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