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 <bool ExtraIteratorBits> struct ilist_iterator_bits;
31template <unsigned InternalLen> class SmallString;
32template <typename ValueSubClass, typename ... Args> 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, ilist_iterator_bits<true>>;
46 friend class Value;
47
48/// @name Types
49/// @{
50public:
51 /// A mapping of names to values.
52 using ValueMap = StringMap<Value*>;
53
54 /// An iterator over a ValueMap.
55 using iterator = ValueMap::iterator;
56
57 /// A const_iterator over a ValueMap.
58 using const_iterator = ValueMap::const_iterator;
59
60/// @}
61/// @name Constructors
62/// @{
63
64 ValueSymbolTable(int MaxNameSize = -1) : vmap(0), MaxNameSize(MaxNameSize) {}
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 /// Lookup a named Value.
75 Value *lookup(StringRef Name) const {
76 if (MaxNameSize > -1 && Name.size() > (unsigned)MaxNameSize)
77 Name = Name.substr(Start: 0, N: std::max(a: 1u, b: (unsigned)MaxNameSize));
78
79 return vmap.lookup(Key: Name);
80 }
81
82 /// @returns true iff the symbol table is empty
83 /// Determine if the symbol table is empty
84 inline bool empty() const { return vmap.empty(); }
85
86 /// The number of name/type pairs is returned.
87 inline unsigned size() const { return unsigned(vmap.size()); }
88
89 /// This function can be used from the debugger to display the
90 /// content of the symbol table while debugging.
91 /// Print out symbol table on stderr
92 void dump() const;
93
94/// @}
95/// @name Iteration
96/// @{
97
98 /// Get an iterator that from the beginning of the symbol table.
99 inline iterator begin() { return vmap.begin(); }
100
101 /// Get a const_iterator that from the beginning of the symbol table.
102 inline const_iterator begin() const { return vmap.begin(); }
103
104 /// Get an iterator to the end of the symbol table.
105 inline iterator end() { return vmap.end(); }
106
107 /// Get a const_iterator to the end of the symbol table.
108 inline const_iterator end() const { return vmap.end(); }
109
110 /// @}
111 /// @name Mutators
112 /// @{
113private:
114 ValueName *makeUniqueName(Value *V, SmallString<256> &UniqueName);
115
116 /// This method adds the provided value \p N to the symbol table. The Value
117 /// must have a name which is used to place the value in the symbol table.
118 /// If the inserted name conflicts, this renames the value.
119 /// Add a named value to the symbol table
120 void reinsertValue(Value *V);
121
122 /// createValueName - This method attempts to create a value name and insert
123 /// it into the symbol table with the specified name. If it conflicts, it
124 /// auto-renames the name and returns that instead.
125 ValueName *createValueName(StringRef Name, Value *V);
126
127 /// This method removes a value from the symbol table. It leaves the
128 /// ValueName attached to the value, but it is no longer inserted in the
129 /// symtab.
130 void removeValueName(ValueName *V);
131
132 /// @}
133 /// @name Internal Data
134 /// @{
135
136 ValueMap vmap; ///< The map that holds the symbol table.
137 int MaxNameSize; ///< The maximum size for each name. If the limit is
138 ///< exceeded, the name is capped.
139 mutable uint32_t LastUnique = 0; ///< Counter for tracking unique names
140
141/// @}
142};
143
144} // end namespace llvm
145
146#endif // LLVM_IR_VALUESYMBOLTABLE_H
147

source code of llvm/include/llvm/IR/ValueSymbolTable.h