/*
* Copyright 2009 Google Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may not
* use this file except in compliance with the License. You may obtain a copy of
* the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations under
* the License.
*/
package com.google.gwt.dev.javac.asm;
import com.google.gwt.core.ext.TreeLogger;
import com.google.gwt.core.ext.typeinfo.JClassType;
import com.google.gwt.core.ext.typeinfo.JGenericType;
import com.google.gwt.core.ext.typeinfo.JParameterizedType;
import com.google.gwt.core.ext.typeinfo.JPrimitiveType;
import com.google.gwt.core.ext.typeinfo.JRealClassType;
import com.google.gwt.core.ext.typeinfo.JType;
import com.google.gwt.core.ext.typeinfo.JTypeParameter;
import com.google.gwt.core.ext.typeinfo.JWildcardType;
import com.google.gwt.core.ext.typeinfo.NotFoundException;
import com.google.gwt.core.ext.typeinfo.JWildcardType.BoundType;
import com.google.gwt.dev.asm.signature.SignatureVisitor;
import com.google.gwt.dev.javac.Resolver;
import com.google.gwt.dev.javac.TypeParameterLookup;
import com.google.gwt.dev.util.Name;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
/**
* Resolve a single parameterized type.
*/
public class ResolveTypeSignature extends EmptySignatureVisitor {
private final Resolver resolver;
private final Map<String, JRealClassType> binaryMapper;
private final TreeLogger logger;
private final JType[] returnTypeRef;
private final TypeParameterLookup lookup;
private final char wildcardMatch;
private final JClassType enclosingClass;
private JClassType outerClass;
private List<JType[]> args = new ArrayList<JType[]>();
private int arrayDepth = 0;
/**
* Resolve a parameterized type.
*
* @param resolver
* @param binaryMapper
* @param logger
* @param returnTypeRef "pointer" to return location, ie. 1-element array
* @param lookup
* @param enclosingClass
*/
public ResolveTypeSignature(Resolver resolver,
Map<String, JRealClassType> binaryMapper, TreeLogger logger,
JType[] returnTypeRef, TypeParameterLookup lookup,
JClassType enclosingClass) {
this(resolver, binaryMapper, logger, returnTypeRef, lookup,
enclosingClass, '=');
}
public ResolveTypeSignature(Resolver resovler,
Map<String, JRealClassType> binaryMapper,
TreeLogger logger, JType[] returnTypeRef,
TypeParameterLookup lookup, JClassType enclosingClass,
char wildcardMatch) {
this.resolver = resovler;
this.binaryMapper = binaryMapper;
this.logger = logger;
this.returnTypeRef = returnTypeRef;
this.lookup = lookup;
this.enclosingClass = enclosingClass;
this.wildcardMatch = wildcardMatch;
}
@Override
public SignatureVisitor visitArrayType() {
++arrayDepth;
return this;
}
@Override
public void visitBaseType(char descriptor) {
switch (descriptor) {
case 'V':
returnTypeRef[0] = JPrimitiveType.VOID;
break;
case 'B':
returnTypeRef[0] = JPrimitiveType.BYTE;
break;
case 'J':
returnTypeRef[0] = JPrimitiveType.LONG;
break;
case 'Z':
returnTypeRef[0] = JPrimitiveType.BOOLEAN;
break;
case 'I':
returnTypeRef[0] = JPrimitiveType.INT;
break;
case 'S':
returnTypeRef[0] = JPrimitiveType.SHORT;
break;
case 'C':
returnTypeRef[0] = JPrimitiveType.CHAR;
break;
case 'F':
returnTypeRef[0] = JPrimitiveType.FLOAT;
break;
case 'D':
returnTypeRef[0] = JPrimitiveType.DOUBLE;
break;
default:
throw new IllegalStateException("Unrecognized base type "
+ descriptor);
}
// this is the last visitor called on this visitor
visitEnd();
}
@Override
public void visitClassType(String internalName) {
assert Name.isInternalName(internalName);
outerClass = enclosingClass;
JRealClassType classType = binaryMapper.get(internalName);
// TODO(jat): failures here are likely binary-only annotations or local
// classes that have been elided from TypeOracle -- what should we do in
// those cases? Currently we log an error and replace them with Object,
// but we may can do something better.
boolean resolveSuccess = classType == null ? false
: resolver.resolveClass(logger, classType);
returnTypeRef[0] = classType;
if (!resolveSuccess || returnTypeRef[0] == null) {
logger.log(TreeLogger.ERROR, "Unable to resolve class " + internalName);
// Replace bound with Object if we can't resolve the class.
returnTypeRef[0] = resolver.getTypeOracle().getJavaLangObject();
}
}
@Override
public void visitEnd() {
if (returnTypeRef[0] == null) {
return;
}
resolveGenerics();
}
@Override
public void visitInnerClassType(String innerName) {
// Called after visitClass has already been called, and we will
// successively refine the class by going into its inner classes.
assert returnTypeRef[0] != null;
resolveGenerics();
outerClass = (JClassType) returnTypeRef[0];
JClassType searchClass = outerClass;
try {
JParameterizedType pt = searchClass.isParameterized();
if (pt != null) {
searchClass = pt.getBaseType();
}
returnTypeRef[0] = searchClass.getNestedType(innerName);
} catch (NotFoundException e) {
logger.log(TreeLogger.ERROR, "Unable to resolve inner class "
+ innerName + " in " + searchClass, e);
}
}
@Override
public void visitTypeArgument() {
JType[] arg = new JType[1]; // This could be int[] for example
arg[0] = resolver.getTypeOracle().getWildcardType(
JWildcardType.BoundType.UNBOUND,
resolver.getTypeOracle().getJavaLangObject());
args.add(arg);
}
@Override
public SignatureVisitor visitTypeArgument(char wildcard) {
JType[] arg = new JType[1];
args.add(arg);
// TODO(jat): should we pass enclosingClass here instead of null?
// not sure what the enclosing class of a type argument means, but
// I haven't found a case where it is actually used while processing
// the type argument.
return new ResolveTypeSignature(resolver, binaryMapper, logger,
arg, lookup, null, wildcard);
}
@Override
public void visitTypeVariable(String name) {
returnTypeRef[0] = lookup.lookup(name);
// this is the last visitor called on this visitor
visitEnd();
}
/**
* Merge the bounds from the declared type parameters into the type arguments
* for this type if necessary.
*
* <pre>Example:
* class Foo<T extends Bar> ...
*
* Foo<?> foo
*
* foo needs to have bounds ? extends Bar.
* </pre>
*
* <p>Currently we only deal with unbound wildcards as above, which matches
* existing TypeOracleMediator behavior. However, this may need to be
* extended.
*
* @param typeParams
* @param typeArgs
*/
private void mergeTypeParamBounds(JTypeParameter[] typeParams,
JClassType[] typeArgs) {
int n = typeArgs.length;
for (int i = 0; i < n; ++i) {
JWildcardType wildcard = typeArgs[i].isWildcard();
// right now we only replace Foo<?> with the constraints defined on the
// definition (which appears to match the existing TypeOracleMediator)
// but other cases may need to be handled.
if (wildcard != null && wildcard.getBoundType() == BoundType.UNBOUND
&& wildcard.getBaseType()
== resolver.getTypeOracle().getJavaLangObject()
&& typeParams[i].getBaseType() != null) {
typeArgs[i] = resolver.getTypeOracle().getWildcardType(
BoundType.UNBOUND, typeParams[i].getBaseType());
}
}
}
private JType resolveGeneric(JType type, JClassType outer,
JClassType[] typeArgs) {
JGenericType genericType = type.isGenericType();
if (genericType != null) {
int actual = typeArgs.length;
JTypeParameter[] typeParams = genericType.getTypeParameters();
int expected = typeParams.length;
if (actual == 0 && expected > 0) {
// If no type parameters were supplied, this is a raw type usage.
type = genericType.getRawType();
} else {
if (actual != expected) {
throw new IllegalStateException("Incorrect # of type parameters to "
+ genericType.getQualifiedBinaryName() + ": expected " + expected
+ ", actual=" + actual);
}
JClassType genericEnc = genericType.getEnclosingType();
if (outer == null && genericEnc != null) {
// Sometimes the signature is like Foo$Bar<H> even if Foo is a
// generic class. The cases I have seen are where Foo's type
// parameter is also named H and has the same bounds. That
// manifests itself as getting visitClassType("Foo$Bar") and
// then VisitTypeArgument/etc, rather than the usual
// visitClassType("Foo"), visitTypeArgument/etc,
// visitInnerClass("Bar"), visitTypeArgument/etc.
//
// So, in this case we have to build our own chain of enclosing
// classes here, properly parameterizing any generics along the
// way.
// TODO(jat): more testing to validate this assumption
JClassType[] outerArgs = null;
JGenericType genericEncGeneric = genericEnc.isGenericType();
if (genericEncGeneric != null) {
JTypeParameter[] encTypeParams = genericEncGeneric.getTypeParameters();
int n = encTypeParams.length;
outerArgs = new JClassType[n];
for (int i = 0; i < n; ++i) {
outerArgs[i] = lookup.lookup(encTypeParams[i].getName());
if (outerArgs[i] == null) {
// check to see if our current type has a parameter of the same
// name, and use it if so.
for (int j = 0; j < expected; ++j) {
if (typeParams[j].getName().equals(encTypeParams[j].getName())) {
outerArgs[i] = typeArgs[j];
break;
}
}
}
assert outerArgs[i] != null
: "Unable to resolve type parameter "
+ encTypeParams[i].getName() + " in enclosing type "
+ genericEnc + " of type " + genericType;
}
}
outer = (JClassType) resolveGeneric(genericEnc, null, outerArgs);
}
try {
mergeTypeParamBounds(typeParams, typeArgs);
type = resolver.getTypeOracle().getParameterizedType(genericType,
outer, typeArgs);
} catch (IllegalArgumentException e) {
// Can't use toString on typeArgs as they aren't completely built
// yet, so we have to roll our own.
StringBuilder buf = new StringBuilder();
buf.append("Unable to build parameterized type ");
buf.append(genericType);
String prefix = " with args <";
for (JClassType typeArg : typeArgs) {
buf.append(prefix).append(typeArg.getName());
prefix = ", ";
}
if (", ".equals(prefix)) {
buf.append('>');
}
logger.log(TreeLogger.ERROR, buf.toString(), e);
type = genericType.getRawType();
}
}
}
return type;
}
private void resolveGenerics() {
JGenericType genericType = returnTypeRef[0].isGenericType();
if (genericType != null) {
int actual = args.size();
JClassType[] typeArgs = new JClassType[actual];
for (int i = 0; i < actual; ++i) {
JType type = args.get(i)[0];
if (!(type instanceof JClassType)) {
logger.log(TreeLogger.ERROR, "Parameterized type argument is "
+ type + ", expected reference type");
} else {
typeArgs[i] = (JClassType) type;
}
}
returnTypeRef[0] = resolveGeneric(genericType, outerClass, typeArgs);
args.clear();
}
for (int i = 0; i < arrayDepth; ++i) {
returnTypeRef[0] = resolver.getTypeOracle().getArrayType(
returnTypeRef[0]);
}
switch (wildcardMatch) {
case '=':
// nothing to do for an exact match
break;
case '*':
returnTypeRef[0] = resolver.getTypeOracle().getWildcardType(
JWildcardType.BoundType.UNBOUND, (JClassType) returnTypeRef[0]);
break;
case '+':
// ? extends T
returnTypeRef[0] = resolver.getTypeOracle().getWildcardType(
JWildcardType.BoundType.EXTENDS, (JClassType) returnTypeRef[0]);
break;
case '-':
// ? super T
returnTypeRef[0] = resolver.getTypeOracle().getWildcardType(
JWildcardType.BoundType.SUPER, (JClassType) returnTypeRef[0]);
break;
}
if (returnTypeRef[0] instanceof JClassType) {
// Only JClassTypes can be an outer class
outerClass = (JClassType) returnTypeRef[0];
}
}
}