/*******************************************************************************
* Copyright (c) 2013, 2014 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
* Jesper S Moller - Contributions for
* bug 382701 - [1.8][compiler] Implement semantic analysis of Lambda expressions & Reference expression
* Bug 405066 - [1.8][compiler][codegen] Implement code generation infrastructure for JSR335
* Stephan Herrmann - Contribution for
* Bug 400874 - [1.8][compiler] Inference infrastructure should evolve to meet JLS8 18.x (Part G of JSR335 spec)
* Bug 423504 - [1.8] Implement "18.5.3 Functional Interface Parameterization Inference"
* Bug 425142 - [1.8][compiler] NPE in ConstraintTypeFormula.reduceSubType
* Bug 425153 - [1.8] Having wildcard allows incompatible types in a lambda expression
* Bug 425156 - [1.8] Lambda as an argument is flagged with incompatible error
* Bug 424403 - [1.8][compiler] Generic method call with method reference argument fails to resolve properly.
* Bug 427438 - [1.8][compiler] NPE at org.eclipse.jdt.internal.compiler.ast.ConditionalExpression.generateCode(ConditionalExpression.java:280)
* Bug 428352 - [1.8][compiler] Resolution errors don't always surface
* Andy Clement (GoPivotal, Inc) aclement@gopivotal.com - Contributions for
* Bug 405104 - [1.8][compiler][codegen] Implement support for serializeable lambdas
*******************************************************************************/
package org.eclipse.jdt.internal.compiler.ast;
import static org.eclipse.jdt.internal.compiler.ast.ExpressionContext.VANILLA_CONTEXT;
import org.eclipse.jdt.internal.compiler.CompilationResult;
import org.eclipse.jdt.internal.compiler.DefaultErrorHandlingPolicies;
import org.eclipse.jdt.internal.compiler.IErrorHandlingPolicy;
import org.eclipse.jdt.internal.compiler.flow.FlowInfo;
import org.eclipse.jdt.internal.compiler.impl.Constant;
import org.eclipse.jdt.internal.compiler.impl.ReferenceContext;
import org.eclipse.jdt.internal.compiler.lookup.ArrayBinding;
import org.eclipse.jdt.internal.compiler.lookup.BlockScope;
import org.eclipse.jdt.internal.compiler.lookup.CompilationUnitScope;
import org.eclipse.jdt.internal.compiler.lookup.IntersectionCastTypeBinding;
import org.eclipse.jdt.internal.compiler.lookup.LookupEnvironment;
import org.eclipse.jdt.internal.compiler.lookup.MethodBinding;
import org.eclipse.jdt.internal.compiler.lookup.MethodScope;
import org.eclipse.jdt.internal.compiler.lookup.MethodVerifier;
import org.eclipse.jdt.internal.compiler.lookup.ParameterizedTypeBinding;
import org.eclipse.jdt.internal.compiler.lookup.ProblemReasons;
import org.eclipse.jdt.internal.compiler.lookup.RawTypeBinding;
import org.eclipse.jdt.internal.compiler.lookup.ReferenceBinding;
import org.eclipse.jdt.internal.compiler.lookup.Scope;
import org.eclipse.jdt.internal.compiler.lookup.TypeBinding;
import org.eclipse.jdt.internal.compiler.lookup.TypeBindingVisitor;
import org.eclipse.jdt.internal.compiler.lookup.TypeVariableBinding;
public abstract class FunctionalExpression extends Expression {
protected TypeBinding expectedType;
public MethodBinding descriptor;
public MethodBinding binding; // Code generation binding. May include synthetics. See getMethodBinding()
protected MethodBinding actualMethodBinding; // void of synthetics.
boolean ignoreFurtherInvestigation;
protected ExpressionContext expressionContext = VANILLA_CONTEXT;
static Expression [] NO_EXPRESSIONS = new Expression[0];
protected Expression [] resultExpressions = NO_EXPRESSIONS;
public CompilationResult compilationResult;
public BlockScope enclosingScope;
protected boolean ellipsisArgument;
public int bootstrapMethodNumber = -1;
protected static IErrorHandlingPolicy silentErrorHandlingPolicy = DefaultErrorHandlingPolicies.ignoreAllProblems();
private boolean hasReportedSamProblem = false;
public FunctionalExpression(CompilationResult compilationResult) {
this.compilationResult = compilationResult;
}
public FunctionalExpression() {
super();
}
// for lambda's and reference expressions boxing compatibility is same as vanilla compatibility.
public boolean isBoxingCompatibleWith(TypeBinding targetType, Scope scope) {
return isCompatibleWith(targetType, scope);
}
public void setCompilationResult(CompilationResult compilationResult) {
this.compilationResult = compilationResult;
}
// Return the actual (non-code generation) method binding that is void of synthetics.
public MethodBinding getMethodBinding() {
return null;
}
public void setExpectedType(TypeBinding expectedType) {
this.expectedType = this.ellipsisArgument ? ((ArrayBinding) expectedType).elementsType() : expectedType;
}
public void setExpressionContext(ExpressionContext context) {
this.expressionContext = context;
}
public ExpressionContext getExpressionContext() {
return this.expressionContext;
}
public void tagAsEllipsisArgument() {
this.ellipsisArgument = true;
}
public boolean isPolyExpression(MethodBinding candidate) {
return true;
}
public boolean isPolyExpression() {
return true; // always as per introduction of part D, JSR 335
}
public boolean isPertinentToApplicability(TypeBinding targetType, MethodBinding method) {
if (targetType instanceof TypeVariableBinding) {
if (method != null) { // when called from type inference
if (((TypeVariableBinding)targetType).declaringElement == method)
return false;
if (method.isConstructor() && ((TypeVariableBinding)targetType).declaringElement == method.declaringClass)
return false;
} else { // for internal calls
TypeVariableBinding typeVariable = (TypeVariableBinding) targetType;
if (typeVariable.declaringElement instanceof MethodBinding)
return false;
}
}
return true;
}
public TypeBinding invocationTargetType() {
if (this.expectedType == null) return null;
// when during inference this expression mimics as an invocationSite,
// we simulate an *invocation* of this functional expression,
// where the expected type of the expression is the return type of the sam:
MethodBinding sam = this.expectedType.getSingleAbstractMethod(this.enclosingScope, true);
if (sam != null) {
if (sam.isConstructor())
return sam.declaringClass;
else
return sam.returnType;
}
return null;
}
public TypeBinding expectedType() {
return this.expectedType;
}
public boolean argumentsTypeElided() { return true; /* only exception: lambda with explicit argument types. */ }
// Notify the compilation unit that it contains some functional types, taking care not to add any transient copies. this is assumed not to be a copy
public int recordFunctionalType(Scope scope) {
while (scope != null) {
switch (scope.kind) {
case Scope.METHOD_SCOPE :
ReferenceContext context = ((MethodScope) scope).referenceContext;
if (context instanceof LambdaExpression) {
LambdaExpression expression = (LambdaExpression) context;
if (expression != expression.original) // fake universe.
return 0;
}
break;
case Scope.COMPILATION_UNIT_SCOPE :
CompilationUnitDeclaration unit = ((CompilationUnitScope) scope).referenceContext;
return unit.record(this);
}
scope = scope.parent;
}
return 0; // not reached.
}
public TypeBinding resolveType(BlockScope blockScope) {
this.constant = Constant.NotAConstant;
this.enclosingScope = blockScope;
MethodBinding sam = this.expectedType == null ? null : this.expectedType.getSingleAbstractMethod(blockScope, argumentsTypeElided());
if (sam == null) {
blockScope.problemReporter().targetTypeIsNotAFunctionalInterface(this);
return null;
}
if (!sam.isValidBinding()) {
return reportSamProblem(blockScope, sam);
}
this.descriptor = sam;
if (kosherDescriptor(blockScope, sam, true)) {
return this.resolvedType = this.expectedType;
}
return this.resolvedType = null;
}
protected TypeBinding reportSamProblem(BlockScope blockScope, MethodBinding sam) {
if (this.hasReportedSamProblem)
return null;
switch (sam.problemId()) {
case ProblemReasons.NoSuchSingleAbstractMethod:
blockScope.problemReporter().targetTypeIsNotAFunctionalInterface(this);
this.hasReportedSamProblem = true;
break;
case ProblemReasons.NotAWellFormedParameterizedType:
blockScope.problemReporter().illFormedParameterizationOfFunctionalInterface(this);
this.hasReportedSamProblem = true;
break;
case ProblemReasons.IntersectionHasMultipleFunctionalInterfaces:
blockScope.problemReporter().multipleFunctionalInterfaces(this);
this.hasReportedSamProblem = true;
break;
}
return null;
}
public TypeBinding checkAgainstFinalTargetType(TypeBinding targetType, Scope scope) {
targetType = targetType.uncapture(this.enclosingScope);
return resolveTypeExpecting(this.enclosingScope, targetType);
}
class VisibilityInspector extends TypeBindingVisitor {
private Scope scope;
private boolean shouldChatter;
private boolean visible = true;
private FunctionalExpression expression;
public VisibilityInspector(FunctionalExpression expression, Scope scope, boolean shouldChatter) {
this.scope = scope;
this.shouldChatter = shouldChatter;
this.expression = expression;
}
private void checkVisibility(ReferenceBinding referenceBinding) {
if (!referenceBinding.canBeSeenBy(this.scope)) {
this.visible = false;
if (this.shouldChatter)
this.scope.problemReporter().descriptorHasInvisibleType(this.expression, referenceBinding);
}
}
public boolean visit(ReferenceBinding referenceBinding) {
checkVisibility(referenceBinding);
return true;
}
public boolean visit(ParameterizedTypeBinding parameterizedTypeBinding) {
checkVisibility(parameterizedTypeBinding);
return true;
}
public boolean visit(RawTypeBinding rawTypeBinding) {
checkVisibility(rawTypeBinding);
return true;
}
public boolean visible(TypeBinding type) {
TypeBindingVisitor.visit(this, type);
return this.visible;
}
public boolean visible(TypeBinding[] types) {
TypeBindingVisitor.visit(this, types);
return this.visible;
}
}
public boolean kosherDescriptor(Scope scope, MethodBinding sam, boolean shouldChatter) {
VisibilityInspector inspector = new VisibilityInspector(this, scope, shouldChatter);
boolean status = true;
if (!inspector.visible(sam.returnType))
status = false;
if (!inspector.visible(sam.parameters))
status = false;
if (!inspector.visible(sam.thrownExceptions))
status = false;
return status;
}
public int nullStatus(FlowInfo flowInfo) {
return FlowInfo.NON_NULL;
}
public int diagnosticsSourceEnd() {
return this.sourceEnd;
}
public MethodBinding[] getRequiredBridges() {
class BridgeCollector {
MethodBinding [] bridges;
MethodBinding method;
char [] selector;
LookupEnvironment environment;
Scope scope;
BridgeCollector(ReferenceBinding functionalType, MethodBinding method) {
this.method = method;
this.selector = method.selector;
this.environment = FunctionalExpression.this.enclosingScope.environment();
this.scope = FunctionalExpression.this.enclosingScope;
collectBridges(functionalType.superInterfaces());
}
void collectBridges(ReferenceBinding[] interfaces) {
int length = interfaces == null ? 0 : interfaces.length;
for (int i = 0; i < length; i++) {
ReferenceBinding superInterface = interfaces[i];
if (superInterface == null)
continue;
MethodBinding [] methods = superInterface.getMethods(this.selector);
for (int j = 0, count = methods == null ? 0 : methods.length; j < count; j++) {
MethodBinding inheritedMethod = methods[j];
if (inheritedMethod == null || this.method == inheritedMethod) // descriptor declaring class may not be same functional interface target type.
continue;
if (inheritedMethod.isStatic() || inheritedMethod.isDefaultMethod() || inheritedMethod.redeclaresPublicObjectMethod(this.scope))
continue;
inheritedMethod = MethodVerifier.computeSubstituteMethod(inheritedMethod, this.method, this.environment);
if (inheritedMethod == null || !MethodVerifier.isSubstituteParameterSubsignature(this.method, inheritedMethod, this.environment) ||
!MethodVerifier.areReturnTypesCompatible(this.method, inheritedMethod, this.environment))
continue;
final MethodBinding originalInherited = inheritedMethod.original();
final MethodBinding originalOverride = this.method.original();
if (!originalOverride.areParameterErasuresEqual(originalInherited) || TypeBinding.notEquals(originalOverride.returnType.erasure(), originalInherited.returnType.erasure()))
add(originalInherited);
}
collectBridges(superInterface.superInterfaces());
}
}
void add(MethodBinding inheritedMethod) {
if (this.bridges == null) {
this.bridges = new MethodBinding[] { inheritedMethod };
return;
}
int length = this.bridges.length;
for (int i = 0; i < length; i++) {
if (this.bridges[i].areParameterErasuresEqual(inheritedMethod) && TypeBinding.equalsEquals(this.bridges[i].returnType.erasure(), inheritedMethod.returnType.erasure()))
return;
}
System.arraycopy(this.bridges, 0, this.bridges = new MethodBinding[length + 1], 0, length);
this.bridges[length] = inheritedMethod;
}
MethodBinding [] getBridges () {
return this.bridges;
}
}
ReferenceBinding functionalType;
if (this.expectedType instanceof IntersectionCastTypeBinding) {
functionalType = (ReferenceBinding) ((IntersectionCastTypeBinding)this.expectedType).getSAMType(this.enclosingScope);
} else {
functionalType = (ReferenceBinding) this.expectedType;
}
return new BridgeCollector(functionalType, this.descriptor).getBridges();
}
boolean requiresBridges() {
return getRequiredBridges() != null;
}
}