pollymc/libraries/classparser/src/annotations.h

#pragma once
#include "classfile.h"
#include <map>
#include <vector>

namespace java
{
enum element_value_type : uint8_t
{
	INVALID = 0,
	STRING = 's',
	ENUM_CONSTANT = 'e',
	CLASS = 'c',
	ANNOTATION = '@',
	ARRAY = '[',			// one array dimension
	PRIMITIVE_INT = 'I',	// integer
	PRIMITIVE_BYTE = 'B',   // signed byte
	PRIMITIVE_CHAR = 'C',   // Unicode character code point in the Basic Multilingual Plane,
							// encoded with UTF-16
	PRIMITIVE_DOUBLE = 'D', // double-precision floating-point value
	PRIMITIVE_FLOAT = 'F',  // single-precision floating-point value
	PRIMITIVE_LONG = 'J',   // long integer
	PRIMITIVE_SHORT = 'S',  // signed short
	PRIMITIVE_BOOLEAN = 'Z' // true or false
};
/**
 * The element_value structure is a discriminated union representing the value of an
 *element-value pair.
 * It is used to represent element values in all attributes that describe annotations
 * - RuntimeVisibleAnnotations
 * - RuntimeInvisibleAnnotations
 * - RuntimeVisibleParameterAnnotations
 * - RuntimeInvisibleParameterAnnotations).
 *
 * The element_value structure has the following format:
 */
class element_value
{
protected:
	element_value_type type;
	constant_pool &pool;

public:
	element_value(element_value_type type, constant_pool &pool) : type(type), pool(pool) {};

	element_value_type getElementValueType()
	{
		return type;
	}

	virtual std::string toString() = 0;

	static element_value *readElementValue(util::membuffer &input, constant_pool &pool);
};

/**
 * Each value of the annotations table represents a single runtime-visible annotation on a
 * program element.
 * The annotation structure has the following format:
 */
class annotation
{
public:
	typedef std::vector<std::pair<uint16_t, element_value *>> value_list;

protected:
	/**
	 * The value of the type_index item must be a valid index into the constant_pool table.
	 * The constant_pool entry at that index must be a CONSTANT_Utf8_info (§4.4.7) structure
	 * representing a field descriptor representing the annotation type corresponding
	 * to the annotation represented by this annotation structure.
	 */
	uint16_t type_index;
	/**
	 * map between element_name_index and value.
	 *
	 * The value of the element_name_index item must be a valid index into the constant_pool
	 *table.
	 * The constant_pool entry at that index must be a CONSTANT_Utf8_info (§4.4.7) structure
	 *representing
	 * a valid field descriptor (§4.3.2) that denotes the name of the annotation type element
	 *represented
	 * by this element_value_pairs entry.
	 */
	value_list name_val_pairs;
	/**
	 * Reference to the parent constant pool
	 */
	constant_pool &pool;

public:
	annotation(uint16_t type_index, constant_pool &pool)
		: type_index(type_index), pool(pool) {};
	~annotation()
	{
		for (unsigned i = 0; i < name_val_pairs.size(); i++)
		{
			delete name_val_pairs[i].second;
		}
	}
	void add_pair(uint16_t key, element_value *value)
	{
		name_val_pairs.push_back(std::make_pair(key, value));
	}
	;
	value_list::const_iterator begin()
	{
		return name_val_pairs.cbegin();
	}
	value_list::const_iterator end()
	{
		return name_val_pairs.cend();
	}
	std::string toString();
	static annotation *read(util::membuffer &input, constant_pool &pool);
};
typedef std::vector<annotation *> annotation_table;

/// type for simple value annotation elements
class element_value_simple : public element_value
{
protected:
	/// index of the constant in the constant pool
	uint16_t index;

public:
	element_value_simple(element_value_type type, uint16_t index, constant_pool &pool)
		: element_value(type, pool), index(index) {
										 // TODO: verify consistency
									 };
	uint16_t getIndex()
	{
		return index;
	}
	virtual std::string toString()
	{
		return pool[index].toString();
	}
	;
};
/// The enum_const_value item is used if the tag item is 'e'.
class element_value_enum : public element_value
{
protected:
	/**
	 * The value of the type_name_index item must be a valid index into the constant_pool table.
	 * The constant_pool entry at that index must be a CONSTANT_Utf8_info (§4.4.7) structure
	 * representing a valid field descriptor (§4.3.2) that denotes the internal form of the
	 * binary
	 * name (§4.2.1) of the type of the enum constant represented by this element_value
	 * structure.
	 */
	uint16_t typeIndex;
	/**
	 * The value of the const_name_index item must be a valid index into the constant_pool
	 * table.
	 * The constant_pool entry at that index must be a CONSTANT_Utf8_info (§4.4.7) structure
	 * representing the simple name of the enum constant represented by this element_value
	 * structure.
	 */
	uint16_t valueIndex;

public:
	element_value_enum(element_value_type type, uint16_t typeIndex, uint16_t valueIndex,
					   constant_pool &pool)
		: element_value(type, pool), typeIndex(typeIndex), valueIndex(valueIndex)
	{
		// TODO: verify consistency
	}
	uint16_t getValueIndex()
	{
		return valueIndex;
	}
	uint16_t getTypeIndex()
	{
		return typeIndex;
	}
	virtual std::string toString()
	{
		return "enum value";
	}
	;
};

class element_value_class : public element_value
{
protected:
	/**
	 * The class_info_index item must be a valid index into the constant_pool table.
	 * The constant_pool entry at that index must be a CONSTANT_Utf8_info (§4.4.7) structure
	 * representing the return descriptor (§4.3.3) of the type that is reified by the class
	 * represented by this element_value structure.
	 *
	 * For example, 'V' for Void.class, 'Ljava/lang/Object;' for Object, etc.
	 *
	 * Or in plain english, you can store type information in annotations. Yay.
	 */
	uint16_t classIndex;

public:
	element_value_class(element_value_type type, uint16_t classIndex, constant_pool &pool)
		: element_value(type, pool), classIndex(classIndex)
	{
		// TODO: verify consistency
	}
	uint16_t getIndex()
	{
		return classIndex;
	}
	virtual std::string toString()
	{
		return "class";
	}
	;
};

/// nested annotations... yay
class element_value_annotation : public element_value
{
private:
	annotation *nestedAnnotation;

public:
	element_value_annotation(element_value_type type, annotation *nestedAnnotation,
							 constant_pool &pool)
		: element_value(type, pool), nestedAnnotation(nestedAnnotation) {};
	~element_value_annotation()
	{
		if (nestedAnnotation)
		{
			delete nestedAnnotation;
			nestedAnnotation = nullptr;
		}
	}
	virtual std::string toString()
	{
		return "nested annotation";
	}
	;
};

/// and arrays!
class element_value_array : public element_value
{
public:
	typedef std::vector<element_value *> elem_vec;

protected:
	elem_vec values;

public:
	element_value_array(element_value_type type, std::vector<element_value *> &values,
						constant_pool &pool)
		: element_value(type, pool), values(values) {};
	~element_value_array()
	{
		for (unsigned i = 0; i < values.size(); i++)
		{
			delete values[i];
		}
	}
	;
	elem_vec::const_iterator begin()
	{
		return values.cbegin();
	}
	elem_vec::const_iterator end()
	{
		return values.cend();
	}
	virtual std::string toString()
	{
		return "array";
	}
	;
};
}