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 | |
21 | namespace llvm { |
22 | |
23 | class Argument; |
24 | class BasicBlock; |
25 | class Function; |
26 | class GlobalAlias; |
27 | class GlobalIFunc; |
28 | class GlobalVariable; |
29 | class Instruction; |
30 | template <bool ExtraIteratorBits> struct ilist_iterator_bits; |
31 | template <unsigned InternalLen> class SmallString; |
32 | template <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 | /// |
38 | class 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 | /// @{ |
50 | public: |
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 | /// @{ |
113 | private: |
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 | |