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"
36 //===----------------------------------------------------------------------===//
38 //===----------------------------------------------------------------------===//
40 /// Value - The base class of all values computed by a program that may be used
41 /// as operands to other values.
43 struct Value : public Annotable { // Values are annotable
45 TypeVal, // This is an instance of Type
46 ConstantVal, // This is an instance of Constant
47 ArgumentVal, // This is an instance of Argument
48 InstructionVal, // This is an instance of Instruction
49 BasicBlockVal, // This is an instance of BasicBlock
50 FunctionVal, // This is an instance of Function
51 GlobalVariableVal, // This is an instance of GlobalVariable
60 void operator=(const Value &); // Do not implement
61 Value(const Value &); // Do not implement
63 Value(const Type *Ty, ValueTy vty, const std::string &name = "");
66 /// dump - Support for debugging, callable in GDB: V->dump()
68 virtual void dump() const;
70 /// print - Implement operator<< on Value...
72 virtual void print(std::ostream &O) const = 0;
74 /// All values are typed, get the type of this value.
76 inline const Type *getType() const { return Ty; }
78 // All values can potentially be named...
79 inline bool hasName() const { return Name != ""; }
80 inline const std::string &getName() const { return Name; }
82 virtual void setName(const std::string &name, SymbolTable * = 0) {
86 /// getValueType - Return the immediate subclass of this Value.
88 inline ValueTy getValueType() const { return VTy; }
90 /// replaceAllUsesWith - Go through the uses list for this definition and make
91 /// each use point to "V" instead of "this". After this completes, 'this's
92 /// use list is guaranteed to be empty.
94 void replaceAllUsesWith(Value *V);
96 // uncheckedReplaceAllUsesWith - Just like replaceAllUsesWith but dangerous.
97 // Only use when in type resolution situations!
98 void uncheckedReplaceAllUsesWith(Value *V);
100 //----------------------------------------------------------------------
101 // Methods for handling the vector of uses of this Value.
103 typedef UseListIteratorWrapper use_iterator;
104 typedef UseListConstIteratorWrapper use_const_iterator;
106 unsigned use_size() const { return Uses.size(); }
107 bool use_empty() const { return Uses.empty(); }
108 use_iterator use_begin() { return Uses.begin(); }
109 use_const_iterator use_begin() const { return Uses.begin(); }
110 use_iterator use_end() { return Uses.end(); }
111 use_const_iterator use_end() const { return Uses.end(); }
112 User *use_back() { return Uses.back().getUser(); }
113 const User *use_back() const { return Uses.back().getUser(); }
115 /// hasOneUse - Return true if there is exactly one user of this value. This
116 /// is specialized because it is a common request and does not require
117 /// traversing the whole use list.
119 bool hasOneUse() const {
120 iplist<Use>::const_iterator I = Uses.begin(), E = Uses.end();
121 if (I == E) return false;
125 /// addUse/killUse - These two methods should only be used by the Use class.
127 void addUse(Use &U) { Uses.push_back(&U); }
128 void killUse(Use &U) { Uses.remove(&U); }
131 inline std::ostream &operator<<(std::ostream &OS, const Value *V) {
133 OS << "<null> value!\n";
139 inline std::ostream &operator<<(std::ostream &OS, const Value &V) {
145 inline User *UseListIteratorWrapper::operator*() const {
146 return Super::operator*().getUser();
149 inline const User *UseListConstIteratorWrapper::operator*() const {
150 return Super::operator*().getUser();
154 Use::Use(Value *v, User *user) : Val(v), U(user) {
155 if (Val) Val->addUse(*this);
158 Use::Use(const Use &u) : Val(u.Val), U(u.U) {
159 if (Val) Val->addUse(*this);
163 if (Val) Val->killUse(*this);
166 void Use::set(Value *V) {
167 if (Val) Val->killUse(*this);
169 if (V) V->addUse(*this);
173 // isa - Provide some specializations of isa so that we don't have to include
174 // the subtype header files to test to see if the value is a subclass...
176 template <> inline bool isa_impl<Type, Value>(const Value &Val) {
177 return Val.getValueType() == Value::TypeVal;
179 template <> inline bool isa_impl<Constant, Value>(const Value &Val) {
180 return Val.getValueType() == Value::ConstantVal;
182 template <> inline bool isa_impl<Argument, Value>(const Value &Val) {
183 return Val.getValueType() == Value::ArgumentVal;
185 template <> inline bool isa_impl<Instruction, Value>(const Value &Val) {
186 return Val.getValueType() == Value::InstructionVal;
188 template <> inline bool isa_impl<BasicBlock, Value>(const Value &Val) {
189 return Val.getValueType() == Value::BasicBlockVal;
191 template <> inline bool isa_impl<Function, Value>(const Value &Val) {
192 return Val.getValueType() == Value::FunctionVal;
194 template <> inline bool isa_impl<GlobalVariable, Value>(const Value &Val) {
195 return Val.getValueType() == Value::GlobalVariableVal;
197 template <> inline bool isa_impl<GlobalValue, Value>(const Value &Val) {
198 return isa<GlobalVariable>(Val) || isa<Function>(Val);