| /******************************************************************************* |
| * 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); |
| } |
| } |