A ClassBType represents a class or interface type. The necessary information to build a ClassBType is extracted from compiler symbols and types, see BTypesFromSymbols.
The offset and length fields are used to represent the internal name of the class. They
are indices into some character array. The internal name can be obtained through the method
internalNameString, which is abstract in this component. Name creation is assumed to be
hash-consed, so if two ClassBTypes have the same internal name, they NEED to have the same
offset and length.
The actual implementation in subclass BTypesFromSymbols uses the global chrs array from the
name table. This representation is efficient because the JVM class name is obtained through
classSymbol.javaBinaryName. This already adds the necessary string to the chrs array,
so it makes sense to reuse the same name table in the backend.
ClassBType is not a case class because we want a custom equals method, and because the extractor extracts the internalName, which is what you typically need.
- Companion:
- object
Value members
Concrete methods
Custom equals / hashCode: we only compare the name (offset / length)
Custom equals / hashCode: we only compare the name (offset / length)
- Definition Classes
- Any
Calculate a hash code value for the object.
Calculate a hash code value for the object.
The default hashing algorithm is platform dependent.
Note that it is allowed for two objects to have identical hash codes (o1.hashCode.equals(o2.hashCode)) yet
not be equal (o1.equals(o2) returns false). A degenerate implementation could always return 0.
However, it is required that if two objects are equal (o1.equals(o2) returns true) that they have
identical hash codes (o1.hashCode.equals(o2.hashCode)). Therefore, when overriding this method, be sure
to verify that the behavior is consistent with the equals method.
- Returns:
the hash code value for this object.
- Definition Classes
- Any
Finding the least upper bound in agreement with the bytecode verifier Background: http://gallium.inria.fr/~xleroy/publi/bytecode-verification-JAR.pdf http://comments.gmane.org/gmane.comp.java.vm.languages/2293 https://issues.scala-lang.org/browse/SI-3872
Finding the least upper bound in agreement with the bytecode verifier Background: http://gallium.inria.fr/~xleroy/publi/bytecode-verification-JAR.pdf http://comments.gmane.org/gmane.comp.java.vm.languages/2293 https://issues.scala-lang.org/browse/SI-3872
Inherited methods
The class or array type of this reference type. Used for ANEWARRAY, MULTIANEWARRAY, INSTANCEOF and CHECKCAST instructions. Also used for emitting invokevirtual calls to (a: Array[T]).clone() for any T, see genApply.
The class or array type of this reference type. Used for ANEWARRAY, MULTIANEWARRAY, INSTANCEOF and CHECKCAST instructions. Also used for emitting invokevirtual calls to (a: Array[T]).clone() for any T, see genApply.
In contrast to the descriptor, this string does not contain the surrounding 'L' and ';' for class types, for example "java/lang/String". However, for array types, the full descriptor is used, for example "[Ljava/lang/String;".
This can be verified for example using javap or ASMifier.
- Inherited from:
- RefBType
- Returns:
The Java descriptor of this type. Examples:
- int: I
- java.lang.String: Ljava/lang/String;
- int[]: [I
- Object m(String s, double d): (Ljava/lang/String;D)Ljava/lang/Object;
- Inherited from:
- BType
Compute the upper bound of two types. Takes promotions of numeric primitives into account.
Compute the upper bound of two types. Takes promotions of numeric primitives into account.
- Inherited from:
- BType
The asm.Type corresponding to this BType.
The asm.Type corresponding to this BType.
Note about asm.Type.getObjectType (*): For class types, the method expects the internal name, i.e. without the surrounding 'L' and ';'. For array types on the other hand, the method expects a full descriptor, for example "[Ljava/lang/String;".
See method asm.Type.getType that creates a asm.Type from a type descriptor
- for an OBJECT type, the 'L' and ';' are not part of the range of the created Type
- for an ARRAY type, the full descriptor is part of the range
- Inherited from:
- BType
Some JVM opcodes have typed variants. This method returns the correct opcode according to the type.
Some JVM opcodes have typed variants. This method returns the correct opcode according to the type.
- Value parameters:
- opcode
A JVM instruction opcode. This opcode must be one of ILOAD, ISTORE, IALOAD, IASTORE, IADD, ISUB, IMUL, IDIV, IREM, INEG, ISHL, ISHR, IUSHR, IAND, IOR IXOR and IRETURN.
- Returns:
The opcode adapted to this java type. For example, if this type is
floatandopcodeisIRETURN, this method returnsFRETURN.- Inherited from:
- BType