/*******************************************************************************
* Copyright (c) 2000, 2009 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
*******************************************************************************/
package org.eclipse.jdt.internal.compiler.lookup;
import org.eclipse.jdt.core.compiler.CharOperation;
import org.eclipse.jdt.internal.compiler.ast.Wildcard;
import org.eclipse.jdt.internal.compiler.classfmt.ClassFileConstants;
/**
* Binding for a type parameter, held by source/binary type or method.
*/
public class TypeVariableBinding extends ReferenceBinding {
public Binding declaringElement; // binding of declaring type or method
public int rank; // declaration rank, can be used to match variable in parameterized type
/**
* Denote the first explicit (binding) bound amongst the supertypes (from declaration in source)
* If no superclass was specified, then it denotes the first superinterface, or null if none was
* specified.
*/
public TypeBinding firstBound;
// actual resolved variable supertypes (if no superclass bound, then associated to Object)
public ReferenceBinding superclass;
public ReferenceBinding[] superInterfaces;
public char[] genericTypeSignature;
LookupEnvironment environment;
public TypeVariableBinding(char[] sourceName, Binding declaringElement, int rank, LookupEnvironment environment) {
this.sourceName= sourceName;
this.declaringElement= declaringElement;
this.rank= rank;
this.modifiers= ClassFileConstants.AccPublic | ExtraCompilerModifiers.AccGenericSignature; // treat type var as public
this.tagBits|= TagBits.HasTypeVariable;
this.environment= environment;
}
/**
* Returns true if the argument type satisfies all bounds of the type parameter
*/
public int boundCheck(Substitution substitution, TypeBinding argumentType) {
if (argumentType == TypeBinding.NULL || argumentType == this) {
return TypeConstants.OK;
}
boolean hasSubstitution= substitution != null;
if (!(argumentType instanceof ReferenceBinding || argumentType.isArrayType()))
return TypeConstants.MISMATCH;
// special case for re-entrant source types (selection, code assist, etc)...
// can request additional types during hierarchy walk that are found as source types that also 'need' to connect their hierarchy
if (this.superclass == null)
return TypeConstants.OK;
if (argumentType.kind() == Binding.WILDCARD_TYPE) {
WildcardBinding wildcard= (WildcardBinding)argumentType;
switch (wildcard.boundKind) {
case Wildcard.EXTENDS:
TypeBinding wildcardBound= wildcard.bound;
if (wildcardBound == this)
return TypeConstants.OK;
boolean isArrayBound= wildcardBound.isArrayType();
if (!wildcardBound.isInterface()) {
TypeBinding substitutedSuperType= hasSubstitution ? Scope.substitute(substitution, this.superclass) : this.superclass;
if (substitutedSuperType.id != TypeIds.T_JavaLangObject) {
if (isArrayBound) {
if (!wildcardBound.isCompatibleWith(substitutedSuperType))
return TypeConstants.MISMATCH;
} else {
TypeBinding match= wildcardBound.findSuperTypeOriginatingFrom(substitutedSuperType);
if (match != null) {
if (substitutedSuperType.isProvablyDistinct(match)) {
return TypeConstants.MISMATCH;
}
} else {
match= substitutedSuperType.findSuperTypeOriginatingFrom(wildcardBound);
if (match != null) {
if (match.isProvablyDistinct(wildcardBound)) {
return TypeConstants.MISMATCH;
}
} else {
if (!wildcardBound.isTypeVariable() && !substitutedSuperType.isTypeVariable()) {
return TypeConstants.MISMATCH;
}
}
}
}
}
}
boolean mustImplement= isArrayBound || ((ReferenceBinding)wildcardBound).isFinal();
for (int i= 0, length= this.superInterfaces.length; i < length; i++) {
TypeBinding substitutedSuperType= hasSubstitution ? Scope.substitute(substitution, this.superInterfaces[i]) : this.superInterfaces[i];
if (isArrayBound) {
if (!wildcardBound.isCompatibleWith(substitutedSuperType))
return TypeConstants.MISMATCH;
} else {
TypeBinding match= wildcardBound.findSuperTypeOriginatingFrom(substitutedSuperType);
if (match != null) {
if (substitutedSuperType.isProvablyDistinct(match)) {
return TypeConstants.MISMATCH;
}
} else if (mustImplement) {
return TypeConstants.MISMATCH; // cannot be extended further to satisfy missing bounds
}
}
}
break;
case Wildcard.SUPER:
return boundCheck(substitution, wildcard.bound);
case Wildcard.UNBOUND:
break;
}
return TypeConstants.OK;
}
boolean unchecked= false;
if (this.superclass.id != TypeIds.T_JavaLangObject) {
TypeBinding substitutedSuperType= hasSubstitution ? Scope.substitute(substitution, this.superclass) : this.superclass;
if (substitutedSuperType != argumentType) {
if (!argumentType.isCompatibleWith(substitutedSuperType)) {
return TypeConstants.MISMATCH;
}
TypeBinding match= argumentType.findSuperTypeOriginatingFrom(substitutedSuperType);
if (match != null) {
// Enum#RAW is not a substitute for <E extends Enum<E>> (86838)
if (match.isRawType() && substitutedSuperType.isBoundParameterizedType())
unchecked= true;
}
}
}
for (int i= 0, length= this.superInterfaces.length; i < length; i++) {
TypeBinding substitutedSuperType= hasSubstitution ? Scope.substitute(substitution, this.superInterfaces[i]) : this.superInterfaces[i];
if (substitutedSuperType != argumentType) {
if (!argumentType.isCompatibleWith(substitutedSuperType)) {
return TypeConstants.MISMATCH;
}
TypeBinding match= argumentType.findSuperTypeOriginatingFrom(substitutedSuperType);
if (match != null) {
// Enum#RAW is not a substitute for <E extends Enum<E>> (86838)
if (match.isRawType() && substitutedSuperType.isBoundParameterizedType())
unchecked= true;
}
}
}
return unchecked ? TypeConstants.UNCHECKED : TypeConstants.OK;
}
public int boundsCount() {
if (this.firstBound == null) {
return 0;
} else if (this.firstBound == this.superclass) {
return this.superInterfaces.length + 1;
} else {
return this.superInterfaces.length;
}
}
/**
* @see org.eclipse.jdt.internal.compiler.lookup.ReferenceBinding#canBeInstantiated()
*/
public boolean canBeInstantiated() {
return false;
}
/**
* Collect the substitutes into a map for certain type variables inside the receiver type e.g.
* Collection<T>.collectSubstitutes(Collection<List<X>>, Map), will populate Map with: T -->
* List<X> Constraints: A << F corresponds to: F.collectSubstitutes(..., A, ...,
* CONSTRAINT_EXTENDS (1)) A = F corresponds to: F.collectSubstitutes(..., A, ...,
* CONSTRAINT_EQUAL (0)) A >> F corresponds to: F.collectSubstitutes(..., A, ...,
* CONSTRAINT_SUPER (2))
*/
public void collectSubstitutes(Scope scope, TypeBinding actualType, InferenceContext inferenceContext, int constraint) {
// only infer for type params of the generic method
if (this.declaringElement != inferenceContext.genericMethod)
return;
// cannot infer anything from a null type
switch (actualType.kind()) {
case Binding.BASE_TYPE:
if (actualType == TypeBinding.NULL)
return;
TypeBinding boxedType= scope.environment().computeBoxingType(actualType);
if (boxedType == actualType)
return;
actualType= boxedType;
break;
case Binding.WILDCARD_TYPE:
return; // wildcards are not true type expressions (JLS 15.12.2.7, p.453 2nd discussion)
}
// reverse constraint, to reflect variable on rhs: A << T --> T >: A
int variableConstraint;
switch (constraint) {
case TypeConstants.CONSTRAINT_EQUAL:
variableConstraint= TypeConstants.CONSTRAINT_EQUAL;
break;
case TypeConstants.CONSTRAINT_EXTENDS:
variableConstraint= TypeConstants.CONSTRAINT_SUPER;
break;
default:
//case CONSTRAINT_SUPER :
variableConstraint= TypeConstants.CONSTRAINT_EXTENDS;
break;
}
inferenceContext.recordSubstitute(this, actualType, variableConstraint);
}
/*
* declaringUniqueKey : genericTypeSignature
* p.X<T> { ... } --> Lp/X;:TT;
* p.X { <T> void foo() {...} } --> Lp/X;.foo()V:TT;
*/
public char[] computeUniqueKey(boolean isLeaf) {
StringBuffer buffer= new StringBuffer();
Binding declaring= this.declaringElement;
if (!isLeaf && declaring.kind() == Binding.METHOD) { // see https://bugs.eclipse.org/bugs/show_bug.cgi?id=97902
MethodBinding methodBinding= (MethodBinding)declaring;
ReferenceBinding declaringClass= methodBinding.declaringClass;
buffer.append(declaringClass.computeUniqueKey(false/*not a leaf*/));
buffer.append(':');
MethodBinding[] methods= declaringClass.methods();
if (methods != null)
for (int i= 0, length= methods.length; i < length; i++) {
MethodBinding binding= methods[i];
if (binding == methodBinding) {
buffer.append(i);
break;
}
}
} else {
buffer.append(declaring.computeUniqueKey(false/*not a leaf*/));
buffer.append(':');
}
buffer.append(genericTypeSignature());
int length= buffer.length();
char[] uniqueKey= new char[length];
buffer.getChars(0, length, uniqueKey, 0);
return uniqueKey;
}
public char[] constantPoolName() { /* java/lang/Object */
if (this.firstBound != null) {
return this.firstBound.constantPoolName();
}
return this.superclass.constantPoolName(); // java/lang/Object
}
/**
* @see org.eclipse.jdt.internal.compiler.lookup.TypeBinding#debugName()
*/
public String debugName() {
return new String(this.sourceName);
}
public TypeBinding erasure() {
if (this.firstBound != null) {
return this.firstBound.erasure();
}
return this.superclass; // java/lang/Object
}
/**
* T::Ljava/util/Map;:Ljava/io/Serializable; T:LY<TT;>
*/
public char[] genericSignature() {
StringBuffer sig= new StringBuffer(10);
sig.append(this.sourceName).append(':');
int interfaceLength= this.superInterfaces == null ? 0 : this.superInterfaces.length;
if (interfaceLength == 0 || this.firstBound == this.superclass) {
if (this.superclass != null)
sig.append(this.superclass.genericTypeSignature());
}
for (int i= 0; i < interfaceLength; i++) {
sig.append(':').append(this.superInterfaces[i].genericTypeSignature());
}
int sigLength= sig.length();
char[] genericSignature= new char[sigLength];
sig.getChars(0, sigLength, genericSignature, 0);
return genericSignature;
}
/**
* T::Ljava/util/Map;:Ljava/io/Serializable; T:LY<TT;>
*/
public char[] genericTypeSignature() {
if (this.genericTypeSignature != null)
return this.genericTypeSignature;
return this.genericTypeSignature= CharOperation.concat('T', this.sourceName, ';');
}
boolean hasOnlyRawBounds() {
if (this.superclass != null && this.firstBound == this.superclass)
if (!this.superclass.isRawType())
return false;
if (this.superInterfaces != null)
for (int i= 0, l= this.superInterfaces.length; i < l; i++)
if (!this.superInterfaces[i].isRawType())
return false;
return true;
}
/**
* Returns true if the type variable is directly bound to a given type
*/
public boolean isErasureBoundTo(TypeBinding type) {
if (this.superclass.erasure() == type)
return true;
for (int i= 0, length= this.superInterfaces.length; i < length; i++) {
if (this.superInterfaces[i].erasure() == type)
return true;
}
return false;
}
public boolean isHierarchyConnected() {
return (this.modifiers & ExtraCompilerModifiers.AccUnresolved) == 0;
}
/**
* Returns true if the 2 variables are playing exact same role: they have the same bounds,
* providing one is substituted with the other: <T1 extends List<T1>> is interchangeable with
* <T2 extends List<T2>>.
*/
public boolean isInterchangeableWith(TypeVariableBinding otherVariable, Substitution substitute) {
if (this == otherVariable)
return true;
int length= this.superInterfaces.length;
if (length != otherVariable.superInterfaces.length)
return false;
if (this.superclass != Scope.substitute(substitute, otherVariable.superclass))
return false;
next: for (int i= 0; i < length; i++) {
TypeBinding superType= Scope.substitute(substitute, otherVariable.superInterfaces[i]);
for (int j= 0; j < length; j++)
if (superType == this.superInterfaces[j])
continue next;
return false; // not a match
}
return true;
}
/**
* Returns true if the type was declared as a type variable
*/
public boolean isTypeVariable() {
return true;
}
// /**
// * Returns the original type variable for a given variable.
// * Only different from receiver for type variables of generic methods of parameterized types
// * e.g. X<U> { <V1 extends U> U foo(V1) } --> X<String> { <V2 extends String> String foo(V2) }
// * and V2.original() --> V1
// */
// public TypeVariableBinding original() {
// if (this.declaringElement.kind() == Binding.METHOD) {
// MethodBinding originalMethod = ((MethodBinding)this.declaringElement).original();
// if (originalMethod != this.declaringElement) {
// return originalMethod.typeVariables[this.rank];
// }
// } else {
// ReferenceBinding originalType = (ReferenceBinding)((ReferenceBinding)this.declaringElement).erasure();
// if (originalType != this.declaringElement) {
// return originalType.typeVariables()[this.rank];
// }
// }
// return this;
// }
public int kind() {
return Binding.TYPE_PARAMETER;
}
public TypeBinding[] otherUpperBounds() {
if (this.firstBound == null)
return Binding.NO_TYPES;
if (this.firstBound == this.superclass)
return this.superInterfaces;
int otherLength= this.superInterfaces.length - 1;
if (otherLength > 0) {
TypeBinding[] otherBounds;
System.arraycopy(this.superInterfaces, 1, otherBounds= new TypeBinding[otherLength], 0, otherLength);
return otherBounds;
}
return Binding.NO_TYPES;
}
/**
* @see org.eclipse.jdt.internal.compiler.lookup.ReferenceBinding#readableName()
*/
public char[] readableName() {
return this.sourceName;
}
ReferenceBinding resolve() {
if ((this.modifiers & ExtraCompilerModifiers.AccUnresolved) == 0)
return this;
TypeBinding oldSuperclass= this.superclass, oldFirstInterface= null;
if (this.superclass != null) {
ReferenceBinding resolveType= (ReferenceBinding)BinaryTypeBinding.resolveType(this.superclass, this.environment, true /* raw conversion */);
this.tagBits|= resolveType.tagBits & TagBits.ContainsNestedTypeReferences;
this.superclass= resolveType;
}
ReferenceBinding[] interfaces= this.superInterfaces;
int length;
if ((length= interfaces.length) != 0) {
oldFirstInterface= interfaces[0];
for (int i= length; --i >= 0;) {
ReferenceBinding resolveType= (ReferenceBinding)BinaryTypeBinding.resolveType(interfaces[i], this.environment, true /* raw conversion */);
this.tagBits|= resolveType.tagBits & TagBits.ContainsNestedTypeReferences;
interfaces[i]= resolveType;
}
}
// refresh the firstBound in case it changed
if (this.firstBound != null) {
if (this.firstBound == oldSuperclass) {
this.firstBound= this.superclass;
} else if (this.firstBound == oldFirstInterface) {
this.firstBound= interfaces[0];
}
}
this.modifiers&= ~ExtraCompilerModifiers.AccUnresolved;
return this;
}
/**
* @see org.eclipse.jdt.internal.compiler.lookup.ReferenceBinding#shortReadableName()
*/
public char[] shortReadableName() {
return readableName();
}
public ReferenceBinding superclass() {
return this.superclass;
}
public ReferenceBinding[] superInterfaces() {
return this.superInterfaces;
}
/**
* @see java.lang.Object#toString()
*/
public String toString() {
StringBuffer buffer= new StringBuffer(10);
buffer.append('<').append(this.sourceName);//.append('[').append(this.rank).append(']');
if (this.superclass != null && this.firstBound == this.superclass) {
buffer.append(" extends ").append(this.superclass.debugName()); //$NON-NLS-1$
}
if (this.superInterfaces != null && this.superInterfaces != Binding.NO_SUPERINTERFACES) {
if (this.firstBound != this.superclass) {
buffer.append(" extends "); //$NON-NLS-1$
}
for (int i= 0, length= this.superInterfaces.length; i < length; i++) {
if (i > 0 || this.firstBound == this.superclass) {
buffer.append(" & "); //$NON-NLS-1$
}
buffer.append(this.superInterfaces[i].debugName());
}
}
buffer.append('>');
return buffer.toString();
}
/**
* Upper bound doesn't perform erasure
*/
public TypeBinding upperBound() {
if (this.firstBound != null) {
return this.firstBound;
}
return this.superclass; // java/lang/Object
}
}