Subversion Repositories QNX 8.QNX8 LLVM/Clang compiler suite

//===- llvm/ValueSymbolTable.h - Implement a Value Symtab -------*- C++ -*-===//

//

// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.

// See https://llvm.org/LICENSE.txt for license information.

// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception

//

//===----------------------------------------------------------------------===//

//

// This file implements the name/Value symbol table for LLVM.

//

//===----------------------------------------------------------------------===//

#ifndef LLVM_IR_VALUESYMBOLTABLE_H

#define LLVM_IR_VALUESYMBOLTABLE_H

#include "llvm/ADT/StringMap.h"

#include "llvm/ADT/StringRef.h"

#include "llvm/IR/Value.h"

#include <cstdint>

namespace llvm {

class Argument;

class BasicBlock;

class Function;

class GlobalAlias;

class GlobalIFunc;

class GlobalVariable;

class Instruction;

template <unsigned InternalLen> class SmallString;

template <typename ValueSubClass> class SymbolTableListTraits;

/// This class provides a symbol table of name/value pairs. It is essentially

/// a std::map<std::string,Value*> but has a controlled interface provided by

/// LLVM as well as ensuring uniqueness of names.

///

class ValueSymbolTable {

  friend class SymbolTableListTraits<Argument>;

  friend class SymbolTableListTraits<BasicBlock>;

  friend class SymbolTableListTraits<Function>;

  friend class SymbolTableListTraits<GlobalAlias>;

  friend class SymbolTableListTraits<GlobalIFunc>;

  friend class SymbolTableListTraits<GlobalVariable>;

  friend class SymbolTableListTraits<Instruction>;

  friend class Value;

/// @name Types

/// @{

public:

  /// A mapping of names to values.

  using ValueMap = StringMap<Value*>;

  /// An iterator over a ValueMap.

  using iterator = ValueMap::iterator;

  /// A const_iterator over a ValueMap.

  using const_iterator = ValueMap::const_iterator;

/// @}

/// @name Constructors

/// @{

  ValueSymbolTable(int MaxNameSize = -1) : vmap(0), MaxNameSize(MaxNameSize) {}

  ~ValueSymbolTable();

  /// @}

  /// @name Accessors

  /// @{

  /// This method finds the value with the given \p Name in the

  /// the symbol table.

  /// @returns the value associated with the \p Name

  /// Lookup a named Value.

  Value *lookup(StringRef Name) const {

    if (MaxNameSize > -1 && Name.size() > (unsigned)MaxNameSize)

      Name = Name.substr(0, std::max(1u, (unsigned)MaxNameSize));

    return vmap.lookup(Name);

  }

  /// @returns true iff the symbol table is empty

  /// Determine if the symbol table is empty

  inline bool empty() const { return vmap.empty(); }

  /// The number of name/type pairs is returned.

  inline unsigned size() const { return unsigned(vmap.size()); }

  /// This function can be used from the debugger to display the

  /// content of the symbol table while debugging.

  /// Print out symbol table on stderr

  void dump() const;

/// @}

/// @name Iteration

/// @{

  /// Get an iterator that from the beginning of the symbol table.

  inline iterator begin() { return vmap.begin(); }

  /// Get a const_iterator that from the beginning of the symbol table.

  inline const_iterator begin() const { return vmap.begin(); }

  /// Get an iterator to the end of the symbol table.

  inline iterator end() { return vmap.end(); }

  /// Get a const_iterator to the end of the symbol table.

  inline const_iterator end() const { return vmap.end(); }

  /// @}

  /// @name Mutators

  /// @{

private:

  ValueName *makeUniqueName(Value *V, SmallString<256> &UniqueName);

  /// This method adds the provided value \p N to the symbol table.  The Value

  /// must have a name which is used to place the value in the symbol table.

  /// If the inserted name conflicts, this renames the value.

  /// Add a named value to the symbol table

  void reinsertValue(Value *V);

  /// createValueName - This method attempts to create a value name and insert

  /// it into the symbol table with the specified name.  If it conflicts, it

  /// auto-renames the name and returns that instead.

  ValueName *createValueName(StringRef Name, Value *V);

  /// This method removes a value from the symbol table.  It leaves the

  /// ValueName attached to the value, but it is no longer inserted in the

  /// symtab.

  void removeValueName(ValueName *V);

  /// @}

  /// @name Internal Data

  /// @{

  ValueMap vmap;                    ///< The map that holds the symbol table.

  int MaxNameSize; ///< The maximum size for each name. If the limit is

                   ///< exceeded, the name is capped.

  mutable uint32_t LastUnique = 0;  ///< Counter for tracking unique names

/// @}

};

} // end namespace llvm

#endif // LLVM_IR_VALUESYMBOLTABLE_H