//===-- llvm/Value.h - Definition of the Value class ------------*- C++ -*-===// // // The LLVM Compiler Infrastructure // // This file was developed by the LLVM research group and is distributed under // the University of Illinois Open Source License. See LICENSE.TXT for details. // //===----------------------------------------------------------------------===// // // This file declares the Value class. // This file also defines the Use<> template for users of value. // //===----------------------------------------------------------------------===// #ifndef LLVM_VALUE_H #define LLVM_VALUE_H #include "llvm/AbstractTypeUser.h" #include "llvm/Use.h" #include "llvm/Support/Casting.h" #include "llvm/Support/Streams.h" #include <string> namespace llvm { class Constant; class Argument; class Instruction; class BasicBlock; class GlobalValue; class Function; class GlobalVariable; class InlineAsm; class SymbolTable; //===----------------------------------------------------------------------===// // Value Class //===----------------------------------------------------------------------===// /// This is a very important LLVM class. It is the base class of all values /// computed by a program that may be used as operands to other values. Value is /// the super class of other important classes such as Instruction and Function. /// All Values have a Type. Type is not a subclass of Value. All types can have /// a name and they should belong to some Module. Setting the name on the Value /// automatically update's the module's symbol table. /// /// Every value has a "use list" that keeps track of which other Values are /// using this Value. /// @brief LLVM Value Representation class Value { const unsigned short SubclassID; // Subclass identifier (for isa/dyn_cast) protected: /// SubclassData - This member is defined by this class, but is not used for /// anything. Subclasses can use it to hold whatever state they find useful. /// This field is initialized to zero by the ctor. unsigned short SubclassData; private: PATypeHolder Ty; Use *UseList; friend class ValueSymbolTable; // Allow ValueSymbolTable to directly mod Name. friend class SymbolTable; // Allow SymbolTable to directly poke Name. std::string Name; void operator=(const Value &); // Do not implement Value(const Value &); // Do not implement public: Value(const Type *Ty, unsigned scid, const std::string &name = ""); virtual ~Value(); /// dump - Support for debugging, callable in GDB: V->dump() // virtual void dump() const; /// print - Implement operator<< on Value... /// virtual void print(std::ostream &O) const = 0; void print(std::ostream *O) const { if (O) print(*O); } /// All values are typed, get the type of this value. /// inline const Type *getType() const { return Ty; } // All values can potentially be named... inline bool hasName() const { return !Name.empty(); } inline const std::string &getName() const { return Name; } void setName(const std::string &name); /// replaceAllUsesWith - Go through the uses list for this definition and make /// each use point to "V" instead of "this". After this completes, 'this's /// use list is guaranteed to be empty. /// void replaceAllUsesWith(Value *V); // uncheckedReplaceAllUsesWith - Just like replaceAllUsesWith but dangerous. // Only use when in type resolution situations! void uncheckedReplaceAllUsesWith(Value *V); //---------------------------------------------------------------------- // Methods for handling the vector of uses of this Value. // typedef value_use_iterator<User> use_iterator; typedef value_use_iterator<const User> use_const_iterator; bool use_empty() const { return UseList == 0; } use_iterator use_begin() { return use_iterator(UseList); } use_const_iterator use_begin() const { return use_const_iterator(UseList); } use_iterator use_end() { return use_iterator(0); } use_const_iterator use_end() const { return use_const_iterator(0); } User *use_back() { return *use_begin(); } const User *use_back() const { return *use_begin(); } /// hasOneUse - Return true if there is exactly one user of this value. This /// is specialized because it is a common request and does not require /// traversing the whole use list. /// bool hasOneUse() const { use_const_iterator I = use_begin(), E = use_end(); if (I == E) return false; return ++I == E; } /// hasNUses - Return true if this Value has exactly N users. /// bool hasNUses(unsigned N) const; /// hasNUsesOrMore - Return true if this value has N users or more. This is /// logically equivalent to getNumUses() >= N. /// bool hasNUsesOrMore(unsigned N) const; /// getNumUses - This method computes the number of uses of this Value. This /// is a linear time operation. Use hasOneUse, hasNUses, or hasMoreThanNUses /// to check for specific values. unsigned getNumUses() const; /// addUse/killUse - These two methods should only be used by the Use class. /// void addUse(Use &U) { U.addToList(&UseList); } /// An enumeration for keeping track of the concrete subclass of Value that /// is actually instantiated. Values of this enumeration are kept in the /// Value classes SubclassID field. They are used for concrete type /// identification. enum ValueTy { ArgumentVal, // This is an instance of Argument BasicBlockVal, // This is an instance of BasicBlock FunctionVal, // This is an instance of Function GlobalVariableVal, // This is an instance of GlobalVariable UndefValueVal, // This is an instance of UndefValue ConstantExprVal, // This is an instance of ConstantExpr ConstantAggregateZeroVal, // This is an instance of ConstantAggregateNull ConstantIntVal, // This is an instance of ConstantInt ConstantFPVal, // This is an instance of ConstantFP ConstantArrayVal, // This is an instance of ConstantArray ConstantStructVal, // This is an instance of ConstantStruct ConstantPackedVal, // This is an instance of ConstantPacked ConstantPointerNullVal, // This is an instance of ConstantPointerNull InlineAsmVal, // This is an instance of InlineAsm InstructionVal, // This is an instance of Instruction // Markers: ConstantFirstVal = FunctionVal, ConstantLastVal = ConstantPointerNullVal }; /// getValueType - Return an ID for the concrete type of this object. This is /// used to implement the classof checks. This should not be used for any /// other purpose, as the values may change as LLVM evolves. Also, note that /// starting with the InstructionVal value, the value stored is actually the /// Instruction opcode, so there are more than just these values possible here /// (and Instruction must be last). /// unsigned getValueType() const { return SubclassID; } // Methods for support type inquiry through isa, cast, and dyn_cast: static inline bool classof(const Value *) { return true; // Values are always values. } /// getRawType - This should only be used to implement the vmcore library. /// const Type *getRawType() const { return Ty.getRawType(); } }; inline std::ostream &operator<<(std::ostream &OS, const Value &V) { V.print(OS); return OS; } void Use::init(Value *v, User *user) { Val = v; U = user; if (Val) Val->addUse(*this); } Use::~Use() { if (Val) removeFromList(); } void Use::set(Value *V) { if (Val) removeFromList(); Val = V; if (V) V->addUse(*this); } // isa - Provide some specializations of isa so that we don't have to include // the subtype header files to test to see if the value is a subclass... // template <> inline bool isa_impl<Constant, Value>(const Value &Val) { return Val.getValueType() >= Value::ConstantFirstVal && Val.getValueType() <= Value::ConstantLastVal; } template <> inline bool isa_impl<Argument, Value>(const Value &Val) { return Val.getValueType() == Value::ArgumentVal; } template <> inline bool isa_impl<InlineAsm, Value>(const Value &Val) { return Val.getValueType() == Value::InlineAsmVal; } template <> inline bool isa_impl<Instruction, Value>(const Value &Val) { return Val.getValueType() >= Value::InstructionVal; } template <> inline bool isa_impl<BasicBlock, Value>(const Value &Val) { return Val.getValueType() == Value::BasicBlockVal; } template <> inline bool isa_impl<Function, Value>(const Value &Val) { return Val.getValueType() == Value::FunctionVal; } template <> inline bool isa_impl<GlobalVariable, Value>(const Value &Val) { return Val.getValueType() == Value::GlobalVariableVal; } template <> inline bool isa_impl<GlobalValue, Value>(const Value &Val) { return isa<GlobalVariable>(Val) || isa<Function>(Val); } } // End llvm namespace #endif