escjava.translate
Class Purity

java.lang.Object
  escjava.translate.Purity

public abstract class Purity

extends java.lang.Object

Field Summary

(package private) static ASTDecoration

translateDecoration Decorates VarInit nodes with purity information.

Constructor Summary

Purity()

Method Summary

static void	decorate(VarInit expr) Decorate expr and its subexpressions with purity information.
static boolean	impure(VarInit expr) Return true iff expr or any of its subexpressions mutates the heap or local variables.
private static void	makeImpure(VarInit expr) Set the decoration indicating the expr is impure.
static boolean	pure(VarInit expr) Return true iff neither expr nor any of its subexpressions mutate the heap or local variables.

Methods inherited from class java.lang.Object

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

Field Detail

translateDecoration

static ASTDecoration translateDecoration

Decorates VarInit nodes with purity information. Null means a VarInit is pure; non-null means it's impure. Also used by Translate class to decorate LocalVarDecls marked with "uninitialized" with the declaration of the corresponding boolean that keeps track of the variable's initialization state.

Constructor Detail

Purity

public Purity()

Method Detail

impure

public static boolean impure(VarInit expr)

Return true iff expr or any of its subexpressions mutates the heap or local variables. Requires that expr or an expression containing it has been decorated by a call to decorate.

pure

public static boolean pure(VarInit expr)

Return true iff neither expr nor any of its subexpressions mutate the heap or local variables. Requires that expr or an expression containing it has been decorated by a call to decorate.

makeImpure

private static void makeImpure(VarInit expr)

Set the decoration indicating the expr is impure.

decorate

public static void decorate(VarInit expr)

Decorate expr and its subexpressions with purity information.