CodeGenTypes.cpp revision 202379
1//===--- CodeGenTypes.cpp - Type translation for LLVM CodeGen -------------===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// This is the code that handles AST -> LLVM type lowering. 11// 12//===----------------------------------------------------------------------===// 13 14#include "CodeGenTypes.h" 15#include "clang/AST/ASTContext.h" 16#include "clang/AST/DeclObjC.h" 17#include "clang/AST/DeclCXX.h" 18#include "clang/AST/Expr.h" 19#include "clang/AST/RecordLayout.h" 20#include "llvm/DerivedTypes.h" 21#include "llvm/Module.h" 22#include "llvm/Target/TargetData.h" 23 24#include "CGCall.h" 25#include "CGRecordLayoutBuilder.h" 26 27using namespace clang; 28using namespace CodeGen; 29 30CodeGenTypes::CodeGenTypes(ASTContext &Ctx, llvm::Module& M, 31 const llvm::TargetData &TD, const ABIInfo &Info) 32 : Context(Ctx), Target(Ctx.Target), TheModule(M), TheTargetData(TD), 33 TheABIInfo(Info) { 34} 35 36CodeGenTypes::~CodeGenTypes() { 37 for (llvm::DenseMap<const Type *, CGRecordLayout *>::iterator 38 I = CGRecordLayouts.begin(), E = CGRecordLayouts.end(); 39 I != E; ++I) 40 delete I->second; 41 42 for (llvm::FoldingSet<CGFunctionInfo>::iterator 43 I = FunctionInfos.begin(), E = FunctionInfos.end(); I != E; ) 44 delete &*I++; 45} 46 47/// ConvertType - Convert the specified type to its LLVM form. 48const llvm::Type *CodeGenTypes::ConvertType(QualType T) { 49 llvm::PATypeHolder Result = ConvertTypeRecursive(T); 50 51 // Any pointers that were converted defered evaluation of their pointee type, 52 // creating an opaque type instead. This is in order to avoid problems with 53 // circular types. Loop through all these defered pointees, if any, and 54 // resolve them now. 55 while (!PointersToResolve.empty()) { 56 std::pair<QualType, llvm::OpaqueType*> P = PointersToResolve.pop_back_val(); 57 58 // We can handle bare pointers here because we know that the only pointers 59 // to the Opaque type are P.second and from other types. Refining the 60 // opqaue type away will invalidate P.second, but we don't mind :). 61 const llvm::Type *NT = ConvertTypeForMemRecursive(P.first); 62 P.second->refineAbstractTypeTo(NT); 63 } 64 65 return Result; 66} 67 68const llvm::Type *CodeGenTypes::ConvertTypeRecursive(QualType T) { 69 T = Context.getCanonicalType(T); 70 71 // See if type is already cached. 72 llvm::DenseMap<Type *, llvm::PATypeHolder>::iterator 73 I = TypeCache.find(T.getTypePtr()); 74 // If type is found in map and this is not a definition for a opaque 75 // place holder type then use it. Otherwise, convert type T. 76 if (I != TypeCache.end()) 77 return I->second.get(); 78 79 const llvm::Type *ResultType = ConvertNewType(T); 80 TypeCache.insert(std::make_pair(T.getTypePtr(), 81 llvm::PATypeHolder(ResultType))); 82 return ResultType; 83} 84 85const llvm::Type *CodeGenTypes::ConvertTypeForMemRecursive(QualType T) { 86 const llvm::Type *ResultType = ConvertTypeRecursive(T); 87 if (ResultType->isInteger(1)) 88 return llvm::IntegerType::get(getLLVMContext(), 89 (unsigned)Context.getTypeSize(T)); 90 // FIXME: Should assert that the llvm type and AST type has the same size. 91 return ResultType; 92} 93 94/// ConvertTypeForMem - Convert type T into a llvm::Type. This differs from 95/// ConvertType in that it is used to convert to the memory representation for 96/// a type. For example, the scalar representation for _Bool is i1, but the 97/// memory representation is usually i8 or i32, depending on the target. 98const llvm::Type *CodeGenTypes::ConvertTypeForMem(QualType T) { 99 const llvm::Type *R = ConvertType(T); 100 101 // If this is a non-bool type, don't map it. 102 if (!R->isInteger(1)) 103 return R; 104 105 // Otherwise, return an integer of the target-specified size. 106 return llvm::IntegerType::get(getLLVMContext(), 107 (unsigned)Context.getTypeSize(T)); 108 109} 110 111// Code to verify a given function type is complete, i.e. the return type 112// and all of the argument types are complete. 113static const TagType *VerifyFuncTypeComplete(const Type* T) { 114 const FunctionType *FT = cast<FunctionType>(T); 115 if (const TagType* TT = FT->getResultType()->getAs<TagType>()) 116 if (!TT->getDecl()->isDefinition()) 117 return TT; 118 if (const FunctionProtoType *FPT = dyn_cast<FunctionProtoType>(T)) 119 for (unsigned i = 0; i < FPT->getNumArgs(); i++) 120 if (const TagType* TT = FPT->getArgType(i)->getAs<TagType>()) 121 if (!TT->getDecl()->isDefinition()) 122 return TT; 123 return 0; 124} 125 126/// UpdateCompletedType - When we find the full definition for a TagDecl, 127/// replace the 'opaque' type we previously made for it if applicable. 128void CodeGenTypes::UpdateCompletedType(const TagDecl *TD) { 129 const Type *Key = Context.getTagDeclType(TD).getTypePtr(); 130 llvm::DenseMap<const Type*, llvm::PATypeHolder>::iterator TDTI = 131 TagDeclTypes.find(Key); 132 if (TDTI == TagDeclTypes.end()) return; 133 134 // Remember the opaque LLVM type for this tagdecl. 135 llvm::PATypeHolder OpaqueHolder = TDTI->second; 136 assert(isa<llvm::OpaqueType>(OpaqueHolder.get()) && 137 "Updating compilation of an already non-opaque type?"); 138 139 // Remove it from TagDeclTypes so that it will be regenerated. 140 TagDeclTypes.erase(TDTI); 141 142 // Generate the new type. 143 const llvm::Type *NT = ConvertTagDeclType(TD); 144 145 // Refine the old opaque type to its new definition. 146 cast<llvm::OpaqueType>(OpaqueHolder.get())->refineAbstractTypeTo(NT); 147 148 // Since we just completed a tag type, check to see if any function types 149 // were completed along with the tag type. 150 // FIXME: This is very inefficient; if we track which function types depend 151 // on which tag types, though, it should be reasonably efficient. 152 llvm::DenseMap<const Type*, llvm::PATypeHolder>::iterator i; 153 for (i = FunctionTypes.begin(); i != FunctionTypes.end(); ++i) { 154 if (const TagType* TT = VerifyFuncTypeComplete(i->first)) { 155 // This function type still depends on an incomplete tag type; make sure 156 // that tag type has an associated opaque type. 157 ConvertTagDeclType(TT->getDecl()); 158 } else { 159 // This function no longer depends on an incomplete tag type; create the 160 // function type, and refine the opaque type to the new function type. 161 llvm::PATypeHolder OpaqueHolder = i->second; 162 const llvm::Type *NFT = ConvertNewType(QualType(i->first, 0)); 163 cast<llvm::OpaqueType>(OpaqueHolder.get())->refineAbstractTypeTo(NFT); 164 FunctionTypes.erase(i); 165 } 166 } 167} 168 169static const llvm::Type* getTypeForFormat(llvm::LLVMContext &VMContext, 170 const llvm::fltSemantics &format) { 171 if (&format == &llvm::APFloat::IEEEsingle) 172 return llvm::Type::getFloatTy(VMContext); 173 if (&format == &llvm::APFloat::IEEEdouble) 174 return llvm::Type::getDoubleTy(VMContext); 175 if (&format == &llvm::APFloat::IEEEquad) 176 return llvm::Type::getFP128Ty(VMContext); 177 if (&format == &llvm::APFloat::PPCDoubleDouble) 178 return llvm::Type::getPPC_FP128Ty(VMContext); 179 if (&format == &llvm::APFloat::x87DoubleExtended) 180 return llvm::Type::getX86_FP80Ty(VMContext); 181 assert(0 && "Unknown float format!"); 182 return 0; 183} 184 185const llvm::Type *CodeGenTypes::ConvertNewType(QualType T) { 186 const clang::Type &Ty = *Context.getCanonicalType(T).getTypePtr(); 187 188 switch (Ty.getTypeClass()) { 189#define TYPE(Class, Base) 190#define ABSTRACT_TYPE(Class, Base) 191#define NON_CANONICAL_TYPE(Class, Base) case Type::Class: 192#define DEPENDENT_TYPE(Class, Base) case Type::Class: 193#include "clang/AST/TypeNodes.def" 194 assert(false && "Non-canonical or dependent types aren't possible."); 195 break; 196 197 case Type::Builtin: { 198 switch (cast<BuiltinType>(Ty).getKind()) { 199 case BuiltinType::Void: 200 case BuiltinType::ObjCId: 201 case BuiltinType::ObjCClass: 202 case BuiltinType::ObjCSel: 203 // LLVM void type can only be used as the result of a function call. Just 204 // map to the same as char. 205 return llvm::IntegerType::get(getLLVMContext(), 8); 206 207 case BuiltinType::Bool: 208 // Note that we always return bool as i1 for use as a scalar type. 209 return llvm::Type::getInt1Ty(getLLVMContext()); 210 211 case BuiltinType::Char_S: 212 case BuiltinType::Char_U: 213 case BuiltinType::SChar: 214 case BuiltinType::UChar: 215 case BuiltinType::Short: 216 case BuiltinType::UShort: 217 case BuiltinType::Int: 218 case BuiltinType::UInt: 219 case BuiltinType::Long: 220 case BuiltinType::ULong: 221 case BuiltinType::LongLong: 222 case BuiltinType::ULongLong: 223 case BuiltinType::WChar: 224 case BuiltinType::Char16: 225 case BuiltinType::Char32: 226 return llvm::IntegerType::get(getLLVMContext(), 227 static_cast<unsigned>(Context.getTypeSize(T))); 228 229 case BuiltinType::Float: 230 case BuiltinType::Double: 231 case BuiltinType::LongDouble: 232 return getTypeForFormat(getLLVMContext(), 233 Context.getFloatTypeSemantics(T)); 234 235 case BuiltinType::NullPtr: { 236 // Model std::nullptr_t as i8* 237 const llvm::Type *Ty = llvm::IntegerType::get(getLLVMContext(), 8); 238 return llvm::PointerType::getUnqual(Ty); 239 } 240 241 case BuiltinType::UInt128: 242 case BuiltinType::Int128: 243 return llvm::IntegerType::get(getLLVMContext(), 128); 244 245 case BuiltinType::Overload: 246 case BuiltinType::Dependent: 247 case BuiltinType::UndeducedAuto: 248 assert(0 && "Unexpected builtin type!"); 249 break; 250 } 251 assert(0 && "Unknown builtin type!"); 252 break; 253 } 254 case Type::Complex: { 255 const llvm::Type *EltTy = 256 ConvertTypeRecursive(cast<ComplexType>(Ty).getElementType()); 257 return llvm::StructType::get(TheModule.getContext(), EltTy, EltTy, NULL); 258 } 259 case Type::LValueReference: 260 case Type::RValueReference: { 261 const ReferenceType &RTy = cast<ReferenceType>(Ty); 262 QualType ETy = RTy.getPointeeType(); 263 llvm::OpaqueType *PointeeType = llvm::OpaqueType::get(getLLVMContext()); 264 PointersToResolve.push_back(std::make_pair(ETy, PointeeType)); 265 return llvm::PointerType::get(PointeeType, ETy.getAddressSpace()); 266 } 267 case Type::Pointer: { 268 const PointerType &PTy = cast<PointerType>(Ty); 269 QualType ETy = PTy.getPointeeType(); 270 llvm::OpaqueType *PointeeType = llvm::OpaqueType::get(getLLVMContext()); 271 PointersToResolve.push_back(std::make_pair(ETy, PointeeType)); 272 return llvm::PointerType::get(PointeeType, ETy.getAddressSpace()); 273 } 274 275 case Type::VariableArray: { 276 const VariableArrayType &A = cast<VariableArrayType>(Ty); 277 assert(A.getIndexTypeCVRQualifiers() == 0 && 278 "FIXME: We only handle trivial array types so far!"); 279 // VLAs resolve to the innermost element type; this matches 280 // the return of alloca, and there isn't any obviously better choice. 281 return ConvertTypeForMemRecursive(A.getElementType()); 282 } 283 case Type::IncompleteArray: { 284 const IncompleteArrayType &A = cast<IncompleteArrayType>(Ty); 285 assert(A.getIndexTypeCVRQualifiers() == 0 && 286 "FIXME: We only handle trivial array types so far!"); 287 // int X[] -> [0 x int] 288 return llvm::ArrayType::get(ConvertTypeForMemRecursive(A.getElementType()), 0); 289 } 290 case Type::ConstantArray: { 291 const ConstantArrayType &A = cast<ConstantArrayType>(Ty); 292 const llvm::Type *EltTy = ConvertTypeForMemRecursive(A.getElementType()); 293 return llvm::ArrayType::get(EltTy, A.getSize().getZExtValue()); 294 } 295 case Type::ExtVector: 296 case Type::Vector: { 297 const VectorType &VT = cast<VectorType>(Ty); 298 return llvm::VectorType::get(ConvertTypeRecursive(VT.getElementType()), 299 VT.getNumElements()); 300 } 301 case Type::FunctionNoProto: 302 case Type::FunctionProto: { 303 // First, check whether we can build the full function type. 304 if (const TagType* TT = VerifyFuncTypeComplete(&Ty)) { 305 // This function's type depends on an incomplete tag type; make sure 306 // we have an opaque type corresponding to the tag type. 307 ConvertTagDeclType(TT->getDecl()); 308 // Create an opaque type for this function type, save it, and return it. 309 llvm::Type *ResultType = llvm::OpaqueType::get(getLLVMContext()); 310 FunctionTypes.insert(std::make_pair(&Ty, ResultType)); 311 return ResultType; 312 } 313 // The function type can be built; call the appropriate routines to 314 // build it. 315 if (const FunctionProtoType *FPT = dyn_cast<FunctionProtoType>(&Ty)) 316 return GetFunctionType(getFunctionInfo(FPT), FPT->isVariadic()); 317 318 const FunctionNoProtoType *FNPT = cast<FunctionNoProtoType>(&Ty); 319 return GetFunctionType(getFunctionInfo(FNPT), true); 320 } 321 322 case Type::ObjCInterface: { 323 // Objective-C interfaces are always opaque (outside of the 324 // runtime, which can do whatever it likes); we never refine 325 // these. 326 const llvm::Type *&T = InterfaceTypes[cast<ObjCInterfaceType>(&Ty)]; 327 if (!T) 328 T = llvm::OpaqueType::get(getLLVMContext()); 329 return T; 330 } 331 332 case Type::ObjCObjectPointer: { 333 // Protocol qualifications do not influence the LLVM type, we just return a 334 // pointer to the underlying interface type. We don't need to worry about 335 // recursive conversion. 336 const llvm::Type *T = 337 ConvertTypeRecursive(cast<ObjCObjectPointerType>(Ty).getPointeeType()); 338 return llvm::PointerType::getUnqual(T); 339 } 340 341 case Type::Record: 342 case Type::Enum: { 343 const TagDecl *TD = cast<TagType>(Ty).getDecl(); 344 const llvm::Type *Res = ConvertTagDeclType(TD); 345 346 std::string TypeName(TD->getKindName()); 347 TypeName += '.'; 348 349 // Name the codegen type after the typedef name 350 // if there is no tag type name available 351 if (TD->getIdentifier()) 352 // FIXME: We should not have to check for a null decl context here. 353 // Right now we do it because the implicit Obj-C decls don't have one. 354 TypeName += TD->getDeclContext() ? TD->getQualifiedNameAsString() : 355 TD->getNameAsString(); 356 else if (const TypedefType *TdT = dyn_cast<TypedefType>(T)) 357 // FIXME: We should not have to check for a null decl context here. 358 // Right now we do it because the implicit Obj-C decls don't have one. 359 TypeName += TdT->getDecl()->getDeclContext() ? 360 TdT->getDecl()->getQualifiedNameAsString() : 361 TdT->getDecl()->getNameAsString(); 362 else 363 TypeName += "anon"; 364 365 TheModule.addTypeName(TypeName, Res); 366 return Res; 367 } 368 369 case Type::BlockPointer: { 370 const QualType FTy = cast<BlockPointerType>(Ty).getPointeeType(); 371 llvm::OpaqueType *PointeeType = llvm::OpaqueType::get(getLLVMContext()); 372 PointersToResolve.push_back(std::make_pair(FTy, PointeeType)); 373 return llvm::PointerType::get(PointeeType, FTy.getAddressSpace()); 374 } 375 376 case Type::MemberPointer: { 377 // FIXME: This is ABI dependent. We use the Itanium C++ ABI. 378 // http://www.codesourcery.com/public/cxx-abi/abi.html#member-pointers 379 // If we ever want to support other ABIs this needs to be abstracted. 380 381 QualType ETy = cast<MemberPointerType>(Ty).getPointeeType(); 382 const llvm::Type *PtrDiffTy = 383 ConvertTypeRecursive(Context.getPointerDiffType()); 384 if (ETy->isFunctionType()) 385 return llvm::StructType::get(TheModule.getContext(), PtrDiffTy, PtrDiffTy, 386 NULL); 387 return PtrDiffTy; 388 } 389 390 case Type::TemplateSpecialization: 391 assert(false && "Dependent types can't get here"); 392 } 393 394 // FIXME: implement. 395 return llvm::OpaqueType::get(getLLVMContext()); 396} 397 398/// ConvertTagDeclType - Lay out a tagged decl type like struct or union or 399/// enum. 400const llvm::Type *CodeGenTypes::ConvertTagDeclType(const TagDecl *TD) { 401 402 // FIXME. This may have to move to a better place. 403 if (const CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(TD)) { 404 for (CXXRecordDecl::base_class_const_iterator i = RD->bases_begin(), 405 e = RD->bases_end(); i != e; ++i) { 406 if (!i->isVirtual()) { 407 const CXXRecordDecl *Base = 408 cast<CXXRecordDecl>(i->getType()->getAs<RecordType>()->getDecl()); 409 ConvertTagDeclType(Base); 410 } 411 } 412 } 413 414 // TagDecl's are not necessarily unique, instead use the (clang) 415 // type connected to the decl. 416 const Type *Key = 417 Context.getTagDeclType(TD).getTypePtr(); 418 llvm::DenseMap<const Type*, llvm::PATypeHolder>::iterator TDTI = 419 TagDeclTypes.find(Key); 420 421 // If we've already compiled this tag type, use the previous definition. 422 if (TDTI != TagDeclTypes.end()) 423 return TDTI->second; 424 425 // If this is still a forward definition, just define an opaque type to use 426 // for this tagged decl. 427 if (!TD->isDefinition()) { 428 llvm::Type *ResultType = llvm::OpaqueType::get(getLLVMContext()); 429 TagDeclTypes.insert(std::make_pair(Key, ResultType)); 430 return ResultType; 431 } 432 433 // Okay, this is a definition of a type. Compile the implementation now. 434 435 if (TD->isEnum()) // Don't bother storing enums in TagDeclTypes. 436 return ConvertTypeRecursive(cast<EnumDecl>(TD)->getIntegerType()); 437 438 // This decl could well be recursive. In this case, insert an opaque 439 // definition of this type, which the recursive uses will get. We will then 440 // refine this opaque version later. 441 442 // Create new OpaqueType now for later use in case this is a recursive 443 // type. This will later be refined to the actual type. 444 llvm::PATypeHolder ResultHolder = llvm::OpaqueType::get(getLLVMContext()); 445 TagDeclTypes.insert(std::make_pair(Key, ResultHolder)); 446 447 const RecordDecl *RD = cast<const RecordDecl>(TD); 448 449 // Layout fields. 450 CGRecordLayout *Layout = CGRecordLayoutBuilder::ComputeLayout(*this, RD); 451 452 CGRecordLayouts[Key] = Layout; 453 const llvm::Type *ResultType = Layout->getLLVMType(); 454 455 // Refine our Opaque type to ResultType. This can invalidate ResultType, so 456 // make sure to read the result out of the holder. 457 cast<llvm::OpaqueType>(ResultHolder.get()) 458 ->refineAbstractTypeTo(ResultType); 459 460 return ResultHolder.get(); 461} 462 463/// getLLVMFieldNo - Return llvm::StructType element number 464/// that corresponds to the field FD. 465unsigned CodeGenTypes::getLLVMFieldNo(const FieldDecl *FD) { 466 assert(!FD->isBitField() && "Don't use getLLVMFieldNo on bit fields!"); 467 468 llvm::DenseMap<const FieldDecl*, unsigned>::iterator I = FieldInfo.find(FD); 469 assert (I != FieldInfo.end() && "Unable to find field info"); 470 return I->second; 471} 472 473/// addFieldInfo - Assign field number to field FD. 474void CodeGenTypes::addFieldInfo(const FieldDecl *FD, unsigned No) { 475 FieldInfo[FD] = No; 476} 477 478/// getBitFieldInfo - Return the BitFieldInfo that corresponds to the field FD. 479CodeGenTypes::BitFieldInfo CodeGenTypes::getBitFieldInfo(const FieldDecl *FD) { 480 llvm::DenseMap<const FieldDecl *, BitFieldInfo>::iterator 481 I = BitFields.find(FD); 482 assert (I != BitFields.end() && "Unable to find bitfield info"); 483 return I->second; 484} 485 486/// addBitFieldInfo - Assign a start bit and a size to field FD. 487void CodeGenTypes::addBitFieldInfo(const FieldDecl *FD, unsigned FieldNo, 488 unsigned Start, unsigned Size) { 489 BitFields.insert(std::make_pair(FD, BitFieldInfo(FieldNo, Start, Size))); 490} 491 492/// getCGRecordLayout - Return record layout info for the given llvm::Type. 493const CGRecordLayout & 494CodeGenTypes::getCGRecordLayout(const TagDecl *TD) const { 495 const Type *Key = Context.getTagDeclType(TD).getTypePtr(); 496 llvm::DenseMap<const Type*, CGRecordLayout *>::const_iterator I 497 = CGRecordLayouts.find(Key); 498 assert (I != CGRecordLayouts.end() 499 && "Unable to find record layout information for type"); 500 return *I->second; 501} 502