jif.types.label
Class AccessPath

java.lang.Object
  jif.types.label.AccessPath

All Implemented Interfaces:

java.io.Serializable, java.lang.Cloneable, polyglot.util.Copy

Direct Known Subclasses:

AccessPathField, AccessPathRoot

public abstract class AccessPath
extends java.lang.Object
implements java.io.Serializable, polyglot.util.Copy

An AccessPath represents a final access path. A final access path is of the form "R.f1. ... .fn", where "R" is one of

• a final local variable
• the special expression "this"
• a class type

and each "fi" is a final field dereference.

AccessPaths are used in the Jif type system to represent dynamic principals and dynamic labels.

For technical reasons, there are two subclasses of AccessPath that do not directly represent final access paths. AccessPathConstantis used to represent label or principal expressions, such as "new label {Alice:}" or "Alice". (@link jif.types.label.AccessPathUninterpreted AccessPathUninterpreted} is used to represent non-final access paths, for example "this.m()".

See Also:

Serialized Form

Constructor Summary

protected

AccessPath(polyglot.util.Position pos)

Method Summary

java.lang.Object	copy()
abstract boolean	equals(java.lang.Object o)
abstract boolean	equivalentTo(AccessPath p, LabelEnv env)
java.lang.String	exprString()
abstract int	hashCode()
abstract boolean	isCanonical()
abstract boolean	isNeverNull()
abstract boolean	isUninterpreted()
abstract PathMap	labelcheck(JifContext A, LabelChecker lc)
polyglot.util.Position	position()
abstract AccessPathRoot	root()
abstract AccessPath	subst(AccessPathRoot r, AccessPath e) Return the result of substituting the root r with the access path e.
java.util.List	throwTypes(polyglot.types.TypeSystem ts) Return a list of types that may be thrown as a result of the runtime evaluation of this path.
abstract polyglot.types.Type	type() The type of the access path (when the access path is regarded as an expression).
void	verify(JifContext A) Go through the path, check that all the type information is set correctly, and check that every field access is to a final field, and any local used is final

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

AccessPath

protected AccessPath(polyglot.util.Position pos)

Method Detail

equals

public abstract boolean equals(java.lang.Object o)

Overrides:

equals in class java.lang.Object

isCanonical

public abstract boolean isCanonical()

isUninterpreted

public abstract boolean isUninterpreted()

subst

public abstract AccessPath subst(AccessPathRoot r,
                                 AccessPath e)

Return the result of substituting the root r with the access path e. For example, given a field access path "this.f", substituting the access path root "this" for the access path "o.g" will result in the access path "o.g.f". This method is used to instantiate procedures for calls, and labels of fields.

type

public abstract polyglot.types.Type type()

The type of the access path (when the access path is regarded as an expression).

hashCode

public abstract int hashCode()

Overrides:

hashCode in class java.lang.Object

isNeverNull

public abstract boolean isNeverNull()

labelcheck

public abstract PathMap labelcheck(JifContext A,
                                   LabelChecker lc)

root

public abstract AccessPathRoot root()

position

public final polyglot.util.Position position()

verify

public void verify(JifContext A)
            throws polyglot.types.SemanticException

Go through the path, check that all the type information is set correctly, and check that every field access is to a final field, and any local used is final

Parameters:

A -

Throws:

polyglot.types.SemanticException

exprString

public java.lang.String exprString()

throwTypes

public java.util.List throwTypes(polyglot.types.TypeSystem ts)

Return a list of types that may be thrown as a result of the runtime evaluation of this path.

copy

public java.lang.Object copy()

Specified by:

copy in interface polyglot.util.Copy

equivalentTo

public abstract boolean equivalentTo(AccessPath p,
                                     LabelEnv env)