include/llvm/IR/ValueSymbolTable.h

   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 <unsigned InternalLen> class SmallString;
  31 template <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 ///
  37 class 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 /// @{
  49 public:
  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   /// @{
 107 private:
 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