Parameters.xs

   1 /*
   2 Copyright 2012 Lukas Mai.
   3
   4 This program is free software; you can redistribute it and/or modify it
   5 under the terms of either: the GNU General Public License as published
   6 by the Free Software Foundation; or the Artistic License.
   7
   8 See http://dev.perl.org/licenses/ for more information.
   9  */
  10
  11 #ifdef __GNUC__
  12  #if (__GNUC__ == 4 && __GNUC_MINOR__ >= 6) || __GNUC__ >= 5
  13   #define PRAGMA_GCC_(X) _Pragma(#X)
  14   #define PRAGMA_GCC(X) PRAGMA_GCC_(GCC X)
  15  #endif
  16 #endif
  17
  18 #ifndef PRAGMA_GCC
  19  #define PRAGMA_GCC(X)
  20 #endif
  21
  22 #ifdef DEVEL
  23  #define WARNINGS_RESET PRAGMA_GCC(diagnostic pop)
  24  #define WARNINGS_ENABLEW(X) PRAGMA_GCC(diagnostic warning #X)
  25  #define WARNINGS_ENABLE \
  26         WARNINGS_ENABLEW(-Wall) \
  27         WARNINGS_ENABLEW(-Wextra) \
  28         WARNINGS_ENABLEW(-Wundef) \
  29         /* WARNINGS_ENABLEW(-Wshadow) :-( */ \
  30         WARNINGS_ENABLEW(-Wbad-function-cast) \
  31         WARNINGS_ENABLEW(-Wcast-align) \
  32         WARNINGS_ENABLEW(-Wwrite-strings) \
  33         /* WARNINGS_ENABLEW(-Wnested-externs) wtf? */ \
  34         WARNINGS_ENABLEW(-Wstrict-prototypes) \
  35         WARNINGS_ENABLEW(-Wmissing-prototypes) \
  36         WARNINGS_ENABLEW(-Winline) \
  37         WARNINGS_ENABLEW(-Wdisabled-optimization)
  38
  39 #else
  40  #define WARNINGS_RESET
  41  #define WARNINGS_ENABLE
  42 #endif
  43
  44
  45 #define PERL_NO_GET_CONTEXT
  46 #include "EXTERN.h"
  47 #include "perl.h"
  48 #include "XSUB.h"
  49
  50 #include <string.h>
  51
  52
  53 WARNINGS_ENABLE
  54
  55
  56 #define HAVE_PERL_VERSION(R, V, S) \
  57         (PERL_REVISION > (R) || (PERL_REVISION == (R) && (PERL_VERSION > (V) || (PERL_VERSION == (V) && (PERL_SUBVERSION >= (S))))))
  58
  59 #if HAVE_PERL_VERSION(5, 16, 0)
  60  #define IF_HAVE_PERL_5_16(YES, NO) YES
  61 #else
  62  #define IF_HAVE_PERL_5_16(YES, NO) NO
  63 #endif
  64
  65 #if 0
  66  #if HAVE_PERL_VERSION(5, 17, 6)
  67   #error "internal error: missing definition of KEY_my (your perl is too new)"
  68  #elif HAVE_PERL_VERSION(5, 15, 8)
  69   #define S_KEY_my 134
  70  #elif HAVE_PERL_VERSION(5, 15, 6)
  71   #define S_KEY_my 133
  72  #elif HAVE_PERL_VERSION(5, 15, 5)
  73   #define S_KEY_my 132
  74  #elif HAVE_PERL_VERSION(5, 13, 0)
  75   #define S_KEY_my 131
  76  #else
  77   #error "internal error: missing definition of KEY_my (your perl is too old)"
  78  #endif
  79 #endif
  80
  81
  82 #define MY_PKG "Function::Parameters"
  83
  84 #define HINTK_KEYWORDS MY_PKG "/keywords"
  85 #define HINTK_FLAGS_   MY_PKG "/flags:"
  86 #define HINTK_SHIFT_   MY_PKG "/shift:"
  87 #define HINTK_ATTRS_   MY_PKG "/attrs:"
  88
  89 #define DEFSTRUCT(T) typedef struct T T; struct T
  90
  91 #define UV_BITS (sizeof (UV) * CHAR_BIT)
  92
  93 enum {
  94         FLAG_NAME_OK      = 0x01,
  95         FLAG_ANON_OK      = 0x02,
  96         FLAG_DEFAULT_ARGS = 0x04,
  97         FLAG_CHECK_NARGS  = 0x08,
  98         FLAG_INVOCANT     = 0x10,
  99         FLAG_NAMED_PARAMS = 0x20
 100 };
 101
 102 DEFSTRUCT(KWSpec) {
 103         unsigned flags;
 104         SV *shift;
 105         SV *attrs;
 106 };
 107
 108 static int (*next_keyword_plugin)(pTHX_ char *, STRLEN, OP **);
 109
 110 DEFSTRUCT(Resource) {
 111         Resource *next;
 112         void *data;
 113         void (*destroy)(pTHX_ void *);
 114 };
 115
 116 typedef Resource *Sentinel[1];
 117
 118 static void sentinel_clear_void(pTHX_ void *p) {
 119         Resource **pp = p;
 120         while (*pp) {
 121                 Resource *cur = *pp;
 122                 cur->destroy(aTHX_ cur->data);
 123                 cur->data = (void *)"no";
 124                 cur->destroy = NULL;
 125                 *pp = cur->next;
 126                 Safefree(cur);
 127         }
 128 }
 129
 130 static void sentinel_register(Sentinel sen, void *data, void (*destroy)(pTHX_ void *)) {
 131         Resource *cur;
 132
 133         Newx(cur, 1, Resource);
 134         cur->data = data;
 135         cur->destroy = destroy;
 136         cur->next = *sen;
 137         *sen = cur;
 138 }
 139
 140 static void my_sv_refcnt_dec_void(pTHX_ void *p) {
 141         SV *sv = p;
 142         SvREFCNT_dec(sv);
 143 }
 144
 145 static SV *sentinel_mortalize(Sentinel sen, SV *sv) {
 146         sentinel_register(sen, sv, my_sv_refcnt_dec_void);
 147         return sv;
 148 }
 149
 150 static int kw_flags(pTHX_ Sentinel sen, const char *kw_ptr, STRLEN kw_len, KWSpec *spec) {
 151         HV *hints;
 152         SV *sv, **psv;
 153         const char *p, *kw_active;
 154         STRLEN kw_active_len;
 155
 156         spec->flags = 0;
 157         spec->shift = sentinel_mortalize(sen, newSVpvs(""));
 158         spec->attrs = sentinel_mortalize(sen, newSVpvs(""));
 159
 160         if (!(hints = GvHV(PL_hintgv))) {
 161                 return FALSE;
 162         }
 163         if (!(psv = hv_fetchs(hints, HINTK_KEYWORDS, 0))) {
 164                 return FALSE;
 165         }
 166         sv = *psv;
 167         kw_active = SvPV(sv, kw_active_len);
 168         if (kw_active_len <= kw_len) {
 169                 return FALSE;
 170         }
 171         for (
 172                 p = kw_active;
 173                 (p = strchr(p, *kw_ptr)) &&
 174                 p < kw_active + kw_active_len - kw_len;
 175                 p++
 176         ) {
 177                 if (
 178                         (p == kw_active || p[-1] == ' ') &&
 179                         p[kw_len] == ' ' &&
 180                         memcmp(kw_ptr, p, kw_len) == 0
 181                 ) {
 182
 183 #define FETCH_HINTK_INTO(NAME, PTR, LEN, X) STMT_START { \
 184         const char *fk_ptr_; \
 185         STRLEN fk_len_; \
 186         SV *fk_sv_; \
 187         fk_sv_ = sentinel_mortalize(sen, newSVpvs(HINTK_ ## NAME)); \
 188         sv_catpvn(fk_sv_, PTR, LEN); \
 189         fk_ptr_ = SvPV(fk_sv_, fk_len_); \
 190         if (!((X) = hv_fetch(hints, fk_ptr_, fk_len_, 0))) { \
 191                 croak("%s: internal error: $^H{'%.*s'} not set", MY_PKG, (int)fk_len_, fk_ptr_); \
 192         } \
 193 } STMT_END
 194
 195                         FETCH_HINTK_INTO(FLAGS_, kw_ptr, kw_len, psv);
 196                         spec->flags = SvIV(*psv);
 197
 198                         FETCH_HINTK_INTO(SHIFT_, kw_ptr, kw_len, psv);
 199                         SvSetSV(spec->shift, *psv);
 200
 201                         FETCH_HINTK_INTO(ATTRS_, kw_ptr, kw_len, psv);
 202                         SvSetSV(spec->attrs, *psv);
 203
 204 #undef FETCH_HINTK_INTO
 205                         return TRUE;
 206                 }
 207         }
 208         return FALSE;
 209 }
 210
 211
 212 static void free_ptr_op(pTHX_ void *vp) {
 213         OP **pp = vp;
 214         op_free(*pp);
 215         Safefree(pp);
 216 }
 217
 218 #define sv_eq_pvs(SV, S) my_sv_eq_pvn(aTHX_ SV, "" S "", sizeof (S) - 1)
 219
 220 static int my_sv_eq_pvn(pTHX_ SV *sv, const char *p, STRLEN n) {
 221         STRLEN sv_len;
 222         const char *sv_p = SvPV(sv, sv_len);
 223         return memcmp(sv_p, p, n) == 0;
 224 }
 225
 226
 227 #include "padop_on_crack.c.inc"
 228
 229
 230 enum {
 231         MY_ATTR_LVALUE = 0x01,
 232         MY_ATTR_METHOD = 0x02,
 233         MY_ATTR_SPECIAL = 0x04
 234 };
 235
 236 static void my_sv_cat_c(pTHX_ SV *sv, U32 c) {
 237         char ds[UTF8_MAXBYTES + 1], *d;
 238         d = (char *)uvchr_to_utf8((U8 *)ds, c);
 239         if (d - ds > 1) {
 240                 sv_utf8_upgrade(sv);
 241         }
 242         sv_catpvn(sv, ds, d - ds);
 243 }
 244
 245 static bool my_is_uni_xidfirst(pTHX_ UV c) {
 246         U8 tmpbuf[UTF8_MAXBYTES + 1];
 247         uvchr_to_utf8(tmpbuf, c);
 248         return is_utf8_xidfirst(tmpbuf);
 249 }
 250
 251 static bool my_is_uni_xidcont(pTHX_ UV c) {
 252         U8 tmpbuf[UTF8_MAXBYTES + 1];
 253         uvchr_to_utf8(tmpbuf, c);
 254         return is_utf8_xidcont(tmpbuf);
 255 }
 256
 257 static SV *my_scan_word(pTHX_ Sentinel sen, bool allow_package) {
 258         bool at_start, at_substart;
 259         I32 c;
 260         SV *sv = sentinel_mortalize(sen, newSVpvs(""));
 261         if (lex_bufutf8()) {
 262                 SvUTF8_on(sv);
 263         }
 264
 265         at_start = at_substart = TRUE;
 266         c = lex_peek_unichar(0);
 267
 268         while (c != -1) {
 269                 if (at_substart ? my_is_uni_xidfirst(aTHX_ c) : my_is_uni_xidcont(aTHX_ c)) {
 270                         lex_read_unichar(0);
 271                         my_sv_cat_c(aTHX_ sv, c);
 272                         at_substart = FALSE;
 273                         c = lex_peek_unichar(0);
 274                 } else if (allow_package && !at_substart && c == '\'') {
 275                         lex_read_unichar(0);
 276                         c = lex_peek_unichar(0);
 277                         if (!my_is_uni_xidfirst(aTHX_ c)) {
 278                                 lex_stuff_pvs("'", 0);
 279                                 break;
 280                         }
 281                         sv_catpvs(sv, "'");
 282                         at_substart = TRUE;
 283                 } else if (allow_package && (at_start || !at_substart) && c == ':') {
 284                         lex_read_unichar(0);
 285                         if (lex_peek_unichar(0) != ':') {
 286                                 lex_stuff_pvs(":", 0);
 287                                 break;
 288                         }
 289                         lex_read_unichar(0);
 290                         c = lex_peek_unichar(0);
 291                         if (!my_is_uni_xidfirst(aTHX_ c)) {
 292                                 lex_stuff_pvs("::", 0);
 293                                 break;
 294                         }
 295                         sv_catpvs(sv, "::");
 296                         at_substart = TRUE;
 297                 } else {
 298                         break;
 299                 }
 300                 at_start = FALSE;
 301         }
 302
 303         return SvCUR(sv) ? sv : NULL;
 304 }
 305
 306 static SV *my_scan_parens_tail(pTHX_ Sentinel sen, bool keep_backslash) {
 307         I32 c, nesting;
 308         SV *sv;
 309         line_t start;
 310
 311         start = CopLINE(PL_curcop);
 312
 313         sv = sentinel_mortalize(sen, newSVpvs(""));
 314         if (lex_bufutf8()) {
 315                 SvUTF8_on(sv);
 316         }
 317
 318         nesting = 0;
 319         for (;;) {
 320                 c = lex_read_unichar(0);
 321                 if (c == EOF) {
 322                         CopLINE_set(PL_curcop, start);
 323                         return NULL;
 324                 }
 325
 326                 if (c == '\\') {
 327                         c = lex_read_unichar(0);
 328                         if (c == EOF) {
 329                                 CopLINE_set(PL_curcop, start);
 330                                 return NULL;
 331                         }
 332                         if (keep_backslash || (c != '(' && c != ')')) {
 333                                 sv_catpvs(sv, "\\");
 334                         }
 335                 } else if (c == '(') {
 336                         nesting++;
 337                 } else if (c == ')') {
 338                         if (!nesting) {
 339                                 break;
 340                         }
 341                         nesting--;
 342                 }
 343
 344                 my_sv_cat_c(aTHX_ sv, c);
 345         }
 346
 347         return sv;
 348 }
 349
 350 static void my_check_prototype(pTHX_ Sentinel sen, const SV *declarator, SV *proto) {
 351         char *start, *r, *w, *end;
 352         STRLEN len;
 353
 354         /* strip spaces */
 355         start = SvPV(proto, len);
 356         end = start + len;
 357
 358         for (w = r = start; r < end; r++) {
 359                 if (!isSPACE(*r)) {
 360                         *w++ = *r;
 361                 }
 362         }
 363         *w = '\0';
 364         SvCUR_set(proto, w - start);
 365         end = w;
 366         len = end - start;
 367
 368         if (!ckWARN(WARN_ILLEGALPROTO)) {
 369                 return;
 370         }
 371
 372         /* check for bad characters */
 373         if (strspn(start, "$@%*;[]&\\_+") != len) {
 374                 SV *dsv = sentinel_mortalize(sen, newSVpvs(""));
 375                 warner(
 376                         packWARN(WARN_ILLEGALPROTO),
 377                         "Illegal character in prototype for %"SVf" : %s",
 378                         SVfARG(declarator),
 379                         SvUTF8(proto)
 380                                 ? sv_uni_display(
 381                                         dsv,
 382                                         proto,
 383                                         len,
 384                                         UNI_DISPLAY_ISPRINT
 385                                 )
 386                                 : pv_pretty(dsv, start, len, 60, NULL, NULL,
 387                                         PERL_PV_ESCAPE_NONASCII
 388                                 )
 389                 );
 390                 return;
 391         }
 392
 393         for (r = start; r < end; r++) {
 394                 switch (*r) {
 395                         default:
 396                                 warner(
 397                                         packWARN(WARN_ILLEGALPROTO),
 398                                         "Illegal character in prototype for %"SVf" : %s",
 399                                         SVfARG(declarator), r
 400                                 );
 401                                 return;
 402
 403                         case '_':
 404                                 if (r[1] && !strchr(";@%", *r)) {
 405                                         warner(
 406                                                 packWARN(WARN_ILLEGALPROTO),
 407                                                 "Illegal character after '_' in prototype for %"SVf" : %s",
 408                                                 SVfARG(declarator), r
 409                                         );
 410                                         return;
 411                                 }
 412                                 break;
 413
 414                         case '@':
 415                         case '%':
 416                                 if (r[1]) {
 417                                         warner(
 418                                                 packWARN(WARN_ILLEGALPROTO),
 419                                                 "prototype after '%c' for %"SVf": %s",
 420                                                 *r, SVfARG(declarator), r + 1
 421                                         );
 422                                         return;
 423                                 }
 424                                 break;
 425
 426                         case '\\':
 427                                 r++;
 428                                 if (strchr("$@%&*", *r)) {
 429                                         break;
 430                                 }
 431                                 if (*r == '[') {
 432                                         r++;
 433                                         for (; r < end && *r != ']'; r++) {
 434                                                 if (!strchr("$@%&*", *r)) {
 435                                                         break;
 436                                                 }
 437                                         }
 438                                         if (*r == ']' && r[-1] != '[') {
 439                                                 break;
 440                                         }
 441                                 }
 442                                 warner(
 443                                         packWARN(WARN_ILLEGALPROTO),
 444                                         "Illegal character after '\\' in prototype for %"SVf" : %s",
 445                                         SVfARG(declarator), r
 446                                 );
 447                                 return;
 448
 449                         case '$':
 450                         case '*':
 451                         case '&':
 452                         case ';':
 453                         case '+':
 454                                 break;
 455                 }
 456         }
 457 }
 458
 459
 460 DEFSTRUCT(Param) {
 461         SV *name;
 462         PADOFFSET padoff;
 463 };
 464
 465 DEFSTRUCT(ParamInit) {
 466         Param param;
 467         OP *init;
 468 };
 469
 470 #define VEC(B) B ## _Vec
 471
 472 #define DEFVECTOR(B) DEFSTRUCT(VEC(B)) { \
 473         B (*data); \
 474         size_t used, size; \
 475 }
 476
 477 DEFVECTOR(Param);
 478 DEFVECTOR(ParamInit);
 479
 480 #define DEFVECTOR_INIT(N, B) static void N(VEC(B) *p) { \
 481         p->used = 0; \
 482         p->size = 23; \
 483         Newx(p->data, p->size, B); \
 484 } static void N(VEC(B) *)
 485
 486 DEFSTRUCT(ParamSpec) {
 487         Param invocant;
 488         VEC(Param) positional_required;
 489         VEC(ParamInit) positional_optional;
 490         VEC(Param) named_required;
 491         VEC(ParamInit) named_optional;
 492         Param slurpy;
 493         PADOFFSET rest_hash;
 494 };
 495
 496 DEFVECTOR_INIT(pv_init, Param);
 497 DEFVECTOR_INIT(piv_init, ParamInit);
 498
 499 static void p_init(Param *p) {
 500         p->name = NULL;
 501         p->padoff = NOT_IN_PAD;
 502 }
 503
 504 static void ps_init(ParamSpec *ps) {
 505         p_init(&ps->invocant);
 506         pv_init(&ps->positional_required);
 507         piv_init(&ps->positional_optional);
 508         pv_init(&ps->named_required);
 509         piv_init(&ps->named_optional);
 510         p_init(&ps->slurpy);
 511         ps->rest_hash = NOT_IN_PAD;
 512 }
 513
 514 #define DEFVECTOR_EXTEND(N, B) static B (*N(VEC(B) *p)) { \
 515         assert(p->used <= p->size); \
 516         if (p->used == p->size) { \
 517                 const size_t n = p->size / 2 * 3 + 1; \
 518                 Renew(p->data, n, B); \
 519                 p->size = n; \
 520         } \
 521         return &p->data[p->used]; \
 522 } static B (*N(VEC(B) *))
 523
 524 DEFVECTOR_EXTEND(pv_extend, Param);
 525 DEFVECTOR_EXTEND(piv_extend, ParamInit);
 526
 527 #define DEFVECTOR_CLEAR(N, B, F) static void N(pTHX_ VEC(B) *p) { \
 528         while (p->used) { \
 529                 p->used--; \
 530                 F(aTHX_ &p->data[p->used]); \
 531         } \
 532         Safefree(p->data); \
 533         p->data = NULL; \
 534         p->size = 0; \
 535 } static void N(pTHX_ VEC(B) *)
 536
 537 static void p_clear(pTHX_ Param *p) {
 538         p->name = NULL;
 539         p->padoff = NOT_IN_PAD;
 540 }
 541
 542 static void pi_clear(pTHX_ ParamInit *pi) {
 543         p_clear(aTHX_ &pi->param);
 544         if (pi->init) {
 545                 op_free(pi->init);
 546                 pi->init = NULL;
 547         }
 548 }
 549
 550 DEFVECTOR_CLEAR(pv_clear, Param, p_clear);
 551 DEFVECTOR_CLEAR(piv_clear, ParamInit, pi_clear);
 552
 553 static void ps_clear(pTHX_ ParamSpec *ps) {
 554         p_clear(aTHX_ &ps->invocant);
 555
 556         pv_clear(aTHX_ &ps->positional_required);
 557         piv_clear(aTHX_ &ps->positional_optional);
 558
 559         pv_clear(aTHX_ &ps->named_required);
 560         piv_clear(aTHX_ &ps->named_optional);
 561
 562         p_clear(aTHX_ &ps->slurpy);
 563 }
 564
 565 static int ps_contains(pTHX_ const ParamSpec *ps, SV *sv) {
 566         size_t i, lim;
 567
 568         if (ps->invocant.name && sv_eq(sv, ps->invocant.name)) {
 569                 return 1;
 570         }
 571
 572         for (i = 0, lim = ps->positional_required.used; i < lim; i++) {
 573                 if (sv_eq(sv, ps->positional_required.data[i].name)) {
 574                         return 1;
 575                 }
 576         }
 577
 578         for (i = 0, lim = ps->positional_optional.used; i < lim; i++) {
 579                 if (sv_eq(sv, ps->positional_optional.data[i].param.name)) {
 580                         return 1;
 581                 }
 582         }
 583
 584         for (i = 0, lim = ps->named_required.used; i < lim; i++) {
 585                 if (sv_eq(sv, ps->named_required.data[i].name)) {
 586                         return 1;
 587                 }
 588         }
 589
 590         for (i = 0, lim = ps->named_optional.used; i < lim; i++) {
 591                 if (sv_eq(sv, ps->named_optional.data[i].param.name)) {
 592                         return 1;
 593                 }
 594         }
 595
 596         return 0;
 597 }
 598
 599 static void ps_free_void(pTHX_ void *p) {
 600         ps_clear(aTHX_ p);
 601         Safefree(p);
 602 }
 603
 604 static int args_min(pTHX_ const ParamSpec *ps, const KWSpec *ks) {
 605         int n = 0;
 606         if (!ps) {
 607                 return SvTRUE(ks->shift) ? 1 : 0;
 608         }
 609         if (ps->invocant.name) {
 610                 n++;
 611         }
 612         n += ps->positional_required.used;
 613         n += ps->named_required.used * 2;
 614         return n;
 615 }
 616
 617 static int args_max(const ParamSpec *ps) {
 618         int n = 0;
 619         if (!ps) {
 620                 return -1;
 621         }
 622         if (ps->invocant.name) {
 623                 n++;
 624         }
 625         n += ps->positional_required.used;
 626         n += ps->positional_optional.used;
 627         if (ps->named_required.used || ps->named_optional.used || ps->slurpy.name) {
 628                 n = -1;
 629         }
 630         return n;
 631 }
 632
 633 static size_t count_positional_params(const ParamSpec *ps) {
 634         return ps->positional_required.used + ps->positional_optional.used;
 635 }
 636
 637 static size_t count_named_params(const ParamSpec *ps) {
 638         return ps->named_required.used + ps->named_optional.used;
 639 }
 640
 641 enum {
 642         PARAM_INVOCANT = 0x01,
 643         PARAM_NAMED    = 0x02
 644 };
 645
 646 /* *pinit must be NULL on entry.
 647  * caller must free *pinit on error.
 648  */
 649 static PADOFFSET parse_param(
 650         pTHX_
 651         Sentinel sen,
 652         const SV *declarator, const KWSpec *spec, ParamSpec *param_spec,
 653         int *pflags, SV **pname, OP **pinit
 654 ) {
 655         I32 c;
 656         char sigil;
 657         SV *name;
 658
 659         assert(!*pinit);
 660         *pflags = 0;
 661
 662         c = lex_peek_unichar(0);
 663
 664         if (c == ':') {
 665                 lex_read_unichar(0);
 666                 lex_read_space(0);
 667
 668                 *pflags |= PARAM_NAMED;
 669
 670                 c = lex_peek_unichar(0);
 671         }
 672
 673         if (c == -1) {
 674                 croak("In %"SVf": unterminated parameter list", SVfARG(declarator));
 675         }
 676         if (!(c == '$' || c == '@' || c == '%')) {
 677                 croak("In %"SVf": unexpected '%c' in parameter list (expecting a sigil)", SVfARG(declarator), (int)c);
 678         }
 679
 680         sigil = c;
 681
 682         lex_read_unichar(0);
 683         lex_read_space(0);
 684
 685         if (!(name = my_scan_word(aTHX_ sen, FALSE))) {
 686                 croak("In %"SVf": missing identifier after '%c'", SVfARG(declarator), sigil);
 687         }
 688         sv_insert(name, 0, 0, &sigil, 1);
 689         *pname = name;
 690
 691         lex_read_space(0);
 692         c = lex_peek_unichar(0);
 693
 694         if (c == '=') {
 695                 lex_read_unichar(0);
 696                 lex_read_space(0);
 697
 698
 699                 if (!param_spec->invocant.name && SvTRUE(spec->shift)) {
 700                         param_spec->invocant.name = spec->shift;
 701                         param_spec->invocant.padoff = pad_add_name_sv(param_spec->invocant.name, 0, NULL, NULL);
 702                 }
 703
 704                 *pinit = parse_termexpr(0);
 705
 706                 lex_read_space(0);
 707                 c = lex_peek_unichar(0);
 708         }
 709
 710         if (c == ':') {
 711                 *pflags |= PARAM_INVOCANT;
 712                 lex_read_unichar(0);
 713                 lex_read_space(0);
 714         } else if (c == ',') {
 715                 lex_read_unichar(0);
 716                 lex_read_space(0);
 717         } else if (c != ')') {
 718                 if (c == -1) {
 719                         croak("In %"SVf": unterminated parameter list", SVfARG(declarator));
 720                 }
 721                 croak("In %"SVf": unexpected '%c' in parameter list (expecting ',')", SVfARG(declarator), (int)c);
 722         }
 723
 724         return pad_add_name_sv(*pname, IF_HAVE_PERL_5_16(padadd_NO_DUP_CHECK, 0), NULL, NULL);
 725 }
 726
 727 static OP *my_var_g(pTHX_ I32 type, I32 flags, PADOFFSET padoff) {
 728         OP *var = newOP(type, flags);
 729         var->op_targ = padoff;
 730         return var;
 731 }
 732
 733 static OP *my_var(pTHX_ I32 flags, PADOFFSET padoff) {
 734         return my_var_g(aTHX_ OP_PADSV, flags, padoff);
 735 }
 736
 737 static OP *mkhvelem(pTHX_ PADOFFSET h, OP *k) {
 738         OP *hv = my_var_g(aTHX_ OP_PADHV, OPf_REF, h);
 739         return newBINOP(OP_HELEM, 0, hv, k);
 740 }
 741
 742 static OP *mkconstsv(pTHX_ SV *sv) {
 743         return newSVOP(OP_CONST, 0, sv);
 744 }
 745
 746 static OP *mkconstiv(pTHX_ IV i) {
 747         return mkconstsv(aTHX_ newSViv(i));
 748 }
 749
 750 static OP *mkconstpv(pTHX_ const char *p, size_t n) {
 751         return mkconstsv(aTHX_ newSVpv(p, n));
 752 }
 753
 754 #define mkconstpvs(S) mkconstpv(aTHX_ "" S "", sizeof S - 1)
 755
 756 static int parse_fun(pTHX_ Sentinel sen, OP **pop, const char *keyword_ptr, STRLEN keyword_len, const KWSpec *spec) {
 757         ParamSpec *param_spec;
 758         SV *declarator;
 759         I32 floor_ix;
 760         int save_ix;
 761         SV *saw_name;
 762         OP **prelude_sentinel;
 763         SV *proto;
 764         OP **attrs_sentinel, *body;
 765         unsigned builtin_attrs;
 766         I32 c;
 767
 768         declarator = sentinel_mortalize(sen, newSVpvn(keyword_ptr, keyword_len));
 769
 770         lex_read_space(0);
 771
 772         builtin_attrs = 0;
 773
 774         /* function name */
 775         saw_name = NULL;
 776         if ((spec->flags & FLAG_NAME_OK) && (saw_name = my_scan_word(aTHX_ sen, TRUE))) {
 777
 778                 if (PL_parser->expect != XSTATE) {
 779                         /* bail out early so we don't predeclare $saw_name */
 780                         croak("In %"SVf": I was expecting a function body, not \"%"SVf"\"", SVfARG(declarator), SVfARG(saw_name));
 781                 }
 782
 783                 sv_catpvs(declarator, " ");
 784                 sv_catsv(declarator, saw_name);
 785
 786                 if (
 787                         sv_eq_pvs(saw_name, "BEGIN") ||
 788                         sv_eq_pvs(saw_name, "END") ||
 789                         sv_eq_pvs(saw_name, "INIT") ||
 790                         sv_eq_pvs(saw_name, "CHECK") ||
 791                         sv_eq_pvs(saw_name, "UNITCHECK")
 792                 ) {
 793                         builtin_attrs |= MY_ATTR_SPECIAL;
 794                 }
 795
 796                 lex_read_space(0);
 797         } else if (!(spec->flags & FLAG_ANON_OK)) {
 798                 croak("I was expecting a function name, not \"%.*s\"", (int)(PL_parser->bufend - PL_parser->bufptr), PL_parser->bufptr);
 799         } else {
 800                 sv_catpvs(declarator, " (anon)");
 801         }
 802
 803         /* we're a subroutine declaration */
 804         floor_ix = start_subparse(FALSE, saw_name ? 0 : CVf_ANON);
 805         SAVEFREESV(PL_compcv);
 806
 807         /* create outer block: '{' */
 808         save_ix = S_block_start(aTHX_ TRUE);
 809
 810         /* initialize synthetic optree */
 811         Newx(prelude_sentinel, 1, OP *);
 812         *prelude_sentinel = NULL;
 813         sentinel_register(sen, prelude_sentinel, free_ptr_op);
 814
 815         /* parameters */
 816         param_spec = NULL;
 817
 818         c = lex_peek_unichar(0);
 819         if (c == '(') {
 820                 OP **init_sentinel;
 821
 822                 Newx(init_sentinel, 1, OP *);
 823                 *init_sentinel = NULL;
 824                 sentinel_register(sen, init_sentinel, free_ptr_op);
 825
 826                 Newx(param_spec, 1, ParamSpec);
 827                 ps_init(param_spec);
 828                 sentinel_register(sen, param_spec, ps_free_void);
 829
 830                 lex_read_unichar(0);
 831                 lex_read_space(0);
 832
 833                 while ((c = lex_peek_unichar(0)) != ')') {
 834                         int flags;
 835                         SV *name;
 836                         char sigil;
 837                         PADOFFSET padoff;
 838
 839                         padoff = parse_param(aTHX_ sen, declarator, spec, param_spec, &flags, &name, init_sentinel);
 840
 841                         S_intro_my(aTHX);
 842
 843                         sigil = SvPV_nolen(name)[0];
 844
 845                         /* internal consistency */
 846                         if (flags & PARAM_NAMED) {
 847                                 if (flags & PARAM_INVOCANT) {
 848                                         croak("In %"SVf": invocant %"SVf" can't be a named parameter", SVfARG(declarator), SVfARG(name));
 849                                 }
 850                                 if (sigil != '$') {
 851                                         croak("In %"SVf": named parameter %"SVf" can't be a%s", SVfARG(declarator), SVfARG(name), sigil == '@' ? "n array" : " hash");
 852                                 }
 853                         } else if (flags & PARAM_INVOCANT) {
 854                                 if (*init_sentinel) {
 855                                         croak("In %"SVf": invocant %"SVf" can't have a default value", SVfARG(declarator), SVfARG(name));
 856                                 }
 857                                 if (sigil != '$') {
 858                                         croak("In %"SVf": invocant %"SVf" can't be a%s", SVfARG(declarator), SVfARG(name), sigil == '@' ? "n array" : " hash");
 859                                 }
 860                         } else if (sigil != '$' && *init_sentinel) {
 861                                 croak("In %"SVf": %s %"SVf" can't have a default value", SVfARG(declarator), sigil == '@' ? "array" : "hash", SVfARG(name));
 862                         }
 863
 864                         /* external constraints */
 865                         if (param_spec->slurpy.name) {
 866                                 croak("In %"SVf": I was expecting \")\" after \"%"SVf"\", not \"%"SVf"\"", SVfARG(declarator), SVfARG(param_spec->slurpy.name), SVfARG(name));
 867                         }
 868                         if (sigil != '$') {
 869                                 assert(!*init_sentinel);
 870                                 param_spec->slurpy.name = name;
 871                                 param_spec->slurpy.padoff = padoff;
 872                                 continue;
 873                         }
 874
 875                         if (!(flags & PARAM_NAMED) && count_named_params(param_spec)) {
 876                                 croak("In %"SVf": positional parameter %"SVf" can't appear after named parameter %"SVf"", SVfARG(declarator), SVfARG(name), SVfARG((param_spec->named_required.used ? param_spec->named_required.data[0] : param_spec->named_optional.data[0].param).name));
 877                         }
 878
 879                         if (flags & PARAM_INVOCANT) {
 880                                 if (param_spec->invocant.name) {
 881                                         croak("In %"SVf": invalid double invocants %"SVf", %"SVf"", SVfARG(declarator), SVfARG(param_spec->invocant.name), SVfARG(name));
 882                                 }
 883                                 if (count_positional_params(param_spec) || count_named_params(param_spec)) {
 884                                         croak("In %"SVf": invocant %"SVf" must be first in parameter list", SVfARG(declarator), SVfARG(name));
 885                                 }
 886                                 if (!(spec->flags & FLAG_INVOCANT)) {
 887                                         croak("In %"SVf": invocant %"SVf" not allowed here", SVfARG(declarator), SVfARG(name));
 888                                 }
 889                                 param_spec->invocant.name = name;
 890                                 param_spec->invocant.padoff = padoff;
 891                                 continue;
 892                         }
 893
 894                         if (*init_sentinel && !(spec->flags & FLAG_DEFAULT_ARGS)) {
 895                                 croak("In %"SVf": default argument for %"SVf" not allowed here", SVfARG(declarator), SVfARG(name));
 896                         }
 897
 898                         if (ps_contains(aTHX_ param_spec, name)) {
 899                                 croak("In %"SVf": %"SVf" can't appear twice in the same parameter list", SVfARG(declarator), SVfARG(name));
 900                         }
 901
 902                         if (flags & PARAM_NAMED) {
 903                                 if (!(spec->flags & FLAG_NAMED_PARAMS)) {
 904                                         croak("In %"SVf": named parameter :%"SVf" not allowed here", SVfARG(declarator), SVfARG(name));
 905                                 }
 906
 907                                 if (*init_sentinel) {
 908                                         ParamInit *pi = piv_extend(&param_spec->named_optional);
 909                                         pi->param.name = name;
 910                                         pi->param.padoff = padoff;
 911                                         pi->init = *init_sentinel;
 912                                         *init_sentinel = NULL;
 913                                         param_spec->named_optional.used++;
 914                                 } else {
 915                                         Param *p;
 916
 917                                         if (param_spec->positional_optional.used) {
 918                                                 croak("In %"SVf": can't combine optional positional (%"SVf") and required named (%"SVf") parameters", SVfARG(declarator), SVfARG(param_spec->positional_optional.data[0].param.name), SVfARG(name));
 919                                         }
 920
 921                                         p = pv_extend(&param_spec->named_required);
 922                                         p->name = name;
 923                                         p->padoff = padoff;
 924                                         param_spec->named_required.used++;
 925                                 }
 926                         } else {
 927                                 if (*init_sentinel || param_spec->positional_optional.used) {
 928                                         ParamInit *pi = piv_extend(&param_spec->positional_optional);
 929                                         pi->param.name = name;
 930                                         pi->param.padoff = padoff;
 931                                         pi->init = *init_sentinel;
 932                                         *init_sentinel = NULL;
 933                                         param_spec->positional_optional.used++;
 934                                 } else {
 935                                         Param *p = pv_extend(&param_spec->positional_required);
 936                                         p->name = name;
 937                                         p->padoff = padoff;
 938                                         param_spec->positional_required.used++;
 939                                 }
 940                         }
 941
 942                 }
 943                 lex_read_unichar(0);
 944                 lex_read_space(0);
 945                 *init_sentinel = NULL;
 946
 947                 if (!param_spec->invocant.name && SvTRUE(spec->shift)) {
 948                         if (ps_contains(aTHX_ param_spec, spec->shift)) {
 949                                 croak("In %"SVf": %"SVf" can't appear twice in the same parameter list", SVfARG(declarator), SVfARG(spec->shift));
 950                         }
 951
 952                         param_spec->invocant.name = spec->shift;
 953                         param_spec->invocant.padoff = pad_add_name_sv(param_spec->invocant.name, 0, NULL, NULL);
 954                 }
 955         }
 956
 957         /* prototype */
 958         proto = NULL;
 959         c = lex_peek_unichar(0);
 960         if (c == ':') {
 961                 lex_read_unichar(0);
 962                 lex_read_space(0);
 963
 964                 c = lex_peek_unichar(0);
 965                 if (c != '(') {
 966                         lex_stuff_pvs(":", 0);
 967                         c = ':';
 968                 } else {
 969                         lex_read_unichar(0);
 970                         if (!(proto = my_scan_parens_tail(aTHX_ sen, FALSE))) {
 971                                 croak("In %"SVf": prototype not terminated", SVfARG(declarator));
 972                         }
 973                         my_check_prototype(aTHX_ sen, declarator, proto);
 974                         lex_read_space(0);
 975                         c = lex_peek_unichar(0);
 976                         if (!(c == ':' || c == '{')) {
 977                                 lex_stuff_pvs(":", 0);
 978                                 c = ':';
 979                         }
 980                 }
 981         }
 982
 983         /* attributes */
 984         Newx(attrs_sentinel, 1, OP *);
 985         *attrs_sentinel = NULL;
 986         sentinel_register(sen, attrs_sentinel, free_ptr_op);
 987
 988         if (c == ':' || c == '{') /* '}' - hi, vim */ {
 989
 990                 /* kludge default attributes in */
 991                 if (SvTRUE(spec->attrs) && SvPV_nolen(spec->attrs)[0] == ':') {
 992                         lex_stuff_sv(spec->attrs, 0);
 993                         c = ':';
 994                 }
 995
 996                 if (c == ':') {
 997                         lex_read_unichar(0);
 998                         lex_read_space(0);
 999                         c = lex_peek_unichar(0);
1000
1001                         for (;;) {
1002                                 SV *attr;
1003
1004                                 if (!(attr = my_scan_word(aTHX_ sen, FALSE))) {
1005                                         break;
1006                                 }
1007
1008                                 lex_read_space(0);
1009                                 c = lex_peek_unichar(0);
1010
1011                                 if (c != '(') {
1012                                         if (sv_eq_pvs(attr, "lvalue")) {
1013                                                 builtin_attrs |= MY_ATTR_LVALUE;
1014                                                 attr = NULL;
1015                                         } else if (sv_eq_pvs(attr, "method")) {
1016                                                 builtin_attrs |= MY_ATTR_METHOD;
1017                                                 attr = NULL;
1018                                         }
1019                                 } else {
1020                                         SV *sv;
1021                                         lex_read_unichar(0);
1022                                         if (!(sv = my_scan_parens_tail(aTHX_ sen, TRUE))) {
1023                                                 croak("In %"SVf": unterminated attribute parameter in attribute list", SVfARG(declarator));
1024                                         }
1025                                         sv_catpvs(attr, "(");
1026                                         sv_catsv(attr, sv);
1027                                         sv_catpvs(attr, ")");
1028
1029                                         lex_read_space(0);
1030                                         c = lex_peek_unichar(0);
1031                                 }
1032
1033                                 if (attr) {
1034                                         *attrs_sentinel = op_append_elem(OP_LIST, *attrs_sentinel, mkconstsv(aTHX_ SvREFCNT_inc_simple_NN(attr)));
1035                                 }
1036
1037                                 if (c == ':') {
1038                                         lex_read_unichar(0);
1039                                         lex_read_space(0);
1040                                         c = lex_peek_unichar(0);
1041                                 }
1042                         }
1043                 }
1044         }
1045
1046         /* body */
1047         if (c != '{') /* '}' - hi, vim */ {
1048                 croak("In %"SVf": I was expecting a function body, not \"%c\"", SVfARG(declarator), (int)c);
1049         }
1050
1051         /* surprise predeclaration! */
1052         if (saw_name) {
1053                 /* 'sub NAME (PROTO);' to make name/proto known to perl before it
1054                    starts parsing the body */
1055                 const I32 sub_ix = start_subparse(FALSE, 0);
1056                 SAVEFREESV(PL_compcv);
1057
1058                 SvREFCNT_inc_simple_void(PL_compcv);
1059
1060                 newATTRSUB(
1061                         sub_ix,
1062                         mkconstsv(aTHX_ SvREFCNT_inc_simple_NN(saw_name)),
1063                         proto ? mkconstsv(aTHX_ SvREFCNT_inc_simple_NN(proto)) : NULL,
1064                         NULL,
1065                         NULL
1066                 );
1067         }
1068
1069         if (builtin_attrs & MY_ATTR_LVALUE) {
1070                 CvLVALUE_on(PL_compcv);
1071         }
1072         if (builtin_attrs & MY_ATTR_METHOD) {
1073                 CvMETHOD_on(PL_compcv);
1074         }
1075         if (builtin_attrs & MY_ATTR_SPECIAL) {
1076                 CvSPECIAL_on(PL_compcv);
1077         }
1078
1079         /* check number of arguments */
1080         if (spec->flags & FLAG_CHECK_NARGS) {
1081                 int amin, amax;
1082
1083                 amin = args_min(aTHX_ param_spec, spec);
1084                 if (amin > 0) {
1085                         OP *chk, *cond, *err, *xcroak;
1086
1087                         err = mkconstsv(aTHX_ newSVpvf("Not enough arguments for %"SVf" (expected %d, got ", SVfARG(declarator), amin));
1088                         err = newBINOP(
1089                                 OP_CONCAT, 0,
1090                                 err,
1091                                 newAVREF(newGVOP(OP_GV, 0, PL_defgv))
1092                         );
1093                         err = newBINOP(
1094                                 OP_CONCAT, 0,
1095                                 err,
1096                                 mkconstpvs(")")
1097                         );
1098
1099                         xcroak = newCVREF(OPf_WANT_SCALAR,
1100                                           newGVOP(OP_GV, 0, gv_fetchpvs("Carp::croak", 0, SVt_PVCV)));
1101                         err = newUNOP(OP_ENTERSUB, OPf_STACKED,
1102                                       op_append_elem(OP_LIST, err, xcroak));
1103
1104                         cond = newBINOP(OP_LT, 0,
1105                                         newAVREF(newGVOP(OP_GV, 0, PL_defgv)),
1106                                         mkconstiv(aTHX_ amin));
1107                         chk = newLOGOP(OP_AND, 0, cond, err);
1108
1109                         *prelude_sentinel = op_append_list(OP_LINESEQ, *prelude_sentinel, newSTATEOP(0, NULL, chk));
1110                 }
1111
1112                 amax = args_max(param_spec);
1113                 if (amax >= 0) {
1114                         OP *chk, *cond, *err, *xcroak;
1115
1116                         err = mkconstsv(aTHX_ newSVpvf("Too many arguments for %"SVf" (expected %d, got ", SVfARG(declarator), amax));
1117                         err = newBINOP(
1118                                 OP_CONCAT, 0,
1119                                 err,
1120                                 newAVREF(newGVOP(OP_GV, 0, PL_defgv))
1121                         );
1122                         err = newBINOP(
1123                                 OP_CONCAT, 0,
1124                                 err,
1125                                 mkconstpvs(")")
1126                         );
1127
1128                         xcroak = newCVREF(
1129                                 OPf_WANT_SCALAR,
1130                                 newGVOP(OP_GV, 0, gv_fetchpvs("Carp::croak", 0, SVt_PVCV))
1131                         );
1132                         err = newUNOP(OP_ENTERSUB, OPf_STACKED,
1133                         op_append_elem(OP_LIST, err, xcroak));
1134
1135                         cond = newBINOP(
1136                                 OP_GT, 0,
1137                                 newAVREF(newGVOP(OP_GV, 0, PL_defgv)),
1138                                 mkconstiv(aTHX_ amax)
1139                         );
1140                         chk = newLOGOP(OP_AND, 0, cond, err);
1141
1142                         *prelude_sentinel = op_append_list(OP_LINESEQ, *prelude_sentinel, newSTATEOP(0, NULL, chk));
1143                 }
1144
1145                 if (param_spec && (count_named_params(param_spec) || (param_spec->slurpy.name && SvPV_nolen(param_spec->slurpy.name)[0] == '%'))) {
1146                         OP *chk, *cond, *err, *xcroak;
1147                         const UV fixed = count_positional_params(param_spec) + !!param_spec->invocant.name;
1148
1149                         err = mkconstsv(aTHX_ newSVpvf("Odd number of paired arguments for %"SVf"", SVfARG(declarator)));
1150
1151                         xcroak = newCVREF(
1152                                 OPf_WANT_SCALAR,
1153                                 newGVOP(OP_GV, 0, gv_fetchpvs("Carp::croak", 0, SVt_PVCV))
1154                         );
1155                         err = newUNOP(OP_ENTERSUB, OPf_STACKED,
1156                         op_append_elem(OP_LIST, err, xcroak));
1157
1158                         cond = newBINOP(OP_GT, 0,
1159                                         newAVREF(newGVOP(OP_GV, 0, PL_defgv)),
1160                                         mkconstiv(aTHX_ fixed));
1161                         cond = newLOGOP(OP_AND, 0,
1162                                         cond,
1163                                         newBINOP(OP_MODULO, 0,
1164                                                  fixed
1165                                                  ? newBINOP(OP_SUBTRACT, 0,
1166                                                             newAVREF(newGVOP(OP_GV, 0, PL_defgv)),
1167                                                             mkconstiv(aTHX_ fixed))
1168                                                  : newAVREF(newGVOP(OP_GV, 0, PL_defgv)),
1169                                                  mkconstiv(aTHX_ 2)));
1170                         chk = newLOGOP(OP_AND, 0, cond, err);
1171
1172                         *prelude_sentinel = op_append_list(OP_LINESEQ, *prelude_sentinel, newSTATEOP(0, NULL, chk));
1173                 }
1174         }
1175
1176         if (!param_spec) {
1177                 /* my $invocant = shift; */
1178                 if (SvTRUE(spec->shift)) {
1179                         OP *var;
1180
1181                         var = my_var(
1182                                 aTHX_
1183                                 OPf_MOD | (OPpLVAL_INTRO << 8),
1184                                 pad_add_name_sv(spec->shift, 0, NULL, NULL)
1185                         );
1186                         var = newASSIGNOP(OPf_STACKED, var, 0, newOP(OP_SHIFT, 0));
1187
1188                         *prelude_sentinel = op_append_list(OP_LINESEQ, *prelude_sentinel, newSTATEOP(0, NULL, var));
1189                 }
1190         } else {
1191                 /* my $invocant = shift; */
1192                 if (param_spec->invocant.name) {
1193                         OP *var;
1194
1195                         var = my_var(
1196                                 aTHX_
1197                                 OPf_MOD | (OPpLVAL_INTRO << 8),
1198                                 param_spec->invocant.padoff
1199                         );
1200                         var = newASSIGNOP(OPf_STACKED, var, 0, newOP(OP_SHIFT, 0));
1201
1202                         *prelude_sentinel = op_append_list(OP_LINESEQ, *prelude_sentinel, newSTATEOP(0, NULL, var));
1203                 }
1204
1205                 /* my (...) = @_; */
1206                 {
1207                         OP *lhs;
1208                         size_t i, lim;
1209
1210                         lhs = NULL;
1211
1212                         for (i = 0, lim = param_spec->positional_required.used; i < lim; i++) {
1213                                 OP *const var = my_var(
1214                                         aTHX_
1215                                         OPf_WANT_LIST | (OPpLVAL_INTRO << 8),
1216                                         param_spec->positional_required.data[i].padoff
1217                                 );
1218                                 lhs = op_append_elem(OP_LIST, lhs, var);
1219                         }
1220
1221                         for (i = 0, lim = param_spec->positional_optional.used; i < lim; i++) {
1222                                 OP *const var = my_var(
1223                                         aTHX_
1224                                         OPf_WANT_LIST | (OPpLVAL_INTRO << 8),
1225                                         param_spec->positional_optional.data[i].param.padoff
1226                                 );
1227                                 lhs = op_append_elem(OP_LIST, lhs, var);
1228                         }
1229
1230                         {
1231                                 PADOFFSET padoff;
1232                                 I32 type;
1233                                 bool slurpy_hash;
1234
1235                                 /*
1236                                  * cases:
1237                                  *  1) no named params
1238                                  *   1.1) slurpy
1239                                  *       => put it in
1240                                  *   1.2) no slurpy
1241                                  *       => nop
1242                                  *  2) named params
1243                                  *   2.1) no slurpy
1244                                  *       => synthetic %{rest}
1245                                  *   2.2) slurpy is a hash
1246                                  *       => put it in
1247                                  *   2.3) slurpy is an array
1248                                  *       => synthetic %{rest}
1249                                  *          remember to declare array later
1250                                  */
1251
1252                                 slurpy_hash = param_spec->slurpy.name && SvPV_nolen(param_spec->slurpy.name)[0] == '%';
1253                                 if (!count_named_params(param_spec)) {
1254                                         if (param_spec->slurpy.name) {
1255                                                 padoff = param_spec->slurpy.padoff;
1256                                                 type = slurpy_hash ? OP_PADHV : OP_PADAV;
1257                                         } else {
1258                                                 padoff = NOT_IN_PAD;
1259                                                 type = OP_PADSV;
1260                                         }
1261                                 } else if (slurpy_hash) {
1262                                         padoff = param_spec->slurpy.padoff;
1263                                         type = OP_PADHV;
1264                                 } else {
1265                                         padoff = param_spec->rest_hash = pad_add_name_pvs("%{rest}", 0, NULL, NULL);
1266                                         type = OP_PADHV;
1267                                 }
1268
1269                                 if (padoff != NOT_IN_PAD) {
1270                                         OP *const var = my_var_g(
1271                                                 aTHX_
1272                                                 type,
1273                                                 OPf_WANT_LIST | (OPpLVAL_INTRO << 8),
1274                                                 padoff
1275                                         );
1276
1277                                         lhs = op_append_elem(OP_LIST, lhs, var);
1278
1279                                         if (type == OP_PADHV) {
1280                                                 param_spec->rest_hash = padoff;
1281                                         }
1282                                 }
1283                         }
1284
1285                         if (lhs) {
1286                                 OP *rhs;
1287                                 lhs->op_flags |= OPf_PARENS;
1288                                 rhs = newAVREF(newGVOP(OP_GV, 0, PL_defgv));
1289
1290                                 *prelude_sentinel = op_append_list(
1291                                         OP_LINESEQ, *prelude_sentinel,
1292                                         newSTATEOP(
1293                                                 0, NULL,
1294                                                 newASSIGNOP(OPf_STACKED, lhs, 0, rhs)
1295                                         )
1296                                 );
1297                         }
1298                 }
1299
1300                 /* default positional arguments */
1301                 {
1302                         size_t i, lim, req;
1303                         OP *nest;
1304
1305                         nest = NULL;
1306
1307                         req = param_spec->positional_required.used;
1308                         for (i = 0, lim = param_spec->positional_optional.used; i < lim; i++) {
1309                                 ParamInit *cur = &param_spec->positional_optional.data[i];
1310                                 OP *var, *cond;
1311
1312                                 cond = newBINOP(
1313                                         OP_LT, 0,
1314                                         newAVREF(newGVOP(OP_GV, 0, PL_defgv)),
1315                                         mkconstiv(aTHX_ req + i + 1)
1316                                 );
1317
1318                                 var = my_var(aTHX_ 0, cur->param.padoff);
1319
1320                                 nest = op_append_list(
1321                                         OP_LINESEQ, nest,
1322                                         newASSIGNOP(OPf_STACKED, var, 0, cur->init)
1323                                 );
1324                                 cur->init = NULL;
1325                                 nest = newCONDOP(
1326                                         0,
1327                                         cond,
1328                                         nest,
1329                                         NULL
1330                                 );
1331                         }
1332
1333                         *prelude_sentinel = op_append_list(
1334                                 OP_LINESEQ, *prelude_sentinel,
1335                                 nest
1336                         );
1337                 }
1338
1339                 /* named parameters */
1340                 if (count_named_params(param_spec)) {
1341                         size_t i, lim;
1342
1343                         assert(param_spec->rest_hash != NOT_IN_PAD);
1344
1345                         for (i = 0, lim = param_spec->named_required.used; i < lim; i++) {
1346                                 Param *cur = &param_spec->named_required.data[i];
1347                                 size_t n;
1348                                 char *p = SvPV(cur->name, n);
1349                                 OP *var, *cond;
1350
1351                                 cond = mkhvelem(aTHX_ param_spec->rest_hash, mkconstpv(aTHX_ p + 1, n - 1));
1352
1353                                 if (spec->flags & FLAG_CHECK_NARGS) {
1354                                         OP *xcroak, *msg;
1355
1356                                         var = mkhvelem(aTHX_ param_spec->rest_hash, mkconstpv(aTHX_ p + 1, n - 1));
1357                                         var = newUNOP(OP_DELETE, 0, var);
1358
1359                                         msg = mkconstsv(aTHX_ newSVpvf("In %"SVf": missing named parameter: %.*s", SVfARG(declarator), (int)(n - 1), p + 1));
1360                                         xcroak = newCVREF(
1361                                                 OPf_WANT_SCALAR,
1362                                                 newGVOP(OP_GV, 0, gv_fetchpvs("Carp::croak", 0, SVt_PVCV))
1363                                         );
1364                                         xcroak = newUNOP(OP_ENTERSUB, OPf_STACKED, op_append_elem(OP_LIST, msg, xcroak));
1365
1366                                         cond = newUNOP(OP_EXISTS, 0, cond);
1367
1368                                         cond = newCONDOP(0, cond, var, xcroak);
1369                                 }
1370
1371                                 var = my_var(
1372                                         aTHX_
1373                                         OPf_MOD | (OPpLVAL_INTRO << 8),
1374                                         cur->padoff
1375                                 );
1376                                 var = newASSIGNOP(OPf_STACKED, var, 0, cond);
1377
1378                                 *prelude_sentinel = op_append_list(OP_LINESEQ, *prelude_sentinel, newSTATEOP(0, NULL, var));
1379                         }
1380
1381                         for (i = 0, lim = param_spec->named_optional.used; i < lim; i++) {
1382                                 ParamInit *cur = &param_spec->named_optional.data[i];
1383                                 size_t n;
1384                                 char *p = SvPV(cur->param.name, n);
1385                                 OP *var, *cond;
1386
1387                                 var = mkhvelem(aTHX_ param_spec->rest_hash, mkconstpv(aTHX_ p + 1, n - 1));
1388                                 var = newUNOP(OP_DELETE, 0, var);
1389
1390                                 cond = mkhvelem(aTHX_ param_spec->rest_hash, mkconstpv(aTHX_ p + 1, n - 1));
1391                                 cond = newUNOP(OP_EXISTS, 0, cond);
1392
1393                                 cond = newCONDOP(0, cond, var, cur->init);
1394                                 cur->init = NULL;
1395
1396                                 var = my_var(
1397                                         aTHX_
1398                                         OPf_MOD | (OPpLVAL_INTRO << 8),
1399                                         cur->param.padoff
1400                                 );
1401                                 var = newASSIGNOP(OPf_STACKED, var, 0, cond);
1402
1403                                 *prelude_sentinel = op_append_list(OP_LINESEQ, *prelude_sentinel, newSTATEOP(0, NULL, var));
1404                         }
1405
1406                         if (!param_spec->slurpy.name) {
1407                                 if (spec->flags & FLAG_CHECK_NARGS) {
1408                                         /* croak if %{rest} */
1409                                         OP *xcroak, *cond, *keys, *msg;
1410
1411                                         keys = newUNOP(OP_KEYS, 0, my_var_g(aTHX_ OP_PADHV, 0, param_spec->rest_hash));
1412                                         keys = newLISTOP(OP_SORT, 0, newOP(OP_PUSHMARK, 0), keys);
1413                                         {
1414                                                 OP *first, *mid, *last;
1415
1416                                                 last = keys;
1417
1418                                                 mid = mkconstpvs(", ");
1419                                                 mid->op_sibling = last;
1420
1421                                                 first = newOP(OP_PUSHMARK, 0);
1422
1423                                                 keys = newLISTOP(OP_JOIN, 0, first, mid);
1424                                                 keys->op_targ = pad_alloc(OP_JOIN, SVs_PADTMP);
1425                                                 ((LISTOP *)keys)->op_last = last;
1426                                         }
1427
1428                                         msg = mkconstsv(aTHX_ newSVpvf("In %"SVf": no such named parameter: ", SVfARG(declarator)));
1429                                         msg = newBINOP(OP_CONCAT, 0, msg, keys);
1430
1431                                         xcroak = newCVREF(
1432                                                 OPf_WANT_SCALAR,
1433                                                 newGVOP(OP_GV, 0, gv_fetchpvs("Carp::croak", 0, SVt_PVCV))
1434                                         );
1435                                         xcroak = newUNOP(OP_ENTERSUB, OPf_STACKED, op_append_elem(OP_LIST, msg, xcroak));
1436
1437                                         cond = newUNOP(OP_KEYS, 0, my_var_g(aTHX_ OP_PADHV, 0, param_spec->rest_hash));
1438                                         xcroak = newCONDOP(0, cond, xcroak, NULL);
1439
1440                                         *prelude_sentinel = op_append_list(OP_LINESEQ, *prelude_sentinel, newSTATEOP(0, NULL, xcroak));
1441                                 } else {
1442                                         OP *clear;
1443
1444                                         clear = newASSIGNOP(
1445                                                 OPf_STACKED,
1446                                                 my_var_g(aTHX_ OP_PADHV, 0, param_spec->rest_hash),
1447                                                 0,
1448                                                 newNULLLIST()
1449                                         );
1450
1451                                         *prelude_sentinel = op_append_list(OP_LINESEQ, *prelude_sentinel, newSTATEOP(0, NULL, clear));
1452                                 }
1453                         } else if (param_spec->slurpy.padoff != param_spec->rest_hash) {
1454                                 OP *var, *clear;
1455
1456                                 assert(SvPV_nolen(param_spec->slurpy.name)[0] == '@');
1457
1458                                 var = my_var_g(
1459                                         aTHX_
1460                                         OP_PADAV,
1461                                         OPf_MOD | (OPpLVAL_INTRO << 8),
1462                                         param_spec->slurpy.padoff
1463                                 );
1464
1465                                 var = newASSIGNOP(OPf_STACKED, var, 0, my_var_g(aTHX_ OP_PADHV, 0, param_spec->rest_hash));
1466
1467                                 *prelude_sentinel = op_append_list(OP_LINESEQ, *prelude_sentinel, newSTATEOP(0, NULL, var));
1468
1469                                 clear = newASSIGNOP(
1470                                         OPf_STACKED,
1471                                         my_var_g(aTHX_ OP_PADHV, 0, param_spec->rest_hash),
1472                                         0,
1473                                         newNULLLIST()
1474                                 );
1475
1476                                 *prelude_sentinel = op_append_list(OP_LINESEQ, *prelude_sentinel, newSTATEOP(0, NULL, clear));
1477                         }
1478                 }
1479         }
1480
1481         /* finally let perl parse the actual subroutine body */
1482         body = parse_block(0);
1483
1484         /* add '();' to make function return nothing by default */
1485         /* (otherwise the invisible parameter initialization can "leak" into
1486            the return value: fun ($x) {}->("asdf", 0) == 2) */
1487         if (*prelude_sentinel) {
1488                 body = newSTATEOP(0, NULL, body);
1489         }
1490
1491         body = op_append_list(OP_LINESEQ, *prelude_sentinel, body);
1492         *prelude_sentinel = NULL;
1493
1494         /* it's go time. */
1495         {
1496                 OP *const attrs = *attrs_sentinel;
1497                 *attrs_sentinel = NULL;
1498                 SvREFCNT_inc_simple_void(PL_compcv);
1499
1500                 /* close outer block: '}' */
1501                 S_block_end(aTHX_ save_ix, body);
1502
1503                 if (!saw_name) {
1504                         *pop = newANONATTRSUB(
1505                                 floor_ix,
1506                                 proto ? newSVOP(OP_CONST, 0, SvREFCNT_inc_simple_NN(proto)) : NULL,
1507                                 attrs,
1508                                 body
1509                         );
1510                         return KEYWORD_PLUGIN_EXPR;
1511                 }
1512
1513                 newATTRSUB(
1514                         floor_ix,
1515                         newSVOP(OP_CONST, 0, SvREFCNT_inc_simple_NN(saw_name)),
1516                         proto ? newSVOP(OP_CONST, 0, SvREFCNT_inc_simple_NN(proto)) : NULL,
1517                         attrs,
1518                         body
1519                 );
1520                 *pop = newOP(OP_NULL, 0);
1521                 return KEYWORD_PLUGIN_STMT;
1522         }
1523 }
1524
1525 static int my_keyword_plugin(pTHX_ char *keyword_ptr, STRLEN keyword_len, OP **op_ptr) {
1526         KWSpec spec;
1527         int ret;
1528         Sentinel sen = { NULL };
1529
1530         ENTER;
1531         SAVETMPS;
1532
1533         SAVEDESTRUCTOR_X(sentinel_clear_void, sen);
1534
1535         if (kw_flags(aTHX_ sen, keyword_ptr, keyword_len, &spec)) {
1536                 ret = parse_fun(aTHX_ sen, op_ptr, keyword_ptr, keyword_len, &spec);
1537         } else {
1538                 ret = next_keyword_plugin(aTHX_ keyword_ptr, keyword_len, op_ptr);
1539         }
1540
1541         FREETMPS;
1542         LEAVE;
1543
1544         return ret;
1545 }
1546
1547 WARNINGS_RESET
1548
1549 MODULE = Function::Parameters   PACKAGE = Function::Parameters
1550 PROTOTYPES: ENABLE
1551
1552 BOOT:
1553 WARNINGS_ENABLE {
1554         HV *const stash = gv_stashpvs(MY_PKG, GV_ADD);
1555         /**/
1556         newCONSTSUB(stash, "FLAG_NAME_OK",      newSViv(FLAG_NAME_OK));
1557         newCONSTSUB(stash, "FLAG_ANON_OK",      newSViv(FLAG_ANON_OK));
1558         newCONSTSUB(stash, "FLAG_DEFAULT_ARGS", newSViv(FLAG_DEFAULT_ARGS));
1559         newCONSTSUB(stash, "FLAG_CHECK_NARGS",  newSViv(FLAG_CHECK_NARGS));
1560         newCONSTSUB(stash, "FLAG_INVOCANT",     newSViv(FLAG_INVOCANT));
1561         newCONSTSUB(stash, "FLAG_NAMED_PARAMS", newSViv(FLAG_NAMED_PARAMS));
1562         newCONSTSUB(stash, "HINTK_KEYWORDS", newSVpvs(HINTK_KEYWORDS));
1563         newCONSTSUB(stash, "HINTK_FLAGS_",   newSVpvs(HINTK_FLAGS_));
1564         newCONSTSUB(stash, "HINTK_SHIFT_",   newSVpvs(HINTK_SHIFT_));
1565         newCONSTSUB(stash, "HINTK_ATTRS_",   newSVpvs(HINTK_ATTRS_));
1566         /**/
1567         next_keyword_plugin = PL_keyword_plugin;
1568         PL_keyword_plugin = my_keyword_plugin;
1569 } WARNINGS_RESET