polyglot.visit

Class ExceptionChecker

java.lang.Object

polyglot.visit.NodeVisitor

polyglot.visit.HaltingVisitor

polyglot.visit.ErrorHandlingVisitor

polyglot.visit.ExceptionChecker

All Implemented Interfaces:

java.lang.Cloneable, Copy<NodeVisitor>

public class ExceptionChecker
extends ErrorHandlingVisitor

Visitor which checks if exceptions are caught or declared properly.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	ExceptionChecker.CodeTypeReporter
static class	ExceptionChecker.UncaughtReporter

Nested classes/interfaces inherited from interface polyglot.util.Copy

Copy.Util

Field Summary

Fields

Modifier and Type	Field and Description
protected java.util.Set<Type>	catchable Set of exceptions that can be caught.
protected boolean	catchAllThrowable Should the propagation of exceptions upwards go past this point?
protected ExceptionChecker	outer
protected ExceptionChecker.UncaughtReporter	reporter Responsible for creating an appropriate SemanticException to report an uncaught exception.
protected SubtypeSet	throwsSet The throws set, calculated bottom up.

Fields inherited from class polyglot.visit.ErrorHandlingVisitor

error, job, nf, ts

Fields inherited from class polyglot.visit.HaltingVisitor

bypass, bypassParent

Constructor Summary

Constructors

Constructor and Description
ExceptionChecker(Job job, TypeSystem ts, NodeFactory nf)

Method Summary

Methods

Modifier and Type	Method and Description
protected NodeVisitor	enterCall(Node n)
protected NodeVisitor	enterError(Node n) This method determines what should be returned by enter() should its call to enterCall() throw a SemanticException.
JLang	lang()
protected Node	leaveCall(Node old, Node n, NodeVisitor v) Call exceptionCheck(ExceptionChecker) on the node.
ExceptionChecker	pop()
ExceptionChecker	push()
ExceptionChecker	push(java.util.Collection<? extends Type> catchableTypes)
ExceptionChecker	push(ExceptionChecker.UncaughtReporter reporter)
ExceptionChecker	push(Type catchableType)
ExceptionChecker	pushCatchAllThrowable()
protected void	reportUncaughtException(Type t, Position pos)
void	throwsException(Type t, Position pos) The AST nodes will use this callback to notify us that they throw an exception of type t.
SubtypeSet	throwsSet()

Methods inherited from class polyglot.visit.ErrorHandlingVisitor

begin, catchErrors, enter, enterCall, errorQueue, hasErrors, job, leave, leaveCall, leaveCall, nodeFactory, typeSystem

Methods inherited from class polyglot.visit.HaltingVisitor

bypass, bypass, bypassChildren, override, visitChildren

Methods inherited from class polyglot.visit.NodeVisitor

copy, enter, finish, finish, leave, override, toString, visitEdge, visitEdgeNoOverride

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

outer

protected ExceptionChecker outer

catchable

protected java.util.Set<Type> catchable

Set of exceptions that can be caught. Combined with the outer field, these sets form a stack of exceptions, representing all and only the exceptions that are permitted to be thrown at this point in the code. Note: Consider the following code, where A,B,C,D are Exception subclasses. void m() throws A, B { try { ... } catch (C ex) { ... } catch (D ex) { ... } } Inside the try-block, the stack of catchable sets is: { C } { D } { A, B }

throwsSet

protected SubtypeSet throwsSet

The throws set, calculated bottom up. That is, what exceptions can be thrown by the AST node that is being analyzed by this ExceptionChecker?

reporter

protected ExceptionChecker.UncaughtReporter reporter

Responsible for creating an appropriate SemanticException to report an uncaught exception.

catchAllThrowable

protected boolean catchAllThrowable

Should the propagation of exceptions upwards go past this point?

Constructor Detail

ExceptionChecker

public ExceptionChecker(Job job,
                TypeSystem ts,
                NodeFactory nf)

Method Detail

lang

public JLang lang()

Overrides:

lang in class NodeVisitor

push

public ExceptionChecker push(ExceptionChecker.UncaughtReporter reporter)

push

public ExceptionChecker push(Type catchableType)

push

public ExceptionChecker push(java.util.Collection<? extends Type> catchableTypes)

pushCatchAllThrowable

public ExceptionChecker pushCatchAllThrowable()

push

public ExceptionChecker push()

pop

public ExceptionChecker pop()

enterCall

protected NodeVisitor enterCall(Node n)
                         throws SemanticException

Overrides:

enterCall in class ErrorHandlingVisitor

Throws:

SemanticException

enterError

protected NodeVisitor enterError(Node n)

Description copied from class: ErrorHandlingVisitor

This method determines what should be returned by enter() should its call to enterCall() throw a SemanticException.

Overrides:

enterError in class ErrorHandlingVisitor

Parameters:

n - The root of the subtree that was traversed.

Returns:

The ErrorHandlingVisitor which should be used to visit the children of n.

leaveCall

protected Node leaveCall(Node old,
             Node n,
             NodeVisitor v)
                  throws SemanticException

Call exceptionCheck(ExceptionChecker) on the node.

Overrides:

leaveCall in class ErrorHandlingVisitor

Parameters:

old - The original state of root of the current subtree.

n - The current state of the root of the current subtree.

v - The NodeVisitor object used to visit the children.

Returns:

The final result of the traversal of the tree rooted at n.

Throws:

SemanticException

throwsException

public void throwsException(Type t,
                   Position pos)
                     throws SemanticException

The AST nodes will use this callback to notify us that they throw an exception of type t. This method will throw a SemanticException if the type t is not allowed to be thrown at this point; the exception t will be added to the throwsSet of all exception checkers in the stack, up to (and not including) the exception checker that catches the exception.

Parameters:

t - The type of exception that the node throws.

Throws:

SemanticException

throwsSet

public SubtypeSet throwsSet()

reportUncaughtException

protected void reportUncaughtException(Type t,
                           Position pos)
                                throws SemanticException

Throws:

SemanticException