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 void my_safefree(void *p) {
 151         Safefree(p);
 152 }
 153
 154 #define SENTINEL_ALLOC(SEN, P, N, T) STMT_START { \
 155         Newx(P, N, T); \
 156         sentinel_register(SEN, P, my_safefree); \
 157 } STMT_END
 158
 159 #define SENTINEL_MDUP(SEN, P, O, N, T) STMT_START { \
 160         void *const _sentinel_mdup_tmp_ = (P); \
 161         SENTINEL_ALLOC(SEN, P, N, T); \
 162         memcpy(P, _sentinel_mdup_tmp_, O * sizeof (T)); \
 163 } STMT_END
 164
 165 #define SENTINEL_REALLOC(SEN, P, N, T) STMT_START { \
 166         assert((N) > 0); \
 167         if (!(P)) { \
 168                 SENTINEL_ALLOC(SEN, P, N, T); \
 169         } else { \
 170                 Resource **_sentinel_realloc_tmp_ = (SEN); \
 171                 for (;;) { \
 172                         assert(*_sentinel_realloc_tmp_ != NULL); \
 173                         if ((*_sentinel_realloc_tmp_)->data == (P)) { \
 174                                 Renew((*_sentinel_realloc_tmp_)->data, N, T); \
 175                                 (P) = (*_sentinel_realloc_tmp_)->data; \
 176                                 break; \
 177                         } \
 178                         _sentinel_realloc_tmp_ = &(*_sentinel_realloc_tmp_)->next; \
 179                 } \
 180         } \
 181 } STMT_END
 182
 183 static int kw_flags(pTHX_ Sentinel sen, const char *kw_ptr, STRLEN kw_len, KWSpec *spec) {
 184         HV *hints;
 185         SV *sv, **psv;
 186         const char *p, *kw_active;
 187         STRLEN kw_active_len;
 188
 189         spec->flags = 0;
 190         spec->shift = sentinel_mortalize(sen, newSVpvs(""));
 191         spec->attrs = sentinel_mortalize(sen, newSVpvs(""));
 192
 193         if (!(hints = GvHV(PL_hintgv))) {
 194                 return FALSE;
 195         }
 196         if (!(psv = hv_fetchs(hints, HINTK_KEYWORDS, 0))) {
 197                 return FALSE;
 198         }
 199         sv = *psv;
 200         kw_active = SvPV(sv, kw_active_len);
 201         if (kw_active_len <= kw_len) {
 202                 return FALSE;
 203         }
 204         for (
 205                 p = kw_active;
 206                 (p = strchr(p, *kw_ptr)) &&
 207                 p < kw_active + kw_active_len - kw_len;
 208                 p++
 209         ) {
 210                 if (
 211                         (p == kw_active || p[-1] == ' ') &&
 212                         p[kw_len] == ' ' &&
 213                         memcmp(kw_ptr, p, kw_len) == 0
 214                 ) {
 215
 216 #define FETCH_HINTK_INTO(NAME, PTR, LEN, X) STMT_START { \
 217         const char *fk_ptr_; \
 218         STRLEN fk_len_; \
 219         SV *fk_sv_; \
 220         fk_sv_ = sentinel_mortalize(sen, newSVpvs(HINTK_ ## NAME)); \
 221         sv_catpvn(fk_sv_, PTR, LEN); \
 222         fk_ptr_ = SvPV(fk_sv_, fk_len_); \
 223         if (!((X) = hv_fetch(hints, fk_ptr_, fk_len_, 0))) { \
 224                 croak("%s: internal error: $^H{'%.*s'} not set", MY_PKG, (int)fk_len_, fk_ptr_); \
 225         } \
 226 } STMT_END
 227
 228                         FETCH_HINTK_INTO(FLAGS_, kw_ptr, kw_len, psv);
 229                         spec->flags = SvIV(*psv);
 230
 231                         FETCH_HINTK_INTO(SHIFT_, kw_ptr, kw_len, psv);
 232                         SvSetSV(spec->shift, *psv);
 233
 234                         FETCH_HINTK_INTO(ATTRS_, kw_ptr, kw_len, psv);
 235                         SvSetSV(spec->attrs, *psv);
 236
 237 #undef FETCH_HINTK_INTO
 238                         return TRUE;
 239                 }
 240         }
 241         return FALSE;
 242 }
 243
 244
 245 static void free_ptr_op(pTHX_ void *vp) {
 246         OP **pp = vp;
 247         op_free(*pp);
 248         Safefree(pp);
 249 }
 250
 251 #define sv_eq_pvs(SV, S) my_sv_eq_pvn(aTHX_ SV, "" S "", sizeof (S) - 1)
 252
 253 static int my_sv_eq_pvn(pTHX_ SV *sv, const char *p, STRLEN n) {
 254         STRLEN sv_len;
 255         const char *sv_p = SvPV(sv, sv_len);
 256         return memcmp(sv_p, p, n) == 0;
 257 }
 258
 259
 260 #include "padop_on_crack.c.inc"
 261
 262
 263 enum {
 264         MY_ATTR_LVALUE = 0x01,
 265         MY_ATTR_METHOD = 0x02,
 266         MY_ATTR_SPECIAL = 0x04
 267 };
 268
 269 static void my_sv_cat_c(pTHX_ SV *sv, U32 c) {
 270         char ds[UTF8_MAXBYTES + 1], *d;
 271         d = uvchr_to_utf8(ds, c);
 272         if (d - ds > 1) {
 273                 sv_utf8_upgrade(sv);
 274         }
 275         sv_catpvn(sv, ds, d - ds);
 276 }
 277
 278 static bool my_is_uni_xidfirst(pTHX_ UV c) {
 279         U8 tmpbuf[UTF8_MAXBYTES + 1];
 280         uvchr_to_utf8(tmpbuf, c);
 281         return is_utf8_xidfirst(tmpbuf);
 282 }
 283
 284 static bool my_is_uni_xidcont(pTHX_ UV c) {
 285         U8 tmpbuf[UTF8_MAXBYTES + 1];
 286         uvchr_to_utf8(tmpbuf, c);
 287         return is_utf8_xidcont(tmpbuf);
 288 }
 289
 290 static SV *my_scan_word(pTHX_ Sentinel sen, bool allow_package) {
 291         bool at_start, at_substart;
 292         I32 c;
 293         SV *sv = sentinel_mortalize(sen, newSVpvs(""));
 294         if (lex_bufutf8()) {
 295                 SvUTF8_on(sv);
 296         }
 297
 298         at_start = at_substart = TRUE;
 299         c = lex_peek_unichar(0);
 300
 301         while (c != -1) {
 302                 if (at_substart ? my_is_uni_xidfirst(aTHX_ c) : my_is_uni_xidcont(aTHX_ c)) {
 303                         lex_read_unichar(0);
 304                         my_sv_cat_c(aTHX_ sv, c);
 305                         at_substart = FALSE;
 306                         c = lex_peek_unichar(0);
 307                 } else if (allow_package && !at_substart && c == '\'') {
 308                         lex_read_unichar(0);
 309                         c = lex_peek_unichar(0);
 310                         if (!my_is_uni_xidfirst(aTHX_ c)) {
 311                                 lex_stuff_pvs("'", 0);
 312                                 break;
 313                         }
 314                         sv_catpvs(sv, "'");
 315                         at_substart = TRUE;
 316                 } else if (allow_package && (at_start || !at_substart) && c == ':') {
 317                         lex_read_unichar(0);
 318                         if (lex_peek_unichar(0) != ':') {
 319                                 lex_stuff_pvs(":", 0);
 320                                 break;
 321                         }
 322                         lex_read_unichar(0);
 323                         c = lex_peek_unichar(0);
 324                         if (!my_is_uni_xidfirst(aTHX_ c)) {
 325                                 lex_stuff_pvs("::", 0);
 326                                 break;
 327                         }
 328                         sv_catpvs(sv, "::");
 329                         at_substart = TRUE;
 330                 } else {
 331                         break;
 332                 }
 333                 at_start = FALSE;
 334         }
 335
 336         return SvCUR(sv) ? sv : NULL;
 337 }
 338
 339 static SV *my_scan_parens_tail(pTHX_ Sentinel sen, bool keep_backslash) {
 340         I32 c, nesting;
 341         SV *sv;
 342         line_t start;
 343
 344         start = CopLINE(PL_curcop);
 345
 346         sv = sentinel_mortalize(sen, newSVpvs(""));
 347         if (lex_bufutf8()) {
 348                 SvUTF8_on(sv);
 349         }
 350
 351         nesting = 0;
 352         for (;;) {
 353                 c = lex_read_unichar(0);
 354                 if (c == EOF) {
 355                         CopLINE_set(PL_curcop, start);
 356                         return NULL;
 357                 }
 358
 359                 if (c == '\\') {
 360                         c = lex_read_unichar(0);
 361                         if (c == EOF) {
 362                                 CopLINE_set(PL_curcop, start);
 363                                 return NULL;
 364                         }
 365                         if (keep_backslash || (c != '(' && c != ')')) {
 366                                 sv_catpvs(sv, "\\");
 367                         }
 368                 } else if (c == '(') {
 369                         nesting++;
 370                 } else if (c == ')') {
 371                         if (!nesting) {
 372                                 break;
 373                         }
 374                         nesting--;
 375                 }
 376
 377                 my_sv_cat_c(aTHX_ sv, c);
 378         }
 379
 380         return sv;
 381 }
 382
 383 static void my_check_prototype(pTHX_ Sentinel sen, const SV *declarator, SV *proto) {
 384         char *start, *r, *w, *end;
 385         STRLEN len;
 386
 387         /* strip spaces */
 388         start = SvPV(proto, len);
 389         end = start + len;
 390
 391         for (w = r = start; r < end; r++) {
 392                 if (!isSPACE(*r)) {
 393                         *w++ = *r;
 394                 }
 395         }
 396         *w = '\0';
 397         SvCUR_set(proto, w - start);
 398         end = w;
 399         len = end - start;
 400
 401         if (!ckWARN(WARN_ILLEGALPROTO)) {
 402                 return;
 403         }
 404
 405         /* check for bad characters */
 406         if (strspn(start, "$@%*;[]&\\_+") != len) {
 407                 SV *dsv = sentinel_mortalize(sen, newSVpvs(""));
 408                 warner(
 409                         packWARN(WARN_ILLEGALPROTO),
 410                         "Illegal character in prototype for %"SVf" : %s",
 411                         SVfARG(declarator),
 412                         SvUTF8(proto)
 413                                 ? sv_uni_display(
 414                                         dsv,
 415                                         proto,
 416                                         len,
 417                                         UNI_DISPLAY_ISPRINT
 418                                 )
 419                                 : pv_pretty(dsv, start, len, 60, NULL, NULL,
 420                                         PERL_PV_ESCAPE_NONASCII
 421                                 )
 422                 );
 423                 return;
 424         }
 425
 426         for (r = start; r < end; r++) {
 427                 switch (*r) {
 428                         default:
 429                                 warner(
 430                                         packWARN(WARN_ILLEGALPROTO),
 431                                         "Illegal character in prototype for %"SVf" : %s",
 432                                         SVfARG(declarator), r
 433                                 );
 434                                 return;
 435
 436                         case '_':
 437                                 if (r[1] && !strchr(";@%", *r)) {
 438                                         warner(
 439                                                 packWARN(WARN_ILLEGALPROTO),
 440                                                 "Illegal character after '_' in prototype for %"SVf" : %s",
 441                                                 SVfARG(declarator), r
 442                                         );
 443                                         return;
 444                                 }
 445                                 break;
 446
 447                         case '@':
 448                         case '%':
 449                                 if (r[1]) {
 450                                         warner(
 451                                                 packWARN(WARN_ILLEGALPROTO),
 452                                                 "prototype after '%c' for %"SVf": %s",
 453                                                 *r, SVfARG(declarator), r + 1
 454                                         );
 455                                         return;
 456                                 }
 457                                 break;
 458
 459                         case '\\':
 460                                 r++;
 461                                 if (strchr("$@%&*", *r)) {
 462                                         break;
 463                                 }
 464                                 if (*r == '[') {
 465                                         r++;
 466                                         for (; r < end && *r != ']'; r++) {
 467                                                 if (!strchr("$@%&*", *r)) {
 468                                                         break;
 469                                                 }
 470                                         }
 471                                         if (*r == ']' && r[-1] != '[') {
 472                                                 break;
 473                                         }
 474                                 }
 475                                 warner(
 476                                         packWARN(WARN_ILLEGALPROTO),
 477                                         "Illegal character after '\\' in prototype for %"SVf" : %s",
 478                                         SVfARG(declarator), r
 479                                 );
 480                                 return;
 481
 482                         case '$':
 483                         case '*':
 484                         case '&':
 485                         case ';':
 486                         case '+':
 487                                 break;
 488                 }
 489         }
 490 }
 491
 492
 493 DEFSTRUCT(Param) {
 494         SV *name;
 495         PADOFFSET padoff;
 496 };
 497
 498 DEFSTRUCT(ParamInit) {
 499         Param param;
 500         OP *init;
 501 };
 502
 503 #define VEC(B) B ## _Vec
 504
 505 #define DEFVECTOR(B) DEFSTRUCT(VEC(B)) { \
 506         B (*data); \
 507         size_t used, size; \
 508 }
 509
 510 DEFVECTOR(Param);
 511 DEFVECTOR(ParamInit);
 512
 513 #define DEFVECTOR_INIT(N, B) static void N(VEC(B) *p) { \
 514         p->used = 0; \
 515         p->size = 23; \
 516         Newx(p->data, p->size, B); \
 517 } static void N(VEC(B) *)
 518
 519 DEFSTRUCT(ParamSpec) {
 520         Param invocant;
 521         VEC(Param) positional_required;
 522         VEC(ParamInit) positional_optional;
 523         VEC(Param) named_required;
 524         VEC(ParamInit) named_optional;
 525         Param slurpy;
 526         PADOFFSET rest_hash;
 527 };
 528
 529 DEFVECTOR_INIT(pv_init, Param);
 530 DEFVECTOR_INIT(piv_init, ParamInit);
 531
 532 static void p_init(Param *p) {
 533         p->name = NULL;
 534         p->padoff = NOT_IN_PAD;
 535 }
 536
 537 static void ps_init(ParamSpec *ps) {
 538         p_init(&ps->invocant);
 539         pv_init(&ps->positional_required);
 540         piv_init(&ps->positional_optional);
 541         pv_init(&ps->named_required);
 542         piv_init(&ps->named_optional);
 543         p_init(&ps->slurpy);
 544         ps->rest_hash = NOT_IN_PAD;
 545 }
 546
 547 #define DEFVECTOR_EXTEND(N, B) static B (*N(VEC(B) *p)) { \
 548         assert(p->used <= p->size); \
 549         if (p->used == p->size) { \
 550                 const size_t n = p->size / 2 * 3 + 1; \
 551                 Renew(p->data, n, B); \
 552                 p->size = n; \
 553         } \
 554         return &p->data[p->used]; \
 555 } static B (*N(VEC(B) *))
 556
 557 DEFVECTOR_EXTEND(pv_extend, Param);
 558 DEFVECTOR_EXTEND(piv_extend, ParamInit);
 559
 560 #define DEFVECTOR_CLEAR(N, B, F) static void N(pTHX_ VEC(B) *p) { \
 561         while (p->used) { \
 562                 p->used--; \
 563                 F(aTHX_ &p->data[p->used]); \
 564         } \
 565         Safefree(p->data); \
 566         p->data = NULL; \
 567         p->size = 0; \
 568 } static void N(pTHX_ VEC(B) *)
 569
 570 static void p_clear(pTHX_ Param *p) {
 571         p->name = NULL;
 572         p->padoff = NOT_IN_PAD;
 573 }
 574
 575 static void pi_clear(pTHX_ ParamInit *pi) {
 576         p_clear(aTHX_ &pi->param);
 577         if (pi->init) {
 578                 op_free(pi->init);
 579                 pi->init = NULL;
 580         }
 581 }
 582
 583 DEFVECTOR_CLEAR(pv_clear, Param, p_clear);
 584 DEFVECTOR_CLEAR(piv_clear, ParamInit, pi_clear);
 585
 586 static void ps_clear(pTHX_ ParamSpec *ps) {
 587         p_clear(aTHX_ &ps->invocant);
 588
 589         pv_clear(aTHX_ &ps->positional_required);
 590         piv_clear(aTHX_ &ps->positional_optional);
 591
 592         pv_clear(aTHX_ &ps->named_required);
 593         piv_clear(aTHX_ &ps->named_optional);
 594
 595         p_clear(aTHX_ &ps->slurpy);
 596 }
 597
 598 static int ps_contains(pTHX_ const ParamSpec *ps, SV *sv) {
 599         size_t i, lim;
 600
 601         if (ps->invocant.name && sv_eq(sv, ps->invocant.name)) {
 602                 return 1;
 603         }
 604
 605         for (i = 0, lim = ps->positional_required.used; i < lim; i++) {
 606                 if (sv_eq(sv, ps->positional_required.data[i].name)) {
 607                         return 1;
 608                 }
 609         }
 610
 611         for (i = 0, lim = ps->positional_optional.used; i < lim; i++) {
 612                 if (sv_eq(sv, ps->positional_optional.data[i].param.name)) {
 613                         return 1;
 614                 }
 615         }
 616
 617         for (i = 0, lim = ps->named_required.used; i < lim; i++) {
 618                 if (sv_eq(sv, ps->named_required.data[i].name)) {
 619                         return 1;
 620                 }
 621         }
 622
 623         for (i = 0, lim = ps->named_optional.used; i < lim; i++) {
 624                 if (sv_eq(sv, ps->named_optional.data[i].param.name)) {
 625                         return 1;
 626                 }
 627         }
 628
 629         return 0;
 630 }
 631
 632 static void ps_free_void(pTHX_ void *p) {
 633         ps_clear(aTHX_ p);
 634         Safefree(p);
 635 }
 636
 637 static int args_min(pTHX_ const ParamSpec *ps, const KWSpec *ks) {
 638         int n = 0;
 639         if (!ps) {
 640                 return SvTRUE(ks->shift) ? 1 : 0;
 641         }
 642         if (ps->invocant.name) {
 643                 n++;
 644         }
 645         n += ps->positional_required.used;
 646         n += ps->named_required.used * 2;
 647         return n;
 648 }
 649
 650 static int args_max(const ParamSpec *ps) {
 651         int n = 0;
 652         if (!ps) {
 653                 return -1;
 654         }
 655         if (ps->invocant.name) {
 656                 n++;
 657         }
 658         n += ps->positional_required.used;
 659         n += ps->positional_optional.used;
 660         if (ps->named_required.used || ps->named_optional.used || ps->slurpy.name) {
 661                 n = -1;
 662         }
 663         return n;
 664 }
 665
 666 static size_t count_positional_params(const ParamSpec *ps) {
 667         return ps->positional_required.used + ps->positional_optional.used;
 668 }
 669
 670 static size_t count_named_params(const ParamSpec *ps) {
 671         return ps->named_required.used + ps->named_optional.used;
 672 }
 673
 674 enum {
 675         PARAM_INVOCANT = 0x01,
 676         PARAM_NAMED    = 0x02
 677 };
 678
 679 /* *pinit must be NULL on entry.
 680  * caller must free *pinit on error.
 681  */
 682 static PADOFFSET parse_param(
 683         pTHX_
 684         Sentinel sen,
 685         const SV *declarator, const KWSpec *spec, ParamSpec *param_spec,
 686         int *pflags, SV **pname, OP **pinit
 687 ) {
 688         I32 c;
 689         char sigil;
 690         SV *name;
 691
 692         assert(!*pinit);
 693         *pflags = 0;
 694
 695         c = lex_peek_unichar(0);
 696
 697         if (c == ':') {
 698                 lex_read_unichar(0);
 699                 lex_read_space(0);
 700
 701                 *pflags |= PARAM_NAMED;
 702
 703                 c = lex_peek_unichar(0);
 704         }
 705
 706         if (c == -1) {
 707                 croak("In %"SVf": unterminated parameter list", SVfARG(declarator));
 708         }
 709         if (!(c == '$' || c == '@' || c == '%')) {
 710                 croak("In %"SVf": unexpected '%c' in parameter list (expecting a sigil)", SVfARG(declarator), (int)c);
 711         }
 712
 713         sigil = c;
 714
 715         lex_read_unichar(0);
 716         lex_read_space(0);
 717
 718         if (!(name = my_scan_word(aTHX_ sen, FALSE))) {
 719                 croak("In %"SVf": missing identifier after '%c'", SVfARG(declarator), sigil);
 720         }
 721         sv_insert(name, 0, 0, &sigil, 1);
 722         *pname = name;
 723
 724         lex_read_space(0);
 725         c = lex_peek_unichar(0);
 726
 727         if (c == '=') {
 728                 lex_read_unichar(0);
 729                 lex_read_space(0);
 730
 731
 732                 if (!param_spec->invocant.name && SvTRUE(spec->shift)) {
 733                         param_spec->invocant.name = spec->shift;
 734                         param_spec->invocant.padoff = pad_add_name_sv(param_spec->invocant.name, 0, NULL, NULL);
 735                 }
 736
 737                 *pinit = parse_termexpr(0);
 738
 739                 lex_read_space(0);
 740                 c = lex_peek_unichar(0);
 741         }
 742
 743         if (c == ':') {
 744                 *pflags |= PARAM_INVOCANT;
 745                 lex_read_unichar(0);
 746                 lex_read_space(0);
 747         } else if (c == ',') {
 748                 lex_read_unichar(0);
 749                 lex_read_space(0);
 750         } else if (c != ')') {
 751                 if (c == -1) {
 752                         croak("In %"SVf": unterminated parameter list", SVfARG(declarator));
 753                 }
 754                 croak("In %"SVf": unexpected '%c' in parameter list (expecting ',')", SVfARG(declarator), (int)c);
 755         }
 756
 757         return pad_add_name_sv(*pname, IF_HAVE_PERL_5_16(padadd_NO_DUP_CHECK, 0), NULL, NULL);
 758 }
 759
 760 static OP *my_var_g(pTHX_ I32 type, I32 flags, PADOFFSET padoff) {
 761         OP *var = newOP(type, flags);
 762         var->op_targ = padoff;
 763         return var;
 764 }
 765
 766 static OP *my_var(pTHX_ I32 flags, PADOFFSET padoff) {
 767         return my_var_g(aTHX_ OP_PADSV, flags, padoff);
 768 }
 769
 770 static OP *mkhvelem(pTHX_ PADOFFSET h, OP *k) {
 771         OP *hv = my_var_g(aTHX_ OP_PADHV, OPf_REF, h);
 772         return newBINOP(OP_HELEM, 0, hv, k);
 773 }
 774
 775 static OP *mkconstsv(pTHX_ SV *sv) {
 776         return newSVOP(OP_CONST, 0, sv);
 777 }
 778
 779 static OP *mkconstiv(pTHX_ IV i) {
 780         return mkconstsv(aTHX_ newSViv(i));
 781 }
 782
 783 static OP *mkconstpv(pTHX_ const char *p, size_t n) {
 784         return mkconstsv(aTHX_ newSVpv(p, n));
 785 }
 786
 787 #define mkconstpvs(S) mkconstpv(aTHX_ "" S "", sizeof S - 1)
 788
 789 static int parse_fun(pTHX_ Sentinel sen, OP **pop, const char *keyword_ptr, STRLEN keyword_len, const KWSpec *spec) {
 790         ParamSpec *param_spec;
 791         SV *declarator;
 792         I32 floor_ix;
 793         int save_ix;
 794         SV *saw_name;
 795         OP **prelude_sentinel;
 796         SV *proto;
 797         OP **attrs_sentinel, *body;
 798         unsigned builtin_attrs;
 799         I32 c;
 800
 801         declarator = sentinel_mortalize(sen, newSVpvn(keyword_ptr, keyword_len));
 802
 803         lex_read_space(0);
 804
 805         builtin_attrs = 0;
 806
 807         /* function name */
 808         saw_name = NULL;
 809         if ((spec->flags & FLAG_NAME_OK) && (saw_name = my_scan_word(aTHX_ sen, TRUE))) {
 810
 811                 if (PL_parser->expect != XSTATE) {
 812                         /* bail out early so we don't predeclare $saw_name */
 813                         croak("In %"SVf": I was expecting a function body, not \"%"SVf"\"", SVfARG(declarator), SVfARG(saw_name));
 814                 }
 815
 816                 sv_catpvs(declarator, " ");
 817                 sv_catsv(declarator, saw_name);
 818
 819                 if (
 820                         sv_eq_pvs(saw_name, "BEGIN") ||
 821                         sv_eq_pvs(saw_name, "END") ||
 822                         sv_eq_pvs(saw_name, "INIT") ||
 823                         sv_eq_pvs(saw_name, "CHECK") ||
 824                         sv_eq_pvs(saw_name, "UNITCHECK")
 825                 ) {
 826                         builtin_attrs |= MY_ATTR_SPECIAL;
 827                 }
 828
 829                 lex_read_space(0);
 830         } else if (!(spec->flags & FLAG_ANON_OK)) {
 831                 croak("I was expecting a function name, not \"%.*s\"", (int)(PL_parser->bufend - PL_parser->bufptr), PL_parser->bufptr);
 832         } else {
 833                 sv_catpvs(declarator, " (anon)");
 834         }
 835
 836         /* we're a subroutine declaration */
 837         floor_ix = start_subparse(FALSE, saw_name ? 0 : CVf_ANON);
 838         SAVEFREESV(PL_compcv);
 839
 840         /* create outer block: '{' */
 841         save_ix = S_block_start(aTHX_ TRUE);
 842
 843         /* initialize synthetic optree */
 844         Newx(prelude_sentinel, 1, OP *);
 845         *prelude_sentinel = NULL;
 846         sentinel_register(sen, prelude_sentinel, free_ptr_op);
 847
 848         /* parameters */
 849         param_spec = NULL;
 850
 851         c = lex_peek_unichar(0);
 852         if (c == '(') {
 853                 OP **init_sentinel;
 854
 855                 Newx(init_sentinel, 1, OP *);
 856                 *init_sentinel = NULL;
 857                 sentinel_register(sen, init_sentinel, free_ptr_op);
 858
 859                 Newx(param_spec, 1, ParamSpec);
 860                 ps_init(param_spec);
 861                 sentinel_register(sen, param_spec, ps_free_void);
 862
 863                 lex_read_unichar(0);
 864                 lex_read_space(0);
 865
 866                 while ((c = lex_peek_unichar(0)) != ')') {
 867                         int flags;
 868                         SV *name;
 869                         char sigil;
 870                         PADOFFSET padoff;
 871
 872                         padoff = parse_param(aTHX_ sen, declarator, spec, param_spec, &flags, &name, init_sentinel);
 873
 874                         S_intro_my(aTHX);
 875
 876                         sigil = SvPV_nolen(name)[0];
 877
 878                         /* internal consistency */
 879                         if (flags & PARAM_NAMED) {
 880                                 if (flags & PARAM_INVOCANT) {
 881                                         croak("In %"SVf": invocant %"SVf" can't be a named parameter", SVfARG(declarator), SVfARG(name));
 882                                 }
 883                                 if (sigil != '$') {
 884                                         croak("In %"SVf": named parameter %"SVf" can't be a%s", SVfARG(declarator), SVfARG(name), sigil == '@' ? "n array" : " hash");
 885                                 }
 886                         } else if (flags & PARAM_INVOCANT) {
 887                                 if (*init_sentinel) {
 888                                         croak("In %"SVf": invocant %"SVf" can't have a default value", SVfARG(declarator), SVfARG(name));
 889                                 }
 890                                 if (sigil != '$') {
 891                                         croak("In %"SVf": invocant %"SVf" can't be a%s", SVfARG(declarator), SVfARG(name), sigil == '@' ? "n array" : " hash");
 892                                 }
 893                         } else if (sigil != '$' && *init_sentinel) {
 894                                 croak("In %"SVf": %s %"SVf" can't have a default value", SVfARG(declarator), sigil == '@' ? "array" : "hash", SVfARG(name));
 895                         }
 896
 897                         /* external constraints */
 898                         if (param_spec->slurpy.name) {
 899                                 croak("In %"SVf": I was expecting \")\" after \"%"SVf"\", not \"%"SVf"\"", SVfARG(declarator), SVfARG(param_spec->slurpy.name), SVfARG(name));
 900                         }
 901                         if (sigil != '$') {
 902                                 assert(!*init_sentinel);
 903                                 param_spec->slurpy.name = name;
 904                                 param_spec->slurpy.padoff = padoff;
 905                                 continue;
 906                         }
 907
 908                         if (!(flags & PARAM_NAMED) && count_named_params(param_spec)) {
 909                                 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));
 910                         }
 911
 912                         if (flags & PARAM_INVOCANT) {
 913                                 if (param_spec->invocant.name) {
 914                                         croak("In %"SVf": invalid double invocants %"SVf", %"SVf"", SVfARG(declarator), SVfARG(param_spec->invocant.name), SVfARG(name));
 915                                 }
 916                                 if (count_positional_params(param_spec) || count_named_params(param_spec)) {
 917                                         croak("In %"SVf": invocant %"SVf" must be first in parameter list", SVfARG(declarator), SVfARG(name));
 918                                 }
 919                                 if (!(spec->flags & FLAG_INVOCANT)) {
 920                                         croak("In %"SVf": invocant %"SVf" not allowed here", SVfARG(declarator), SVfARG(name));
 921                                 }
 922                                 param_spec->invocant.name = name;
 923                                 param_spec->invocant.padoff = padoff;
 924                                 continue;
 925                         }
 926
 927                         if (*init_sentinel && !(spec->flags & FLAG_DEFAULT_ARGS)) {
 928                                 croak("In %"SVf": default argument for %"SVf" not allowed here", SVfARG(declarator), SVfARG(name));
 929                         }
 930
 931                         if (ps_contains(aTHX_ param_spec, name)) {
 932                                 croak("In %"SVf": %"SVf" can't appear twice in the same parameter list", SVfARG(declarator), SVfARG(name));
 933                         }
 934
 935                         if (flags & PARAM_NAMED) {
 936                                 if (!(spec->flags & FLAG_NAMED_PARAMS)) {
 937                                         croak("In %"SVf": named parameter :%"SVf" not allowed here", SVfARG(declarator), SVfARG(name));
 938                                 }
 939
 940                                 if (*init_sentinel) {
 941                                         ParamInit *pi = piv_extend(&param_spec->named_optional);
 942                                         pi->param.name = name;
 943                                         pi->param.padoff = padoff;
 944                                         pi->init = *init_sentinel;
 945                                         *init_sentinel = NULL;
 946                                         param_spec->named_optional.used++;
 947                                 } else {
 948                                         if (param_spec->positional_optional.used) {
 949                                                 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));
 950                                         }
 951
 952                                         Param *p = pv_extend(&param_spec->named_required);
 953                                         p->name = name;
 954                                         p->padoff = padoff;
 955                                         param_spec->named_required.used++;
 956                                 }
 957                         } else {
 958                                 if (*init_sentinel || param_spec->positional_optional.used) {
 959                                         ParamInit *pi = piv_extend(&param_spec->positional_optional);
 960                                         pi->param.name = name;
 961                                         pi->param.padoff = padoff;
 962                                         pi->init = *init_sentinel;
 963                                         *init_sentinel = NULL;
 964                                         param_spec->positional_optional.used++;
 965                                 } else {
 966                                         Param *p = pv_extend(&param_spec->positional_required);
 967                                         p->name = name;
 968                                         p->padoff = padoff;
 969                                         param_spec->positional_required.used++;
 970                                 }
 971                         }
 972
 973                 }
 974                 lex_read_unichar(0);
 975                 lex_read_space(0);
 976                 *init_sentinel = NULL;
 977
 978                 if (!param_spec->invocant.name && SvTRUE(spec->shift)) {
 979                         if (ps_contains(aTHX_ param_spec, spec->shift)) {
 980                                 croak("In %"SVf": %"SVf" can't appear twice in the same parameter list", SVfARG(declarator), SVfARG(spec->shift));
 981                         }
 982
 983                         param_spec->invocant.name = spec->shift;
 984                         param_spec->invocant.padoff = pad_add_name_sv(param_spec->invocant.name, 0, NULL, NULL);
 985                 }
 986         }
 987
 988         /* prototype */
 989         proto = NULL;
 990         c = lex_peek_unichar(0);
 991         if (c == ':') {
 992                 lex_read_unichar(0);
 993                 lex_read_space(0);
 994
 995                 c = lex_peek_unichar(0);
 996                 if (c != '(') {
 997                         lex_stuff_pvs(":", 0);
 998                         c = ':';
 999                 } else {
1000                         lex_read_unichar(0);
1001                         if (!(proto = my_scan_parens_tail(aTHX_ sen, FALSE))) {
1002                                 croak("In %"SVf": prototype not terminated", SVfARG(declarator));
1003                         }
1004                         my_check_prototype(aTHX_ sen, declarator, proto);
1005                         lex_read_space(0);
1006                         c = lex_peek_unichar(0);
1007                         if (!(c == ':' || c == '{')) {
1008                                 lex_stuff_pvs(":", 0);
1009                                 c = ':';
1010                         }
1011                 }
1012         }
1013
1014         /* attributes */
1015         Newx(attrs_sentinel, 1, OP *);
1016         *attrs_sentinel = NULL;
1017         sentinel_register(sen, attrs_sentinel, free_ptr_op);
1018
1019         if (c == ':' || c == '{') /* '}' - hi, vim */ {
1020
1021                 /* kludge default attributes in */
1022                 if (SvTRUE(spec->attrs) && SvPV_nolen(spec->attrs)[0] == ':') {
1023                         lex_stuff_sv(spec->attrs, 0);
1024                         c = ':';
1025                 }
1026
1027                 if (c == ':') {
1028                         lex_read_unichar(0);
1029                         lex_read_space(0);
1030                         c = lex_peek_unichar(0);
1031
1032                         for (;;) {
1033                                 SV *attr;
1034
1035                                 if (!(attr = my_scan_word(aTHX_ sen, FALSE))) {
1036                                         break;
1037                                 }
1038
1039                                 lex_read_space(0);
1040                                 c = lex_peek_unichar(0);
1041
1042                                 if (c != '(') {
1043                                         if (sv_eq_pvs(attr, "lvalue")) {
1044                                                 builtin_attrs |= MY_ATTR_LVALUE;
1045                                                 attr = NULL;
1046                                         } else if (sv_eq_pvs(attr, "method")) {
1047                                                 builtin_attrs |= MY_ATTR_METHOD;
1048                                                 attr = NULL;
1049                                         }
1050                                 } else {
1051                                         SV *sv;
1052                                         lex_read_unichar(0);
1053                                         if (!(sv = my_scan_parens_tail(aTHX_ sen, TRUE))) {
1054                                                 croak("In %"SVf": unterminated attribute parameter in attribute list", SVfARG(declarator));
1055                                         }
1056                                         sv_catpvs(attr, "(");
1057                                         sv_catsv(attr, sv);
1058                                         sv_catpvs(attr, ")");
1059
1060                                         lex_read_space(0);
1061                                         c = lex_peek_unichar(0);
1062                                 }
1063
1064                                 if (attr) {
1065                                         *attrs_sentinel = op_append_elem(OP_LIST, *attrs_sentinel, mkconstsv(aTHX_ SvREFCNT_inc_simple_NN(attr)));
1066                                 }
1067
1068                                 if (c == ':') {
1069                                         lex_read_unichar(0);
1070                                         lex_read_space(0);
1071                                         c = lex_peek_unichar(0);
1072                                 }
1073                         }
1074                 }
1075         }
1076
1077         /* body */
1078         if (c != '{') /* '}' - hi, vim */ {
1079                 croak("In %"SVf": I was expecting a function body, not \"%c\"", SVfARG(declarator), (int)c);
1080         }
1081
1082         /* surprise predeclaration! */
1083         if (saw_name) {
1084                 /* 'sub NAME (PROTO);' to make name/proto known to perl before it
1085                    starts parsing the body */
1086                 const I32 sub_ix = start_subparse(FALSE, 0);
1087                 SAVEFREESV(PL_compcv);
1088
1089                 SvREFCNT_inc_simple_void(PL_compcv);
1090
1091                 newATTRSUB(
1092                         sub_ix,
1093                         mkconstsv(aTHX_ SvREFCNT_inc_simple_NN(saw_name)),
1094                         proto ? mkconstsv(aTHX_ SvREFCNT_inc_simple_NN(proto)) : NULL,
1095                         NULL,
1096                         NULL
1097                 );
1098         }
1099
1100         if (builtin_attrs & MY_ATTR_LVALUE) {
1101                 CvLVALUE_on(PL_compcv);
1102         }
1103         if (builtin_attrs & MY_ATTR_METHOD) {
1104                 CvMETHOD_on(PL_compcv);
1105         }
1106         if (builtin_attrs & MY_ATTR_SPECIAL) {
1107                 CvSPECIAL_on(PL_compcv);
1108         }
1109
1110         /* check number of arguments */
1111         if (spec->flags & FLAG_CHECK_NARGS) {
1112                 int amin, amax;
1113                 size_t named;
1114
1115                 amin = args_min(aTHX_ param_spec, spec);
1116                 if (amin > 0) {
1117                         OP *chk, *cond, *err, *croak;
1118
1119                         err = mkconstsv(aTHX_ newSVpvf("Not enough arguments for %"SVf" (expected %d, got ", SVfARG(declarator), amin));
1120                         err = newBINOP(
1121                                 OP_CONCAT, 0,
1122                                 err,
1123                                 newAVREF(newGVOP(OP_GV, 0, PL_defgv))
1124                         );
1125                         err = newBINOP(
1126                                 OP_CONCAT, 0,
1127                                 err,
1128                                 mkconstpvs(")")
1129                         );
1130
1131                         croak = newCVREF(OPf_WANT_SCALAR,
1132                                          newGVOP(OP_GV, 0, gv_fetchpvs("Carp::croak", 0, SVt_PVCV)));
1133                         err = newUNOP(OP_ENTERSUB, OPf_STACKED,
1134                                       op_append_elem(OP_LIST, err, croak));
1135
1136                         cond = newBINOP(OP_LT, 0,
1137                                         newAVREF(newGVOP(OP_GV, 0, PL_defgv)),
1138                                         mkconstiv(aTHX_ amin));
1139                         chk = newLOGOP(OP_AND, 0, cond, err);
1140
1141                         *prelude_sentinel = op_append_list(OP_LINESEQ, *prelude_sentinel, newSTATEOP(0, NULL, chk));
1142                 }
1143
1144                 amax = args_max(param_spec);
1145                 if (amax >= 0) {
1146                         OP *chk, *cond, *err, *croak;
1147
1148                         err = mkconstsv(aTHX_ newSVpvf("Too many arguments for %"SVf" (expected %d, got ", SVfARG(declarator), amax));
1149                         err = newBINOP(
1150                                 OP_CONCAT, 0,
1151                                 err,
1152                                 newAVREF(newGVOP(OP_GV, 0, PL_defgv))
1153                         );
1154                         err = newBINOP(
1155                                 OP_CONCAT, 0,
1156                                 err,
1157                                 mkconstpvs(")")
1158                         );
1159
1160                         croak = newCVREF(
1161                                 OPf_WANT_SCALAR,
1162                                 newGVOP(OP_GV, 0, gv_fetchpvs("Carp::croak", 0, SVt_PVCV))
1163                         );
1164                         err = newUNOP(OP_ENTERSUB, OPf_STACKED,
1165                         op_append_elem(OP_LIST, err, croak));
1166
1167                         cond = newBINOP(
1168                                 OP_GT, 0,
1169                                 newAVREF(newGVOP(OP_GV, 0, PL_defgv)),
1170                                 mkconstiv(aTHX_ amax)
1171                         );
1172                         chk = newLOGOP(OP_AND, 0, cond, err);
1173
1174                         *prelude_sentinel = op_append_list(OP_LINESEQ, *prelude_sentinel, newSTATEOP(0, NULL, chk));
1175                 }
1176
1177                 if (param_spec && (count_named_params(param_spec) || (param_spec->slurpy.name && SvPV_nolen(param_spec->slurpy.name)[0] == '%'))) {
1178                         OP *chk, *cond, *err, *croak;
1179                         const UV fixed = count_positional_params(param_spec) + !!param_spec->invocant.name;
1180
1181                         err = mkconstsv(aTHX_ newSVpvf("Odd number of paired arguments for %"SVf"", SVfARG(declarator)));
1182
1183                         croak = newCVREF(
1184                                 OPf_WANT_SCALAR,
1185                                 newGVOP(OP_GV, 0, gv_fetchpvs("Carp::croak", 0, SVt_PVCV))
1186                         );
1187                         err = newUNOP(OP_ENTERSUB, OPf_STACKED,
1188                         op_append_elem(OP_LIST, err, croak));
1189
1190                         cond = newBINOP(OP_GT, 0,
1191                                         newAVREF(newGVOP(OP_GV, 0, PL_defgv)),
1192                                         mkconstiv(aTHX_ fixed));
1193                         cond = newLOGOP(OP_AND, 0,
1194                                         cond,
1195                                         newBINOP(OP_MODULO, 0,
1196                                                  fixed
1197                                                  ? newBINOP(OP_SUBTRACT, 0,
1198                                                             newAVREF(newGVOP(OP_GV, 0, PL_defgv)),
1199                                                             mkconstiv(aTHX_ fixed))
1200                                                  : newAVREF(newGVOP(OP_GV, 0, PL_defgv)),
1201                                                  mkconstiv(aTHX_ 2)));
1202                         chk = newLOGOP(OP_AND, 0, cond, err);
1203
1204                         *prelude_sentinel = op_append_list(OP_LINESEQ, *prelude_sentinel, newSTATEOP(0, NULL, chk));
1205                 }
1206         }
1207
1208         if (!param_spec) {
1209                 /* my $invocant = shift; */
1210                 if (SvTRUE(spec->shift)) {
1211                         OP *var;
1212
1213                         var = my_var(
1214                                 aTHX_
1215                                 OPf_MOD | (OPpLVAL_INTRO << 8),
1216                                 pad_add_name_sv(spec->shift, 0, NULL, NULL)
1217                         );
1218                         var = newASSIGNOP(OPf_STACKED, var, 0, newOP(OP_SHIFT, 0));
1219
1220                         *prelude_sentinel = op_append_list(OP_LINESEQ, *prelude_sentinel, newSTATEOP(0, NULL, var));
1221                 }
1222         } else {
1223                 /* my $invocant = shift; */
1224                 if (param_spec->invocant.name) {
1225                         OP *var;
1226
1227                         var = my_var(
1228                                 aTHX_
1229                                 OPf_MOD | (OPpLVAL_INTRO << 8),
1230                                 param_spec->invocant.padoff
1231                         );
1232                         var = newASSIGNOP(OPf_STACKED, var, 0, newOP(OP_SHIFT, 0));
1233
1234                         *prelude_sentinel = op_append_list(OP_LINESEQ, *prelude_sentinel, newSTATEOP(0, NULL, var));
1235                 }
1236
1237                 /* my (...) = @_; */
1238                 {
1239                         OP *lhs;
1240                         size_t i, lim;
1241
1242                         lhs = NULL;
1243
1244                         for (i = 0, lim = param_spec->positional_required.used; i < lim; i++) {
1245                                 OP *const var = my_var(
1246                                         aTHX_
1247                                         OPf_WANT_LIST | (OPpLVAL_INTRO << 8),
1248                                         param_spec->positional_required.data[i].padoff
1249                                 );
1250                                 lhs = op_append_elem(OP_LIST, lhs, var);
1251                         }
1252
1253                         for (i = 0, lim = param_spec->positional_optional.used; i < lim; i++) {
1254                                 OP *const var = my_var(
1255                                         aTHX_
1256                                         OPf_WANT_LIST | (OPpLVAL_INTRO << 8),
1257                                         param_spec->positional_optional.data[i].param.padoff
1258                                 );
1259                                 lhs = op_append_elem(OP_LIST, lhs, var);
1260                         }
1261
1262                         {
1263                                 PADOFFSET padoff;
1264                                 I32 type;
1265                                 bool slurpy_hash;
1266
1267                                 /*
1268                                  * cases:
1269                                  *  1) no named params
1270                                  *   1.1) slurpy
1271                                  *       => put it in
1272                                  *   1.2) no slurpy
1273                                  *       => nop
1274                                  *  2) named params
1275                                  *   2.1) no slurpy
1276                                  *       => synthetic %{rest}
1277                                  *   2.2) slurpy is a hash
1278                                  *       => put it in
1279                                  *   2.3) slurpy is an array
1280                                  *       => synthetic %{rest}
1281                                  *          remember to declare array later
1282                                  */
1283
1284                                 slurpy_hash = param_spec->slurpy.name && SvPV_nolen(param_spec->slurpy.name)[0] == '%';
1285                                 if (!count_named_params(param_spec)) {
1286                                         if (param_spec->slurpy.name) {
1287                                                 padoff = param_spec->slurpy.padoff;
1288                                                 type = slurpy_hash ? OP_PADHV : OP_PADAV;
1289                                         } else {
1290                                                 padoff = NOT_IN_PAD;
1291                                                 type = OP_PADSV;
1292                                         }
1293                                 } else if (slurpy_hash) {
1294                                         padoff = param_spec->slurpy.padoff;
1295                                         type = OP_PADHV;
1296                                 } else {
1297                                         padoff = param_spec->rest_hash = pad_add_name_pvs("%{rest}", 0, NULL, NULL);
1298                                         type = OP_PADHV;
1299                                 }
1300
1301                                 if (padoff != NOT_IN_PAD) {
1302                                         OP *const var = my_var_g(
1303                                                 aTHX_
1304                                                 type,
1305                                                 OPf_WANT_LIST | (OPpLVAL_INTRO << 8),
1306                                                 padoff
1307                                         );
1308
1309                                         lhs = op_append_elem(OP_LIST, lhs, var);
1310
1311                                         if (type == OP_PADHV) {
1312                                                 param_spec->rest_hash = padoff;
1313                                         }
1314                                 }
1315                         }
1316
1317                         if (lhs) {
1318                                 OP *rhs;
1319                                 lhs->op_flags |= OPf_PARENS;
1320                                 rhs = newAVREF(newGVOP(OP_GV, 0, PL_defgv));
1321
1322                                 *prelude_sentinel = op_append_list(
1323                                         OP_LINESEQ, *prelude_sentinel,
1324                                         newSTATEOP(
1325                                                 0, NULL,
1326                                                 newASSIGNOP(OPf_STACKED, lhs, 0, rhs)
1327                                         )
1328                                 );
1329                         }
1330                 }
1331
1332                 /* default positional arguments */
1333                 {
1334                         size_t i, lim, req;
1335                         OP *nest;
1336
1337                         nest = NULL;
1338
1339                         req = param_spec->positional_required.used;
1340                         for (i = 0, lim = param_spec->positional_optional.used; i < lim; i++) {
1341                                 ParamInit *cur = &param_spec->positional_optional.data[i];
1342                                 OP *var, *cond;
1343
1344                                 cond = newBINOP(
1345                                         OP_LT, 0,
1346                                         newAVREF(newGVOP(OP_GV, 0, PL_defgv)),
1347                                         mkconstiv(aTHX_ req + i + 1)
1348                                 );
1349
1350                                 var = my_var(aTHX_ 0, cur->param.padoff);
1351
1352                                 nest = op_append_list(
1353                                         OP_LINESEQ, nest,
1354                                         newASSIGNOP(OPf_STACKED, var, 0, cur->init)
1355                                 );
1356                                 cur->init = NULL;
1357                                 nest = newCONDOP(
1358                                         0,
1359                                         cond,
1360                                         nest,
1361                                         NULL
1362                                 );
1363                         }
1364
1365                         *prelude_sentinel = op_append_list(
1366                                 OP_LINESEQ, *prelude_sentinel,
1367                                 nest
1368                         );
1369                 }
1370
1371                 /* named parameters */
1372                 if (count_named_params(param_spec)) {
1373                         size_t i, lim;
1374
1375                         assert(param_spec->rest_hash != NOT_IN_PAD);
1376
1377                         for (i = 0, lim = param_spec->named_required.used; i < lim; i++) {
1378                                 Param *cur = &param_spec->named_required.data[i];
1379                                 size_t n;
1380                                 char *p = SvPV(cur->name, n);
1381                                 OP *var, *cond;
1382
1383                                 cond = mkhvelem(aTHX_ param_spec->rest_hash, mkconstpv(aTHX_ p + 1, n - 1));
1384
1385                                 if (spec->flags & FLAG_CHECK_NARGS) {
1386                                         OP *croak, *msg;
1387
1388                                         var = mkhvelem(aTHX_ param_spec->rest_hash, mkconstpv(aTHX_ p + 1, n - 1));
1389                                         var = newUNOP(OP_DELETE, 0, var);
1390
1391                                         msg = mkconstsv(aTHX_ newSVpvf("In %"SVf": missing named parameter: %.*s", SVfARG(declarator), (int)(n - 1), p + 1));
1392                                         croak = newCVREF(
1393                                                 OPf_WANT_SCALAR,
1394                                                 newGVOP(OP_GV, 0, gv_fetchpvs("Carp::croak", 0, SVt_PVCV))
1395                                         );
1396                                         croak = newUNOP(OP_ENTERSUB, OPf_STACKED, op_append_elem(OP_LIST, msg, croak));
1397
1398                                         cond = newUNOP(OP_EXISTS, 0, cond);
1399
1400                                         cond = newCONDOP(0, cond, var, croak);
1401                                 }
1402
1403                                 var = my_var(
1404                                         aTHX_
1405                                         OPf_MOD | (OPpLVAL_INTRO << 8),
1406                                         cur->padoff
1407                                 );
1408                                 var = newASSIGNOP(OPf_STACKED, var, 0, cond);
1409
1410                                 *prelude_sentinel = op_append_list(OP_LINESEQ, *prelude_sentinel, newSTATEOP(0, NULL, var));
1411                         }
1412
1413                         for (i = 0, lim = param_spec->named_optional.used; i < lim; i++) {
1414                                 ParamInit *cur = &param_spec->named_optional.data[i];
1415                                 size_t n;
1416                                 char *p = SvPV(cur->param.name, n);
1417                                 OP *var, *cond;
1418
1419                                 var = mkhvelem(aTHX_ param_spec->rest_hash, mkconstpv(aTHX_ p + 1, n - 1));
1420                                 var = newUNOP(OP_DELETE, 0, var);
1421
1422                                 cond = mkhvelem(aTHX_ param_spec->rest_hash, mkconstpv(aTHX_ p + 1, n - 1));
1423                                 cond = newUNOP(OP_EXISTS, 0, cond);
1424
1425                                 cond = newCONDOP(0, cond, var, cur->init);
1426                                 cur->init = NULL;
1427
1428                                 var = my_var(
1429                                         aTHX_
1430                                         OPf_MOD | (OPpLVAL_INTRO << 8),
1431                                         cur->param.padoff
1432                                 );
1433                                 var = newASSIGNOP(OPf_STACKED, var, 0, cond);
1434
1435                                 *prelude_sentinel = op_append_list(OP_LINESEQ, *prelude_sentinel, newSTATEOP(0, NULL, var));
1436                         }
1437
1438                         if (!param_spec->slurpy.name) {
1439                                 if (spec->flags & FLAG_CHECK_NARGS) {
1440                                         /* croak if %{rest} */
1441                                         OP *croak, *cond, *keys, *msg;
1442
1443                                         keys = newUNOP(OP_KEYS, 0, my_var_g(aTHX_ OP_PADHV, 0, param_spec->rest_hash));
1444                                         keys = newLISTOP(OP_SORT, 0, newOP(OP_PUSHMARK, 0), keys);
1445                                         {
1446                                                 OP *first, *mid, *last;
1447
1448                                                 last = keys;
1449
1450                                                 mid = mkconstpvs(", ");
1451                                                 mid->op_sibling = last;
1452
1453                                                 first = newOP(OP_PUSHMARK, 0);
1454
1455                                                 keys = newLISTOP(OP_JOIN, 0, first, mid);
1456                                                 keys->op_targ = pad_alloc(OP_JOIN, SVs_PADTMP);
1457                                                 ((LISTOP *)keys)->op_last = last;
1458                                         }
1459
1460                                         msg = mkconstsv(aTHX_ newSVpvf("In %"SVf": no such named parameter: ", SVfARG(declarator)));
1461                                         msg = newBINOP(OP_CONCAT, 0, msg, keys);
1462
1463                                         croak = newCVREF(
1464                                                 OPf_WANT_SCALAR,
1465                                                 newGVOP(OP_GV, 0, gv_fetchpvs("Carp::croak", 0, SVt_PVCV))
1466                                         );
1467                                         croak = newUNOP(OP_ENTERSUB, OPf_STACKED, op_append_elem(OP_LIST, msg, croak));
1468
1469                                         cond = newUNOP(OP_KEYS, 0, my_var_g(aTHX_ OP_PADHV, 0, param_spec->rest_hash));
1470                                         croak = newCONDOP(0, cond, croak, NULL);
1471
1472                                         *prelude_sentinel = op_append_list(OP_LINESEQ, *prelude_sentinel, newSTATEOP(0, NULL, croak));
1473                                 } else {
1474                                         OP *clear;
1475
1476                                         clear = newASSIGNOP(
1477                                                 OPf_STACKED,
1478                                                 my_var_g(aTHX_ OP_PADHV, 0, param_spec->rest_hash),
1479                                                 0,
1480                                                 newNULLLIST()
1481                                         );
1482
1483                                         *prelude_sentinel = op_append_list(OP_LINESEQ, *prelude_sentinel, newSTATEOP(0, NULL, clear));
1484                                 }
1485                         } else if (param_spec->slurpy.padoff != param_spec->rest_hash) {
1486                                 OP *var, *clear;
1487
1488                                 assert(SvPV_nolen(param_spec->slurpy.name)[0] == '@');
1489
1490                                 var = my_var_g(
1491                                         aTHX_
1492                                         OP_PADAV,
1493                                         OPf_MOD | (OPpLVAL_INTRO << 8),
1494                                         param_spec->slurpy.padoff
1495                                 );
1496
1497                                 var = newASSIGNOP(OPf_STACKED, var, 0, my_var_g(aTHX_ OP_PADHV, 0, param_spec->rest_hash));
1498
1499                                 *prelude_sentinel = op_append_list(OP_LINESEQ, *prelude_sentinel, newSTATEOP(0, NULL, var));
1500
1501                                 clear = newASSIGNOP(
1502                                         OPf_STACKED,
1503                                         my_var_g(aTHX_ OP_PADHV, 0, param_spec->rest_hash),
1504                                         0,
1505                                         newNULLLIST()
1506                                 );
1507
1508                                 *prelude_sentinel = op_append_list(OP_LINESEQ, *prelude_sentinel, newSTATEOP(0, NULL, clear));
1509                         }
1510                 }
1511         }
1512
1513         /* finally let perl parse the actual subroutine body */
1514         body = parse_block(0);
1515
1516         /* add '();' to make function return nothing by default */
1517         /* (otherwise the invisible parameter initialization can "leak" into
1518            the return value: fun ($x) {}->("asdf", 0) == 2) */
1519         if (*prelude_sentinel) {
1520                 body = newSTATEOP(0, NULL, body);
1521         }
1522
1523         body = op_append_list(OP_LINESEQ, *prelude_sentinel, body);
1524         *prelude_sentinel = NULL;
1525
1526         /* it's go time. */
1527         {
1528                 OP *const attrs = *attrs_sentinel;
1529                 *attrs_sentinel = NULL;
1530                 SvREFCNT_inc_simple_void(PL_compcv);
1531
1532                 /* close outer block: '}' */
1533                 S_block_end(aTHX_ save_ix, body);
1534
1535                 if (!saw_name) {
1536                         *pop = newANONATTRSUB(
1537                                 floor_ix,
1538                                 proto ? newSVOP(OP_CONST, 0, SvREFCNT_inc_simple_NN(proto)) : NULL,
1539                                 attrs,
1540                                 body
1541                         );
1542                         return KEYWORD_PLUGIN_EXPR;
1543                 }
1544
1545                 newATTRSUB(
1546                         floor_ix,
1547                         newSVOP(OP_CONST, 0, SvREFCNT_inc_simple_NN(saw_name)),
1548                         proto ? newSVOP(OP_CONST, 0, SvREFCNT_inc_simple_NN(proto)) : NULL,
1549                         attrs,
1550                         body
1551                 );
1552                 *pop = newOP(OP_NULL, 0);
1553                 return KEYWORD_PLUGIN_STMT;
1554         }
1555 }
1556
1557 static int my_keyword_plugin(pTHX_ char *keyword_ptr, STRLEN keyword_len, OP **op_ptr) {
1558         KWSpec spec;
1559         int ret;
1560         Sentinel sen = { NULL };
1561
1562         ENTER;
1563         SAVETMPS;
1564
1565         SAVEDESTRUCTOR_X(sentinel_clear_void, sen);
1566
1567         if (kw_flags(aTHX_ sen, keyword_ptr, keyword_len, &spec)) {
1568                 ret = parse_fun(aTHX_ sen, op_ptr, keyword_ptr, keyword_len, &spec);
1569         } else {
1570                 ret = next_keyword_plugin(aTHX_ keyword_ptr, keyword_len, op_ptr);
1571         }
1572
1573         FREETMPS;
1574         LEAVE;
1575
1576         return ret;
1577 }
1578
1579 WARNINGS_RESET
1580
1581 MODULE = Function::Parameters   PACKAGE = Function::Parameters
1582 PROTOTYPES: ENABLE
1583
1584 BOOT:
1585 WARNINGS_ENABLE {
1586         HV *const stash = gv_stashpvs(MY_PKG, GV_ADD);
1587         /**/
1588         newCONSTSUB(stash, "FLAG_NAME_OK",      newSViv(FLAG_NAME_OK));
1589         newCONSTSUB(stash, "FLAG_ANON_OK",      newSViv(FLAG_ANON_OK));
1590         newCONSTSUB(stash, "FLAG_DEFAULT_ARGS", newSViv(FLAG_DEFAULT_ARGS));
1591         newCONSTSUB(stash, "FLAG_CHECK_NARGS",  newSViv(FLAG_CHECK_NARGS));
1592         newCONSTSUB(stash, "FLAG_INVOCANT",     newSViv(FLAG_INVOCANT));
1593         newCONSTSUB(stash, "FLAG_NAMED_PARAMS", newSViv(FLAG_NAMED_PARAMS));
1594         newCONSTSUB(stash, "HINTK_KEYWORDS", newSVpvs(HINTK_KEYWORDS));
1595         newCONSTSUB(stash, "HINTK_FLAGS_",   newSVpvs(HINTK_FLAGS_));
1596         newCONSTSUB(stash, "HINTK_SHIFT_",   newSVpvs(HINTK_SHIFT_));
1597         newCONSTSUB(stash, "HINTK_ATTRS_",   newSVpvs(HINTK_ATTRS_));
1598         /**/
1599         next_keyword_plugin = PL_keyword_plugin;
1600         PL_keyword_plugin = my_keyword_plugin;
1601 } WARNINGS_RESET