dawn-cmake/src/symbol.h

122 lines
3.6 KiB
C++

// Copyright 2020 The Tint Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#ifndef SRC_SYMBOL_H_
#define SRC_SYMBOL_H_
// If TINT_SYMBOL_STORE_DEBUG_NAME is 1, Symbol instances store a `debug_name_`
// member initialized with the name of the identifier they represent. This
// member is not exposed, but is useful for debugging purposes.
#ifndef TINT_SYMBOL_STORE_DEBUG_NAME
#define TINT_SYMBOL_STORE_DEBUG_NAME 0
#endif
#include <string>
#include "src/program_id.h"
namespace tint {
/// A symbol representing a string in the system
class Symbol {
public:
/// Constructor
/// An invalid symbol
Symbol();
/// Constructor
/// @param val the symbol value
/// @param program_id the identifier of the program that owns this Symbol
Symbol(uint32_t val, tint::ProgramID program_id);
#if TINT_SYMBOL_STORE_DEBUG_NAME
/// Constructor
/// @param val the symbol value
/// @param program_id the identifier of the program that owns this Symbol
/// @param debug_name name of symbols used only for debugging
Symbol(uint32_t val, tint::ProgramID program_id, std::string debug_name);
#endif
/// Copy constructor
/// @param o the symbol to copy
Symbol(const Symbol& o);
/// Move constructor
/// @param o the symbol to move
Symbol(Symbol&& o);
/// Destructor
~Symbol();
/// Copy assignment
/// @param o the other symbol
/// @returns the symbol after doing the copy
Symbol& operator=(const Symbol& o);
/// Move assignment
/// @param o the other symbol
/// @returns teh symbol after doing the move
Symbol& operator=(Symbol&& o);
/// Comparison operator
/// @param o the other symbol
/// @returns true if the symbols are the same
bool operator==(const Symbol& o) const;
/// Less-than operator
/// @param o the other symbol
/// @returns true if this symbol is ordered before symbol `o`
bool operator<(const Symbol& o) const;
/// @returns true if the symbol is valid
bool IsValid() const { return val_ != static_cast<uint32_t>(-1); }
/// @returns the value for the symbol
uint32_t value() const { return val_; }
/// Convert the symbol to a string
/// @return the string representation of the symbol
std::string to_str() const;
/// @returns the identifier of the Program that owns this symbol.
tint::ProgramID ProgramID() const { return program_id_; }
private:
uint32_t val_ = static_cast<uint32_t>(-1);
tint::ProgramID program_id_;
#if TINT_SYMBOL_STORE_DEBUG_NAME
std::string debug_name_;
#endif
};
/// @param sym the Symbol
/// @returns the ProgramID that owns the given Symbol
inline ProgramID ProgramIDOf(Symbol sym) {
return sym.IsValid() ? sym.ProgramID() : ProgramID();
}
} // namespace tint
namespace std {
/// Custom std::hash specialization for tint::Symbol so symbols can be used as
/// keys for std::unordered_map and std::unordered_set.
template <>
class hash<tint::Symbol> {
public:
/// @param sym the symbol to return
/// @return the Symbol internal value
inline std::size_t operator()(const tint::Symbol& sym) const {
return static_cast<std::size_t>(sym.value());
}
};
} // namespace std
#endif // SRC_SYMBOL_H_