gnu.bytecode

Class Type

public abstract class Type extends Object

Field Summary
static Method	booleanValue_method
static ClassType	boolean_ctype
static PrimType	boolean_type
static PrimType	byte_type
static PrimType	char_type
static Method	clone_method
static Method	doubleValue_method
static PrimType	double_type
static Method	floatValue_method
static PrimType	float_type
static Method	intValue_method
static PrimType	int_type
static ClassType	java_lang_Class_type
static Method	longValue_method
static PrimType	long_type
static PrimType	neverReturnsType The "return type" of an expression that never returns, such as a throw.
static ObjectType	nullType The magic type of null.
static ClassType	number_type
static ClassType	pointer_type
protected Class	reflectClass
static PrimType	short_type
static ClassType	string_type
static ClassType	throwable_type
static ClassType	tostring_type
static Method	toString_method
static Type[]	typeArray0
static PrimType	void_type

Constructor Summary
protected	Type()
	Type(Type type)

Method Summary
abstract Object	coerceFromObject(Object obj) Convert an object to a value of this Type.
Object	coerceToObject(Object obj)
abstract int	compare(Type other) Return a numeric code showing "subtype" relationship: 1: if other is a pure subtype of this; 0: if has the same values; -1: if this is a pure subtype of other; -2: if they have values in common but neither is a subtype of the other; -3: if the types have no values in common.
void	emitCoerceFromObject(CodeAttr code) Compile code to coerce/convert from Object to this type.
void	emitCoerceToObject(CodeAttr code) Compile code to convert a object of this type on the stack to Object.
void	emitIsInstance(CodeAttr code)
Type	getImplementationType() The type used to implement types not natively understood by the JVM.
String	getName()
Class	getReflectClass() Get the java.lang.Class object for the representation type.
String	getSignature()
int	getSize()
int	getSizeInWords()
static Type	getType(String name) Find an Type with the given name, or create a new one.
int	hashCode()
boolean	isInstance(Object obj)
static boolean	isMoreSpecific(Type[] t1, Type[] t2) Return true iff t1[i].isSubtype(t2[i]) for all i.
boolean	isSubtype(Type other) Return true if this is a "subtype" of other.
static boolean	isValidJavaTypeName(String name)
boolean	isVoid()
static Type	lookupType(String name)
static Type	lowestCommonSuperType(Type t1, Type t2) Computes the common supertype Interfaces are not taken into account.
static Type	make(Class reflectClass)
Type	promote()
static void	registerTypeForClass(Class clas, Type type) Register that the Type for class is type.
protected void	setName(String name)
void	setReflectClass(Class rclass)
protected void	setSignature(String sig)
static int	signatureLength(String sig, int pos) Return the length of the signature starting at a given string position.
static int	signatureLength(String sig)
static String	signatureToName(String sig) Returns the Java-level type name from a given signature.
static PrimType	signatureToPrimitive(char sig) Returns the primitive type corresponding to a signature character.
static Type	signatureToType(String sig, int off, int len) Get a Type corresponding to the given signature string.
static Type	signatureToType(String sig) Get a Type corresponding to the given signature string.
protected static int	swappedCompareResult(int code) Change result from compare to compensate for argument swapping.
String	toString()

Field Detail

booleanValue_method

public static final Method booleanValue_method

boolean_ctype

public static final ClassType boolean_ctype

boolean_type

public static final PrimType boolean_type

doubleValue_method

public static final Method doubleValue_method

double_type

public static final PrimType double_type

floatValue_method

public static final Method floatValue_method

intValue_method

public static final Method intValue_method

java_lang_Class_type

public static final ClassType java_lang_Class_type

longValue_method

public static final Method longValue_method

neverReturnsType

public static final PrimType neverReturnsType

The "return type" of an expression that never returns, such as a throw.

nullType

public static final ObjectType nullType

The magic type of null.

number_type

public static final ClassType number_type

pointer_type

public static final ClassType pointer_type

throwable_type

public static final ClassType throwable_type

tostring_type

public static final ClassType tostring_type

toString_method

public static final Method toString_method

Method Detail

coerceFromObject

public abstract Object coerceFromObject(Object obj)

Convert an object to a value of this Type. Throw a ClassCastException when this is not possible.

coerceToObject

public Object coerceToObject(Object obj)

Return a numeric code showing "subtype" relationship: 1: if other is a pure subtype of this; 0: if has the same values; -1: if this is a pure subtype of other; -2: if they have values in common but neither is a subtype of the other; -3: if the types have no values in common. "Same member" is rather loose; by "A is a subtype of B" we mean that all instance of A can be "widened" to B. More formally, A.compare(B) returns: 1: all B values can be converted to A without a coercion failure (i.e. a ClassCastException or overflow or major loss of information), but not vice versa. 0: all A values can be converted to B without a coercion failure and vice versa; -1: all A values can be converted to B without a coercion failure not not vice versa; -2: there are (potentially) some A values that can be converted to B, and some B values can be converted to A; -3: there are no A values that can be converted to B, and neither are there any B values that can be converted to A.

emitCoerceFromObject

public void emitCoerceFromObject(CodeAttr code)

Compile code to coerce/convert from Object to this type.

emitCoerceToObject

public void emitCoerceToObject(CodeAttr code)

Compile code to convert a object of this type on the stack to Object.

emitIsInstance

public void emitIsInstance(CodeAttr code)

getImplementationType

public Type getImplementationType()

The type used to implement types not natively understood by the JVM. Usually, the identity function. However, a language might handle union types or template types or type expressions calculated at run time. In that case return the type used at the JVM level, and known at compile time.

getName

public final String getName()

getReflectClass

public Class getReflectClass()

Get the java.lang.Class object for the representation type.

getSignature

public final String getSignature()

getSize

public final int getSize()

getSizeInWords

public int getSizeInWords()

getType

public static Type getType(String name)

Find an Type with the given name, or create a new one. Use this for "library classes", where you need the field/method types, but not one where you are about to generate code for.

Parameters: name the name of the class (e..g. "java.lang.String").

hashCode

public int hashCode()

isInstance

public boolean isInstance(Object obj)

isMoreSpecific

public static boolean isMoreSpecific(Type[] t1, Type[] t2)

Return true iff t1[i].isSubtype(t2[i]) for all i.

isSubtype

public final boolean isSubtype(Type other)

Return true if this is a "subtype" of other.

isValidJavaTypeName

public static boolean isValidJavaTypeName(String name)

isVoid

public final boolean isVoid()

lookupType

public static Type lookupType(String name)

lowestCommonSuperType

public static Type lowestCommonSuperType(Type t1, Type t2)

Computes the common supertype Interfaces are not taken into account. This would be difficult, since interfaces allow multiple-inheritance. This means that there may exists multiple common supertypes to t1 and t2 that are not comparable.

Returns: the lowest type that is both above t1 and t2, or null if t1 and t2 have no common supertype.

Returns: a primitive type, or null if there is no such type.