librune/type.c

   1 /*
   2  * TYPE.C
   3  *
   4  * (c)Copyright 1993-2014, Matthew Dillon, All Rights Reserved.  See the
   5  *    COPYRIGHT file at the base of the distribution.
   6  */
   7
   8 #include "defs.h"
   9
  10 Type DynamicLValueType;
  11 Type DynamicRValueType;
  12
  13 Type NumericType;       /* generic numeric placeholder */
  14 Type IntegralType;      /* generic integral placeholder */
  15 Type SIntegerType;      /* generic signed integer placeholder */
  16 Type UIntegerType;      /* generic unsigned integer placeholder */
  17
  18 Type VoidType;
  19 Type BoolType;
  20 Type Int8Type;
  21 Type UInt8Type;
  22 Type Int16Type;
  23 Type UInt16Type;
  24 Type Int32Type;
  25 Type UInt32Type;
  26 Type Int64Type;
  27 Type UInt64Type;
  28 Type Int128Type;
  29 Type UInt128Type;
  30
  31 Type IntPtrType;
  32 Type UIntPtrType;
  33 Type OffType;
  34 Type SizeType;
  35
  36 Type FloatType;         /* generic float placeholder */
  37 Type Float32Type;
  38 Type Float64Type;
  39 Type Float128Type;
  40
  41 Type PointerType;       /* generic pointer placeholder */
  42 Type CCharType;         /* const char           */
  43 Type StrType;           /* const char *         */
  44 Type CharPtrType;       /* char *               */
  45 Type CharPtrPtrType;    /* char **              */
  46 Type VoidPtrType;       /* void *               */
  47 Type VoidRefType;       /* void @               */
  48 Type CVoidPtrType;      /* const void *         */
  49 Type LVoidPtrType;      /* lvalue void *        */
  50
  51 Type LexRefType;        /* run-time access class tie-ins */
  52 Type ScopeType;
  53 Type DeclarationType;
  54 Type SemGroupType;
  55 Type TypeType;
  56 Type FILLERTypeType;
  57 Type FILLERDeclType;
  58
  59 typelist_t DynamicTypeList = RUNE_HEAD_INITIALIZER(DynamicTypeList);
  60 typelist_t CompoundTypeList = RUNE_HEAD_INITIALIZER(CompoundTypeList);
  61 typelist_t ArgsTypeList = RUNE_HEAD_INITIALIZER(ArgsTypeList);
  62 typelist_t StorageTypeList = RUNE_HEAD_INITIALIZER(StorageTypeList);
  63
  64 static void initInternalClassType(Type *type, Declaration *d);
  65
  66 Type *BaseTypeAry[] = {
  67                 &DynamicLValueType, &DynamicRValueType, &NumericType,
  68                 &IntegralType, &SIntegerType, &UIntegerType,
  69                 &VoidType, &BoolType, &Int8Type, &UInt8Type,
  70                 &Int16Type, &UInt16Type, &Int32Type, &UInt32Type,
  71                 &Int64Type, &UInt64Type, &Int128Type, &UInt128Type,
  72
  73                 &IntPtrType, &UIntPtrType, &OffType, &SizeType,
  74
  75                 &FloatType, &Float32Type, &Float64Type, &Float128Type,
  76
  77                 &PointerType, &CCharType, &StrType, &CharPtrType,
  78                 &CharPtrPtrType, &VoidPtrType, &VoidRefType, &CVoidPtrType,
  79                 &LVoidPtrType,
  80
  81                 &LexRefType, &ScopeType, &DeclarationType, &SemGroupType,
  82                 &TypeType, &FILLERTypeType, &FILLERDeclType,
  83                 NULL
  84 };
  85
  86 void
  87 initType(Type *type, typelist_t *list, int op)
  88 {
  89         type->ty_Op = op;
  90         RUNE_INIT(&type->ty_QList);
  91         if (list)
  92                 RUNE_INSERT_TAIL(list, type, ty_Node);
  93         type->ty_SQList = list;
  94 }
  95
  96 void
  97 initQualType(Type *type, typelist_t *list, int op, int sqflags)
  98 {
  99         initType(type, list, op);
 100         type->ty_SQFlags = sqflags;
 101 }
 102
 103 void
 104 initPtrType(Type *type, Type *ptrto, int sqflags)
 105 {
 106         initQualType(type, &ptrto->ty_QList, TY_PTRTO, sqflags);
 107         type->ty_PtrType.et_Type = ptrto;
 108         /*type->ty_Bytes = sizeof(PointerStor);*/
 109         type->ty_AlignMask = sizeof(void *) - 1;
 110 }
 111
 112 void
 113 initCPtrType(Type *type, Type *ptrto, int sqflags)
 114 {
 115         initQualType(type, &ptrto->ty_QList, TY_CPTRTO, sqflags);
 116         type->ty_PtrType.et_Type = ptrto;
 117         /*type->ty_Bytes = sizeof(void *);*/
 118         type->ty_AlignMask = sizeof(void *) - 1;
 119 }
 120
 121 static void
 122 initRefType(Type *type, Type *refto, int sqflags)
 123 {
 124         initQualType(type, &refto->ty_QList, TY_REFTO, sqflags);
 125         type->ty_RefType.et_Type = refto;
 126         type->ty_AlignMask = sizeof(void *) - 1;
 127         /*type->ty_Bytes = sizeof(PointerStor);*/
 128 }
 129
 130 void
 131 TypeInit(void)
 132 {
 133         int i;
 134
 135         initQualType(&DynamicLValueType, &DynamicTypeList,
 136                      TY_DYNAMIC, SF_LVALUE);
 137         initType(&DynamicRValueType, &DynamicTypeList, TY_DYNAMIC);
 138         initType(&NumericType, NULL, TY_UNRESOLVED);
 139         initType(&IntegralType, NULL, TY_UNRESOLVED);
 140         initType(&SIntegerType, NULL, TY_UNRESOLVED);
 141         initType(&UIntegerType, NULL, TY_UNRESOLVED);
 142         initType(&FloatType, NULL, TY_UNRESOLVED);
 143         initType(&PointerType, NULL, TY_UNRESOLVED);
 144         PointerType.ty_AlignMask = sizeof(void *) - 1;
 145
 146         initType(&VoidType, NULL, TY_UNRESOLVED);
 147         initType(&BoolType, NULL, TY_UNRESOLVED);
 148         initType(&Int8Type, NULL, TY_UNRESOLVED);
 149         initType(&UInt8Type, NULL, TY_UNRESOLVED);
 150         initType(&Int16Type, NULL, TY_UNRESOLVED);
 151         initType(&UInt16Type, NULL, TY_UNRESOLVED);
 152         initType(&Int32Type, NULL, TY_UNRESOLVED);
 153         initType(&UInt32Type, NULL, TY_UNRESOLVED);
 154         initType(&Int64Type, NULL, TY_UNRESOLVED);
 155         initType(&UInt64Type, NULL, TY_UNRESOLVED);
 156
 157         initType(&IntPtrType, NULL, TY_UNRESOLVED);
 158         initType(&UIntPtrType, NULL, TY_UNRESOLVED);
 159         initType(&OffType, NULL, TY_UNRESOLVED);
 160         initType(&SizeType, NULL, TY_UNRESOLVED);
 161
 162         initType(&Float32Type, NULL, TY_UNRESOLVED);
 163         initType(&Float64Type, NULL, TY_UNRESOLVED);
 164         initType(&Float128Type, NULL, TY_UNRESOLVED);
 165
 166         initQualType(&CCharType, NULL, TY_UNRESOLVED, SF_CONST);
 167         initPtrType(&StrType, &CCharType, 0);
 168         initPtrType(&CharPtrType, &UInt8Type, 0);
 169         initPtrType(&CharPtrPtrType, &CharPtrType, 0);
 170         initPtrType(&VoidPtrType, &VoidType, 0);
 171         initRefType(&VoidRefType, &VoidType, 0);
 172         initCPtrType(&CVoidPtrType, &VoidType, SF_CONST);
 173         initPtrType(&LVoidPtrType, &VoidType, SF_LVALUE);
 174
 175         /*
 176          * Mark internal types (not all are bound to classes so it is
 177          * easiest to just do it here).  This will prevent the collapse
 178          * code from trying to collapse our base types.
 179          */
 180         for (i = 0; BaseTypeAry[i]; ++i)
 181                 BaseTypeAry[i]->ty_Flags |= TF_ISINTERNAL;
 182
 183         StrTableAlloc("void", 4, SPECIAL_INTERNAL_VOID);
 184         StrTableAlloc("bool", 4, SPECIAL_INTERNAL_BOOL);
 185         StrTableAlloc("int8_t", 6, SPECIAL_INTERNAL_INT8);
 186         StrTableAlloc("uint8_t", 7, SPECIAL_INTERNAL_UINT8);
 187         StrTableAlloc("int16_t", 7, SPECIAL_INTERNAL_INT16);
 188         StrTableAlloc("uint16_t", 8, SPECIAL_INTERNAL_UINT16);
 189         StrTableAlloc("int32_t", 7, SPECIAL_INTERNAL_INT32);
 190         StrTableAlloc("uint32_t", 8, SPECIAL_INTERNAL_UINT32);
 191         StrTableAlloc("int64_t", 7, SPECIAL_INTERNAL_INT64);
 192         StrTableAlloc("uint64_t", 8, SPECIAL_INTERNAL_UINT64);
 193         StrTableAlloc("int128_t", 8, SPECIAL_INTERNAL_INT128);
 194         StrTableAlloc("uint128_t", 9, SPECIAL_INTERNAL_UINT128);
 195
 196         StrTableAlloc("float32_t", 9, SPECIAL_INTERNAL_FLOAT32);
 197         StrTableAlloc("float64_t", 9, SPECIAL_INTERNAL_FLOAT64);
 198         StrTableAlloc("float128_t", 10, SPECIAL_INTERNAL_FLOAT128);
 199
 200         StrTableAlloc("intptr_t", 8, SPECIAL_INTERNAL_INTPTR);
 201         StrTableAlloc("uintptr_t", 9, SPECIAL_INTERNAL_UINTPTR);
 202         StrTableAlloc("size_t", 6, SPECIAL_INTERNAL_SIZE);
 203         StrTableAlloc("off_t", 5, SPECIAL_INTERNAL_OFF);
 204
 205         StrTableAlloc("Float", 5, SPECIAL_INTERNAL_FLOAT);
 206         StrTableAlloc("Pointer", 7, SPECIAL_INTERNAL_POINTER);
 207         StrTableAlloc("Numeric", 7, SPECIAL_INTERNAL_NUMERIC);
 208         StrTableAlloc("Integral", 8, SPECIAL_INTERNAL_INTEGRAL);
 209         StrTableAlloc("SInteger", 8, SPECIAL_INTERNAL_SINTEGER);
 210         StrTableAlloc("UInteger", 8, SPECIAL_INTERNAL_UINTEGER);
 211
 212         StrTableAlloc("LexRef", 6, SPECIAL_INTERNAL_LEXREF);
 213         StrTableAlloc("Scope", 5, SPECIAL_INTERNAL_SCOPE);
 214         StrTableAlloc("Declaration", 11, SPECIAL_INTERNAL_DECLARATION);
 215         StrTableAlloc("SemGroup", 8, SPECIAL_INTERNAL_SEMGROUP);
 216         StrTableAlloc("Type", 4, SPECIAL_INTERNAL_TYPE);
 217         StrTableAlloc("FILLERType", 10, SPECIAL_INTERNAL_FILLERTYPE);
 218         StrTableAlloc("FILLERDecl", 10, SPECIAL_INTERNAL_FILLERDECL);
 219
 220         StrTableAlloc("__count",        7,      SPECIAL_COUNT);
 221         StrTableAlloc("__data",         6,      SPECIAL_DATA);
 222         StrTableAlloc("__varcount",     10,     SPECIAL_VAR_COUNT);
 223         StrTableAlloc("__vardata",      9,      SPECIAL_VAR_DATA);
 224         StrTableAlloc("__typeid",       8,      SPECIAL_TYPEID);
 225         StrTableAlloc("__typestr",      9,      SPECIAL_TYPESTR);
 226         StrTableAlloc("NULL",           4,      SPECIAL_NULL);
 227 }
 228
 229 /*
 230  * Attach an internal class, creating a global summary type for it that
 231  * allows our interpreter and code generator to make various assumptions.
 232  */
 233 int
 234 InternalClassAttach(Parse *p __unused, int t, Declaration *d)
 235 {
 236         Type *itype = NULL;
 237         int s;
 238
 239         dassert_decl(d, d->d_Op == DOP_CLASS);
 240
 241         if ((s = StrTableSpecial(d->d_Id)) & SPECIALF_INTERNAL) {
 242                 switch(s) {
 243                 case SPECIAL_INTERNAL_VOID:
 244                         itype = &VoidType;
 245                         break;
 246                 case SPECIAL_INTERNAL_BOOL:
 247                         /*
 248                          * Special flag helper (resolver sets TF_ISBOOL in
 249                          * in the type)
 250                          */
 251                         itype = &BoolType;
 252                         d->d_ClassDecl.ed_SemGroup->sg_Flags |= SGF_ISBOOL;
 253                         break;
 254                 case SPECIAL_INTERNAL_INT8:
 255                         itype = &Int8Type;
 256                         break;
 257                 case SPECIAL_INTERNAL_UINT8:
 258                         itype = &UInt8Type;
 259                         break;
 260                 case SPECIAL_INTERNAL_INT16:
 261                         itype = &Int16Type;
 262                         break;
 263                 case SPECIAL_INTERNAL_UINT16:
 264                         itype = &UInt16Type;
 265                         break;
 266                 case SPECIAL_INTERNAL_INT32:
 267                         itype = &Int32Type;
 268                         break;
 269                 case SPECIAL_INTERNAL_UINT32:
 270                         itype = &UInt32Type;
 271                         break;
 272                 case SPECIAL_INTERNAL_INT64:
 273                         itype = &Int64Type;
 274                         break;
 275                 case SPECIAL_INTERNAL_UINT64:
 276                         itype = &UInt64Type;
 277                         break;
 278                 case SPECIAL_INTERNAL_INT128:
 279                         itype = &Int128Type;
 280                         break;
 281                 case SPECIAL_INTERNAL_UINT128:
 282                         itype = &UInt128Type;
 283                         break;
 284
 285                 case SPECIAL_INTERNAL_FLOAT:
 286                         /*
 287                          * Special flag helper (resolver sets TF_ISFLOATING in
 288                          * in the type)
 289                          */
 290                         itype = &FloatType;
 291                         d->d_ClassDecl.ed_SemGroup->sg_Flags |= SGF_ISFLOATING;
 292                         break;
 293                 case SPECIAL_INTERNAL_FLOAT32:
 294                         itype = &Float32Type;
 295                         break;
 296                 case SPECIAL_INTERNAL_FLOAT64:
 297                         itype = &Float64Type;
 298                         break;
 299                 case SPECIAL_INTERNAL_FLOAT128:
 300                         itype = &Float128Type;
 301                         break;
 302
 303                 case SPECIAL_INTERNAL_INTPTR:
 304                         itype = &IntPtrType;
 305                         break;
 306                 case SPECIAL_INTERNAL_UINTPTR:
 307                         itype = &UIntPtrType;
 308                         break;
 309                 case SPECIAL_INTERNAL_OFF:
 310                         itype = &OffType;
 311                         break;
 312                 case SPECIAL_INTERNAL_SIZE:
 313                         itype = &SizeType;
 314                         break;
 315                 /* NOTE: There is no ssize_t in rune. size_t is signed */
 316
 317                 case SPECIAL_INTERNAL_POINTER:
 318                         itype = &PointerType;
 319                         break;
 320                 case SPECIAL_INTERNAL_NUMERIC:
 321                         itype = &NumericType;
 322                         break;
 323                 case SPECIAL_INTERNAL_INTEGRAL:
 324                         itype = &IntegralType;
 325                         break;
 326                 case SPECIAL_INTERNAL_SINTEGER:
 327                         /*
 328                          * Special flag helper (resolver sets TF_ISINTEGER in
 329                          * in the type)
 330                          */
 331                         itype = &SIntegerType;
 332                         d->d_ClassDecl.ed_SemGroup->sg_Flags |= SGF_ISINTEGER;
 333                         break;
 334                 case SPECIAL_INTERNAL_UINTEGER:
 335                         /*
 336                          * Special flag helper (resolver sets TF_ISINTEGER
 337                          * and TF_ISUNSIGNED in the type)
 338                          */
 339                         itype = &UIntegerType;
 340                         d->d_ClassDecl.ed_SemGroup->sg_Flags |= SGF_ISUNSIGNED;
 341                         d->d_ClassDecl.ed_SemGroup->sg_Flags |= SGF_ISINTEGER;
 342                         break;
 343
 344                 case SPECIAL_INTERNAL_LEXREF:
 345                         itype = &LexRefType;
 346                         break;
 347                 case SPECIAL_INTERNAL_SCOPE:
 348                         itype = &ScopeType;
 349                         break;
 350                 case SPECIAL_INTERNAL_DECLARATION:
 351                         itype = &DeclarationType;
 352                         break;
 353                 case SPECIAL_INTERNAL_SEMGROUP:
 354                         itype = &SemGroupType;
 355                         break;
 356                 case SPECIAL_INTERNAL_TYPE:
 357                         itype = &TypeType;
 358                         break;
 359                 case SPECIAL_INTERNAL_FILLERTYPE:
 360                         itype = &FILLERTypeType;
 361                         break;
 362                 case SPECIAL_INTERNAL_FILLERDECL:
 363                         itype = &FILLERDeclType;
 364                         break;
 365                 default:
 366                         dassert(0);
 367                         break;
 368                 }
 369         }
 370         initInternalClassType(itype, d);
 371
 372         /*
 373          * Fixup for const int8 pointers... we did not have
 374          * a QList to put CCharType on until now.  It will
 375          * wind up on the SemGroup's sg_ClassList.
 376          */
 377         if (itype == &UInt8Type) {
 378                 TypeToQualType(itype, &CCharType,
 379                                itype->ty_SQFlags | SF_CONST, NULL);
 380         }
 381
 382         return(t);
 383 }
 384
 385 /*
 386  * This is mostly deprecated except for official type aliases such as
 387  * intptr_t.
 388  */
 389 int
 390 InternalTypeAttach(Parse *p, int t, Declaration *d)
 391 {
 392         Type *itype = NULL;
 393         int s;
 394
 395         dassert_decl(d, d->d_Op == DOP_TYPEDEF);
 396
 397         if ((s = StrTableSpecial(d->d_Id)) & SPECIALF_INTERNAL) {
 398                 switch(s) {
 399                 case SPECIAL_INTERNAL_VOID:
 400                         itype = &VoidType;
 401                         break;
 402                 case SPECIAL_INTERNAL_BOOL:
 403                         itype = &BoolType;
 404                         break;
 405                 case SPECIAL_INTERNAL_INT8:
 406                         itype = &Int8Type;
 407                         break;
 408                 case SPECIAL_INTERNAL_UINT8:
 409                         itype = &UInt8Type;
 410                         break;
 411                 case SPECIAL_INTERNAL_INT16:
 412                         itype = &Int16Type;
 413                         break;
 414                 case SPECIAL_INTERNAL_UINT16:
 415                         itype = &UInt16Type;
 416                         break;
 417                 case SPECIAL_INTERNAL_INT32:
 418                         itype = &Int32Type;
 419                         break;
 420                 case SPECIAL_INTERNAL_UINT32:
 421                         itype = &UInt32Type;
 422                         break;
 423                 case SPECIAL_INTERNAL_INT64:
 424                         itype = &Int64Type;
 425                         break;
 426                 case SPECIAL_INTERNAL_UINT64:
 427                         itype = &UInt64Type;
 428                         break;
 429
 430                 case SPECIAL_INTERNAL_FLOAT32:
 431                         itype = &Float32Type;
 432                         break;
 433                 case SPECIAL_INTERNAL_FLOAT64:
 434                         itype = &Float64Type;
 435                         break;
 436                 case SPECIAL_INTERNAL_FLOAT128:
 437                         itype = &Float128Type;
 438                         break;
 439
 440                 case SPECIAL_INTERNAL_INTPTR:
 441                         itype = &IntPtrType;
 442                         break;
 443                 case SPECIAL_INTERNAL_UINTPTR:
 444                         itype = &UIntPtrType;
 445                         break;
 446                 case SPECIAL_INTERNAL_OFF:
 447                         itype = &OffType;
 448                         break;
 449                 case SPECIAL_INTERNAL_SIZE:
 450                         itype = &SizeType;
 451                         break;
 452                 /* NOTE: There is no ssize_t in rune. size_t is signed */
 453
 454                 case SPECIAL_INTERNAL_POINTER:
 455                         itype = &PointerType;
 456                         break;
 457                 case SPECIAL_INTERNAL_NUMERIC:
 458                         itype = &NumericType;
 459                         break;
 460                 case SPECIAL_INTERNAL_INTEGRAL:
 461                         itype = &IntegralType;
 462                         break;
 463                 case SPECIAL_INTERNAL_SINTEGER:
 464                         itype = &SIntegerType;
 465                         break;
 466                 case SPECIAL_INTERNAL_UINTEGER:
 467                         itype = &UIntegerType;
 468                         break;
 469                 default:
 470                         itype = InternalRegisteredTypeLookup(d->d_Id);
 471                         if (itype == NULL)
 472                                 dassert(0);
 473                         break;
 474                 }
 475         }
 476         if (itype) {
 477                 if (itype->ty_Op != TY_UNRESOLVED) {
 478                         t = LexError(&p->p_Token, TOK_ERR_DUPLICATE_ATTACH);
 479                 } else {
 480                         Type *ntype = d->d_TypedefDecl.ed_Type;
 481
 482                         TypeToQualType(ntype, itype, ntype->ty_SQFlags, NULL);
 483                 }
 484         } else {
 485                 t = LexError(&p->p_Token, TOK_ERR_UNRECOGNIZED_ATTACH);
 486         }
 487         return(t);
 488 }
 489
 490 Type *
 491 AllocType(typelist_t *list, int op)
 492 {
 493         Type *type = zalloc(sizeof(Type));
 494
 495         initType(type, list, op);
 496         return(type);
 497 }
 498
 499 /*
 500  * XXX match the compound type(s)
 501  *
 502  * May be used to generate a varargs compound type, in which case the
 503  * semgroup may already be resolved.
 504  */
 505 Type *
 506 AllocCompoundType(SemGroup *sg)
 507 {
 508         Type *type;
 509
 510         type = AllocType(&CompoundTypeList, TY_COMPOUND);
 511         type->ty_CompType.et_SemGroup = sg;
 512         dassert((sg->sg_Flags & SGF_RESOLVED) == 0);
 513         return(type);
 514 }
 515
 516 /*
 517  * XXX match the compound type(s)
 518  */
 519 Type *
 520 AllocArgsType(SemGroup *sg)
 521 {
 522         Type *type;
 523
 524         type = AllocType(&ArgsTypeList, TY_ARGS);
 525         type->ty_ArgsType.et_SemGroup = sg;
 526         return(type);
 527 }
 528
 529 Type *
 530 AllocStorageType(runesize_t bytes)
 531 {
 532         Type *type;
 533
 534         RUNE_FOREACH(type, &StorageTypeList, ty_Node) {
 535                 if (type->ty_Op == TY_STORAGE &&
 536                         type->ty_StorType.et_Bytes == bytes
 537                 ) {
 538                         return(type);
 539                 }
 540         }
 541         type = AllocType(&StorageTypeList, TY_STORAGE);
 542         type->ty_StorType.et_Bytes = bytes;
 543         return(type);
 544 }
 545
 546 Type *
 547 AllocUnresolvedType(SemGroup *isg, SemGroup *sg, string_t *ary, int eatAry)
 548 {
 549         Type *type = NULL;
 550
 551         dassert_semgrp(sg, ary != NULL);
 552
 553         RUNE_FOREACH(type, &sg->sg_ClassList, ty_Node) {
 554                 int i;
 555
 556                 if (type->ty_Op != TY_UNRESOLVED)
 557                         continue;
 558                 if (type->ty_UnresType.et_ImportSemGroup != isg)
 559                         continue;
 560
 561                 for (i = 0; ary[i]; ++i) {
 562                         if (ary[i] != type->ty_UnresType.et_DottedId[i])
 563                                 break;
 564                 }
 565                 if (ary[i] == NULL &&
 566                     type->ty_UnresType.et_DottedId[i] == NULL) {
 567                         if (eatAry)
 568                                 FreeDotIdAry(ary);
 569                         return(type);
 570                 }
 571         }
 572         type = AllocType((sg ? &sg->sg_ClassList : NULL), TY_UNRESOLVED);
 573         type->ty_UnresType.et_DottedId = ary;
 574         type->ty_UnresType.et_SemGroup = sg;            /* may be NULL */
 575         type->ty_UnresType.et_ImportSemGroup = isg;     /* may be NULL */
 576         return(type);
 577 }
 578
 579 /*
 580  * AllocClassType() - allocate a type representing a the semgroup which
 581  *                      in turn represents (typically) a class.
 582  */
 583 Type *
 584 AllocClassType(typelist_t *list, Type *super, SemGroup *sg, int visibility)
 585 {
 586         Type *type;
 587
 588         dassert(sg != NULL);
 589         list = &sg->sg_ClassList;
 590
 591         RUNE_FOREACH(type, list, ty_Node) {
 592                 if (type->ty_Op == TY_CLASS &&
 593                     type->ty_ClassType.et_SemGroup == sg &&
 594                     type->ty_ClassType.et_Super == super &&
 595                     type->ty_Visibility == visibility
 596                 ) {
 597                         return(type);
 598                 }
 599         }
 600         if (sg)
 601                 dassert(&sg->sg_ClassList == list);
 602         type = AllocType(list, TY_CLASS);
 603         type->ty_ClassType.et_SemGroup = sg;
 604         type->ty_ClassType.et_Super = super;
 605         type->ty_Visibility = visibility;
 606         return(type);
 607 }
 608
 609 static
 610 void
 611 initInternalClassType(Type *type, Declaration *d)
 612 {
 613         SemGroup *sg = d->d_ClassDecl.ed_SemGroup;
 614
 615         initType(type, &sg->sg_ClassList, TY_CLASS);
 616         RUNE_REMOVE(&sg->sg_ClassList, type, ty_Node);
 617         RUNE_INSERT_HEAD(&sg->sg_ClassList, type, ty_Node);
 618         type->ty_ClassType.et_SemGroup = d->d_ClassDecl.ed_SemGroup;
 619         type->ty_ClassType.et_Super = d->d_ClassDecl.ed_Super;
 620         type->ty_Visibility = d->d_ScopeFlags & SCOPE_ALL_VISIBLE;
 621         type->ty_Flags |= TF_ISINTERNAL;
 622 }
 623
 624 Type *
 625 AllocImportType(typelist_t *list, SemGroup *sg, int visibility)
 626 {
 627         Type *type = AllocType(list, TY_IMPORT);
 628
 629         type->ty_ImportType.et_SemGroup = sg;
 630         type->ty_Visibility = visibility;
 631         return(type);
 632 }
 633
 634 /*
 635  * adjtype must be moved to type's QList because type is being modified
 636  * such that that is where it is expected to be.
 637  */
 638 Type *
 639 TypeAdjustQList(Type *type, Type *adjtype)
 640 {
 641         if (adjtype) {
 642                 if (adjtype->ty_SQList)
 643                         RUNE_REMOVE(adjtype->ty_SQList, adjtype, ty_Node);
 644                 adjtype->ty_SQList = &type->ty_QList;
 645                 RUNE_INSERT_TAIL(adjtype->ty_SQList, adjtype, ty_Node);
 646         }
 647         return type;
 648 }
 649
 650 Type *
 651 TypeToQualType(Type *otype, Type *ntype, int sqFlags, Exp *exp)
 652 {
 653         SemGroup *sg;
 654
 655         /*
 656          * Combine with existing qualifiers, Shortcut if no changes made.
 657          */
 658         if (ntype == NULL &&
 659             sqFlags == otype->ty_SQFlags &&
 660             (exp == NULL || exp == otype->ty_AssExp)
 661         ) {
 662                 return(otype);
 663         }
 664
 665         /*
 666          * See if we already have a matching qualified type (only if storage
 667          * for the new type is not being provided).  Note: the provided storage
 668          * has already been initType()d
 669          */
 670         if (ntype == NULL) {
 671                 RUNE_FOREACH(ntype, otype->ty_SQList, ty_Node) {
 672                         if (ntype->ty_Op == otype->ty_Op &&
 673                             ntype->ty_SQFlags == sqFlags &&
 674                             (exp == NULL || ntype->ty_AssExp == exp)
 675                         ) {
 676                                 if (SameType(ntype, otype, sqFlags))
 677                                         return(ntype);
 678                         }
 679                 }
 680         }
 681
 682         /*
 683          * Build a new qualified type and set its qualifiers, then duplicate
 684          * appropriate sections of the old type.
 685          *
 686          * Default to the same SQList as otype.
 687          */
 688         if (ntype == NULL) {
 689                 ntype = AllocType(otype->ty_SQList, otype->ty_Op);
 690         } else {
 691                 if (ntype->ty_SQList)
 692                         RUNE_REMOVE(ntype->ty_SQList, ntype, ty_Node);
 693                 ntype->ty_SQList = otype->ty_SQList;
 694                 RUNE_INSERT_TAIL(ntype->ty_SQList, ntype, ty_Node);
 695         }
 696
 697         /*
 698          * Set the op and the expression.  Unlike SQFlags, if exp is passed as
 699          * NULL we inherit the old type's default.
 700          *
 701          * The DupExp() call here is special, see DupExp()'s handling of
 702          * ex_Decl.
 703          *
 704          * Normally DupExp() is called during resolution prior to ex_Decl
 705          * being set.  This is the one case where it may be called with
 706          * ex_Decl already set.
 707          *
 708          * WARNING! We do not try to resolve the type here.  Various resolve
 709          *          related flags in ty_Flags will be resolved later.  This
 710          *          includes TF_ISUNSIGNED and other TF_* flags.
 711          */
 712         ntype->ty_Op = otype->ty_Op;
 713         if (exp)
 714                 ntype->ty_AssExp = exp;
 715         else if (otype->ty_AssExp)
 716                 ntype->ty_AssExp = SetDupExp(NULL, otype->ty_AssExp);
 717         ntype->ty_SQFlags = sqFlags;
 718         ntype->ty_Visibility = otype->ty_Visibility;
 719
 720         switch(otype->ty_Op) {
 721         case TY_CLASS:
 722                 /*
 723                  * When updating the class, alternative forms are collapsed
 724                  * into it's SemGroup->sg_ClassList and not into some
 725                  * potentially long recursive chain based on ty_QList.
 726                  */
 727                 sg = otype->ty_ClassType.et_SemGroup;
 728
 729                 dassert(ntype->ty_SQList == &sg->sg_ClassList);
 730                 if (ntype->ty_ClassType.et_SemGroup != sg) {
 731                         ntype->ty_ClassType.et_SemGroup = sg;
 732                 }
 733                 ntype->ty_ClassType.et_Super = otype->ty_ClassType.et_Super;
 734                 break;
 735         case TY_IMPORT:
 736                 ntype->ty_Visibility = otype->ty_Visibility;
 737                 ntype->ty_ImportType.et_SemGroup = otype->ty_ImportType.et_SemGroup;
 738                 break;
 739         case TY_CPTRTO:
 740                 ntype->ty_CPtrType.et_Type = otype->ty_CPtrType.et_Type;
 741                 break;
 742         case TY_PTRTO:
 743                 ntype->ty_PtrType.et_Type = otype->ty_PtrType.et_Type;
 744                 break;
 745         case TY_REFTO:
 746                 ntype->ty_RefType.et_Type = otype->ty_RefType.et_Type;
 747                 break;
 748         case TY_ARYOF:
 749                 /*
 750                  * note: multiple type structures may share the same array size
 751                  * expression in simple qualified-type cases.  YYY XXX bad bad.
 752                  */
 753                 ntype->ty_AryType.et_Type = otype->ty_AryType.et_Type;
 754                 ntype->ty_AryType.et_ArySize = otype->ty_AryType.et_ArySize;
 755                 ntype->ty_AryType.et_SemGroup = otype->ty_AryType.et_SemGroup;
 756                 break;
 757         case TY_COMPOUND:
 758                 ntype->ty_CompType.et_SemGroup = otype->ty_CompType.et_SemGroup;
 759                 break;
 760         case TY_VAR:
 761                 ntype->ty_VarType.et_Type = otype->ty_VarType.et_Type;
 762                 ntype->ty_VarType.et_SemGroup = otype->ty_VarType.et_SemGroup;
 763                 break;
 764         case TY_ARGS:
 765                 ntype->ty_ArgsType.et_SemGroup = otype->ty_ArgsType.et_SemGroup;
 766                 break;
 767         case TY_PROC:
 768                 ntype->ty_ProcType.et_ArgsType = otype->ty_ProcType.et_ArgsType;
 769                 ntype->ty_ProcType.et_RetType = otype->ty_ProcType.et_RetType;
 770                 ntype->ty_ProcType.et_ArgCount = otype->ty_ProcType.et_ArgCount;
 771                 dassert(ntype->ty_SQList ==
 772                         &otype->ty_ProcType.et_RetType->ty_QList);
 773                 break;
 774         case TY_STORAGE:
 775                 ntype->ty_StorType.et_Bytes = otype->ty_StorType.et_Bytes;
 776                 break;
 777         case TY_DYNAMIC:
 778                 /*
 779                  * It is not legal to qualify a dynamic type other then to
 780                  * add or remove SF_LVALUE.
 781                  */
 782                 dassert(0);
 783                 break;
 784         case TY_UNRESOLVED:
 785                 ntype->ty_UnresType.et_DottedId =
 786                         otype->ty_UnresType.et_DottedId;
 787                 ntype->ty_UnresType.et_SemGroup =
 788                         otype->ty_UnresType.et_SemGroup;
 789                 break;
 790         default:
 791                 dassert_type(otype, 0);
 792         }
 793         return(ntype);
 794 }
 795
 796 /*
 797  * XXX match the procedure type(s)
 798  */
 799 Type *
 800 TypeToProcType(Type *rtype, Type *atype)
 801 {
 802         Type *type;
 803         runesize_t count = 0;
 804         Declaration *d;
 805         SemGroup *sg;
 806
 807         dassert_type(atype, atype->ty_Op == TY_ARGS);
 808         sg = atype->ty_CompType.et_SemGroup;
 809
 810         RUNE_FOREACH(d, &sg->sg_DeclList, d_Node) {
 811                 ++count;
 812         }
 813         RUNE_FOREACH(type, &rtype->ty_QList, ty_Node) {
 814                 if (type->ty_Op == TY_PROC) {
 815                         if (type->ty_ProcType.et_ArgsType == atype &&
 816                             type->ty_ProcType.et_RetType == rtype &&
 817                             type->ty_ProcType.et_ArgCount == count
 818                         ) {
 819                                 puts("SG1"); /* YYY */
 820                                 return(type);
 821                         }
 822                 }
 823         }
 824         type = AllocType(&rtype->ty_QList, TY_PROC);
 825         type->ty_ProcType.et_ArgsType = AllocArgsType(sg);
 826         type->ty_ProcType.et_RetType = rtype;
 827         type->ty_ProcType.et_ArgCount = count;
 828         return(type);
 829 }
 830
 831 /*
 832  * Convert type to pointer-to-type
 833  */
 834 Type *
 835 TypeToPtrType(Type *otype)
 836 {
 837         Type *type;
 838
 839         RUNE_FOREACH(type, &otype->ty_QList, ty_Node) {
 840                 if (type->ty_Op == TY_PTRTO)
 841                         return(type);
 842         }
 843         type = AllocType(&otype->ty_QList, TY_PTRTO);
 844         type->ty_PtrType.et_Type = otype;
 845         return(type);
 846 }
 847
 848 /*
 849  * Convert type to pointer-to-type
 850  */
 851 Type *
 852 TypeToCPtrType(Type *otype)
 853 {
 854         Type *type;
 855
 856         RUNE_FOREACH(type, &otype->ty_QList, ty_Node) {
 857                 if (type->ty_Op == TY_CPTRTO)
 858                         return(type);
 859         }
 860         type = AllocType(&otype->ty_QList, TY_CPTRTO);
 861         type->ty_CPtrType.et_Type = otype;
 862         return(type);
 863 }
 864
 865 /*
 866  * Convert type to ref-to-type
 867  *
 868  *      A reference type is similar to a pointer type except that the
 869  *      resolver is not able to entirely know what it is pointing to.
 870  *      The reference type is a superclass, but the actual type is
 871  *      stored in the run-time structure.
 872  */
 873 Type *
 874 TypeToRefType(Type *otype)
 875 {
 876         Type *type;
 877
 878         RUNE_FOREACH(type, &otype->ty_QList, ty_Node) {
 879                 if (type->ty_Op == TY_REFTO)
 880                         return(type);
 881         }
 882         type = AllocType(&otype->ty_QList, TY_REFTO);
 883         type->ty_RefType.et_Type = otype;
 884         return(type);
 885 }
 886
 887 Type *
 888 TypeToAryType(Type *otype, Exp *exp, SemGroup *sg)
 889 {
 890         Type *type;
 891
 892         /*
 893          * XXX handle constant expression optimization for QList
 894          * XXX handle qualifiers
 895          */
 896         type = AllocType(&otype->ty_QList, TY_ARYOF);
 897         type->ty_AryType.et_ArySize = exp;
 898         type->ty_AryType.et_Type = DelTypeQual(otype, SF_MASK_ARY_INHERIT);
 899         type->ty_AryType.et_SemGroup = sg;
 900         type->ty_SQFlags |= otype->ty_SQFlags & SF_MASK_ARY_INHERIT;
 901         return(type);
 902 }
 903
 904 #if 0
 905
 906 Type *
 907 TypeToRunTimeAryType(Type *otype, int count)
 908 {
 909         Type *type;
 910         Type *t2 = DelTypeQual(otype, SF_MASK_ARY_INHERIT);
 911
 912         RUNE_FOREACH(type, &otype->ty_QList, ty_Node) {
 913                 if (type->ty_Op == TY_ARYOF &&
 914                         type->ty_AryType.et_Type == t2 &&
 915                         type->ty_AryType.et_Count == count &&
 916                         type->ty_SQFlags ==
 917                          (otype->ty_SQFlags & SF_MASK_ARY_INHERIT)
 918                 ) {
 919                         return(type);
 920                 }
 921         }
 922         type = AllocType(&otype->ty_QList, TY_ARYOF);
 923         type->ty_AryType.et_Count = count;
 924         type->ty_AryType.et_Type = t2;
 925         type->ty_SQFlags |= otype->ty_SQFlags & SF_MASK_ARY_INHERIT;
 926         return(type);
 927 }
 928
 929 #endif
 930
 931 Type *
 932 TypeToVarType(Type *otype, SemGroup *sg)
 933 {
 934         Type *type;
 935
 936         dassert(sg->sg_Flags & SGF_RESOLVED);
 937         dassert(otype->ty_Flags & TF_RESOLVED);
 938
 939         RUNE_FOREACH(type, &otype->ty_QList, ty_Node) {
 940                 if (type->ty_Op == TY_VAR &&
 941                     type->ty_VarType.et_Type == otype &&
 942                     type->ty_VarType.et_SemGroup == sg
 943                 ) {
 944                         puts("SG2"); /* YYY */
 945                         return(type);
 946                 }
 947         }
 948         type = AllocType(&otype->ty_QList, TY_VAR);
 949         type->ty_VarType.et_Type = otype;
 950         type->ty_VarType.et_SemGroup = sg;
 951 #if 0
 952         /* XXX doesn't work for var-args */
 953         if (sg->sg_Flags & SGF_RESOLVED) {
 954                 type->ty_Flags |= TF_RESOLVED;
 955                 type->ty_Bytes = sg->sg_Bytes;
 956                 type->ty_AlignMask = sg->sg_AlignMask;
 957         }
 958 #endif
 959         return(type);
 960 }
 961
 962 /*
 963  * ChangeType() - given pointer, C pointer, or array of something,
 964  *                return 'op' of something instead.
 965  */
 966 Type *
 967 ChangeType(Type *type, int op)
 968 {
 969         switch(type->ty_Op) {
 970         case TY_PTRTO:
 971                 switch(op) {
 972                 case TY_CPTRTO:
 973                         type = TypeToCPtrType(type->ty_PtrType.et_Type);
 974                         break;
 975                 case TY_ARYOF:
 976                         type = TypeToAryType(type->ty_PtrType.et_Type,
 977                                              NULL, NULL);
 978                         break;
 979                 default:
 980                         dassert(0);
 981                 }
 982                 break;
 983         case TY_CPTRTO:
 984                 switch(op) {
 985                 case TY_PTRTO:
 986                         type = TypeToPtrType(type->ty_CPtrType.et_Type);
 987                         break;
 988                 case TY_ARYOF:
 989                         type = TypeToAryType(type->ty_CPtrType.et_Type,
 990                                              NULL, NULL);
 991                         break;
 992                 default:
 993                         dassert(0);
 994                 }
 995                 break;
 996         case TY_ARYOF:
 997                 switch(op) {
 998                 case TY_PTRTO:
 999                         type = TypeToPtrType(type->ty_AryType.et_Type);
1000                         break;
1001                 case TY_CPTRTO:
1002                         type = TypeToCPtrType(type->ty_AryType.et_Type);
1003                         break;
1004                 default:
1005                         dassert(0);
1006                 }
1007                 break;
1008         default:
1009                 dassert(0);
1010         }
1011         return(type);
1012 }
1013
1014 /*
1015  * BaseType() - return base type
1016  *
1017  *      Traverse the type to locate the base type.  Store the base type
1018  *      in *ptype and return the SemGroup, or return NULL if the base type
1019  *      does not have a SemGroup.
1020  */
1021 SemGroup *
1022 BaseType(Type **ptype)
1023 {
1024         Type *type = *ptype;
1025
1026         for (;;) {
1027                 switch(type->ty_Op) {
1028                 case TY_CPTRTO:
1029                         type = type->ty_CPtrType.et_Type;
1030                         continue;
1031                 case TY_PTRTO:
1032                         type = type->ty_PtrType.et_Type;
1033                         continue;
1034                 case TY_REFTO:
1035                         type = type->ty_RefType.et_Type;
1036                         continue;
1037                 case TY_ARYOF:
1038                         type = type->ty_AryType.et_Type;
1039                         continue;
1040                 }
1041                 break;
1042         }
1043
1044         *ptype = type;
1045
1046         switch(type->ty_Op) {
1047         case TY_CLASS:
1048                 return(type->ty_ClassType.et_SemGroup);
1049         case TY_COMPOUND:
1050                 return(type->ty_CompType.et_SemGroup);
1051         case TY_ARGS:
1052                 return(type->ty_ArgsType.et_SemGroup);
1053         case TY_PROC:
1054         case TY_VAR:
1055         case TY_DYNAMIC:
1056         case TY_STORAGE:
1057                 return(NULL);
1058         case TY_UNRESOLVED:
1059         default:
1060                 dassert_type(type, 0);
1061                 return(NULL);   /* avoid compiler complaints */
1062         }
1063 }
1064
1065 /*
1066  * DupType()     - create a duplicate of a type, possibly in a new SemGroup.
1067  *
1068  *      This code is used when duplicating procedures and other elements
1069  *      when merging a superclass into a subclass.
1070  *
1071  *      If sg is NULL, stype is simply returned.  The case is used when we
1072  *      try to duplciate an expression with DupExp()... in that case we
1073  *      want to dup the expression tree but use the same types.
1074  */
1075 Type *
1076 DupType(SemGroup *sg, Type *stype)
1077 {
1078         Type *type = NULL;
1079
1080         if (sg == NULL)
1081                 return(stype);
1082
1083         /*
1084          * XXX type may be resolved if it is part of a varargs dup
1085          */
1086 #if 0
1087         dassert_type(stype,
1088                      (stype->ty_Flags & (TF_RESOLVED|TF_RESOLVING)) == 0);
1089 #endif
1090
1091         switch(stype->ty_Op) {
1092         case TY_CLASS:
1093                 /*
1094                  * This only occurs because the resolver has resolved an
1095                  * unresolved type on the original SemGroup.  We duplicate
1096                  * that on the new SemGroup.
1097                  */
1098                 type = AllocClassType(&sg->sg_ClassList,
1099                                       stype->ty_ClassType.et_Super,
1100                                       stype->ty_ClassType.et_SemGroup,
1101                                       stype->ty_Visibility);
1102                 break;
1103         case TY_IMPORT:
1104         case TY_DYNAMIC:
1105                 type = stype;
1106                 break;
1107         case TY_CPTRTO:
1108                 type = TypeToCPtrType(DupType(sg, stype->ty_CPtrType.et_Type));
1109                 break;
1110         case TY_PTRTO:
1111                 type = TypeToPtrType(DupType(sg, stype->ty_PtrType.et_Type));
1112                 break;
1113         case TY_REFTO:
1114                 type = TypeToRefType(DupType(sg, stype->ty_RefType.et_Type));
1115                 break;
1116         case TY_ARYOF:
1117                 type = TypeToAryType(DupType(sg, stype->ty_AryType.et_Type),
1118                                 SetDupExp(sg, stype->ty_AryType.et_ArySize),
1119                                 stype->ty_AryType.et_SemGroup);
1120                 break;
1121         case TY_VAR:
1122                 type = TypeToVarType(DupType(sg, stype->ty_VarType.et_Type),
1123                                 DupSemGroup(sg, NULL,
1124                                             stype->ty_VarType.et_SemGroup, 1));
1125                 break;
1126         case TY_COMPOUND:
1127                 type = AllocCompoundType(
1128                                 DupSemGroup(sg, NULL,
1129                                             stype->ty_CompType.et_SemGroup, 1));
1130                 break;
1131         case TY_ARGS:
1132                 /*
1133                  * At the moment we always formally duplicate the arguments
1134                  * so we can modify them for methods below.
1135                  */
1136                 type = AllocArgsType(
1137                                 DupSemGroup(sg, NULL,
1138                                             stype->ty_CompType.et_SemGroup, 1));
1139                 break;
1140         case TY_PROC:
1141                 type = DupType(sg, stype->ty_ProcType.et_RetType);
1142                 type = TypeToProcType(type,
1143                                       DupType(sg,
1144                                               stype->ty_ProcType.et_ArgsType));
1145
1146                 /*
1147                  * If this is a method procedure, we have to change the
1148                  * first argument to point at our new subclass.  It was
1149                  * previously pointing at our superclass.   XXX the
1150                  * programmer can override the argument.  If it isn't a
1151                  * reference we have to assert.
1152                  */
1153                 if (stype->ty_SQFlags & SF_METHOD) {
1154                         SemGroup *asg = type->ty_ProcType.et_ArgsType->ty_ArgsType.et_SemGroup;
1155                         Declaration *d = RUNE_FIRST(&asg->sg_DeclList);
1156                         Type *thisType = d->d_StorDecl.ed_Type;
1157
1158                         dassert_decl(d, d->d_Id == String_This &&
1159                                         d->d_Op == DOP_ARGS_STORAGE);
1160                         dassert_decl(d, sg->sg_Stmt->st_Op == ST_Class);
1161                         if (thisType->ty_Op == TY_CLASS) {
1162                                 /* XXX sg_ClassList? right sg? */
1163                                 /* XXX correct visibility? */
1164                                 if (d->d_Search == NULL) {
1165                                         d->d_Search = d->d_StorDecl.ed_Type->
1166                                                       ty_ClassType.et_SemGroup;
1167                                 }
1168                                 d->d_StorDecl.ed_Type =
1169                                         AllocClassType(&sg->sg_ClassList,
1170                                                        sg->sg_Stmt->st_ClassStmt.es_Super,
1171                                                        sg->sg_Stmt->st_MyGroup,
1172                                                        SCOPE_ALL_VISIBLE);
1173                         } else {
1174                                 dassert_decl(d, thisType->ty_Op == TY_REFTO);
1175                         }
1176                 } else if (stype->ty_SQFlags & SF_GMETHOD) {
1177                         SemGroup *asg;
1178                         Declaration *d;
1179
1180                         asg = type->ty_ProcType.et_ArgsType->
1181                                 ty_ArgsType.et_SemGroup;
1182                         d = RUNE_FIRST(&asg->sg_DeclList);
1183
1184                         dassert_decl(d, d->d_Id == String_This &&
1185                                      d->d_Op == DOP_TYPEDEF);
1186                         dassert_decl(d, sg->sg_Stmt->st_Op == ST_Class);
1187                         dassert_decl(d, d->d_TypedefDecl.ed_Type->ty_Op ==
1188                                         TY_CLASS);
1189                         /* XXX sg_ClassList? right sg? */
1190                         /* XXX correct visibility? */
1191                         if (d->d_Search == NULL) {
1192                                 d->d_Search = d->d_TypedefDecl.ed_Type->
1193                                                ty_ClassType.et_SemGroup;
1194                         }
1195                         d->d_TypedefDecl.ed_Type =
1196                                 AllocClassType(&sg->sg_ClassList,
1197                                                sg->sg_Stmt->st_ClassStmt.es_Super,
1198                                                sg->sg_Stmt->st_MyGroup,
1199                                                SCOPE_ALL_VISIBLE);
1200                 }
1201                 break;
1202         case TY_STORAGE:
1203                 type = stype;
1204                 break;
1205         case TY_UNRESOLVED:
1206                 /*
1207                  * e.g. so elements in a superclass will see refined elements
1208                  * in the subclass.  Note that the original import semgroup
1209                  * is left intact so the semantic search mechanism uses it
1210                  * when the base sg (typically a subclass) fails.
1211                  */
1212                 type = AllocUnresolvedType(
1213                                 stype->ty_UnresType.et_ImportSemGroup,
1214                                 sg,
1215                                 stype->ty_UnresType.et_DottedId,
1216                                 0);
1217                 break;
1218         default:
1219                 dassert_type(stype, 0);
1220         }
1221
1222         if (type != stype) {
1223                 type->ty_Flags = stype->ty_Flags & ~TF_ISINTERNAL;
1224                 type->ty_Bytes = stype->ty_Bytes;
1225                 type->ty_AlignMask = stype->ty_AlignMask;
1226                 type->ty_Visibility = stype->ty_Visibility;
1227         }
1228         if (stype->ty_AssExp || stype->ty_SQFlags != type->ty_SQFlags) {
1229                 type = TypeToQualType(type, NULL,
1230                                       stype->ty_SQFlags,
1231                                       SetDupExp(sg, stype->ty_AssExp));
1232         }
1233
1234         return(type);
1235 }
1236
1237 struct TypeRegNode;
1238 typedef RUNE_HEAD(typereglist, TypeRegNode) typereglist_t;
1239
1240 typedef struct TypeRegNode {
1241         RUNE_ENTRY(TypeRegNode) tr_Node;
1242         string_t        tr_Id;
1243         Type            *tr_Type;
1244 } TypeRegNode;
1245
1246 typereglist_t TypeRegList = RUNE_HEAD_INITIALIZER(TypeRegList);
1247
1248 void
1249 InternalRegisterType(const char *str, Type *type)
1250 {
1251         static int Special = SPECIALF_REGISTERED|SPECIALF_INTERNAL|1;
1252         TypeRegNode *tr;
1253
1254         dassert(Special & SPECIALF_MASK);
1255         tr = zalloc(sizeof(TypeRegNode));
1256         tr->tr_Id = StrTableAlloc(str, strlen(str), Special++);
1257         tr->tr_Type = type;
1258         RUNE_INSERT_TAIL(&TypeRegList, tr, tr_Node);
1259 }
1260
1261 Type *
1262 InternalRegisteredTypeLookup(string_t id)
1263 {
1264         TypeRegNode *tr;
1265
1266         RUNE_FOREACH(tr, &TypeRegList, tr_Node) {
1267                 if (tr->tr_Id == id)
1268                         return(tr->tr_Type);
1269         }
1270         return(NULL);
1271 }