/*******************************************************************************
* Copyright (c) 2013, 2014 GK Software AG.
* 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:
* Stephan Herrmann - initial API and implementation
*******************************************************************************/
package org.eclipse.jdt.internal.compiler.classfmt;
import org.eclipse.jdt.internal.compiler.codegen.AnnotationTargetTypeConstants;
import org.eclipse.jdt.internal.compiler.env.IBinaryAnnotation;
import org.eclipse.jdt.internal.compiler.env.IBinaryTypeAnnotation;
/**
* A TypeAnnotationWalker is initialized with all type annotations found at a given element.
* It can be used to walk into the types at the given element and finally answer the
* actual annotations at any node of the walk.
*
* The walker is implemented as immutable objects. During the walk either new instances
* are created, or the current instance is shared if no difference is encountered.
*/
public class TypeAnnotationWalker {
public static final IBinaryAnnotation[] NO_ANNOTATIONS = new IBinaryAnnotation[0];
/**
* A no-effect annotation walker, all walking methods are implemented as identity-functions.
* At the end of any walk an empty array of annotations is returned.
*/
public static final TypeAnnotationWalker EMPTY_ANNOTATION_WALKER = new TypeAnnotationWalker(new IBinaryTypeAnnotation[0], 0L) {
public TypeAnnotationWalker toField() { return this; }
public TypeAnnotationWalker toTarget(int targetType) { return this; }
public TypeAnnotationWalker toThrows(int rank) { return this; }
public TypeAnnotationWalker toTypeArgument(int rank) { return this; }
public TypeAnnotationWalker toMethodParameter(short index) { return this; }
public TypeAnnotationWalker toSupertype(short index) { return this; }
public TypeAnnotationWalker toTypeParameterBounds(boolean isClassTypeParameter, int parameterRank) { return this; }
public TypeAnnotationWalker toTypeBound(short boundIndex) { return this; }
public TypeAnnotationWalker toTypeParameter(boolean isClassTypeParameter, int rank) { return this; }
public TypeAnnotationWalker toNextDetail(int detailKind) { return this; }
public IBinaryAnnotation[] getAnnotationsAtCursor() { return NO_ANNOTATIONS; }
};
final protected IBinaryTypeAnnotation[] typeAnnotations; // the actual material we're managing here
final protected long matches; // bit mask of indices into typeAnnotations, 1 means active, 0 is filtered during the walk
final protected int pathPtr; // pointer into the typePath
// precondition: not-empty typeAnnotations
public TypeAnnotationWalker(IBinaryTypeAnnotation[] typeAnnotations) {
this(typeAnnotations, -1L >>> (64-typeAnnotations.length)); // initialize so lowest length bits are 1
}
TypeAnnotationWalker(IBinaryTypeAnnotation[] typeAnnotations, long matchBits) {
this(typeAnnotations, matchBits, 0);
}
protected TypeAnnotationWalker(IBinaryTypeAnnotation[] typeAnnotations, long matchBits, int pathPtr) {
this.typeAnnotations = typeAnnotations;
this.matches = matchBits;
this.pathPtr = pathPtr;
}
protected TypeAnnotationWalker restrict(long newMatches, int newPathPtr) {
if (this.matches == newMatches && this.pathPtr == newPathPtr) return this;
if (newMatches == 0 || this.typeAnnotations == null || this.typeAnnotations.length == 0)
return EMPTY_ANNOTATION_WALKER;
return new TypeAnnotationWalker(this.typeAnnotations, newMatches, newPathPtr);
}
// ==== filter by top-level targetType: ====
/** Walk to a field. */
public TypeAnnotationWalker toField() {
return toTarget(AnnotationTargetTypeConstants.FIELD);
}
/** Walk to the return type of a method. */
public TypeAnnotationWalker toMethodReturn() {
return toTarget(AnnotationTargetTypeConstants.METHOD_RETURN);
}
/**
* Walk to the receiver type of a method.
* Note: Type annotations on receiver are not currently used by the compiler.
*/
public TypeAnnotationWalker toReceiver() {
return toTarget(AnnotationTargetTypeConstants.METHOD_RECEIVER);
}
/*
* Implementation for walking to methodReturn, receiver type or field.
*/
protected TypeAnnotationWalker toTarget(int targetType) {
long newMatches = this.matches;
if (newMatches == 0)
return EMPTY_ANNOTATION_WALKER;
int length = this.typeAnnotations.length;
long mask = 1;
for (int i = 0; i < length; i++, mask = mask << 1) {
if (this.typeAnnotations[i].getTargetType() != targetType)
newMatches &= ~mask;
}
return restrict(newMatches, 0);
}
/**
* Walk to the type parameter of the given rank.
* @param isClassTypeParameter whether we are looking for a class type parameter (else: method type type parameter)
* @param rank rank of the type parameter
*/
public TypeAnnotationWalker toTypeParameter(boolean isClassTypeParameter, int rank) {
long newMatches = this.matches;
if (newMatches == 0)
return EMPTY_ANNOTATION_WALKER;
int targetType = isClassTypeParameter ? AnnotationTargetTypeConstants.CLASS_TYPE_PARAMETER : AnnotationTargetTypeConstants.METHOD_TYPE_PARAMETER;
int length = this.typeAnnotations.length;
long mask = 1;
for (int i = 0; i < length; i++, mask = mask << 1) {
IBinaryTypeAnnotation candidate = this.typeAnnotations[i];
if (candidate.getTargetType() != targetType || candidate.getTypeParameterIndex() != rank) {
newMatches &= ~mask;
}
}
return restrict(newMatches, 0);
}
/**
* Walk to the bounds of a type parameter of either a class or a method (signaled by isClassTypeParameter).
* Clients must then call {@link #toTypeBound(short)} on the resulting walker.
* @param isClassTypeParameter whether we are looking at a class type parameter (else: method type type parameter)
* @param parameterRank rank of the type parameter.
*/
public TypeAnnotationWalker toTypeParameterBounds(boolean isClassTypeParameter, int parameterRank) {
long newMatches = this.matches;
if (newMatches == 0)
return EMPTY_ANNOTATION_WALKER;
int length = this.typeAnnotations.length;
int targetType = isClassTypeParameter ?
AnnotationTargetTypeConstants.CLASS_TYPE_PARAMETER_BOUND : AnnotationTargetTypeConstants.METHOD_TYPE_PARAMETER_BOUND;
long mask = 1;
for (int i = 0; i < length; i++, mask = mask << 1) {
IBinaryTypeAnnotation candidate = this.typeAnnotations[i];
if (candidate.getTargetType() != targetType || (short)candidate.getTypeParameterIndex() != parameterRank) {
newMatches &= ~mask;
}
}
return restrict(newMatches, 0);
}
/**
* Detail of {@link #toTypeParameterBounds(boolean, int)}: walk to the bounds
* of the previously selected type parameter.
* @param boundIndex
*/
public TypeAnnotationWalker toTypeBound(short boundIndex) {
long newMatches = this.matches;
if (newMatches == 0)
return EMPTY_ANNOTATION_WALKER;
int length = this.typeAnnotations.length;
long mask = 1;
for (int i = 0; i < length; i++, mask = mask << 1) {
IBinaryTypeAnnotation candidate = this.typeAnnotations[i];
if ((short)candidate.getBoundIndex() != boundIndex) {
newMatches &= ~mask;
}
}
return restrict(newMatches, 0);
}
/** Walk to the specified supertype: -1 is superclass, else the superinterface at the given index. */
public TypeAnnotationWalker toSupertype(short index) {
long newMatches = this.matches;
if (newMatches == 0)
return EMPTY_ANNOTATION_WALKER;
int length = this.typeAnnotations.length;
long mask = 1;
for (int i = 0; i < length; i++, mask = mask << 1) {
IBinaryTypeAnnotation candidate = this.typeAnnotations[i];
if (candidate.getTargetType() != AnnotationTargetTypeConstants.CLASS_EXTENDS || (short)candidate.getSupertypeIndex() != index) {
newMatches &= ~mask;
}
}
return restrict(newMatches, 0);
}
/** Walk to the index'th visible formal method parameter (i.e., not counting synthetic args). */
public TypeAnnotationWalker toMethodParameter(short index) {
long newMatches = this.matches;
if (newMatches == 0)
return EMPTY_ANNOTATION_WALKER;
int length = this.typeAnnotations.length;
long mask = 1;
for (int i = 0; i < length; i++, mask = mask << 1) {
IBinaryTypeAnnotation candidate = this.typeAnnotations[i];
if (candidate.getTargetType() != AnnotationTargetTypeConstants.METHOD_FORMAL_PARAMETER || (short)candidate.getMethodFormalParameterIndex() != index) {
newMatches &= ~mask;
}
}
return restrict(newMatches, 0);
}
/**
* Walk to the throws type at the given index.
*/
public TypeAnnotationWalker toThrows(int index) {
long newMatches = this.matches;
if (newMatches == 0)
return EMPTY_ANNOTATION_WALKER;
int length = this.typeAnnotations.length;
long mask = 1;
for (int i = 0; i < length; i++, mask = mask << 1) {
IBinaryTypeAnnotation candidate = this.typeAnnotations[i];
if (candidate.getTargetType() != AnnotationTargetTypeConstants.THROWS || candidate.getThrowsTypeIndex() != index) {
newMatches &= ~mask;
}
}
return restrict(newMatches, 0);
}
// ==== descending into details: ====
/** Walk to the type argument of the given rank. */
public TypeAnnotationWalker toTypeArgument(int rank) {
// like toNextDetail() but also checking byte 2 against rank
long newMatches = this.matches;
if (newMatches == 0)
return EMPTY_ANNOTATION_WALKER;
int length = this.typeAnnotations.length;
long mask = 1;
for (int i = 0; i < length; i++, mask = mask << 1) {
IBinaryTypeAnnotation candidate = this.typeAnnotations[i];
int[] path = candidate.getTypePath();
if (this.pathPtr >= path.length
|| path[this.pathPtr] != AnnotationTargetTypeConstants.TYPE_ARGUMENT
|| path[this.pathPtr+1] != rank) {
newMatches &= ~mask;
}
}
return restrict(newMatches, this.pathPtr+2);
}
/** Walk to the bound of a wildcard. */
public TypeAnnotationWalker toWildcardBound() {
long newMatches = this.matches;
if (newMatches == 0)
return EMPTY_ANNOTATION_WALKER;
int length = this.typeAnnotations.length;
long mask = 1;
for (int i = 0; i < length; i++, mask = mask << 1) {
IBinaryTypeAnnotation candidate = this.typeAnnotations[i];
int[] path = candidate.getTypePath();
if (this.pathPtr >= path.length
|| path[this.pathPtr] != AnnotationTargetTypeConstants.WILDCARD_BOUND) {
newMatches &= ~mask;
}
}
return restrict(newMatches, this.pathPtr+2);
}
/**
* Descend down one level of array dimensions.
*/
public TypeAnnotationWalker toNextArrayDimension() {
return toNextDetail(AnnotationTargetTypeConstants.NEXT_ARRAY_DIMENSION);
}
/**
* Descend down one level of type nesting.
*/
public TypeAnnotationWalker toNextNestedType() {
return toNextDetail(AnnotationTargetTypeConstants.NEXT_NESTED_TYPE);
}
/*
* Implementation for walking along the type_path for array dimensions & nested types.
* FIXME(stephan): support wildcard bounds.
*/
protected TypeAnnotationWalker toNextDetail(int detailKind) {
long newMatches = this.matches;
if (newMatches == 0)
return EMPTY_ANNOTATION_WALKER;
int length = this.typeAnnotations.length;
long mask = 1;
for (int i = 0; i < length; i++, mask = mask << 1) {
IBinaryTypeAnnotation candidate = this.typeAnnotations[i];
int[] path = candidate.getTypePath();
if (this.pathPtr >= path.length || path[this.pathPtr] != detailKind) {
newMatches &= ~mask;
}
}
return restrict(newMatches, this.pathPtr+2);
}
// ==== leaves: the actual annotations: ====
/**
* Retrieve the type annotations at the current position
* reached by invocations of toXYZ() methods.
*/
public IBinaryAnnotation[] getAnnotationsAtCursor() {
int length = this.typeAnnotations.length;
IBinaryAnnotation[] filtered = new IBinaryAnnotation[length];
long ptr = 1;
int count = 0;
for (int i = 0; i < length; i++, ptr<<=1) {
if ((this.matches & ptr) == 0)
continue;
IBinaryTypeAnnotation candidate = this.typeAnnotations[i];
if (candidate.getTypePath().length > this.pathPtr)
continue;
filtered[count++] = candidate.getAnnotation();
}
if (count == 0)
return NO_ANNOTATIONS;
if (count < length)
System.arraycopy(filtered, 0, filtered = new IBinaryAnnotation[count], 0, count);
return filtered;
}
}