Value.h revision b163f1c3e551cb3e5abd9bead0eae7a753502540 
1//===-- llvm/Value.h - Definition of the Value class -------------*- C++ -*--=//
2//
3// This file defines the very important Value class.  This is subclassed by a
4// bunch of other important classes, like Instruction, Function, Type, etc...
5//
6// This file also defines the Use<> template for users of value.
7//
8//===----------------------------------------------------------------------===//
9
10#ifndef LLVM_VALUE_H
11#define LLVM_VALUE_H
12
13#include <vector>
14#include "llvm/Annotation.h"
15#include "llvm/AbstractTypeUser.h"
16#include "Support/Casting.h"
17#include <iostream>
18
19class User;
20class Type;
21class Constant;
22class Argument;
23class Instruction;
24class BasicBlock;
25class GlobalValue;
26class Function;
27class GlobalVariable;
28class SymbolTable;
29
30//===----------------------------------------------------------------------===//
31//                                 Value Class
32//===----------------------------------------------------------------------===//
33
34/// Value - The base class of all values computed by a program that may be used
35/// as operands to other values.
36///
37class Value : public Annotable,         // Values are annotable
38	      public AbstractTypeUser { // Values use potentially abstract types
39public:
40  enum ValueTy {
41    TypeVal,                // This is an instance of Type
42    ConstantVal,            // This is an instance of Constant
43    ArgumentVal,            // This is an instance of Argument
44    InstructionVal,         // This is an instance of Instruction
45    BasicBlockVal,          // This is an instance of BasicBlock
46    FunctionVal,            // This is an instance of Function
47    GlobalVariableVal,      // This is an instance of GlobalVariable
48  };
49
50private:
51  std::vector<User *> Uses;
52  std::string Name;
53  PATypeHandle<Type> Ty;
54  ValueTy VTy;
55
56  void operator=(const Value &);     // Do not implement
57  Value(const Value &);              // Do not implement
58public:
59  Value(const Type *Ty, ValueTy vty, const std::string &name = "");
60  virtual ~Value();
61
62  /// dump - Support for debugging, callable in GDB: V->dump()
63  //
64  void dump() const;
65
66  /// print - Implement operator<< on Value...
67  ///
68  virtual void print(std::ostream &O) const = 0;
69
70  /// All values are typed, get the type of this value.
71  ///
72  inline const Type *getType() const { return Ty; }
73
74  // All values can potentially be named...
75  inline bool               hasName() const { return Name != ""; }
76  inline const std::string &getName() const { return Name; }
77
78  virtual void setName(const std::string &name, SymbolTable * = 0) {
79    Name = name;
80  }
81
82  /// getValueType - Return the immediate subclass of this Value.
83  ///
84  inline ValueTy getValueType() const { return VTy; }
85
86  /// replaceAllUsesWith - Go through the uses list for this definition and make
87  /// each use point to "V" instead of "this".  After this completes, 'this's
88  /// use list is guaranteed to be empty.
89  ///
90  void replaceAllUsesWith(Value *V);
91
92  /// refineAbstractType - This function is implemented because we use
93  /// potentially abstract types, and these types may be resolved to more
94  /// concrete types after we are constructed.
95  ///
96  virtual void refineAbstractType(const DerivedType *OldTy, const Type *NewTy);
97
98  //----------------------------------------------------------------------
99  // Methods for handling the vector of uses of this Value.
100  //
101  typedef std::vector<User*>::iterator       use_iterator;
102  typedef std::vector<User*>::const_iterator use_const_iterator;
103
104  inline unsigned           use_size()  const { return Uses.size();  }
105  inline bool               use_empty() const { return Uses.empty(); }
106  inline use_iterator       use_begin()       { return Uses.begin(); }
107  inline use_const_iterator use_begin() const { return Uses.begin(); }
108  inline use_iterator       use_end()         { return Uses.end();   }
109  inline use_const_iterator use_end()   const { return Uses.end();   }
110  inline User              *use_back()        { return Uses.back();  }
111  inline const User        *use_back()  const { return Uses.back();  }
112
113  inline void use_push_back(User *I)   { Uses.push_back(I); }
114  User *use_remove(use_iterator &I);
115
116  inline void addUse(User *I)      { Uses.push_back(I); }
117  void killUse(User *I);
118};
119
120inline std::ostream &operator<<(std::ostream &OS, const Value *V) {
121  if (V == 0)
122    OS << "<null> value!\n";
123  else
124    V->print(OS);
125  return OS;
126}
127
128inline std::ostream &operator<<(std::ostream &OS, const Value &V) {
129  V.print(OS);
130  return OS;
131}
132
133
134//===----------------------------------------------------------------------===//
135//                                 UseTy Class
136//===----------------------------------------------------------------------===//
137
138// UseTy and it's friendly typedefs (Use) are here to make keeping the "use"
139// list of a definition node up-to-date really easy.
140//
141template<class ValueSubclass>
142class UseTy {
143  ValueSubclass *Val;
144  User *U;
145public:
146  inline UseTy<ValueSubclass>(ValueSubclass *v, User *user) {
147    Val = v; U = user;
148    if (Val) Val->addUse(U);
149  }
150
151  inline ~UseTy<ValueSubclass>() { if (Val) Val->killUse(U); }
152
153  inline operator ValueSubclass *() const { return Val; }
154
155  inline UseTy<ValueSubclass>(const UseTy<ValueSubclass> &user) {
156    Val = 0;
157    U = user.U;
158    operator=(user.Val);
159  }
160  inline ValueSubclass *operator=(ValueSubclass *V) {
161    if (Val) Val->killUse(U);
162    Val = V;
163    if (V) V->addUse(U);
164    return V;
165  }
166
167  inline       ValueSubclass *operator->()       { return Val; }
168  inline const ValueSubclass *operator->() const { return Val; }
169
170  inline       ValueSubclass *get()       { return Val; }
171  inline const ValueSubclass *get() const { return Val; }
172
173  inline UseTy<ValueSubclass> &operator=(const UseTy<ValueSubclass> &user) {
174    if (Val) Val->killUse(U);
175    Val = user.Val;
176    Val->addUse(U);
177    return *this;
178  }
179};
180
181typedef UseTy<Value> Use;    // Provide Use as a common UseTy type
182
183template<typename From> struct simplify_type<UseTy<From> > {
184  typedef typename simplify_type<From*>::SimpleType SimpleType;
185
186  static SimpleType getSimplifiedValue(const UseTy<From> &Val) {
187    return (SimpleType)Val.get();
188  }
189};
190template<typename From> struct simplify_type<const UseTy<From> > {
191  typedef typename simplify_type<From*>::SimpleType SimpleType;
192
193  static SimpleType getSimplifiedValue(const UseTy<From> &Val) {
194    return (SimpleType)Val.get();
195  }
196};
197
198// isa - Provide some specializations of isa so that we don't have to include
199// the subtype header files to test to see if the value is a subclass...
200//
201template <> inline bool isa_impl<Type, Value>(const Value &Val) {
202  return Val.getValueType() == Value::TypeVal;
203}
204template <> inline bool isa_impl<Constant, Value>(const Value &Val) {
205  return Val.getValueType() == Value::ConstantVal;
206}
207template <> inline bool isa_impl<Argument, Value>(const Value &Val) {
208  return Val.getValueType() == Value::ArgumentVal;
209}
210template <> inline bool isa_impl<Instruction, Value>(const Value &Val) {
211  return Val.getValueType() == Value::InstructionVal;
212}
213template <> inline bool isa_impl<BasicBlock, Value>(const Value &Val) {
214  return Val.getValueType() == Value::BasicBlockVal;
215}
216template <> inline bool isa_impl<Function, Value>(const Value &Val) {
217  return Val.getValueType() == Value::FunctionVal;
218}
219template <> inline bool isa_impl<GlobalVariable, Value>(const Value &Val) {
220  return Val.getValueType() == Value::GlobalVariableVal;
221}
222template <> inline bool isa_impl<GlobalValue, Value>(const Value &Val) {
223  return isa<GlobalVariable>(Val) || isa<Function>(Val);
224}
225
226#endif
227