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/Casting.h"
35 //===----------------------------------------------------------------------===//
37 //===----------------------------------------------------------------------===//
39 /// Value - The base class of all values computed by a program that may be used
40 /// as operands to other values.
44 unsigned SubclassID; // Subclass identifier (for isa/dyn_cast)
49 void operator=(const Value &); // Do not implement
50 Value(const Value &); // Do not implement
53 Value(const Type *Ty, unsigned scid, const std::string &name = "");
56 /// dump - Support for debugging, callable in GDB: V->dump()
58 virtual void dump() const;
60 /// print - Implement operator<< on Value...
62 virtual void print(std::ostream &O) const = 0;
64 /// All values are typed, get the type of this value.
66 inline const Type *getType() const { return Ty; }
68 // All values can potentially be named...
69 inline bool hasName() const { return !Name.empty(); }
70 inline const std::string &getName() const { return Name; }
72 virtual void setName(const std::string &name, SymbolTable * = 0) {
76 /// replaceAllUsesWith - Go through the uses list for this definition and make
77 /// each use point to "V" instead of "this". After this completes, 'this's
78 /// use list is guaranteed to be empty.
80 void replaceAllUsesWith(Value *V);
82 // uncheckedReplaceAllUsesWith - Just like replaceAllUsesWith but dangerous.
83 // Only use when in type resolution situations!
84 void uncheckedReplaceAllUsesWith(Value *V);
86 //----------------------------------------------------------------------
87 // Methods for handling the vector of uses of this Value.
89 typedef UseListIteratorWrapper use_iterator;
90 typedef UseListConstIteratorWrapper use_const_iterator;
92 unsigned use_size() const { return Uses.size(); }
93 bool use_empty() const { return Uses.empty(); }
94 use_iterator use_begin() { return Uses.begin(); }
95 use_const_iterator use_begin() const { return Uses.begin(); }
96 use_iterator use_end() { return Uses.end(); }
97 use_const_iterator use_end() const { return Uses.end(); }
98 User *use_back() { return Uses.back().getUser(); }
99 const User *use_back() const { return Uses.back().getUser(); }
101 /// hasOneUse - Return true if there is exactly one user of this value. This
102 /// is specialized because it is a common request and does not require
103 /// traversing the whole use list.
105 bool hasOneUse() const {
106 iplist<Use>::const_iterator I = Uses.begin(), E = Uses.end();
107 if (I == E) return false;
111 /// addUse/killUse - These two methods should only be used by the Use class.
113 void addUse(Use &U) { Uses.push_back(&U); }
114 void killUse(Use &U) { Uses.remove(&U); }
116 /// getValueType - Return an ID for the concrete type of this object. This is
117 /// used to implement the classof checks. This should not be used for any
118 /// other purpose, as the values may change as LLVM evolves. Also, note that
119 /// starting with the InstructionVal value, the value stored is actually the
120 /// Instruction opcode, so there are more than just these values possible here
121 /// (and Instruction must be last).
124 ArgumentVal, // This is an instance of Argument
125 BasicBlockVal, // This is an instance of BasicBlock
126 FunctionVal, // This is an instance of Function
127 GlobalVariableVal, // This is an instance of GlobalVariable
128 ConstantVal, // This is an instance of Constant
129 InstructionVal, // This is an instance of Instruction
131 unsigned getValueType() const {
136 /// FIXME: this is a gross hack, needed by another gross hack. Eliminate!
137 void setValueType(unsigned VT) { SubclassID = VT; }
138 friend class Instruction;
141 inline std::ostream &operator<<(std::ostream &OS, const Value *V) {
143 OS << "<null> value!\n";
149 inline std::ostream &operator<<(std::ostream &OS, const Value &V) {
155 inline User *UseListIteratorWrapper::operator*() const {
156 return Super::operator*().getUser();
159 inline const User *UseListConstIteratorWrapper::operator*() const {
160 return Super::operator*().getUser();
164 Use::Use(Value *v, User *user) : Val(v), U(user) {
165 if (Val) Val->addUse(*this);
168 Use::Use(const Use &u) : Val(u.Val), U(u.U) {
169 if (Val) Val->addUse(*this);
173 if (Val) Val->killUse(*this);
176 void Use::set(Value *V) {
177 if (Val) Val->killUse(*this);
179 if (V) V->addUse(*this);
183 // isa - Provide some specializations of isa so that we don't have to include
184 // the subtype header files to test to see if the value is a subclass...
186 template <> inline bool isa_impl<Constant, Value>(const Value &Val) {
187 return Val.getValueType() == Value::ConstantVal;
189 template <> inline bool isa_impl<Argument, Value>(const Value &Val) {
190 return Val.getValueType() == Value::ArgumentVal;
192 template <> inline bool isa_impl<Instruction, Value>(const Value &Val) {
193 return Val.getValueType() >= Value::InstructionVal;
195 template <> inline bool isa_impl<BasicBlock, Value>(const Value &Val) {
196 return Val.getValueType() == Value::BasicBlockVal;
198 template <> inline bool isa_impl<Function, Value>(const Value &Val) {
199 return Val.getValueType() == Value::FunctionVal;
201 template <> inline bool isa_impl<GlobalVariable, Value>(const Value &Val) {
202 return Val.getValueType() == Value::GlobalVariableVal;
204 template <> inline bool isa_impl<GlobalValue, Value>(const Value &Val) {
205 return isa<GlobalVariable>(Val) || isa<Function>(Val);
208 } // End llvm namespace