org.aspectj.compiler.base.ast
Class NullExpr

java.lang.Object
  org.aspectj.compiler.base.CompilerObject
      org.aspectj.compiler.base.ast.ASTObject
          org.aspectj.compiler.base.ast.Expr
              org.aspectj.compiler.base.ast.JavaExpr
                  org.aspectj.compiler.base.ast.NullExpr

All Implemented Interfaces:

MajPrimaryExpr

public class NullExpr

extends JavaExpr

implements MajPrimaryExpr

Field Summary

Fields inherited from class org.aspectj.compiler.base.ast.Expr

type

Fields inherited from class org.aspectj.compiler.base.ast.ASTObject

dummySource, parent, sourceLocation

Constructor Summary

NullExpr()

NullExpr(SourceLocation location)

Method Summary

boolean	canBeCopied() Can this expression be copied without changing the semantics of the program.
protected void	cgEffect(org.aspectj.compiler.base.bcg.CodeBuilder cb) Evaluates the expression in a context where its value is unnecessary (i.e., from ExprStmt, or in a FieldAccessExpr when the field is static but there is an expression there nonetheless).
protected void	cgValue(org.aspectj.compiler.base.bcg.CodeBuilder cb) Leaves the value of this expression on the stack.
ASTObject	copyWalk(CopyWalker walker)
Type	discoverType()
java.lang.String	getDefaultDisplayName()
boolean	isConstantZero() is this expression zero or null?
boolean	isUltimatelyLiteral() Is this expression ultimately a literal expression.
Expr	toExpr()
void	unparse(org.aspectj.compiler.base.CodeWriter writer)

Methods inherited from class org.aspectj.compiler.base.ast.Expr

assertType, cgBuffer, cgTest, cgValue, checkSpec, cleanup, getType, isAssignableTo, isConstantFalse, isConstantTrue, isInConstructorCallExpr, isInExprStmt, isLegalStmt, isMethodConvertableTo, makeQualifiedThis, makeReference, postCopy, setType, showOperatorTypeError, showOperatorTypeError, walkCleanup, walkFrameLoc

Methods inherited from class org.aspectj.compiler.base.ast.ASTObject

addComment, buildAccessMethod, checkNoSharing, clearComment, clearParent, contains, containsTypes, copy, display, fixAccessPost, fixAST, fromSource, getAST, getBeginColumn, getBeginLine, getBytecodeType, getBytecodeTypeDec, getChildAt, getChildCount, getChildNameAt, getComment, getCompilationUnit, getDeclaringType, getEnclosingCodeDec, getEnclosingDec, getEndColumn, getEndLine, getEndPosition, getFormalComment, getLexicalType, getOutermostBytecodeType, getOutermostLexicalType, getParent, getSourceDirectoryName, getSourceFile, getSourceFileName, getSourceLocation, getStartPosition, hasLegalProtectedAccess, hasSource, hasSourceLocation, implementMixin, indexOf, inStaticContext, isLanguageVisible, isLeaf, isSynthetic, makeChild, makeChild, postAssignmentCheck, postCleanup, postFixAST, postImplementMixin, postInnerAccess, postInnerInfo, postLift, postMove, postScope, postThreading, preAssignmentCheck, preCopy, preIntroduction, preLift, preMove, preScope, preThreading, remove, remove, removeChildAt, replaceWith, setChildAt, setFormalComment, setParent, setParents, setSource, setSourceLocation, setSyntheticSource, showError, showMessage, showTypeError, showWarning, toShortString, toString, unparse, walk, walkAnalysis, walkAssignmentCheck, walkFlow, walkForwardReference, walkInnerInfo, walkMemberMunger, walkScope

Methods inherited from class org.aspectj.compiler.base.CompilerObject

getCompiler, getOptions, getTypeManager, getWorld

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.aspectj.compiler.base.ast.MajPrimaryExpr

unparse

Constructor Detail

NullExpr

public NullExpr(SourceLocation location)

NullExpr

public NullExpr()

Method Detail

toExpr

public Expr toExpr()

discoverType

public Type discoverType()

Specified by:

discoverType in class Expr

unparse

public void unparse(org.aspectj.compiler.base.CodeWriter writer)
             throws java.io.IOException

Overrides:

unparse in class ASTObject

Throws:

java.io.IOException

canBeCopied

public boolean canBeCopied()

Description copied from class: Expr

Can this expression be copied without changing the semantics of the program.

Overrides:

canBeCopied in class Expr

isUltimatelyLiteral

public boolean isUltimatelyLiteral()

Description copied from class: Expr

Is this expression ultimately a literal expression. The only difference between this and canBeCopied is that 'this' is NOT ultimatelyLiteral, and that a cast is only copiable if its expression is ultimatelyLiteral.

Overrides:

isUltimatelyLiteral in class Expr

cgValue

protected void cgValue(org.aspectj.compiler.base.bcg.CodeBuilder cb)

Description copied from class: Expr

Leaves the value of this expression on the stack. May self-call Expr.cgTest(CodeBuilder, Label, Label).

Overrides:

cgValue in class Expr

cgEffect

protected void cgEffect(org.aspectj.compiler.base.bcg.CodeBuilder cb)

Description copied from class: Expr

Evaluates the expression in a context where its value is unnecessary (i.e., from ExprStmt, or in a FieldAccessExpr when the field is static but there is an expression there nonetheless). May self-call Expr.cgValue(CodeBuilder).

Overrides:

cgEffect in class Expr

isConstantZero

public boolean isConstantZero()

Description copied from class: Expr

is this expression zero or null?

Overrides:

isConstantZero in class Expr

copyWalk

public ASTObject copyWalk(CopyWalker walker)

Overrides:

copyWalk in class ASTObject

getDefaultDisplayName

public java.lang.String getDefaultDisplayName()

Overrides:

getDefaultDisplayName in class Expr