1 //===-- llvm/Value.h - Definition of the Value class ------------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file was developed by the LLVM research group and is distributed under
6 // the University of Illinois Open Source License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file defines the very important Value class. This is subclassed by a
11 // bunch of other important classes, like Instruction, Function, Type, etc...
13 // This file also defines the Use<> template for users of value.
15 //===----------------------------------------------------------------------===//
20 #include "llvm/AbstractTypeUser.h"
22 #include "Support/Annotation.h"
23 #include "Support/Casting.h"
38 //===----------------------------------------------------------------------===//
40 //===----------------------------------------------------------------------===//
42 /// Value - The base class of all values computed by a program that may be used
43 /// as operands to other values.
45 struct Value : public Annotable { // Values are annotable
47 TypeVal, // This is an instance of Type
48 ConstantVal, // This is an instance of Constant
49 ArgumentVal, // This is an instance of Argument
50 InstructionVal, // This is an instance of Instruction
51 BasicBlockVal, // This is an instance of BasicBlock
52 FunctionVal, // This is an instance of Function
53 GlobalVariableVal, // This is an instance of GlobalVariable
62 void operator=(const Value &); // Do not implement
63 Value(const Value &); // Do not implement
65 Value(const Type *Ty, ValueTy vty, const std::string &name = "");
68 /// dump - Support for debugging, callable in GDB: V->dump()
70 virtual void dump() const;
72 /// print - Implement operator<< on Value...
74 virtual void print(std::ostream &O) const = 0;
76 /// All values are typed, get the type of this value.
78 inline const Type *getType() const { return Ty; }
80 // All values can potentially be named...
81 inline bool hasName() const { return !Name.empty(); }
82 inline const std::string &getName() const { return Name; }
84 virtual void setName(const std::string &name, SymbolTable * = 0) {
88 /// getValueType - Return the immediate subclass of this Value.
90 inline ValueTy getValueType() const { return VTy; }
92 /// replaceAllUsesWith - Go through the uses list for this definition and make
93 /// each use point to "V" instead of "this". After this completes, 'this's
94 /// use list is guaranteed to be empty.
96 void replaceAllUsesWith(Value *V);
98 // uncheckedReplaceAllUsesWith - Just like replaceAllUsesWith but dangerous.
99 // Only use when in type resolution situations!
100 void uncheckedReplaceAllUsesWith(Value *V);
102 //----------------------------------------------------------------------
103 // Methods for handling the vector of uses of this Value.
105 typedef UseListIteratorWrapper use_iterator;
106 typedef UseListConstIteratorWrapper use_const_iterator;
108 unsigned use_size() const { return Uses.size(); }
109 bool use_empty() const { return Uses.empty(); }
110 use_iterator use_begin() { return Uses.begin(); }
111 use_const_iterator use_begin() const { return Uses.begin(); }
112 use_iterator use_end() { return Uses.end(); }
113 use_const_iterator use_end() const { return Uses.end(); }
114 User *use_back() { return Uses.back().getUser(); }
115 const User *use_back() const { return Uses.back().getUser(); }
117 /// hasOneUse - Return true if there is exactly one user of this value. This
118 /// is specialized because it is a common request and does not require
119 /// traversing the whole use list.
121 bool hasOneUse() const {
122 iplist<Use>::const_iterator I = Uses.begin(), E = Uses.end();
123 if (I == E) return false;
127 /// addUse/killUse - These two methods should only be used by the Use class.
129 void addUse(Use &U) { Uses.push_back(&U); }
130 void killUse(Use &U) { Uses.remove(&U); }
133 inline std::ostream &operator<<(std::ostream &OS, const Value *V) {
135 OS << "<null> value!\n";
141 inline std::ostream &operator<<(std::ostream &OS, const Value &V) {
147 inline User *UseListIteratorWrapper::operator*() const {
148 return Super::operator*().getUser();
151 inline const User *UseListConstIteratorWrapper::operator*() const {
152 return Super::operator*().getUser();
156 Use::Use(Value *v, User *user) : Val(v), U(user) {
157 if (Val) Val->addUse(*this);
160 Use::Use(const Use &u) : Val(u.Val), U(u.U) {
161 if (Val) Val->addUse(*this);
165 if (Val) Val->killUse(*this);
168 void Use::set(Value *V) {
169 if (Val) Val->killUse(*this);
171 if (V) V->addUse(*this);
175 // isa - Provide some specializations of isa so that we don't have to include
176 // the subtype header files to test to see if the value is a subclass...
178 template <> inline bool isa_impl<Type, Value>(const Value &Val) {
179 return Val.getValueType() == Value::TypeVal;
181 template <> inline bool isa_impl<Constant, Value>(const Value &Val) {
182 return Val.getValueType() == Value::ConstantVal;
184 template <> inline bool isa_impl<Argument, Value>(const Value &Val) {
185 return Val.getValueType() == Value::ArgumentVal;
187 template <> inline bool isa_impl<Instruction, Value>(const Value &Val) {
188 return Val.getValueType() == Value::InstructionVal;
190 template <> inline bool isa_impl<BasicBlock, Value>(const Value &Val) {
191 return Val.getValueType() == Value::BasicBlockVal;
193 template <> inline bool isa_impl<Function, Value>(const Value &Val) {
194 return Val.getValueType() == Value::FunctionVal;
196 template <> inline bool isa_impl<GlobalVariable, Value>(const Value &Val) {
197 return Val.getValueType() == Value::GlobalVariableVal;
199 template <> inline bool isa_impl<GlobalValue, Value>(const Value &Val) {
200 return isa<GlobalVariable>(Val) || isa<Function>(Val);
203 } // End llvm namespace