// Copyright 2016 The SwiftShader Authors. All Rights Reserved.
//
// 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 COMPILER_PREPROCESSOR_TOKEN_H_
#define COMPILER_PREPROCESSOR_TOKEN_H_

#include <ostream>
#include <string>

#include "SourceLocation.h"

namespace pp
{

struct Token
{
	enum Type
	{
		LAST = 0,  // EOF.

		IDENTIFIER = 258,

		CONST_INT,
		CONST_FLOAT,

		OP_INC,
		OP_DEC,
		OP_LEFT,
		OP_RIGHT,
		OP_LE,
		OP_GE,
		OP_EQ,
		OP_NE,
		OP_AND,
		OP_XOR,
		OP_OR,
		OP_ADD_ASSIGN,
		OP_SUB_ASSIGN,
		OP_MUL_ASSIGN,
		OP_DIV_ASSIGN,
		OP_MOD_ASSIGN,
		OP_LEFT_ASSIGN,
		OP_RIGHT_ASSIGN,
		OP_AND_ASSIGN,
		OP_XOR_ASSIGN,
		OP_OR_ASSIGN,

		// Preprocessing token types.
		// These types are used by the preprocessor internally.
		// Preprocessor clients must not depend or check for them.
		PP_HASH,
		PP_NUMBER,
		PP_OTHER
	};
	enum Flags
	{
		AT_START_OF_LINE   = 1 << 0,
		HAS_LEADING_SPACE  = 1 << 1,
		EXPANSION_DISABLED = 1 << 2
	};

	Token() : type(0), flags(0) { }

	void reset();
	bool equals(const Token& other) const;

	// Returns true if this is the first token on line.
	// It disregards any leading whitespace.
	bool atStartOfLine() const { return (flags & AT_START_OF_LINE) != 0; }
	void setAtStartOfLine(bool start);

	bool hasLeadingSpace() const { return (flags & HAS_LEADING_SPACE) != 0; }
	void setHasLeadingSpace(bool space);

	bool expansionDisabled() const { return (flags & EXPANSION_DISABLED) != 0; }
	void setExpansionDisabled(bool disable);

	// Converts text into numeric value for CONST_INT and CONST_FLOAT token.
	// Returns false if the parsed value cannot fit into an int or float.
	bool iValue(int* value) const;
	bool uValue(unsigned int* value) const;
	bool fValue(float* value) const;

	int type;
	unsigned int flags;
	SourceLocation location;
	std::string text;
};

inline bool operator==(const Token& lhs, const Token& rhs)
{
	return lhs.equals(rhs);
}

inline bool operator!=(const Token& lhs, const Token& rhs)
{
	return !lhs.equals(rhs);
}

extern std::ostream& operator<<(std::ostream& out, const Token& token);

}  // namepsace pp
#endif  // COMPILER_PREPROCESSOR_TOKEN_H_