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 enum {
  92         FLAG_NAME_OK      = 0x01,
  93         FLAG_ANON_OK      = 0x02,
  94         FLAG_DEFAULT_ARGS = 0x04,
  95         FLAG_CHECK_NARGS  = 0x08,
  96         FLAG_INVOCANT     = 0x10,
  97         FLAG_NAMED_PARAMS = 0x20
  98 };
  99
 100 DEFSTRUCT(KWSpec) {
 101         unsigned flags;
 102         SV *shift;
 103         SV *attrs;
 104 };
 105
 106 static int (*next_keyword_plugin)(pTHX_ char *, STRLEN, OP **);
 107
 108 static int kw_flags(pTHX_ const char *kw_ptr, STRLEN kw_len, KWSpec *spec) {
 109         HV *hints;
 110         SV *sv, **psv;
 111         const char *p, *kw_active;
 112         STRLEN kw_active_len;
 113
 114         spec->flags = 0;
 115         spec->shift = sv_2mortal(newSVpvs(""));
 116         spec->attrs = sv_2mortal(newSVpvs(""));
 117
 118         if (!(hints = GvHV(PL_hintgv))) {
 119                 return FALSE;
 120         }
 121         if (!(psv = hv_fetchs(hints, HINTK_KEYWORDS, 0))) {
 122                 return FALSE;
 123         }
 124         sv = *psv;
 125         kw_active = SvPV(sv, kw_active_len);
 126         if (kw_active_len <= kw_len) {
 127                 return FALSE;
 128         }
 129         for (
 130                 p = kw_active;
 131                 (p = strchr(p, *kw_ptr)) &&
 132                 p < kw_active + kw_active_len - kw_len;
 133                 p++
 134         ) {
 135                 if (
 136                         (p == kw_active || p[-1] == ' ') &&
 137                         p[kw_len] == ' ' &&
 138                         memcmp(kw_ptr, p, kw_len) == 0
 139                 ) {
 140
 141 #define FETCH_HINTK_INTO(NAME, PTR, LEN, X) STMT_START { \
 142         const char *fk_ptr_; \
 143         STRLEN fk_len_; \
 144         SV *fk_sv_; \
 145         fk_sv_ = sv_2mortal(newSVpvs(HINTK_ ## NAME)); \
 146         sv_catpvn(fk_sv_, PTR, LEN); \
 147         fk_ptr_ = SvPV(fk_sv_, fk_len_); \
 148         if (!((X) = hv_fetch(hints, fk_ptr_, fk_len_, 0))) { \
 149                 croak("%s: internal error: $^H{'%.*s'} not set", MY_PKG, (int)fk_len_, fk_ptr_); \
 150         } \
 151 } STMT_END
 152
 153                         FETCH_HINTK_INTO(FLAGS_, kw_ptr, kw_len, psv);
 154                         spec->flags = SvIV(*psv);
 155
 156                         FETCH_HINTK_INTO(SHIFT_, kw_ptr, kw_len, psv);
 157                         SvSetSV(spec->shift, *psv);
 158
 159                         FETCH_HINTK_INTO(ATTRS_, kw_ptr, kw_len, psv);
 160                         SvSetSV(spec->attrs, *psv);
 161
 162 #undef FETCH_HINTK_INTO
 163                         return TRUE;
 164                 }
 165         }
 166         return FALSE;
 167 }
 168
 169
 170 static void free_ptr_op(pTHX_ void *vp) {
 171         OP **pp = vp;
 172         op_free(*pp);
 173         Safefree(pp);
 174 }
 175
 176 #define sv_eq_pvs(SV, S) my_sv_eq_pvn(aTHX_ SV, "" S "", sizeof (S) - 1)
 177
 178 static int my_sv_eq_pvn(pTHX_ SV *sv, const char *p, STRLEN n) {
 179         STRLEN sv_len;
 180         const char *sv_p = SvPV(sv, sv_len);
 181         return memcmp(sv_p, p, n) == 0;
 182 }
 183
 184
 185 #include "padop_on_crack.c.inc"
 186
 187
 188 enum {
 189         MY_ATTR_LVALUE = 0x01,
 190         MY_ATTR_METHOD = 0x02,
 191         MY_ATTR_SPECIAL = 0x04
 192 };
 193
 194 static void my_sv_cat_c(pTHX_ SV *sv, U32 c) {
 195         char ds[UTF8_MAXBYTES + 1], *d;
 196         d = uvchr_to_utf8(ds, c);
 197         if (d - ds > 1) {
 198                 sv_utf8_upgrade(sv);
 199         }
 200         sv_catpvn(sv, ds, d - ds);
 201 }
 202
 203 static bool my_is_uni_xidfirst(pTHX_ UV c) {
 204         U8 tmpbuf[UTF8_MAXBYTES + 1];
 205         uvchr_to_utf8(tmpbuf, c);
 206         return is_utf8_xidfirst(tmpbuf);
 207 }
 208
 209 static bool my_is_uni_xidcont(pTHX_ UV c) {
 210         U8 tmpbuf[UTF8_MAXBYTES + 1];
 211         uvchr_to_utf8(tmpbuf, c);
 212         return is_utf8_xidcont(tmpbuf);
 213 }
 214
 215 static SV *my_scan_word(pTHX_ bool allow_package) {
 216         bool at_start, at_substart;
 217         I32 c;
 218         SV *sv = sv_2mortal(newSVpvs(""));
 219         if (lex_bufutf8()) {
 220                 SvUTF8_on(sv);
 221         }
 222
 223         at_start = at_substart = TRUE;
 224         c = lex_peek_unichar(0);
 225
 226         while (c != -1) {
 227                 if (at_substart ? my_is_uni_xidfirst(aTHX_ c) : my_is_uni_xidcont(aTHX_ c)) {
 228                         lex_read_unichar(0);
 229                         my_sv_cat_c(aTHX_ sv, c);
 230                         at_substart = FALSE;
 231                         c = lex_peek_unichar(0);
 232                 } else if (allow_package && !at_substart && c == '\'') {
 233                         lex_read_unichar(0);
 234                         c = lex_peek_unichar(0);
 235                         if (!my_is_uni_xidfirst(aTHX_ c)) {
 236                                 lex_stuff_pvs("'", 0);
 237                                 break;
 238                         }
 239                         sv_catpvs(sv, "'");
 240                         at_substart = TRUE;
 241                 } else if (allow_package && (at_start || !at_substart) && c == ':') {
 242                         lex_read_unichar(0);
 243                         if (lex_peek_unichar(0) != ':') {
 244                                 lex_stuff_pvs(":", 0);
 245                                 break;
 246                         }
 247                         lex_read_unichar(0);
 248                         c = lex_peek_unichar(0);
 249                         if (!my_is_uni_xidfirst(aTHX_ c)) {
 250                                 lex_stuff_pvs("::", 0);
 251                                 break;
 252                         }
 253                         sv_catpvs(sv, "::");
 254                         at_substart = TRUE;
 255                 } else {
 256                         break;
 257                 }
 258                 at_start = FALSE;
 259         }
 260
 261         return SvCUR(sv) ? sv : NULL;
 262 }
 263
 264 static SV *my_scan_parens_tail(pTHX_ bool keep_backslash) {
 265         I32 c, nesting;
 266         SV *sv;
 267         line_t start;
 268
 269         start = CopLINE(PL_curcop);
 270
 271         sv = sv_2mortal(newSVpvs(""));
 272         if (lex_bufutf8()) {
 273                 SvUTF8_on(sv);
 274         }
 275
 276         nesting = 0;
 277         for (;;) {
 278                 c = lex_read_unichar(0);
 279                 if (c == EOF) {
 280                         CopLINE_set(PL_curcop, start);
 281                         return NULL;
 282                 }
 283
 284                 if (c == '\\') {
 285                         c = lex_read_unichar(0);
 286                         if (c == EOF) {
 287                                 CopLINE_set(PL_curcop, start);
 288                                 return NULL;
 289                         }
 290                         if (keep_backslash || (c != '(' && c != ')')) {
 291                                 sv_catpvs(sv, "\\");
 292                         }
 293                 } else if (c == '(') {
 294                         nesting++;
 295                 } else if (c == ')') {
 296                         if (!nesting) {
 297                                 break;
 298                         }
 299                         nesting--;
 300                 }
 301
 302                 my_sv_cat_c(aTHX_ sv, c);
 303         }
 304
 305         return sv;
 306 }
 307
 308 static void my_check_prototype(pTHX_ const SV *declarator, SV *proto) {
 309         char *start, *r, *w, *end;
 310         STRLEN len;
 311
 312         /* strip spaces */
 313         start = SvPV(proto, len);
 314         end = start + len;
 315
 316         for (w = r = start; r < end; r++) {
 317                 if (!isSPACE(*r)) {
 318                         *w++ = *r;
 319                 }
 320         }
 321         *w = '\0';
 322         SvCUR_set(proto, w - start);
 323         end = w;
 324         len = end - start;
 325
 326         if (!ckWARN(WARN_ILLEGALPROTO)) {
 327                 return;
 328         }
 329
 330         /* check for bad characters */
 331         if (strspn(start, "$@%*;[]&\\_+") != len) {
 332                 SV *dsv = newSVpvs_flags("", SVs_TEMP);
 333                 warner(
 334                         packWARN(WARN_ILLEGALPROTO),
 335                         "Illegal character in prototype for %"SVf" : %s",
 336                         SVfARG(declarator),
 337                         SvUTF8(proto)
 338                                 ? sv_uni_display(
 339                                         dsv,
 340                                         proto,
 341                                         len,
 342                                         UNI_DISPLAY_ISPRINT
 343                                 )
 344                                 : pv_pretty(dsv, start, len, 60, NULL, NULL,
 345                                         PERL_PV_ESCAPE_NONASCII
 346                                 )
 347                 );
 348                 return;
 349         }
 350
 351         for (r = start; r < end; r++) {
 352                 switch (*r) {
 353                         default:
 354                                 warner(
 355                                         packWARN(WARN_ILLEGALPROTO),
 356                                         "Illegal character in prototype for %"SVf" : %s",
 357                                         SVfARG(declarator), r
 358                                 );
 359                                 return;
 360
 361                         case '_':
 362                                 if (r[1] && !strchr(";@%", *r)) {
 363                                         warner(
 364                                                 packWARN(WARN_ILLEGALPROTO),
 365                                                 "Illegal character after '_' in prototype for %"SVf" : %s",
 366                                                 SVfARG(declarator), r
 367                                         );
 368                                         return;
 369                                 }
 370                                 break;
 371
 372                         case '@':
 373                         case '%':
 374                                 if (r[1]) {
 375                                         warner(
 376                                                 packWARN(WARN_ILLEGALPROTO),
 377                                                 "prototype after '%c' for %"SVf": %s",
 378                                                 *r, SVfARG(declarator), r + 1
 379                                         );
 380                                         return;
 381                                 }
 382                                 break;
 383
 384                         case '\\':
 385                                 r++;
 386                                 if (strchr("$@%&*", *r)) {
 387                                         break;
 388                                 }
 389                                 if (*r == '[') {
 390                                         r++;
 391                                         for (; r < end && *r != ']'; r++) {
 392                                                 if (!strchr("$@%&*", *r)) {
 393                                                         break;
 394                                                 }
 395                                         }
 396                                         if (*r == ']' && r[-1] != '[') {
 397                                                 break;
 398                                         }
 399                                 }
 400                                 warner(
 401                                         packWARN(WARN_ILLEGALPROTO),
 402                                         "Illegal character after '\\' in prototype for %"SVf" : %s",
 403                                         SVfARG(declarator), r
 404                                 );
 405                                 return;
 406
 407                         case '$':
 408                         case '*':
 409                         case '&':
 410                         case ';':
 411                         case '+':
 412                                 break;
 413                 }
 414         }
 415 }
 416
 417
 418 DEFSTRUCT(Param) {
 419         SV *name;
 420         PADOFFSET padoff;
 421 };
 422
 423 DEFSTRUCT(ParamInit) {
 424         Param param;
 425         OP *init;
 426 };
 427
 428 #define VEC(B) B ## _Vec
 429
 430 #define DEFVECTOR(B) DEFSTRUCT(VEC(B)) { \
 431         B (*data); \
 432         size_t used, size; \
 433 }
 434
 435 DEFVECTOR(Param);
 436 DEFVECTOR(ParamInit);
 437
 438 #define DEFVECTOR_INIT(N, B) static void N(VEC(B) *p) { \
 439         p->used = 0; \
 440         p->size = 23; \
 441         Newx(p->data, p->size, B); \
 442 } static void N(VEC(B) *)
 443
 444 DEFSTRUCT(ParamSpec) {
 445         Param invocant;
 446         VEC(Param) positional_required;
 447         VEC(ParamInit) positional_optional;
 448         VEC(Param) named_required;
 449         VEC(ParamInit) named_optional;
 450         Param slurpy;
 451 };
 452
 453 DEFVECTOR_INIT(pv_init, Param);
 454 DEFVECTOR_INIT(piv_init, ParamInit);
 455
 456 static void p_init(Param *p) {
 457         p->name = NULL;
 458         p->padoff = NOT_IN_PAD;
 459 }
 460
 461 static void ps_init(ParamSpec *ps) {
 462         p_init(&ps->invocant);
 463         pv_init(&ps->positional_required);
 464         piv_init(&ps->positional_optional);
 465         pv_init(&ps->named_required);
 466         piv_init(&ps->named_optional);
 467         p_init(&ps->slurpy);
 468 }
 469
 470 #define DEFVECTOR_EXTEND(N, B) static B (*N(VEC(B) *p)) { \
 471         assert(p->used <= p->size); \
 472         if (p->used == p->size) { \
 473                 const size_t n = p->size / 2 * 3 + 1; \
 474                 Renew(p->data, n, B); \
 475                 p->size = n; \
 476         } \
 477         return &p->data[p->used]; \
 478 } static B (*N(VEC(B) *))
 479
 480 DEFVECTOR_EXTEND(pv_extend, Param);
 481 DEFVECTOR_EXTEND(piv_extend, ParamInit);
 482
 483 #define DEFVECTOR_CLEAR(N, B, F) static void N(pTHX_ VEC(B) *p) { \
 484         while (p->used) { \
 485                 p->used--; \
 486                 F(aTHX_ &p->data[p->used]); \
 487         } \
 488         Safefree(p->data); \
 489         p->data = NULL; \
 490         p->size = 0; \
 491 } static void N(pTHX_ VEC(B) *)
 492
 493 static void p_clear(pTHX_ Param *p) {
 494         p->name = NULL;
 495         p->padoff = NOT_IN_PAD;
 496 }
 497
 498 static void pi_clear(pTHX_ ParamInit *pi) {
 499         p_clear(aTHX_ &pi->param);
 500         if (pi->init) {
 501                 op_free(pi->init);
 502                 pi->init = NULL;
 503         }
 504 }
 505
 506 DEFVECTOR_CLEAR(pv_clear, Param, p_clear);
 507 DEFVECTOR_CLEAR(piv_clear, ParamInit, pi_clear);
 508
 509 static void ps_clear(pTHX_ ParamSpec *ps) {
 510         p_clear(aTHX_ &ps->invocant);
 511
 512         pv_clear(aTHX_ &ps->positional_required);
 513         piv_clear(aTHX_ &ps->positional_optional);
 514
 515         pv_clear(aTHX_ &ps->named_required);
 516         piv_clear(aTHX_ &ps->named_optional);
 517
 518         p_clear(aTHX_ &ps->slurpy);
 519 }
 520
 521 static int ps_contains(pTHX_ const ParamSpec *ps, SV *sv) {
 522         size_t i, lim;
 523
 524         if (ps->invocant.name && sv_eq(sv, ps->invocant.name)) {
 525                 return 1;
 526         }
 527
 528         for (i = 0, lim = ps->positional_required.used; i < lim; i++) {
 529                 if (sv_eq(sv, ps->positional_required.data[i].name)) {
 530                         return 1;
 531                 }
 532         }
 533
 534         for (i = 0, lim = ps->positional_optional.used; i < lim; i++) {
 535                 if (sv_eq(sv, ps->positional_optional.data[i].param.name)) {
 536                         return 1;
 537                 }
 538         }
 539
 540         for (i = 0, lim = ps->named_required.used; i < lim; i++) {
 541                 if (sv_eq(sv, ps->named_required.data[i].name)) {
 542                         return 1;
 543                 }
 544         }
 545
 546         for (i = 0, lim = ps->named_optional.used; i < lim; i++) {
 547                 if (sv_eq(sv, ps->named_optional.data[i].param.name)) {
 548                         return 1;
 549                 }
 550         }
 551
 552         return 0;
 553 }
 554
 555 static void ps_free_void(pTHX_ void *p) {
 556         ps_clear(aTHX_ p);
 557         Safefree(p);
 558 }
 559
 560 static int args_min(pTHX_ const ParamSpec *ps, const KWSpec *ks) {
 561         int n = 0;
 562         if (!ps) {
 563                 return SvTRUE(ks->shift) ? 1 : 0;
 564         }
 565         if (ps->invocant.name) {
 566                 n++;
 567         }
 568         n += ps->positional_required.used;
 569         n += ps->named_required.used * 2;
 570         return n;
 571 }
 572
 573 static int args_max(const ParamSpec *ps) {
 574         int n = 0;
 575         if (!ps) {
 576                 return -1;
 577         }
 578         if (ps->invocant.name) {
 579                 n++;
 580         }
 581         n += ps->positional_required.used;
 582         n += ps->positional_optional.used;
 583         if (ps->named_required.used || ps->named_optional.used || ps->slurpy.name) {
 584                 n = -1;
 585         }
 586         return n;
 587 }
 588
 589 static size_t count_positional_params(const ParamSpec *ps) {
 590         return ps->positional_required.used + ps->positional_optional.used;
 591 }
 592
 593 static size_t count_named_params(const ParamSpec *ps) {
 594         return ps->named_required.used + ps->named_optional.used;
 595 }
 596
 597 enum {
 598         PARAM_INVOCANT = 0x01,
 599         PARAM_NAMED    = 0x02
 600 };
 601
 602 /* *pinit must be NULL on entry.
 603  * caller must free *pinit on error.
 604  */
 605 static PADOFFSET parse_param(
 606         pTHX_
 607         const SV *declarator, const KWSpec *spec, ParamSpec *param_spec,
 608         int *pflags, SV **pname, OP **pinit
 609 ) {
 610         I32 c;
 611         char sigil;
 612         SV *name;
 613
 614         assert(!*pinit);
 615         *pflags = 0;
 616
 617         c = lex_peek_unichar(0);
 618
 619         if (c == ':') {
 620                 lex_read_unichar(0);
 621                 lex_read_space(0);
 622
 623                 *pflags |= PARAM_NAMED;
 624
 625                 c = lex_peek_unichar(0);
 626         }
 627
 628         if (c == -1) {
 629                 croak("In %"SVf": unterminated parameter list", SVfARG(declarator));
 630         }
 631         if (!(c == '$' || c == '@' || c == '%')) {
 632                 croak("In %"SVf": unexpected '%c' in parameter list (expecting a sigil)", SVfARG(declarator), (int)c);
 633         }
 634
 635         sigil = c;
 636
 637         lex_read_unichar(0);
 638         lex_read_space(0);
 639
 640         if (!(name = my_scan_word(aTHX_ FALSE))) {
 641                 croak("In %"SVf": missing identifier after '%c'", SVfARG(declarator), sigil);
 642         }
 643         sv_insert(name, 0, 0, &sigil, 1);
 644         *pname = name;
 645
 646         lex_read_space(0);
 647         c = lex_peek_unichar(0);
 648
 649         if (c == '=') {
 650                 lex_read_unichar(0);
 651                 lex_read_space(0);
 652
 653
 654                 if (!param_spec->invocant.name && SvTRUE(spec->shift)) {
 655                         param_spec->invocant.name = spec->shift;
 656                         param_spec->invocant.padoff = pad_add_name_sv(param_spec->invocant.name, 0, NULL, NULL);
 657                 }
 658
 659                 *pinit = parse_termexpr(0);
 660
 661                 lex_read_space(0);
 662                 c = lex_peek_unichar(0);
 663         }
 664
 665         if (c == ':') {
 666                 *pflags |= PARAM_INVOCANT;
 667                 lex_read_unichar(0);
 668                 lex_read_space(0);
 669         } else if (c == ',') {
 670                 lex_read_unichar(0);
 671                 lex_read_space(0);
 672         } else if (c != ')') {
 673                 if (c == -1) {
 674                         croak("In %"SVf": unterminated parameter list", SVfARG(declarator));
 675                 }
 676                 croak("In %"SVf": unexpected '%c' in parameter list (expecting ',')", SVfARG(declarator), (int)c);
 677         }
 678
 679         return pad_add_name_sv(*pname, IF_HAVE_PERL_5_16(padadd_NO_DUP_CHECK, 0), NULL, NULL);
 680 }
 681
 682 static OP *my_var_g(pTHX_ I32 type, I32 flags, PADOFFSET padoff) {
 683         OP *var = newOP(type, flags);
 684         var->op_targ = padoff;
 685         return var;
 686 }
 687
 688 static OP *my_var(pTHX_ I32 flags, PADOFFSET padoff) {
 689         return my_var_g(aTHX_ OP_PADSV, flags, padoff);
 690 }
 691
 692 static SV *mkbits1(pTHX_ size_t n) {
 693         size_t bytes = n / 8, bits = n % 8;
 694         SV *sv = newSV(bytes + !!bits);
 695         char *p = SvPVX(sv), *q = p;
 696         while (bytes--) {
 697                 *p++ = '\xff';
 698         }
 699         if (bits) {
 700                 *p++ = (1u << bits) - 1;
 701         }
 702         *p = '\0';
 703         SvCUR_set(sv, p - q);
 704         SvPOK_on(sv);
 705         return sv;
 706 }
 707
 708 static OP *mkvecbits(pTHX_ PADOFFSET padoff, size_t i) {
 709         OP *first, *mid, *last, *vec;
 710
 711         last = newSVOP(OP_CONST, 0, newSViv(1));
 712         first = last;
 713
 714         mid = newSVOP(OP_CONST, 0, newSViv(i));
 715         mid->op_sibling = first;
 716         first = mid;
 717
 718         mid = my_var(aTHX_ 0, padoff);
 719         mid->op_sibling = first;
 720
 721         first = newOP(OP_PUSHMARK, 0);
 722
 723         vec = newLISTOP(OP_VEC, 0, first, mid);
 724         vec->op_targ = pad_alloc(OP_VEC, SVs_PADTMP);
 725         ((LISTOP *)vec)->op_last = last;
 726         op_null(((LISTOP *)vec)->op_first);
 727
 728         return vec;
 729 }
 730
 731 static OP *mkargselem(pTHX_ OP *index) {
 732         OP *args = newAVREF(newGVOP(OP_GV, 0, PL_defgv));
 733         args->op_flags |= OPf_REF;
 734
 735         return newBINOP(OP_AELEM, 0, args, index);
 736 }
 737
 738 static OP *mkargselemv(pTHX_ PADOFFSET v) {
 739         return mkargselem(aTHX_ my_var(aTHX_ 0, v));
 740 }
 741
 742 static int parse_fun(pTHX_ OP **pop, const char *keyword_ptr, STRLEN keyword_len, const KWSpec *spec) {
 743         ParamSpec *param_spec;
 744         SV *declarator;
 745         I32 floor_ix;
 746         int save_ix;
 747         SV *saw_name;
 748         OP **prelude_sentinel;
 749         SV *proto;
 750         OP **attrs_sentinel, *body;
 751         unsigned builtin_attrs;
 752         I32 c;
 753
 754         declarator = sv_2mortal(newSVpvn(keyword_ptr, keyword_len));
 755
 756         lex_read_space(0);
 757
 758         builtin_attrs = 0;
 759
 760         /* function name */
 761         saw_name = NULL;
 762         if ((spec->flags & FLAG_NAME_OK) && (saw_name = my_scan_word(aTHX_ TRUE))) {
 763
 764                 if (PL_parser->expect != XSTATE) {
 765                         /* bail out early so we don't predeclare $saw_name */
 766                         croak("In %"SVf": I was expecting a function body, not \"%"SVf"\"", SVfARG(declarator), SVfARG(saw_name));
 767                 }
 768
 769                 sv_catpvs(declarator, " ");
 770                 sv_catsv(declarator, saw_name);
 771
 772                 if (
 773                         sv_eq_pvs(saw_name, "BEGIN") ||
 774                         sv_eq_pvs(saw_name, "END") ||
 775                         sv_eq_pvs(saw_name, "INIT") ||
 776                         sv_eq_pvs(saw_name, "CHECK") ||
 777                         sv_eq_pvs(saw_name, "UNITCHECK")
 778                 ) {
 779                         builtin_attrs |= MY_ATTR_SPECIAL;
 780                 }
 781
 782                 lex_read_space(0);
 783         } else if (!(spec->flags & FLAG_ANON_OK)) {
 784                 croak("I was expecting a function name, not \"%.*s\"", (int)(PL_parser->bufend - PL_parser->bufptr), PL_parser->bufptr);
 785         } else {
 786                 sv_catpvs(declarator, " (anon)");
 787         }
 788
 789         /* we're a subroutine declaration */
 790         floor_ix = start_subparse(FALSE, saw_name ? 0 : CVf_ANON);
 791         SAVEFREESV(PL_compcv);
 792
 793         /* create outer block: '{' */
 794         save_ix = S_block_start(aTHX_ TRUE);
 795
 796         /* initialize synthetic optree */
 797         Newx(prelude_sentinel, 1, OP *);
 798         *prelude_sentinel = NULL;
 799         SAVEDESTRUCTOR_X(free_ptr_op, prelude_sentinel);
 800
 801         /* parameters */
 802         param_spec = NULL;
 803
 804         c = lex_peek_unichar(0);
 805         if (c == '(') {
 806                 OP **init_sentinel;
 807
 808                 Newx(init_sentinel, 1, OP *);
 809                 *init_sentinel = NULL;
 810                 SAVEDESTRUCTOR_X(free_ptr_op, init_sentinel);
 811
 812                 Newx(param_spec, 1, ParamSpec);
 813                 ps_init(param_spec);
 814                 SAVEDESTRUCTOR_X(ps_free_void, param_spec);
 815
 816                 lex_read_unichar(0);
 817                 lex_read_space(0);
 818
 819                 while ((c = lex_peek_unichar(0)) != ')') {
 820                         int flags;
 821                         SV *name;
 822                         char sigil;
 823                         PADOFFSET padoff;
 824
 825                         padoff = parse_param(aTHX_ declarator, spec, param_spec, &flags, &name, init_sentinel);
 826
 827                         S_intro_my(aTHX);
 828
 829                         sigil = SvPV_nolen(name)[0];
 830
 831                         /* internal consistency */
 832                         if (flags & PARAM_NAMED) {
 833                                 if (flags & PARAM_INVOCANT) {
 834                                         croak("In %"SVf": invocant %"SVf" can't be a named parameter", SVfARG(declarator), SVfARG(name));
 835                                 }
 836                                 if (sigil != '$') {
 837                                         croak("In %"SVf": named parameter %"SVf" can't be a%s", SVfARG(declarator), SVfARG(name), sigil == '@' ? "n array" : " hash");
 838                                 }
 839                         } else if (flags & PARAM_INVOCANT) {
 840                                 if (*init_sentinel) {
 841                                         croak("In %"SVf": invocant %"SVf" can't have a default value", SVfARG(declarator), SVfARG(name));
 842                                 }
 843                                 if (sigil != '$') {
 844                                         croak("In %"SVf": invocant %"SVf" can't be a%s", SVfARG(declarator), SVfARG(name), sigil == '@' ? "n array" : " hash");
 845                                 }
 846                         } else if (sigil != '$' && *init_sentinel) {
 847                                 croak("In %"SVf": %s %"SVf" can't have a default value", SVfARG(declarator), sigil == '@' ? "array" : "hash", SVfARG(name));
 848                         }
 849
 850                         /* external constraints */
 851                         if (param_spec->slurpy.name) {
 852                                 croak("In %"SVf": I was expecting \")\" after \"%"SVf"\", not \"%"SVf"\"", SVfARG(declarator), SVfARG(param_spec->slurpy.name), SVfARG(name));
 853                         }
 854                         if (sigil != '$') {
 855                                 assert(!*init_sentinel);
 856                                 param_spec->slurpy.name = name;
 857                                 param_spec->slurpy.padoff = padoff;
 858                                 continue;
 859                         }
 860
 861                         if (!(flags & PARAM_NAMED) && count_named_params(param_spec)) {
 862                                 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));
 863                         }
 864
 865                         if (flags & PARAM_INVOCANT) {
 866                                 if (param_spec->invocant.name) {
 867                                         croak("In %"SVf": invalid double invocants %"SVf", %"SVf"", SVfARG(declarator), SVfARG(param_spec->invocant.name), SVfARG(name));
 868                                 }
 869                                 if (count_positional_params(param_spec) || count_named_params(param_spec)) {
 870                                         croak("In %"SVf": invocant %"SVf" must be first in parameter list", SVfARG(declarator), SVfARG(name));
 871                                 }
 872                                 if (!(spec->flags & FLAG_INVOCANT)) {
 873                                         croak("In %"SVf": invocant %"SVf" not allowed here", SVfARG(declarator), SVfARG(name));
 874                                 }
 875                                 param_spec->invocant.name = name;
 876                                 param_spec->invocant.padoff = padoff;
 877                                 continue;
 878                         }
 879
 880                         if (*init_sentinel && !(spec->flags & FLAG_DEFAULT_ARGS)) {
 881                                 croak("In %"SVf": default argument for %"SVf" not allowed here", SVfARG(declarator), SVfARG(name));
 882                         }
 883
 884                         if (ps_contains(aTHX_ param_spec, name)) {
 885                                 croak("In %"SVf": %"SVf" can't appear twice in the same parameter list", SVfARG(declarator), SVfARG(name));
 886                         }
 887
 888                         if (flags & PARAM_NAMED) {
 889                                 if (!(spec->flags & FLAG_NAMED_PARAMS)) {
 890                                         croak("In %"SVf": named parameter :%"SVf" not allowed here", SVfARG(declarator), SVfARG(name));
 891                                 }
 892
 893                                 if (*init_sentinel) {
 894                                         ParamInit *pi = piv_extend(&param_spec->named_optional);
 895                                         pi->param.name = name;
 896                                         pi->param.padoff = padoff;
 897                                         pi->init = *init_sentinel;
 898                                         *init_sentinel = NULL;
 899                                         param_spec->named_optional.used++;
 900                                 } else {
 901                                         if (param_spec->positional_optional.used) {
 902                                                 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));
 903                                         }
 904
 905                                         Param *p = pv_extend(&param_spec->named_required);
 906                                         p->name = name;
 907                                         p->padoff = padoff;
 908                                         param_spec->named_required.used++;
 909                                 }
 910                         } else {
 911                                 if (*init_sentinel || param_spec->positional_optional.used) {
 912                                         ParamInit *pi = piv_extend(&param_spec->positional_optional);
 913                                         pi->param.name = name;
 914                                         pi->param.padoff = padoff;
 915                                         pi->init = *init_sentinel;
 916                                         *init_sentinel = NULL;
 917                                         param_spec->positional_optional.used++;
 918                                 } else {
 919                                         Param *p = pv_extend(&param_spec->positional_required);
 920                                         p->name = name;
 921                                         p->padoff = padoff;
 922                                         param_spec->positional_required.used++;
 923                                 }
 924                         }
 925
 926                 }
 927                 lex_read_unichar(0);
 928                 lex_read_space(0);
 929                 *init_sentinel = NULL;
 930
 931                 if (!param_spec->invocant.name && SvTRUE(spec->shift)) {
 932                         if (ps_contains(aTHX_ param_spec, spec->shift)) {
 933                                 croak("In %"SVf": %"SVf" can't appear twice in the same parameter list", SVfARG(declarator), SVfARG(spec->shift));
 934                         }
 935
 936                         param_spec->invocant.name = spec->shift;
 937                         param_spec->invocant.padoff = pad_add_name_sv(param_spec->invocant.name, 0, NULL, NULL);
 938                 }
 939         }
 940
 941         /* prototype */
 942         proto = NULL;
 943         c = lex_peek_unichar(0);
 944         if (c == ':') {
 945                 lex_read_unichar(0);
 946                 lex_read_space(0);
 947
 948                 c = lex_peek_unichar(0);
 949                 if (c != '(') {
 950                         lex_stuff_pvs(":", 0);
 951                         c = ':';
 952                 } else {
 953                         lex_read_unichar(0);
 954                         if (!(proto = my_scan_parens_tail(aTHX_ FALSE))) {
 955                                 croak("In %"SVf": prototype not terminated", SVfARG(declarator));
 956                         }
 957                         my_check_prototype(aTHX_ declarator, proto);
 958                         lex_read_space(0);
 959                         c = lex_peek_unichar(0);
 960                 }
 961         }
 962
 963         /* attributes */
 964         Newx(attrs_sentinel, 1, OP *);
 965         *attrs_sentinel = NULL;
 966         SAVEDESTRUCTOR_X(free_ptr_op, attrs_sentinel);
 967
 968         if (c == ':' || c == '{') /* '}' - hi, vim */ {
 969
 970                 /* kludge default attributes in */
 971                 if (SvTRUE(spec->attrs) && SvPV_nolen(spec->attrs)[0] == ':') {
 972                         lex_stuff_sv(spec->attrs, 0);
 973                         c = ':';
 974                 }
 975
 976                 if (c == ':') {
 977                         lex_read_unichar(0);
 978                         lex_read_space(0);
 979                         c = lex_peek_unichar(0);
 980
 981                         for (;;) {
 982                                 SV *attr;
 983
 984                                 if (!(attr = my_scan_word(aTHX_ FALSE))) {
 985                                         break;
 986                                 }
 987
 988                                 lex_read_space(0);
 989                                 c = lex_peek_unichar(0);
 990
 991                                 if (c != '(') {
 992                                         if (sv_eq_pvs(attr, "lvalue")) {
 993                                                 builtin_attrs |= MY_ATTR_LVALUE;
 994                                                 attr = NULL;
 995                                         } else if (sv_eq_pvs(attr, "method")) {
 996                                                 builtin_attrs |= MY_ATTR_METHOD;
 997                                                 attr = NULL;
 998                                         }
 999                                 } else {
1000                                         SV *sv;
1001                                         lex_read_unichar(0);
1002                                         if (!(sv = my_scan_parens_tail(aTHX_ TRUE))) {
1003                                                 croak("In %"SVf": unterminated attribute parameter in attribute list", SVfARG(declarator));
1004                                         }
1005                                         sv_catpvs(attr, "(");
1006                                         sv_catsv(attr, sv);
1007                                         sv_catpvs(attr, ")");
1008
1009                                         lex_read_space(0);
1010                                         c = lex_peek_unichar(0);
1011                                 }
1012
1013                                 if (attr) {
1014                                         *attrs_sentinel = op_append_elem(OP_LIST, *attrs_sentinel, newSVOP(OP_CONST, 0, SvREFCNT_inc_simple_NN(attr)));
1015                                 }
1016
1017                                 if (c == ':') {
1018                                         lex_read_unichar(0);
1019                                         lex_read_space(0);
1020                                         c = lex_peek_unichar(0);
1021                                 }
1022                         }
1023                 }
1024         }
1025
1026         /* body */
1027         if (c != '{') /* '}' - hi, vim */ {
1028                 croak("In %"SVf": I was expecting a function body, not \"%c\"", SVfARG(declarator), (int)c);
1029         }
1030
1031         /* surprise predeclaration! */
1032         if (saw_name) {
1033                 /* 'sub NAME (PROTO);' to make name/proto known to perl before it
1034                    starts parsing the body */
1035                 const I32 sub_ix = start_subparse(FALSE, 0);
1036                 SAVEFREESV(PL_compcv);
1037
1038                 SvREFCNT_inc_simple_void(PL_compcv);
1039
1040                 newATTRSUB(
1041                         sub_ix,
1042                         newSVOP(OP_CONST, 0, SvREFCNT_inc_simple_NN(saw_name)),
1043                         proto ? newSVOP(OP_CONST, 0, SvREFCNT_inc_simple_NN(proto)) : NULL,
1044                         NULL,
1045                         NULL
1046                 );
1047         }
1048
1049         if (builtin_attrs & MY_ATTR_LVALUE) {
1050                 CvLVALUE_on(PL_compcv);
1051         }
1052         if (builtin_attrs & MY_ATTR_METHOD) {
1053                 CvMETHOD_on(PL_compcv);
1054         }
1055         if (builtin_attrs & MY_ATTR_SPECIAL) {
1056                 CvSPECIAL_on(PL_compcv);
1057         }
1058
1059         /* check number of arguments */
1060         if (spec->flags & FLAG_CHECK_NARGS) {
1061                 int amin, amax;
1062                 size_t named;
1063
1064                 amin = args_min(aTHX_ param_spec, spec);
1065                 if (amin > 0) {
1066                         OP *chk, *cond, *err, *croak;
1067
1068                         err = newSVOP(OP_CONST, 0,
1069                                           newSVpvf("Not enough arguments for %"SVf" (expected %d, got ", SVfARG(declarator), amin));
1070                         err = newBINOP(OP_CONCAT, 0,
1071                                            err,
1072                                            newAVREF(newGVOP(OP_GV, 0, PL_defgv)));
1073                         err = newBINOP(OP_CONCAT, 0,
1074                                            err,
1075                                            newSVOP(OP_CONST, 0, newSVpvs(")")));
1076
1077                         croak = newCVREF(OPf_WANT_SCALAR,
1078                                              newGVOP(OP_GV, 0, gv_fetchpvs("Carp::croak", 0, SVt_PVCV)));
1079                         err = newUNOP(OP_ENTERSUB, OPf_STACKED,
1080                                           op_append_elem(OP_LIST, err, croak));
1081
1082                         cond = newBINOP(OP_LT, 0,
1083                                             newAVREF(newGVOP(OP_GV, 0, PL_defgv)),
1084                                             newSVOP(OP_CONST, 0, newSViv(amin)));
1085                         chk = newLOGOP(OP_AND, 0, cond, err);
1086
1087                         *prelude_sentinel = op_append_list(OP_LINESEQ, *prelude_sentinel, newSTATEOP(0, NULL, chk));
1088                 }
1089
1090                 amax = args_max(param_spec);
1091                 if (amax >= 0) {
1092                         OP *chk, *cond, *err, *croak;
1093
1094                         err = newSVOP(OP_CONST, 0,
1095                                           newSVpvf("Too many arguments for %"SVf" (expected %d, got ", SVfARG(declarator), amax));
1096                         err = newBINOP(OP_CONCAT, 0,
1097                                            err,
1098                                            newAVREF(newGVOP(OP_GV, 0, PL_defgv)));
1099                         err = newBINOP(OP_CONCAT, 0,
1100                                            err,
1101                                            newSVOP(OP_CONST, 0, newSVpvs(")")));
1102
1103                         croak = newCVREF(OPf_WANT_SCALAR,
1104                                              newGVOP(OP_GV, 0, gv_fetchpvs("Carp::croak", 0, SVt_PVCV)));
1105                         err = newUNOP(OP_ENTERSUB, OPf_STACKED,
1106                                           op_append_elem(OP_LIST, err, croak));
1107
1108                         cond = newBINOP(OP_GT, 0,
1109                                             newAVREF(newGVOP(OP_GV, 0, PL_defgv)),
1110                                             newSVOP(OP_CONST, 0, newSViv(amax)));
1111                         chk = newLOGOP(OP_AND, 0, cond, err);
1112
1113                         *prelude_sentinel = op_append_list(OP_LINESEQ, *prelude_sentinel, newSTATEOP(0, NULL, chk));
1114                 }
1115
1116                 if (param_spec && (count_named_params(param_spec) || (param_spec->slurpy.name && SvPV_nolen(param_spec->slurpy.name)[0] == '%'))) {
1117                         OP *chk, *cond, *err, *croak;
1118                         const UV fixed = count_positional_params(param_spec) + !!param_spec->invocant.name;
1119
1120                         err = newSVOP(OP_CONST, 0,
1121                                           newSVpvf("Odd number of paired arguments for %"SVf"", SVfARG(declarator)));
1122
1123                         croak = newCVREF(OPf_WANT_SCALAR,
1124                                              newGVOP(OP_GV, 0, gv_fetchpvs("Carp::croak", 0, SVt_PVCV)));
1125                         err = newUNOP(OP_ENTERSUB, OPf_STACKED,
1126                                           op_append_elem(OP_LIST, err, croak));
1127
1128                         cond = newBINOP(OP_GT, 0,
1129                                             fixed
1130                                             ? newBINOP(OP_SUBTRACT, 0,
1131                                                        newAVREF(newGVOP(OP_GV, 0, PL_defgv)),
1132                                                        newSVOP(OP_CONST, 0, newSVuv(fixed)))
1133                                             : newAVREF(newGVOP(OP_GV, 0, PL_defgv)),
1134                                             newSVOP(OP_CONST, 0, newSViv(0)));
1135                         cond = newLOGOP(OP_AND, 0,
1136                                             cond,
1137                                             newBINOP(OP_MODULO, 0,
1138                                                      fixed
1139                                                      ? newBINOP(OP_SUBTRACT, 0,
1140                                                                 newAVREF(newGVOP(OP_GV, 0, PL_defgv)),
1141                                                                 newSVOP(OP_CONST, 0, newSVuv(fixed)))
1142                                                      : newAVREF(newGVOP(OP_GV, 0, PL_defgv)),
1143                                                      newSVOP(OP_CONST, 0, newSViv(2))));
1144                         chk = newLOGOP(OP_AND, 0, cond, err);
1145
1146                         *prelude_sentinel = op_append_list(OP_LINESEQ, *prelude_sentinel, newSTATEOP(0, NULL, chk));
1147                 }
1148         }
1149
1150         if (!param_spec) {
1151                 /* my $invocant = shift; */
1152                 if (SvTRUE(spec->shift)) {
1153                         OP *var;
1154
1155                         var = my_var(
1156                                 aTHX_
1157                                 OPf_MOD | (OPpLVAL_INTRO << 8),
1158                                 pad_add_name_sv(spec->shift, 0, NULL, NULL)
1159                         );
1160                         var = newASSIGNOP(OPf_STACKED, var, 0, newOP(OP_SHIFT, 0));
1161
1162                         *prelude_sentinel = op_append_list(OP_LINESEQ, *prelude_sentinel, newSTATEOP(0, NULL, var));
1163                 }
1164         } else {
1165                 /* my $invocant = shift; */
1166                 if (param_spec->invocant.name) {
1167                         OP *var;
1168
1169                         var = my_var(
1170                                 aTHX_
1171                                 OPf_MOD | (OPpLVAL_INTRO << 8),
1172                                 param_spec->invocant.padoff
1173                         );
1174                         var = newASSIGNOP(OPf_STACKED, var, 0, newOP(OP_SHIFT, 0));
1175
1176                         *prelude_sentinel = op_append_list(OP_LINESEQ, *prelude_sentinel, newSTATEOP(0, NULL, var));
1177                 }
1178
1179                 /* my (...) = @_; */
1180                 {
1181                         OP *lhs;
1182                         size_t i, lim;
1183
1184                         lhs = NULL;
1185
1186                         for (i = 0, lim = param_spec->positional_required.used; i < lim; i++) {
1187                                 OP *const var = my_var(
1188                                         aTHX_
1189                                         OPf_WANT_LIST | (OPpLVAL_INTRO << 8),
1190                                         param_spec->positional_required.data[i].padoff
1191                                 );
1192                                 lhs = op_append_elem(OP_LIST, lhs, var);
1193                         }
1194
1195                         for (i = 0, lim = param_spec->positional_optional.used; i < lim; i++) {
1196                                 OP *const var = my_var(
1197                                         aTHX_
1198                                         OPf_WANT_LIST | (OPpLVAL_INTRO << 8),
1199                                         param_spec->positional_optional.data[i].param.padoff
1200                                 );
1201                                 lhs = op_append_elem(OP_LIST, lhs, var);
1202                         }
1203
1204                         if (param_spec->slurpy.name) {
1205                                 if (count_named_params(param_spec)) {
1206                                         OP *const var = my_var_g(
1207                                                 aTHX_
1208                                                 SvPV_nolen(param_spec->slurpy.name)[0] == '@' ? OP_PADAV : OP_PADHV,
1209                                                 OPf_MOD | (OPpLVAL_INTRO << 8),
1210                                                 param_spec->slurpy.padoff
1211                                         );
1212                                         *prelude_sentinel = op_append_list(OP_LINESEQ, *prelude_sentinel, newSTATEOP(0, NULL, var));
1213                                 } else {
1214                                         OP *const var = my_var_g(
1215                                                 aTHX_
1216                                                 SvPV_nolen(param_spec->slurpy.name)[0] == '@' ? OP_PADAV : OP_PADHV,
1217                                                 OPf_WANT_LIST | (OPpLVAL_INTRO << 8),
1218                                                 param_spec->slurpy.padoff
1219                                         );
1220                                         lhs = op_append_elem(OP_LIST, lhs, var);
1221                                 }
1222                         }
1223
1224                         if (lhs) {
1225                                 OP *rhs;
1226                                 lhs->op_flags |= OPf_PARENS;
1227                                 rhs = newAVREF(newGVOP(OP_GV, 0, PL_defgv));
1228
1229                                 *prelude_sentinel = op_append_list(
1230                                         OP_LINESEQ, *prelude_sentinel,
1231                                         newSTATEOP(
1232                                                 0, NULL,
1233                                                 newASSIGNOP(OPf_STACKED, lhs, 0, rhs)
1234                                         )
1235                                 );
1236                         }
1237                 }
1238
1239                 /* default arguments */
1240                 {
1241                         size_t i, lim, req;
1242                         OP *nest;
1243
1244                         nest = NULL;
1245
1246                         req = param_spec->positional_required.used;
1247                         for (i = 0, lim = param_spec->positional_optional.used; i < lim; i++) {
1248                                 ParamInit *cur = &param_spec->positional_optional.data[i];
1249                                 OP *var, *cond;
1250
1251                                 cond = newBINOP(
1252                                         OP_LT, 0,
1253                                         newAVREF(newGVOP(OP_GV, 0, PL_defgv)),
1254                                         newSVOP(OP_CONST, 0, newSViv(req + i + 1))
1255                                 );
1256
1257                                 var = my_var(aTHX_ 0, cur->param.padoff);
1258
1259                                 nest = op_append_list(
1260                                         OP_LINESEQ, nest,
1261                                         newASSIGNOP(OPf_STACKED, var, 0, cur->init)
1262                                 );
1263                                 cur->init = NULL;
1264                                 nest = newCONDOP(
1265                                         0,
1266                                         cond,
1267                                         nest,
1268                                         NULL
1269                                 );
1270                         }
1271
1272                         *prelude_sentinel = op_append_list(
1273                                 OP_LINESEQ, *prelude_sentinel,
1274                                 nest
1275                         );
1276                 }
1277
1278                 /* named parameters */
1279                 if (count_named_params(param_spec)) {
1280                         int nameblock_ix;
1281                         OP *nameblock;
1282                         PADOFFSET vb, vc, vi, vk;
1283                         const size_t pos = count_positional_params(param_spec);
1284
1285                         nameblock = NULL;
1286                         nameblock_ix = S_block_start(aTHX_ TRUE);
1287
1288                         {
1289                                 OP *decl, *var;
1290
1291                                 decl = NULL;
1292
1293                                 if (!param_spec->named_required.used || !(spec->flags & FLAG_CHECK_NARGS)) {
1294                                         vb = 0;
1295                                 } else {
1296                                         var = newOP(OP_PADSV, OPf_MOD | (OPpLVAL_INTRO << 8));
1297                                         var->op_targ = vb = pad_add_name_pvs("$__B", 0, NULL, NULL);
1298                                         var = newASSIGNOP(OPf_STACKED, var, 0, newSVOP(OP_CONST, 0, newSVpvs("")));
1299                                         decl = op_append_list(OP_LINESEQ, decl, newSTATEOP(0, NULL, var));
1300                                 }
1301
1302                                 if (!param_spec->named_optional.used) {
1303                                         vc = 0;
1304                                 } else {
1305                                         var = newOP(OP_PADSV, OPf_MOD | (OPpLVAL_INTRO << 8));
1306                                         var->op_targ = vc = pad_add_name_pvs("$__C", 0, NULL, NULL);
1307                                         var = newASSIGNOP(OPf_STACKED, var, 0, newSVOP(OP_CONST, 0, newSVpvs("")));
1308                                         decl = op_append_list(OP_LINESEQ, decl, newSTATEOP(0, NULL, var));
1309                                 }
1310
1311                                 var = newOP(OP_PADSV, OPf_MOD | (OPpLVAL_INTRO << 8));
1312                                 var->op_targ = vk = pad_add_name_pvs("$__K", 0, NULL, NULL);
1313                                 decl = op_append_list(OP_LINESEQ, decl, newSTATEOP(0, NULL, var));
1314
1315                                 var = newOP(OP_PADSV, OPf_MOD | (OPpLVAL_INTRO << 8));
1316                                 var->op_targ = vi = pad_add_name_pvs("$__I", 0, NULL, NULL);
1317                                 var = newASSIGNOP(OPf_STACKED, var, 0, newSVOP(OP_CONST, 0, newSViv(pos)));
1318                                 decl = op_append_list(OP_LINESEQ, decl, newSTATEOP(0, NULL, var));
1319
1320                                 //S_intro_my(aTHX);
1321                                 nameblock = op_append_list(OP_LINESEQ, nameblock, decl);
1322                         }
1323
1324                         {
1325                                 OP *loop;
1326
1327                                 loop = NULL;
1328
1329                                 loop = op_append_list(
1330                                         OP_LINESEQ,
1331                                         loop,
1332                                         newSTATEOP(
1333                                                 0, NULL,
1334                                                 newASSIGNOP(
1335                                                         OPf_STACKED,
1336                                                         my_var(aTHX_ 0, vk),
1337                                                         0,
1338                                                         mkargselemv(aTHX_ vi)
1339                                                 )
1340                                         )
1341                                 );
1342
1343                                 {
1344                                         OP *nest;
1345                                         size_t i;
1346
1347                                         if (param_spec->slurpy.name) {
1348                                                 if (SvPV_nolen(param_spec->slurpy.name)[0] == '@') {
1349                                                         OP *first, *mid, *last;
1350
1351                                                         last = mkargselem(
1352                                                                 aTHX_
1353                                                                 newBINOP(
1354                                                                         OP_ADD, 0,
1355                                                                         my_var(aTHX_ 0, vi),
1356                                                                         newSVOP(OP_CONST, 0, newSViv(1))
1357                                                                 )
1358                                                         );
1359                                                         mid = last;
1360
1361                                                         first = my_var(aTHX_ 0, vk);
1362                                                         first->op_sibling = mid;
1363                                                         mid = first;
1364
1365                                                         first = my_var_g(aTHX_ OP_PADAV, 0, param_spec->slurpy.padoff);
1366                                                         first->op_sibling = mid;
1367                                                         mid = first;
1368
1369                                                         first = newOP(OP_PUSHMARK, 0);
1370                                                         nest = newLISTOP(OP_PUSH, 0, first, mid);
1371                                                         nest->op_targ = pad_alloc(OP_PUSH, SVs_PADTMP);
1372                                                         ((LISTOP *)nest)->op_last = last;
1373                                                 } else {
1374                                                         nest = newASSIGNOP(
1375                                                                 OPf_STACKED,
1376                                                                 newBINOP(
1377                                                                         OP_HELEM, 0,
1378                                                                         my_var_g(aTHX_ OP_PADHV, 0, param_spec->slurpy.padoff),
1379                                                                         my_var(aTHX_ 0, vk)
1380                                                                 ),
1381                                                                 0,
1382                                                                 mkargselem(
1383                                                                         aTHX_
1384                                                                         newBINOP(
1385                                                                                 OP_ADD, 0,
1386                                                                                 my_var(aTHX_ 0, vi),
1387                                                                                 newSVOP(OP_CONST, 0, newSViv(1))
1388                                                                         )
1389                                                                 )
1390                                                         );
1391                                                 }
1392                                         } else if (spec->flags & FLAG_CHECK_NARGS) {
1393                                                 OP *err, *croak;
1394
1395                                                 err = newSVOP(OP_CONST, 0,
1396                                                               newSVpvf("In %"SVf": No such named parameter: ", SVfARG(declarator)));
1397                                                 err = newBINOP(
1398                                                         OP_CONCAT, 0,
1399                                                         err,
1400                                                         my_var(aTHX_ 0, vk)
1401                                                 );
1402
1403                                                 croak = newCVREF(OPf_WANT_SCALAR,
1404                                                                  newGVOP(OP_GV, 0, gv_fetchpvs("Carp::croak", 0, SVt_PVCV)));
1405                                                 nest = newUNOP(OP_ENTERSUB, OPf_STACKED,
1406                                                                op_append_elem(OP_LIST, err, croak));
1407                                         } else {
1408                                                 nest = NULL;
1409                                         }
1410
1411                                         for (i = param_spec->named_optional.used; i--; ) {
1412                                                 Param *cur = &param_spec->named_optional.data[i].param;
1413                                                 size_t dn;
1414                                                 char *dp = SvPV(cur->name, dn);
1415                                                 OP *vec;
1416
1417                                                 if (!(spec->flags & FLAG_CHECK_NARGS)) {
1418                                                         vec = NULL;
1419                                                 } else {
1420                                                         vec = newASSIGNOP(
1421                                                                 OPf_STACKED,
1422                                                                 mkvecbits(aTHX_ vc, i),
1423                                                                 0,
1424                                                                 newSVOP(OP_CONST, 0, newSViv(1))
1425                                                         );
1426                                                 }
1427
1428                                                 nest = newCONDOP(
1429                                                         0,
1430                                                         newBINOP(
1431                                                                 OP_SEQ, 0,
1432                                                                 my_var(aTHX_ 0, vk),
1433                                                                 newSVOP(OP_CONST, 0, newSVpvn_utf8(dp + 1, dn - 1, SvUTF8(cur->name)))
1434                                                         ),
1435                                                         op_append_list(
1436                                                                 OP_LINESEQ,
1437                                                                 newASSIGNOP(
1438                                                                         OPf_STACKED,
1439                                                                         my_var(aTHX_ 0, cur->padoff),
1440                                                                         0,
1441                                                                         mkargselem(
1442                                                                                 aTHX_
1443                                                                                 newBINOP(
1444                                                                                         OP_ADD, 0,
1445                                                                                         my_var(aTHX_ 0, vi),
1446                                                                                         newSVOP(OP_CONST, 0, newSViv(1))
1447                                                                                 )
1448                                                                         )
1449                                                                 ),
1450                                                                 vec
1451                                                         ),
1452                                                         nest
1453                                                 );
1454                                         }
1455
1456                                         for (i = param_spec->named_required.used; i--; ) {
1457                                                 Param *cur = &param_spec->named_required.data[i];
1458                                                 size_t dn;
1459                                                 char *dp = SvPV(cur->name, dn);
1460                                                 OP *vec;
1461
1462                                                 if (!(spec->flags & FLAG_CHECK_NARGS)) {
1463                                                         vec = NULL;
1464                                                 } else {
1465                                                         vec = newASSIGNOP(
1466                                                                 OPf_STACKED,
1467                                                                 mkvecbits(aTHX_ vb, i),
1468                                                                 0,
1469                                                                 newSVOP(OP_CONST, 0, newSViv(1))
1470                                                         );
1471                                                 }
1472
1473                                                 nest = newCONDOP(
1474                                                         0,
1475                                                         newBINOP(
1476                                                                 OP_SEQ, 0,
1477                                                                 my_var(aTHX_ 0, vk),
1478                                                                 newSVOP(OP_CONST, 0, newSVpvn_utf8(dp + 1, dn - 1, SvUTF8(cur->name)))
1479                                                         ),
1480                                                         op_append_list(
1481                                                                 OP_LINESEQ,
1482                                                                 newASSIGNOP(
1483                                                                         OPf_STACKED,
1484                                                                         my_var(aTHX_ 0, cur->padoff),
1485                                                                         0,
1486                                                                         mkargselem(
1487                                                                                 aTHX_
1488                                                                                 newBINOP(
1489                                                                                         OP_ADD, 0,
1490                                                                                         my_var(aTHX_ 0, vi),
1491                                                                                         newSVOP(OP_CONST, 0, newSViv(1))
1492                                                                                 )
1493                                                                         )
1494                                                                 ),
1495                                                                 vec
1496                                                         ),
1497                                                         nest
1498                                                 );
1499                                         }
1500
1501                                         loop = op_append_elem(OP_LINESEQ, loop, newSTATEOP(0, NULL, nest));
1502                                 }
1503
1504                                 loop = newWHILEOP(
1505                                         0, 1,
1506                                         NULL,
1507                                         newBINOP(
1508                                                 OP_LT, 0,
1509                                                 my_var(aTHX_ 0, vi),
1510                                                 newAVREF(newGVOP(OP_GV, 0, PL_defgv))
1511                                         ),
1512                                         loop,
1513                                         newASSIGNOP(
1514                                                 OPf_STACKED,
1515                                                 my_var(aTHX_ 0, vi),
1516                                                 OP_ADD,
1517                                                 newSVOP(OP_CONST, 0, newSViv(2))
1518                                         ),
1519                                         0
1520                                 );
1521
1522                                 nameblock = op_append_list(OP_LINESEQ, nameblock, newSTATEOP(0, NULL, loop));
1523                         }
1524
1525                         if (param_spec->named_required.used && (spec->flags & FLAG_CHECK_NARGS)) {
1526                                 OP *cond, *err, *croak, *join;
1527
1528                                 {
1529                                         size_t i, lim;
1530                                         OP *first, *mid, *last;
1531
1532                                         last = newNULLLIST();
1533                                         mid = last;
1534
1535                                         for (i = param_spec->named_required.used; i--; ) {
1536                                                 OP *cur;
1537                                                 SV *sv = param_spec->named_required.data[i].name;
1538                                                 size_t n;
1539                                                 char *p = SvPV(sv, n);
1540                                                 cur = newCONDOP(
1541                                                         0,
1542                                                         mkvecbits(aTHX_ vb, i),
1543                                                         newNULLLIST(),
1544                                                         newSVOP(OP_CONST, 0, newSVpvn_utf8(p + 1, n - 1, SvUTF8(sv)))
1545                                                 );
1546                                                 cur->op_sibling = mid;
1547                                                 mid = cur;
1548                                         }
1549
1550                                         first = newSVOP(OP_CONST, 0, newSVpvs(", "));
1551                                         first->op_sibling = mid;
1552                                         mid = first;
1553
1554                                         first = newOP(OP_PUSHMARK, 0);
1555
1556                                         join = newLISTOP(OP_JOIN, 0, first, mid);
1557                                         join->op_targ = pad_alloc(OP_JOIN, SVs_PADTMP);
1558                                         ((LISTOP *)join)->op_last = last;
1559                                 }
1560
1561                                 err = newSVOP(
1562                                         OP_CONST, 0,
1563                                         newSVpvf("In %"SVf": Missing named parameter(s): ", SVfARG(declarator))
1564                                 );
1565                                 err = newBINOP(OP_CONCAT, 0, err, join);
1566                                 croak = newCVREF(
1567                                         OPf_WANT_SCALAR,
1568                                         newGVOP(OP_GV, 0, gv_fetchpvs("Carp::croak", 0, SVt_PVCV))
1569                                 );
1570                                 err = newUNOP(
1571                                         OP_ENTERSUB,
1572                                         OPf_STACKED,
1573                                         op_append_elem(OP_LIST, err, croak)
1574                                 );
1575                                 cond = newBINOP(
1576                                         OP_SNE, 0,
1577                                         my_var(aTHX_ 0, vb),
1578                                         newSVOP(OP_CONST, 0, mkbits1(aTHX_ param_spec->named_required.used))
1579                                 );
1580                                 err = newCONDOP(
1581                                         0,
1582                                         cond,
1583                                         err,
1584                                         NULL
1585                                 );
1586
1587                                 nameblock = op_append_list(OP_LINESEQ, nameblock, err);
1588                         }
1589
1590                         if (param_spec->named_optional.used) {
1591                                 size_t i, lim;
1592
1593                                 for (i = 0, lim = param_spec->named_optional.used; i < lim; i++) {
1594                                         ParamInit *const cur = &param_spec->named_optional.data[i];
1595                                         OP *init, *cond;
1596
1597                                         init = newASSIGNOP(
1598                                                 OPf_STACKED,
1599                                                 my_var(aTHX_ 0, cur->param.padoff),
1600                                                 0,
1601                                                 cur->init
1602                                         );
1603                                         cur->init = NULL;
1604
1605                                         cond = newUNOP(OP_NOT, OPf_SPECIAL, mkvecbits(aTHX_ vc, i));
1606
1607                                         init = newCONDOP(0, cond, init, NULL);
1608
1609                                         nameblock = op_append_list(OP_LINESEQ, nameblock, newSTATEOP(0, NULL, init));
1610                                 }
1611                         }
1612
1613                         nameblock = S_block_end(aTHX_ nameblock_ix, nameblock);
1614                         nameblock = op_scope(nameblock);
1615
1616                         *prelude_sentinel = op_append_list(OP_LINESEQ, *prelude_sentinel, nameblock);
1617                 }
1618         }
1619
1620         /* finally let perl parse the actual subroutine body */
1621         body = parse_block(0);
1622
1623         /* add '();' to make function return nothing by default */
1624         /* (otherwise the invisible parameter initialization can "leak" into
1625            the return value: fun ($x) {}->("asdf", 0) == 2) */
1626         if (*prelude_sentinel) {
1627                 body = newSTATEOP(0, NULL, body);
1628         }
1629
1630         body = op_append_list(OP_LINESEQ, *prelude_sentinel, body);
1631         *prelude_sentinel = NULL;
1632
1633         /* it's go time. */
1634         {
1635                 OP *const attrs = *attrs_sentinel;
1636                 *attrs_sentinel = NULL;
1637                 SvREFCNT_inc_simple_void(PL_compcv);
1638
1639                 /* close outer block: '}' */
1640                 S_block_end(aTHX_ save_ix, body);
1641
1642                 if (!saw_name) {
1643                         *pop = newANONATTRSUB(
1644                                 floor_ix,
1645                                 proto ? newSVOP(OP_CONST, 0, SvREFCNT_inc_simple_NN(proto)) : NULL,
1646                                 attrs,
1647                                 body
1648                         );
1649                         return KEYWORD_PLUGIN_EXPR;
1650                 }
1651
1652                 newATTRSUB(
1653                         floor_ix,
1654                         newSVOP(OP_CONST, 0, SvREFCNT_inc_simple_NN(saw_name)),
1655                         proto ? newSVOP(OP_CONST, 0, SvREFCNT_inc_simple_NN(proto)) : NULL,
1656                         attrs,
1657                         body
1658                 );
1659                 *pop = newOP(OP_NULL, 0);
1660                 return KEYWORD_PLUGIN_STMT;
1661         }
1662 }
1663
1664 static int my_keyword_plugin(pTHX_ char *keyword_ptr, STRLEN keyword_len, OP **op_ptr) {
1665         KWSpec spec;
1666         int ret;
1667
1668         SAVETMPS;
1669
1670         if (kw_flags(aTHX_ keyword_ptr, keyword_len, &spec)) {
1671                 ret = parse_fun(aTHX_ op_ptr, keyword_ptr, keyword_len, &spec);
1672         } else {
1673                 ret = next_keyword_plugin(aTHX_ keyword_ptr, keyword_len, op_ptr);
1674         }
1675
1676         FREETMPS;
1677
1678         return ret;
1679 }
1680
1681 WARNINGS_RESET
1682
1683 MODULE = Function::Parameters   PACKAGE = Function::Parameters
1684 PROTOTYPES: ENABLE
1685
1686 BOOT:
1687 WARNINGS_ENABLE {
1688         HV *const stash = gv_stashpvs(MY_PKG, GV_ADD);
1689         /**/
1690         newCONSTSUB(stash, "FLAG_NAME_OK",      newSViv(FLAG_NAME_OK));
1691         newCONSTSUB(stash, "FLAG_ANON_OK",      newSViv(FLAG_ANON_OK));
1692         newCONSTSUB(stash, "FLAG_DEFAULT_ARGS", newSViv(FLAG_DEFAULT_ARGS));
1693         newCONSTSUB(stash, "FLAG_CHECK_NARGS",  newSViv(FLAG_CHECK_NARGS));
1694         newCONSTSUB(stash, "FLAG_INVOCANT",     newSViv(FLAG_INVOCANT));
1695         newCONSTSUB(stash, "FLAG_NAMED_PARAMS", newSViv(FLAG_NAMED_PARAMS));
1696         newCONSTSUB(stash, "HINTK_KEYWORDS", newSVpvs(HINTK_KEYWORDS));
1697         newCONSTSUB(stash, "HINTK_FLAGS_",   newSVpvs(HINTK_FLAGS_));
1698         newCONSTSUB(stash, "HINTK_SHIFT_",   newSVpvs(HINTK_SHIFT_));
1699         newCONSTSUB(stash, "HINTK_ATTRS_",   newSVpvs(HINTK_ATTRS_));
1700         /**/
1701         next_keyword_plugin = PL_keyword_plugin;
1702         PL_keyword_plugin = my_keyword_plugin;
1703 } WARNINGS_RESET