WIP Reconsider contracts for derived type bindings

org.eclipse.jdt.core.compiler.batch/src/org/eclipse/jdt/internal/compiler/lookup/LookupEnvironment.java

@@ -2323,7 +2323,17 @@ public void addResolutionListener(IQualifiedTypeResolutionListener resolutionLis
 
 
 public TypeBinding getUnannotatedType(TypeBinding typeBinding) {
-	return this.typeSystem.getUnannotatedType(typeBinding);
+	TypeBinding unannotatedType = this.typeSystem.getUnannotatedType(typeBinding);
+	if (typeBinding.getClass() == TypeVariableBinding.class && unannotatedType.hasTypeAnnotations()) {
+		for (TypeBinding derived : this.typeSystem.getAnnotatedTypes(unannotatedType)) {
+			if (!derived.hasTypeAnnotations())
+				return derived;
+		}
+		TypeBinding clone = ((TypeVariableBinding) unannotatedType).clone(null);
+		this.typeSystem.cacheDerivedType(unannotatedType, unannotatedType, clone);
+		return clone;
+	}
+	return unannotatedType;
 }
 
 // Given a type, return all its variously annotated versions.

org.eclipse.jdt.core.compiler.batch/src/org/eclipse/jdt/internal/compiler/lookup/TypeSystem.java

@@ -20,7 +20,6 @@
 package org.eclipse.jdt.internal.compiler.lookup;
 
 import java.util.HashMap;
-import java.util.function.Consumer;
 
 import org.eclipse.jdt.internal.compiler.ast.ASTNode;
 import org.eclipse.jdt.internal.compiler.util.SimpleLookupTable;
@@ -83,26 +82,11 @@ public PTBKey(ReferenceBinding type, TypeBinding[] arguments, ReferenceBinding e
 					if (type instanceof UnresolvedReferenceBinding)
 						((UnresolvedReferenceBinding) type).addWrapper(this, environment);
 					if (arguments != null) {
-						for (int i = 0; i < arguments.length; i++) {
-							TypeBinding argument = arguments[i];
+						for (TypeBinding argument : arguments) {
 							if (argument instanceof UnresolvedReferenceBinding)
 								((UnresolvedReferenceBinding) argument).addWrapper(this, environment);
 							if (argument.hasNullTypeAnnotations())
 								this.tagBits |= TagBits.HasNullTypeAnnotation;
-							if (argument.getClass() == TypeVariableBinding.class) {
-								final int idx = i;
-								TypeVariableBinding typeVariableBinding = (TypeVariableBinding) argument;
-								Consumer<TypeVariableBinding> previousConsumer = typeVariableBinding.updateWhenSettingTypeAnnotations;
-								typeVariableBinding.updateWhenSettingTypeAnnotations = (newTvb) -> {
-									// update the TVB argument and simulate a re-hash:
-									ParameterizedTypeBinding[] value = HashedParameterizedTypes.this.hashedParameterizedTypes.get(this);
-									arguments[idx] = newTvb;
-									HashedParameterizedTypes.this.hashedParameterizedTypes.put(this, value);
-									// for the unlikely case of multiple PTBKeys referring to this TVB chain to the next consumer:
-									if (previousConsumer != null)
-										previousConsumer.accept(newTvb);
-								};
-							}
 						}
 					}
 				}
@@ -240,6 +224,18 @@ public final TypeBinding getUnannotatedType(TypeBinding type) {
 				type = resolvedType;
 			}
 		}
+		if (type.getClass() == TypeVariableBinding.class) {
+			// register the type as normal ...
+			if (type.id == TypeIds.NoId) {
+				int typesLength = this.types.length;
+				if (this.typeid == typesLength)
+					System.arraycopy(this.types, 0, this.types = new TypeBinding[typesLength * 2][], 0, typesLength);
+				this.types[type.id = this.typeid++] = new TypeBinding[4];
+				this.types[type.id][0] = type;
+			}
+			// ... but rely on prototype() for getting the "original" type as per the type parameter declaration
+			return type.prototype();
+		}
 		try {
 			if (type.id == TypeIds.NoId) {
 				if (type.hasTypeAnnotations())
@@ -269,16 +265,13 @@ public final TypeBinding getUnannotatedType(TypeBinding type) {
 	 * If it itself is already registered as the key unannotated type of its family,
 	 * create a clone to play that role from now on and swap types in the types cache.
 	 */
-	public void forceRegisterAsDerived(TypeVariableBinding derived) {
+	public void forceRegisterAsDerived(TypeBinding derived) {
 		int id = derived.id;
 		if (id != TypeIds.NoId && this.types[id] != null) {
 			TypeBinding unannotated = this.types[id][0];
 			if (unannotated == derived) { //$IDENTITY-COMPARISON$
 				// was previously registered as unannotated, replace by a fresh clone to remain unannotated:
 				this.types[id][0] = unannotated = derived.clone(null);
-				if (derived.updateWhenSettingTypeAnnotations != null) {
-					derived.updateWhenSettingTypeAnnotations.accept((TypeVariableBinding) unannotated);
-				}
 			}
 			// proceed as normal:
 			cacheDerivedType(unannotated, derived);

org.eclipse.jdt.core.compiler.batch/src/org/eclipse/jdt/internal/compiler/lookup/TypeVariableBinding.java

@@ -44,7 +44,6 @@
 
 import java.util.Arrays;
 import java.util.Set;
-import java.util.function.Consumer;
 
 import org.eclipse.jdt.core.compiler.CharOperation;
 import org.eclipse.jdt.internal.compiler.ast.ASTNode;
@@ -78,13 +77,10 @@
 	public char[] genericTypeSignature;
 	LookupEnvironment environment;
 
-	/*
-	 * In one particular situation a TVB will be cloned and the clone will be used as the 'naked' type
-	 * within TypeSystem. This may require some updating inside TypeSystem's hash structure.
-	 */
-	Consumer<TypeVariableBinding> updateWhenSettingTypeAnnotations;
+	private ReferenceBinding prototype;
 
 	public TypeVariableBinding(char[] sourceName, Binding declaringElement, int rank, LookupEnvironment environment) {
+		this.prototype = this;
 		this.sourceName = sourceName;
 		this.declaringElement = declaringElement;
 		this.rank = rank;
@@ -97,6 +93,7 @@
 
 	// for subclass CaptureBinding
 	protected TypeVariableBinding(char[] sourceName, LookupEnvironment environment) {
+		this.prototype = this;
 		this.sourceName = sourceName;
 		this.modifiers = ClassFileConstants.AccPublic | ExtraCompilerModifiers.AccGenericSignature; // treat type var as public
 		this.tagBits |= TagBits.HasTypeVariable;
@@ -122,8 +119,13 @@
 		this.environment = prototype.environment;
 		prototype.tagBits |= TagBits.HasAnnotatedVariants;
 		this.tagBits &= ~TagBits.HasAnnotatedVariants;
+		this.prototype = prototype.prototype;
 	}
 
+	@Override
+	public TypeBinding prototype() {
+		return this.prototype;
+	}
 	/**
 	 * Returns true if the argument type satisfies all bounds of the type parameter
 	 * @param location if non-null this may be used for reporting errors relating to null type annotations (if enabled)
@@ -955,7 +957,7 @@
 					typeVariables = ((MethodBinding) this.declaringElement).typeVariables();
 				}
 				if (typeVariables != null && typeVariables.length > this.rank) {
 					TypeVariableBinding prototype = typeVariables[this.rank];
 					if (prototype != this)//$IDENTITY-COMPARISON$
 						prototype.appendNullAnnotation(nameBuffer, options);
 				}