org.jboss.byteman.rule.expression

Class Variable

java.lang.Object

org.jboss.byteman.rule.RuleElement

org.jboss.byteman.rule.expression.Expression

org.jboss.byteman.rule.expression.AssignableExpression

org.jboss.byteman.rule.expression.Variable

public class Variable
extends AssignableExpression

an expression which identifies a variable occurring either as an LVALUE on the LHS of an event binding in the rule's event or as an RVALUE mentioned in the RHS of an event binding or in thre rule's conditon or action.

Field Summary

Fields inherited from class org.jboss.byteman.rule.expression.Expression

charPos, line, rule, token, type

Constructor Summary

Constructors

Constructor and Description
Variable(Rule rule, Type type, ParseNode token)
Variable(Rule rule, Type type, ParseNode token, String name)

Method Summary

Modifier and Type	Method and Description
void	bind() verify that variables mentioned in this expression are actually available in the supplied bindings list and infer/validate the type of this expression or its subexpressions where possible
void	bindAssign() verify that variables mentioned in this expression are actually available in the supplied bindings list.
void	compile(org.objectweb.asm.MethodVisitor mv, CompileContext compileContext)
void	compileAssign(org.objectweb.asm.MethodVisitor mv, CompileContext compileContext) compile an assignment to the referenced location using the value on the top of the Java stack.
Object	interpret(HelperAdapter helper) evaluate the expression by interpreting the expression tree
Object	interpretAssign(HelperAdapter helperAdapter, Object value) execute an assignment to the referenced location by interpretation of the expression, using the object passed in this call
Type	typeCheck(Type expected) ensure that all type references in the expression and its component expressions can be resolved, that the type of the expression is well-defined and that it is compatible with the type expected in the context in which it occurs.
void	typeCheckAny()
Type	typeCheckAssign(Type expected) typecheck the expression as an lvalue of an assignment operation
void	writeTo(StringWriter stringWriter)

Methods inherited from class org.jboss.byteman.rule.expression.Expression

getPos, getType

Methods inherited from class org.jboss.byteman.rule.RuleElement

compileBooleanConversion, compileBox, compileNumericConversion, compileObjectConversion, compilePrimitiveConversion, compileStringConversion, compileTypeConversion, compileUnbox, getBindings, getTypeGroup, rebox, toString

Methods inherited from class java.lang.Object

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

Constructor Detail

Variable

public Variable(Rule rule,
                Type type,
                ParseNode token)

Variable

public Variable(Rule rule,
                Type type,
                ParseNode token,
                String name)

Method Detail

bind

public void bind()
          throws TypeException

verify that variables mentioned in this expression are actually available in the supplied bindings list and infer/validate the type of this expression or its subexpressions where possible

Specified by:

bind in class Expression

Throws:

TypeException - if any variable is missing or has the wrong type

bindAssign

public void bindAssign()
                throws TypeException

verify that variables mentioned in this expression are actually available in the supplied bindings list. infer/validate the type of this expression or its subexpressions where possible

Specified by:

bindAssign in class AssignableExpression

Throws:

TypeException - if any variable is missing or has the wrong type

typeCheck

public Type typeCheck(Type expected)
               throws TypeException

Description copied from class: Expression

ensure that all type references in the expression and its component expressions can be resolved, that the type of the expression is well-defined and that it is compatible with the type expected in the context in which it occurs.

Specified by:

typeCheck in class Expression

Parameters:

expected - the type expected for the expression in the contxet in which it occurs. this may be void but should not be undefined at the point where type checking is performed.

Returns:

the type of the expression

Throws:

TypeException - if a type check failure occurs

typeCheckAssign

public Type typeCheckAssign(Type expected)
                     throws TypeException

Description copied from class: AssignableExpression

typecheck the expression as an lvalue of an assignment operation

Specified by:

typeCheckAssign in class AssignableExpression

Parameters:

expected - the expected type for the expression

Returns:

the expression type

Throws:

TypeException - if a type check error occurs

typeCheckAny

public void typeCheckAny()
                  throws TypeException

Throws:

TypeException

interpret

public Object interpret(HelperAdapter helper)
                 throws ExecuteException

Description copied from class: Expression

evaluate the expression by interpreting the expression tree

Specified by:

interpret in class Expression

Parameters:

helper - an execution context associated with the rule which contains a map of current bindings for rule variables and another map of their declared types both of which are indexed by variable name. This includes entries for the helper (name "-1"), the recipient if the trigger method is not static (name "0") and the trigger method arguments (names "1", ...)

Returns:

the result of evaluation as an Object

Throws:

ExecuteException - if an error occurs during execution

compile

public void compile(org.objectweb.asm.MethodVisitor mv,
                    CompileContext compileContext)
             throws CompileException

Specified by:

compile in class RuleElement

Throws:

CompileException

interpretAssign

public Object interpretAssign(HelperAdapter helperAdapter,
                              Object value)
                       throws ExecuteException

Description copied from class: AssignableExpression

execute an assignment to the referenced location by interpretation of the expression, using the object passed in this call

Specified by:

interpretAssign in class AssignableExpression

Parameters:

helperAdapter - an execution context associated with the rule which contains a map of current bindings for rule variables and another map of their declared types both of which are indexed by variable name. This includes entries for the helper (name "-1"), the recipient if the trigger method is not static (name "0") and the trigger method arguments (names "1", ...)

value - the value to be assigned to this object

Returns:

the result of evaluation as an Object

Throws:

ExecuteException - if an error occurs during execution

compileAssign

public void compileAssign(org.objectweb.asm.MethodVisitor mv,
                          CompileContext compileContext)
                   throws CompileException

Description copied from class: AssignableExpression

compile an assignment to the referenced location using the value on the top of the Java stack.

Specified by:

compileAssign in class AssignableExpression

Parameters:

mv - the current method visitor

compileContext - the current compile context

Throws:

CompileException - if a compile error occurs

writeTo

public void writeTo(StringWriter stringWriter)

Specified by:

writeTo in class Expression