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/*
* Copyright (c) 2016, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
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*/
package jdk.jshell;
import java.util.HashSet;
import com.sun.tools.javac.code.Type;
import com.sun.tools.javac.code.Type.ClassType;
import com.sun.tools.javac.util.JavacMessages;
import java.util.Locale;
import java.util.Set;
import java.util.function.BinaryOperator;
import com.sun.tools.javac.code.BoundKind;
import com.sun.tools.javac.code.Flags;
import com.sun.tools.javac.code.Symtab;
import com.sun.tools.javac.code.Type.CapturedType;
import com.sun.tools.javac.code.Type.StructuralTypeMapping;
import com.sun.tools.javac.code.Type.TypeVar;
import com.sun.tools.javac.code.Type.WildcardType;
import com.sun.tools.javac.code.Types;
import com.sun.tools.javac.code.Types.SimpleVisitor;
import com.sun.tools.javac.util.List;
import static com.sun.tools.javac.code.BoundKind.EXTENDS;
import static com.sun.tools.javac.code.BoundKind.SUPER;
import static com.sun.tools.javac.code.BoundKind.UNBOUND;
import static com.sun.tools.javac.code.Type.ArrayType;
import static com.sun.tools.javac.code.TypeTag.BOT;
import static com.sun.tools.javac.code.TypeTag.WILDCARD;
/**
* Print variable types in source form.
* TypeProjection and CaptureScanner are copied from Types in the JEP-286
* Sandbox by Maurizio. The checks for Non-Denotable in TypePrinter are
* cribbed from denotableChecker of the same source.
*
* @author Maurizio Cimadamore
* @author Robert Field
*/
class VarTypePrinter extends TypePrinter {
private static final String WILD = "?";
private final Symtab syms;
private final Types types;
VarTypePrinter(JavacMessages messages, BinaryOperator<String> fullClassNameAndPackageToClass,
Symtab syms, Types types) {
super(messages, fullClassNameAndPackageToClass);
this.syms = syms;
this.types = types;
}
@Override
String toString(Type t) {
return super.toString(upward(t));
}
@Override
public String visitTypeVar(TypeVar t, Locale locale) {
/* Any type variable mentioned in the inferred type must have been declared as a type parameter
(i.e cannot have been produced by inference (18.4))
*/
// and beyond that, there are no global type vars, so if there are any
// type variables left, they need to be eliminated
return WILD; // Non-denotable
}
@Override
public String visitCapturedType(CapturedType t, Locale locale) {
/* Any type variable mentioned in the inferred type must have been declared as a type parameter
(i.e cannot have been produced by capture conversion (5.1.10))
*/
return WILD; // Non-denotable
}
public Type upward(Type t) {
List<Type> captures = captures(t);
return upward(t, captures);
}
/************* Following from JEP-286 Types.java ***********/
public Type upward(Type t, List<Type> vars) {
return t.map(new TypeProjection(vars), true);
}
public List<Type> captures(Type t) {
CaptureScanner cs = new CaptureScanner();
Set<Type> captures = new HashSet<>();
cs.visit(t, captures);
return List.from(captures);
}
class CaptureScanner extends SimpleVisitor<Void, Set<Type>> {
@Override
public Void visitType(Type t, Set<Type> types) {
return null;
}
@Override
public Void visitClassType(ClassType t, Set<Type> seen) {
if (t.isCompound()) {
types.directSupertypes(t).forEach(s -> visit(s, seen));
} else {
t.allparams().forEach(ta -> visit(ta, seen));
}
return null;
}
@Override
public Void visitArrayType(ArrayType t, Set<Type> seen) {
return visit(t.elemtype, seen);
}
@Override
public Void visitWildcardType(WildcardType t, Set<Type> seen) {
visit(t.type, seen);
return null;
}
@Override
public Void visitTypeVar(TypeVar t, Set<Type> seen) {
if ((t.tsym.flags() & Flags.SYNTHETIC) != 0 && seen.add(t)) {
visit(t.getUpperBound(), seen);
}
return null;
}
@Override
public Void visitCapturedType(CapturedType t, Set<Type> seen) {
if (seen.add(t)) {
visit(t.getUpperBound(), seen);
visit(t.getLowerBound(), seen);
}
return null;
}
}
class TypeProjection extends StructuralTypeMapping<Boolean> {
List<Type> vars;
Set<Type> seen = new HashSet<>();
public TypeProjection(List<Type> vars) {
this.vars = vars;
}
@Override
public Type visitClassType(ClassType t, Boolean upward) {
if (upward && !t.isCompound() && t.tsym.name.isEmpty()) {
//lift anonymous class type to first supertype (class or interface)
return types.directSupertypes(t).last();
} else if (t.isCompound()) {
List<Type> components = types.directSupertypes(t);
List<Type> components1 = components.map(c -> c.map(this, upward));
if (components == components1) return t;
else return types.makeIntersectionType(components1);
} else {
Type outer = t.getEnclosingType();
Type outer1 = visit(outer, upward);
List<Type> typarams = t.getTypeArguments();
List<Type> typarams1 = typarams.map(ta -> mapTypeArgument(ta, upward));
if (typarams1.stream().anyMatch(ta -> ta.hasTag(BOT))) {
//not defined
return syms.botType;
}
if (outer1 == outer && typarams1 == typarams) return t;
else return new ClassType(outer1, typarams1, t.tsym, t.getMetadata()) {
@Override
protected boolean needsStripping() {
return true;
}
};
}
}
protected Type makeWildcard(Type upper, Type lower) {
BoundKind bk;
Type bound;
if (upper.hasTag(BOT)) {
upper = syms.objectType;
}
boolean isUpperObject = types.isSameType(upper, syms.objectType);
if (!lower.hasTag(BOT) && isUpperObject) {
bound = lower;
bk = SUPER;
} else {
bound = upper;
bk = isUpperObject ? UNBOUND : EXTENDS;
}
return new WildcardType(bound, bk, syms.boundClass);
}
@Override
public Type visitTypeVar(TypeVar t, Boolean upward) {
if (vars.contains(t)) {
try {
if (seen.add(t)) {
return (upward ?
t.getUpperBound() :
(t.getLowerBound() == null) ?
syms.botType :
t.getLowerBound())
.map(this, upward);
} else {
//cycle
return syms.objectType;
}
} finally {
seen.remove(t);
}
} else {
return t;
}
}
@Override
public Type visitWildcardType(WildcardType wt, Boolean upward) {
if (upward) {
return wt.isExtendsBound() ?
wt.type.map(this, upward) :
syms.objectType;
} else {
return wt.isSuperBound() ?
wt.type.map(this, upward) :
syms.botType;
}
}
private Type mapTypeArgument(Type t, boolean upward) {
if (!t.containsAny(vars)) {
return t;
} else if (!t.hasTag(WILDCARD) && !upward) {
//not defined
return syms.botType;
} else {
Type upper = t.map(this, upward);
Type lower = t.map(this, !upward);
return makeWildcard(upper, lower);
}
}
}
}