diff.con commit commit-graph: fix buffer read-overflow (d2b86fb)
   1/*
   2 * Copyright (C) 2005 Junio C Hamano
   3 */
   4#include "cache.h"
   5#include "config.h"
   6#include "tempfile.h"
   7#include "quote.h"
   8#include "diff.h"
   9#include "diffcore.h"
  10#include "delta.h"
  11#include "xdiff-interface.h"
  12#include "color.h"
  13#include "attr.h"
  14#include "run-command.h"
  15#include "utf8.h"
  16#include "object-store.h"
  17#include "userdiff.h"
  18#include "submodule-config.h"
  19#include "submodule.h"
  20#include "hashmap.h"
  21#include "ll-merge.h"
  22#include "string-list.h"
  23#include "argv-array.h"
  24#include "graph.h"
  25#include "packfile.h"
  26#include "help.h"
  27
  28#ifdef NO_FAST_WORKING_DIRECTORY
  29#define FAST_WORKING_DIRECTORY 0
  30#else
  31#define FAST_WORKING_DIRECTORY 1
  32#endif
  33
  34static int diff_detect_rename_default;
  35static int diff_indent_heuristic = 1;
  36static int diff_rename_limit_default = 400;
  37static int diff_suppress_blank_empty;
  38static int diff_use_color_default = -1;
  39static int diff_color_moved_default;
  40static int diff_color_moved_ws_default;
  41static int diff_context_default = 3;
  42static int diff_interhunk_context_default;
  43static const char *diff_word_regex_cfg;
  44static const char *external_diff_cmd_cfg;
  45static const char *diff_order_file_cfg;
  46int diff_auto_refresh_index = 1;
  47static int diff_mnemonic_prefix;
  48static int diff_no_prefix;
  49static int diff_stat_graph_width;
  50static int diff_dirstat_permille_default = 30;
  51static struct diff_options default_diff_options;
  52static long diff_algorithm;
  53static unsigned ws_error_highlight_default = WSEH_NEW;
  54
  55static char diff_colors[][COLOR_MAXLEN] = {
  56        GIT_COLOR_RESET,
  57        GIT_COLOR_NORMAL,       /* CONTEXT */
  58        GIT_COLOR_BOLD,         /* METAINFO */
  59        GIT_COLOR_CYAN,         /* FRAGINFO */
  60        GIT_COLOR_RED,          /* OLD */
  61        GIT_COLOR_GREEN,        /* NEW */
  62        GIT_COLOR_YELLOW,       /* COMMIT */
  63        GIT_COLOR_BG_RED,       /* WHITESPACE */
  64        GIT_COLOR_NORMAL,       /* FUNCINFO */
  65        GIT_COLOR_BOLD_MAGENTA, /* OLD_MOVED */
  66        GIT_COLOR_BOLD_BLUE,    /* OLD_MOVED ALTERNATIVE */
  67        GIT_COLOR_FAINT,        /* OLD_MOVED_DIM */
  68        GIT_COLOR_FAINT_ITALIC, /* OLD_MOVED_ALTERNATIVE_DIM */
  69        GIT_COLOR_BOLD_CYAN,    /* NEW_MOVED */
  70        GIT_COLOR_BOLD_YELLOW,  /* NEW_MOVED ALTERNATIVE */
  71        GIT_COLOR_FAINT,        /* NEW_MOVED_DIM */
  72        GIT_COLOR_FAINT_ITALIC, /* NEW_MOVED_ALTERNATIVE_DIM */
  73        GIT_COLOR_FAINT,        /* CONTEXT_DIM */
  74        GIT_COLOR_FAINT_RED,    /* OLD_DIM */
  75        GIT_COLOR_FAINT_GREEN,  /* NEW_DIM */
  76        GIT_COLOR_BOLD,         /* CONTEXT_BOLD */
  77        GIT_COLOR_BOLD_RED,     /* OLD_BOLD */
  78        GIT_COLOR_BOLD_GREEN,   /* NEW_BOLD */
  79};
  80
  81static const char *color_diff_slots[] = {
  82        [DIFF_CONTEXT]                = "context",
  83        [DIFF_METAINFO]               = "meta",
  84        [DIFF_FRAGINFO]               = "frag",
  85        [DIFF_FILE_OLD]               = "old",
  86        [DIFF_FILE_NEW]               = "new",
  87        [DIFF_COMMIT]                 = "commit",
  88        [DIFF_WHITESPACE]             = "whitespace",
  89        [DIFF_FUNCINFO]               = "func",
  90        [DIFF_FILE_OLD_MOVED]         = "oldMoved",
  91        [DIFF_FILE_OLD_MOVED_ALT]     = "oldMovedAlternative",
  92        [DIFF_FILE_OLD_MOVED_DIM]     = "oldMovedDimmed",
  93        [DIFF_FILE_OLD_MOVED_ALT_DIM] = "oldMovedAlternativeDimmed",
  94        [DIFF_FILE_NEW_MOVED]         = "newMoved",
  95        [DIFF_FILE_NEW_MOVED_ALT]     = "newMovedAlternative",
  96        [DIFF_FILE_NEW_MOVED_DIM]     = "newMovedDimmed",
  97        [DIFF_FILE_NEW_MOVED_ALT_DIM] = "newMovedAlternativeDimmed",
  98        [DIFF_CONTEXT_DIM]            = "contextDimmed",
  99        [DIFF_FILE_OLD_DIM]           = "oldDimmed",
 100        [DIFF_FILE_NEW_DIM]           = "newDimmed",
 101        [DIFF_CONTEXT_BOLD]           = "contextBold",
 102        [DIFF_FILE_OLD_BOLD]          = "oldBold",
 103        [DIFF_FILE_NEW_BOLD]          = "newBold",
 104};
 105
 106static NORETURN void die_want_option(const char *option_name)
 107{
 108        die(_("option '%s' requires a value"), option_name);
 109}
 110
 111define_list_config_array_extra(color_diff_slots, {"plain"});
 112
 113static int parse_diff_color_slot(const char *var)
 114{
 115        if (!strcasecmp(var, "plain"))
 116                return DIFF_CONTEXT;
 117        return LOOKUP_CONFIG(color_diff_slots, var);
 118}
 119
 120static int parse_dirstat_params(struct diff_options *options, const char *params_string,
 121                                struct strbuf *errmsg)
 122{
 123        char *params_copy = xstrdup(params_string);
 124        struct string_list params = STRING_LIST_INIT_NODUP;
 125        int ret = 0;
 126        int i;
 127
 128        if (*params_copy)
 129                string_list_split_in_place(&params, params_copy, ',', -1);
 130        for (i = 0; i < params.nr; i++) {
 131                const char *p = params.items[i].string;
 132                if (!strcmp(p, "changes")) {
 133                        options->flags.dirstat_by_line = 0;
 134                        options->flags.dirstat_by_file = 0;
 135                } else if (!strcmp(p, "lines")) {
 136                        options->flags.dirstat_by_line = 1;
 137                        options->flags.dirstat_by_file = 0;
 138                } else if (!strcmp(p, "files")) {
 139                        options->flags.dirstat_by_line = 0;
 140                        options->flags.dirstat_by_file = 1;
 141                } else if (!strcmp(p, "noncumulative")) {
 142                        options->flags.dirstat_cumulative = 0;
 143                } else if (!strcmp(p, "cumulative")) {
 144                        options->flags.dirstat_cumulative = 1;
 145                } else if (isdigit(*p)) {
 146                        char *end;
 147                        int permille = strtoul(p, &end, 10) * 10;
 148                        if (*end == '.' && isdigit(*++end)) {
 149                                /* only use first digit */
 150                                permille += *end - '0';
 151                                /* .. and ignore any further digits */
 152                                while (isdigit(*++end))
 153                                        ; /* nothing */
 154                        }
 155                        if (!*end)
 156                                options->dirstat_permille = permille;
 157                        else {
 158                                strbuf_addf(errmsg, _("  Failed to parse dirstat cut-off percentage '%s'\n"),
 159                                            p);
 160                                ret++;
 161                        }
 162                } else {
 163                        strbuf_addf(errmsg, _("  Unknown dirstat parameter '%s'\n"), p);
 164                        ret++;
 165                }
 166
 167        }
 168        string_list_clear(&params, 0);
 169        free(params_copy);
 170        return ret;
 171}
 172
 173static int parse_submodule_params(struct diff_options *options, const char *value)
 174{
 175        if (!strcmp(value, "log"))
 176                options->submodule_format = DIFF_SUBMODULE_LOG;
 177        else if (!strcmp(value, "short"))
 178                options->submodule_format = DIFF_SUBMODULE_SHORT;
 179        else if (!strcmp(value, "diff"))
 180                options->submodule_format = DIFF_SUBMODULE_INLINE_DIFF;
 181        else
 182                return -1;
 183        return 0;
 184}
 185
 186int git_config_rename(const char *var, const char *value)
 187{
 188        if (!value)
 189                return DIFF_DETECT_RENAME;
 190        if (!strcasecmp(value, "copies") || !strcasecmp(value, "copy"))
 191                return  DIFF_DETECT_COPY;
 192        return git_config_bool(var,value) ? DIFF_DETECT_RENAME : 0;
 193}
 194
 195long parse_algorithm_value(const char *value)
 196{
 197        if (!value)
 198                return -1;
 199        else if (!strcasecmp(value, "myers") || !strcasecmp(value, "default"))
 200                return 0;
 201        else if (!strcasecmp(value, "minimal"))
 202                return XDF_NEED_MINIMAL;
 203        else if (!strcasecmp(value, "patience"))
 204                return XDF_PATIENCE_DIFF;
 205        else if (!strcasecmp(value, "histogram"))
 206                return XDF_HISTOGRAM_DIFF;
 207        return -1;
 208}
 209
 210static int parse_one_token(const char **arg, const char *token)
 211{
 212        const char *rest;
 213        if (skip_prefix(*arg, token, &rest) && (!*rest || *rest == ',')) {
 214                *arg = rest;
 215                return 1;
 216        }
 217        return 0;
 218}
 219
 220static int parse_ws_error_highlight(const char *arg)
 221{
 222        const char *orig_arg = arg;
 223        unsigned val = 0;
 224
 225        while (*arg) {
 226                if (parse_one_token(&arg, "none"))
 227                        val = 0;
 228                else if (parse_one_token(&arg, "default"))
 229                        val = WSEH_NEW;
 230                else if (parse_one_token(&arg, "all"))
 231                        val = WSEH_NEW | WSEH_OLD | WSEH_CONTEXT;
 232                else if (parse_one_token(&arg, "new"))
 233                        val |= WSEH_NEW;
 234                else if (parse_one_token(&arg, "old"))
 235                        val |= WSEH_OLD;
 236                else if (parse_one_token(&arg, "context"))
 237                        val |= WSEH_CONTEXT;
 238                else {
 239                        return -1 - (int)(arg - orig_arg);
 240                }
 241                if (*arg)
 242                        arg++;
 243        }
 244        return val;
 245}
 246
 247/*
 248 * These are to give UI layer defaults.
 249 * The core-level commands such as git-diff-files should
 250 * never be affected by the setting of diff.renames
 251 * the user happens to have in the configuration file.
 252 */
 253void init_diff_ui_defaults(void)
 254{
 255        diff_detect_rename_default = DIFF_DETECT_RENAME;
 256}
 257
 258int git_diff_heuristic_config(const char *var, const char *value, void *cb)
 259{
 260        if (!strcmp(var, "diff.indentheuristic"))
 261                diff_indent_heuristic = git_config_bool(var, value);
 262        return 0;
 263}
 264
 265static int parse_color_moved(const char *arg)
 266{
 267        switch (git_parse_maybe_bool(arg)) {
 268        case 0:
 269                return COLOR_MOVED_NO;
 270        case 1:
 271                return COLOR_MOVED_DEFAULT;
 272        default:
 273                break;
 274        }
 275
 276        if (!strcmp(arg, "no"))
 277                return COLOR_MOVED_NO;
 278        else if (!strcmp(arg, "plain"))
 279                return COLOR_MOVED_PLAIN;
 280        else if (!strcmp(arg, "blocks"))
 281                return COLOR_MOVED_BLOCKS;
 282        else if (!strcmp(arg, "zebra"))
 283                return COLOR_MOVED_ZEBRA;
 284        else if (!strcmp(arg, "default"))
 285                return COLOR_MOVED_DEFAULT;
 286        else if (!strcmp(arg, "dimmed-zebra"))
 287                return COLOR_MOVED_ZEBRA_DIM;
 288        else if (!strcmp(arg, "dimmed_zebra"))
 289                return COLOR_MOVED_ZEBRA_DIM;
 290        else
 291                return error(_("color moved setting must be one of 'no', 'default', 'blocks', 'zebra', 'dimmed-zebra', 'plain'"));
 292}
 293
 294static unsigned parse_color_moved_ws(const char *arg)
 295{
 296        int ret = 0;
 297        struct string_list l = STRING_LIST_INIT_DUP;
 298        struct string_list_item *i;
 299
 300        string_list_split(&l, arg, ',', -1);
 301
 302        for_each_string_list_item(i, &l) {
 303                struct strbuf sb = STRBUF_INIT;
 304                strbuf_addstr(&sb, i->string);
 305                strbuf_trim(&sb);
 306
 307                if (!strcmp(sb.buf, "ignore-space-change"))
 308                        ret |= XDF_IGNORE_WHITESPACE_CHANGE;
 309                else if (!strcmp(sb.buf, "ignore-space-at-eol"))
 310                        ret |= XDF_IGNORE_WHITESPACE_AT_EOL;
 311                else if (!strcmp(sb.buf, "ignore-all-space"))
 312                        ret |= XDF_IGNORE_WHITESPACE;
 313                else if (!strcmp(sb.buf, "allow-indentation-change"))
 314                        ret |= COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE;
 315                else {
 316                        ret |= COLOR_MOVED_WS_ERROR;
 317                        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);
 318                }
 319
 320                strbuf_release(&sb);
 321        }
 322
 323        if ((ret & COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE) &&
 324            (ret & XDF_WHITESPACE_FLAGS)) {
 325                error(_("color-moved-ws: allow-indentation-change cannot be combined with other white space modes"));
 326                ret |= COLOR_MOVED_WS_ERROR;
 327        }
 328
 329        string_list_clear(&l, 0);
 330
 331        return ret;
 332}
 333
 334int git_diff_ui_config(const char *var, const char *value, void *cb)
 335{
 336        if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
 337                diff_use_color_default = git_config_colorbool(var, value);
 338                return 0;
 339        }
 340        if (!strcmp(var, "diff.colormoved")) {
 341                int cm = parse_color_moved(value);
 342                if (cm < 0)
 343                        return -1;
 344                diff_color_moved_default = cm;
 345                return 0;
 346        }
 347        if (!strcmp(var, "diff.colormovedws")) {
 348                unsigned cm = parse_color_moved_ws(value);
 349                if (cm & COLOR_MOVED_WS_ERROR)
 350                        return -1;
 351                diff_color_moved_ws_default = cm;
 352                return 0;
 353        }
 354        if (!strcmp(var, "diff.context")) {
 355                diff_context_default = git_config_int(var, value);
 356                if (diff_context_default < 0)
 357                        return -1;
 358                return 0;
 359        }
 360        if (!strcmp(var, "diff.interhunkcontext")) {
 361                diff_interhunk_context_default = git_config_int(var, value);
 362                if (diff_interhunk_context_default < 0)
 363                        return -1;
 364                return 0;
 365        }
 366        if (!strcmp(var, "diff.renames")) {
 367                diff_detect_rename_default = git_config_rename(var, value);
 368                return 0;
 369        }
 370        if (!strcmp(var, "diff.autorefreshindex")) {
 371                diff_auto_refresh_index = git_config_bool(var, value);
 372                return 0;
 373        }
 374        if (!strcmp(var, "diff.mnemonicprefix")) {
 375                diff_mnemonic_prefix = git_config_bool(var, value);
 376                return 0;
 377        }
 378        if (!strcmp(var, "diff.noprefix")) {
 379                diff_no_prefix = git_config_bool(var, value);
 380                return 0;
 381        }
 382        if (!strcmp(var, "diff.statgraphwidth")) {
 383                diff_stat_graph_width = git_config_int(var, value);
 384                return 0;
 385        }
 386        if (!strcmp(var, "diff.external"))
 387                return git_config_string(&external_diff_cmd_cfg, var, value);
 388        if (!strcmp(var, "diff.wordregex"))
 389                return git_config_string(&diff_word_regex_cfg, var, value);
 390        if (!strcmp(var, "diff.orderfile"))
 391                return git_config_pathname(&diff_order_file_cfg, var, value);
 392
 393        if (!strcmp(var, "diff.ignoresubmodules"))
 394                handle_ignore_submodules_arg(&default_diff_options, value);
 395
 396        if (!strcmp(var, "diff.submodule")) {
 397                if (parse_submodule_params(&default_diff_options, value))
 398                        warning(_("Unknown value for 'diff.submodule' config variable: '%s'"),
 399                                value);
 400                return 0;
 401        }
 402
 403        if (!strcmp(var, "diff.algorithm")) {
 404                diff_algorithm = parse_algorithm_value(value);
 405                if (diff_algorithm < 0)
 406                        return -1;
 407                return 0;
 408        }
 409
 410        if (!strcmp(var, "diff.wserrorhighlight")) {
 411                int val = parse_ws_error_highlight(value);
 412                if (val < 0)
 413                        return -1;
 414                ws_error_highlight_default = val;
 415                return 0;
 416        }
 417
 418        if (git_color_config(var, value, cb) < 0)
 419                return -1;
 420
 421        return git_diff_basic_config(var, value, cb);
 422}
 423
 424int git_diff_basic_config(const char *var, const char *value, void *cb)
 425{
 426        const char *name;
 427
 428        if (!strcmp(var, "diff.renamelimit")) {
 429                diff_rename_limit_default = git_config_int(var, value);
 430                return 0;
 431        }
 432
 433        if (userdiff_config(var, value) < 0)
 434                return -1;
 435
 436        if (skip_prefix(var, "diff.color.", &name) ||
 437            skip_prefix(var, "color.diff.", &name)) {
 438                int slot = parse_diff_color_slot(name);
 439                if (slot < 0)
 440                        return 0;
 441                if (!value)
 442                        return config_error_nonbool(var);
 443                return color_parse(value, diff_colors[slot]);
 444        }
 445
 446        /* like GNU diff's --suppress-blank-empty option  */
 447        if (!strcmp(var, "diff.suppressblankempty") ||
 448                        /* for backwards compatibility */
 449                        !strcmp(var, "diff.suppress-blank-empty")) {
 450                diff_suppress_blank_empty = git_config_bool(var, value);
 451                return 0;
 452        }
 453
 454        if (!strcmp(var, "diff.dirstat")) {
 455                struct strbuf errmsg = STRBUF_INIT;
 456                default_diff_options.dirstat_permille = diff_dirstat_permille_default;
 457                if (parse_dirstat_params(&default_diff_options, value, &errmsg))
 458                        warning(_("Found errors in 'diff.dirstat' config variable:\n%s"),
 459                                errmsg.buf);
 460                strbuf_release(&errmsg);
 461                diff_dirstat_permille_default = default_diff_options.dirstat_permille;
 462                return 0;
 463        }
 464
 465        if (git_diff_heuristic_config(var, value, cb) < 0)
 466                return -1;
 467
 468        return git_default_config(var, value, cb);
 469}
 470
 471static char *quote_two(const char *one, const char *two)
 472{
 473        int need_one = quote_c_style(one, NULL, NULL, 1);
 474        int need_two = quote_c_style(two, NULL, NULL, 1);
 475        struct strbuf res = STRBUF_INIT;
 476
 477        if (need_one + need_two) {
 478                strbuf_addch(&res, '"');
 479                quote_c_style(one, &res, NULL, 1);
 480                quote_c_style(two, &res, NULL, 1);
 481                strbuf_addch(&res, '"');
 482        } else {
 483                strbuf_addstr(&res, one);
 484                strbuf_addstr(&res, two);
 485        }
 486        return strbuf_detach(&res, NULL);
 487}
 488
 489static const char *external_diff(void)
 490{
 491        static const char *external_diff_cmd = NULL;
 492        static int done_preparing = 0;
 493
 494        if (done_preparing)
 495                return external_diff_cmd;
 496        external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
 497        if (!external_diff_cmd)
 498                external_diff_cmd = external_diff_cmd_cfg;
 499        done_preparing = 1;
 500        return external_diff_cmd;
 501}
 502
 503/*
 504 * Keep track of files used for diffing. Sometimes such an entry
 505 * refers to a temporary file, sometimes to an existing file, and
 506 * sometimes to "/dev/null".
 507 */
 508static struct diff_tempfile {
 509        /*
 510         * filename external diff should read from, or NULL if this
 511         * entry is currently not in use:
 512         */
 513        const char *name;
 514
 515        char hex[GIT_MAX_HEXSZ + 1];
 516        char mode[10];
 517
 518        /*
 519         * If this diff_tempfile instance refers to a temporary file,
 520         * this tempfile object is used to manage its lifetime.
 521         */
 522        struct tempfile *tempfile;
 523} diff_temp[2];
 524
 525struct emit_callback {
 526        int color_diff;
 527        unsigned ws_rule;
 528        int blank_at_eof_in_preimage;
 529        int blank_at_eof_in_postimage;
 530        int lno_in_preimage;
 531        int lno_in_postimage;
 532        const char **label_path;
 533        struct diff_words_data *diff_words;
 534        struct diff_options *opt;
 535        struct strbuf *header;
 536};
 537
 538static int count_lines(const char *data, int size)
 539{
 540        int count, ch, completely_empty = 1, nl_just_seen = 0;
 541        count = 0;
 542        while (0 < size--) {
 543                ch = *data++;
 544                if (ch == '\n') {
 545                        count++;
 546                        nl_just_seen = 1;
 547                        completely_empty = 0;
 548                }
 549                else {
 550                        nl_just_seen = 0;
 551                        completely_empty = 0;
 552                }
 553        }
 554        if (completely_empty)
 555                return 0;
 556        if (!nl_just_seen)
 557                count++; /* no trailing newline */
 558        return count;
 559}
 560
 561static int fill_mmfile(struct repository *r, mmfile_t *mf,
 562                       struct diff_filespec *one)
 563{
 564        if (!DIFF_FILE_VALID(one)) {
 565                mf->ptr = (char *)""; /* does not matter */
 566                mf->size = 0;
 567                return 0;
 568        }
 569        else if (diff_populate_filespec(r, one, 0))
 570                return -1;
 571
 572        mf->ptr = one->data;
 573        mf->size = one->size;
 574        return 0;
 575}
 576
 577/* like fill_mmfile, but only for size, so we can avoid retrieving blob */
 578static unsigned long diff_filespec_size(struct repository *r,
 579                                        struct diff_filespec *one)
 580{
 581        if (!DIFF_FILE_VALID(one))
 582                return 0;
 583        diff_populate_filespec(r, one, CHECK_SIZE_ONLY);
 584        return one->size;
 585}
 586
 587static int count_trailing_blank(mmfile_t *mf, unsigned ws_rule)
 588{
 589        char *ptr = mf->ptr;
 590        long size = mf->size;
 591        int cnt = 0;
 592
 593        if (!size)
 594                return cnt;
 595        ptr += size - 1; /* pointing at the very end */
 596        if (*ptr != '\n')
 597                ; /* incomplete line */
 598        else
 599                ptr--; /* skip the last LF */
 600        while (mf->ptr < ptr) {
 601                char *prev_eol;
 602                for (prev_eol = ptr; mf->ptr <= prev_eol; prev_eol--)
 603                        if (*prev_eol == '\n')
 604                                break;
 605                if (!ws_blank_line(prev_eol + 1, ptr - prev_eol, ws_rule))
 606                        break;
 607                cnt++;
 608                ptr = prev_eol - 1;
 609        }
 610        return cnt;
 611}
 612
 613static void check_blank_at_eof(mmfile_t *mf1, mmfile_t *mf2,
 614                               struct emit_callback *ecbdata)
 615{
 616        int l1, l2, at;
 617        unsigned ws_rule = ecbdata->ws_rule;
 618        l1 = count_trailing_blank(mf1, ws_rule);
 619        l2 = count_trailing_blank(mf2, ws_rule);
 620        if (l2 <= l1) {
 621                ecbdata->blank_at_eof_in_preimage = 0;
 622                ecbdata->blank_at_eof_in_postimage = 0;
 623                return;
 624        }
 625        at = count_lines(mf1->ptr, mf1->size);
 626        ecbdata->blank_at_eof_in_preimage = (at - l1) + 1;
 627
 628        at = count_lines(mf2->ptr, mf2->size);
 629        ecbdata->blank_at_eof_in_postimage = (at - l2) + 1;
 630}
 631
 632static void emit_line_0(struct diff_options *o,
 633                        const char *set_sign, const char *set, unsigned reverse, const char *reset,
 634                        int first, const char *line, int len)
 635{
 636        int has_trailing_newline, has_trailing_carriage_return;
 637        int needs_reset = 0; /* at the end of the line */
 638        FILE *file = o->file;
 639
 640        fputs(diff_line_prefix(o), file);
 641
 642        has_trailing_newline = (len > 0 && line[len-1] == '\n');
 643        if (has_trailing_newline)
 644                len--;
 645
 646        has_trailing_carriage_return = (len > 0 && line[len-1] == '\r');
 647        if (has_trailing_carriage_return)
 648                len--;
 649
 650        if (!len && !first)
 651                goto end_of_line;
 652
 653        if (reverse && want_color(o->use_color)) {
 654                fputs(GIT_COLOR_REVERSE, file);
 655                needs_reset = 1;
 656        }
 657
 658        if (set_sign) {
 659                fputs(set_sign, file);
 660                needs_reset = 1;
 661        }
 662
 663        if (first)
 664                fputc(first, file);
 665
 666        if (!len)
 667                goto end_of_line;
 668
 669        if (set) {
 670                if (set_sign && set != set_sign)
 671                        fputs(reset, file);
 672                fputs(set, file);
 673                needs_reset = 1;
 674        }
 675        fwrite(line, len, 1, file);
 676        needs_reset = 1; /* 'line' may contain color codes. */
 677
 678end_of_line:
 679        if (needs_reset)
 680                fputs(reset, file);
 681        if (has_trailing_carriage_return)
 682                fputc('\r', file);
 683        if (has_trailing_newline)
 684                fputc('\n', file);
 685}
 686
 687static void emit_line(struct diff_options *o, const char *set, const char *reset,
 688                      const char *line, int len)
 689{
 690        emit_line_0(o, set, NULL, 0, reset, 0, line, len);
 691}
 692
 693enum diff_symbol {
 694        DIFF_SYMBOL_BINARY_DIFF_HEADER,
 695        DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA,
 696        DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL,
 697        DIFF_SYMBOL_BINARY_DIFF_BODY,
 698        DIFF_SYMBOL_BINARY_DIFF_FOOTER,
 699        DIFF_SYMBOL_STATS_SUMMARY_NO_FILES,
 700        DIFF_SYMBOL_STATS_SUMMARY_ABBREV,
 701        DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES,
 702        DIFF_SYMBOL_STATS_LINE,
 703        DIFF_SYMBOL_WORD_DIFF,
 704        DIFF_SYMBOL_STAT_SEP,
 705        DIFF_SYMBOL_SUMMARY,
 706        DIFF_SYMBOL_SUBMODULE_ADD,
 707        DIFF_SYMBOL_SUBMODULE_DEL,
 708        DIFF_SYMBOL_SUBMODULE_UNTRACKED,
 709        DIFF_SYMBOL_SUBMODULE_MODIFIED,
 710        DIFF_SYMBOL_SUBMODULE_HEADER,
 711        DIFF_SYMBOL_SUBMODULE_ERROR,
 712        DIFF_SYMBOL_SUBMODULE_PIPETHROUGH,
 713        DIFF_SYMBOL_REWRITE_DIFF,
 714        DIFF_SYMBOL_BINARY_FILES,
 715        DIFF_SYMBOL_HEADER,
 716        DIFF_SYMBOL_FILEPAIR_PLUS,
 717        DIFF_SYMBOL_FILEPAIR_MINUS,
 718        DIFF_SYMBOL_WORDS_PORCELAIN,
 719        DIFF_SYMBOL_WORDS,
 720        DIFF_SYMBOL_CONTEXT,
 721        DIFF_SYMBOL_CONTEXT_INCOMPLETE,
 722        DIFF_SYMBOL_PLUS,
 723        DIFF_SYMBOL_MINUS,
 724        DIFF_SYMBOL_NO_LF_EOF,
 725        DIFF_SYMBOL_CONTEXT_FRAGINFO,
 726        DIFF_SYMBOL_CONTEXT_MARKER,
 727        DIFF_SYMBOL_SEPARATOR
 728};
 729/*
 730 * Flags for content lines:
 731 * 0..12 are whitespace rules
 732 * 13-15 are WSEH_NEW | WSEH_OLD | WSEH_CONTEXT
 733 * 16 is marking if the line is blank at EOF
 734 */
 735#define DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF      (1<<16)
 736#define DIFF_SYMBOL_MOVED_LINE                  (1<<17)
 737#define DIFF_SYMBOL_MOVED_LINE_ALT              (1<<18)
 738#define DIFF_SYMBOL_MOVED_LINE_UNINTERESTING    (1<<19)
 739#define DIFF_SYMBOL_CONTENT_WS_MASK (WSEH_NEW | WSEH_OLD | WSEH_CONTEXT | WS_RULE_MASK)
 740
 741/*
 742 * This struct is used when we need to buffer the output of the diff output.
 743 *
 744 * NEEDSWORK: Instead of storing a copy of the line, add an offset pointer
 745 * into the pre/post image file. This pointer could be a union with the
 746 * line pointer. By storing an offset into the file instead of the literal line,
 747 * we can decrease the memory footprint for the buffered output. At first we
 748 * may want to only have indirection for the content lines, but we could also
 749 * enhance the state for emitting prefabricated lines, e.g. the similarity
 750 * score line or hunk/file headers would only need to store a number or path
 751 * and then the output can be constructed later on depending on state.
 752 */
 753struct emitted_diff_symbol {
 754        const char *line;
 755        int len;
 756        int flags;
 757        enum diff_symbol s;
 758};
 759#define EMITTED_DIFF_SYMBOL_INIT {NULL}
 760
 761struct emitted_diff_symbols {
 762        struct emitted_diff_symbol *buf;
 763        int nr, alloc;
 764};
 765#define EMITTED_DIFF_SYMBOLS_INIT {NULL, 0, 0}
 766
 767static void append_emitted_diff_symbol(struct diff_options *o,
 768                                       struct emitted_diff_symbol *e)
 769{
 770        struct emitted_diff_symbol *f;
 771
 772        ALLOC_GROW(o->emitted_symbols->buf,
 773                   o->emitted_symbols->nr + 1,
 774                   o->emitted_symbols->alloc);
 775        f = &o->emitted_symbols->buf[o->emitted_symbols->nr++];
 776
 777        memcpy(f, e, sizeof(struct emitted_diff_symbol));
 778        f->line = e->line ? xmemdupz(e->line, e->len) : NULL;
 779}
 780
 781struct moved_entry {
 782        struct hashmap_entry ent;
 783        const struct emitted_diff_symbol *es;
 784        struct moved_entry *next_line;
 785};
 786
 787/**
 788 * The struct ws_delta holds white space differences between moved lines, i.e.
 789 * between '+' and '-' lines that have been detected to be a move.
 790 * The string contains the difference in leading white spaces, before the
 791 * rest of the line is compared using the white space config for move
 792 * coloring. The current_longer indicates if the first string in the
 793 * comparision is longer than the second.
 794 */
 795struct ws_delta {
 796        char *string;
 797        unsigned int current_longer : 1;
 798};
 799#define WS_DELTA_INIT { NULL, 0 }
 800
 801struct moved_block {
 802        struct moved_entry *match;
 803        struct ws_delta wsd;
 804};
 805
 806static void moved_block_clear(struct moved_block *b)
 807{
 808        FREE_AND_NULL(b->wsd.string);
 809        b->match = NULL;
 810}
 811
 812static int compute_ws_delta(const struct emitted_diff_symbol *a,
 813                             const struct emitted_diff_symbol *b,
 814                             struct ws_delta *out)
 815{
 816        const struct emitted_diff_symbol *longer =  a->len > b->len ? a : b;
 817        const struct emitted_diff_symbol *shorter = a->len > b->len ? b : a;
 818        int d = longer->len - shorter->len;
 819
 820        if (strncmp(longer->line + d, shorter->line, shorter->len))
 821                return 0;
 822
 823        out->string = xmemdupz(longer->line, d);
 824        out->current_longer = (a == longer);
 825
 826        return 1;
 827}
 828
 829static int cmp_in_block_with_wsd(const struct diff_options *o,
 830                                 const struct moved_entry *cur,
 831                                 const struct moved_entry *match,
 832                                 struct moved_block *pmb,
 833                                 int n)
 834{
 835        struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
 836        int al = cur->es->len, cl = l->len;
 837        const char *a = cur->es->line,
 838                   *b = match->es->line,
 839                   *c = l->line;
 840
 841        int wslen;
 842
 843        /*
 844         * We need to check if 'cur' is equal to 'match'.
 845         * As those are from the same (+/-) side, we do not need to adjust for
 846         * indent changes. However these were found using fuzzy matching
 847         * so we do have to check if they are equal.
 848         */
 849        if (strcmp(a, b))
 850                return 1;
 851
 852        if (!pmb->wsd.string)
 853                /*
 854                 * The white space delta is not active? This can happen
 855                 * when we exit early in this function.
 856                 */
 857                return 1;
 858
 859        /*
 860         * The indent changes of the block are known and stored in
 861         * pmb->wsd; however we need to check if the indent changes of the
 862         * current line are still the same as before.
 863         *
 864         * To do so we need to compare 'l' to 'cur', adjusting the
 865         * one of them for the white spaces, depending which was longer.
 866         */
 867
 868        wslen = strlen(pmb->wsd.string);
 869        if (pmb->wsd.current_longer) {
 870                c += wslen;
 871                cl -= wslen;
 872        } else {
 873                a += wslen;
 874                al -= wslen;
 875        }
 876
 877        if (al != cl || memcmp(a, c, al))
 878                return 1;
 879
 880        return 0;
 881}
 882
 883static int moved_entry_cmp(const void *hashmap_cmp_fn_data,
 884                           const void *entry,
 885                           const void *entry_or_key,
 886                           const void *keydata)
 887{
 888        const struct diff_options *diffopt = hashmap_cmp_fn_data;
 889        const struct moved_entry *a = entry;
 890        const struct moved_entry *b = entry_or_key;
 891        unsigned flags = diffopt->color_moved_ws_handling
 892                         & XDF_WHITESPACE_FLAGS;
 893
 894        if (diffopt->color_moved_ws_handling &
 895            COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
 896                /*
 897                 * As there is not specific white space config given,
 898                 * we'd need to check for a new block, so ignore all
 899                 * white space. The setup of the white space
 900                 * configuration for the next block is done else where
 901                 */
 902                flags |= XDF_IGNORE_WHITESPACE;
 903
 904        return !xdiff_compare_lines(a->es->line, a->es->len,
 905                                    b->es->line, b->es->len,
 906                                    flags);
 907}
 908
 909static struct moved_entry *prepare_entry(struct diff_options *o,
 910                                         int line_no)
 911{
 912        struct moved_entry *ret = xmalloc(sizeof(*ret));
 913        struct emitted_diff_symbol *l = &o->emitted_symbols->buf[line_no];
 914        unsigned flags = o->color_moved_ws_handling & XDF_WHITESPACE_FLAGS;
 915
 916        ret->ent.hash = xdiff_hash_string(l->line, l->len, flags);
 917        ret->es = l;
 918        ret->next_line = NULL;
 919
 920        return ret;
 921}
 922
 923static void add_lines_to_move_detection(struct diff_options *o,
 924                                        struct hashmap *add_lines,
 925                                        struct hashmap *del_lines)
 926{
 927        struct moved_entry *prev_line = NULL;
 928
 929        int n;
 930        for (n = 0; n < o->emitted_symbols->nr; n++) {
 931                struct hashmap *hm;
 932                struct moved_entry *key;
 933
 934                switch (o->emitted_symbols->buf[n].s) {
 935                case DIFF_SYMBOL_PLUS:
 936                        hm = add_lines;
 937                        break;
 938                case DIFF_SYMBOL_MINUS:
 939                        hm = del_lines;
 940                        break;
 941                default:
 942                        prev_line = NULL;
 943                        continue;
 944                }
 945
 946                key = prepare_entry(o, n);
 947                if (prev_line && prev_line->es->s == o->emitted_symbols->buf[n].s)
 948                        prev_line->next_line = key;
 949
 950                hashmap_add(hm, key);
 951                prev_line = key;
 952        }
 953}
 954
 955static void pmb_advance_or_null(struct diff_options *o,
 956                                struct moved_entry *match,
 957                                struct hashmap *hm,
 958                                struct moved_block *pmb,
 959                                int pmb_nr)
 960{
 961        int i;
 962        for (i = 0; i < pmb_nr; i++) {
 963                struct moved_entry *prev = pmb[i].match;
 964                struct moved_entry *cur = (prev && prev->next_line) ?
 965                                prev->next_line : NULL;
 966                if (cur && !hm->cmpfn(o, cur, match, NULL)) {
 967                        pmb[i].match = cur;
 968                } else {
 969                        pmb[i].match = NULL;
 970                }
 971        }
 972}
 973
 974static void pmb_advance_or_null_multi_match(struct diff_options *o,
 975                                            struct moved_entry *match,
 976                                            struct hashmap *hm,
 977                                            struct moved_block *pmb,
 978                                            int pmb_nr, int n)
 979{
 980        int i;
 981        char *got_match = xcalloc(1, pmb_nr);
 982
 983        for (; match; match = hashmap_get_next(hm, match)) {
 984                for (i = 0; i < pmb_nr; i++) {
 985                        struct moved_entry *prev = pmb[i].match;
 986                        struct moved_entry *cur = (prev && prev->next_line) ?
 987                                        prev->next_line : NULL;
 988                        if (!cur)
 989                                continue;
 990                        if (!cmp_in_block_with_wsd(o, cur, match, &pmb[i], n))
 991                                got_match[i] |= 1;
 992                }
 993        }
 994
 995        for (i = 0; i < pmb_nr; i++) {
 996                if (got_match[i]) {
 997                        /* Advance to the next line */
 998                        pmb[i].match = pmb[i].match->next_line;
 999                } else {
1000                        moved_block_clear(&pmb[i]);
1001                }
1002        }
1003
1004        free(got_match);
1005}
1006
1007static int shrink_potential_moved_blocks(struct moved_block *pmb,
1008                                         int pmb_nr)
1009{
1010        int lp, rp;
1011
1012        /* Shrink the set of potential block to the remaining running */
1013        for (lp = 0, rp = pmb_nr - 1; lp <= rp;) {
1014                while (lp < pmb_nr && pmb[lp].match)
1015                        lp++;
1016                /* lp points at the first NULL now */
1017
1018                while (rp > -1 && !pmb[rp].match)
1019                        rp--;
1020                /* rp points at the last non-NULL */
1021
1022                if (lp < pmb_nr && rp > -1 && lp < rp) {
1023                        pmb[lp] = pmb[rp];
1024                        pmb[rp].match = NULL;
1025                        pmb[rp].wsd.string = NULL;
1026                        rp--;
1027                        lp++;
1028                }
1029        }
1030
1031        /* Remember the number of running sets */
1032        return rp + 1;
1033}
1034
1035/*
1036 * If o->color_moved is COLOR_MOVED_PLAIN, this function does nothing.
1037 *
1038 * Otherwise, if the last block has fewer alphanumeric characters than
1039 * COLOR_MOVED_MIN_ALNUM_COUNT, unset DIFF_SYMBOL_MOVED_LINE on all lines in
1040 * that block.
1041 *
1042 * The last block consists of the (n - block_length)'th line up to but not
1043 * including the nth line.
1044 *
1045 * NEEDSWORK: This uses the same heuristic as blame_entry_score() in blame.c.
1046 * Think of a way to unify them.
1047 */
1048static void adjust_last_block(struct diff_options *o, int n, int block_length)
1049{
1050        int i, alnum_count = 0;
1051        if (o->color_moved == COLOR_MOVED_PLAIN)
1052                return;
1053        for (i = 1; i < block_length + 1; i++) {
1054                const char *c = o->emitted_symbols->buf[n - i].line;
1055                for (; *c; c++) {
1056                        if (!isalnum(*c))
1057                                continue;
1058                        alnum_count++;
1059                        if (alnum_count >= COLOR_MOVED_MIN_ALNUM_COUNT)
1060                                return;
1061                }
1062        }
1063        for (i = 1; i < block_length + 1; i++)
1064                o->emitted_symbols->buf[n - i].flags &= ~DIFF_SYMBOL_MOVED_LINE;
1065}
1066
1067/* Find blocks of moved code, delegate actual coloring decision to helper */
1068static void mark_color_as_moved(struct diff_options *o,
1069                                struct hashmap *add_lines,
1070                                struct hashmap *del_lines)
1071{
1072        struct moved_block *pmb = NULL; /* potentially moved blocks */
1073        int pmb_nr = 0, pmb_alloc = 0;
1074        int n, flipped_block = 1, block_length = 0;
1075
1076
1077        for (n = 0; n < o->emitted_symbols->nr; n++) {
1078                struct hashmap *hm = NULL;
1079                struct moved_entry *key;
1080                struct moved_entry *match = NULL;
1081                struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
1082
1083                switch (l->s) {
1084                case DIFF_SYMBOL_PLUS:
1085                        hm = del_lines;
1086                        key = prepare_entry(o, n);
1087                        match = hashmap_get(hm, key, NULL);
1088                        free(key);
1089                        break;
1090                case DIFF_SYMBOL_MINUS:
1091                        hm = add_lines;
1092                        key = prepare_entry(o, n);
1093                        match = hashmap_get(hm, key, NULL);
1094                        free(key);
1095                        break;
1096                default:
1097                        flipped_block = 1;
1098                }
1099
1100                if (!match) {
1101                        int i;
1102
1103                        adjust_last_block(o, n, block_length);
1104                        for(i = 0; i < pmb_nr; i++)
1105                                moved_block_clear(&pmb[i]);
1106                        pmb_nr = 0;
1107                        block_length = 0;
1108                        continue;
1109                }
1110
1111                l->flags |= DIFF_SYMBOL_MOVED_LINE;
1112
1113                if (o->color_moved == COLOR_MOVED_PLAIN)
1114                        continue;
1115
1116                if (o->color_moved_ws_handling &
1117                    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
1118                        pmb_advance_or_null_multi_match(o, match, hm, pmb, pmb_nr, n);
1119                else
1120                        pmb_advance_or_null(o, match, hm, pmb, pmb_nr);
1121
1122                pmb_nr = shrink_potential_moved_blocks(pmb, pmb_nr);
1123
1124                if (pmb_nr == 0) {
1125                        /*
1126                         * The current line is the start of a new block.
1127                         * Setup the set of potential blocks.
1128                         */
1129                        for (; match; match = hashmap_get_next(hm, match)) {
1130                                ALLOC_GROW(pmb, pmb_nr + 1, pmb_alloc);
1131                                if (o->color_moved_ws_handling &
1132                                    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE) {
1133                                        if (compute_ws_delta(l, match->es,
1134                                                             &pmb[pmb_nr].wsd))
1135                                                pmb[pmb_nr++].match = match;
1136                                } else {
1137                                        pmb[pmb_nr].wsd.string = NULL;
1138                                        pmb[pmb_nr++].match = match;
1139                                }
1140                        }
1141
1142                        flipped_block = (flipped_block + 1) % 2;
1143
1144                        adjust_last_block(o, n, block_length);
1145                        block_length = 0;
1146                }
1147
1148                block_length++;
1149
1150                if (flipped_block && o->color_moved != COLOR_MOVED_BLOCKS)
1151                        l->flags |= DIFF_SYMBOL_MOVED_LINE_ALT;
1152        }
1153        adjust_last_block(o, n, block_length);
1154
1155        for(n = 0; n < pmb_nr; n++)
1156                moved_block_clear(&pmb[n]);
1157        free(pmb);
1158}
1159
1160#define DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK \
1161  (DIFF_SYMBOL_MOVED_LINE | DIFF_SYMBOL_MOVED_LINE_ALT)
1162static void dim_moved_lines(struct diff_options *o)
1163{
1164        int n;
1165        for (n = 0; n < o->emitted_symbols->nr; n++) {
1166                struct emitted_diff_symbol *prev = (n != 0) ?
1167                                &o->emitted_symbols->buf[n - 1] : NULL;
1168                struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
1169                struct emitted_diff_symbol *next =
1170                                (n < o->emitted_symbols->nr - 1) ?
1171                                &o->emitted_symbols->buf[n + 1] : NULL;
1172
1173                /* Not a plus or minus line? */
1174                if (l->s != DIFF_SYMBOL_PLUS && l->s != DIFF_SYMBOL_MINUS)
1175                        continue;
1176
1177                /* Not a moved line? */
1178                if (!(l->flags & DIFF_SYMBOL_MOVED_LINE))
1179                        continue;
1180
1181                /*
1182                 * If prev or next are not a plus or minus line,
1183                 * pretend they don't exist
1184                 */
1185                if (prev && prev->s != DIFF_SYMBOL_PLUS &&
1186                            prev->s != DIFF_SYMBOL_MINUS)
1187                        prev = NULL;
1188                if (next && next->s != DIFF_SYMBOL_PLUS &&
1189                            next->s != DIFF_SYMBOL_MINUS)
1190                        next = NULL;
1191
1192                /* Inside a block? */
1193                if ((prev &&
1194                    (prev->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK) ==
1195                    (l->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK)) &&
1196                    (next &&
1197                    (next->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK) ==
1198                    (l->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK))) {
1199                        l->flags |= DIFF_SYMBOL_MOVED_LINE_UNINTERESTING;
1200                        continue;
1201                }
1202
1203                /* Check if we are at an interesting bound: */
1204                if (prev && (prev->flags & DIFF_SYMBOL_MOVED_LINE) &&
1205                    (prev->flags & DIFF_SYMBOL_MOVED_LINE_ALT) !=
1206                       (l->flags & DIFF_SYMBOL_MOVED_LINE_ALT))
1207                        continue;
1208                if (next && (next->flags & DIFF_SYMBOL_MOVED_LINE) &&
1209                    (next->flags & DIFF_SYMBOL_MOVED_LINE_ALT) !=
1210                       (l->flags & DIFF_SYMBOL_MOVED_LINE_ALT))
1211                        continue;
1212
1213                /*
1214                 * The boundary to prev and next are not interesting,
1215                 * so this line is not interesting as a whole
1216                 */
1217                l->flags |= DIFF_SYMBOL_MOVED_LINE_UNINTERESTING;
1218        }
1219}
1220
1221static void emit_line_ws_markup(struct diff_options *o,
1222                                const char *set_sign, const char *set,
1223                                const char *reset,
1224                                int sign_index, const char *line, int len,
1225                                unsigned ws_rule, int blank_at_eof)
1226{
1227        const char *ws = NULL;
1228        int sign = o->output_indicators[sign_index];
1229
1230        if (o->ws_error_highlight & ws_rule) {
1231                ws = diff_get_color_opt(o, DIFF_WHITESPACE);
1232                if (!*ws)
1233                        ws = NULL;
1234        }
1235
1236        if (!ws && !set_sign)
1237                emit_line_0(o, set, NULL, 0, reset, sign, line, len);
1238        else if (!ws) {
1239                emit_line_0(o, set_sign, set, !!set_sign, reset, sign, line, len);
1240        } else if (blank_at_eof)
1241                /* Blank line at EOF - paint '+' as well */
1242                emit_line_0(o, ws, NULL, 0, reset, sign, line, len);
1243        else {
1244                /* Emit just the prefix, then the rest. */
1245                emit_line_0(o, set_sign ? set_sign : set, NULL, !!set_sign, reset,
1246                            sign, "", 0);
1247                ws_check_emit(line, len, ws_rule,
1248                              o->file, set, reset, ws);
1249        }
1250}
1251
1252static void emit_diff_symbol_from_struct(struct diff_options *o,
1253                                         struct emitted_diff_symbol *eds)
1254{
1255        static const char *nneof = " No newline at end of file\n";
1256        const char *context, *reset, *set, *set_sign, *meta, *fraginfo;
1257        struct strbuf sb = STRBUF_INIT;
1258
1259        enum diff_symbol s = eds->s;
1260        const char *line = eds->line;
1261        int len = eds->len;
1262        unsigned flags = eds->flags;
1263
1264        switch (s) {
1265        case DIFF_SYMBOL_NO_LF_EOF:
1266                context = diff_get_color_opt(o, DIFF_CONTEXT);
1267                reset = diff_get_color_opt(o, DIFF_RESET);
1268                putc('\n', o->file);
1269                emit_line_0(o, context, NULL, 0, reset, '\\',
1270                            nneof, strlen(nneof));
1271                break;
1272        case DIFF_SYMBOL_SUBMODULE_HEADER:
1273        case DIFF_SYMBOL_SUBMODULE_ERROR:
1274        case DIFF_SYMBOL_SUBMODULE_PIPETHROUGH:
1275        case DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES:
1276        case DIFF_SYMBOL_SUMMARY:
1277        case DIFF_SYMBOL_STATS_LINE:
1278        case DIFF_SYMBOL_BINARY_DIFF_BODY:
1279        case DIFF_SYMBOL_CONTEXT_FRAGINFO:
1280                emit_line(o, "", "", line, len);
1281                break;
1282        case DIFF_SYMBOL_CONTEXT_INCOMPLETE:
1283        case DIFF_SYMBOL_CONTEXT_MARKER:
1284                context = diff_get_color_opt(o, DIFF_CONTEXT);
1285                reset = diff_get_color_opt(o, DIFF_RESET);
1286                emit_line(o, context, reset, line, len);
1287                break;
1288        case DIFF_SYMBOL_SEPARATOR:
1289                fprintf(o->file, "%s%c",
1290                        diff_line_prefix(o),
1291                        o->line_termination);
1292                break;
1293        case DIFF_SYMBOL_CONTEXT:
1294                set = diff_get_color_opt(o, DIFF_CONTEXT);
1295                reset = diff_get_color_opt(o, DIFF_RESET);
1296                set_sign = NULL;
1297                if (o->flags.dual_color_diffed_diffs) {
1298                        char c = !len ? 0 : line[0];
1299
1300                        if (c == '+')
1301                                set = diff_get_color_opt(o, DIFF_FILE_NEW);
1302                        else if (c == '@')
1303                                set = diff_get_color_opt(o, DIFF_FRAGINFO);
1304                        else if (c == '-')
1305                                set = diff_get_color_opt(o, DIFF_FILE_OLD);
1306                }
1307                emit_line_ws_markup(o, set_sign, set, reset,
1308                                    OUTPUT_INDICATOR_CONTEXT, line, len,
1309                                    flags & (DIFF_SYMBOL_CONTENT_WS_MASK), 0);
1310                break;
1311        case DIFF_SYMBOL_PLUS:
1312                switch (flags & (DIFF_SYMBOL_MOVED_LINE |
1313                                 DIFF_SYMBOL_MOVED_LINE_ALT |
1314                                 DIFF_SYMBOL_MOVED_LINE_UNINTERESTING)) {
1315                case DIFF_SYMBOL_MOVED_LINE |
1316                     DIFF_SYMBOL_MOVED_LINE_ALT |
1317                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1318                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED_ALT_DIM);
1319                        break;
1320                case DIFF_SYMBOL_MOVED_LINE |
1321                     DIFF_SYMBOL_MOVED_LINE_ALT:
1322                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED_ALT);
1323                        break;
1324                case DIFF_SYMBOL_MOVED_LINE |
1325                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1326                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED_DIM);
1327                        break;
1328                case DIFF_SYMBOL_MOVED_LINE:
1329                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED);
1330                        break;
1331                default:
1332                        set = diff_get_color_opt(o, DIFF_FILE_NEW);
1333                }
1334                reset = diff_get_color_opt(o, DIFF_RESET);
1335                if (!o->flags.dual_color_diffed_diffs)
1336                        set_sign = NULL;
1337                else {
1338                        char c = !len ? 0 : line[0];
1339
1340                        set_sign = set;
1341                        if (c == '-')
1342                                set = diff_get_color_opt(o, DIFF_FILE_OLD_BOLD);
1343                        else if (c == '@')
1344                                set = diff_get_color_opt(o, DIFF_FRAGINFO);
1345                        else if (c == '+')
1346                                set = diff_get_color_opt(o, DIFF_FILE_NEW_BOLD);
1347                        else
1348                                set = diff_get_color_opt(o, DIFF_CONTEXT_BOLD);
1349                        flags &= ~DIFF_SYMBOL_CONTENT_WS_MASK;
1350                }
1351                emit_line_ws_markup(o, set_sign, set, reset,
1352                                    OUTPUT_INDICATOR_NEW, line, len,
1353                                    flags & DIFF_SYMBOL_CONTENT_WS_MASK,
1354                                    flags & DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF);
1355                break;
1356        case DIFF_SYMBOL_MINUS:
1357                switch (flags & (DIFF_SYMBOL_MOVED_LINE |
1358                                 DIFF_SYMBOL_MOVED_LINE_ALT |
1359                                 DIFF_SYMBOL_MOVED_LINE_UNINTERESTING)) {
1360                case DIFF_SYMBOL_MOVED_LINE |
1361                     DIFF_SYMBOL_MOVED_LINE_ALT |
1362                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1363                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_ALT_DIM);
1364                        break;
1365                case DIFF_SYMBOL_MOVED_LINE |
1366                     DIFF_SYMBOL_MOVED_LINE_ALT:
1367                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_ALT);
1368                        break;
1369                case DIFF_SYMBOL_MOVED_LINE |
1370                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1371                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_DIM);
1372                        break;
1373                case DIFF_SYMBOL_MOVED_LINE:
1374                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED);
1375                        break;
1376                default:
1377                        set = diff_get_color_opt(o, DIFF_FILE_OLD);
1378                }
1379                reset = diff_get_color_opt(o, DIFF_RESET);
1380                if (!o->flags.dual_color_diffed_diffs)
1381                        set_sign = NULL;
1382                else {
1383                        char c = !len ? 0 : line[0];
1384
1385                        set_sign = set;
1386                        if (c == '+')
1387                                set = diff_get_color_opt(o, DIFF_FILE_NEW_DIM);
1388                        else if (c == '@')
1389                                set = diff_get_color_opt(o, DIFF_FRAGINFO);
1390                        else if (c == '-')
1391                                set = diff_get_color_opt(o, DIFF_FILE_OLD_DIM);
1392                        else
1393                                set = diff_get_color_opt(o, DIFF_CONTEXT_DIM);
1394                }
1395                emit_line_ws_markup(o, set_sign, set, reset,
1396                                    OUTPUT_INDICATOR_OLD, line, len,
1397                                    flags & DIFF_SYMBOL_CONTENT_WS_MASK, 0);
1398                break;
1399        case DIFF_SYMBOL_WORDS_PORCELAIN:
1400                context = diff_get_color_opt(o, DIFF_CONTEXT);
1401                reset = diff_get_color_opt(o, DIFF_RESET);
1402                emit_line(o, context, reset, line, len);
1403                fputs("~\n", o->file);
1404                break;
1405        case DIFF_SYMBOL_WORDS:
1406                context = diff_get_color_opt(o, DIFF_CONTEXT);
1407                reset = diff_get_color_opt(o, DIFF_RESET);
1408                /*
1409                 * Skip the prefix character, if any.  With
1410                 * diff_suppress_blank_empty, there may be
1411                 * none.
1412                 */
1413                if (line[0] != '\n') {
1414                        line++;
1415                        len--;
1416                }
1417                emit_line(o, context, reset, line, len);
1418                break;
1419        case DIFF_SYMBOL_FILEPAIR_PLUS:
1420                meta = diff_get_color_opt(o, DIFF_METAINFO);
1421                reset = diff_get_color_opt(o, DIFF_RESET);
1422                fprintf(o->file, "%s%s+++ %s%s%s\n", diff_line_prefix(o), meta,
1423                        line, reset,
1424                        strchr(line, ' ') ? "\t" : "");
1425                break;
1426        case DIFF_SYMBOL_FILEPAIR_MINUS:
1427                meta = diff_get_color_opt(o, DIFF_METAINFO);
1428                reset = diff_get_color_opt(o, DIFF_RESET);
1429                fprintf(o->file, "%s%s--- %s%s%s\n", diff_line_prefix(o), meta,
1430                        line, reset,
1431                        strchr(line, ' ') ? "\t" : "");
1432                break;
1433        case DIFF_SYMBOL_BINARY_FILES:
1434        case DIFF_SYMBOL_HEADER:
1435                fprintf(o->file, "%s", line);
1436                break;
1437        case DIFF_SYMBOL_BINARY_DIFF_HEADER:
1438                fprintf(o->file, "%sGIT binary patch\n", diff_line_prefix(o));
1439                break;
1440        case DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA:
1441                fprintf(o->file, "%sdelta %s\n", diff_line_prefix(o), line);
1442                break;
1443        case DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL:
1444                fprintf(o->file, "%sliteral %s\n", diff_line_prefix(o), line);
1445                break;
1446        case DIFF_SYMBOL_BINARY_DIFF_FOOTER:
1447                fputs(diff_line_prefix(o), o->file);
1448                fputc('\n', o->file);
1449                break;
1450        case DIFF_SYMBOL_REWRITE_DIFF:
1451                fraginfo = diff_get_color(o->use_color, DIFF_FRAGINFO);
1452                reset = diff_get_color_opt(o, DIFF_RESET);
1453                emit_line(o, fraginfo, reset, line, len);
1454                break;
1455        case DIFF_SYMBOL_SUBMODULE_ADD:
1456                set = diff_get_color_opt(o, DIFF_FILE_NEW);
1457                reset = diff_get_color_opt(o, DIFF_RESET);
1458                emit_line(o, set, reset, line, len);
1459                break;
1460        case DIFF_SYMBOL_SUBMODULE_DEL:
1461                set = diff_get_color_opt(o, DIFF_FILE_OLD);
1462                reset = diff_get_color_opt(o, DIFF_RESET);
1463                emit_line(o, set, reset, line, len);
1464                break;
1465        case DIFF_SYMBOL_SUBMODULE_UNTRACKED:
1466                fprintf(o->file, "%sSubmodule %s contains untracked content\n",
1467                        diff_line_prefix(o), line);
1468                break;
1469        case DIFF_SYMBOL_SUBMODULE_MODIFIED:
1470                fprintf(o->file, "%sSubmodule %s contains modified content\n",
1471                        diff_line_prefix(o), line);
1472                break;
1473        case DIFF_SYMBOL_STATS_SUMMARY_NO_FILES:
1474                emit_line(o, "", "", " 0 files changed\n",
1475                          strlen(" 0 files changed\n"));
1476                break;
1477        case DIFF_SYMBOL_STATS_SUMMARY_ABBREV:
1478                emit_line(o, "", "", " ...\n", strlen(" ...\n"));
1479                break;
1480        case DIFF_SYMBOL_WORD_DIFF:
1481                fprintf(o->file, "%.*s", len, line);
1482                break;
1483        case DIFF_SYMBOL_STAT_SEP:
1484                fputs(o->stat_sep, o->file);
1485                break;
1486        default:
1487                BUG("unknown diff symbol");
1488        }
1489        strbuf_release(&sb);
1490}
1491
1492static void emit_diff_symbol(struct diff_options *o, enum diff_symbol s,
1493                             const char *line, int len, unsigned flags)
1494{
1495        struct emitted_diff_symbol e = {line, len, flags, s};
1496
1497        if (o->emitted_symbols)
1498                append_emitted_diff_symbol(o, &e);
1499        else
1500                emit_diff_symbol_from_struct(o, &e);
1501}
1502
1503void diff_emit_submodule_del(struct diff_options *o, const char *line)
1504{
1505        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_DEL, line, strlen(line), 0);
1506}
1507
1508void diff_emit_submodule_add(struct diff_options *o, const char *line)
1509{
1510        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_ADD, line, strlen(line), 0);
1511}
1512
1513void diff_emit_submodule_untracked(struct diff_options *o, const char *path)
1514{
1515        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_UNTRACKED,
1516                         path, strlen(path), 0);
1517}
1518
1519void diff_emit_submodule_modified(struct diff_options *o, const char *path)
1520{
1521        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_MODIFIED,
1522                         path, strlen(path), 0);
1523}
1524
1525void diff_emit_submodule_header(struct diff_options *o, const char *header)
1526{
1527        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_HEADER,
1528                         header, strlen(header), 0);
1529}
1530
1531void diff_emit_submodule_error(struct diff_options *o, const char *err)
1532{
1533        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_ERROR, err, strlen(err), 0);
1534}
1535
1536void diff_emit_submodule_pipethrough(struct diff_options *o,
1537                                     const char *line, int len)
1538{
1539        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_PIPETHROUGH, line, len, 0);
1540}
1541
1542static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line, int len)
1543{
1544        if (!((ecbdata->ws_rule & WS_BLANK_AT_EOF) &&
1545              ecbdata->blank_at_eof_in_preimage &&
1546              ecbdata->blank_at_eof_in_postimage &&
1547              ecbdata->blank_at_eof_in_preimage <= ecbdata->lno_in_preimage &&
1548              ecbdata->blank_at_eof_in_postimage <= ecbdata->lno_in_postimage))
1549                return 0;
1550        return ws_blank_line(line, len, ecbdata->ws_rule);
1551}
1552
1553static void emit_add_line(const char *reset,
1554                          struct emit_callback *ecbdata,
1555                          const char *line, int len)
1556{
1557        unsigned flags = WSEH_NEW | ecbdata->ws_rule;
1558        if (new_blank_line_at_eof(ecbdata, line, len))
1559                flags |= DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF;
1560
1561        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_PLUS, line, len, flags);
1562}
1563
1564static void emit_del_line(const char *reset,
1565                          struct emit_callback *ecbdata,
1566                          const char *line, int len)
1567{
1568        unsigned flags = WSEH_OLD | ecbdata->ws_rule;
1569        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_MINUS, line, len, flags);
1570}
1571
1572static void emit_context_line(const char *reset,
1573                              struct emit_callback *ecbdata,
1574                              const char *line, int len)
1575{
1576        unsigned flags = WSEH_CONTEXT | ecbdata->ws_rule;
1577        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_CONTEXT, line, len, flags);
1578}
1579
1580static void emit_hunk_header(struct emit_callback *ecbdata,
1581                             const char *line, int len)
1582{
1583        const char *context = diff_get_color(ecbdata->color_diff, DIFF_CONTEXT);
1584        const char *frag = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
1585        const char *func = diff_get_color(ecbdata->color_diff, DIFF_FUNCINFO);
1586        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
1587        const char *reverse = ecbdata->color_diff ? GIT_COLOR_REVERSE : "";
1588        static const char atat[2] = { '@', '@' };
1589        const char *cp, *ep;
1590        struct strbuf msgbuf = STRBUF_INIT;
1591        int org_len = len;
1592        int i = 1;
1593
1594        /*
1595         * As a hunk header must begin with "@@ -<old>, +<new> @@",
1596         * it always is at least 10 bytes long.
1597         */
1598        if (len < 10 ||
1599            memcmp(line, atat, 2) ||
1600            !(ep = memmem(line + 2, len - 2, atat, 2))) {
1601                emit_diff_symbol(ecbdata->opt,
1602                                 DIFF_SYMBOL_CONTEXT_MARKER, line, len, 0);
1603                return;
1604        }
1605        ep += 2; /* skip over @@ */
1606
1607        /* The hunk header in fraginfo color */
1608        if (ecbdata->opt->flags.dual_color_diffed_diffs)
1609                strbuf_addstr(&msgbuf, reverse);
1610        strbuf_addstr(&msgbuf, frag);
1611        strbuf_add(&msgbuf, line, ep - line);
1612        strbuf_addstr(&msgbuf, reset);
1613
1614        /*
1615         * trailing "\r\n"
1616         */
1617        for ( ; i < 3; i++)
1618                if (line[len - i] == '\r' || line[len - i] == '\n')
1619                        len--;
1620
1621        /* blank before the func header */
1622        for (cp = ep; ep - line < len; ep++)
1623                if (*ep != ' ' && *ep != '\t')
1624                        break;
1625        if (ep != cp) {
1626                strbuf_addstr(&msgbuf, context);
1627                strbuf_add(&msgbuf, cp, ep - cp);
1628                strbuf_addstr(&msgbuf, reset);
1629        }
1630
1631        if (ep < line + len) {
1632                strbuf_addstr(&msgbuf, func);
1633                strbuf_add(&msgbuf, ep, line + len - ep);
1634                strbuf_addstr(&msgbuf, reset);
1635        }
1636
1637        strbuf_add(&msgbuf, line + len, org_len - len);
1638        strbuf_complete_line(&msgbuf);
1639        emit_diff_symbol(ecbdata->opt,
1640                         DIFF_SYMBOL_CONTEXT_FRAGINFO, msgbuf.buf, msgbuf.len, 0);
1641        strbuf_release(&msgbuf);
1642}
1643
1644static struct diff_tempfile *claim_diff_tempfile(void) {
1645        int i;
1646        for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
1647                if (!diff_temp[i].name)
1648                        return diff_temp + i;
1649        BUG("diff is failing to clean up its tempfiles");
1650}
1651
1652static void remove_tempfile(void)
1653{
1654        int i;
1655        for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
1656                if (is_tempfile_active(diff_temp[i].tempfile))
1657                        delete_tempfile(&diff_temp[i].tempfile);
1658                diff_temp[i].name = NULL;
1659        }
1660}
1661
1662static void add_line_count(struct strbuf *out, int count)
1663{
1664        switch (count) {
1665        case 0:
1666                strbuf_addstr(out, "0,0");
1667                break;
1668        case 1:
1669                strbuf_addstr(out, "1");
1670                break;
1671        default:
1672                strbuf_addf(out, "1,%d", count);
1673                break;
1674        }
1675}
1676
1677static void emit_rewrite_lines(struct emit_callback *ecb,
1678                               int prefix, const char *data, int size)
1679{
1680        const char *endp = NULL;
1681        const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
1682
1683        while (0 < size) {
1684                int len;
1685
1686                endp = memchr(data, '\n', size);
1687                len = endp ? (endp - data + 1) : size;
1688                if (prefix != '+') {
1689                        ecb->lno_in_preimage++;
1690                        emit_del_line(reset, ecb, data, len);
1691                } else {
1692                        ecb->lno_in_postimage++;
1693                        emit_add_line(reset, ecb, data, len);
1694                }
1695                size -= len;
1696                data += len;
1697        }
1698        if (!endp)
1699                emit_diff_symbol(ecb->opt, DIFF_SYMBOL_NO_LF_EOF, NULL, 0, 0);
1700}
1701
1702static void emit_rewrite_diff(const char *name_a,
1703                              const char *name_b,
1704                              struct diff_filespec *one,
1705                              struct diff_filespec *two,
1706                              struct userdiff_driver *textconv_one,
1707                              struct userdiff_driver *textconv_two,
1708                              struct diff_options *o)
1709{
1710        int lc_a, lc_b;
1711        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
1712        const char *a_prefix, *b_prefix;
1713        char *data_one, *data_two;
1714        size_t size_one, size_two;
1715        struct emit_callback ecbdata;
1716        struct strbuf out = STRBUF_INIT;
1717
1718        if (diff_mnemonic_prefix && o->flags.reverse_diff) {
1719                a_prefix = o->b_prefix;
1720                b_prefix = o->a_prefix;
1721        } else {
1722                a_prefix = o->a_prefix;
1723                b_prefix = o->b_prefix;
1724        }
1725
1726        name_a += (*name_a == '/');
1727        name_b += (*name_b == '/');
1728
1729        strbuf_reset(&a_name);
1730        strbuf_reset(&b_name);
1731        quote_two_c_style(&a_name, a_prefix, name_a, 0);
1732        quote_two_c_style(&b_name, b_prefix, name_b, 0);
1733
1734        size_one = fill_textconv(o->repo, textconv_one, one, &data_one);
1735        size_two = fill_textconv(o->repo, textconv_two, two, &data_two);
1736
1737        memset(&ecbdata, 0, sizeof(ecbdata));
1738        ecbdata.color_diff = want_color(o->use_color);
1739        ecbdata.ws_rule = whitespace_rule(o->repo->index, name_b);
1740        ecbdata.opt = o;
1741        if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
1742                mmfile_t mf1, mf2;
1743                mf1.ptr = (char *)data_one;
1744                mf2.ptr = (char *)data_two;
1745                mf1.size = size_one;
1746                mf2.size = size_two;
1747                check_blank_at_eof(&mf1, &mf2, &ecbdata);
1748        }
1749        ecbdata.lno_in_preimage = 1;
1750        ecbdata.lno_in_postimage = 1;
1751
1752        lc_a = count_lines(data_one, size_one);
1753        lc_b = count_lines(data_two, size_two);
1754
1755        emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_MINUS,
1756                         a_name.buf, a_name.len, 0);
1757        emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_PLUS,
1758                         b_name.buf, b_name.len, 0);
1759
1760        strbuf_addstr(&out, "@@ -");
1761        if (!o->irreversible_delete)
1762                add_line_count(&out, lc_a);
1763        else
1764                strbuf_addstr(&out, "?,?");
1765        strbuf_addstr(&out, " +");
1766        add_line_count(&out, lc_b);
1767        strbuf_addstr(&out, " @@\n");
1768        emit_diff_symbol(o, DIFF_SYMBOL_REWRITE_DIFF, out.buf, out.len, 0);
1769        strbuf_release(&out);
1770
1771        if (lc_a && !o->irreversible_delete)
1772                emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
1773        if (lc_b)
1774                emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
1775        if (textconv_one)
1776                free((char *)data_one);
1777        if (textconv_two)
1778                free((char *)data_two);
1779}
1780
1781struct diff_words_buffer {
1782        mmfile_t text;
1783        unsigned long alloc;
1784        struct diff_words_orig {
1785                const char *begin, *end;
1786        } *orig;
1787        int orig_nr, orig_alloc;
1788};
1789
1790static void diff_words_append(char *line, unsigned long len,
1791                struct diff_words_buffer *buffer)
1792{
1793        ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
1794        line++;
1795        len--;
1796        memcpy(buffer->text.ptr + buffer->text.size, line, len);
1797        buffer->text.size += len;
1798        buffer->text.ptr[buffer->text.size] = '\0';
1799}
1800
1801struct diff_words_style_elem {
1802        const char *prefix;
1803        const char *suffix;
1804        const char *color; /* NULL; filled in by the setup code if
1805                            * color is enabled */
1806};
1807
1808struct diff_words_style {
1809        enum diff_words_type type;
1810        struct diff_words_style_elem new_word, old_word, ctx;
1811        const char *newline;
1812};
1813
1814static struct diff_words_style diff_words_styles[] = {
1815        { DIFF_WORDS_PORCELAIN, {"+", "\n"}, {"-", "\n"}, {" ", "\n"}, "~\n" },
1816        { DIFF_WORDS_PLAIN, {"{+", "+}"}, {"[-", "-]"}, {"", ""}, "\n" },
1817        { DIFF_WORDS_COLOR, {"", ""}, {"", ""}, {"", ""}, "\n" }
1818};
1819
1820struct diff_words_data {
1821        struct diff_words_buffer minus, plus;
1822        const char *current_plus;
1823        int last_minus;
1824        struct diff_options *opt;
1825        regex_t *word_regex;
1826        enum diff_words_type type;
1827        struct diff_words_style *style;
1828};
1829
1830static int fn_out_diff_words_write_helper(struct diff_options *o,
1831                                          struct diff_words_style_elem *st_el,
1832                                          const char *newline,
1833                                          size_t count, const char *buf)
1834{
1835        int print = 0;
1836        struct strbuf sb = STRBUF_INIT;
1837
1838        while (count) {
1839                char *p = memchr(buf, '\n', count);
1840                if (print)
1841                        strbuf_addstr(&sb, diff_line_prefix(o));
1842
1843                if (p != buf) {
1844                        const char *reset = st_el->color && *st_el->color ?
1845                                            GIT_COLOR_RESET : NULL;
1846                        if (st_el->color && *st_el->color)
1847                                strbuf_addstr(&sb, st_el->color);
1848                        strbuf_addstr(&sb, st_el->prefix);
1849                        strbuf_add(&sb, buf, p ? p - buf : count);
1850                        strbuf_addstr(&sb, st_el->suffix);
1851                        if (reset)
1852                                strbuf_addstr(&sb, reset);
1853                }
1854                if (!p)
1855                        goto out;
1856
1857                strbuf_addstr(&sb, newline);
1858                count -= p + 1 - buf;
1859                buf = p + 1;
1860                print = 1;
1861                if (count) {
1862                        emit_diff_symbol(o, DIFF_SYMBOL_WORD_DIFF,
1863                                         sb.buf, sb.len, 0);
1864                        strbuf_reset(&sb);
1865                }
1866        }
1867
1868out:
1869        if (sb.len)
1870                emit_diff_symbol(o, DIFF_SYMBOL_WORD_DIFF,
1871                                 sb.buf, sb.len, 0);
1872        strbuf_release(&sb);
1873        return 0;
1874}
1875
1876/*
1877 * '--color-words' algorithm can be described as:
1878 *
1879 *   1. collect the minus/plus lines of a diff hunk, divided into
1880 *      minus-lines and plus-lines;
1881 *
1882 *   2. break both minus-lines and plus-lines into words and
1883 *      place them into two mmfile_t with one word for each line;
1884 *
1885 *   3. use xdiff to run diff on the two mmfile_t to get the words level diff;
1886 *
1887 * And for the common parts of the both file, we output the plus side text.
1888 * diff_words->current_plus is used to trace the current position of the plus file
1889 * which printed. diff_words->last_minus is used to trace the last minus word
1890 * printed.
1891 *
1892 * For '--graph' to work with '--color-words', we need to output the graph prefix
1893 * on each line of color words output. Generally, there are two conditions on
1894 * which we should output the prefix.
1895 *
1896 *   1. diff_words->last_minus == 0 &&
1897 *      diff_words->current_plus == diff_words->plus.text.ptr
1898 *
1899 *      that is: the plus text must start as a new line, and if there is no minus
1900 *      word printed, a graph prefix must be printed.
1901 *
1902 *   2. diff_words->current_plus > diff_words->plus.text.ptr &&
1903 *      *(diff_words->current_plus - 1) == '\n'
1904 *
1905 *      that is: a graph prefix must be printed following a '\n'
1906 */
1907static int color_words_output_graph_prefix(struct diff_words_data *diff_words)
1908{
1909        if ((diff_words->last_minus == 0 &&
1910                diff_words->current_plus == diff_words->plus.text.ptr) ||
1911                (diff_words->current_plus > diff_words->plus.text.ptr &&
1912                *(diff_words->current_plus - 1) == '\n')) {
1913                return 1;
1914        } else {
1915                return 0;
1916        }
1917}
1918
1919static void fn_out_diff_words_aux(void *priv,
1920                                  long minus_first, long minus_len,
1921                                  long plus_first, long plus_len,
1922                                  const char *func, long funclen)
1923{
1924        struct diff_words_data *diff_words = priv;
1925        struct diff_words_style *style = diff_words->style;
1926        const char *minus_begin, *minus_end, *plus_begin, *plus_end;
1927        struct diff_options *opt = diff_words->opt;
1928        const char *line_prefix;
1929
1930        assert(opt);
1931        line_prefix = diff_line_prefix(opt);
1932
1933        /* POSIX requires that first be decremented by one if len == 0... */
1934        if (minus_len) {
1935                minus_begin = diff_words->minus.orig[minus_first].begin;
1936                minus_end =
1937                        diff_words->minus.orig[minus_first + minus_len - 1].end;
1938        } else
1939                minus_begin = minus_end =
1940                        diff_words->minus.orig[minus_first].end;
1941
1942        if (plus_len) {
1943                plus_begin = diff_words->plus.orig[plus_first].begin;
1944                plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
1945        } else
1946                plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
1947
1948        if (color_words_output_graph_prefix(diff_words)) {
1949                fputs(line_prefix, diff_words->opt->file);
1950        }
1951        if (diff_words->current_plus != plus_begin) {
1952                fn_out_diff_words_write_helper(diff_words->opt,
1953                                &style->ctx, style->newline,
1954                                plus_begin - diff_words->current_plus,
1955                                diff_words->current_plus);
1956        }
1957        if (minus_begin != minus_end) {
1958                fn_out_diff_words_write_helper(diff_words->opt,
1959                                &style->old_word, style->newline,
1960                                minus_end - minus_begin, minus_begin);
1961        }
1962        if (plus_begin != plus_end) {
1963                fn_out_diff_words_write_helper(diff_words->opt,
1964                                &style->new_word, style->newline,
1965                                plus_end - plus_begin, plus_begin);
1966        }
1967
1968        diff_words->current_plus = plus_end;
1969        diff_words->last_minus = minus_first;
1970}
1971
1972/* This function starts looking at *begin, and returns 0 iff a word was found. */
1973static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
1974                int *begin, int *end)
1975{
1976        if (word_regex && *begin < buffer->size) {
1977                regmatch_t match[1];
1978                if (!regexec_buf(word_regex, buffer->ptr + *begin,
1979                                 buffer->size - *begin, 1, match, 0)) {
1980                        char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
1981                                        '\n', match[0].rm_eo - match[0].rm_so);
1982                        *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
1983                        *begin += match[0].rm_so;
1984                        return *begin >= *end;
1985                }
1986                return -1;
1987        }
1988
1989        /* find the next word */
1990        while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
1991                (*begin)++;
1992        if (*begin >= buffer->size)
1993                return -1;
1994
1995        /* find the end of the word */
1996        *end = *begin + 1;
1997        while (*end < buffer->size && !isspace(buffer->ptr[*end]))
1998                (*end)++;
1999
2000        return 0;
2001}
2002
2003/*
2004 * This function splits the words in buffer->text, stores the list with
2005 * newline separator into out, and saves the offsets of the original words
2006 * in buffer->orig.
2007 */
2008static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
2009                regex_t *word_regex)
2010{
2011        int i, j;
2012        long alloc = 0;
2013
2014        out->size = 0;
2015        out->ptr = NULL;
2016
2017        /* fake an empty "0th" word */
2018        ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
2019        buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
2020        buffer->orig_nr = 1;
2021
2022        for (i = 0; i < buffer->text.size; i++) {
2023                if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
2024                        return;
2025
2026                /* store original boundaries */
2027                ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
2028                                buffer->orig_alloc);
2029                buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
2030                buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
2031                buffer->orig_nr++;
2032
2033                /* store one word */
2034                ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
2035                memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
2036                out->ptr[out->size + j - i] = '\n';
2037                out->size += j - i + 1;
2038
2039                i = j - 1;
2040        }
2041}
2042
2043/* this executes the word diff on the accumulated buffers */
2044static void diff_words_show(struct diff_words_data *diff_words)
2045{
2046        xpparam_t xpp;
2047        xdemitconf_t xecfg;
2048        mmfile_t minus, plus;
2049        struct diff_words_style *style = diff_words->style;
2050
2051        struct diff_options *opt = diff_words->opt;
2052        const char *line_prefix;
2053
2054        assert(opt);
2055        line_prefix = diff_line_prefix(opt);
2056
2057        /* special case: only removal */
2058        if (!diff_words->plus.text.size) {
2059                emit_diff_symbol(diff_words->opt, DIFF_SYMBOL_WORD_DIFF,
2060                                 line_prefix, strlen(line_prefix), 0);
2061                fn_out_diff_words_write_helper(diff_words->opt,
2062                        &style->old_word, style->newline,
2063                        diff_words->minus.text.size,
2064                        diff_words->minus.text.ptr);
2065                diff_words->minus.text.size = 0;
2066                return;
2067        }
2068
2069        diff_words->current_plus = diff_words->plus.text.ptr;
2070        diff_words->last_minus = 0;
2071
2072        memset(&xpp, 0, sizeof(xpp));
2073        memset(&xecfg, 0, sizeof(xecfg));
2074        diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
2075        diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
2076        xpp.flags = 0;
2077        /* as only the hunk header will be parsed, we need a 0-context */
2078        xecfg.ctxlen = 0;
2079        if (xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, NULL,
2080                          diff_words, &xpp, &xecfg))
2081                die("unable to generate word diff");
2082        free(minus.ptr);
2083        free(plus.ptr);
2084        if (diff_words->current_plus != diff_words->plus.text.ptr +
2085                        diff_words->plus.text.size) {
2086                if (color_words_output_graph_prefix(diff_words))
2087                        emit_diff_symbol(diff_words->opt, DIFF_SYMBOL_WORD_DIFF,
2088                                         line_prefix, strlen(line_prefix), 0);
2089                fn_out_diff_words_write_helper(diff_words->opt,
2090                        &style->ctx, style->newline,
2091                        diff_words->plus.text.ptr + diff_words->plus.text.size
2092                        - diff_words->current_plus, diff_words->current_plus);
2093        }
2094        diff_words->minus.text.size = diff_words->plus.text.size = 0;
2095}
2096
2097/* In "color-words" mode, show word-diff of words accumulated in the buffer */
2098static void diff_words_flush(struct emit_callback *ecbdata)
2099{
2100        struct diff_options *wo = ecbdata->diff_words->opt;
2101
2102        if (ecbdata->diff_words->minus.text.size ||
2103            ecbdata->diff_words->plus.text.size)
2104                diff_words_show(ecbdata->diff_words);
2105
2106        if (wo->emitted_symbols) {
2107                struct diff_options *o = ecbdata->opt;
2108                struct emitted_diff_symbols *wol = wo->emitted_symbols;
2109                int i;
2110
2111                /*
2112                 * NEEDSWORK:
2113                 * Instead of appending each, concat all words to a line?
2114                 */
2115                for (i = 0; i < wol->nr; i++)
2116                        append_emitted_diff_symbol(o, &wol->buf[i]);
2117
2118                for (i = 0; i < wol->nr; i++)
2119                        free((void *)wol->buf[i].line);
2120
2121                wol->nr = 0;
2122        }
2123}
2124
2125static void diff_filespec_load_driver(struct diff_filespec *one,
2126                                      struct index_state *istate)
2127{
2128        /* Use already-loaded driver */
2129        if (one->driver)
2130                return;
2131
2132        if (S_ISREG(one->mode))
2133                one->driver = userdiff_find_by_path(istate, one->path);
2134
2135        /* Fallback to default settings */
2136        if (!one->driver)
2137                one->driver = userdiff_find_by_name("default");
2138}
2139
2140static const char *userdiff_word_regex(struct diff_filespec *one,
2141                                       struct index_state *istate)
2142{
2143        diff_filespec_load_driver(one, istate);
2144        return one->driver->word_regex;
2145}
2146
2147static void init_diff_words_data(struct emit_callback *ecbdata,
2148                                 struct diff_options *orig_opts,
2149                                 struct diff_filespec *one,
2150                                 struct diff_filespec *two)
2151{
2152        int i;
2153        struct diff_options *o = xmalloc(sizeof(struct diff_options));
2154        memcpy(o, orig_opts, sizeof(struct diff_options));
2155
2156        ecbdata->diff_words =
2157                xcalloc(1, sizeof(struct diff_words_data));
2158        ecbdata->diff_words->type = o->word_diff;
2159        ecbdata->diff_words->opt = o;
2160
2161        if (orig_opts->emitted_symbols)
2162                o->emitted_symbols =
2163                        xcalloc(1, sizeof(struct emitted_diff_symbols));
2164
2165        if (!o->word_regex)
2166                o->word_regex = userdiff_word_regex(one, o->repo->index);
2167        if (!o->word_regex)
2168                o->word_regex = userdiff_word_regex(two, o->repo->index);
2169        if (!o->word_regex)
2170                o->word_regex = diff_word_regex_cfg;
2171        if (o->word_regex) {
2172                ecbdata->diff_words->word_regex = (regex_t *)
2173                        xmalloc(sizeof(regex_t));
2174                if (regcomp(ecbdata->diff_words->word_regex,
2175                            o->word_regex,
2176                            REG_EXTENDED | REG_NEWLINE))
2177                        die("invalid regular expression: %s",
2178                            o->word_regex);
2179        }
2180        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
2181                if (o->word_diff == diff_words_styles[i].type) {
2182                        ecbdata->diff_words->style =
2183                                &diff_words_styles[i];
2184                        break;
2185                }
2186        }
2187        if (want_color(o->use_color)) {
2188                struct diff_words_style *st = ecbdata->diff_words->style;
2189                st->old_word.color = diff_get_color_opt(o, DIFF_FILE_OLD);
2190                st->new_word.color = diff_get_color_opt(o, DIFF_FILE_NEW);
2191                st->ctx.color = diff_get_color_opt(o, DIFF_CONTEXT);
2192        }
2193}
2194
2195static void free_diff_words_data(struct emit_callback *ecbdata)
2196{
2197        if (ecbdata->diff_words) {
2198                diff_words_flush(ecbdata);
2199                free (ecbdata->diff_words->opt->emitted_symbols);
2200                free (ecbdata->diff_words->opt);
2201                free (ecbdata->diff_words->minus.text.ptr);
2202                free (ecbdata->diff_words->minus.orig);
2203                free (ecbdata->diff_words->plus.text.ptr);
2204                free (ecbdata->diff_words->plus.orig);
2205                if (ecbdata->diff_words->word_regex) {
2206                        regfree(ecbdata->diff_words->word_regex);
2207                        free(ecbdata->diff_words->word_regex);
2208                }
2209                FREE_AND_NULL(ecbdata->diff_words);
2210        }
2211}
2212
2213const char *diff_get_color(int diff_use_color, enum color_diff ix)
2214{
2215        if (want_color(diff_use_color))
2216                return diff_colors[ix];
2217        return "";
2218}
2219
2220const char *diff_line_prefix(struct diff_options *opt)
2221{
2222        struct strbuf *msgbuf;
2223        if (!opt->output_prefix)
2224                return "";
2225
2226        msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
2227        return msgbuf->buf;
2228}
2229
2230static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
2231{
2232        const char *cp;
2233        unsigned long allot;
2234        size_t l = len;
2235
2236        cp = line;
2237        allot = l;
2238        while (0 < l) {
2239                (void) utf8_width(&cp, &l);
2240                if (!cp)
2241                        break; /* truncated in the middle? */
2242        }
2243        return allot - l;
2244}
2245
2246static void find_lno(const char *line, struct emit_callback *ecbdata)
2247{
2248        const char *p;
2249        ecbdata->lno_in_preimage = 0;
2250        ecbdata->lno_in_postimage = 0;
2251        p = strchr(line, '-');
2252        if (!p)
2253                return; /* cannot happen */
2254        ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
2255        p = strchr(p, '+');
2256        if (!p)
2257                return; /* cannot happen */
2258        ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
2259}
2260
2261static void fn_out_consume(void *priv, char *line, unsigned long len)
2262{
2263        struct emit_callback *ecbdata = priv;
2264        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
2265        struct diff_options *o = ecbdata->opt;
2266
2267        o->found_changes = 1;
2268
2269        if (ecbdata->header) {
2270                emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
2271                                 ecbdata->header->buf, ecbdata->header->len, 0);
2272                strbuf_reset(ecbdata->header);
2273                ecbdata->header = NULL;
2274        }
2275
2276        if (ecbdata->label_path[0]) {
2277                emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_MINUS,
2278                                 ecbdata->label_path[0],
2279                                 strlen(ecbdata->label_path[0]), 0);
2280                emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_PLUS,
2281                                 ecbdata->label_path[1],
2282                                 strlen(ecbdata->label_path[1]), 0);
2283                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
2284        }
2285
2286        if (diff_suppress_blank_empty
2287            && len == 2 && line[0] == ' ' && line[1] == '\n') {
2288                line[0] = '\n';
2289                len = 1;
2290        }
2291
2292        if (line[0] == '@') {
2293                if (ecbdata->diff_words)
2294                        diff_words_flush(ecbdata);
2295                len = sane_truncate_line(ecbdata, line, len);
2296                find_lno(line, ecbdata);
2297                emit_hunk_header(ecbdata, line, len);
2298                return;
2299        }
2300
2301        if (ecbdata->diff_words) {
2302                enum diff_symbol s =
2303                        ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN ?
2304                        DIFF_SYMBOL_WORDS_PORCELAIN : DIFF_SYMBOL_WORDS;
2305                if (line[0] == '-') {
2306                        diff_words_append(line, len,
2307                                          &ecbdata->diff_words->minus);
2308                        return;
2309                } else if (line[0] == '+') {
2310                        diff_words_append(line, len,
2311                                          &ecbdata->diff_words->plus);
2312                        return;
2313                } else if (starts_with(line, "\\ ")) {
2314                        /*
2315                         * Eat the "no newline at eof" marker as if we
2316                         * saw a "+" or "-" line with nothing on it,
2317                         * and return without diff_words_flush() to
2318                         * defer processing. If this is the end of
2319                         * preimage, more "+" lines may come after it.
2320                         */
2321                        return;
2322                }
2323                diff_words_flush(ecbdata);
2324                emit_diff_symbol(o, s, line, len, 0);
2325                return;
2326        }
2327
2328        switch (line[0]) {
2329        case '+':
2330                ecbdata->lno_in_postimage++;
2331                emit_add_line(reset, ecbdata, line + 1, len - 1);
2332                break;
2333        case '-':
2334                ecbdata->lno_in_preimage++;
2335                emit_del_line(reset, ecbdata, line + 1, len - 1);
2336                break;
2337        case ' ':
2338                ecbdata->lno_in_postimage++;
2339                ecbdata->lno_in_preimage++;
2340                emit_context_line(reset, ecbdata, line + 1, len - 1);
2341                break;
2342        default:
2343                /* incomplete line at the end */
2344                ecbdata->lno_in_preimage++;
2345                emit_diff_symbol(o, DIFF_SYMBOL_CONTEXT_INCOMPLETE,
2346                                 line, len, 0);
2347                break;
2348        }
2349}
2350
2351static void pprint_rename(struct strbuf *name, const char *a, const char *b)
2352{
2353        const char *old_name = a;
2354        const char *new_name = b;
2355        int pfx_length, sfx_length;
2356        int pfx_adjust_for_slash;
2357        int len_a = strlen(a);
2358        int len_b = strlen(b);
2359        int a_midlen, b_midlen;
2360        int qlen_a = quote_c_style(a, NULL, NULL, 0);
2361        int qlen_b = quote_c_style(b, NULL, NULL, 0);
2362
2363        if (qlen_a || qlen_b) {
2364                quote_c_style(a, name, NULL, 0);
2365                strbuf_addstr(name, " => ");
2366                quote_c_style(b, name, NULL, 0);
2367                return;
2368        }
2369
2370        /* Find common prefix */
2371        pfx_length = 0;
2372        while (*old_name && *new_name && *old_name == *new_name) {
2373                if (*old_name == '/')
2374                        pfx_length = old_name - a + 1;
2375                old_name++;
2376                new_name++;
2377        }
2378
2379        /* Find common suffix */
2380        old_name = a + len_a;
2381        new_name = b + len_b;
2382        sfx_length = 0;
2383        /*
2384         * If there is a common prefix, it must end in a slash.  In
2385         * that case we let this loop run 1 into the prefix to see the
2386         * same slash.
2387         *
2388         * If there is no common prefix, we cannot do this as it would
2389         * underrun the input strings.
2390         */
2391        pfx_adjust_for_slash = (pfx_length ? 1 : 0);
2392        while (a + pfx_length - pfx_adjust_for_slash <= old_name &&
2393               b + pfx_length - pfx_adjust_for_slash <= new_name &&
2394               *old_name == *new_name) {
2395                if (*old_name == '/')
2396                        sfx_length = len_a - (old_name - a);
2397                old_name--;
2398                new_name--;
2399        }
2400
2401        /*
2402         * pfx{mid-a => mid-b}sfx
2403         * {pfx-a => pfx-b}sfx
2404         * pfx{sfx-a => sfx-b}
2405         * name-a => name-b
2406         */
2407        a_midlen = len_a - pfx_length - sfx_length;
2408        b_midlen = len_b - pfx_length - sfx_length;
2409        if (a_midlen < 0)
2410                a_midlen = 0;
2411        if (b_midlen < 0)
2412                b_midlen = 0;
2413
2414        strbuf_grow(name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
2415        if (pfx_length + sfx_length) {
2416                strbuf_add(name, a, pfx_length);
2417                strbuf_addch(name, '{');
2418        }
2419        strbuf_add(name, a + pfx_length, a_midlen);
2420        strbuf_addstr(name, " => ");
2421        strbuf_add(name, b + pfx_length, b_midlen);
2422        if (pfx_length + sfx_length) {
2423                strbuf_addch(name, '}');
2424                strbuf_add(name, a + len_a - sfx_length, sfx_length);
2425        }
2426}
2427
2428struct diffstat_t {
2429        int nr;
2430        int alloc;
2431        struct diffstat_file {
2432                char *from_name;
2433                char *name;
2434                char *print_name;
2435                const char *comments;
2436                unsigned is_unmerged:1;
2437                unsigned is_binary:1;
2438                unsigned is_renamed:1;
2439                unsigned is_interesting:1;
2440                uintmax_t added, deleted;
2441        } **files;
2442};
2443
2444static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
2445                                          const char *name_a,
2446                                          const char *name_b)
2447{
2448        struct diffstat_file *x;
2449        x = xcalloc(1, sizeof(*x));
2450        ALLOC_GROW(diffstat->files, diffstat->nr + 1, diffstat->alloc);
2451        diffstat->files[diffstat->nr++] = x;
2452        if (name_b) {
2453                x->from_name = xstrdup(name_a);
2454                x->name = xstrdup(name_b);
2455                x->is_renamed = 1;
2456        }
2457        else {
2458                x->from_name = NULL;
2459                x->name = xstrdup(name_a);
2460        }
2461        return x;
2462}
2463
2464static void diffstat_consume(void *priv, char *line, unsigned long len)
2465{
2466        struct diffstat_t *diffstat = priv;
2467        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
2468
2469        if (line[0] == '+')
2470                x->added++;
2471        else if (line[0] == '-')
2472                x->deleted++;
2473}
2474
2475const char mime_boundary_leader[] = "------------";
2476
2477static int scale_linear(int it, int width, int max_change)
2478{
2479        if (!it)
2480                return 0;
2481        /*
2482         * make sure that at least one '-' or '+' is printed if
2483         * there is any change to this path. The easiest way is to
2484         * scale linearly as if the alloted width is one column shorter
2485         * than it is, and then add 1 to the result.
2486         */
2487        return 1 + (it * (width - 1) / max_change);
2488}
2489
2490static void show_graph(struct strbuf *out, char ch, int cnt,
2491                       const char *set, const char *reset)
2492{
2493        if (cnt <= 0)
2494                return;
2495        strbuf_addstr(out, set);
2496        strbuf_addchars(out, ch, cnt);
2497        strbuf_addstr(out, reset);
2498}
2499
2500static void fill_print_name(struct diffstat_file *file)
2501{
2502        struct strbuf pname = STRBUF_INIT;
2503
2504        if (file->print_name)
2505                return;
2506
2507        if (file->is_renamed)
2508                pprint_rename(&pname, file->from_name, file->name);
2509        else
2510                quote_c_style(file->name, &pname, NULL, 0);
2511
2512        if (file->comments)
2513                strbuf_addf(&pname, " (%s)", file->comments);
2514
2515        file->print_name = strbuf_detach(&pname, NULL);
2516}
2517
2518static void print_stat_summary_inserts_deletes(struct diff_options *options,
2519                int files, int insertions, int deletions)
2520{
2521        struct strbuf sb = STRBUF_INIT;
2522
2523        if (!files) {
2524                assert(insertions == 0 && deletions == 0);
2525                emit_diff_symbol(options, DIFF_SYMBOL_STATS_SUMMARY_NO_FILES,
2526                                 NULL, 0, 0);
2527                return;
2528        }
2529
2530        strbuf_addf(&sb,
2531                    (files == 1) ? " %d file changed" : " %d files changed",
2532                    files);
2533
2534        /*
2535         * For binary diff, the caller may want to print "x files
2536         * changed" with insertions == 0 && deletions == 0.
2537         *
2538         * Not omitting "0 insertions(+), 0 deletions(-)" in this case
2539         * is probably less confusing (i.e skip over "2 files changed
2540         * but nothing about added/removed lines? Is this a bug in Git?").
2541         */
2542        if (insertions || deletions == 0) {
2543                strbuf_addf(&sb,
2544                            (insertions == 1) ? ", %d insertion(+)" : ", %d insertions(+)",
2545                            insertions);
2546        }
2547
2548        if (deletions || insertions == 0) {
2549                strbuf_addf(&sb,
2550                            (deletions == 1) ? ", %d deletion(-)" : ", %d deletions(-)",
2551                            deletions);
2552        }
2553        strbuf_addch(&sb, '\n');
2554        emit_diff_symbol(options, DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES,
2555                         sb.buf, sb.len, 0);
2556        strbuf_release(&sb);
2557}
2558
2559void print_stat_summary(FILE *fp, int files,
2560                        int insertions, int deletions)
2561{
2562        struct diff_options o;
2563        memset(&o, 0, sizeof(o));
2564        o.file = fp;
2565
2566        print_stat_summary_inserts_deletes(&o, files, insertions, deletions);
2567}
2568
2569static void show_stats(struct diffstat_t *data, struct diff_options *options)
2570{
2571        int i, len, add, del, adds = 0, dels = 0;
2572        uintmax_t max_change = 0, max_len = 0;
2573        int total_files = data->nr, count;
2574        int width, name_width, graph_width, number_width = 0, bin_width = 0;
2575        const char *reset, *add_c, *del_c;
2576        int extra_shown = 0;
2577        const char *line_prefix = diff_line_prefix(options);
2578        struct strbuf out = STRBUF_INIT;
2579
2580        if (data->nr == 0)
2581                return;
2582
2583        count = options->stat_count ? options->stat_count : data->nr;
2584
2585        reset = diff_get_color_opt(options, DIFF_RESET);
2586        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
2587        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
2588
2589        /*
2590         * Find the longest filename and max number of changes
2591         */
2592        for (i = 0; (i < count) && (i < data->nr); i++) {
2593                struct diffstat_file *file = data->files[i];
2594                uintmax_t change = file->added + file->deleted;
2595
2596                if (!file->is_interesting && (change == 0)) {
2597                        count++; /* not shown == room for one more */
2598                        continue;
2599                }
2600                fill_print_name(file);
2601                len = strlen(file->print_name);
2602                if (max_len < len)
2603                        max_len = len;
2604
2605                if (file->is_unmerged) {
2606                        /* "Unmerged" is 8 characters */
2607                        bin_width = bin_width < 8 ? 8 : bin_width;
2608                        continue;
2609                }
2610                if (file->is_binary) {
2611                        /* "Bin XXX -> YYY bytes" */
2612                        int w = 14 + decimal_width(file->added)
2613                                + decimal_width(file->deleted);
2614                        bin_width = bin_width < w ? w : bin_width;
2615                        /* Display change counts aligned with "Bin" */
2616                        number_width = 3;
2617                        continue;
2618                }
2619
2620                if (max_change < change)
2621                        max_change = change;
2622        }
2623        count = i; /* where we can stop scanning in data->files[] */
2624
2625        /*
2626         * We have width = stat_width or term_columns() columns total.
2627         * We want a maximum of min(max_len, stat_name_width) for the name part.
2628         * We want a maximum of min(max_change, stat_graph_width) for the +- part.
2629         * We also need 1 for " " and 4 + decimal_width(max_change)
2630         * for " | NNNN " and one the empty column at the end, altogether
2631         * 6 + decimal_width(max_change).
2632         *
2633         * If there's not enough space, we will use the smaller of
2634         * stat_name_width (if set) and 5/8*width for the filename,
2635         * and the rest for constant elements + graph part, but no more
2636         * than stat_graph_width for the graph part.
2637         * (5/8 gives 50 for filename and 30 for the constant parts + graph
2638         * for the standard terminal size).
2639         *
2640         * In other words: stat_width limits the maximum width, and
2641         * stat_name_width fixes the maximum width of the filename,
2642         * and is also used to divide available columns if there
2643         * aren't enough.
2644         *
2645         * Binary files are displayed with "Bin XXX -> YYY bytes"
2646         * instead of the change count and graph. This part is treated
2647         * similarly to the graph part, except that it is not
2648         * "scaled". If total width is too small to accommodate the
2649         * guaranteed minimum width of the filename part and the
2650         * separators and this message, this message will "overflow"
2651         * making the line longer than the maximum width.
2652         */
2653
2654        if (options->stat_width == -1)
2655                width = term_columns() - strlen(line_prefix);
2656        else
2657                width = options->stat_width ? options->stat_width : 80;
2658        number_width = decimal_width(max_change) > number_width ?
2659                decimal_width(max_change) : number_width;
2660
2661        if (options->stat_graph_width == -1)
2662                options->stat_graph_width = diff_stat_graph_width;
2663
2664        /*
2665         * Guarantee 3/8*16==6 for the graph part
2666         * and 5/8*16==10 for the filename part
2667         */
2668        if (width < 16 + 6 + number_width)
2669                width = 16 + 6 + number_width;
2670
2671        /*
2672         * First assign sizes that are wanted, ignoring available width.
2673         * strlen("Bin XXX -> YYY bytes") == bin_width, and the part
2674         * starting from "XXX" should fit in graph_width.
2675         */
2676        graph_width = max_change + 4 > bin_width ? max_change : bin_width - 4;
2677        if (options->stat_graph_width &&
2678            options->stat_graph_width < graph_width)
2679                graph_width = options->stat_graph_width;
2680
2681        name_width = (options->stat_name_width > 0 &&
2682                      options->stat_name_width < max_len) ?
2683                options->stat_name_width : max_len;
2684
2685        /*
2686         * Adjust adjustable widths not to exceed maximum width
2687         */
2688        if (name_width + number_width + 6 + graph_width > width) {
2689                if (graph_width > width * 3/8 - number_width - 6) {
2690                        graph_width = width * 3/8 - number_width - 6;
2691                        if (graph_width < 6)
2692                                graph_width = 6;
2693                }
2694
2695                if (options->stat_graph_width &&
2696                    graph_width > options->stat_graph_width)
2697                        graph_width = options->stat_graph_width;
2698                if (name_width > width - number_width - 6 - graph_width)
2699                        name_width = width - number_width - 6 - graph_width;
2700                else
2701                        graph_width = width - number_width - 6 - name_width;
2702        }
2703
2704        /*
2705         * From here name_width is the width of the name area,
2706         * and graph_width is the width of the graph area.
2707         * max_change is used to scale graph properly.
2708         */
2709        for (i = 0; i < count; i++) {
2710                const char *prefix = "";
2711                struct diffstat_file *file = data->files[i];
2712                char *name = file->print_name;
2713                uintmax_t added = file->added;
2714                uintmax_t deleted = file->deleted;
2715                int name_len;
2716
2717                if (!file->is_interesting && (added + deleted == 0))
2718                        continue;
2719
2720                /*
2721                 * "scale" the filename
2722                 */
2723                len = name_width;
2724                name_len = strlen(name);
2725                if (name_width < name_len) {
2726                        char *slash;
2727                        prefix = "...";
2728                        len -= 3;
2729                        name += name_len - len;
2730                        slash = strchr(name, '/');
2731                        if (slash)
2732                                name = slash;
2733                }
2734
2735                if (file->is_binary) {
2736                        strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2737                        strbuf_addf(&out, " %*s", number_width, "Bin");
2738                        if (!added && !deleted) {
2739                                strbuf_addch(&out, '\n');
2740                                emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2741                                                 out.buf, out.len, 0);
2742                                strbuf_reset(&out);
2743                                continue;
2744                        }
2745                        strbuf_addf(&out, " %s%"PRIuMAX"%s",
2746                                del_c, deleted, reset);
2747                        strbuf_addstr(&out, " -> ");
2748                        strbuf_addf(&out, "%s%"PRIuMAX"%s",
2749                                add_c, added, reset);
2750                        strbuf_addstr(&out, " bytes\n");
2751                        emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2752                                         out.buf, out.len, 0);
2753                        strbuf_reset(&out);
2754                        continue;
2755                }
2756                else if (file->is_unmerged) {
2757                        strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2758                        strbuf_addstr(&out, " Unmerged\n");
2759                        emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2760                                         out.buf, out.len, 0);
2761                        strbuf_reset(&out);
2762                        continue;
2763                }
2764
2765                /*
2766                 * scale the add/delete
2767                 */
2768                add = added;
2769                del = deleted;
2770
2771                if (graph_width <= max_change) {
2772                        int total = scale_linear(add + del, graph_width, max_change);
2773                        if (total < 2 && add && del)
2774                                /* width >= 2 due to the sanity check */
2775                                total = 2;
2776                        if (add < del) {
2777                                add = scale_linear(add, graph_width, max_change);
2778                                del = total - add;
2779                        } else {
2780                                del = scale_linear(del, graph_width, max_change);
2781                                add = total - del;
2782                        }
2783                }
2784                strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2785                strbuf_addf(&out, " %*"PRIuMAX"%s",
2786                        number_width, added + deleted,
2787                        added + deleted ? " " : "");
2788                show_graph(&out, '+', add, add_c, reset);
2789                show_graph(&out, '-', del, del_c, reset);
2790                strbuf_addch(&out, '\n');
2791                emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2792                                 out.buf, out.len, 0);
2793                strbuf_reset(&out);
2794        }
2795
2796        for (i = 0; i < data->nr; i++) {
2797                struct diffstat_file *file = data->files[i];
2798                uintmax_t added = file->added;
2799                uintmax_t deleted = file->deleted;
2800
2801                if (file->is_unmerged ||
2802                    (!file->is_interesting && (added + deleted == 0))) {
2803                        total_files--;
2804                        continue;
2805                }
2806
2807                if (!file->is_binary) {
2808                        adds += added;
2809                        dels += deleted;
2810                }
2811                if (i < count)
2812                        continue;
2813                if (!extra_shown)
2814                        emit_diff_symbol(options,
2815                                         DIFF_SYMBOL_STATS_SUMMARY_ABBREV,
2816                                         NULL, 0, 0);
2817                extra_shown = 1;
2818        }
2819
2820        print_stat_summary_inserts_deletes(options, total_files, adds, dels);
2821        strbuf_release(&out);
2822}
2823
2824static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
2825{
2826        int i, adds = 0, dels = 0, total_files = data->nr;
2827
2828        if (data->nr == 0)
2829                return;
2830
2831        for (i = 0; i < data->nr; i++) {
2832                int added = data->files[i]->added;
2833                int deleted = data->files[i]->deleted;
2834
2835                if (data->files[i]->is_unmerged ||
2836                    (!data->files[i]->is_interesting && (added + deleted == 0))) {
2837                        total_files--;
2838                } else if (!data->files[i]->is_binary) { /* don't count bytes */
2839                        adds += added;
2840                        dels += deleted;
2841                }
2842        }
2843        print_stat_summary_inserts_deletes(options, total_files, adds, dels);
2844}
2845
2846static void show_numstat(struct diffstat_t *data, struct diff_options *options)
2847{
2848        int i;
2849
2850        if (data->nr == 0)
2851                return;
2852
2853        for (i = 0; i < data->nr; i++) {
2854                struct diffstat_file *file = data->files[i];
2855
2856                fprintf(options->file, "%s", diff_line_prefix(options));
2857
2858                if (file->is_binary)
2859                        fprintf(options->file, "-\t-\t");
2860                else
2861                        fprintf(options->file,
2862                                "%"PRIuMAX"\t%"PRIuMAX"\t",
2863                                file->added, file->deleted);
2864                if (options->line_termination) {
2865                        fill_print_name(file);
2866                        if (!file->is_renamed)
2867                                write_name_quoted(file->name, options->file,
2868                                                  options->line_termination);
2869                        else {
2870                                fputs(file->print_name, options->file);
2871                                putc(options->line_termination, options->file);
2872                        }
2873                } else {
2874                        if (file->is_renamed) {
2875                                putc('\0', options->file);
2876                                write_name_quoted(file->from_name, options->file, '\0');
2877                        }
2878                        write_name_quoted(file->name, options->file, '\0');
2879                }
2880        }
2881}
2882
2883struct dirstat_file {
2884        const char *name;
2885        unsigned long changed;
2886};
2887
2888struct dirstat_dir {
2889        struct dirstat_file *files;
2890        int alloc, nr, permille, cumulative;
2891};
2892
2893static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
2894                unsigned long changed, const char *base, int baselen)
2895{
2896        unsigned long sum_changes = 0;
2897        unsigned int sources = 0;
2898        const char *line_prefix = diff_line_prefix(opt);
2899
2900        while (dir->nr) {
2901                struct dirstat_file *f = dir->files;
2902                int namelen = strlen(f->name);
2903                unsigned long changes;
2904                char *slash;
2905
2906                if (namelen < baselen)
2907                        break;
2908                if (memcmp(f->name, base, baselen))
2909                        break;
2910                slash = strchr(f->name + baselen, '/');
2911                if (slash) {
2912                        int newbaselen = slash + 1 - f->name;
2913                        changes = gather_dirstat(opt, dir, changed, f->name, newbaselen);
2914                        sources++;
2915                } else {
2916                        changes = f->changed;
2917                        dir->files++;
2918                        dir->nr--;
2919                        sources += 2;
2920                }
2921                sum_changes += changes;
2922        }
2923
2924        /*
2925         * We don't report dirstat's for
2926         *  - the top level
2927         *  - or cases where everything came from a single directory
2928         *    under this directory (sources == 1).
2929         */
2930        if (baselen && sources != 1) {
2931                if (sum_changes) {
2932                        int permille = sum_changes * 1000 / changed;
2933                        if (permille >= dir->permille) {
2934                                fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
2935                                        permille / 10, permille % 10, baselen, base);
2936                                if (!dir->cumulative)
2937                                        return 0;
2938                        }
2939                }
2940        }
2941        return sum_changes;
2942}
2943
2944static int dirstat_compare(const void *_a, const void *_b)
2945{
2946        const struct dirstat_file *a = _a;
2947        const struct dirstat_file *b = _b;
2948        return strcmp(a->name, b->name);
2949}
2950
2951static void show_dirstat(struct diff_options *options)
2952{
2953        int i;
2954        unsigned long changed;
2955        struct dirstat_dir dir;
2956        struct diff_queue_struct *q = &diff_queued_diff;
2957
2958        dir.files = NULL;
2959        dir.alloc = 0;
2960        dir.nr = 0;
2961        dir.permille = options->dirstat_permille;
2962        dir.cumulative = options->flags.dirstat_cumulative;
2963
2964        changed = 0;
2965        for (i = 0; i < q->nr; i++) {
2966                struct diff_filepair *p = q->queue[i];
2967                const char *name;
2968                unsigned long copied, added, damage;
2969
2970                name = p->two->path ? p->two->path : p->one->path;
2971
2972                if (p->one->oid_valid && p->two->oid_valid &&
2973                    oideq(&p->one->oid, &p->two->oid)) {
2974                        /*
2975                         * The SHA1 has not changed, so pre-/post-content is
2976                         * identical. We can therefore skip looking at the
2977                         * file contents altogether.
2978                         */
2979                        damage = 0;
2980                        goto found_damage;
2981                }
2982
2983                if (options->flags.dirstat_by_file) {
2984                        /*
2985                         * In --dirstat-by-file mode, we don't really need to
2986                         * look at the actual file contents at all.
2987                         * The fact that the SHA1 changed is enough for us to
2988                         * add this file to the list of results
2989                         * (with each file contributing equal damage).
2990                         */
2991                        damage = 1;
2992                        goto found_damage;
2993                }
2994
2995                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
2996                        diff_populate_filespec(options->repo, p->one, 0);
2997                        diff_populate_filespec(options->repo, p->two, 0);
2998                        diffcore_count_changes(options->repo,
2999                                               p->one, p->two, NULL, NULL,
3000                                               &copied, &added);
3001                        diff_free_filespec_data(p->one);
3002                        diff_free_filespec_data(p->two);
3003                } else if (DIFF_FILE_VALID(p->one)) {
3004                        diff_populate_filespec(options->repo, p->one, CHECK_SIZE_ONLY);
3005                        copied = added = 0;
3006                        diff_free_filespec_data(p->one);
3007                } else if (DIFF_FILE_VALID(p->two)) {
3008                        diff_populate_filespec(options->repo, p->two, CHECK_SIZE_ONLY);
3009                        copied = 0;
3010                        added = p->two->size;
3011                        diff_free_filespec_data(p->two);
3012                } else
3013                        continue;
3014
3015                /*
3016                 * Original minus copied is the removed material,
3017                 * added is the new material.  They are both damages
3018                 * made to the preimage.
3019                 * If the resulting damage is zero, we know that
3020                 * diffcore_count_changes() considers the two entries to
3021                 * be identical, but since the oid changed, we
3022                 * know that there must have been _some_ kind of change,
3023                 * so we force all entries to have damage > 0.
3024                 */
3025                damage = (p->one->size - copied) + added;
3026                if (!damage)
3027                        damage = 1;
3028
3029found_damage:
3030                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
3031                dir.files[dir.nr].name = name;
3032                dir.files[dir.nr].changed = damage;
3033                changed += damage;
3034                dir.nr++;
3035        }
3036
3037        /* This can happen even with many files, if everything was renames */
3038        if (!changed)
3039                return;
3040
3041        /* Show all directories with more than x% of the changes */
3042        QSORT(dir.files, dir.nr, dirstat_compare);
3043        gather_dirstat(options, &dir, changed, "", 0);
3044}
3045
3046static void show_dirstat_by_line(struct diffstat_t *data, struct diff_options *options)
3047{
3048        int i;
3049        unsigned long changed;
3050        struct dirstat_dir dir;
3051
3052        if (data->nr == 0)
3053                return;
3054
3055        dir.files = NULL;
3056        dir.alloc = 0;
3057        dir.nr = 0;
3058        dir.permille = options->dirstat_permille;
3059        dir.cumulative = options->flags.dirstat_cumulative;
3060
3061        changed = 0;
3062        for (i = 0; i < data->nr; i++) {
3063                struct diffstat_file *file = data->files[i];
3064                unsigned long damage = file->added + file->deleted;
3065                if (file->is_binary)
3066                        /*
3067                         * binary files counts bytes, not lines. Must find some
3068                         * way to normalize binary bytes vs. textual lines.
3069                         * The following heuristic assumes that there are 64
3070                         * bytes per "line".
3071                         * This is stupid and ugly, but very cheap...
3072                         */
3073                        damage = DIV_ROUND_UP(damage, 64);
3074                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
3075                dir.files[dir.nr].name = file->name;
3076                dir.files[dir.nr].changed = damage;
3077                changed += damage;
3078                dir.nr++;
3079        }
3080
3081        /* This can happen even with many files, if everything was renames */
3082        if (!changed)
3083                return;
3084
3085        /* Show all directories with more than x% of the changes */
3086        QSORT(dir.files, dir.nr, dirstat_compare);
3087        gather_dirstat(options, &dir, changed, "", 0);
3088}
3089
3090static void free_diffstat_info(struct diffstat_t *diffstat)
3091{
3092        int i;
3093        for (i = 0; i < diffstat->nr; i++) {
3094                struct diffstat_file *f = diffstat->files[i];
3095                free(f->print_name);
3096                free(f->name);
3097                free(f->from_name);
3098                free(f);
3099        }
3100        free(diffstat->files);
3101}
3102
3103struct checkdiff_t {
3104        const char *filename;
3105        int lineno;
3106        int conflict_marker_size;
3107        struct diff_options *o;
3108        unsigned ws_rule;
3109        unsigned status;
3110};
3111
3112static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
3113{
3114        char firstchar;
3115        int cnt;
3116
3117        if (len < marker_size + 1)
3118                return 0;
3119        firstchar = line[0];
3120        switch (firstchar) {
3121        case '=': case '>': case '<': case '|':
3122                break;
3123        default:
3124                return 0;
3125        }
3126        for (cnt = 1; cnt < marker_size; cnt++)
3127                if (line[cnt] != firstchar)
3128                        return 0;
3129        /* line[1] thru line[marker_size-1] are same as firstchar */
3130        if (len < marker_size + 1 || !isspace(line[marker_size]))
3131                return 0;
3132        return 1;
3133}
3134
3135static void checkdiff_consume_hunk(void *priv,
3136                                   long ob, long on, long nb, long nn,
3137                                   const char *func, long funclen)
3138
3139{
3140        struct checkdiff_t *data = priv;
3141        data->lineno = nb - 1;
3142}
3143
3144static void checkdiff_consume(void *priv, char *line, unsigned long len)
3145{
3146        struct checkdiff_t *data = priv;
3147        int marker_size = data->conflict_marker_size;
3148        const char *ws = diff_get_color(data->o->use_color, DIFF_WHITESPACE);
3149        const char *reset = diff_get_color(data->o->use_color, DIFF_RESET);
3150        const char *set = diff_get_color(data->o->use_color, DIFF_FILE_NEW);
3151        char *err;
3152        const char *line_prefix;
3153
3154        assert(data->o);
3155        line_prefix = diff_line_prefix(data->o);
3156
3157        if (line[0] == '+') {
3158                unsigned bad;
3159                data->lineno++;
3160                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
3161                        data->status |= 1;
3162                        fprintf(data->o->file,
3163                                "%s%s:%d: leftover conflict marker\n",
3164                                line_prefix, data->filename, data->lineno);
3165                }
3166                bad = ws_check(line + 1, len - 1, data->ws_rule);
3167                if (!bad)
3168                        return;
3169                data->status |= bad;
3170                err = whitespace_error_string(bad);
3171                fprintf(data->o->file, "%s%s:%d: %s.\n",
3172                        line_prefix, data->filename, data->lineno, err);
3173                free(err);
3174                emit_line(data->o, set, reset, line, 1);
3175                ws_check_emit(line + 1, len - 1, data->ws_rule,
3176                              data->o->file, set, reset, ws);
3177        } else if (line[0] == ' ') {
3178                data->lineno++;
3179        }
3180}
3181
3182static unsigned char *deflate_it(char *data,
3183                                 unsigned long size,
3184                                 unsigned long *result_size)
3185{
3186        int bound;
3187        unsigned char *deflated;
3188        git_zstream stream;
3189
3190        git_deflate_init(&stream, zlib_compression_level);
3191        bound = git_deflate_bound(&stream, size);
3192        deflated = xmalloc(bound);
3193        stream.next_out = deflated;
3194        stream.avail_out = bound;
3195
3196        stream.next_in = (unsigned char *)data;
3197        stream.avail_in = size;
3198        while (git_deflate(&stream, Z_FINISH) == Z_OK)
3199                ; /* nothing */
3200        git_deflate_end(&stream);
3201        *result_size = stream.total_out;
3202        return deflated;
3203}
3204
3205static void emit_binary_diff_body(struct diff_options *o,
3206                                  mmfile_t *one, mmfile_t *two)
3207{
3208        void *cp;
3209        void *delta;
3210        void *deflated;
3211        void *data;
3212        unsigned long orig_size;
3213        unsigned long delta_size;
3214        unsigned long deflate_size;
3215        unsigned long data_size;
3216
3217        /* We could do deflated delta, or we could do just deflated two,
3218         * whichever is smaller.
3219         */
3220        delta = NULL;
3221        deflated = deflate_it(two->ptr, two->size, &deflate_size);
3222        if (one->size && two->size) {
3223                delta = diff_delta(one->ptr, one->size,
3224                                   two->ptr, two->size,
3225                                   &delta_size, deflate_size);
3226                if (delta) {
3227                        void *to_free = delta;
3228                        orig_size = delta_size;
3229                        delta = deflate_it(delta, delta_size, &delta_size);
3230                        free(to_free);
3231                }
3232        }
3233
3234        if (delta && delta_size < deflate_size) {
3235                char *s = xstrfmt("%"PRIuMAX , (uintmax_t)orig_size);
3236                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA,
3237                                 s, strlen(s), 0);
3238                free(s);
3239                free(deflated);
3240                data = delta;
3241                data_size = delta_size;
3242        } else {
3243                char *s = xstrfmt("%lu", two->size);
3244                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL,
3245                                 s, strlen(s), 0);
3246                free(s);
3247                free(delta);
3248                data = deflated;
3249                data_size = deflate_size;
3250        }
3251
3252        /* emit data encoded in base85 */
3253        cp = data;
3254        while (data_size) {
3255                int len;
3256                int bytes = (52 < data_size) ? 52 : data_size;
3257                char line[71];
3258                data_size -= bytes;
3259                if (bytes <= 26)
3260                        line[0] = bytes + 'A' - 1;
3261                else
3262                        line[0] = bytes - 26 + 'a' - 1;
3263                encode_85(line + 1, cp, bytes);
3264                cp = (char *) cp + bytes;
3265
3266                len = strlen(line);
3267                line[len++] = '\n';
3268                line[len] = '\0';
3269
3270                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_BODY,
3271                                 line, len, 0);
3272        }
3273        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_FOOTER, NULL, 0, 0);
3274        free(data);
3275}
3276
3277static void emit_binary_diff(struct diff_options *o,
3278                             mmfile_t *one, mmfile_t *two)
3279{
3280        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER, NULL, 0, 0);
3281        emit_binary_diff_body(o, one, two);
3282        emit_binary_diff_body(o, two, one);
3283}
3284
3285int diff_filespec_is_binary(struct repository *r,
3286                            struct diff_filespec *one)
3287{
3288        if (one->is_binary == -1) {
3289                diff_filespec_load_driver(one, r->index);
3290                if (one->driver->binary != -1)
3291                        one->is_binary = one->driver->binary;
3292                else {
3293                        if (!one->data && DIFF_FILE_VALID(one))
3294                                diff_populate_filespec(r, one, CHECK_BINARY);
3295                        if (one->is_binary == -1 && one->data)
3296                                one->is_binary = buffer_is_binary(one->data,
3297                                                one->size);
3298                        if (one->is_binary == -1)
3299                                one->is_binary = 0;
3300                }
3301        }
3302        return one->is_binary;
3303}
3304
3305static const struct userdiff_funcname *
3306diff_funcname_pattern(struct diff_options *o, struct diff_filespec *one)
3307{
3308        diff_filespec_load_driver(one, o->repo->index);
3309        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
3310}
3311
3312void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
3313{
3314        if (!options->a_prefix)
3315                options->a_prefix = a;
3316        if (!options->b_prefix)
3317                options->b_prefix = b;
3318}
3319
3320struct userdiff_driver *get_textconv(struct repository *r,
3321                                     struct diff_filespec *one)
3322{
3323        if (!DIFF_FILE_VALID(one))
3324                return NULL;
3325
3326        diff_filespec_load_driver(one, r->index);
3327        return userdiff_get_textconv(r, one->driver);
3328}
3329
3330static void builtin_diff(const char *name_a,
3331                         const char *name_b,
3332                         struct diff_filespec *one,
3333                         struct diff_filespec *two,
3334                         const char *xfrm_msg,
3335                         int must_show_header,
3336                         struct diff_options *o,
3337                         int complete_rewrite)
3338{
3339        mmfile_t mf1, mf2;
3340        const char *lbl[2];
3341        char *a_one, *b_two;
3342        const char *meta = diff_get_color_opt(o, DIFF_METAINFO);
3343        const char *reset = diff_get_color_opt(o, DIFF_RESET);
3344        const char *a_prefix, *b_prefix;
3345        struct userdiff_driver *textconv_one = NULL;
3346        struct userdiff_driver *textconv_two = NULL;
3347        struct strbuf header = STRBUF_INIT;
3348        const char *line_prefix = diff_line_prefix(o);
3349
3350        diff_set_mnemonic_prefix(o, "a/", "b/");
3351        if (o->flags.reverse_diff) {
3352                a_prefix = o->b_prefix;
3353                b_prefix = o->a_prefix;
3354        } else {
3355                a_prefix = o->a_prefix;
3356                b_prefix = o->b_prefix;
3357        }
3358
3359        if (o->submodule_format == DIFF_SUBMODULE_LOG &&
3360            (!one->mode || S_ISGITLINK(one->mode)) &&
3361            (!two->mode || S_ISGITLINK(two->mode))) {
3362                show_submodule_summary(o, one->path ? one->path : two->path,
3363                                &one->oid, &two->oid,
3364                                two->dirty_submodule);
3365                return;
3366        } else if (o->submodule_format == DIFF_SUBMODULE_INLINE_DIFF &&
3367                   (!one->mode || S_ISGITLINK(one->mode)) &&
3368                   (!two->mode || S_ISGITLINK(two->mode))) {
3369                show_submodule_inline_diff(o, one->path ? one->path : two->path,
3370                                &one->oid, &two->oid,
3371                                two->dirty_submodule);
3372                return;
3373        }
3374
3375        if (o->flags.allow_textconv) {
3376                textconv_one = get_textconv(o->repo, one);
3377                textconv_two = get_textconv(o->repo, two);
3378        }
3379
3380        /* Never use a non-valid filename anywhere if at all possible */
3381        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
3382        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
3383
3384        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
3385        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
3386        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
3387        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
3388        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, meta, a_one, b_two, reset);
3389        if (lbl[0][0] == '/') {
3390                /* /dev/null */
3391                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, meta, two->mode, reset);
3392                if (xfrm_msg)
3393                        strbuf_addstr(&header, xfrm_msg);
3394                must_show_header = 1;
3395        }
3396        else if (lbl[1][0] == '/') {
3397                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, meta, one->mode, reset);
3398                if (xfrm_msg)
3399                        strbuf_addstr(&header, xfrm_msg);
3400                must_show_header = 1;
3401        }
3402        else {
3403                if (one->mode != two->mode) {
3404                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, meta, one->mode, reset);
3405                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, meta, two->mode, reset);
3406                        must_show_header = 1;
3407                }
3408                if (xfrm_msg)
3409                        strbuf_addstr(&header, xfrm_msg);
3410
3411                /*
3412                 * we do not run diff between different kind
3413                 * of objects.
3414                 */
3415                if ((one->mode ^ two->mode) & S_IFMT)
3416                        goto free_ab_and_return;
3417                if (complete_rewrite &&
3418                    (textconv_one || !diff_filespec_is_binary(o->repo, one)) &&
3419                    (textconv_two || !diff_filespec_is_binary(o->repo, two))) {
3420                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3421                                         header.buf, header.len, 0);
3422                        strbuf_reset(&header);
3423                        emit_rewrite_diff(name_a, name_b, one, two,
3424                                          textconv_one, textconv_two, o);
3425                        o->found_changes = 1;
3426                        goto free_ab_and_return;
3427                }
3428        }
3429
3430        if (o->irreversible_delete && lbl[1][0] == '/') {
3431                emit_diff_symbol(o, DIFF_SYMBOL_HEADER, header.buf,
3432                                 header.len, 0);
3433                strbuf_reset(&header);
3434                goto free_ab_and_return;
3435        } else if (!o->flags.text &&
3436                   ( (!textconv_one && diff_filespec_is_binary(o->repo, one)) ||
3437                     (!textconv_two && diff_filespec_is_binary(o->repo, two)) )) {
3438                struct strbuf sb = STRBUF_INIT;
3439                if (!one->data && !two->data &&
3440                    S_ISREG(one->mode) && S_ISREG(two->mode) &&
3441                    !o->flags.binary) {
3442                        if (oideq(&one->oid, &two->oid)) {
3443                                if (must_show_header)
3444                                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3445                                                         header.buf, header.len,
3446                                                         0);
3447                                goto free_ab_and_return;
3448                        }
3449                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3450                                         header.buf, header.len, 0);
3451                        strbuf_addf(&sb, "%sBinary files %s and %s differ\n",
3452                                    diff_line_prefix(o), lbl[0], lbl[1]);
3453                        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_FILES,
3454                                         sb.buf, sb.len, 0);
3455                        strbuf_release(&sb);
3456                        goto free_ab_and_return;
3457                }
3458                if (fill_mmfile(o->repo, &mf1, one) < 0 ||
3459                    fill_mmfile(o->repo, &mf2, two) < 0)
3460                        die("unable to read files to diff");
3461                /* Quite common confusing case */
3462                if (mf1.size == mf2.size &&
3463                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
3464                        if (must_show_header)
3465                                emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3466                                                 header.buf, header.len, 0);
3467                        goto free_ab_and_return;
3468                }
3469                emit_diff_symbol(o, DIFF_SYMBOL_HEADER, header.buf, header.len, 0);
3470                strbuf_reset(&header);
3471                if (o->flags.binary)
3472                        emit_binary_diff(o, &mf1, &mf2);
3473                else {
3474                        strbuf_addf(&sb, "%sBinary files %s and %s differ\n",
3475                                    diff_line_prefix(o), lbl[0], lbl[1]);
3476                        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_FILES,
3477                                         sb.buf, sb.len, 0);
3478                        strbuf_release(&sb);
3479                }
3480                o->found_changes = 1;
3481        } else {
3482                /* Crazy xdl interfaces.. */
3483                const char *diffopts = getenv("GIT_DIFF_OPTS");
3484                const char *v;
3485                xpparam_t xpp;
3486                xdemitconf_t xecfg;
3487                struct emit_callback ecbdata;
3488                const struct userdiff_funcname *pe;
3489
3490                if (must_show_header) {
3491                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3492                                         header.buf, header.len, 0);
3493                        strbuf_reset(&header);
3494                }
3495
3496                mf1.size = fill_textconv(o->repo, textconv_one, one, &mf1.ptr);
3497                mf2.size = fill_textconv(o->repo, textconv_two, two, &mf2.ptr);
3498
3499                pe = diff_funcname_pattern(o, one);
3500                if (!pe)
3501                        pe = diff_funcname_pattern(o, two);
3502
3503                memset(&xpp, 0, sizeof(xpp));
3504                memset(&xecfg, 0, sizeof(xecfg));
3505                memset(&ecbdata, 0, sizeof(ecbdata));
3506                if (o->flags.suppress_diff_headers)
3507                        lbl[0] = NULL;
3508                ecbdata.label_path = lbl;
3509                ecbdata.color_diff = want_color(o->use_color);
3510                ecbdata.ws_rule = whitespace_rule(o->repo->index, name_b);
3511                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
3512                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
3513                ecbdata.opt = o;
3514                if (header.len && !o->flags.suppress_diff_headers)
3515                        ecbdata.header = &header;
3516                xpp.flags = o->xdl_opts;
3517                xpp.anchors = o->anchors;
3518                xpp.anchors_nr = o->anchors_nr;
3519                xecfg.ctxlen = o->context;
3520                xecfg.interhunkctxlen = o->interhunkcontext;
3521                xecfg.flags = XDL_EMIT_FUNCNAMES;
3522                if (o->flags.funccontext)
3523                        xecfg.flags |= XDL_EMIT_FUNCCONTEXT;
3524                if (pe)
3525                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
3526                if (!diffopts)
3527                        ;
3528                else if (skip_prefix(diffopts, "--unified=", &v))
3529                        xecfg.ctxlen = strtoul(v, NULL, 10);
3530                else if (skip_prefix(diffopts, "-u", &v))
3531                        xecfg.ctxlen = strtoul(v, NULL, 10);
3532                if (o->word_diff)
3533                        init_diff_words_data(&ecbdata, o, one, two);
3534                if (xdi_diff_outf(&mf1, &mf2, NULL, fn_out_consume,
3535                                  &ecbdata, &xpp, &xecfg))
3536                        die("unable to generate diff for %s", one->path);
3537                if (o->word_diff)
3538                        free_diff_words_data(&ecbdata);
3539                if (textconv_one)
3540                        free(mf1.ptr);
3541                if (textconv_two)
3542                        free(mf2.ptr);
3543                xdiff_clear_find_func(&xecfg);
3544        }
3545
3546 free_ab_and_return:
3547        strbuf_release(&header);
3548        diff_free_filespec_data(one);
3549        diff_free_filespec_data(two);
3550        free(a_one);
3551        free(b_two);
3552        return;
3553}
3554
3555static char *get_compact_summary(const struct diff_filepair *p, int is_renamed)
3556{
3557        if (!is_renamed) {
3558                if (p->status == DIFF_STATUS_ADDED) {
3559                        if (S_ISLNK(p->two->mode))
3560                                return "new +l";
3561                        else if ((p->two->mode & 0777) == 0755)
3562                                return "new +x";
3563                        else
3564                                return "new";
3565                } else if (p->status == DIFF_STATUS_DELETED)
3566                        return "gone";
3567        }
3568        if (S_ISLNK(p->one->mode) && !S_ISLNK(p->two->mode))
3569                return "mode -l";
3570        else if (!S_ISLNK(p->one->mode) && S_ISLNK(p->two->mode))
3571                return "mode +l";
3572        else if ((p->one->mode & 0777) == 0644 &&
3573                 (p->two->mode & 0777) == 0755)
3574                return "mode +x";
3575        else if ((p->one->mode & 0777) == 0755 &&
3576                 (p->two->mode & 0777) == 0644)
3577                return "mode -x";
3578        return NULL;
3579}
3580
3581static void builtin_diffstat(const char *name_a, const char *name_b,
3582                             struct diff_filespec *one,
3583                             struct diff_filespec *two,
3584                             struct diffstat_t *diffstat,
3585                             struct diff_options *o,
3586                             struct diff_filepair *p)
3587{
3588        mmfile_t mf1, mf2;
3589        struct diffstat_file *data;
3590        int same_contents;
3591        int complete_rewrite = 0;
3592
3593        if (!DIFF_PAIR_UNMERGED(p)) {
3594                if (p->status == DIFF_STATUS_MODIFIED && p->score)
3595                        complete_rewrite = 1;
3596        }
3597
3598        data = diffstat_add(diffstat, name_a, name_b);
3599        data->is_interesting = p->status != DIFF_STATUS_UNKNOWN;
3600        if (o->flags.stat_with_summary)
3601                data->comments = get_compact_summary(p, data->is_renamed);
3602
3603        if (!one || !two) {
3604                data->is_unmerged = 1;
3605                return;
3606        }
3607
3608        same_contents = oideq(&one->oid, &two->oid);
3609
3610        if (diff_filespec_is_binary(o->repo, one) ||
3611            diff_filespec_is_binary(o->repo, two)) {
3612                data->is_binary = 1;
3613                if (same_contents) {
3614                        data->added = 0;
3615                        data->deleted = 0;
3616                } else {
3617                        data->added = diff_filespec_size(o->repo, two);
3618                        data->deleted = diff_filespec_size(o->repo, one);
3619                }
3620        }
3621
3622        else if (complete_rewrite) {
3623                diff_populate_filespec(o->repo, one, 0);
3624                diff_populate_filespec(o->repo, two, 0);
3625                data->deleted = count_lines(one->data, one->size);
3626                data->added = count_lines(two->data, two->size);
3627        }
3628
3629        else if (!same_contents) {
3630                /* Crazy xdl interfaces.. */
3631                xpparam_t xpp;
3632                xdemitconf_t xecfg;
3633
3634                if (fill_mmfile(o->repo, &mf1, one) < 0 ||
3635                    fill_mmfile(o->repo, &mf2, two) < 0)
3636                        die("unable to read files to diff");
3637
3638                memset(&xpp, 0, sizeof(xpp));
3639                memset(&xecfg, 0, sizeof(xecfg));
3640                xpp.flags = o->xdl_opts;
3641                xpp.anchors = o->anchors;
3642                xpp.anchors_nr = o->anchors_nr;
3643                xecfg.ctxlen = o->context;
3644                xecfg.interhunkctxlen = o->interhunkcontext;
3645                if (xdi_diff_outf(&mf1, &mf2, discard_hunk_line,
3646                                  diffstat_consume, diffstat, &xpp, &xecfg))
3647                        die("unable to generate diffstat for %s", one->path);
3648        }
3649
3650        diff_free_filespec_data(one);
3651        diff_free_filespec_data(two);
3652}
3653
3654static void builtin_checkdiff(const char *name_a, const char *name_b,
3655                              const char *attr_path,
3656                              struct diff_filespec *one,
3657                              struct diff_filespec *two,
3658                              struct diff_options *o)
3659{
3660        mmfile_t mf1, mf2;
3661        struct checkdiff_t data;
3662
3663        if (!two)
3664                return;
3665
3666        memset(&data, 0, sizeof(data));
3667        data.filename = name_b ? name_b : name_a;
3668        data.lineno = 0;
3669        data.o = o;
3670        data.ws_rule = whitespace_rule(o->repo->index, attr_path);
3671        data.conflict_marker_size = ll_merge_marker_size(o->repo->index, attr_path);
3672
3673        if (fill_mmfile(o->repo, &mf1, one) < 0 ||
3674            fill_mmfile(o->repo, &mf2, two) < 0)
3675                die("unable to read files to diff");
3676
3677        /*
3678         * All the other codepaths check both sides, but not checking
3679         * the "old" side here is deliberate.  We are checking the newly
3680         * introduced changes, and as long as the "new" side is text, we
3681         * can and should check what it introduces.
3682         */
3683        if (diff_filespec_is_binary(o->repo, two))
3684                goto free_and_return;
3685        else {
3686                /* Crazy xdl interfaces.. */
3687                xpparam_t xpp;
3688                xdemitconf_t xecfg;
3689
3690                memset(&xpp, 0, sizeof(xpp));
3691                memset(&xecfg, 0, sizeof(xecfg));
3692                xecfg.ctxlen = 1; /* at least one context line */
3693                xpp.flags = 0;
3694                if (xdi_diff_outf(&mf1, &mf2, checkdiff_consume_hunk,
3695                                  checkdiff_consume, &data,
3696                                  &xpp, &xecfg))
3697                        die("unable to generate checkdiff for %s", one->path);
3698
3699                if (data.ws_rule & WS_BLANK_AT_EOF) {
3700                        struct emit_callback ecbdata;
3701                        int blank_at_eof;
3702
3703                        ecbdata.ws_rule = data.ws_rule;
3704                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
3705                        blank_at_eof = ecbdata.blank_at_eof_in_postimage;
3706
3707                        if (blank_at_eof) {
3708                                static char *err;
3709                                if (!err)
3710                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
3711                                fprintf(o->file, "%s:%d: %s.\n",
3712                                        data.filename, blank_at_eof, err);
3713                                data.status = 1; /* report errors */
3714                        }
3715                }
3716        }
3717 free_and_return:
3718        diff_free_filespec_data(one);
3719        diff_free_filespec_data(two);
3720        if (data.status)
3721                o->flags.check_failed = 1;
3722}
3723
3724struct diff_filespec *alloc_filespec(const char *path)
3725{
3726        struct diff_filespec *spec;
3727
3728        FLEXPTR_ALLOC_STR(spec, path, path);
3729        spec->count = 1;
3730        spec->is_binary = -1;
3731        return spec;
3732}
3733
3734void free_filespec(struct diff_filespec *spec)
3735{
3736        if (!--spec->count) {
3737                diff_free_filespec_data(spec);
3738                free(spec);
3739        }
3740}
3741
3742void fill_filespec(struct diff_filespec *spec, const struct object_id *oid,
3743                   int oid_valid, unsigned short mode)
3744{
3745        if (mode) {
3746                spec->mode = canon_mode(mode);
3747                oidcpy(&spec->oid, oid);
3748                spec->oid_valid = oid_valid;
3749        }
3750}
3751
3752/*
3753 * Given a name and sha1 pair, if the index tells us the file in
3754 * the work tree has that object contents, return true, so that
3755 * prepare_temp_file() does not have to inflate and extract.
3756 */
3757static int reuse_worktree_file(struct index_state *istate,
3758                               const char *name,
3759                               const struct object_id *oid,
3760                               int want_file)
3761{
3762        const struct cache_entry *ce;
3763        struct stat st;
3764        int pos, len;
3765
3766        /*
3767         * We do not read the cache ourselves here, because the
3768         * benchmark with my previous version that always reads cache
3769         * shows that it makes things worse for diff-tree comparing
3770         * two linux-2.6 kernel trees in an already checked out work
3771         * tree.  This is because most diff-tree comparisons deal with
3772         * only a small number of files, while reading the cache is
3773         * expensive for a large project, and its cost outweighs the
3774         * savings we get by not inflating the object to a temporary
3775         * file.  Practically, this code only helps when we are used
3776         * by diff-cache --cached, which does read the cache before
3777         * calling us.
3778         */
3779        if (!istate->cache)
3780                return 0;
3781
3782        /* We want to avoid the working directory if our caller
3783         * doesn't need the data in a normal file, this system
3784         * is rather slow with its stat/open/mmap/close syscalls,
3785         * and the object is contained in a pack file.  The pack
3786         * is probably already open and will be faster to obtain
3787         * the data through than the working directory.  Loose
3788         * objects however would tend to be slower as they need
3789         * to be individually opened and inflated.
3790         */
3791        if (!FAST_WORKING_DIRECTORY && !want_file && has_object_pack(oid))
3792                return 0;
3793
3794        /*
3795         * Similarly, if we'd have to convert the file contents anyway, that
3796         * makes the optimization not worthwhile.
3797         */
3798        if (!want_file && would_convert_to_git(istate, name))
3799                return 0;
3800
3801        len = strlen(name);
3802        pos = index_name_pos(istate, name, len);
3803        if (pos < 0)
3804                return 0;
3805        ce = istate->cache[pos];
3806
3807        /*
3808         * This is not the sha1 we are looking for, or
3809         * unreusable because it is not a regular file.
3810         */
3811        if (!oideq(oid, &ce->oid) || !S_ISREG(ce->ce_mode))
3812                return 0;
3813
3814        /*
3815         * If ce is marked as "assume unchanged", there is no
3816         * guarantee that work tree matches what we are looking for.
3817         */
3818        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
3819                return 0;
3820
3821        /*
3822         * If ce matches the file in the work tree, we can reuse it.
3823         */
3824        if (ce_uptodate(ce) ||
3825            (!lstat(name, &st) && !ie_match_stat(istate, ce, &st, 0)))
3826                return 1;
3827
3828        return 0;
3829}
3830
3831static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
3832{
3833        struct strbuf buf = STRBUF_INIT;
3834        char *dirty = "";
3835
3836        /* Are we looking at the work tree? */
3837        if (s->dirty_submodule)
3838                dirty = "-dirty";
3839
3840        strbuf_addf(&buf, "Subproject commit %s%s\n",
3841                    oid_to_hex(&s->oid), dirty);
3842        s->size = buf.len;
3843        if (size_only) {
3844                s->data = NULL;
3845                strbuf_release(&buf);
3846        } else {
3847                s->data = strbuf_detach(&buf, NULL);
3848                s->should_free = 1;
3849        }
3850        return 0;
3851}
3852
3853/*
3854 * While doing rename detection and pickaxe operation, we may need to
3855 * grab the data for the blob (or file) for our own in-core comparison.
3856 * diff_filespec has data and size fields for this purpose.
3857 */
3858int diff_populate_filespec(struct repository *r,
3859                           struct diff_filespec *s,
3860                           unsigned int flags)
3861{
3862        int size_only = flags & CHECK_SIZE_ONLY;
3863        int err = 0;
3864        int conv_flags = global_conv_flags_eol;
3865        /*
3866         * demote FAIL to WARN to allow inspecting the situation
3867         * instead of refusing.
3868         */
3869        if (conv_flags & CONV_EOL_RNDTRP_DIE)
3870                conv_flags = CONV_EOL_RNDTRP_WARN;
3871
3872        if (!DIFF_FILE_VALID(s))
3873                die("internal error: asking to populate invalid file.");
3874        if (S_ISDIR(s->mode))
3875                return -1;
3876
3877        if (s->data)
3878                return 0;
3879
3880        if (size_only && 0 < s->size)
3881                return 0;
3882
3883        if (S_ISGITLINK(s->mode))
3884                return diff_populate_gitlink(s, size_only);
3885
3886        if (!s->oid_valid ||
3887            reuse_worktree_file(r->index, s->path, &s->oid, 0)) {
3888                struct strbuf buf = STRBUF_INIT;
3889                struct stat st;
3890                int fd;
3891
3892                if (lstat(s->path, &st) < 0) {
3893                err_empty:
3894                        err = -1;
3895                empty:
3896                        s->data = (char *)"";
3897                        s->size = 0;
3898                        return err;
3899                }
3900                s->size = xsize_t(st.st_size);
3901                if (!s->size)
3902                        goto empty;
3903                if (S_ISLNK(st.st_mode)) {
3904                        struct strbuf sb = STRBUF_INIT;
3905
3906                        if (strbuf_readlink(&sb, s->path, s->size))
3907                                goto err_empty;
3908                        s->size = sb.len;
3909                        s->data = strbuf_detach(&sb, NULL);
3910                        s->should_free = 1;
3911                        return 0;
3912                }
3913
3914                /*
3915                 * Even if the caller would be happy with getting
3916                 * only the size, we cannot return early at this
3917                 * point if the path requires us to run the content
3918                 * conversion.
3919                 */
3920                if (size_only && !would_convert_to_git(r->index, s->path))
3921                        return 0;
3922
3923                /*
3924                 * Note: this check uses xsize_t(st.st_size) that may
3925                 * not be the true size of the blob after it goes
3926                 * through convert_to_git().  This may not strictly be
3927                 * correct, but the whole point of big_file_threshold
3928                 * and is_binary check being that we want to avoid
3929                 * opening the file and inspecting the contents, this
3930                 * is probably fine.
3931                 */
3932                if ((flags & CHECK_BINARY) &&
3933                    s->size > big_file_threshold && s->is_binary == -1) {
3934                        s->is_binary = 1;
3935                        return 0;
3936                }
3937                fd = open(s->path, O_RDONLY);
3938                if (fd < 0)
3939                        goto err_empty;
3940                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
3941                close(fd);
3942                s->should_munmap = 1;
3943
3944                /*
3945                 * Convert from working tree format to canonical git format
3946                 */
3947                if (convert_to_git(r->index, s->path, s->data, s->size, &buf, conv_flags)) {
3948                        size_t size = 0;
3949                        munmap(s->data, s->size);
3950                        s->should_munmap = 0;
3951                        s->data = strbuf_detach(&buf, &size);
3952                        s->size = size;
3953                        s->should_free = 1;
3954                }
3955        }
3956        else {
3957                enum object_type type;
3958                if (size_only || (flags & CHECK_BINARY)) {
3959                        type = oid_object_info(r, &s->oid, &s->size);
3960                        if (type < 0)
3961                                die("unable to read %s",
3962                                    oid_to_hex(&s->oid));
3963                        if (size_only)
3964                                return 0;
3965                        if (s->size > big_file_threshold && s->is_binary == -1) {
3966                                s->is_binary = 1;
3967                                return 0;
3968                        }
3969                }
3970                s->data = read_object_file(&s->oid, &type, &s->size);
3971                if (!s->data)
3972                        die("unable to read %s", oid_to_hex(&s->oid));
3973                s->should_free = 1;
3974        }
3975        return 0;
3976}
3977
3978void diff_free_filespec_blob(struct diff_filespec *s)
3979{
3980        if (s->should_free)
3981                free(s->data);
3982        else if (s->should_munmap)
3983                munmap(s->data, s->size);
3984
3985        if (s->should_free || s->should_munmap) {
3986                s->should_free = s->should_munmap = 0;
3987                s->data = NULL;
3988        }
3989}
3990
3991void diff_free_filespec_data(struct diff_filespec *s)
3992{
3993        diff_free_filespec_blob(s);
3994        FREE_AND_NULL(s->cnt_data);
3995}
3996
3997static void prep_temp_blob(struct index_state *istate,
3998                           const char *path, struct diff_tempfile *temp,
3999                           void *blob,
4000                           unsigned long size,
4001                           const struct object_id *oid,
4002                           int mode)
4003{
4004        struct strbuf buf = STRBUF_INIT;
4005        struct strbuf tempfile = STRBUF_INIT;
4006        char *path_dup = xstrdup(path);
4007        const char *base = basename(path_dup);
4008
4009        /* Generate "XXXXXX_basename.ext" */
4010        strbuf_addstr(&tempfile, "XXXXXX_");
4011        strbuf_addstr(&tempfile, base);
4012
4013        temp->tempfile = mks_tempfile_ts(tempfile.buf, strlen(base) + 1);
4014        if (!temp->tempfile)
4015                die_errno("unable to create temp-file");
4016        if (convert_to_working_tree(istate, path,
4017                        (const char *)blob, (size_t)size, &buf)) {
4018                blob = buf.buf;
4019                size = buf.len;
4020        }
4021        if (write_in_full(temp->tempfile->fd, blob, size) < 0 ||
4022            close_tempfile_gently(temp->tempfile))
4023                die_errno("unable to write temp-file");
4024        temp->name = get_tempfile_path(temp->tempfile);
4025        oid_to_hex_r(temp->hex, oid);
4026        xsnprintf(temp->mode, sizeof(temp->mode), "%06o", mode);
4027        strbuf_release(&buf);
4028        strbuf_release(&tempfile);
4029        free(path_dup);
4030}
4031
4032static struct diff_tempfile *prepare_temp_file(struct repository *r,
4033                                               const char *name,
4034                                               struct diff_filespec *one)
4035{
4036        struct diff_tempfile *temp = claim_diff_tempfile();
4037
4038        if (!DIFF_FILE_VALID(one)) {
4039        not_a_valid_file:
4040                /* A '-' entry produces this for file-2, and
4041                 * a '+' entry produces this for file-1.
4042                 */
4043                temp->name = "/dev/null";
4044                xsnprintf(temp->hex, sizeof(temp->hex), ".");
4045                xsnprintf(temp->mode, sizeof(temp->mode), ".");
4046                return temp;
4047        }
4048
4049        if (!S_ISGITLINK(one->mode) &&
4050            (!one->oid_valid ||
4051             reuse_worktree_file(r->index, name, &one->oid, 1))) {
4052                struct stat st;
4053                if (lstat(name, &st) < 0) {
4054                        if (errno == ENOENT)
4055                                goto not_a_valid_file;
4056                        die_errno("stat(%s)", name);
4057                }
4058                if (S_ISLNK(st.st_mode)) {
4059                        struct strbuf sb = STRBUF_INIT;
4060                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
4061                                die_errno("readlink(%s)", name);
4062                        prep_temp_blob(r->index, name, temp, sb.buf, sb.len,
4063                                       (one->oid_valid ?
4064                                        &one->oid : &null_oid),
4065                                       (one->oid_valid ?
4066                                        one->mode : S_IFLNK));
4067                        strbuf_release(&sb);
4068                }
4069                else {
4070                        /* we can borrow from the file in the work tree */
4071                        temp->name = name;
4072                        if (!one->oid_valid)
4073                                oid_to_hex_r(temp->hex, &null_oid);
4074                        else
4075                                oid_to_hex_r(temp->hex, &one->oid);
4076                        /* Even though we may sometimes borrow the
4077                         * contents from the work tree, we always want
4078                         * one->mode.  mode is trustworthy even when
4079                         * !(one->oid_valid), as long as
4080                         * DIFF_FILE_VALID(one).
4081                         */
4082                        xsnprintf(temp->mode, sizeof(temp->mode), "%06o", one->mode);
4083                }
4084                return temp;
4085        }
4086        else {
4087                if (diff_populate_filespec(r, one, 0))
4088                        die("cannot read data blob for %s", one->path);
4089                prep_temp_blob(r->index, name, temp,
4090                               one->data, one->size,
4091                               &one->oid, one->mode);
4092        }
4093        return temp;
4094}
4095
4096static void add_external_diff_name(struct repository *r,
4097                                   struct argv_array *argv,
4098                                   const char *name,
4099                                   struct diff_filespec *df)
4100{
4101        struct diff_tempfile *temp = prepare_temp_file(r, name, df);
4102        argv_array_push(argv, temp->name);
4103        argv_array_push(argv, temp->hex);
4104        argv_array_push(argv, temp->mode);
4105}
4106
4107/* An external diff command takes:
4108 *
4109 * diff-cmd name infile1 infile1-sha1 infile1-mode \
4110 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
4111 *
4112 */
4113static void run_external_diff(const char *pgm,
4114                              const char *name,
4115                              const char *other,
4116                              struct diff_filespec *one,
4117                              struct diff_filespec *two,
4118                              const char *xfrm_msg,
4119                              int complete_rewrite,
4120                              struct diff_options *o)
4121{
4122        struct argv_array argv = ARGV_ARRAY_INIT;
4123        struct argv_array env = ARGV_ARRAY_INIT;
4124        struct diff_queue_struct *q = &diff_queued_diff;
4125
4126        argv_array_push(&argv, pgm);
4127        argv_array_push(&argv, name);
4128
4129        if (one && two) {
4130                add_external_diff_name(o->repo, &argv, name, one);
4131                if (!other)
4132                        add_external_diff_name(o->repo, &argv, name, two);
4133                else {
4134                        add_external_diff_name(o->repo, &argv, other, two);
4135                        argv_array_push(&argv, other);
4136                        argv_array_push(&argv, xfrm_msg);
4137                }
4138        }
4139
4140        argv_array_pushf(&env, "GIT_DIFF_PATH_COUNTER=%d", ++o->diff_path_counter);
4141        argv_array_pushf(&env, "GIT_DIFF_PATH_TOTAL=%d", q->nr);
4142
4143        if (run_command_v_opt_cd_env(argv.argv, RUN_USING_SHELL, NULL, env.argv))
4144                die(_("external diff died, stopping at %s"), name);
4145
4146        remove_tempfile();
4147        argv_array_clear(&argv);
4148        argv_array_clear(&env);
4149}
4150
4151static int similarity_index(struct diff_filepair *p)
4152{
4153        return p->score * 100 / MAX_SCORE;
4154}
4155
4156static const char *diff_abbrev_oid(const struct object_id *oid, int abbrev)
4157{
4158        if (startup_info->have_repository)
4159                return find_unique_abbrev(oid, abbrev);
4160        else {
4161                char *hex = oid_to_hex(oid);
4162                if (abbrev < 0)
4163                        abbrev = FALLBACK_DEFAULT_ABBREV;
4164                if (abbrev > the_hash_algo->hexsz)
4165                        BUG("oid abbreviation out of range: %d", abbrev);
4166                if (abbrev)
4167                        hex[abbrev] = '\0';
4168                return hex;
4169        }
4170}
4171
4172static void fill_metainfo(struct strbuf *msg,
4173                          const char *name,
4174                          const char *other,
4175                          struct diff_filespec *one,
4176                          struct diff_filespec *two,
4177                          struct diff_options *o,
4178                          struct diff_filepair *p,
4179                          int *must_show_header,
4180                          int use_color)
4181{
4182        const char *set = diff_get_color(use_color, DIFF_METAINFO);
4183        const char *reset = diff_get_color(use_color, DIFF_RESET);
4184        const char *line_prefix = diff_line_prefix(o);
4185
4186        *must_show_header = 1;
4187        strbuf_init(msg, PATH_MAX * 2 + 300);
4188        switch (p->status) {
4189        case DIFF_STATUS_COPIED:
4190                strbuf_addf(msg, "%s%ssimilarity index %d%%",
4191                            line_prefix, set, similarity_index(p));
4192                strbuf_addf(msg, "%s\n%s%scopy from ",
4193                            reset,  line_prefix, set);
4194                quote_c_style(name, msg, NULL, 0);
4195                strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
4196                quote_c_style(other, msg, NULL, 0);
4197                strbuf_addf(msg, "%s\n", reset);
4198                break;
4199        case DIFF_STATUS_RENAMED:
4200                strbuf_addf(msg, "%s%ssimilarity index %d%%",
4201                            line_prefix, set, similarity_index(p));
4202                strbuf_addf(msg, "%s\n%s%srename from ",
4203                            reset, line_prefix, set);
4204                quote_c_style(name, msg, NULL, 0);
4205                strbuf_addf(msg, "%s\n%s%srename to ",
4206                            reset, line_prefix, set);
4207                quote_c_style(other, msg, NULL, 0);
4208                strbuf_addf(msg, "%s\n", reset);
4209                break;
4210        case DIFF_STATUS_MODIFIED:
4211                if (p->score) {
4212                        strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
4213                                    line_prefix,
4214                                    set, similarity_index(p), reset);
4215                        break;
4216                }
4217                /* fallthru */
4218        default:
4219                *must_show_header = 0;
4220        }
4221        if (one && two && !oideq(&one->oid, &two->oid)) {
4222                const unsigned hexsz = the_hash_algo->hexsz;
4223                int abbrev = o->flags.full_index ? hexsz : DEFAULT_ABBREV;
4224
4225                if (o->flags.binary) {
4226                        mmfile_t mf;
4227                        if ((!fill_mmfile(o->repo, &mf, one) &&
4228                             diff_filespec_is_binary(o->repo, one)) ||
4229                            (!fill_mmfile(o->repo, &mf, two) &&
4230                             diff_filespec_is_binary(o->repo, two)))
4231                                abbrev = hexsz;
4232                }
4233                strbuf_addf(msg, "%s%sindex %s..%s", line_prefix, set,
4234                            diff_abbrev_oid(&one->oid, abbrev),
4235                            diff_abbrev_oid(&two->oid, abbrev));
4236                if (one->mode == two->mode)
4237                        strbuf_addf(msg, " %06o", one->mode);
4238                strbuf_addf(msg, "%s\n", reset);
4239        }
4240}
4241
4242static void run_diff_cmd(const char *pgm,
4243                         const char *name,
4244                         const char *other,
4245                         const char *attr_path,
4246                         struct diff_filespec *one,
4247                         struct diff_filespec *two,
4248                         struct strbuf *msg,
4249                         struct diff_options *o,
4250                         struct diff_filepair *p)
4251{
4252        const char *xfrm_msg = NULL;
4253        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
4254        int must_show_header = 0;
4255
4256
4257        if (o->flags.allow_external) {
4258                struct userdiff_driver *drv;
4259
4260                drv = userdiff_find_by_path(o->repo->index, attr_path);
4261                if (drv && drv->external)
4262                        pgm = drv->external;
4263        }
4264
4265        if (msg) {
4266                /*
4267                 * don't use colors when the header is intended for an
4268                 * external diff driver
4269                 */
4270                fill_metainfo(msg, name, other, one, two, o, p,
4271                              &must_show_header,
4272                              want_color(o->use_color) && !pgm);
4273                xfrm_msg = msg->len ? msg->buf : NULL;
4274        }
4275
4276        if (pgm) {
4277                run_external_diff(pgm, name, other, one, two, xfrm_msg,
4278                                  complete_rewrite, o);
4279                return;
4280        }
4281        if (one && two)
4282                builtin_diff(name, other ? other : name,
4283                             one, two, xfrm_msg, must_show_header,
4284                             o, complete_rewrite);
4285        else
4286                fprintf(o->file, "* Unmerged path %s\n", name);
4287}
4288
4289static void diff_fill_oid_info(struct diff_filespec *one, struct index_state *istate)
4290{
4291        if (DIFF_FILE_VALID(one)) {
4292                if (!one->oid_valid) {
4293                        struct stat st;
4294                        if (one->is_stdin) {
4295                                oidclr(&one->oid);
4296                                return;
4297                        }
4298                        if (lstat(one->path, &st) < 0)
4299                                die_errno("stat '%s'", one->path);
4300                        if (index_path(istate, &one->oid, one->path, &st, 0))
4301                                die("cannot hash %s", one->path);
4302                }
4303        }
4304        else
4305                oidclr(&one->oid);
4306}
4307
4308static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
4309{
4310        /* Strip the prefix but do not molest /dev/null and absolute paths */
4311        if (*namep && !is_absolute_path(*namep)) {
4312                *namep += prefix_length;
4313                if (**namep == '/')
4314                        ++*namep;
4315        }
4316        if (*otherp && !is_absolute_path(*otherp)) {
4317                *otherp += prefix_length;
4318                if (**otherp == '/')
4319                        ++*otherp;
4320        }
4321}
4322
4323static void run_diff(struct diff_filepair *p, struct diff_options *o)
4324{
4325        const char *pgm = external_diff();
4326        struct strbuf msg;
4327        struct diff_filespec *one = p->one;
4328        struct diff_filespec *two = p->two;
4329        const char *name;
4330        const char *other;
4331        const char *attr_path;
4332
4333        name  = one->path;
4334        other = (strcmp(name, two->path) ? two->path : NULL);
4335        attr_path = name;
4336        if (o->prefix_length)
4337                strip_prefix(o->prefix_length, &name, &other);
4338
4339        if (!o->flags.allow_external)
4340                pgm = NULL;
4341
4342        if (DIFF_PAIR_UNMERGED(p)) {
4343                run_diff_cmd(pgm, name, NULL, attr_path,
4344                             NULL, NULL, NULL, o, p);
4345                return;
4346        }
4347
4348        diff_fill_oid_info(one, o->repo->index);
4349        diff_fill_oid_info(two, o->repo->index);
4350
4351        if (!pgm &&
4352            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
4353            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
4354                /*
4355                 * a filepair that changes between file and symlink
4356                 * needs to be split into deletion and creation.
4357                 */
4358                struct diff_filespec *null = alloc_filespec(two->path);
4359                run_diff_cmd(NULL, name, other, attr_path,
4360                             one, null, &msg,
4361                             o, p);
4362                free(null);
4363                strbuf_release(&msg);
4364
4365                null = alloc_filespec(one->path);
4366                run_diff_cmd(NULL, name, other, attr_path,
4367                             null, two, &msg, o, p);
4368                free(null);
4369        }
4370        else
4371                run_diff_cmd(pgm, name, other, attr_path,
4372                             one, two, &msg, o, p);
4373
4374        strbuf_release(&msg);
4375}
4376
4377static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
4378                         struct diffstat_t *diffstat)
4379{
4380        const char *name;
4381        const char *other;
4382
4383        if (DIFF_PAIR_UNMERGED(p)) {
4384                /* unmerged */
4385                builtin_diffstat(p->one->path, NULL, NULL, NULL,
4386                                 diffstat, o, p);
4387                return;
4388        }
4389
4390        name = p->one->path;
4391        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
4392
4393        if (o->prefix_length)
4394                strip_prefix(o->prefix_length, &name, &other);
4395
4396        diff_fill_oid_info(p->one, o->repo->index);
4397        diff_fill_oid_info(p->two, o->repo->index);
4398
4399        builtin_diffstat(name, other, p->one, p->two,
4400                         diffstat, o, p);
4401}
4402
4403static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
4404{
4405        const char *name;
4406        const char *other;
4407        const char *attr_path;
4408
4409        if (DIFF_PAIR_UNMERGED(p)) {
4410                /* unmerged */
4411                return;
4412        }
4413
4414        name = p->one->path;
4415        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
4416        attr_path = other ? other : name;
4417
4418        if (o->prefix_length)
4419                strip_prefix(o->prefix_length, &name, &other);
4420
4421        diff_fill_oid_info(p->one, o->repo->index);
4422        diff_fill_oid_info(p->two, o->repo->index);
4423
4424        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
4425}
4426
4427void repo_diff_setup(struct repository *r, struct diff_options *options)
4428{
4429        memcpy(options, &default_diff_options, sizeof(*options));
4430
4431        options->file = stdout;
4432        options->repo = r;
4433
4434        options->output_indicators[OUTPUT_INDICATOR_NEW] = '+';
4435        options->output_indicators[OUTPUT_INDICATOR_OLD] = '-';
4436        options->output_indicators[OUTPUT_INDICATOR_CONTEXT] = ' ';
4437        options->abbrev = DEFAULT_ABBREV;
4438        options->line_termination = '\n';
4439        options->break_opt = -1;
4440        options->rename_limit = -1;
4441        options->dirstat_permille = diff_dirstat_permille_default;
4442        options->context = diff_context_default;
4443        options->interhunkcontext = diff_interhunk_context_default;
4444        options->ws_error_highlight = ws_error_highlight_default;
4445        options->flags.rename_empty = 1;
4446        options->objfind = NULL;
4447
4448        /* pathchange left =NULL by default */
4449        options->change = diff_change;
4450        options->add_remove = diff_addremove;
4451        options->use_color = diff_use_color_default;
4452        options->detect_rename = diff_detect_rename_default;
4453        options->xdl_opts |= diff_algorithm;
4454        if (diff_indent_heuristic)
4455                DIFF_XDL_SET(options, INDENT_HEURISTIC);
4456
4457        options->orderfile = diff_order_file_cfg;
4458
4459        if (diff_no_prefix) {
4460                options->a_prefix = options->b_prefix = "";
4461        } else if (!diff_mnemonic_prefix) {
4462                options->a_prefix = "a/";
4463                options->b_prefix = "b/";
4464        }
4465
4466        options->color_moved = diff_color_moved_default;
4467        options->color_moved_ws_handling = diff_color_moved_ws_default;
4468}
4469
4470void diff_setup_done(struct diff_options *options)
4471{
4472        unsigned check_mask = DIFF_FORMAT_NAME |
4473                              DIFF_FORMAT_NAME_STATUS |
4474                              DIFF_FORMAT_CHECKDIFF |
4475                              DIFF_FORMAT_NO_OUTPUT;
4476        /*
4477         * This must be signed because we're comparing against a potentially
4478         * negative value.
4479         */
4480        const int hexsz = the_hash_algo->hexsz;
4481
4482        if (options->set_default)
4483                options->set_default(options);
4484
4485        if (HAS_MULTI_BITS(options->output_format & check_mask))
4486                die(_("--name-only, --name-status, --check and -s are mutually exclusive"));
4487
4488        if (HAS_MULTI_BITS(options->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK))
4489                die(_("-G, -S and --find-object are mutually exclusive"));
4490
4491        /*
4492         * Most of the time we can say "there are changes"
4493         * only by checking if there are changed paths, but
4494         * --ignore-whitespace* options force us to look
4495         * inside contents.
4496         */
4497
4498        if ((options->xdl_opts & XDF_WHITESPACE_FLAGS))
4499                options->flags.diff_from_contents = 1;
4500        else
4501                options->flags.diff_from_contents = 0;
4502
4503        if (options->flags.find_copies_harder)
4504                options->detect_rename = DIFF_DETECT_COPY;
4505
4506        if (!options->flags.relative_name)
4507                options->prefix = NULL;
4508        if (options->prefix)
4509                options->prefix_length = strlen(options->prefix);
4510        else
4511                options->prefix_length = 0;
4512
4513        if (options->output_format & (DIFF_FORMAT_NAME |
4514                                      DIFF_FORMAT_NAME_STATUS |
4515                                      DIFF_FORMAT_CHECKDIFF |
4516                                      DIFF_FORMAT_NO_OUTPUT))
4517                options->output_format &= ~(DIFF_FORMAT_RAW |
4518                                            DIFF_FORMAT_NUMSTAT |
4519                                            DIFF_FORMAT_DIFFSTAT |
4520                                            DIFF_FORMAT_SHORTSTAT |
4521                                            DIFF_FORMAT_DIRSTAT |
4522                                            DIFF_FORMAT_SUMMARY |
4523                                            DIFF_FORMAT_PATCH);
4524
4525        /*
4526         * These cases always need recursive; we do not drop caller-supplied
4527         * recursive bits for other formats here.
4528         */
4529        if (options->output_format & (DIFF_FORMAT_PATCH |
4530                                      DIFF_FORMAT_NUMSTAT |
4531                                      DIFF_FORMAT_DIFFSTAT |
4532                                      DIFF_FORMAT_SHORTSTAT |
4533                                      DIFF_FORMAT_DIRSTAT |
4534                                      DIFF_FORMAT_SUMMARY |
4535                                      DIFF_FORMAT_CHECKDIFF))
4536                options->flags.recursive = 1;
4537        /*
4538         * Also pickaxe would not work very well if you do not say recursive
4539         */
4540        if (options->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK)
4541                options->flags.recursive = 1;
4542        /*
4543         * When patches are generated, submodules diffed against the work tree
4544         * must be checked for dirtiness too so it can be shown in the output
4545         */
4546        if (options->output_format & DIFF_FORMAT_PATCH)
4547                options->flags.dirty_submodules = 1;
4548
4549        if (options->detect_rename && options->rename_limit < 0)
4550                options->rename_limit = diff_rename_limit_default;
4551        if (hexsz < options->abbrev)
4552                options->abbrev = hexsz; /* full */
4553
4554        /*
4555         * It does not make sense to show the first hit we happened
4556         * to have found.  It does not make sense not to return with
4557         * exit code in such a case either.
4558         */
4559        if (options->flags.quick) {
4560                options->output_format = DIFF_FORMAT_NO_OUTPUT;
4561                options->flags.exit_with_status = 1;
4562        }
4563
4564        options->diff_path_counter = 0;
4565
4566        if (options->flags.follow_renames && options->pathspec.nr != 1)
4567                die(_("--follow requires exactly one pathspec"));
4568
4569        if (!options->use_color || external_diff())
4570                options->color_moved = 0;
4571}
4572
4573static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
4574{
4575        char c, *eq;
4576        int len;
4577
4578        if (*arg != '-')
4579                return 0;
4580        c = *++arg;
4581        if (!c)
4582                return 0;
4583        if (c == arg_short) {
4584                c = *++arg;
4585                if (!c)
4586                        return 1;
4587                if (val && isdigit(c)) {
4588                        char *end;
4589                        int n = strtoul(arg, &end, 10);
4590                        if (*end)
4591                                return 0;
4592                        *val = n;
4593                        return 1;
4594                }
4595                return 0;
4596        }
4597        if (c != '-')
4598                return 0;
4599        arg++;
4600        eq = strchrnul(arg, '=');
4601        len = eq - arg;
4602        if (!len || strncmp(arg, arg_long, len))
4603                return 0;
4604        if (*eq) {
4605                int n;
4606                char *end;
4607                if (!isdigit(*++eq))
4608                        return 0;
4609                n = strtoul(eq, &end, 10);
4610                if (*end)
4611                        return 0;
4612                *val = n;
4613        }
4614        return 1;
4615}
4616
4617static int diff_scoreopt_parse(const char *opt);
4618
4619static inline int short_opt(char opt, const char **argv,
4620                            const char **optarg)
4621{
4622        const char *arg = argv[0];
4623        if (arg[0] != '-' || arg[1] != opt)
4624                return 0;
4625        if (arg[2] != '\0') {
4626                *optarg = arg + 2;
4627                return 1;
4628        }
4629        if (!argv[1])
4630                die("Option '%c' requires a value", opt);
4631        *optarg = argv[1];
4632        return 2;
4633}
4634
4635int parse_long_opt(const char *opt, const char **argv,
4636                   const char **optarg)
4637{
4638        const char *arg = argv[0];
4639        if (!skip_prefix(arg, "--", &arg))
4640                return 0;
4641        if (!skip_prefix(arg, opt, &arg))
4642                return 0;
4643        if (*arg == '=') { /* stuck form: --option=value */
4644                *optarg = arg + 1;
4645                return 1;
4646        }
4647        if (*arg != '\0')
4648                return 0;
4649        /* separate form: --option value */
4650        if (!argv[1])
4651                die("Option '--%s' requires a value", opt);
4652        *optarg = argv[1];
4653        return 2;
4654}
4655
4656static int stat_opt(struct diff_options *options, const char **av)
4657{
4658        const char *arg = av[0];
4659        char *end;
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        int argcount = 1;
4665
4666        if (!skip_prefix(arg, "--stat", &arg))
4667                BUG("stat option does not begin with --stat: %s", arg);
4668        end = (char *)arg;
4669
4670        switch (*arg) {
4671        case '-':
4672                if (skip_prefix(arg, "-width", &arg)) {
4673                        if (*arg == '=')
4674                                width = strtoul(arg + 1, &end, 10);
4675                        else if (!*arg && !av[1])
4676                                die_want_option("--stat-width");
4677                        else if (!*arg) {
4678                                width = strtoul(av[1], &end, 10);
4679                                argcount = 2;
4680                        }
4681                } else if (skip_prefix(arg, "-name-width", &arg)) {
4682                        if (*arg == '=')
4683                                name_width = strtoul(arg + 1, &end, 10);
4684                        else if (!*arg && !av[1])
4685                                die_want_option("--stat-name-width");
4686                        else if (!*arg) {
4687                                name_width = strtoul(av[1], &end, 10);
4688                                argcount = 2;
4689                        }
4690                } else if (skip_prefix(arg, "-graph-width", &arg)) {
4691                        if (*arg == '=')
4692                                graph_width = strtoul(arg + 1, &end, 10);
4693                        else if (!*arg && !av[1])
4694                                die_want_option("--stat-graph-width");
4695                        else if (!*arg) {
4696                                graph_width = strtoul(av[1], &end, 10);
4697                                argcount = 2;
4698                        }
4699                } else if (skip_prefix(arg, "-count", &arg)) {
4700                        if (*arg == '=')
4701                                count = strtoul(arg + 1, &end, 10);
4702                        else if (!*arg && !av[1])
4703                                die_want_option("--stat-count");
4704                        else if (!*arg) {
4705                                count = strtoul(av[1], &end, 10);
4706                                argcount = 2;
4707                        }
4708                }
4709                break;
4710        case '=':
4711                width = strtoul(arg+1, &end, 10);
4712                if (*end == ',')
4713                        name_width = strtoul(end+1, &end, 10);
4714                if (*end == ',')
4715                        count = strtoul(end+1, &end, 10);
4716        }
4717
4718        /* Important! This checks all the error cases! */
4719        if (*end)
4720                return 0;
4721        options->output_format |= DIFF_FORMAT_DIFFSTAT;
4722        options->stat_name_width = name_width;
4723        options->stat_graph_width = graph_width;
4724        options->stat_width = width;
4725        options->stat_count = count;
4726        return argcount;
4727}
4728
4729static int parse_dirstat_opt(struct diff_options *options, const char *params)
4730{
4731        struct strbuf errmsg = STRBUF_INIT;
4732        if (parse_dirstat_params(options, params, &errmsg))
4733                die(_("Failed to parse --dirstat/-X option parameter:\n%s"),
4734                    errmsg.buf);
4735        strbuf_release(&errmsg);
4736        /*
4737         * The caller knows a dirstat-related option is given from the command
4738         * line; allow it to say "return this_function();"
4739         */
4740        options->output_format |= DIFF_FORMAT_DIRSTAT;
4741        return 1;
4742}
4743
4744static int parse_submodule_opt(struct diff_options *options, const char *value)
4745{
4746        if (parse_submodule_params(options, value))
4747                die(_("Failed to parse --submodule option parameter: '%s'"),
4748                        value);
4749        return 1;
4750}
4751
4752static const char diff_status_letters[] = {
4753        DIFF_STATUS_ADDED,
4754        DIFF_STATUS_COPIED,
4755        DIFF_STATUS_DELETED,
4756        DIFF_STATUS_MODIFIED,
4757        DIFF_STATUS_RENAMED,
4758        DIFF_STATUS_TYPE_CHANGED,
4759        DIFF_STATUS_UNKNOWN,
4760        DIFF_STATUS_UNMERGED,
4761        DIFF_STATUS_FILTER_AON,
4762        DIFF_STATUS_FILTER_BROKEN,
4763        '\0',
4764};
4765
4766static unsigned int filter_bit['Z' + 1];
4767
4768static void prepare_filter_bits(void)
4769{
4770        int i;
4771
4772        if (!filter_bit[DIFF_STATUS_ADDED]) {
4773                for (i = 0; diff_status_letters[i]; i++)
4774                        filter_bit[(int) diff_status_letters[i]] = (1 << i);
4775        }
4776}
4777
4778static unsigned filter_bit_tst(char status, const struct diff_options *opt)
4779{
4780        return opt->filter & filter_bit[(int) status];
4781}
4782
4783static int parse_diff_filter_opt(const char *optarg, struct diff_options *opt)
4784{
4785        int i, optch;
4786
4787        prepare_filter_bits();
4788
4789        /*
4790         * If there is a negation e.g. 'd' in the input, and we haven't
4791         * initialized the filter field with another --diff-filter, start
4792         * from full set of bits, except for AON.
4793         */
4794        if (!opt->filter) {
4795                for (i = 0; (optch = optarg[i]) != '\0'; i++) {
4796                        if (optch < 'a' || 'z' < optch)
4797                                continue;
4798                        opt->filter = (1 << (ARRAY_SIZE(diff_status_letters) - 1)) - 1;
4799                        opt->filter &= ~filter_bit[DIFF_STATUS_FILTER_AON];
4800                        break;
4801                }
4802        }
4803
4804        for (i = 0; (optch = optarg[i]) != '\0'; i++) {
4805                unsigned int bit;
4806                int negate;
4807
4808                if ('a' <= optch && optch <= 'z') {
4809                        negate = 1;
4810                        optch = toupper(optch);
4811                } else {
4812                        negate = 0;
4813                }
4814
4815                bit = (0 <= optch && optch <= 'Z') ? filter_bit[optch] : 0;
4816                if (!bit)
4817                        return optarg[i];
4818                if (negate)
4819                        opt->filter &= ~bit;
4820                else
4821                        opt->filter |= bit;
4822        }
4823        return 0;
4824}
4825
4826static void enable_patch_output(int *fmt) {
4827        *fmt &= ~DIFF_FORMAT_NO_OUTPUT;
4828        *fmt |= DIFF_FORMAT_PATCH;
4829}
4830
4831static int parse_ws_error_highlight_opt(struct diff_options *opt, const char *arg)
4832{
4833        int val = parse_ws_error_highlight(arg);
4834
4835        if (val < 0) {
4836                error("unknown value after ws-error-highlight=%.*s",
4837                      -1 - val, arg);
4838                return 0;
4839        }
4840        opt->ws_error_highlight = val;
4841        return 1;
4842}
4843
4844static int parse_objfind_opt(struct diff_options *opt, const char *arg)
4845{
4846        struct object_id oid;
4847
4848        if (get_oid(arg, &oid))
4849                return error("unable to resolve '%s'", arg);
4850
4851        if (!opt->objfind)
4852                opt->objfind = xcalloc(1, sizeof(*opt->objfind));
4853
4854        opt->pickaxe_opts |= DIFF_PICKAXE_KIND_OBJFIND;
4855        opt->flags.recursive = 1;
4856        opt->flags.tree_in_recursive = 1;
4857        oidset_insert(opt->objfind, &oid);
4858        return 1;
4859}
4860
4861int diff_opt_parse(struct diff_options *options,
4862                   const char **av, int ac, const char *prefix)
4863{
4864        const char *arg = av[0];
4865        const char *optarg;
4866        int argcount;
4867
4868        if (!prefix)
4869                prefix = "";
4870
4871        /* Output format options */
4872        if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch")
4873            || opt_arg(arg, 'U', "unified", &options->context))
4874                enable_patch_output(&options->output_format);
4875        else if (!strcmp(arg, "--raw"))
4876                options->output_format |= DIFF_FORMAT_RAW;
4877        else if (!strcmp(arg, "--patch-with-raw")) {
4878                enable_patch_output(&options->output_format);
4879                options->output_format |= DIFF_FORMAT_RAW;
4880        } else if (!strcmp(arg, "--numstat"))
4881                options->output_format |= DIFF_FORMAT_NUMSTAT;
4882        else if (!strcmp(arg, "--shortstat"))
4883                options->output_format |= DIFF_FORMAT_SHORTSTAT;
4884        else if (skip_prefix(arg, "-X", &arg) ||
4885                 skip_to_optional_arg(arg, "--dirstat", &arg))
4886                return parse_dirstat_opt(options, arg);
4887        else if (!strcmp(arg, "--cumulative"))
4888                return parse_dirstat_opt(options, "cumulative");
4889        else if (skip_to_optional_arg(arg, "--dirstat-by-file", &arg)) {
4890                parse_dirstat_opt(options, "files");
4891                return parse_dirstat_opt(options, arg);
4892        }
4893        else if (!strcmp(arg, "--check"))
4894                options->output_format |= DIFF_FORMAT_CHECKDIFF;
4895        else if (!strcmp(arg, "--summary"))
4896                options->output_format |= DIFF_FORMAT_SUMMARY;
4897        else if (!strcmp(arg, "--patch-with-stat")) {
4898                enable_patch_output(&options->output_format);
4899                options->output_format |= DIFF_FORMAT_DIFFSTAT;
4900        } else if (!strcmp(arg, "--name-only"))
4901                options->output_format |= DIFF_FORMAT_NAME;
4902        else if (!strcmp(arg, "--name-status"))
4903                options->output_format |= DIFF_FORMAT_NAME_STATUS;
4904        else if (!strcmp(arg, "-s") || !strcmp(arg, "--no-patch"))
4905                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
4906        else if (starts_with(arg, "--stat"))
4907                /* --stat, --stat-width, --stat-name-width, or --stat-count */
4908                return stat_opt(options, av);
4909        else if (!strcmp(arg, "--compact-summary")) {
4910                 options->flags.stat_with_summary = 1;
4911                 options->output_format |= DIFF_FORMAT_DIFFSTAT;
4912        } else if (!strcmp(arg, "--no-compact-summary"))
4913                 options->flags.stat_with_summary = 0;
4914        else if (skip_prefix(arg, "--output-indicator-new=", &arg))
4915                options->output_indicators[OUTPUT_INDICATOR_NEW] = arg[0];
4916        else if (skip_prefix(arg, "--output-indicator-old=", &arg))
4917                options->output_indicators[OUTPUT_INDICATOR_OLD] = arg[0];
4918        else if (skip_prefix(arg, "--output-indicator-context=", &arg))
4919                options->output_indicators[OUTPUT_INDICATOR_CONTEXT] = arg[0];
4920
4921        /* renames options */
4922        else if (starts_with(arg, "-B") ||
4923                 skip_to_optional_arg(arg, "--break-rewrites", NULL)) {
4924                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
4925                        return error("invalid argument to -B: %s", arg+2);
4926        }
4927        else if (starts_with(arg, "-M") ||
4928                 skip_to_optional_arg(arg, "--find-renames", NULL)) {
4929                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
4930                        return error("invalid argument to -M: %s", arg+2);
4931                options->detect_rename = DIFF_DETECT_RENAME;
4932        }
4933        else if (!strcmp(arg, "-D") || !strcmp(arg, "--irreversible-delete")) {
4934                options->irreversible_delete = 1;
4935        }
4936        else if (starts_with(arg, "-C") ||
4937                 skip_to_optional_arg(arg, "--find-copies", NULL)) {
4938                if (options->detect_rename == DIFF_DETECT_COPY)
4939                        options->flags.find_copies_harder = 1;
4940                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
4941                        return error("invalid argument to -C: %s", arg+2);
4942                options->detect_rename = DIFF_DETECT_COPY;
4943        }
4944        else if (!strcmp(arg, "--no-renames"))
4945                options->detect_rename = 0;
4946        else if (!strcmp(arg, "--rename-empty"))
4947                options->flags.rename_empty = 1;
4948        else if (!strcmp(arg, "--no-rename-empty"))
4949                options->flags.rename_empty = 0;
4950        else if (skip_to_optional_arg_default(arg, "--relative", &arg, NULL)) {
4951                options->flags.relative_name = 1;
4952                if (arg)
4953                        options->prefix = arg;
4954        }
4955
4956        /* xdiff options */
4957        else if (!strcmp(arg, "--minimal"))
4958                DIFF_XDL_SET(options, NEED_MINIMAL);
4959        else if (!strcmp(arg, "--no-minimal"))
4960                DIFF_XDL_CLR(options, NEED_MINIMAL);
4961        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
4962                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
4963        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
4964                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
4965        else if (!strcmp(arg, "--ignore-space-at-eol"))
4966                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
4967        else if (!strcmp(arg, "--ignore-cr-at-eol"))
4968                DIFF_XDL_SET(options, IGNORE_CR_AT_EOL);
4969        else if (!strcmp(arg, "--ignore-blank-lines"))
4970                DIFF_XDL_SET(options, IGNORE_BLANK_LINES);
4971        else if (!strcmp(arg, "--indent-heuristic"))
4972                DIFF_XDL_SET(options, INDENT_HEURISTIC);
4973        else if (!strcmp(arg, "--no-indent-heuristic"))
4974                DIFF_XDL_CLR(options, INDENT_HEURISTIC);
4975        else if (!strcmp(arg, "--patience")) {
4976                int i;
4977                options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
4978                /*
4979                 * Both --patience and --anchored use PATIENCE_DIFF
4980                 * internally, so remove any anchors previously
4981                 * specified.
4982                 */
4983                for (i = 0; i < options->anchors_nr; i++)
4984                        free(options->anchors[i]);
4985                options->anchors_nr = 0;
4986        } else if (!strcmp(arg, "--histogram"))
4987                options->xdl_opts = DIFF_WITH_ALG(options, HISTOGRAM_DIFF);
4988        else if ((argcount = parse_long_opt("diff-algorithm", av, &optarg))) {
4989                long value = parse_algorithm_value(optarg);
4990                if (value < 0)
4991                        return error("option diff-algorithm accepts \"myers\", "
4992                                     "\"minimal\", \"patience\" and \"histogram\"");
4993                /* clear out previous settings */
4994                DIFF_XDL_CLR(options, NEED_MINIMAL);
4995                options->xdl_opts &= ~XDF_DIFF_ALGORITHM_MASK;
4996                options->xdl_opts |= value;
4997                return argcount;
4998        } else if (skip_prefix(arg, "--anchored=", &arg)) {
4999                options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
5000                ALLOC_GROW(options->anchors, options->anchors_nr + 1,
5001                           options->anchors_alloc);
5002                options->anchors[options->anchors_nr++] = xstrdup(arg);
5003        }
5004
5005        /* flags options */
5006        else if (!strcmp(arg, "--binary")) {
5007                enable_patch_output(&options->output_format);
5008                options->flags.binary = 1;
5009        }
5010        else if (!strcmp(arg, "--full-index"))
5011                options->flags.full_index = 1;
5012        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
5013                options->flags.text = 1;
5014        else if (!strcmp(arg, "-R"))
5015                options->flags.reverse_diff = 1;
5016        else if (!strcmp(arg, "--find-copies-harder"))
5017                options->flags.find_copies_harder = 1;
5018        else if (!strcmp(arg, "--follow"))
5019                options->flags.follow_renames = 1;
5020        else if (!strcmp(arg, "--no-follow")) {
5021                options->flags.follow_renames = 0;
5022                options->flags.default_follow_renames = 0;
5023        } else if (skip_to_optional_arg_default(arg, "--color", &arg, "always")) {
5024                int value = git_config_colorbool(NULL, arg);
5025                if (value < 0)
5026                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
5027                options->use_color = value;
5028        }
5029        else if (!strcmp(arg, "--no-color"))
5030                options->use_color = 0;
5031        else if (!strcmp(arg, "--color-moved")) {
5032                if (diff_color_moved_default)
5033                        options->color_moved = diff_color_moved_default;
5034                if (options->color_moved == COLOR_MOVED_NO)
5035                        options->color_moved = COLOR_MOVED_DEFAULT;
5036        } else if (!strcmp(arg, "--no-color-moved"))
5037                options->color_moved = COLOR_MOVED_NO;
5038        else if (skip_prefix(arg, "--color-moved=", &arg)) {
5039                int cm = parse_color_moved(arg);
5040                if (cm < 0)
5041                        return error("bad --color-moved argument: %s", arg);
5042                options->color_moved = cm;
5043        } else if (skip_prefix(arg, "--color-moved-ws=", &arg)) {
5044                unsigned cm = parse_color_moved_ws(arg);
5045                if (cm & COLOR_MOVED_WS_ERROR)
5046                        return -1;
5047                options->color_moved_ws_handling = cm;
5048        } else if (skip_to_optional_arg_default(arg, "--color-words", &options->word_regex, NULL)) {
5049                options->use_color = 1;
5050                options->word_diff = DIFF_WORDS_COLOR;
5051        }
5052        else if (!strcmp(arg, "--word-diff")) {
5053                if (options->word_diff == DIFF_WORDS_NONE)
5054                        options->word_diff = DIFF_WORDS_PLAIN;
5055        }
5056        else if (skip_prefix(arg, "--word-diff=", &arg)) {
5057                if (!strcmp(arg, "plain"))
5058                        options->word_diff = DIFF_WORDS_PLAIN;
5059                else if (!strcmp(arg, "color")) {
5060                        options->use_color = 1;
5061                        options->word_diff = DIFF_WORDS_COLOR;
5062                }
5063                else if (!strcmp(arg, "porcelain"))
5064                        options->word_diff = DIFF_WORDS_PORCELAIN;
5065                else if (!strcmp(arg, "none"))
5066                        options->word_diff = DIFF_WORDS_NONE;
5067                else
5068                        die("bad --word-diff argument: %s", arg);
5069        }
5070        else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
5071                if (options->word_diff == DIFF_WORDS_NONE)
5072                        options->word_diff = DIFF_WORDS_PLAIN;
5073                options->word_regex = optarg;
5074                return argcount;
5075        }
5076        else if (!strcmp(arg, "--exit-code"))
5077                options->flags.exit_with_status = 1;
5078        else if (!strcmp(arg, "--quiet"))
5079                options->flags.quick = 1;
5080        else if (!strcmp(arg, "--ext-diff"))
5081                options->flags.allow_external = 1;
5082        else if (!strcmp(arg, "--no-ext-diff"))
5083                options->flags.allow_external = 0;
5084        else if (!strcmp(arg, "--textconv")) {
5085                options->flags.allow_textconv = 1;
5086                options->flags.textconv_set_via_cmdline = 1;
5087        } else if (!strcmp(arg, "--no-textconv"))
5088                options->flags.allow_textconv = 0;
5089        else if (skip_to_optional_arg_default(arg, "--ignore-submodules", &arg, "all")) {
5090                options->flags.override_submodule_config = 1;
5091                handle_ignore_submodules_arg(options, arg);
5092        } else if (skip_to_optional_arg_default(arg, "--submodule", &arg, "log"))
5093                return parse_submodule_opt(options, arg);
5094        else if (skip_prefix(arg, "--ws-error-highlight=", &arg))
5095                return parse_ws_error_highlight_opt(options, arg);
5096        else if (!strcmp(arg, "--ita-invisible-in-index"))
5097                options->ita_invisible_in_index = 1;
5098        else if (!strcmp(arg, "--ita-visible-in-index"))
5099                options->ita_invisible_in_index = 0;
5100
5101        /* misc options */
5102        else if (!strcmp(arg, "-z"))
5103                options->line_termination = 0;
5104        else if ((argcount = short_opt('l', av, &optarg))) {
5105                options->rename_limit = strtoul(optarg, NULL, 10);
5106                return argcount;
5107        }
5108        else if ((argcount = short_opt('S', av, &optarg))) {
5109                options->pickaxe = optarg;
5110                options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
5111                return argcount;
5112        } else if ((argcount = short_opt('G', av, &optarg))) {
5113                options->pickaxe = optarg;
5114                options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
5115                return argcount;
5116        }
5117        else if (!strcmp(arg, "--pickaxe-all"))
5118                options->pickaxe_opts |= DIFF_PICKAXE_ALL;
5119        else if (!strcmp(arg, "--pickaxe-regex"))
5120                options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
5121        else if ((argcount = short_opt('O', av, &optarg))) {
5122                options->orderfile = prefix_filename(prefix, optarg);
5123                return argcount;
5124        } else if (skip_prefix(arg, "--find-object=", &arg))
5125                return parse_objfind_opt(options, arg);
5126        else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
5127                int offending = parse_diff_filter_opt(optarg, options);
5128                if (offending)
5129                        die("unknown change class '%c' in --diff-filter=%s",
5130                            offending, optarg);
5131                return argcount;
5132        }
5133        else if (!strcmp(arg, "--no-abbrev"))
5134                options->abbrev = 0;
5135        else if (!strcmp(arg, "--abbrev"))
5136                options->abbrev = DEFAULT_ABBREV;
5137        else if (skip_prefix(arg, "--abbrev=", &arg)) {
5138                options->abbrev = strtoul(arg, NULL, 10);
5139                if (options->abbrev < MINIMUM_ABBREV)
5140                        options->abbrev = MINIMUM_ABBREV;
5141                else if (the_hash_algo->hexsz < options->abbrev)
5142                        options->abbrev = the_hash_algo->hexsz;
5143        }
5144        else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
5145                options->a_prefix = optarg;
5146                return argcount;
5147        }
5148        else if ((argcount = parse_long_opt("line-prefix", av, &optarg))) {
5149                options->line_prefix = optarg;
5150                options->line_prefix_length = strlen(options->line_prefix);
5151                graph_setup_line_prefix(options);
5152                return argcount;
5153        }
5154        else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
5155                options->b_prefix = optarg;
5156                return argcount;
5157        }
5158        else if (!strcmp(arg, "--no-prefix"))
5159                options->a_prefix = options->b_prefix = "";
5160        else if (opt_arg(arg, '\0', "inter-hunk-context",
5161                         &options->interhunkcontext))
5162                ;
5163        else if (!strcmp(arg, "-W"))
5164                options->flags.funccontext = 1;
5165        else if (!strcmp(arg, "--function-context"))
5166                options->flags.funccontext = 1;
5167        else if (!strcmp(arg, "--no-function-context"))
5168                options->flags.funccontext = 0;
5169        else if ((argcount = parse_long_opt("output", av, &optarg))) {
5170                char *path = prefix_filename(prefix, optarg);
5171                options->file = xfopen(path, "w");
5172                options->close_file = 1;
5173                if (options->use_color != GIT_COLOR_ALWAYS)
5174                        options->use_color = GIT_COLOR_NEVER;
5175                free(path);
5176                return argcount;
5177        } else
5178                return 0;
5179        return 1;
5180}
5181
5182int parse_rename_score(const char **cp_p)
5183{
5184        unsigned long num, scale;
5185        int ch, dot;
5186        const char *cp = *cp_p;
5187
5188        num = 0;
5189        scale = 1;
5190        dot = 0;
5191        for (;;) {
5192                ch = *cp;
5193                if ( !dot && ch == '.' ) {
5194                        scale = 1;
5195                        dot = 1;
5196                } else if ( ch == '%' ) {
5197                        scale = dot ? scale*100 : 100;
5198                        cp++;   /* % is always at the end */
5199                        break;
5200                } else if ( ch >= '0' && ch <= '9' ) {
5201                        if ( scale < 100000 ) {
5202                                scale *= 10;
5203                                num = (num*10) + (ch-'0');
5204                        }
5205                } else {
5206                        break;
5207                }
5208                cp++;
5209        }
5210        *cp_p = cp;
5211
5212        /* user says num divided by scale and we say internally that
5213         * is MAX_SCORE * num / scale.
5214         */
5215        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
5216}
5217
5218static int diff_scoreopt_parse(const char *opt)
5219{
5220        int opt1, opt2, cmd;
5221
5222        if (*opt++ != '-')
5223                return -1;
5224        cmd = *opt++;
5225        if (cmd == '-') {
5226                /* convert the long-form arguments into short-form versions */
5227                if (skip_prefix(opt, "break-rewrites", &opt)) {
5228                        if (*opt == 0 || *opt++ == '=')
5229                                cmd = 'B';
5230                } else if (skip_prefix(opt, "find-copies", &opt)) {
5231                        if (*opt == 0 || *opt++ == '=')
5232                                cmd = 'C';
5233                } else if (skip_prefix(opt, "find-renames", &opt)) {
5234                        if (*opt == 0 || *opt++ == '=')
5235                                cmd = 'M';
5236                }
5237        }
5238        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
5239                return -1; /* that is not a -M, -C, or -B option */
5240
5241        opt1 = parse_rename_score(&opt);
5242        if (cmd != 'B')
5243                opt2 = 0;
5244        else {
5245                if (*opt == 0)
5246                        opt2 = 0;
5247                else if (*opt != '/')
5248                        return -1; /* we expect -B80/99 or -B80 */
5249                else {
5250                        opt++;
5251                        opt2 = parse_rename_score(&opt);
5252                }
5253        }
5254        if (*opt != 0)
5255                return -1;
5256        return opt1 | (opt2 << 16);
5257}
5258
5259struct diff_queue_struct diff_queued_diff;
5260
5261void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
5262{
5263        ALLOC_GROW(queue->queue, queue->nr + 1, queue->alloc);
5264        queue->queue[queue->nr++] = dp;
5265}
5266
5267struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
5268                                 struct diff_filespec *one,
5269                                 struct diff_filespec *two)
5270{
5271        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
5272        dp->one = one;
5273        dp->two = two;
5274        if (queue)
5275                diff_q(queue, dp);
5276        return dp;
5277}
5278
5279void diff_free_filepair(struct diff_filepair *p)
5280{
5281        free_filespec(p->one);
5282        free_filespec(p->two);
5283        free(p);
5284}
5285
5286const char *diff_aligned_abbrev(const struct object_id *oid, int len)
5287{
5288        int abblen;
5289        const char *abbrev;
5290
5291        /* Do we want all 40 hex characters? */
5292        if (len == the_hash_algo->hexsz)
5293                return oid_to_hex(oid);
5294
5295        /* An abbreviated value is fine, possibly followed by an ellipsis. */
5296        abbrev = diff_abbrev_oid(oid, len);
5297
5298        if (!print_sha1_ellipsis())
5299                return abbrev;
5300
5301        abblen = strlen(abbrev);
5302
5303        /*
5304         * In well-behaved cases, where the abbreviated result is the
5305         * same as the requested length, append three dots after the
5306         * abbreviation (hence the whole logic is limited to the case
5307         * where abblen < 37); when the actual abbreviated result is a
5308         * bit longer than the requested length, we reduce the number
5309         * of dots so that they match the well-behaved ones.  However,
5310         * if the actual abbreviation is longer than the requested
5311         * length by more than three, we give up on aligning, and add
5312         * three dots anyway, to indicate that the output is not the
5313         * full object name.  Yes, this may be suboptimal, but this
5314         * appears only in "diff --raw --abbrev" output and it is not
5315         * worth the effort to change it now.  Note that this would
5316         * likely to work fine when the automatic sizing of default
5317         * abbreviation length is used--we would be fed -1 in "len" in
5318         * that case, and will end up always appending three-dots, but
5319         * the automatic sizing is supposed to give abblen that ensures
5320         * uniqueness across all objects (statistically speaking).
5321         */
5322        if (abblen < the_hash_algo->hexsz - 3) {
5323                static char hex[GIT_MAX_HEXSZ + 1];
5324                if (len < abblen && abblen <= len + 2)
5325                        xsnprintf(hex, sizeof(hex), "%s%.*s", abbrev, len+3-abblen, "..");
5326                else
5327                        xsnprintf(hex, sizeof(hex), "%s...", abbrev);
5328                return hex;
5329        }
5330
5331        return oid_to_hex(oid);
5332}
5333
5334static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
5335{
5336        int line_termination = opt->line_termination;
5337        int inter_name_termination = line_termination ? '\t' : '\0';
5338
5339        fprintf(opt->file, "%s", diff_line_prefix(opt));
5340        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
5341                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
5342                        diff_aligned_abbrev(&p->one->oid, opt->abbrev));
5343                fprintf(opt->file, "%s ",
5344                        diff_aligned_abbrev(&p->two->oid, opt->abbrev));
5345        }
5346        if (p->score) {
5347                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
5348                        inter_name_termination);
5349        } else {
5350                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
5351        }
5352
5353        if (p->status == DIFF_STATUS_COPIED ||
5354            p->status == DIFF_STATUS_RENAMED) {
5355                const char *name_a, *name_b;
5356                name_a = p->one->path;
5357                name_b = p->two->path;
5358                strip_prefix(opt->prefix_length, &name_a, &name_b);
5359                write_name_quoted(name_a, opt->file, inter_name_termination);
5360                write_name_quoted(name_b, opt->file, line_termination);
5361        } else {
5362                const char *name_a, *name_b;
5363                name_a = p->one->mode ? p->one->path : p->two->path;
5364                name_b = NULL;
5365                strip_prefix(opt->prefix_length, &name_a, &name_b);
5366                write_name_quoted(name_a, opt->file, line_termination);
5367        }
5368}
5369
5370int diff_unmodified_pair(struct diff_filepair *p)
5371{
5372        /* This function is written stricter than necessary to support
5373         * the currently implemented transformers, but the idea is to
5374         * let transformers to produce diff_filepairs any way they want,
5375         * and filter and clean them up here before producing the output.
5376         */
5377        struct diff_filespec *one = p->one, *two = p->two;
5378
5379        if (DIFF_PAIR_UNMERGED(p))
5380                return 0; /* unmerged is interesting */
5381
5382        /* deletion, addition, mode or type change
5383         * and rename are all interesting.
5384         */
5385        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
5386            DIFF_PAIR_MODE_CHANGED(p) ||
5387            strcmp(one->path, two->path))
5388                return 0;
5389
5390        /* both are valid and point at the same path.  that is, we are
5391         * dealing with a change.
5392         */
5393        if (one->oid_valid && two->oid_valid &&
5394            oideq(&one->oid, &two->oid) &&
5395            !one->dirty_submodule && !two->dirty_submodule)
5396                return 1; /* no change */
5397        if (!one->oid_valid && !two->oid_valid)
5398                return 1; /* both look at the same file on the filesystem. */
5399        return 0;
5400}
5401
5402static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
5403{
5404        if (diff_unmodified_pair(p))
5405                return;
5406
5407        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5408            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5409                return; /* no tree diffs in patch format */
5410
5411        run_diff(p, o);
5412}
5413
5414static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
5415                            struct diffstat_t *diffstat)
5416{
5417        if (diff_unmodified_pair(p))
5418                return;
5419
5420        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5421            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5422                return; /* no useful stat for tree diffs */
5423
5424        run_diffstat(p, o, diffstat);
5425}
5426
5427static void diff_flush_checkdiff(struct diff_filepair *p,
5428                struct diff_options *o)
5429{
5430        if (diff_unmodified_pair(p))
5431                return;
5432
5433        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5434            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5435                return; /* nothing to check in tree diffs */
5436
5437        run_checkdiff(p, o);
5438}
5439
5440int diff_queue_is_empty(void)
5441{
5442        struct diff_queue_struct *q = &diff_queued_diff;
5443        int i;
5444        for (i = 0; i < q->nr; i++)
5445                if (!diff_unmodified_pair(q->queue[i]))
5446                        return 0;
5447        return 1;
5448}
5449
5450#if DIFF_DEBUG
5451void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
5452{
5453        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
5454                x, one ? one : "",
5455                s->path,
5456                DIFF_FILE_VALID(s) ? "valid" : "invalid",
5457                s->mode,
5458                s->oid_valid ? oid_to_hex(&s->oid) : "");
5459        fprintf(stderr, "queue[%d] %s size %lu\n",
5460                x, one ? one : "",
5461                s->size);
5462}
5463
5464void diff_debug_filepair(const struct diff_filepair *p, int i)
5465{
5466        diff_debug_filespec(p->one, i, "one");
5467        diff_debug_filespec(p->two, i, "two");
5468        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
5469                p->score, p->status ? p->status : '?',
5470                p->one->rename_used, p->broken_pair);
5471}
5472
5473void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
5474{
5475        int i;
5476        if (msg)
5477                fprintf(stderr, "%s\n", msg);
5478        fprintf(stderr, "q->nr = %d\n", q->nr);
5479        for (i = 0; i < q->nr; i++) {
5480                struct diff_filepair *p = q->queue[i];
5481                diff_debug_filepair(p, i);
5482        }
5483}
5484#endif
5485
5486static void diff_resolve_rename_copy(void)
5487{
5488        int i;
5489        struct diff_filepair *p;
5490        struct diff_queue_struct *q = &diff_queued_diff;
5491
5492        diff_debug_queue("resolve-rename-copy", q);
5493
5494        for (i = 0; i < q->nr; i++) {
5495                p = q->queue[i];
5496                p->status = 0; /* undecided */
5497                if (DIFF_PAIR_UNMERGED(p))
5498                        p->status = DIFF_STATUS_UNMERGED;
5499                else if (!DIFF_FILE_VALID(p->one))
5500                        p->status = DIFF_STATUS_ADDED;
5501                else if (!DIFF_FILE_VALID(p->two))
5502                        p->status = DIFF_STATUS_DELETED;
5503                else if (DIFF_PAIR_TYPE_CHANGED(p))
5504                        p->status = DIFF_STATUS_TYPE_CHANGED;
5505
5506                /* from this point on, we are dealing with a pair
5507                 * whose both sides are valid and of the same type, i.e.
5508                 * either in-place edit or rename/copy edit.
5509                 */
5510                else if (DIFF_PAIR_RENAME(p)) {
5511                        /*
5512                         * A rename might have re-connected a broken
5513                         * pair up, causing the pathnames to be the
5514                         * same again. If so, that's not a rename at
5515                         * all, just a modification..
5516                         *
5517                         * Otherwise, see if this source was used for
5518                         * multiple renames, in which case we decrement
5519                         * the count, and call it a copy.
5520                         */
5521                        if (!strcmp(p->one->path, p->two->path))
5522                                p->status = DIFF_STATUS_MODIFIED;
5523                        else if (--p->one->rename_used > 0)
5524                                p->status = DIFF_STATUS_COPIED;
5525                        else
5526                                p->status = DIFF_STATUS_RENAMED;
5527                }
5528                else if (!oideq(&p->one->oid, &p->two->oid) ||
5529                         p->one->mode != p->two->mode ||
5530                         p->one->dirty_submodule ||
5531                         p->two->dirty_submodule ||
5532                         is_null_oid(&p->one->oid))
5533                        p->status = DIFF_STATUS_MODIFIED;
5534                else {
5535                        /* This is a "no-change" entry and should not
5536                         * happen anymore, but prepare for broken callers.
5537                         */
5538                        error("feeding unmodified %s to diffcore",
5539                              p->one->path);
5540                        p->status = DIFF_STATUS_UNKNOWN;
5541                }
5542        }
5543        diff_debug_queue("resolve-rename-copy done", q);
5544}
5545
5546static int check_pair_status(struct diff_filepair *p)
5547{
5548        switch (p->status) {
5549        case DIFF_STATUS_UNKNOWN:
5550                return 0;
5551        case 0:
5552                die("internal error in diff-resolve-rename-copy");
5553        default:
5554                return 1;
5555        }
5556}
5557
5558static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
5559{
5560        int fmt = opt->output_format;
5561
5562        if (fmt & DIFF_FORMAT_CHECKDIFF)
5563                diff_flush_checkdiff(p, opt);
5564        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
5565                diff_flush_raw(p, opt);
5566        else if (fmt & DIFF_FORMAT_NAME) {
5567                const char *name_a, *name_b;
5568                name_a = p->two->path;
5569                name_b = NULL;
5570                strip_prefix(opt->prefix_length, &name_a, &name_b);
5571                fprintf(opt->file, "%s", diff_line_prefix(opt));
5572                write_name_quoted(name_a, opt->file, opt->line_termination);
5573        }
5574}
5575
5576static void show_file_mode_name(struct diff_options *opt, const char *newdelete, struct diff_filespec *fs)
5577{
5578        struct strbuf sb = STRBUF_INIT;
5579        if (fs->mode)
5580                strbuf_addf(&sb, " %s mode %06o ", newdelete, fs->mode);
5581        else
5582                strbuf_addf(&sb, " %s ", newdelete);
5583
5584        quote_c_style(fs->path, &sb, NULL, 0);
5585        strbuf_addch(&sb, '\n');
5586        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5587                         sb.buf, sb.len, 0);
5588        strbuf_release(&sb);
5589}
5590
5591static void show_mode_change(struct diff_options *opt, struct diff_filepair *p,
5592                int show_name)
5593{
5594        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
5595                struct strbuf sb = STRBUF_INIT;
5596                strbuf_addf(&sb, " mode change %06o => %06o",
5597                            p->one->mode, p->two->mode);
5598                if (show_name) {
5599                        strbuf_addch(&sb, ' ');
5600                        quote_c_style(p->two->path, &sb, NULL, 0);
5601                }
5602                strbuf_addch(&sb, '\n');
5603                emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5604                                 sb.buf, sb.len, 0);
5605                strbuf_release(&sb);
5606        }
5607}
5608
5609static void show_rename_copy(struct diff_options *opt, const char *renamecopy,
5610                struct diff_filepair *p)
5611{
5612        struct strbuf sb = STRBUF_INIT;
5613        struct strbuf names = STRBUF_INIT;
5614
5615        pprint_rename(&names, p->one->path, p->two->path);
5616        strbuf_addf(&sb, " %s %s (%d%%)\n",
5617                    renamecopy, names.buf, similarity_index(p));
5618        strbuf_release(&names);
5619        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5620                                 sb.buf, sb.len, 0);
5621        show_mode_change(opt, p, 0);
5622        strbuf_release(&sb);
5623}
5624
5625static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
5626{
5627        switch(p->status) {
5628        case DIFF_STATUS_DELETED:
5629                show_file_mode_name(opt, "delete", p->one);
5630                break;
5631        case DIFF_STATUS_ADDED:
5632                show_file_mode_name(opt, "create", p->two);
5633                break;
5634        case DIFF_STATUS_COPIED:
5635                show_rename_copy(opt, "copy", p);
5636                break;
5637        case DIFF_STATUS_RENAMED:
5638                show_rename_copy(opt, "rename", p);
5639                break;
5640        default:
5641                if (p->score) {
5642                        struct strbuf sb = STRBUF_INIT;
5643                        strbuf_addstr(&sb, " rewrite ");
5644                        quote_c_style(p->two->path, &sb, NULL, 0);
5645                        strbuf_addf(&sb, " (%d%%)\n", similarity_index(p));
5646                        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5647                                         sb.buf, sb.len, 0);
5648                        strbuf_release(&sb);
5649                }
5650                show_mode_change(opt, p, !p->score);
5651                break;
5652        }
5653}
5654
5655struct patch_id_t {
5656        git_SHA_CTX *ctx;
5657        int patchlen;
5658};
5659
5660static int remove_space(char *line, int len)
5661{
5662        int i;
5663        char *dst = line;
5664        unsigned char c;
5665
5666        for (i = 0; i < len; i++)
5667                if (!isspace((c = line[i])))
5668                        *dst++ = c;
5669
5670        return dst - line;
5671}
5672
5673static void patch_id_consume(void *priv, char *line, unsigned long len)
5674{
5675        struct patch_id_t *data = priv;
5676        int new_len;
5677
5678        new_len = remove_space(line, len);
5679
5680        git_SHA1_Update(data->ctx, line, new_len);
5681        data->patchlen += new_len;
5682}
5683
5684static void patch_id_add_string(git_SHA_CTX *ctx, const char *str)
5685{
5686        git_SHA1_Update(ctx, str, strlen(str));
5687}
5688
5689static void patch_id_add_mode(git_SHA_CTX *ctx, unsigned mode)
5690{
5691        /* large enough for 2^32 in octal */
5692        char buf[12];
5693        int len = xsnprintf(buf, sizeof(buf), "%06o", mode);
5694        git_SHA1_Update(ctx, buf, len);
5695}
5696
5697/* returns 0 upon success, and writes result into sha1 */
5698static int diff_get_patch_id(struct diff_options *options, struct object_id *oid, int diff_header_only)
5699{
5700        struct diff_queue_struct *q = &diff_queued_diff;
5701        int i;
5702        git_SHA_CTX ctx;
5703        struct patch_id_t data;
5704
5705        git_SHA1_Init(&ctx);
5706        memset(&data, 0, sizeof(struct patch_id_t));
5707        data.ctx = &ctx;
5708
5709        for (i = 0; i < q->nr; i++) {
5710                xpparam_t xpp;
5711                xdemitconf_t xecfg;
5712                mmfile_t mf1, mf2;
5713                struct diff_filepair *p = q->queue[i];
5714                int len1, len2;
5715
5716                memset(&xpp, 0, sizeof(xpp));
5717                memset(&xecfg, 0, sizeof(xecfg));
5718                if (p->status == 0)
5719                        return error("internal diff status error");
5720                if (p->status == DIFF_STATUS_UNKNOWN)
5721                        continue;
5722                if (diff_unmodified_pair(p))
5723                        continue;
5724                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5725                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5726                        continue;
5727                if (DIFF_PAIR_UNMERGED(p))
5728                        continue;
5729
5730                diff_fill_oid_info(p->one, options->repo->index);
5731                diff_fill_oid_info(p->two, options->repo->index);
5732
5733                len1 = remove_space(p->one->path, strlen(p->one->path));
5734                len2 = remove_space(p->two->path, strlen(p->two->path));
5735                patch_id_add_string(&ctx, "diff--git");
5736                patch_id_add_string(&ctx, "a/");
5737                git_SHA1_Update(&ctx, p->one->path, len1);
5738                patch_id_add_string(&ctx, "b/");
5739                git_SHA1_Update(&ctx, p->two->path, len2);
5740
5741                if (p->one->mode == 0) {
5742                        patch_id_add_string(&ctx, "newfilemode");
5743                        patch_id_add_mode(&ctx, p->two->mode);
5744                        patch_id_add_string(&ctx, "---/dev/null");
5745                        patch_id_add_string(&ctx, "+++b/");
5746                        git_SHA1_Update(&ctx, p->two->path, len2);
5747                } else if (p->two->mode == 0) {
5748                        patch_id_add_string(&ctx, "deletedfilemode");
5749                        patch_id_add_mode(&ctx, p->one->mode);
5750                        patch_id_add_string(&ctx, "---a/");
5751                        git_SHA1_Update(&ctx, p->one->path, len1);
5752                        patch_id_add_string(&ctx, "+++/dev/null");
5753                } else {
5754                        patch_id_add_string(&ctx, "---a/");
5755                        git_SHA1_Update(&ctx, p->one->path, len1);
5756                        patch_id_add_string(&ctx, "+++b/");
5757                        git_SHA1_Update(&ctx, p->two->path, len2);
5758                }
5759
5760                if (diff_header_only)
5761                        continue;
5762
5763                if (fill_mmfile(options->repo, &mf1, p->one) < 0 ||
5764                    fill_mmfile(options->repo, &mf2, p->two) < 0)
5765                        return error("unable to read files to diff");
5766
5767                if (diff_filespec_is_binary(options->repo, p->one) ||
5768                    diff_filespec_is_binary(options->repo, p->two)) {
5769                        git_SHA1_Update(&ctx, oid_to_hex(&p->one->oid),
5770                                        GIT_SHA1_HEXSZ);
5771                        git_SHA1_Update(&ctx, oid_to_hex(&p->two->oid),
5772                                        GIT_SHA1_HEXSZ);
5773                        continue;
5774                }
5775
5776                xpp.flags = 0;
5777                xecfg.ctxlen = 3;
5778                xecfg.flags = 0;
5779                if (xdi_diff_outf(&mf1, &mf2, discard_hunk_line,
5780                                  patch_id_consume, &data, &xpp, &xecfg))
5781                        return error("unable to generate patch-id diff for %s",
5782                                     p->one->path);
5783        }
5784
5785        git_SHA1_Final(oid->hash, &ctx);
5786        return 0;
5787}
5788
5789int diff_flush_patch_id(struct diff_options *options, struct object_id *oid, int diff_header_only)
5790{
5791        struct diff_queue_struct *q = &diff_queued_diff;
5792        int i;
5793        int result = diff_get_patch_id(options, oid, diff_header_only);
5794
5795        for (i = 0; i < q->nr; i++)
5796                diff_free_filepair(q->queue[i]);
5797
5798        free(q->queue);
5799        DIFF_QUEUE_CLEAR(q);
5800
5801        return result;
5802}
5803
5804static int is_summary_empty(const struct diff_queue_struct *q)
5805{
5806        int i;
5807
5808        for (i = 0; i < q->nr; i++) {
5809                const struct diff_filepair *p = q->queue[i];
5810
5811                switch (p->status) {
5812                case DIFF_STATUS_DELETED:
5813                case DIFF_STATUS_ADDED:
5814                case DIFF_STATUS_COPIED:
5815                case DIFF_STATUS_RENAMED:
5816                        return 0;
5817                default:
5818                        if (p->score)
5819                                return 0;
5820                        if (p->one->mode && p->two->mode &&
5821                            p->one->mode != p->two->mode)
5822                                return 0;
5823                        break;
5824                }
5825        }
5826        return 1;
5827}
5828
5829static const char rename_limit_warning[] =
5830N_("inexact rename detection was skipped due to too many files.");
5831
5832static const char degrade_cc_to_c_warning[] =
5833N_("only found copies from modified paths due to too many files.");
5834
5835static const char rename_limit_advice[] =
5836N_("you may want to set your %s variable to at least "
5837   "%d and retry the command.");
5838
5839void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc)
5840{
5841        fflush(stdout);
5842        if (degraded_cc)
5843                warning(_(degrade_cc_to_c_warning));
5844        else if (needed)
5845                warning(_(rename_limit_warning));
5846        else
5847                return;
5848        if (0 < needed)
5849                warning(_(rename_limit_advice), varname, needed);
5850}
5851
5852static void diff_flush_patch_all_file_pairs(struct diff_options *o)
5853{
5854        int i;
5855        static struct emitted_diff_symbols esm = EMITTED_DIFF_SYMBOLS_INIT;
5856        struct diff_queue_struct *q = &diff_queued_diff;
5857
5858        if (WSEH_NEW & WS_RULE_MASK)
5859                BUG("WS rules bit mask overlaps with diff symbol flags");
5860
5861        if (o->color_moved)
5862                o->emitted_symbols = &esm;
5863
5864        for (i = 0; i < q->nr; i++) {
5865                struct diff_filepair *p = q->queue[i];
5866                if (check_pair_status(p))
5867                        diff_flush_patch(p, o);
5868        }
5869
5870        if (o->emitted_symbols) {
5871                if (o->color_moved) {
5872                        struct hashmap add_lines, del_lines;
5873
5874                        if (o->color_moved_ws_handling &
5875                            COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
5876                                o->color_moved_ws_handling |= XDF_IGNORE_WHITESPACE;
5877
5878                        hashmap_init(&del_lines, moved_entry_cmp, o, 0);
5879                        hashmap_init(&add_lines, moved_entry_cmp, o, 0);
5880
5881                        add_lines_to_move_detection(o, &add_lines, &del_lines);
5882                        mark_color_as_moved(o, &add_lines, &del_lines);
5883                        if (o->color_moved == COLOR_MOVED_ZEBRA_DIM)
5884                                dim_moved_lines(o);
5885
5886                        hashmap_free(&add_lines, 1);
5887                        hashmap_free(&del_lines, 1);
5888                }
5889
5890                for (i = 0; i < esm.nr; i++)
5891                        emit_diff_symbol_from_struct(o, &esm.buf[i]);
5892
5893                for (i = 0; i < esm.nr; i++)
5894                        free((void *)esm.buf[i].line);
5895        }
5896        esm.nr = 0;
5897}
5898
5899void diff_flush(struct diff_options *options)
5900{
5901        struct diff_queue_struct *q = &diff_queued_diff;
5902        int i, output_format = options->output_format;
5903        int separator = 0;
5904        int dirstat_by_line = 0;
5905
5906        /*
5907         * Order: raw, stat, summary, patch
5908         * or:    name/name-status/checkdiff (other bits clear)
5909         */
5910        if (!q->nr)
5911                goto free_queue;
5912
5913        if (output_format & (DIFF_FORMAT_RAW |
5914                             DIFF_FORMAT_NAME |
5915                             DIFF_FORMAT_NAME_STATUS |
5916                             DIFF_FORMAT_CHECKDIFF)) {
5917                for (i = 0; i < q->nr; i++) {
5918                        struct diff_filepair *p = q->queue[i];
5919                        if (check_pair_status(p))
5920                                flush_one_pair(p, options);
5921                }
5922                separator++;
5923        }
5924
5925        if (output_format & DIFF_FORMAT_DIRSTAT && options->flags.dirstat_by_line)
5926                dirstat_by_line = 1;
5927
5928        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT) ||
5929            dirstat_by_line) {
5930                struct diffstat_t diffstat;
5931
5932                memset(&diffstat, 0, sizeof(struct diffstat_t));
5933                for (i = 0; i < q->nr; i++) {
5934                        struct diff_filepair *p = q->queue[i];
5935                        if (check_pair_status(p))
5936                                diff_flush_stat(p, options, &diffstat);
5937                }
5938                if (output_format & DIFF_FORMAT_NUMSTAT)
5939                        show_numstat(&diffstat, options);
5940                if (output_format & DIFF_FORMAT_DIFFSTAT)
5941                        show_stats(&diffstat, options);
5942                if (output_format & DIFF_FORMAT_SHORTSTAT)
5943                        show_shortstats(&diffstat, options);
5944                if (output_format & DIFF_FORMAT_DIRSTAT && dirstat_by_line)
5945                        show_dirstat_by_line(&diffstat, options);
5946                free_diffstat_info(&diffstat);
5947                separator++;
5948        }
5949        if ((output_format & DIFF_FORMAT_DIRSTAT) && !dirstat_by_line)
5950                show_dirstat(options);
5951
5952        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
5953                for (i = 0; i < q->nr; i++) {
5954                        diff_summary(options, q->queue[i]);
5955                }
5956                separator++;
5957        }
5958
5959        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
5960            options->flags.exit_with_status &&
5961            options->flags.diff_from_contents) {
5962                /*
5963                 * run diff_flush_patch for the exit status. setting
5964                 * options->file to /dev/null should be safe, because we
5965                 * aren't supposed to produce any output anyway.
5966                 */
5967                if (options->close_file)
5968                        fclose(options->file);
5969                options->file = xfopen("/dev/null", "w");
5970                options->close_file = 1;
5971                options->color_moved = 0;
5972                for (i = 0; i < q->nr; i++) {
5973                        struct diff_filepair *p = q->queue[i];
5974                        if (check_pair_status(p))
5975                                diff_flush_patch(p, options);
5976                        if (options->found_changes)
5977                                break;
5978                }
5979        }
5980
5981        if (output_format & DIFF_FORMAT_PATCH) {
5982                if (separator) {
5983                        emit_diff_symbol(options, DIFF_SYMBOL_SEPARATOR, NULL, 0, 0);
5984                        if (options->stat_sep)
5985                                /* attach patch instead of inline */
5986                                emit_diff_symbol(options, DIFF_SYMBOL_STAT_SEP,
5987                                                 NULL, 0, 0);
5988                }
5989
5990                diff_flush_patch_all_file_pairs(options);
5991        }
5992
5993        if (output_format & DIFF_FORMAT_CALLBACK)
5994                options->format_callback(q, options, options->format_callback_data);
5995
5996        for (i = 0; i < q->nr; i++)
5997                diff_free_filepair(q->queue[i]);
5998free_queue:
5999        free(q->queue);
6000        DIFF_QUEUE_CLEAR(q);
6001        if (options->close_file)
6002                fclose(options->file);
6003
6004        /*
6005         * Report the content-level differences with HAS_CHANGES;
6006         * diff_addremove/diff_change does not set the bit when
6007         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
6008         */
6009        if (options->flags.diff_from_contents) {
6010                if (options->found_changes)
6011                        options->flags.has_changes = 1;
6012                else
6013                        options->flags.has_changes = 0;
6014        }
6015}
6016
6017static int match_filter(const struct diff_options *options, const struct diff_filepair *p)
6018{
6019        return (((p->status == DIFF_STATUS_MODIFIED) &&
6020                 ((p->score &&
6021                   filter_bit_tst(DIFF_STATUS_FILTER_BROKEN, options)) ||
6022                  (!p->score &&
6023                   filter_bit_tst(DIFF_STATUS_MODIFIED, options)))) ||
6024                ((p->status != DIFF_STATUS_MODIFIED) &&
6025                 filter_bit_tst(p->status, options)));
6026}
6027
6028static void diffcore_apply_filter(struct diff_options *options)
6029{
6030        int i;
6031        struct diff_queue_struct *q = &diff_queued_diff;
6032        struct diff_queue_struct outq;
6033
6034        DIFF_QUEUE_CLEAR(&outq);
6035
6036        if (!options->filter)
6037                return;
6038
6039        if (filter_bit_tst(DIFF_STATUS_FILTER_AON, options)) {
6040                int found;
6041                for (i = found = 0; !found && i < q->nr; i++) {
6042                        if (match_filter(options, q->queue[i]))
6043                                found++;
6044                }
6045                if (found)
6046                        return;
6047
6048                /* otherwise we will clear the whole queue
6049                 * by copying the empty outq at the end of this
6050                 * function, but first clear the current entries
6051                 * in the queue.
6052                 */
6053                for (i = 0; i < q->nr; i++)
6054                        diff_free_filepair(q->queue[i]);
6055        }
6056        else {
6057                /* Only the matching ones */
6058                for (i = 0; i < q->nr; i++) {
6059                        struct diff_filepair *p = q->queue[i];
6060                        if (match_filter(options, p))
6061                                diff_q(&outq, p);
6062                        else
6063                                diff_free_filepair(p);
6064                }
6065        }
6066        free(q->queue);
6067        *q = outq;
6068}
6069
6070/* Check whether two filespecs with the same mode and size are identical */
6071static int diff_filespec_is_identical(struct repository *r,
6072                                      struct diff_filespec *one,
6073                                      struct diff_filespec *two)
6074{
6075        if (S_ISGITLINK(one->mode))
6076                return 0;
6077        if (diff_populate_filespec(r, one, 0))
6078                return 0;
6079        if (diff_populate_filespec(r, two, 0))
6080                return 0;
6081        return !memcmp(one->data, two->data, one->size);
6082}
6083
6084static int diff_filespec_check_stat_unmatch(struct repository *r,
6085                                            struct diff_filepair *p)
6086{
6087        if (p->done_skip_stat_unmatch)
6088                return p->skip_stat_unmatch_result;
6089
6090        p->done_skip_stat_unmatch = 1;
6091        p->skip_stat_unmatch_result = 0;
6092        /*
6093         * 1. Entries that come from stat info dirtiness
6094         *    always have both sides (iow, not create/delete),
6095         *    one side of the object name is unknown, with
6096         *    the same mode and size.  Keep the ones that
6097         *    do not match these criteria.  They have real
6098         *    differences.
6099         *
6100         * 2. At this point, the file is known to be modified,
6101         *    with the same mode and size, and the object
6102         *    name of one side is unknown.  Need to inspect
6103         *    the identical contents.
6104         */
6105        if (!DIFF_FILE_VALID(p->one) || /* (1) */
6106            !DIFF_FILE_VALID(p->two) ||
6107            (p->one->oid_valid && p->two->oid_valid) ||
6108            (p->one->mode != p->two->mode) ||
6109            diff_populate_filespec(r, p->one, CHECK_SIZE_ONLY) ||
6110            diff_populate_filespec(r, p->two, CHECK_SIZE_ONLY) ||
6111            (p->one->size != p->two->size) ||
6112            !diff_filespec_is_identical(r, p->one, p->two)) /* (2) */
6113                p->skip_stat_unmatch_result = 1;
6114        return p->skip_stat_unmatch_result;
6115}
6116
6117static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
6118{
6119        int i;
6120        struct diff_queue_struct *q = &diff_queued_diff;
6121        struct diff_queue_struct outq;
6122        DIFF_QUEUE_CLEAR(&outq);
6123
6124        for (i = 0; i < q->nr; i++) {
6125                struct diff_filepair *p = q->queue[i];
6126
6127                if (diff_filespec_check_stat_unmatch(diffopt->repo, p))
6128                        diff_q(&outq, p);
6129                else {
6130                        /*
6131                         * The caller can subtract 1 from skip_stat_unmatch
6132                         * to determine how many paths were dirty only
6133                         * due to stat info mismatch.
6134                         */
6135                        if (!diffopt->flags.no_index)
6136                                diffopt->skip_stat_unmatch++;
6137                        diff_free_filepair(p);
6138                }
6139        }
6140        free(q->queue);
6141        *q = outq;
6142}
6143
6144static int diffnamecmp(const void *a_, const void *b_)
6145{
6146        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
6147        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
6148        const char *name_a, *name_b;
6149
6150        name_a = a->one ? a->one->path : a->two->path;
6151        name_b = b->one ? b->one->path : b->two->path;
6152        return strcmp(name_a, name_b);
6153}
6154
6155void diffcore_fix_diff_index(struct diff_options *options)
6156{
6157        struct diff_queue_struct *q = &diff_queued_diff;
6158        QSORT(q->queue, q->nr, diffnamecmp);
6159}
6160
6161void diffcore_std(struct diff_options *options)
6162{
6163        /* NOTE please keep the following in sync with diff_tree_combined() */
6164        if (options->skip_stat_unmatch)
6165                diffcore_skip_stat_unmatch(options);
6166        if (!options->found_follow) {
6167                /* See try_to_follow_renames() in tree-diff.c */
6168                if (options->break_opt != -1)
6169                        diffcore_break(options->repo,
6170                                       options->break_opt);
6171                if (options->detect_rename)
6172                        diffcore_rename(options);
6173                if (options->break_opt != -1)
6174                        diffcore_merge_broken();
6175        }
6176        if (options->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK)
6177                diffcore_pickaxe(options);
6178        if (options->orderfile)
6179                diffcore_order(options->orderfile);
6180        if (!options->found_follow)
6181                /* See try_to_follow_renames() in tree-diff.c */
6182                diff_resolve_rename_copy();
6183        diffcore_apply_filter(options);
6184
6185        if (diff_queued_diff.nr && !options->flags.diff_from_contents)
6186                options->flags.has_changes = 1;
6187        else
6188                options->flags.has_changes = 0;
6189
6190        options->found_follow = 0;
6191}
6192
6193int diff_result_code(struct diff_options *opt, int status)
6194{
6195        int result = 0;
6196
6197        diff_warn_rename_limit("diff.renameLimit",
6198                               opt->needed_rename_limit,
6199                               opt->degraded_cc_to_c);
6200        if (!opt->flags.exit_with_status &&
6201            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
6202                return status;
6203        if (opt->flags.exit_with_status &&
6204            opt->flags.has_changes)
6205                result |= 01;
6206        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
6207            opt->flags.check_failed)
6208                result |= 02;
6209        return result;
6210}
6211
6212int diff_can_quit_early(struct diff_options *opt)
6213{
6214        return (opt->flags.quick &&
6215                !opt->filter &&
6216                opt->flags.has_changes);
6217}
6218
6219/*
6220 * Shall changes to this submodule be ignored?
6221 *
6222 * Submodule changes can be configured to be ignored separately for each path,
6223 * but that configuration can be overridden from the command line.
6224 */
6225static int is_submodule_ignored(const char *path, struct diff_options *options)
6226{
6227        int ignored = 0;
6228        struct diff_flags orig_flags = options->flags;
6229        if (!options->flags.override_submodule_config)
6230                set_diffopt_flags_from_submodule_config(options, path);
6231        if (options->flags.ignore_submodules)
6232                ignored = 1;
6233        options->flags = orig_flags;
6234        return ignored;
6235}
6236
6237void diff_addremove(struct diff_options *options,
6238                    int addremove, unsigned mode,
6239                    const struct object_id *oid,
6240                    int oid_valid,
6241                    const char *concatpath, unsigned dirty_submodule)
6242{
6243        struct diff_filespec *one, *two;
6244
6245        if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
6246                return;
6247
6248        /* This may look odd, but it is a preparation for
6249         * feeding "there are unchanged files which should
6250         * not produce diffs, but when you are doing copy
6251         * detection you would need them, so here they are"
6252         * entries to the diff-core.  They will be prefixed
6253         * with something like '=' or '*' (I haven't decided
6254         * which but should not make any difference).
6255         * Feeding the same new and old to diff_change()
6256         * also has the same effect.
6257         * Before the final output happens, they are pruned after
6258         * merged into rename/copy pairs as appropriate.
6259         */
6260        if (options->flags.reverse_diff)
6261                addremove = (addremove == '+' ? '-' :
6262                             addremove == '-' ? '+' : addremove);
6263
6264        if (options->prefix &&
6265            strncmp(concatpath, options->prefix, options->prefix_length))
6266                return;
6267
6268        one = alloc_filespec(concatpath);
6269        two = alloc_filespec(concatpath);
6270
6271        if (addremove != '+')
6272                fill_filespec(one, oid, oid_valid, mode);
6273        if (addremove != '-') {
6274                fill_filespec(two, oid, oid_valid, mode);
6275                two->dirty_submodule = dirty_submodule;
6276        }
6277
6278        diff_queue(&diff_queued_diff, one, two);
6279        if (!options->flags.diff_from_contents)
6280                options->flags.has_changes = 1;
6281}
6282
6283void diff_change(struct diff_options *options,
6284                 unsigned old_mode, unsigned new_mode,
6285                 const struct object_id *old_oid,
6286                 const struct object_id *new_oid,
6287                 int old_oid_valid, int new_oid_valid,
6288                 const char *concatpath,
6289                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
6290{
6291        struct diff_filespec *one, *two;
6292        struct diff_filepair *p;
6293
6294        if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
6295            is_submodule_ignored(concatpath, options))
6296                return;
6297
6298        if (options->flags.reverse_diff) {
6299                SWAP(old_mode, new_mode);
6300                SWAP(old_oid, new_oid);
6301                SWAP(old_oid_valid, new_oid_valid);
6302                SWAP(old_dirty_submodule, new_dirty_submodule);
6303        }
6304
6305        if (options->prefix &&
6306            strncmp(concatpath, options->prefix, options->prefix_length))
6307                return;
6308
6309        one = alloc_filespec(concatpath);
6310        two = alloc_filespec(concatpath);
6311        fill_filespec(one, old_oid, old_oid_valid, old_mode);
6312        fill_filespec(two, new_oid, new_oid_valid, new_mode);
6313        one->dirty_submodule = old_dirty_submodule;
6314        two->dirty_submodule = new_dirty_submodule;
6315        p = diff_queue(&diff_queued_diff, one, two);
6316
6317        if (options->flags.diff_from_contents)
6318                return;
6319
6320        if (options->flags.quick && options->skip_stat_unmatch &&
6321            !diff_filespec_check_stat_unmatch(options->repo, p))
6322                return;
6323
6324        options->flags.has_changes = 1;
6325}
6326
6327struct diff_filepair *diff_unmerge(struct diff_options *options, const char *path)
6328{
6329        struct diff_filepair *pair;
6330        struct diff_filespec *one, *two;
6331
6332        if (options->prefix &&
6333            strncmp(path, options->prefix, options->prefix_length))
6334                return NULL;
6335
6336        one = alloc_filespec(path);
6337        two = alloc_filespec(path);
6338        pair = diff_queue(&diff_queued_diff, one, two);
6339        pair->is_unmerged = 1;
6340        return pair;
6341}
6342
6343static char *run_textconv(struct repository *r,
6344                          const char *pgm,
6345                          struct diff_filespec *spec,
6346                          size_t *outsize)
6347{
6348        struct diff_tempfile *temp;
6349        const char *argv[3];
6350        const char **arg = argv;
6351        struct child_process child = CHILD_PROCESS_INIT;
6352        struct strbuf buf = STRBUF_INIT;
6353        int err = 0;
6354
6355        temp = prepare_temp_file(r, spec->path, spec);
6356        *arg++ = pgm;
6357        *arg++ = temp->name;
6358        *arg = NULL;
6359
6360        child.use_shell = 1;
6361        child.argv = argv;
6362        child.out = -1;
6363        if (start_command(&child)) {
6364                remove_tempfile();
6365                return NULL;
6366        }
6367
6368        if (strbuf_read(&buf, child.out, 0) < 0)
6369                err = error("error reading from textconv command '%s'", pgm);
6370        close(child.out);
6371
6372        if (finish_command(&child) || err) {
6373                strbuf_release(&buf);
6374                remove_tempfile();
6375                return NULL;
6376        }
6377        remove_tempfile();
6378
6379        return strbuf_detach(&buf, outsize);
6380}
6381
6382size_t fill_textconv(struct repository *r,
6383                     struct userdiff_driver *driver,
6384                     struct diff_filespec *df,
6385                     char **outbuf)
6386{
6387        size_t size;
6388
6389        if (!driver) {
6390                if (!DIFF_FILE_VALID(df)) {
6391                        *outbuf = "";
6392                        return 0;
6393                }
6394                if (diff_populate_filespec(r, df, 0))
6395                        die("unable to read files to diff");
6396                *outbuf = df->data;
6397                return df->size;
6398        }
6399
6400        if (!driver->textconv)
6401                BUG("fill_textconv called with non-textconv driver");
6402
6403        if (driver->textconv_cache && df->oid_valid) {
6404                *outbuf = notes_cache_get(driver->textconv_cache,
6405                                          &df->oid,
6406                                          &size);
6407                if (*outbuf)
6408                        return size;
6409        }
6410
6411        *outbuf = run_textconv(r, driver->textconv, df, &size);
6412        if (!*outbuf)
6413                die("unable to read files to diff");
6414
6415        if (driver->textconv_cache && df->oid_valid) {
6416                /* ignore errors, as we might be in a readonly repository */
6417                notes_cache_put(driver->textconv_cache, &df->oid, *outbuf,
6418                                size);
6419                /*
6420                 * we could save up changes and flush them all at the end,
6421                 * but we would need an extra call after all diffing is done.
6422                 * Since generating a cache entry is the slow path anyway,
6423                 * this extra overhead probably isn't a big deal.
6424                 */
6425                notes_cache_write(driver->textconv_cache);
6426        }
6427
6428        return size;
6429}
6430
6431int textconv_object(struct repository *r,
6432                    const char *path,
6433                    unsigned mode,
6434                    const struct object_id *oid,
6435                    int oid_valid,
6436                    char **buf,
6437                    unsigned long *buf_size)
6438{
6439        struct diff_filespec *df;
6440        struct userdiff_driver *textconv;
6441
6442        df = alloc_filespec(path);
6443        fill_filespec(df, oid, oid_valid, mode);
6444        textconv = get_textconv(r, df);
6445        if (!textconv) {
6446                free_filespec(df);
6447                return 0;
6448        }
6449
6450        *buf_size = fill_textconv(r, textconv, df, buf);
6451        free_filespec(df);
6452        return 1;
6453}
6454
6455void setup_diff_pager(struct diff_options *opt)
6456{
6457        /*
6458         * If the user asked for our exit code, then either they want --quiet
6459         * or --exit-code. We should definitely not bother with a pager in the
6460         * former case, as we will generate no output. Since we still properly
6461         * report our exit code even when a pager is run, we _could_ run a
6462         * pager with --exit-code. But since we have not done so historically,
6463         * and because it is easy to find people oneline advising "git diff
6464         * --exit-code" in hooks and other scripts, we do not do so.
6465         */
6466        if (!opt->flags.exit_with_status &&
6467            check_pager_config("diff") != 0)
6468                setup_pager();
6469}