b648f67413d31766332eece7ebec522ab0d9b237
   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, "no"))
 308                        ret = 0;
 309                else if (!strcmp(sb.buf, "ignore-space-change"))
 310                        ret |= XDF_IGNORE_WHITESPACE_CHANGE;
 311                else if (!strcmp(sb.buf, "ignore-space-at-eol"))
 312                        ret |= XDF_IGNORE_WHITESPACE_AT_EOL;
 313                else if (!strcmp(sb.buf, "ignore-all-space"))
 314                        ret |= XDF_IGNORE_WHITESPACE;
 315                else if (!strcmp(sb.buf, "allow-indentation-change"))
 316                        ret |= COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE;
 317                else
 318                        error(_("ignoring unknown color-moved-ws mode '%s'"), sb.buf);
 319
 320                strbuf_release(&sb);
 321        }
 322
 323        if ((ret & COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE) &&
 324            (ret & XDF_WHITESPACE_FLAGS))
 325                die(_("color-moved-ws: allow-indentation-change cannot be combined with other whitespace modes"));
 326
 327        string_list_clear(&l, 0);
 328
 329        return ret;
 330}
 331
 332int git_diff_ui_config(const char *var, const char *value, void *cb)
 333{
 334        if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
 335                diff_use_color_default = git_config_colorbool(var, value);
 336                return 0;
 337        }
 338        if (!strcmp(var, "diff.colormoved")) {
 339                int cm = parse_color_moved(value);
 340                if (cm < 0)
 341                        return -1;
 342                diff_color_moved_default = cm;
 343                return 0;
 344        }
 345        if (!strcmp(var, "diff.colormovedws")) {
 346                int cm = parse_color_moved_ws(value);
 347                if (cm < 0)
 348                        return -1;
 349                diff_color_moved_ws_default = cm;
 350                return 0;
 351        }
 352        if (!strcmp(var, "diff.context")) {
 353                diff_context_default = git_config_int(var, value);
 354                if (diff_context_default < 0)
 355                        return -1;
 356                return 0;
 357        }
 358        if (!strcmp(var, "diff.interhunkcontext")) {
 359                diff_interhunk_context_default = git_config_int(var, value);
 360                if (diff_interhunk_context_default < 0)
 361                        return -1;
 362                return 0;
 363        }
 364        if (!strcmp(var, "diff.renames")) {
 365                diff_detect_rename_default = git_config_rename(var, value);
 366                return 0;
 367        }
 368        if (!strcmp(var, "diff.autorefreshindex")) {
 369                diff_auto_refresh_index = git_config_bool(var, value);
 370                return 0;
 371        }
 372        if (!strcmp(var, "diff.mnemonicprefix")) {
 373                diff_mnemonic_prefix = git_config_bool(var, value);
 374                return 0;
 375        }
 376        if (!strcmp(var, "diff.noprefix")) {
 377                diff_no_prefix = git_config_bool(var, value);
 378                return 0;
 379        }
 380        if (!strcmp(var, "diff.statgraphwidth")) {
 381                diff_stat_graph_width = git_config_int(var, value);
 382                return 0;
 383        }
 384        if (!strcmp(var, "diff.external"))
 385                return git_config_string(&external_diff_cmd_cfg, var, value);
 386        if (!strcmp(var, "diff.wordregex"))
 387                return git_config_string(&diff_word_regex_cfg, var, value);
 388        if (!strcmp(var, "diff.orderfile"))
 389                return git_config_pathname(&diff_order_file_cfg, var, value);
 390
 391        if (!strcmp(var, "diff.ignoresubmodules"))
 392                handle_ignore_submodules_arg(&default_diff_options, value);
 393
 394        if (!strcmp(var, "diff.submodule")) {
 395                if (parse_submodule_params(&default_diff_options, value))
 396                        warning(_("Unknown value for 'diff.submodule' config variable: '%s'"),
 397                                value);
 398                return 0;
 399        }
 400
 401        if (!strcmp(var, "diff.algorithm")) {
 402                diff_algorithm = parse_algorithm_value(value);
 403                if (diff_algorithm < 0)
 404                        return -1;
 405                return 0;
 406        }
 407
 408        if (!strcmp(var, "diff.wserrorhighlight")) {
 409                int val = parse_ws_error_highlight(value);
 410                if (val < 0)
 411                        return -1;
 412                ws_error_highlight_default = val;
 413                return 0;
 414        }
 415
 416        if (git_color_config(var, value, cb) < 0)
 417                return -1;
 418
 419        return git_diff_basic_config(var, value, cb);
 420}
 421
 422int git_diff_basic_config(const char *var, const char *value, void *cb)
 423{
 424        const char *name;
 425
 426        if (!strcmp(var, "diff.renamelimit")) {
 427                diff_rename_limit_default = git_config_int(var, value);
 428                return 0;
 429        }
 430
 431        if (userdiff_config(var, value) < 0)
 432                return -1;
 433
 434        if (skip_prefix(var, "diff.color.", &name) ||
 435            skip_prefix(var, "color.diff.", &name)) {
 436                int slot = parse_diff_color_slot(name);
 437                if (slot < 0)
 438                        return 0;
 439                if (!value)
 440                        return config_error_nonbool(var);
 441                return color_parse(value, diff_colors[slot]);
 442        }
 443
 444        /* like GNU diff's --suppress-blank-empty option  */
 445        if (!strcmp(var, "diff.suppressblankempty") ||
 446                        /* for backwards compatibility */
 447                        !strcmp(var, "diff.suppress-blank-empty")) {
 448                diff_suppress_blank_empty = git_config_bool(var, value);
 449                return 0;
 450        }
 451
 452        if (!strcmp(var, "diff.dirstat")) {
 453                struct strbuf errmsg = STRBUF_INIT;
 454                default_diff_options.dirstat_permille = diff_dirstat_permille_default;
 455                if (parse_dirstat_params(&default_diff_options, value, &errmsg))
 456                        warning(_("Found errors in 'diff.dirstat' config variable:\n%s"),
 457                                errmsg.buf);
 458                strbuf_release(&errmsg);
 459                diff_dirstat_permille_default = default_diff_options.dirstat_permille;
 460                return 0;
 461        }
 462
 463        if (git_diff_heuristic_config(var, value, cb) < 0)
 464                return -1;
 465
 466        return git_default_config(var, value, cb);
 467}
 468
 469static char *quote_two(const char *one, const char *two)
 470{
 471        int need_one = quote_c_style(one, NULL, NULL, 1);
 472        int need_two = quote_c_style(two, NULL, NULL, 1);
 473        struct strbuf res = STRBUF_INIT;
 474
 475        if (need_one + need_two) {
 476                strbuf_addch(&res, '"');
 477                quote_c_style(one, &res, NULL, 1);
 478                quote_c_style(two, &res, NULL, 1);
 479                strbuf_addch(&res, '"');
 480        } else {
 481                strbuf_addstr(&res, one);
 482                strbuf_addstr(&res, two);
 483        }
 484        return strbuf_detach(&res, NULL);
 485}
 486
 487static const char *external_diff(void)
 488{
 489        static const char *external_diff_cmd = NULL;
 490        static int done_preparing = 0;
 491
 492        if (done_preparing)
 493                return external_diff_cmd;
 494        external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
 495        if (!external_diff_cmd)
 496                external_diff_cmd = external_diff_cmd_cfg;
 497        done_preparing = 1;
 498        return external_diff_cmd;
 499}
 500
 501/*
 502 * Keep track of files used for diffing. Sometimes such an entry
 503 * refers to a temporary file, sometimes to an existing file, and
 504 * sometimes to "/dev/null".
 505 */
 506static struct diff_tempfile {
 507        /*
 508         * filename external diff should read from, or NULL if this
 509         * entry is currently not in use:
 510         */
 511        const char *name;
 512
 513        char hex[GIT_MAX_HEXSZ + 1];
 514        char mode[10];
 515
 516        /*
 517         * If this diff_tempfile instance refers to a temporary file,
 518         * this tempfile object is used to manage its lifetime.
 519         */
 520        struct tempfile *tempfile;
 521} diff_temp[2];
 522
 523struct emit_callback {
 524        int color_diff;
 525        unsigned ws_rule;
 526        int blank_at_eof_in_preimage;
 527        int blank_at_eof_in_postimage;
 528        int lno_in_preimage;
 529        int lno_in_postimage;
 530        const char **label_path;
 531        struct diff_words_data *diff_words;
 532        struct diff_options *opt;
 533        struct strbuf *header;
 534};
 535
 536static int count_lines(const char *data, int size)
 537{
 538        int count, ch, completely_empty = 1, nl_just_seen = 0;
 539        count = 0;
 540        while (0 < size--) {
 541                ch = *data++;
 542                if (ch == '\n') {
 543                        count++;
 544                        nl_just_seen = 1;
 545                        completely_empty = 0;
 546                }
 547                else {
 548                        nl_just_seen = 0;
 549                        completely_empty = 0;
 550                }
 551        }
 552        if (completely_empty)
 553                return 0;
 554        if (!nl_just_seen)
 555                count++; /* no trailing newline */
 556        return count;
 557}
 558
 559static int fill_mmfile(struct repository *r, mmfile_t *mf,
 560                       struct diff_filespec *one)
 561{
 562        if (!DIFF_FILE_VALID(one)) {
 563                mf->ptr = (char *)""; /* does not matter */
 564                mf->size = 0;
 565                return 0;
 566        }
 567        else if (diff_populate_filespec(r, one, 0))
 568                return -1;
 569
 570        mf->ptr = one->data;
 571        mf->size = one->size;
 572        return 0;
 573}
 574
 575/* like fill_mmfile, but only for size, so we can avoid retrieving blob */
 576static unsigned long diff_filespec_size(struct repository *r,
 577                                        struct diff_filespec *one)
 578{
 579        if (!DIFF_FILE_VALID(one))
 580                return 0;
 581        diff_populate_filespec(r, one, CHECK_SIZE_ONLY);
 582        return one->size;
 583}
 584
 585static int count_trailing_blank(mmfile_t *mf, unsigned ws_rule)
 586{
 587        char *ptr = mf->ptr;
 588        long size = mf->size;
 589        int cnt = 0;
 590
 591        if (!size)
 592                return cnt;
 593        ptr += size - 1; /* pointing at the very end */
 594        if (*ptr != '\n')
 595                ; /* incomplete line */
 596        else
 597                ptr--; /* skip the last LF */
 598        while (mf->ptr < ptr) {
 599                char *prev_eol;
 600                for (prev_eol = ptr; mf->ptr <= prev_eol; prev_eol--)
 601                        if (*prev_eol == '\n')
 602                                break;
 603                if (!ws_blank_line(prev_eol + 1, ptr - prev_eol, ws_rule))
 604                        break;
 605                cnt++;
 606                ptr = prev_eol - 1;
 607        }
 608        return cnt;
 609}
 610
 611static void check_blank_at_eof(mmfile_t *mf1, mmfile_t *mf2,
 612                               struct emit_callback *ecbdata)
 613{
 614        int l1, l2, at;
 615        unsigned ws_rule = ecbdata->ws_rule;
 616        l1 = count_trailing_blank(mf1, ws_rule);
 617        l2 = count_trailing_blank(mf2, ws_rule);
 618        if (l2 <= l1) {
 619                ecbdata->blank_at_eof_in_preimage = 0;
 620                ecbdata->blank_at_eof_in_postimage = 0;
 621                return;
 622        }
 623        at = count_lines(mf1->ptr, mf1->size);
 624        ecbdata->blank_at_eof_in_preimage = (at - l1) + 1;
 625
 626        at = count_lines(mf2->ptr, mf2->size);
 627        ecbdata->blank_at_eof_in_postimage = (at - l2) + 1;
 628}
 629
 630static void emit_line_0(struct diff_options *o,
 631                        const char *set_sign, const char *set, unsigned reverse, const char *reset,
 632                        int first, const char *line, int len)
 633{
 634        int has_trailing_newline, has_trailing_carriage_return;
 635        int needs_reset = 0; /* at the end of the line */
 636        FILE *file = o->file;
 637
 638        fputs(diff_line_prefix(o), file);
 639
 640        has_trailing_newline = (len > 0 && line[len-1] == '\n');
 641        if (has_trailing_newline)
 642                len--;
 643
 644        has_trailing_carriage_return = (len > 0 && line[len-1] == '\r');
 645        if (has_trailing_carriage_return)
 646                len--;
 647
 648        if (!len && !first)
 649                goto end_of_line;
 650
 651        if (reverse && want_color(o->use_color)) {
 652                fputs(GIT_COLOR_REVERSE, file);
 653                needs_reset = 1;
 654        }
 655
 656        if (set_sign) {
 657                fputs(set_sign, file);
 658                needs_reset = 1;
 659        }
 660
 661        if (first)
 662                fputc(first, file);
 663
 664        if (!len)
 665                goto end_of_line;
 666
 667        if (set) {
 668                if (set_sign && set != set_sign)
 669                        fputs(reset, file);
 670                fputs(set, file);
 671                needs_reset = 1;
 672        }
 673        fwrite(line, len, 1, file);
 674        needs_reset = 1; /* 'line' may contain color codes. */
 675
 676end_of_line:
 677        if (needs_reset)
 678                fputs(reset, file);
 679        if (has_trailing_carriage_return)
 680                fputc('\r', file);
 681        if (has_trailing_newline)
 682                fputc('\n', file);
 683}
 684
 685static void emit_line(struct diff_options *o, const char *set, const char *reset,
 686                      const char *line, int len)
 687{
 688        emit_line_0(o, set, NULL, 0, reset, 0, line, len);
 689}
 690
 691enum diff_symbol {
 692        DIFF_SYMBOL_BINARY_DIFF_HEADER,
 693        DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA,
 694        DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL,
 695        DIFF_SYMBOL_BINARY_DIFF_BODY,
 696        DIFF_SYMBOL_BINARY_DIFF_FOOTER,
 697        DIFF_SYMBOL_STATS_SUMMARY_NO_FILES,
 698        DIFF_SYMBOL_STATS_SUMMARY_ABBREV,
 699        DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES,
 700        DIFF_SYMBOL_STATS_LINE,
 701        DIFF_SYMBOL_WORD_DIFF,
 702        DIFF_SYMBOL_STAT_SEP,
 703        DIFF_SYMBOL_SUMMARY,
 704        DIFF_SYMBOL_SUBMODULE_ADD,
 705        DIFF_SYMBOL_SUBMODULE_DEL,
 706        DIFF_SYMBOL_SUBMODULE_UNTRACKED,
 707        DIFF_SYMBOL_SUBMODULE_MODIFIED,
 708        DIFF_SYMBOL_SUBMODULE_HEADER,
 709        DIFF_SYMBOL_SUBMODULE_ERROR,
 710        DIFF_SYMBOL_SUBMODULE_PIPETHROUGH,
 711        DIFF_SYMBOL_REWRITE_DIFF,
 712        DIFF_SYMBOL_BINARY_FILES,
 713        DIFF_SYMBOL_HEADER,
 714        DIFF_SYMBOL_FILEPAIR_PLUS,
 715        DIFF_SYMBOL_FILEPAIR_MINUS,
 716        DIFF_SYMBOL_WORDS_PORCELAIN,
 717        DIFF_SYMBOL_WORDS,
 718        DIFF_SYMBOL_CONTEXT,
 719        DIFF_SYMBOL_CONTEXT_INCOMPLETE,
 720        DIFF_SYMBOL_PLUS,
 721        DIFF_SYMBOL_MINUS,
 722        DIFF_SYMBOL_NO_LF_EOF,
 723        DIFF_SYMBOL_CONTEXT_FRAGINFO,
 724        DIFF_SYMBOL_CONTEXT_MARKER,
 725        DIFF_SYMBOL_SEPARATOR
 726};
 727/*
 728 * Flags for content lines:
 729 * 0..12 are whitespace rules
 730 * 13-15 are WSEH_NEW | WSEH_OLD | WSEH_CONTEXT
 731 * 16 is marking if the line is blank at EOF
 732 */
 733#define DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF      (1<<16)
 734#define DIFF_SYMBOL_MOVED_LINE                  (1<<17)
 735#define DIFF_SYMBOL_MOVED_LINE_ALT              (1<<18)
 736#define DIFF_SYMBOL_MOVED_LINE_UNINTERESTING    (1<<19)
 737#define DIFF_SYMBOL_CONTENT_WS_MASK (WSEH_NEW | WSEH_OLD | WSEH_CONTEXT | WS_RULE_MASK)
 738
 739/*
 740 * This struct is used when we need to buffer the output of the diff output.
 741 *
 742 * NEEDSWORK: Instead of storing a copy of the line, add an offset pointer
 743 * into the pre/post image file. This pointer could be a union with the
 744 * line pointer. By storing an offset into the file instead of the literal line,
 745 * we can decrease the memory footprint for the buffered output. At first we
 746 * may want to only have indirection for the content lines, but we could also
 747 * enhance the state for emitting prefabricated lines, e.g. the similarity
 748 * score line or hunk/file headers would only need to store a number or path
 749 * and then the output can be constructed later on depending on state.
 750 */
 751struct emitted_diff_symbol {
 752        const char *line;
 753        int len;
 754        int flags;
 755        enum diff_symbol s;
 756};
 757#define EMITTED_DIFF_SYMBOL_INIT {NULL}
 758
 759struct emitted_diff_symbols {
 760        struct emitted_diff_symbol *buf;
 761        int nr, alloc;
 762};
 763#define EMITTED_DIFF_SYMBOLS_INIT {NULL, 0, 0}
 764
 765static void append_emitted_diff_symbol(struct diff_options *o,
 766                                       struct emitted_diff_symbol *e)
 767{
 768        struct emitted_diff_symbol *f;
 769
 770        ALLOC_GROW(o->emitted_symbols->buf,
 771                   o->emitted_symbols->nr + 1,
 772                   o->emitted_symbols->alloc);
 773        f = &o->emitted_symbols->buf[o->emitted_symbols->nr++];
 774
 775        memcpy(f, e, sizeof(struct emitted_diff_symbol));
 776        f->line = e->line ? xmemdupz(e->line, e->len) : NULL;
 777}
 778
 779struct moved_entry {
 780        struct hashmap_entry ent;
 781        const struct emitted_diff_symbol *es;
 782        struct moved_entry *next_line;
 783};
 784
 785/**
 786 * The struct ws_delta holds white space differences between moved lines, i.e.
 787 * between '+' and '-' lines that have been detected to be a move.
 788 * The string contains the difference in leading white spaces, before the
 789 * rest of the line is compared using the white space config for move
 790 * coloring. The current_longer indicates if the first string in the
 791 * comparision is longer than the second.
 792 */
 793struct ws_delta {
 794        char *string;
 795        unsigned int current_longer : 1;
 796};
 797#define WS_DELTA_INIT { NULL, 0 }
 798
 799struct moved_block {
 800        struct moved_entry *match;
 801        struct ws_delta wsd;
 802};
 803
 804static void moved_block_clear(struct moved_block *b)
 805{
 806        FREE_AND_NULL(b->wsd.string);
 807        b->match = NULL;
 808}
 809
 810static int compute_ws_delta(const struct emitted_diff_symbol *a,
 811                             const struct emitted_diff_symbol *b,
 812                             struct ws_delta *out)
 813{
 814        const struct emitted_diff_symbol *longer =  a->len > b->len ? a : b;
 815        const struct emitted_diff_symbol *shorter = a->len > b->len ? b : a;
 816        int d = longer->len - shorter->len;
 817
 818        if (strncmp(longer->line + d, shorter->line, shorter->len))
 819                return 0;
 820
 821        out->string = xmemdupz(longer->line, d);
 822        out->current_longer = (a == longer);
 823
 824        return 1;
 825}
 826
 827static int cmp_in_block_with_wsd(const struct diff_options *o,
 828                                 const struct moved_entry *cur,
 829                                 const struct moved_entry *match,
 830                                 struct moved_block *pmb,
 831                                 int n)
 832{
 833        struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
 834        int al = cur->es->len, cl = l->len;
 835        const char *a = cur->es->line,
 836                   *b = match->es->line,
 837                   *c = l->line;
 838
 839        int wslen;
 840
 841        /*
 842         * We need to check if 'cur' is equal to 'match'.
 843         * As those are from the same (+/-) side, we do not need to adjust for
 844         * indent changes. However these were found using fuzzy matching
 845         * so we do have to check if they are equal.
 846         */
 847        if (strcmp(a, b))
 848                return 1;
 849
 850        if (!pmb->wsd.string)
 851                /*
 852                 * The white space delta is not active? This can happen
 853                 * when we exit early in this function.
 854                 */
 855                return 1;
 856
 857        /*
 858         * The indent changes of the block are known and stored in
 859         * pmb->wsd; however we need to check if the indent changes of the
 860         * current line are still the same as before.
 861         *
 862         * To do so we need to compare 'l' to 'cur', adjusting the
 863         * one of them for the white spaces, depending which was longer.
 864         */
 865
 866        wslen = strlen(pmb->wsd.string);
 867        if (pmb->wsd.current_longer) {
 868                c += wslen;
 869                cl -= wslen;
 870        } else {
 871                a += wslen;
 872                al -= wslen;
 873        }
 874
 875        if (al != cl || memcmp(a, c, al))
 876                return 1;
 877
 878        return 0;
 879}
 880
 881static int moved_entry_cmp(const void *hashmap_cmp_fn_data,
 882                           const void *entry,
 883                           const void *entry_or_key,
 884                           const void *keydata)
 885{
 886        const struct diff_options *diffopt = hashmap_cmp_fn_data;
 887        const struct moved_entry *a = entry;
 888        const struct moved_entry *b = entry_or_key;
 889        unsigned flags = diffopt->color_moved_ws_handling
 890                         & XDF_WHITESPACE_FLAGS;
 891
 892        if (diffopt->color_moved_ws_handling &
 893            COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
 894                /*
 895                 * As there is not specific white space config given,
 896                 * we'd need to check for a new block, so ignore all
 897                 * white space. The setup of the white space
 898                 * configuration for the next block is done else where
 899                 */
 900                flags |= XDF_IGNORE_WHITESPACE;
 901
 902        return !xdiff_compare_lines(a->es->line, a->es->len,
 903                                    b->es->line, b->es->len,
 904                                    flags);
 905}
 906
 907static struct moved_entry *prepare_entry(struct diff_options *o,
 908                                         int line_no)
 909{
 910        struct moved_entry *ret = xmalloc(sizeof(*ret));
 911        struct emitted_diff_symbol *l = &o->emitted_symbols->buf[line_no];
 912        unsigned flags = o->color_moved_ws_handling & XDF_WHITESPACE_FLAGS;
 913
 914        ret->ent.hash = xdiff_hash_string(l->line, l->len, flags);
 915        ret->es = l;
 916        ret->next_line = NULL;
 917
 918        return ret;
 919}
 920
 921static void add_lines_to_move_detection(struct diff_options *o,
 922                                        struct hashmap *add_lines,
 923                                        struct hashmap *del_lines)
 924{
 925        struct moved_entry *prev_line = NULL;
 926
 927        int n;
 928        for (n = 0; n < o->emitted_symbols->nr; n++) {
 929                struct hashmap *hm;
 930                struct moved_entry *key;
 931
 932                switch (o->emitted_symbols->buf[n].s) {
 933                case DIFF_SYMBOL_PLUS:
 934                        hm = add_lines;
 935                        break;
 936                case DIFF_SYMBOL_MINUS:
 937                        hm = del_lines;
 938                        break;
 939                default:
 940                        prev_line = NULL;
 941                        continue;
 942                }
 943
 944                key = prepare_entry(o, n);
 945                if (prev_line && prev_line->es->s == o->emitted_symbols->buf[n].s)
 946                        prev_line->next_line = key;
 947
 948                hashmap_add(hm, key);
 949                prev_line = key;
 950        }
 951}
 952
 953static void pmb_advance_or_null(struct diff_options *o,
 954                                struct moved_entry *match,
 955                                struct hashmap *hm,
 956                                struct moved_block *pmb,
 957                                int pmb_nr)
 958{
 959        int i;
 960        for (i = 0; i < pmb_nr; i++) {
 961                struct moved_entry *prev = pmb[i].match;
 962                struct moved_entry *cur = (prev && prev->next_line) ?
 963                                prev->next_line : NULL;
 964                if (cur && !hm->cmpfn(o, cur, match, NULL)) {
 965                        pmb[i].match = cur;
 966                } else {
 967                        pmb[i].match = NULL;
 968                }
 969        }
 970}
 971
 972static void pmb_advance_or_null_multi_match(struct diff_options *o,
 973                                            struct moved_entry *match,
 974                                            struct hashmap *hm,
 975                                            struct moved_block *pmb,
 976                                            int pmb_nr, int n)
 977{
 978        int i;
 979        char *got_match = xcalloc(1, pmb_nr);
 980
 981        for (; match; match = hashmap_get_next(hm, match)) {
 982                for (i = 0; i < pmb_nr; i++) {
 983                        struct moved_entry *prev = pmb[i].match;
 984                        struct moved_entry *cur = (prev && prev->next_line) ?
 985                                        prev->next_line : NULL;
 986                        if (!cur)
 987                                continue;
 988                        if (!cmp_in_block_with_wsd(o, cur, match, &pmb[i], n))
 989                                got_match[i] |= 1;
 990                }
 991        }
 992
 993        for (i = 0; i < pmb_nr; i++) {
 994                if (got_match[i]) {
 995                        /* Advance to the next line */
 996                        pmb[i].match = pmb[i].match->next_line;
 997                } else {
 998                        moved_block_clear(&pmb[i]);
 999                }
1000        }
1001
1002        free(got_match);
1003}
1004
1005static int shrink_potential_moved_blocks(struct moved_block *pmb,
1006                                         int pmb_nr)
1007{
1008        int lp, rp;
1009
1010        /* Shrink the set of potential block to the remaining running */
1011        for (lp = 0, rp = pmb_nr - 1; lp <= rp;) {
1012                while (lp < pmb_nr && pmb[lp].match)
1013                        lp++;
1014                /* lp points at the first NULL now */
1015
1016                while (rp > -1 && !pmb[rp].match)
1017                        rp--;
1018                /* rp points at the last non-NULL */
1019
1020                if (lp < pmb_nr && rp > -1 && lp < rp) {
1021                        pmb[lp] = pmb[rp];
1022                        pmb[rp].match = NULL;
1023                        pmb[rp].wsd.string = NULL;
1024                        rp--;
1025                        lp++;
1026                }
1027        }
1028
1029        /* Remember the number of running sets */
1030        return rp + 1;
1031}
1032
1033/*
1034 * If o->color_moved is COLOR_MOVED_PLAIN, this function does nothing.
1035 *
1036 * Otherwise, if the last block has fewer alphanumeric characters than
1037 * COLOR_MOVED_MIN_ALNUM_COUNT, unset DIFF_SYMBOL_MOVED_LINE on all lines in
1038 * that block.
1039 *
1040 * The last block consists of the (n - block_length)'th line up to but not
1041 * including the nth line.
1042 *
1043 * Returns 0 if the last block is empty or is unset by this function, non zero
1044 * otherwise.
1045 *
1046 * NEEDSWORK: This uses the same heuristic as blame_entry_score() in blame.c.
1047 * Think of a way to unify them.
1048 */
1049static int adjust_last_block(struct diff_options *o, int n, int block_length)
1050{
1051        int i, alnum_count = 0;
1052        if (o->color_moved == COLOR_MOVED_PLAIN)
1053                return block_length;
1054        for (i = 1; i < block_length + 1; i++) {
1055                const char *c = o->emitted_symbols->buf[n - i].line;
1056                for (; *c; c++) {
1057                        if (!isalnum(*c))
1058                                continue;
1059                        alnum_count++;
1060                        if (alnum_count >= COLOR_MOVED_MIN_ALNUM_COUNT)
1061                                return 1;
1062                }
1063        }
1064        for (i = 1; i < block_length + 1; i++)
1065                o->emitted_symbols->buf[n - i].flags &= ~DIFF_SYMBOL_MOVED_LINE;
1066        return 0;
1067}
1068
1069/* Find blocks of moved code, delegate actual coloring decision to helper */
1070static void mark_color_as_moved(struct diff_options *o,
1071                                struct hashmap *add_lines,
1072                                struct hashmap *del_lines)
1073{
1074        struct moved_block *pmb = NULL; /* potentially moved blocks */
1075        int pmb_nr = 0, pmb_alloc = 0;
1076        int n, flipped_block = 0, block_length = 0;
1077
1078
1079        for (n = 0; n < o->emitted_symbols->nr; n++) {
1080                struct hashmap *hm = NULL;
1081                struct moved_entry *key;
1082                struct moved_entry *match = NULL;
1083                struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
1084                enum diff_symbol last_symbol = 0;
1085
1086                switch (l->s) {
1087                case DIFF_SYMBOL_PLUS:
1088                        hm = del_lines;
1089                        key = prepare_entry(o, n);
1090                        match = hashmap_get(hm, key, NULL);
1091                        free(key);
1092                        break;
1093                case DIFF_SYMBOL_MINUS:
1094                        hm = add_lines;
1095                        key = prepare_entry(o, n);
1096                        match = hashmap_get(hm, key, NULL);
1097                        free(key);
1098                        break;
1099                default:
1100                        flipped_block = 0;
1101                }
1102
1103                if (!match) {
1104                        int i;
1105
1106                        adjust_last_block(o, n, block_length);
1107                        for(i = 0; i < pmb_nr; i++)
1108                                moved_block_clear(&pmb[i]);
1109                        pmb_nr = 0;
1110                        block_length = 0;
1111                        flipped_block = 0;
1112                        last_symbol = l->s;
1113                        continue;
1114                }
1115
1116                if (o->color_moved == COLOR_MOVED_PLAIN) {
1117                        last_symbol = l->s;
1118                        l->flags |= DIFF_SYMBOL_MOVED_LINE;
1119                        continue;
1120                }
1121
1122                if (o->color_moved_ws_handling &
1123                    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
1124                        pmb_advance_or_null_multi_match(o, match, hm, pmb, pmb_nr, n);
1125                else
1126                        pmb_advance_or_null(o, match, hm, pmb, pmb_nr);
1127
1128                pmb_nr = shrink_potential_moved_blocks(pmb, pmb_nr);
1129
1130                if (pmb_nr == 0) {
1131                        /*
1132                         * The current line is the start of a new block.
1133                         * Setup the set of potential blocks.
1134                         */
1135                        for (; match; match = hashmap_get_next(hm, match)) {
1136                                ALLOC_GROW(pmb, pmb_nr + 1, pmb_alloc);
1137                                if (o->color_moved_ws_handling &
1138                                    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE) {
1139                                        if (compute_ws_delta(l, match->es,
1140                                                             &pmb[pmb_nr].wsd))
1141                                                pmb[pmb_nr++].match = match;
1142                                } else {
1143                                        pmb[pmb_nr].wsd.string = NULL;
1144                                        pmb[pmb_nr++].match = match;
1145                                }
1146                        }
1147
1148                        if (adjust_last_block(o, n, block_length) &&
1149                            pmb_nr && last_symbol != l->s)
1150                                flipped_block = (flipped_block + 1) % 2;
1151                        else
1152                                flipped_block = 0;
1153
1154                        block_length = 0;
1155                }
1156
1157                if (pmb_nr) {
1158                        block_length++;
1159                        l->flags |= DIFF_SYMBOL_MOVED_LINE;
1160                        if (flipped_block && o->color_moved != COLOR_MOVED_BLOCKS)
1161                                l->flags |= DIFF_SYMBOL_MOVED_LINE_ALT;
1162                }
1163                last_symbol = l->s;
1164        }
1165        adjust_last_block(o, n, block_length);
1166
1167        for(n = 0; n < pmb_nr; n++)
1168                moved_block_clear(&pmb[n]);
1169        free(pmb);
1170}
1171
1172#define DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK \
1173  (DIFF_SYMBOL_MOVED_LINE | DIFF_SYMBOL_MOVED_LINE_ALT)
1174static void dim_moved_lines(struct diff_options *o)
1175{
1176        int n;
1177        for (n = 0; n < o->emitted_symbols->nr; n++) {
1178                struct emitted_diff_symbol *prev = (n != 0) ?
1179                                &o->emitted_symbols->buf[n - 1] : NULL;
1180                struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
1181                struct emitted_diff_symbol *next =
1182                                (n < o->emitted_symbols->nr - 1) ?
1183                                &o->emitted_symbols->buf[n + 1] : NULL;
1184
1185                /* Not a plus or minus line? */
1186                if (l->s != DIFF_SYMBOL_PLUS && l->s != DIFF_SYMBOL_MINUS)
1187                        continue;
1188
1189                /* Not a moved line? */
1190                if (!(l->flags & DIFF_SYMBOL_MOVED_LINE))
1191                        continue;
1192
1193                /*
1194                 * If prev or next are not a plus or minus line,
1195                 * pretend they don't exist
1196                 */
1197                if (prev && prev->s != DIFF_SYMBOL_PLUS &&
1198                            prev->s != DIFF_SYMBOL_MINUS)
1199                        prev = NULL;
1200                if (next && next->s != DIFF_SYMBOL_PLUS &&
1201                            next->s != DIFF_SYMBOL_MINUS)
1202                        next = NULL;
1203
1204                /* Inside a block? */
1205                if ((prev &&
1206                    (prev->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK) ==
1207                    (l->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK)) &&
1208                    (next &&
1209                    (next->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK) ==
1210                    (l->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK))) {
1211                        l->flags |= DIFF_SYMBOL_MOVED_LINE_UNINTERESTING;
1212                        continue;
1213                }
1214
1215                /* Check if we are at an interesting bound: */
1216                if (prev && (prev->flags & DIFF_SYMBOL_MOVED_LINE) &&
1217                    (prev->flags & DIFF_SYMBOL_MOVED_LINE_ALT) !=
1218                       (l->flags & DIFF_SYMBOL_MOVED_LINE_ALT))
1219                        continue;
1220                if (next && (next->flags & DIFF_SYMBOL_MOVED_LINE) &&
1221                    (next->flags & DIFF_SYMBOL_MOVED_LINE_ALT) !=
1222                       (l->flags & DIFF_SYMBOL_MOVED_LINE_ALT))
1223                        continue;
1224
1225                /*
1226                 * The boundary to prev and next are not interesting,
1227                 * so this line is not interesting as a whole
1228                 */
1229                l->flags |= DIFF_SYMBOL_MOVED_LINE_UNINTERESTING;
1230        }
1231}
1232
1233static void emit_line_ws_markup(struct diff_options *o,
1234                                const char *set_sign, const char *set,
1235                                const char *reset,
1236                                int sign_index, const char *line, int len,
1237                                unsigned ws_rule, int blank_at_eof)
1238{
1239        const char *ws = NULL;
1240        int sign = o->output_indicators[sign_index];
1241
1242        if (o->ws_error_highlight & ws_rule) {
1243                ws = diff_get_color_opt(o, DIFF_WHITESPACE);
1244                if (!*ws)
1245                        ws = NULL;
1246        }
1247
1248        if (!ws && !set_sign)
1249                emit_line_0(o, set, NULL, 0, reset, sign, line, len);
1250        else if (!ws) {
1251                emit_line_0(o, set_sign, set, !!set_sign, reset, sign, line, len);
1252        } else if (blank_at_eof)
1253                /* Blank line at EOF - paint '+' as well */
1254                emit_line_0(o, ws, NULL, 0, reset, sign, line, len);
1255        else {
1256                /* Emit just the prefix, then the rest. */
1257                emit_line_0(o, set_sign ? set_sign : set, NULL, !!set_sign, reset,
1258                            sign, "", 0);
1259                ws_check_emit(line, len, ws_rule,
1260                              o->file, set, reset, ws);
1261        }
1262}
1263
1264static void emit_diff_symbol_from_struct(struct diff_options *o,
1265                                         struct emitted_diff_symbol *eds)
1266{
1267        static const char *nneof = " No newline at end of file\n";
1268        const char *context, *reset, *set, *set_sign, *meta, *fraginfo;
1269        struct strbuf sb = STRBUF_INIT;
1270
1271        enum diff_symbol s = eds->s;
1272        const char *line = eds->line;
1273        int len = eds->len;
1274        unsigned flags = eds->flags;
1275
1276        switch (s) {
1277        case DIFF_SYMBOL_NO_LF_EOF:
1278                context = diff_get_color_opt(o, DIFF_CONTEXT);
1279                reset = diff_get_color_opt(o, DIFF_RESET);
1280                putc('\n', o->file);
1281                emit_line_0(o, context, NULL, 0, reset, '\\',
1282                            nneof, strlen(nneof));
1283                break;
1284        case DIFF_SYMBOL_SUBMODULE_HEADER:
1285        case DIFF_SYMBOL_SUBMODULE_ERROR:
1286        case DIFF_SYMBOL_SUBMODULE_PIPETHROUGH:
1287        case DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES:
1288        case DIFF_SYMBOL_SUMMARY:
1289        case DIFF_SYMBOL_STATS_LINE:
1290        case DIFF_SYMBOL_BINARY_DIFF_BODY:
1291        case DIFF_SYMBOL_CONTEXT_FRAGINFO:
1292                emit_line(o, "", "", line, len);
1293                break;
1294        case DIFF_SYMBOL_CONTEXT_INCOMPLETE:
1295        case DIFF_SYMBOL_CONTEXT_MARKER:
1296                context = diff_get_color_opt(o, DIFF_CONTEXT);
1297                reset = diff_get_color_opt(o, DIFF_RESET);
1298                emit_line(o, context, reset, line, len);
1299                break;
1300        case DIFF_SYMBOL_SEPARATOR:
1301                fprintf(o->file, "%s%c",
1302                        diff_line_prefix(o),
1303                        o->line_termination);
1304                break;
1305        case DIFF_SYMBOL_CONTEXT:
1306                set = diff_get_color_opt(o, DIFF_CONTEXT);
1307                reset = diff_get_color_opt(o, DIFF_RESET);
1308                set_sign = NULL;
1309                if (o->flags.dual_color_diffed_diffs) {
1310                        char c = !len ? 0 : line[0];
1311
1312                        if (c == '+')
1313                                set = diff_get_color_opt(o, DIFF_FILE_NEW);
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_OLD);
1318                }
1319                emit_line_ws_markup(o, set_sign, set, reset,
1320                                    OUTPUT_INDICATOR_CONTEXT, line, len,
1321                                    flags & (DIFF_SYMBOL_CONTENT_WS_MASK), 0);
1322                break;
1323        case DIFF_SYMBOL_PLUS:
1324                switch (flags & (DIFF_SYMBOL_MOVED_LINE |
1325                                 DIFF_SYMBOL_MOVED_LINE_ALT |
1326                                 DIFF_SYMBOL_MOVED_LINE_UNINTERESTING)) {
1327                case DIFF_SYMBOL_MOVED_LINE |
1328                     DIFF_SYMBOL_MOVED_LINE_ALT |
1329                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1330                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED_ALT_DIM);
1331                        break;
1332                case DIFF_SYMBOL_MOVED_LINE |
1333                     DIFF_SYMBOL_MOVED_LINE_ALT:
1334                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED_ALT);
1335                        break;
1336                case DIFF_SYMBOL_MOVED_LINE |
1337                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1338                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED_DIM);
1339                        break;
1340                case DIFF_SYMBOL_MOVED_LINE:
1341                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED);
1342                        break;
1343                default:
1344                        set = diff_get_color_opt(o, DIFF_FILE_NEW);
1345                }
1346                reset = diff_get_color_opt(o, DIFF_RESET);
1347                if (!o->flags.dual_color_diffed_diffs)
1348                        set_sign = NULL;
1349                else {
1350                        char c = !len ? 0 : line[0];
1351
1352                        set_sign = set;
1353                        if (c == '-')
1354                                set = diff_get_color_opt(o, DIFF_FILE_OLD_BOLD);
1355                        else if (c == '@')
1356                                set = diff_get_color_opt(o, DIFF_FRAGINFO);
1357                        else if (c == '+')
1358                                set = diff_get_color_opt(o, DIFF_FILE_NEW_BOLD);
1359                        else
1360                                set = diff_get_color_opt(o, DIFF_CONTEXT_BOLD);
1361                        flags &= ~DIFF_SYMBOL_CONTENT_WS_MASK;
1362                }
1363                emit_line_ws_markup(o, set_sign, set, reset,
1364                                    OUTPUT_INDICATOR_NEW, line, len,
1365                                    flags & DIFF_SYMBOL_CONTENT_WS_MASK,
1366                                    flags & DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF);
1367                break;
1368        case DIFF_SYMBOL_MINUS:
1369                switch (flags & (DIFF_SYMBOL_MOVED_LINE |
1370                                 DIFF_SYMBOL_MOVED_LINE_ALT |
1371                                 DIFF_SYMBOL_MOVED_LINE_UNINTERESTING)) {
1372                case DIFF_SYMBOL_MOVED_LINE |
1373                     DIFF_SYMBOL_MOVED_LINE_ALT |
1374                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1375                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_ALT_DIM);
1376                        break;
1377                case DIFF_SYMBOL_MOVED_LINE |
1378                     DIFF_SYMBOL_MOVED_LINE_ALT:
1379                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_ALT);
1380                        break;
1381                case DIFF_SYMBOL_MOVED_LINE |
1382                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1383                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_DIM);
1384                        break;
1385                case DIFF_SYMBOL_MOVED_LINE:
1386                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED);
1387                        break;
1388                default:
1389                        set = diff_get_color_opt(o, DIFF_FILE_OLD);
1390                }
1391                reset = diff_get_color_opt(o, DIFF_RESET);
1392                if (!o->flags.dual_color_diffed_diffs)
1393                        set_sign = NULL;
1394                else {
1395                        char c = !len ? 0 : line[0];
1396
1397                        set_sign = set;
1398                        if (c == '+')
1399                                set = diff_get_color_opt(o, DIFF_FILE_NEW_DIM);
1400                        else if (c == '@')
1401                                set = diff_get_color_opt(o, DIFF_FRAGINFO);
1402                        else if (c == '-')
1403                                set = diff_get_color_opt(o, DIFF_FILE_OLD_DIM);
1404                        else
1405                                set = diff_get_color_opt(o, DIFF_CONTEXT_DIM);
1406                }
1407                emit_line_ws_markup(o, set_sign, set, reset,
1408                                    OUTPUT_INDICATOR_OLD, line, len,
1409                                    flags & DIFF_SYMBOL_CONTENT_WS_MASK, 0);
1410                break;
1411        case DIFF_SYMBOL_WORDS_PORCELAIN:
1412                context = diff_get_color_opt(o, DIFF_CONTEXT);
1413                reset = diff_get_color_opt(o, DIFF_RESET);
1414                emit_line(o, context, reset, line, len);
1415                fputs("~\n", o->file);
1416                break;
1417        case DIFF_SYMBOL_WORDS:
1418                context = diff_get_color_opt(o, DIFF_CONTEXT);
1419                reset = diff_get_color_opt(o, DIFF_RESET);
1420                /*
1421                 * Skip the prefix character, if any.  With
1422                 * diff_suppress_blank_empty, there may be
1423                 * none.
1424                 */
1425                if (line[0] != '\n') {
1426                        line++;
1427                        len--;
1428                }
1429                emit_line(o, context, reset, line, len);
1430                break;
1431        case DIFF_SYMBOL_FILEPAIR_PLUS:
1432                meta = diff_get_color_opt(o, DIFF_METAINFO);
1433                reset = diff_get_color_opt(o, DIFF_RESET);
1434                fprintf(o->file, "%s%s+++ %s%s%s\n", diff_line_prefix(o), meta,
1435                        line, reset,
1436                        strchr(line, ' ') ? "\t" : "");
1437                break;
1438        case DIFF_SYMBOL_FILEPAIR_MINUS:
1439                meta = diff_get_color_opt(o, DIFF_METAINFO);
1440                reset = diff_get_color_opt(o, DIFF_RESET);
1441                fprintf(o->file, "%s%s--- %s%s%s\n", diff_line_prefix(o), meta,
1442                        line, reset,
1443                        strchr(line, ' ') ? "\t" : "");
1444                break;
1445        case DIFF_SYMBOL_BINARY_FILES:
1446        case DIFF_SYMBOL_HEADER:
1447                fprintf(o->file, "%s", line);
1448                break;
1449        case DIFF_SYMBOL_BINARY_DIFF_HEADER:
1450                fprintf(o->file, "%sGIT binary patch\n", diff_line_prefix(o));
1451                break;
1452        case DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA:
1453                fprintf(o->file, "%sdelta %s\n", diff_line_prefix(o), line);
1454                break;
1455        case DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL:
1456                fprintf(o->file, "%sliteral %s\n", diff_line_prefix(o), line);
1457                break;
1458        case DIFF_SYMBOL_BINARY_DIFF_FOOTER:
1459                fputs(diff_line_prefix(o), o->file);
1460                fputc('\n', o->file);
1461                break;
1462        case DIFF_SYMBOL_REWRITE_DIFF:
1463                fraginfo = diff_get_color(o->use_color, DIFF_FRAGINFO);
1464                reset = diff_get_color_opt(o, DIFF_RESET);
1465                emit_line(o, fraginfo, reset, line, len);
1466                break;
1467        case DIFF_SYMBOL_SUBMODULE_ADD:
1468                set = diff_get_color_opt(o, DIFF_FILE_NEW);
1469                reset = diff_get_color_opt(o, DIFF_RESET);
1470                emit_line(o, set, reset, line, len);
1471                break;
1472        case DIFF_SYMBOL_SUBMODULE_DEL:
1473                set = diff_get_color_opt(o, DIFF_FILE_OLD);
1474                reset = diff_get_color_opt(o, DIFF_RESET);
1475                emit_line(o, set, reset, line, len);
1476                break;
1477        case DIFF_SYMBOL_SUBMODULE_UNTRACKED:
1478                fprintf(o->file, "%sSubmodule %s contains untracked content\n",
1479                        diff_line_prefix(o), line);
1480                break;
1481        case DIFF_SYMBOL_SUBMODULE_MODIFIED:
1482                fprintf(o->file, "%sSubmodule %s contains modified content\n",
1483                        diff_line_prefix(o), line);
1484                break;
1485        case DIFF_SYMBOL_STATS_SUMMARY_NO_FILES:
1486                emit_line(o, "", "", " 0 files changed\n",
1487                          strlen(" 0 files changed\n"));
1488                break;
1489        case DIFF_SYMBOL_STATS_SUMMARY_ABBREV:
1490                emit_line(o, "", "", " ...\n", strlen(" ...\n"));
1491                break;
1492        case DIFF_SYMBOL_WORD_DIFF:
1493                fprintf(o->file, "%.*s", len, line);
1494                break;
1495        case DIFF_SYMBOL_STAT_SEP:
1496                fputs(o->stat_sep, o->file);
1497                break;
1498        default:
1499                BUG("unknown diff symbol");
1500        }
1501        strbuf_release(&sb);
1502}
1503
1504static void emit_diff_symbol(struct diff_options *o, enum diff_symbol s,
1505                             const char *line, int len, unsigned flags)
1506{
1507        struct emitted_diff_symbol e = {line, len, flags, s};
1508
1509        if (o->emitted_symbols)
1510                append_emitted_diff_symbol(o, &e);
1511        else
1512                emit_diff_symbol_from_struct(o, &e);
1513}
1514
1515void diff_emit_submodule_del(struct diff_options *o, const char *line)
1516{
1517        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_DEL, line, strlen(line), 0);
1518}
1519
1520void diff_emit_submodule_add(struct diff_options *o, const char *line)
1521{
1522        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_ADD, line, strlen(line), 0);
1523}
1524
1525void diff_emit_submodule_untracked(struct diff_options *o, const char *path)
1526{
1527        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_UNTRACKED,
1528                         path, strlen(path), 0);
1529}
1530
1531void diff_emit_submodule_modified(struct diff_options *o, const char *path)
1532{
1533        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_MODIFIED,
1534                         path, strlen(path), 0);
1535}
1536
1537void diff_emit_submodule_header(struct diff_options *o, const char *header)
1538{
1539        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_HEADER,
1540                         header, strlen(header), 0);
1541}
1542
1543void diff_emit_submodule_error(struct diff_options *o, const char *err)
1544{
1545        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_ERROR, err, strlen(err), 0);
1546}
1547
1548void diff_emit_submodule_pipethrough(struct diff_options *o,
1549                                     const char *line, int len)
1550{
1551        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_PIPETHROUGH, line, len, 0);
1552}
1553
1554static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line, int len)
1555{
1556        if (!((ecbdata->ws_rule & WS_BLANK_AT_EOF) &&
1557              ecbdata->blank_at_eof_in_preimage &&
1558              ecbdata->blank_at_eof_in_postimage &&
1559              ecbdata->blank_at_eof_in_preimage <= ecbdata->lno_in_preimage &&
1560              ecbdata->blank_at_eof_in_postimage <= ecbdata->lno_in_postimage))
1561                return 0;
1562        return ws_blank_line(line, len, ecbdata->ws_rule);
1563}
1564
1565static void emit_add_line(const char *reset,
1566                          struct emit_callback *ecbdata,
1567                          const char *line, int len)
1568{
1569        unsigned flags = WSEH_NEW | ecbdata->ws_rule;
1570        if (new_blank_line_at_eof(ecbdata, line, len))
1571                flags |= DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF;
1572
1573        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_PLUS, line, len, flags);
1574}
1575
1576static void emit_del_line(const char *reset,
1577                          struct emit_callback *ecbdata,
1578                          const char *line, int len)
1579{
1580        unsigned flags = WSEH_OLD | ecbdata->ws_rule;
1581        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_MINUS, line, len, flags);
1582}
1583
1584static void emit_context_line(const char *reset,
1585                              struct emit_callback *ecbdata,
1586                              const char *line, int len)
1587{
1588        unsigned flags = WSEH_CONTEXT | ecbdata->ws_rule;
1589        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_CONTEXT, line, len, flags);
1590}
1591
1592static void emit_hunk_header(struct emit_callback *ecbdata,
1593                             const char *line, int len)
1594{
1595        const char *context = diff_get_color(ecbdata->color_diff, DIFF_CONTEXT);
1596        const char *frag = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
1597        const char *func = diff_get_color(ecbdata->color_diff, DIFF_FUNCINFO);
1598        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
1599        const char *reverse = ecbdata->color_diff ? GIT_COLOR_REVERSE : "";
1600        static const char atat[2] = { '@', '@' };
1601        const char *cp, *ep;
1602        struct strbuf msgbuf = STRBUF_INIT;
1603        int org_len = len;
1604        int i = 1;
1605
1606        /*
1607         * As a hunk header must begin with "@@ -<old>, +<new> @@",
1608         * it always is at least 10 bytes long.
1609         */
1610        if (len < 10 ||
1611            memcmp(line, atat, 2) ||
1612            !(ep = memmem(line + 2, len - 2, atat, 2))) {
1613                emit_diff_symbol(ecbdata->opt,
1614                                 DIFF_SYMBOL_CONTEXT_MARKER, line, len, 0);
1615                return;
1616        }
1617        ep += 2; /* skip over @@ */
1618
1619        /* The hunk header in fraginfo color */
1620        if (ecbdata->opt->flags.dual_color_diffed_diffs)
1621                strbuf_addstr(&msgbuf, reverse);
1622        strbuf_addstr(&msgbuf, frag);
1623        strbuf_add(&msgbuf, line, ep - line);
1624        strbuf_addstr(&msgbuf, reset);
1625
1626        /*
1627         * trailing "\r\n"
1628         */
1629        for ( ; i < 3; i++)
1630                if (line[len - i] == '\r' || line[len - i] == '\n')
1631                        len--;
1632
1633        /* blank before the func header */
1634        for (cp = ep; ep - line < len; ep++)
1635                if (*ep != ' ' && *ep != '\t')
1636                        break;
1637        if (ep != cp) {
1638                strbuf_addstr(&msgbuf, context);
1639                strbuf_add(&msgbuf, cp, ep - cp);
1640                strbuf_addstr(&msgbuf, reset);
1641        }
1642
1643        if (ep < line + len) {
1644                strbuf_addstr(&msgbuf, func);
1645                strbuf_add(&msgbuf, ep, line + len - ep);
1646                strbuf_addstr(&msgbuf, reset);
1647        }
1648
1649        strbuf_add(&msgbuf, line + len, org_len - len);
1650        strbuf_complete_line(&msgbuf);
1651        emit_diff_symbol(ecbdata->opt,
1652                         DIFF_SYMBOL_CONTEXT_FRAGINFO, msgbuf.buf, msgbuf.len, 0);
1653        strbuf_release(&msgbuf);
1654}
1655
1656static struct diff_tempfile *claim_diff_tempfile(void) {
1657        int i;
1658        for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
1659                if (!diff_temp[i].name)
1660                        return diff_temp + i;
1661        BUG("diff is failing to clean up its tempfiles");
1662}
1663
1664static void remove_tempfile(void)
1665{
1666        int i;
1667        for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
1668                if (is_tempfile_active(diff_temp[i].tempfile))
1669                        delete_tempfile(&diff_temp[i].tempfile);
1670                diff_temp[i].name = NULL;
1671        }
1672}
1673
1674static void add_line_count(struct strbuf *out, int count)
1675{
1676        switch (count) {
1677        case 0:
1678                strbuf_addstr(out, "0,0");
1679                break;
1680        case 1:
1681                strbuf_addstr(out, "1");
1682                break;
1683        default:
1684                strbuf_addf(out, "1,%d", count);
1685                break;
1686        }
1687}
1688
1689static void emit_rewrite_lines(struct emit_callback *ecb,
1690                               int prefix, const char *data, int size)
1691{
1692        const char *endp = NULL;
1693        const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
1694
1695        while (0 < size) {
1696                int len;
1697
1698                endp = memchr(data, '\n', size);
1699                len = endp ? (endp - data + 1) : size;
1700                if (prefix != '+') {
1701                        ecb->lno_in_preimage++;
1702                        emit_del_line(reset, ecb, data, len);
1703                } else {
1704                        ecb->lno_in_postimage++;
1705                        emit_add_line(reset, ecb, data, len);
1706                }
1707                size -= len;
1708                data += len;
1709        }
1710        if (!endp)
1711                emit_diff_symbol(ecb->opt, DIFF_SYMBOL_NO_LF_EOF, NULL, 0, 0);
1712}
1713
1714static void emit_rewrite_diff(const char *name_a,
1715                              const char *name_b,
1716                              struct diff_filespec *one,
1717                              struct diff_filespec *two,
1718                              struct userdiff_driver *textconv_one,
1719                              struct userdiff_driver *textconv_two,
1720                              struct diff_options *o)
1721{
1722        int lc_a, lc_b;
1723        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
1724        const char *a_prefix, *b_prefix;
1725        char *data_one, *data_two;
1726        size_t size_one, size_two;
1727        struct emit_callback ecbdata;
1728        struct strbuf out = STRBUF_INIT;
1729
1730        if (diff_mnemonic_prefix && o->flags.reverse_diff) {
1731                a_prefix = o->b_prefix;
1732                b_prefix = o->a_prefix;
1733        } else {
1734                a_prefix = o->a_prefix;
1735                b_prefix = o->b_prefix;
1736        }
1737
1738        name_a += (*name_a == '/');
1739        name_b += (*name_b == '/');
1740
1741        strbuf_reset(&a_name);
1742        strbuf_reset(&b_name);
1743        quote_two_c_style(&a_name, a_prefix, name_a, 0);
1744        quote_two_c_style(&b_name, b_prefix, name_b, 0);
1745
1746        size_one = fill_textconv(o->repo, textconv_one, one, &data_one);
1747        size_two = fill_textconv(o->repo, textconv_two, two, &data_two);
1748
1749        memset(&ecbdata, 0, sizeof(ecbdata));
1750        ecbdata.color_diff = want_color(o->use_color);
1751        ecbdata.ws_rule = whitespace_rule(o->repo->index, name_b);
1752        ecbdata.opt = o;
1753        if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
1754                mmfile_t mf1, mf2;
1755                mf1.ptr = (char *)data_one;
1756                mf2.ptr = (char *)data_two;
1757                mf1.size = size_one;
1758                mf2.size = size_two;
1759                check_blank_at_eof(&mf1, &mf2, &ecbdata);
1760        }
1761        ecbdata.lno_in_preimage = 1;
1762        ecbdata.lno_in_postimage = 1;
1763
1764        lc_a = count_lines(data_one, size_one);
1765        lc_b = count_lines(data_two, size_two);
1766
1767        emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_MINUS,
1768                         a_name.buf, a_name.len, 0);
1769        emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_PLUS,
1770                         b_name.buf, b_name.len, 0);
1771
1772        strbuf_addstr(&out, "@@ -");
1773        if (!o->irreversible_delete)
1774                add_line_count(&out, lc_a);
1775        else
1776                strbuf_addstr(&out, "?,?");
1777        strbuf_addstr(&out, " +");
1778        add_line_count(&out, lc_b);
1779        strbuf_addstr(&out, " @@\n");
1780        emit_diff_symbol(o, DIFF_SYMBOL_REWRITE_DIFF, out.buf, out.len, 0);
1781        strbuf_release(&out);
1782
1783        if (lc_a && !o->irreversible_delete)
1784                emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
1785        if (lc_b)
1786                emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
1787        if (textconv_one)
1788                free((char *)data_one);
1789        if (textconv_two)
1790                free((char *)data_two);
1791}
1792
1793struct diff_words_buffer {
1794        mmfile_t text;
1795        unsigned long alloc;
1796        struct diff_words_orig {
1797                const char *begin, *end;
1798        } *orig;
1799        int orig_nr, orig_alloc;
1800};
1801
1802static void diff_words_append(char *line, unsigned long len,
1803                struct diff_words_buffer *buffer)
1804{
1805        ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
1806        line++;
1807        len--;
1808        memcpy(buffer->text.ptr + buffer->text.size, line, len);
1809        buffer->text.size += len;
1810        buffer->text.ptr[buffer->text.size] = '\0';
1811}
1812
1813struct diff_words_style_elem {
1814        const char *prefix;
1815        const char *suffix;
1816        const char *color; /* NULL; filled in by the setup code if
1817                            * color is enabled */
1818};
1819
1820struct diff_words_style {
1821        enum diff_words_type type;
1822        struct diff_words_style_elem new_word, old_word, ctx;
1823        const char *newline;
1824};
1825
1826static struct diff_words_style diff_words_styles[] = {
1827        { DIFF_WORDS_PORCELAIN, {"+", "\n"}, {"-", "\n"}, {" ", "\n"}, "~\n" },
1828        { DIFF_WORDS_PLAIN, {"{+", "+}"}, {"[-", "-]"}, {"", ""}, "\n" },
1829        { DIFF_WORDS_COLOR, {"", ""}, {"", ""}, {"", ""}, "\n" }
1830};
1831
1832struct diff_words_data {
1833        struct diff_words_buffer minus, plus;
1834        const char *current_plus;
1835        int last_minus;
1836        struct diff_options *opt;
1837        regex_t *word_regex;
1838        enum diff_words_type type;
1839        struct diff_words_style *style;
1840};
1841
1842static int fn_out_diff_words_write_helper(struct diff_options *o,
1843                                          struct diff_words_style_elem *st_el,
1844                                          const char *newline,
1845                                          size_t count, const char *buf)
1846{
1847        int print = 0;
1848        struct strbuf sb = STRBUF_INIT;
1849
1850        while (count) {
1851                char *p = memchr(buf, '\n', count);
1852                if (print)
1853                        strbuf_addstr(&sb, diff_line_prefix(o));
1854
1855                if (p != buf) {
1856                        const char *reset = st_el->color && *st_el->color ?
1857                                            GIT_COLOR_RESET : NULL;
1858                        if (st_el->color && *st_el->color)
1859                                strbuf_addstr(&sb, st_el->color);
1860                        strbuf_addstr(&sb, st_el->prefix);
1861                        strbuf_add(&sb, buf, p ? p - buf : count);
1862                        strbuf_addstr(&sb, st_el->suffix);
1863                        if (reset)
1864                                strbuf_addstr(&sb, reset);
1865                }
1866                if (!p)
1867                        goto out;
1868
1869                strbuf_addstr(&sb, newline);
1870                count -= p + 1 - buf;
1871                buf = p + 1;
1872                print = 1;
1873                if (count) {
1874                        emit_diff_symbol(o, DIFF_SYMBOL_WORD_DIFF,
1875                                         sb.buf, sb.len, 0);
1876                        strbuf_reset(&sb);
1877                }
1878        }
1879
1880out:
1881        if (sb.len)
1882                emit_diff_symbol(o, DIFF_SYMBOL_WORD_DIFF,
1883                                 sb.buf, sb.len, 0);
1884        strbuf_release(&sb);
1885        return 0;
1886}
1887
1888/*
1889 * '--color-words' algorithm can be described as:
1890 *
1891 *   1. collect the minus/plus lines of a diff hunk, divided into
1892 *      minus-lines and plus-lines;
1893 *
1894 *   2. break both minus-lines and plus-lines into words and
1895 *      place them into two mmfile_t with one word for each line;
1896 *
1897 *   3. use xdiff to run diff on the two mmfile_t to get the words level diff;
1898 *
1899 * And for the common parts of the both file, we output the plus side text.
1900 * diff_words->current_plus is used to trace the current position of the plus file
1901 * which printed. diff_words->last_minus is used to trace the last minus word
1902 * printed.
1903 *
1904 * For '--graph' to work with '--color-words', we need to output the graph prefix
1905 * on each line of color words output. Generally, there are two conditions on
1906 * which we should output the prefix.
1907 *
1908 *   1. diff_words->last_minus == 0 &&
1909 *      diff_words->current_plus == diff_words->plus.text.ptr
1910 *
1911 *      that is: the plus text must start as a new line, and if there is no minus
1912 *      word printed, a graph prefix must be printed.
1913 *
1914 *   2. diff_words->current_plus > diff_words->plus.text.ptr &&
1915 *      *(diff_words->current_plus - 1) == '\n'
1916 *
1917 *      that is: a graph prefix must be printed following a '\n'
1918 */
1919static int color_words_output_graph_prefix(struct diff_words_data *diff_words)
1920{
1921        if ((diff_words->last_minus == 0 &&
1922                diff_words->current_plus == diff_words->plus.text.ptr) ||
1923                (diff_words->current_plus > diff_words->plus.text.ptr &&
1924                *(diff_words->current_plus - 1) == '\n')) {
1925                return 1;
1926        } else {
1927                return 0;
1928        }
1929}
1930
1931static void fn_out_diff_words_aux(void *priv,
1932                                  long minus_first, long minus_len,
1933                                  long plus_first, long plus_len,
1934                                  const char *func, long funclen)
1935{
1936        struct diff_words_data *diff_words = priv;
1937        struct diff_words_style *style = diff_words->style;
1938        const char *minus_begin, *minus_end, *plus_begin, *plus_end;
1939        struct diff_options *opt = diff_words->opt;
1940        const char *line_prefix;
1941
1942        assert(opt);
1943        line_prefix = diff_line_prefix(opt);
1944
1945        /* POSIX requires that first be decremented by one if len == 0... */
1946        if (minus_len) {
1947                minus_begin = diff_words->minus.orig[minus_first].begin;
1948                minus_end =
1949                        diff_words->minus.orig[minus_first + minus_len - 1].end;
1950        } else
1951                minus_begin = minus_end =
1952                        diff_words->minus.orig[minus_first].end;
1953
1954        if (plus_len) {
1955                plus_begin = diff_words->plus.orig[plus_first].begin;
1956                plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
1957        } else
1958                plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
1959
1960        if (color_words_output_graph_prefix(diff_words)) {
1961                fputs(line_prefix, diff_words->opt->file);
1962        }
1963        if (diff_words->current_plus != plus_begin) {
1964                fn_out_diff_words_write_helper(diff_words->opt,
1965                                &style->ctx, style->newline,
1966                                plus_begin - diff_words->current_plus,
1967                                diff_words->current_plus);
1968        }
1969        if (minus_begin != minus_end) {
1970                fn_out_diff_words_write_helper(diff_words->opt,
1971                                &style->old_word, style->newline,
1972                                minus_end - minus_begin, minus_begin);
1973        }
1974        if (plus_begin != plus_end) {
1975                fn_out_diff_words_write_helper(diff_words->opt,
1976                                &style->new_word, style->newline,
1977                                plus_end - plus_begin, plus_begin);
1978        }
1979
1980        diff_words->current_plus = plus_end;
1981        diff_words->last_minus = minus_first;
1982}
1983
1984/* This function starts looking at *begin, and returns 0 iff a word was found. */
1985static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
1986                int *begin, int *end)
1987{
1988        if (word_regex && *begin < buffer->size) {
1989                regmatch_t match[1];
1990                if (!regexec_buf(word_regex, buffer->ptr + *begin,
1991                                 buffer->size - *begin, 1, match, 0)) {
1992                        char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
1993                                        '\n', match[0].rm_eo - match[0].rm_so);
1994                        *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
1995                        *begin += match[0].rm_so;
1996                        return *begin >= *end;
1997                }
1998                return -1;
1999        }
2000
2001        /* find the next word */
2002        while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
2003                (*begin)++;
2004        if (*begin >= buffer->size)
2005                return -1;
2006
2007        /* find the end of the word */
2008        *end = *begin + 1;
2009        while (*end < buffer->size && !isspace(buffer->ptr[*end]))
2010                (*end)++;
2011
2012        return 0;
2013}
2014
2015/*
2016 * This function splits the words in buffer->text, stores the list with
2017 * newline separator into out, and saves the offsets of the original words
2018 * in buffer->orig.
2019 */
2020static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
2021                regex_t *word_regex)
2022{
2023        int i, j;
2024        long alloc = 0;
2025
2026        out->size = 0;
2027        out->ptr = NULL;
2028
2029        /* fake an empty "0th" word */
2030        ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
2031        buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
2032        buffer->orig_nr = 1;
2033
2034        for (i = 0; i < buffer->text.size; i++) {
2035                if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
2036                        return;
2037
2038                /* store original boundaries */
2039                ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
2040                                buffer->orig_alloc);
2041                buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
2042                buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
2043                buffer->orig_nr++;
2044
2045                /* store one word */
2046                ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
2047                memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
2048                out->ptr[out->size + j - i] = '\n';
2049                out->size += j - i + 1;
2050
2051                i = j - 1;
2052        }
2053}
2054
2055/* this executes the word diff on the accumulated buffers */
2056static void diff_words_show(struct diff_words_data *diff_words)
2057{
2058        xpparam_t xpp;
2059        xdemitconf_t xecfg;
2060        mmfile_t minus, plus;
2061        struct diff_words_style *style = diff_words->style;
2062
2063        struct diff_options *opt = diff_words->opt;
2064        const char *line_prefix;
2065
2066        assert(opt);
2067        line_prefix = diff_line_prefix(opt);
2068
2069        /* special case: only removal */
2070        if (!diff_words->plus.text.size) {
2071                emit_diff_symbol(diff_words->opt, DIFF_SYMBOL_WORD_DIFF,
2072                                 line_prefix, strlen(line_prefix), 0);
2073                fn_out_diff_words_write_helper(diff_words->opt,
2074                        &style->old_word, style->newline,
2075                        diff_words->minus.text.size,
2076                        diff_words->minus.text.ptr);
2077                diff_words->minus.text.size = 0;
2078                return;
2079        }
2080
2081        diff_words->current_plus = diff_words->plus.text.ptr;
2082        diff_words->last_minus = 0;
2083
2084        memset(&xpp, 0, sizeof(xpp));
2085        memset(&xecfg, 0, sizeof(xecfg));
2086        diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
2087        diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
2088        xpp.flags = 0;
2089        /* as only the hunk header will be parsed, we need a 0-context */
2090        xecfg.ctxlen = 0;
2091        if (xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, NULL,
2092                          diff_words, &xpp, &xecfg))
2093                die("unable to generate word diff");
2094        free(minus.ptr);
2095        free(plus.ptr);
2096        if (diff_words->current_plus != diff_words->plus.text.ptr +
2097                        diff_words->plus.text.size) {
2098                if (color_words_output_graph_prefix(diff_words))
2099                        emit_diff_symbol(diff_words->opt, DIFF_SYMBOL_WORD_DIFF,
2100                                         line_prefix, strlen(line_prefix), 0);
2101                fn_out_diff_words_write_helper(diff_words->opt,
2102                        &style->ctx, style->newline,
2103                        diff_words->plus.text.ptr + diff_words->plus.text.size
2104                        - diff_words->current_plus, diff_words->current_plus);
2105        }
2106        diff_words->minus.text.size = diff_words->plus.text.size = 0;
2107}
2108
2109/* In "color-words" mode, show word-diff of words accumulated in the buffer */
2110static void diff_words_flush(struct emit_callback *ecbdata)
2111{
2112        struct diff_options *wo = ecbdata->diff_words->opt;
2113
2114        if (ecbdata->diff_words->minus.text.size ||
2115            ecbdata->diff_words->plus.text.size)
2116                diff_words_show(ecbdata->diff_words);
2117
2118        if (wo->emitted_symbols) {
2119                struct diff_options *o = ecbdata->opt;
2120                struct emitted_diff_symbols *wol = wo->emitted_symbols;
2121                int i;
2122
2123                /*
2124                 * NEEDSWORK:
2125                 * Instead of appending each, concat all words to a line?
2126                 */
2127                for (i = 0; i < wol->nr; i++)
2128                        append_emitted_diff_symbol(o, &wol->buf[i]);
2129
2130                for (i = 0; i < wol->nr; i++)
2131                        free((void *)wol->buf[i].line);
2132
2133                wol->nr = 0;
2134        }
2135}
2136
2137static void diff_filespec_load_driver(struct diff_filespec *one,
2138                                      struct index_state *istate)
2139{
2140        /* Use already-loaded driver */
2141        if (one->driver)
2142                return;
2143
2144        if (S_ISREG(one->mode))
2145                one->driver = userdiff_find_by_path(istate, one->path);
2146
2147        /* Fallback to default settings */
2148        if (!one->driver)
2149                one->driver = userdiff_find_by_name("default");
2150}
2151
2152static const char *userdiff_word_regex(struct diff_filespec *one,
2153                                       struct index_state *istate)
2154{
2155        diff_filespec_load_driver(one, istate);
2156        return one->driver->word_regex;
2157}
2158
2159static void init_diff_words_data(struct emit_callback *ecbdata,
2160                                 struct diff_options *orig_opts,
2161                                 struct diff_filespec *one,
2162                                 struct diff_filespec *two)
2163{
2164        int i;
2165        struct diff_options *o = xmalloc(sizeof(struct diff_options));
2166        memcpy(o, orig_opts, sizeof(struct diff_options));
2167
2168        ecbdata->diff_words =
2169                xcalloc(1, sizeof(struct diff_words_data));
2170        ecbdata->diff_words->type = o->word_diff;
2171        ecbdata->diff_words->opt = o;
2172
2173        if (orig_opts->emitted_symbols)
2174                o->emitted_symbols =
2175                        xcalloc(1, sizeof(struct emitted_diff_symbols));
2176
2177        if (!o->word_regex)
2178                o->word_regex = userdiff_word_regex(one, o->repo->index);
2179        if (!o->word_regex)
2180                o->word_regex = userdiff_word_regex(two, o->repo->index);
2181        if (!o->word_regex)
2182                o->word_regex = diff_word_regex_cfg;
2183        if (o->word_regex) {
2184                ecbdata->diff_words->word_regex = (regex_t *)
2185                        xmalloc(sizeof(regex_t));
2186                if (regcomp(ecbdata->diff_words->word_regex,
2187                            o->word_regex,
2188                            REG_EXTENDED | REG_NEWLINE))
2189                        die("invalid regular expression: %s",
2190                            o->word_regex);
2191        }
2192        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
2193                if (o->word_diff == diff_words_styles[i].type) {
2194                        ecbdata->diff_words->style =
2195                                &diff_words_styles[i];
2196                        break;
2197                }
2198        }
2199        if (want_color(o->use_color)) {
2200                struct diff_words_style *st = ecbdata->diff_words->style;
2201                st->old_word.color = diff_get_color_opt(o, DIFF_FILE_OLD);
2202                st->new_word.color = diff_get_color_opt(o, DIFF_FILE_NEW);
2203                st->ctx.color = diff_get_color_opt(o, DIFF_CONTEXT);
2204        }
2205}
2206
2207static void free_diff_words_data(struct emit_callback *ecbdata)
2208{
2209        if (ecbdata->diff_words) {
2210                diff_words_flush(ecbdata);
2211                free (ecbdata->diff_words->opt->emitted_symbols);
2212                free (ecbdata->diff_words->opt);
2213                free (ecbdata->diff_words->minus.text.ptr);
2214                free (ecbdata->diff_words->minus.orig);
2215                free (ecbdata->diff_words->plus.text.ptr);
2216                free (ecbdata->diff_words->plus.orig);
2217                if (ecbdata->diff_words->word_regex) {
2218                        regfree(ecbdata->diff_words->word_regex);
2219                        free(ecbdata->diff_words->word_regex);
2220                }
2221                FREE_AND_NULL(ecbdata->diff_words);
2222        }
2223}
2224
2225const char *diff_get_color(int diff_use_color, enum color_diff ix)
2226{
2227        if (want_color(diff_use_color))
2228                return diff_colors[ix];
2229        return "";
2230}
2231
2232const char *diff_line_prefix(struct diff_options *opt)
2233{
2234        struct strbuf *msgbuf;
2235        if (!opt->output_prefix)
2236                return "";
2237
2238        msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
2239        return msgbuf->buf;
2240}
2241
2242static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
2243{
2244        const char *cp;
2245        unsigned long allot;
2246        size_t l = len;
2247
2248        cp = line;
2249        allot = l;
2250        while (0 < l) {
2251                (void) utf8_width(&cp, &l);
2252                if (!cp)
2253                        break; /* truncated in the middle? */
2254        }
2255        return allot - l;
2256}
2257
2258static void find_lno(const char *line, struct emit_callback *ecbdata)
2259{
2260        const char *p;
2261        ecbdata->lno_in_preimage = 0;
2262        ecbdata->lno_in_postimage = 0;
2263        p = strchr(line, '-');
2264        if (!p)
2265                return; /* cannot happen */
2266        ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
2267        p = strchr(p, '+');
2268        if (!p)
2269                return; /* cannot happen */
2270        ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
2271}
2272
2273static void fn_out_consume(void *priv, char *line, unsigned long len)
2274{
2275        struct emit_callback *ecbdata = priv;
2276        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
2277        struct diff_options *o = ecbdata->opt;
2278
2279        o->found_changes = 1;
2280
2281        if (ecbdata->header) {
2282                emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
2283                                 ecbdata->header->buf, ecbdata->header->len, 0);
2284                strbuf_reset(ecbdata->header);
2285                ecbdata->header = NULL;
2286        }
2287
2288        if (ecbdata->label_path[0]) {
2289                emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_MINUS,
2290                                 ecbdata->label_path[0],
2291                                 strlen(ecbdata->label_path[0]), 0);
2292                emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_PLUS,
2293                                 ecbdata->label_path[1],
2294                                 strlen(ecbdata->label_path[1]), 0);
2295                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
2296        }
2297
2298        if (diff_suppress_blank_empty
2299            && len == 2 && line[0] == ' ' && line[1] == '\n') {
2300                line[0] = '\n';
2301                len = 1;
2302        }
2303
2304        if (line[0] == '@') {
2305                if (ecbdata->diff_words)
2306                        diff_words_flush(ecbdata);
2307                len = sane_truncate_line(ecbdata, line, len);
2308                find_lno(line, ecbdata);
2309                emit_hunk_header(ecbdata, line, len);
2310                return;
2311        }
2312
2313        if (ecbdata->diff_words) {
2314                enum diff_symbol s =
2315                        ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN ?
2316                        DIFF_SYMBOL_WORDS_PORCELAIN : DIFF_SYMBOL_WORDS;
2317                if (line[0] == '-') {
2318                        diff_words_append(line, len,
2319                                          &ecbdata->diff_words->minus);
2320                        return;
2321                } else if (line[0] == '+') {
2322                        diff_words_append(line, len,
2323                                          &ecbdata->diff_words->plus);
2324                        return;
2325                } else if (starts_with(line, "\\ ")) {
2326                        /*
2327                         * Eat the "no newline at eof" marker as if we
2328                         * saw a "+" or "-" line with nothing on it,
2329                         * and return without diff_words_flush() to
2330                         * defer processing. If this is the end of
2331                         * preimage, more "+" lines may come after it.
2332                         */
2333                        return;
2334                }
2335                diff_words_flush(ecbdata);
2336                emit_diff_symbol(o, s, line, len, 0);
2337                return;
2338        }
2339
2340        switch (line[0]) {
2341        case '+':
2342                ecbdata->lno_in_postimage++;
2343                emit_add_line(reset, ecbdata, line + 1, len - 1);
2344                break;
2345        case '-':
2346                ecbdata->lno_in_preimage++;
2347                emit_del_line(reset, ecbdata, line + 1, len - 1);
2348                break;
2349        case ' ':
2350                ecbdata->lno_in_postimage++;
2351                ecbdata->lno_in_preimage++;
2352                emit_context_line(reset, ecbdata, line + 1, len - 1);
2353                break;
2354        default:
2355                /* incomplete line at the end */
2356                ecbdata->lno_in_preimage++;
2357                emit_diff_symbol(o, DIFF_SYMBOL_CONTEXT_INCOMPLETE,
2358                                 line, len, 0);
2359                break;
2360        }
2361}
2362
2363static void pprint_rename(struct strbuf *name, const char *a, const char *b)
2364{
2365        const char *old_name = a;
2366        const char *new_name = b;
2367        int pfx_length, sfx_length;
2368        int pfx_adjust_for_slash;
2369        int len_a = strlen(a);
2370        int len_b = strlen(b);
2371        int a_midlen, b_midlen;
2372        int qlen_a = quote_c_style(a, NULL, NULL, 0);
2373        int qlen_b = quote_c_style(b, NULL, NULL, 0);
2374
2375        if (qlen_a || qlen_b) {
2376                quote_c_style(a, name, NULL, 0);
2377                strbuf_addstr(name, " => ");
2378                quote_c_style(b, name, NULL, 0);
2379                return;
2380        }
2381
2382        /* Find common prefix */
2383        pfx_length = 0;
2384        while (*old_name && *new_name && *old_name == *new_name) {
2385                if (*old_name == '/')
2386                        pfx_length = old_name - a + 1;
2387                old_name++;
2388                new_name++;
2389        }
2390
2391        /* Find common suffix */
2392        old_name = a + len_a;
2393        new_name = b + len_b;
2394        sfx_length = 0;
2395        /*
2396         * If there is a common prefix, it must end in a slash.  In
2397         * that case we let this loop run 1 into the prefix to see the
2398         * same slash.
2399         *
2400         * If there is no common prefix, we cannot do this as it would
2401         * underrun the input strings.
2402         */
2403        pfx_adjust_for_slash = (pfx_length ? 1 : 0);
2404        while (a + pfx_length - pfx_adjust_for_slash <= old_name &&
2405               b + pfx_length - pfx_adjust_for_slash <= new_name &&
2406               *old_name == *new_name) {
2407                if (*old_name == '/')
2408                        sfx_length = len_a - (old_name - a);
2409                old_name--;
2410                new_name--;
2411        }
2412
2413        /*
2414         * pfx{mid-a => mid-b}sfx
2415         * {pfx-a => pfx-b}sfx
2416         * pfx{sfx-a => sfx-b}
2417         * name-a => name-b
2418         */
2419        a_midlen = len_a - pfx_length - sfx_length;
2420        b_midlen = len_b - pfx_length - sfx_length;
2421        if (a_midlen < 0)
2422                a_midlen = 0;
2423        if (b_midlen < 0)
2424                b_midlen = 0;
2425
2426        strbuf_grow(name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
2427        if (pfx_length + sfx_length) {
2428                strbuf_add(name, a, pfx_length);
2429                strbuf_addch(name, '{');
2430        }
2431        strbuf_add(name, a + pfx_length, a_midlen);
2432        strbuf_addstr(name, " => ");
2433        strbuf_add(name, b + pfx_length, b_midlen);
2434        if (pfx_length + sfx_length) {
2435                strbuf_addch(name, '}');
2436                strbuf_add(name, a + len_a - sfx_length, sfx_length);
2437        }
2438}
2439
2440struct diffstat_t {
2441        int nr;
2442        int alloc;
2443        struct diffstat_file {
2444                char *from_name;
2445                char *name;
2446                char *print_name;
2447                const char *comments;
2448                unsigned is_unmerged:1;
2449                unsigned is_binary:1;
2450                unsigned is_renamed:1;
2451                unsigned is_interesting:1;
2452                uintmax_t added, deleted;
2453        } **files;
2454};
2455
2456static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
2457                                          const char *name_a,
2458                                          const char *name_b)
2459{
2460        struct diffstat_file *x;
2461        x = xcalloc(1, sizeof(*x));
2462        ALLOC_GROW(diffstat->files, diffstat->nr + 1, diffstat->alloc);
2463        diffstat->files[diffstat->nr++] = x;
2464        if (name_b) {
2465                x->from_name = xstrdup(name_a);
2466                x->name = xstrdup(name_b);
2467                x->is_renamed = 1;
2468        }
2469        else {
2470                x->from_name = NULL;
2471                x->name = xstrdup(name_a);
2472        }
2473        return x;
2474}
2475
2476static void diffstat_consume(void *priv, char *line, unsigned long len)
2477{
2478        struct diffstat_t *diffstat = priv;
2479        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
2480
2481        if (line[0] == '+')
2482                x->added++;
2483        else if (line[0] == '-')
2484                x->deleted++;
2485}
2486
2487const char mime_boundary_leader[] = "------------";
2488
2489static int scale_linear(int it, int width, int max_change)
2490{
2491        if (!it)
2492                return 0;
2493        /*
2494         * make sure that at least one '-' or '+' is printed if
2495         * there is any change to this path. The easiest way is to
2496         * scale linearly as if the alloted width is one column shorter
2497         * than it is, and then add 1 to the result.
2498         */
2499        return 1 + (it * (width - 1) / max_change);
2500}
2501
2502static void show_graph(struct strbuf *out, char ch, int cnt,
2503                       const char *set, const char *reset)
2504{
2505        if (cnt <= 0)
2506                return;
2507        strbuf_addstr(out, set);
2508        strbuf_addchars(out, ch, cnt);
2509        strbuf_addstr(out, reset);
2510}
2511
2512static void fill_print_name(struct diffstat_file *file)
2513{
2514        struct strbuf pname = STRBUF_INIT;
2515
2516        if (file->print_name)
2517                return;
2518
2519        if (file->is_renamed)
2520                pprint_rename(&pname, file->from_name, file->name);
2521        else
2522                quote_c_style(file->name, &pname, NULL, 0);
2523
2524        if (file->comments)
2525                strbuf_addf(&pname, " (%s)", file->comments);
2526
2527        file->print_name = strbuf_detach(&pname, NULL);
2528}
2529
2530static void print_stat_summary_inserts_deletes(struct diff_options *options,
2531                int files, int insertions, int deletions)
2532{
2533        struct strbuf sb = STRBUF_INIT;
2534
2535        if (!files) {
2536                assert(insertions == 0 && deletions == 0);
2537                emit_diff_symbol(options, DIFF_SYMBOL_STATS_SUMMARY_NO_FILES,
2538                                 NULL, 0, 0);
2539                return;
2540        }
2541
2542        strbuf_addf(&sb,
2543                    (files == 1) ? " %d file changed" : " %d files changed",
2544                    files);
2545
2546        /*
2547         * For binary diff, the caller may want to print "x files
2548         * changed" with insertions == 0 && deletions == 0.
2549         *
2550         * Not omitting "0 insertions(+), 0 deletions(-)" in this case
2551         * is probably less confusing (i.e skip over "2 files changed
2552         * but nothing about added/removed lines? Is this a bug in Git?").
2553         */
2554        if (insertions || deletions == 0) {
2555                strbuf_addf(&sb,
2556                            (insertions == 1) ? ", %d insertion(+)" : ", %d insertions(+)",
2557                            insertions);
2558        }
2559
2560        if (deletions || insertions == 0) {
2561                strbuf_addf(&sb,
2562                            (deletions == 1) ? ", %d deletion(-)" : ", %d deletions(-)",
2563                            deletions);
2564        }
2565        strbuf_addch(&sb, '\n');
2566        emit_diff_symbol(options, DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES,
2567                         sb.buf, sb.len, 0);
2568        strbuf_release(&sb);
2569}
2570
2571void print_stat_summary(FILE *fp, int files,
2572                        int insertions, int deletions)
2573{
2574        struct diff_options o;
2575        memset(&o, 0, sizeof(o));
2576        o.file = fp;
2577
2578        print_stat_summary_inserts_deletes(&o, files, insertions, deletions);
2579}
2580
2581static void show_stats(struct diffstat_t *data, struct diff_options *options)
2582{
2583        int i, len, add, del, adds = 0, dels = 0;
2584        uintmax_t max_change = 0, max_len = 0;
2585        int total_files = data->nr, count;
2586        int width, name_width, graph_width, number_width = 0, bin_width = 0;
2587        const char *reset, *add_c, *del_c;
2588        int extra_shown = 0;
2589        const char *line_prefix = diff_line_prefix(options);
2590        struct strbuf out = STRBUF_INIT;
2591
2592        if (data->nr == 0)
2593                return;
2594
2595        count = options->stat_count ? options->stat_count : data->nr;
2596
2597        reset = diff_get_color_opt(options, DIFF_RESET);
2598        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
2599        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
2600
2601        /*
2602         * Find the longest filename and max number of changes
2603         */
2604        for (i = 0; (i < count) && (i < data->nr); i++) {
2605                struct diffstat_file *file = data->files[i];
2606                uintmax_t change = file->added + file->deleted;
2607
2608                if (!file->is_interesting && (change == 0)) {
2609                        count++; /* not shown == room for one more */
2610                        continue;
2611                }
2612                fill_print_name(file);
2613                len = strlen(file->print_name);
2614                if (max_len < len)
2615                        max_len = len;
2616
2617                if (file->is_unmerged) {
2618                        /* "Unmerged" is 8 characters */
2619                        bin_width = bin_width < 8 ? 8 : bin_width;
2620                        continue;
2621                }
2622                if (file->is_binary) {
2623                        /* "Bin XXX -> YYY bytes" */
2624                        int w = 14 + decimal_width(file->added)
2625                                + decimal_width(file->deleted);
2626                        bin_width = bin_width < w ? w : bin_width;
2627                        /* Display change counts aligned with "Bin" */
2628                        number_width = 3;
2629                        continue;
2630                }
2631
2632                if (max_change < change)
2633                        max_change = change;
2634        }
2635        count = i; /* where we can stop scanning in data->files[] */
2636
2637        /*
2638         * We have width = stat_width or term_columns() columns total.
2639         * We want a maximum of min(max_len, stat_name_width) for the name part.
2640         * We want a maximum of min(max_change, stat_graph_width) for the +- part.
2641         * We also need 1 for " " and 4 + decimal_width(max_change)
2642         * for " | NNNN " and one the empty column at the end, altogether
2643         * 6 + decimal_width(max_change).
2644         *
2645         * If there's not enough space, we will use the smaller of
2646         * stat_name_width (if set) and 5/8*width for the filename,
2647         * and the rest for constant elements + graph part, but no more
2648         * than stat_graph_width for the graph part.
2649         * (5/8 gives 50 for filename and 30 for the constant parts + graph
2650         * for the standard terminal size).
2651         *
2652         * In other words: stat_width limits the maximum width, and
2653         * stat_name_width fixes the maximum width of the filename,
2654         * and is also used to divide available columns if there
2655         * aren't enough.
2656         *
2657         * Binary files are displayed with "Bin XXX -> YYY bytes"
2658         * instead of the change count and graph. This part is treated
2659         * similarly to the graph part, except that it is not
2660         * "scaled". If total width is too small to accommodate the
2661         * guaranteed minimum width of the filename part and the
2662         * separators and this message, this message will "overflow"
2663         * making the line longer than the maximum width.
2664         */
2665
2666        if (options->stat_width == -1)
2667                width = term_columns() - strlen(line_prefix);
2668        else
2669                width = options->stat_width ? options->stat_width : 80;
2670        number_width = decimal_width(max_change) > number_width ?
2671                decimal_width(max_change) : number_width;
2672
2673        if (options->stat_graph_width == -1)
2674                options->stat_graph_width = diff_stat_graph_width;
2675
2676        /*
2677         * Guarantee 3/8*16==6 for the graph part
2678         * and 5/8*16==10 for the filename part
2679         */
2680        if (width < 16 + 6 + number_width)
2681                width = 16 + 6 + number_width;
2682
2683        /*
2684         * First assign sizes that are wanted, ignoring available width.
2685         * strlen("Bin XXX -> YYY bytes") == bin_width, and the part
2686         * starting from "XXX" should fit in graph_width.
2687         */
2688        graph_width = max_change + 4 > bin_width ? max_change : bin_width - 4;
2689        if (options->stat_graph_width &&
2690            options->stat_graph_width < graph_width)
2691                graph_width = options->stat_graph_width;
2692
2693        name_width = (options->stat_name_width > 0 &&
2694                      options->stat_name_width < max_len) ?
2695                options->stat_name_width : max_len;
2696
2697        /*
2698         * Adjust adjustable widths not to exceed maximum width
2699         */
2700        if (name_width + number_width + 6 + graph_width > width) {
2701                if (graph_width > width * 3/8 - number_width - 6) {
2702                        graph_width = width * 3/8 - number_width - 6;
2703                        if (graph_width < 6)
2704                                graph_width = 6;
2705                }
2706
2707                if (options->stat_graph_width &&
2708                    graph_width > options->stat_graph_width)
2709                        graph_width = options->stat_graph_width;
2710                if (name_width > width - number_width - 6 - graph_width)
2711                        name_width = width - number_width - 6 - graph_width;
2712                else
2713                        graph_width = width - number_width - 6 - name_width;
2714        }
2715
2716        /*
2717         * From here name_width is the width of the name area,
2718         * and graph_width is the width of the graph area.
2719         * max_change is used to scale graph properly.
2720         */
2721        for (i = 0; i < count; i++) {
2722                const char *prefix = "";
2723                struct diffstat_file *file = data->files[i];
2724                char *name = file->print_name;
2725                uintmax_t added = file->added;
2726                uintmax_t deleted = file->deleted;
2727                int name_len;
2728
2729                if (!file->is_interesting && (added + deleted == 0))
2730                        continue;
2731
2732                /*
2733                 * "scale" the filename
2734                 */
2735                len = name_width;
2736                name_len = strlen(name);
2737                if (name_width < name_len) {
2738                        char *slash;
2739                        prefix = "...";
2740                        len -= 3;
2741                        name += name_len - len;
2742                        slash = strchr(name, '/');
2743                        if (slash)
2744                                name = slash;
2745                }
2746
2747                if (file->is_binary) {
2748                        strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2749                        strbuf_addf(&out, " %*s", number_width, "Bin");
2750                        if (!added && !deleted) {
2751                                strbuf_addch(&out, '\n');
2752                                emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2753                                                 out.buf, out.len, 0);
2754                                strbuf_reset(&out);
2755                                continue;
2756                        }
2757                        strbuf_addf(&out, " %s%"PRIuMAX"%s",
2758                                del_c, deleted, reset);
2759                        strbuf_addstr(&out, " -> ");
2760                        strbuf_addf(&out, "%s%"PRIuMAX"%s",
2761                                add_c, added, reset);
2762                        strbuf_addstr(&out, " bytes\n");
2763                        emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2764                                         out.buf, out.len, 0);
2765                        strbuf_reset(&out);
2766                        continue;
2767                }
2768                else if (file->is_unmerged) {
2769                        strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2770                        strbuf_addstr(&out, " Unmerged\n");
2771                        emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2772                                         out.buf, out.len, 0);
2773                        strbuf_reset(&out);
2774                        continue;
2775                }
2776
2777                /*
2778                 * scale the add/delete
2779                 */
2780                add = added;
2781                del = deleted;
2782
2783                if (graph_width <= max_change) {
2784                        int total = scale_linear(add + del, graph_width, max_change);
2785                        if (total < 2 && add && del)
2786                                /* width >= 2 due to the sanity check */
2787                                total = 2;
2788                        if (add < del) {
2789                                add = scale_linear(add, graph_width, max_change);
2790                                del = total - add;
2791                        } else {
2792                                del = scale_linear(del, graph_width, max_change);
2793                                add = total - del;
2794                        }
2795                }
2796                strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2797                strbuf_addf(&out, " %*"PRIuMAX"%s",
2798                        number_width, added + deleted,
2799                        added + deleted ? " " : "");
2800                show_graph(&out, '+', add, add_c, reset);
2801                show_graph(&out, '-', del, del_c, reset);
2802                strbuf_addch(&out, '\n');
2803                emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2804                                 out.buf, out.len, 0);
2805                strbuf_reset(&out);
2806        }
2807
2808        for (i = 0; i < data->nr; i++) {
2809                struct diffstat_file *file = data->files[i];
2810                uintmax_t added = file->added;
2811                uintmax_t deleted = file->deleted;
2812
2813                if (file->is_unmerged ||
2814                    (!file->is_interesting && (added + deleted == 0))) {
2815                        total_files--;
2816                        continue;
2817                }
2818
2819                if (!file->is_binary) {
2820                        adds += added;
2821                        dels += deleted;
2822                }
2823                if (i < count)
2824                        continue;
2825                if (!extra_shown)
2826                        emit_diff_symbol(options,
2827                                         DIFF_SYMBOL_STATS_SUMMARY_ABBREV,
2828                                         NULL, 0, 0);
2829                extra_shown = 1;
2830        }
2831
2832        print_stat_summary_inserts_deletes(options, total_files, adds, dels);
2833        strbuf_release(&out);
2834}
2835
2836static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
2837{
2838        int i, adds = 0, dels = 0, total_files = data->nr;
2839
2840        if (data->nr == 0)
2841                return;
2842
2843        for (i = 0; i < data->nr; i++) {
2844                int added = data->files[i]->added;
2845                int deleted = data->files[i]->deleted;
2846
2847                if (data->files[i]->is_unmerged ||
2848                    (!data->files[i]->is_interesting && (added + deleted == 0))) {
2849                        total_files--;
2850                } else if (!data->files[i]->is_binary) { /* don't count bytes */
2851                        adds += added;
2852                        dels += deleted;
2853                }
2854        }
2855        print_stat_summary_inserts_deletes(options, total_files, adds, dels);
2856}
2857
2858static void show_numstat(struct diffstat_t *data, struct diff_options *options)
2859{
2860        int i;
2861
2862        if (data->nr == 0)
2863                return;
2864
2865        for (i = 0; i < data->nr; i++) {
2866                struct diffstat_file *file = data->files[i];
2867
2868                fprintf(options->file, "%s", diff_line_prefix(options));
2869
2870                if (file->is_binary)
2871                        fprintf(options->file, "-\t-\t");
2872                else
2873                        fprintf(options->file,
2874                                "%"PRIuMAX"\t%"PRIuMAX"\t",
2875                                file->added, file->deleted);
2876                if (options->line_termination) {
2877                        fill_print_name(file);
2878                        if (!file->is_renamed)
2879                                write_name_quoted(file->name, options->file,
2880                                                  options->line_termination);
2881                        else {
2882                                fputs(file->print_name, options->file);
2883                                putc(options->line_termination, options->file);
2884                        }
2885                } else {
2886                        if (file->is_renamed) {
2887                                putc('\0', options->file);
2888                                write_name_quoted(file->from_name, options->file, '\0');
2889                        }
2890                        write_name_quoted(file->name, options->file, '\0');
2891                }
2892        }
2893}
2894
2895struct dirstat_file {
2896        const char *name;
2897        unsigned long changed;
2898};
2899
2900struct dirstat_dir {
2901        struct dirstat_file *files;
2902        int alloc, nr, permille, cumulative;
2903};
2904
2905static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
2906                unsigned long changed, const char *base, int baselen)
2907{
2908        unsigned long sum_changes = 0;
2909        unsigned int sources = 0;
2910        const char *line_prefix = diff_line_prefix(opt);
2911
2912        while (dir->nr) {
2913                struct dirstat_file *f = dir->files;
2914                int namelen = strlen(f->name);
2915                unsigned long changes;
2916                char *slash;
2917
2918                if (namelen < baselen)
2919                        break;
2920                if (memcmp(f->name, base, baselen))
2921                        break;
2922                slash = strchr(f->name + baselen, '/');
2923                if (slash) {
2924                        int newbaselen = slash + 1 - f->name;
2925                        changes = gather_dirstat(opt, dir, changed, f->name, newbaselen);
2926                        sources++;
2927                } else {
2928                        changes = f->changed;
2929                        dir->files++;
2930                        dir->nr--;
2931                        sources += 2;
2932                }
2933                sum_changes += changes;
2934        }
2935
2936        /*
2937         * We don't report dirstat's for
2938         *  - the top level
2939         *  - or cases where everything came from a single directory
2940         *    under this directory (sources == 1).
2941         */
2942        if (baselen && sources != 1) {
2943                if (sum_changes) {
2944                        int permille = sum_changes * 1000 / changed;
2945                        if (permille >= dir->permille) {
2946                                fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
2947                                        permille / 10, permille % 10, baselen, base);
2948                                if (!dir->cumulative)
2949                                        return 0;
2950                        }
2951                }
2952        }
2953        return sum_changes;
2954}
2955
2956static int dirstat_compare(const void *_a, const void *_b)
2957{
2958        const struct dirstat_file *a = _a;
2959        const struct dirstat_file *b = _b;
2960        return strcmp(a->name, b->name);
2961}
2962
2963static void show_dirstat(struct diff_options *options)
2964{
2965        int i;
2966        unsigned long changed;
2967        struct dirstat_dir dir;
2968        struct diff_queue_struct *q = &diff_queued_diff;
2969
2970        dir.files = NULL;
2971        dir.alloc = 0;
2972        dir.nr = 0;
2973        dir.permille = options->dirstat_permille;
2974        dir.cumulative = options->flags.dirstat_cumulative;
2975
2976        changed = 0;
2977        for (i = 0; i < q->nr; i++) {
2978                struct diff_filepair *p = q->queue[i];
2979                const char *name;
2980                unsigned long copied, added, damage;
2981
2982                name = p->two->path ? p->two->path : p->one->path;
2983
2984                if (p->one->oid_valid && p->two->oid_valid &&
2985                    oideq(&p->one->oid, &p->two->oid)) {
2986                        /*
2987                         * The SHA1 has not changed, so pre-/post-content is
2988                         * identical. We can therefore skip looking at the
2989                         * file contents altogether.
2990                         */
2991                        damage = 0;
2992                        goto found_damage;
2993                }
2994
2995                if (options->flags.dirstat_by_file) {
2996                        /*
2997                         * In --dirstat-by-file mode, we don't really need to
2998                         * look at the actual file contents at all.
2999                         * The fact that the SHA1 changed is enough for us to
3000                         * add this file to the list of results
3001                         * (with each file contributing equal damage).
3002                         */
3003                        damage = 1;
3004                        goto found_damage;
3005                }
3006
3007                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
3008                        diff_populate_filespec(options->repo, p->one, 0);
3009                        diff_populate_filespec(options->repo, p->two, 0);
3010                        diffcore_count_changes(options->repo,
3011                                               p->one, p->two, NULL, NULL,
3012                                               &copied, &added);
3013                        diff_free_filespec_data(p->one);
3014                        diff_free_filespec_data(p->two);
3015                } else if (DIFF_FILE_VALID(p->one)) {
3016                        diff_populate_filespec(options->repo, p->one, CHECK_SIZE_ONLY);
3017                        copied = added = 0;
3018                        diff_free_filespec_data(p->one);
3019                } else if (DIFF_FILE_VALID(p->two)) {
3020                        diff_populate_filespec(options->repo, p->two, CHECK_SIZE_ONLY);
3021                        copied = 0;
3022                        added = p->two->size;
3023                        diff_free_filespec_data(p->two);
3024                } else
3025                        continue;
3026
3027                /*
3028                 * Original minus copied is the removed material,
3029                 * added is the new material.  They are both damages
3030                 * made to the preimage.
3031                 * If the resulting damage is zero, we know that
3032                 * diffcore_count_changes() considers the two entries to
3033                 * be identical, but since the oid changed, we
3034                 * know that there must have been _some_ kind of change,
3035                 * so we force all entries to have damage > 0.
3036                 */
3037                damage = (p->one->size - copied) + added;
3038                if (!damage)
3039                        damage = 1;
3040
3041found_damage:
3042                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
3043                dir.files[dir.nr].name = name;
3044                dir.files[dir.nr].changed = damage;
3045                changed += damage;
3046                dir.nr++;
3047        }
3048
3049        /* This can happen even with many files, if everything was renames */
3050        if (!changed)
3051                return;
3052
3053        /* Show all directories with more than x% of the changes */
3054        QSORT(dir.files, dir.nr, dirstat_compare);
3055        gather_dirstat(options, &dir, changed, "", 0);
3056}
3057
3058static void show_dirstat_by_line(struct diffstat_t *data, struct diff_options *options)
3059{
3060        int i;
3061        unsigned long changed;
3062        struct dirstat_dir dir;
3063
3064        if (data->nr == 0)
3065                return;
3066
3067        dir.files = NULL;
3068        dir.alloc = 0;
3069        dir.nr = 0;
3070        dir.permille = options->dirstat_permille;
3071        dir.cumulative = options->flags.dirstat_cumulative;
3072
3073        changed = 0;
3074        for (i = 0; i < data->nr; i++) {
3075                struct diffstat_file *file = data->files[i];
3076                unsigned long damage = file->added + file->deleted;
3077                if (file->is_binary)
3078                        /*
3079                         * binary files counts bytes, not lines. Must find some
3080                         * way to normalize binary bytes vs. textual lines.
3081                         * The following heuristic assumes that there are 64
3082                         * bytes per "line".
3083                         * This is stupid and ugly, but very cheap...
3084                         */
3085                        damage = DIV_ROUND_UP(damage, 64);
3086                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
3087                dir.files[dir.nr].name = file->name;
3088                dir.files[dir.nr].changed = damage;
3089                changed += damage;
3090                dir.nr++;
3091        }
3092
3093        /* This can happen even with many files, if everything was renames */
3094        if (!changed)
3095                return;
3096
3097        /* Show all directories with more than x% of the changes */
3098        QSORT(dir.files, dir.nr, dirstat_compare);
3099        gather_dirstat(options, &dir, changed, "", 0);
3100}
3101
3102static void free_diffstat_info(struct diffstat_t *diffstat)
3103{
3104        int i;
3105        for (i = 0; i < diffstat->nr; i++) {
3106                struct diffstat_file *f = diffstat->files[i];
3107                free(f->print_name);
3108                free(f->name);
3109                free(f->from_name);
3110                free(f);
3111        }
3112        free(diffstat->files);
3113}
3114
3115struct checkdiff_t {
3116        const char *filename;
3117        int lineno;
3118        int conflict_marker_size;
3119        struct diff_options *o;
3120        unsigned ws_rule;
3121        unsigned status;
3122};
3123
3124static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
3125{
3126        char firstchar;
3127        int cnt;
3128
3129        if (len < marker_size + 1)
3130                return 0;
3131        firstchar = line[0];
3132        switch (firstchar) {
3133        case '=': case '>': case '<': case '|':
3134                break;
3135        default:
3136                return 0;
3137        }
3138        for (cnt = 1; cnt < marker_size; cnt++)
3139                if (line[cnt] != firstchar)
3140                        return 0;
3141        /* line[1] thru line[marker_size-1] are same as firstchar */
3142        if (len < marker_size + 1 || !isspace(line[marker_size]))
3143                return 0;
3144        return 1;
3145}
3146
3147static void checkdiff_consume_hunk(void *priv,
3148                                   long ob, long on, long nb, long nn,
3149                                   const char *func, long funclen)
3150
3151{
3152        struct checkdiff_t *data = priv;
3153        data->lineno = nb - 1;
3154}
3155
3156static void checkdiff_consume(void *priv, char *line, unsigned long len)
3157{
3158        struct checkdiff_t *data = priv;
3159        int marker_size = data->conflict_marker_size;
3160        const char *ws = diff_get_color(data->o->use_color, DIFF_WHITESPACE);
3161        const char *reset = diff_get_color(data->o->use_color, DIFF_RESET);
3162        const char *set = diff_get_color(data->o->use_color, DIFF_FILE_NEW);
3163        char *err;
3164        const char *line_prefix;
3165
3166        assert(data->o);
3167        line_prefix = diff_line_prefix(data->o);
3168
3169        if (line[0] == '+') {
3170                unsigned bad;
3171                data->lineno++;
3172                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
3173                        data->status |= 1;
3174                        fprintf(data->o->file,
3175                                "%s%s:%d: leftover conflict marker\n",
3176                                line_prefix, data->filename, data->lineno);
3177                }
3178                bad = ws_check(line + 1, len - 1, data->ws_rule);
3179                if (!bad)
3180                        return;
3181                data->status |= bad;
3182                err = whitespace_error_string(bad);
3183                fprintf(data->o->file, "%s%s:%d: %s.\n",
3184                        line_prefix, data->filename, data->lineno, err);
3185                free(err);
3186                emit_line(data->o, set, reset, line, 1);
3187                ws_check_emit(line + 1, len - 1, data->ws_rule,
3188                              data->o->file, set, reset, ws);
3189        } else if (line[0] == ' ') {
3190                data->lineno++;
3191        }
3192}
3193
3194static unsigned char *deflate_it(char *data,
3195                                 unsigned long size,
3196                                 unsigned long *result_size)
3197{
3198        int bound;
3199        unsigned char *deflated;
3200        git_zstream stream;
3201
3202        git_deflate_init(&stream, zlib_compression_level);
3203        bound = git_deflate_bound(&stream, size);
3204        deflated = xmalloc(bound);
3205        stream.next_out = deflated;
3206        stream.avail_out = bound;
3207
3208        stream.next_in = (unsigned char *)data;
3209        stream.avail_in = size;
3210        while (git_deflate(&stream, Z_FINISH) == Z_OK)
3211                ; /* nothing */
3212        git_deflate_end(&stream);
3213        *result_size = stream.total_out;
3214        return deflated;
3215}
3216
3217static void emit_binary_diff_body(struct diff_options *o,
3218                                  mmfile_t *one, mmfile_t *two)
3219{
3220        void *cp;
3221        void *delta;
3222        void *deflated;
3223        void *data;
3224        unsigned long orig_size;
3225        unsigned long delta_size;
3226        unsigned long deflate_size;
3227        unsigned long data_size;
3228
3229        /* We could do deflated delta, or we could do just deflated two,
3230         * whichever is smaller.
3231         */
3232        delta = NULL;
3233        deflated = deflate_it(two->ptr, two->size, &deflate_size);
3234        if (one->size && two->size) {
3235                delta = diff_delta(one->ptr, one->size,
3236                                   two->ptr, two->size,
3237                                   &delta_size, deflate_size);
3238                if (delta) {
3239                        void *to_free = delta;
3240                        orig_size = delta_size;
3241                        delta = deflate_it(delta, delta_size, &delta_size);
3242                        free(to_free);
3243                }
3244        }
3245
3246        if (delta && delta_size < deflate_size) {
3247                char *s = xstrfmt("%"PRIuMAX , (uintmax_t)orig_size);
3248                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA,
3249                                 s, strlen(s), 0);
3250                free(s);
3251                free(deflated);
3252                data = delta;
3253                data_size = delta_size;
3254        } else {
3255                char *s = xstrfmt("%lu", two->size);
3256                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL,
3257                                 s, strlen(s), 0);
3258                free(s);
3259                free(delta);
3260                data = deflated;
3261                data_size = deflate_size;
3262        }
3263
3264        /* emit data encoded in base85 */
3265        cp = data;
3266        while (data_size) {
3267                int len;
3268                int bytes = (52 < data_size) ? 52 : data_size;
3269                char line[71];
3270                data_size -= bytes;
3271                if (bytes <= 26)
3272                        line[0] = bytes + 'A' - 1;
3273                else
3274                        line[0] = bytes - 26 + 'a' - 1;
3275                encode_85(line + 1, cp, bytes);
3276                cp = (char *) cp + bytes;
3277
3278                len = strlen(line);
3279                line[len++] = '\n';
3280                line[len] = '\0';
3281
3282                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_BODY,
3283                                 line, len, 0);
3284        }
3285        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_FOOTER, NULL, 0, 0);
3286        free(data);
3287}
3288
3289static void emit_binary_diff(struct diff_options *o,
3290                             mmfile_t *one, mmfile_t *two)
3291{
3292        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER, NULL, 0, 0);
3293        emit_binary_diff_body(o, one, two);
3294        emit_binary_diff_body(o, two, one);
3295}
3296
3297int diff_filespec_is_binary(struct repository *r,
3298                            struct diff_filespec *one)
3299{
3300        if (one->is_binary == -1) {
3301                diff_filespec_load_driver(one, r->index);
3302                if (one->driver->binary != -1)
3303                        one->is_binary = one->driver->binary;
3304                else {
3305                        if (!one->data && DIFF_FILE_VALID(one))
3306                                diff_populate_filespec(r, one, CHECK_BINARY);
3307                        if (one->is_binary == -1 && one->data)
3308                                one->is_binary = buffer_is_binary(one->data,
3309                                                one->size);
3310                        if (one->is_binary == -1)
3311                                one->is_binary = 0;
3312                }
3313        }
3314        return one->is_binary;
3315}
3316
3317static const struct userdiff_funcname *
3318diff_funcname_pattern(struct diff_options *o, struct diff_filespec *one)
3319{
3320        diff_filespec_load_driver(one, o->repo->index);
3321        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
3322}
3323
3324void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
3325{
3326        if (!options->a_prefix)
3327                options->a_prefix = a;
3328        if (!options->b_prefix)
3329                options->b_prefix = b;
3330}
3331
3332struct userdiff_driver *get_textconv(struct index_state *istate,
3333                                     struct diff_filespec *one)
3334{
3335        if (!DIFF_FILE_VALID(one))
3336                return NULL;
3337
3338        diff_filespec_load_driver(one, istate);
3339        return userdiff_get_textconv(one->driver);
3340}
3341
3342static void builtin_diff(const char *name_a,
3343                         const char *name_b,
3344                         struct diff_filespec *one,
3345                         struct diff_filespec *two,
3346                         const char *xfrm_msg,
3347                         int must_show_header,
3348                         struct diff_options *o,
3349                         int complete_rewrite)
3350{
3351        mmfile_t mf1, mf2;
3352        const char *lbl[2];
3353        char *a_one, *b_two;
3354        const char *meta = diff_get_color_opt(o, DIFF_METAINFO);
3355        const char *reset = diff_get_color_opt(o, DIFF_RESET);
3356        const char *a_prefix, *b_prefix;
3357        struct userdiff_driver *textconv_one = NULL;
3358        struct userdiff_driver *textconv_two = NULL;
3359        struct strbuf header = STRBUF_INIT;
3360        const char *line_prefix = diff_line_prefix(o);
3361
3362        diff_set_mnemonic_prefix(o, "a/", "b/");
3363        if (o->flags.reverse_diff) {
3364                a_prefix = o->b_prefix;
3365                b_prefix = o->a_prefix;
3366        } else {
3367                a_prefix = o->a_prefix;
3368                b_prefix = o->b_prefix;
3369        }
3370
3371        if (o->submodule_format == DIFF_SUBMODULE_LOG &&
3372            (!one->mode || S_ISGITLINK(one->mode)) &&
3373            (!two->mode || S_ISGITLINK(two->mode))) {
3374                show_submodule_summary(o, one->path ? one->path : two->path,
3375                                &one->oid, &two->oid,
3376                                two->dirty_submodule);
3377                return;
3378        } else if (o->submodule_format == DIFF_SUBMODULE_INLINE_DIFF &&
3379                   (!one->mode || S_ISGITLINK(one->mode)) &&
3380                   (!two->mode || S_ISGITLINK(two->mode))) {
3381                show_submodule_inline_diff(o, one->path ? one->path : two->path,
3382                                &one->oid, &two->oid,
3383                                two->dirty_submodule);
3384                return;
3385        }
3386
3387        if (o->flags.allow_textconv) {
3388                textconv_one = get_textconv(o->repo->index, one);
3389                textconv_two = get_textconv(o->repo->index, two);
3390        }
3391
3392        /* Never use a non-valid filename anywhere if at all possible */
3393        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
3394        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
3395
3396        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
3397        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
3398        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
3399        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
3400        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, meta, a_one, b_two, reset);
3401        if (lbl[0][0] == '/') {
3402                /* /dev/null */
3403                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, meta, two->mode, reset);
3404                if (xfrm_msg)
3405                        strbuf_addstr(&header, xfrm_msg);
3406                must_show_header = 1;
3407        }
3408        else if (lbl[1][0] == '/') {
3409                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, meta, one->mode, reset);
3410                if (xfrm_msg)
3411                        strbuf_addstr(&header, xfrm_msg);
3412                must_show_header = 1;
3413        }
3414        else {
3415                if (one->mode != two->mode) {
3416                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, meta, one->mode, reset);
3417                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, meta, two->mode, reset);
3418                        must_show_header = 1;
3419                }
3420                if (xfrm_msg)
3421                        strbuf_addstr(&header, xfrm_msg);
3422
3423                /*
3424                 * we do not run diff between different kind
3425                 * of objects.
3426                 */
3427                if ((one->mode ^ two->mode) & S_IFMT)
3428                        goto free_ab_and_return;
3429                if (complete_rewrite &&
3430                    (textconv_one || !diff_filespec_is_binary(o->repo, one)) &&
3431                    (textconv_two || !diff_filespec_is_binary(o->repo, two))) {
3432                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3433                                         header.buf, header.len, 0);
3434                        strbuf_reset(&header);
3435                        emit_rewrite_diff(name_a, name_b, one, two,
3436                                          textconv_one, textconv_two, o);
3437                        o->found_changes = 1;
3438                        goto free_ab_and_return;
3439                }
3440        }
3441
3442        if (o->irreversible_delete && lbl[1][0] == '/') {
3443                emit_diff_symbol(o, DIFF_SYMBOL_HEADER, header.buf,
3444                                 header.len, 0);
3445                strbuf_reset(&header);
3446                goto free_ab_and_return;
3447        } else if (!o->flags.text &&
3448                   ( (!textconv_one && diff_filespec_is_binary(o->repo, one)) ||
3449                     (!textconv_two && diff_filespec_is_binary(o->repo, two)) )) {
3450                struct strbuf sb = STRBUF_INIT;
3451                if (!one->data && !two->data &&
3452                    S_ISREG(one->mode) && S_ISREG(two->mode) &&
3453                    !o->flags.binary) {
3454                        if (oideq(&one->oid, &two->oid)) {
3455                                if (must_show_header)
3456                                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3457                                                         header.buf, header.len,
3458                                                         0);
3459                                goto free_ab_and_return;
3460                        }
3461                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3462                                         header.buf, header.len, 0);
3463                        strbuf_addf(&sb, "%sBinary files %s and %s differ\n",
3464                                    diff_line_prefix(o), lbl[0], lbl[1]);
3465                        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_FILES,
3466                                         sb.buf, sb.len, 0);
3467                        strbuf_release(&sb);
3468                        goto free_ab_and_return;
3469                }
3470                if (fill_mmfile(o->repo, &mf1, one) < 0 ||
3471                    fill_mmfile(o->repo, &mf2, two) < 0)
3472                        die("unable to read files to diff");
3473                /* Quite common confusing case */
3474                if (mf1.size == mf2.size &&
3475                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
3476                        if (must_show_header)
3477                                emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3478                                                 header.buf, header.len, 0);
3479                        goto free_ab_and_return;
3480                }
3481                emit_diff_symbol(o, DIFF_SYMBOL_HEADER, header.buf, header.len, 0);
3482                strbuf_reset(&header);
3483                if (o->flags.binary)
3484                        emit_binary_diff(o, &mf1, &mf2);
3485                else {
3486                        strbuf_addf(&sb, "%sBinary files %s and %s differ\n",
3487                                    diff_line_prefix(o), lbl[0], lbl[1]);
3488                        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_FILES,
3489                                         sb.buf, sb.len, 0);
3490                        strbuf_release(&sb);
3491                }
3492                o->found_changes = 1;
3493        } else {
3494                /* Crazy xdl interfaces.. */
3495                const char *diffopts = getenv("GIT_DIFF_OPTS");
3496                const char *v;
3497                xpparam_t xpp;
3498                xdemitconf_t xecfg;
3499                struct emit_callback ecbdata;
3500                const struct userdiff_funcname *pe;
3501
3502                if (must_show_header) {
3503                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3504                                         header.buf, header.len, 0);
3505                        strbuf_reset(&header);
3506                }
3507
3508                mf1.size = fill_textconv(o->repo, textconv_one, one, &mf1.ptr);
3509                mf2.size = fill_textconv(o->repo, textconv_two, two, &mf2.ptr);
3510
3511                pe = diff_funcname_pattern(o, one);
3512                if (!pe)
3513                        pe = diff_funcname_pattern(o, two);
3514
3515                memset(&xpp, 0, sizeof(xpp));
3516                memset(&xecfg, 0, sizeof(xecfg));
3517                memset(&ecbdata, 0, sizeof(ecbdata));
3518                if (o->flags.suppress_diff_headers)
3519                        lbl[0] = NULL;
3520                ecbdata.label_path = lbl;
3521                ecbdata.color_diff = want_color(o->use_color);
3522                ecbdata.ws_rule = whitespace_rule(o->repo->index, name_b);
3523                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
3524                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
3525                ecbdata.opt = o;
3526                if (header.len && !o->flags.suppress_diff_headers)
3527                        ecbdata.header = &header;
3528                xpp.flags = o->xdl_opts;
3529                xpp.anchors = o->anchors;
3530                xpp.anchors_nr = o->anchors_nr;
3531                xecfg.ctxlen = o->context;
3532                xecfg.interhunkctxlen = o->interhunkcontext;
3533                xecfg.flags = XDL_EMIT_FUNCNAMES;
3534                if (o->flags.funccontext)
3535                        xecfg.flags |= XDL_EMIT_FUNCCONTEXT;
3536                if (pe)
3537                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
3538                if (!diffopts)
3539                        ;
3540                else if (skip_prefix(diffopts, "--unified=", &v))
3541                        xecfg.ctxlen = strtoul(v, NULL, 10);
3542                else if (skip_prefix(diffopts, "-u", &v))
3543                        xecfg.ctxlen = strtoul(v, NULL, 10);
3544                if (o->word_diff)
3545                        init_diff_words_data(&ecbdata, o, one, two);
3546                if (xdi_diff_outf(&mf1, &mf2, NULL, fn_out_consume,
3547                                  &ecbdata, &xpp, &xecfg))
3548                        die("unable to generate diff for %s", one->path);
3549                if (o->word_diff)
3550                        free_diff_words_data(&ecbdata);
3551                if (textconv_one)
3552                        free(mf1.ptr);
3553                if (textconv_two)
3554                        free(mf2.ptr);
3555                xdiff_clear_find_func(&xecfg);
3556        }
3557
3558 free_ab_and_return:
3559        strbuf_release(&header);
3560        diff_free_filespec_data(one);
3561        diff_free_filespec_data(two);
3562        free(a_one);
3563        free(b_two);
3564        return;
3565}
3566
3567static char *get_compact_summary(const struct diff_filepair *p, int is_renamed)
3568{
3569        if (!is_renamed) {
3570                if (p->status == DIFF_STATUS_ADDED) {
3571                        if (S_ISLNK(p->two->mode))
3572                                return "new +l";
3573                        else if ((p->two->mode & 0777) == 0755)
3574                                return "new +x";
3575                        else
3576                                return "new";
3577                } else if (p->status == DIFF_STATUS_DELETED)
3578                        return "gone";
3579        }
3580        if (S_ISLNK(p->one->mode) && !S_ISLNK(p->two->mode))
3581                return "mode -l";
3582        else if (!S_ISLNK(p->one->mode) && S_ISLNK(p->two->mode))
3583                return "mode +l";
3584        else if ((p->one->mode & 0777) == 0644 &&
3585                 (p->two->mode & 0777) == 0755)
3586                return "mode +x";
3587        else if ((p->one->mode & 0777) == 0755 &&
3588                 (p->two->mode & 0777) == 0644)
3589                return "mode -x";
3590        return NULL;
3591}
3592
3593static void builtin_diffstat(const char *name_a, const char *name_b,
3594                             struct diff_filespec *one,
3595                             struct diff_filespec *two,
3596                             struct diffstat_t *diffstat,
3597                             struct diff_options *o,
3598                             struct diff_filepair *p)
3599{
3600        mmfile_t mf1, mf2;
3601        struct diffstat_file *data;
3602        int same_contents;
3603        int complete_rewrite = 0;
3604
3605        if (!DIFF_PAIR_UNMERGED(p)) {
3606                if (p->status == DIFF_STATUS_MODIFIED && p->score)
3607                        complete_rewrite = 1;
3608        }
3609
3610        data = diffstat_add(diffstat, name_a, name_b);
3611        data->is_interesting = p->status != DIFF_STATUS_UNKNOWN;
3612        if (o->flags.stat_with_summary)
3613                data->comments = get_compact_summary(p, data->is_renamed);
3614
3615        if (!one || !two) {
3616                data->is_unmerged = 1;
3617                return;
3618        }
3619
3620        same_contents = oideq(&one->oid, &two->oid);
3621
3622        if (diff_filespec_is_binary(o->repo, one) ||
3623            diff_filespec_is_binary(o->repo, two)) {
3624                data->is_binary = 1;
3625                if (same_contents) {
3626                        data->added = 0;
3627                        data->deleted = 0;
3628                } else {
3629                        data->added = diff_filespec_size(o->repo, two);
3630                        data->deleted = diff_filespec_size(o->repo, one);
3631                }
3632        }
3633
3634        else if (complete_rewrite) {
3635                diff_populate_filespec(o->repo, one, 0);
3636                diff_populate_filespec(o->repo, two, 0);
3637                data->deleted = count_lines(one->data, one->size);
3638                data->added = count_lines(two->data, two->size);
3639        }
3640
3641        else if (!same_contents) {
3642                /* Crazy xdl interfaces.. */
3643                xpparam_t xpp;
3644                xdemitconf_t xecfg;
3645
3646                if (fill_mmfile(o->repo, &mf1, one) < 0 ||
3647                    fill_mmfile(o->repo, &mf2, two) < 0)
3648                        die("unable to read files to diff");
3649
3650                memset(&xpp, 0, sizeof(xpp));
3651                memset(&xecfg, 0, sizeof(xecfg));
3652                xpp.flags = o->xdl_opts;
3653                xpp.anchors = o->anchors;
3654                xpp.anchors_nr = o->anchors_nr;
3655                xecfg.ctxlen = o->context;
3656                xecfg.interhunkctxlen = o->interhunkcontext;
3657                if (xdi_diff_outf(&mf1, &mf2, discard_hunk_line,
3658                                  diffstat_consume, diffstat, &xpp, &xecfg))
3659                        die("unable to generate diffstat for %s", one->path);
3660        }
3661
3662        diff_free_filespec_data(one);
3663        diff_free_filespec_data(two);
3664}
3665
3666static void builtin_checkdiff(const char *name_a, const char *name_b,
3667                              const char *attr_path,
3668                              struct diff_filespec *one,
3669                              struct diff_filespec *two,
3670                              struct diff_options *o)
3671{
3672        mmfile_t mf1, mf2;
3673        struct checkdiff_t data;
3674
3675        if (!two)
3676                return;
3677
3678        memset(&data, 0, sizeof(data));
3679        data.filename = name_b ? name_b : name_a;
3680        data.lineno = 0;
3681        data.o = o;
3682        data.ws_rule = whitespace_rule(o->repo->index, attr_path);
3683        data.conflict_marker_size = ll_merge_marker_size(o->repo->index, attr_path);
3684
3685        if (fill_mmfile(o->repo, &mf1, one) < 0 ||
3686            fill_mmfile(o->repo, &mf2, two) < 0)
3687                die("unable to read files to diff");
3688
3689        /*
3690         * All the other codepaths check both sides, but not checking
3691         * the "old" side here is deliberate.  We are checking the newly
3692         * introduced changes, and as long as the "new" side is text, we
3693         * can and should check what it introduces.
3694         */
3695        if (diff_filespec_is_binary(o->repo, two))
3696                goto free_and_return;
3697        else {
3698                /* Crazy xdl interfaces.. */
3699                xpparam_t xpp;
3700                xdemitconf_t xecfg;
3701
3702                memset(&xpp, 0, sizeof(xpp));
3703                memset(&xecfg, 0, sizeof(xecfg));
3704                xecfg.ctxlen = 1; /* at least one context line */
3705                xpp.flags = 0;
3706                if (xdi_diff_outf(&mf1, &mf2, checkdiff_consume_hunk,
3707                                  checkdiff_consume, &data,
3708                                  &xpp, &xecfg))
3709                        die("unable to generate checkdiff for %s", one->path);
3710
3711                if (data.ws_rule & WS_BLANK_AT_EOF) {
3712                        struct emit_callback ecbdata;
3713                        int blank_at_eof;
3714
3715                        ecbdata.ws_rule = data.ws_rule;
3716                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
3717                        blank_at_eof = ecbdata.blank_at_eof_in_postimage;
3718
3719                        if (blank_at_eof) {
3720                                static char *err;
3721                                if (!err)
3722                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
3723                                fprintf(o->file, "%s:%d: %s.\n",
3724                                        data.filename, blank_at_eof, err);
3725                                data.status = 1; /* report errors */
3726                        }
3727                }
3728        }
3729 free_and_return:
3730        diff_free_filespec_data(one);
3731        diff_free_filespec_data(two);
3732        if (data.status)
3733                o->flags.check_failed = 1;
3734}
3735
3736struct diff_filespec *alloc_filespec(const char *path)
3737{
3738        struct diff_filespec *spec;
3739
3740        FLEXPTR_ALLOC_STR(spec, path, path);
3741        spec->count = 1;
3742        spec->is_binary = -1;
3743        return spec;
3744}
3745
3746void free_filespec(struct diff_filespec *spec)
3747{
3748        if (!--spec->count) {
3749                diff_free_filespec_data(spec);
3750                free(spec);
3751        }
3752}
3753
3754void fill_filespec(struct diff_filespec *spec, const struct object_id *oid,
3755                   int oid_valid, unsigned short mode)
3756{
3757        if (mode) {
3758                spec->mode = canon_mode(mode);
3759                oidcpy(&spec->oid, oid);
3760                spec->oid_valid = oid_valid;
3761        }
3762}
3763
3764/*
3765 * Given a name and sha1 pair, if the index tells us the file in
3766 * the work tree has that object contents, return true, so that
3767 * prepare_temp_file() does not have to inflate and extract.
3768 */
3769static int reuse_worktree_file(struct index_state *istate,
3770                               const char *name,
3771                               const struct object_id *oid,
3772                               int want_file)
3773{
3774        const struct cache_entry *ce;
3775        struct stat st;
3776        int pos, len;
3777
3778        /*
3779         * We do not read the cache ourselves here, because the
3780         * benchmark with my previous version that always reads cache
3781         * shows that it makes things worse for diff-tree comparing
3782         * two linux-2.6 kernel trees in an already checked out work
3783         * tree.  This is because most diff-tree comparisons deal with
3784         * only a small number of files, while reading the cache is
3785         * expensive for a large project, and its cost outweighs the
3786         * savings we get by not inflating the object to a temporary
3787         * file.  Practically, this code only helps when we are used
3788         * by diff-cache --cached, which does read the cache before
3789         * calling us.
3790         */
3791        if (!istate->cache)
3792                return 0;
3793
3794        /* We want to avoid the working directory if our caller
3795         * doesn't need the data in a normal file, this system
3796         * is rather slow with its stat/open/mmap/close syscalls,
3797         * and the object is contained in a pack file.  The pack
3798         * is probably already open and will be faster to obtain
3799         * the data through than the working directory.  Loose
3800         * objects however would tend to be slower as they need
3801         * to be individually opened and inflated.
3802         */
3803        if (!FAST_WORKING_DIRECTORY && !want_file && has_object_pack(oid))
3804                return 0;
3805
3806        /*
3807         * Similarly, if we'd have to convert the file contents anyway, that
3808         * makes the optimization not worthwhile.
3809         */
3810        if (!want_file && would_convert_to_git(istate, name))
3811                return 0;
3812
3813        len = strlen(name);
3814        pos = index_name_pos(istate, name, len);
3815        if (pos < 0)
3816                return 0;
3817        ce = istate->cache[pos];
3818
3819        /*
3820         * This is not the sha1 we are looking for, or
3821         * unreusable because it is not a regular file.
3822         */
3823        if (!oideq(oid, &ce->oid) || !S_ISREG(ce->ce_mode))
3824                return 0;
3825
3826        /*
3827         * If ce is marked as "assume unchanged", there is no
3828         * guarantee that work tree matches what we are looking for.
3829         */
3830        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
3831                return 0;
3832
3833        /*
3834         * If ce matches the file in the work tree, we can reuse it.
3835         */
3836        if (ce_uptodate(ce) ||
3837            (!lstat(name, &st) && !ie_match_stat(istate, ce, &st, 0)))
3838                return 1;
3839
3840        return 0;
3841}
3842
3843static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
3844{
3845        struct strbuf buf = STRBUF_INIT;
3846        char *dirty = "";
3847
3848        /* Are we looking at the work tree? */
3849        if (s->dirty_submodule)
3850                dirty = "-dirty";
3851
3852        strbuf_addf(&buf, "Subproject commit %s%s\n",
3853                    oid_to_hex(&s->oid), dirty);
3854        s->size = buf.len;
3855        if (size_only) {
3856                s->data = NULL;
3857                strbuf_release(&buf);
3858        } else {
3859                s->data = strbuf_detach(&buf, NULL);
3860                s->should_free = 1;
3861        }
3862        return 0;
3863}
3864
3865/*
3866 * While doing rename detection and pickaxe operation, we may need to
3867 * grab the data for the blob (or file) for our own in-core comparison.
3868 * diff_filespec has data and size fields for this purpose.
3869 */
3870int diff_populate_filespec(struct repository *r,
3871                           struct diff_filespec *s,
3872                           unsigned int flags)
3873{
3874        int size_only = flags & CHECK_SIZE_ONLY;
3875        int err = 0;
3876        int conv_flags = global_conv_flags_eol;
3877        /*
3878         * demote FAIL to WARN to allow inspecting the situation
3879         * instead of refusing.
3880         */
3881        if (conv_flags & CONV_EOL_RNDTRP_DIE)
3882                conv_flags = CONV_EOL_RNDTRP_WARN;
3883
3884        if (!DIFF_FILE_VALID(s))
3885                die("internal error: asking to populate invalid file.");
3886        if (S_ISDIR(s->mode))
3887                return -1;
3888
3889        if (s->data)
3890                return 0;
3891
3892        if (size_only && 0 < s->size)
3893                return 0;
3894
3895        if (S_ISGITLINK(s->mode))
3896                return diff_populate_gitlink(s, size_only);
3897
3898        if (!s->oid_valid ||
3899            reuse_worktree_file(r->index, s->path, &s->oid, 0)) {
3900                struct strbuf buf = STRBUF_INIT;
3901                struct stat st;
3902                int fd;
3903
3904                if (lstat(s->path, &st) < 0) {
3905                err_empty:
3906                        err = -1;
3907                empty:
3908                        s->data = (char *)"";
3909                        s->size = 0;
3910                        return err;
3911                }
3912                s->size = xsize_t(st.st_size);
3913                if (!s->size)
3914                        goto empty;
3915                if (S_ISLNK(st.st_mode)) {
3916                        struct strbuf sb = STRBUF_INIT;
3917
3918                        if (strbuf_readlink(&sb, s->path, s->size))
3919                                goto err_empty;
3920                        s->size = sb.len;
3921                        s->data = strbuf_detach(&sb, NULL);
3922                        s->should_free = 1;
3923                        return 0;
3924                }
3925
3926                /*
3927                 * Even if the caller would be happy with getting
3928                 * only the size, we cannot return early at this
3929                 * point if the path requires us to run the content
3930                 * conversion.
3931                 */
3932                if (size_only && !would_convert_to_git(r->index, s->path))
3933                        return 0;
3934
3935                /*
3936                 * Note: this check uses xsize_t(st.st_size) that may
3937                 * not be the true size of the blob after it goes
3938                 * through convert_to_git().  This may not strictly be
3939                 * correct, but the whole point of big_file_threshold
3940                 * and is_binary check being that we want to avoid
3941                 * opening the file and inspecting the contents, this
3942                 * is probably fine.
3943                 */
3944                if ((flags & CHECK_BINARY) &&
3945                    s->size > big_file_threshold && s->is_binary == -1) {
3946                        s->is_binary = 1;
3947                        return 0;
3948                }
3949                fd = open(s->path, O_RDONLY);
3950                if (fd < 0)
3951                        goto err_empty;
3952                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
3953                close(fd);
3954                s->should_munmap = 1;
3955
3956                /*
3957                 * Convert from working tree format to canonical git format
3958                 */
3959                if (convert_to_git(r->index, s->path, s->data, s->size, &buf, conv_flags)) {
3960                        size_t size = 0;
3961                        munmap(s->data, s->size);
3962                        s->should_munmap = 0;
3963                        s->data = strbuf_detach(&buf, &size);
3964                        s->size = size;
3965                        s->should_free = 1;
3966                }
3967        }
3968        else {
3969                enum object_type type;
3970                if (size_only || (flags & CHECK_BINARY)) {
3971                        type = oid_object_info(r, &s->oid, &s->size);
3972                        if (type < 0)
3973                                die("unable to read %s",
3974                                    oid_to_hex(&s->oid));
3975                        if (size_only)
3976                                return 0;
3977                        if (s->size > big_file_threshold && s->is_binary == -1) {
3978                                s->is_binary = 1;
3979                                return 0;
3980                        }
3981                }
3982                s->data = read_object_file(&s->oid, &type, &s->size);
3983                if (!s->data)
3984                        die("unable to read %s", oid_to_hex(&s->oid));
3985                s->should_free = 1;
3986        }
3987        return 0;
3988}
3989
3990void diff_free_filespec_blob(struct diff_filespec *s)
3991{
3992        if (s->should_free)
3993                free(s->data);
3994        else if (s->should_munmap)
3995                munmap(s->data, s->size);
3996
3997        if (s->should_free || s->should_munmap) {
3998                s->should_free = s->should_munmap = 0;
3999                s->data = NULL;
4000        }
4001}
4002
4003void diff_free_filespec_data(struct diff_filespec *s)
4004{
4005        diff_free_filespec_blob(s);
4006        FREE_AND_NULL(s->cnt_data);
4007}
4008
4009static void prep_temp_blob(struct index_state *istate,
4010                           const char *path, struct diff_tempfile *temp,
4011                           void *blob,
4012                           unsigned long size,
4013                           const struct object_id *oid,
4014                           int mode)
4015{
4016        struct strbuf buf = STRBUF_INIT;
4017        struct strbuf tempfile = STRBUF_INIT;
4018        char *path_dup = xstrdup(path);
4019        const char *base = basename(path_dup);
4020
4021        /* Generate "XXXXXX_basename.ext" */
4022        strbuf_addstr(&tempfile, "XXXXXX_");
4023        strbuf_addstr(&tempfile, base);
4024
4025        temp->tempfile = mks_tempfile_ts(tempfile.buf, strlen(base) + 1);
4026        if (!temp->tempfile)
4027                die_errno("unable to create temp-file");
4028        if (convert_to_working_tree(istate, path,
4029                        (const char *)blob, (size_t)size, &buf)) {
4030                blob = buf.buf;
4031                size = buf.len;
4032        }
4033        if (write_in_full(temp->tempfile->fd, blob, size) < 0 ||
4034            close_tempfile_gently(temp->tempfile))
4035                die_errno("unable to write temp-file");
4036        temp->name = get_tempfile_path(temp->tempfile);
4037        oid_to_hex_r(temp->hex, oid);
4038        xsnprintf(temp->mode, sizeof(temp->mode), "%06o", mode);
4039        strbuf_release(&buf);
4040        strbuf_release(&tempfile);
4041        free(path_dup);
4042}
4043
4044static struct diff_tempfile *prepare_temp_file(struct repository *r,
4045                                               const char *name,
4046                                               struct diff_filespec *one)
4047{
4048        struct diff_tempfile *temp = claim_diff_tempfile();
4049
4050        if (!DIFF_FILE_VALID(one)) {
4051        not_a_valid_file:
4052                /* A '-' entry produces this for file-2, and
4053                 * a '+' entry produces this for file-1.
4054                 */
4055                temp->name = "/dev/null";
4056                xsnprintf(temp->hex, sizeof(temp->hex), ".");
4057                xsnprintf(temp->mode, sizeof(temp->mode), ".");
4058                return temp;
4059        }
4060
4061        if (!S_ISGITLINK(one->mode) &&
4062            (!one->oid_valid ||
4063             reuse_worktree_file(r->index, name, &one->oid, 1))) {
4064                struct stat st;
4065                if (lstat(name, &st) < 0) {
4066                        if (errno == ENOENT)
4067                                goto not_a_valid_file;
4068                        die_errno("stat(%s)", name);
4069                }
4070                if (S_ISLNK(st.st_mode)) {
4071                        struct strbuf sb = STRBUF_INIT;
4072                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
4073                                die_errno("readlink(%s)", name);
4074                        prep_temp_blob(r->index, name, temp, sb.buf, sb.len,
4075                                       (one->oid_valid ?
4076                                        &one->oid : &null_oid),
4077                                       (one->oid_valid ?
4078                                        one->mode : S_IFLNK));
4079                        strbuf_release(&sb);
4080                }
4081                else {
4082                        /* we can borrow from the file in the work tree */
4083                        temp->name = name;
4084                        if (!one->oid_valid)
4085                                oid_to_hex_r(temp->hex, &null_oid);
4086                        else
4087                                oid_to_hex_r(temp->hex, &one->oid);
4088                        /* Even though we may sometimes borrow the
4089                         * contents from the work tree, we always want
4090                         * one->mode.  mode is trustworthy even when
4091                         * !(one->oid_valid), as long as
4092                         * DIFF_FILE_VALID(one).
4093                         */
4094                        xsnprintf(temp->mode, sizeof(temp->mode), "%06o", one->mode);
4095                }
4096                return temp;
4097        }
4098        else {
4099                if (diff_populate_filespec(r, one, 0))
4100                        die("cannot read data blob for %s", one->path);
4101                prep_temp_blob(r->index, name, temp,
4102                               one->data, one->size,
4103                               &one->oid, one->mode);
4104        }
4105        return temp;
4106}
4107
4108static void add_external_diff_name(struct repository *r,
4109                                   struct argv_array *argv,
4110                                   const char *name,
4111                                   struct diff_filespec *df)
4112{
4113        struct diff_tempfile *temp = prepare_temp_file(r, name, df);
4114        argv_array_push(argv, temp->name);
4115        argv_array_push(argv, temp->hex);
4116        argv_array_push(argv, temp->mode);
4117}
4118
4119/* An external diff command takes:
4120 *
4121 * diff-cmd name infile1 infile1-sha1 infile1-mode \
4122 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
4123 *
4124 */
4125static void run_external_diff(const char *pgm,
4126                              const char *name,
4127                              const char *other,
4128                              struct diff_filespec *one,
4129                              struct diff_filespec *two,
4130                              const char *xfrm_msg,
4131                              int complete_rewrite,
4132                              struct diff_options *o)
4133{
4134        struct argv_array argv = ARGV_ARRAY_INIT;
4135        struct argv_array env = ARGV_ARRAY_INIT;
4136        struct diff_queue_struct *q = &diff_queued_diff;
4137
4138        argv_array_push(&argv, pgm);
4139        argv_array_push(&argv, name);
4140
4141        if (one && two) {
4142                add_external_diff_name(o->repo, &argv, name, one);
4143                if (!other)
4144                        add_external_diff_name(o->repo, &argv, name, two);
4145                else {
4146                        add_external_diff_name(o->repo, &argv, other, two);
4147                        argv_array_push(&argv, other);
4148                        argv_array_push(&argv, xfrm_msg);
4149                }
4150        }
4151
4152        argv_array_pushf(&env, "GIT_DIFF_PATH_COUNTER=%d", ++o->diff_path_counter);
4153        argv_array_pushf(&env, "GIT_DIFF_PATH_TOTAL=%d", q->nr);
4154
4155        if (run_command_v_opt_cd_env(argv.argv, RUN_USING_SHELL, NULL, env.argv))
4156                die(_("external diff died, stopping at %s"), name);
4157
4158        remove_tempfile();
4159        argv_array_clear(&argv);
4160        argv_array_clear(&env);
4161}
4162
4163static int similarity_index(struct diff_filepair *p)
4164{
4165        return p->score * 100 / MAX_SCORE;
4166}
4167
4168static const char *diff_abbrev_oid(const struct object_id *oid, int abbrev)
4169{
4170        if (startup_info->have_repository)
4171                return find_unique_abbrev(oid, abbrev);
4172        else {
4173                char *hex = oid_to_hex(oid);
4174                if (abbrev < 0)
4175                        abbrev = FALLBACK_DEFAULT_ABBREV;
4176                if (abbrev > the_hash_algo->hexsz)
4177                        BUG("oid abbreviation out of range: %d", abbrev);
4178                if (abbrev)
4179                        hex[abbrev] = '\0';
4180                return hex;
4181        }
4182}
4183
4184static void fill_metainfo(struct strbuf *msg,
4185                          const char *name,
4186                          const char *other,
4187                          struct diff_filespec *one,
4188                          struct diff_filespec *two,
4189                          struct diff_options *o,
4190                          struct diff_filepair *p,
4191                          int *must_show_header,
4192                          int use_color)
4193{
4194        const char *set = diff_get_color(use_color, DIFF_METAINFO);
4195        const char *reset = diff_get_color(use_color, DIFF_RESET);
4196        const char *line_prefix = diff_line_prefix(o);
4197
4198        *must_show_header = 1;
4199        strbuf_init(msg, PATH_MAX * 2 + 300);
4200        switch (p->status) {
4201        case DIFF_STATUS_COPIED:
4202                strbuf_addf(msg, "%s%ssimilarity index %d%%",
4203                            line_prefix, set, similarity_index(p));
4204                strbuf_addf(msg, "%s\n%s%scopy from ",
4205                            reset,  line_prefix, set);
4206                quote_c_style(name, msg, NULL, 0);
4207                strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
4208                quote_c_style(other, msg, NULL, 0);
4209                strbuf_addf(msg, "%s\n", reset);
4210                break;
4211        case DIFF_STATUS_RENAMED:
4212                strbuf_addf(msg, "%s%ssimilarity index %d%%",
4213                            line_prefix, set, similarity_index(p));
4214                strbuf_addf(msg, "%s\n%s%srename from ",
4215                            reset, line_prefix, set);
4216                quote_c_style(name, msg, NULL, 0);
4217                strbuf_addf(msg, "%s\n%s%srename to ",
4218                            reset, line_prefix, set);
4219                quote_c_style(other, msg, NULL, 0);
4220                strbuf_addf(msg, "%s\n", reset);
4221                break;
4222        case DIFF_STATUS_MODIFIED:
4223                if (p->score) {
4224                        strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
4225                                    line_prefix,
4226                                    set, similarity_index(p), reset);
4227                        break;
4228                }
4229                /* fallthru */
4230        default:
4231                *must_show_header = 0;
4232        }
4233        if (one && two && !oideq(&one->oid, &two->oid)) {
4234                const unsigned hexsz = the_hash_algo->hexsz;
4235                int abbrev = o->flags.full_index ? hexsz : DEFAULT_ABBREV;
4236
4237                if (o->flags.binary) {
4238                        mmfile_t mf;
4239                        if ((!fill_mmfile(o->repo, &mf, one) &&
4240                             diff_filespec_is_binary(o->repo, one)) ||
4241                            (!fill_mmfile(o->repo, &mf, two) &&
4242                             diff_filespec_is_binary(o->repo, two)))
4243                                abbrev = hexsz;
4244                }
4245                strbuf_addf(msg, "%s%sindex %s..%s", line_prefix, set,
4246                            diff_abbrev_oid(&one->oid, abbrev),
4247                            diff_abbrev_oid(&two->oid, abbrev));
4248                if (one->mode == two->mode)
4249                        strbuf_addf(msg, " %06o", one->mode);
4250                strbuf_addf(msg, "%s\n", reset);
4251        }
4252}
4253
4254static void run_diff_cmd(const char *pgm,
4255                         const char *name,
4256                         const char *other,
4257                         const char *attr_path,
4258                         struct diff_filespec *one,
4259                         struct diff_filespec *two,
4260                         struct strbuf *msg,
4261                         struct diff_options *o,
4262                         struct diff_filepair *p)
4263{
4264        const char *xfrm_msg = NULL;
4265        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
4266        int must_show_header = 0;
4267
4268
4269        if (o->flags.allow_external) {
4270                struct userdiff_driver *drv;
4271
4272                drv = userdiff_find_by_path(o->repo->index, attr_path);
4273                if (drv && drv->external)
4274                        pgm = drv->external;
4275        }
4276
4277        if (msg) {
4278                /*
4279                 * don't use colors when the header is intended for an
4280                 * external diff driver
4281                 */
4282                fill_metainfo(msg, name, other, one, two, o, p,
4283                              &must_show_header,
4284                              want_color(o->use_color) && !pgm);
4285                xfrm_msg = msg->len ? msg->buf : NULL;
4286        }
4287
4288        if (pgm) {
4289                run_external_diff(pgm, name, other, one, two, xfrm_msg,
4290                                  complete_rewrite, o);
4291                return;
4292        }
4293        if (one && two)
4294                builtin_diff(name, other ? other : name,
4295                             one, two, xfrm_msg, must_show_header,
4296                             o, complete_rewrite);
4297        else
4298                fprintf(o->file, "* Unmerged path %s\n", name);
4299}
4300
4301static void diff_fill_oid_info(struct diff_filespec *one, struct index_state *istate)
4302{
4303        if (DIFF_FILE_VALID(one)) {
4304                if (!one->oid_valid) {
4305                        struct stat st;
4306                        if (one->is_stdin) {
4307                                oidclr(&one->oid);
4308                                return;
4309                        }
4310                        if (lstat(one->path, &st) < 0)
4311                                die_errno("stat '%s'", one->path);
4312                        if (index_path(istate, &one->oid, one->path, &st, 0))
4313                                die("cannot hash %s", one->path);
4314                }
4315        }
4316        else
4317                oidclr(&one->oid);
4318}
4319
4320static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
4321{
4322        /* Strip the prefix but do not molest /dev/null and absolute paths */
4323        if (*namep && !is_absolute_path(*namep)) {
4324                *namep += prefix_length;
4325                if (**namep == '/')
4326                        ++*namep;
4327        }
4328        if (*otherp && !is_absolute_path(*otherp)) {
4329                *otherp += prefix_length;
4330                if (**otherp == '/')
4331                        ++*otherp;
4332        }
4333}
4334
4335static void run_diff(struct diff_filepair *p, struct diff_options *o)
4336{
4337        const char *pgm = external_diff();
4338        struct strbuf msg;
4339        struct diff_filespec *one = p->one;
4340        struct diff_filespec *two = p->two;
4341        const char *name;
4342        const char *other;
4343        const char *attr_path;
4344
4345        name  = one->path;
4346        other = (strcmp(name, two->path) ? two->path : NULL);
4347        attr_path = name;
4348        if (o->prefix_length)
4349                strip_prefix(o->prefix_length, &name, &other);
4350
4351        if (!o->flags.allow_external)
4352                pgm = NULL;
4353
4354        if (DIFF_PAIR_UNMERGED(p)) {
4355                run_diff_cmd(pgm, name, NULL, attr_path,
4356                             NULL, NULL, NULL, o, p);
4357                return;
4358        }
4359
4360        diff_fill_oid_info(one, o->repo->index);
4361        diff_fill_oid_info(two, o->repo->index);
4362
4363        if (!pgm &&
4364            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
4365            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
4366                /*
4367                 * a filepair that changes between file and symlink
4368                 * needs to be split into deletion and creation.
4369                 */
4370                struct diff_filespec *null = alloc_filespec(two->path);
4371                run_diff_cmd(NULL, name, other, attr_path,
4372                             one, null, &msg,
4373                             o, p);
4374                free(null);
4375                strbuf_release(&msg);
4376
4377                null = alloc_filespec(one->path);
4378                run_diff_cmd(NULL, name, other, attr_path,
4379                             null, two, &msg, o, p);
4380                free(null);
4381        }
4382        else
4383                run_diff_cmd(pgm, name, other, attr_path,
4384                             one, two, &msg, o, p);
4385
4386        strbuf_release(&msg);
4387}
4388
4389static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
4390                         struct diffstat_t *diffstat)
4391{
4392        const char *name;
4393        const char *other;
4394
4395        if (DIFF_PAIR_UNMERGED(p)) {
4396                /* unmerged */
4397                builtin_diffstat(p->one->path, NULL, NULL, NULL,
4398                                 diffstat, o, p);
4399                return;
4400        }
4401
4402        name = p->one->path;
4403        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
4404
4405        if (o->prefix_length)
4406                strip_prefix(o->prefix_length, &name, &other);
4407
4408        diff_fill_oid_info(p->one, o->repo->index);
4409        diff_fill_oid_info(p->two, o->repo->index);
4410
4411        builtin_diffstat(name, other, p->one, p->two,
4412                         diffstat, o, p);
4413}
4414
4415static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
4416{
4417        const char *name;
4418        const char *other;
4419        const char *attr_path;
4420
4421        if (DIFF_PAIR_UNMERGED(p)) {
4422                /* unmerged */
4423                return;
4424        }
4425
4426        name = p->one->path;
4427        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
4428        attr_path = other ? other : name;
4429
4430        if (o->prefix_length)
4431                strip_prefix(o->prefix_length, &name, &other);
4432
4433        diff_fill_oid_info(p->one, o->repo->index);
4434        diff_fill_oid_info(p->two, o->repo->index);
4435
4436        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
4437}
4438
4439void repo_diff_setup(struct repository *r, struct diff_options *options)
4440{
4441        memcpy(options, &default_diff_options, sizeof(*options));
4442
4443        options->file = stdout;
4444        options->repo = r;
4445
4446        options->output_indicators[OUTPUT_INDICATOR_NEW] = '+';
4447        options->output_indicators[OUTPUT_INDICATOR_OLD] = '-';
4448        options->output_indicators[OUTPUT_INDICATOR_CONTEXT] = ' ';
4449        options->abbrev = DEFAULT_ABBREV;
4450        options->line_termination = '\n';
4451        options->break_opt = -1;
4452        options->rename_limit = -1;
4453        options->dirstat_permille = diff_dirstat_permille_default;
4454        options->context = diff_context_default;
4455        options->interhunkcontext = diff_interhunk_context_default;
4456        options->ws_error_highlight = ws_error_highlight_default;
4457        options->flags.rename_empty = 1;
4458        options->objfind = NULL;
4459
4460        /* pathchange left =NULL by default */
4461        options->change = diff_change;
4462        options->add_remove = diff_addremove;
4463        options->use_color = diff_use_color_default;
4464        options->detect_rename = diff_detect_rename_default;
4465        options->xdl_opts |= diff_algorithm;
4466        if (diff_indent_heuristic)
4467                DIFF_XDL_SET(options, INDENT_HEURISTIC);
4468
4469        options->orderfile = diff_order_file_cfg;
4470
4471        if (diff_no_prefix) {
4472                options->a_prefix = options->b_prefix = "";
4473        } else if (!diff_mnemonic_prefix) {
4474                options->a_prefix = "a/";
4475                options->b_prefix = "b/";
4476        }
4477
4478        options->color_moved = diff_color_moved_default;
4479        options->color_moved_ws_handling = diff_color_moved_ws_default;
4480}
4481
4482void diff_setup_done(struct diff_options *options)
4483{
4484        unsigned check_mask = DIFF_FORMAT_NAME |
4485                              DIFF_FORMAT_NAME_STATUS |
4486                              DIFF_FORMAT_CHECKDIFF |
4487                              DIFF_FORMAT_NO_OUTPUT;
4488        /*
4489         * This must be signed because we're comparing against a potentially
4490         * negative value.
4491         */
4492        const int hexsz = the_hash_algo->hexsz;
4493
4494        if (options->set_default)
4495                options->set_default(options);
4496
4497        if (HAS_MULTI_BITS(options->output_format & check_mask))
4498                die(_("--name-only, --name-status, --check and -s are mutually exclusive"));
4499
4500        if (HAS_MULTI_BITS(options->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK))
4501                die(_("-G, -S and --find-object are mutually exclusive"));
4502
4503        /*
4504         * Most of the time we can say "there are changes"
4505         * only by checking if there are changed paths, but
4506         * --ignore-whitespace* options force us to look
4507         * inside contents.
4508         */
4509
4510        if ((options->xdl_opts & XDF_WHITESPACE_FLAGS))
4511                options->flags.diff_from_contents = 1;
4512        else
4513                options->flags.diff_from_contents = 0;
4514
4515        if (options->flags.find_copies_harder)
4516                options->detect_rename = DIFF_DETECT_COPY;
4517
4518        if (!options->flags.relative_name)
4519                options->prefix = NULL;
4520        if (options->prefix)
4521                options->prefix_length = strlen(options->prefix);
4522        else
4523                options->prefix_length = 0;
4524
4525        if (options->output_format & (DIFF_FORMAT_NAME |
4526                                      DIFF_FORMAT_NAME_STATUS |
4527                                      DIFF_FORMAT_CHECKDIFF |
4528                                      DIFF_FORMAT_NO_OUTPUT))
4529                options->output_format &= ~(DIFF_FORMAT_RAW |
4530                                            DIFF_FORMAT_NUMSTAT |
4531                                            DIFF_FORMAT_DIFFSTAT |
4532                                            DIFF_FORMAT_SHORTSTAT |
4533                                            DIFF_FORMAT_DIRSTAT |
4534                                            DIFF_FORMAT_SUMMARY |
4535                                            DIFF_FORMAT_PATCH);
4536
4537        /*
4538         * These cases always need recursive; we do not drop caller-supplied
4539         * recursive bits for other formats here.
4540         */
4541        if (options->output_format & (DIFF_FORMAT_PATCH |
4542                                      DIFF_FORMAT_NUMSTAT |
4543                                      DIFF_FORMAT_DIFFSTAT |
4544                                      DIFF_FORMAT_SHORTSTAT |
4545                                      DIFF_FORMAT_DIRSTAT |
4546                                      DIFF_FORMAT_SUMMARY |
4547                                      DIFF_FORMAT_CHECKDIFF))
4548                options->flags.recursive = 1;
4549        /*
4550         * Also pickaxe would not work very well if you do not say recursive
4551         */
4552        if (options->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK)
4553                options->flags.recursive = 1;
4554        /*
4555         * When patches are generated, submodules diffed against the work tree
4556         * must be checked for dirtiness too so it can be shown in the output
4557         */
4558        if (options->output_format & DIFF_FORMAT_PATCH)
4559                options->flags.dirty_submodules = 1;
4560
4561        if (options->detect_rename && options->rename_limit < 0)
4562                options->rename_limit = diff_rename_limit_default;
4563        if (hexsz < options->abbrev)
4564                options->abbrev = hexsz; /* full */
4565
4566        /*
4567         * It does not make sense to show the first hit we happened
4568         * to have found.  It does not make sense not to return with
4569         * exit code in such a case either.
4570         */
4571        if (options->flags.quick) {
4572                options->output_format = DIFF_FORMAT_NO_OUTPUT;
4573                options->flags.exit_with_status = 1;
4574        }
4575
4576        options->diff_path_counter = 0;
4577
4578        if (options->flags.follow_renames && options->pathspec.nr != 1)
4579                die(_("--follow requires exactly one pathspec"));
4580
4581        if (!options->use_color || external_diff())
4582                options->color_moved = 0;
4583}
4584
4585static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
4586{
4587        char c, *eq;
4588        int len;
4589
4590        if (*arg != '-')
4591                return 0;
4592        c = *++arg;
4593        if (!c)
4594                return 0;
4595        if (c == arg_short) {
4596                c = *++arg;
4597                if (!c)
4598                        return 1;
4599                if (val && isdigit(c)) {
4600                        char *end;
4601                        int n = strtoul(arg, &end, 10);
4602                        if (*end)
4603                                return 0;
4604                        *val = n;
4605                        return 1;
4606                }
4607                return 0;
4608        }
4609        if (c != '-')
4610                return 0;
4611        arg++;
4612        eq = strchrnul(arg, '=');
4613        len = eq - arg;
4614        if (!len || strncmp(arg, arg_long, len))
4615                return 0;
4616        if (*eq) {
4617                int n;
4618                char *end;
4619                if (!isdigit(*++eq))
4620                        return 0;
4621                n = strtoul(eq, &end, 10);
4622                if (*end)
4623                        return 0;
4624                *val = n;
4625        }
4626        return 1;
4627}
4628
4629static int diff_scoreopt_parse(const char *opt);
4630
4631static inline int short_opt(char opt, const char **argv,
4632                            const char **optarg)
4633{
4634        const char *arg = argv[0];
4635        if (arg[0] != '-' || arg[1] != opt)
4636                return 0;
4637        if (arg[2] != '\0') {
4638                *optarg = arg + 2;
4639                return 1;
4640        }
4641        if (!argv[1])
4642                die("Option '%c' requires a value", opt);
4643        *optarg = argv[1];
4644        return 2;
4645}
4646
4647int parse_long_opt(const char *opt, const char **argv,
4648                   const char **optarg)
4649{
4650        const char *arg = argv[0];
4651        if (!skip_prefix(arg, "--", &arg))
4652                return 0;
4653        if (!skip_prefix(arg, opt, &arg))
4654                return 0;
4655        if (*arg == '=') { /* stuck form: --option=value */
4656                *optarg = arg + 1;
4657                return 1;
4658        }
4659        if (*arg != '\0')
4660                return 0;
4661        /* separate form: --option value */
4662        if (!argv[1])
4663                die("Option '--%s' requires a value", opt);
4664        *optarg = argv[1];
4665        return 2;
4666}
4667
4668static int stat_opt(struct diff_options *options, const char **av)
4669{
4670        const char *arg = av[0];
4671        char *end;
4672        int width = options->stat_width;
4673        int name_width = options->stat_name_width;
4674        int graph_width = options->stat_graph_width;
4675        int count = options->stat_count;
4676        int argcount = 1;
4677
4678        if (!skip_prefix(arg, "--stat", &arg))
4679                BUG("stat option does not begin with --stat: %s", arg);
4680        end = (char *)arg;
4681
4682        switch (*arg) {
4683        case '-':
4684                if (skip_prefix(arg, "-width", &arg)) {
4685                        if (*arg == '=')
4686                                width = strtoul(arg + 1, &end, 10);
4687                        else if (!*arg && !av[1])
4688                                die_want_option("--stat-width");
4689                        else if (!*arg) {
4690                                width = strtoul(av[1], &end, 10);
4691                                argcount = 2;
4692                        }
4693                } else if (skip_prefix(arg, "-name-width", &arg)) {
4694                        if (*arg == '=')
4695                                name_width = strtoul(arg + 1, &end, 10);
4696                        else if (!*arg && !av[1])
4697                                die_want_option("--stat-name-width");
4698                        else if (!*arg) {
4699                                name_width = strtoul(av[1], &end, 10);
4700                                argcount = 2;
4701                        }
4702                } else if (skip_prefix(arg, "-graph-width", &arg)) {
4703                        if (*arg == '=')
4704                                graph_width = strtoul(arg + 1, &end, 10);
4705                        else if (!*arg && !av[1])
4706                                die_want_option("--stat-graph-width");
4707                        else if (!*arg) {
4708                                graph_width = strtoul(av[1], &end, 10);
4709                                argcount = 2;
4710                        }
4711                } else if (skip_prefix(arg, "-count", &arg)) {
4712                        if (*arg == '=')
4713                                count = strtoul(arg + 1, &end, 10);
4714                        else if (!*arg && !av[1])
4715                                die_want_option("--stat-count");
4716                        else if (!*arg) {
4717                                count = strtoul(av[1], &end, 10);
4718                                argcount = 2;
4719                        }
4720                }
4721                break;
4722        case '=':
4723                width = strtoul(arg+1, &end, 10);
4724                if (*end == ',')
4725                        name_width = strtoul(end+1, &end, 10);
4726                if (*end == ',')
4727                        count = strtoul(end+1, &end, 10);
4728        }
4729
4730        /* Important! This checks all the error cases! */
4731        if (*end)
4732                return 0;
4733        options->output_format |= DIFF_FORMAT_DIFFSTAT;
4734        options->stat_name_width = name_width;
4735        options->stat_graph_width = graph_width;
4736        options->stat_width = width;
4737        options->stat_count = count;
4738        return argcount;
4739}
4740
4741static int parse_dirstat_opt(struct diff_options *options, const char *params)
4742{
4743        struct strbuf errmsg = STRBUF_INIT;
4744        if (parse_dirstat_params(options, params, &errmsg))
4745                die(_("Failed to parse --dirstat/-X option parameter:\n%s"),
4746                    errmsg.buf);
4747        strbuf_release(&errmsg);
4748        /*
4749         * The caller knows a dirstat-related option is given from the command
4750         * line; allow it to say "return this_function();"
4751         */
4752        options->output_format |= DIFF_FORMAT_DIRSTAT;
4753        return 1;
4754}
4755
4756static int parse_submodule_opt(struct diff_options *options, const char *value)
4757{
4758        if (parse_submodule_params(options, value))
4759                die(_("Failed to parse --submodule option parameter: '%s'"),
4760                        value);
4761        return 1;
4762}
4763
4764static const char diff_status_letters[] = {
4765        DIFF_STATUS_ADDED,
4766        DIFF_STATUS_COPIED,
4767        DIFF_STATUS_DELETED,
4768        DIFF_STATUS_MODIFIED,
4769        DIFF_STATUS_RENAMED,
4770        DIFF_STATUS_TYPE_CHANGED,
4771        DIFF_STATUS_UNKNOWN,
4772        DIFF_STATUS_UNMERGED,
4773        DIFF_STATUS_FILTER_AON,
4774        DIFF_STATUS_FILTER_BROKEN,
4775        '\0',
4776};
4777
4778static unsigned int filter_bit['Z' + 1];
4779
4780static void prepare_filter_bits(void)
4781{
4782        int i;
4783
4784        if (!filter_bit[DIFF_STATUS_ADDED]) {
4785                for (i = 0; diff_status_letters[i]; i++)
4786                        filter_bit[(int) diff_status_letters[i]] = (1 << i);
4787        }
4788}
4789
4790static unsigned filter_bit_tst(char status, const struct diff_options *opt)
4791{
4792        return opt->filter & filter_bit[(int) status];
4793}
4794
4795static int parse_diff_filter_opt(const char *optarg, struct diff_options *opt)
4796{
4797        int i, optch;
4798
4799        prepare_filter_bits();
4800
4801        /*
4802         * If there is a negation e.g. 'd' in the input, and we haven't
4803         * initialized the filter field with another --diff-filter, start
4804         * from full set of bits, except for AON.
4805         */
4806        if (!opt->filter) {
4807                for (i = 0; (optch = optarg[i]) != '\0'; i++) {
4808                        if (optch < 'a' || 'z' < optch)
4809                                continue;
4810                        opt->filter = (1 << (ARRAY_SIZE(diff_status_letters) - 1)) - 1;
4811                        opt->filter &= ~filter_bit[DIFF_STATUS_FILTER_AON];
4812                        break;
4813                }
4814        }
4815
4816        for (i = 0; (optch = optarg[i]) != '\0'; i++) {
4817                unsigned int bit;
4818                int negate;
4819
4820                if ('a' <= optch && optch <= 'z') {
4821                        negate = 1;
4822                        optch = toupper(optch);
4823                } else {
4824                        negate = 0;
4825                }
4826
4827                bit = (0 <= optch && optch <= 'Z') ? filter_bit[optch] : 0;
4828                if (!bit)
4829                        return optarg[i];
4830                if (negate)
4831                        opt->filter &= ~bit;
4832                else
4833                        opt->filter |= bit;
4834        }
4835        return 0;
4836}
4837
4838static void enable_patch_output(int *fmt) {
4839        *fmt &= ~DIFF_FORMAT_NO_OUTPUT;
4840        *fmt |= DIFF_FORMAT_PATCH;
4841}
4842
4843static int parse_ws_error_highlight_opt(struct diff_options *opt, const char *arg)
4844{
4845        int val = parse_ws_error_highlight(arg);
4846
4847        if (val < 0) {
4848                error("unknown value after ws-error-highlight=%.*s",
4849                      -1 - val, arg);
4850                return 0;
4851        }
4852        opt->ws_error_highlight = val;
4853        return 1;
4854}
4855
4856static int parse_objfind_opt(struct diff_options *opt, const char *arg)
4857{
4858        struct object_id oid;
4859
4860        if (get_oid(arg, &oid))
4861                return error("unable to resolve '%s'", arg);
4862
4863        if (!opt->objfind)
4864                opt->objfind = xcalloc(1, sizeof(*opt->objfind));
4865
4866        opt->pickaxe_opts |= DIFF_PICKAXE_KIND_OBJFIND;
4867        opt->flags.recursive = 1;
4868        opt->flags.tree_in_recursive = 1;
4869        oidset_insert(opt->objfind, &oid);
4870        return 1;
4871}
4872
4873int diff_opt_parse(struct diff_options *options,
4874                   const char **av, int ac, const char *prefix)
4875{
4876        const char *arg = av[0];
4877        const char *optarg;
4878        int argcount;
4879
4880        if (!prefix)
4881                prefix = "";
4882
4883        /* Output format options */
4884        if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch")
4885            || opt_arg(arg, 'U', "unified", &options->context))
4886                enable_patch_output(&options->output_format);
4887        else if (!strcmp(arg, "--raw"))
4888                options->output_format |= DIFF_FORMAT_RAW;
4889        else if (!strcmp(arg, "--patch-with-raw")) {
4890                enable_patch_output(&options->output_format);
4891                options->output_format |= DIFF_FORMAT_RAW;
4892        } else if (!strcmp(arg, "--numstat"))
4893                options->output_format |= DIFF_FORMAT_NUMSTAT;
4894        else if (!strcmp(arg, "--shortstat"))
4895                options->output_format |= DIFF_FORMAT_SHORTSTAT;
4896        else if (skip_prefix(arg, "-X", &arg) ||
4897                 skip_to_optional_arg(arg, "--dirstat", &arg))
4898                return parse_dirstat_opt(options, arg);
4899        else if (!strcmp(arg, "--cumulative"))
4900                return parse_dirstat_opt(options, "cumulative");
4901        else if (skip_to_optional_arg(arg, "--dirstat-by-file", &arg)) {
4902                parse_dirstat_opt(options, "files");
4903                return parse_dirstat_opt(options, arg);
4904        }
4905        else if (!strcmp(arg, "--check"))
4906                options->output_format |= DIFF_FORMAT_CHECKDIFF;
4907        else if (!strcmp(arg, "--summary"))
4908                options->output_format |= DIFF_FORMAT_SUMMARY;
4909        else if (!strcmp(arg, "--patch-with-stat")) {
4910                enable_patch_output(&options->output_format);
4911                options->output_format |= DIFF_FORMAT_DIFFSTAT;
4912        } else if (!strcmp(arg, "--name-only"))
4913                options->output_format |= DIFF_FORMAT_NAME;
4914        else if (!strcmp(arg, "--name-status"))
4915                options->output_format |= DIFF_FORMAT_NAME_STATUS;
4916        else if (!strcmp(arg, "-s") || !strcmp(arg, "--no-patch"))
4917                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
4918        else if (starts_with(arg, "--stat"))
4919                /* --stat, --stat-width, --stat-name-width, or --stat-count */
4920                return stat_opt(options, av);
4921        else if (!strcmp(arg, "--compact-summary")) {
4922                 options->flags.stat_with_summary = 1;
4923                 options->output_format |= DIFF_FORMAT_DIFFSTAT;
4924        } else if (!strcmp(arg, "--no-compact-summary"))
4925                 options->flags.stat_with_summary = 0;
4926        else if (skip_prefix(arg, "--output-indicator-new=", &arg))
4927                options->output_indicators[OUTPUT_INDICATOR_NEW] = arg[0];
4928        else if (skip_prefix(arg, "--output-indicator-old=", &arg))
4929                options->output_indicators[OUTPUT_INDICATOR_OLD] = arg[0];
4930        else if (skip_prefix(arg, "--output-indicator-context=", &arg))
4931                options->output_indicators[OUTPUT_INDICATOR_CONTEXT] = arg[0];
4932
4933        /* renames options */
4934        else if (starts_with(arg, "-B") ||
4935                 skip_to_optional_arg(arg, "--break-rewrites", NULL)) {
4936                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
4937                        return error("invalid argument to -B: %s", arg+2);
4938        }
4939        else if (starts_with(arg, "-M") ||
4940                 skip_to_optional_arg(arg, "--find-renames", NULL)) {
4941                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
4942                        return error("invalid argument to -M: %s", arg+2);
4943                options->detect_rename = DIFF_DETECT_RENAME;
4944        }
4945        else if (!strcmp(arg, "-D") || !strcmp(arg, "--irreversible-delete")) {
4946                options->irreversible_delete = 1;
4947        }
4948        else if (starts_with(arg, "-C") ||
4949                 skip_to_optional_arg(arg, "--find-copies", NULL)) {
4950                if (options->detect_rename == DIFF_DETECT_COPY)
4951                        options->flags.find_copies_harder = 1;
4952                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
4953                        return error("invalid argument to -C: %s", arg+2);
4954                options->detect_rename = DIFF_DETECT_COPY;
4955        }
4956        else if (!strcmp(arg, "--no-renames"))
4957                options->detect_rename = 0;
4958        else if (!strcmp(arg, "--rename-empty"))
4959                options->flags.rename_empty = 1;
4960        else if (!strcmp(arg, "--no-rename-empty"))
4961                options->flags.rename_empty = 0;
4962        else if (skip_to_optional_arg_default(arg, "--relative", &arg, NULL)) {
4963                options->flags.relative_name = 1;
4964                if (arg)
4965                        options->prefix = arg;
4966        }
4967
4968        /* xdiff options */
4969        else if (!strcmp(arg, "--minimal"))
4970                DIFF_XDL_SET(options, NEED_MINIMAL);
4971        else if (!strcmp(arg, "--no-minimal"))
4972                DIFF_XDL_CLR(options, NEED_MINIMAL);
4973        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
4974                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
4975        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
4976                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
4977        else if (!strcmp(arg, "--ignore-space-at-eol"))
4978                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
4979        else if (!strcmp(arg, "--ignore-cr-at-eol"))
4980                DIFF_XDL_SET(options, IGNORE_CR_AT_EOL);
4981        else if (!strcmp(arg, "--ignore-blank-lines"))
4982                DIFF_XDL_SET(options, IGNORE_BLANK_LINES);
4983        else if (!strcmp(arg, "--indent-heuristic"))
4984                DIFF_XDL_SET(options, INDENT_HEURISTIC);
4985        else if (!strcmp(arg, "--no-indent-heuristic"))
4986                DIFF_XDL_CLR(options, INDENT_HEURISTIC);
4987        else if (!strcmp(arg, "--patience")) {
4988                int i;
4989                options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
4990                /*
4991                 * Both --patience and --anchored use PATIENCE_DIFF
4992                 * internally, so remove any anchors previously
4993                 * specified.
4994                 */
4995                for (i = 0; i < options->anchors_nr; i++)
4996                        free(options->anchors[i]);
4997                options->anchors_nr = 0;
4998        } else if (!strcmp(arg, "--histogram"))
4999                options->xdl_opts = DIFF_WITH_ALG(options, HISTOGRAM_DIFF);
5000        else if ((argcount = parse_long_opt("diff-algorithm", av, &optarg))) {
5001                long value = parse_algorithm_value(optarg);
5002                if (value < 0)
5003                        return error("option diff-algorithm accepts \"myers\", "
5004                                     "\"minimal\", \"patience\" and \"histogram\"");
5005                /* clear out previous settings */
5006                DIFF_XDL_CLR(options, NEED_MINIMAL);
5007                options->xdl_opts &= ~XDF_DIFF_ALGORITHM_MASK;
5008                options->xdl_opts |= value;
5009                return argcount;
5010        } else if (skip_prefix(arg, "--anchored=", &arg)) {
5011                options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
5012                ALLOC_GROW(options->anchors, options->anchors_nr + 1,
5013                           options->anchors_alloc);
5014                options->anchors[options->anchors_nr++] = xstrdup(arg);
5015        }
5016
5017        /* flags options */
5018        else if (!strcmp(arg, "--binary")) {
5019                enable_patch_output(&options->output_format);
5020                options->flags.binary = 1;
5021        }
5022        else if (!strcmp(arg, "--full-index"))
5023                options->flags.full_index = 1;
5024        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
5025                options->flags.text = 1;
5026        else if (!strcmp(arg, "-R"))
5027                options->flags.reverse_diff = 1;
5028        else if (!strcmp(arg, "--find-copies-harder"))
5029                options->flags.find_copies_harder = 1;
5030        else if (!strcmp(arg, "--follow"))
5031                options->flags.follow_renames = 1;
5032        else if (!strcmp(arg, "--no-follow")) {
5033                options->flags.follow_renames = 0;
5034                options->flags.default_follow_renames = 0;
5035        } else if (skip_to_optional_arg_default(arg, "--color", &arg, "always")) {
5036                int value = git_config_colorbool(NULL, arg);
5037                if (value < 0)
5038                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
5039                options->use_color = value;
5040        }
5041        else if (!strcmp(arg, "--no-color"))
5042                options->use_color = 0;
5043        else if (!strcmp(arg, "--color-moved")) {
5044                if (diff_color_moved_default)
5045                        options->color_moved = diff_color_moved_default;
5046                if (options->color_moved == COLOR_MOVED_NO)
5047                        options->color_moved = COLOR_MOVED_DEFAULT;
5048        } else if (!strcmp(arg, "--no-color-moved"))
5049                options->color_moved = COLOR_MOVED_NO;
5050        else if (skip_prefix(arg, "--color-moved=", &arg)) {
5051                int cm = parse_color_moved(arg);
5052                if (cm < 0)
5053                        die("bad --color-moved argument: %s", arg);
5054                options->color_moved = cm;
5055        } else if (!strcmp(arg, "--no-color-moved-ws")) {
5056                options->color_moved_ws_handling = 0;
5057        } else if (skip_prefix(arg, "--color-moved-ws=", &arg)) {
5058                options->color_moved_ws_handling = parse_color_moved_ws(arg);
5059        } else if (skip_to_optional_arg_default(arg, "--color-words", &options->word_regex, NULL)) {
5060                options->use_color = 1;
5061                options->word_diff = DIFF_WORDS_COLOR;
5062        }
5063        else if (!strcmp(arg, "--word-diff")) {
5064                if (options->word_diff == DIFF_WORDS_NONE)
5065                        options->word_diff = DIFF_WORDS_PLAIN;
5066        }
5067        else if (skip_prefix(arg, "--word-diff=", &arg)) {
5068                if (!strcmp(arg, "plain"))
5069                        options->word_diff = DIFF_WORDS_PLAIN;
5070                else if (!strcmp(arg, "color")) {
5071                        options->use_color = 1;
5072                        options->word_diff = DIFF_WORDS_COLOR;
5073                }
5074                else if (!strcmp(arg, "porcelain"))
5075                        options->word_diff = DIFF_WORDS_PORCELAIN;
5076                else if (!strcmp(arg, "none"))
5077                        options->word_diff = DIFF_WORDS_NONE;
5078                else
5079                        die("bad --word-diff argument: %s", arg);
5080        }
5081        else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
5082                if (options->word_diff == DIFF_WORDS_NONE)
5083                        options->word_diff = DIFF_WORDS_PLAIN;
5084                options->word_regex = optarg;
5085                return argcount;
5086        }
5087        else if (!strcmp(arg, "--exit-code"))
5088                options->flags.exit_with_status = 1;
5089        else if (!strcmp(arg, "--quiet"))
5090                options->flags.quick = 1;
5091        else if (!strcmp(arg, "--ext-diff"))
5092                options->flags.allow_external = 1;
5093        else if (!strcmp(arg, "--no-ext-diff"))
5094                options->flags.allow_external = 0;
5095        else if (!strcmp(arg, "--textconv")) {
5096                options->flags.allow_textconv = 1;
5097                options->flags.textconv_set_via_cmdline = 1;
5098        } else if (!strcmp(arg, "--no-textconv"))
5099                options->flags.allow_textconv = 0;
5100        else if (skip_to_optional_arg_default(arg, "--ignore-submodules", &arg, "all")) {
5101                options->flags.override_submodule_config = 1;
5102                handle_ignore_submodules_arg(options, arg);
5103        } else if (skip_to_optional_arg_default(arg, "--submodule", &arg, "log"))
5104                return parse_submodule_opt(options, arg);
5105        else if (skip_prefix(arg, "--ws-error-highlight=", &arg))
5106                return parse_ws_error_highlight_opt(options, arg);
5107        else if (!strcmp(arg, "--ita-invisible-in-index"))
5108                options->ita_invisible_in_index = 1;
5109        else if (!strcmp(arg, "--ita-visible-in-index"))
5110                options->ita_invisible_in_index = 0;
5111
5112        /* misc options */
5113        else if (!strcmp(arg, "-z"))
5114                options->line_termination = 0;
5115        else if ((argcount = short_opt('l', av, &optarg))) {
5116                options->rename_limit = strtoul(optarg, NULL, 10);
5117                return argcount;
5118        }
5119        else if ((argcount = short_opt('S', av, &optarg))) {
5120                options->pickaxe = optarg;
5121                options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
5122                return argcount;
5123        } else if ((argcount = short_opt('G', av, &optarg))) {
5124                options->pickaxe = optarg;
5125                options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
5126                return argcount;
5127        }
5128        else if (!strcmp(arg, "--pickaxe-all"))
5129                options->pickaxe_opts |= DIFF_PICKAXE_ALL;
5130        else if (!strcmp(arg, "--pickaxe-regex"))
5131                options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
5132        else if ((argcount = short_opt('O', av, &optarg))) {
5133                options->orderfile = prefix_filename(prefix, optarg);
5134                return argcount;
5135        } else if (skip_prefix(arg, "--find-object=", &arg))
5136                return parse_objfind_opt(options, arg);
5137        else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
5138                int offending = parse_diff_filter_opt(optarg, options);
5139                if (offending)
5140                        die("unknown change class '%c' in --diff-filter=%s",
5141                            offending, optarg);
5142                return argcount;
5143        }
5144        else if (!strcmp(arg, "--no-abbrev"))
5145                options->abbrev = 0;
5146        else if (!strcmp(arg, "--abbrev"))
5147                options->abbrev = DEFAULT_ABBREV;
5148        else if (skip_prefix(arg, "--abbrev=", &arg)) {
5149                options->abbrev = strtoul(arg, NULL, 10);
5150                if (options->abbrev < MINIMUM_ABBREV)
5151                        options->abbrev = MINIMUM_ABBREV;
5152                else if (the_hash_algo->hexsz < options->abbrev)
5153                        options->abbrev = the_hash_algo->hexsz;
5154        }
5155        else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
5156                options->a_prefix = optarg;
5157                return argcount;
5158        }
5159        else if ((argcount = parse_long_opt("line-prefix", av, &optarg))) {
5160                options->line_prefix = optarg;
5161                options->line_prefix_length = strlen(options->line_prefix);
5162                graph_setup_line_prefix(options);
5163                return argcount;
5164        }
5165        else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
5166                options->b_prefix = optarg;
5167                return argcount;
5168        }
5169        else if (!strcmp(arg, "--no-prefix"))
5170                options->a_prefix = options->b_prefix = "";
5171        else if (opt_arg(arg, '\0', "inter-hunk-context",
5172                         &options->interhunkcontext))
5173                ;
5174        else if (!strcmp(arg, "-W"))
5175                options->flags.funccontext = 1;
5176        else if (!strcmp(arg, "--function-context"))
5177                options->flags.funccontext = 1;
5178        else if (!strcmp(arg, "--no-function-context"))
5179                options->flags.funccontext = 0;
5180        else if ((argcount = parse_long_opt("output", av, &optarg))) {
5181                char *path = prefix_filename(prefix, optarg);
5182                options->file = xfopen(path, "w");
5183                options->close_file = 1;
5184                if (options->use_color != GIT_COLOR_ALWAYS)
5185                        options->use_color = GIT_COLOR_NEVER;
5186                free(path);
5187                return argcount;
5188        } else
5189                return 0;
5190        return 1;
5191}
5192
5193int parse_rename_score(const char **cp_p)
5194{
5195        unsigned long num, scale;
5196        int ch, dot;
5197        const char *cp = *cp_p;
5198
5199        num = 0;
5200        scale = 1;
5201        dot = 0;
5202        for (;;) {
5203                ch = *cp;
5204                if ( !dot && ch == '.' ) {
5205                        scale = 1;
5206                        dot = 1;
5207                } else if ( ch == '%' ) {
5208                        scale = dot ? scale*100 : 100;
5209                        cp++;   /* % is always at the end */
5210                        break;
5211                } else if ( ch >= '0' && ch <= '9' ) {
5212                        if ( scale < 100000 ) {
5213                                scale *= 10;
5214                                num = (num*10) + (ch-'0');
5215                        }
5216                } else {
5217                        break;
5218                }
5219                cp++;
5220        }
5221        *cp_p = cp;
5222
5223        /* user says num divided by scale and we say internally that
5224         * is MAX_SCORE * num / scale.
5225         */
5226        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
5227}
5228
5229static int diff_scoreopt_parse(const char *opt)
5230{
5231        int opt1, opt2, cmd;
5232
5233        if (*opt++ != '-')
5234                return -1;
5235        cmd = *opt++;
5236        if (cmd == '-') {
5237                /* convert the long-form arguments into short-form versions */
5238                if (skip_prefix(opt, "break-rewrites", &opt)) {
5239                        if (*opt == 0 || *opt++ == '=')
5240                                cmd = 'B';
5241                } else if (skip_prefix(opt, "find-copies", &opt)) {
5242                        if (*opt == 0 || *opt++ == '=')
5243                                cmd = 'C';
5244                } else if (skip_prefix(opt, "find-renames", &opt)) {
5245                        if (*opt == 0 || *opt++ == '=')
5246                                cmd = 'M';
5247                }
5248        }
5249        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
5250                return -1; /* that is not a -M, -C, or -B option */
5251
5252        opt1 = parse_rename_score(&opt);
5253        if (cmd != 'B')
5254                opt2 = 0;
5255        else {
5256                if (*opt == 0)
5257                        opt2 = 0;
5258                else if (*opt != '/')
5259                        return -1; /* we expect -B80/99 or -B80 */
5260                else {
5261                        opt++;
5262                        opt2 = parse_rename_score(&opt);
5263                }
5264        }
5265        if (*opt != 0)
5266                return -1;
5267        return opt1 | (opt2 << 16);
5268}
5269
5270struct diff_queue_struct diff_queued_diff;
5271
5272void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
5273{
5274        ALLOC_GROW(queue->queue, queue->nr + 1, queue->alloc);
5275        queue->queue[queue->nr++] = dp;
5276}
5277
5278struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
5279                                 struct diff_filespec *one,
5280                                 struct diff_filespec *two)
5281{
5282        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
5283        dp->one = one;
5284        dp->two = two;
5285        if (queue)
5286                diff_q(queue, dp);
5287        return dp;
5288}
5289
5290void diff_free_filepair(struct diff_filepair *p)
5291{
5292        free_filespec(p->one);
5293        free_filespec(p->two);
5294        free(p);
5295}
5296
5297const char *diff_aligned_abbrev(const struct object_id *oid, int len)
5298{
5299        int abblen;
5300        const char *abbrev;
5301
5302        /* Do we want all 40 hex characters? */
5303        if (len == the_hash_algo->hexsz)
5304                return oid_to_hex(oid);
5305
5306        /* An abbreviated value is fine, possibly followed by an ellipsis. */
5307        abbrev = diff_abbrev_oid(oid, len);
5308
5309        if (!print_sha1_ellipsis())
5310                return abbrev;
5311
5312        abblen = strlen(abbrev);
5313
5314        /*
5315         * In well-behaved cases, where the abbreviated result is the
5316         * same as the requested length, append three dots after the
5317         * abbreviation (hence the whole logic is limited to the case
5318         * where abblen < 37); when the actual abbreviated result is a
5319         * bit longer than the requested length, we reduce the number
5320         * of dots so that they match the well-behaved ones.  However,
5321         * if the actual abbreviation is longer than the requested
5322         * length by more than three, we give up on aligning, and add
5323         * three dots anyway, to indicate that the output is not the
5324         * full object name.  Yes, this may be suboptimal, but this
5325         * appears only in "diff --raw --abbrev" output and it is not
5326         * worth the effort to change it now.  Note that this would
5327         * likely to work fine when the automatic sizing of default
5328         * abbreviation length is used--we would be fed -1 in "len" in
5329         * that case, and will end up always appending three-dots, but
5330         * the automatic sizing is supposed to give abblen that ensures
5331         * uniqueness across all objects (statistically speaking).
5332         */
5333        if (abblen < the_hash_algo->hexsz - 3) {
5334                static char hex[GIT_MAX_HEXSZ + 1];
5335                if (len < abblen && abblen <= len + 2)
5336                        xsnprintf(hex, sizeof(hex), "%s%.*s", abbrev, len+3-abblen, "..");
5337                else
5338                        xsnprintf(hex, sizeof(hex), "%s...", abbrev);
5339                return hex;
5340        }
5341
5342        return oid_to_hex(oid);
5343}
5344
5345static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
5346{
5347        int line_termination = opt->line_termination;
5348        int inter_name_termination = line_termination ? '\t' : '\0';
5349
5350        fprintf(opt->file, "%s", diff_line_prefix(opt));
5351        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
5352                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
5353                        diff_aligned_abbrev(&p->one->oid, opt->abbrev));
5354                fprintf(opt->file, "%s ",
5355                        diff_aligned_abbrev(&p->two->oid, opt->abbrev));
5356        }
5357        if (p->score) {
5358                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
5359                        inter_name_termination);
5360        } else {
5361                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
5362        }
5363
5364        if (p->status == DIFF_STATUS_COPIED ||
5365            p->status == DIFF_STATUS_RENAMED) {
5366                const char *name_a, *name_b;
5367                name_a = p->one->path;
5368                name_b = p->two->path;
5369                strip_prefix(opt->prefix_length, &name_a, &name_b);
5370                write_name_quoted(name_a, opt->file, inter_name_termination);
5371                write_name_quoted(name_b, opt->file, line_termination);
5372        } else {
5373                const char *name_a, *name_b;
5374                name_a = p->one->mode ? p->one->path : p->two->path;
5375                name_b = NULL;
5376                strip_prefix(opt->prefix_length, &name_a, &name_b);
5377                write_name_quoted(name_a, opt->file, line_termination);
5378        }
5379}
5380
5381int diff_unmodified_pair(struct diff_filepair *p)
5382{
5383        /* This function is written stricter than necessary to support
5384         * the currently implemented transformers, but the idea is to
5385         * let transformers to produce diff_filepairs any way they want,
5386         * and filter and clean them up here before producing the output.
5387         */
5388        struct diff_filespec *one = p->one, *two = p->two;
5389
5390        if (DIFF_PAIR_UNMERGED(p))
5391                return 0; /* unmerged is interesting */
5392
5393        /* deletion, addition, mode or type change
5394         * and rename are all interesting.
5395         */
5396        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
5397            DIFF_PAIR_MODE_CHANGED(p) ||
5398            strcmp(one->path, two->path))
5399                return 0;
5400
5401        /* both are valid and point at the same path.  that is, we are
5402         * dealing with a change.
5403         */
5404        if (one->oid_valid && two->oid_valid &&
5405            oideq(&one->oid, &two->oid) &&
5406            !one->dirty_submodule && !two->dirty_submodule)
5407                return 1; /* no change */
5408        if (!one->oid_valid && !two->oid_valid)
5409                return 1; /* both look at the same file on the filesystem. */
5410        return 0;
5411}
5412
5413static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
5414{
5415        if (diff_unmodified_pair(p))
5416                return;
5417
5418        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5419            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5420                return; /* no tree diffs in patch format */
5421
5422        run_diff(p, o);
5423}
5424
5425static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
5426                            struct diffstat_t *diffstat)
5427{
5428        if (diff_unmodified_pair(p))
5429                return;
5430
5431        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5432            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5433                return; /* no useful stat for tree diffs */
5434
5435        run_diffstat(p, o, diffstat);
5436}
5437
5438static void diff_flush_checkdiff(struct diff_filepair *p,
5439                struct diff_options *o)
5440{
5441        if (diff_unmodified_pair(p))
5442                return;
5443
5444        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5445            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5446                return; /* nothing to check in tree diffs */
5447
5448        run_checkdiff(p, o);
5449}
5450
5451int diff_queue_is_empty(void)
5452{
5453        struct diff_queue_struct *q = &diff_queued_diff;
5454        int i;
5455        for (i = 0; i < q->nr; i++)
5456                if (!diff_unmodified_pair(q->queue[i]))
5457                        return 0;
5458        return 1;
5459}
5460
5461#if DIFF_DEBUG
5462void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
5463{
5464        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
5465                x, one ? one : "",
5466                s->path,
5467                DIFF_FILE_VALID(s) ? "valid" : "invalid",
5468                s->mode,
5469                s->oid_valid ? oid_to_hex(&s->oid) : "");
5470        fprintf(stderr, "queue[%d] %s size %lu\n",
5471                x, one ? one : "",
5472                s->size);
5473}
5474
5475void diff_debug_filepair(const struct diff_filepair *p, int i)
5476{
5477        diff_debug_filespec(p->one, i, "one");
5478        diff_debug_filespec(p->two, i, "two");
5479        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
5480                p->score, p->status ? p->status : '?',
5481                p->one->rename_used, p->broken_pair);
5482}
5483
5484void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
5485{
5486        int i;
5487        if (msg)
5488                fprintf(stderr, "%s\n", msg);
5489        fprintf(stderr, "q->nr = %d\n", q->nr);
5490        for (i = 0; i < q->nr; i++) {
5491                struct diff_filepair *p = q->queue[i];
5492                diff_debug_filepair(p, i);
5493        }
5494}
5495#endif
5496
5497static void diff_resolve_rename_copy(void)
5498{
5499        int i;
5500        struct diff_filepair *p;
5501        struct diff_queue_struct *q = &diff_queued_diff;
5502
5503        diff_debug_queue("resolve-rename-copy", q);
5504
5505        for (i = 0; i < q->nr; i++) {
5506                p = q->queue[i];
5507                p->status = 0; /* undecided */
5508                if (DIFF_PAIR_UNMERGED(p))
5509                        p->status = DIFF_STATUS_UNMERGED;
5510                else if (!DIFF_FILE_VALID(p->one))
5511                        p->status = DIFF_STATUS_ADDED;
5512                else if (!DIFF_FILE_VALID(p->two))
5513                        p->status = DIFF_STATUS_DELETED;
5514                else if (DIFF_PAIR_TYPE_CHANGED(p))
5515                        p->status = DIFF_STATUS_TYPE_CHANGED;
5516
5517                /* from this point on, we are dealing with a pair
5518                 * whose both sides are valid and of the same type, i.e.
5519                 * either in-place edit or rename/copy edit.
5520                 */
5521                else if (DIFF_PAIR_RENAME(p)) {
5522                        /*
5523                         * A rename might have re-connected a broken
5524                         * pair up, causing the pathnames to be the
5525                         * same again. If so, that's not a rename at
5526                         * all, just a modification..
5527                         *
5528                         * Otherwise, see if this source was used for
5529                         * multiple renames, in which case we decrement
5530                         * the count, and call it a copy.
5531                         */
5532                        if (!strcmp(p->one->path, p->two->path))
5533                                p->status = DIFF_STATUS_MODIFIED;
5534                        else if (--p->one->rename_used > 0)
5535                                p->status = DIFF_STATUS_COPIED;
5536                        else
5537                                p->status = DIFF_STATUS_RENAMED;
5538                }
5539                else if (!oideq(&p->one->oid, &p->two->oid) ||
5540                         p->one->mode != p->two->mode ||
5541                         p->one->dirty_submodule ||
5542                         p->two->dirty_submodule ||
5543                         is_null_oid(&p->one->oid))
5544                        p->status = DIFF_STATUS_MODIFIED;
5545                else {
5546                        /* This is a "no-change" entry and should not
5547                         * happen anymore, but prepare for broken callers.
5548                         */
5549                        error("feeding unmodified %s to diffcore",
5550                              p->one->path);
5551                        p->status = DIFF_STATUS_UNKNOWN;
5552                }
5553        }
5554        diff_debug_queue("resolve-rename-copy done", q);
5555}
5556
5557static int check_pair_status(struct diff_filepair *p)
5558{
5559        switch (p->status) {
5560        case DIFF_STATUS_UNKNOWN:
5561                return 0;
5562        case 0:
5563                die("internal error in diff-resolve-rename-copy");
5564        default:
5565                return 1;
5566        }
5567}
5568
5569static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
5570{
5571        int fmt = opt->output_format;
5572
5573        if (fmt & DIFF_FORMAT_CHECKDIFF)
5574                diff_flush_checkdiff(p, opt);
5575        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
5576                diff_flush_raw(p, opt);
5577        else if (fmt & DIFF_FORMAT_NAME) {
5578                const char *name_a, *name_b;
5579                name_a = p->two->path;
5580                name_b = NULL;
5581                strip_prefix(opt->prefix_length, &name_a, &name_b);
5582                fprintf(opt->file, "%s", diff_line_prefix(opt));
5583                write_name_quoted(name_a, opt->file, opt->line_termination);
5584        }
5585}
5586
5587static void show_file_mode_name(struct diff_options *opt, const char *newdelete, struct diff_filespec *fs)
5588{
5589        struct strbuf sb = STRBUF_INIT;
5590        if (fs->mode)
5591                strbuf_addf(&sb, " %s mode %06o ", newdelete, fs->mode);
5592        else
5593                strbuf_addf(&sb, " %s ", newdelete);
5594
5595        quote_c_style(fs->path, &sb, NULL, 0);
5596        strbuf_addch(&sb, '\n');
5597        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5598                         sb.buf, sb.len, 0);
5599        strbuf_release(&sb);
5600}
5601
5602static void show_mode_change(struct diff_options *opt, struct diff_filepair *p,
5603                int show_name)
5604{
5605        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
5606                struct strbuf sb = STRBUF_INIT;
5607                strbuf_addf(&sb, " mode change %06o => %06o",
5608                            p->one->mode, p->two->mode);
5609                if (show_name) {
5610                        strbuf_addch(&sb, ' ');
5611                        quote_c_style(p->two->path, &sb, NULL, 0);
5612                }
5613                strbuf_addch(&sb, '\n');
5614                emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5615                                 sb.buf, sb.len, 0);
5616                strbuf_release(&sb);
5617        }
5618}
5619
5620static void show_rename_copy(struct diff_options *opt, const char *renamecopy,
5621                struct diff_filepair *p)
5622{
5623        struct strbuf sb = STRBUF_INIT;
5624        struct strbuf names = STRBUF_INIT;
5625
5626        pprint_rename(&names, p->one->path, p->two->path);
5627        strbuf_addf(&sb, " %s %s (%d%%)\n",
5628                    renamecopy, names.buf, similarity_index(p));
5629        strbuf_release(&names);
5630        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5631                                 sb.buf, sb.len, 0);
5632        show_mode_change(opt, p, 0);
5633        strbuf_release(&sb);
5634}
5635
5636static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
5637{
5638        switch(p->status) {
5639        case DIFF_STATUS_DELETED:
5640                show_file_mode_name(opt, "delete", p->one);
5641                break;
5642        case DIFF_STATUS_ADDED:
5643                show_file_mode_name(opt, "create", p->two);
5644                break;
5645        case DIFF_STATUS_COPIED:
5646                show_rename_copy(opt, "copy", p);
5647                break;
5648        case DIFF_STATUS_RENAMED:
5649                show_rename_copy(opt, "rename", p);
5650                break;
5651        default:
5652                if (p->score) {
5653                        struct strbuf sb = STRBUF_INIT;
5654                        strbuf_addstr(&sb, " rewrite ");
5655                        quote_c_style(p->two->path, &sb, NULL, 0);
5656                        strbuf_addf(&sb, " (%d%%)\n", similarity_index(p));
5657                        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5658                                         sb.buf, sb.len, 0);
5659                        strbuf_release(&sb);
5660                }
5661                show_mode_change(opt, p, !p->score);
5662                break;
5663        }
5664}
5665
5666struct patch_id_t {
5667        git_SHA_CTX *ctx;
5668        int patchlen;
5669};
5670
5671static int remove_space(char *line, int len)
5672{
5673        int i;
5674        char *dst = line;
5675        unsigned char c;
5676
5677        for (i = 0; i < len; i++)
5678                if (!isspace((c = line[i])))
5679                        *dst++ = c;
5680
5681        return dst - line;
5682}
5683
5684static void patch_id_consume(void *priv, char *line, unsigned long len)
5685{
5686        struct patch_id_t *data = priv;
5687        int new_len;
5688
5689        new_len = remove_space(line, len);
5690
5691        git_SHA1_Update(data->ctx, line, new_len);
5692        data->patchlen += new_len;
5693}
5694
5695static void patch_id_add_string(git_SHA_CTX *ctx, const char *str)
5696{
5697        git_SHA1_Update(ctx, str, strlen(str));
5698}
5699
5700static void patch_id_add_mode(git_SHA_CTX *ctx, unsigned mode)
5701{
5702        /* large enough for 2^32 in octal */
5703        char buf[12];
5704        int len = xsnprintf(buf, sizeof(buf), "%06o", mode);
5705        git_SHA1_Update(ctx, buf, len);
5706}
5707
5708/* returns 0 upon success, and writes result into sha1 */
5709static int diff_get_patch_id(struct diff_options *options, struct object_id *oid, int diff_header_only)
5710{
5711        struct diff_queue_struct *q = &diff_queued_diff;
5712        int i;
5713        git_SHA_CTX ctx;
5714        struct patch_id_t data;
5715
5716        git_SHA1_Init(&ctx);
5717        memset(&data, 0, sizeof(struct patch_id_t));
5718        data.ctx = &ctx;
5719
5720        for (i = 0; i < q->nr; i++) {
5721                xpparam_t xpp;
5722                xdemitconf_t xecfg;
5723                mmfile_t mf1, mf2;
5724                struct diff_filepair *p = q->queue[i];
5725                int len1, len2;
5726
5727                memset(&xpp, 0, sizeof(xpp));
5728                memset(&xecfg, 0, sizeof(xecfg));
5729                if (p->status == 0)
5730                        return error("internal diff status error");
5731                if (p->status == DIFF_STATUS_UNKNOWN)
5732                        continue;
5733                if (diff_unmodified_pair(p))
5734                        continue;
5735                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5736                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5737                        continue;
5738                if (DIFF_PAIR_UNMERGED(p))
5739                        continue;
5740
5741                diff_fill_oid_info(p->one, options->repo->index);
5742                diff_fill_oid_info(p->two, options->repo->index);
5743
5744                len1 = remove_space(p->one->path, strlen(p->one->path));
5745                len2 = remove_space(p->two->path, strlen(p->two->path));
5746                patch_id_add_string(&ctx, "diff--git");
5747                patch_id_add_string(&ctx, "a/");
5748                git_SHA1_Update(&ctx, p->one->path, len1);
5749                patch_id_add_string(&ctx, "b/");
5750                git_SHA1_Update(&ctx, p->two->path, len2);
5751
5752                if (p->one->mode == 0) {
5753                        patch_id_add_string(&ctx, "newfilemode");
5754                        patch_id_add_mode(&ctx, p->two->mode);
5755                        patch_id_add_string(&ctx, "---/dev/null");
5756                        patch_id_add_string(&ctx, "+++b/");
5757                        git_SHA1_Update(&ctx, p->two->path, len2);
5758                } else if (p->two->mode == 0) {
5759                        patch_id_add_string(&ctx, "deletedfilemode");
5760                        patch_id_add_mode(&ctx, p->one->mode);
5761                        patch_id_add_string(&ctx, "---a/");
5762                        git_SHA1_Update(&ctx, p->one->path, len1);
5763                        patch_id_add_string(&ctx, "+++/dev/null");
5764                } else {
5765                        patch_id_add_string(&ctx, "---a/");
5766                        git_SHA1_Update(&ctx, p->one->path, len1);
5767                        patch_id_add_string(&ctx, "+++b/");
5768                        git_SHA1_Update(&ctx, p->two->path, len2);
5769                }
5770
5771                if (diff_header_only)
5772                        continue;
5773
5774                if (fill_mmfile(options->repo, &mf1, p->one) < 0 ||
5775                    fill_mmfile(options->repo, &mf2, p->two) < 0)
5776                        return error("unable to read files to diff");
5777
5778                if (diff_filespec_is_binary(options->repo, p->one) ||
5779                    diff_filespec_is_binary(options->repo, p->two)) {
5780                        git_SHA1_Update(&ctx, oid_to_hex(&p->one->oid),
5781                                        GIT_SHA1_HEXSZ);
5782                        git_SHA1_Update(&ctx, oid_to_hex(&p->two->oid),
5783                                        GIT_SHA1_HEXSZ);
5784                        continue;
5785                }
5786
5787                xpp.flags = 0;
5788                xecfg.ctxlen = 3;
5789                xecfg.flags = 0;
5790                if (xdi_diff_outf(&mf1, &mf2, discard_hunk_line,
5791                                  patch_id_consume, &data, &xpp, &xecfg))
5792                        return error("unable to generate patch-id diff for %s",
5793                                     p->one->path);
5794        }
5795
5796        git_SHA1_Final(oid->hash, &ctx);
5797        return 0;
5798}
5799
5800int diff_flush_patch_id(struct diff_options *options, struct object_id *oid, int diff_header_only)
5801{
5802        struct diff_queue_struct *q = &diff_queued_diff;
5803        int i;
5804        int result = diff_get_patch_id(options, oid, diff_header_only);
5805
5806        for (i = 0; i < q->nr; i++)
5807                diff_free_filepair(q->queue[i]);
5808
5809        free(q->queue);
5810        DIFF_QUEUE_CLEAR(q);
5811
5812        return result;
5813}
5814
5815static int is_summary_empty(const struct diff_queue_struct *q)
5816{
5817        int i;
5818
5819        for (i = 0; i < q->nr; i++) {
5820                const struct diff_filepair *p = q->queue[i];
5821
5822                switch (p->status) {
5823                case DIFF_STATUS_DELETED:
5824                case DIFF_STATUS_ADDED:
5825                case DIFF_STATUS_COPIED:
5826                case DIFF_STATUS_RENAMED:
5827                        return 0;
5828                default:
5829                        if (p->score)
5830                                return 0;
5831                        if (p->one->mode && p->two->mode &&
5832                            p->one->mode != p->two->mode)
5833                                return 0;
5834                        break;
5835                }
5836        }
5837        return 1;
5838}
5839
5840static const char rename_limit_warning[] =
5841N_("inexact rename detection was skipped due to too many files.");
5842
5843static const char degrade_cc_to_c_warning[] =
5844N_("only found copies from modified paths due to too many files.");
5845
5846static const char rename_limit_advice[] =
5847N_("you may want to set your %s variable to at least "
5848   "%d and retry the command.");
5849
5850void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc)
5851{
5852        fflush(stdout);
5853        if (degraded_cc)
5854                warning(_(degrade_cc_to_c_warning));
5855        else if (needed)
5856                warning(_(rename_limit_warning));
5857        else
5858                return;
5859        if (0 < needed)
5860                warning(_(rename_limit_advice), varname, needed);
5861}
5862
5863static void diff_flush_patch_all_file_pairs(struct diff_options *o)
5864{
5865        int i;
5866        static struct emitted_diff_symbols esm = EMITTED_DIFF_SYMBOLS_INIT;
5867        struct diff_queue_struct *q = &diff_queued_diff;
5868
5869        if (WSEH_NEW & WS_RULE_MASK)
5870                BUG("WS rules bit mask overlaps with diff symbol flags");
5871
5872        if (o->color_moved)
5873                o->emitted_symbols = &esm;
5874
5875        for (i = 0; i < q->nr; i++) {
5876                struct diff_filepair *p = q->queue[i];
5877                if (check_pair_status(p))
5878                        diff_flush_patch(p, o);
5879        }
5880
5881        if (o->emitted_symbols) {
5882                if (o->color_moved) {
5883                        struct hashmap add_lines, del_lines;
5884
5885                        if (o->color_moved_ws_handling &
5886                            COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
5887                                o->color_moved_ws_handling |= XDF_IGNORE_WHITESPACE;
5888
5889                        hashmap_init(&del_lines, moved_entry_cmp, o, 0);
5890                        hashmap_init(&add_lines, moved_entry_cmp, o, 0);
5891
5892                        add_lines_to_move_detection(o, &add_lines, &del_lines);
5893                        mark_color_as_moved(o, &add_lines, &del_lines);
5894                        if (o->color_moved == COLOR_MOVED_ZEBRA_DIM)
5895                                dim_moved_lines(o);
5896
5897                        hashmap_free(&add_lines, 1);
5898                        hashmap_free(&del_lines, 1);
5899                }
5900
5901                for (i = 0; i < esm.nr; i++)
5902                        emit_diff_symbol_from_struct(o, &esm.buf[i]);
5903
5904                for (i = 0; i < esm.nr; i++)
5905                        free((void *)esm.buf[i].line);
5906        }
5907        esm.nr = 0;
5908}
5909
5910void diff_flush(struct diff_options *options)
5911{
5912        struct diff_queue_struct *q = &diff_queued_diff;
5913        int i, output_format = options->output_format;
5914        int separator = 0;
5915        int dirstat_by_line = 0;
5916
5917        /*
5918         * Order: raw, stat, summary, patch
5919         * or:    name/name-status/checkdiff (other bits clear)
5920         */
5921        if (!q->nr)
5922                goto free_queue;
5923
5924        if (output_format & (DIFF_FORMAT_RAW |
5925                             DIFF_FORMAT_NAME |
5926                             DIFF_FORMAT_NAME_STATUS |
5927                             DIFF_FORMAT_CHECKDIFF)) {
5928                for (i = 0; i < q->nr; i++) {
5929                        struct diff_filepair *p = q->queue[i];
5930                        if (check_pair_status(p))
5931                                flush_one_pair(p, options);
5932                }
5933                separator++;
5934        }
5935
5936        if (output_format & DIFF_FORMAT_DIRSTAT && options->flags.dirstat_by_line)
5937                dirstat_by_line = 1;
5938
5939        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT) ||
5940            dirstat_by_line) {
5941                struct diffstat_t diffstat;
5942
5943                memset(&diffstat, 0, sizeof(struct diffstat_t));
5944                for (i = 0; i < q->nr; i++) {
5945                        struct diff_filepair *p = q->queue[i];
5946                        if (check_pair_status(p))
5947                                diff_flush_stat(p, options, &diffstat);
5948                }
5949                if (output_format & DIFF_FORMAT_NUMSTAT)
5950                        show_numstat(&diffstat, options);
5951                if (output_format & DIFF_FORMAT_DIFFSTAT)
5952                        show_stats(&diffstat, options);
5953                if (output_format & DIFF_FORMAT_SHORTSTAT)
5954                        show_shortstats(&diffstat, options);
5955                if (output_format & DIFF_FORMAT_DIRSTAT && dirstat_by_line)
5956                        show_dirstat_by_line(&diffstat, options);
5957                free_diffstat_info(&diffstat);
5958                separator++;
5959        }
5960        if ((output_format & DIFF_FORMAT_DIRSTAT) && !dirstat_by_line)
5961                show_dirstat(options);
5962
5963        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
5964                for (i = 0; i < q->nr; i++) {
5965                        diff_summary(options, q->queue[i]);
5966                }
5967                separator++;
5968        }
5969
5970        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
5971            options->flags.exit_with_status &&
5972            options->flags.diff_from_contents) {
5973                /*
5974                 * run diff_flush_patch for the exit status. setting
5975                 * options->file to /dev/null should be safe, because we
5976                 * aren't supposed to produce any output anyway.
5977                 */
5978                if (options->close_file)
5979                        fclose(options->file);
5980                options->file = xfopen("/dev/null", "w");
5981                options->close_file = 1;
5982                options->color_moved = 0;
5983                for (i = 0; i < q->nr; i++) {
5984                        struct diff_filepair *p = q->queue[i];
5985                        if (check_pair_status(p))
5986                                diff_flush_patch(p, options);
5987                        if (options->found_changes)
5988                                break;
5989                }
5990        }
5991
5992        if (output_format & DIFF_FORMAT_PATCH) {
5993                if (separator) {
5994                        emit_diff_symbol(options, DIFF_SYMBOL_SEPARATOR, NULL, 0, 0);
5995                        if (options->stat_sep)
5996                                /* attach patch instead of inline */
5997                                emit_diff_symbol(options, DIFF_SYMBOL_STAT_SEP,
5998                                                 NULL, 0, 0);
5999                }
6000
6001                diff_flush_patch_all_file_pairs(options);
6002        }
6003
6004        if (output_format & DIFF_FORMAT_CALLBACK)
6005                options->format_callback(q, options, options->format_callback_data);
6006
6007        for (i = 0; i < q->nr; i++)
6008                diff_free_filepair(q->queue[i]);
6009free_queue:
6010        free(q->queue);
6011        DIFF_QUEUE_CLEAR(q);
6012        if (options->close_file)
6013                fclose(options->file);
6014
6015        /*
6016         * Report the content-level differences with HAS_CHANGES;
6017         * diff_addremove/diff_change does not set the bit when
6018         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
6019         */
6020        if (options->flags.diff_from_contents) {
6021                if (options->found_changes)
6022                        options->flags.has_changes = 1;
6023                else
6024                        options->flags.has_changes = 0;
6025        }
6026}
6027
6028static int match_filter(const struct diff_options *options, const struct diff_filepair *p)
6029{
6030        return (((p->status == DIFF_STATUS_MODIFIED) &&
6031                 ((p->score &&
6032                   filter_bit_tst(DIFF_STATUS_FILTER_BROKEN, options)) ||
6033                  (!p->score &&
6034                   filter_bit_tst(DIFF_STATUS_MODIFIED, options)))) ||
6035                ((p->status != DIFF_STATUS_MODIFIED) &&
6036                 filter_bit_tst(p->status, options)));
6037}
6038
6039static void diffcore_apply_filter(struct diff_options *options)
6040{
6041        int i;
6042        struct diff_queue_struct *q = &diff_queued_diff;
6043        struct diff_queue_struct outq;
6044
6045        DIFF_QUEUE_CLEAR(&outq);
6046
6047        if (!options->filter)
6048                return;
6049
6050        if (filter_bit_tst(DIFF_STATUS_FILTER_AON, options)) {
6051                int found;
6052                for (i = found = 0; !found && i < q->nr; i++) {
6053                        if (match_filter(options, q->queue[i]))
6054                                found++;
6055                }
6056                if (found)
6057                        return;
6058
6059                /* otherwise we will clear the whole queue
6060                 * by copying the empty outq at the end of this
6061                 * function, but first clear the current entries
6062                 * in the queue.
6063                 */
6064                for (i = 0; i < q->nr; i++)
6065                        diff_free_filepair(q->queue[i]);
6066        }
6067        else {
6068                /* Only the matching ones */
6069                for (i = 0; i < q->nr; i++) {
6070                        struct diff_filepair *p = q->queue[i];
6071                        if (match_filter(options, p))
6072                                diff_q(&outq, p);
6073                        else
6074                                diff_free_filepair(p);
6075                }
6076        }
6077        free(q->queue);
6078        *q = outq;
6079}
6080
6081/* Check whether two filespecs with the same mode and size are identical */
6082static int diff_filespec_is_identical(struct repository *r,
6083                                      struct diff_filespec *one,
6084                                      struct diff_filespec *two)
6085{
6086        if (S_ISGITLINK(one->mode))
6087                return 0;
6088        if (diff_populate_filespec(r, one, 0))
6089                return 0;
6090        if (diff_populate_filespec(r, two, 0))
6091                return 0;
6092        return !memcmp(one->data, two->data, one->size);
6093}
6094
6095static int diff_filespec_check_stat_unmatch(struct repository *r,
6096                                            struct diff_filepair *p)
6097{
6098        if (p->done_skip_stat_unmatch)
6099                return p->skip_stat_unmatch_result;
6100
6101        p->done_skip_stat_unmatch = 1;
6102        p->skip_stat_unmatch_result = 0;
6103        /*
6104         * 1. Entries that come from stat info dirtiness
6105         *    always have both sides (iow, not create/delete),
6106         *    one side of the object name is unknown, with
6107         *    the same mode and size.  Keep the ones that
6108         *    do not match these criteria.  They have real
6109         *    differences.
6110         *
6111         * 2. At this point, the file is known to be modified,
6112         *    with the same mode and size, and the object
6113         *    name of one side is unknown.  Need to inspect
6114         *    the identical contents.
6115         */
6116        if (!DIFF_FILE_VALID(p->one) || /* (1) */
6117            !DIFF_FILE_VALID(p->two) ||
6118            (p->one->oid_valid && p->two->oid_valid) ||
6119            (p->one->mode != p->two->mode) ||
6120            diff_populate_filespec(r, p->one, CHECK_SIZE_ONLY) ||
6121            diff_populate_filespec(r, p->two, CHECK_SIZE_ONLY) ||
6122            (p->one->size != p->two->size) ||
6123            !diff_filespec_is_identical(r, p->one, p->two)) /* (2) */
6124                p->skip_stat_unmatch_result = 1;
6125        return p->skip_stat_unmatch_result;
6126}
6127
6128static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
6129{
6130        int i;
6131        struct diff_queue_struct *q = &diff_queued_diff;
6132        struct diff_queue_struct outq;
6133        DIFF_QUEUE_CLEAR(&outq);
6134
6135        for (i = 0; i < q->nr; i++) {
6136                struct diff_filepair *p = q->queue[i];
6137
6138                if (diff_filespec_check_stat_unmatch(diffopt->repo, p))
6139                        diff_q(&outq, p);
6140                else {
6141                        /*
6142                         * The caller can subtract 1 from skip_stat_unmatch
6143                         * to determine how many paths were dirty only
6144                         * due to stat info mismatch.
6145                         */
6146                        if (!diffopt->flags.no_index)
6147                                diffopt->skip_stat_unmatch++;
6148                        diff_free_filepair(p);
6149                }
6150        }
6151        free(q->queue);
6152        *q = outq;
6153}
6154
6155static int diffnamecmp(const void *a_, const void *b_)
6156{
6157        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
6158        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
6159        const char *name_a, *name_b;
6160
6161        name_a = a->one ? a->one->path : a->two->path;
6162        name_b = b->one ? b->one->path : b->two->path;
6163        return strcmp(name_a, name_b);
6164}
6165
6166void diffcore_fix_diff_index(struct diff_options *options)
6167{
6168        struct diff_queue_struct *q = &diff_queued_diff;
6169        QSORT(q->queue, q->nr, diffnamecmp);
6170}
6171
6172void diffcore_std(struct diff_options *options)
6173{
6174        /* NOTE please keep the following in sync with diff_tree_combined() */
6175        if (options->skip_stat_unmatch)
6176                diffcore_skip_stat_unmatch(options);
6177        if (!options->found_follow) {
6178                /* See try_to_follow_renames() in tree-diff.c */
6179                if (options->break_opt != -1)
6180                        diffcore_break(options->repo,
6181                                       options->break_opt);
6182                if (options->detect_rename)
6183                        diffcore_rename(options);
6184                if (options->break_opt != -1)
6185                        diffcore_merge_broken();
6186        }
6187        if (options->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK)
6188                diffcore_pickaxe(options);
6189        if (options->orderfile)
6190                diffcore_order(options->orderfile);
6191        if (!options->found_follow)
6192                /* See try_to_follow_renames() in tree-diff.c */
6193                diff_resolve_rename_copy();
6194        diffcore_apply_filter(options);
6195
6196        if (diff_queued_diff.nr && !options->flags.diff_from_contents)
6197                options->flags.has_changes = 1;
6198        else
6199                options->flags.has_changes = 0;
6200
6201        options->found_follow = 0;
6202}
6203
6204int diff_result_code(struct diff_options *opt, int status)
6205{
6206        int result = 0;
6207
6208        diff_warn_rename_limit("diff.renameLimit",
6209                               opt->needed_rename_limit,
6210                               opt->degraded_cc_to_c);
6211        if (!opt->flags.exit_with_status &&
6212            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
6213                return status;
6214        if (opt->flags.exit_with_status &&
6215            opt->flags.has_changes)
6216                result |= 01;
6217        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
6218            opt->flags.check_failed)
6219                result |= 02;
6220        return result;
6221}
6222
6223int diff_can_quit_early(struct diff_options *opt)
6224{
6225        return (opt->flags.quick &&
6226                !opt->filter &&
6227                opt->flags.has_changes);
6228}
6229
6230/*
6231 * Shall changes to this submodule be ignored?
6232 *
6233 * Submodule changes can be configured to be ignored separately for each path,
6234 * but that configuration can be overridden from the command line.
6235 */
6236static int is_submodule_ignored(const char *path, struct diff_options *options)
6237{
6238        int ignored = 0;
6239        struct diff_flags orig_flags = options->flags;
6240        if (!options->flags.override_submodule_config)
6241                set_diffopt_flags_from_submodule_config(options, path);
6242        if (options->flags.ignore_submodules)
6243                ignored = 1;
6244        options->flags = orig_flags;
6245        return ignored;
6246}
6247
6248void diff_addremove(struct diff_options *options,
6249                    int addremove, unsigned mode,
6250                    const struct object_id *oid,
6251                    int oid_valid,
6252                    const char *concatpath, unsigned dirty_submodule)
6253{
6254        struct diff_filespec *one, *two;
6255
6256        if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
6257                return;
6258
6259        /* This may look odd, but it is a preparation for
6260         * feeding "there are unchanged files which should
6261         * not produce diffs, but when you are doing copy
6262         * detection you would need them, so here they are"
6263         * entries to the diff-core.  They will be prefixed
6264         * with something like '=' or '*' (I haven't decided
6265         * which but should not make any difference).
6266         * Feeding the same new and old to diff_change()
6267         * also has the same effect.
6268         * Before the final output happens, they are pruned after
6269         * merged into rename/copy pairs as appropriate.
6270         */
6271        if (options->flags.reverse_diff)
6272                addremove = (addremove == '+' ? '-' :
6273                             addremove == '-' ? '+' : addremove);
6274
6275        if (options->prefix &&
6276            strncmp(concatpath, options->prefix, options->prefix_length))
6277                return;
6278
6279        one = alloc_filespec(concatpath);
6280        two = alloc_filespec(concatpath);
6281
6282        if (addremove != '+')
6283                fill_filespec(one, oid, oid_valid, mode);
6284        if (addremove != '-') {
6285                fill_filespec(two, oid, oid_valid, mode);
6286                two->dirty_submodule = dirty_submodule;
6287        }
6288
6289        diff_queue(&diff_queued_diff, one, two);
6290        if (!options->flags.diff_from_contents)
6291                options->flags.has_changes = 1;
6292}
6293
6294void diff_change(struct diff_options *options,
6295                 unsigned old_mode, unsigned new_mode,
6296                 const struct object_id *old_oid,
6297                 const struct object_id *new_oid,
6298                 int old_oid_valid, int new_oid_valid,
6299                 const char *concatpath,
6300                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
6301{
6302        struct diff_filespec *one, *two;
6303        struct diff_filepair *p;
6304
6305        if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
6306            is_submodule_ignored(concatpath, options))
6307                return;
6308
6309        if (options->flags.reverse_diff) {
6310                SWAP(old_mode, new_mode);
6311                SWAP(old_oid, new_oid);
6312                SWAP(old_oid_valid, new_oid_valid);
6313                SWAP(old_dirty_submodule, new_dirty_submodule);
6314        }
6315
6316        if (options->prefix &&
6317            strncmp(concatpath, options->prefix, options->prefix_length))
6318                return;
6319
6320        one = alloc_filespec(concatpath);
6321        two = alloc_filespec(concatpath);
6322        fill_filespec(one, old_oid, old_oid_valid, old_mode);
6323        fill_filespec(two, new_oid, new_oid_valid, new_mode);
6324        one->dirty_submodule = old_dirty_submodule;
6325        two->dirty_submodule = new_dirty_submodule;
6326        p = diff_queue(&diff_queued_diff, one, two);
6327
6328        if (options->flags.diff_from_contents)
6329                return;
6330
6331        if (options->flags.quick && options->skip_stat_unmatch &&
6332            !diff_filespec_check_stat_unmatch(options->repo, p))
6333                return;
6334
6335        options->flags.has_changes = 1;
6336}
6337
6338struct diff_filepair *diff_unmerge(struct diff_options *options, const char *path)
6339{
6340        struct diff_filepair *pair;
6341        struct diff_filespec *one, *two;
6342
6343        if (options->prefix &&
6344            strncmp(path, options->prefix, options->prefix_length))
6345                return NULL;
6346
6347        one = alloc_filespec(path);
6348        two = alloc_filespec(path);
6349        pair = diff_queue(&diff_queued_diff, one, two);
6350        pair->is_unmerged = 1;
6351        return pair;
6352}
6353
6354static char *run_textconv(struct repository *r,
6355                          const char *pgm,
6356                          struct diff_filespec *spec,
6357                          size_t *outsize)
6358{
6359        struct diff_tempfile *temp;
6360        const char *argv[3];
6361        const char **arg = argv;
6362        struct child_process child = CHILD_PROCESS_INIT;
6363        struct strbuf buf = STRBUF_INIT;
6364        int err = 0;
6365
6366        temp = prepare_temp_file(r, spec->path, spec);
6367        *arg++ = pgm;
6368        *arg++ = temp->name;
6369        *arg = NULL;
6370
6371        child.use_shell = 1;
6372        child.argv = argv;
6373        child.out = -1;
6374        if (start_command(&child)) {
6375                remove_tempfile();
6376                return NULL;
6377        }
6378
6379        if (strbuf_read(&buf, child.out, 0) < 0)
6380                err = error("error reading from textconv command '%s'", pgm);
6381        close(child.out);
6382
6383        if (finish_command(&child) || err) {
6384                strbuf_release(&buf);
6385                remove_tempfile();
6386                return NULL;
6387        }
6388        remove_tempfile();
6389
6390        return strbuf_detach(&buf, outsize);
6391}
6392
6393size_t fill_textconv(struct repository *r,
6394                     struct userdiff_driver *driver,
6395                     struct diff_filespec *df,
6396                     char **outbuf)
6397{
6398        size_t size;
6399
6400        if (!driver) {
6401                if (!DIFF_FILE_VALID(df)) {
6402                        *outbuf = "";
6403                        return 0;
6404                }
6405                if (diff_populate_filespec(r, df, 0))
6406                        die("unable to read files to diff");
6407                *outbuf = df->data;
6408                return df->size;
6409        }
6410
6411        if (!driver->textconv)
6412                BUG("fill_textconv called with non-textconv driver");
6413
6414        if (driver->textconv_cache && df->oid_valid) {
6415                *outbuf = notes_cache_get(driver->textconv_cache,
6416                                          &df->oid,
6417                                          &size);
6418                if (*outbuf)
6419                        return size;
6420        }
6421
6422        *outbuf = run_textconv(r, driver->textconv, df, &size);
6423        if (!*outbuf)
6424                die("unable to read files to diff");
6425
6426        if (driver->textconv_cache && df->oid_valid) {
6427                /* ignore errors, as we might be in a readonly repository */
6428                notes_cache_put(driver->textconv_cache, &df->oid, *outbuf,
6429                                size);
6430                /*
6431                 * we could save up changes and flush them all at the end,
6432                 * but we would need an extra call after all diffing is done.
6433                 * Since generating a cache entry is the slow path anyway,
6434                 * this extra overhead probably isn't a big deal.
6435                 */
6436                notes_cache_write(driver->textconv_cache);
6437        }
6438
6439        return size;
6440}
6441
6442int textconv_object(struct repository *r,
6443                    const char *path,
6444                    unsigned mode,
6445                    const struct object_id *oid,
6446                    int oid_valid,
6447                    char **buf,
6448                    unsigned long *buf_size)
6449{
6450        struct diff_filespec *df;
6451        struct userdiff_driver *textconv;
6452
6453        df = alloc_filespec(path);
6454        fill_filespec(df, oid, oid_valid, mode);
6455        textconv = get_textconv(r->index, df);
6456        if (!textconv) {
6457                free_filespec(df);
6458                return 0;
6459        }
6460
6461        *buf_size = fill_textconv(r, textconv, df, buf);
6462        free_filespec(df);
6463        return 1;
6464}
6465
6466void setup_diff_pager(struct diff_options *opt)
6467{
6468        /*
6469         * If the user asked for our exit code, then either they want --quiet
6470         * or --exit-code. We should definitely not bother with a pager in the
6471         * former case, as we will generate no output. Since we still properly
6472         * report our exit code even when a pager is run, we _could_ run a
6473         * pager with --exit-code. But since we have not done so historically,
6474         * and because it is easy to find people oneline advising "git diff
6475         * --exit-code" in hooks and other scripts, we do not do so.
6476         */
6477        if (!opt->flags.exit_with_status &&
6478            check_pager_config("diff") != 0)
6479                setup_pager();
6480}