/*******************************************************************************
* Copyright (c) 2000, 2011 IBM Corporation and others.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
* IBM Corporation - initial API and implementation
* Stephan Herrmann <stephan@cs.tu-berlin.de> - Contributions for
* bug 319201 - [null] no warning when unboxing SingleNameReference causes NPE
* bug 292478 - Report potentially null across variable assignment
* bug 335093 - [compiler][null] minimal hook for future null annotation support
*******************************************************************************/
package org.eclipse.jdt.internal.compiler.ast;
import org.eclipse.jdt.internal.compiler.ASTVisitor;
import org.eclipse.jdt.internal.compiler.impl.*;
import org.eclipse.jdt.internal.compiler.classfmt.ClassFileConstants;
import org.eclipse.jdt.internal.compiler.codegen.*;
import org.eclipse.jdt.internal.compiler.flow.*;
import org.eclipse.jdt.internal.compiler.lookup.*;
public class LocalDeclaration extends AbstractVariableDeclaration {
public LocalVariableBinding binding;
public LocalDeclaration(
char[] name,
int sourceStart,
int sourceEnd) {
this.name = name;
this.sourceStart = sourceStart;
this.sourceEnd = sourceEnd;
this.declarationEnd = sourceEnd;
}
public FlowInfo analyseCode(BlockScope currentScope, FlowContext flowContext, FlowInfo flowInfo) {
// record variable initialization if any
if ((flowInfo.tagBits & FlowInfo.UNREACHABLE_OR_DEAD) == 0) {
this.bits |= ASTNode.IsLocalDeclarationReachable; // only set if actually reached
}
if (this.binding != null && this.type.resolvedType instanceof TypeVariableBinding) {
MethodScope methodScope= this.binding.declaringScope.methodScope();
AbstractMethodDeclaration methodDeclaration = methodScope.referenceMethod();
if (methodDeclaration != null && ((methodDeclaration.bits & ASTNode.CanBeStatic) != 0) && methodDeclaration.binding != null) {
TypeVariableBinding[] typeVariables = methodDeclaration.binding.typeVariables();
if (typeVariables == Binding.NO_TYPE_VARIABLES) {
// Method declares no type variables.
currentScope.resetEnclosingMethodStaticFlag();
} else {
// to check whether the resolved type for this is declared by enclosing method as a type variable
boolean usesEnclosingTypeVar = false;
for (int i = 0; i < typeVariables.length ; i ++) {
if (typeVariables[i] == this.type.resolvedType){
usesEnclosingTypeVar = true;
break;
}
}
if (!usesEnclosingTypeVar) {
// uses a type variable not declared by enclosing method
currentScope.resetEnclosingMethodStaticFlag();
}
}
}
}
if (this.initialization == null) {
return flowInfo;
}
if ((this.initialization.implicitConversion & TypeIds.UNBOXING) != 0) {
this.initialization.checkNPE(currentScope, flowContext, flowInfo);
}
flowInfo =
this.initialization
.analyseCode(currentScope, flowContext, flowInfo)
.unconditionalInits();
int nullStatus = this.initialization.nullStatus(flowInfo);
if (!flowInfo.isDefinitelyAssigned(this.binding)){// for local variable debug attributes
this.bits |= FirstAssignmentToLocal;
} else {
this.bits &= ~FirstAssignmentToLocal; // int i = (i = 0);
}
flowInfo.markAsDefinitelyAssigned(this.binding);
nullStatus = checkAgainstNullAnnotation(currentScope, this.binding, nullStatus);
if ((this.binding.type.tagBits & TagBits.IsBaseType) == 0) {
flowInfo.markNullStatus(this.binding, nullStatus);
// no need to inform enclosing try block since its locals won't get
// known by the finally block
}
return flowInfo;
}
public void checkModifiers() {
//only potential valid modifier is <<final>>
if (((this.modifiers & ExtraCompilerModifiers.AccJustFlag) & ~ClassFileConstants.AccFinal) != 0)
//AccModifierProblem -> other (non-visibility problem)
//AccAlternateModifierProblem -> duplicate modifier
//AccModifierProblem | AccAlternateModifierProblem -> visibility problem"
this.modifiers = (this.modifiers & ~ExtraCompilerModifiers.AccAlternateModifierProblem) | ExtraCompilerModifiers.AccModifierProblem;
}
/**
* Code generation for a local declaration:
* i.e. normal assignment to a local variable + unused variable handling
*/
public void generateCode(BlockScope currentScope, CodeStream codeStream) {
// even if not reachable, variable must be added to visible if allocated (28298)
if (this.binding.resolvedPosition != -1) {
codeStream.addVisibleLocalVariable(this.binding);
}
if ((this.bits & IsReachable) == 0) {
return;
}
int pc = codeStream.position;
// something to initialize?
generateInit: {
if (this.initialization == null)
break generateInit;
// forget initializing unused or final locals set to constant value (final ones are inlined)
if (this.binding.resolvedPosition < 0) {
if (this.initialization.constant != Constant.NotAConstant)
break generateInit;
// if binding unused generate then discard the value
this.initialization.generateCode(currentScope, codeStream, false);
break generateInit;
}
this.initialization.generateCode(currentScope, codeStream, true);
// 26903, need extra cast to store null in array local var
if (this.binding.type.isArrayType()
&& (this.initialization.resolvedType == TypeBinding.NULL // arrayLoc = null
|| ((this.initialization instanceof CastExpression) // arrayLoc = (type[])null
&& (((CastExpression)this.initialization).innermostCastedExpression().resolvedType == TypeBinding.NULL)))){
codeStream.checkcast(this.binding.type);
}
codeStream.store(this.binding, false);
if ((this.bits & ASTNode.FirstAssignmentToLocal) != 0) {
/* Variable may have been initialized during the code initializing it
e.g. int i = (i = 1);
*/
this.binding.recordInitializationStartPC(codeStream.position);
}
}
codeStream.recordPositionsFrom(pc, this.sourceStart);
}
/**
* @see org.eclipse.jdt.internal.compiler.ast.AbstractVariableDeclaration#getKind()
*/
public int getKind() {
return LOCAL_VARIABLE;
}
public void resolve(BlockScope scope) {
// create a binding and add it to the scope
TypeBinding variableType = this.type.resolveType(scope, true /* check bounds*/);
checkModifiers();
if (variableType != null) {
if (variableType == TypeBinding.VOID) {
scope.problemReporter().variableTypeCannotBeVoid(this);
return;
}
if (variableType.isArrayType() && ((ArrayBinding) variableType).leafComponentType == TypeBinding.VOID) {
scope.problemReporter().variableTypeCannotBeVoidArray(this);
return;
}
}
Binding existingVariable = scope.getBinding(this.name, Binding.VARIABLE, this, false /*do not resolve hidden field*/);
if (existingVariable != null && existingVariable.isValidBinding()){
if (existingVariable instanceof LocalVariableBinding && this.hiddenVariableDepth == 0) {
scope.problemReporter().redefineLocal(this);
} else {
scope.problemReporter().localVariableHiding(this, existingVariable, false);
}
}
if ((this.modifiers & ClassFileConstants.AccFinal)!= 0 && this.initialization == null) {
this.modifiers |= ExtraCompilerModifiers.AccBlankFinal;
}
this.binding = new LocalVariableBinding(this, variableType, this.modifiers, false);
scope.addLocalVariable(this.binding);
this.binding.setConstant(Constant.NotAConstant);
// allow to recursivelly target the binding....
// the correct constant is harmed if correctly computed at the end of this method
if (variableType == null) {
if (this.initialization != null)
this.initialization.resolveType(scope); // want to report all possible errors
return;
}
// store the constant for final locals
if (this.initialization != null) {
if (this.initialization instanceof ArrayInitializer) {
TypeBinding initializationType = this.initialization.resolveTypeExpecting(scope, variableType);
if (initializationType != null) {
((ArrayInitializer) this.initialization).binding = (ArrayBinding) initializationType;
this.initialization.computeConversion(scope, variableType, initializationType);
}
} else {
this.initialization.setExpectedType(variableType);
TypeBinding initializationType = this.initialization.resolveType(scope);
if (initializationType != null) {
if (variableType != initializationType) // must call before computeConversion() and typeMismatchError()
scope.compilationUnitScope().recordTypeConversion(variableType, initializationType);
if (this.initialization.isConstantValueOfTypeAssignableToType(initializationType, variableType)
|| initializationType.isCompatibleWith(variableType)) {
this.initialization.computeConversion(scope, variableType, initializationType);
if (initializationType.needsUncheckedConversion(variableType)) {
scope.problemReporter().unsafeTypeConversion(this.initialization, initializationType, variableType);
}
if (this.initialization instanceof CastExpression
&& (this.initialization.bits & ASTNode.UnnecessaryCast) == 0) {
CastExpression.checkNeedForAssignedCast(scope, variableType, (CastExpression) this.initialization);
}
} else if (isBoxingCompatible(initializationType, variableType, this.initialization, scope)) {
this.initialization.computeConversion(scope, variableType, initializationType);
if (this.initialization instanceof CastExpression
&& (this.initialization.bits & ASTNode.UnnecessaryCast) == 0) {
CastExpression.checkNeedForAssignedCast(scope, variableType, (CastExpression) this.initialization);
}
} else {
if ((variableType.tagBits & TagBits.HasMissingType) == 0) {
// if problem already got signaled on type, do not report secondary problem
scope.problemReporter().typeMismatchError(initializationType, variableType, this.initialization, null);
}
}
}
}
// check for assignment with no effect
if (this.binding == Expression.getDirectBinding(this.initialization)) {
scope.problemReporter().assignmentHasNoEffect(this, this.name);
}
// change the constant in the binding when it is final
// (the optimization of the constant propagation will be done later on)
// cast from constant actual type to variable type
this.binding.setConstant(
this.binding.isFinal()
? this.initialization.constant.castTo((variableType.id << 4) + this.initialization.constant.typeID())
: Constant.NotAConstant);
}
// only resolve annotation at the end, for constant to be positioned before (96991)
resolveAnnotations(scope, this.annotations, this.binding);
}
public void traverse(ASTVisitor visitor, BlockScope scope) {
if (visitor.visit(this, scope)) {
if (this.annotations != null) {
int annotationsLength = this.annotations.length;
for (int i = 0; i < annotationsLength; i++)
this.annotations[i].traverse(visitor, scope);
}
this.type.traverse(visitor, scope);
if (this.initialization != null)
this.initialization.traverse(visitor, scope);
}
visitor.endVisit(this, scope);
}
}