ValueSymbolTable.h revision 321369 
1//===- llvm/ValueSymbolTable.h - Implement a Value Symtab -------*- C++ -*-===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This file implements the name/Value symbol table for LLVM.
11//
12//===----------------------------------------------------------------------===//
13
14#ifndef LLVM_IR_VALUESYMBOLTABLE_H
15#define LLVM_IR_VALUESYMBOLTABLE_H
16
17#include "llvm/ADT/StringMap.h"
18#include "llvm/ADT/StringRef.h"
19#include "llvm/IR/Value.h"
20#include <cstdint>
21
22namespace llvm {
23
24class Argument;
25class BasicBlock;
26class Function;
27class GlobalAlias;
28class GlobalIFunc;
29class GlobalVariable;
30class Instruction;
31template <unsigned InternalLen> class SmallString;
32template <typename ValueSubClass> class SymbolTableListTraits;
33
34/// This class provides a symbol table of name/value pairs. It is essentially
35/// a std::map<std::string,Value*> but has a controlled interface provided by
36/// LLVM as well as ensuring uniqueness of names.
37///
38class ValueSymbolTable {
39  friend class SymbolTableListTraits<Argument>;
40  friend class SymbolTableListTraits<BasicBlock>;
41  friend class SymbolTableListTraits<Function>;
42  friend class SymbolTableListTraits<GlobalAlias>;
43  friend class SymbolTableListTraits<GlobalIFunc>;
44  friend class SymbolTableListTraits<GlobalVariable>;
45  friend class SymbolTableListTraits<Instruction>;
46  friend class Value;
47
48/// @name Types
49/// @{
50public:
51  /// @brief A mapping of names to values.
52  using ValueMap = StringMap<Value*>;
53
54  /// @brief An iterator over a ValueMap.
55  using iterator = ValueMap::iterator;
56
57  /// @brief A const_iterator over a ValueMap.
58  using const_iterator = ValueMap::const_iterator;
59
60/// @}
61/// @name Constructors
62/// @{
63
64  ValueSymbolTable() : vmap(0) {}
65  ~ValueSymbolTable();
66
67/// @}
68/// @name Accessors
69/// @{
70
71  /// This method finds the value with the given \p Name in the
72  /// the symbol table.
73  /// @returns the value associated with the \p Name
74  /// @brief Lookup a named Value.
75  Value *lookup(StringRef Name) const { return vmap.lookup(Name); }
76
77  /// @returns true iff the symbol table is empty
78  /// @brief Determine if the symbol table is empty
79  inline bool empty() const { return vmap.empty(); }
80
81  /// @brief The number of name/type pairs is returned.
82  inline unsigned size() const { return unsigned(vmap.size()); }
83
84  /// This function can be used from the debugger to display the
85  /// content of the symbol table while debugging.
86  /// @brief Print out symbol table on stderr
87  void dump() const;
88
89/// @}
90/// @name Iteration
91/// @{
92
93  /// @brief Get an iterator that from the beginning of the symbol table.
94  inline iterator begin() { return vmap.begin(); }
95
96  /// @brief Get a const_iterator that from the beginning of the symbol table.
97  inline const_iterator begin() const { return vmap.begin(); }
98
99  /// @brief Get an iterator to the end of the symbol table.
100  inline iterator end() { return vmap.end(); }
101
102  /// @brief Get a const_iterator to the end of the symbol table.
103  inline const_iterator end() const { return vmap.end(); }
104
105  /// @}
106  /// @name Mutators
107  /// @{
108private:
109  ValueName *makeUniqueName(Value *V, SmallString<256> &UniqueName);
110
111  /// This method adds the provided value \p N to the symbol table.  The Value
112  /// must have a name which is used to place the value in the symbol table.
113  /// If the inserted name conflicts, this renames the value.
114  /// @brief Add a named value to the symbol table
115  void reinsertValue(Value *V);
116
117  /// createValueName - This method attempts to create a value name and insert
118  /// it into the symbol table with the specified name.  If it conflicts, it
119  /// auto-renames the name and returns that instead.
120  ValueName *createValueName(StringRef Name, Value *V);
121
122  /// This method removes a value from the symbol table.  It leaves the
123  /// ValueName attached to the value, but it is no longer inserted in the
124  /// symtab.
125  void removeValueName(ValueName *V);
126
127  /// @}
128  /// @name Internal Data
129  /// @{
130
131  ValueMap vmap;                    ///< The map that holds the symbol table.
132  mutable uint32_t LastUnique = 0;  ///< Counter for tracking unique names
133
134/// @}
135};
136
137} // end namespace llvm
138
139#endif // LLVM_IR_VALUESYMBOLTABLE_H
140