diff.con commit rerere.c: remove implicit dependency on the_index (35843b1)
   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 int 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                        error(_("ignoring unknown color-moved-ws mode '%s'"), sb.buf);
 317
 318                strbuf_release(&sb);
 319        }
 320
 321        if ((ret & COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE) &&
 322            (ret & XDF_WHITESPACE_FLAGS))
 323                die(_("color-moved-ws: allow-indentation-change cannot be combined with other white space modes"));
 324
 325        string_list_clear(&l, 0);
 326
 327        return ret;
 328}
 329
 330int git_diff_ui_config(const char *var, const char *value, void *cb)
 331{
 332        if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
 333                diff_use_color_default = git_config_colorbool(var, value);
 334                return 0;
 335        }
 336        if (!strcmp(var, "diff.colormoved")) {
 337                int cm = parse_color_moved(value);
 338                if (cm < 0)
 339                        return -1;
 340                diff_color_moved_default = cm;
 341                return 0;
 342        }
 343        if (!strcmp(var, "diff.colormovedws")) {
 344                int cm = parse_color_moved_ws(value);
 345                if (cm < 0)
 346                        return -1;
 347                diff_color_moved_ws_default = cm;
 348                return 0;
 349        }
 350        if (!strcmp(var, "diff.context")) {
 351                diff_context_default = git_config_int(var, value);
 352                if (diff_context_default < 0)
 353                        return -1;
 354                return 0;
 355        }
 356        if (!strcmp(var, "diff.interhunkcontext")) {
 357                diff_interhunk_context_default = git_config_int(var, value);
 358                if (diff_interhunk_context_default < 0)
 359                        return -1;
 360                return 0;
 361        }
 362        if (!strcmp(var, "diff.renames")) {
 363                diff_detect_rename_default = git_config_rename(var, value);
 364                return 0;
 365        }
 366        if (!strcmp(var, "diff.autorefreshindex")) {
 367                diff_auto_refresh_index = git_config_bool(var, value);
 368                return 0;
 369        }
 370        if (!strcmp(var, "diff.mnemonicprefix")) {
 371                diff_mnemonic_prefix = git_config_bool(var, value);
 372                return 0;
 373        }
 374        if (!strcmp(var, "diff.noprefix")) {
 375                diff_no_prefix = git_config_bool(var, value);
 376                return 0;
 377        }
 378        if (!strcmp(var, "diff.statgraphwidth")) {
 379                diff_stat_graph_width = git_config_int(var, value);
 380                return 0;
 381        }
 382        if (!strcmp(var, "diff.external"))
 383                return git_config_string(&external_diff_cmd_cfg, var, value);
 384        if (!strcmp(var, "diff.wordregex"))
 385                return git_config_string(&diff_word_regex_cfg, var, value);
 386        if (!strcmp(var, "diff.orderfile"))
 387                return git_config_pathname(&diff_order_file_cfg, var, value);
 388
 389        if (!strcmp(var, "diff.ignoresubmodules"))
 390                handle_ignore_submodules_arg(&default_diff_options, value);
 391
 392        if (!strcmp(var, "diff.submodule")) {
 393                if (parse_submodule_params(&default_diff_options, value))
 394                        warning(_("Unknown value for 'diff.submodule' config variable: '%s'"),
 395                                value);
 396                return 0;
 397        }
 398
 399        if (!strcmp(var, "diff.algorithm")) {
 400                diff_algorithm = parse_algorithm_value(value);
 401                if (diff_algorithm < 0)
 402                        return -1;
 403                return 0;
 404        }
 405
 406        if (!strcmp(var, "diff.wserrorhighlight")) {
 407                int val = parse_ws_error_highlight(value);
 408                if (val < 0)
 409                        return -1;
 410                ws_error_highlight_default = val;
 411                return 0;
 412        }
 413
 414        if (git_color_config(var, value, cb) < 0)
 415                return -1;
 416
 417        return git_diff_basic_config(var, value, cb);
 418}
 419
 420int git_diff_basic_config(const char *var, const char *value, void *cb)
 421{
 422        const char *name;
 423
 424        if (!strcmp(var, "diff.renamelimit")) {
 425                diff_rename_limit_default = git_config_int(var, value);
 426                return 0;
 427        }
 428
 429        if (userdiff_config(var, value) < 0)
 430                return -1;
 431
 432        if (skip_prefix(var, "diff.color.", &name) ||
 433            skip_prefix(var, "color.diff.", &name)) {
 434                int slot = parse_diff_color_slot(name);
 435                if (slot < 0)
 436                        return 0;
 437                if (!value)
 438                        return config_error_nonbool(var);
 439                return color_parse(value, diff_colors[slot]);
 440        }
 441
 442        /* like GNU diff's --suppress-blank-empty option  */
 443        if (!strcmp(var, "diff.suppressblankempty") ||
 444                        /* for backwards compatibility */
 445                        !strcmp(var, "diff.suppress-blank-empty")) {
 446                diff_suppress_blank_empty = git_config_bool(var, value);
 447                return 0;
 448        }
 449
 450        if (!strcmp(var, "diff.dirstat")) {
 451                struct strbuf errmsg = STRBUF_INIT;
 452                default_diff_options.dirstat_permille = diff_dirstat_permille_default;
 453                if (parse_dirstat_params(&default_diff_options, value, &errmsg))
 454                        warning(_("Found errors in 'diff.dirstat' config variable:\n%s"),
 455                                errmsg.buf);
 456                strbuf_release(&errmsg);
 457                diff_dirstat_permille_default = default_diff_options.dirstat_permille;
 458                return 0;
 459        }
 460
 461        if (git_diff_heuristic_config(var, value, cb) < 0)
 462                return -1;
 463
 464        return git_default_config(var, value, cb);
 465}
 466
 467static char *quote_two(const char *one, const char *two)
 468{
 469        int need_one = quote_c_style(one, NULL, NULL, 1);
 470        int need_two = quote_c_style(two, NULL, NULL, 1);
 471        struct strbuf res = STRBUF_INIT;
 472
 473        if (need_one + need_two) {
 474                strbuf_addch(&res, '"');
 475                quote_c_style(one, &res, NULL, 1);
 476                quote_c_style(two, &res, NULL, 1);
 477                strbuf_addch(&res, '"');
 478        } else {
 479                strbuf_addstr(&res, one);
 480                strbuf_addstr(&res, two);
 481        }
 482        return strbuf_detach(&res, NULL);
 483}
 484
 485static const char *external_diff(void)
 486{
 487        static const char *external_diff_cmd = NULL;
 488        static int done_preparing = 0;
 489
 490        if (done_preparing)
 491                return external_diff_cmd;
 492        external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
 493        if (!external_diff_cmd)
 494                external_diff_cmd = external_diff_cmd_cfg;
 495        done_preparing = 1;
 496        return external_diff_cmd;
 497}
 498
 499/*
 500 * Keep track of files used for diffing. Sometimes such an entry
 501 * refers to a temporary file, sometimes to an existing file, and
 502 * sometimes to "/dev/null".
 503 */
 504static struct diff_tempfile {
 505        /*
 506         * filename external diff should read from, or NULL if this
 507         * entry is currently not in use:
 508         */
 509        const char *name;
 510
 511        char hex[GIT_MAX_HEXSZ + 1];
 512        char mode[10];
 513
 514        /*
 515         * If this diff_tempfile instance refers to a temporary file,
 516         * this tempfile object is used to manage its lifetime.
 517         */
 518        struct tempfile *tempfile;
 519} diff_temp[2];
 520
 521struct emit_callback {
 522        int color_diff;
 523        unsigned ws_rule;
 524        int blank_at_eof_in_preimage;
 525        int blank_at_eof_in_postimage;
 526        int lno_in_preimage;
 527        int lno_in_postimage;
 528        const char **label_path;
 529        struct diff_words_data *diff_words;
 530        struct diff_options *opt;
 531        struct strbuf *header;
 532};
 533
 534static int count_lines(const char *data, int size)
 535{
 536        int count, ch, completely_empty = 1, nl_just_seen = 0;
 537        count = 0;
 538        while (0 < size--) {
 539                ch = *data++;
 540                if (ch == '\n') {
 541                        count++;
 542                        nl_just_seen = 1;
 543                        completely_empty = 0;
 544                }
 545                else {
 546                        nl_just_seen = 0;
 547                        completely_empty = 0;
 548                }
 549        }
 550        if (completely_empty)
 551                return 0;
 552        if (!nl_just_seen)
 553                count++; /* no trailing newline */
 554        return count;
 555}
 556
 557static int fill_mmfile(struct repository *r, mmfile_t *mf,
 558                       struct diff_filespec *one)
 559{
 560        if (!DIFF_FILE_VALID(one)) {
 561                mf->ptr = (char *)""; /* does not matter */
 562                mf->size = 0;
 563                return 0;
 564        }
 565        else if (diff_populate_filespec(r, one, 0))
 566                return -1;
 567
 568        mf->ptr = one->data;
 569        mf->size = one->size;
 570        return 0;
 571}
 572
 573/* like fill_mmfile, but only for size, so we can avoid retrieving blob */
 574static unsigned long diff_filespec_size(struct repository *r,
 575                                        struct diff_filespec *one)
 576{
 577        if (!DIFF_FILE_VALID(one))
 578                return 0;
 579        diff_populate_filespec(r, one, CHECK_SIZE_ONLY);
 580        return one->size;
 581}
 582
 583static int count_trailing_blank(mmfile_t *mf, unsigned ws_rule)
 584{
 585        char *ptr = mf->ptr;
 586        long size = mf->size;
 587        int cnt = 0;
 588
 589        if (!size)
 590                return cnt;
 591        ptr += size - 1; /* pointing at the very end */
 592        if (*ptr != '\n')
 593                ; /* incomplete line */
 594        else
 595                ptr--; /* skip the last LF */
 596        while (mf->ptr < ptr) {
 597                char *prev_eol;
 598                for (prev_eol = ptr; mf->ptr <= prev_eol; prev_eol--)
 599                        if (*prev_eol == '\n')
 600                                break;
 601                if (!ws_blank_line(prev_eol + 1, ptr - prev_eol, ws_rule))
 602                        break;
 603                cnt++;
 604                ptr = prev_eol - 1;
 605        }
 606        return cnt;
 607}
 608
 609static void check_blank_at_eof(mmfile_t *mf1, mmfile_t *mf2,
 610                               struct emit_callback *ecbdata)
 611{
 612        int l1, l2, at;
 613        unsigned ws_rule = ecbdata->ws_rule;
 614        l1 = count_trailing_blank(mf1, ws_rule);
 615        l2 = count_trailing_blank(mf2, ws_rule);
 616        if (l2 <= l1) {
 617                ecbdata->blank_at_eof_in_preimage = 0;
 618                ecbdata->blank_at_eof_in_postimage = 0;
 619                return;
 620        }
 621        at = count_lines(mf1->ptr, mf1->size);
 622        ecbdata->blank_at_eof_in_preimage = (at - l1) + 1;
 623
 624        at = count_lines(mf2->ptr, mf2->size);
 625        ecbdata->blank_at_eof_in_postimage = (at - l2) + 1;
 626}
 627
 628static void emit_line_0(struct diff_options *o,
 629                        const char *set, unsigned reverse, const char *reset,
 630                        int first, const char *line, int len)
 631{
 632        int has_trailing_newline, has_trailing_carriage_return;
 633        int nofirst;
 634        FILE *file = o->file;
 635
 636        if (first)
 637                fputs(diff_line_prefix(o), file);
 638        else if (!len)
 639                return;
 640
 641        if (len == 0) {
 642                has_trailing_newline = (first == '\n');
 643                has_trailing_carriage_return = (!has_trailing_newline &&
 644                                                (first == '\r'));
 645                nofirst = has_trailing_newline || has_trailing_carriage_return;
 646        } else {
 647                has_trailing_newline = (len > 0 && line[len-1] == '\n');
 648                if (has_trailing_newline)
 649                        len--;
 650                has_trailing_carriage_return = (len > 0 && line[len-1] == '\r');
 651                if (has_trailing_carriage_return)
 652                        len--;
 653                nofirst = 0;
 654        }
 655
 656        if (len || !nofirst) {
 657                if (reverse && want_color(o->use_color))
 658                        fputs(GIT_COLOR_REVERSE, file);
 659                fputs(set, file);
 660                if (first && !nofirst)
 661                        fputc(first, file);
 662                fwrite(line, len, 1, file);
 663                fputs(reset, file);
 664        }
 665        if (has_trailing_carriage_return)
 666                fputc('\r', file);
 667        if (has_trailing_newline)
 668                fputc('\n', file);
 669}
 670
 671static void emit_line(struct diff_options *o, const char *set, const char *reset,
 672                      const char *line, int len)
 673{
 674        emit_line_0(o, set, 0, reset, line[0], line+1, len-1);
 675}
 676
 677enum diff_symbol {
 678        DIFF_SYMBOL_BINARY_DIFF_HEADER,
 679        DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA,
 680        DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL,
 681        DIFF_SYMBOL_BINARY_DIFF_BODY,
 682        DIFF_SYMBOL_BINARY_DIFF_FOOTER,
 683        DIFF_SYMBOL_STATS_SUMMARY_NO_FILES,
 684        DIFF_SYMBOL_STATS_SUMMARY_ABBREV,
 685        DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES,
 686        DIFF_SYMBOL_STATS_LINE,
 687        DIFF_SYMBOL_WORD_DIFF,
 688        DIFF_SYMBOL_STAT_SEP,
 689        DIFF_SYMBOL_SUMMARY,
 690        DIFF_SYMBOL_SUBMODULE_ADD,
 691        DIFF_SYMBOL_SUBMODULE_DEL,
 692        DIFF_SYMBOL_SUBMODULE_UNTRACKED,
 693        DIFF_SYMBOL_SUBMODULE_MODIFIED,
 694        DIFF_SYMBOL_SUBMODULE_HEADER,
 695        DIFF_SYMBOL_SUBMODULE_ERROR,
 696        DIFF_SYMBOL_SUBMODULE_PIPETHROUGH,
 697        DIFF_SYMBOL_REWRITE_DIFF,
 698        DIFF_SYMBOL_BINARY_FILES,
 699        DIFF_SYMBOL_HEADER,
 700        DIFF_SYMBOL_FILEPAIR_PLUS,
 701        DIFF_SYMBOL_FILEPAIR_MINUS,
 702        DIFF_SYMBOL_WORDS_PORCELAIN,
 703        DIFF_SYMBOL_WORDS,
 704        DIFF_SYMBOL_CONTEXT,
 705        DIFF_SYMBOL_CONTEXT_INCOMPLETE,
 706        DIFF_SYMBOL_PLUS,
 707        DIFF_SYMBOL_MINUS,
 708        DIFF_SYMBOL_NO_LF_EOF,
 709        DIFF_SYMBOL_CONTEXT_FRAGINFO,
 710        DIFF_SYMBOL_CONTEXT_MARKER,
 711        DIFF_SYMBOL_SEPARATOR
 712};
 713/*
 714 * Flags for content lines:
 715 * 0..12 are whitespace rules
 716 * 13-15 are WSEH_NEW | WSEH_OLD | WSEH_CONTEXT
 717 * 16 is marking if the line is blank at EOF
 718 */
 719#define DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF      (1<<16)
 720#define DIFF_SYMBOL_MOVED_LINE                  (1<<17)
 721#define DIFF_SYMBOL_MOVED_LINE_ALT              (1<<18)
 722#define DIFF_SYMBOL_MOVED_LINE_UNINTERESTING    (1<<19)
 723#define DIFF_SYMBOL_CONTENT_WS_MASK (WSEH_NEW | WSEH_OLD | WSEH_CONTEXT | WS_RULE_MASK)
 724
 725/*
 726 * This struct is used when we need to buffer the output of the diff output.
 727 *
 728 * NEEDSWORK: Instead of storing a copy of the line, add an offset pointer
 729 * into the pre/post image file. This pointer could be a union with the
 730 * line pointer. By storing an offset into the file instead of the literal line,
 731 * we can decrease the memory footprint for the buffered output. At first we
 732 * may want to only have indirection for the content lines, but we could also
 733 * enhance the state for emitting prefabricated lines, e.g. the similarity
 734 * score line or hunk/file headers would only need to store a number or path
 735 * and then the output can be constructed later on depending on state.
 736 */
 737struct emitted_diff_symbol {
 738        const char *line;
 739        int len;
 740        int flags;
 741        enum diff_symbol s;
 742};
 743#define EMITTED_DIFF_SYMBOL_INIT {NULL}
 744
 745struct emitted_diff_symbols {
 746        struct emitted_diff_symbol *buf;
 747        int nr, alloc;
 748};
 749#define EMITTED_DIFF_SYMBOLS_INIT {NULL, 0, 0}
 750
 751static void append_emitted_diff_symbol(struct diff_options *o,
 752                                       struct emitted_diff_symbol *e)
 753{
 754        struct emitted_diff_symbol *f;
 755
 756        ALLOC_GROW(o->emitted_symbols->buf,
 757                   o->emitted_symbols->nr + 1,
 758                   o->emitted_symbols->alloc);
 759        f = &o->emitted_symbols->buf[o->emitted_symbols->nr++];
 760
 761        memcpy(f, e, sizeof(struct emitted_diff_symbol));
 762        f->line = e->line ? xmemdupz(e->line, e->len) : NULL;
 763}
 764
 765struct moved_entry {
 766        struct hashmap_entry ent;
 767        const struct emitted_diff_symbol *es;
 768        struct moved_entry *next_line;
 769        struct ws_delta *wsd;
 770};
 771
 772/**
 773 * The struct ws_delta holds white space differences between moved lines, i.e.
 774 * between '+' and '-' lines that have been detected to be a move.
 775 * The string contains the difference in leading white spaces, before the
 776 * rest of the line is compared using the white space config for move
 777 * coloring. The current_longer indicates if the first string in the
 778 * comparision is longer than the second.
 779 */
 780struct ws_delta {
 781        char *string;
 782        unsigned int current_longer : 1;
 783};
 784#define WS_DELTA_INIT { NULL, 0 }
 785
 786static int compute_ws_delta(const struct emitted_diff_symbol *a,
 787                             const struct emitted_diff_symbol *b,
 788                             struct ws_delta *out)
 789{
 790        const struct emitted_diff_symbol *longer =  a->len > b->len ? a : b;
 791        const struct emitted_diff_symbol *shorter = a->len > b->len ? b : a;
 792        int d = longer->len - shorter->len;
 793
 794        out->string = xmemdupz(longer->line, d);
 795        out->current_longer = (a == longer);
 796
 797        return !strncmp(longer->line + d, shorter->line, shorter->len);
 798}
 799
 800static int cmp_in_block_with_wsd(const struct diff_options *o,
 801                                 const struct moved_entry *cur,
 802                                 const struct moved_entry *match,
 803                                 struct moved_entry *pmb,
 804                                 int n)
 805{
 806        struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
 807        int al = cur->es->len, cl = l->len;
 808        const char *a = cur->es->line,
 809                   *b = match->es->line,
 810                   *c = l->line;
 811
 812        int wslen;
 813
 814        /*
 815         * We need to check if 'cur' is equal to 'match'.
 816         * As those are from the same (+/-) side, we do not need to adjust for
 817         * indent changes. However these were found using fuzzy matching
 818         * so we do have to check if they are equal.
 819         */
 820        if (strcmp(a, b))
 821                return 1;
 822
 823        if (!pmb->wsd)
 824                /*
 825                 * No white space delta was carried forward? This can happen
 826                 * when we exit early in this function and do not carry
 827                 * forward ws.
 828                 */
 829                return 1;
 830
 831        /*
 832         * The indent changes of the block are known and carried forward in
 833         * pmb->wsd; however we need to check if the indent changes of the
 834         * current line are still the same as before.
 835         *
 836         * To do so we need to compare 'l' to 'cur', adjusting the
 837         * one of them for the white spaces, depending which was longer.
 838         */
 839
 840        wslen = strlen(pmb->wsd->string);
 841        if (pmb->wsd->current_longer) {
 842                c += wslen;
 843                cl -= wslen;
 844        } else {
 845                a += wslen;
 846                al -= wslen;
 847        }
 848
 849        if (strcmp(a, c))
 850                return 1;
 851
 852        return 0;
 853}
 854
 855static int moved_entry_cmp(const void *hashmap_cmp_fn_data,
 856                           const void *entry,
 857                           const void *entry_or_key,
 858                           const void *keydata)
 859{
 860        const struct diff_options *diffopt = hashmap_cmp_fn_data;
 861        const struct moved_entry *a = entry;
 862        const struct moved_entry *b = entry_or_key;
 863        unsigned flags = diffopt->color_moved_ws_handling
 864                         & XDF_WHITESPACE_FLAGS;
 865
 866        if (diffopt->color_moved_ws_handling &
 867            COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
 868                /*
 869                 * As there is not specific white space config given,
 870                 * we'd need to check for a new block, so ignore all
 871                 * white space. The setup of the white space
 872                 * configuration for the next block is done else where
 873                 */
 874                flags |= XDF_IGNORE_WHITESPACE;
 875
 876        return !xdiff_compare_lines(a->es->line, a->es->len,
 877                                    b->es->line, b->es->len,
 878                                    flags);
 879}
 880
 881static struct moved_entry *prepare_entry(struct diff_options *o,
 882                                         int line_no)
 883{
 884        struct moved_entry *ret = xmalloc(sizeof(*ret));
 885        struct emitted_diff_symbol *l = &o->emitted_symbols->buf[line_no];
 886        unsigned flags = o->color_moved_ws_handling & XDF_WHITESPACE_FLAGS;
 887
 888        ret->ent.hash = xdiff_hash_string(l->line, l->len, flags);
 889        ret->es = l;
 890        ret->next_line = NULL;
 891        ret->wsd = NULL;
 892
 893        return ret;
 894}
 895
 896static void add_lines_to_move_detection(struct diff_options *o,
 897                                        struct hashmap *add_lines,
 898                                        struct hashmap *del_lines)
 899{
 900        struct moved_entry *prev_line = NULL;
 901
 902        int n;
 903        for (n = 0; n < o->emitted_symbols->nr; n++) {
 904                struct hashmap *hm;
 905                struct moved_entry *key;
 906
 907                switch (o->emitted_symbols->buf[n].s) {
 908                case DIFF_SYMBOL_PLUS:
 909                        hm = add_lines;
 910                        break;
 911                case DIFF_SYMBOL_MINUS:
 912                        hm = del_lines;
 913                        break;
 914                default:
 915                        prev_line = NULL;
 916                        continue;
 917                }
 918
 919                key = prepare_entry(o, n);
 920                if (prev_line && prev_line->es->s == o->emitted_symbols->buf[n].s)
 921                        prev_line->next_line = key;
 922
 923                hashmap_add(hm, key);
 924                prev_line = key;
 925        }
 926}
 927
 928static void pmb_advance_or_null(struct diff_options *o,
 929                                struct moved_entry *match,
 930                                struct hashmap *hm,
 931                                struct moved_entry **pmb,
 932                                int pmb_nr)
 933{
 934        int i;
 935        for (i = 0; i < pmb_nr; i++) {
 936                struct moved_entry *prev = pmb[i];
 937                struct moved_entry *cur = (prev && prev->next_line) ?
 938                                prev->next_line : NULL;
 939                if (cur && !hm->cmpfn(o, cur, match, NULL)) {
 940                        pmb[i] = cur;
 941                } else {
 942                        pmb[i] = NULL;
 943                }
 944        }
 945}
 946
 947static void pmb_advance_or_null_multi_match(struct diff_options *o,
 948                                            struct moved_entry *match,
 949                                            struct hashmap *hm,
 950                                            struct moved_entry **pmb,
 951                                            int pmb_nr, int n)
 952{
 953        int i;
 954        char *got_match = xcalloc(1, pmb_nr);
 955
 956        for (; match; match = hashmap_get_next(hm, match)) {
 957                for (i = 0; i < pmb_nr; i++) {
 958                        struct moved_entry *prev = pmb[i];
 959                        struct moved_entry *cur = (prev && prev->next_line) ?
 960                                        prev->next_line : NULL;
 961                        if (!cur)
 962                                continue;
 963                        if (!cmp_in_block_with_wsd(o, cur, match, pmb[i], n))
 964                                got_match[i] |= 1;
 965                }
 966        }
 967
 968        for (i = 0; i < pmb_nr; i++) {
 969                if (got_match[i]) {
 970                        /* Carry the white space delta forward */
 971                        pmb[i]->next_line->wsd = pmb[i]->wsd;
 972                        pmb[i] = pmb[i]->next_line;
 973                } else
 974                        pmb[i] = NULL;
 975        }
 976}
 977
 978static int shrink_potential_moved_blocks(struct moved_entry **pmb,
 979                                         int pmb_nr)
 980{
 981        int lp, rp;
 982
 983        /* Shrink the set of potential block to the remaining running */
 984        for (lp = 0, rp = pmb_nr - 1; lp <= rp;) {
 985                while (lp < pmb_nr && pmb[lp])
 986                        lp++;
 987                /* lp points at the first NULL now */
 988
 989                while (rp > -1 && !pmb[rp])
 990                        rp--;
 991                /* rp points at the last non-NULL */
 992
 993                if (lp < pmb_nr && rp > -1 && lp < rp) {
 994                        pmb[lp] = pmb[rp];
 995                        if (pmb[rp]->wsd) {
 996                                free(pmb[rp]->wsd->string);
 997                                FREE_AND_NULL(pmb[rp]->wsd);
 998                        }
 999                        pmb[rp] = NULL;
1000                        rp--;
1001                        lp++;
1002                }
1003        }
1004
1005        /* Remember the number of running sets */
1006        return rp + 1;
1007}
1008
1009/*
1010 * If o->color_moved is COLOR_MOVED_PLAIN, this function does nothing.
1011 *
1012 * Otherwise, if the last block has fewer alphanumeric characters than
1013 * COLOR_MOVED_MIN_ALNUM_COUNT, unset DIFF_SYMBOL_MOVED_LINE on all lines in
1014 * that block.
1015 *
1016 * The last block consists of the (n - block_length)'th line up to but not
1017 * including the nth line.
1018 *
1019 * NEEDSWORK: This uses the same heuristic as blame_entry_score() in blame.c.
1020 * Think of a way to unify them.
1021 */
1022static void adjust_last_block(struct diff_options *o, int n, int block_length)
1023{
1024        int i, alnum_count = 0;
1025        if (o->color_moved == COLOR_MOVED_PLAIN)
1026                return;
1027        for (i = 1; i < block_length + 1; i++) {
1028                const char *c = o->emitted_symbols->buf[n - i].line;
1029                for (; *c; c++) {
1030                        if (!isalnum(*c))
1031                                continue;
1032                        alnum_count++;
1033                        if (alnum_count >= COLOR_MOVED_MIN_ALNUM_COUNT)
1034                                return;
1035                }
1036        }
1037        for (i = 1; i < block_length + 1; i++)
1038                o->emitted_symbols->buf[n - i].flags &= ~DIFF_SYMBOL_MOVED_LINE;
1039}
1040
1041/* Find blocks of moved code, delegate actual coloring decision to helper */
1042static void mark_color_as_moved(struct diff_options *o,
1043                                struct hashmap *add_lines,
1044                                struct hashmap *del_lines)
1045{
1046        struct moved_entry **pmb = NULL; /* potentially moved blocks */
1047        int pmb_nr = 0, pmb_alloc = 0;
1048        int n, flipped_block = 1, block_length = 0;
1049
1050
1051        for (n = 0; n < o->emitted_symbols->nr; n++) {
1052                struct hashmap *hm = NULL;
1053                struct moved_entry *key;
1054                struct moved_entry *match = NULL;
1055                struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
1056
1057                switch (l->s) {
1058                case DIFF_SYMBOL_PLUS:
1059                        hm = del_lines;
1060                        key = prepare_entry(o, n);
1061                        match = hashmap_get(hm, key, NULL);
1062                        free(key);
1063                        break;
1064                case DIFF_SYMBOL_MINUS:
1065                        hm = add_lines;
1066                        key = prepare_entry(o, n);
1067                        match = hashmap_get(hm, key, NULL);
1068                        free(key);
1069                        break;
1070                default:
1071                        flipped_block = 1;
1072                }
1073
1074                if (!match) {
1075                        adjust_last_block(o, n, block_length);
1076                        pmb_nr = 0;
1077                        block_length = 0;
1078                        continue;
1079                }
1080
1081                l->flags |= DIFF_SYMBOL_MOVED_LINE;
1082
1083                if (o->color_moved == COLOR_MOVED_PLAIN)
1084                        continue;
1085
1086                if (o->color_moved_ws_handling &
1087                    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
1088                        pmb_advance_or_null_multi_match(o, match, hm, pmb, pmb_nr, n);
1089                else
1090                        pmb_advance_or_null(o, match, hm, pmb, pmb_nr);
1091
1092                pmb_nr = shrink_potential_moved_blocks(pmb, pmb_nr);
1093
1094                if (pmb_nr == 0) {
1095                        /*
1096                         * The current line is the start of a new block.
1097                         * Setup the set of potential blocks.
1098                         */
1099                        for (; match; match = hashmap_get_next(hm, match)) {
1100                                ALLOC_GROW(pmb, pmb_nr + 1, pmb_alloc);
1101                                if (o->color_moved_ws_handling &
1102                                    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE) {
1103                                        struct ws_delta *wsd = xmalloc(sizeof(*match->wsd));
1104                                        if (compute_ws_delta(l, match->es, wsd)) {
1105                                                match->wsd = wsd;
1106                                                pmb[pmb_nr++] = match;
1107                                        } else
1108                                                free(wsd);
1109                                } else {
1110                                        pmb[pmb_nr++] = match;
1111                                }
1112                        }
1113
1114                        flipped_block = (flipped_block + 1) % 2;
1115
1116                        adjust_last_block(o, n, block_length);
1117                        block_length = 0;
1118                }
1119
1120                block_length++;
1121
1122                if (flipped_block && o->color_moved != COLOR_MOVED_BLOCKS)
1123                        l->flags |= DIFF_SYMBOL_MOVED_LINE_ALT;
1124        }
1125        adjust_last_block(o, n, block_length);
1126
1127        free(pmb);
1128}
1129
1130#define DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK \
1131  (DIFF_SYMBOL_MOVED_LINE | DIFF_SYMBOL_MOVED_LINE_ALT)
1132static void dim_moved_lines(struct diff_options *o)
1133{
1134        int n;
1135        for (n = 0; n < o->emitted_symbols->nr; n++) {
1136                struct emitted_diff_symbol *prev = (n != 0) ?
1137                                &o->emitted_symbols->buf[n - 1] : NULL;
1138                struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
1139                struct emitted_diff_symbol *next =
1140                                (n < o->emitted_symbols->nr - 1) ?
1141                                &o->emitted_symbols->buf[n + 1] : NULL;
1142
1143                /* Not a plus or minus line? */
1144                if (l->s != DIFF_SYMBOL_PLUS && l->s != DIFF_SYMBOL_MINUS)
1145                        continue;
1146
1147                /* Not a moved line? */
1148                if (!(l->flags & DIFF_SYMBOL_MOVED_LINE))
1149                        continue;
1150
1151                /*
1152                 * If prev or next are not a plus or minus line,
1153                 * pretend they don't exist
1154                 */
1155                if (prev && prev->s != DIFF_SYMBOL_PLUS &&
1156                            prev->s != DIFF_SYMBOL_MINUS)
1157                        prev = NULL;
1158                if (next && next->s != DIFF_SYMBOL_PLUS &&
1159                            next->s != DIFF_SYMBOL_MINUS)
1160                        next = NULL;
1161
1162                /* Inside a block? */
1163                if ((prev &&
1164                    (prev->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK) ==
1165                    (l->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK)) &&
1166                    (next &&
1167                    (next->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK) ==
1168                    (l->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK))) {
1169                        l->flags |= DIFF_SYMBOL_MOVED_LINE_UNINTERESTING;
1170                        continue;
1171                }
1172
1173                /* Check if we are at an interesting bound: */
1174                if (prev && (prev->flags & DIFF_SYMBOL_MOVED_LINE) &&
1175                    (prev->flags & DIFF_SYMBOL_MOVED_LINE_ALT) !=
1176                       (l->flags & DIFF_SYMBOL_MOVED_LINE_ALT))
1177                        continue;
1178                if (next && (next->flags & DIFF_SYMBOL_MOVED_LINE) &&
1179                    (next->flags & DIFF_SYMBOL_MOVED_LINE_ALT) !=
1180                       (l->flags & DIFF_SYMBOL_MOVED_LINE_ALT))
1181                        continue;
1182
1183                /*
1184                 * The boundary to prev and next are not interesting,
1185                 * so this line is not interesting as a whole
1186                 */
1187                l->flags |= DIFF_SYMBOL_MOVED_LINE_UNINTERESTING;
1188        }
1189}
1190
1191static void emit_line_ws_markup(struct diff_options *o,
1192                                const char *set, const char *reset,
1193                                const char *line, int len,
1194                                const char *set_sign, char sign,
1195                                unsigned ws_rule, int blank_at_eof)
1196{
1197        const char *ws = NULL;
1198
1199        if (o->ws_error_highlight & ws_rule) {
1200                ws = diff_get_color_opt(o, DIFF_WHITESPACE);
1201                if (!*ws)
1202                        ws = NULL;
1203        }
1204
1205        if (!ws && !set_sign)
1206                emit_line_0(o, set, 0, reset, sign, line, len);
1207        else if (!ws) {
1208                /* Emit just the prefix, then the rest. */
1209                emit_line_0(o, set_sign ? set_sign : set, !!set_sign, reset,
1210                            sign, "", 0);
1211                emit_line_0(o, set, 0, reset, 0, line, len);
1212        } else if (blank_at_eof)
1213                /* Blank line at EOF - paint '+' as well */
1214                emit_line_0(o, ws, 0, reset, sign, line, len);
1215        else {
1216                /* Emit just the prefix, then the rest. */
1217                emit_line_0(o, set_sign ? set_sign : set, !!set_sign, reset,
1218                            sign, "", 0);
1219                ws_check_emit(line, len, ws_rule,
1220                              o->file, set, reset, ws);
1221        }
1222}
1223
1224static void emit_diff_symbol_from_struct(struct diff_options *o,
1225                                         struct emitted_diff_symbol *eds)
1226{
1227        static const char *nneof = " No newline at end of file\n";
1228        const char *context, *reset, *set, *set_sign, *meta, *fraginfo;
1229        struct strbuf sb = STRBUF_INIT;
1230
1231        enum diff_symbol s = eds->s;
1232        const char *line = eds->line;
1233        int len = eds->len;
1234        unsigned flags = eds->flags;
1235
1236        switch (s) {
1237        case DIFF_SYMBOL_NO_LF_EOF:
1238                context = diff_get_color_opt(o, DIFF_CONTEXT);
1239                reset = diff_get_color_opt(o, DIFF_RESET);
1240                putc('\n', o->file);
1241                emit_line_0(o, context, 0, reset, '\\',
1242                            nneof, strlen(nneof));
1243                break;
1244        case DIFF_SYMBOL_SUBMODULE_HEADER:
1245        case DIFF_SYMBOL_SUBMODULE_ERROR:
1246        case DIFF_SYMBOL_SUBMODULE_PIPETHROUGH:
1247        case DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES:
1248        case DIFF_SYMBOL_SUMMARY:
1249        case DIFF_SYMBOL_STATS_LINE:
1250        case DIFF_SYMBOL_BINARY_DIFF_BODY:
1251        case DIFF_SYMBOL_CONTEXT_FRAGINFO:
1252                emit_line(o, "", "", line, len);
1253                break;
1254        case DIFF_SYMBOL_CONTEXT_INCOMPLETE:
1255        case DIFF_SYMBOL_CONTEXT_MARKER:
1256                context = diff_get_color_opt(o, DIFF_CONTEXT);
1257                reset = diff_get_color_opt(o, DIFF_RESET);
1258                emit_line(o, context, reset, line, len);
1259                break;
1260        case DIFF_SYMBOL_SEPARATOR:
1261                fprintf(o->file, "%s%c",
1262                        diff_line_prefix(o),
1263                        o->line_termination);
1264                break;
1265        case DIFF_SYMBOL_CONTEXT:
1266                set = diff_get_color_opt(o, DIFF_CONTEXT);
1267                reset = diff_get_color_opt(o, DIFF_RESET);
1268                set_sign = NULL;
1269                if (o->flags.dual_color_diffed_diffs) {
1270                        char c = !len ? 0 : line[0];
1271
1272                        if (c == '+')
1273                                set = diff_get_color_opt(o, DIFF_FILE_NEW);
1274                        else if (c == '@')
1275                                set = diff_get_color_opt(o, DIFF_FRAGINFO);
1276                        else if (c == '-')
1277                                set = diff_get_color_opt(o, DIFF_FILE_OLD);
1278                }
1279                emit_line_ws_markup(o, set, reset, line, len, set_sign, ' ',
1280                                    flags & (DIFF_SYMBOL_CONTENT_WS_MASK), 0);
1281                break;
1282        case DIFF_SYMBOL_PLUS:
1283                switch (flags & (DIFF_SYMBOL_MOVED_LINE |
1284                                 DIFF_SYMBOL_MOVED_LINE_ALT |
1285                                 DIFF_SYMBOL_MOVED_LINE_UNINTERESTING)) {
1286                case DIFF_SYMBOL_MOVED_LINE |
1287                     DIFF_SYMBOL_MOVED_LINE_ALT |
1288                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1289                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED_ALT_DIM);
1290                        break;
1291                case DIFF_SYMBOL_MOVED_LINE |
1292                     DIFF_SYMBOL_MOVED_LINE_ALT:
1293                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED_ALT);
1294                        break;
1295                case DIFF_SYMBOL_MOVED_LINE |
1296                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1297                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED_DIM);
1298                        break;
1299                case DIFF_SYMBOL_MOVED_LINE:
1300                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED);
1301                        break;
1302                default:
1303                        set = diff_get_color_opt(o, DIFF_FILE_NEW);
1304                }
1305                reset = diff_get_color_opt(o, DIFF_RESET);
1306                if (!o->flags.dual_color_diffed_diffs)
1307                        set_sign = NULL;
1308                else {
1309                        char c = !len ? 0 : line[0];
1310
1311                        set_sign = set;
1312                        if (c == '-')
1313                                set = diff_get_color_opt(o, DIFF_FILE_OLD_BOLD);
1314                        else if (c == '@')
1315                                set = diff_get_color_opt(o, DIFF_FRAGINFO);
1316                        else if (c == '+')
1317                                set = diff_get_color_opt(o, DIFF_FILE_NEW_BOLD);
1318                        else
1319                                set = diff_get_color_opt(o, DIFF_CONTEXT_BOLD);
1320                        flags &= ~DIFF_SYMBOL_CONTENT_WS_MASK;
1321                }
1322                emit_line_ws_markup(o, set, reset, line, len, set_sign, '+',
1323                                    flags & DIFF_SYMBOL_CONTENT_WS_MASK,
1324                                    flags & DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF);
1325                break;
1326        case DIFF_SYMBOL_MINUS:
1327                switch (flags & (DIFF_SYMBOL_MOVED_LINE |
1328                                 DIFF_SYMBOL_MOVED_LINE_ALT |
1329                                 DIFF_SYMBOL_MOVED_LINE_UNINTERESTING)) {
1330                case DIFF_SYMBOL_MOVED_LINE |
1331                     DIFF_SYMBOL_MOVED_LINE_ALT |
1332                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1333                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_ALT_DIM);
1334                        break;
1335                case DIFF_SYMBOL_MOVED_LINE |
1336                     DIFF_SYMBOL_MOVED_LINE_ALT:
1337                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_ALT);
1338                        break;
1339                case DIFF_SYMBOL_MOVED_LINE |
1340                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1341                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_DIM);
1342                        break;
1343                case DIFF_SYMBOL_MOVED_LINE:
1344                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED);
1345                        break;
1346                default:
1347                        set = diff_get_color_opt(o, DIFF_FILE_OLD);
1348                }
1349                reset = diff_get_color_opt(o, DIFF_RESET);
1350                if (!o->flags.dual_color_diffed_diffs)
1351                        set_sign = NULL;
1352                else {
1353                        char c = !len ? 0 : line[0];
1354
1355                        set_sign = set;
1356                        if (c == '+')
1357                                set = diff_get_color_opt(o, DIFF_FILE_NEW_DIM);
1358                        else if (c == '@')
1359                                set = diff_get_color_opt(o, DIFF_FRAGINFO);
1360                        else if (c == '-')
1361                                set = diff_get_color_opt(o, DIFF_FILE_OLD_DIM);
1362                        else
1363                                set = diff_get_color_opt(o, DIFF_CONTEXT_DIM);
1364                }
1365                emit_line_ws_markup(o, set, reset, line, len, set_sign, '-',
1366                                    flags & DIFF_SYMBOL_CONTENT_WS_MASK, 0);
1367                break;
1368        case DIFF_SYMBOL_WORDS_PORCELAIN:
1369                context = diff_get_color_opt(o, DIFF_CONTEXT);
1370                reset = diff_get_color_opt(o, DIFF_RESET);
1371                emit_line(o, context, reset, line, len);
1372                fputs("~\n", o->file);
1373                break;
1374        case DIFF_SYMBOL_WORDS:
1375                context = diff_get_color_opt(o, DIFF_CONTEXT);
1376                reset = diff_get_color_opt(o, DIFF_RESET);
1377                /*
1378                 * Skip the prefix character, if any.  With
1379                 * diff_suppress_blank_empty, there may be
1380                 * none.
1381                 */
1382                if (line[0] != '\n') {
1383                        line++;
1384                        len--;
1385                }
1386                emit_line(o, context, reset, line, len);
1387                break;
1388        case DIFF_SYMBOL_FILEPAIR_PLUS:
1389                meta = diff_get_color_opt(o, DIFF_METAINFO);
1390                reset = diff_get_color_opt(o, DIFF_RESET);
1391                fprintf(o->file, "%s%s+++ %s%s%s\n", diff_line_prefix(o), meta,
1392                        line, reset,
1393                        strchr(line, ' ') ? "\t" : "");
1394                break;
1395        case DIFF_SYMBOL_FILEPAIR_MINUS:
1396                meta = diff_get_color_opt(o, DIFF_METAINFO);
1397                reset = diff_get_color_opt(o, DIFF_RESET);
1398                fprintf(o->file, "%s%s--- %s%s%s\n", diff_line_prefix(o), meta,
1399                        line, reset,
1400                        strchr(line, ' ') ? "\t" : "");
1401                break;
1402        case DIFF_SYMBOL_BINARY_FILES:
1403        case DIFF_SYMBOL_HEADER:
1404                fprintf(o->file, "%s", line);
1405                break;
1406        case DIFF_SYMBOL_BINARY_DIFF_HEADER:
1407                fprintf(o->file, "%sGIT binary patch\n", diff_line_prefix(o));
1408                break;
1409        case DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA:
1410                fprintf(o->file, "%sdelta %s\n", diff_line_prefix(o), line);
1411                break;
1412        case DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL:
1413                fprintf(o->file, "%sliteral %s\n", diff_line_prefix(o), line);
1414                break;
1415        case DIFF_SYMBOL_BINARY_DIFF_FOOTER:
1416                fputs(diff_line_prefix(o), o->file);
1417                fputc('\n', o->file);
1418                break;
1419        case DIFF_SYMBOL_REWRITE_DIFF:
1420                fraginfo = diff_get_color(o->use_color, DIFF_FRAGINFO);
1421                reset = diff_get_color_opt(o, DIFF_RESET);
1422                emit_line(o, fraginfo, reset, line, len);
1423                break;
1424        case DIFF_SYMBOL_SUBMODULE_ADD:
1425                set = diff_get_color_opt(o, DIFF_FILE_NEW);
1426                reset = diff_get_color_opt(o, DIFF_RESET);
1427                emit_line(o, set, reset, line, len);
1428                break;
1429        case DIFF_SYMBOL_SUBMODULE_DEL:
1430                set = diff_get_color_opt(o, DIFF_FILE_OLD);
1431                reset = diff_get_color_opt(o, DIFF_RESET);
1432                emit_line(o, set, reset, line, len);
1433                break;
1434        case DIFF_SYMBOL_SUBMODULE_UNTRACKED:
1435                fprintf(o->file, "%sSubmodule %s contains untracked content\n",
1436                        diff_line_prefix(o), line);
1437                break;
1438        case DIFF_SYMBOL_SUBMODULE_MODIFIED:
1439                fprintf(o->file, "%sSubmodule %s contains modified content\n",
1440                        diff_line_prefix(o), line);
1441                break;
1442        case DIFF_SYMBOL_STATS_SUMMARY_NO_FILES:
1443                emit_line(o, "", "", " 0 files changed\n",
1444                          strlen(" 0 files changed\n"));
1445                break;
1446        case DIFF_SYMBOL_STATS_SUMMARY_ABBREV:
1447                emit_line(o, "", "", " ...\n", strlen(" ...\n"));
1448                break;
1449        case DIFF_SYMBOL_WORD_DIFF:
1450                fprintf(o->file, "%.*s", len, line);
1451                break;
1452        case DIFF_SYMBOL_STAT_SEP:
1453                fputs(o->stat_sep, o->file);
1454                break;
1455        default:
1456                BUG("unknown diff symbol");
1457        }
1458        strbuf_release(&sb);
1459}
1460
1461static void emit_diff_symbol(struct diff_options *o, enum diff_symbol s,
1462                             const char *line, int len, unsigned flags)
1463{
1464        struct emitted_diff_symbol e = {line, len, flags, s};
1465
1466        if (o->emitted_symbols)
1467                append_emitted_diff_symbol(o, &e);
1468        else
1469                emit_diff_symbol_from_struct(o, &e);
1470}
1471
1472void diff_emit_submodule_del(struct diff_options *o, const char *line)
1473{
1474        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_DEL, line, strlen(line), 0);
1475}
1476
1477void diff_emit_submodule_add(struct diff_options *o, const char *line)
1478{
1479        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_ADD, line, strlen(line), 0);
1480}
1481
1482void diff_emit_submodule_untracked(struct diff_options *o, const char *path)
1483{
1484        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_UNTRACKED,
1485                         path, strlen(path), 0);
1486}
1487
1488void diff_emit_submodule_modified(struct diff_options *o, const char *path)
1489{
1490        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_MODIFIED,
1491                         path, strlen(path), 0);
1492}
1493
1494void diff_emit_submodule_header(struct diff_options *o, const char *header)
1495{
1496        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_HEADER,
1497                         header, strlen(header), 0);
1498}
1499
1500void diff_emit_submodule_error(struct diff_options *o, const char *err)
1501{
1502        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_ERROR, err, strlen(err), 0);
1503}
1504
1505void diff_emit_submodule_pipethrough(struct diff_options *o,
1506                                     const char *line, int len)
1507{
1508        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_PIPETHROUGH, line, len, 0);
1509}
1510
1511static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line, int len)
1512{
1513        if (!((ecbdata->ws_rule & WS_BLANK_AT_EOF) &&
1514              ecbdata->blank_at_eof_in_preimage &&
1515              ecbdata->blank_at_eof_in_postimage &&
1516              ecbdata->blank_at_eof_in_preimage <= ecbdata->lno_in_preimage &&
1517              ecbdata->blank_at_eof_in_postimage <= ecbdata->lno_in_postimage))
1518                return 0;
1519        return ws_blank_line(line, len, ecbdata->ws_rule);
1520}
1521
1522static void emit_add_line(const char *reset,
1523                          struct emit_callback *ecbdata,
1524                          const char *line, int len)
1525{
1526        unsigned flags = WSEH_NEW | ecbdata->ws_rule;
1527        if (new_blank_line_at_eof(ecbdata, line, len))
1528                flags |= DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF;
1529
1530        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_PLUS, line, len, flags);
1531}
1532
1533static void emit_del_line(const char *reset,
1534                          struct emit_callback *ecbdata,
1535                          const char *line, int len)
1536{
1537        unsigned flags = WSEH_OLD | ecbdata->ws_rule;
1538        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_MINUS, line, len, flags);
1539}
1540
1541static void emit_context_line(const char *reset,
1542                              struct emit_callback *ecbdata,
1543                              const char *line, int len)
1544{
1545        unsigned flags = WSEH_CONTEXT | ecbdata->ws_rule;
1546        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_CONTEXT, line, len, flags);
1547}
1548
1549static void emit_hunk_header(struct emit_callback *ecbdata,
1550                             const char *line, int len)
1551{
1552        const char *context = diff_get_color(ecbdata->color_diff, DIFF_CONTEXT);
1553        const char *frag = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
1554        const char *func = diff_get_color(ecbdata->color_diff, DIFF_FUNCINFO);
1555        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
1556        const char *reverse = ecbdata->color_diff ? GIT_COLOR_REVERSE : "";
1557        static const char atat[2] = { '@', '@' };
1558        const char *cp, *ep;
1559        struct strbuf msgbuf = STRBUF_INIT;
1560        int org_len = len;
1561        int i = 1;
1562
1563        /*
1564         * As a hunk header must begin with "@@ -<old>, +<new> @@",
1565         * it always is at least 10 bytes long.
1566         */
1567        if (len < 10 ||
1568            memcmp(line, atat, 2) ||
1569            !(ep = memmem(line + 2, len - 2, atat, 2))) {
1570                emit_diff_symbol(ecbdata->opt,
1571                                 DIFF_SYMBOL_CONTEXT_MARKER, line, len, 0);
1572                return;
1573        }
1574        ep += 2; /* skip over @@ */
1575
1576        /* The hunk header in fraginfo color */
1577        if (ecbdata->opt->flags.dual_color_diffed_diffs)
1578                strbuf_addstr(&msgbuf, reverse);
1579        strbuf_addstr(&msgbuf, frag);
1580        strbuf_add(&msgbuf, line, ep - line);
1581        strbuf_addstr(&msgbuf, reset);
1582
1583        /*
1584         * trailing "\r\n"
1585         */
1586        for ( ; i < 3; i++)
1587                if (line[len - i] == '\r' || line[len - i] == '\n')
1588                        len--;
1589
1590        /* blank before the func header */
1591        for (cp = ep; ep - line < len; ep++)
1592                if (*ep != ' ' && *ep != '\t')
1593                        break;
1594        if (ep != cp) {
1595                strbuf_addstr(&msgbuf, context);
1596                strbuf_add(&msgbuf, cp, ep - cp);
1597                strbuf_addstr(&msgbuf, reset);
1598        }
1599
1600        if (ep < line + len) {
1601                strbuf_addstr(&msgbuf, func);
1602                strbuf_add(&msgbuf, ep, line + len - ep);
1603                strbuf_addstr(&msgbuf, reset);
1604        }
1605
1606        strbuf_add(&msgbuf, line + len, org_len - len);
1607        strbuf_complete_line(&msgbuf);
1608        emit_diff_symbol(ecbdata->opt,
1609                         DIFF_SYMBOL_CONTEXT_FRAGINFO, msgbuf.buf, msgbuf.len, 0);
1610        strbuf_release(&msgbuf);
1611}
1612
1613static struct diff_tempfile *claim_diff_tempfile(void) {
1614        int i;
1615        for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
1616                if (!diff_temp[i].name)
1617                        return diff_temp + i;
1618        BUG("diff is failing to clean up its tempfiles");
1619}
1620
1621static void remove_tempfile(void)
1622{
1623        int i;
1624        for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
1625                if (is_tempfile_active(diff_temp[i].tempfile))
1626                        delete_tempfile(&diff_temp[i].tempfile);
1627                diff_temp[i].name = NULL;
1628        }
1629}
1630
1631static void add_line_count(struct strbuf *out, int count)
1632{
1633        switch (count) {
1634        case 0:
1635                strbuf_addstr(out, "0,0");
1636                break;
1637        case 1:
1638                strbuf_addstr(out, "1");
1639                break;
1640        default:
1641                strbuf_addf(out, "1,%d", count);
1642                break;
1643        }
1644}
1645
1646static void emit_rewrite_lines(struct emit_callback *ecb,
1647                               int prefix, const char *data, int size)
1648{
1649        const char *endp = NULL;
1650        const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
1651
1652        while (0 < size) {
1653                int len;
1654
1655                endp = memchr(data, '\n', size);
1656                len = endp ? (endp - data + 1) : size;
1657                if (prefix != '+') {
1658                        ecb->lno_in_preimage++;
1659                        emit_del_line(reset, ecb, data, len);
1660                } else {
1661                        ecb->lno_in_postimage++;
1662                        emit_add_line(reset, ecb, data, len);
1663                }
1664                size -= len;
1665                data += len;
1666        }
1667        if (!endp)
1668                emit_diff_symbol(ecb->opt, DIFF_SYMBOL_NO_LF_EOF, NULL, 0, 0);
1669}
1670
1671static void emit_rewrite_diff(const char *name_a,
1672                              const char *name_b,
1673                              struct diff_filespec *one,
1674                              struct diff_filespec *two,
1675                              struct userdiff_driver *textconv_one,
1676                              struct userdiff_driver *textconv_two,
1677                              struct diff_options *o)
1678{
1679        int lc_a, lc_b;
1680        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
1681        const char *a_prefix, *b_prefix;
1682        char *data_one, *data_two;
1683        size_t size_one, size_two;
1684        struct emit_callback ecbdata;
1685        struct strbuf out = STRBUF_INIT;
1686
1687        if (diff_mnemonic_prefix && o->flags.reverse_diff) {
1688                a_prefix = o->b_prefix;
1689                b_prefix = o->a_prefix;
1690        } else {
1691                a_prefix = o->a_prefix;
1692                b_prefix = o->b_prefix;
1693        }
1694
1695        name_a += (*name_a == '/');
1696        name_b += (*name_b == '/');
1697
1698        strbuf_reset(&a_name);
1699        strbuf_reset(&b_name);
1700        quote_two_c_style(&a_name, a_prefix, name_a, 0);
1701        quote_two_c_style(&b_name, b_prefix, name_b, 0);
1702
1703        size_one = fill_textconv(o->repo, textconv_one, one, &data_one);
1704        size_two = fill_textconv(o->repo, textconv_two, two, &data_two);
1705
1706        memset(&ecbdata, 0, sizeof(ecbdata));
1707        ecbdata.color_diff = want_color(o->use_color);
1708        ecbdata.ws_rule = whitespace_rule(name_b);
1709        ecbdata.opt = o;
1710        if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
1711                mmfile_t mf1, mf2;
1712                mf1.ptr = (char *)data_one;
1713                mf2.ptr = (char *)data_two;
1714                mf1.size = size_one;
1715                mf2.size = size_two;
1716                check_blank_at_eof(&mf1, &mf2, &ecbdata);
1717        }
1718        ecbdata.lno_in_preimage = 1;
1719        ecbdata.lno_in_postimage = 1;
1720
1721        lc_a = count_lines(data_one, size_one);
1722        lc_b = count_lines(data_two, size_two);
1723
1724        emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_MINUS,
1725                         a_name.buf, a_name.len, 0);
1726        emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_PLUS,
1727                         b_name.buf, b_name.len, 0);
1728
1729        strbuf_addstr(&out, "@@ -");
1730        if (!o->irreversible_delete)
1731                add_line_count(&out, lc_a);
1732        else
1733                strbuf_addstr(&out, "?,?");
1734        strbuf_addstr(&out, " +");
1735        add_line_count(&out, lc_b);
1736        strbuf_addstr(&out, " @@\n");
1737        emit_diff_symbol(o, DIFF_SYMBOL_REWRITE_DIFF, out.buf, out.len, 0);
1738        strbuf_release(&out);
1739
1740        if (lc_a && !o->irreversible_delete)
1741                emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
1742        if (lc_b)
1743                emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
1744        if (textconv_one)
1745                free((char *)data_one);
1746        if (textconv_two)
1747                free((char *)data_two);
1748}
1749
1750struct diff_words_buffer {
1751        mmfile_t text;
1752        unsigned long alloc;
1753        struct diff_words_orig {
1754                const char *begin, *end;
1755        } *orig;
1756        int orig_nr, orig_alloc;
1757};
1758
1759static void diff_words_append(char *line, unsigned long len,
1760                struct diff_words_buffer *buffer)
1761{
1762        ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
1763        line++;
1764        len--;
1765        memcpy(buffer->text.ptr + buffer->text.size, line, len);
1766        buffer->text.size += len;
1767        buffer->text.ptr[buffer->text.size] = '\0';
1768}
1769
1770struct diff_words_style_elem {
1771        const char *prefix;
1772        const char *suffix;
1773        const char *color; /* NULL; filled in by the setup code if
1774                            * color is enabled */
1775};
1776
1777struct diff_words_style {
1778        enum diff_words_type type;
1779        struct diff_words_style_elem new_word, old_word, ctx;
1780        const char *newline;
1781};
1782
1783static struct diff_words_style diff_words_styles[] = {
1784        { DIFF_WORDS_PORCELAIN, {"+", "\n"}, {"-", "\n"}, {" ", "\n"}, "~\n" },
1785        { DIFF_WORDS_PLAIN, {"{+", "+}"}, {"[-", "-]"}, {"", ""}, "\n" },
1786        { DIFF_WORDS_COLOR, {"", ""}, {"", ""}, {"", ""}, "\n" }
1787};
1788
1789struct diff_words_data {
1790        struct diff_words_buffer minus, plus;
1791        const char *current_plus;
1792        int last_minus;
1793        struct diff_options *opt;
1794        regex_t *word_regex;
1795        enum diff_words_type type;
1796        struct diff_words_style *style;
1797};
1798
1799static int fn_out_diff_words_write_helper(struct diff_options *o,
1800                                          struct diff_words_style_elem *st_el,
1801                                          const char *newline,
1802                                          size_t count, const char *buf)
1803{
1804        int print = 0;
1805        struct strbuf sb = STRBUF_INIT;
1806
1807        while (count) {
1808                char *p = memchr(buf, '\n', count);
1809                if (print)
1810                        strbuf_addstr(&sb, diff_line_prefix(o));
1811
1812                if (p != buf) {
1813                        const char *reset = st_el->color && *st_el->color ?
1814                                            GIT_COLOR_RESET : NULL;
1815                        if (st_el->color && *st_el->color)
1816                                strbuf_addstr(&sb, st_el->color);
1817                        strbuf_addstr(&sb, st_el->prefix);
1818                        strbuf_add(&sb, buf, p ? p - buf : count);
1819                        strbuf_addstr(&sb, st_el->suffix);
1820                        if (reset)
1821                                strbuf_addstr(&sb, reset);
1822                }
1823                if (!p)
1824                        goto out;
1825
1826                strbuf_addstr(&sb, newline);
1827                count -= p + 1 - buf;
1828                buf = p + 1;
1829                print = 1;
1830                if (count) {
1831                        emit_diff_symbol(o, DIFF_SYMBOL_WORD_DIFF,
1832                                         sb.buf, sb.len, 0);
1833                        strbuf_reset(&sb);
1834                }
1835        }
1836
1837out:
1838        if (sb.len)
1839                emit_diff_symbol(o, DIFF_SYMBOL_WORD_DIFF,
1840                                 sb.buf, sb.len, 0);
1841        strbuf_release(&sb);
1842        return 0;
1843}
1844
1845/*
1846 * '--color-words' algorithm can be described as:
1847 *
1848 *   1. collect the minus/plus lines of a diff hunk, divided into
1849 *      minus-lines and plus-lines;
1850 *
1851 *   2. break both minus-lines and plus-lines into words and
1852 *      place them into two mmfile_t with one word for each line;
1853 *
1854 *   3. use xdiff to run diff on the two mmfile_t to get the words level diff;
1855 *
1856 * And for the common parts of the both file, we output the plus side text.
1857 * diff_words->current_plus is used to trace the current position of the plus file
1858 * which printed. diff_words->last_minus is used to trace the last minus word
1859 * printed.
1860 *
1861 * For '--graph' to work with '--color-words', we need to output the graph prefix
1862 * on each line of color words output. Generally, there are two conditions on
1863 * which we should output the prefix.
1864 *
1865 *   1. diff_words->last_minus == 0 &&
1866 *      diff_words->current_plus == diff_words->plus.text.ptr
1867 *
1868 *      that is: the plus text must start as a new line, and if there is no minus
1869 *      word printed, a graph prefix must be printed.
1870 *
1871 *   2. diff_words->current_plus > diff_words->plus.text.ptr &&
1872 *      *(diff_words->current_plus - 1) == '\n'
1873 *
1874 *      that is: a graph prefix must be printed following a '\n'
1875 */
1876static int color_words_output_graph_prefix(struct diff_words_data *diff_words)
1877{
1878        if ((diff_words->last_minus == 0 &&
1879                diff_words->current_plus == diff_words->plus.text.ptr) ||
1880                (diff_words->current_plus > diff_words->plus.text.ptr &&
1881                *(diff_words->current_plus - 1) == '\n')) {
1882                return 1;
1883        } else {
1884                return 0;
1885        }
1886}
1887
1888static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
1889{
1890        struct diff_words_data *diff_words = priv;
1891        struct diff_words_style *style = diff_words->style;
1892        int minus_first, minus_len, plus_first, plus_len;
1893        const char *minus_begin, *minus_end, *plus_begin, *plus_end;
1894        struct diff_options *opt = diff_words->opt;
1895        const char *line_prefix;
1896
1897        if (line[0] != '@' || parse_hunk_header(line, len,
1898                        &minus_first, &minus_len, &plus_first, &plus_len))
1899                return;
1900
1901        assert(opt);
1902        line_prefix = diff_line_prefix(opt);
1903
1904        /* POSIX requires that first be decremented by one if len == 0... */
1905        if (minus_len) {
1906                minus_begin = diff_words->minus.orig[minus_first].begin;
1907                minus_end =
1908                        diff_words->minus.orig[minus_first + minus_len - 1].end;
1909        } else
1910                minus_begin = minus_end =
1911                        diff_words->minus.orig[minus_first].end;
1912
1913        if (plus_len) {
1914                plus_begin = diff_words->plus.orig[plus_first].begin;
1915                plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
1916        } else
1917                plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
1918
1919        if (color_words_output_graph_prefix(diff_words)) {
1920                fputs(line_prefix, diff_words->opt->file);
1921        }
1922        if (diff_words->current_plus != plus_begin) {
1923                fn_out_diff_words_write_helper(diff_words->opt,
1924                                &style->ctx, style->newline,
1925                                plus_begin - diff_words->current_plus,
1926                                diff_words->current_plus);
1927        }
1928        if (minus_begin != minus_end) {
1929                fn_out_diff_words_write_helper(diff_words->opt,
1930                                &style->old_word, style->newline,
1931                                minus_end - minus_begin, minus_begin);
1932        }
1933        if (plus_begin != plus_end) {
1934                fn_out_diff_words_write_helper(diff_words->opt,
1935                                &style->new_word, style->newline,
1936                                plus_end - plus_begin, plus_begin);
1937        }
1938
1939        diff_words->current_plus = plus_end;
1940        diff_words->last_minus = minus_first;
1941}
1942
1943/* This function starts looking at *begin, and returns 0 iff a word was found. */
1944static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
1945                int *begin, int *end)
1946{
1947        if (word_regex && *begin < buffer->size) {
1948                regmatch_t match[1];
1949                if (!regexec_buf(word_regex, buffer->ptr + *begin,
1950                                 buffer->size - *begin, 1, match, 0)) {
1951                        char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
1952                                        '\n', match[0].rm_eo - match[0].rm_so);
1953                        *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
1954                        *begin += match[0].rm_so;
1955                        return *begin >= *end;
1956                }
1957                return -1;
1958        }
1959
1960        /* find the next word */
1961        while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
1962                (*begin)++;
1963        if (*begin >= buffer->size)
1964                return -1;
1965
1966        /* find the end of the word */
1967        *end = *begin + 1;
1968        while (*end < buffer->size && !isspace(buffer->ptr[*end]))
1969                (*end)++;
1970
1971        return 0;
1972}
1973
1974/*
1975 * This function splits the words in buffer->text, stores the list with
1976 * newline separator into out, and saves the offsets of the original words
1977 * in buffer->orig.
1978 */
1979static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
1980                regex_t *word_regex)
1981{
1982        int i, j;
1983        long alloc = 0;
1984
1985        out->size = 0;
1986        out->ptr = NULL;
1987
1988        /* fake an empty "0th" word */
1989        ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
1990        buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
1991        buffer->orig_nr = 1;
1992
1993        for (i = 0; i < buffer->text.size; i++) {
1994                if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
1995                        return;
1996
1997                /* store original boundaries */
1998                ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
1999                                buffer->orig_alloc);
2000                buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
2001                buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
2002                buffer->orig_nr++;
2003
2004                /* store one word */
2005                ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
2006                memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
2007                out->ptr[out->size + j - i] = '\n';
2008                out->size += j - i + 1;
2009
2010                i = j - 1;
2011        }
2012}
2013
2014/* this executes the word diff on the accumulated buffers */
2015static void diff_words_show(struct diff_words_data *diff_words)
2016{
2017        xpparam_t xpp;
2018        xdemitconf_t xecfg;
2019        mmfile_t minus, plus;
2020        struct diff_words_style *style = diff_words->style;
2021
2022        struct diff_options *opt = diff_words->opt;
2023        const char *line_prefix;
2024
2025        assert(opt);
2026        line_prefix = diff_line_prefix(opt);
2027
2028        /* special case: only removal */
2029        if (!diff_words->plus.text.size) {
2030                emit_diff_symbol(diff_words->opt, DIFF_SYMBOL_WORD_DIFF,
2031                                 line_prefix, strlen(line_prefix), 0);
2032                fn_out_diff_words_write_helper(diff_words->opt,
2033                        &style->old_word, style->newline,
2034                        diff_words->minus.text.size,
2035                        diff_words->minus.text.ptr);
2036                diff_words->minus.text.size = 0;
2037                return;
2038        }
2039
2040        diff_words->current_plus = diff_words->plus.text.ptr;
2041        diff_words->last_minus = 0;
2042
2043        memset(&xpp, 0, sizeof(xpp));
2044        memset(&xecfg, 0, sizeof(xecfg));
2045        diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
2046        diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
2047        xpp.flags = 0;
2048        /* as only the hunk header will be parsed, we need a 0-context */
2049        xecfg.ctxlen = 0;
2050        if (xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
2051                          &xpp, &xecfg))
2052                die("unable to generate word diff");
2053        free(minus.ptr);
2054        free(plus.ptr);
2055        if (diff_words->current_plus != diff_words->plus.text.ptr +
2056                        diff_words->plus.text.size) {
2057                if (color_words_output_graph_prefix(diff_words))
2058                        emit_diff_symbol(diff_words->opt, DIFF_SYMBOL_WORD_DIFF,
2059                                         line_prefix, strlen(line_prefix), 0);
2060                fn_out_diff_words_write_helper(diff_words->opt,
2061                        &style->ctx, style->newline,
2062                        diff_words->plus.text.ptr + diff_words->plus.text.size
2063                        - diff_words->current_plus, diff_words->current_plus);
2064        }
2065        diff_words->minus.text.size = diff_words->plus.text.size = 0;
2066}
2067
2068/* In "color-words" mode, show word-diff of words accumulated in the buffer */
2069static void diff_words_flush(struct emit_callback *ecbdata)
2070{
2071        struct diff_options *wo = ecbdata->diff_words->opt;
2072
2073        if (ecbdata->diff_words->minus.text.size ||
2074            ecbdata->diff_words->plus.text.size)
2075                diff_words_show(ecbdata->diff_words);
2076
2077        if (wo->emitted_symbols) {
2078                struct diff_options *o = ecbdata->opt;
2079                struct emitted_diff_symbols *wol = wo->emitted_symbols;
2080                int i;
2081
2082                /*
2083                 * NEEDSWORK:
2084                 * Instead of appending each, concat all words to a line?
2085                 */
2086                for (i = 0; i < wol->nr; i++)
2087                        append_emitted_diff_symbol(o, &wol->buf[i]);
2088
2089                for (i = 0; i < wol->nr; i++)
2090                        free((void *)wol->buf[i].line);
2091
2092                wol->nr = 0;
2093        }
2094}
2095
2096static void diff_filespec_load_driver(struct diff_filespec *one)
2097{
2098        /* Use already-loaded driver */
2099        if (one->driver)
2100                return;
2101
2102        if (S_ISREG(one->mode))
2103                one->driver = userdiff_find_by_path(one->path);
2104
2105        /* Fallback to default settings */
2106        if (!one->driver)
2107                one->driver = userdiff_find_by_name("default");
2108}
2109
2110static const char *userdiff_word_regex(struct diff_filespec *one)
2111{
2112        diff_filespec_load_driver(one);
2113        return one->driver->word_regex;
2114}
2115
2116static void init_diff_words_data(struct emit_callback *ecbdata,
2117                                 struct diff_options *orig_opts,
2118                                 struct diff_filespec *one,
2119                                 struct diff_filespec *two)
2120{
2121        int i;
2122        struct diff_options *o = xmalloc(sizeof(struct diff_options));
2123        memcpy(o, orig_opts, sizeof(struct diff_options));
2124
2125        ecbdata->diff_words =
2126                xcalloc(1, sizeof(struct diff_words_data));
2127        ecbdata->diff_words->type = o->word_diff;
2128        ecbdata->diff_words->opt = o;
2129
2130        if (orig_opts->emitted_symbols)
2131                o->emitted_symbols =
2132                        xcalloc(1, sizeof(struct emitted_diff_symbols));
2133
2134        if (!o->word_regex)
2135                o->word_regex = userdiff_word_regex(one);
2136        if (!o->word_regex)
2137                o->word_regex = userdiff_word_regex(two);
2138        if (!o->word_regex)
2139                o->word_regex = diff_word_regex_cfg;
2140        if (o->word_regex) {
2141                ecbdata->diff_words->word_regex = (regex_t *)
2142                        xmalloc(sizeof(regex_t));
2143                if (regcomp(ecbdata->diff_words->word_regex,
2144                            o->word_regex,
2145                            REG_EXTENDED | REG_NEWLINE))
2146                        die("invalid regular expression: %s",
2147                            o->word_regex);
2148        }
2149        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
2150                if (o->word_diff == diff_words_styles[i].type) {
2151                        ecbdata->diff_words->style =
2152                                &diff_words_styles[i];
2153                        break;
2154                }
2155        }
2156        if (want_color(o->use_color)) {
2157                struct diff_words_style *st = ecbdata->diff_words->style;
2158                st->old_word.color = diff_get_color_opt(o, DIFF_FILE_OLD);
2159                st->new_word.color = diff_get_color_opt(o, DIFF_FILE_NEW);
2160                st->ctx.color = diff_get_color_opt(o, DIFF_CONTEXT);
2161        }
2162}
2163
2164static void free_diff_words_data(struct emit_callback *ecbdata)
2165{
2166        if (ecbdata->diff_words) {
2167                diff_words_flush(ecbdata);
2168                free (ecbdata->diff_words->opt->emitted_symbols);
2169                free (ecbdata->diff_words->opt);
2170                free (ecbdata->diff_words->minus.text.ptr);
2171                free (ecbdata->diff_words->minus.orig);
2172                free (ecbdata->diff_words->plus.text.ptr);
2173                free (ecbdata->diff_words->plus.orig);
2174                if (ecbdata->diff_words->word_regex) {
2175                        regfree(ecbdata->diff_words->word_regex);
2176                        free(ecbdata->diff_words->word_regex);
2177                }
2178                FREE_AND_NULL(ecbdata->diff_words);
2179        }
2180}
2181
2182const char *diff_get_color(int diff_use_color, enum color_diff ix)
2183{
2184        if (want_color(diff_use_color))
2185                return diff_colors[ix];
2186        return "";
2187}
2188
2189const char *diff_line_prefix(struct diff_options *opt)
2190{
2191        struct strbuf *msgbuf;
2192        if (!opt->output_prefix)
2193                return "";
2194
2195        msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
2196        return msgbuf->buf;
2197}
2198
2199static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
2200{
2201        const char *cp;
2202        unsigned long allot;
2203        size_t l = len;
2204
2205        cp = line;
2206        allot = l;
2207        while (0 < l) {
2208                (void) utf8_width(&cp, &l);
2209                if (!cp)
2210                        break; /* truncated in the middle? */
2211        }
2212        return allot - l;
2213}
2214
2215static void find_lno(const char *line, struct emit_callback *ecbdata)
2216{
2217        const char *p;
2218        ecbdata->lno_in_preimage = 0;
2219        ecbdata->lno_in_postimage = 0;
2220        p = strchr(line, '-');
2221        if (!p)
2222                return; /* cannot happen */
2223        ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
2224        p = strchr(p, '+');
2225        if (!p)
2226                return; /* cannot happen */
2227        ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
2228}
2229
2230static void fn_out_consume(void *priv, char *line, unsigned long len)
2231{
2232        struct emit_callback *ecbdata = priv;
2233        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
2234        struct diff_options *o = ecbdata->opt;
2235
2236        o->found_changes = 1;
2237
2238        if (ecbdata->header) {
2239                emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
2240                                 ecbdata->header->buf, ecbdata->header->len, 0);
2241                strbuf_reset(ecbdata->header);
2242                ecbdata->header = NULL;
2243        }
2244
2245        if (ecbdata->label_path[0]) {
2246                emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_MINUS,
2247                                 ecbdata->label_path[0],
2248                                 strlen(ecbdata->label_path[0]), 0);
2249                emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_PLUS,
2250                                 ecbdata->label_path[1],
2251                                 strlen(ecbdata->label_path[1]), 0);
2252                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
2253        }
2254
2255        if (diff_suppress_blank_empty
2256            && len == 2 && line[0] == ' ' && line[1] == '\n') {
2257                line[0] = '\n';
2258                len = 1;
2259        }
2260
2261        if (line[0] == '@') {
2262                if (ecbdata->diff_words)
2263                        diff_words_flush(ecbdata);
2264                len = sane_truncate_line(ecbdata, line, len);
2265                find_lno(line, ecbdata);
2266                emit_hunk_header(ecbdata, line, len);
2267                return;
2268        }
2269
2270        if (ecbdata->diff_words) {
2271                enum diff_symbol s =
2272                        ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN ?
2273                        DIFF_SYMBOL_WORDS_PORCELAIN : DIFF_SYMBOL_WORDS;
2274                if (line[0] == '-') {
2275                        diff_words_append(line, len,
2276                                          &ecbdata->diff_words->minus);
2277                        return;
2278                } else if (line[0] == '+') {
2279                        diff_words_append(line, len,
2280                                          &ecbdata->diff_words->plus);
2281                        return;
2282                } else if (starts_with(line, "\\ ")) {
2283                        /*
2284                         * Eat the "no newline at eof" marker as if we
2285                         * saw a "+" or "-" line with nothing on it,
2286                         * and return without diff_words_flush() to
2287                         * defer processing. If this is the end of
2288                         * preimage, more "+" lines may come after it.
2289                         */
2290                        return;
2291                }
2292                diff_words_flush(ecbdata);
2293                emit_diff_symbol(o, s, line, len, 0);
2294                return;
2295        }
2296
2297        switch (line[0]) {
2298        case '+':
2299                ecbdata->lno_in_postimage++;
2300                emit_add_line(reset, ecbdata, line + 1, len - 1);
2301                break;
2302        case '-':
2303                ecbdata->lno_in_preimage++;
2304                emit_del_line(reset, ecbdata, line + 1, len - 1);
2305                break;
2306        case ' ':
2307                ecbdata->lno_in_postimage++;
2308                ecbdata->lno_in_preimage++;
2309                emit_context_line(reset, ecbdata, line + 1, len - 1);
2310                break;
2311        default:
2312                /* incomplete line at the end */
2313                ecbdata->lno_in_preimage++;
2314                emit_diff_symbol(o, DIFF_SYMBOL_CONTEXT_INCOMPLETE,
2315                                 line, len, 0);
2316                break;
2317        }
2318}
2319
2320static void pprint_rename(struct strbuf *name, const char *a, const char *b)
2321{
2322        const char *old_name = a;
2323        const char *new_name = b;
2324        int pfx_length, sfx_length;
2325        int pfx_adjust_for_slash;
2326        int len_a = strlen(a);
2327        int len_b = strlen(b);
2328        int a_midlen, b_midlen;
2329        int qlen_a = quote_c_style(a, NULL, NULL, 0);
2330        int qlen_b = quote_c_style(b, NULL, NULL, 0);
2331
2332        if (qlen_a || qlen_b) {
2333                quote_c_style(a, name, NULL, 0);
2334                strbuf_addstr(name, " => ");
2335                quote_c_style(b, name, NULL, 0);
2336                return;
2337        }
2338
2339        /* Find common prefix */
2340        pfx_length = 0;
2341        while (*old_name && *new_name && *old_name == *new_name) {
2342                if (*old_name == '/')
2343                        pfx_length = old_name - a + 1;
2344                old_name++;
2345                new_name++;
2346        }
2347
2348        /* Find common suffix */
2349        old_name = a + len_a;
2350        new_name = b + len_b;
2351        sfx_length = 0;
2352        /*
2353         * If there is a common prefix, it must end in a slash.  In
2354         * that case we let this loop run 1 into the prefix to see the
2355         * same slash.
2356         *
2357         * If there is no common prefix, we cannot do this as it would
2358         * underrun the input strings.
2359         */
2360        pfx_adjust_for_slash = (pfx_length ? 1 : 0);
2361        while (a + pfx_length - pfx_adjust_for_slash <= old_name &&
2362               b + pfx_length - pfx_adjust_for_slash <= new_name &&
2363               *old_name == *new_name) {
2364                if (*old_name == '/')
2365                        sfx_length = len_a - (old_name - a);
2366                old_name--;
2367                new_name--;
2368        }
2369
2370        /*
2371         * pfx{mid-a => mid-b}sfx
2372         * {pfx-a => pfx-b}sfx
2373         * pfx{sfx-a => sfx-b}
2374         * name-a => name-b
2375         */
2376        a_midlen = len_a - pfx_length - sfx_length;
2377        b_midlen = len_b - pfx_length - sfx_length;
2378        if (a_midlen < 0)
2379                a_midlen = 0;
2380        if (b_midlen < 0)
2381                b_midlen = 0;
2382
2383        strbuf_grow(name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
2384        if (pfx_length + sfx_length) {
2385                strbuf_add(name, a, pfx_length);
2386                strbuf_addch(name, '{');
2387        }
2388        strbuf_add(name, a + pfx_length, a_midlen);
2389        strbuf_addstr(name, " => ");
2390        strbuf_add(name, b + pfx_length, b_midlen);
2391        if (pfx_length + sfx_length) {
2392                strbuf_addch(name, '}');
2393                strbuf_add(name, a + len_a - sfx_length, sfx_length);
2394        }
2395}
2396
2397struct diffstat_t {
2398        int nr;
2399        int alloc;
2400        struct diffstat_file {
2401                char *from_name;
2402                char *name;
2403                char *print_name;
2404                const char *comments;
2405                unsigned is_unmerged:1;
2406                unsigned is_binary:1;
2407                unsigned is_renamed:1;
2408                unsigned is_interesting:1;
2409                uintmax_t added, deleted;
2410        } **files;
2411};
2412
2413static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
2414                                          const char *name_a,
2415                                          const char *name_b)
2416{
2417        struct diffstat_file *x;
2418        x = xcalloc(1, sizeof(*x));
2419        ALLOC_GROW(diffstat->files, diffstat->nr + 1, diffstat->alloc);
2420        diffstat->files[diffstat->nr++] = x;
2421        if (name_b) {
2422                x->from_name = xstrdup(name_a);
2423                x->name = xstrdup(name_b);
2424                x->is_renamed = 1;
2425        }
2426        else {
2427                x->from_name = NULL;
2428                x->name = xstrdup(name_a);
2429        }
2430        return x;
2431}
2432
2433static void diffstat_consume(void *priv, char *line, unsigned long len)
2434{
2435        struct diffstat_t *diffstat = priv;
2436        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
2437
2438        if (line[0] == '+')
2439                x->added++;
2440        else if (line[0] == '-')
2441                x->deleted++;
2442}
2443
2444const char mime_boundary_leader[] = "------------";
2445
2446static int scale_linear(int it, int width, int max_change)
2447{
2448        if (!it)
2449                return 0;
2450        /*
2451         * make sure that at least one '-' or '+' is printed if
2452         * there is any change to this path. The easiest way is to
2453         * scale linearly as if the alloted width is one column shorter
2454         * than it is, and then add 1 to the result.
2455         */
2456        return 1 + (it * (width - 1) / max_change);
2457}
2458
2459static void show_graph(struct strbuf *out, char ch, int cnt,
2460                       const char *set, const char *reset)
2461{
2462        if (cnt <= 0)
2463                return;
2464        strbuf_addstr(out, set);
2465        strbuf_addchars(out, ch, cnt);
2466        strbuf_addstr(out, reset);
2467}
2468
2469static void fill_print_name(struct diffstat_file *file)
2470{
2471        struct strbuf pname = STRBUF_INIT;
2472
2473        if (file->print_name)
2474                return;
2475
2476        if (file->is_renamed)
2477                pprint_rename(&pname, file->from_name, file->name);
2478        else
2479                quote_c_style(file->name, &pname, NULL, 0);
2480
2481        if (file->comments)
2482                strbuf_addf(&pname, " (%s)", file->comments);
2483
2484        file->print_name = strbuf_detach(&pname, NULL);
2485}
2486
2487static void print_stat_summary_inserts_deletes(struct diff_options *options,
2488                int files, int insertions, int deletions)
2489{
2490        struct strbuf sb = STRBUF_INIT;
2491
2492        if (!files) {
2493                assert(insertions == 0 && deletions == 0);
2494                emit_diff_symbol(options, DIFF_SYMBOL_STATS_SUMMARY_NO_FILES,
2495                                 NULL, 0, 0);
2496                return;
2497        }
2498
2499        strbuf_addf(&sb,
2500                    (files == 1) ? " %d file changed" : " %d files changed",
2501                    files);
2502
2503        /*
2504         * For binary diff, the caller may want to print "x files
2505         * changed" with insertions == 0 && deletions == 0.
2506         *
2507         * Not omitting "0 insertions(+), 0 deletions(-)" in this case
2508         * is probably less confusing (i.e skip over "2 files changed
2509         * but nothing about added/removed lines? Is this a bug in Git?").
2510         */
2511        if (insertions || deletions == 0) {
2512                strbuf_addf(&sb,
2513                            (insertions == 1) ? ", %d insertion(+)" : ", %d insertions(+)",
2514                            insertions);
2515        }
2516
2517        if (deletions || insertions == 0) {
2518                strbuf_addf(&sb,
2519                            (deletions == 1) ? ", %d deletion(-)" : ", %d deletions(-)",
2520                            deletions);
2521        }
2522        strbuf_addch(&sb, '\n');
2523        emit_diff_symbol(options, DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES,
2524                         sb.buf, sb.len, 0);
2525        strbuf_release(&sb);
2526}
2527
2528void print_stat_summary(FILE *fp, int files,
2529                        int insertions, int deletions)
2530{
2531        struct diff_options o;
2532        memset(&o, 0, sizeof(o));
2533        o.file = fp;
2534
2535        print_stat_summary_inserts_deletes(&o, files, insertions, deletions);
2536}
2537
2538static void show_stats(struct diffstat_t *data, struct diff_options *options)
2539{
2540        int i, len, add, del, adds = 0, dels = 0;
2541        uintmax_t max_change = 0, max_len = 0;
2542        int total_files = data->nr, count;
2543        int width, name_width, graph_width, number_width = 0, bin_width = 0;
2544        const char *reset, *add_c, *del_c;
2545        int extra_shown = 0;
2546        const char *line_prefix = diff_line_prefix(options);
2547        struct strbuf out = STRBUF_INIT;
2548
2549        if (data->nr == 0)
2550                return;
2551
2552        count = options->stat_count ? options->stat_count : data->nr;
2553
2554        reset = diff_get_color_opt(options, DIFF_RESET);
2555        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
2556        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
2557
2558        /*
2559         * Find the longest filename and max number of changes
2560         */
2561        for (i = 0; (i < count) && (i < data->nr); i++) {
2562                struct diffstat_file *file = data->files[i];
2563                uintmax_t change = file->added + file->deleted;
2564
2565                if (!file->is_interesting && (change == 0)) {
2566                        count++; /* not shown == room for one more */
2567                        continue;
2568                }
2569                fill_print_name(file);
2570                len = strlen(file->print_name);
2571                if (max_len < len)
2572                        max_len = len;
2573
2574                if (file->is_unmerged) {
2575                        /* "Unmerged" is 8 characters */
2576                        bin_width = bin_width < 8 ? 8 : bin_width;
2577                        continue;
2578                }
2579                if (file->is_binary) {
2580                        /* "Bin XXX -> YYY bytes" */
2581                        int w = 14 + decimal_width(file->added)
2582                                + decimal_width(file->deleted);
2583                        bin_width = bin_width < w ? w : bin_width;
2584                        /* Display change counts aligned with "Bin" */
2585                        number_width = 3;
2586                        continue;
2587                }
2588
2589                if (max_change < change)
2590                        max_change = change;
2591        }
2592        count = i; /* where we can stop scanning in data->files[] */
2593
2594        /*
2595         * We have width = stat_width or term_columns() columns total.
2596         * We want a maximum of min(max_len, stat_name_width) for the name part.
2597         * We want a maximum of min(max_change, stat_graph_width) for the +- part.
2598         * We also need 1 for " " and 4 + decimal_width(max_change)
2599         * for " | NNNN " and one the empty column at the end, altogether
2600         * 6 + decimal_width(max_change).
2601         *
2602         * If there's not enough space, we will use the smaller of
2603         * stat_name_width (if set) and 5/8*width for the filename,
2604         * and the rest for constant elements + graph part, but no more
2605         * than stat_graph_width for the graph part.
2606         * (5/8 gives 50 for filename and 30 for the constant parts + graph
2607         * for the standard terminal size).
2608         *
2609         * In other words: stat_width limits the maximum width, and
2610         * stat_name_width fixes the maximum width of the filename,
2611         * and is also used to divide available columns if there
2612         * aren't enough.
2613         *
2614         * Binary files are displayed with "Bin XXX -> YYY bytes"
2615         * instead of the change count and graph. This part is treated
2616         * similarly to the graph part, except that it is not
2617         * "scaled". If total width is too small to accommodate the
2618         * guaranteed minimum width of the filename part and the
2619         * separators and this message, this message will "overflow"
2620         * making the line longer than the maximum width.
2621         */
2622
2623        if (options->stat_width == -1)
2624                width = term_columns() - strlen(line_prefix);
2625        else
2626                width = options->stat_width ? options->stat_width : 80;
2627        number_width = decimal_width(max_change) > number_width ?
2628                decimal_width(max_change) : number_width;
2629
2630        if (options->stat_graph_width == -1)
2631                options->stat_graph_width = diff_stat_graph_width;
2632
2633        /*
2634         * Guarantee 3/8*16==6 for the graph part
2635         * and 5/8*16==10 for the filename part
2636         */
2637        if (width < 16 + 6 + number_width)
2638                width = 16 + 6 + number_width;
2639
2640        /*
2641         * First assign sizes that are wanted, ignoring available width.
2642         * strlen("Bin XXX -> YYY bytes") == bin_width, and the part
2643         * starting from "XXX" should fit in graph_width.
2644         */
2645        graph_width = max_change + 4 > bin_width ? max_change : bin_width - 4;
2646        if (options->stat_graph_width &&
2647            options->stat_graph_width < graph_width)
2648                graph_width = options->stat_graph_width;
2649
2650        name_width = (options->stat_name_width > 0 &&
2651                      options->stat_name_width < max_len) ?
2652                options->stat_name_width : max_len;
2653
2654        /*
2655         * Adjust adjustable widths not to exceed maximum width
2656         */
2657        if (name_width + number_width + 6 + graph_width > width) {
2658                if (graph_width > width * 3/8 - number_width - 6) {
2659                        graph_width = width * 3/8 - number_width - 6;
2660                        if (graph_width < 6)
2661                                graph_width = 6;
2662                }
2663
2664                if (options->stat_graph_width &&
2665                    graph_width > options->stat_graph_width)
2666                        graph_width = options->stat_graph_width;
2667                if (name_width > width - number_width - 6 - graph_width)
2668                        name_width = width - number_width - 6 - graph_width;
2669                else
2670                        graph_width = width - number_width - 6 - name_width;
2671        }
2672
2673        /*
2674         * From here name_width is the width of the name area,
2675         * and graph_width is the width of the graph area.
2676         * max_change is used to scale graph properly.
2677         */
2678        for (i = 0; i < count; i++) {
2679                const char *prefix = "";
2680                struct diffstat_file *file = data->files[i];
2681                char *name = file->print_name;
2682                uintmax_t added = file->added;
2683                uintmax_t deleted = file->deleted;
2684                int name_len;
2685
2686                if (!file->is_interesting && (added + deleted == 0))
2687                        continue;
2688
2689                /*
2690                 * "scale" the filename
2691                 */
2692                len = name_width;
2693                name_len = strlen(name);
2694                if (name_width < name_len) {
2695                        char *slash;
2696                        prefix = "...";
2697                        len -= 3;
2698                        name += name_len - len;
2699                        slash = strchr(name, '/');
2700                        if (slash)
2701                                name = slash;
2702                }
2703
2704                if (file->is_binary) {
2705                        strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2706                        strbuf_addf(&out, " %*s", number_width, "Bin");
2707                        if (!added && !deleted) {
2708                                strbuf_addch(&out, '\n');
2709                                emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2710                                                 out.buf, out.len, 0);
2711                                strbuf_reset(&out);
2712                                continue;
2713                        }
2714                        strbuf_addf(&out, " %s%"PRIuMAX"%s",
2715                                del_c, deleted, reset);
2716                        strbuf_addstr(&out, " -> ");
2717                        strbuf_addf(&out, "%s%"PRIuMAX"%s",
2718                                add_c, added, reset);
2719                        strbuf_addstr(&out, " bytes\n");
2720                        emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2721                                         out.buf, out.len, 0);
2722                        strbuf_reset(&out);
2723                        continue;
2724                }
2725                else if (file->is_unmerged) {
2726                        strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2727                        strbuf_addstr(&out, " Unmerged\n");
2728                        emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2729                                         out.buf, out.len, 0);
2730                        strbuf_reset(&out);
2731                        continue;
2732                }
2733
2734                /*
2735                 * scale the add/delete
2736                 */
2737                add = added;
2738                del = deleted;
2739
2740                if (graph_width <= max_change) {
2741                        int total = scale_linear(add + del, graph_width, max_change);
2742                        if (total < 2 && add && del)
2743                                /* width >= 2 due to the sanity check */
2744                                total = 2;
2745                        if (add < del) {
2746                                add = scale_linear(add, graph_width, max_change);
2747                                del = total - add;
2748                        } else {
2749                                del = scale_linear(del, graph_width, max_change);
2750                                add = total - del;
2751                        }
2752                }
2753                strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2754                strbuf_addf(&out, " %*"PRIuMAX"%s",
2755                        number_width, added + deleted,
2756                        added + deleted ? " " : "");
2757                show_graph(&out, '+', add, add_c, reset);
2758                show_graph(&out, '-', del, del_c, reset);
2759                strbuf_addch(&out, '\n');
2760                emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2761                                 out.buf, out.len, 0);
2762                strbuf_reset(&out);
2763        }
2764
2765        for (i = 0; i < data->nr; i++) {
2766                struct diffstat_file *file = data->files[i];
2767                uintmax_t added = file->added;
2768                uintmax_t deleted = file->deleted;
2769
2770                if (file->is_unmerged ||
2771                    (!file->is_interesting && (added + deleted == 0))) {
2772                        total_files--;
2773                        continue;
2774                }
2775
2776                if (!file->is_binary) {
2777                        adds += added;
2778                        dels += deleted;
2779                }
2780                if (i < count)
2781                        continue;
2782                if (!extra_shown)
2783                        emit_diff_symbol(options,
2784                                         DIFF_SYMBOL_STATS_SUMMARY_ABBREV,
2785                                         NULL, 0, 0);
2786                extra_shown = 1;
2787        }
2788
2789        print_stat_summary_inserts_deletes(options, total_files, adds, dels);
2790        strbuf_release(&out);
2791}
2792
2793static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
2794{
2795        int i, adds = 0, dels = 0, total_files = data->nr;
2796
2797        if (data->nr == 0)
2798                return;
2799
2800        for (i = 0; i < data->nr; i++) {
2801                int added = data->files[i]->added;
2802                int deleted = data->files[i]->deleted;
2803
2804                if (data->files[i]->is_unmerged ||
2805                    (!data->files[i]->is_interesting && (added + deleted == 0))) {
2806                        total_files--;
2807                } else if (!data->files[i]->is_binary) { /* don't count bytes */
2808                        adds += added;
2809                        dels += deleted;
2810                }
2811        }
2812        print_stat_summary_inserts_deletes(options, total_files, adds, dels);
2813}
2814
2815static void show_numstat(struct diffstat_t *data, struct diff_options *options)
2816{
2817        int i;
2818
2819        if (data->nr == 0)
2820                return;
2821
2822        for (i = 0; i < data->nr; i++) {
2823                struct diffstat_file *file = data->files[i];
2824
2825                fprintf(options->file, "%s", diff_line_prefix(options));
2826
2827                if (file->is_binary)
2828                        fprintf(options->file, "-\t-\t");
2829                else
2830                        fprintf(options->file,
2831                                "%"PRIuMAX"\t%"PRIuMAX"\t",
2832                                file->added, file->deleted);
2833                if (options->line_termination) {
2834                        fill_print_name(file);
2835                        if (!file->is_renamed)
2836                                write_name_quoted(file->name, options->file,
2837                                                  options->line_termination);
2838                        else {
2839                                fputs(file->print_name, options->file);
2840                                putc(options->line_termination, options->file);
2841                        }
2842                } else {
2843                        if (file->is_renamed) {
2844                                putc('\0', options->file);
2845                                write_name_quoted(file->from_name, options->file, '\0');
2846                        }
2847                        write_name_quoted(file->name, options->file, '\0');
2848                }
2849        }
2850}
2851
2852struct dirstat_file {
2853        const char *name;
2854        unsigned long changed;
2855};
2856
2857struct dirstat_dir {
2858        struct dirstat_file *files;
2859        int alloc, nr, permille, cumulative;
2860};
2861
2862static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
2863                unsigned long changed, const char *base, int baselen)
2864{
2865        unsigned long sum_changes = 0;
2866        unsigned int sources = 0;
2867        const char *line_prefix = diff_line_prefix(opt);
2868
2869        while (dir->nr) {
2870                struct dirstat_file *f = dir->files;
2871                int namelen = strlen(f->name);
2872                unsigned long changes;
2873                char *slash;
2874
2875                if (namelen < baselen)
2876                        break;
2877                if (memcmp(f->name, base, baselen))
2878                        break;
2879                slash = strchr(f->name + baselen, '/');
2880                if (slash) {
2881                        int newbaselen = slash + 1 - f->name;
2882                        changes = gather_dirstat(opt, dir, changed, f->name, newbaselen);
2883                        sources++;
2884                } else {
2885                        changes = f->changed;
2886                        dir->files++;
2887                        dir->nr--;
2888                        sources += 2;
2889                }
2890                sum_changes += changes;
2891        }
2892
2893        /*
2894         * We don't report dirstat's for
2895         *  - the top level
2896         *  - or cases where everything came from a single directory
2897         *    under this directory (sources == 1).
2898         */
2899        if (baselen && sources != 1) {
2900                if (sum_changes) {
2901                        int permille = sum_changes * 1000 / changed;
2902                        if (permille >= dir->permille) {
2903                                fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
2904                                        permille / 10, permille % 10, baselen, base);
2905                                if (!dir->cumulative)
2906                                        return 0;
2907                        }
2908                }
2909        }
2910        return sum_changes;
2911}
2912
2913static int dirstat_compare(const void *_a, const void *_b)
2914{
2915        const struct dirstat_file *a = _a;
2916        const struct dirstat_file *b = _b;
2917        return strcmp(a->name, b->name);
2918}
2919
2920static void show_dirstat(struct diff_options *options)
2921{
2922        int i;
2923        unsigned long changed;
2924        struct dirstat_dir dir;
2925        struct diff_queue_struct *q = &diff_queued_diff;
2926
2927        dir.files = NULL;
2928        dir.alloc = 0;
2929        dir.nr = 0;
2930        dir.permille = options->dirstat_permille;
2931        dir.cumulative = options->flags.dirstat_cumulative;
2932
2933        changed = 0;
2934        for (i = 0; i < q->nr; i++) {
2935                struct diff_filepair *p = q->queue[i];
2936                const char *name;
2937                unsigned long copied, added, damage;
2938                int content_changed;
2939
2940                name = p->two->path ? p->two->path : p->one->path;
2941
2942                if (p->one->oid_valid && p->two->oid_valid)
2943                        content_changed = oidcmp(&p->one->oid, &p->two->oid);
2944                else
2945                        content_changed = 1;
2946
2947                if (!content_changed) {
2948                        /*
2949                         * The SHA1 has not changed, so pre-/post-content is
2950                         * identical. We can therefore skip looking at the
2951                         * file contents altogether.
2952                         */
2953                        damage = 0;
2954                        goto found_damage;
2955                }
2956
2957                if (options->flags.dirstat_by_file) {
2958                        /*
2959                         * In --dirstat-by-file mode, we don't really need to
2960                         * look at the actual file contents at all.
2961                         * The fact that the SHA1 changed is enough for us to
2962                         * add this file to the list of results
2963                         * (with each file contributing equal damage).
2964                         */
2965                        damage = 1;
2966                        goto found_damage;
2967                }
2968
2969                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
2970                        diff_populate_filespec(options->repo, p->one, 0);
2971                        diff_populate_filespec(options->repo, p->two, 0);
2972                        diffcore_count_changes(options->repo,
2973                                               p->one, p->two, NULL, NULL,
2974                                               &copied, &added);
2975                        diff_free_filespec_data(p->one);
2976                        diff_free_filespec_data(p->two);
2977                } else if (DIFF_FILE_VALID(p->one)) {
2978                        diff_populate_filespec(options->repo, p->one, CHECK_SIZE_ONLY);
2979                        copied = added = 0;
2980                        diff_free_filespec_data(p->one);
2981                } else if (DIFF_FILE_VALID(p->two)) {
2982                        diff_populate_filespec(options->repo, p->two, CHECK_SIZE_ONLY);
2983                        copied = 0;
2984                        added = p->two->size;
2985                        diff_free_filespec_data(p->two);
2986                } else
2987                        continue;
2988
2989                /*
2990                 * Original minus copied is the removed material,
2991                 * added is the new material.  They are both damages
2992                 * made to the preimage.
2993                 * If the resulting damage is zero, we know that
2994                 * diffcore_count_changes() considers the two entries to
2995                 * be identical, but since content_changed is true, we
2996                 * know that there must have been _some_ kind of change,
2997                 * so we force all entries to have damage > 0.
2998                 */
2999                damage = (p->one->size - copied) + added;
3000                if (!damage)
3001                        damage = 1;
3002
3003found_damage:
3004                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
3005                dir.files[dir.nr].name = name;
3006                dir.files[dir.nr].changed = damage;
3007                changed += damage;
3008                dir.nr++;
3009        }
3010
3011        /* This can happen even with many files, if everything was renames */
3012        if (!changed)
3013                return;
3014
3015        /* Show all directories with more than x% of the changes */
3016        QSORT(dir.files, dir.nr, dirstat_compare);
3017        gather_dirstat(options, &dir, changed, "", 0);
3018}
3019
3020static void show_dirstat_by_line(struct diffstat_t *data, struct diff_options *options)
3021{
3022        int i;
3023        unsigned long changed;
3024        struct dirstat_dir dir;
3025
3026        if (data->nr == 0)
3027                return;
3028
3029        dir.files = NULL;
3030        dir.alloc = 0;
3031        dir.nr = 0;
3032        dir.permille = options->dirstat_permille;
3033        dir.cumulative = options->flags.dirstat_cumulative;
3034
3035        changed = 0;
3036        for (i = 0; i < data->nr; i++) {
3037                struct diffstat_file *file = data->files[i];
3038                unsigned long damage = file->added + file->deleted;
3039                if (file->is_binary)
3040                        /*
3041                         * binary files counts bytes, not lines. Must find some
3042                         * way to normalize binary bytes vs. textual lines.
3043                         * The following heuristic assumes that there are 64
3044                         * bytes per "line".
3045                         * This is stupid and ugly, but very cheap...
3046                         */
3047                        damage = DIV_ROUND_UP(damage, 64);
3048                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
3049                dir.files[dir.nr].name = file->name;
3050                dir.files[dir.nr].changed = damage;
3051                changed += damage;
3052                dir.nr++;
3053        }
3054
3055        /* This can happen even with many files, if everything was renames */
3056        if (!changed)
3057                return;
3058
3059        /* Show all directories with more than x% of the changes */
3060        QSORT(dir.files, dir.nr, dirstat_compare);
3061        gather_dirstat(options, &dir, changed, "", 0);
3062}
3063
3064static void free_diffstat_info(struct diffstat_t *diffstat)
3065{
3066        int i;
3067        for (i = 0; i < diffstat->nr; i++) {
3068                struct diffstat_file *f = diffstat->files[i];
3069                free(f->print_name);
3070                free(f->name);
3071                free(f->from_name);
3072                free(f);
3073        }
3074        free(diffstat->files);
3075}
3076
3077struct checkdiff_t {
3078        const char *filename;
3079        int lineno;
3080        int conflict_marker_size;
3081        struct diff_options *o;
3082        unsigned ws_rule;
3083        unsigned status;
3084};
3085
3086static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
3087{
3088        char firstchar;
3089        int cnt;
3090
3091        if (len < marker_size + 1)
3092                return 0;
3093        firstchar = line[0];
3094        switch (firstchar) {
3095        case '=': case '>': case '<': case '|':
3096                break;
3097        default:
3098                return 0;
3099        }
3100        for (cnt = 1; cnt < marker_size; cnt++)
3101                if (line[cnt] != firstchar)
3102                        return 0;
3103        /* line[1] thru line[marker_size-1] are same as firstchar */
3104        if (len < marker_size + 1 || !isspace(line[marker_size]))
3105                return 0;
3106        return 1;
3107}
3108
3109static void checkdiff_consume(void *priv, char *line, unsigned long len)
3110{
3111        struct checkdiff_t *data = priv;
3112        int marker_size = data->conflict_marker_size;
3113        const char *ws = diff_get_color(data->o->use_color, DIFF_WHITESPACE);
3114        const char *reset = diff_get_color(data->o->use_color, DIFF_RESET);
3115        const char *set = diff_get_color(data->o->use_color, DIFF_FILE_NEW);
3116        char *err;
3117        const char *line_prefix;
3118
3119        assert(data->o);
3120        line_prefix = diff_line_prefix(data->o);
3121
3122        if (line[0] == '+') {
3123                unsigned bad;
3124                data->lineno++;
3125                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
3126                        data->status |= 1;
3127                        fprintf(data->o->file,
3128                                "%s%s:%d: leftover conflict marker\n",
3129                                line_prefix, data->filename, data->lineno);
3130                }
3131                bad = ws_check(line + 1, len - 1, data->ws_rule);
3132                if (!bad)
3133                        return;
3134                data->status |= bad;
3135                err = whitespace_error_string(bad);
3136                fprintf(data->o->file, "%s%s:%d: %s.\n",
3137                        line_prefix, data->filename, data->lineno, err);
3138                free(err);
3139                emit_line(data->o, set, reset, line, 1);
3140                ws_check_emit(line + 1, len - 1, data->ws_rule,
3141                              data->o->file, set, reset, ws);
3142        } else if (line[0] == ' ') {
3143                data->lineno++;
3144        } else if (line[0] == '@') {
3145                char *plus = strchr(line, '+');
3146                if (plus)
3147                        data->lineno = strtol(plus, NULL, 10) - 1;
3148                else
3149                        die("invalid diff");
3150        }
3151}
3152
3153static unsigned char *deflate_it(char *data,
3154                                 unsigned long size,
3155                                 unsigned long *result_size)
3156{
3157        int bound;
3158        unsigned char *deflated;
3159        git_zstream stream;
3160
3161        git_deflate_init(&stream, zlib_compression_level);
3162        bound = git_deflate_bound(&stream, size);
3163        deflated = xmalloc(bound);
3164        stream.next_out = deflated;
3165        stream.avail_out = bound;
3166
3167        stream.next_in = (unsigned char *)data;
3168        stream.avail_in = size;
3169        while (git_deflate(&stream, Z_FINISH) == Z_OK)
3170                ; /* nothing */
3171        git_deflate_end(&stream);
3172        *result_size = stream.total_out;
3173        return deflated;
3174}
3175
3176static void emit_binary_diff_body(struct diff_options *o,
3177                                  mmfile_t *one, mmfile_t *two)
3178{
3179        void *cp;
3180        void *delta;
3181        void *deflated;
3182        void *data;
3183        unsigned long orig_size;
3184        unsigned long delta_size;
3185        unsigned long deflate_size;
3186        unsigned long data_size;
3187
3188        /* We could do deflated delta, or we could do just deflated two,
3189         * whichever is smaller.
3190         */
3191        delta = NULL;
3192        deflated = deflate_it(two->ptr, two->size, &deflate_size);
3193        if (one->size && two->size) {
3194                delta = diff_delta(one->ptr, one->size,
3195                                   two->ptr, two->size,
3196                                   &delta_size, deflate_size);
3197                if (delta) {
3198                        void *to_free = delta;
3199                        orig_size = delta_size;
3200                        delta = deflate_it(delta, delta_size, &delta_size);
3201                        free(to_free);
3202                }
3203        }
3204
3205        if (delta && delta_size < deflate_size) {
3206                char *s = xstrfmt("%lu", orig_size);
3207                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA,
3208                                 s, strlen(s), 0);
3209                free(s);
3210                free(deflated);
3211                data = delta;
3212                data_size = delta_size;
3213        } else {
3214                char *s = xstrfmt("%lu", two->size);
3215                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL,
3216                                 s, strlen(s), 0);
3217                free(s);
3218                free(delta);
3219                data = deflated;
3220                data_size = deflate_size;
3221        }
3222
3223        /* emit data encoded in base85 */
3224        cp = data;
3225        while (data_size) {
3226                int len;
3227                int bytes = (52 < data_size) ? 52 : data_size;
3228                char line[71];
3229                data_size -= bytes;
3230                if (bytes <= 26)
3231                        line[0] = bytes + 'A' - 1;
3232                else
3233                        line[0] = bytes - 26 + 'a' - 1;
3234                encode_85(line + 1, cp, bytes);
3235                cp = (char *) cp + bytes;
3236
3237                len = strlen(line);
3238                line[len++] = '\n';
3239                line[len] = '\0';
3240
3241                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_BODY,
3242                                 line, len, 0);
3243        }
3244        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_FOOTER, NULL, 0, 0);
3245        free(data);
3246}
3247
3248static void emit_binary_diff(struct diff_options *o,
3249                             mmfile_t *one, mmfile_t *two)
3250{
3251        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER, NULL, 0, 0);
3252        emit_binary_diff_body(o, one, two);
3253        emit_binary_diff_body(o, two, one);
3254}
3255
3256int diff_filespec_is_binary(struct repository *r,
3257                            struct diff_filespec *one)
3258{
3259        if (one->is_binary == -1) {
3260                diff_filespec_load_driver(one);
3261                if (one->driver->binary != -1)
3262                        one->is_binary = one->driver->binary;
3263                else {
3264                        if (!one->data && DIFF_FILE_VALID(one))
3265                                diff_populate_filespec(r, one, CHECK_BINARY);
3266                        if (one->is_binary == -1 && one->data)
3267                                one->is_binary = buffer_is_binary(one->data,
3268                                                one->size);
3269                        if (one->is_binary == -1)
3270                                one->is_binary = 0;
3271                }
3272        }
3273        return one->is_binary;
3274}
3275
3276static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
3277{
3278        diff_filespec_load_driver(one);
3279        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
3280}
3281
3282void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
3283{
3284        if (!options->a_prefix)
3285                options->a_prefix = a;
3286        if (!options->b_prefix)
3287                options->b_prefix = b;
3288}
3289
3290struct userdiff_driver *get_textconv(struct diff_filespec *one)
3291{
3292        if (!DIFF_FILE_VALID(one))
3293                return NULL;
3294
3295        diff_filespec_load_driver(one);
3296        return userdiff_get_textconv(one->driver);
3297}
3298
3299static void builtin_diff(const char *name_a,
3300                         const char *name_b,
3301                         struct diff_filespec *one,
3302                         struct diff_filespec *two,
3303                         const char *xfrm_msg,
3304                         int must_show_header,
3305                         struct diff_options *o,
3306                         int complete_rewrite)
3307{
3308        mmfile_t mf1, mf2;
3309        const char *lbl[2];
3310        char *a_one, *b_two;
3311        const char *meta = diff_get_color_opt(o, DIFF_METAINFO);
3312        const char *reset = diff_get_color_opt(o, DIFF_RESET);
3313        const char *a_prefix, *b_prefix;
3314        struct userdiff_driver *textconv_one = NULL;
3315        struct userdiff_driver *textconv_two = NULL;
3316        struct strbuf header = STRBUF_INIT;
3317        const char *line_prefix = diff_line_prefix(o);
3318
3319        diff_set_mnemonic_prefix(o, "a/", "b/");
3320        if (o->flags.reverse_diff) {
3321                a_prefix = o->b_prefix;
3322                b_prefix = o->a_prefix;
3323        } else {
3324                a_prefix = o->a_prefix;
3325                b_prefix = o->b_prefix;
3326        }
3327
3328        if (o->submodule_format == DIFF_SUBMODULE_LOG &&
3329            (!one->mode || S_ISGITLINK(one->mode)) &&
3330            (!two->mode || S_ISGITLINK(two->mode))) {
3331                show_submodule_summary(o, one->path ? one->path : two->path,
3332                                &one->oid, &two->oid,
3333                                two->dirty_submodule);
3334                return;
3335        } else if (o->submodule_format == DIFF_SUBMODULE_INLINE_DIFF &&
3336                   (!one->mode || S_ISGITLINK(one->mode)) &&
3337                   (!two->mode || S_ISGITLINK(two->mode))) {
3338                show_submodule_inline_diff(o, one->path ? one->path : two->path,
3339                                &one->oid, &two->oid,
3340                                two->dirty_submodule);
3341                return;
3342        }
3343
3344        if (o->flags.allow_textconv) {
3345                textconv_one = get_textconv(one);
3346                textconv_two = get_textconv(two);
3347        }
3348
3349        /* Never use a non-valid filename anywhere if at all possible */
3350        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
3351        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
3352
3353        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
3354        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
3355        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
3356        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
3357        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, meta, a_one, b_two, reset);
3358        if (lbl[0][0] == '/') {
3359                /* /dev/null */
3360                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, meta, two->mode, reset);
3361                if (xfrm_msg)
3362                        strbuf_addstr(&header, xfrm_msg);
3363                must_show_header = 1;
3364        }
3365        else if (lbl[1][0] == '/') {
3366                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, meta, one->mode, reset);
3367                if (xfrm_msg)
3368                        strbuf_addstr(&header, xfrm_msg);
3369                must_show_header = 1;
3370        }
3371        else {
3372                if (one->mode != two->mode) {
3373                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, meta, one->mode, reset);
3374                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, meta, two->mode, reset);
3375                        must_show_header = 1;
3376                }
3377                if (xfrm_msg)
3378                        strbuf_addstr(&header, xfrm_msg);
3379
3380                /*
3381                 * we do not run diff between different kind
3382                 * of objects.
3383                 */
3384                if ((one->mode ^ two->mode) & S_IFMT)
3385                        goto free_ab_and_return;
3386                if (complete_rewrite &&
3387                    (textconv_one || !diff_filespec_is_binary(o->repo, one)) &&
3388                    (textconv_two || !diff_filespec_is_binary(o->repo, two))) {
3389                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3390                                         header.buf, header.len, 0);
3391                        strbuf_reset(&header);
3392                        emit_rewrite_diff(name_a, name_b, one, two,
3393                                          textconv_one, textconv_two, o);
3394                        o->found_changes = 1;
3395                        goto free_ab_and_return;
3396                }
3397        }
3398
3399        if (o->irreversible_delete && lbl[1][0] == '/') {
3400                emit_diff_symbol(o, DIFF_SYMBOL_HEADER, header.buf,
3401                                 header.len, 0);
3402                strbuf_reset(&header);
3403                goto free_ab_and_return;
3404        } else if (!o->flags.text &&
3405                   ( (!textconv_one && diff_filespec_is_binary(o->repo, one)) ||
3406                     (!textconv_two && diff_filespec_is_binary(o->repo, two)) )) {
3407                struct strbuf sb = STRBUF_INIT;
3408                if (!one->data && !two->data &&
3409                    S_ISREG(one->mode) && S_ISREG(two->mode) &&
3410                    !o->flags.binary) {
3411                        if (!oidcmp(&one->oid, &two->oid)) {
3412                                if (must_show_header)
3413                                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3414                                                         header.buf, header.len,
3415                                                         0);
3416                                goto free_ab_and_return;
3417                        }
3418                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3419                                         header.buf, header.len, 0);
3420                        strbuf_addf(&sb, "%sBinary files %s and %s differ\n",
3421                                    diff_line_prefix(o), lbl[0], lbl[1]);
3422                        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_FILES,
3423                                         sb.buf, sb.len, 0);
3424                        strbuf_release(&sb);
3425                        goto free_ab_and_return;
3426                }
3427                if (fill_mmfile(o->repo, &mf1, one) < 0 ||
3428                    fill_mmfile(o->repo, &mf2, two) < 0)
3429                        die("unable to read files to diff");
3430                /* Quite common confusing case */
3431                if (mf1.size == mf2.size &&
3432                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
3433                        if (must_show_header)
3434                                emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3435                                                 header.buf, header.len, 0);
3436                        goto free_ab_and_return;
3437                }
3438                emit_diff_symbol(o, DIFF_SYMBOL_HEADER, header.buf, header.len, 0);
3439                strbuf_reset(&header);
3440                if (o->flags.binary)
3441                        emit_binary_diff(o, &mf1, &mf2);
3442                else {
3443                        strbuf_addf(&sb, "%sBinary files %s and %s differ\n",
3444                                    diff_line_prefix(o), lbl[0], lbl[1]);
3445                        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_FILES,
3446                                         sb.buf, sb.len, 0);
3447                        strbuf_release(&sb);
3448                }
3449                o->found_changes = 1;
3450        } else {
3451                /* Crazy xdl interfaces.. */
3452                const char *diffopts = getenv("GIT_DIFF_OPTS");
3453                const char *v;
3454                xpparam_t xpp;
3455                xdemitconf_t xecfg;
3456                struct emit_callback ecbdata;
3457                const struct userdiff_funcname *pe;
3458
3459                if (must_show_header) {
3460                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3461                                         header.buf, header.len, 0);
3462                        strbuf_reset(&header);
3463                }
3464
3465                mf1.size = fill_textconv(o->repo, textconv_one, one, &mf1.ptr);
3466                mf2.size = fill_textconv(o->repo, textconv_two, two, &mf2.ptr);
3467
3468                pe = diff_funcname_pattern(one);
3469                if (!pe)
3470                        pe = diff_funcname_pattern(two);
3471
3472                memset(&xpp, 0, sizeof(xpp));
3473                memset(&xecfg, 0, sizeof(xecfg));
3474                memset(&ecbdata, 0, sizeof(ecbdata));
3475                if (o->flags.suppress_diff_headers)
3476                        lbl[0] = NULL;
3477                ecbdata.label_path = lbl;
3478                ecbdata.color_diff = want_color(o->use_color);
3479                ecbdata.ws_rule = whitespace_rule(name_b);
3480                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
3481                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
3482                ecbdata.opt = o;
3483                if (header.len && !o->flags.suppress_diff_headers)
3484                        ecbdata.header = &header;
3485                xpp.flags = o->xdl_opts;
3486                xpp.anchors = o->anchors;
3487                xpp.anchors_nr = o->anchors_nr;
3488                xecfg.ctxlen = o->context;
3489                xecfg.interhunkctxlen = o->interhunkcontext;
3490                xecfg.flags = XDL_EMIT_FUNCNAMES;
3491                if (o->flags.funccontext)
3492                        xecfg.flags |= XDL_EMIT_FUNCCONTEXT;
3493                if (pe)
3494                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
3495                if (!diffopts)
3496                        ;
3497                else if (skip_prefix(diffopts, "--unified=", &v))
3498                        xecfg.ctxlen = strtoul(v, NULL, 10);
3499                else if (skip_prefix(diffopts, "-u", &v))
3500                        xecfg.ctxlen = strtoul(v, NULL, 10);
3501                if (o->word_diff)
3502                        init_diff_words_data(&ecbdata, o, one, two);
3503                if (xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
3504                                  &xpp, &xecfg))
3505                        die("unable to generate diff for %s", one->path);
3506                if (o->word_diff)
3507                        free_diff_words_data(&ecbdata);
3508                if (textconv_one)
3509                        free(mf1.ptr);
3510                if (textconv_two)
3511                        free(mf2.ptr);
3512                xdiff_clear_find_func(&xecfg);
3513        }
3514
3515 free_ab_and_return:
3516        strbuf_release(&header);
3517        diff_free_filespec_data(one);
3518        diff_free_filespec_data(two);
3519        free(a_one);
3520        free(b_two);
3521        return;
3522}
3523
3524static char *get_compact_summary(const struct diff_filepair *p, int is_renamed)
3525{
3526        if (!is_renamed) {
3527                if (p->status == DIFF_STATUS_ADDED) {
3528                        if (S_ISLNK(p->two->mode))
3529                                return "new +l";
3530                        else if ((p->two->mode & 0777) == 0755)
3531                                return "new +x";
3532                        else
3533                                return "new";
3534                } else if (p->status == DIFF_STATUS_DELETED)
3535                        return "gone";
3536        }
3537        if (S_ISLNK(p->one->mode) && !S_ISLNK(p->two->mode))
3538                return "mode -l";
3539        else if (!S_ISLNK(p->one->mode) && S_ISLNK(p->two->mode))
3540                return "mode +l";
3541        else if ((p->one->mode & 0777) == 0644 &&
3542                 (p->two->mode & 0777) == 0755)
3543                return "mode +x";
3544        else if ((p->one->mode & 0777) == 0755 &&
3545                 (p->two->mode & 0777) == 0644)
3546                return "mode -x";
3547        return NULL;
3548}
3549
3550static void builtin_diffstat(const char *name_a, const char *name_b,
3551                             struct diff_filespec *one,
3552                             struct diff_filespec *two,
3553                             struct diffstat_t *diffstat,
3554                             struct diff_options *o,
3555                             struct diff_filepair *p)
3556{
3557        mmfile_t mf1, mf2;
3558        struct diffstat_file *data;
3559        int same_contents;
3560        int complete_rewrite = 0;
3561
3562        if (!DIFF_PAIR_UNMERGED(p)) {
3563                if (p->status == DIFF_STATUS_MODIFIED && p->score)
3564                        complete_rewrite = 1;
3565        }
3566
3567        data = diffstat_add(diffstat, name_a, name_b);
3568        data->is_interesting = p->status != DIFF_STATUS_UNKNOWN;
3569        if (o->flags.stat_with_summary)
3570                data->comments = get_compact_summary(p, data->is_renamed);
3571
3572        if (!one || !two) {
3573                data->is_unmerged = 1;
3574                return;
3575        }
3576
3577        same_contents = !oidcmp(&one->oid, &two->oid);
3578
3579        if (diff_filespec_is_binary(o->repo, one) ||
3580            diff_filespec_is_binary(o->repo, two)) {
3581                data->is_binary = 1;
3582                if (same_contents) {
3583                        data->added = 0;
3584                        data->deleted = 0;
3585                } else {
3586                        data->added = diff_filespec_size(o->repo, two);
3587                        data->deleted = diff_filespec_size(o->repo, one);
3588                }
3589        }
3590
3591        else if (complete_rewrite) {
3592                diff_populate_filespec(o->repo, one, 0);
3593                diff_populate_filespec(o->repo, two, 0);
3594                data->deleted = count_lines(one->data, one->size);
3595                data->added = count_lines(two->data, two->size);
3596        }
3597
3598        else if (!same_contents) {
3599                /* Crazy xdl interfaces.. */
3600                xpparam_t xpp;
3601                xdemitconf_t xecfg;
3602
3603                if (fill_mmfile(o->repo, &mf1, one) < 0 ||
3604                    fill_mmfile(o->repo, &mf2, two) < 0)
3605                        die("unable to read files to diff");
3606
3607                memset(&xpp, 0, sizeof(xpp));
3608                memset(&xecfg, 0, sizeof(xecfg));
3609                xpp.flags = o->xdl_opts;
3610                xpp.anchors = o->anchors;
3611                xpp.anchors_nr = o->anchors_nr;
3612                xecfg.ctxlen = o->context;
3613                xecfg.interhunkctxlen = o->interhunkcontext;
3614                if (xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
3615                                  &xpp, &xecfg))
3616                        die("unable to generate diffstat for %s", one->path);
3617        }
3618
3619        diff_free_filespec_data(one);
3620        diff_free_filespec_data(two);
3621}
3622
3623static void builtin_checkdiff(const char *name_a, const char *name_b,
3624                              const char *attr_path,
3625                              struct diff_filespec *one,
3626                              struct diff_filespec *two,
3627                              struct diff_options *o)
3628{
3629        mmfile_t mf1, mf2;
3630        struct checkdiff_t data;
3631
3632        if (!two)
3633                return;
3634
3635        memset(&data, 0, sizeof(data));
3636        data.filename = name_b ? name_b : name_a;
3637        data.lineno = 0;
3638        data.o = o;
3639        data.ws_rule = whitespace_rule(attr_path);
3640        data.conflict_marker_size = ll_merge_marker_size(o->repo->index, attr_path);
3641
3642        if (fill_mmfile(o->repo, &mf1, one) < 0 ||
3643            fill_mmfile(o->repo, &mf2, two) < 0)
3644                die("unable to read files to diff");
3645
3646        /*
3647         * All the other codepaths check both sides, but not checking
3648         * the "old" side here is deliberate.  We are checking the newly
3649         * introduced changes, and as long as the "new" side is text, we
3650         * can and should check what it introduces.
3651         */
3652        if (diff_filespec_is_binary(o->repo, two))
3653                goto free_and_return;
3654        else {
3655                /* Crazy xdl interfaces.. */
3656                xpparam_t xpp;
3657                xdemitconf_t xecfg;
3658
3659                memset(&xpp, 0, sizeof(xpp));
3660                memset(&xecfg, 0, sizeof(xecfg));
3661                xecfg.ctxlen = 1; /* at least one context line */
3662                xpp.flags = 0;
3663                if (xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
3664                                  &xpp, &xecfg))
3665                        die("unable to generate checkdiff for %s", one->path);
3666
3667                if (data.ws_rule & WS_BLANK_AT_EOF) {
3668                        struct emit_callback ecbdata;
3669                        int blank_at_eof;
3670
3671                        ecbdata.ws_rule = data.ws_rule;
3672                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
3673                        blank_at_eof = ecbdata.blank_at_eof_in_postimage;
3674
3675                        if (blank_at_eof) {
3676                                static char *err;
3677                                if (!err)
3678                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
3679                                fprintf(o->file, "%s:%d: %s.\n",
3680                                        data.filename, blank_at_eof, err);
3681                                data.status = 1; /* report errors */
3682                        }
3683                }
3684        }
3685 free_and_return:
3686        diff_free_filespec_data(one);
3687        diff_free_filespec_data(two);
3688        if (data.status)
3689                o->flags.check_failed = 1;
3690}
3691
3692struct diff_filespec *alloc_filespec(const char *path)
3693{
3694        struct diff_filespec *spec;
3695
3696        FLEXPTR_ALLOC_STR(spec, path, path);
3697        spec->count = 1;
3698        spec->is_binary = -1;
3699        return spec;
3700}
3701
3702void free_filespec(struct diff_filespec *spec)
3703{
3704        if (!--spec->count) {
3705                diff_free_filespec_data(spec);
3706                free(spec);
3707        }
3708}
3709
3710void fill_filespec(struct diff_filespec *spec, const struct object_id *oid,
3711                   int oid_valid, unsigned short mode)
3712{
3713        if (mode) {
3714                spec->mode = canon_mode(mode);
3715                oidcpy(&spec->oid, oid);
3716                spec->oid_valid = oid_valid;
3717        }
3718}
3719
3720/*
3721 * Given a name and sha1 pair, if the index tells us the file in
3722 * the work tree has that object contents, return true, so that
3723 * prepare_temp_file() does not have to inflate and extract.
3724 */
3725static int reuse_worktree_file(struct index_state *istate,
3726                               const char *name,
3727                               const struct object_id *oid,
3728                               int want_file)
3729{
3730        const struct cache_entry *ce;
3731        struct stat st;
3732        int pos, len;
3733
3734        /*
3735         * We do not read the cache ourselves here, because the
3736         * benchmark with my previous version that always reads cache
3737         * shows that it makes things worse for diff-tree comparing
3738         * two linux-2.6 kernel trees in an already checked out work
3739         * tree.  This is because most diff-tree comparisons deal with
3740         * only a small number of files, while reading the cache is
3741         * expensive for a large project, and its cost outweighs the
3742         * savings we get by not inflating the object to a temporary
3743         * file.  Practically, this code only helps when we are used
3744         * by diff-cache --cached, which does read the cache before
3745         * calling us.
3746         */
3747        if (!istate->cache)
3748                return 0;
3749
3750        /* We want to avoid the working directory if our caller
3751         * doesn't need the data in a normal file, this system
3752         * is rather slow with its stat/open/mmap/close syscalls,
3753         * and the object is contained in a pack file.  The pack
3754         * is probably already open and will be faster to obtain
3755         * the data through than the working directory.  Loose
3756         * objects however would tend to be slower as they need
3757         * to be individually opened and inflated.
3758         */
3759        if (!FAST_WORKING_DIRECTORY && !want_file && has_object_pack(oid))
3760                return 0;
3761
3762        /*
3763         * Similarly, if we'd have to convert the file contents anyway, that
3764         * makes the optimization not worthwhile.
3765         */
3766        if (!want_file && would_convert_to_git(istate, name))
3767                return 0;
3768
3769        len = strlen(name);
3770        pos = index_name_pos(istate, name, len);
3771        if (pos < 0)
3772                return 0;
3773        ce = istate->cache[pos];
3774
3775        /*
3776         * This is not the sha1 we are looking for, or
3777         * unreusable because it is not a regular file.
3778         */
3779        if (oidcmp(oid, &ce->oid) || !S_ISREG(ce->ce_mode))
3780                return 0;
3781
3782        /*
3783         * If ce is marked as "assume unchanged", there is no
3784         * guarantee that work tree matches what we are looking for.
3785         */
3786        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
3787                return 0;
3788
3789        /*
3790         * If ce matches the file in the work tree, we can reuse it.
3791         */
3792        if (ce_uptodate(ce) ||
3793            (!lstat(name, &st) && !ie_match_stat(istate, ce, &st, 0)))
3794                return 1;
3795
3796        return 0;
3797}
3798
3799static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
3800{
3801        struct strbuf buf = STRBUF_INIT;
3802        char *dirty = "";
3803
3804        /* Are we looking at the work tree? */
3805        if (s->dirty_submodule)
3806                dirty = "-dirty";
3807
3808        strbuf_addf(&buf, "Subproject commit %s%s\n",
3809                    oid_to_hex(&s->oid), dirty);
3810        s->size = buf.len;
3811        if (size_only) {
3812                s->data = NULL;
3813                strbuf_release(&buf);
3814        } else {
3815                s->data = strbuf_detach(&buf, NULL);
3816                s->should_free = 1;
3817        }
3818        return 0;
3819}
3820
3821/*
3822 * While doing rename detection and pickaxe operation, we may need to
3823 * grab the data for the blob (or file) for our own in-core comparison.
3824 * diff_filespec has data and size fields for this purpose.
3825 */
3826int diff_populate_filespec(struct repository *r,
3827                           struct diff_filespec *s,
3828                           unsigned int flags)
3829{
3830        int size_only = flags & CHECK_SIZE_ONLY;
3831        int err = 0;
3832        int conv_flags = global_conv_flags_eol;
3833        /*
3834         * demote FAIL to WARN to allow inspecting the situation
3835         * instead of refusing.
3836         */
3837        if (conv_flags & CONV_EOL_RNDTRP_DIE)
3838                conv_flags = CONV_EOL_RNDTRP_WARN;
3839
3840        if (!DIFF_FILE_VALID(s))
3841                die("internal error: asking to populate invalid file.");
3842        if (S_ISDIR(s->mode))
3843                return -1;
3844
3845        if (s->data)
3846                return 0;
3847
3848        if (size_only && 0 < s->size)
3849                return 0;
3850
3851        if (S_ISGITLINK(s->mode))
3852                return diff_populate_gitlink(s, size_only);
3853
3854        if (!s->oid_valid ||
3855            reuse_worktree_file(r->index, s->path, &s->oid, 0)) {
3856                struct strbuf buf = STRBUF_INIT;
3857                struct stat st;
3858                int fd;
3859
3860                if (lstat(s->path, &st) < 0) {
3861                err_empty:
3862                        err = -1;
3863                empty:
3864                        s->data = (char *)"";
3865                        s->size = 0;
3866                        return err;
3867                }
3868                s->size = xsize_t(st.st_size);
3869                if (!s->size)
3870                        goto empty;
3871                if (S_ISLNK(st.st_mode)) {
3872                        struct strbuf sb = STRBUF_INIT;
3873
3874                        if (strbuf_readlink(&sb, s->path, s->size))
3875                                goto err_empty;
3876                        s->size = sb.len;
3877                        s->data = strbuf_detach(&sb, NULL);
3878                        s->should_free = 1;
3879                        return 0;
3880                }
3881
3882                /*
3883                 * Even if the caller would be happy with getting
3884                 * only the size, we cannot return early at this
3885                 * point if the path requires us to run the content
3886                 * conversion.
3887                 */
3888                if (size_only && !would_convert_to_git(r->index, s->path))
3889                        return 0;
3890
3891                /*
3892                 * Note: this check uses xsize_t(st.st_size) that may
3893                 * not be the true size of the blob after it goes
3894                 * through convert_to_git().  This may not strictly be
3895                 * correct, but the whole point of big_file_threshold
3896                 * and is_binary check being that we want to avoid
3897                 * opening the file and inspecting the contents, this
3898                 * is probably fine.
3899                 */
3900                if ((flags & CHECK_BINARY) &&
3901                    s->size > big_file_threshold && s->is_binary == -1) {
3902                        s->is_binary = 1;
3903                        return 0;
3904                }
3905                fd = open(s->path, O_RDONLY);
3906                if (fd < 0)
3907                        goto err_empty;
3908                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
3909                close(fd);
3910                s->should_munmap = 1;
3911
3912                /*
3913                 * Convert from working tree format to canonical git format
3914                 */
3915                if (convert_to_git(r->index, s->path, s->data, s->size, &buf, conv_flags)) {
3916                        size_t size = 0;
3917                        munmap(s->data, s->size);
3918                        s->should_munmap = 0;
3919                        s->data = strbuf_detach(&buf, &size);
3920                        s->size = size;
3921                        s->should_free = 1;
3922                }
3923        }
3924        else {
3925                enum object_type type;
3926                if (size_only || (flags & CHECK_BINARY)) {
3927                        type = oid_object_info(r, &s->oid, &s->size);
3928                        if (type < 0)
3929                                die("unable to read %s",
3930                                    oid_to_hex(&s->oid));
3931                        if (size_only)
3932                                return 0;
3933                        if (s->size > big_file_threshold && s->is_binary == -1) {
3934                                s->is_binary = 1;
3935                                return 0;
3936                        }
3937                }
3938                s->data = read_object_file(&s->oid, &type, &s->size);
3939                if (!s->data)
3940                        die("unable to read %s", oid_to_hex(&s->oid));
3941                s->should_free = 1;
3942        }
3943        return 0;
3944}
3945
3946void diff_free_filespec_blob(struct diff_filespec *s)
3947{
3948        if (s->should_free)
3949                free(s->data);
3950        else if (s->should_munmap)
3951                munmap(s->data, s->size);
3952
3953        if (s->should_free || s->should_munmap) {
3954                s->should_free = s->should_munmap = 0;
3955                s->data = NULL;
3956        }
3957}
3958
3959void diff_free_filespec_data(struct diff_filespec *s)
3960{
3961        diff_free_filespec_blob(s);
3962        FREE_AND_NULL(s->cnt_data);
3963}
3964
3965static void prep_temp_blob(struct index_state *istate,
3966                           const char *path, struct diff_tempfile *temp,
3967                           void *blob,
3968                           unsigned long size,
3969                           const struct object_id *oid,
3970                           int mode)
3971{
3972        struct strbuf buf = STRBUF_INIT;
3973        struct strbuf tempfile = STRBUF_INIT;
3974        char *path_dup = xstrdup(path);
3975        const char *base = basename(path_dup);
3976
3977        /* Generate "XXXXXX_basename.ext" */
3978        strbuf_addstr(&tempfile, "XXXXXX_");
3979        strbuf_addstr(&tempfile, base);
3980
3981        temp->tempfile = mks_tempfile_ts(tempfile.buf, strlen(base) + 1);
3982        if (!temp->tempfile)
3983                die_errno("unable to create temp-file");
3984        if (convert_to_working_tree(istate, path,
3985                        (const char *)blob, (size_t)size, &buf)) {
3986                blob = buf.buf;
3987                size = buf.len;
3988        }
3989        if (write_in_full(temp->tempfile->fd, blob, size) < 0 ||
3990            close_tempfile_gently(temp->tempfile))
3991                die_errno("unable to write temp-file");
3992        temp->name = get_tempfile_path(temp->tempfile);
3993        oid_to_hex_r(temp->hex, oid);
3994        xsnprintf(temp->mode, sizeof(temp->mode), "%06o", mode);
3995        strbuf_release(&buf);
3996        strbuf_release(&tempfile);
3997        free(path_dup);
3998}
3999
4000static struct diff_tempfile *prepare_temp_file(struct repository *r,
4001                                               const char *name,
4002                                               struct diff_filespec *one)
4003{
4004        struct diff_tempfile *temp = claim_diff_tempfile();
4005
4006        if (!DIFF_FILE_VALID(one)) {
4007        not_a_valid_file:
4008                /* A '-' entry produces this for file-2, and
4009                 * a '+' entry produces this for file-1.
4010                 */
4011                temp->name = "/dev/null";
4012                xsnprintf(temp->hex, sizeof(temp->hex), ".");
4013                xsnprintf(temp->mode, sizeof(temp->mode), ".");
4014                return temp;
4015        }
4016
4017        if (!S_ISGITLINK(one->mode) &&
4018            (!one->oid_valid ||
4019             reuse_worktree_file(r->index, name, &one->oid, 1))) {
4020                struct stat st;
4021                if (lstat(name, &st) < 0) {
4022                        if (errno == ENOENT)
4023                                goto not_a_valid_file;
4024                        die_errno("stat(%s)", name);
4025                }
4026                if (S_ISLNK(st.st_mode)) {
4027                        struct strbuf sb = STRBUF_INIT;
4028                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
4029                                die_errno("readlink(%s)", name);
4030                        prep_temp_blob(r->index, name, temp, sb.buf, sb.len,
4031                                       (one->oid_valid ?
4032                                        &one->oid : &null_oid),
4033                                       (one->oid_valid ?
4034                                        one->mode : S_IFLNK));
4035                        strbuf_release(&sb);
4036                }
4037                else {
4038                        /* we can borrow from the file in the work tree */
4039                        temp->name = name;
4040                        if (!one->oid_valid)
4041                                oid_to_hex_r(temp->hex, &null_oid);
4042                        else
4043                                oid_to_hex_r(temp->hex, &one->oid);
4044                        /* Even though we may sometimes borrow the
4045                         * contents from the work tree, we always want
4046                         * one->mode.  mode is trustworthy even when
4047                         * !(one->oid_valid), as long as
4048                         * DIFF_FILE_VALID(one).
4049                         */
4050                        xsnprintf(temp->mode, sizeof(temp->mode), "%06o", one->mode);
4051                }
4052                return temp;
4053        }
4054        else {
4055                if (diff_populate_filespec(r, one, 0))
4056                        die("cannot read data blob for %s", one->path);
4057                prep_temp_blob(r->index, name, temp,
4058                               one->data, one->size,
4059                               &one->oid, one->mode);
4060        }
4061        return temp;
4062}
4063
4064static void add_external_diff_name(struct repository *r,
4065                                   struct argv_array *argv,
4066                                   const char *name,
4067                                   struct diff_filespec *df)
4068{
4069        struct diff_tempfile *temp = prepare_temp_file(r, name, df);
4070        argv_array_push(argv, temp->name);
4071        argv_array_push(argv, temp->hex);
4072        argv_array_push(argv, temp->mode);
4073}
4074
4075/* An external diff command takes:
4076 *
4077 * diff-cmd name infile1 infile1-sha1 infile1-mode \
4078 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
4079 *
4080 */
4081static void run_external_diff(const char *pgm,
4082                              const char *name,
4083                              const char *other,
4084                              struct diff_filespec *one,
4085                              struct diff_filespec *two,
4086                              const char *xfrm_msg,
4087                              int complete_rewrite,
4088                              struct diff_options *o)
4089{
4090        struct argv_array argv = ARGV_ARRAY_INIT;
4091        struct argv_array env = ARGV_ARRAY_INIT;
4092        struct diff_queue_struct *q = &diff_queued_diff;
4093
4094        argv_array_push(&argv, pgm);
4095        argv_array_push(&argv, name);
4096
4097        if (one && two) {
4098                add_external_diff_name(o->repo, &argv, name, one);
4099                if (!other)
4100                        add_external_diff_name(o->repo, &argv, name, two);
4101                else {
4102                        add_external_diff_name(o->repo, &argv, other, two);
4103                        argv_array_push(&argv, other);
4104                        argv_array_push(&argv, xfrm_msg);
4105                }
4106        }
4107
4108        argv_array_pushf(&env, "GIT_DIFF_PATH_COUNTER=%d", ++o->diff_path_counter);
4109        argv_array_pushf(&env, "GIT_DIFF_PATH_TOTAL=%d", q->nr);
4110
4111        if (run_command_v_opt_cd_env(argv.argv, RUN_USING_SHELL, NULL, env.argv))
4112                die(_("external diff died, stopping at %s"), name);
4113
4114        remove_tempfile();
4115        argv_array_clear(&argv);
4116        argv_array_clear(&env);
4117}
4118
4119static int similarity_index(struct diff_filepair *p)
4120{
4121        return p->score * 100 / MAX_SCORE;
4122}
4123
4124static const char *diff_abbrev_oid(const struct object_id *oid, int abbrev)
4125{
4126        if (startup_info->have_repository)
4127                return find_unique_abbrev(oid, abbrev);
4128        else {
4129                char *hex = oid_to_hex(oid);
4130                if (abbrev < 0)
4131                        abbrev = FALLBACK_DEFAULT_ABBREV;
4132                if (abbrev > the_hash_algo->hexsz)
4133                        BUG("oid abbreviation out of range: %d", abbrev);
4134                if (abbrev)
4135                        hex[abbrev] = '\0';
4136                return hex;
4137        }
4138}
4139
4140static void fill_metainfo(struct strbuf *msg,
4141                          const char *name,
4142                          const char *other,
4143                          struct diff_filespec *one,
4144                          struct diff_filespec *two,
4145                          struct diff_options *o,
4146                          struct diff_filepair *p,
4147                          int *must_show_header,
4148                          int use_color)
4149{
4150        const char *set = diff_get_color(use_color, DIFF_METAINFO);
4151        const char *reset = diff_get_color(use_color, DIFF_RESET);
4152        const char *line_prefix = diff_line_prefix(o);
4153
4154        *must_show_header = 1;
4155        strbuf_init(msg, PATH_MAX * 2 + 300);
4156        switch (p->status) {
4157        case DIFF_STATUS_COPIED:
4158                strbuf_addf(msg, "%s%ssimilarity index %d%%",
4159                            line_prefix, set, similarity_index(p));
4160                strbuf_addf(msg, "%s\n%s%scopy from ",
4161                            reset,  line_prefix, set);
4162                quote_c_style(name, msg, NULL, 0);
4163                strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
4164                quote_c_style(other, msg, NULL, 0);
4165                strbuf_addf(msg, "%s\n", reset);
4166                break;
4167        case DIFF_STATUS_RENAMED:
4168                strbuf_addf(msg, "%s%ssimilarity index %d%%",
4169                            line_prefix, set, similarity_index(p));
4170                strbuf_addf(msg, "%s\n%s%srename from ",
4171                            reset, line_prefix, set);
4172                quote_c_style(name, msg, NULL, 0);
4173                strbuf_addf(msg, "%s\n%s%srename to ",
4174                            reset, line_prefix, set);
4175                quote_c_style(other, msg, NULL, 0);
4176                strbuf_addf(msg, "%s\n", reset);
4177                break;
4178        case DIFF_STATUS_MODIFIED:
4179                if (p->score) {
4180                        strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
4181                                    line_prefix,
4182                                    set, similarity_index(p), reset);
4183                        break;
4184                }
4185                /* fallthru */
4186        default:
4187                *must_show_header = 0;
4188        }
4189        if (one && two && oidcmp(&one->oid, &two->oid)) {
4190                const unsigned hexsz = the_hash_algo->hexsz;
4191                int abbrev = o->flags.full_index ? hexsz : DEFAULT_ABBREV;
4192
4193                if (o->flags.binary) {
4194                        mmfile_t mf;
4195                        if ((!fill_mmfile(o->repo, &mf, one) &&
4196                             diff_filespec_is_binary(o->repo, one)) ||
4197                            (!fill_mmfile(o->repo, &mf, two) &&
4198                             diff_filespec_is_binary(o->repo, two)))
4199                                abbrev = hexsz;
4200                }
4201                strbuf_addf(msg, "%s%sindex %s..%s", line_prefix, set,
4202                            diff_abbrev_oid(&one->oid, abbrev),
4203                            diff_abbrev_oid(&two->oid, abbrev));
4204                if (one->mode == two->mode)
4205                        strbuf_addf(msg, " %06o", one->mode);
4206                strbuf_addf(msg, "%s\n", reset);
4207        }
4208}
4209
4210static void run_diff_cmd(const char *pgm,
4211                         const char *name,
4212                         const char *other,
4213                         const char *attr_path,
4214                         struct diff_filespec *one,
4215                         struct diff_filespec *two,
4216                         struct strbuf *msg,
4217                         struct diff_options *o,
4218                         struct diff_filepair *p)
4219{
4220        const char *xfrm_msg = NULL;
4221        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
4222        int must_show_header = 0;
4223
4224
4225        if (o->flags.allow_external) {
4226                struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
4227                if (drv && drv->external)
4228                        pgm = drv->external;
4229        }
4230
4231        if (msg) {
4232                /*
4233                 * don't use colors when the header is intended for an
4234                 * external diff driver
4235                 */
4236                fill_metainfo(msg, name, other, one, two, o, p,
4237                              &must_show_header,
4238                              want_color(o->use_color) && !pgm);
4239                xfrm_msg = msg->len ? msg->buf : NULL;
4240        }
4241
4242        if (pgm) {
4243                run_external_diff(pgm, name, other, one, two, xfrm_msg,
4244                                  complete_rewrite, o);
4245                return;
4246        }
4247        if (one && two)
4248                builtin_diff(name, other ? other : name,
4249                             one, two, xfrm_msg, must_show_header,
4250                             o, complete_rewrite);
4251        else
4252                fprintf(o->file, "* Unmerged path %s\n", name);
4253}
4254
4255static void diff_fill_oid_info(struct diff_filespec *one, struct index_state *istate)
4256{
4257        if (DIFF_FILE_VALID(one)) {
4258                if (!one->oid_valid) {
4259                        struct stat st;
4260                        if (one->is_stdin) {
4261                                oidclr(&one->oid);
4262                                return;
4263                        }
4264                        if (lstat(one->path, &st) < 0)
4265                                die_errno("stat '%s'", one->path);
4266                        if (index_path(istate, &one->oid, one->path, &st, 0))
4267                                die("cannot hash %s", one->path);
4268                }
4269        }
4270        else
4271                oidclr(&one->oid);
4272}
4273
4274static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
4275{
4276        /* Strip the prefix but do not molest /dev/null and absolute paths */
4277        if (*namep && **namep != '/') {
4278                *namep += prefix_length;
4279                if (**namep == '/')
4280                        ++*namep;
4281        }
4282        if (*otherp && **otherp != '/') {
4283                *otherp += prefix_length;
4284                if (**otherp == '/')
4285                        ++*otherp;
4286        }
4287}
4288
4289static void run_diff(struct diff_filepair *p, struct diff_options *o)
4290{
4291        const char *pgm = external_diff();
4292        struct strbuf msg;
4293        struct diff_filespec *one = p->one;
4294        struct diff_filespec *two = p->two;
4295        const char *name;
4296        const char *other;
4297        const char *attr_path;
4298
4299        name  = one->path;
4300        other = (strcmp(name, two->path) ? two->path : NULL);
4301        attr_path = name;
4302        if (o->prefix_length)
4303                strip_prefix(o->prefix_length, &name, &other);
4304
4305        if (!o->flags.allow_external)
4306                pgm = NULL;
4307
4308        if (DIFF_PAIR_UNMERGED(p)) {
4309                run_diff_cmd(pgm, name, NULL, attr_path,
4310                             NULL, NULL, NULL, o, p);
4311                return;
4312        }
4313
4314        diff_fill_oid_info(one, o->repo->index);
4315        diff_fill_oid_info(two, o->repo->index);
4316
4317        if (!pgm &&
4318            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
4319            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
4320                /*
4321                 * a filepair that changes between file and symlink
4322                 * needs to be split into deletion and creation.
4323                 */
4324                struct diff_filespec *null = alloc_filespec(two->path);
4325                run_diff_cmd(NULL, name, other, attr_path,
4326                             one, null, &msg,
4327                             o, p);
4328                free(null);
4329                strbuf_release(&msg);
4330
4331                null = alloc_filespec(one->path);
4332                run_diff_cmd(NULL, name, other, attr_path,
4333                             null, two, &msg, o, p);
4334                free(null);
4335        }
4336        else
4337                run_diff_cmd(pgm, name, other, attr_path,
4338                             one, two, &msg, o, p);
4339
4340        strbuf_release(&msg);
4341}
4342
4343static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
4344                         struct diffstat_t *diffstat)
4345{
4346        const char *name;
4347        const char *other;
4348
4349        if (DIFF_PAIR_UNMERGED(p)) {
4350                /* unmerged */
4351                builtin_diffstat(p->one->path, NULL, NULL, NULL,
4352                                 diffstat, o, p);
4353                return;
4354        }
4355
4356        name = p->one->path;
4357        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
4358
4359        if (o->prefix_length)
4360                strip_prefix(o->prefix_length, &name, &other);
4361
4362        diff_fill_oid_info(p->one, o->repo->index);
4363        diff_fill_oid_info(p->two, o->repo->index);
4364
4365        builtin_diffstat(name, other, p->one, p->two,
4366                         diffstat, o, p);
4367}
4368
4369static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
4370{
4371        const char *name;
4372        const char *other;
4373        const char *attr_path;
4374
4375        if (DIFF_PAIR_UNMERGED(p)) {
4376                /* unmerged */
4377                return;
4378        }
4379
4380        name = p->one->path;
4381        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
4382        attr_path = other ? other : name;
4383
4384        if (o->prefix_length)
4385                strip_prefix(o->prefix_length, &name, &other);
4386
4387        diff_fill_oid_info(p->one, o->repo->index);
4388        diff_fill_oid_info(p->two, o->repo->index);
4389
4390        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
4391}
4392
4393void repo_diff_setup(struct repository *r, struct diff_options *options)
4394{
4395        memcpy(options, &default_diff_options, sizeof(*options));
4396
4397        options->file = stdout;
4398        options->repo = r;
4399
4400        options->abbrev = DEFAULT_ABBREV;
4401        options->line_termination = '\n';
4402        options->break_opt = -1;
4403        options->rename_limit = -1;
4404        options->dirstat_permille = diff_dirstat_permille_default;
4405        options->context = diff_context_default;
4406        options->interhunkcontext = diff_interhunk_context_default;
4407        options->ws_error_highlight = ws_error_highlight_default;
4408        options->flags.rename_empty = 1;
4409        options->objfind = NULL;
4410
4411        /* pathchange left =NULL by default */
4412        options->change = diff_change;
4413        options->add_remove = diff_addremove;
4414        options->use_color = diff_use_color_default;
4415        options->detect_rename = diff_detect_rename_default;
4416        options->xdl_opts |= diff_algorithm;
4417        if (diff_indent_heuristic)
4418                DIFF_XDL_SET(options, INDENT_HEURISTIC);
4419
4420        options->orderfile = diff_order_file_cfg;
4421
4422        if (diff_no_prefix) {
4423                options->a_prefix = options->b_prefix = "";
4424        } else if (!diff_mnemonic_prefix) {
4425                options->a_prefix = "a/";
4426                options->b_prefix = "b/";
4427        }
4428
4429        options->color_moved = diff_color_moved_default;
4430        options->color_moved_ws_handling = diff_color_moved_ws_default;
4431}
4432
4433void diff_setup_done(struct diff_options *options)
4434{
4435        unsigned check_mask = DIFF_FORMAT_NAME |
4436                              DIFF_FORMAT_NAME_STATUS |
4437                              DIFF_FORMAT_CHECKDIFF |
4438                              DIFF_FORMAT_NO_OUTPUT;
4439        /*
4440         * This must be signed because we're comparing against a potentially
4441         * negative value.
4442         */
4443        const int hexsz = the_hash_algo->hexsz;
4444
4445        if (options->set_default)
4446                options->set_default(options);
4447
4448        if (HAS_MULTI_BITS(options->output_format & check_mask))
4449                die(_("--name-only, --name-status, --check and -s are mutually exclusive"));
4450
4451        if (HAS_MULTI_BITS(options->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK))
4452                die(_("-G, -S and --find-object are mutually exclusive"));
4453
4454        /*
4455         * Most of the time we can say "there are changes"
4456         * only by checking if there are changed paths, but
4457         * --ignore-whitespace* options force us to look
4458         * inside contents.
4459         */
4460
4461        if ((options->xdl_opts & XDF_WHITESPACE_FLAGS))
4462                options->flags.diff_from_contents = 1;
4463        else
4464                options->flags.diff_from_contents = 0;
4465
4466        if (options->flags.find_copies_harder)
4467                options->detect_rename = DIFF_DETECT_COPY;
4468
4469        if (!options->flags.relative_name)
4470                options->prefix = NULL;
4471        if (options->prefix)
4472                options->prefix_length = strlen(options->prefix);
4473        else
4474                options->prefix_length = 0;
4475
4476        if (options->output_format & (DIFF_FORMAT_NAME |
4477                                      DIFF_FORMAT_NAME_STATUS |
4478                                      DIFF_FORMAT_CHECKDIFF |
4479                                      DIFF_FORMAT_NO_OUTPUT))
4480                options->output_format &= ~(DIFF_FORMAT_RAW |
4481                                            DIFF_FORMAT_NUMSTAT |
4482                                            DIFF_FORMAT_DIFFSTAT |
4483                                            DIFF_FORMAT_SHORTSTAT |
4484                                            DIFF_FORMAT_DIRSTAT |
4485                                            DIFF_FORMAT_SUMMARY |
4486                                            DIFF_FORMAT_PATCH);
4487
4488        /*
4489         * These cases always need recursive; we do not drop caller-supplied
4490         * recursive bits for other formats here.
4491         */
4492        if (options->output_format & (DIFF_FORMAT_PATCH |
4493                                      DIFF_FORMAT_NUMSTAT |
4494                                      DIFF_FORMAT_DIFFSTAT |
4495                                      DIFF_FORMAT_SHORTSTAT |
4496                                      DIFF_FORMAT_DIRSTAT |
4497                                      DIFF_FORMAT_SUMMARY |
4498                                      DIFF_FORMAT_CHECKDIFF))
4499                options->flags.recursive = 1;
4500        /*
4501         * Also pickaxe would not work very well if you do not say recursive
4502         */
4503        if (options->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK)
4504                options->flags.recursive = 1;
4505        /*
4506         * When patches are generated, submodules diffed against the work tree
4507         * must be checked for dirtiness too so it can be shown in the output
4508         */
4509        if (options->output_format & DIFF_FORMAT_PATCH)
4510                options->flags.dirty_submodules = 1;
4511
4512        if (options->detect_rename && options->rename_limit < 0)
4513                options->rename_limit = diff_rename_limit_default;
4514        if (hexsz < options->abbrev)
4515                options->abbrev = hexsz; /* full */
4516
4517        /*
4518         * It does not make sense to show the first hit we happened
4519         * to have found.  It does not make sense not to return with
4520         * exit code in such a case either.
4521         */
4522        if (options->flags.quick) {
4523                options->output_format = DIFF_FORMAT_NO_OUTPUT;
4524                options->flags.exit_with_status = 1;
4525        }
4526
4527        options->diff_path_counter = 0;
4528
4529        if (options->flags.follow_renames && options->pathspec.nr != 1)
4530                die(_("--follow requires exactly one pathspec"));
4531
4532        if (!options->use_color || external_diff())
4533                options->color_moved = 0;
4534}
4535
4536static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
4537{
4538        char c, *eq;
4539        int len;
4540
4541        if (*arg != '-')
4542                return 0;
4543        c = *++arg;
4544        if (!c)
4545                return 0;
4546        if (c == arg_short) {
4547                c = *++arg;
4548                if (!c)
4549                        return 1;
4550                if (val && isdigit(c)) {
4551                        char *end;
4552                        int n = strtoul(arg, &end, 10);
4553                        if (*end)
4554                                return 0;
4555                        *val = n;
4556                        return 1;
4557                }
4558                return 0;
4559        }
4560        if (c != '-')
4561                return 0;
4562        arg++;
4563        eq = strchrnul(arg, '=');
4564        len = eq - arg;
4565        if (!len || strncmp(arg, arg_long, len))
4566                return 0;
4567        if (*eq) {
4568                int n;
4569                char *end;
4570                if (!isdigit(*++eq))
4571                        return 0;
4572                n = strtoul(eq, &end, 10);
4573                if (*end)
4574                        return 0;
4575                *val = n;
4576        }
4577        return 1;
4578}
4579
4580static int diff_scoreopt_parse(const char *opt);
4581
4582static inline int short_opt(char opt, const char **argv,
4583                            const char **optarg)
4584{
4585        const char *arg = argv[0];
4586        if (arg[0] != '-' || arg[1] != opt)
4587                return 0;
4588        if (arg[2] != '\0') {
4589                *optarg = arg + 2;
4590                return 1;
4591        }
4592        if (!argv[1])
4593                die("Option '%c' requires a value", opt);
4594        *optarg = argv[1];
4595        return 2;
4596}
4597
4598int parse_long_opt(const char *opt, const char **argv,
4599                   const char **optarg)
4600{
4601        const char *arg = argv[0];
4602        if (!skip_prefix(arg, "--", &arg))
4603                return 0;
4604        if (!skip_prefix(arg, opt, &arg))
4605                return 0;
4606        if (*arg == '=') { /* stuck form: --option=value */
4607                *optarg = arg + 1;
4608                return 1;
4609        }
4610        if (*arg != '\0')
4611                return 0;
4612        /* separate form: --option value */
4613        if (!argv[1])
4614                die("Option '--%s' requires a value", opt);
4615        *optarg = argv[1];
4616        return 2;
4617}
4618
4619static int stat_opt(struct diff_options *options, const char **av)
4620{
4621        const char *arg = av[0];
4622        char *end;
4623        int width = options->stat_width;
4624        int name_width = options->stat_name_width;
4625        int graph_width = options->stat_graph_width;
4626        int count = options->stat_count;
4627        int argcount = 1;
4628
4629        if (!skip_prefix(arg, "--stat", &arg))
4630                BUG("stat option does not begin with --stat: %s", arg);
4631        end = (char *)arg;
4632
4633        switch (*arg) {
4634        case '-':
4635                if (skip_prefix(arg, "-width", &arg)) {
4636                        if (*arg == '=')
4637                                width = strtoul(arg + 1, &end, 10);
4638                        else if (!*arg && !av[1])
4639                                die_want_option("--stat-width");
4640                        else if (!*arg) {
4641                                width = strtoul(av[1], &end, 10);
4642                                argcount = 2;
4643                        }
4644                } else if (skip_prefix(arg, "-name-width", &arg)) {
4645                        if (*arg == '=')
4646                                name_width = strtoul(arg + 1, &end, 10);
4647                        else if (!*arg && !av[1])
4648                                die_want_option("--stat-name-width");
4649                        else if (!*arg) {
4650                                name_width = strtoul(av[1], &end, 10);
4651                                argcount = 2;
4652                        }
4653                } else if (skip_prefix(arg, "-graph-width", &arg)) {
4654                        if (*arg == '=')
4655                                graph_width = strtoul(arg + 1, &end, 10);
4656                        else if (!*arg && !av[1])
4657                                die_want_option("--stat-graph-width");
4658                        else if (!*arg) {
4659                                graph_width = strtoul(av[1], &end, 10);
4660                                argcount = 2;
4661                        }
4662                } else if (skip_prefix(arg, "-count", &arg)) {
4663                        if (*arg == '=')
4664                                count = strtoul(arg + 1, &end, 10);
4665                        else if (!*arg && !av[1])
4666                                die_want_option("--stat-count");
4667                        else if (!*arg) {
4668                                count = strtoul(av[1], &end, 10);
4669                                argcount = 2;
4670                        }
4671                }
4672                break;
4673        case '=':
4674                width = strtoul(arg+1, &end, 10);
4675                if (*end == ',')
4676                        name_width = strtoul(end+1, &end, 10);
4677                if (*end == ',')
4678                        count = strtoul(end+1, &end, 10);
4679        }
4680
4681        /* Important! This checks all the error cases! */
4682        if (*end)
4683                return 0;
4684        options->output_format |= DIFF_FORMAT_DIFFSTAT;
4685        options->stat_name_width = name_width;
4686        options->stat_graph_width = graph_width;
4687        options->stat_width = width;
4688        options->stat_count = count;
4689        return argcount;
4690}
4691
4692static int parse_dirstat_opt(struct diff_options *options, const char *params)
4693{
4694        struct strbuf errmsg = STRBUF_INIT;
4695        if (parse_dirstat_params(options, params, &errmsg))
4696                die(_("Failed to parse --dirstat/-X option parameter:\n%s"),
4697                    errmsg.buf);
4698        strbuf_release(&errmsg);
4699        /*
4700         * The caller knows a dirstat-related option is given from the command
4701         * line; allow it to say "return this_function();"
4702         */
4703        options->output_format |= DIFF_FORMAT_DIRSTAT;
4704        return 1;
4705}
4706
4707static int parse_submodule_opt(struct diff_options *options, const char *value)
4708{
4709        if (parse_submodule_params(options, value))
4710                die(_("Failed to parse --submodule option parameter: '%s'"),
4711                        value);
4712        return 1;
4713}
4714
4715static const char diff_status_letters[] = {
4716        DIFF_STATUS_ADDED,
4717        DIFF_STATUS_COPIED,
4718        DIFF_STATUS_DELETED,
4719        DIFF_STATUS_MODIFIED,
4720        DIFF_STATUS_RENAMED,
4721        DIFF_STATUS_TYPE_CHANGED,
4722        DIFF_STATUS_UNKNOWN,
4723        DIFF_STATUS_UNMERGED,
4724        DIFF_STATUS_FILTER_AON,
4725        DIFF_STATUS_FILTER_BROKEN,
4726        '\0',
4727};
4728
4729static unsigned int filter_bit['Z' + 1];
4730
4731static void prepare_filter_bits(void)
4732{
4733        int i;
4734
4735        if (!filter_bit[DIFF_STATUS_ADDED]) {
4736                for (i = 0; diff_status_letters[i]; i++)
4737                        filter_bit[(int) diff_status_letters[i]] = (1 << i);
4738        }
4739}
4740
4741static unsigned filter_bit_tst(char status, const struct diff_options *opt)
4742{
4743        return opt->filter & filter_bit[(int) status];
4744}
4745
4746static int parse_diff_filter_opt(const char *optarg, struct diff_options *opt)
4747{
4748        int i, optch;
4749
4750        prepare_filter_bits();
4751
4752        /*
4753         * If there is a negation e.g. 'd' in the input, and we haven't
4754         * initialized the filter field with another --diff-filter, start
4755         * from full set of bits, except for AON.
4756         */
4757        if (!opt->filter) {
4758                for (i = 0; (optch = optarg[i]) != '\0'; i++) {
4759                        if (optch < 'a' || 'z' < optch)
4760                                continue;
4761                        opt->filter = (1 << (ARRAY_SIZE(diff_status_letters) - 1)) - 1;
4762                        opt->filter &= ~filter_bit[DIFF_STATUS_FILTER_AON];
4763                        break;
4764                }
4765        }
4766
4767        for (i = 0; (optch = optarg[i]) != '\0'; i++) {
4768                unsigned int bit;
4769                int negate;
4770
4771                if ('a' <= optch && optch <= 'z') {
4772                        negate = 1;
4773                        optch = toupper(optch);
4774                } else {
4775                        negate = 0;
4776                }
4777
4778                bit = (0 <= optch && optch <= 'Z') ? filter_bit[optch] : 0;
4779                if (!bit)
4780                        return optarg[i];
4781                if (negate)
4782                        opt->filter &= ~bit;
4783                else
4784                        opt->filter |= bit;
4785        }
4786        return 0;
4787}
4788
4789static void enable_patch_output(int *fmt) {
4790        *fmt &= ~DIFF_FORMAT_NO_OUTPUT;
4791        *fmt |= DIFF_FORMAT_PATCH;
4792}
4793
4794static int parse_ws_error_highlight_opt(struct diff_options *opt, const char *arg)
4795{
4796        int val = parse_ws_error_highlight(arg);
4797
4798        if (val < 0) {
4799                error("unknown value after ws-error-highlight=%.*s",
4800                      -1 - val, arg);
4801                return 0;
4802        }
4803        opt->ws_error_highlight = val;
4804        return 1;
4805}
4806
4807static int parse_objfind_opt(struct diff_options *opt, const char *arg)
4808{
4809        struct object_id oid;
4810
4811        if (get_oid(arg, &oid))
4812                return error("unable to resolve '%s'", arg);
4813
4814        if (!opt->objfind)
4815                opt->objfind = xcalloc(1, sizeof(*opt->objfind));
4816
4817        opt->pickaxe_opts |= DIFF_PICKAXE_KIND_OBJFIND;
4818        opt->flags.recursive = 1;
4819        opt->flags.tree_in_recursive = 1;
4820        oidset_insert(opt->objfind, &oid);
4821        return 1;
4822}
4823
4824int diff_opt_parse(struct diff_options *options,
4825                   const char **av, int ac, const char *prefix)
4826{
4827        const char *arg = av[0];
4828        const char *optarg;
4829        int argcount;
4830
4831        if (!prefix)
4832                prefix = "";
4833
4834        /* Output format options */
4835        if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch")
4836            || opt_arg(arg, 'U', "unified", &options->context))
4837                enable_patch_output(&options->output_format);
4838        else if (!strcmp(arg, "--raw"))
4839                options->output_format |= DIFF_FORMAT_RAW;
4840        else if (!strcmp(arg, "--patch-with-raw")) {
4841                enable_patch_output(&options->output_format);
4842                options->output_format |= DIFF_FORMAT_RAW;
4843        } else if (!strcmp(arg, "--numstat"))
4844                options->output_format |= DIFF_FORMAT_NUMSTAT;
4845        else if (!strcmp(arg, "--shortstat"))
4846                options->output_format |= DIFF_FORMAT_SHORTSTAT;
4847        else if (skip_prefix(arg, "-X", &arg) ||
4848                 skip_to_optional_arg(arg, "--dirstat", &arg))
4849                return parse_dirstat_opt(options, arg);
4850        else if (!strcmp(arg, "--cumulative"))
4851                return parse_dirstat_opt(options, "cumulative");
4852        else if (skip_to_optional_arg(arg, "--dirstat-by-file", &arg)) {
4853                parse_dirstat_opt(options, "files");
4854                return parse_dirstat_opt(options, arg);
4855        }
4856        else if (!strcmp(arg, "--check"))
4857                options->output_format |= DIFF_FORMAT_CHECKDIFF;
4858        else if (!strcmp(arg, "--summary"))
4859                options->output_format |= DIFF_FORMAT_SUMMARY;
4860        else if (!strcmp(arg, "--patch-with-stat")) {
4861                enable_patch_output(&options->output_format);
4862                options->output_format |= DIFF_FORMAT_DIFFSTAT;
4863        } else if (!strcmp(arg, "--name-only"))
4864                options->output_format |= DIFF_FORMAT_NAME;
4865        else if (!strcmp(arg, "--name-status"))
4866                options->output_format |= DIFF_FORMAT_NAME_STATUS;
4867        else if (!strcmp(arg, "-s") || !strcmp(arg, "--no-patch"))
4868                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
4869        else if (starts_with(arg, "--stat"))
4870                /* --stat, --stat-width, --stat-name-width, or --stat-count */
4871                return stat_opt(options, av);
4872        else if (!strcmp(arg, "--compact-summary")) {
4873                 options->flags.stat_with_summary = 1;
4874                 options->output_format |= DIFF_FORMAT_DIFFSTAT;
4875        } else if (!strcmp(arg, "--no-compact-summary"))
4876                 options->flags.stat_with_summary = 0;
4877
4878        /* renames options */
4879        else if (starts_with(arg, "-B") ||
4880                 skip_to_optional_arg(arg, "--break-rewrites", NULL)) {
4881                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
4882                        return error("invalid argument to -B: %s", arg+2);
4883        }
4884        else if (starts_with(arg, "-M") ||
4885                 skip_to_optional_arg(arg, "--find-renames", NULL)) {
4886                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
4887                        return error("invalid argument to -M: %s", arg+2);
4888                options->detect_rename = DIFF_DETECT_RENAME;
4889        }
4890        else if (!strcmp(arg, "-D") || !strcmp(arg, "--irreversible-delete")) {
4891                options->irreversible_delete = 1;
4892        }
4893        else if (starts_with(arg, "-C") ||
4894                 skip_to_optional_arg(arg, "--find-copies", NULL)) {
4895                if (options->detect_rename == DIFF_DETECT_COPY)
4896                        options->flags.find_copies_harder = 1;
4897                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
4898                        return error("invalid argument to -C: %s", arg+2);
4899                options->detect_rename = DIFF_DETECT_COPY;
4900        }
4901        else if (!strcmp(arg, "--no-renames"))
4902                options->detect_rename = 0;
4903        else if (!strcmp(arg, "--rename-empty"))
4904                options->flags.rename_empty = 1;
4905        else if (!strcmp(arg, "--no-rename-empty"))
4906                options->flags.rename_empty = 0;
4907        else if (skip_to_optional_arg_default(arg, "--relative", &arg, NULL)) {
4908                options->flags.relative_name = 1;
4909                if (arg)
4910                        options->prefix = arg;
4911        }
4912
4913        /* xdiff options */
4914        else if (!strcmp(arg, "--minimal"))
4915                DIFF_XDL_SET(options, NEED_MINIMAL);
4916        else if (!strcmp(arg, "--no-minimal"))
4917                DIFF_XDL_CLR(options, NEED_MINIMAL);
4918        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
4919                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
4920        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
4921                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
4922        else if (!strcmp(arg, "--ignore-space-at-eol"))
4923                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
4924        else if (!strcmp(arg, "--ignore-cr-at-eol"))
4925                DIFF_XDL_SET(options, IGNORE_CR_AT_EOL);
4926        else if (!strcmp(arg, "--ignore-blank-lines"))
4927                DIFF_XDL_SET(options, IGNORE_BLANK_LINES);
4928        else if (!strcmp(arg, "--indent-heuristic"))
4929                DIFF_XDL_SET(options, INDENT_HEURISTIC);
4930        else if (!strcmp(arg, "--no-indent-heuristic"))
4931                DIFF_XDL_CLR(options, INDENT_HEURISTIC);
4932        else if (!strcmp(arg, "--patience")) {
4933                int i;
4934                options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
4935                /*
4936                 * Both --patience and --anchored use PATIENCE_DIFF
4937                 * internally, so remove any anchors previously
4938                 * specified.
4939                 */
4940                for (i = 0; i < options->anchors_nr; i++)
4941                        free(options->anchors[i]);
4942                options->anchors_nr = 0;
4943        } else if (!strcmp(arg, "--histogram"))
4944                options->xdl_opts = DIFF_WITH_ALG(options, HISTOGRAM_DIFF);
4945        else if ((argcount = parse_long_opt("diff-algorithm", av, &optarg))) {
4946                long value = parse_algorithm_value(optarg);
4947                if (value < 0)
4948                        return error("option diff-algorithm accepts \"myers\", "
4949                                     "\"minimal\", \"patience\" and \"histogram\"");
4950                /* clear out previous settings */
4951                DIFF_XDL_CLR(options, NEED_MINIMAL);
4952                options->xdl_opts &= ~XDF_DIFF_ALGORITHM_MASK;
4953                options->xdl_opts |= value;
4954                return argcount;
4955        } else if (skip_prefix(arg, "--anchored=", &arg)) {
4956                options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
4957                ALLOC_GROW(options->anchors, options->anchors_nr + 1,
4958                           options->anchors_alloc);
4959                options->anchors[options->anchors_nr++] = xstrdup(arg);
4960        }
4961
4962        /* flags options */
4963        else if (!strcmp(arg, "--binary")) {
4964                enable_patch_output(&options->output_format);
4965                options->flags.binary = 1;
4966        }
4967        else if (!strcmp(arg, "--full-index"))
4968                options->flags.full_index = 1;
4969        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
4970                options->flags.text = 1;
4971        else if (!strcmp(arg, "-R"))
4972                options->flags.reverse_diff = 1;
4973        else if (!strcmp(arg, "--find-copies-harder"))
4974                options->flags.find_copies_harder = 1;
4975        else if (!strcmp(arg, "--follow"))
4976                options->flags.follow_renames = 1;
4977        else if (!strcmp(arg, "--no-follow")) {
4978                options->flags.follow_renames = 0;
4979                options->flags.default_follow_renames = 0;
4980        } else if (skip_to_optional_arg_default(arg, "--color", &arg, "always")) {
4981                int value = git_config_colorbool(NULL, arg);
4982                if (value < 0)
4983                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
4984                options->use_color = value;
4985        }
4986        else if (!strcmp(arg, "--no-color"))
4987                options->use_color = 0;
4988        else if (!strcmp(arg, "--color-moved")) {
4989                if (diff_color_moved_default)
4990                        options->color_moved = diff_color_moved_default;
4991                if (options->color_moved == COLOR_MOVED_NO)
4992                        options->color_moved = COLOR_MOVED_DEFAULT;
4993        } else if (!strcmp(arg, "--no-color-moved"))
4994                options->color_moved = COLOR_MOVED_NO;
4995        else if (skip_prefix(arg, "--color-moved=", &arg)) {
4996                int cm = parse_color_moved(arg);
4997                if (cm < 0)
4998                        die("bad --color-moved argument: %s", arg);
4999                options->color_moved = cm;
5000        } else if (skip_prefix(arg, "--color-moved-ws=", &arg)) {
5001                options->color_moved_ws_handling = parse_color_moved_ws(arg);
5002        } else if (skip_to_optional_arg_default(arg, "--color-words", &options->word_regex, NULL)) {
5003                options->use_color = 1;
5004                options->word_diff = DIFF_WORDS_COLOR;
5005        }
5006        else if (!strcmp(arg, "--word-diff")) {
5007                if (options->word_diff == DIFF_WORDS_NONE)
5008                        options->word_diff = DIFF_WORDS_PLAIN;
5009        }
5010        else if (skip_prefix(arg, "--word-diff=", &arg)) {
5011                if (!strcmp(arg, "plain"))
5012                        options->word_diff = DIFF_WORDS_PLAIN;
5013                else if (!strcmp(arg, "color")) {
5014                        options->use_color = 1;
5015                        options->word_diff = DIFF_WORDS_COLOR;
5016                }
5017                else if (!strcmp(arg, "porcelain"))
5018                        options->word_diff = DIFF_WORDS_PORCELAIN;
5019                else if (!strcmp(arg, "none"))
5020                        options->word_diff = DIFF_WORDS_NONE;
5021                else
5022                        die("bad --word-diff argument: %s", arg);
5023        }
5024        else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
5025                if (options->word_diff == DIFF_WORDS_NONE)
5026                        options->word_diff = DIFF_WORDS_PLAIN;
5027                options->word_regex = optarg;
5028                return argcount;
5029        }
5030        else if (!strcmp(arg, "--exit-code"))
5031                options->flags.exit_with_status = 1;
5032        else if (!strcmp(arg, "--quiet"))
5033                options->flags.quick = 1;
5034        else if (!strcmp(arg, "--ext-diff"))
5035                options->flags.allow_external = 1;
5036        else if (!strcmp(arg, "--no-ext-diff"))
5037                options->flags.allow_external = 0;
5038        else if (!strcmp(arg, "--textconv")) {
5039                options->flags.allow_textconv = 1;
5040                options->flags.textconv_set_via_cmdline = 1;
5041        } else if (!strcmp(arg, "--no-textconv"))
5042                options->flags.allow_textconv = 0;
5043        else if (skip_to_optional_arg_default(arg, "--ignore-submodules", &arg, "all")) {
5044                options->flags.override_submodule_config = 1;
5045                handle_ignore_submodules_arg(options, arg);
5046        } else if (skip_to_optional_arg_default(arg, "--submodule", &arg, "log"))
5047                return parse_submodule_opt(options, arg);
5048        else if (skip_prefix(arg, "--ws-error-highlight=", &arg))
5049                return parse_ws_error_highlight_opt(options, arg);
5050        else if (!strcmp(arg, "--ita-invisible-in-index"))
5051                options->ita_invisible_in_index = 1;
5052        else if (!strcmp(arg, "--ita-visible-in-index"))
5053                options->ita_invisible_in_index = 0;
5054
5055        /* misc options */
5056        else if (!strcmp(arg, "-z"))
5057                options->line_termination = 0;
5058        else if ((argcount = short_opt('l', av, &optarg))) {
5059                options->rename_limit = strtoul(optarg, NULL, 10);
5060                return argcount;
5061        }
5062        else if ((argcount = short_opt('S', av, &optarg))) {
5063                options->pickaxe = optarg;
5064                options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
5065                return argcount;
5066        } else if ((argcount = short_opt('G', av, &optarg))) {
5067                options->pickaxe = optarg;
5068                options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
5069                return argcount;
5070        }
5071        else if (!strcmp(arg, "--pickaxe-all"))
5072                options->pickaxe_opts |= DIFF_PICKAXE_ALL;
5073        else if (!strcmp(arg, "--pickaxe-regex"))
5074                options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
5075        else if ((argcount = short_opt('O', av, &optarg))) {
5076                options->orderfile = prefix_filename(prefix, optarg);
5077                return argcount;
5078        } else if (skip_prefix(arg, "--find-object=", &arg))
5079                return parse_objfind_opt(options, arg);
5080        else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
5081                int offending = parse_diff_filter_opt(optarg, options);
5082                if (offending)
5083                        die("unknown change class '%c' in --diff-filter=%s",
5084                            offending, optarg);
5085                return argcount;
5086        }
5087        else if (!strcmp(arg, "--no-abbrev"))
5088                options->abbrev = 0;
5089        else if (!strcmp(arg, "--abbrev"))
5090                options->abbrev = DEFAULT_ABBREV;
5091        else if (skip_prefix(arg, "--abbrev=", &arg)) {
5092                options->abbrev = strtoul(arg, NULL, 10);
5093                if (options->abbrev < MINIMUM_ABBREV)
5094                        options->abbrev = MINIMUM_ABBREV;
5095                else if (the_hash_algo->hexsz < options->abbrev)
5096                        options->abbrev = the_hash_algo->hexsz;
5097        }
5098        else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
5099                options->a_prefix = optarg;
5100                return argcount;
5101        }
5102        else if ((argcount = parse_long_opt("line-prefix", av, &optarg))) {
5103                options->line_prefix = optarg;
5104                options->line_prefix_length = strlen(options->line_prefix);
5105                graph_setup_line_prefix(options);
5106                return argcount;
5107        }
5108        else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
5109                options->b_prefix = optarg;
5110                return argcount;
5111        }
5112        else if (!strcmp(arg, "--no-prefix"))
5113                options->a_prefix = options->b_prefix = "";
5114        else if (opt_arg(arg, '\0', "inter-hunk-context",
5115                         &options->interhunkcontext))
5116                ;
5117        else if (!strcmp(arg, "-W"))
5118                options->flags.funccontext = 1;
5119        else if (!strcmp(arg, "--function-context"))
5120                options->flags.funccontext = 1;
5121        else if (!strcmp(arg, "--no-function-context"))
5122                options->flags.funccontext = 0;
5123        else if ((argcount = parse_long_opt("output", av, &optarg))) {
5124                char *path = prefix_filename(prefix, optarg);
5125                options->file = xfopen(path, "w");
5126                options->close_file = 1;
5127                if (options->use_color != GIT_COLOR_ALWAYS)
5128                        options->use_color = GIT_COLOR_NEVER;
5129                free(path);
5130                return argcount;
5131        } else
5132                return 0;
5133        return 1;
5134}
5135
5136int parse_rename_score(const char **cp_p)
5137{
5138        unsigned long num, scale;
5139        int ch, dot;
5140        const char *cp = *cp_p;
5141
5142        num = 0;
5143        scale = 1;
5144        dot = 0;
5145        for (;;) {
5146                ch = *cp;
5147                if ( !dot && ch == '.' ) {
5148                        scale = 1;
5149                        dot = 1;
5150                } else if ( ch == '%' ) {
5151                        scale = dot ? scale*100 : 100;
5152                        cp++;   /* % is always at the end */
5153                        break;
5154                } else if ( ch >= '0' && ch <= '9' ) {
5155                        if ( scale < 100000 ) {
5156                                scale *= 10;
5157                                num = (num*10) + (ch-'0');
5158                        }
5159                } else {
5160                        break;
5161                }
5162                cp++;
5163        }
5164        *cp_p = cp;
5165
5166        /* user says num divided by scale and we say internally that
5167         * is MAX_SCORE * num / scale.
5168         */
5169        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
5170}
5171
5172static int diff_scoreopt_parse(const char *opt)
5173{
5174        int opt1, opt2, cmd;
5175
5176        if (*opt++ != '-')
5177                return -1;
5178        cmd = *opt++;
5179        if (cmd == '-') {
5180                /* convert the long-form arguments into short-form versions */
5181                if (skip_prefix(opt, "break-rewrites", &opt)) {
5182                        if (*opt == 0 || *opt++ == '=')
5183                                cmd = 'B';
5184                } else if (skip_prefix(opt, "find-copies", &opt)) {
5185                        if (*opt == 0 || *opt++ == '=')
5186                                cmd = 'C';
5187                } else if (skip_prefix(opt, "find-renames", &opt)) {
5188                        if (*opt == 0 || *opt++ == '=')
5189                                cmd = 'M';
5190                }
5191        }
5192        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
5193                return -1; /* that is not a -M, -C, or -B option */
5194
5195        opt1 = parse_rename_score(&opt);
5196        if (cmd != 'B')
5197                opt2 = 0;
5198        else {
5199                if (*opt == 0)
5200                        opt2 = 0;
5201                else if (*opt != '/')
5202                        return -1; /* we expect -B80/99 or -B80 */
5203                else {
5204                        opt++;
5205                        opt2 = parse_rename_score(&opt);
5206                }
5207        }
5208        if (*opt != 0)
5209                return -1;
5210        return opt1 | (opt2 << 16);
5211}
5212
5213struct diff_queue_struct diff_queued_diff;
5214
5215void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
5216{
5217        ALLOC_GROW(queue->queue, queue->nr + 1, queue->alloc);
5218        queue->queue[queue->nr++] = dp;
5219}
5220
5221struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
5222                                 struct diff_filespec *one,
5223                                 struct diff_filespec *two)
5224{
5225        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
5226        dp->one = one;
5227        dp->two = two;
5228        if (queue)
5229                diff_q(queue, dp);
5230        return dp;
5231}
5232
5233void diff_free_filepair(struct diff_filepair *p)
5234{
5235        free_filespec(p->one);
5236        free_filespec(p->two);
5237        free(p);
5238}
5239
5240const char *diff_aligned_abbrev(const struct object_id *oid, int len)
5241{
5242        int abblen;
5243        const char *abbrev;
5244
5245        /* Do we want all 40 hex characters? */
5246        if (len == the_hash_algo->hexsz)
5247                return oid_to_hex(oid);
5248
5249        /* An abbreviated value is fine, possibly followed by an ellipsis. */
5250        abbrev = diff_abbrev_oid(oid, len);
5251
5252        if (!print_sha1_ellipsis())
5253                return abbrev;
5254
5255        abblen = strlen(abbrev);
5256
5257        /*
5258         * In well-behaved cases, where the abbreviated result is the
5259         * same as the requested length, append three dots after the
5260         * abbreviation (hence the whole logic is limited to the case
5261         * where abblen < 37); when the actual abbreviated result is a
5262         * bit longer than the requested length, we reduce the number
5263         * of dots so that they match the well-behaved ones.  However,
5264         * if the actual abbreviation is longer than the requested
5265         * length by more than three, we give up on aligning, and add
5266         * three dots anyway, to indicate that the output is not the
5267         * full object name.  Yes, this may be suboptimal, but this
5268         * appears only in "diff --raw --abbrev" output and it is not
5269         * worth the effort to change it now.  Note that this would
5270         * likely to work fine when the automatic sizing of default
5271         * abbreviation length is used--we would be fed -1 in "len" in
5272         * that case, and will end up always appending three-dots, but
5273         * the automatic sizing is supposed to give abblen that ensures
5274         * uniqueness across all objects (statistically speaking).
5275         */
5276        if (abblen < the_hash_algo->hexsz - 3) {
5277                static char hex[GIT_MAX_HEXSZ + 1];
5278                if (len < abblen && abblen <= len + 2)
5279                        xsnprintf(hex, sizeof(hex), "%s%.*s", abbrev, len+3-abblen, "..");
5280                else
5281                        xsnprintf(hex, sizeof(hex), "%s...", abbrev);
5282                return hex;
5283        }
5284
5285        return oid_to_hex(oid);
5286}
5287
5288static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
5289{
5290        int line_termination = opt->line_termination;
5291        int inter_name_termination = line_termination ? '\t' : '\0';
5292
5293        fprintf(opt->file, "%s", diff_line_prefix(opt));
5294        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
5295                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
5296                        diff_aligned_abbrev(&p->one->oid, opt->abbrev));
5297                fprintf(opt->file, "%s ",
5298                        diff_aligned_abbrev(&p->two->oid, opt->abbrev));
5299        }
5300        if (p->score) {
5301                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
5302                        inter_name_termination);
5303        } else {
5304                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
5305        }
5306
5307        if (p->status == DIFF_STATUS_COPIED ||
5308            p->status == DIFF_STATUS_RENAMED) {
5309                const char *name_a, *name_b;
5310                name_a = p->one->path;
5311                name_b = p->two->path;
5312                strip_prefix(opt->prefix_length, &name_a, &name_b);
5313                write_name_quoted(name_a, opt->file, inter_name_termination);
5314                write_name_quoted(name_b, opt->file, line_termination);
5315        } else {
5316                const char *name_a, *name_b;
5317                name_a = p->one->mode ? p->one->path : p->two->path;
5318                name_b = NULL;
5319                strip_prefix(opt->prefix_length, &name_a, &name_b);
5320                write_name_quoted(name_a, opt->file, line_termination);
5321        }
5322}
5323
5324int diff_unmodified_pair(struct diff_filepair *p)
5325{
5326        /* This function is written stricter than necessary to support
5327         * the currently implemented transformers, but the idea is to
5328         * let transformers to produce diff_filepairs any way they want,
5329         * and filter and clean them up here before producing the output.
5330         */
5331        struct diff_filespec *one = p->one, *two = p->two;
5332
5333        if (DIFF_PAIR_UNMERGED(p))
5334                return 0; /* unmerged is interesting */
5335
5336        /* deletion, addition, mode or type change
5337         * and rename are all interesting.
5338         */
5339        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
5340            DIFF_PAIR_MODE_CHANGED(p) ||
5341            strcmp(one->path, two->path))
5342                return 0;
5343
5344        /* both are valid and point at the same path.  that is, we are
5345         * dealing with a change.
5346         */
5347        if (one->oid_valid && two->oid_valid &&
5348            !oidcmp(&one->oid, &two->oid) &&
5349            !one->dirty_submodule && !two->dirty_submodule)
5350                return 1; /* no change */
5351        if (!one->oid_valid && !two->oid_valid)
5352                return 1; /* both look at the same file on the filesystem. */
5353        return 0;
5354}
5355
5356static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
5357{
5358        if (diff_unmodified_pair(p))
5359                return;
5360
5361        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5362            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5363                return; /* no tree diffs in patch format */
5364
5365        run_diff(p, o);
5366}
5367
5368static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
5369                            struct diffstat_t *diffstat)
5370{
5371        if (diff_unmodified_pair(p))
5372                return;
5373
5374        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5375            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5376                return; /* no useful stat for tree diffs */
5377
5378        run_diffstat(p, o, diffstat);
5379}
5380
5381static void diff_flush_checkdiff(struct diff_filepair *p,
5382                struct diff_options *o)
5383{
5384        if (diff_unmodified_pair(p))
5385                return;
5386
5387        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5388            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5389                return; /* nothing to check in tree diffs */
5390
5391        run_checkdiff(p, o);
5392}
5393
5394int diff_queue_is_empty(void)
5395{
5396        struct diff_queue_struct *q = &diff_queued_diff;
5397        int i;
5398        for (i = 0; i < q->nr; i++)
5399                if (!diff_unmodified_pair(q->queue[i]))
5400                        return 0;
5401        return 1;
5402}
5403
5404#if DIFF_DEBUG
5405void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
5406{
5407        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
5408                x, one ? one : "",
5409                s->path,
5410                DIFF_FILE_VALID(s) ? "valid" : "invalid",
5411                s->mode,
5412                s->oid_valid ? oid_to_hex(&s->oid) : "");
5413        fprintf(stderr, "queue[%d] %s size %lu\n",
5414                x, one ? one : "",
5415                s->size);
5416}
5417
5418void diff_debug_filepair(const struct diff_filepair *p, int i)
5419{
5420        diff_debug_filespec(p->one, i, "one");
5421        diff_debug_filespec(p->two, i, "two");
5422        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
5423                p->score, p->status ? p->status : '?',
5424                p->one->rename_used, p->broken_pair);
5425}
5426
5427void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
5428{
5429        int i;
5430        if (msg)
5431                fprintf(stderr, "%s\n", msg);
5432        fprintf(stderr, "q->nr = %d\n", q->nr);
5433        for (i = 0; i < q->nr; i++) {
5434                struct diff_filepair *p = q->queue[i];
5435                diff_debug_filepair(p, i);
5436        }
5437}
5438#endif
5439
5440static void diff_resolve_rename_copy(void)
5441{
5442        int i;
5443        struct diff_filepair *p;
5444        struct diff_queue_struct *q = &diff_queued_diff;
5445
5446        diff_debug_queue("resolve-rename-copy", q);
5447
5448        for (i = 0; i < q->nr; i++) {
5449                p = q->queue[i];
5450                p->status = 0; /* undecided */
5451                if (DIFF_PAIR_UNMERGED(p))
5452                        p->status = DIFF_STATUS_UNMERGED;
5453                else if (!DIFF_FILE_VALID(p->one))
5454                        p->status = DIFF_STATUS_ADDED;
5455                else if (!DIFF_FILE_VALID(p->two))
5456                        p->status = DIFF_STATUS_DELETED;
5457                else if (DIFF_PAIR_TYPE_CHANGED(p))
5458                        p->status = DIFF_STATUS_TYPE_CHANGED;
5459
5460                /* from this point on, we are dealing with a pair
5461                 * whose both sides are valid and of the same type, i.e.
5462                 * either in-place edit or rename/copy edit.
5463                 */
5464                else if (DIFF_PAIR_RENAME(p)) {
5465                        /*
5466                         * A rename might have re-connected a broken
5467                         * pair up, causing the pathnames to be the
5468                         * same again. If so, that's not a rename at
5469                         * all, just a modification..
5470                         *
5471                         * Otherwise, see if this source was used for
5472                         * multiple renames, in which case we decrement
5473                         * the count, and call it a copy.
5474                         */
5475                        if (!strcmp(p->one->path, p->two->path))
5476                                p->status = DIFF_STATUS_MODIFIED;
5477                        else if (--p->one->rename_used > 0)
5478                                p->status = DIFF_STATUS_COPIED;
5479                        else
5480                                p->status = DIFF_STATUS_RENAMED;
5481                }
5482                else if (oidcmp(&p->one->oid, &p->two->oid) ||
5483                         p->one->mode != p->two->mode ||
5484                         p->one->dirty_submodule ||
5485                         p->two->dirty_submodule ||
5486                         is_null_oid(&p->one->oid))
5487                        p->status = DIFF_STATUS_MODIFIED;
5488                else {
5489                        /* This is a "no-change" entry and should not
5490                         * happen anymore, but prepare for broken callers.
5491                         */
5492                        error("feeding unmodified %s to diffcore",
5493                              p->one->path);
5494                        p->status = DIFF_STATUS_UNKNOWN;
5495                }
5496        }
5497        diff_debug_queue("resolve-rename-copy done", q);
5498}
5499
5500static int check_pair_status(struct diff_filepair *p)
5501{
5502        switch (p->status) {
5503        case DIFF_STATUS_UNKNOWN:
5504                return 0;
5505        case 0:
5506                die("internal error in diff-resolve-rename-copy");
5507        default:
5508                return 1;
5509        }
5510}
5511
5512static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
5513{
5514        int fmt = opt->output_format;
5515
5516        if (fmt & DIFF_FORMAT_CHECKDIFF)
5517                diff_flush_checkdiff(p, opt);
5518        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
5519                diff_flush_raw(p, opt);
5520        else if (fmt & DIFF_FORMAT_NAME) {
5521                const char *name_a, *name_b;
5522                name_a = p->two->path;
5523                name_b = NULL;
5524                strip_prefix(opt->prefix_length, &name_a, &name_b);
5525                fprintf(opt->file, "%s", diff_line_prefix(opt));
5526                write_name_quoted(name_a, opt->file, opt->line_termination);
5527        }
5528}
5529
5530static void show_file_mode_name(struct diff_options *opt, const char *newdelete, struct diff_filespec *fs)
5531{
5532        struct strbuf sb = STRBUF_INIT;
5533        if (fs->mode)
5534                strbuf_addf(&sb, " %s mode %06o ", newdelete, fs->mode);
5535        else
5536                strbuf_addf(&sb, " %s ", newdelete);
5537
5538        quote_c_style(fs->path, &sb, NULL, 0);
5539        strbuf_addch(&sb, '\n');
5540        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5541                         sb.buf, sb.len, 0);
5542        strbuf_release(&sb);
5543}
5544
5545static void show_mode_change(struct diff_options *opt, struct diff_filepair *p,
5546                int show_name)
5547{
5548        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
5549                struct strbuf sb = STRBUF_INIT;
5550                strbuf_addf(&sb, " mode change %06o => %06o",
5551                            p->one->mode, p->two->mode);
5552                if (show_name) {
5553                        strbuf_addch(&sb, ' ');
5554                        quote_c_style(p->two->path, &sb, NULL, 0);
5555                }
5556                strbuf_addch(&sb, '\n');
5557                emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5558                                 sb.buf, sb.len, 0);
5559                strbuf_release(&sb);
5560        }
5561}
5562
5563static void show_rename_copy(struct diff_options *opt, const char *renamecopy,
5564                struct diff_filepair *p)
5565{
5566        struct strbuf sb = STRBUF_INIT;
5567        struct strbuf names = STRBUF_INIT;
5568
5569        pprint_rename(&names, p->one->path, p->two->path);
5570        strbuf_addf(&sb, " %s %s (%d%%)\n",
5571                    renamecopy, names.buf, similarity_index(p));
5572        strbuf_release(&names);
5573        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5574                                 sb.buf, sb.len, 0);
5575        show_mode_change(opt, p, 0);
5576        strbuf_release(&sb);
5577}
5578
5579static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
5580{
5581        switch(p->status) {
5582        case DIFF_STATUS_DELETED:
5583                show_file_mode_name(opt, "delete", p->one);
5584                break;
5585        case DIFF_STATUS_ADDED:
5586                show_file_mode_name(opt, "create", p->two);
5587                break;
5588        case DIFF_STATUS_COPIED:
5589                show_rename_copy(opt, "copy", p);
5590                break;
5591        case DIFF_STATUS_RENAMED:
5592                show_rename_copy(opt, "rename", p);
5593                break;
5594        default:
5595                if (p->score) {
5596                        struct strbuf sb = STRBUF_INIT;
5597                        strbuf_addstr(&sb, " rewrite ");
5598                        quote_c_style(p->two->path, &sb, NULL, 0);
5599                        strbuf_addf(&sb, " (%d%%)\n", similarity_index(p));
5600                        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5601                                         sb.buf, sb.len, 0);
5602                        strbuf_release(&sb);
5603                }
5604                show_mode_change(opt, p, !p->score);
5605                break;
5606        }
5607}
5608
5609struct patch_id_t {
5610        git_SHA_CTX *ctx;
5611        int patchlen;
5612};
5613
5614static int remove_space(char *line, int len)
5615{
5616        int i;
5617        char *dst = line;
5618        unsigned char c;
5619
5620        for (i = 0; i < len; i++)
5621                if (!isspace((c = line[i])))
5622                        *dst++ = c;
5623
5624        return dst - line;
5625}
5626
5627static void patch_id_consume(void *priv, char *line, unsigned long len)
5628{
5629        struct patch_id_t *data = priv;
5630        int new_len;
5631
5632        /* Ignore line numbers when computing the SHA1 of the patch */
5633        if (starts_with(line, "@@ -"))
5634                return;
5635
5636        new_len = remove_space(line, len);
5637
5638        git_SHA1_Update(data->ctx, line, new_len);
5639        data->patchlen += new_len;
5640}
5641
5642static void patch_id_add_string(git_SHA_CTX *ctx, const char *str)
5643{
5644        git_SHA1_Update(ctx, str, strlen(str));
5645}
5646
5647static void patch_id_add_mode(git_SHA_CTX *ctx, unsigned mode)
5648{
5649        /* large enough for 2^32 in octal */
5650        char buf[12];
5651        int len = xsnprintf(buf, sizeof(buf), "%06o", mode);
5652        git_SHA1_Update(ctx, buf, len);
5653}
5654
5655/* returns 0 upon success, and writes result into sha1 */
5656static int diff_get_patch_id(struct diff_options *options, struct object_id *oid, int diff_header_only)
5657{
5658        struct diff_queue_struct *q = &diff_queued_diff;
5659        int i;
5660        git_SHA_CTX ctx;
5661        struct patch_id_t data;
5662
5663        git_SHA1_Init(&ctx);
5664        memset(&data, 0, sizeof(struct patch_id_t));
5665        data.ctx = &ctx;
5666
5667        for (i = 0; i < q->nr; i++) {
5668                xpparam_t xpp;
5669                xdemitconf_t xecfg;
5670                mmfile_t mf1, mf2;
5671                struct diff_filepair *p = q->queue[i];
5672                int len1, len2;
5673
5674                memset(&xpp, 0, sizeof(xpp));
5675                memset(&xecfg, 0, sizeof(xecfg));
5676                if (p->status == 0)
5677                        return error("internal diff status error");
5678                if (p->status == DIFF_STATUS_UNKNOWN)
5679                        continue;
5680                if (diff_unmodified_pair(p))
5681                        continue;
5682                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5683                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5684                        continue;
5685                if (DIFF_PAIR_UNMERGED(p))
5686                        continue;
5687
5688                diff_fill_oid_info(p->one, options->repo->index);
5689                diff_fill_oid_info(p->two, options->repo->index);
5690
5691                len1 = remove_space(p->one->path, strlen(p->one->path));
5692                len2 = remove_space(p->two->path, strlen(p->two->path));
5693                patch_id_add_string(&ctx, "diff--git");
5694                patch_id_add_string(&ctx, "a/");
5695                git_SHA1_Update(&ctx, p->one->path, len1);
5696                patch_id_add_string(&ctx, "b/");
5697                git_SHA1_Update(&ctx, p->two->path, len2);
5698
5699                if (p->one->mode == 0) {
5700                        patch_id_add_string(&ctx, "newfilemode");
5701                        patch_id_add_mode(&ctx, p->two->mode);
5702                        patch_id_add_string(&ctx, "---/dev/null");
5703                        patch_id_add_string(&ctx, "+++b/");
5704                        git_SHA1_Update(&ctx, p->two->path, len2);
5705                } else if (p->two->mode == 0) {
5706                        patch_id_add_string(&ctx, "deletedfilemode");
5707                        patch_id_add_mode(&ctx, p->one->mode);
5708                        patch_id_add_string(&ctx, "---a/");
5709                        git_SHA1_Update(&ctx, p->one->path, len1);
5710                        patch_id_add_string(&ctx, "+++/dev/null");
5711                } else {
5712                        patch_id_add_string(&ctx, "---a/");
5713                        git_SHA1_Update(&ctx, p->one->path, len1);
5714                        patch_id_add_string(&ctx, "+++b/");
5715                        git_SHA1_Update(&ctx, p->two->path, len2);
5716                }
5717
5718                if (diff_header_only)
5719                        continue;
5720
5721                if (fill_mmfile(options->repo, &mf1, p->one) < 0 ||
5722                    fill_mmfile(options->repo, &mf2, p->two) < 0)
5723                        return error("unable to read files to diff");
5724
5725                if (diff_filespec_is_binary(options->repo, p->one) ||
5726                    diff_filespec_is_binary(options->repo, p->two)) {
5727                        git_SHA1_Update(&ctx, oid_to_hex(&p->one->oid),
5728                                        GIT_SHA1_HEXSZ);
5729                        git_SHA1_Update(&ctx, oid_to_hex(&p->two->oid),
5730                                        GIT_SHA1_HEXSZ);
5731                        continue;
5732                }
5733
5734                xpp.flags = 0;
5735                xecfg.ctxlen = 3;
5736                xecfg.flags = 0;
5737                if (xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
5738                                  &xpp, &xecfg))
5739                        return error("unable to generate patch-id diff for %s",
5740                                     p->one->path);
5741        }
5742
5743        git_SHA1_Final(oid->hash, &ctx);
5744        return 0;
5745}
5746
5747int diff_flush_patch_id(struct diff_options *options, struct object_id *oid, int diff_header_only)
5748{
5749        struct diff_queue_struct *q = &diff_queued_diff;
5750        int i;
5751        int result = diff_get_patch_id(options, oid, diff_header_only);
5752
5753        for (i = 0; i < q->nr; i++)
5754                diff_free_filepair(q->queue[i]);
5755
5756        free(q->queue);
5757        DIFF_QUEUE_CLEAR(q);
5758
5759        return result;
5760}
5761
5762static int is_summary_empty(const struct diff_queue_struct *q)
5763{
5764        int i;
5765
5766        for (i = 0; i < q->nr; i++) {
5767                const struct diff_filepair *p = q->queue[i];
5768
5769                switch (p->status) {
5770                case DIFF_STATUS_DELETED:
5771                case DIFF_STATUS_ADDED:
5772                case DIFF_STATUS_COPIED:
5773                case DIFF_STATUS_RENAMED:
5774                        return 0;
5775                default:
5776                        if (p->score)
5777                                return 0;
5778                        if (p->one->mode && p->two->mode &&
5779                            p->one->mode != p->two->mode)
5780                                return 0;
5781                        break;
5782                }
5783        }
5784        return 1;
5785}
5786
5787static const char rename_limit_warning[] =
5788N_("inexact rename detection was skipped due to too many files.");
5789
5790static const char degrade_cc_to_c_warning[] =
5791N_("only found copies from modified paths due to too many files.");
5792
5793static const char rename_limit_advice[] =
5794N_("you may want to set your %s variable to at least "
5795   "%d and retry the command.");
5796
5797void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc)
5798{
5799        fflush(stdout);
5800        if (degraded_cc)
5801                warning(_(degrade_cc_to_c_warning));
5802        else if (needed)
5803                warning(_(rename_limit_warning));
5804        else
5805                return;
5806        if (0 < needed)
5807                warning(_(rename_limit_advice), varname, needed);
5808}
5809
5810static void diff_flush_patch_all_file_pairs(struct diff_options *o)
5811{
5812        int i;
5813        static struct emitted_diff_symbols esm = EMITTED_DIFF_SYMBOLS_INIT;
5814        struct diff_queue_struct *q = &diff_queued_diff;
5815
5816        if (WSEH_NEW & WS_RULE_MASK)
5817                BUG("WS rules bit mask overlaps with diff symbol flags");
5818
5819        if (o->color_moved)
5820                o->emitted_symbols = &esm;
5821
5822        for (i = 0; i < q->nr; i++) {
5823                struct diff_filepair *p = q->queue[i];
5824                if (check_pair_status(p))
5825                        diff_flush_patch(p, o);
5826        }
5827
5828        if (o->emitted_symbols) {
5829                if (o->color_moved) {
5830                        struct hashmap add_lines, del_lines;
5831
5832                        if (o->color_moved_ws_handling &
5833                            COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
5834                                o->color_moved_ws_handling |= XDF_IGNORE_WHITESPACE;
5835
5836                        hashmap_init(&del_lines, moved_entry_cmp, o, 0);
5837                        hashmap_init(&add_lines, moved_entry_cmp, o, 0);
5838
5839                        add_lines_to_move_detection(o, &add_lines, &del_lines);
5840                        mark_color_as_moved(o, &add_lines, &del_lines);
5841                        if (o->color_moved == COLOR_MOVED_ZEBRA_DIM)
5842                                dim_moved_lines(o);
5843
5844                        hashmap_free(&add_lines, 0);
5845                        hashmap_free(&del_lines, 0);
5846                }
5847
5848                for (i = 0; i < esm.nr; i++)
5849                        emit_diff_symbol_from_struct(o, &esm.buf[i]);
5850
5851                for (i = 0; i < esm.nr; i++)
5852                        free((void *)esm.buf[i].line);
5853        }
5854        esm.nr = 0;
5855}
5856
5857void diff_flush(struct diff_options *options)
5858{
5859        struct diff_queue_struct *q = &diff_queued_diff;
5860        int i, output_format = options->output_format;
5861        int separator = 0;
5862        int dirstat_by_line = 0;
5863
5864        /*
5865         * Order: raw, stat, summary, patch
5866         * or:    name/name-status/checkdiff (other bits clear)
5867         */
5868        if (!q->nr)
5869                goto free_queue;
5870
5871        if (output_format & (DIFF_FORMAT_RAW |
5872                             DIFF_FORMAT_NAME |
5873                             DIFF_FORMAT_NAME_STATUS |
5874                             DIFF_FORMAT_CHECKDIFF)) {
5875                for (i = 0; i < q->nr; i++) {
5876                        struct diff_filepair *p = q->queue[i];
5877                        if (check_pair_status(p))
5878                                flush_one_pair(p, options);
5879                }
5880                separator++;
5881        }
5882
5883        if (output_format & DIFF_FORMAT_DIRSTAT && options->flags.dirstat_by_line)
5884                dirstat_by_line = 1;
5885
5886        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT) ||
5887            dirstat_by_line) {
5888                struct diffstat_t diffstat;
5889
5890                memset(&diffstat, 0, sizeof(struct diffstat_t));
5891                for (i = 0; i < q->nr; i++) {
5892                        struct diff_filepair *p = q->queue[i];
5893                        if (check_pair_status(p))
5894                                diff_flush_stat(p, options, &diffstat);
5895                }
5896                if (output_format & DIFF_FORMAT_NUMSTAT)
5897                        show_numstat(&diffstat, options);
5898                if (output_format & DIFF_FORMAT_DIFFSTAT)
5899                        show_stats(&diffstat, options);
5900                if (output_format & DIFF_FORMAT_SHORTSTAT)
5901                        show_shortstats(&diffstat, options);
5902                if (output_format & DIFF_FORMAT_DIRSTAT && dirstat_by_line)
5903                        show_dirstat_by_line(&diffstat, options);
5904                free_diffstat_info(&diffstat);
5905                separator++;
5906        }
5907        if ((output_format & DIFF_FORMAT_DIRSTAT) && !dirstat_by_line)
5908                show_dirstat(options);
5909
5910        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
5911                for (i = 0; i < q->nr; i++) {
5912                        diff_summary(options, q->queue[i]);
5913                }
5914                separator++;
5915        }
5916
5917        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
5918            options->flags.exit_with_status &&
5919            options->flags.diff_from_contents) {
5920                /*
5921                 * run diff_flush_patch for the exit status. setting
5922                 * options->file to /dev/null should be safe, because we
5923                 * aren't supposed to produce any output anyway.
5924                 */
5925                if (options->close_file)
5926                        fclose(options->file);
5927                options->file = xfopen("/dev/null", "w");
5928                options->close_file = 1;
5929                options->color_moved = 0;
5930                for (i = 0; i < q->nr; i++) {
5931                        struct diff_filepair *p = q->queue[i];
5932                        if (check_pair_status(p))
5933                                diff_flush_patch(p, options);
5934                        if (options->found_changes)
5935                                break;
5936                }
5937        }
5938
5939        if (output_format & DIFF_FORMAT_PATCH) {
5940                if (separator) {
5941                        emit_diff_symbol(options, DIFF_SYMBOL_SEPARATOR, NULL, 0, 0);
5942                        if (options->stat_sep)
5943                                /* attach patch instead of inline */
5944                                emit_diff_symbol(options, DIFF_SYMBOL_STAT_SEP,
5945                                                 NULL, 0, 0);
5946                }
5947
5948                diff_flush_patch_all_file_pairs(options);
5949        }
5950
5951        if (output_format & DIFF_FORMAT_CALLBACK)
5952                options->format_callback(q, options, options->format_callback_data);
5953
5954        for (i = 0; i < q->nr; i++)
5955                diff_free_filepair(q->queue[i]);
5956free_queue:
5957        free(q->queue);
5958        DIFF_QUEUE_CLEAR(q);
5959        if (options->close_file)
5960                fclose(options->file);
5961
5962        /*
5963         * Report the content-level differences with HAS_CHANGES;
5964         * diff_addremove/diff_change does not set the bit when
5965         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
5966         */
5967        if (options->flags.diff_from_contents) {
5968                if (options->found_changes)
5969                        options->flags.has_changes = 1;
5970                else
5971                        options->flags.has_changes = 0;
5972        }
5973}
5974
5975static int match_filter(const struct diff_options *options, const struct diff_filepair *p)
5976{
5977        return (((p->status == DIFF_STATUS_MODIFIED) &&
5978                 ((p->score &&
5979                   filter_bit_tst(DIFF_STATUS_FILTER_BROKEN, options)) ||
5980                  (!p->score &&
5981                   filter_bit_tst(DIFF_STATUS_MODIFIED, options)))) ||
5982                ((p->status != DIFF_STATUS_MODIFIED) &&
5983                 filter_bit_tst(p->status, options)));
5984}
5985
5986static void diffcore_apply_filter(struct diff_options *options)
5987{
5988        int i;
5989        struct diff_queue_struct *q = &diff_queued_diff;
5990        struct diff_queue_struct outq;
5991
5992        DIFF_QUEUE_CLEAR(&outq);
5993
5994        if (!options->filter)
5995                return;
5996
5997        if (filter_bit_tst(DIFF_STATUS_FILTER_AON, options)) {
5998                int found;
5999                for (i = found = 0; !found && i < q->nr; i++) {
6000                        if (match_filter(options, q->queue[i]))
6001                                found++;
6002                }
6003                if (found)
6004                        return;
6005
6006                /* otherwise we will clear the whole queue
6007                 * by copying the empty outq at the end of this
6008                 * function, but first clear the current entries
6009                 * in the queue.
6010                 */
6011                for (i = 0; i < q->nr; i++)
6012                        diff_free_filepair(q->queue[i]);
6013        }
6014        else {
6015                /* Only the matching ones */
6016                for (i = 0; i < q->nr; i++) {
6017                        struct diff_filepair *p = q->queue[i];
6018                        if (match_filter(options, p))
6019                                diff_q(&outq, p);
6020                        else
6021                                diff_free_filepair(p);
6022                }
6023        }
6024        free(q->queue);
6025        *q = outq;
6026}
6027
6028/* Check whether two filespecs with the same mode and size are identical */
6029static int diff_filespec_is_identical(struct repository *r,
6030                                      struct diff_filespec *one,
6031                                      struct diff_filespec *two)
6032{
6033        if (S_ISGITLINK(one->mode))
6034                return 0;
6035        if (diff_populate_filespec(r, one, 0))
6036                return 0;
6037        if (diff_populate_filespec(r, two, 0))
6038                return 0;
6039        return !memcmp(one->data, two->data, one->size);
6040}
6041
6042static int diff_filespec_check_stat_unmatch(struct repository *r,
6043                                            struct diff_filepair *p)
6044{
6045        if (p->done_skip_stat_unmatch)
6046                return p->skip_stat_unmatch_result;
6047
6048        p->done_skip_stat_unmatch = 1;
6049        p->skip_stat_unmatch_result = 0;
6050        /*
6051         * 1. Entries that come from stat info dirtiness
6052         *    always have both sides (iow, not create/delete),
6053         *    one side of the object name is unknown, with
6054         *    the same mode and size.  Keep the ones that
6055         *    do not match these criteria.  They have real
6056         *    differences.
6057         *
6058         * 2. At this point, the file is known to be modified,
6059         *    with the same mode and size, and the object
6060         *    name of one side is unknown.  Need to inspect
6061         *    the identical contents.
6062         */
6063        if (!DIFF_FILE_VALID(p->one) || /* (1) */
6064            !DIFF_FILE_VALID(p->two) ||
6065            (p->one->oid_valid && p->two->oid_valid) ||
6066            (p->one->mode != p->two->mode) ||
6067            diff_populate_filespec(r, p->one, CHECK_SIZE_ONLY) ||
6068            diff_populate_filespec(r, p->two, CHECK_SIZE_ONLY) ||
6069            (p->one->size != p->two->size) ||
6070            !diff_filespec_is_identical(r, p->one, p->two)) /* (2) */
6071                p->skip_stat_unmatch_result = 1;
6072        return p->skip_stat_unmatch_result;
6073}
6074
6075static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
6076{
6077        int i;
6078        struct diff_queue_struct *q = &diff_queued_diff;
6079        struct diff_queue_struct outq;
6080        DIFF_QUEUE_CLEAR(&outq);
6081
6082        for (i = 0; i < q->nr; i++) {
6083                struct diff_filepair *p = q->queue[i];
6084
6085                if (diff_filespec_check_stat_unmatch(diffopt->repo, p))
6086                        diff_q(&outq, p);
6087                else {
6088                        /*
6089                         * The caller can subtract 1 from skip_stat_unmatch
6090                         * to determine how many paths were dirty only
6091                         * due to stat info mismatch.
6092                         */
6093                        if (!diffopt->flags.no_index)
6094                                diffopt->skip_stat_unmatch++;
6095                        diff_free_filepair(p);
6096                }
6097        }
6098        free(q->queue);
6099        *q = outq;
6100}
6101
6102static int diffnamecmp(const void *a_, const void *b_)
6103{
6104        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
6105        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
6106        const char *name_a, *name_b;
6107
6108        name_a = a->one ? a->one->path : a->two->path;
6109        name_b = b->one ? b->one->path : b->two->path;
6110        return strcmp(name_a, name_b);
6111}
6112
6113void diffcore_fix_diff_index(struct diff_options *options)
6114{
6115        struct diff_queue_struct *q = &diff_queued_diff;
6116        QSORT(q->queue, q->nr, diffnamecmp);
6117}
6118
6119void diffcore_std(struct diff_options *options)
6120{
6121        /* NOTE please keep the following in sync with diff_tree_combined() */
6122        if (options->skip_stat_unmatch)
6123                diffcore_skip_stat_unmatch(options);
6124        if (!options->found_follow) {
6125                /* See try_to_follow_renames() in tree-diff.c */
6126                if (options->break_opt != -1)
6127                        diffcore_break(options->repo,
6128                                       options->break_opt);
6129                if (options->detect_rename)
6130                        diffcore_rename(options);
6131                if (options->break_opt != -1)
6132                        diffcore_merge_broken();
6133        }
6134        if (options->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK)
6135                diffcore_pickaxe(options);
6136        if (options->orderfile)
6137                diffcore_order(options->orderfile);
6138        if (!options->found_follow)
6139                /* See try_to_follow_renames() in tree-diff.c */
6140                diff_resolve_rename_copy();
6141        diffcore_apply_filter(options);
6142
6143        if (diff_queued_diff.nr && !options->flags.diff_from_contents)
6144                options->flags.has_changes = 1;
6145        else
6146                options->flags.has_changes = 0;
6147
6148        options->found_follow = 0;
6149}
6150
6151int diff_result_code(struct diff_options *opt, int status)
6152{
6153        int result = 0;
6154
6155        diff_warn_rename_limit("diff.renameLimit",
6156                               opt->needed_rename_limit,
6157                               opt->degraded_cc_to_c);
6158        if (!opt->flags.exit_with_status &&
6159            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
6160                return status;
6161        if (opt->flags.exit_with_status &&
6162            opt->flags.has_changes)
6163                result |= 01;
6164        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
6165            opt->flags.check_failed)
6166                result |= 02;
6167        return result;
6168}
6169
6170int diff_can_quit_early(struct diff_options *opt)
6171{
6172        return (opt->flags.quick &&
6173                !opt->filter &&
6174                opt->flags.has_changes);
6175}
6176
6177/*
6178 * Shall changes to this submodule be ignored?
6179 *
6180 * Submodule changes can be configured to be ignored separately for each path,
6181 * but that configuration can be overridden from the command line.
6182 */
6183static int is_submodule_ignored(const char *path, struct diff_options *options)
6184{
6185        int ignored = 0;
6186        struct diff_flags orig_flags = options->flags;
6187        if (!options->flags.override_submodule_config)
6188                set_diffopt_flags_from_submodule_config(options, path);
6189        if (options->flags.ignore_submodules)
6190                ignored = 1;
6191        options->flags = orig_flags;
6192        return ignored;
6193}
6194
6195void diff_addremove(struct diff_options *options,
6196                    int addremove, unsigned mode,
6197                    const struct object_id *oid,
6198                    int oid_valid,
6199                    const char *concatpath, unsigned dirty_submodule)
6200{
6201        struct diff_filespec *one, *two;
6202
6203        if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
6204                return;
6205
6206        /* This may look odd, but it is a preparation for
6207         * feeding "there are unchanged files which should
6208         * not produce diffs, but when you are doing copy
6209         * detection you would need them, so here they are"
6210         * entries to the diff-core.  They will be prefixed
6211         * with something like '=' or '*' (I haven't decided
6212         * which but should not make any difference).
6213         * Feeding the same new and old to diff_change()
6214         * also has the same effect.
6215         * Before the final output happens, they are pruned after
6216         * merged into rename/copy pairs as appropriate.
6217         */
6218        if (options->flags.reverse_diff)
6219                addremove = (addremove == '+' ? '-' :
6220                             addremove == '-' ? '+' : addremove);
6221
6222        if (options->prefix &&
6223            strncmp(concatpath, options->prefix, options->prefix_length))
6224                return;
6225
6226        one = alloc_filespec(concatpath);
6227        two = alloc_filespec(concatpath);
6228
6229        if (addremove != '+')
6230                fill_filespec(one, oid, oid_valid, mode);
6231        if (addremove != '-') {
6232                fill_filespec(two, oid, oid_valid, mode);
6233                two->dirty_submodule = dirty_submodule;
6234        }
6235
6236        diff_queue(&diff_queued_diff, one, two);
6237        if (!options->flags.diff_from_contents)
6238                options->flags.has_changes = 1;
6239}
6240
6241void diff_change(struct diff_options *options,
6242                 unsigned old_mode, unsigned new_mode,
6243                 const struct object_id *old_oid,
6244                 const struct object_id *new_oid,
6245                 int old_oid_valid, int new_oid_valid,
6246                 const char *concatpath,
6247                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
6248{
6249        struct diff_filespec *one, *two;
6250        struct diff_filepair *p;
6251
6252        if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
6253            is_submodule_ignored(concatpath, options))
6254                return;
6255
6256        if (options->flags.reverse_diff) {
6257                SWAP(old_mode, new_mode);
6258                SWAP(old_oid, new_oid);
6259                SWAP(old_oid_valid, new_oid_valid);
6260                SWAP(old_dirty_submodule, new_dirty_submodule);
6261        }
6262
6263        if (options->prefix &&
6264            strncmp(concatpath, options->prefix, options->prefix_length))
6265                return;
6266
6267        one = alloc_filespec(concatpath);
6268        two = alloc_filespec(concatpath);
6269        fill_filespec(one, old_oid, old_oid_valid, old_mode);
6270        fill_filespec(two, new_oid, new_oid_valid, new_mode);
6271        one->dirty_submodule = old_dirty_submodule;
6272        two->dirty_submodule = new_dirty_submodule;
6273        p = diff_queue(&diff_queued_diff, one, two);
6274
6275        if (options->flags.diff_from_contents)
6276                return;
6277
6278        if (options->flags.quick && options->skip_stat_unmatch &&
6279            !diff_filespec_check_stat_unmatch(options->repo, p))
6280                return;
6281
6282        options->flags.has_changes = 1;
6283}
6284
6285struct diff_filepair *diff_unmerge(struct diff_options *options, const char *path)
6286{
6287        struct diff_filepair *pair;
6288        struct diff_filespec *one, *two;
6289
6290        if (options->prefix &&
6291            strncmp(path, options->prefix, options->prefix_length))
6292                return NULL;
6293
6294        one = alloc_filespec(path);
6295        two = alloc_filespec(path);
6296        pair = diff_queue(&diff_queued_diff, one, two);
6297        pair->is_unmerged = 1;
6298        return pair;
6299}
6300
6301static char *run_textconv(struct repository *r,
6302                          const char *pgm,
6303                          struct diff_filespec *spec,
6304                          size_t *outsize)
6305{
6306        struct diff_tempfile *temp;
6307        const char *argv[3];
6308        const char **arg = argv;
6309        struct child_process child = CHILD_PROCESS_INIT;
6310        struct strbuf buf = STRBUF_INIT;
6311        int err = 0;
6312
6313        temp = prepare_temp_file(r, spec->path, spec);
6314        *arg++ = pgm;
6315        *arg++ = temp->name;
6316        *arg = NULL;
6317
6318        child.use_shell = 1;
6319        child.argv = argv;
6320        child.out = -1;
6321        if (start_command(&child)) {
6322                remove_tempfile();
6323                return NULL;
6324        }
6325
6326        if (strbuf_read(&buf, child.out, 0) < 0)
6327                err = error("error reading from textconv command '%s'", pgm);
6328        close(child.out);
6329
6330        if (finish_command(&child) || err) {
6331                strbuf_release(&buf);
6332                remove_tempfile();
6333                return NULL;
6334        }
6335        remove_tempfile();
6336
6337        return strbuf_detach(&buf, outsize);
6338}
6339
6340size_t fill_textconv(struct repository *r,
6341                     struct userdiff_driver *driver,
6342                     struct diff_filespec *df,
6343                     char **outbuf)
6344{
6345        size_t size;
6346
6347        if (!driver) {
6348                if (!DIFF_FILE_VALID(df)) {
6349                        *outbuf = "";
6350                        return 0;
6351                }
6352                if (diff_populate_filespec(r, df, 0))
6353                        die("unable to read files to diff");
6354                *outbuf = df->data;
6355                return df->size;
6356        }
6357
6358        if (!driver->textconv)
6359                BUG("fill_textconv called with non-textconv driver");
6360
6361        if (driver->textconv_cache && df->oid_valid) {
6362                *outbuf = notes_cache_get(driver->textconv_cache,
6363                                          &df->oid,
6364                                          &size);
6365                if (*outbuf)
6366                        return size;
6367        }
6368
6369        *outbuf = run_textconv(r, driver->textconv, df, &size);
6370        if (!*outbuf)
6371                die("unable to read files to diff");
6372
6373        if (driver->textconv_cache && df->oid_valid) {
6374                /* ignore errors, as we might be in a readonly repository */
6375                notes_cache_put(driver->textconv_cache, &df->oid, *outbuf,
6376                                size);
6377                /*
6378                 * we could save up changes and flush them all at the end,
6379                 * but we would need an extra call after all diffing is done.
6380                 * Since generating a cache entry is the slow path anyway,
6381                 * this extra overhead probably isn't a big deal.
6382                 */
6383                notes_cache_write(driver->textconv_cache);
6384        }
6385
6386        return size;
6387}
6388
6389int textconv_object(struct repository *r,
6390                    const char *path,
6391                    unsigned mode,
6392                    const struct object_id *oid,
6393                    int oid_valid,
6394                    char **buf,
6395                    unsigned long *buf_size)
6396{
6397        struct diff_filespec *df;
6398        struct userdiff_driver *textconv;
6399
6400        df = alloc_filespec(path);
6401        fill_filespec(df, oid, oid_valid, mode);
6402        textconv = get_textconv(df);
6403        if (!textconv) {
6404                free_filespec(df);
6405                return 0;
6406        }
6407
6408        *buf_size = fill_textconv(r, textconv, df, buf);
6409        free_filespec(df);
6410        return 1;
6411}
6412
6413void setup_diff_pager(struct diff_options *opt)
6414{
6415        /*
6416         * If the user asked for our exit code, then either they want --quiet
6417         * or --exit-code. We should definitely not bother with a pager in the
6418         * former case, as we will generate no output. Since we still properly
6419         * report our exit code even when a pager is run, we _could_ run a
6420         * pager with --exit-code. But since we have not done so historically,
6421         * and because it is easy to find people oneline advising "git diff
6422         * --exit-code" in hooks and other scripts, we do not do so.
6423         */
6424        if (!opt->flags.exit_with_status &&
6425            check_pager_config("diff") != 0)
6426                setup_pager();
6427}