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Diffstat (limited to 'include/llvm/Type.h')
-rw-r--r-- | include/llvm/Type.h | 467 |
1 files changed, 467 insertions, 0 deletions
diff --git a/include/llvm/Type.h b/include/llvm/Type.h new file mode 100644 index 0000000000000..5ce23ef4e4b75 --- /dev/null +++ b/include/llvm/Type.h @@ -0,0 +1,467 @@ +//===-- llvm/Type.h - Classes for handling data types -----------*- C++ -*-===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// + + +#ifndef LLVM_TYPE_H +#define LLVM_TYPE_H + +#include "llvm/AbstractTypeUser.h" +#include "llvm/Support/Casting.h" +#include "llvm/Support/DataTypes.h" +#include "llvm/ADT/GraphTraits.h" +#include "llvm/ADT/iterator.h" +#include <string> +#include <vector> + +namespace llvm { + +class DerivedType; +class PointerType; +class IntegerType; +class TypeMapBase; +class raw_ostream; +class Module; + +/// This file contains the declaration of the Type class. For more "Type" type +/// stuff, look in DerivedTypes.h. +/// +/// The instances of the Type class are immutable: once they are created, +/// they are never changed. Also note that only one instance of a particular +/// type is ever created. Thus seeing if two types are equal is a matter of +/// doing a trivial pointer comparison. To enforce that no two equal instances +/// are created, Type instances can only be created via static factory methods +/// in class Type and in derived classes. +/// +/// Once allocated, Types are never free'd, unless they are an abstract type +/// that is resolved to a more concrete type. +/// +/// Types themself don't have a name, and can be named either by: +/// - using SymbolTable instance, typically from some Module, +/// - using convenience methods in the Module class (which uses module's +/// SymbolTable too). +/// +/// Opaque types are simple derived types with no state. There may be many +/// different Opaque type objects floating around, but two are only considered +/// identical if they are pointer equals of each other. This allows us to have +/// two opaque types that end up resolving to different concrete types later. +/// +/// Opaque types are also kinda weird and scary and different because they have +/// to keep a list of uses of the type. When, through linking, parsing, or +/// bitcode reading, they become resolved, they need to find and update all +/// users of the unknown type, causing them to reference a new, more concrete +/// type. Opaque types are deleted when their use list dwindles to zero users. +/// +/// @brief Root of type hierarchy +class Type : public AbstractTypeUser { +public: + //===-------------------------------------------------------------------===// + /// Definitions of all of the base types for the Type system. Based on this + /// value, you can cast to a "DerivedType" subclass (see DerivedTypes.h) + /// Note: If you add an element to this, you need to add an element to the + /// Type::getPrimitiveType function, or else things will break! + /// + enum TypeID { + // PrimitiveTypes .. make sure LastPrimitiveTyID stays up to date + VoidTyID = 0, ///< 0: type with no size + FloatTyID, ///< 1: 32 bit floating point type + DoubleTyID, ///< 2: 64 bit floating point type + X86_FP80TyID, ///< 3: 80 bit floating point type (X87) + FP128TyID, ///< 4: 128 bit floating point type (112-bit mantissa) + PPC_FP128TyID, ///< 5: 128 bit floating point type (two 64-bits) + LabelTyID, ///< 6: Labels + MetadataTyID, ///< 7: Metadata + + // Derived types... see DerivedTypes.h file... + // Make sure FirstDerivedTyID stays up to date!!! + IntegerTyID, ///< 8: Arbitrary bit width integers + FunctionTyID, ///< 9: Functions + StructTyID, ///< 10: Structures + ArrayTyID, ///< 11: Arrays + PointerTyID, ///< 12: Pointers + OpaqueTyID, ///< 13: Opaque: type with unknown structure + VectorTyID, ///< 14: SIMD 'packed' format, or other vector type + + NumTypeIDs, // Must remain as last defined ID + LastPrimitiveTyID = LabelTyID, + FirstDerivedTyID = IntegerTyID + }; + +private: + TypeID ID : 8; // The current base type of this type. + bool Abstract : 1; // True if type contains an OpaqueType + unsigned SubclassData : 23; //Space for subclasses to store data + + /// RefCount - This counts the number of PATypeHolders that are pointing to + /// this type. When this number falls to zero, if the type is abstract and + /// has no AbstractTypeUsers, the type is deleted. This is only sensical for + /// derived types. + /// + mutable unsigned RefCount; + + const Type *getForwardedTypeInternal() const; + + // Some Type instances are allocated as arrays, some aren't. So we provide + // this method to get the right kind of destruction for the type of Type. + void destroy() const; // const is a lie, this does "delete this"! + +protected: + explicit Type(TypeID id) : ID(id), Abstract(false), SubclassData(0), + RefCount(0), ForwardType(0), NumContainedTys(0), + ContainedTys(0) {} + virtual ~Type() { + assert(AbstractTypeUsers.empty() && "Abstract types remain"); + } + + /// Types can become nonabstract later, if they are refined. + /// + inline void setAbstract(bool Val) { Abstract = Val; } + + unsigned getRefCount() const { return RefCount; } + + unsigned getSubclassData() const { return SubclassData; } + void setSubclassData(unsigned val) { SubclassData = val; } + + /// ForwardType - This field is used to implement the union find scheme for + /// abstract types. When types are refined to other types, this field is set + /// to the more refined type. Only abstract types can be forwarded. + mutable const Type *ForwardType; + + + /// AbstractTypeUsers - Implement a list of the users that need to be notified + /// if I am a type, and I get resolved into a more concrete type. + /// + mutable std::vector<AbstractTypeUser *> AbstractTypeUsers; + + /// NumContainedTys - Keeps track of how many PATypeHandle instances there + /// are at the end of this type instance for the list of contained types. It + /// is the subclasses responsibility to set this up. Set to 0 if there are no + /// contained types in this type. + unsigned NumContainedTys; + + /// ContainedTys - A pointer to the array of Types (PATypeHandle) contained + /// by this Type. For example, this includes the arguments of a function + /// type, the elements of a structure, the pointee of a pointer, the element + /// type of an array, etc. This pointer may be 0 for types that don't + /// contain other types (Integer, Double, Float). In general, the subclass + /// should arrange for space for the PATypeHandles to be included in the + /// allocation of the type object and set this pointer to the address of the + /// first element. This allows the Type class to manipulate the ContainedTys + /// without understanding the subclass's placement for this array. keeping + /// it here also allows the subtype_* members to be implemented MUCH more + /// efficiently, and dynamically very few types do not contain any elements. + PATypeHandle *ContainedTys; + +public: + void print(raw_ostream &O) const; + void print(std::ostream &O) const; + + /// @brief Debugging support: print to stderr + void dump() const; + + /// @brief Debugging support: print to stderr (use type names from context + /// module). + void dump(const Module *Context) const; + + //===--------------------------------------------------------------------===// + // Property accessors for dealing with types... Some of these virtual methods + // are defined in private classes defined in Type.cpp for primitive types. + // + + /// getTypeID - Return the type id for the type. This will return one + /// of the TypeID enum elements defined above. + /// + inline TypeID getTypeID() const { return ID; } + + /// getDescription - Return the string representation of the type. + std::string getDescription() const; + + /// isInteger - True if this is an instance of IntegerType. + /// + bool isInteger() const { return ID == IntegerTyID; } + + /// isIntOrIntVector - Return true if this is an integer type or a vector of + /// integer types. + /// + bool isIntOrIntVector() const; + + /// isFloatingPoint - Return true if this is one of the two floating point + /// types + bool isFloatingPoint() const { return ID == FloatTyID || ID == DoubleTyID || + ID == X86_FP80TyID || ID == FP128TyID || ID == PPC_FP128TyID; } + + /// isFPOrFPVector - Return true if this is a FP type or a vector of FP types. + /// + bool isFPOrFPVector() const; + + /// isAbstract - True if the type is either an Opaque type, or is a derived + /// type that includes an opaque type somewhere in it. + /// + inline bool isAbstract() const { return Abstract; } + + /// canLosslesslyBitCastTo - Return true if this type could be converted + /// with a lossless BitCast to type 'Ty'. For example, uint to int. BitCasts + /// are valid for types of the same size only where no re-interpretation of + /// the bits is done. + /// @brief Determine if this type could be losslessly bitcast to Ty + bool canLosslesslyBitCastTo(const Type *Ty) const; + + + /// Here are some useful little methods to query what type derived types are + /// Note that all other types can just compare to see if this == Type::xxxTy; + /// + inline bool isPrimitiveType() const { return ID <= LastPrimitiveTyID; } + inline bool isDerivedType() const { return ID >= FirstDerivedTyID; } + + /// isFirstClassType - Return true if the type is "first class", meaning it + /// is a valid type for a Value. + /// + inline bool isFirstClassType() const { + // There are more first-class kinds than non-first-class kinds, so a + // negative test is simpler than a positive one. + return ID != FunctionTyID && ID != VoidTyID && ID != OpaqueTyID; + } + + /// isSingleValueType - Return true if the type is a valid type for a + /// virtual register in codegen. This includes all first-class types + /// except struct and array types. + /// + inline bool isSingleValueType() const { + return (ID != VoidTyID && ID <= LastPrimitiveTyID) || + ID == IntegerTyID || ID == PointerTyID || ID == VectorTyID; + } + + /// isAggregateType - Return true if the type is an aggregate type. This + /// means it is valid as the first operand of an insertvalue or + /// extractvalue instruction. This includes struct and array types, but + /// does not include vector types. + /// + inline bool isAggregateType() const { + return ID == StructTyID || ID == ArrayTyID; + } + + /// isSized - Return true if it makes sense to take the size of this type. To + /// get the actual size for a particular target, it is reasonable to use the + /// TargetData subsystem to do this. + /// + bool isSized() const { + // If it's a primitive, it is always sized. + if (ID == IntegerTyID || isFloatingPoint() || ID == PointerTyID) + return true; + // If it is not something that can have a size (e.g. a function or label), + // it doesn't have a size. + if (ID != StructTyID && ID != ArrayTyID && ID != VectorTyID) + return false; + // If it is something that can have a size and it's concrete, it definitely + // has a size, otherwise we have to try harder to decide. + return !isAbstract() || isSizedDerivedType(); + } + + /// getPrimitiveSizeInBits - Return the basic size of this type if it is a + /// primitive type. These are fixed by LLVM and are not target dependent. + /// This will return zero if the type does not have a size or is not a + /// primitive type. + /// + unsigned getPrimitiveSizeInBits() const; + + /// getFPMantissaWidth - Return the width of the mantissa of this type. This + /// is only valid on scalar floating point types. If the FP type does not + /// have a stable mantissa (e.g. ppc long double), this method returns -1. + int getFPMantissaWidth() const { + assert(isFloatingPoint() && "Not a floating point type!"); + if (ID == FloatTyID) return 24; + if (ID == DoubleTyID) return 53; + if (ID == X86_FP80TyID) return 64; + if (ID == FP128TyID) return 113; + assert(ID == PPC_FP128TyID && "unknown fp type"); + return -1; + } + + /// getForwardedType - Return the type that this type has been resolved to if + /// it has been resolved to anything. This is used to implement the + /// union-find algorithm for type resolution, and shouldn't be used by general + /// purpose clients. + const Type *getForwardedType() const { + if (!ForwardType) return 0; + return getForwardedTypeInternal(); + } + + /// getVAArgsPromotedType - Return the type an argument of this type + /// will be promoted to if passed through a variable argument + /// function. + const Type *getVAArgsPromotedType() const; + + //===--------------------------------------------------------------------===// + // Type Iteration support + // + typedef PATypeHandle *subtype_iterator; + subtype_iterator subtype_begin() const { return ContainedTys; } + subtype_iterator subtype_end() const { return &ContainedTys[NumContainedTys];} + + /// getContainedType - This method is used to implement the type iterator + /// (defined a the end of the file). For derived types, this returns the + /// types 'contained' in the derived type. + /// + const Type *getContainedType(unsigned i) const { + assert(i < NumContainedTys && "Index out of range!"); + return ContainedTys[i].get(); + } + + /// getNumContainedTypes - Return the number of types in the derived type. + /// + unsigned getNumContainedTypes() const { return NumContainedTys; } + + //===--------------------------------------------------------------------===// + // Static members exported by the Type class itself. Useful for getting + // instances of Type. + // + + /// getPrimitiveType - Return a type based on an identifier. + static const Type *getPrimitiveType(TypeID IDNumber); + + //===--------------------------------------------------------------------===// + // These are the builtin types that are always available... + // + static const Type *VoidTy, *LabelTy, *FloatTy, *DoubleTy, *MetadataTy; + static const Type *X86_FP80Ty, *FP128Ty, *PPC_FP128Ty; + static const IntegerType *Int1Ty, *Int8Ty, *Int16Ty, *Int32Ty, *Int64Ty; + + /// Methods for support type inquiry through isa, cast, and dyn_cast: + static inline bool classof(const Type *) { return true; } + + void addRef() const { + assert(isAbstract() && "Cannot add a reference to a non-abstract type!"); + ++RefCount; + } + + void dropRef() const { + assert(isAbstract() && "Cannot drop a reference to a non-abstract type!"); + assert(RefCount && "No objects are currently referencing this object!"); + + // If this is the last PATypeHolder using this object, and there are no + // PATypeHandles using it, the type is dead, delete it now. + if (--RefCount == 0 && AbstractTypeUsers.empty()) + this->destroy(); + } + + /// addAbstractTypeUser - Notify an abstract type that there is a new user of + /// it. This function is called primarily by the PATypeHandle class. + /// + void addAbstractTypeUser(AbstractTypeUser *U) const { + assert(isAbstract() && "addAbstractTypeUser: Current type not abstract!"); + AbstractTypeUsers.push_back(U); + } + + /// removeAbstractTypeUser - Notify an abstract type that a user of the class + /// no longer has a handle to the type. This function is called primarily by + /// the PATypeHandle class. When there are no users of the abstract type, it + /// is annihilated, because there is no way to get a reference to it ever + /// again. + /// + void removeAbstractTypeUser(AbstractTypeUser *U) const; + + /// getPointerTo - Return a pointer to the current type. This is equivalent + /// to PointerType::get(Foo, AddrSpace). + PointerType *getPointerTo(unsigned AddrSpace = 0) const; + +private: + /// isSizedDerivedType - Derived types like structures and arrays are sized + /// iff all of the members of the type are sized as well. Since asking for + /// their size is relatively uncommon, move this operation out of line. + bool isSizedDerivedType() const; + + virtual void refineAbstractType(const DerivedType *OldTy, const Type *NewTy); + virtual void typeBecameConcrete(const DerivedType *AbsTy); + +protected: + // PromoteAbstractToConcrete - This is an internal method used to calculate + // change "Abstract" from true to false when types are refined. + void PromoteAbstractToConcrete(); + friend class TypeMapBase; +}; + +//===----------------------------------------------------------------------===// +// Define some inline methods for the AbstractTypeUser.h:PATypeHandle class. +// These are defined here because they MUST be inlined, yet are dependent on +// the definition of the Type class. +// +inline void PATypeHandle::addUser() { + assert(Ty && "Type Handle has a null type!"); + if (Ty->isAbstract()) + Ty->addAbstractTypeUser(User); +} +inline void PATypeHandle::removeUser() { + if (Ty->isAbstract()) + Ty->removeAbstractTypeUser(User); +} + +// Define inline methods for PATypeHolder. + +/// get - This implements the forwarding part of the union-find algorithm for +/// abstract types. Before every access to the Type*, we check to see if the +/// type we are pointing to is forwarding to a new type. If so, we drop our +/// reference to the type. +/// +inline Type* PATypeHolder::get() const { + const Type *NewTy = Ty->getForwardedType(); + if (!NewTy) return const_cast<Type*>(Ty); + return *const_cast<PATypeHolder*>(this) = NewTy; +} + +inline void PATypeHolder::addRef() { + assert(Ty && "Type Holder has a null type!"); + if (Ty->isAbstract()) + Ty->addRef(); +} + +inline void PATypeHolder::dropRef() { + if (Ty->isAbstract()) + Ty->dropRef(); +} + + +//===----------------------------------------------------------------------===// +// Provide specializations of GraphTraits to be able to treat a type as a +// graph of sub types... + +template <> struct GraphTraits<Type*> { + typedef Type NodeType; + typedef Type::subtype_iterator ChildIteratorType; + + static inline NodeType *getEntryNode(Type *T) { return T; } + static inline ChildIteratorType child_begin(NodeType *N) { + return N->subtype_begin(); + } + static inline ChildIteratorType child_end(NodeType *N) { + return N->subtype_end(); + } +}; + +template <> struct GraphTraits<const Type*> { + typedef const Type NodeType; + typedef Type::subtype_iterator ChildIteratorType; + + static inline NodeType *getEntryNode(const Type *T) { return T; } + static inline ChildIteratorType child_begin(NodeType *N) { + return N->subtype_begin(); + } + static inline ChildIteratorType child_end(NodeType *N) { + return N->subtype_end(); + } +}; + +template <> inline bool isa_impl<PointerType, Type>(const Type &Ty) { + return Ty.getTypeID() == Type::PointerTyID; +} + +std::ostream &operator<<(std::ostream &OS, const Type &T); +raw_ostream &operator<<(raw_ostream &OS, const Type &T); + +} // End llvm namespace + +#endif |