,
 829                                 int n)
 830{
 831        struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
 832        int al = cur->es->len, cl = l->len;
 833        const char *a = cur->es->line,
 834                   *b = match->es->line,
 835                   *c = l->line;
 836
 837        int wslen;
 838
 839        /*
 840         * We need to check if 'cur' is equal to 'match'.
 841         * As those are from the same (+/-) side, we do not need to adjust for
 842         * indent changes. However these were found using fuzzy matching
 843         * so we do have to check if they are equal.
 844         */
 845        if (strcmp(a, b))
 846                return 1;
 847
 848        if (!pmb->wsd.string)
 849                /*
 850                 * The white space delta is not active? This can happen
 851                 * when we exit early in this function.
 852                 */
 853                return 1;
 854
 855        /*
 856         * The indent changes of the block are known and stored in
 857         * pmb->wsd; however we need to check if the indent changes of the
 858         * current line are still the same as before.
 859         *
 860         * To do so we need to compare 'l' to 'cur', adjusting the
 861         * one of them for the white spaces, depending which was longer.
 862         */
 863
 864        wslen = strlen(pmb->wsd.string);
 865        if (pmb->wsd.current_longer) {
 866                c += wslen;
 867                cl -= wslen;
 868        } else {
 869                a += wslen;
 870                al -= wslen;
 871        }
 872
 873        if (al != cl || memcmp(a, c, al))
 874                return 1;
 875
 876        return 0;
 877}
 878
 879static int moved_entry_cmp(const void *hashmap_cmp_fn_data,
 880                           const void *entry,
 881                           const void *entry_or_key,
 882                           const void *keydata)
 883{
 884        const struct diff_options *diffopt = hashmap_cmp_fn_data;
 885        const struct moved_entry *a = entry;
 886        const struct moved_entry *b = entry_or_key;
 887        unsigned flags = diffopt->color_moved_ws_handling
 888                         & XDF_WHITESPACE_FLAGS;
 889
 890        if (diffopt->color_moved_ws_handling &
 891            COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
 892                /*
 893                 * As there is not specific white space config given,
 894                 * we'd need to check for a new block, so ignore all
 895                 * white space. The setup of the white space
 896                 * configuration for the next block is done else where
 897                 */
 898                flags |= XDF_IGNORE_WHITESPACE;
 899
 900        return !xdiff_compare_lines(a->es->line, a->es->len,
 901                                    b->es->line, b->es->len,
 902                                    flags);
 903}
 904
 905static struct moved_entry *prepare_entry(struct diff_options *o,
 906                                         int line_no)
 907{
 908        struct moved_entry *ret = xmalloc(sizeof(*ret));
 909        struct emitted_diff_symbol *l = &o->emitted_symbols->buf[line_no];
 910        unsigned flags = o->color_moved_ws_handling & XDF_WHITESPACE_FLAGS;
 911
 912        ret->ent.hash = xdiff_hash_string(l->line, l->len, flags);
 913        ret->es = l;
 914        ret->next_line = NULL;
 915
 916        return ret;
 917}
 918
 919static void add_lines_to_move_detection(struct diff_options *o,
 920                                        struct hashmap *add_lines,
 921                                        struct hashmap *del_lines)
 922{
 923        struct moved_entry *prev_line = NULL;
 924
 925        int n;
 926        for (n = 0; n < o->emitted_symbols->nr; n++) {
 927                struct hashmap *hm;
 928                struct moved_entry *key;
 929
 930                switch (o->emitted_symbols->buf[n].s) {
 931                case DIFF_SYMBOL_PLUS:
 932                        hm = add_lines;
 933                        break;
 934                case DIFF_SYMBOL_MINUS:
 935                        hm = del_lines;
 936                        break;
 937                default:
 938                        prev_line = NULL;
 939                        continue;
 940                }
 941
 942                key = prepare_entry(o, n);
 943                if (prev_line && prev_line->es->s == o->emitted_symbols->buf[n].s)
 944                        prev_line->next_line = key;
 945
 946                hashmap_add(hm, key);
 947                prev_line = key;
 948        }
 949}
 950
 951static void pmb_advance_or_null(struct diff_options *o,
 952                                struct moved_entry *match,
 953                                struct hashmap *hm,
 954                                struct moved_block *pmb,
 955                                int pmb_nr)
 956{
 957        int i;
 958        for (i = 0; i < pmb_nr; i++) {
 959                struct moved_entry *prev = pmb[i].match;
 960                struct moved_entry *cur = (prev && prev->next_line) ?
 961                                prev->next_line : NULL;
 962                if (cur && !hm->cmpfn(o, cur, match, NULL)) {
 963                        pmb[i].match = cur;
 964                } else {
 965                        pmb[i].match = NULL;
 966                }
 967        }
 968}
 969
 970static void pmb_advance_or_null_multi_match(struct diff_options *o,
 971                                            struct moved_entry *match,
 972                                            struct hashmap *hm,
 973                                            struct moved_block *pmb,
 974                                            int pmb_nr, int n)
 975{
 976        int i;
 977        char *got_match = xcalloc(1, pmb_nr);
 978
 979        for (; match; match = hashmap_get_next(hm, match)) {
 980                for (i = 0; i < pmb_nr; i++) {
 981                        struct moved_entry *prev = pmb[i].match;
 982                        struct moved_entry *cur = (prev && prev->next_line) ?
 983                                        prev->next_line : NULL;
 984                        if (!cur)
 985                                continue;
 986                        if (!cmp_in_block_with_wsd(o, cur, match, &pmb[i], n))
 987                                got_match[i] |= 1;
 988                }
 989        }
 990
 991        for (i = 0; i < pmb_nr; i++) {
 992                if (got_match[i]) {
 993                        /* Advance to the next line */
 994                        pmb[i].match = pmb[i].match->next_line;
 995                } else {
 996                        moved_block_clear(&pmb[i]);
 997                }
 998        }
 999
1000        free(got_match);
1001}
1002
1003static int shrink_potential_moved_blocks(struct moved_block *pmb,
1004                                         int pmb_nr)
1005{
1006        int lp, rp;
1007
1008        /* Shrink the set of potential block to the remaining running */
1009        for (lp = 0, rp = pmb_nr - 1; lp <= rp;) {
1010                while (lp < pmb_nr && pmb[lp].match)
1011                        lp++;
1012                /* lp points at the first NULL now */
1013
1014                while (rp > -1 && !pmb[rp].match)
1015                        rp--;
1016                /* rp points at the last non-NULL */
1017
1018                if (lp < pmb_nr && rp > -1 && lp < rp) {
1019                        pmb[lp] = pmb[rp];
1020                        pmb[rp].match = NULL;
1021                        pmb[rp].wsd.string = NULL;
1022                        rp--;
1023                        lp++;
1024                }
1025        }
1026
1027        /* Remember the number of running sets */
1028        return rp + 1;
1029}
1030
1031/*
1032 * If o->color_moved is COLOR_MOVED_PLAIN, this function does nothing.
1033 *
1034 * Otherwise, if the last block has fewer alphanumeric characters than
1035 * COLOR_MOVED_MIN_ALNUM_COUNT, unset DIFF_SYMBOL_MOVED_LINE on all lines in
1036 * that block.
1037 *
1038 * The last block consists of the (n - block_length)'th line up to but not
1039 * including the nth line.
1040 *
1041 * NEEDSWORK: This uses the same heuristic as blame_entry_score() in blame.c.
1042 * Think of a way to unify them.
1043 */
1044static void adjust_last_block(struct diff_options *o, int n, int block_length)
1045{
1046        int i, alnum_count = 0;
1047        if (o->color_moved == COLOR_MOVED_PLAIN)
1048                return;
1049        for (i = 1; i < block_length + 1; i++) {
1050                const char *c = o->emitted_symbols->buf[n - i].line;
1051                for (; *c; c++) {
1052                        if (!isalnum(*c))
1053                                continue;
1054                        alnum_count++;
1055                        if (alnum_count >= COLOR_MOVED_MIN_ALNUM_COUNT)
1056                                return;
1057                }
1058        }
1059        for (i = 1; i < block_length + 1; i++)
1060                o->emitted_symbols->buf[n - i].flags &= ~DIFF_SYMBOL_MOVED_LINE;
1061}
1062
1063/* Find blocks of moved code, delegate actual coloring decision to helper */
1064static void mark_color_as_moved(struct diff_options *o,
1065                                struct hashmap *add_lines,
1066                                struct hashmap *del_lines)
1067{
1068        struct moved_block *pmb = NULL; /* potentially moved blocks */
1069        int pmb_nr = 0, pmb_alloc = 0;
1070        int n, flipped_block = 1, block_length = 0;
1071
1072
1073        for (n = 0; n < o->emitted_symbols->nr; n++) {
1074                struct hashmap *hm = NULL;
1075                struct moved_entry *key;
1076                struct moved_entry *match = NULL;
1077                struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
1078
1079                switch (l->s) {
1080                case DIFF_SYMBOL_PLUS:
1081                        hm = del_lines;
1082                        key = prepare_entry(o, n);
1083                        match = hashmap_get(hm, key, NULL);
1084                        free(key);
1085                        break;
1086                case DIFF_SYMBOL_MINUS:
1087                        hm = add_lines;
1088                        key = prepare_entry(o, n);
1089                        match = hashmap_get(hm, key, NULL);
1090                        free(key);
1091                        break;
1092                default:
1093                        flipped_block = 1;
1094                }
1095
1096                if (!match) {
1097                        int i;
1098
1099                        adjust_last_block(o, n, block_length);
1100                        for(i = 0; i < pmb_nr; i++)
1101                                moved_block_clear(&pmb[i]);
1102                        pmb_nr = 0;
1103                        block_length = 0;
1104                        continue;
1105                }
1106
1107                l->flags |= DIFF_SYMBOL_MOVED_LINE;
1108
1109                if (o->color_moved == COLOR_MOVED_PLAIN)
1110                        continue;
1111
1112                if (o->color_moved_ws_handling &
1113                    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
1114                        pmb_advance_or_null_multi_match(o, match, hm, pmb, pmb_nr, n);
1115                else
1116                        pmb_advance_or_null(o, match, hm, pmb, pmb_nr);
1117
1118                pmb_nr = shrink_potential_moved_blocks(pmb, pmb_nr);
1119
1120                if (pmb_nr == 0) {
1121                        /*
1122                         * The current line is the start of a new block.
1123                         * Setup the set of potential blocks.
1124                         */
1125                        for (; match; match = hashmap_get_next(hm, match)) {
1126                                ALLOC_GROW(pmb, pmb_nr + 1, pmb_alloc);
1127                                if (o->color_moved_ws_handling &
1128                                    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE) {
1129                                        if (compute_ws_delta(l, match->es,
1130                                                             &pmb[pmb_nr].wsd))
1131                                                pmb[pmb_nr++].match = match;
1132                                } else {
1133                                        pmb[pmb_nr].wsd.string = NULL;
1134                                        pmb[pmb_nr++].match = match;
1135                                }
1136                        }
1137
1138                        flipped_block = (flipped_block + 1) % 2;
1139
1140                        adjust_last_block(o, n, block_length);
1141                        block_length = 0;
1142                }
1143
1144                block_length++;
1145
1146                if (flipped_block && o->color_moved != COLOR_MOVED_BLOCKS)
1147                        l->flags |= DIFF_SYMBOL_MOVED_LINE_ALT;
1148        }
1149        adjust_last_block(o, n, block_length);
1150
1151        for(n = 0; n < pmb_nr; n++)
1152                moved_block_clear(&pmb[n]);
1153        free(pmb);
1154}
1155
1156#define DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK \
1157  (DIFF_SYMBOL_MOVED_LINE | DIFF_SYMBOL_MOVED_LINE_ALT)
1158static void dim_moved_lines(struct diff_options *o)
1159{
1160        int n;
1161        for (n = 0; n < o->emitted_symbols->nr; n++) {
1162                struct emitted_diff_symbol *prev = (n != 0) ?
1163                                &o->emitted_symbols->buf[n - 1] : NULL;
1164                struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
1165                struct emitted_diff_symbol *next =
1166                                (n < o->emitted_symbols->nr - 1) ?
1167                                &o->emitted_symbols->buf[n + 1] : NULL;
1168
1169                /* Not a plus or minus line? */
1170                if (l->s != DIFF_SYMBOL_PLUS && l->s != DIFF_SYMBOL_MINUS)
1171                        continue;
1172
1173                /* Not a moved line? */
1174                if (!(l->flags & DIFF_SYMBOL_MOVED_LINE))
1175                        continue;
1176
1177                /*
1178                 * If prev or next are not a plus or minus line,
1179                 * pretend they don't exist
1180                 */
1181                if (prev && prev->s != DIFF_SYMBOL_PLUS &&
1182                            prev->s != DIFF_SYMBOL_MINUS)
1183                        prev = NULL;
1184                if (next && next->s != DIFF_SYMBOL_PLUS &&
1185                            next->s != DIFF_SYMBOL_MINUS)
1186                        next = NULL;
1187
1188                /* Inside a block? */
1189                if ((prev &&
1190                    (prev->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK) ==
1191                    (l->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK)) &&
1192                    (next &&
1193                    (next->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK) ==
1194                    (l->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK))) {
1195                        l->flags |= DIFF_SYMBOL_MOVED_LINE_UNINTERESTING;
1196                        continue;
1197                }
1198
1199                /* Check if we are at an interesting bound: */
1200                if (prev && (prev->flags & DIFF_SYMBOL_MOVED_LINE) &&
1201                    (prev->flags & DIFF_SYMBOL_MOVED_LINE_ALT) !=
1202                       (l->flags & DIFF_SYMBOL_MOVED_LINE_ALT))
1203                        continue;
1204                if (next && (next->flags & DIFF_SYMBOL_MOVED_LINE) &&
1205                    (next->flags & DIFF_SYMBOL_MOVED_LINE_ALT) !=
1206                       (l->flags & DIFF_SYMBOL_MOVED_LINE_ALT))
1207                        continue;
1208
1209                /*
1210                 * The boundary to prev and next are not interesting,
1211                 * so this line is not interesting as a whole
1212                 */
1213                l->flags |= DIFF_SYMBOL_MOVED_LINE_UNINTERESTING;
1214        }
1215}
1216
1217static void emit_line_ws_markup(struct diff_options *o,
1218                                const char *set_sign, const char *set,
1219                                const char *reset,
1220                                int sign_index, const char *line, int len,
1221                                unsigned ws_rule, int blank_at_eof)
1222{
1223        const char *ws = NULL;
1224        int sign = o->output_indicators[sign_index];
1225
1226        if (o->ws_error_highlight & ws_rule) {
1227                ws = diff_get_color_opt(o, DIFF_WHITESPACE);
1228                if (!*ws)
1229                        ws = NULL;
1230        }
1231
1232        if (!ws && !set_sign)
1233                emit_line_0(o, set, NULL, 0, reset, sign, line, len);
1234        else if (!ws) {
1235                emit_line_0(o, set_sign, set, !!set_sign, reset, sign, line, len);
1236        } else if (blank_at_eof)
1237                /* Blank line at EOF - paint '+' as well */
1238                emit_line_0(o, ws, NULL, 0, reset, sign, line, len);
1239        else {
1240                /* Emit just the prefix, then the rest. */
1241                emit_line_0(o, set_sign ? set_sign : set, NULL, !!set_sign, reset,
1242                            sign, "", 0);
1243                ws_check_emit(line, len, ws_rule,
1244                              o->file, set, reset, ws);
1245        }
1246}
1247
1248static void emit_diff_symbol_from_struct(struct diff_options *o,
1249                                         struct emitted_diff_symbol *eds)
1250{
1251        static const char *nneof = " No newline at end of file\n";
1252        const char *context, *reset, *set, *set_sign, *meta, *fraginfo;
1253        struct strbuf sb = STRBUF_INIT;
1254
1255        enum diff_symbol s = eds->s;
1256        const char *line = eds->line;
1257        int len = eds->len;
1258        unsigned flags = eds->flags;
1259
1260        switch (s) {
1261        case DIFF_SYMBOL_NO_LF_EOF:
1262                context = diff_get_color_opt(o, DIFF_CONTEXT);
1263                reset = diff_get_color_opt(o, DIFF_RESET);
1264                putc('\n', o->file);
1265                emit_line_0(o, context, NULL, 0, reset, '\\',
1266                            nneof, strlen(nneof));
1267                break;
1268        case DIFF_SYMBOL_SUBMODULE_HEADER:
1269        case DIFF_SYMBOL_SUBMODULE_ERROR:
1270        case DIFF_SYMBOL_SUBMODULE_PIPETHROUGH:
1271        case DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES:
1272        case DIFF_SYMBOL_SUMMARY:
1273        case DIFF_SYMBOL_STATS_LINE:
1274        case DIFF_SYMBOL_BINARY_DIFF_BODY:
1275        case DIFF_SYMBOL_CONTEXT_FRAGINFO:
1276                emit_line(o, "", "", line, len);
1277                break;
1278        case DIFF_SYMBOL_CONTEXT_INCOMPLETE:
1279        case DIFF_SYMBOL_CONTEXT_MARKER:
1280                context = diff_get_color_opt(o, DIFF_CONTEXT);
1281                reset = diff_get_color_opt(o, DIFF_RESET);
1282                emit_line(o, context, reset, line, len);
1283                break;
1284        case DIFF_SYMBOL_SEPARATOR:
1285                fprintf(o->file, "%s%c",
1286                        diff_line_prefix(o),
1287                        o->line_termination);
1288                break;
1289        case DIFF_SYMBOL_CONTEXT:
1290                set = diff_get_color_opt(o, DIFF_CONTEXT);
1291                reset = diff_get_color_opt(o, DIFF_RESET);
1292                set_sign = NULL;
1293                if (o->flags.dual_color_diffed_diffs) {
1294                        char c = !len ? 0 : line[0];
1295
1296                        if (c == '+')
1297                                set = diff_get_color_opt(o, DIFF_FILE_NEW);
1298                        else if (c == '@')
1299                                set = diff_get_color_opt(o, DIFF_FRAGINFO);
1300                        else if (c == '-')
1301                                set = diff_get_color_opt(o, DIFF_FILE_OLD);
1302                }
1303                emit_line_ws_markup(o, set_sign, set, reset,
1304                                    OUTPUT_INDICATOR_CONTEXT, line, len,
1305                                    flags & (DIFF_SYMBOL_CONTENT_WS_MASK), 0);
1306                break;
1307        case DIFF_SYMBOL_PLUS:
1308                switch (flags & (DIFF_SYMBOL_MOVED_LINE |
1309                                 DIFF_SYMBOL_MOVED_LINE_ALT |
1310                                 DIFF_SYMBOL_MOVED_LINE_UNINTERESTING)) {
1311                case DIFF_SYMBOL_MOVED_LINE |
1312                     DIFF_SYMBOL_MOVED_LINE_ALT |
1313                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1314                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED_ALT_DIM);
1315                        break;
1316                case DIFF_SYMBOL_MOVED_LINE |
1317                     DIFF_SYMBOL_MOVED_LINE_ALT:
1318                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED_ALT);
1319                        break;
1320                case DIFF_SYMBOL_MOVED_LINE |
1321                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1322                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED_DIM);
1323                        break;
1324                case DIFF_SYMBOL_MOVED_LINE:
1325                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED);
1326                        break;
1327                default:
1328                        set = diff_get_color_opt(o, DIFF_FILE_NEW);
1329                }
1330                reset = diff_get_color_opt(o, DIFF_RESET);
1331                if (!o->flags.dual_color_diffed_diffs)
1332                        set_sign = NULL;
1333                else {
1334                        char c = !len ? 0 : line[0];
1335
1336                        set_sign = set;
1337                        if (c == '-')
1338                                set = diff_get_color_opt(o, DIFF_FILE_OLD_BOLD);
1339                        else if (c == '@')
1340                                set = diff_get_color_opt(o, DIFF_FRAGINFO);
1341                        else if (c == '+')
1342                                set = diff_get_color_opt(o, DIFF_FILE_NEW_BOLD);
1343                        else
1344                                set = diff_get_color_opt(o, DIFF_CONTEXT_BOLD);
1345                        flags &= ~DIFF_SYMBOL_CONTENT_WS_MASK;
1346                }
1347                emit_line_ws_markup(o, set_sign, set, reset,
1348                                    OUTPUT_INDICATOR_NEW, line, len,
1349                                    flags & DIFF_SYMBOL_CONTENT_WS_MASK,
1350                                    flags & DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF);
1351                break;
1352        case DIFF_SYMBOL_MINUS:
1353                switch (flags & (DIFF_SYMBOL_MOVED_LINE |
1354                                 DIFF_SYMBOL_MOVED_LINE_ALT |
1355                                 DIFF_SYMBOL_MOVED_LINE_UNINTERESTING)) {
1356                case DIFF_SYMBOL_MOVED_LINE |
1357                     DIFF_SYMBOL_MOVED_LINE_ALT |
1358                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1359                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_ALT_DIM);
1360                        break;
1361                case DIFF_SYMBOL_MOVED_LINE |
1362                     DIFF_SYMBOL_MOVED_LINE_ALT:
1363                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_ALT);
1364                        break;
1365                case DIFF_SYMBOL_MOVED_LINE |
1366                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1367                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_DIM);
1368                        break;
1369                case DIFF_SYMBOL_MOVED_LINE:
1370                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED);
1371                        break;
1372                default:
1373                        set = diff_get_color_opt(o, DIFF_FILE_OLD);
1374                }
1375                reset = diff_get_color_opt(o, DIFF_RESET);
1376                if (!o->flags.dual_color_diffed_diffs)
1377                        set_sign = NULL;
1378                else {
1379                        char c = !len ? 0 : line[0];
1380
1381                        set_sign = set;
1382                        if (c == '+')
1383                                set = diff_get_color_opt(o, DIFF_FILE_NEW_DIM);
1384                        else if (c == '@')
1385                                set = diff_get_color_opt(o, DIFF_FRAGINFO);
1386                        else if (c == '-')
1387                                set = diff_get_color_opt(o, DIFF_FILE_OLD_DIM);
1388                        else
1389                                set = diff_get_color_opt(o, DIFF_CONTEXT_DIM);
1390                }
1391                emit_line_ws_markup(o, set_sign, set, reset,
1392                                    OUTPUT_INDICATOR_OLD, line, len,
1393                                    flags & DIFF_SYMBOL_CONTENT_WS_MASK, 0);
1394                break;
1395        case DIFF_SYMBOL_WORDS_PORCELAIN:
1396                context = diff_get_color_opt(o, DIFF_CONTEXT);
1397                reset = diff_get_color_opt(o, DIFF_RESET);
1398                emit_line(o, context, reset, line, len);
1399                fputs("~\n", o->file);
1400                break;
1401        case DIFF_SYMBOL_WORDS:
1402                context = diff_get_color_opt(o, DIFF_CONTEXT);
1403                reset = diff_get_color_opt(o, DIFF_RESET);
1404                /*
1405                 * Skip the prefix character, if any.  With
1406                 * diff_suppress_blank_empty, there may be
1407                 * none.
1408                 */
1409                if (line[0] != '\n') {
1410                        line++;
1411                        len--;
1412                }
1413                emit_line(o, context, reset, line, len);
1414                break;
1415        case DIFF_SYMBOL_FILEPAIR_PLUS:
1416                meta = diff_get_color_opt(o, DIFF_METAINFO);
1417                reset = diff_get_color_opt(o, DIFF_RESET);
1418                fprintf(o->file, "%s%s+++ %s%s%s\n", diff_line_prefix(o), meta,
1419                        line, reset,
1420                        strchr(line, ' ') ? "\t" : "");
1421                break;
1422        case DIFF_SYMBOL_FILEPAIR_MINUS:
1423                meta = diff_get_color_opt(o, DIFF_METAINFO);
1424                reset = diff_get_color_opt(o, DIFF_RESET);
1425                fprintf(o->file, "%s%s--- %s%s%s\n", diff_line_prefix(o), meta,
1426                        line, reset,
1427                        strchr(line, ' ') ? "\t" : "");
1428                break;
1429        case DIFF_SYMBOL_BINARY_FILES:
1430        case DIFF_SYMBOL_HEADER:
1431                fprintf(o->file, "%s", line);
1432                break;
1433        case DIFF_SYMBOL_BINARY_DIFF_HEADER:
1434                fprintf(o->file, "%sGIT binary patch\n", diff_line_prefix(o));
1435                break;
1436        case DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA:
1437                fprintf(o->file, "%sdelta %s\n", diff_line_prefix(o), line);
1438                break;
1439        case DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL:
1440                fprintf(o->file, "%sliteral %s\n", diff_line_prefix(o), line);
1441                break;
1442        case DIFF_SYMBOL_BINARY_DIFF_FOOTER:
1443                fputs(diff_line_prefix(o), o->file);
1444                fputc('\n', o->file);
1445                break;
1446        case DIFF_SYMBOL_REWRITE_DIFF:
1447                fraginfo = diff_get_color(o->use_color, DIFF_FRAGINFO);
1448                reset = diff_get_color_opt(o, DIFF_RESET);
1449                emit_line(o, fraginfo, reset, line, len);
1450                break;
1451        case DIFF_SYMBOL_SUBMODULE_ADD:
1452                set = diff_get_color_opt(o, DIFF_FILE_NEW);
1453                reset = diff_get_color_opt(o, DIFF_RESET);
1454                emit_line(o, set, reset, line, len);
1455                break;
1456        case DIFF_SYMBOL_SUBMODULE_DEL:
1457                set = diff_get_color_opt(o, DIFF_FILE_OLD);
1458                reset = diff_get_color_opt(o, DIFF_RESET);
1459                emit_line(o, set, reset, line, len);
1460                break;
1461        case DIFF_SYMBOL_SUBMODULE_UNTRACKED:
1462                fprintf(o->file, "%sSubmodule %s contains untracked content\n",
1463                        diff_line_prefix(o), line);
1464                break;
1465        case DIFF_SYMBOL_SUBMODULE_MODIFIED:
1466                fprintf(o->file, "%sSubmodule %s contains modified content\n",
1467                        diff_line_prefix(o), line);
1468                break;
1469        case DIFF_SYMBOL_STATS_SUMMARY_NO_FILES:
1470                emit_line(o, "", "", " 0 files changed\n",
1471                          strlen(" 0 files changed\n"));
1472                break;
1473        case DIFF_SYMBOL_STATS_SUMMARY_ABBREV:
1474                emit_line(o, "", "", " ...\n", strlen(" ...\n"));
1475                break;
1476        case DIFF_SYMBOL_WORD_DIFF:
1477                fprintf(o->file, "%.*s", len, line);
1478                break;
1479        case DIFF_SYMBOL_STAT_SEP:
1480                fputs(o->stat_sep, o->file);
1481                break;
1482        default:
1483                BUG("unknown diff symbol");
1484        }
1485        strbuf_release(&sb);
1486}
1487
1488static void emit_diff_symbol(struct diff_options *o, enum diff_symbol s,
1489                             const char *line, int len, unsigned flags)
1490{
1491        struct emitted_diff_symbol e = {line, len, flags, s};
1492
1493        if (o->emitted_symbols)
1494                append_emitted_diff_symbol(o, &e);
1495        else
1496                emit_diff_symbol_from_struct(o, &e);
1497}
1498
1499void diff_emit_submodule_del(struct diff_options *o, const char *line)
1500{
1501        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_DEL, line, strlen(line), 0);
1502}
1503
1504void diff_emit_submodule_add(struct diff_options *o, const char *line)
1505{
1506        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_ADD, line, strlen(line), 0);
1507}
1508
1509void diff_emit_submodule_untracked(struct diff_options *o, const char *path)
1510{
1511        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_UNTRACKED,
1512                         path, strlen(path), 0);
1513}
1514
1515void diff_emit_submodule_modified(struct diff_options *o, const char *path)
1516{
1517        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_MODIFIED,
1518                         path, strlen(path), 0);
1519}
1520
1521void diff_emit_submodule_header(struct diff_options *o, const char *header)
1522{
1523        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_HEADER,
1524                         header, strlen(header), 0);
1525}
1526
1527void diff_emit_submodule_error(struct diff_options *o, const char *err)
1528{
1529        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_ERROR, err, strlen(err), 0);
1530}
1531
1532void diff_emit_submodule_pipethrough(struct diff_options *o,
1533                                     const char *line, int len)
1534{
1535        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_PIPETHROUGH, line, len, 0);
1536}
1537
1538static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line, int len)
1539{
1540        if (!((ecbdata->ws_rule & WS_BLANK_AT_EOF) &&
1541              ecbdata->blank_at_eof_in_preimage &&
1542              ecbdata->blank_at_eof_in_postimage &&
1543              ecbdata->blank_at_eof_in_preimage <= ecbdata->lno_in_preimage &&
1544              ecbdata->blank_at_eof_in_postimage <= ecbdata->lno_in_postimage))
1545                return 0;
1546        return ws_blank_line(line, len, ecbdata->ws_rule);
1547}
1548
1549static void emit_add_line(const char *reset,
1550                          struct emit_callback *ecbdata,
1551                          const char *line, int len)
1552{
1553        unsigned flags = WSEH_NEW | ecbdata->ws_rule;
1554        if (new_blank_line_at_eof(ecbdata, line, len))
1555                flags |= DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF;
1556
1557        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_PLUS, line, len, flags);
1558}
1559
1560static void emit_del_line(const char *reset,
1561                          struct emit_callback *ecbdata,
1562                          const char *line, int len)
1563{
1564        unsigned flags = WSEH_OLD | ecbdata->ws_rule;
1565        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_MINUS, line, len, flags);
1566}
1567
1568static void emit_context_line(const char *reset,
1569                              struct emit_callback *ecbdata,
1570                              const char *line, int len)
1571{
1572        unsigned flags = WSEH_CONTEXT | ecbdata->ws_rule;
1573        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_CONTEXT, line, len, flags);
1574}
1575
1576static void emit_hunk_header(struct emit_callback *ecbdata,
1577                             const char *line, int len)
1578{
1579        const char *context = diff_get_color(ecbdata->color_diff, DIFF_CONTEXT);
1580        const char *frag = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
1581        const char *func = diff_get_color(ecbdata->color_diff, DIFF_FUNCINFO);
1582        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
1583        const char *reverse = ecbdata->color_diff ? GIT_COLOR_REVERSE : "";
1584        static const char atat[2] = { '@', '@' };
1585        const char *cp, *ep;
1586        struct strbuf msgbuf = STRBUF_INIT;
1587        int org_len = len;
1588        int i = 1;
1589
1590        /*
1591         * As a hunk header must begin with "@@ -<old>, +<new> @@",
1592         * it always is at least 10 bytes long.
1593         */
1594        if (len < 10 ||
1595            memcmp(line, atat, 2) ||
1596            !(ep = memmem(line + 2, len - 2, atat, 2))) {
1597                emit_diff_symbol(ecbdata->opt,
1598                                 DIFF_SYMBOL_CONTEXT_MARKER, line, len, 0);
1599                return;
1600        }
1601        ep += 2; /* skip over @@ */
1602
1603        /* The hunk header in fraginfo color */
1604        if (ecbdata->opt->flags.dual_color_diffed_diffs)
1605                strbuf_addstr(&msgbuf, reverse);
1606        strbuf_addstr(&msgbuf, frag);
1607        strbuf_add(&msgbuf, line, ep - line);
1608        strbuf_addstr(&msgbuf, reset);
1609
1610        /*
1611         * trailing "\r\n"
1612         */
1613        for ( ; i < 3; i++)
1614                if (line[len - i] == '\r' || line[len - i] == '\n')
1615                        len--;
1616
1617        /* blank before the func header */
1618        for (cp = ep; ep - line < len; ep++)
1619                if (*ep != ' ' && *ep != '\t')
1620                        break;
1621        if (ep != cp) {
1622                strbuf_addstr(&msgbuf, context);
1623                strbuf_add(&msgbuf, cp, ep - cp);
1624                strbuf_addstr(&msgbuf, reset);
1625        }
1626
1627        if (ep < line + len) {
1628                strbuf_addstr(&msgbuf, func);
1629                strbuf_add(&msgbuf, ep, line + len - ep);
1630                strbuf_addstr(&msgbuf, reset);
1631        }
1632
1633        strbuf_add(&msgbuf, line + len, org_len - len);
1634        strbuf_complete_line(&msgbuf);
1635        emit_diff_symbol(ecbdata->opt,
1636                         DIFF_SYMBOL_CONTEXT_FRAGINFO, msgbuf.buf, msgbuf.len, 0);
1637        strbuf_release(&msgbuf);
1638}
1639
1640static struct diff_tempfile *claim_diff_tempfile(void)
1641{
1642        int i;
1643        for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
1644                if (!diff_temp[i].name)
1645                        return diff_temp + i;
1646        BUG("diff is failing to clean up its tempfiles");
1647}
1648
1649static void remove_tempfile(void)
1650{
1651        int i;
1652        for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
1653                if (is_tempfile_active(diff_temp[i].tempfile))
1654                        delete_tempfile(&diff_temp[i].tempfile);
1655                diff_temp[i].name = NULL;
1656        }
1657}
1658
1659static void add_line_count(struct strbuf *out, int count)
1660{
1661        switch (count) {
1662        case 0:
1663                strbuf_addstr(out, "0,0");
1664                break;
1665        case 1:
1666                strbuf_addstr(out, "1");
1667                break;
1668        default:
1669                strbuf_addf(out, "1,%d", count);
1670                break;
1671        }
1672}
1673
1674static void emit_rewrite_lines(struct emit_callback *ecb,
1675                               int prefix, const char *data, int size)
1676{
1677        const char *endp = NULL;
1678        const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
1679
1680        while (0 < size) {
1681                int len;
1682
1683                endp = memchr(data, '\n', size);
1684                len = endp ? (endp - data + 1) : size;
1685                if (prefix != '+') {
1686                        ecb->lno_in_preimage++;
1687                        emit_del_line(reset, ecb, data, len);
1688                } else {
1689                        ecb->lno_in_postimage++;
1690                        emit_add_line(reset, ecb, data, len);
1691                }
1692                size -= len;
1693                data += len;
1694        }
1695        if (!endp)
1696                emit_diff_symbol(ecb->opt, DIFF_SYMBOL_NO_LF_EOF, NULL, 0, 0);
1697}
1698
1699static void emit_rewrite_diff(const char *name_a,
1700                              const char *name_b,
1701                              struct diff_filespec *one,
1702                              struct diff_filespec *two,
1703                              struct userdiff_driver *textconv_one,
1704                              struct userdiff_driver *textconv_two,
1705                              struct diff_options *o)
1706{
1707        int lc_a, lc_b;
1708        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
1709        const char *a_prefix, *b_prefix;
1710        char *data_one, *data_two;
1711        size_t size_one, size_two;
1712        struct emit_callback ecbdata;
1713        struct strbuf out = STRBUF_INIT;
1714
1715        if (diff_mnemonic_prefix && o->flags.reverse_diff) {
1716                a_prefix = o->b_prefix;
1717                b_prefix = o->a_prefix;
1718        } else {
1719                a_prefix = o->a_prefix;
1720                b_prefix = o->b_prefix;
1721        }
1722
1723        name_a += (*name_a == '/');
1724        name_b += (*name_b == '/');
1725
1726        strbuf_reset(&a_name);
1727        strbuf_reset(&b_name);
1728        quote_two_c_style(&a_name, a_prefix, name_a, 0);
1729        quote_two_c_style(&b_name, b_prefix, name_b, 0);
1730
1731        size_one = fill_textconv(o->repo, textconv_one, one, &data_one);
1732        size_two = fill_textconv(o->repo, textconv_two, two, &data_two);
1733
1734        memset(&ecbdata, 0, sizeof(ecbdata));
1735        ecbdata.color_diff = want_color(o->use_color);
1736        ecbdata.ws_rule = whitespace_rule(o->repo->index, name_b);
1737        ecbdata.opt = o;
1738        if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
1739                mmfile_t mf1, mf2;
1740                mf1.ptr = (char *)data_one;
1741                mf2.ptr = (char *)data_two;
1742                mf1.size = size_one;
1743                mf2.size = size_two;
1744                check_blank_at_eof(&mf1, &mf2, &ecbdata);
1745        }
1746        ecbdata.lno_in_preimage = 1;
1747        ecbdata.lno_in_postimage = 1;
1748
1749        lc_a = count_lines(data_one, size_one);
1750        lc_b = count_lines(data_two, size_two);
1751
1752        emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_MINUS,
1753                         a_name.buf, a_name.len, 0);
1754        emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_PLUS,
1755                         b_name.buf, b_name.len, 0);
1756
1757        strbuf_addstr(&out, "@@ -");
1758        if (!o->irreversible_delete)
1759                add_line_count(&out, lc_a);
1760        else
1761                strbuf_addstr(&out, "?,?");
1762        strbuf_addstr(&out, " +");
1763        add_line_count(&out, lc_b);
1764        strbuf_addstr(&out, " @@\n");
1765        emit_diff_symbol(o, DIFF_SYMBOL_REWRITE_DIFF, out.buf, out.len, 0);
1766        strbuf_release(&out);
1767
1768        if (lc_a && !o->irreversible_delete)
1769                emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
1770        if (lc_b)
1771                emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
1772        if (textconv_one)
1773                free((char *)data_one);
1774        if (textconv_two)
1775                free((char *)data_two);
1776}
1777
1778struct diff_words_buffer {
1779        mmfile_t text;
1780        unsigned long alloc;
1781        struct diff_words_orig {
1782                const char *begin, *end;
1783        } *orig;
1784        int orig_nr, orig_alloc;
1785};
1786
1787static void diff_words_append(char *line, unsigned long len,
1788                struct diff_words_buffer *buffer)
1789{
1790        ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
1791        line++;
1792        len--;
1793        memcpy(buffer->text.ptr + buffer->text.size, line, len);
1794        buffer->text.size += len;
1795        buffer->text.ptr[buffer->text.size] = '\0';
1796}
1797
1798struct diff_words_style_elem {
1799        const char *prefix;
1800        const char *suffix;
1801        const char *color; /* NULL; filled in by the setup code if
1802                            * color is enabled */
1803};
1804
1805struct diff_words_style {
1806        enum diff_words_type type;
1807        struct diff_words_style_elem new_word, old_word, ctx;
1808        const char *newline;
1809};
1810
1811static struct diff_words_style diff_words_styles[] = {
1812        { DIFF_WORDS_PORCELAIN, {"+", "\n"}, {"-", "\n"}, {" ", "\n"}, "~\n" },
1813        { DIFF_WORDS_PLAIN, {"{+", "+}"}, {"[-", "-]"}, {"", ""}, "\n" },
1814        { DIFF_WORDS_COLOR, {"", ""}, {"", ""}, {"", ""}, "\n" }
1815};
1816
1817struct diff_words_data {
1818        struct diff_words_buffer minus, plus;
1819        const char *current_plus;
1820        int last_minus;
1821        struct diff_options *opt;
1822        regex_t *word_regex;
1823        enum diff_words_type type;
1824        struct diff_words_style *style;
1825};
1826
1827static int fn_out_diff_words_write_helper(struct diff_options *o,
1828                                          struct diff_words_style_elem *st_el,
1829                                          const char *newline,
1830                                          size_t count, const char *buf)
1831{
1832        int print = 0;
1833        struct strbuf sb = STRBUF_INIT;
1834
1835        while (count) {
1836                char *p = memchr(buf, '\n', count);
1837                if (print)
1838                        strbuf_addstr(&sb, diff_line_prefix(o));
1839
1840                if (p != buf) {
1841                        const char *reset = st_el->color && *st_el->color ?
1842                                            GIT_COLOR_RESET : NULL;
1843                        if (st_el->color && *st_el->color)
1844                                strbuf_addstr(&sb, st_el->color);
1845                        strbuf_addstr(&sb, st_el->prefix);
1846                        strbuf_add(&sb, buf, p ? p - buf : count);
1847                        strbuf_addstr(&sb, st_el->suffix);
1848                        if (reset)
1849                                strbuf_addstr(&sb, reset);
1850                }
1851                if (!p)
1852                        goto out;
1853
1854                strbuf_addstr(&sb, newline);
1855                count -= p + 1 - buf;
1856                buf = p + 1;
1857                print = 1;
1858                if (count) {
1859                        emit_diff_symbol(o, DIFF_SYMBOL_WORD_DIFF,
1860                                         sb.buf, sb.len, 0);
1861                        strbuf_reset(&sb);
1862                }
1863        }
1864
1865out:
1866        if (sb.len)
1867                emit_diff_symbol(o, DIFF_SYMBOL_WORD_DIFF,
1868                                 sb.buf, sb.len, 0);
1869        strbuf_release(&sb);
1870        return 0;
1871}
1872
1873/*
1874 * '--color-words' algorithm can be described as:
1875 *
1876 *   1. collect the minus/plus lines of a diff hunk, divided into
1877 *      minus-lines and plus-lines;
1878 *
1879 *   2. break both minus-lines and plus-lines into words and
1880 *      place them into two mmfile_t with one word for each line;
1881 *
1882 *   3. use xdiff to run diff on the two mmfile_t to get the words level diff;
1883 *
1884 * And for the common parts of the both file, we output the plus side text.
1885 * diff_words->current_plus is used to trace the current position of the plus file
1886 * which printed. diff_words->last_minus is used to trace the last minus word
1887 * printed.
1888 *
1889 * For '--graph' to work with '--color-words', we need to output the graph prefix
1890 * on each line of color words output. Generally, there are two conditions on
1891 * which we should output the prefix.
1892 *
1893 *   1. diff_words->last_minus == 0 &&
1894 *      diff_words->current_plus == diff_words->plus.text.ptr
1895 *
1896 *      that is: the plus text must start as a new line, and if there is no minus
1897 *      word printed, a graph prefix must be printed.
1898 *
1899 *   2. diff_words->current_plus > diff_words->plus.text.ptr &&
1900 *      *(diff_words->current_plus - 1) == '\n'
1901 *
1902 *      that is: a graph prefix must be printed following a '\n'
1903 */
1904static int color_words_output_graph_prefix(struct diff_words_data *diff_words)
1905{
1906        if ((diff_words->last_minus == 0 &&
1907                diff_words->current_plus == diff_words->plus.text.ptr) ||
1908                (diff_words->current_plus > diff_words->plus.text.ptr &&
1909                *(diff_words->current_plus - 1) == '\n')) {
1910                return 1;
1911        } else {
1912                return 0;
1913        }
1914}
1915
1916static void fn_out_diff_words_aux(void *priv,
1917                                  long minus_first, long minus_len,
1918                                  long plus_first, long plus_len,
1919                                  const char *func, long funclen)
1920{
1921        struct diff_words_data *diff_words = priv;
1922        struct diff_words_style *style = diff_words->style;
1923        const char *minus_begin, *minus_end, *plus_begin, *plus_end;
1924        struct diff_options *opt = diff_words->opt;
1925        const char *line_prefix;
1926
1927        assert(opt);
1928        line_prefix = diff_line_prefix(opt);
1929
1930        /* POSIX requires that first be decremented by one if len == 0... */
1931        if (minus_len) {
1932                minus_begin = diff_words->minus.orig[minus_first].begin;
1933                minus_end =
1934                        diff_words->minus.orig[minus_first + minus_len - 1].end;
1935        } else
1936                minus_begin = minus_end =
1937                        diff_words->minus.orig[minus_first].end;
1938
1939        if (plus_len) {
1940                plus_begin = diff_words->plus.orig[plus_first].begin;
1941                plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
1942        } else
1943                plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
1944
1945        if (color_words_output_graph_prefix(diff_words)) {
1946                fputs(line_prefix, diff_words->opt->file);
1947        }
1948        if (diff_words->current_plus != plus_begin) {
1949                fn_out_diff_words_write_helper(diff_words->opt,
1950                                &style->ctx, style->newline,
1951                                plus_begin - diff_words->current_plus,
1952                                diff_words->current_plus);
1953        }
1954        if (minus_begin != minus_end) {
1955                fn_out_diff_words_write_helper(diff_words->opt,
1956                                &style->old_word, style->newline,
1957                                minus_end - minus_begin, minus_begin);
1958        }
1959        if (plus_begin != plus_end) {
1960                fn_out_diff_words_write_helper(diff_words->opt,
1961                                &style->new_word, style->newline,
1962                                plus_end - plus_begin, plus_begin);
1963        }
1964
1965        diff_words->current_plus = plus_end;
1966        diff_words->last_minus = minus_first;
1967}
1968
1969/* This function starts looking at *begin, and returns 0 iff a word was found. */
1970static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
1971                int *begin, int *end)
1972{
1973        if (word_regex && *begin < buffer->size) {
1974                regmatch_t match[1];
1975                if (!regexec_buf(word_regex, buffer->ptr + *begin,
1976                                 buffer->size - *begin, 1, match, 0)) {
1977                        char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
1978                                        '\n', match[0].rm_eo - match[0].rm_so);
1979                        *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
1980                        *begin += match[0].rm_so;
1981                        return *begin >= *end;
1982                }
1983                return -1;
1984        }
1985
1986        /* find the next word */
1987        while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
1988                (*begin)++;
1989        if (*begin >= buffer->size)
1990                return -1;
1991
1992        /* find the end of the word */
1993        *end = *begin + 1;
1994        while (*end < buffer->size && !isspace(buffer->ptr[*end]))
1995                (*end)++;
1996
1997        return 0;
1998}
1999
2000/*
2001 * This function splits the words in buffer->text, stores the list with
2002 * newline separator into out, and saves the offsets of the original words
2003 * in buffer->orig.
2004 */
2005static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
2006                regex_t *word_regex)
2007{
2008        int i, j;
2009        long alloc = 0;
2010
2011        out->size = 0;
2012        out->ptr = NULL;
2013
2014        /* fake an empty "0th" word */
2015        ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
2016        buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
2017        buffer->orig_nr = 1;
2018
2019        for (i = 0; i < buffer->text.size; i++) {
2020                if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
2021                        return;
2022
2023                /* store original boundaries */
2024                ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
2025                                buffer->orig_alloc);
2026                buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
2027                buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
2028                buffer->orig_nr++;
2029
2030                /* store one word */
2031                ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
2032                memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
2033                out->ptr[out->size + j - i] = '\n';
2034                out->size += j - i + 1;
2035
2036                i = j - 1;
2037        }
2038}
2039
2040/* this executes the word diff on the accumulated buffers */
2041static void diff_words_show(struct diff_words_data *diff_words)
2042{
2043        xpparam_t xpp;
2044        xdemitconf_t xecfg;
2045        mmfile_t minus, plus;
2046        struct diff_words_style *style = diff_words->style;
2047
2048        struct diff_options *opt = diff_words->opt;
2049        const char *line_prefix;
2050
2051        assert(opt);
2052        line_prefix = diff_line_prefix(opt);
2053
2054        /* special case: only removal */
2055        if (!diff_words->plus.text.size) {
2056                emit_diff_symbol(diff_words->opt, DIFF_SYMBOL_WORD_DIFF,
2057                                 line_prefix, strlen(line_prefix), 0);
2058                fn_out_diff_words_write_helper(diff_words->opt,
2059                        &style->old_word, style->newline,
2060                        diff_words->minus.text.size,
2061                        diff_words->minus.text.ptr);
2062                diff_words->minus.text.size = 0;
2063                return;
2064        }
2065
2066        diff_words->current_plus = diff_words->plus.text.ptr;
2067        diff_words->last_minus = 0;
2068
2069        memset(&xpp, 0, sizeof(xpp));
2070        memset(&xecfg, 0, sizeof(xecfg));
2071        diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
2072        diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
2073        xpp.flags = 0;
2074        /* as only the hunk header will be parsed, we need a 0-context */
2075        xecfg.ctxlen = 0;
2076        if (xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, NULL,
2077                          diff_words, &xpp, &xecfg))
2078                die("unable to generate word diff");
2079        free(minus.ptr);
2080        free(plus.ptr);
2081        if (diff_words->current_plus != diff_words->plus.text.ptr +
2082                        diff_words->plus.text.size) {
2083                if (color_words_output_graph_prefix(diff_words))
2084                        emit_diff_symbol(diff_words->opt, DIFF_SYMBOL_WORD_DIFF,
2085                                         line_prefix, strlen(line_prefix), 0);
2086                fn_out_diff_words_write_helper(diff_words->opt,
2087                        &style->ctx, style->newline,
2088                        diff_words->plus.text.ptr + diff_words->plus.text.size
2089                        - diff_words->current_plus, diff_words->current_plus);
2090        }
2091        diff_words->minus.text.size = diff_words->plus.text.size = 0;
2092}
2093
2094/* In "color-words" mode, show word-diff of words accumulated in the buffer */
2095static void diff_words_flush(struct emit_callback *ecbdata)
2096{
2097        struct diff_options *wo = ecbdata->diff_words->opt;
2098
2099        if (ecbdata->diff_words->minus.text.size ||
2100            ecbdata->diff_words->plus.text.size)
2101                diff_words_show(ecbdata->diff_words);
2102
2103        if (wo->emitted_symbols) {
2104                struct diff_options *o = ecbdata->opt;
2105                struct emitted_diff_symbols *wol = wo->emitted_symbols;
2106                int i;
2107
2108                /*
2109                 * NEEDSWORK:
2110                 * Instead of appending each, concat all words to a line?
2111                 */
2112                for (i = 0; i < wol->nr; i++)
2113                        append_emitted_diff_symbol(o, &wol->buf[i]);
2114
2115                for (i = 0; i < wol->nr; i++)
2116                        free((void *)wol->buf[i].line);
2117
2118                wol->nr = 0;
2119        }
2120}
2121
2122static void diff_filespec_load_driver(struct diff_filespec *one,
2123                                      struct index_state *istate)
2124{
2125        /* Use already-loaded driver */
2126        if (one->driver)
2127                return;
2128
2129        if (S_ISREG(one->mode))
2130                one->driver = userdiff_find_by_path(istate, one->path);
2131
2132        /* Fallback to default settings */
2133        if (!one->driver)
2134                one->driver = userdiff_find_by_name("default");
2135}
2136
2137static const char *userdiff_word_regex(struct diff_filespec *one,
2138                                       struct index_state *istate)
2139{
2140        diff_filespec_load_driver(one, istate);
2141        return one->driver->word_regex;
2142}
2143
2144static void init_diff_words_data(struct emit_callback *ecbdata,
2145                                 struct diff_options *orig_opts,
2146                                 struct diff_filespec *one,
2147                                 struct diff_filespec *two)
2148{
2149        int i;
2150        struct diff_options *o = xmalloc(sizeof(struct diff_options));
2151        memcpy(o, orig_opts, sizeof(struct diff_options));
2152
2153        ecbdata->diff_words =
2154                xcalloc(1, sizeof(struct diff_words_data));
2155        ecbdata->diff_words->type = o->word_diff;
2156        ecbdata->diff_words->opt = o;
2157
2158        if (orig_opts->emitted_symbols)
2159                o->emitted_symbols =
2160                        xcalloc(1, sizeof(struct emitted_diff_symbols));
2161
2162        if (!o->word_regex)
2163                o->word_regex = userdiff_word_regex(one, o->repo->index);
2164        if (!o->word_regex)
2165                o->word_regex = userdiff_word_regex(two, o->repo->index);
2166        if (!o->word_regex)
2167                o->word_regex = diff_word_regex_cfg;
2168        if (o->word_regex) {
2169                ecbdata->diff_words->word_regex = (regex_t *)
2170                        xmalloc(sizeof(regex_t));
2171                if (regcomp(ecbdata->diff_words->word_regex,
2172                            o->word_regex,
2173                            REG_EXTENDED | REG_NEWLINE))
2174                        die("invalid regular expression: %s",
2175                            o->word_regex);
2176        }
2177        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
2178                if (o->word_diff == diff_words_styles[i].type) {
2179                        ecbdata->diff_words->style =
2180                                &diff_words_styles[i];
2181                        break;
2182                }
2183        }
2184        if (want_color(o->use_color)) {
2185                struct diff_words_style *st = ecbdata->diff_words->style;
2186                st->old_word.color = diff_get_color_opt(o, DIFF_FILE_OLD);
2187                st->new_word.color = diff_get_color_opt(o, DIFF_FILE_NEW);
2188                st->ctx.color = diff_get_color_opt(o, DIFF_CONTEXT);
2189        }
2190}
2191
2192static void free_diff_words_data(struct emit_callback *ecbdata)
2193{
2194        if (ecbdata->diff_words) {
2195                diff_words_flush(ecbdata);
2196                free (ecbdata->diff_words->opt->emitted_symbols);
2197                free (ecbdata->diff_words->opt);
2198                free (ecbdata->diff_words->minus.text.ptr);
2199                free (ecbdata->diff_words->minus.orig);
2200                free (ecbdata->diff_words->plus.text.ptr);
2201                free (ecbdata->diff_words->plus.orig);
2202                if (ecbdata->diff_words->word_regex) {
2203                        regfree(ecbdata->diff_words->word_regex);
2204                        free(ecbdata->diff_words->word_regex);
2205                }
2206                FREE_AND_NULL(ecbdata->diff_words);
2207        }
2208}
2209
2210const char *diff_get_color(int diff_use_color, enum color_diff ix)
2211{
2212        if (want_color(diff_use_color))
2213                return diff_colors[ix];
2214        return "";
2215}
2216
2217const char *diff_line_prefix(struct diff_options *opt)
2218{
2219        struct strbuf *msgbuf;
2220        if (!opt->output_prefix)
2221                return "";
2222
2223        msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
2224        return msgbuf->buf;
2225}
2226
2227static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
2228{
2229        const char *cp;
2230        unsigned long allot;
2231        size_t l = len;
2232
2233        cp = line;
2234        allot = l;
2235        while (0 < l) {
2236                (void) utf8_width(&cp, &l);
2237                if (!cp)
2238                        break; /* truncated in the middle? */
2239        }
2240        return allot - l;
2241}
2242
2243static void find_lno(const char *line, struct emit_callback *ecbdata)
2244{
2245        const char *p;
2246        ecbdata->lno_in_preimage = 0;
2247        ecbdata->lno_in_postimage = 0;
2248        p = strchr(line, '-');
2249        if (!p)
2250                return; /* cannot happen */
2251        ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
2252        p = strchr(p, '+');
2253        if (!p)
2254                return; /* cannot happen */
2255        ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
2256}
2257
2258static void fn_out_consume(void *priv, char *line, unsigned long len)
2259{
2260        struct emit_callback *ecbdata = priv;
2261        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
2262        struct diff_options *o = ecbdata->opt;
2263
2264        o->found_changes = 1;
2265
2266        if (ecbdata->header) {
2267                emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
2268                                 ecbdata->header->buf, ecbdata->header->len, 0);
2269                strbuf_reset(ecbdata->header);
2270                ecbdata->header = NULL;
2271        }
2272
2273        if (ecbdata->label_path[0]) {
2274                emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_MINUS,
2275                                 ecbdata->label_path[0],
2276                                 strlen(ecbdata->label_path[0]), 0);
2277                emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_PLUS,
2278                                 ecbdata->label_path[1],
2279                                 strlen(ecbdata->label_path[1]), 0);
2280                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
2281        }
2282
2283        if (diff_suppress_blank_empty
2284            && len == 2 && line[0] == ' ' && line[1] == '\n') {
2285                line[0] = '\n';
2286                len = 1;
2287        }
2288
2289        if (line[0] == '@') {
2290                if (ecbdata->diff_words)
2291                        diff_words_flush(ecbdata);
2292                len = sane_truncate_line(ecbdata, line, len);
2293                find_lno(line, ecbdata);
2294                emit_hunk_header(ecbdata, line, len);
2295                return;
2296        }
2297
2298        if (ecbdata->diff_words) {
2299                enum diff_symbol s =
2300                        ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN ?
2301                        DIFF_SYMBOL_WORDS_PORCELAIN : DIFF_SYMBOL_WORDS;
2302                if (line[0] == '-') {
2303                        diff_words_append(line, len,
2304                                          &ecbdata->diff_words->minus);
2305                        return;
2306                } else if (line[0] == '+') {
2307                        diff_words_append(line, len,
2308                                          &ecbdata->diff_words->plus);
2309                        return;
2310                } else if (starts_with(line, "\\ ")) {
2311                        /*
2312                         * Eat the "no newline at eof" marker as if we
2313                         * saw a "+" or "-" line with nothing on it,
2314                         * and return without diff_words_flush() to
2315                         * defer processing. If this is the end of
2316                         * preimage, more "+" lines may come after it.
2317                         */
2318                        return;
2319                }
2320                diff_words_flush(ecbdata);
2321                emit_diff_symbol(o, s, line, len, 0);
2322                return;
2323        }
2324
2325        switch (line[0]) {
2326        case '+':
2327                ecbdata->lno_in_postimage++;
2328                emit_add_line(reset, ecbdata, line + 1, len - 1);
2329                break;
2330        case '-':
2331                ecbdata->lno_in_preimage++;
2332                emit_del_line(reset, ecbdata, line + 1, len - 1);
2333                break;
2334        case ' ':
2335                ecbdata->lno_in_postimage++;
2336                ecbdata->lno_in_preimage++;
2337                emit_context_line(reset, ecbdata, line + 1, len - 1);
2338                break;
2339        default:
2340                /* incomplete line at the end */
2341                ecbdata->lno_in_preimage++;
2342                emit_diff_symbol(o, DIFF_SYMBOL_CONTEXT_INCOMPLETE,
2343                                 line, len, 0);
2344                break;
2345        }
2346}
2347
2348static void pprint_rename(struct strbuf *name, const char *a, const char *b)
2349{
2350        const char *old_name = a;
2351        const char *new_name = b;
2352        int pfx_length, sfx_length;
2353        int pfx_adjust_for_slash;
2354        int len_a = strlen(a);
2355        int len_b = strlen(b);
2356        int a_midlen, b_midlen;
2357        int qlen_a = quote_c_style(a, NULL, NULL, 0);
2358        int qlen_b = quote_c_style(b, NULL, NULL, 0);
2359
2360        if (qlen_a || qlen_b) {
2361                quote_c_style(a, name, NULL, 0);
2362                strbuf_addstr(name, " => ");
2363                quote_c_style(b, name, NULL, 0);
2364                return;
2365        }
2366
2367        /* Find common prefix */
2368        pfx_length = 0;
2369        while (*old_name && *new_name && *old_name == *new_name) {
2370                if (*old_name == '/')
2371                        pfx_length = old_name - a + 1;
2372                old_name++;
2373                new_name++;
2374        }
2375
2376        /* Find common suffix */
2377        old_name = a + len_a;
2378        new_name = b + len_b;
2379        sfx_length = 0;
2380        /*
2381         * If there is a common prefix, it must end in a slash.  In
2382         * that case we let this loop run 1 into the prefix to see the
2383         * same slash.
2384         *
2385         * If there is no common prefix, we cannot do this as it would
2386         * underrun the input strings.
2387         */
2388        pfx_adjust_for_slash = (pfx_length ? 1 : 0);
2389        while (a + pfx_length - pfx_adjust_for_slash <= old_name &&
2390               b + pfx_length - pfx_adjust_for_slash <= new_name &&
2391               *old_name == *new_name) {
2392                if (*old_name == '/')
2393                        sfx_length = len_a - (old_name - a);
2394                old_name--;
2395                new_name--;
2396        }
2397
2398        /*
2399         * pfx{mid-a => mid-b}sfx
2400         * {pfx-a => pfx-b}sfx
2401         * pfx{sfx-a => sfx-b}
2402         * name-a => name-b
2403         */
2404        a_midlen = len_a - pfx_length - sfx_length;
2405        b_midlen = len_b - pfx_length - sfx_length;
2406        if (a_midlen < 0)
2407                a_midlen = 0;
2408        if (b_midlen < 0)
2409                b_midlen = 0;
2410
2411        strbuf_grow(name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
2412        if (pfx_length + sfx_length) {
2413                strbuf_add(name, a, pfx_length);
2414                strbuf_addch(name, '{');
2415        }
2416        strbuf_add(name, a + pfx_length, a_midlen);
2417        strbuf_addstr(name, " => ");
2418        strbuf_add(name, b + pfx_length, b_midlen);
2419        if (pfx_length + sfx_length) {
2420                strbuf_addch(name, '}');
2421                strbuf_add(name, a + len_a - sfx_length, sfx_length);
2422        }
2423}
2424
2425struct diffstat_t {
2426        int nr;
2427        int alloc;
2428        struct diffstat_file {
2429                char *from_name;
2430                char *name;
2431                char *print_name;
2432                const char *comments;
2433                unsigned is_unmerged:1;
2434                unsigned is_binary:1;
2435                unsigned is_renamed:1;
2436                unsigned is_interesting:1;
2437                uintmax_t added, deleted;
2438        } **files;
2439};
2440
2441static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
2442                                          const char *name_a,
2443                                          const char *name_b)
2444{
2445        struct diffstat_file *x;
2446        x = xcalloc(1, sizeof(*x));
2447        ALLOC_GROW(diffstat->files, diffstat->nr + 1, diffstat->alloc);
2448        diffstat->files[diffstat->nr++] = x;
2449        if (name_b) {
2450                x->from_name = xstrdup(name_a);
2451                x->name = xstrdup(name_b);
2452                x->is_renamed = 1;
2453        }
2454        else {
2455                x->from_name = NULL;
2456                x->name = xstrdup(name_a);
2457        }
2458        return x;
2459}
2460
2461static void diffstat_consume(void *priv, char *line, unsigned long len)
2462{
2463        struct diffstat_t *diffstat = priv;
2464        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
2465
2466        if (line[0] == '+')
2467                x->added++;
2468        else if (line[0] == '-')
2469                x->deleted++;
2470}
2471
2472const char mime_boundary_leader[] = "------------";
2473
2474static int scale_linear(int it, int width, int max_change)
2475{
2476        if (!it)
2477                return 0;
2478        /*
2479         * make sure that at least one '-' or '+' is printed if
2480         * there is any change to this path. The easiest way is to
2481         * scale linearly as if the alloted width is one column shorter
2482         * than it is, and then add 1 to the result.
2483         */
2484        return 1 + (it * (width - 1) / max_change);
2485}
2486
2487static void show_graph(struct strbuf *out, char ch, int cnt,
2488                       const char *set, const char *reset)
2489{
2490        if (cnt <= 0)
2491                return;
2492        strbuf_addstr(out, set);
2493        strbuf_addchars(out, ch, cnt);
2494        strbuf_addstr(out, reset);
2495}
2496
2497static void fill_print_name(struct diffstat_file *file)
2498{
2499        struct strbuf pname = STRBUF_INIT;
2500
2501        if (file->print_name)
2502                return;
2503
2504        if (file->is_renamed)
2505                pprint_rename(&pname, file->from_name, file->name);
2506        else
2507                quote_c_style(file->name, &pname, NULL, 0);
2508
2509        if (file->comments)
2510                strbuf_addf(&pname, " (%s)", file->comments);
2511
2512        file->print_name = strbuf_detach(&pname, NULL);
2513}
2514
2515static void print_stat_summary_inserts_deletes(struct diff_options *options,
2516                int files, int insertions, int deletions)
2517{
2518        struct strbuf sb = STRBUF_INIT;
2519
2520        if (!files) {
2521                assert(insertions == 0 && deletions == 0);
2522                emit_diff_symbol(options, DIFF_SYMBOL_STATS_SUMMARY_NO_FILES,
2523                                 NULL, 0, 0);
2524                return;
2525        }
2526
2527        strbuf_addf(&sb,
2528                    (files == 1) ? " %d file changed" : " %d files changed",
2529                    files);
2530
2531        /*
2532         * For binary diff, the caller may want to print "x files
2533         * changed" with insertions == 0 && deletions == 0.
2534         *
2535         * Not omitting "0 insertions(+), 0 deletions(-)" in this case
2536         * is probably less confusing (i.e skip over "2 files changed
2537         * but nothing about added/removed lines? Is this a bug in Git?").
2538         */
2539        if (insertions || deletions == 0) {
2540                strbuf_addf(&sb,
2541                            (insertions == 1) ? ", %d insertion(+)" : ", %d insertions(+)",
2542                            insertions);
2543        }
2544
2545        if (deletions || insertions == 0) {
2546                strbuf_addf(&sb,
2547                            (deletions == 1) ? ", %d deletion(-)" : ", %d deletions(-)",
2548                            deletions);
2549        }
2550        strbuf_addch(&sb, '\n');
2551        emit_diff_symbol(options, DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES,
2552                         sb.buf, sb.len, 0);
2553        strbuf_release(&sb);
2554}
2555
2556void print_stat_summary(FILE *fp, int files,
2557                        int insertions, int deletions)
2558{
2559        struct diff_options o;
2560        memset(&o, 0, sizeof(o));
2561        o.file = fp;
2562
2563        print_stat_summary_inserts_deletes(&o, files, insertions, deletions);
2564}
2565
2566static void show_stats(struct diffstat_t *data, struct diff_options *options)
2567{
2568        int i, len, add, del, adds = 0, dels = 0;
2569        uintmax_t max_change = 0, max_len = 0;
2570        int total_files = data->nr, count;
2571        int width, name_width, graph_width, number_width = 0, bin_width = 0;
2572        const char *reset, *add_c, *del_c;
2573        int extra_shown = 0;
2574        const char *line_prefix = diff_line_prefix(options);
2575        struct strbuf out = STRBUF_INIT;
2576
2577        if (data->nr == 0)
2578                return;
2579
2580        count = options->stat_count ? options->stat_count : data->nr;
2581
2582        reset = diff_get_color_opt(options, DIFF_RESET);
2583        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
2584        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
2585
2586        /*
2587         * Find the longest filename and max number of changes
2588         */
2589        for (i = 0; (i < count) && (i < data->nr); i++) {
2590                struct diffstat_file *file = data->files[i];
2591                uintmax_t change = file->added + file->deleted;
2592
2593                if (!file->is_interesting && (change == 0)) {
2594                        count++; /* not shown == room for one more */
2595                        continue;
2596                }
2597                fill_print_name(file);
2598                len = strlen(file->print_name);
2599                if (max_len < len)
2600                        max_len = len;
2601
2602                if (file->is_unmerged) {
2603                        /* "Unmerged" is 8 characters */
2604                        bin_width = bin_width < 8 ? 8 : bin_width;
2605                        continue;
2606                }
2607                if (file->is_binary) {
2608                        /* "Bin XXX -> YYY bytes" */
2609                        int w = 14 + decimal_width(file->added)
2610                                + decimal_width(file->deleted);
2611                        bin_width = bin_width < w ? w : bin_width;
2612                        /* Display change counts aligned with "Bin" */
2613                        number_width = 3;
2614                        continue;
2615                }
2616
2617                if (max_change < change)
2618                        max_change = change;
2619        }
2620        count = i; /* where we can stop scanning in data->files[] */
2621
2622        /*
2623         * We have width = stat_width or term_columns() columns total.
2624         * We want a maximum of min(max_len, stat_name_width) for the name part.
2625         * We want a maximum of min(max_change, stat_graph_width) for the +- part.
2626         * We also need 1 for " " and 4 + decimal_width(max_change)
2627         * for " | NNNN " and one the empty column at the end, altogether
2628         * 6 + decimal_width(max_change).
2629         *
2630         * If there's not enough space, we will use the smaller of
2631         * stat_name_width (if set) and 5/8*width for the filename,
2632         * and the rest for constant elements + graph part, but no more
2633         * than stat_graph_width for the graph part.
2634         * (5/8 gives 50 for filename and 30 for the constant parts + graph
2635         * for the standard terminal size).
2636         *
2637         * In other words: stat_width limits the maximum width, and
2638         * stat_name_width fixes the maximum width of the filename,
2639         * and is also used to divide available columns if there
2640         * aren't enough.
2641         *
2642         * Binary files are displayed with "Bin XXX -> YYY bytes"
2643         * instead of the change count and graph. This part is treated
2644         * similarly to the graph part, except that it is not
2645         * "scaled". If total width is too small to accommodate the
2646         * guaranteed minimum width of the filename part and the
2647         * separators and this message, this message will "overflow"
2648         * making the line longer than the maximum width.
2649         */
2650
2651        if (options->stat_width == -1)
2652                width = term_columns() - strlen(line_prefix);
2653        else
2654                width = options->stat_width ? options->stat_width : 80;
2655        number_width = decimal_width(max_change) > number_width ?
2656                decimal_width(max_change) : number_width;
2657
2658        if (options->stat_graph_width == -1)
2659                options->stat_graph_width = diff_stat_graph_width;
2660
2661        /*
2662         * Guarantee 3/8*16==6 for the graph part
2663         * and 5/8*16==10 for the filename part
2664         */
2665        if (width < 16 + 6 + number_width)
2666                width = 16 + 6 + number_width;
2667
2668        /*
2669         * First assign sizes that are wanted, ignoring available width.
2670         * strlen("Bin XXX -> YYY bytes") == bin_width, and the part
2671         * starting from "XXX" should fit in graph_width.
2672         */
2673        graph_width = max_change + 4 > bin_width ? max_change : bin_width - 4;
2674        if (options->stat_graph_width &&
2675            options->stat_graph_width < graph_width)
2676                graph_width = options->stat_graph_width;
2677
2678        name_width = (options->stat_name_width > 0 &&
2679                      options->stat_name_width < max_len) ?
2680                options->stat_name_width : max_len;
2681
2682        /*
2683         * Adjust adjustable widths not to exceed maximum width
2684         */
2685        if (name_width + number_width + 6 + graph_width > width) {
2686                if (graph_width > width * 3/8 - number_width - 6) {
2687                        graph_width = width * 3/8 - number_width - 6;
2688                        if (graph_width < 6)
2689                                graph_width = 6;
2690                }
2691
2692                if (options->stat_graph_width &&
2693                    graph_width > options->stat_graph_width)
2694                        graph_width = options->stat_graph_width;
2695                if (name_width > width - number_width - 6 - graph_width)
2696                        name_width = width - number_width - 6 - graph_width;
2697                else
2698                        graph_width = width - number_width - 6 - name_width;
2699        }
2700
2701        /*
2702         * From here name_width is the width of the name area,
2703         * and graph_width is the width of the graph area.
2704         * max_change is used to scale graph properly.
2705         */
2706        for (i = 0; i < count; i++) {
2707                const char *prefix = "";
2708                struct diffstat_file *file = data->files[i];
2709                char *name = file->print_name;
2710                uintmax_t added = file->added;
2711                uintmax_t deleted = file->deleted;
2712                int name_len;
2713
2714                if (!file->is_interesting && (added + deleted == 0))
2715                        continue;
2716
2717                /*
2718                 * "scale" the filename
2719                 */
2720                len = name_width;
2721                name_len = strlen(name);
2722                if (name_width < name_len) {
2723                        char *slash;
2724                        prefix = "...";
2725                        len -= 3;
2726                        name += name_len - len;
2727                        slash = strchr(name, '/');
2728                        if (slash)
2729                                name = slash;
2730                }
2731
2732                if (file->is_binary) {
2733                        strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2734                        strbuf_addf(&out, " %*s", number_width, "Bin");
2735                        if (!added && !deleted) {
2736                                strbuf_addch(&out, '\n');
2737                                emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2738                                                 out.buf, out.len, 0);
2739                                strbuf_reset(&out);
2740                                continue;
2741                        }
2742                        strbuf_addf(&out, " %s%"PRIuMAX"%s",
2743                                del_c, deleted, reset);
2744                        strbuf_addstr(&out, " -> ");
2745                        strbuf_addf(&out, "%s%"PRIuMAX"%s",
2746                                add_c, added, reset);
2747                        strbuf_addstr(&out, " bytes\n");
2748                        emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2749                                         out.buf, out.len, 0);
2750                        strbuf_reset(&out);
2751                        continue;
2752                }
2753                else if (file->is_unmerged) {
2754                        strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2755                        strbuf_addstr(&out, " Unmerged\n");
2756                        emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2757                                         out.buf, out.len, 0);
2758                        strbuf_reset(&out);
2759                        continue;
2760                }
2761
2762                /*
2763                 * scale the add/delete
2764                 */
2765                add = added;
2766                del = deleted;
2767
2768                if (graph_width <= max_change) {
2769                        int total = scale_linear(add + del, graph_width, max_change);
2770                        if (total < 2 && add && del)
2771                                /* width >= 2 due to the sanity check */
2772                                total = 2;
2773                        if (add < del) {
2774                                add = scale_linear(add, graph_width, max_change);
2775                                del = total - add;
2776                        } else {
2777                                del = scale_linear(del, graph_width, max_change);
2778                                add = total - del;
2779                        }
2780                }
2781                strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2782                strbuf_addf(&out, " %*"PRIuMAX"%s",
2783                        number_width, added + deleted,
2784                        added + deleted ? " " : "");
2785                show_graph(&out, '+', add, add_c, reset);
2786                show_graph(&out, '-', del, del_c, reset);
2787                strbuf_addch(&out, '\n');
2788                emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2789                                 out.buf, out.len, 0);
2790                strbuf_reset(&out);
2791        }
2792
2793        for (i = 0; i < data->nr; i++) {
2794                struct diffstat_file *file = data->files[i];
2795                uintmax_t added = file->added;
2796                uintmax_t deleted = file->deleted;
2797
2798                if (file->is_unmerged ||
2799                    (!file->is_interesting && (added + deleted == 0))) {
2800                        total_files--;
2801                        continue;
2802                }
2803
2804                if (!file->is_binary) {
2805                        adds += added;
2806                        dels += deleted;
2807                }
2808                if (i < count)
2809                        continue;
2810                if (!extra_shown)
2811                        emit_diff_symbol(options,
2812                                         DIFF_SYMBOL_STATS_SUMMARY_ABBREV,
2813                                         NULL, 0, 0);
2814                extra_shown = 1;
2815        }
2816
2817        print_stat_summary_inserts_deletes(options, total_files, adds, dels);
2818        strbuf_release(&out);
2819}
2820
2821static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
2822{
2823        int i, adds = 0, dels = 0, total_files = data->nr;
2824
2825        if (data->nr == 0)
2826                return;
2827
2828        for (i = 0; i < data->nr; i++) {
2829                int added = data->files[i]->added;
2830                int deleted = data->files[i]->deleted;
2831
2832                if (data->files[i]->is_unmerged ||
2833                    (!data->files[i]->is_interesting && (added + deleted == 0))) {
2834                        total_files--;
2835                } else if (!data->files[i]->is_binary) { /* don't count bytes */
2836                        adds += added;
2837                        dels += deleted;
2838                }
2839        }
2840        print_stat_summary_inserts_deletes(options, total_files, adds, dels);
2841}
2842
2843static void show_numstat(struct diffstat_t *data, struct diff_options *options)
2844{
2845        int i;
2846
2847        if (data->nr == 0)
2848                return;
2849
2850        for (i = 0; i < data->nr; i++) {
2851                struct diffstat_file *file = data->files[i];
2852
2853                fprintf(options->file, "%s", diff_line_prefix(options));
2854
2855                if (file->is_binary)
2856                        fprintf(options->file, "-\t-\t");
2857                else
2858                        fprintf(options->file,
2859                                "%"PRIuMAX"\t%"PRIuMAX"\t",
2860                                file->added, file->deleted);
2861                if (options->line_termination) {
2862                        fill_print_name(file);
2863                        if (!file->is_renamed)
2864                                write_name_quoted(file->name, options->file,
2865                                                  options->line_termination);
2866                        else {
2867                                fputs(file->print_name, options->file);
2868                                putc(options->line_termination, options->file);
2869                        }
2870                } else {
2871                        if (file->is_renamed) {
2872                                putc('\0', options->file);
2873                                write_name_quoted(file->from_name, options->file, '\0');
2874                        }
2875                        write_name_quoted(file->name, options->file, '\0');
2876                }
2877        }
2878}
2879
2880struct dirstat_file {
2881        const char *name;
2882        unsigned long changed;
2883};
2884
2885struct dirstat_dir {
2886        struct dirstat_file *files;
2887        int alloc, nr, permille, cumulative;
2888};
2889
2890static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
2891                unsigned long changed, const char *base, int baselen)
2892{
2893        unsigned long sum_changes = 0;
2894        unsigned int sources = 0;
2895        const char *line_prefix = diff_line_prefix(opt);
2896
2897        while (dir->nr) {
2898                struct dirstat_file *f = dir->files;
2899                int namelen = strlen(f->name);
2900                unsigned long changes;
2901                char *slash;
2902
2903                if (namelen < baselen)
2904                        break;
2905                if (memcmp(f->name, base, baselen))
2906                        break;
2907                slash = strchr(f->name + baselen, '/');
2908                if (slash) {
2909                        int newbaselen = slash + 1 - f->name;
2910                        changes = gather_dirstat(opt, dir, changed, f->name, newbaselen);
2911                        sources++;
2912                } else {
2913                        changes = f->changed;
2914                        dir->files++;
2915                        dir->nr--;
2916                        sources += 2;
2917                }
2918                sum_changes += changes;
2919        }
2920
2921        /*
2922         * We don't report dirstat's for
2923         *  - the top level
2924         *  - or cases where everything came from a single directory
2925         *    under this directory (sources == 1).
2926         */
2927        if (baselen && sources != 1) {
2928                if (sum_changes) {
2929                        int permille = sum_changes * 1000 / changed;
2930                        if (permille >= dir->permille) {
2931                                fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
2932                                        permille / 10, permille % 10, baselen, base);
2933                                if (!dir->cumulative)
2934                                        return 0;
2935                        }
2936                }
2937        }
2938        return sum_changes;
2939}
2940
2941static int dirstat_compare(const void *_a, const void *_b)
2942{
2943        const struct dirstat_file *a = _a;
2944        const struct dirstat_file *b = _b;
2945        return strcmp(a->name, b->name);
2946}
2947
2948static void show_dirstat(struct diff_options *options)
2949{
2950        int i;
2951        unsigned long changed;
2952        struct dirstat_dir dir;
2953        struct diff_queue_struct *q = &diff_queued_diff;
2954
2955        dir.files = NULL;
2956        dir.alloc = 0;
2957        dir.nr = 0;
2958        dir.permille = options->dirstat_permille;
2959        dir.cumulative = options->flags.dirstat_cumulative;
2960
2961        changed = 0;
2962        for (i = 0; i < q->nr; i++) {
2963                struct diff_filepair *p = q->queue[i];
2964                const char *name;
2965                unsigned long copied, added, damage;
2966
2967                name = p->two->path ? p->two->path : p->one->path;
2968
2969                if (p->one->oid_valid && p->two->oid_valid &&
2970                    oideq(&p->one->oid, &p->two->oid)) {
2971                        /*
2972                         * The SHA1 has not changed, so pre-/post-content is
2973                         * identical. We can therefore skip looking at the
2974                         * file contents altogether.
2975                         */
2976                        damage = 0;
2977                        goto found_damage;
2978                }
2979
2980                if (options->flags.dirstat_by_file) {
2981                        /*
2982                         * In --dirstat-by-file mode, we don't really need to
2983                         * look at the actual file contents at all.
2984                         * The fact that the SHA1 changed is enough for us to
2985                         * add this file to the list of results
2986                         * (with each file contributing equal damage).
2987                         */
2988                        damage = 1;
2989                        goto found_damage;
2990                }
2991
2992                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
2993                        diff_populate_filespec(options->repo, p->one, 0);
2994                        diff_populate_filespec(options->repo, p->two, 0);
2995                        diffcore_count_changes(options->repo,
2996                                               p->one, p->two, NULL, NULL,
2997                                               &copied, &added);
2998                        diff_free_filespec_data(p->one);
2999                        diff_free_filespec_data(p->two);
3000                } else if (DIFF_FILE_VALID(p->one)) {
3001                        diff_populate_filespec(options->repo, p->one, CHECK_SIZE_ONLY);
3002                        copied = added = 0;
3003                        diff_free_filespec_data(p->one);
3004                } else if (DIFF_FILE_VALID(p->two)) {
3005                        diff_populate_filespec(options->repo, p->two, CHECK_SIZE_ONLY);
3006                        copied = 0;
3007                        added = p->two->size;
3008                        diff_free_filespec_data(p->two);
3009                } else
3010                        continue;
3011
3012                /*
3013                 * Original minus copied is the removed material,
3014                 * added is the new material.  They are both damages
3015                 * made to the preimage.
3016                 * If the resulting damage is zero, we know that
3017                 * diffcore_count_changes() considers the two entries to
3018                 * be identical, but since the oid changed, we
3019                 * know that there must have been _some_ kind of change,
3020                 * so we force all entries to have damage > 0.
3021                 */
3022                damage = (p->one->size - copied) + added;
3023                if (!damage)
3024                        damage = 1;
3025
3026found_damage:
3027                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
3028                dir.files[dir.nr].name = name;
3029                dir.files[dir.nr].changed = damage;
3030                changed += damage;
3031                dir.nr++;
3032        }
3033
3034        /* This can happen even with many files, if everything was renames */
3035        if (!changed)
3036                return;
3037
3038        /* Show all directories with more than x% of the changes */
3039        QSORT(dir.files, dir.nr, dirstat_compare);
3040        gather_dirstat(options, &dir, changed, "", 0);
3041}
3042
3043static void show_dirstat_by_line(struct diffstat_t *data, struct diff_options *options)
3044{
3045        int i;
3046        unsigned long changed;
3047        struct dirstat_dir dir;
3048
3049        if (data->nr == 0)
3050                return;
3051
3052        dir.files = NULL;
3053        dir.alloc = 0;
3054        dir.nr = 0;
3055        dir.permille = options->dirstat_permille;
3056        dir.cumulative = options->flags.dirstat_cumulative;
3057
3058        changed = 0;
3059        for (i = 0; i < data->nr; i++) {
3060                struct diffstat_file *file = data->files[i];
3061                unsigned long damage = file->added + file->deleted;
3062                if (file->is_binary)
3063                        /*
3064                         * binary files counts bytes, not lines. Must find some
3065                         * way to normalize binary bytes vs. textual lines.
3066                         * The following heuristic assumes that there are 64
3067                         * bytes per "line".
3068                         * This is stupid and ugly, but very cheap...
3069                         */
3070                        damage = DIV_ROUND_UP(damage, 64);
3071                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
3072                dir.files[dir.nr].name = file->name;
3073                dir.files[dir.nr].changed = damage;
3074                changed += damage;
3075                dir.nr++;
3076        }
3077
3078        /* This can happen even with many files, if everything was renames */
3079        if (!changed)
3080                return;
3081
3082        /* Show all directories with more than x% of the changes */
3083        QSORT(dir.files, dir.nr, dirstat_compare);
3084        gather_dirstat(options, &dir, changed, "", 0);
3085}
3086
3087static void free_diffstat_info(struct diffstat_t *diffstat)
3088{
3089        int i;
3090        for (i = 0; i < diffstat->nr; i++) {
3091                struct diffstat_file *f = diffstat->files[i];
3092                free(f->print_name);
3093                free(f->name);
3094                free(f->from_name);
3095                free(f);
3096        }
3097        free(diffstat->files);
3098}
3099
3100struct checkdiff_t {
3101        const char *filename;
3102        int lineno;
3103        int conflict_marker_size;
3104        struct diff_options *o;
3105        unsigned ws_rule;
3106        unsigned status;
3107};
3108
3109static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
3110{
3111        char firstchar;
3112        int cnt;
3113
3114        if (len < marker_size + 1)
3115                return 0;
3116        firstchar = line[0];
3117        switch (firstchar) {
3118        case '=': case '>': case '<': case '|':
3119                break;
3120        default:
3121                return 0;
3122        }
3123        for (cnt = 1; cnt < marker_size; cnt++)
3124                if (line[cnt] != firstchar)
3125                        return 0;
3126        /* line[1] thru line[marker_size-1] are same as firstchar */
3127        if (len < marker_size + 1 || !isspace(line[marker_size]))
3128                return 0;
3129        return 1;
3130}
3131
3132static void checkdiff_consume_hunk(void *priv,
3133                                   long ob, long on, long nb, long nn,
3134                                   const char *func, long funclen)
3135
3136{
3137        struct checkdiff_t *data = priv;
3138        data->lineno = nb - 1;
3139}
3140
3141static void checkdiff_consume(void *priv, char *line, unsigned long len)
3142{
3143        struct checkdiff_t *data = priv;
3144        int marker_size = data->conflict_marker_size;
3145        const char *ws = diff_get_color(data->o->use_color, DIFF_WHITESPACE);
3146        const char *reset = diff_get_color(data->o->use_color, DIFF_RESET);
3147        const char *set = diff_get_color(data->o->use_color, DIFF_FILE_NEW);
3148        char *err;
3149        const char *line_prefix;
3150
3151        assert(data->o);
3152        line_prefix = diff_line_prefix(data->o);
3153
3154        if (line[0] == '+') {
3155                unsigned bad;
3156                data->lineno++;
3157                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
3158                        data->status |= 1;
3159                        fprintf(data->o->file,
3160                                "%s%s:%d: leftover conflict marker\n",
3161                                line_prefix, data->filename, data->lineno);
3162                }
3163                bad = ws_check(line + 1, len - 1, data->ws_rule);
3164                if (!bad)
3165                        return;
3166                data->status |= bad;
3167                err = whitespace_error_string(bad);
3168                fprintf(data->o->file, "%s%s:%d: %s.\n",
3169                        line_prefix, data->filename, data->lineno, err);
3170                free(err);
3171                emit_line(data->o, set, reset, line, 1);
3172                ws_check_emit(line + 1, len - 1, data->ws_rule,
3173                              data->o->file, set, reset, ws);
3174        } else if (line[0] == ' ') {
3175                data->lineno++;
3176        }
3177}
3178
3179static unsigned char *deflate_it(char *data,
3180                                 unsigned long size,
3181                                 unsigned long *result_size)
3182{
3183        int bound;
3184        unsigned char *deflated;
3185        git_zstream stream;
3186
3187        git_deflate_init(&stream, zlib_compression_level);
3188        bound = git_deflate_bound(&stream, size);
3189        deflated = xmalloc(bound);
3190        stream.next_out = deflated;
3191        stream.avail_out = bound;
3192
3193        stream.next_in = (unsigned char *)data;
3194        stream.avail_in = size;
3195        while (git_deflate(&stream, Z_FINISH) == Z_OK)
3196                ; /* nothing */
3197        git_deflate_end(&stream);
3198        *result_size = stream.total_out;
3199        return deflated;
3200}
3201
3202static void emit_binary_diff_body(struct diff_options *o,
3203                                  mmfile_t *one, mmfile_t *two)
3204{
3205        void *cp;
3206        void *delta;
3207        void *deflated;
3208        void *data;
3209        unsigned long orig_size;
3210        unsigned long delta_size;
3211        unsigned long deflate_size;
3212        unsigned long data_size;
3213
3214        /* We could do deflated delta, or we could do just deflated two,
3215         * whichever is smaller.
3216         */
3217        delta = NULL;
3218        deflated = deflate_it(two->ptr, two->size, &deflate_size);
3219        if (one->size && two->size) {
3220                delta = diff_delta(one->ptr, one->size,
3221                                   two->ptr, two->size,
3222                                   &delta_size, deflate_size);
3223                if (delta) {
3224                        void *to_free = delta;
3225                        orig_size = delta_size;
3226                        delta = deflate_it(delta, delta_size, &delta_size);
3227                        free(to_free);
3228                }
3229        }
3230
3231        if (delta && delta_size < deflate_size) {
3232                char *s = xstrfmt("%"PRIuMAX , (uintmax_t)orig_size);
3233                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA,
3234                                 s, strlen(s), 0);
3235                free(s);
3236                free(deflated);
3237                data = delta;
3238                data_size = delta_size;
3239        } else {
3240                char *s = xstrfmt("%lu", two->size);
3241                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL,
3242                                 s, strlen(s), 0);
3243                free(s);
3244                free(delta);
3245                data = deflated;
3246                data_size = deflate_size;
3247        }
3248
3249        /* emit data encoded in base85 */
3250        cp = data;
3251        while (data_size) {
3252                int len;
3253                int bytes = (52 < data_size) ? 52 : data_size;
3254                char line[71];
3255                data_size -= bytes;
3256                if (bytes <= 26)
3257                        line[0] = bytes + 'A' - 1;
3258                else
3259                        line[0] = bytes - 26 + 'a' - 1;
3260                encode_85(line + 1, cp, bytes);
3261                cp = (char *) cp + bytes;
3262
3263                len = strlen(line);
3264                line[len++] = '\n';
3265                line[len] = '\0';
3266
3267                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_BODY,
3268                                 line, len, 0);
3269        }
3270        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_FOOTER, NULL, 0, 0);
3271        free(data);
3272}
3273
3274static void emit_binary_diff(struct diff_options *o,
3275                             mmfile_t *one, mmfile_t *two)
3276{
3277        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER, NULL, 0, 0);
3278        emit_binary_diff_body(o, one, two);
3279        emit_binary_diff_body(o, two, one);
3280}
3281
3282int diff_filespec_is_binary(struct repository *r,
3283                            struct diff_filespec *one)
3284{
3285        if (one->is_binary == -1) {
3286                diff_filespec_load_driver(one, r->index);
3287                if (one->driver->binary != -1)
3288                        one->is_binary = one->driver->binary;
3289                else {
3290                        if (!one->data && DIFF_FILE_VALID(one))
3291                                diff_populate_filespec(r, one, CHECK_BINARY);
3292                        if (one->is_binary == -1 && one->data)
3293                                one->is_binary = buffer_is_binary(one->data,
3294                                                one->size);
3295                        if (one->is_binary == -1)
3296                                one->is_binary = 0;
3297                }
3298        }
3299        return one->is_binary;
3300}
3301
3302static const struct userdiff_funcname *
3303diff_funcname_pattern(struct diff_options *o, struct diff_filespec *one)
3304{
3305        diff_filespec_load_driver(one, o->repo->index);
3306        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
3307}
3308
3309void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
3310{
3311        if (!options->a_prefix)
3312                options->a_prefix = a;
3313        if (!options->b_prefix)
3314                options->b_prefix = b;
3315}
3316
3317struct userdiff_driver *get_textconv(struct repository *r,
3318                                     struct diff_filespec *one)
3319{
3320        if (!DIFF_FILE_VALID(one))
3321                return NULL;
3322
3323        diff_filespec_load_driver(one, r->index);
3324        return userdiff_get_textconv(r, one->driver);
3325}
3326
3327static void builtin_diff(const char *name_a,
3328                         const char *name_b,
3329                         struct diff_filespec *one,
3330                         struct diff_filespec *two,
3331                         const char *xfrm_msg,
3332                         int must_show_header,
3333                         struct diff_options *o,
3334                         int complete_rewrite)
3335{
3336        mmfile_t mf1, mf2;
3337        const char *lbl[2];
3338        char *a_one, *b_two;
3339        const char *meta = diff_get_color_opt(o, DIFF_METAINFO);
3340        const char *reset = diff_get_color_opt(o, DIFF_RESET);
3341        const char *a_prefix, *b_prefix;
3342        struct userdiff_driver *textconv_one = NULL;
3343        struct userdiff_driver *textconv_two = NULL;
3344        struct strbuf header = STRBUF_INIT;
3345        const char *line_prefix = diff_line_prefix(o);
3346
3347        diff_set_mnemonic_prefix(o, "a/", "b/");
3348        if (o->flags.reverse_diff) {
3349                a_prefix = o->b_prefix;
3350                b_prefix = o->a_prefix;
3351        } else {
3352                a_prefix = o->a_prefix;
3353                b_prefix = o->b_prefix;
3354        }
3355
3356        if (o->submodule_format == DIFF_SUBMODULE_LOG &&
3357            (!one->mode || S_ISGITLINK(one->mode)) &&
3358            (!two->mode || S_ISGITLINK(two->mode))) {
3359                show_submodule_summary(o, one->path ? one->path : two->path,
3360                                &one->oid, &two->oid,
3361                                two->dirty_submodule);
3362                return;
3363        } else if (o->submodule_format == DIFF_SUBMODULE_INLINE_DIFF &&
3364                   (!one->mode || S_ISGITLINK(one->mode)) &&
3365                   (!two->mode || S_ISGITLINK(two->mode))) {
3366                show_submodule_inline_diff(o, one->path ? one->path : two->path,
3367                                &one->oid, &two->oid,
3368                                two->dirty_submodule);
3369                return;
3370        }
3371
3372        if (o->flags.allow_textconv) {
3373                textconv_one = get_textconv(o->repo, one);
3374                textconv_two = get_textconv(o->repo, two);
3375        }
3376
3377        /* Never use a non-valid filename anywhere if at all possible */
3378        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
3379        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
3380
3381        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
3382        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
3383        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
3384        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
3385        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, meta, a_one, b_two, reset);
3386        if (lbl[0][0] == '/') {
3387                /* /dev/null */
3388                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, meta, two->mode, reset);
3389                if (xfrm_msg)
3390                        strbuf_addstr(&header, xfrm_msg);
3391                must_show_header = 1;
3392        }
3393        else if (lbl[1][0] == '/') {
3394                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, meta, one->mode, reset);
3395                if (xfrm_msg)
3396                        strbuf_addstr(&header, xfrm_msg);
3397                must_show_header = 1;
3398        }
3399        else {
3400                if (one->mode != two->mode) {
3401                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, meta, one->mode, reset);
3402                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, meta, two->mode, reset);
3403                        must_show_header = 1;
3404                }
3405                if (xfrm_msg)
3406                        strbuf_addstr(&header, xfrm_msg);
3407
3408                /*
3409                 * we do not run diff between different kind
3410                 * of objects.
3411                 */
3412                if ((one->mode ^ two->mode) & S_IFMT)
3413                        goto free_ab_and_return;
3414                if (complete_rewrite &&
3415                    (textconv_one || !diff_filespec_is_binary(o->repo, one)) &&
3416                    (textconv_two || !diff_filespec_is_binary(o->repo, two))) {
3417                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3418                                         header.buf, header.len, 0);
3419                        strbuf_reset(&header);
3420                        emit_rewrite_diff(name_a, name_b, one, two,
3421                                          textconv_one, textconv_two, o);
3422                        o->found_changes = 1;
3423                        goto free_ab_and_return;
3424                }
3425        }
3426
3427        if (o->irreversible_delete && lbl[1][0] == '/') {
3428                emit_diff_symbol(o, DIFF_SYMBOL_HEADER, header.buf,
3429                                 header.len, 0);
3430                strbuf_reset(&header);
3431                goto free_ab_and_return;
3432        } else if (!o->flags.text &&
3433                   ( (!textconv_one && diff_filespec_is_binary(o->repo, one)) ||
3434                     (!textconv_two && diff_filespec_is_binary(o->repo, two)) )) {
3435                struct strbuf sb = STRBUF_INIT;
3436                if (!one->data && !two->data &&
3437                    S_ISREG(one->mode) && S_ISREG(two->mode) &&
3438                    !o->flags.binary) {
3439                        if (oideq(&one->oid, &two->oid)) {
3440                                if (must_show_header)
3441                                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3442                                                         header.buf, header.len,
3443                                                         0);
3444                                goto free_ab_and_return;
3445                        }
3446                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3447                                         header.buf, header.len, 0);
3448                        strbuf_addf(&sb, "%sBinary files %s and %s differ\n",
3449                                    diff_line_prefix(o), lbl[0], lbl[1]);
3450                        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_FILES,
3451                                         sb.buf, sb.len, 0);
3452                        strbuf_release(&sb);
3453                        goto free_ab_and_return;
3454                }
3455                if (fill_mmfile(o->repo, &mf1, one) < 0 ||
3456                    fill_mmfile(o->repo, &mf2, two) < 0)
3457                        die("unable to read files to diff");
3458                /* Quite common confusing case */
3459                if (mf1.size == mf2.size &&
3460                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
3461                        if (must_show_header)
3462                                emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3463                                                 header.buf, header.len, 0);
3464                        goto free_ab_and_return;
3465                }
3466                emit_diff_symbol(o, DIFF_SYMBOL_HEADER, header.buf, header.len, 0);
3467                strbuf_reset(&header);
3468                if (o->flags.binary)
3469                        emit_binary_diff(o, &mf1, &mf2);
3470                else {
3471                        strbuf_addf(&sb, "%sBinary files %s and %s differ\n",
3472                                    diff_line_prefix(o), lbl[0], lbl[1]);
3473                        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_FILES,
3474                                         sb.buf, sb.len, 0);
3475                        strbuf_release(&sb);
3476                }
3477                o->found_changes = 1;
3478        } else {
3479                /* Crazy xdl interfaces.. */
3480                const char *diffopts = getenv("GIT_DIFF_OPTS");
3481                const char *v;
3482                xpparam_t xpp;
3483                xdemitconf_t xecfg;
3484                struct emit_callback ecbdata;
3485                const struct userdiff_funcname *pe;
3486
3487                if (must_show_header) {
3488                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3489                                         header.buf, header.len, 0);
3490                        strbuf_reset(&header);
3491                }
3492
3493                mf1.size = fill_textconv(o->repo, textconv_one, one, &mf1.ptr);
3494                mf2.size = fill_textconv(o->repo, textconv_two, two, &mf2.ptr);
3495
3496                pe = diff_funcname_pattern(o, one);
3497                if (!pe)
3498                        pe = diff_funcname_pattern(o, two);
3499
3500                memset(&xpp, 0, sizeof(xpp));
3501                memset(&xecfg, 0, sizeof(xecfg));
3502                memset(&ecbdata, 0, sizeof(ecbdata));
3503                if (o->flags.suppress_diff_headers)
3504                        lbl[0] = NULL;
3505                ecbdata.label_path = lbl;
3506                ecbdata.color_diff = want_color(o->use_color);
3507                ecbdata.ws_rule = whitespace_rule(o->repo->index, name_b);
3508                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
3509                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
3510                ecbdata.opt = o;
3511                if (header.len && !o->flags.suppress_diff_headers)
3512                        ecbdata.header = &header;
3513                xpp.flags = o->xdl_opts;
3514                xpp.anchors = o->anchors;
3515                xpp.anchors_nr = o->anchors_nr;
3516                xecfg.ctxlen = o->context;
3517                xecfg.interhunkctxlen = o->interhunkcontext;
3518                xecfg.flags = XDL_EMIT_FUNCNAMES;
3519                if (o->flags.funccontext)
3520                        xecfg.flags |= XDL_EMIT_FUNCCONTEXT;
3521                if (pe)
3522                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
3523                if (!diffopts)
3524                        ;
3525                else if (skip_prefix(diffopts, "--unified=", &v))
3526                        xecfg.ctxlen = strtoul(v, NULL, 10);
3527                else if (skip_prefix(diffopts, "-u", &v))
3528                        xecfg.ctxlen = strtoul(v, NULL, 10);
3529                if (o->word_diff)
3530                        init_diff_words_data(&ecbdata, o, one, two);
3531                if (xdi_diff_outf(&mf1, &mf2, NULL, fn_out_consume,
3532                                  &ecbdata, &xpp, &xecfg))
3533                        die("unable to generate diff for %s", one->path);
3534                if (o->word_diff)
3535                        free_diff_words_data(&ecbdata);
3536                if (textconv_one)
3537                        free(mf1.ptr);
3538                if (textconv_two)
3539                        free(mf2.ptr);
3540                xdiff_clear_find_func(&xecfg);
3541        }
3542
3543 free_ab_and_return:
3544        strbuf_release(&header);
3545        diff_free_filespec_data(one);
3546        diff_free_filespec_data(two);
3547        free(a_one);
3548        free(b_two);
3549        return;
3550}
3551
3552static char *get_compact_summary(const struct diff_filepair *p, int is_renamed)
3553{
3554        if (!is_renamed) {
3555                if (p->status == DIFF_STATUS_ADDED) {
3556                        if (S_ISLNK(p->two->mode))
3557                                return "new +l";
3558                        else if ((p->two->mode & 0777) == 0755)
3559                                return "new +x";
3560                        else
3561                                return "new";
3562                } else if (p->status == DIFF_STATUS_DELETED)
3563                        return "gone";
3564        }
3565        if (S_ISLNK(p->one->mode) && !S_ISLNK(p->two->mode))
3566                return "mode -l";
3567        else if (!S_ISLNK(p->one->mode) && S_ISLNK(p->two->mode))
3568                return "mode +l";
3569        else if ((p->one->mode & 0777) == 0644 &&
3570                 (p->two->mode & 0777) == 0755)
3571                return "mode +x";
3572        else if ((p->one->mode & 0777) == 0755 &&
3573                 (p->two->mode & 0777) == 0644)
3574                return "mode -x";
3575        return NULL;
3576}
3577
3578static void builtin_diffstat(const char *name_a, const char *name_b,
3579                             struct diff_filespec *one,
3580                             struct diff_filespec *two,
3581                             struct diffstat_t *diffstat,
3582                             struct diff_options *o,
3583                             struct diff_filepair *p)
3584{
3585        mmfile_t mf1, mf2;
3586        struct diffstat_file *data;
3587        int same_contents;
3588        int complete_rewrite = 0;
3589
3590        if (!DIFF_PAIR_UNMERGED(p)) {
3591                if (p->status == DIFF_STATUS_MODIFIED && p->score)
3592                        complete_rewrite = 1;
3593        }
3594
3595        data = diffstat_add(diffstat, name_a, name_b);
3596        data->is_interesting = p->status != DIFF_STATUS_UNKNOWN;
3597        if (o->flags.stat_with_summary)
3598                data->comments = get_compact_summary(p, data->is_renamed);
3599
3600        if (!one || !two) {
3601                data->is_unmerged = 1;
3602                return;
3603        }
3604
3605        same_contents = oideq(&one->oid, &two->oid);
3606
3607        if (diff_filespec_is_binary(o->repo, one) ||
3608            diff_filespec_is_binary(o->repo, two)) {
3609                data->is_binary = 1;
3610                if (same_contents) {
3611                        data->added = 0;
3612                        data->deleted = 0;
3613                } else {
3614                        data->added = diff_filespec_size(o->repo, two);
3615                        data->deleted = diff_filespec_size(o->repo, one);
3616                }
3617        }
3618
3619        else if (complete_rewrite) {
3620                diff_populate_filespec(o->repo, one, 0);
3621                diff_populate_filespec(o->repo, two, 0);
3622                data->deleted = count_lines(one->data, one->size);
3623                data->added = count_lines(two->data, two->size);
3624        }
3625
3626        else if (!same_contents) {
3627                /* Crazy xdl interfaces.. */
3628                xpparam_t xpp;
3629                xdemitconf_t xecfg;
3630
3631                if (fill_mmfile(o->repo, &mf1, one) < 0 ||
3632                    fill_mmfile(o->repo, &mf2, two) < 0)
3633                        die("unable to read files to diff");
3634
3635                memset(&xpp, 0, sizeof(xpp));
3636                memset(&xecfg, 0, sizeof(xecfg));
3637                xpp.flags = o->xdl_opts;
3638                xpp.anchors = o->anchors;
3639                xpp.anchors_nr = o->anchors_nr;
3640                xecfg.ctxlen = o->context;
3641                xecfg.interhunkctxlen = o->interhunkcontext;
3642                if (xdi_diff_outf(&mf1, &mf2, discard_hunk_line,
3643                                  diffstat_consume, diffstat, &xpp, &xecfg))
3644                        die("unable to generate diffstat for %s", one->path);
3645        }
3646
3647        diff_free_filespec_data(one);
3648        diff_free_filespec_data(two);
3649}
3650
3651static void builtin_checkdiff(const char *name_a, const char *name_b,
3652                              const char *attr_path,
3653                              struct diff_filespec *one,
3654                              struct diff_filespec *two,
3655                              struct diff_options *o)
3656{
3657        mmfile_t mf1, mf2;
3658        struct checkdiff_t data;
3659
3660        if (!two)
3661                return;
3662
3663        memset(&data, 0, sizeof(data));
3664        data.filename = name_b ? name_b : name_a;
3665        data.lineno = 0;
3666        data.o = o;
3667        data.ws_rule = whitespace_rule(o->repo->index, attr_path);
3668        data.conflict_marker_size = ll_merge_marker_size(o->repo->index, attr_path);
3669
3670        if (fill_mmfile(o->repo, &mf1, one) < 0 ||
3671            fill_mmfile(o->repo, &mf2, two) < 0)
3672                die("unable to read files to diff");
3673
3674        /*
3675         * All the other codepaths check both sides, but not checking
3676         * the "old" side here is deliberate.  We are checking the newly
3677         * introduced changes, and as long as the "new" side is text, we
3678         * can and should check what it introduces.
3679         */
3680        if (diff_filespec_is_binary(o->repo, two))
3681                goto free_and_return;
3682        else {
3683                /* Crazy xdl interfaces.. */
3684                xpparam_t xpp;
3685                xdemitconf_t xecfg;
3686
3687                memset(&xpp, 0, sizeof(xpp));
3688                memset(&xecfg, 0, sizeof(xecfg));
3689                xecfg.ctxlen = 1; /* at least one context line */
3690                xpp.flags = 0;
3691                if (xdi_diff_outf(&mf1, &mf2, checkdiff_consume_hunk,
3692                                  checkdiff_consume, &data,
3693                                  &xpp, &xecfg))
3694                        die("unable to generate checkdiff for %s", one->path);
3695
3696                if (data.ws_rule & WS_BLANK_AT_EOF) {
3697                        struct emit_callback ecbdata;
3698                        int blank_at_eof;
3699
3700                        ecbdata.ws_rule = data.ws_rule;
3701                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
3702                        blank_at_eof = ecbdata.blank_at_eof_in_postimage;
3703
3704                        if (blank_at_eof) {
3705                                static char *err;
3706                                if (!err)
3707                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
3708                                fprintf(o->file, "%s:%d: %s.\n",
3709                                        data.filename, blank_at_eof, err);
3710                                data.status = 1; /* report errors */
3711                        }
3712                }
3713        }
3714 free_and_return:
3715        diff_free_filespec_data(one);
3716        diff_free_filespec_data(two);
3717        if (data.status)
3718                o->flags.check_failed = 1;
3719}
3720
3721struct diff_filespec *alloc_filespec(const char *path)
3722{
3723        struct diff_filespec *spec;
3724
3725        FLEXPTR_ALLOC_STR(spec, path, path);
3726        spec->count = 1;
3727        spec->is_binary = -1;
3728        return spec;
3729}
3730
3731void free_filespec(struct diff_filespec *spec)
3732{
3733        if (!--spec->count) {
3734                diff_free_filespec_data(spec);
3735                free(spec);
3736        }
3737}
3738
3739void fill_filespec(struct diff_filespec *spec, const struct object_id *oid,
3740                   int oid_valid, unsigned short mode)
3741{
3742        if (mode) {
3743                spec->mode = canon_mode(mode);
3744                oidcpy(&spec->oid, oid);
3745                spec->oid_valid = oid_valid;
3746        }
3747}
3748
3749/*
3750 * Given a name and sha1 pair, if the index tells us the file in
3751 * the work tree has that object contents, return true, so that
3752 * prepare_temp_file() does not have to inflate and extract.
3753 */
3754static int reuse_worktree_file(struct index_state *istate,
3755                               const char *name,
3756                               const struct object_id *oid,
3757                               int want_file)
3758{
3759        const struct cache_entry *ce;
3760        struct stat st;
3761        int pos, len;
3762
3763        /*
3764         * We do not read the cache ourselves here, because the
3765         * benchmark with my previous version that always reads cache
3766         * shows that it makes things worse for diff-tree comparing
3767         * two linux-2.6 kernel trees in an already checked out work
3768         * tree.  This is because most diff-tree comparisons deal with
3769         * only a small number of files, while reading the cache is
3770         * expensive for a large project, and its cost outweighs the
3771         * savings we get by not inflating the object to a temporary
3772         * file.  Practically, this code only helps when we are used
3773         * by diff-cache --cached, which does read the cache before
3774         * calling us.
3775         */
3776        if (!istate->cache)
3777                return 0;
3778
3779        /* We want to avoid the working directory if our caller
3780         * doesn't need the data in a normal file, this system
3781         * is rather slow with its stat/open/mmap/close syscalls,
3782         * and the object is contained in a pack file.  The pack
3783         * is probably already open and will be faster to obtain
3784         * the data through than the working directory.  Loose
3785         * objects however would tend to be slower as they need
3786         * to be individually opened and inflated.
3787         */
3788        if (!FAST_WORKING_DIRECTORY && !want_file && has_object_pack(oid))
3789                return 0;
3790
3791        /*
3792         * Similarly, if we'd have to convert the file contents anyway, that
3793         * makes the optimization not worthwhile.
3794         */
3795        if (!want_file && would_convert_to_git(istate, name))
3796                return 0;
3797
3798        len = strlen(name);
3799        pos = index_name_pos(istate, name, len);
3800        if (pos < 0)
3801                return 0;
3802        ce = istate->cache[pos];
3803
3804        /*
3805         * This is not the sha1 we are looking for, or
3806         * unreusable because it is not a regular file.
3807         */
3808        if (!oideq(oid, &ce->oid) || !S_ISREG(ce->ce_mode))
3809                return 0;
3810
3811        /*
3812         * If ce is marked as "assume unchanged", there is no
3813         * guarantee that work tree matches what we are looking for.
3814         */
3815        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
3816                return 0;
3817
3818        /*
3819         * If ce matches the file in the work tree, we can reuse it.
3820         */
3821        if (ce_uptodate(ce) ||
3822            (!lstat(name, &st) && !ie_match_stat(istate, ce, &st, 0)))
3823                return 1;
3824
3825        return 0;
3826}
3827
3828static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
3829{
3830        struct strbuf buf = STRBUF_INIT;
3831        char *dirty = "";
3832
3833        /* Are we looking at the work tree? */
3834        if (s->dirty_submodule)
3835                dirty = "-dirty";
3836
3837        strbuf_addf(&buf, "Subproject commit %s%s\n",
3838                    oid_to_hex(&s->oid), dirty);
3839        s->size = buf.len;
3840        if (size_only) {
3841                s->data = NULL;
3842                strbuf_release(&buf);
3843        } else {
3844                s->data = strbuf_detach(&buf, NULL);
3845                s->should_free = 1;
3846        }
3847        return 0;
3848}
3849
3850/*
3851 * While doing rename detection and pickaxe operation, we may need to
3852 * grab the data for the blob (or file) for our own in-core comparison.
3853 * diff_filespec has data and size fields for this purpose.
3854 */
3855int diff_populate_filespec(struct repository *r,
3856                           struct diff_filespec *s,
3857                           unsigned int flags)
3858{
3859        int size_only = flags & CHECK_SIZE_ONLY;
3860        int err = 0;
3861        int conv_flags = global_conv_flags_eol;
3862        /*
3863         * demote FAIL to WARN to allow inspecting the situation
3864         * instead of refusing.
3865         */
3866        if (conv_flags & CONV_EOL_RNDTRP_DIE)
3867                conv_flags = CONV_EOL_RNDTRP_WARN;
3868
3869        if (!DIFF_FILE_VALID(s))
3870                die("internal error: asking to populate invalid file.");
3871        if (S_ISDIR(s->mode))
3872                return -1;
3873
3874        if (s->data)
3875                return 0;
3876
3877        if (size_only && 0 < s->size)
3878                return 0;
3879
3880        if (S_ISGITLINK(s->mode))
3881                return diff_populate_gitlink(s, size_only);
3882
3883        if (!s->oid_valid ||
3884            reuse_worktree_file(r->index, s->path, &s->oid, 0)) {
3885                struct strbuf buf = STRBUF_INIT;
3886                struct stat st;
3887                int fd;
3888
3889                if (lstat(s->path, &st) < 0) {
3890                err_empty:
3891                        err = -1;
3892                empty:
3893                        s->data = (char *)"";
3894                        s->size = 0;
3895                        return err;
3896                }
3897                s->size = xsize_t(st.st_size);
3898                if (!s->size)
3899                        goto empty;
3900                if (S_ISLNK(st.st_mode)) {
3901                        struct strbuf sb = STRBUF_INIT;
3902
3903                        if (strbuf_readlink(&sb, s->path, s->size))
3904                                goto err_empty;
3905                        s->size = sb.len;
3906                        s->data = strbuf_detach(&sb, NULL);
3907                        s->should_free = 1;
3908                        return 0;
3909                }
3910
3911                /*
3912                 * Even if the caller would be happy with getting
3913                 * only the size, we cannot return early at this
3914                 * point if the path requires us to run the content
3915                 * conversion.
3916                 */
3917                if (size_only && !would_convert_to_git(r->index, s->path))
3918                        return 0;
3919
3920                /*
3921                 * Note: this check uses xsize_t(st.st_size) that may
3922                 * not be the true size of the blob after it goes
3923                 * through convert_to_git().  This may not strictly be
3924                 * correct, but the whole point of big_file_threshold
3925                 * and is_binary check being that we want to avoid
3926                 * opening the file and inspecting the contents, this
3927                 * is probably fine.
3928                 */
3929                if ((flags & CHECK_BINARY) &&
3930                    s->size > big_file_threshold && s->is_binary == -1) {
3931                        s->is_binary = 1;
3932                        return 0;
3933                }
3934                fd = open(s->path, O_RDONLY);
3935                if (fd < 0)
3936                        goto err_empty;
3937                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
3938                close(fd);
3939                s->should_munmap = 1;
3940
3941                /*
3942                 * Convert from working tree format to canonical git format
3943                 */
3944                if (convert_to_git(r->index, s->path, s->data, s->size, &buf, conv_flags)) {
3945                        size_t size = 0;
3946                        munmap(s->data, s->size);
3947                        s->should_munmap = 0;
3948                        s->data = strbuf_detach(&buf, &size);
3949                        s->size = size;
3950                        s->should_free = 1;
3951                }
3952        }
3953        else {
3954                enum object_type type;
3955                if (size_only || (flags & CHECK_BINARY)) {
3956                        type = oid_object_info(r, &s->oid, &s->size);
3957                        if (type < 0)
3958                                die("unable to read %s",
3959                                    oid_to_hex(&s->oid));
3960                        if (size_only)
3961                                return 0;
3962                        if (s->size > big_file_threshold && s->is_binary == -1) {
3963                                s->is_binary = 1;
3964                                return 0;
3965                        }
3966                }
3967                s->data = read_object_file(&s->oid, &type, &s->size);
3968                if (!s->data)
3969                        die("unable to read %s", oid_to_hex(&s->oid));
3970                s->should_free = 1;
3971        }
3972        return 0;
3973}
3974
3975void diff_free_filespec_blob(struct diff_filespec *s)
3976{
3977        if (s->should_free)
3978                free(s->data);
3979        else if (s->should_munmap)
3980                munmap(s->data, s->size);
3981
3982        if (s->should_free || s->should_munmap) {
3983                s->should_free = s->should_munmap = 0;
3984                s->data = NULL;
3985        }
3986}
3987
3988void diff_free_filespec_data(struct diff_filespec *s)
3989{
3990        diff_free_filespec_blob(s);
3991        FREE_AND_NULL(s->cnt_data);
3992}
3993
3994static void prep_temp_blob(struct index_state *istate,
3995                           const char *path, struct diff_tempfile *temp,
3996                           void *blob,
3997                           unsigned long size,
3998                           const struct object_id *oid,
3999                           int mode)
4000{
4001        struct strbuf buf = STRBUF_INIT;
4002        struct strbuf tempfile = STRBUF_INIT;
4003        char *path_dup = xstrdup(path);
4004        const char *base = basename(path_dup);
4005
4006        /* Generate "XXXXXX_basename.ext" */
4007        strbuf_addstr(&tempfile, "XXXXXX_");
4008        strbuf_addstr(&tempfile, base);
4009
4010        temp->tempfile = mks_tempfile_ts(tempfile.buf, strlen(base) + 1);
4011        if (!temp->tempfile)
4012                die_errno("unable to create temp-file");
4013        if (convert_to_working_tree(istate, path,
4014                        (const char *)blob, (size_t)size, &buf)) {
4015                blob = buf.buf;
4016                size = buf.len;
4017        }
4018        if (write_in_full(temp->tempfile->fd, blob, size) < 0 ||
4019            close_tempfile_gently(temp->tempfile))
4020                die_errno("unable to write temp-file");
4021        temp->name = get_tempfile_path(temp->tempfile);
4022        oid_to_hex_r(temp->hex, oid);
4023        xsnprintf(temp->mode, sizeof(temp->mode), "%06o", mode);
4024        strbuf_release(&buf);
4025        strbuf_release(&tempfile);
4026        free(path_dup);
4027}
4028
4029static struct diff_tempfile *prepare_temp_file(struct repository *r,
4030                                               const char *name,
4031                                               struct diff_filespec *one)
4032{
4033        struct diff_tempfile *temp = claim_diff_tempfile();
4034
4035        if (!DIFF_FILE_VALID(one)) {
4036        not_a_valid_file:
4037                /* A '-' entry produces this for file-2, and
4038                 * a '+' entry produces this for file-1.
4039                 */
4040                temp->name = "/dev/null";
4041                xsnprintf(temp->hex, sizeof(temp->hex), ".");
4042                xsnprintf(temp->mode, sizeof(temp->mode), ".");
4043                return temp;
4044        }
4045
4046        if (!S_ISGITLINK(one->mode) &&
4047            (!one->oid_valid ||
4048             reuse_worktree_file(r->index, name, &one->oid, 1))) {
4049                struct stat st;
4050                if (lstat(name, &st) < 0) {
4051                        if (errno == ENOENT)
4052                                goto not_a_valid_file;
4053                        die_errno("stat(%s)", name);
4054                }
4055                if (S_ISLNK(st.st_mode)) {
4056                        struct strbuf sb = STRBUF_INIT;
4057                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
4058                                die_errno("readlink(%s)", name);
4059                        prep_temp_blob(r->index, name, temp, sb.buf, sb.len,
4060                                       (one->oid_valid ?
4061                                        &one->oid : &null_oid),
4062                                       (one->oid_valid ?
4063                                        one->mode : S_IFLNK));
4064                        strbuf_release(&sb);
4065                }
4066                else {
4067                        /* we can borrow from the file in the work tree */
4068                        temp->name = name;
4069                        if (!one->oid_valid)
4070                                oid_to_hex_r(temp->hex, &null_oid);
4071                        else
4072                                oid_to_hex_r(temp->hex, &one->oid);
4073                        /* Even though we may sometimes borrow the
4074                         * contents from the work tree, we always want
4075                         * one->mode.  mode is trustworthy even when
4076                         * !(one->oid_valid), as long as
4077                         * DIFF_FILE_VALID(one).
4078                         */
4079                        xsnprintf(temp->mode, sizeof(temp->mode), "%06o", one->mode);
4080                }
4081                return temp;
4082        }
4083        else {
4084                if (diff_populate_filespec(r, one, 0))
4085                        die("cannot read data blob for %s", one->path);
4086                prep_temp_blob(r->index, name, temp,
4087                               one->data, one->size,
4088                               &one->oid, one->mode);
4089        }
4090        return temp;
4091}
4092
4093static void add_external_diff_name(struct repository *r,
4094                                   struct argv_array *argv,
4095                                   const char *name,
4096                                   struct diff_filespec *df)
4097{
4098        struct diff_tempfile *temp = prepare_temp_file(r, name, df);
4099        argv_array_push(argv, temp->name);
4100        argv_array_push(argv, temp->hex);
4101        argv_array_push(argv, temp->mode);
4102}
4103
4104/* An external diff command takes:
4105 *
4106 * diff-cmd name infile1 infile1-sha1 infile1-mode \
4107 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
4108 *
4109 */
4110static void run_external_diff(const char *pgm,
4111                              const char *name,
4112                              const char *other,
4113                              struct diff_filespec *one,
4114                              struct diff_filespec *two,
4115                              const char *xfrm_msg,
4116                              int complete_rewrite,
4117                              struct diff_options *o)
4118{
4119        struct argv_array argv = ARGV_ARRAY_INIT;
4120        struct argv_array env = ARGV_ARRAY_INIT;
4121        struct diff_queue_struct *q = &diff_queued_diff;
4122
4123        argv_array_push(&argv, pgm);
4124        argv_array_push(&argv, name);
4125
4126        if (one && two) {
4127                add_external_diff_name(o->repo, &argv, name, one);
4128                if (!other)
4129                        add_external_diff_name(o->repo, &argv, name, two);
4130                else {
4131                        add_external_diff_name(o->repo, &argv, other, two);
4132                        argv_array_push(&argv, other);
4133                        argv_array_push(&argv, xfrm_msg);
4134                }
4135        }
4136
4137        argv_array_pushf(&env, "GIT_DIFF_PATH_COUNTER=%d", ++o->diff_path_counter);
4138        argv_array_pushf(&env, "GIT_DIFF_PATH_TOTAL=%d", q->nr);
4139
4140        if (run_command_v_opt_cd_env(argv.argv, RUN_USING_SHELL, NULL, env.argv))
4141                die(_("external diff died, stopping at %s"), name);
4142
4143        remove_tempfile();
4144        argv_array_clear(&argv);
4145        argv_array_clear(&env);
4146}
4147
4148static int similarity_index(struct diff_filepair *p)
4149{
4150        return p->score * 100 / MAX_SCORE;
4151}
4152
4153static const char *diff_abbrev_oid(const struct object_id *oid, int abbrev)
4154{
4155        if (startup_info->have_repository)
4156                return find_unique_abbrev(oid, abbrev);
4157        else {
4158                char *hex = oid_to_hex(oid);
4159                if (abbrev < 0)
4160                        abbrev = FALLBACK_DEFAULT_ABBREV;
4161                if (abbrev > the_hash_algo->hexsz)
4162                        BUG("oid abbreviation out of range: %d", abbrev);
4163                if (abbrev)
4164                        hex[abbrev] = '\0';
4165                return hex;
4166        }
4167}
4168
4169static void fill_metainfo(struct strbuf *msg,
4170                          const char *name,
4171                          const char *other,
4172                          struct diff_filespec *one,
4173                          struct diff_filespec *two,
4174                          struct diff_options *o,
4175                          struct diff_filepair *p,
4176                          int *must_show_header,
4177                          int use_color)
4178{
4179        const char *set = diff_get_color(use_color, DIFF_METAINFO);
4180        const char *reset = diff_get_color(use_color, DIFF_RESET);
4181        const char *line_prefix = diff_line_prefix(o);
4182
4183        *must_show_header = 1;
4184        strbuf_init(msg, PATH_MAX * 2 + 300);
4185        switch (p->status) {
4186        case DIFF_STATUS_COPIED:
4187                strbuf_addf(msg, "%s%ssimilarity index %d%%",
4188                            line_prefix, set, similarity_index(p));
4189                strbuf_addf(msg, "%s\n%s%scopy from ",
4190                            reset,  line_prefix, set);
4191                quote_c_style(name, msg, NULL, 0);
4192                strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
4193                quote_c_style(other, msg, NULL, 0);
4194                strbuf_addf(msg, "%s\n", reset);
4195                break;
4196        case DIFF_STATUS_RENAMED:
4197                strbuf_addf(msg, "%s%ssimilarity index %d%%",
4198                            line_prefix, set, similarity_index(p));
4199                strbuf_addf(msg, "%s\n%s%srename from ",
4200                            reset, line_prefix, set);
4201                quote_c_style(name, msg, NULL, 0);
4202                strbuf_addf(msg, "%s\n%s%srename to ",
4203                            reset, line_prefix, set);
4204                quote_c_style(other, msg, NULL, 0);
4205                strbuf_addf(msg, "%s\n", reset);
4206                break;
4207        case DIFF_STATUS_MODIFIED:
4208                if (p->score) {
4209                        strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
4210                                    line_prefix,
4211                                    set, similarity_index(p), reset);
4212                        break;
4213                }
4214                /* fallthru */
4215        default:
4216                *must_show_header = 0;
4217        }
4218        if (one && two && !oideq(&one->oid, &two->oid)) {
4219                const unsigned hexsz = the_hash_algo->hexsz;
4220                int abbrev = o->flags.full_index ? hexsz : DEFAULT_ABBREV;
4221
4222                if (o->flags.binary) {
4223                        mmfile_t mf;
4224                        if ((!fill_mmfile(o->repo, &mf, one) &&
4225                             diff_filespec_is_binary(o->repo, one)) ||
4226                            (!fill_mmfile(o->repo, &mf, two) &&
4227                             diff_filespec_is_binary(o->repo, two)))
4228                                abbrev = hexsz;
4229                }
4230                strbuf_addf(msg, "%s%sindex %s..%s", line_prefix, set,
4231                            diff_abbrev_oid(&one->oid, abbrev),
4232                            diff_abbrev_oid(&two->oid, abbrev));
4233                if (one->mode == two->mode)
4234                        strbuf_addf(msg, " %06o", one->mode);
4235                strbuf_addf(msg, "%s\n", reset);
4236        }
4237}
4238
4239static void run_diff_cmd(const char *pgm,
4240                         const char *name,
4241                         const char *other,
4242                         const char *attr_path,
4243                         struct diff_filespec *one,
4244                         struct diff_filespec *two,
4245                         struct strbuf *msg,
4246                         struct diff_options *o,
4247                         struct diff_filepair *p)
4248{
4249        const char *xfrm_msg = NULL;
4250        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
4251        int must_show_header = 0;
4252
4253
4254        if (o->flags.allow_external) {
4255                struct userdiff_driver *drv;
4256
4257                drv = userdiff_find_by_path(o->repo->index, attr_path);
4258                if (drv && drv->external)
4259                        pgm = drv->external;
4260        }
4261
4262        if (msg) {
4263                /*
4264                 * don't use colors when the header is intended for an
4265                 * external diff driver
4266                 */
4267                fill_metainfo(msg, name, other, one, two, o, p,
4268                              &must_show_header,
4269                              want_color(o->use_color) && !pgm);
4270                xfrm_msg = msg->len ? msg->buf : NULL;
4271        }
4272
4273        if (pgm) {
4274                run_external_diff(pgm, name, other, one, two, xfrm_msg,
4275                                  complete_rewrite, o);
4276                return;
4277        }
4278        if (one && two)
4279                builtin_diff(name, other ? other : name,
4280                             one, two, xfrm_msg, must_show_header,
4281                             o, complete_rewrite);
4282        else
4283                fprintf(o->file, "* Unmerged path %s\n", name);
4284}
4285
4286static void diff_fill_oid_info(struct diff_filespec *one, struct index_state *istate)
4287{
4288        if (DIFF_FILE_VALID(one)) {
4289                if (!one->oid_valid) {
4290                        struct stat st;
4291                        if (one->is_stdin) {
4292                                oidclr(&one->oid);
4293                                return;
4294                        }
4295                        if (lstat(one->path, &st) < 0)
4296                                die_errno("stat '%s'", one->path);
4297                        if (index_path(istate, &one->oid, one->path, &st, 0))
4298                                die("cannot hash %s", one->path);
4299                }
4300        }
4301        else
4302                oidclr(&one->oid);
4303}
4304
4305static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
4306{
4307        /* Strip the prefix but do not molest /dev/null and absolute paths */
4308        if (*namep && !is_absolute_path(*namep)) {
4309                *namep += prefix_length;
4310                if (**namep == '/')
4311                        ++*namep;
4312        }
4313        if (*otherp && !is_absolute_path(*otherp)) {
4314                *otherp += prefix_length;
4315                if (**otherp == '/')
4316                        ++*otherp;
4317        }
4318}
4319
4320static void run_diff(struct diff_filepair *p, struct diff_options *o)
4321{
4322        const char *pgm = external_diff();
4323        struct strbuf msg;
4324        struct diff_filespec *one = p->one;
4325        struct diff_filespec *two = p->two;
4326        const char *name;
4327        const char *other;
4328        const char *attr_path;
4329
4330        name  = one->path;
4331        other = (strcmp(name, two->path) ? two->path : NULL);
4332        attr_path = name;
4333        if (o->prefix_length)
4334                strip_prefix(o->prefix_length, &name, &other);
4335
4336        if (!o->flags.allow_external)
4337                pgm = NULL;
4338
4339        if (DIFF_PAIR_UNMERGED(p)) {
4340                run_diff_cmd(pgm, name, NULL, attr_path,
4341                             NULL, NULL, NULL, o, p);
4342                return;
4343        }
4344
4345        diff_fill_oid_info(one, o->repo->index);
4346        diff_fill_oid_info(two, o->repo->index);
4347
4348        if (!pgm &&
4349            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
4350            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
4351                /*
4352                 * a filepair that changes between file and symlink
4353                 * needs to be split into deletion and creation.
4354                 */
4355                struct diff_filespec *null = alloc_filespec(two->path);
4356                run_diff_cmd(NULL, name, other, attr_path,
4357                             one, null, &msg,
4358                             o, p);
4359                free(null);
4360                strbuf_release(&msg);
4361
4362                null = alloc_filespec(one->path);
4363                run_diff_cmd(NULL, name, other, attr_path,
4364                             null, two, &msg, o, p);
4365                free(null);
4366        }
4367        else
4368                run_diff_cmd(pgm, name, other, attr_path,
4369                             one, two, &msg, o, p);
4370
4371        strbuf_release(&msg);
4372}
4373
4374static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
4375                         struct diffstat_t *diffstat)
4376{
4377        const char *name;
4378        const char *other;
4379
4380        if (DIFF_PAIR_UNMERGED(p)) {
4381                /* unmerged */
4382                builtin_diffstat(p->one->path, NULL, NULL, NULL,
4383                                 diffstat, o, p);
4384                return;
4385        }
4386
4387        name = p->one->path;
4388        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
4389
4390        if (o->prefix_length)
4391                strip_prefix(o->prefix_length, &name, &other);
4392
4393        diff_fill_oid_info(p->one, o->repo->index);
4394        diff_fill_oid_info(p->two, o->repo->index);
4395
4396        builtin_diffstat(name, other, p->one, p->two,
4397                         diffstat, o, p);
4398}
4399
4400static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
4401{
4402        const char *name;
4403        const char *other;
4404        const char *attr_path;
4405
4406        if (DIFF_PAIR_UNMERGED(p)) {
4407                /* unmerged */
4408                return;
4409        }
4410
4411        name = p->one->path;
4412        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
4413        attr_path = other ? other : name;
4414
4415        if (o->prefix_length)
4416                strip_prefix(o->prefix_length, &name, &other);
4417
4418        diff_fill_oid_info(p->one, o->repo->index);
4419        diff_fill_oid_info(p->two, o->repo->index);
4420
4421        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
4422}
4423
4424static void prep_parse_options(struct diff_options *options);
4425
4426void repo_diff_setup(struct repository *r, struct diff_options *options)
4427{
4428        memcpy(options, &default_diff_options, sizeof(*options));
4429
4430        options->file = stdout;
4431        options->repo = r;
4432
4433        options->output_indicators[OUTPUT_INDICATOR_NEW] = '+';
4434        options->output_indicators[OUTPUT_INDICATOR_OLD] = '-';
4435        options->output_indicators[OUTPUT_INDICATOR_CONTEXT] = ' ';
4436        options->abbrev = DEFAULT_ABBREV;
4437        options->line_termination = '\n';
4438        options->break_opt = -1;
4439        options->rename_limit = -1;
4440        options->dirstat_permille = diff_dirstat_permille_default;
4441        options->context = diff_context_default;
4442        options->interhunkcontext = diff_interhunk_context_default;
4443        options->ws_error_highlight = ws_error_highlight_default;
4444        options->flags.rename_empty = 1;
4445        options->objfind = NULL;
4446
4447        /* pathchange left =NULL by default */
4448        options->change = diff_change;
4449        options->add_remove = diff_addremove;
4450        options->use_color = diff_use_color_default;
4451        options->detect_rename = diff_detect_rename_default;
4452        options->xdl_opts |= diff_algorithm;
4453        if (diff_indent_heuristic)
4454                DIFF_XDL_SET(options, INDENT_HEURISTIC);
4455
4456        options->orderfile = diff_order_file_cfg;
4457
4458        if (diff_no_prefix) {
4459                options->a_prefix = options->b_prefix = "";
4460        } else if (!diff_mnemonic_prefix) {
4461                options->a_prefix = "a/";
4462                options->b_prefix = "b/";
4463        }
4464
4465        options->color_moved = diff_color_moved_default;
4466        options->color_moved_ws_handling = diff_color_moved_ws_default;
4467
4468        prep_parse_options(options);
4469}
4470
4471void diff_setup_done(struct diff_options *options)
4472{
4473        unsigned check_mask = DIFF_FORMAT_NAME |
4474                              DIFF_FORMAT_NAME_STATUS |
4475                              DIFF_FORMAT_CHECKDIFF |
4476                              DIFF_FORMAT_NO_OUTPUT;
4477        /*
4478         * This must be signed because we're comparing against a potentially
4479         * negative value.
4480         */
4481        const int hexsz = the_hash_algo->hexsz;
4482
4483        if (options->set_default)
4484                options->set_default(options);
4485
4486        if (HAS_MULTI_BITS(options->output_format & check_mask))
4487                die(_("--name-only, --name-status, --check and -s are mutually exclusive"));
4488
4489        if (HAS_MULTI_BITS(options->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK))
4490                die(_("-G, -S and --find-object are mutually exclusive"));
4491
4492        /*
4493         * Most of the time we can say "there are changes"
4494         * only by checking if there are changed paths, but
4495         * --ignore-whitespace* options force us to look
4496         * inside contents.
4497         */
4498
4499        if ((options->xdl_opts & XDF_WHITESPACE_FLAGS))
4500                options->flags.diff_from_contents = 1;
4501        else
4502                options->flags.diff_from_contents = 0;
4503
4504        if (options->flags.find_copies_harder)
4505                options->detect_rename = DIFF_DETECT_COPY;
4506
4507        if (!options->flags.relative_name)
4508                options->prefix = NULL;
4509        if (options->prefix)
4510                options->prefix_length = strlen(options->prefix);
4511        else
4512                options->prefix_length = 0;
4513
4514        if (options->output_format & (DIFF_FORMAT_NAME |
4515                                      DIFF_FORMAT_NAME_STATUS |
4516                                      DIFF_FORMAT_CHECKDIFF |
4517                                      DIFF_FORMAT_NO_OUTPUT))
4518                options->output_format &= ~(DIFF_FORMAT_RAW |
4519                                            DIFF_FORMAT_NUMSTAT |
4520                                            DIFF_FORMAT_DIFFSTAT |
4521                                            DIFF_FORMAT_SHORTSTAT |
4522                                            DIFF_FORMAT_DIRSTAT |
4523                                            DIFF_FORMAT_SUMMARY |
4524                                            DIFF_FORMAT_PATCH);
4525
4526        /*
4527         * These cases always need recursive; we do not drop caller-supplied
4528         * recursive bits for other formats here.
4529         */
4530        if (options->output_format & (DIFF_FORMAT_PATCH |
4531                                      DIFF_FORMAT_NUMSTAT |
4532                                      DIFF_FORMAT_DIFFSTAT |
4533                                      DIFF_FORMAT_SHORTSTAT |
4534                                      DIFF_FORMAT_DIRSTAT |
4535                                      DIFF_FORMAT_SUMMARY |
4536                                      DIFF_FORMAT_CHECKDIFF))
4537                options->flags.recursive = 1;
4538        /*
4539         * Also pickaxe would not work very well if you do not say recursive
4540         */
4541        if (options->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK)
4542                options->flags.recursive = 1;
4543        /*
4544         * When patches are generated, submodules diffed against the work tree
4545         * must be checked for dirtiness too so it can be shown in the output
4546         */
4547        if (options->output_format & DIFF_FORMAT_PATCH)
4548                options->flags.dirty_submodules = 1;
4549
4550        if (options->detect_rename && options->rename_limit < 0)
4551                options->rename_limit = diff_rename_limit_default;
4552        if (hexsz < options->abbrev)
4553                options->abbrev = hexsz; /* full */
4554
4555        /*
4556         * It does not make sense to show the first hit we happened
4557         * to have found.  It does not make sense not to return with
4558         * exit code in such a case either.
4559         */
4560        if (options->flags.quick) {
4561                options->output_format = DIFF_FORMAT_NO_OUTPUT;
4562                options->flags.exit_with_status = 1;
4563        }
4564
4565        options->diff_path_counter = 0;
4566
4567        if (options->flags.follow_renames && options->pathspec.nr != 1)
4568                die(_("--follow requires exactly one pathspec"));
4569
4570        if (!options->use_color || external_diff())
4571                options->color_moved = 0;
4572
4573        FREE_AND_NULL(options->parseopts);
4574}
4575
4576static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
4577{
4578        char c, *eq;
4579        int len;
4580
4581        if (*arg != '-')
4582                return 0;
4583        c = *++arg;
4584        if (!c)
4585                return 0;
4586        if (c == arg_short) {
4587                c = *++arg;
4588                if (!c)
4589                        return 1;
4590                if (val && isdigit(c)) {
4591                        char *end;
4592                        int n = strtoul(arg, &end, 10);
4593                        if (*end)
4594                                return 0;
4595                        *val = n;
4596                        return 1;
4597                }
4598                return 0;
4599        }
4600        if (c != '-')
4601                return 0;
4602        arg++;
4603        eq = strchrnul(arg, '=');
4604        len = eq - arg;
4605        if (!len || strncmp(arg, arg_long, len))
4606                return 0;
4607        if (*eq) {
4608                int n;
4609                char *end;
4610                if (!isdigit(*++eq))
4611                        return 0;
4612                n = strtoul(eq, &end, 10);
4613                if (*end)
4614                        return 0;
4615                *val = n;
4616        }
4617        return 1;
4618}
4619
4620static inline int short_opt(char opt, const char **argv,
4621                            const char **optarg)
4622{
4623        const char *arg = argv[0];
4624        if (arg[0] != '-' || arg[1] != opt)
4625                return 0;
4626        if (arg[2] != '\0') {
4627                *optarg = arg + 2;
4628                return 1;
4629        }
4630        if (!argv[1])
4631                die("Option '%c' requires a value", opt);
4632        *optarg = argv[1];
4633        return 2;
4634}
4635
4636int parse_long_opt(const char *opt, const char **argv,
4637                   const char **optarg)
4638{
4639        const char *arg = argv[0];
4640        if (!skip_prefix(arg, "--", &arg))
4641                return 0;
4642        if (!skip_prefix(arg, opt, &arg))
4643                return 0;
4644        if (*arg == '=') { /* stuck form: --option=value */
4645                *optarg = arg + 1;
4646                return 1;
4647        }
4648        if (*arg != '\0')
4649                return 0;
4650        /* separate form: --option value */
4651        if (!argv[1])
4652                die("Option '--%s' requires a value", opt);
4653        *optarg = argv[1];
4654        return 2;
4655}
4656
4657static int diff_opt_stat(const struct option *opt, const char *value, int unset)
4658{
4659        struct diff_options *options = opt->value;
4660        int width = options->stat_width;
4661        int name_width = options->stat_name_width;
4662        int graph_width = options->stat_graph_width;
4663        int count = options->stat_count;
4664        char *end;
4665
4666        BUG_ON_OPT_NEG(unset);
4667
4668        if (!strcmp(opt->long_name, "stat")) {
4669                if (value) {
4670                        width = strtoul(value, &end, 10);
4671                        if (*end == ',')
4672                                name_width = strtoul(end+1, &end, 10);
4673                        if (*end == ',')
4674                                count = strtoul(end+1, &end, 10);
4675                        if (*end)
4676                                return error(_("invalid --stat value: %s"), value);
4677                }
4678        } else if (!strcmp(opt->long_name, "stat-width")) {
4679                width = strtoul(value, &end, 10);
4680                if (*end)
4681                        return error(_("%s expects a numerical value"),
4682                                     opt->long_name);
4683        } else if (!strcmp(opt->long_name, "stat-name-width")) {
4684                name_width = strtoul(value, &end, 10);
4685                if (*end)
4686                        return error(_("%s expects a numerical value"),
4687                                     opt->long_name);
4688        } else if (!strcmp(opt->long_name, "stat-graph-width")) {
4689                graph_width = strtoul(value, &end, 10);
4690                if (*end)
4691                        return error(_("%s expects a numerical value"),
4692                                     opt->long_name);
4693        } else if (!strcmp(opt->long_name, "stat-count")) {
4694                count = strtoul(value, &end, 10);
4695                if (*end)
4696                        return error(_("%s expects a numerical value"),
4697                                     opt->long_name);
4698        } else
4699                BUG("%s should not get here", opt->long_name);
4700
4701        options->output_format |= DIFF_FORMAT_DIFFSTAT;
4702        options->stat_name_width = name_width;
4703        options->stat_graph_width = graph_width;
4704        options->stat_width = width;
4705        options->stat_count = count;
4706        return 0;
4707}
4708
4709static int parse_dirstat_opt(struct diff_options *options, const char *params)
4710{
4711        struct strbuf errmsg = STRBUF_INIT;
4712        if (parse_dirstat_params(options, params, &errmsg))
4713                die(_("Failed to parse --dirstat/-X option parameter:\n%s"),
4714                    errmsg.buf);
4715        strbuf_release(&errmsg);
4716        /*
4717         * The caller knows a dirstat-related option is given from the command
4718         * line; allow it to say "return this_function();"
4719         */
4720        options->output_format |= DIFF_FORMAT_DIRSTAT;
4721        return 1;
4722}
4723
4724static int parse_submodule_opt(struct diff_options *options, const char *value)
4725{
4726        if (parse_submodule_params(options, value))
4727                die(_("Failed to parse --submodule option parameter: '%s'"),
4728                        value);
4729        return 1;
4730}
4731
4732static const char diff_status_letters[] = {
4733        DIFF_STATUS_ADDED,
4734        DIFF_STATUS_COPIED,
4735        DIFF_STATUS_DELETED,
4736        DIFF_STATUS_MODIFIED,
4737        DIFF_STATUS_RENAMED,
4738        DIFF_STATUS_TYPE_CHANGED,
4739        DIFF_STATUS_UNKNOWN,
4740        DIFF_STATUS_UNMERGED,
4741        DIFF_STATUS_FILTER_AON,
4742        DIFF_STATUS_FILTER_BROKEN,
4743        '\0',
4744};
4745
4746static unsigned int filter_bit['Z' + 1];
4747
4748static void prepare_filter_bits(void)
4749{
4750        int i;
4751
4752        if (!filter_bit[DIFF_STATUS_ADDED]) {
4753                for (i = 0; diff_status_letters[i]; i++)
4754                        filter_bit[(int) diff_status_letters[i]] = (1 << i);
4755        }
4756}
4757
4758static unsigned filter_bit_tst(char status, const struct diff_options *opt)
4759{
4760        return opt->filter & filter_bit[(int) status];
4761}
4762
4763static int parse_diff_filter_opt(const char *optarg, struct diff_options *opt)
4764{
4765        int i, optch;
4766
4767        prepare_filter_bits();
4768
4769        /*
4770         * If there is a negation e.g. 'd' in the input, and we haven't
4771         * initialized the filter field with another --diff-filter, start
4772         * from full set of bits, except for AON.
4773         */
4774        if (!opt->filter) {
4775                for (i = 0; (optch = optarg[i]) != '\0'; i++) {
4776                        if (optch < 'a' || 'z' < optch)
4777                                continue;
4778                        opt->filter = (1 << (ARRAY_SIZE(diff_status_letters) - 1)) - 1;
4779                        opt->filter &= ~filter_bit[DIFF_STATUS_FILTER_AON];
4780                        break;
4781                }
4782        }
4783
4784        for (i = 0; (optch = optarg[i]) != '\0'; i++) {
4785                unsigned int bit;
4786                int negate;
4787
4788                if ('a' <= optch && optch <= 'z') {
4789                        negate = 1;
4790                        optch = toupper(optch);
4791                } else {
4792                        negate = 0;
4793                }
4794
4795                bit = (0 <= optch && optch <= 'Z') ? filter_bit[optch] : 0;
4796                if (!bit)
4797                        return optarg[i];
4798                if (negate)
4799                        opt->filter &= ~bit;
4800                else
4801                        opt->filter |= bit;
4802        }
4803        return 0;
4804}
4805
4806static void enable_patch_output(int *fmt)
4807{
4808        *fmt &= ~DIFF_FORMAT_NO_OUTPUT;
4809        *fmt |= DIFF_FORMAT_PATCH;
4810}
4811
4812static int parse_ws_error_highlight_opt(struct diff_options *opt, const char *arg)
4813{
4814        int val = parse_ws_error_highlight(arg);
4815
4816        if (val < 0) {
4817                error("unknown value after ws-error-highlight=%.*s",
4818                      -1 - val, arg);
4819                return 0;
4820        }
4821        opt->ws_error_highlight = val;
4822        return 1;
4823}
4824
4825static int parse_objfind_opt(struct diff_options *opt, const char *arg)
4826{
4827        struct object_id oid;
4828
4829        if (get_oid(arg, &oid))
4830                return error("unable to resolve '%s'", arg);
4831
4832        if (!opt->objfind)
4833                opt->objfind = xcalloc(1, sizeof(*opt->objfind));
4834
4835        opt->pickaxe_opts |= DIFF_PICKAXE_KIND_OBJFIND;
4836        opt->flags.recursive = 1;
4837        opt->flags.tree_in_recursive = 1;
4838        oidset_insert(opt->objfind, &oid);
4839        return 1;
4840}
4841
4842static int diff_opt_anchored(const struct option *opt,
4843                             const char *arg, int unset)
4844{
4845        struct diff_options *options = opt->value;
4846
4847        BUG_ON_OPT_NEG(unset);
4848        options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
4849        ALLOC_GROW(options->anchors, options->anchors_nr + 1,
4850                   options->anchors_alloc);
4851        options->anchors[options->anchors_nr++] = xstrdup(arg);
4852        return 0;
4853}
4854
4855static int diff_opt_binary(const struct option *opt,
4856                           const char *arg, int unset)
4857{
4858        struct diff_options *options = opt->value;
4859
4860        BUG_ON_OPT_NEG(unset);
4861        BUG_ON_OPT_ARG(arg);
4862        enable_patch_output(&options->output_format);
4863        options->flags.binary = 1;
4864        return 0;
4865}
4866
4867static int diff_opt_break_rewrites(const struct option *opt,
4868                                   const char *arg, int unset)
4869{
4870        int *break_opt = opt->value;
4871        int opt1, opt2;
4872
4873        BUG_ON_OPT_NEG(unset);
4874        if (!arg)
4875                arg = "";
4876        opt1 = parse_rename_score(&arg);
4877        if (*arg == 0)
4878                opt2 = 0;
4879        else if (*arg != '/')
4880                return error(_("%s expects <n>/<m> form"), opt->long_name);
4881        else {
4882                arg++;
4883                opt2 = parse_rename_score(&arg);
4884        }
4885        if (*arg != 0)
4886                return error(_("%s expects <n>/<m> form"), opt->long_name);
4887        *break_opt = opt1 | (opt2 << 16);
4888        return 0;
4889}
4890
4891static int diff_opt_char(const struct option *opt,
4892                         const char *arg, int unset)
4893{
4894        char *value = opt->value;
4895
4896        BUG_ON_OPT_NEG(unset);
4897        if (arg[1])
4898                return error(_("%s expects a character, got '%s'"),
4899                             opt->long_name, arg);
4900        *value = arg[0];
4901        return 0;
4902}
4903
4904static int diff_opt_color_words(const struct option *opt,
4905                                const char *arg, int unset)
4906{
4907        struct diff_options *options = opt->value;
4908
4909        BUG_ON_OPT_NEG(unset);
4910        options->use_color = 1;
4911        options->word_diff = DIFF_WORDS_COLOR;
4912        options->word_regex = arg;
4913        return 0;
4914}
4915
4916static int diff_opt_compact_summary(const struct option *opt,
4917                                    const char *arg, int unset)
4918{
4919        struct diff_options *options = opt->value;
4920
4921        BUG_ON_OPT_ARG(arg);
4922        if (unset) {
4923                options->flags.stat_with_summary = 0;
4924        } else {
4925                options->flags.stat_with_summary = 1;
4926                options->output_format |= DIFF_FORMAT_DIFFSTAT;
4927        }
4928        return 0;
4929}
4930
4931static int diff_opt_diff_algorithm(const struct option *opt,
4932                                   const char *arg, int unset)
4933{
4934        struct diff_options *options = opt->value;
4935        long value = parse_algorithm_value(arg);
4936
4937        BUG_ON_OPT_NEG(unset);
4938        if (value < 0)
4939                return error(_("option diff-algorithm accepts \"myers\", "
4940                               "\"minimal\", \"patience\" and \"histogram\""));
4941
4942        /* clear out previous settings */
4943        DIFF_XDL_CLR(options, NEED_MINIMAL);
4944        options->xdl_opts &= ~XDF_DIFF_ALGORITHM_MASK;
4945        options->xdl_opts |= value;
4946        return 0;
4947}
4948
4949static int diff_opt_dirstat(const struct option *opt,
4950                            const char *arg, int unset)
4951{
4952        struct diff_options *options = opt->value;
4953
4954        BUG_ON_OPT_NEG(unset);
4955        if (!strcmp(opt->long_name, "cumulative")) {
4956                if (arg)
4957                        BUG("how come --cumulative take a value?");
4958                arg = "cumulative";
4959        } else if (!strcmp(opt->long_name, "dirstat-by-file"))
4960                parse_dirstat_opt(options, "files");
4961        parse_dirstat_opt(options, arg ? arg : "");
4962        return 0;
4963}
4964
4965static int diff_opt_find_copies(const struct option *opt,
4966                                const char *arg, int unset)
4967{
4968        struct diff_options *options = opt->value;
4969
4970        BUG_ON_OPT_NEG(unset);
4971        if (!arg)
4972                arg = "";
4973        options->rename_score = parse_rename_score(&arg);
4974        if (*arg != 0)
4975                return error(_("invalid argument to %s"), opt->long_name);
4976
4977        if (options->detect_rename == DIFF_DETECT_COPY)
4978                options->flags.find_copies_harder = 1;
4979        else
4980                options->detect_rename = DIFF_DETECT_COPY;
4981
4982        return 0;
4983}
4984
4985static int diff_opt_find_renames(const struct option *opt,
4986                                 const char *arg, int unset)
4987{
4988        struct diff_options *options = opt->value;
4989
4990        BUG_ON_OPT_NEG(unset);
4991        if (!arg)
4992                arg = "";
4993        options->rename_score = parse_rename_score(&arg);
4994        if (*arg != 0)
4995                return error(_("invalid argument to %s"), opt->long_name);
4996
4997        options->detect_rename = DIFF_DETECT_RENAME;
4998        return 0;
4999}
5000
5001static int diff_opt_follow(const struct option *opt,
5002                           const char *arg, int unset)
5003{
5004        struct diff_options *options = opt->value;
5005
5006        BUG_ON_OPT_ARG(arg);
5007        if (unset) {
5008                options->flags.follow_renames = 0;
5009                options->flags.default_follow_renames = 0;
5010        } else {
5011                options->flags.follow_renames = 1;
5012        }
5013        return 0;
5014}
5015
5016static enum parse_opt_result diff_opt_output(struct parse_opt_ctx_t *ctx,
5017                                             const struct option *opt,
5018                                             const char *arg, int unset)
5019{
5020        struct diff_options *options = opt->value;
5021        char *path;
5022
5023        BUG_ON_OPT_NEG(unset);
5024        path = prefix_filename(ctx->prefix, arg);
5025        options->file = xfopen(path, "w");
5026        options->close_file = 1;
5027        if (options->use_color != GIT_COLOR_ALWAYS)
5028                options->use_color = GIT_COLOR_NEVER;
5029        free(path);
5030        return 0;
5031}
5032
5033static int diff_opt_patience(const struct option *opt,
5034                             const char *arg, int unset)
5035{
5036        struct diff_options *options = opt->value;
5037        int i;
5038
5039        BUG_ON_OPT_NEG(unset);
5040        BUG_ON_OPT_ARG(arg);
5041        options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
5042        /*
5043         * Both --patience and --anchored use PATIENCE_DIFF
5044         * internally, so remove any anchors previously
5045         * specified.
5046         */
5047        for (i = 0; i < options->anchors_nr; i++)
5048                free(options->anchors[i]);
5049        options->anchors_nr = 0;
5050        return 0;
5051}
5052
5053static int diff_opt_relative(const struct option *opt,
5054                             const char *arg, int unset)
5055{
5056        struct diff_options *options = opt->value;
5057
5058        BUG_ON_OPT_NEG(unset);
5059        options->flags.relative_name = 1;
5060        if (arg)
5061                options->prefix = arg;
5062        return 0;
5063}
5064
5065static int diff_opt_unified(const struct option *opt,
5066                            const char *arg, int unset)
5067{
5068        struct diff_options *options = opt->value;
5069        char *s;
5070
5071        BUG_ON_OPT_NEG(unset);
5072
5073        options->context = strtol(arg, &s, 10);
5074        if (*s)
5075                return error(_("%s expects a numerical value"), "--unified");
5076        enable_patch_output(&options->output_format);
5077
5078        return 0;
5079}
5080
5081static int diff_opt_word_diff(const struct option *opt,
5082                              const char *arg, int unset)
5083{
5084        struct diff_options *options = opt->value;
5085
5086        BUG_ON_OPT_NEG(unset);
5087        if (arg) {
5088                if (!strcmp(arg, "plain"))
5089                        options->word_diff = DIFF_WORDS_PLAIN;
5090                else if (!strcmp(arg, "color")) {
5091                        options->use_color = 1;
5092                        options->word_diff = DIFF_WORDS_COLOR;
5093                }
5094                else if (!strcmp(arg, "porcelain"))
5095                        options->word_diff = DIFF_WORDS_PORCELAIN;
5096                else if (!strcmp(arg, "none"))
5097                        options->word_diff = DIFF_WORDS_NONE;
5098                else
5099                        return error(_("bad --word-diff argument: %s"), arg);
5100        } else {
5101                if (options->word_diff == DIFF_WORDS_NONE)
5102                        options->word_diff = DIFF_WORDS_PLAIN;
5103        }
5104        return 0;
5105}
5106
5107static int diff_opt_word_diff_regex(const struct option *opt,
5108                                    const char *arg, int unset)
5109{
5110        struct diff_options *options = opt->value;
5111
5112        BUG_ON_OPT_NEG(unset);
5113        if (options->word_diff == DIFF_WORDS_NONE)
5114                options->word_diff = DIFF_WORDS_PLAIN;
5115        options->word_regex = arg;
5116        return 0;
5117}
5118
5119static void prep_parse_options(struct diff_options *options)
5120{
5121        struct option parseopts[] = {
5122                OPT_GROUP(N_("Diff output format options")),
5123                OPT_BITOP('p', "patch", &options->output_format,
5124                          N_("generate patch"),
5125                          DIFF_FORMAT_PATCH, DIFF_FORMAT_NO_OUTPUT),
5126                OPT_BIT_F('s', "no-patch", &options->output_format,
5127                          N_("suppress diff output"),
5128                          DIFF_FORMAT_NO_OUTPUT, PARSE_OPT_NONEG),
5129                OPT_BITOP('u', NULL, &options->output_format,
5130                          N_("generate patch"),
5131                          DIFF_FORMAT_PATCH, DIFF_FORMAT_NO_OUTPUT),
5132                OPT_CALLBACK_F('U', "unified", options, N_("<n>"),
5133                               N_("generate diffs with <n> lines context"),
5134                               PARSE_OPT_NONEG, diff_opt_unified),
5135                OPT_BOOL('W', "function-context", &options->flags.funccontext,
5136                         N_("generate diffs with <n> lines context")),
5137                OPT_BIT_F(0, "raw", &options->output_format,
5138                          N_("generate the diff in raw format"),
5139                          DIFF_FORMAT_RAW, PARSE_OPT_NONEG),
5140                OPT_BITOP(0, "patch-with-raw", &options->output_format,
5141                          N_("synonym for '-p --raw'"),
5142                          DIFF_FORMAT_PATCH | DIFF_FORMAT_RAW,
5143                          DIFF_FORMAT_NO_OUTPUT),
5144                OPT_BITOP(0, "patch-with-stat", &options->output_format,
5145                          N_("synonym for '-p --stat'"),
5146                          DIFF_FORMAT_PATCH | DIFF_FORMAT_DIFFSTAT,
5147                          DIFF_FORMAT_NO_OUTPUT),
5148                OPT_BIT_F(0, "numstat", &options->output_format,
5149                          N_("machine friendly --stat"),
5150                          DIFF_FORMAT_NUMSTAT, PARSE_OPT_NONEG),
5151                OPT_BIT_F(0, "shortstat", &options->output_format,
5152                          N_("output only the last line of --stat"),
5153                          DIFF_FORMAT_SHORTSTAT, PARSE_OPT_NONEG),
5154                OPT_CALLBACK_F('X', "dirstat", options, N_("<param1,param2>..."),
5155                               N_("output the distribution of relative amount of changes for each sub-directory"),
5156                               PARSE_OPT_NONEG | PARSE_OPT_OPTARG,
5157                               diff_opt_dirstat),
5158                OPT_CALLBACK_F(0, "cumulative", options, NULL,
5159                               N_("synonym for --dirstat=cumulative"),
5160                               PARSE_OPT_NONEG | PARSE_OPT_NOARG,
5161                               diff_opt_dirstat),
5162                OPT_CALLBACK_F(0, "dirstat-by-file", options, N_("<param1,param2>..."),
5163                               N_("synonym for --dirstat=files,param1,param2..."),
5164                               PARSE_OPT_NONEG | PARSE_OPT_OPTARG,
5165                               diff_opt_dirstat),
5166                OPT_BIT_F(0, "check", &options->output_format,
5167                          N_("warn if changes introduce conflict markers or whitespace errors"),
5168                          DIFF_FORMAT_CHECKDIFF, PARSE_OPT_NONEG),
5169                OPT_BIT_F(0, "summary", &options->output_format,
5170                          N_("condensed summary such as creations, renames and mode changes"),
5171                          DIFF_FORMAT_SUMMARY, PARSE_OPT_NONEG),
5172                OPT_BIT_F(0, "name-only", &options->output_format,
5173                          N_("show only names of changed files"),
5174                          DIFF_FORMAT_NAME, PARSE_OPT_NONEG),
5175                OPT_BIT_F(0, "name-status", &options->output_format,
5176                          N_("show only names and status of changed files"),
5177                          DIFF_FORMAT_NAME_STATUS, PARSE_OPT_NONEG),
5178                OPT_CALLBACK_F(0, "stat", options, N_("<width>[,<name-width>[,<count>]]"),
5179                               N_("generate diffstat"),
5180                               PARSE_OPT_NONEG | PARSE_OPT_OPTARG, diff_opt_stat),
5181                OPT_CALLBACK_F(0, "stat-width", options, N_("<width>"),
5182                               N_("generate diffstat with a given width"),
5183                               PARSE_OPT_NONEG, diff_opt_stat),
5184                OPT_CALLBACK_F(0, "stat-name-width", options, N_("<width>"),
5185                               N_("generate diffstat with a given name width"),
5186                               PARSE_OPT_NONEG, diff_opt_stat),
5187                OPT_CALLBACK_F(0, "stat-graph-width", options, N_("<width>"),
5188                               N_("generate diffstat with a given graph width"),
5189                               PARSE_OPT_NONEG, diff_opt_stat),
5190                OPT_CALLBACK_F(0, "stat-count", options, N_("<count>"),
5191                               N_("generate diffstat with limited lines"),
5192                               PARSE_OPT_NONEG, diff_opt_stat),
5193                OPT_CALLBACK_F(0, "compact-summary", options, NULL,
5194                               N_("generate compact summary in diffstat"),
5195                               PARSE_OPT_NOARG, diff_opt_compact_summary),
5196                OPT_CALLBACK_F(0, "binary", options, NULL,
5197                               N_("output a binary diff that can be applied"),
5198                               PARSE_OPT_NONEG | PARSE_OPT_NOARG, diff_opt_binary),
5199                OPT_BOOL(0, "full-index", &options->flags.full_index,
5200                         N_("show full pre- and post-image object names on the \"index\" lines")),
5201                OPT_COLOR_FLAG(0, "color", &options->use_color,
5202                               N_("show colored diff")),
5203                OPT_CALLBACK_F(0, "output-indicator-new",
5204                               &options->output_indicators[OUTPUT_INDICATOR_NEW],
5205                               N_("<char>"),
5206                               N_("specify the character to indicate a new line instead of '+'"),
5207                               PARSE_OPT_NONEG, diff_opt_char),
5208                OPT_CALLBACK_F(0, "output-indicator-old",
5209                               &options->output_indicators[OUTPUT_INDICATOR_OLD],
5210                               N_("<char>"),
5211                               N_("specify the character to indicate an old line instead of '-'"),
5212                               PARSE_OPT_NONEG, diff_opt_char),
5213                OPT_CALLBACK_F(0, "output-indicator-context",
5214                               &options->output_indicators[OUTPUT_INDICATOR_CONTEXT],
5215                               N_("<char>"),
5216                               N_("specify the character to indicate a context instead of ' '"),
5217                               PARSE_OPT_NONEG, diff_opt_char),
5218
5219                OPT_GROUP(N_("Diff rename options")),
5220                OPT_CALLBACK_F('B', "break-rewrites", &options->break_opt, N_("<n>[/<m>]"),
5221                               N_("break complete rewrite changes into pairs of delete and create"),
5222                               PARSE_OPT_NONEG | PARSE_OPT_OPTARG,
5223                               diff_opt_break_rewrites),
5224                OPT_CALLBACK_F('M', "find-renames", options, N_("<n>"),
5225                               N_("detect renames"),
5226                               PARSE_OPT_NONEG | PARSE_OPT_OPTARG,
5227                               diff_opt_find_renames),
5228                OPT_SET_INT_F('D', "irreversible-delete", &options->irreversible_delete,
5229                              N_("omit the preimage for deletes"),
5230                              1, PARSE_OPT_NONEG),
5231                OPT_CALLBACK_F('C', "find-copies", options, N_("<n>"),
5232                               N_("detect copies"),
5233                               PARSE_OPT_NONEG | PARSE_OPT_OPTARG,
5234                               diff_opt_find_copies),
5235                OPT_BOOL(0, "find-copies-harder", &options->flags.find_copies_harder,
5236                         N_("use unmodified files as source to find copies")),
5237                OPT_SET_INT_F(0, "no-renames", &options->detect_rename,
5238                              N_("disable rename detection"),
5239                              0, PARSE_OPT_NONEG),
5240                OPT_BOOL(0, "rename-empty", &options->flags.rename_empty,
5241                         N_("use empty blobs as rename source")),
5242                OPT_CALLBACK_F(0, "follow", options, NULL,
5243                               N_("continue listing the history of a file beyond renames"),
5244                               PARSE_OPT_NOARG, diff_opt_follow),
5245
5246                OPT_GROUP(N_("Diff algorithm options")),
5247                OPT_BIT(0, "minimal", &options->xdl_opts,
5248                        N_("produce the smallest possible diff"),
5249                        XDF_NEED_MINIMAL),
5250                OPT_BIT_F('w', "ignore-all-space", &options->xdl_opts,
5251                          N_("ignore whitespace when comparing lines"),
5252                          XDF_IGNORE_WHITESPACE, PARSE_OPT_NONEG),
5253                OPT_BIT_F('b', "ignore-space-change", &options->xdl_opts,
5254                          N_("ignore changes in amount of whitespace"),
5255                          XDF_IGNORE_WHITESPACE_CHANGE, PARSE_OPT_NONEG),
5256                OPT_BIT_F(0, "ignore-space-at-eol", &options->xdl_opts,
5257                          N_("ignore changes in whitespace at EOL"),
5258                          XDF_IGNORE_WHITESPACE_AT_EOL, PARSE_OPT_NONEG),
5259                OPT_BIT_F(0, "ignore-cr-at-eol", &options->xdl_opts,
5260                          N_("ignore carrier-return at the end of line"),
5261                          XDF_IGNORE_CR_AT_EOL, PARSE_OPT_NONEG),
5262                OPT_BIT_F(0, "ignore-blank-lines", &options->xdl_opts,
5263                          N_("ignore changes whose lines are all blank"),
5264                          XDF_IGNORE_BLANK_LINES, PARSE_OPT_NONEG),
5265                OPT_BIT(0, "indent-heuristic", &options->xdl_opts,
5266                        N_("heuristic to shift diff hunk boundaries for easy reading"),
5267                        XDF_INDENT_HEURISTIC),
5268                OPT_CALLBACK_F(0, "patience", options, NULL,
5269                               N_("generate diff using the \"patience diff\" algorithm"),
5270                               PARSE_OPT_NONEG | PARSE_OPT_NOARG,
5271                               diff_opt_patience),
5272                OPT_BITOP(0, "histogram", &options->xdl_opts,
5273                          N_("generate diff using the \"histogram diff\" algorithm"),
5274                          XDF_HISTOGRAM_DIFF, XDF_DIFF_ALGORITHM_MASK),
5275                OPT_CALLBACK_F(0, "diff-algorithm", options, N_("<algorithm>"),
5276                               N_("choose a diff algorithm"),
5277                               PARSE_OPT_NONEG, diff_opt_diff_algorithm),
5278                OPT_CALLBACK_F(0, "anchored", options, N_("<text>"),
5279                               N_("generate diff using the \"anchored diff\" algorithm"),
5280                               PARSE_OPT_NONEG, diff_opt_anchored),
5281                OPT_CALLBACK_F(0, "word-diff", options, N_("<mode>"),
5282                               N_("show word diff, using <mode> to delimit changed words"),
5283                               PARSE_OPT_NONEG | PARSE_OPT_OPTARG, diff_opt_word_diff),
5284                OPT_CALLBACK_F(0, "word-diff-regex", options, N_("<regex>"),
5285                               N_("use <regex> to decide what a word is"),
5286                               PARSE_OPT_NONEG, diff_opt_word_diff_regex),
5287                OPT_CALLBACK_F(0, "color-words", options, N_("<regex>"),
5288                               N_("equivalent to --word-diff=color --word-diff-regex=<regex>"),
5289                               PARSE_OPT_NONEG | PARSE_OPT_OPTARG, diff_opt_color_words),
5290
5291                OPT_GROUP(N_("Diff other options")),
5292                OPT_CALLBACK_F(0, "relative", options, N_("<prefix>"),
5293                               N_("when run from subdir, exclude changes outside and show relative paths"),
5294                               PARSE_OPT_NONEG | PARSE_OPT_OPTARG,
5295                               diff_opt_relative),
5296                OPT_BOOL('a', "text", &options->flags.text,
5297                         N_("treat all files as text")),
5298                OPT_BOOL('R', NULL, &options->flags.reverse_diff,
5299                         N_("swap two inputs, reverse the diff")),
5300                { OPTION_CALLBACK, 0, "output", options, N_("<file>"),
5301                  N_("Output to a specific file"),
5302                  PARSE_OPT_NONEG, NULL, 0, diff_opt_output },
5303
5304                OPT_END()
5305        };
5306
5307        ALLOC_ARRAY(options->parseopts, ARRAY_SIZE(parseopts));
5308        memcpy(options->parseopts, parseopts, sizeof(parseopts));
5309}
5310
5311int diff_opt_parse(struct diff_options *options,
5312                   const char **av, int ac, const char *prefix)
5313{
5314        const char *arg = av[0];
5315        const char *optarg;
5316        int argcount;
5317
5318        if (!prefix)
5319                prefix = "";
5320
5321        ac = parse_options(ac, av, prefix, options->parseopts, NULL,
5322                           PARSE_OPT_KEEP_DASHDASH |
5323                           PARSE_OPT_KEEP_UNKNOWN |
5324                           PARSE_OPT_NO_INTERNAL_HELP |
5325                           PARSE_OPT_ONE_SHOT |
5326                           PARSE_OPT_STOP_AT_NON_OPTION);
5327
5328        if (ac)
5329                return ac;
5330
5331        /* flags options */
5332        if (!strcmp(arg, "--color-moved")) {
5333                if (diff_color_moved_default)
5334                        options->color_moved = diff_color_moved_default;
5335                if (options->color_moved == COLOR_MOVED_NO)
5336                        options->color_moved = COLOR_MOVED_DEFAULT;
5337        } else if (!strcmp(arg, "--no-color-moved"))
5338                options->color_moved = COLOR_MOVED_NO;
5339        else if (skip_prefix(arg, "--color-moved=", &arg)) {
5340                int cm = parse_color_moved(arg);
5341                if (cm < 0)
5342                        return error("bad --color-moved argument: %s", arg);
5343                options->color_moved = cm;
5344        } else if (skip_prefix(arg, "--color-moved-ws=", &arg)) {
5345                unsigned cm = parse_color_moved_ws(arg);
5346                if (cm & COLOR_MOVED_WS_ERROR)
5347                        return -1;
5348                options->color_moved_ws_handling = cm;
5349        } else if (!strcmp(arg, "--exit-code"))
5350                options->flags.exit_with_status = 1;
5351        else if (!strcmp(arg, "--quiet"))
5352                options->flags.quick = 1;
5353        else if (!strcmp(arg, "--ext-diff"))
5354                options->flags.allow_external = 1;
5355        else if (!strcmp(arg, "--no-ext-diff"))
5356                options->flags.allow_external = 0;
5357        else if (!strcmp(arg, "--textconv")) {
5358                options->flags.allow_textconv = 1;
5359                options->flags.textconv_set_via_cmdline = 1;
5360        } else if (!strcmp(arg, "--no-textconv"))
5361                options->flags.allow_textconv = 0;
5362        else if (skip_to_optional_arg_default(arg, "--ignore-submodules", &arg, "all")) {
5363                options->flags.override_submodule_config = 1;
5364                handle_ignore_submodules_arg(options, arg);
5365        } else if (skip_to_optional_arg_default(arg, "--submodule", &arg, "log"))
5366                return parse_submodule_opt(options, arg);
5367        else if (skip_prefix(arg, "--ws-error-highlight=", &arg))
5368                return parse_ws_error_highlight_opt(options, arg);
5369        else if (!strcmp(arg, "--ita-invisible-in-index"))
5370                options->ita_invisible_in_index = 1;
5371        else if (!strcmp(arg, "--ita-visible-in-index"))
5372                options->ita_invisible_in_index = 0;
5373
5374        /* misc options */
5375        else if (!strcmp(arg, "-z"))
5376                options->line_termination = 0;
5377        else if ((argcount = short_opt('l', av, &optarg))) {
5378                options->rename_limit = strtoul(optarg, NULL, 10);
5379                return argcount;
5380        }
5381        else if ((argcount = short_opt('S', av, &optarg))) {
5382                options->pickaxe = optarg;
5383                options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
5384                return argcount;
5385        } else if ((argcount = short_opt('G', av, &optarg))) {
5386                options->pickaxe = optarg;
5387                options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
5388                return argcount;
5389        }
5390        else if (!strcmp(arg, "--pickaxe-all"))
5391                options->pickaxe_opts |= DIFF_PICKAXE_ALL;
5392        else if (!strcmp(arg, "--pickaxe-regex"))
5393                options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
5394        else if ((argcount = short_opt('O', av, &optarg))) {
5395                options->orderfile = prefix_filename(prefix, optarg);
5396                return argcount;
5397        } else if (skip_prefix(arg, "--find-object=", &arg))
5398                return parse_objfind_opt(options, arg);
5399        else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
5400                int offending = parse_diff_filter_opt(optarg, options);
5401                if (offending)
5402                        die("unknown change class '%c' in --diff-filter=%s",
5403                            offending, optarg);
5404                return argcount;
5405        }
5406        else if (!strcmp(arg, "--no-abbrev"))
5407                options->abbrev = 0;
5408        else if (!strcmp(arg, "--abbrev"))
5409                options->abbrev = DEFAULT_ABBREV;
5410        else if (skip_prefix(arg, "--abbrev=", &arg)) {
5411                options->abbrev = strtoul(arg, NULL, 10);
5412                if (options->abbrev < MINIMUM_ABBREV)
5413                        options->abbrev = MINIMUM_ABBREV;
5414                else if (the_hash_algo->hexsz < options->abbrev)
5415                        options->abbrev = the_hash_algo->hexsz;
5416        }
5417        else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
5418                options->a_prefix = optarg;
5419                return argcount;
5420        }
5421        else if ((argcount = parse_long_opt("line-prefix", av, &optarg))) {
5422                options->line_prefix = optarg;
5423                options->line_prefix_length = strlen(options->line_prefix);
5424                graph_setup_line_prefix(options);
5425                return argcount;
5426        }
5427        else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
5428                options->b_prefix = optarg;
5429                return argcount;
5430        }
5431        else if (!strcmp(arg, "--no-prefix"))
5432                options->a_prefix = options->b_prefix = "";
5433        else if (opt_arg(arg, '\0', "inter-hunk-context",
5434                         &options->interhunkcontext))
5435                ;
5436        else
5437                return 0;
5438        return 1;
5439}
5440
5441int parse_rename_score(const char **cp_p)
5442{
5443        unsigned long num, scale;
5444        int ch, dot;
5445        const char *cp = *cp_p;
5446
5447        num = 0;
5448        scale = 1;
5449        dot = 0;
5450        for (;;) {
5451                ch = *cp;
5452                if ( !dot && ch == '.' ) {
5453                        scale = 1;
5454                        dot = 1;
5455                } else if ( ch == '%' ) {
5456                        scale = dot ? scale*100 : 100;
5457                        cp++;   /* % is always at the end */
5458                        break;
5459                } else if ( ch >= '0' && ch <= '9' ) {
5460                        if ( scale < 100000 ) {
5461                                scale *= 10;
5462                                num = (num*10) + (ch-'0');
5463                        }
5464                } else {
5465                        break;
5466                }
5467                cp++;
5468        }
5469        *cp_p = cp;
5470
5471        /* user says num divided by scale and we say internally that
5472         * is MAX_SCORE * num / scale.
5473         */
5474        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
5475}
5476
5477struct diff_queue_struct diff_queued_diff;
5478
5479void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
5480{
5481        ALLOC_GROW(queue->queue, queue->nr + 1, queue->alloc);
5482        queue->queue[queue->nr++] = dp;
5483}
5484
5485struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
5486                                 struct diff_filespec *one,
5487                                 struct diff_filespec *two)
5488{
5489        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
5490        dp->one = one;
5491        dp->two = two;
5492        if (queue)
5493                diff_q(queue, dp);
5494        return dp;
5495}
5496
5497void diff_free_filepair(struct diff_filepair *p)
5498{
5499        free_filespec(p->one);
5500        free_filespec(p->two);
5501        free(p);
5502}
5503
5504const char *diff_aligned_abbrev(const struct object_id *oid, int len)
5505{
5506        int abblen;
5507        const char *abbrev;
5508
5509        /* Do we want all 40 hex characters? */
5510        if (len == the_hash_algo->hexsz)
5511                return oid_to_hex(oid);
5512
5513        /* An abbreviated value is fine, possibly followed by an ellipsis. */
5514        abbrev = diff_abbrev_oid(oid, len);
5515
5516        if (!print_sha1_ellipsis())
5517                return abbrev;
5518
5519        abblen = strlen(abbrev);
5520
5521        /*
5522         * In well-behaved cases, where the abbreviated result is the
5523         * same as the requested length, append three dots after the
5524         * abbreviation (hence the whole logic is limited to the case
5525         * where abblen < 37); when the actual abbreviated result is a
5526         * bit longer than the requested length, we reduce the number
5527         * of dots so that they match the well-behaved ones.  However,
5528         * if the actual abbreviation is longer than the requested
5529         * length by more than three, we give up on aligning, and add
5530         * three dots anyway, to indicate that the output is not the
5531         * full object name.  Yes, this may be suboptimal, but this
5532         * appears only in "diff --raw --abbrev" output and it is not
5533         * worth the effort to change it now.  Note that this would
5534         * likely to work fine when the automatic sizing of default
5535         * abbreviation length is used--we would be fed -1 in "len" in
5536         * that case, and will end up always appending three-dots, but
5537         * the automatic sizing is supposed to give abblen that ensures
5538         * uniqueness across all objects (statistically speaking).
5539         */
5540        if (abblen < the_hash_algo->hexsz - 3) {
5541                static char hex[GIT_MAX_HEXSZ + 1];
5542                if (len < abblen && abblen <= len + 2)
5543                        xsnprintf(hex, sizeof(hex), "%s%.*s", abbrev, len+3-abblen, "..");
5544                else
5545                        xsnprintf(hex, sizeof(hex), "%s...", abbrev);
5546                return hex;
5547        }
5548
5549        return oid_to_hex(oid);
5550}
5551
5552static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
5553{
5554        int line_termination = opt->line_termination;
5555        int inter_name_termination = line_termination ? '\t' : '\0';
5556
5557        fprintf(opt->file, "%s", diff_line_prefix(opt));
5558        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
5559                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
5560                        diff_aligned_abbrev(&p->one->oid, opt->abbrev));
5561                fprintf(opt->file, "%s ",
5562                        diff_aligned_abbrev(&p->two->oid, opt->abbrev));
5563        }
5564        if (p->score) {
5565                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
5566                        inter_name_termination);
5567        } else {
5568                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
5569        }
5570
5571        if (p->status == DIFF_STATUS_COPIED ||
5572            p->status == DIFF_STATUS_RENAMED) {
5573                const char *name_a, *name_b;
5574                name_a = p->one->path;
5575                name_b = p->two->path;
5576                strip_prefix(opt->prefix_length, &name_a, &name_b);
5577                write_name_quoted(name_a, opt->file, inter_name_termination);
5578                write_name_quoted(name_b, opt->file, line_termination);
5579        } else {
5580                const char *name_a, *name_b;
5581                name_a = p->one->mode ? p->one->path : p->two->path;
5582                name_b = NULL;
5583                strip_prefix(opt->prefix_length, &name_a, &name_b);
5584                write_name_quoted(name_a, opt->file, line_termination);
5585        }
5586}
5587
5588int diff_unmodified_pair(struct diff_filepair *p)
5589{
5590        /* This function is written stricter than necessary to support
5591         * the currently implemented transformers, but the idea is to
5592         * let transformers to produce diff_filepairs any way they want,
5593         * and filter and clean them up here before producing the output.
5594         */
5595        struct diff_filespec *one = p->one, *two = p->two;
5596
5597        if (DIFF_PAIR_UNMERGED(p))
5598                return 0; /* unmerged is interesting */
5599
5600        /* deletion, addition, mode or type change
5601         * and rename are all interesting.
5602         */
5603        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
5604            DIFF_PAIR_MODE_CHANGED(p) ||
5605            strcmp(one->path, two->path))
5606                return 0;
5607
5608        /* both are valid and point at the same path.  that is, we are
5609         * dealing with a change.
5610         */
5611        if (one->oid_valid && two->oid_valid &&
5612            oideq(&one->oid, &two->oid) &&
5613            !one->dirty_submodule && !two->dirty_submodule)
5614                return 1; /* no change */
5615        if (!one->oid_valid && !two->oid_valid)
5616                return 1; /* both look at the same file on the filesystem. */
5617        return 0;
5618}
5619
5620static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
5621{
5622        if (diff_unmodified_pair(p))
5623                return;
5624
5625        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5626            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5627                return; /* no tree diffs in patch format */
5628
5629        run_diff(p, o);
5630}
5631
5632static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
5633                            struct diffstat_t *diffstat)
5634{
5635        if (diff_unmodified_pair(p))
5636                return;
5637
5638        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5639            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5640                return; /* no useful stat for tree diffs */
5641
5642        run_diffstat(p, o, diffstat);
5643}
5644
5645static void diff_flush_checkdiff(struct diff_filepair *p,
5646                struct diff_options *o)
5647{
5648        if (diff_unmodified_pair(p))
5649                return;
5650
5651        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5652            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5653                return; /* nothing to check in tree diffs */
5654
5655        run_checkdiff(p, o);
5656}
5657
5658int diff_queue_is_empty(void)
5659{
5660        struct diff_queue_struct *q = &diff_queued_diff;
5661        int i;
5662        for (i = 0; i < q->nr; i++)
5663                if (!diff_unmodified_pair(q->queue[i]))
5664                        return 0;
5665        return 1;
5666}
5667
5668#if DIFF_DEBUG
5669void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
5670{
5671        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
5672                x, one ? one : "",
5673                s->path,
5674                DIFF_FILE_VALID(s) ? "valid" : "invalid",
5675                s->mode,
5676                s->oid_valid ? oid_to_hex(&s->oid) : "");
5677        fprintf(stderr, "queue[%d] %s size %lu\n",
5678                x, one ? one : "",
5679                s->size);
5680}
5681
5682void diff_debug_filepair(const struct diff_filepair *p, int i)
5683{
5684        diff_debug_filespec(p->one, i, "one");
5685        diff_debug_filespec(p->two, i, "two");
5686        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
5687                p->score, p->status ? p->status : '?',
5688                p->one->rename_used, p->broken_pair);
5689}
5690
5691void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
5692{
5693        int i;
5694        if (msg)
5695                fprintf(stderr, "%s\n", msg);
5696        fprintf(stderr, "q->nr = %d\n", q->nr);
5697        for (i = 0; i < q->nr; i++) {
5698                struct diff_filepair *p = q->queue[i];
5699                diff_debug_filepair(p, i);
5700        }
5701}
5702#endif
5703
5704static void diff_resolve_rename_copy(void)
5705{
5706        int i;
5707        struct diff_filepair *p;
5708        struct diff_queue_struct *q = &diff_queued_diff;
5709
5710        diff_debug_queue("resolve-rename-copy", q);
5711
5712        for (i = 0; i < q->nr; i++) {
5713                p = q->queue[i];
5714                p->status = 0; /* undecided */
5715                if (DIFF_PAIR_UNMERGED(p))
5716                        p->status = DIFF_STATUS_UNMERGED;
5717                else if (!DIFF_FILE_VALID(p->one))
5718                        p->status = DIFF_STATUS_ADDED;
5719                else if (!DIFF_FILE_VALID(p->two))
5720                        p->status = DIFF_STATUS_DELETED;
5721                else if (DIFF_PAIR_TYPE_CHANGED(p))
5722                        p->status = DIFF_STATUS_TYPE_CHANGED;
5723
5724                /* from this point on, we are dealing with a pair
5725                 * whose both sides are valid and of the same type, i.e.
5726                 * either in-place edit or rename/copy edit.
5727                 */
5728                else if (DIFF_PAIR_RENAME(p)) {
5729                        /*
5730                         * A rename might have re-connected a broken
5731                         * pair up, causing the pathnames to be the
5732                         * same again. If so, that's not a rename at
5733                         * all, just a modification..
5734                         *
5735                         * Otherwise, see if this source was used for
5736                         * multiple renames, in which case we decrement
5737                         * the count, and call it a copy.
5738                         */
5739                        if (!strcmp(p->one->path, p->two->path))
5740                                p->status = DIFF_STATUS_MODIFIED;
5741                        else if (--p->one->rename_used > 0)
5742                                p->status = DIFF_STATUS_COPIED;
5743                        else
5744                                p->status = DIFF_STATUS_RENAMED;
5745                }
5746                else if (!oideq(&p->one->oid, &p->two->oid) ||
5747                         p->one->mode != p->two->mode ||
5748                         p->one->dirty_submodule ||
5749                         p->two->dirty_submodule ||
5750                         is_null_oid(&p->one->oid))
5751                        p->status = DIFF_STATUS_MODIFIED;
5752                else {
5753                        /* This is a "no-change" entry and should not
5754                         * happen anymore, but prepare for broken callers.
5755                         */
5756                        error("feeding unmodified %s to diffcore",
5757                              p->one->path);
5758                        p->status = DIFF_STATUS_UNKNOWN;
5759                }
5760        }
5761        diff_debug_queue("resolve-rename-copy done", q);
5762}
5763
5764static int check_pair_status(struct diff_filepair *p)
5765{
5766        switch (p->status) {
5767        case DIFF_STATUS_UNKNOWN:
5768                return 0;
5769        case 0:
5770                die("internal error in diff-resolve-rename-copy");
5771        default:
5772                return 1;
5773        }
5774}
5775
5776static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
5777{
5778        int fmt = opt->output_format;
5779
5780        if (fmt & DIFF_FORMAT_CHECKDIFF)
5781                diff_flush_checkdiff(p, opt);
5782        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
5783                diff_flush_raw(p, opt);
5784        else if (fmt & DIFF_FORMAT_NAME) {
5785                const char *name_a, *name_b;
5786                name_a = p->two->path;
5787                name_b = NULL;
5788                strip_prefix(opt->prefix_length, &name_a, &name_b);
5789                fprintf(opt->file, "%s", diff_line_prefix(opt));
5790                write_name_quoted(name_a, opt->file, opt->line_termination);
5791        }
5792}
5793
5794static void show_file_mode_name(struct diff_options *opt, const char *newdelete, struct diff_filespec *fs)
5795{
5796        struct strbuf sb = STRBUF_INIT;
5797        if (fs->mode)
5798                strbuf_addf(&sb, " %s mode %06o ", newdelete, fs->mode);
5799        else
5800                strbuf_addf(&sb, " %s ", newdelete);
5801
5802        quote_c_style(fs->path, &sb, NULL, 0);
5803        strbuf_addch(&sb, '\n');
5804        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5805                         sb.buf, sb.len, 0);
5806        strbuf_release(&sb);
5807}
5808
5809static void show_mode_change(struct diff_options *opt, struct diff_filepair *p,
5810                int show_name)
5811{
5812        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
5813                struct strbuf sb = STRBUF_INIT;
5814                strbuf_addf(&sb, " mode change %06o => %06o",
5815                            p->one->mode, p->two->mode);
5816                if (show_name) {
5817                        strbuf_addch(&sb, ' ');
5818                        quote_c_style(p->two->path, &sb, NULL, 0);
5819                }
5820                strbuf_addch(&sb, '\n');
5821                emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5822                                 sb.buf, sb.len, 0);
5823                strbuf_release(&sb);
5824        }
5825}
5826
5827static void show_rename_copy(struct diff_options *opt, const char *renamecopy,
5828                struct diff_filepair *p)
5829{
5830        struct strbuf sb = STRBUF_INIT;
5831        struct strbuf names = STRBUF_INIT;
5832
5833        pprint_rename(&names, p->one->path, p->two->path);
5834        strbuf_addf(&sb, " %s %s (%d%%)\n",
5835                    renamecopy, names.buf, similarity_index(p));
5836        strbuf_release(&names);
5837        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5838                                 sb.buf, sb.len, 0);
5839        show_mode_change(opt, p, 0);
5840        strbuf_release(&sb);
5841}
5842
5843static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
5844{
5845        switch(p->status) {
5846        case DIFF_STATUS_DELETED:
5847                show_file_mode_name(opt, "delete", p->one);
5848                break;
5849        case DIFF_STATUS_ADDED:
5850                show_file_mode_name(opt, "create", p->two);
5851                break;
5852        case DIFF_STATUS_COPIED:
5853                show_rename_copy(opt, "copy", p);
5854                break;
5855        case DIFF_STATUS_RENAMED:
5856                show_rename_copy(opt, "rename", p);
5857                break;
5858        default:
5859                if (p->score) {
5860                        struct strbuf sb = STRBUF_INIT;
5861                        strbuf_addstr(&sb, " rewrite ");
5862                        quote_c_style(p->two->path, &sb, NULL, 0);
5863                        strbuf_addf(&sb, " (%d%%)\n", similarity_index(p));
5864                        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5865                                         sb.buf, sb.len, 0);
5866                        strbuf_release(&sb);
5867                }
5868                show_mode_change(opt, p, !p->score);
5869                break;
5870        }
5871}
5872
5873struct patch_id_t {
5874        git_SHA_CTX *ctx;
5875        int patchlen;
5876};
5877
5878static int remove_space(char *line, int len)
5879{
5880        int i;
5881        char *dst = line;
5882        unsigned char c;
5883
5884        for (i = 0; i < len; i++)
5885                if (!isspace((c = line[i])))
5886                        *dst++ = c;
5887
5888        return dst - line;
5889}
5890
5891static void patch_id_consume(void *priv, char *line, unsigned long len)
5892{
5893        struct patch_id_t *data = priv;
5894        int new_len;
5895
5896        new_len = remove_space(line, len);
5897
5898        git_SHA1_Update(data->ctx, line, new_len);
5899        data->patchlen += new_len;
5900}
5901
5902static void patch_id_add_string(git_SHA_CTX *ctx, const char *str)
5903{
5904        git_SHA1_Update(ctx, str, strlen(str));
5905}
5906
5907static void patch_id_add_mode(git_SHA_CTX *ctx, unsigned mode)
5908{
5909        /* large enough for 2^32 in octal */
5910        char buf[12];
5911        int len = xsnprintf(buf, sizeof(buf), "%06o", mode);
5912        git_SHA1_Update(ctx, buf, len);
5913}
5914
5915/* returns 0 upon success, and writes result into sha1 */
5916static int diff_get_patch_id(struct diff_options *options, struct object_id *oid, int diff_header_only)
5917{
5918        struct diff_queue_struct *q = &diff_queued_diff;
5919        int i;
5920        git_SHA_CTX ctx;
5921        struct patch_id_t data;
5922
5923        git_SHA1_Init(&ctx);
5924        memset(&data, 0, sizeof(struct patch_id_t));
5925        data.ctx = &ctx;
5926
5927        for (i = 0; i < q->nr; i++) {
5928                xpparam_t xpp;
5929                xdemitconf_t xecfg;
5930                mmfile_t mf1, mf2;
5931                struct diff_filepair *p = q->queue[i];
5932                int len1, len2;
5933
5934                memset(&xpp, 0, sizeof(xpp));
5935                memset(&xecfg, 0, sizeof(xecfg));
5936                if (p->status == 0)
5937                        return error("internal diff status error");
5938                if (p->status == DIFF_STATUS_UNKNOWN)
5939                        continue;
5940                if (diff_unmodified_pair(p))
5941                        continue;
5942                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5943                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5944                        continue;
5945                if (DIFF_PAIR_UNMERGED(p))
5946                        continue;
5947
5948                diff_fill_oid_info(p->one, options->repo->index);
5949                diff_fill_oid_info(p->two, options->repo->index);
5950
5951                len1 = remove_space(p->one->path, strlen(p->one->path));
5952                len2 = remove_space(p->two->path, strlen(p->two->path));
5953                patch_id_add_string(&ctx, "diff--git");
5954                patch_id_add_string(&ctx, "a/");
5955                git_SHA1_Update(&ctx, p->one->path, len1);
5956                patch_id_add_string(&ctx, "b/");
5957                git_SHA1_Update(&ctx, p->two->path, len2);
5958
5959                if (p->one->mode == 0) {
5960                        patch_id_add_string(&ctx, "newfilemode");
5961                        patch_id_add_mode(&ctx, p->two->mode);
5962                        patch_id_add_string(&ctx, "---/dev/null");
5963                        patch_id_add_string(&ctx, "+++b/");
5964                        git_SHA1_Update(&ctx, p->two->path, len2);
5965                } else if (p->two->mode == 0) {
5966                        patch_id_add_string(&ctx, "deletedfilemode");
5967                        patch_id_add_mode(&ctx, p->one->mode);
5968                        patch_id_add_string(&ctx, "---a/");
5969                        git_SHA1_Update(&ctx, p->one->path, len1);
5970                        patch_id_add_string(&ctx, "+++/dev/null");
5971                } else {
5972                        patch_id_add_string(&ctx, "---a/");
5973                        git_SHA1_Update(&ctx, p->one->path, len1);
5974                        patch_id_add_string(&ctx, "+++b/");
5975                        git_SHA1_Update(&ctx, p->two->path, len2);
5976                }
5977
5978                if (diff_header_only)
5979                        continue;
5980
5981                if (fill_mmfile(options->repo, &mf1, p->one) < 0 ||
5982                    fill_mmfile(options->repo, &mf2, p->two) < 0)
5983                        return error("unable to read files to diff");
5984
5985                if (diff_filespec_is_binary(options->repo, p->one) ||
5986                    diff_filespec_is_binary(options->repo, p->two)) {
5987                        git_SHA1_Update(&ctx, oid_to_hex(&p->one->oid),
5988                                        GIT_SHA1_HEXSZ);
5989                        git_SHA1_Update(&ctx, oid_to_hex(&p->two->oid),
5990                                        GIT_SHA1_HEXSZ);
5991                        continue;
5992                }
5993
5994                xpp.flags = 0;
5995                xecfg.ctxlen = 3;
5996                xecfg.flags = 0;
5997                if (xdi_diff_outf(&mf1, &mf2, discard_hunk_line,
5998                                  patch_id_consume, &data, &xpp, &xecfg))
5999                        return error("unable to generate patch-id diff for %s",
6000                                     p->one->path);
6001        }
6002
6003        git_SHA1_Final(oid->hash, &ctx);
6004        return 0;
6005}
6006
6007int diff_flush_patch_id(struct diff_options *options, struct object_id *oid, int diff_header_only)
6008{
6009        struct diff_queue_struct *q = &diff_queued_diff;
6010        int i;
6011        int result = diff_get_patch_id(options, oid, diff_header_only);
6012
6013        for (i = 0; i < q->nr; i++)
6014                diff_free_filepair(q->queue[i]);
6015
6016        free(q->queue);
6017        DIFF_QUEUE_CLEAR(q);
6018
6019        return result;
6020}
6021
6022static int is_summary_empty(const struct diff_queue_struct *q)
6023{
6024        int i;
6025
6026        for (i = 0; i < q->nr; i++) {
6027                const struct diff_filepair *p = q->queue[i];
6028
6029                switch (p->status) {
6030                case DIFF_STATUS_DELETED:
6031                case DIFF_STATUS_ADDED:
6032                case DIFF_STATUS_COPIED:
6033                case DIFF_STATUS_RENAMED:
6034                        return 0;
6035                default:
6036                        if (p->score)
6037                                return 0;
6038                        if (p->one->mode && p->two->mode &&
6039                            p->one->mode != p->two->mode)
6040                                return 0;
6041                        break;
6042                }
6043        }
6044        return 1;
6045}
6046
6047static const char rename_limit_warning[] =
6048N_("inexact rename detection was skipped due to too many files.");
6049
6050static const char degrade_cc_to_c_warning[] =
6051N_("only found copies from modified paths due to too many files.");
6052
6053static const char rename_limit_advice[] =
6054N_("you may want to set your %s variable to at least "
6055   "%d and retry the command.");
6056
6057void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc)
6058{
6059        fflush(stdout);
6060        if (degraded_cc)
6061                warning(_(degrade_cc_to_c_warning));
6062        else if (needed)
6063                warning(_(rename_limit_warning));
6064        else
6065                return;
6066        if (0 < needed)
6067                warning(_(rename_limit_advice), varname, needed);
6068}
6069
6070static void diff_flush_patch_all_file_pairs(struct diff_options *o)
6071{
6072        int i;
6073        static struct emitted_diff_symbols esm = EMITTED_DIFF_SYMBOLS_INIT;
6074        struct diff_queue_struct *q = &diff_queued_diff;
6075
6076        if (WSEH_NEW & WS_RULE_MASK)
6077                BUG("WS rules bit mask overlaps with diff symbol flags");
6078
6079        if (o->color_moved)
6080                o->emitted_symbols = &esm;
6081
6082        for (i = 0; i < q->nr; i++) {
6083                struct diff_filepair *p = q->queue[i];
6084                if (check_pair_status(p))
6085                        diff_flush_patch(p, o);
6086        }
6087
6088        if (o->emitted_symbols) {
6089                if (o->color_moved) {
6090                        struct hashmap add_lines, del_lines;
6091
6092                        if (o->color_moved_ws_handling &
6093                            COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
6094                                o->color_moved_ws_handling |= XDF_IGNORE_WHITESPACE;
6095
6096                        hashmap_init(&del_lines, moved_entry_cmp, o, 0);
6097                        hashmap_init(&add_lines, moved_entry_cmp, o, 0);
6098
6099                        add_lines_to_move_detection(o, &add_lines, &del_lines);
6100                        mark_color_as_moved(o, &add_lines, &del_lines);
6101                        if (o->color_moved == COLOR_MOVED_ZEBRA_DIM)
6102                                dim_moved_lines(o);
6103
6104                        hashmap_free(&add_lines, 1);
6105                        hashmap_free(&del_lines, 1);
6106                }
6107
6108                for (i = 0; i < esm.nr; i++)
6109                        emit_diff_symbol_from_struct(o, &esm.buf[i]);
6110
6111                for (i = 0; i < esm.nr; i++)
6112                        free((void *)esm.buf[i].line);
6113        }
6114        esm.nr = 0;
6115}
6116
6117void diff_flush(struct diff_options *options)
6118{
6119        struct diff_queue_struct *q = &diff_queued_diff;
6120        int i, output_format = options->output_format;
6121        int separator = 0;
6122        int dirstat_by_line = 0;
6123
6124        /*
6125         * Order: raw, stat, summary, patch
6126         * or:    name/name-status/checkdiff (other bits clear)
6127         */
6128        if (!q->nr)
6129                goto free_queue;
6130
6131        if (output_format & (DIFF_FORMAT_RAW |
6132                             DIFF_FORMAT_NAME |
6133                             DIFF_FORMAT_NAME_STATUS |
6134                             DIFF_FORMAT_CHECKDIFF)) {
6135                for (i = 0; i < q->nr; i++) {
6136                        struct diff_filepair *p = q->queue[i];
6137                        if (check_pair_status(p))
6138                                flush_one_pair(p, options);
6139                }
6140                separator++;
6141        }
6142
6143        if (output_format & DIFF_FORMAT_DIRSTAT && options->flags.dirstat_by_line)
6144                dirstat_by_line = 1;
6145
6146        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT) ||
6147            dirstat_by_line) {
6148                struct diffstat_t diffstat;
6149
6150                memset(&diffstat, 0, sizeof(struct diffstat_t));
6151                for (i = 0; i < q->nr; i++) {
6152                        struct diff_filepair *p = q->queue[i];
6153                        if (check_pair_status(p))
6154                                diff_flush_stat(p, options, &diffstat);
6155                }
6156                if (output_format & DIFF_FORMAT_NUMSTAT)
6157                        show_numstat(&diffstat, options);
6158                if (output_format & DIFF_FORMAT_DIFFSTAT)
6159                        show_stats(&diffstat, options);
6160                if (output_format & DIFF_FORMAT_SHORTSTAT)
6161                        show_shortstats(&diffstat, options);
6162                if (output_format & DIFF_FORMAT_DIRSTAT && dirstat_by_line)
6163                        show_dirstat_by_line(&diffstat, options);
6164                free_diffstat_info(&diffstat);
6165                separator++;
6166        }
6167        if ((output_format & DIFF_FORMAT_DIRSTAT) && !dirstat_by_line)
6168                show_dirstat(options);
6169
6170        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
6171                for (i = 0; i < q->nr; i++) {
6172                        diff_summary(options, q->queue[i]);
6173                }
6174                separator++;
6175        }
6176
6177        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
6178            options->flags.exit_with_status &&
6179            options->flags.diff_from_contents) {
6180                /*
6181                 * run diff_flush_patch for the exit status. setting
6182                 * options->file to /dev/null should be safe, because we
6183                 * aren't supposed to produce any output anyway.
6184                 */
6185                if (options->close_file)
6186                        fclose(options->file);
6187                options->file = xfopen("/dev/null", "w");
6188                options->close_file = 1;
6189                options->color_moved = 0;
6190                for (i = 0; i < q->nr; i++) {
6191                        struct diff_filepair *p = q->queue[i];
6192                        if (check_pair_status(p))
6193                                diff_flush_patch(p, options);
6194                        if (options->found_changes)
6195                                break;
6196                }
6197        }
6198
6199        if (output_format & DIFF_FORMAT_PATCH) {
6200                if (separator) {
6201                        emit_diff_symbol(options, DIFF_SYMBOL_SEPARATOR, NULL, 0, 0);
6202                        if (options->stat_sep)
6203                                /* attach patch instead of inline */
6204                                emit_diff_symbol(options, DIFF_SYMBOL_STAT_SEP,
6205                                                 NULL, 0, 0);
6206                }
6207
6208                diff_flush_patch_all_file_pairs(options);
6209        }
6210
6211        if (output_format & DIFF_FORMAT_CALLBACK)
6212                options->format_callback(q, options, options->format_callback_data);
6213
6214        for (i = 0; i < q->nr; i++)
6215                diff_free_filepair(q->queue[i]);
6216free_queue:
6217        free(q->queue);
6218        DIFF_QUEUE_CLEAR(q);
6219        if (options->close_file)
6220                fclose(options->file);
6221
6222        /*
6223         * Report the content-level differences with HAS_CHANGES;
6224         * diff_addremove/diff_change does not set the bit when
6225         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
6226         */
6227        if (options->flags.diff_from_contents) {
6228                if (options->found_changes)
6229                        options->flags.has_changes = 1;
6230                else
6231                        options->flags.has_changes = 0;
6232        }
6233}
6234
6235static int match_filter(const struct diff_options *options, const struct diff_filepair *p)
6236{
6237        return (((p->status == DIFF_STATUS_MODIFIED) &&
6238                 ((p->score &&
6239                   filter_bit_tst(DIFF_STATUS_FILTER_BROKEN, options)) ||
6240                  (!p->score &&
6241                   filter_bit_tst(DIFF_STATUS_MODIFIED, options)))) ||
6242                ((p->status != DIFF_STATUS_MODIFIED) &&
6243                 filter_bit_tst(p->status, options)));
6244}
6245
6246static void diffcore_apply_filter(struct diff_options *options)
6247{
6248        int i;
6249        struct diff_queue_struct *q = &diff_queued_diff;
6250        struct diff_queue_struct outq;
6251
6252        DIFF_QUEUE_CLEAR(&outq);
6253
6254        if (!options->filter)
6255                return;
6256
6257        if (filter_bit_tst(DIFF_STATUS_FILTER_AON, options)) {
6258                int found;
6259                for (i = found = 0; !found && i < q->nr; i++) {
6260                        if (match_filter(options, q->queue[i]))
6261                                found++;
6262                }
6263                if (found)
6264                        return;
6265
6266                /* otherwise we will clear the whole queue
6267                 * by copying the empty outq at the end of this
6268                 * function, but first clear the current entries
6269                 * in the queue.
6270                 */
6271                for (i = 0; i < q->nr; i++)
6272                        diff_free_filepair(q->queue[i]);
6273        }
6274        else {
6275                /* Only the matching ones */
6276                for (i = 0; i < q->nr; i++) {
6277                        struct diff_filepair *p = q->queue[i];
6278                        if (match_filter(options, p))
6279                                diff_q(&outq, p);
6280                        else
6281                                diff_free_filepair(p);
6282                }
6283        }
6284        free(q->queue);
6285        *q = outq;
6286}
6287
6288/* Check whether two filespecs with the same mode and size are identical */
6289static int diff_filespec_is_identical(struct repository *r,
6290                                      struct diff_filespec *one,
6291                                      struct diff_filespec *two)
6292{
6293        if (S_ISGITLINK(one->mode))
6294                return 0;
6295        if (diff_populate_filespec(r, one, 0))
6296                return 0;
6297        if (diff_populate_filespec(r, two, 0))
6298                return 0;
6299        return !memcmp(one->data, two->data, one->size);
6300}
6301
6302static int diff_filespec_check_stat_unmatch(struct repository *r,
6303                                            struct diff_filepair *p)
6304{
6305        if (p->done_skip_stat_unmatch)
6306                return p->skip_stat_unmatch_result;
6307
6308        p->done_skip_stat_unmatch = 1;
6309        p->skip_stat_unmatch_result = 0;
6310        /*
6311         * 1. Entries that come from stat info dirtiness
6312         *    always have both sides (iow, not create/delete),
6313         *    one side of the object name is unknown, with
6314         *    the same mode and size.  Keep the ones that
6315         *    do not match these criteria.  They have real
6316         *    differences.
6317         *
6318         * 2. At this point, the file is known to be modified,
6319         *    with the same mode and size, and the object
6320         *    name of one side is unknown.  Need to inspect
6321         *    the identical contents.
6322         */
6323        if (!DIFF_FILE_VALID(p->one) || /* (1) */
6324            !DIFF_FILE_VALID(p->two) ||
6325            (p->one->oid_valid && p->two->oid_valid) ||
6326            (p->one->mode != p->two->mode) ||
6327            diff_populate_filespec(r, p->one, CHECK_SIZE_ONLY) ||
6328            diff_populate_filespec(r, p->two, CHECK_SIZE_ONLY) ||
6329            (p->one->size != p->two->size) ||
6330            !diff_filespec_is_identical(r, p->one, p->two)) /* (2) */
6331                p->skip_stat_unmatch_result = 1;
6332        return p->skip_stat_unmatch_result;
6333}
6334
6335static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
6336{
6337        int i;
6338        struct diff_queue_struct *q = &diff_queued_diff;
6339        struct diff_queue_struct outq;
6340        DIFF_QUEUE_CLEAR(&outq);
6341
6342        for (i = 0; i < q->nr; i++) {
6343                struct diff_filepair *p = q->queue[i];
6344
6345                if (diff_filespec_check_stat_unmatch(diffopt->repo, p))
6346                        diff_q(&outq, p);
6347                else {
6348                        /*
6349                         * The caller can subtract 1 from skip_stat_unmatch
6350                         * to determine how many paths were dirty only
6351                         * due to stat info mismatch.
6352                         */
6353                        if (!diffopt->flags.no_index)
6354                                diffopt->skip_stat_unmatch++;
6355                        diff_free_filepair(p);
6356                }
6357        }
6358        free(q->queue);
6359        *q = outq;
6360}
6361
6362static int diffnamecmp(const void *a_, const void *b_)
6363{
6364        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
6365        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
6366        const char *name_a, *name_b;
6367
6368        name_a = a->one ? a->one->path : a->two->path;
6369        name_b = b->one ? b->one->path : b->two->path;
6370        return strcmp(name_a, name_b);
6371}
6372
6373void diffcore_fix_diff_index(struct diff_options *options)
6374{
6375        struct diff_queue_struct *q = &diff_queued_diff;
6376        QSORT(q->queue, q->nr, diffnamecmp);
6377}
6378
6379void diffcore_std(struct diff_options *options)
6380{
6381        /* NOTE please keep the following in sync with diff_tree_combined() */
6382        if (options->skip_stat_unmatch)
6383                diffcore_skip_stat_unmatch(options);
6384        if (!options->found_follow) {
6385                /* See try_to_follow_renames() in tree-diff.c */
6386                if (options->break_opt != -1)
6387                        diffcore_break(options->repo,
6388                                       options->break_opt);
6389                if (options->detect_rename)
6390                        diffcore_rename(options);
6391                if (options->break_opt != -1)
6392                        diffcore_merge_broken();
6393        }
6394        if (options->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK)
6395                diffcore_pickaxe(options);
6396        if (options->orderfile)
6397                diffcore_order(options->orderfile);
6398        if (!options->found_follow)
6399                /* See try_to_follow_renames() in tree-diff.c */
6400                diff_resolve_rename_copy();
6401        diffcore_apply_filter(options);
6402
6403        if (diff_queued_diff.nr && !options->flags.diff_from_contents)
6404                options->flags.has_changes = 1;
6405        else
6406                options->flags.has_changes = 0;
6407
6408        options->found_follow = 0;
6409}
6410
6411int diff_result_code(struct diff_options *opt, int status)
6412{
6413        int result = 0;
6414
6415        diff_warn_rename_limit("diff.renameLimit",
6416                               opt->needed_rename_limit,
6417                               opt->degraded_cc_to_c);
6418        if (!opt->flags.exit_with_status &&
6419            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
6420                return status;
6421        if (opt->flags.exit_with_status &&
6422            opt->flags.has_changes)
6423                result |= 01;
6424        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
6425            opt->flags.check_failed)
6426                result |= 02;
6427        return result;
6428}
6429
6430int diff_can_quit_early(struct diff_options *opt)
6431{
6432        return (opt->flags.quick &&
6433                !opt->filter &&
6434                opt->flags.has_changes);
6435}
6436
6437/*
6438 * Shall changes to this submodule be ignored?
6439 *
6440 * Submodule changes can be configured to be ignored separately for each path,
6441 * but that configuration can be overridden from the command line.
6442 */
6443static int is_submodule_ignored(const char *path, struct diff_options *options)
6444{
6445        int ignored = 0;
6446        struct diff_flags orig_flags = options->flags;
6447        if (!options->flags.override_submodule_config)
6448                set_diffopt_flags_from_submodule_config(options, path);
6449        if (options->flags.ignore_submodules)
6450                ignored = 1;
6451        options->flags = orig_flags;
6452        return ignored;
6453}
6454
6455void diff_addremove(struct diff_options *options,
6456                    int addremove, unsigned mode,
6457                    const struct object_id *oid,
6458                    int oid_valid,
6459                    const char *concatpath, unsigned dirty_submodule)
6460{
6461        struct diff_filespec *one, *two;
6462
6463        if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
6464                return;
6465
6466        /* This may look odd, but it is a preparation for
6467         * feeding "there are unchanged files which should
6468         * not produce diffs, but when you are doing copy
6469         * detection you would need them, so here they are"
6470         * entries to the diff-core.  They will be prefixed
6471         * with something like '=' or '*' (I haven't decided
6472         * which but should not make any difference).
6473         * Feeding the same new and old to diff_change()
6474         * also has the same effect.
6475         * Before the final output happens, they are pruned after
6476         * merged into rename/copy pairs as appropriate.
6477         */
6478        if (options->flags.reverse_diff)
6479                addremove = (addremove == '+' ? '-' :
6480                             addremove == '-' ? '+' : addremove);
6481
6482        if (options->prefix &&
6483            strncmp(concatpath, options->prefix, options->prefix_length))
6484                return;
6485
6486        one = alloc_filespec(concatpath);
6487        two = alloc_filespec(concatpath);
6488
6489        if (addremove != '+')
6490                fill_filespec(one, oid, oid_valid, mode);
6491        if (addremove != '-') {
6492                fill_filespec(two, oid, oid_valid, mode);
6493                two->dirty_submodule = dirty_submodule;
6494        }
6495
6496        diff_queue(&diff_queued_diff, one, two);
6497        if (!options->flags.diff_from_contents)
6498                options->flags.has_changes = 1;
6499}
6500
6501void diff_change(struct diff_options *options,
6502                 unsigned old_mode, unsigned new_mode,
6503                 const struct object_id *old_oid,
6504                 const struct object_id *new_oid,
6505                 int old_oid_valid, int new_oid_valid,
6506                 const char *concatpath,
6507                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
6508{
6509        struct diff_filespec *one, *two;
6510        struct diff_filepair *p;
6511
6512        if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
6513            is_submodule_ignored(concatpath, options))
6514                return;
6515
6516        if (options->flags.reverse_diff) {
6517                SWAP(old_mode, new_mode);
6518                SWAP(old_oid, new_oid);
6519                SWAP(old_oid_valid, new_oid_valid);
6520                SWAP(old_dirty_submodule, new_dirty_submodule);
6521        }
6522
6523        if (options->prefix &&
6524            strncmp(concatpath, options->prefix, options->prefix_length))
6525                return;
6526
6527        one = alloc_filespec(concatpath);
6528        two = alloc_filespec(concatpath);
6529        fill_filespec(one, old_oid, old_oid_valid, old_mode);
6530        fill_filespec(two, new_oid, new_oid_valid, new_mode);
6531        one->dirty_submodule = old_dirty_submodule;
6532        two->dirty_submodule = new_dirty_submodule;
6533        p = diff_queue(&diff_queued_diff, one, two);
6534
6535        if (options->flags.diff_from_contents)
6536                return;
6537
6538        if (options->flags.quick && options->skip_stat_unmatch &&
6539            !diff_filespec_check_stat_unmatch(options->repo, p))
6540                return;
6541
6542        options->flags.has_changes = 1;
6543}
6544
6545struct diff_filepair *diff_unmerge(struct diff_options *options, const char *path)
6546{
6547        struct diff_filepair *pair;
6548        struct diff_filespec *one, *two;
6549
6550        if (options->prefix &&
6551            strncmp(path, options->prefix, options->prefix_length))
6552                return NULL;
6553
6554        one = alloc_filespec(path);
6555        two = alloc_filespec(path);
6556        pair = diff_queue(&diff_queued_diff, one, two);
6557        pair->is_unmerged = 1;
6558        return pair;
6559}
6560
6561static char *run_textconv(struct repository *r,
6562                          const char *pgm,
6563                          struct diff_filespec *spec,
6564                          size_t *outsize)
6565{
6566        struct diff_tempfile *temp;
6567        const char *argv[3];
6568        const char **arg = argv;
6569        struct child_process child = CHILD_PROCESS_INIT;
6570        struct strbuf buf = STRBUF_INIT;
6571        int err = 0;
6572
6573        temp = prepare_temp_file(r, spec->path, spec);
6574        *arg++ = pgm;
6575        *arg++ = temp->name;
6576        *arg = NULL;
6577
6578        child.use_shell = 1;
6579        child.argv = argv;
6580        child.out = -1;
6581        if (start_command(&child)) {
6582                remove_tempfile();
6583                return NULL;
6584        }
6585
6586        if (strbuf_read(&buf, child.out, 0) < 0)
6587                err = error("error reading from textconv command '%s'", pgm);
6588        close(child.out);
6589
6590        if (finish_command(&child) || err) {
6591                strbuf_release(&buf);
6592                remove_tempfile();
6593                return NULL;
6594        }
6595        remove_tempfile();
6596
6597        return strbuf_detach(&buf, outsize);
6598}
6599
6600size_t fill_textconv(struct repository *r,
6601                     struct userdiff_driver *driver,
6602                     struct diff_filespec *df,
6603                     char **outbuf)
6604{
6605        size_t size;
6606
6607        if (!driver) {
6608                if (!DIFF_FILE_VALID(df)) {
6609                        *outbuf = "";
6610                        return 0;
6611                }
6612                if (diff_populate_filespec(r, df, 0))
6613                        die("unable to read files to diff");
6614                *outbuf = df->data;
6615                return df->size;
6616        }
6617
6618        if (!driver->textconv)
6619                BUG("fill_textconv called with non-textconv driver");
6620
6621        if (driver->textconv_cache && df->oid_valid) {
6622                *outbuf = notes_cache_get(driver->textconv_cache,
6623                                          &df->oid,
6624                                          &size);
6625                if (*outbuf)
6626                        return size;
6627        }
6628
6629        *outbuf = run_textconv(r, driver->textconv, df, &size);
6630        if (!*outbuf)
6631                die("unable to read files to diff");
6632
6633        if (driver->textconv_cache && df->oid_valid) {
6634                /* ignore errors, as we might be in a readonly repository */
6635                notes_cache_put(driver->textconv_cache, &df->oid, *outbuf,
6636                                size);
6637                /*
6638                 * we could save up changes and flush them all at the end,
6639                 * but we would need an extra call after all diffing is done.
6640                 * Since generating a cache entry is the slow path anyway,
6641                 * this extra overhead probably isn't a big deal.
6642                 */
6643                notes_cache_write(driver->textconv_cache);
6644        }
6645
6646        return size;
6647}
6648
6649int textconv_object(struct repository *r,
6650                    const char *path,
6651                    unsigned mode,
6652                    const struct object_id *oid,
6653                    int oid_valid,
6654                    char **buf,
6655                    unsigned long *buf_size)
6656{
6657        struct diff_filespec *df;
6658        struct userdiff_driver *textconv;
6659
6660        df = alloc_filespec(path);
6661        fill_filespec(df, oid, oid_valid, mode);
6662        textconv = get_textconv(r, df);
6663        if (!textconv) {
6664                free_filespec(df);
6665                return 0;
6666        }
6667
6668        *buf_size = fill_textconv(r, textconv, df, buf);
6669        free_filespec(df);
6670        return 1;
6671}
6672
6673void setup_diff_pager(struct diff_options *opt)
6674{
6675        /*
6676         * If the user asked for our exit code, then either they want --quiet
6677         * or --exit-code. We should definitely not bother with a pager in the
6678         * former case, as we will generate no output. Since we still properly
6679         * report our exit code even when a pager is run, we _could_ run a
6680         * pager with --exit-code. But since we have not done so historically,
6681         * and because it is easy to find people oneline advising "git diff
6682         * --exit-code" in hooks and other scripts, we do not do so.
6683         */
6684        if (!opt->flags.exit_with_status &&
6685            check_pager_config("diff") != 0)
6686                setup_pager();
6687}