1//===- llvm/ValueSymbolTable.h - Implement a Value Symtab -------*- C++ -*-===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// This file implements the name/Value symbol table for LLVM.
10//
11//===----------------------------------------------------------------------===//
12
13#ifndef LLVM_IR_VALUESYMBOLTABLE_H
14#define LLVM_IR_VALUESYMBOLTABLE_H
15
16#include "llvm/ADT/StringMap.h"
17#include "llvm/ADT/StringRef.h"
18#include "llvm/IR/Value.h"
19#include <cstdint>
20
21namespace llvm {
22
23class Argument;
24class BasicBlock;
25class Function;
26class GlobalAlias;
27class GlobalIFunc;
28class GlobalVariable;
29class Instruction;
30template <unsigned InternalLen> class SmallString;
31template <typename ValueSubClass> class SymbolTableListTraits;
32
33/// This class provides a symbol table of name/value pairs. It is essentially
34/// a std::map<std::string,Value*> but has a controlled interface provided by
35/// LLVM as well as ensuring uniqueness of names.
36///
37class ValueSymbolTable {
38  friend class SymbolTableListTraits<Argument>;
39  friend class SymbolTableListTraits<BasicBlock>;
40  friend class SymbolTableListTraits<Function>;
41  friend class SymbolTableListTraits<GlobalAlias>;
42  friend class SymbolTableListTraits<GlobalIFunc>;
43  friend class SymbolTableListTraits<GlobalVariable>;
44  friend class SymbolTableListTraits<Instruction>;
45  friend class Value;
46
47/// @name Types
48/// @{
49public:
50  /// A mapping of names to values.
51  using ValueMap = StringMap<Value*>;
52
53  /// An iterator over a ValueMap.
54  using iterator = ValueMap::iterator;
55
56  /// A const_iterator over a ValueMap.
57  using const_iterator = ValueMap::const_iterator;
58
59/// @}
60/// @name Constructors
61/// @{
62
63  ValueSymbolTable() : vmap(0) {}
64  ~ValueSymbolTable();
65
66/// @}
67/// @name Accessors
68/// @{
69
70  /// This method finds the value with the given \p Name in the
71  /// the symbol table.
72  /// @returns the value associated with the \p Name
73  /// Lookup a named Value.
74  Value *lookup(StringRef Name) const { return vmap.lookup(Name); }
75
76  /// @returns true iff the symbol table is empty
77  /// Determine if the symbol table is empty
78  inline bool empty() const { return vmap.empty(); }
79
80  /// The number of name/type pairs is returned.
81  inline unsigned size() const { return unsigned(vmap.size()); }
82
83  /// This function can be used from the debugger to display the
84  /// content of the symbol table while debugging.
85  /// Print out symbol table on stderr
86  void dump() const;
87
88/// @}
89/// @name Iteration
90/// @{
91
92  /// Get an iterator that from the beginning of the symbol table.
93  inline iterator begin() { return vmap.begin(); }
94
95  /// Get a const_iterator that from the beginning of the symbol table.
96  inline const_iterator begin() const { return vmap.begin(); }
97
98  /// Get an iterator to the end of the symbol table.
99  inline iterator end() { return vmap.end(); }
100
101  /// Get a const_iterator to the end of the symbol table.
102  inline const_iterator end() const { return vmap.end(); }
103
104  /// @}
105  /// @name Mutators
106  /// @{
107private:
108  ValueName *makeUniqueName(Value *V, SmallString<256> &UniqueName);
109
110  /// This method adds the provided value \p N to the symbol table.  The Value
111  /// must have a name which is used to place the value in the symbol table.
112  /// If the inserted name conflicts, this renames the value.
113  /// Add a named value to the symbol table
114  void reinsertValue(Value *V);
115
116  /// createValueName - This method attempts to create a value name and insert
117  /// it into the symbol table with the specified name.  If it conflicts, it
118  /// auto-renames the name and returns that instead.
119  ValueName *createValueName(StringRef Name, Value *V);
120
121  /// This method removes a value from the symbol table.  It leaves the
122  /// ValueName attached to the value, but it is no longer inserted in the
123  /// symtab.
124  void removeValueName(ValueName *V);
125
126  /// @}
127  /// @name Internal Data
128  /// @{
129
130  ValueMap vmap;                    ///< The map that holds the symbol table.
131  mutable uint32_t LastUnique = 0;  ///< Counter for tracking unique names
132
133/// @}
134};
135
136} // end namespace llvm
137
138#endif // LLVM_IR_VALUESYMBOLTABLE_H
139