| /* |
| * Copyright (c) 2003, 2015, 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 |
| * questions. |
| */ |
| |
| package com.sun.tools.javac.code; |
| |
| import java.lang.ref.SoftReference; |
| import java.util.HashSet; |
| import java.util.HashMap; |
| import java.util.Locale; |
| import java.util.Map; |
| import java.util.Set; |
| import java.util.WeakHashMap; |
| import java.util.function.BiPredicate; |
| import java.util.stream.Collector; |
| |
| import javax.tools.JavaFileObject; |
| |
| import com.sun.tools.javac.code.Attribute.RetentionPolicy; |
| import com.sun.tools.javac.code.Lint.LintCategory; |
| import com.sun.tools.javac.code.Type.UndetVar.InferenceBound; |
| import com.sun.tools.javac.code.TypeMetadata.Entry.Kind; |
| import com.sun.tools.javac.comp.AttrContext; |
| import com.sun.tools.javac.comp.Check; |
| import com.sun.tools.javac.comp.Enter; |
| import com.sun.tools.javac.comp.Env; |
| import com.sun.tools.javac.util.*; |
| |
| import static com.sun.tools.javac.code.BoundKind.*; |
| import static com.sun.tools.javac.code.Flags.*; |
| import static com.sun.tools.javac.code.Kinds.Kind.*; |
| import static com.sun.tools.javac.code.Scope.*; |
| import static com.sun.tools.javac.code.Scope.LookupKind.NON_RECURSIVE; |
| import static com.sun.tools.javac.code.Symbol.*; |
| import static com.sun.tools.javac.code.Type.*; |
| import static com.sun.tools.javac.code.TypeTag.*; |
| import static com.sun.tools.javac.jvm.ClassFile.externalize; |
| |
| /** |
| * Utility class containing various operations on types. |
| * |
| * <p>Unless other names are more illustrative, the following naming |
| * conventions should be observed in this file: |
| * |
| * <dl> |
| * <dt>t</dt> |
| * <dd>If the first argument to an operation is a type, it should be named t.</dd> |
| * <dt>s</dt> |
| * <dd>Similarly, if the second argument to an operation is a type, it should be named s.</dd> |
| * <dt>ts</dt> |
| * <dd>If an operations takes a list of types, the first should be named ts.</dd> |
| * <dt>ss</dt> |
| * <dd>A second list of types should be named ss.</dd> |
| * </dl> |
| * |
| * <p><b>This is NOT part of any supported API. |
| * If you write code that depends on this, you do so at your own risk. |
| * This code and its internal interfaces are subject to change or |
| * deletion without notice.</b> |
| */ |
| public class Types { |
| protected static final Context.Key<Types> typesKey = new Context.Key<>(); |
| |
| final Symtab syms; |
| final JavacMessages messages; |
| final Names names; |
| final boolean allowObjectToPrimitiveCast; |
| final boolean allowDefaultMethods; |
| final Check chk; |
| final Enter enter; |
| JCDiagnostic.Factory diags; |
| List<Warner> warnStack = List.nil(); |
| final Name capturedName; |
| private final FunctionDescriptorLookupError functionDescriptorLookupError; |
| |
| public final Warner noWarnings; |
| |
| // <editor-fold defaultstate="collapsed" desc="Instantiating"> |
| public static Types instance(Context context) { |
| Types instance = context.get(typesKey); |
| if (instance == null) |
| instance = new Types(context); |
| return instance; |
| } |
| |
| protected Types(Context context) { |
| context.put(typesKey, this); |
| syms = Symtab.instance(context); |
| names = Names.instance(context); |
| Source source = Source.instance(context); |
| allowObjectToPrimitiveCast = source.allowObjectToPrimitiveCast(); |
| allowDefaultMethods = source.allowDefaultMethods(); |
| chk = Check.instance(context); |
| enter = Enter.instance(context); |
| capturedName = names.fromString("<captured wildcard>"); |
| messages = JavacMessages.instance(context); |
| diags = JCDiagnostic.Factory.instance(context); |
| functionDescriptorLookupError = new FunctionDescriptorLookupError(); |
| noWarnings = new Warner(null); |
| } |
| // </editor-fold> |
| |
| // <editor-fold defaultstate="collapsed" desc="bounds"> |
| /** |
| * Get a wildcard's upper bound, returning non-wildcards unchanged. |
| * @param t a type argument, either a wildcard or a type |
| */ |
| public Type wildUpperBound(Type t) { |
| if (t.hasTag(WILDCARD)) { |
| WildcardType w = (WildcardType) t; |
| if (w.isSuperBound()) |
| return w.bound == null ? syms.objectType : w.bound.bound; |
| else |
| return wildUpperBound(w.type); |
| } |
| else return t; |
| } |
| |
| /** |
| * Get a capture variable's upper bound, returning other types unchanged. |
| * @param t a type |
| */ |
| public Type cvarUpperBound(Type t) { |
| if (t.hasTag(TYPEVAR)) { |
| TypeVar v = (TypeVar) t; |
| return v.isCaptured() ? cvarUpperBound(v.bound) : v; |
| } |
| else return t; |
| } |
| |
| /** |
| * Get a wildcard's lower bound, returning non-wildcards unchanged. |
| * @param t a type argument, either a wildcard or a type |
| */ |
| public Type wildLowerBound(Type t) { |
| if (t.hasTag(WILDCARD)) { |
| WildcardType w = (WildcardType) t; |
| return w.isExtendsBound() ? syms.botType : wildLowerBound(w.type); |
| } |
| else return t; |
| } |
| |
| /** |
| * Get a capture variable's lower bound, returning other types unchanged. |
| * @param t a type |
| */ |
| public Type cvarLowerBound(Type t) { |
| if (t.hasTag(TYPEVAR) && ((TypeVar) t).isCaptured()) { |
| return cvarLowerBound(t.getLowerBound()); |
| } |
| else return t; |
| } |
| |
| /** |
| * Recursively skip type-variables until a class/array type is found; capture conversion is then |
| * (optionally) applied to the resulting type. This is useful for i.e. computing a site that is |
| * suitable for a method lookup. |
| */ |
| public Type skipTypeVars(Type site, boolean capture) { |
| while (site.hasTag(TYPEVAR)) { |
| site = site.getUpperBound(); |
| } |
| return capture ? capture(site) : site; |
| } |
| // </editor-fold> |
| |
| // <editor-fold defaultstate="collapsed" desc="isUnbounded"> |
| /** |
| * Checks that all the arguments to a class are unbounded |
| * wildcards or something else that doesn't make any restrictions |
| * on the arguments. If a class isUnbounded, a raw super- or |
| * subclass can be cast to it without a warning. |
| * @param t a type |
| * @return true iff the given type is unbounded or raw |
| */ |
| public boolean isUnbounded(Type t) { |
| return isUnbounded.visit(t); |
| } |
| // where |
| private final UnaryVisitor<Boolean> isUnbounded = new UnaryVisitor<Boolean>() { |
| |
| public Boolean visitType(Type t, Void ignored) { |
| return true; |
| } |
| |
| @Override |
| public Boolean visitClassType(ClassType t, Void ignored) { |
| List<Type> parms = t.tsym.type.allparams(); |
| List<Type> args = t.allparams(); |
| while (parms.nonEmpty()) { |
| WildcardType unb = new WildcardType(syms.objectType, |
| BoundKind.UNBOUND, |
| syms.boundClass, |
| (TypeVar)parms.head); |
| if (!containsType(args.head, unb)) |
| return false; |
| parms = parms.tail; |
| args = args.tail; |
| } |
| return true; |
| } |
| }; |
| // </editor-fold> |
| |
| // <editor-fold defaultstate="collapsed" desc="asSub"> |
| /** |
| * Return the least specific subtype of t that starts with symbol |
| * sym. If none exists, return null. The least specific subtype |
| * is determined as follows: |
| * |
| * <p>If there is exactly one parameterized instance of sym that is a |
| * subtype of t, that parameterized instance is returned.<br> |
| * Otherwise, if the plain type or raw type `sym' is a subtype of |
| * type t, the type `sym' itself is returned. Otherwise, null is |
| * returned. |
| */ |
| public Type asSub(Type t, Symbol sym) { |
| return asSub.visit(t, sym); |
| } |
| // where |
| private final SimpleVisitor<Type,Symbol> asSub = new SimpleVisitor<Type,Symbol>() { |
| |
| public Type visitType(Type t, Symbol sym) { |
| return null; |
| } |
| |
| @Override |
| public Type visitClassType(ClassType t, Symbol sym) { |
| if (t.tsym == sym) |
| return t; |
| Type base = asSuper(sym.type, t.tsym); |
| if (base == null) |
| return null; |
| ListBuffer<Type> from = new ListBuffer<>(); |
| ListBuffer<Type> to = new ListBuffer<>(); |
| try { |
| adapt(base, t, from, to); |
| } catch (AdaptFailure ex) { |
| return null; |
| } |
| Type res = subst(sym.type, from.toList(), to.toList()); |
| if (!isSubtype(res, t)) |
| return null; |
| ListBuffer<Type> openVars = new ListBuffer<>(); |
| for (List<Type> l = sym.type.allparams(); |
| l.nonEmpty(); l = l.tail) |
| if (res.contains(l.head) && !t.contains(l.head)) |
| openVars.append(l.head); |
| if (openVars.nonEmpty()) { |
| if (t.isRaw()) { |
| // The subtype of a raw type is raw |
| res = erasure(res); |
| } else { |
| // Unbound type arguments default to ? |
| List<Type> opens = openVars.toList(); |
| ListBuffer<Type> qs = new ListBuffer<>(); |
| for (List<Type> iter = opens; iter.nonEmpty(); iter = iter.tail) { |
| qs.append(new WildcardType(syms.objectType, BoundKind.UNBOUND, |
| syms.boundClass, (TypeVar) iter.head)); |
| } |
| res = subst(res, opens, qs.toList()); |
| } |
| } |
| return res; |
| } |
| |
| @Override |
| public Type visitErrorType(ErrorType t, Symbol sym) { |
| return t; |
| } |
| }; |
| // </editor-fold> |
| |
| // <editor-fold defaultstate="collapsed" desc="isConvertible"> |
| /** |
| * Is t a subtype of or convertible via boxing/unboxing |
| * conversion to s? |
| */ |
| public boolean isConvertible(Type t, Type s, Warner warn) { |
| if (t.hasTag(ERROR)) { |
| return true; |
| } |
| boolean tPrimitive = t.isPrimitive(); |
| boolean sPrimitive = s.isPrimitive(); |
| if (tPrimitive == sPrimitive) { |
| return isSubtypeUnchecked(t, s, warn); |
| } |
| return tPrimitive |
| ? isSubtype(boxedClass(t).type, s) |
| : isSubtype(unboxedType(t), s); |
| } |
| |
| /** |
| * Is t a subtype of or convertible via boxing/unboxing |
| * conversions to s? |
| */ |
| public boolean isConvertible(Type t, Type s) { |
| return isConvertible(t, s, noWarnings); |
| } |
| // </editor-fold> |
| |
| // <editor-fold defaultstate="collapsed" desc="findSam"> |
| |
| /** |
| * Exception used to report a function descriptor lookup failure. The exception |
| * wraps a diagnostic that can be used to generate more details error |
| * messages. |
| */ |
| public static class FunctionDescriptorLookupError extends RuntimeException { |
| private static final long serialVersionUID = 0; |
| |
| JCDiagnostic diagnostic; |
| |
| FunctionDescriptorLookupError() { |
| this.diagnostic = null; |
| } |
| |
| FunctionDescriptorLookupError setMessage(JCDiagnostic diag) { |
| this.diagnostic = diag; |
| return this; |
| } |
| |
| public JCDiagnostic getDiagnostic() { |
| return diagnostic; |
| } |
| } |
| |
| /** |
| * A cache that keeps track of function descriptors associated with given |
| * functional interfaces. |
| */ |
| class DescriptorCache { |
| |
| private WeakHashMap<TypeSymbol, Entry> _map = new WeakHashMap<>(); |
| |
| class FunctionDescriptor { |
| Symbol descSym; |
| |
| FunctionDescriptor(Symbol descSym) { |
| this.descSym = descSym; |
| } |
| |
| public Symbol getSymbol() { |
| return descSym; |
| } |
| |
| public Type getType(Type site) { |
| site = removeWildcards(site); |
| if (!chk.checkValidGenericType(site)) { |
| //if the inferred functional interface type is not well-formed, |
| //or if it's not a subtype of the original target, issue an error |
| throw failure(diags.fragment("no.suitable.functional.intf.inst", site)); |
| } |
| return memberType(site, descSym); |
| } |
| } |
| |
| class Entry { |
| final FunctionDescriptor cachedDescRes; |
| final int prevMark; |
| |
| public Entry(FunctionDescriptor cachedDescRes, |
| int prevMark) { |
| this.cachedDescRes = cachedDescRes; |
| this.prevMark = prevMark; |
| } |
| |
| boolean matches(int mark) { |
| return this.prevMark == mark; |
| } |
| } |
| |
| FunctionDescriptor get(TypeSymbol origin) throws FunctionDescriptorLookupError { |
| Entry e = _map.get(origin); |
| CompoundScope members = membersClosure(origin.type, false); |
| if (e == null || |
| !e.matches(members.getMark())) { |
| FunctionDescriptor descRes = findDescriptorInternal(origin, members); |
| _map.put(origin, new Entry(descRes, members.getMark())); |
| return descRes; |
| } |
| else { |
| return e.cachedDescRes; |
| } |
| } |
| |
| /** |
| * Compute the function descriptor associated with a given functional interface |
| */ |
| public FunctionDescriptor findDescriptorInternal(TypeSymbol origin, |
| CompoundScope membersCache) throws FunctionDescriptorLookupError { |
| if (!origin.isInterface() || (origin.flags() & ANNOTATION) != 0) { |
| //t must be an interface |
| throw failure("not.a.functional.intf", origin); |
| } |
| |
| final ListBuffer<Symbol> abstracts = new ListBuffer<>(); |
| for (Symbol sym : membersCache.getSymbols(new DescriptorFilter(origin))) { |
| Type mtype = memberType(origin.type, sym); |
| if (abstracts.isEmpty() || |
| (sym.name == abstracts.first().name && |
| overrideEquivalent(mtype, memberType(origin.type, abstracts.first())))) { |
| abstracts.append(sym); |
| } else { |
| //the target method(s) should be the only abstract members of t |
| throw failure("not.a.functional.intf.1", origin, |
| diags.fragment("incompatible.abstracts", Kinds.kindName(origin), origin)); |
| } |
| } |
| if (abstracts.isEmpty()) { |
| //t must define a suitable non-generic method |
| throw failure("not.a.functional.intf.1", origin, |
| diags.fragment("no.abstracts", Kinds.kindName(origin), origin)); |
| } else if (abstracts.size() == 1) { |
| return new FunctionDescriptor(abstracts.first()); |
| } else { // size > 1 |
| FunctionDescriptor descRes = mergeDescriptors(origin, abstracts.toList()); |
| if (descRes == null) { |
| //we can get here if the functional interface is ill-formed |
| ListBuffer<JCDiagnostic> descriptors = new ListBuffer<>(); |
| for (Symbol desc : abstracts) { |
| String key = desc.type.getThrownTypes().nonEmpty() ? |
| "descriptor.throws" : "descriptor"; |
| descriptors.append(diags.fragment(key, desc.name, |
| desc.type.getParameterTypes(), |
| desc.type.getReturnType(), |
| desc.type.getThrownTypes())); |
| } |
| JCDiagnostic.MultilineDiagnostic incompatibleDescriptors = |
| new JCDiagnostic.MultilineDiagnostic(diags.fragment("incompatible.descs.in.functional.intf", |
| Kinds.kindName(origin), origin), descriptors.toList()); |
| throw failure(incompatibleDescriptors); |
| } |
| return descRes; |
| } |
| } |
| |
| /** |
| * Compute a synthetic type for the target descriptor given a list |
| * of override-equivalent methods in the functional interface type. |
| * The resulting method type is a method type that is override-equivalent |
| * and return-type substitutable with each method in the original list. |
| */ |
| private FunctionDescriptor mergeDescriptors(TypeSymbol origin, List<Symbol> methodSyms) { |
| //pick argument types - simply take the signature that is a |
| //subsignature of all other signatures in the list (as per JLS 8.4.2) |
| List<Symbol> mostSpecific = List.nil(); |
| outer: for (Symbol msym1 : methodSyms) { |
| Type mt1 = memberType(origin.type, msym1); |
| for (Symbol msym2 : methodSyms) { |
| Type mt2 = memberType(origin.type, msym2); |
| if (!isSubSignature(mt1, mt2)) { |
| continue outer; |
| } |
| } |
| mostSpecific = mostSpecific.prepend(msym1); |
| } |
| if (mostSpecific.isEmpty()) { |
| return null; |
| } |
| |
| |
| //pick return types - this is done in two phases: (i) first, the most |
| //specific return type is chosen using strict subtyping; if this fails, |
| //a second attempt is made using return type substitutability (see JLS 8.4.5) |
| boolean phase2 = false; |
| Symbol bestSoFar = null; |
| while (bestSoFar == null) { |
| outer: for (Symbol msym1 : mostSpecific) { |
| Type mt1 = memberType(origin.type, msym1); |
| for (Symbol msym2 : methodSyms) { |
| Type mt2 = memberType(origin.type, msym2); |
| if (phase2 ? |
| !returnTypeSubstitutable(mt1, mt2) : |
| !isSubtypeInternal(mt1.getReturnType(), mt2.getReturnType())) { |
| continue outer; |
| } |
| } |
| bestSoFar = msym1; |
| } |
| if (phase2) { |
| break; |
| } else { |
| phase2 = true; |
| } |
| } |
| if (bestSoFar == null) return null; |
| |
| //merge thrown types - form the intersection of all the thrown types in |
| //all the signatures in the list |
| boolean toErase = !bestSoFar.type.hasTag(FORALL); |
| List<Type> thrown = null; |
| Type mt1 = memberType(origin.type, bestSoFar); |
| for (Symbol msym2 : methodSyms) { |
| Type mt2 = memberType(origin.type, msym2); |
| List<Type> thrown_mt2 = mt2.getThrownTypes(); |
| if (toErase) { |
| thrown_mt2 = erasure(thrown_mt2); |
| } else { |
| /* If bestSoFar is generic then all the methods are generic. |
| * The opposite is not true: a non generic method can override |
| * a generic method (raw override) so it's safe to cast mt1 and |
| * mt2 to ForAll. |
| */ |
| ForAll fa1 = (ForAll)mt1; |
| ForAll fa2 = (ForAll)mt2; |
| thrown_mt2 = subst(thrown_mt2, fa2.tvars, fa1.tvars); |
| } |
| thrown = (thrown == null) ? |
| thrown_mt2 : |
| chk.intersect(thrown_mt2, thrown); |
| } |
| |
| final List<Type> thrown1 = thrown; |
| return new FunctionDescriptor(bestSoFar) { |
| @Override |
| public Type getType(Type origin) { |
| Type mt = memberType(origin, getSymbol()); |
| return createMethodTypeWithThrown(mt, thrown1); |
| } |
| }; |
| } |
| |
| boolean isSubtypeInternal(Type s, Type t) { |
| return (s.isPrimitive() && t.isPrimitive()) ? |
| isSameType(t, s) : |
| isSubtype(s, t); |
| } |
| |
| FunctionDescriptorLookupError failure(String msg, Object... args) { |
| return failure(diags.fragment(msg, args)); |
| } |
| |
| FunctionDescriptorLookupError failure(JCDiagnostic diag) { |
| return functionDescriptorLookupError.setMessage(diag); |
| } |
| } |
| |
| private DescriptorCache descCache = new DescriptorCache(); |
| |
| /** |
| * Find the method descriptor associated to this class symbol - if the |
| * symbol 'origin' is not a functional interface, an exception is thrown. |
| */ |
| public Symbol findDescriptorSymbol(TypeSymbol origin) throws FunctionDescriptorLookupError { |
| return descCache.get(origin).getSymbol(); |
| } |
| |
| /** |
| * Find the type of the method descriptor associated to this class symbol - |
| * if the symbol 'origin' is not a functional interface, an exception is thrown. |
| */ |
| public Type findDescriptorType(Type origin) throws FunctionDescriptorLookupError { |
| return descCache.get(origin.tsym).getType(origin); |
| } |
| |
| /** |
| * Is given type a functional interface? |
| */ |
| public boolean isFunctionalInterface(TypeSymbol tsym) { |
| try { |
| findDescriptorSymbol(tsym); |
| return true; |
| } catch (FunctionDescriptorLookupError ex) { |
| return false; |
| } |
| } |
| |
| public boolean isFunctionalInterface(Type site) { |
| try { |
| findDescriptorType(site); |
| return true; |
| } catch (FunctionDescriptorLookupError ex) { |
| return false; |
| } |
| } |
| |
| public Type removeWildcards(Type site) { |
| if (site.getTypeArguments().stream().anyMatch(t -> t.hasTag(WILDCARD))) { |
| //compute non-wildcard parameterization - JLS 9.9 |
| List<Type> actuals = site.getTypeArguments(); |
| List<Type> formals = site.tsym.type.getTypeArguments(); |
| ListBuffer<Type> targs = new ListBuffer<>(); |
| for (Type formal : formals) { |
| Type actual = actuals.head; |
| Type bound = formal.getUpperBound(); |
| if (actuals.head.hasTag(WILDCARD)) { |
| WildcardType wt = (WildcardType)actual; |
| //check that bound does not contain other formals |
| if (bound.containsAny(formals)) { |
| targs.add(wt.type); |
| } else { |
| //compute new type-argument based on declared bound and wildcard bound |
| switch (wt.kind) { |
| case UNBOUND: |
| targs.add(bound); |
| break; |
| case EXTENDS: |
| targs.add(glb(bound, wt.type)); |
| break; |
| case SUPER: |
| targs.add(wt.type); |
| break; |
| default: |
| Assert.error("Cannot get here!"); |
| } |
| } |
| } else { |
| //not a wildcard - the new type argument remains unchanged |
| targs.add(actual); |
| } |
| actuals = actuals.tail; |
| } |
| return subst(site.tsym.type, formals, targs.toList()); |
| } else { |
| return site; |
| } |
| } |
| |
| /** |
| * Create a symbol for a class that implements a given functional interface |
| * and overrides its functional descriptor. This routine is used for two |
| * main purposes: (i) checking well-formedness of a functional interface; |
| * (ii) perform functional interface bridge calculation. |
| */ |
| public ClassSymbol makeFunctionalInterfaceClass(Env<AttrContext> env, Name name, List<Type> targets, long cflags) { |
| if (targets.isEmpty()) { |
| return null; |
| } |
| Symbol descSym = findDescriptorSymbol(targets.head.tsym); |
| Type descType = findDescriptorType(targets.head); |
| ClassSymbol csym = new ClassSymbol(cflags, name, env.enclClass.sym.outermostClass()); |
| csym.completer = Completer.NULL_COMPLETER; |
| csym.members_field = WriteableScope.create(csym); |
| MethodSymbol instDescSym = new MethodSymbol(descSym.flags(), descSym.name, descType, csym); |
| csym.members_field.enter(instDescSym); |
| Type.ClassType ctype = new Type.ClassType(Type.noType, List.<Type>nil(), csym); |
| ctype.supertype_field = syms.objectType; |
| ctype.interfaces_field = targets; |
| csym.type = ctype; |
| csym.sourcefile = ((ClassSymbol)csym.owner).sourcefile; |
| return csym; |
| } |
| |
| /** |
| * Find the minimal set of methods that are overridden by the functional |
| * descriptor in 'origin'. All returned methods are assumed to have different |
| * erased signatures. |
| */ |
| public List<Symbol> functionalInterfaceBridges(TypeSymbol origin) { |
| Assert.check(isFunctionalInterface(origin)); |
| Symbol descSym = findDescriptorSymbol(origin); |
| CompoundScope members = membersClosure(origin.type, false); |
| ListBuffer<Symbol> overridden = new ListBuffer<>(); |
| outer: for (Symbol m2 : members.getSymbolsByName(descSym.name, bridgeFilter)) { |
| if (m2 == descSym) continue; |
| else if (descSym.overrides(m2, origin, Types.this, false)) { |
| for (Symbol m3 : overridden) { |
| if (isSameType(m3.erasure(Types.this), m2.erasure(Types.this)) || |
| (m3.overrides(m2, origin, Types.this, false) && |
| (pendingBridges((ClassSymbol)origin, m3.enclClass()) || |
| (((MethodSymbol)m2).binaryImplementation((ClassSymbol)m3.owner, Types.this) != null)))) { |
| continue outer; |
| } |
| } |
| overridden.add(m2); |
| } |
| } |
| return overridden.toList(); |
| } |
| //where |
| private Filter<Symbol> bridgeFilter = new Filter<Symbol>() { |
| public boolean accepts(Symbol t) { |
| return t.kind == MTH && |
| t.name != names.init && |
| t.name != names.clinit && |
| (t.flags() & SYNTHETIC) == 0; |
| } |
| }; |
| private boolean pendingBridges(ClassSymbol origin, TypeSymbol s) { |
| //a symbol will be completed from a classfile if (a) symbol has |
| //an associated file object with CLASS kind and (b) the symbol has |
| //not been entered |
| if (origin.classfile != null && |
| origin.classfile.getKind() == JavaFileObject.Kind.CLASS && |
| enter.getEnv(origin) == null) { |
| return false; |
| } |
| if (origin == s) { |
| return true; |
| } |
| for (Type t : interfaces(origin.type)) { |
| if (pendingBridges((ClassSymbol)t.tsym, s)) { |
| return true; |
| } |
| } |
| return false; |
| } |
| // </editor-fold> |
| |
| /** |
| * Scope filter used to skip methods that should be ignored (such as methods |
| * overridden by j.l.Object) during function interface conversion interface check |
| */ |
| class DescriptorFilter implements Filter<Symbol> { |
| |
| TypeSymbol origin; |
| |
| DescriptorFilter(TypeSymbol origin) { |
| this.origin = origin; |
| } |
| |
| @Override |
| public boolean accepts(Symbol sym) { |
| return sym.kind == MTH && |
| (sym.flags() & (ABSTRACT | DEFAULT)) == ABSTRACT && |
| !overridesObjectMethod(origin, sym) && |
| (interfaceCandidates(origin.type, (MethodSymbol)sym).head.flags() & DEFAULT) == 0; |
| } |
| } |
| |
| // <editor-fold defaultstate="collapsed" desc="isSubtype"> |
| /** |
| * Is t an unchecked subtype of s? |
| */ |
| public boolean isSubtypeUnchecked(Type t, Type s) { |
| return isSubtypeUnchecked(t, s, noWarnings); |
| } |
| /** |
| * Is t an unchecked subtype of s? |
| */ |
| public boolean isSubtypeUnchecked(Type t, Type s, Warner warn) { |
| boolean result = isSubtypeUncheckedInternal(t, s, warn); |
| if (result) { |
| checkUnsafeVarargsConversion(t, s, warn); |
| } |
| return result; |
| } |
| //where |
| private boolean isSubtypeUncheckedInternal(Type t, Type s, Warner warn) { |
| if (t.hasTag(ARRAY) && s.hasTag(ARRAY)) { |
| if (((ArrayType)t).elemtype.isPrimitive()) { |
| return isSameType(elemtype(t), elemtype(s)); |
| } else { |
| return isSubtypeUnchecked(elemtype(t), elemtype(s), warn); |
| } |
| } else if (isSubtype(t, s)) { |
| return true; |
| } else if (t.hasTag(TYPEVAR)) { |
| return isSubtypeUnchecked(t.getUpperBound(), s, warn); |
| } else if (!s.isRaw()) { |
| Type t2 = asSuper(t, s.tsym); |
| if (t2 != null && t2.isRaw()) { |
| if (isReifiable(s)) { |
| warn.silentWarn(LintCategory.UNCHECKED); |
| } else { |
| warn.warn(LintCategory.UNCHECKED); |
| } |
| return true; |
| } |
| } |
| return false; |
| } |
| |
| private void checkUnsafeVarargsConversion(Type t, Type s, Warner warn) { |
| if (!t.hasTag(ARRAY) || isReifiable(t)) { |
| return; |
| } |
| ArrayType from = (ArrayType)t; |
| boolean shouldWarn = false; |
| switch (s.getTag()) { |
| case ARRAY: |
| ArrayType to = (ArrayType)s; |
| shouldWarn = from.isVarargs() && |
| !to.isVarargs() && |
| !isReifiable(from); |
| break; |
| case CLASS: |
| shouldWarn = from.isVarargs(); |
| break; |
| } |
| if (shouldWarn) { |
| warn.warn(LintCategory.VARARGS); |
| } |
| } |
| |
| /** |
| * Is t a subtype of s?<br> |
| * (not defined for Method and ForAll types) |
| */ |
| final public boolean isSubtype(Type t, Type s) { |
| return isSubtype(t, s, true); |
| } |
| final public boolean isSubtypeNoCapture(Type t, Type s) { |
| return isSubtype(t, s, false); |
| } |
| public boolean isSubtype(Type t, Type s, boolean capture) { |
| if (t.equalsIgnoreMetadata(s)) |
| return true; |
| if (s.isPartial()) |
| return isSuperType(s, t); |
| |
| if (s.isCompound()) { |
| for (Type s2 : interfaces(s).prepend(supertype(s))) { |
| if (!isSubtype(t, s2, capture)) |
| return false; |
| } |
| return true; |
| } |
| |
| // Generally, if 's' is a lower-bounded type variable, recur on lower bound; but |
| // for inference variables and intersections, we need to keep 's' |
| // (see JLS 4.10.2 for intersections and 18.2.3 for inference vars) |
| if (!t.hasTag(UNDETVAR) && !t.isCompound()) { |
| // TODO: JDK-8039198, bounds checking sometimes passes in a wildcard as s |
| Type lower = cvarLowerBound(wildLowerBound(s)); |
| if (s != lower && !lower.hasTag(BOT)) |
| return isSubtype(capture ? capture(t) : t, lower, false); |
| } |
| |
| return isSubtype.visit(capture ? capture(t) : t, s); |
| } |
| // where |
| private TypeRelation isSubtype = new TypeRelation() |
| { |
| @Override |
| public Boolean visitType(Type t, Type s) { |
| switch (t.getTag()) { |
| case BYTE: |
| return (!s.hasTag(CHAR) && t.getTag().isSubRangeOf(s.getTag())); |
| case CHAR: |
| return (!s.hasTag(SHORT) && t.getTag().isSubRangeOf(s.getTag())); |
| case SHORT: case INT: case LONG: |
| case FLOAT: case DOUBLE: |
| return t.getTag().isSubRangeOf(s.getTag()); |
| case BOOLEAN: case VOID: |
| return t.hasTag(s.getTag()); |
| case TYPEVAR: |
| return isSubtypeNoCapture(t.getUpperBound(), s); |
| case BOT: |
| return |
| s.hasTag(BOT) || s.hasTag(CLASS) || |
| s.hasTag(ARRAY) || s.hasTag(TYPEVAR); |
| case WILDCARD: //we shouldn't be here - avoids crash (see 7034495) |
| case NONE: |
| return false; |
| default: |
| throw new AssertionError("isSubtype " + t.getTag()); |
| } |
| } |
| |
| private Set<TypePair> cache = new HashSet<>(); |
| |
| private boolean containsTypeRecursive(Type t, Type s) { |
| TypePair pair = new TypePair(t, s); |
| if (cache.add(pair)) { |
| try { |
| return containsType(t.getTypeArguments(), |
| s.getTypeArguments()); |
| } finally { |
| cache.remove(pair); |
| } |
| } else { |
| return containsType(t.getTypeArguments(), |
| rewriteSupers(s).getTypeArguments()); |
| } |
| } |
| |
| private Type rewriteSupers(Type t) { |
| if (!t.isParameterized()) |
| return t; |
| ListBuffer<Type> from = new ListBuffer<>(); |
| ListBuffer<Type> to = new ListBuffer<>(); |
| adaptSelf(t, from, to); |
| if (from.isEmpty()) |
| return t; |
| ListBuffer<Type> rewrite = new ListBuffer<>(); |
| boolean changed = false; |
| for (Type orig : to.toList()) { |
| Type s = rewriteSupers(orig); |
| if (s.isSuperBound() && !s.isExtendsBound()) { |
| s = new WildcardType(syms.objectType, |
| BoundKind.UNBOUND, |
| syms.boundClass, |
| s.getMetadata()); |
| changed = true; |
| } else if (s != orig) { |
| s = new WildcardType(wildUpperBound(s), |
| BoundKind.EXTENDS, |
| syms.boundClass, |
| s.getMetadata()); |
| changed = true; |
| } |
| rewrite.append(s); |
| } |
| if (changed) |
| return subst(t.tsym.type, from.toList(), rewrite.toList()); |
| else |
| return t; |
| } |
| |
| @Override |
| public Boolean visitClassType(ClassType t, Type s) { |
| Type sup = asSuper(t, s.tsym); |
| if (sup == null) return false; |
| // If t is an intersection, sup might not be a class type |
| if (!sup.hasTag(CLASS)) return isSubtypeNoCapture(sup, s); |
| return sup.tsym == s.tsym |
| // Check type variable containment |
| && (!s.isParameterized() || containsTypeRecursive(s, sup)) |
| && isSubtypeNoCapture(sup.getEnclosingType(), |
| s.getEnclosingType()); |
| } |
| |
| @Override |
| public Boolean visitArrayType(ArrayType t, Type s) { |
| if (s.hasTag(ARRAY)) { |
| if (t.elemtype.isPrimitive()) |
| return isSameType(t.elemtype, elemtype(s)); |
| else |
| return isSubtypeNoCapture(t.elemtype, elemtype(s)); |
| } |
| |
| if (s.hasTag(CLASS)) { |
| Name sname = s.tsym.getQualifiedName(); |
| return sname == names.java_lang_Object |
| || sname == names.java_lang_Cloneable |
| || sname == names.java_io_Serializable; |
| } |
| |
| return false; |
| } |
| |
| @Override |
| public Boolean visitUndetVar(UndetVar t, Type s) { |
| //todo: test against origin needed? or replace with substitution? |
| if (t == s || t.qtype == s || s.hasTag(ERROR) || s.hasTag(UNKNOWN)) { |
| return true; |
| } else if (s.hasTag(BOT)) { |
| //if 's' is 'null' there's no instantiated type U for which |
| //U <: s (but 'null' itself, which is not a valid type) |
| return false; |
| } |
| |
| t.addBound(InferenceBound.UPPER, s, Types.this); |
| return true; |
| } |
| |
| @Override |
| public Boolean visitErrorType(ErrorType t, Type s) { |
| return true; |
| } |
| }; |
| |
| /** |
| * Is t a subtype of every type in given list `ts'?<br> |
| * (not defined for Method and ForAll types)<br> |
| * Allows unchecked conversions. |
| */ |
| public boolean isSubtypeUnchecked(Type t, List<Type> ts, Warner warn) { |
| for (List<Type> l = ts; l.nonEmpty(); l = l.tail) |
| if (!isSubtypeUnchecked(t, l.head, warn)) |
| return false; |
| return true; |
| } |
| |
| /** |
| * Are corresponding elements of ts subtypes of ss? If lists are |
| * of different length, return false. |
| */ |
| public boolean isSubtypes(List<Type> ts, List<Type> ss) { |
| while (ts.tail != null && ss.tail != null |
| /*inlined: ts.nonEmpty() && ss.nonEmpty()*/ && |
| isSubtype(ts.head, ss.head)) { |
| ts = ts.tail; |
| ss = ss.tail; |
| } |
| return ts.tail == null && ss.tail == null; |
| /*inlined: ts.isEmpty() && ss.isEmpty();*/ |
| } |
| |
| /** |
| * Are corresponding elements of ts subtypes of ss, allowing |
| * unchecked conversions? If lists are of different length, |
| * return false. |
| **/ |
| public boolean isSubtypesUnchecked(List<Type> ts, List<Type> ss, Warner warn) { |
| while (ts.tail != null && ss.tail != null |
| /*inlined: ts.nonEmpty() && ss.nonEmpty()*/ && |
| isSubtypeUnchecked(ts.head, ss.head, warn)) { |
| ts = ts.tail; |
| ss = ss.tail; |
| } |
| return ts.tail == null && ss.tail == null; |
| /*inlined: ts.isEmpty() && ss.isEmpty();*/ |
| } |
| // </editor-fold> |
| |
| // <editor-fold defaultstate="collapsed" desc="isSuperType"> |
| /** |
| * Is t a supertype of s? |
| */ |
| public boolean isSuperType(Type t, Type s) { |
| switch (t.getTag()) { |
| case ERROR: |
| return true; |
| case UNDETVAR: { |
| UndetVar undet = (UndetVar)t; |
| if (t == s || |
| undet.qtype == s || |
| s.hasTag(ERROR) || |
| s.hasTag(BOT)) { |
| return true; |
| } |
| undet.addBound(InferenceBound.LOWER, s, this); |
| return true; |
| } |
| default: |
| return isSubtype(s, t); |
| } |
| } |
| // </editor-fold> |
| |
| // <editor-fold defaultstate="collapsed" desc="isSameType"> |
| /** |
| * Are corresponding elements of the lists the same type? If |
| * lists are of different length, return false. |
| */ |
| public boolean isSameTypes(List<Type> ts, List<Type> ss) { |
| return isSameTypes(ts, ss, false); |
| } |
| public boolean isSameTypes(List<Type> ts, List<Type> ss, boolean strict) { |
| while (ts.tail != null && ss.tail != null |
| /*inlined: ts.nonEmpty() && ss.nonEmpty()*/ && |
| isSameType(ts.head, ss.head, strict)) { |
| ts = ts.tail; |
| ss = ss.tail; |
| } |
| return ts.tail == null && ss.tail == null; |
| /*inlined: ts.isEmpty() && ss.isEmpty();*/ |
| } |
| |
| /** |
| * A polymorphic signature method (JLS 15.12.3) is a method that |
| * (i) is declared in the java.lang.invoke.MethodHandle class, (ii) takes |
| * a single variable arity parameter (iii) whose declared type is Object[], |
| * (iv) has a return type of Object and (v) is native. |
| */ |
| public boolean isSignaturePolymorphic(MethodSymbol msym) { |
| List<Type> argtypes = msym.type.getParameterTypes(); |
| return (msym.flags_field & NATIVE) != 0 && |
| msym.owner == syms.methodHandleType.tsym && |
| argtypes.tail.tail == null && |
| argtypes.head.hasTag(TypeTag.ARRAY) && |
| msym.type.getReturnType().tsym == syms.objectType.tsym && |
| ((ArrayType)argtypes.head).elemtype.tsym == syms.objectType.tsym; |
| } |
| |
| /** |
| * Is t the same type as s? |
| */ |
| public boolean isSameType(Type t, Type s) { |
| return isSameType(t, s, false); |
| } |
| public boolean isSameType(Type t, Type s, boolean strict) { |
| return strict ? |
| isSameTypeStrict.visit(t, s) : |
| isSameTypeLoose.visit(t, s); |
| } |
| // where |
| abstract class SameTypeVisitor extends TypeRelation { |
| |
| public Boolean visitType(Type t, Type s) { |
| if (t.equalsIgnoreMetadata(s)) |
| return true; |
| |
| if (s.isPartial()) |
| return visit(s, t); |
| |
| switch (t.getTag()) { |
| case BYTE: case CHAR: case SHORT: case INT: case LONG: case FLOAT: |
| case DOUBLE: case BOOLEAN: case VOID: case BOT: case NONE: |
| return t.hasTag(s.getTag()); |
| case TYPEVAR: { |
| if (s.hasTag(TYPEVAR)) { |
| //type-substitution does not preserve type-var types |
| //check that type var symbols and bounds are indeed the same |
| return sameTypeVars((TypeVar)t, (TypeVar)s); |
| } |
| else { |
| //special case for s == ? super X, where upper(s) = u |
| //check that u == t, where u has been set by Type.withTypeVar |
| return s.isSuperBound() && |
| !s.isExtendsBound() && |
| visit(t, wildUpperBound(s)); |
| } |
| } |
| default: |
| throw new AssertionError("isSameType " + t.getTag()); |
| } |
| } |
| |
| abstract boolean sameTypeVars(TypeVar tv1, TypeVar tv2); |
| |
| @Override |
| public Boolean visitWildcardType(WildcardType t, Type s) { |
| if (s.isPartial()) |
| return visit(s, t); |
| else |
| return false; |
| } |
| |
| @Override |
| public Boolean visitClassType(ClassType t, Type s) { |
| if (t == s) |
| return true; |
| |
| if (s.isPartial()) |
| return visit(s, t); |
| |
| if (s.isSuperBound() && !s.isExtendsBound()) |
| return visit(t, wildUpperBound(s)) && visit(t, wildLowerBound(s)); |
| |
| if (t.isCompound() && s.isCompound()) { |
| if (!visit(supertype(t), supertype(s))) |
| return false; |
| |
| HashSet<UniqueType> set = new HashSet<>(); |
| for (Type x : interfaces(t)) |
| set.add(new UniqueType(x, Types.this)); |
| for (Type x : interfaces(s)) { |
| if (!set.remove(new UniqueType(x, Types.this))) |
| return false; |
| } |
| return (set.isEmpty()); |
| } |
| return t.tsym == s.tsym |
| && visit(t.getEnclosingType(), s.getEnclosingType()) |
| && containsTypes(t.getTypeArguments(), s.getTypeArguments()); |
| } |
| |
| abstract protected boolean containsTypes(List<Type> ts1, List<Type> ts2); |
| |
| @Override |
| public Boolean visitArrayType(ArrayType t, Type s) { |
| if (t == s) |
| return true; |
| |
| if (s.isPartial()) |
| return visit(s, t); |
| |
| return s.hasTag(ARRAY) |
| && containsTypeEquivalent(t.elemtype, elemtype(s)); |
| } |
| |
| @Override |
| public Boolean visitMethodType(MethodType t, Type s) { |
| // isSameType for methods does not take thrown |
| // exceptions into account! |
| return hasSameArgs(t, s) && visit(t.getReturnType(), s.getReturnType()); |
| } |
| |
| @Override |
| public Boolean visitPackageType(PackageType t, Type s) { |
| return t == s; |
| } |
| |
| @Override |
| public Boolean visitForAll(ForAll t, Type s) { |
| if (!s.hasTag(FORALL)) { |
| return false; |
| } |
| |
| ForAll forAll = (ForAll)s; |
| return hasSameBounds(t, forAll) |
| && visit(t.qtype, subst(forAll.qtype, forAll.tvars, t.tvars)); |
| } |
| |
| @Override |
| public Boolean visitUndetVar(UndetVar t, Type s) { |
| if (s.hasTag(WILDCARD)) { |
| // FIXME, this might be leftovers from before capture conversion |
| return false; |
| } |
| |
| if (t == s || t.qtype == s || s.hasTag(ERROR) || s.hasTag(UNKNOWN)) { |
| return true; |
| } |
| |
| t.addBound(InferenceBound.EQ, s, Types.this); |
| |
| return true; |
| } |
| |
| @Override |
| public Boolean visitErrorType(ErrorType t, Type s) { |
| return true; |
| } |
| } |
| |
| /** |
| * Standard type-equality relation - type variables are considered |
| * equals if they share the same type symbol. |
| */ |
| TypeRelation isSameTypeLoose = new LooseSameTypeVisitor(); |
| |
| private class LooseSameTypeVisitor extends SameTypeVisitor { |
| |
| /** cache of the type-variable pairs being (recursively) tested. */ |
| private Set<TypePair> cache = new HashSet<>(); |
| |
| @Override |
| boolean sameTypeVars(TypeVar tv1, TypeVar tv2) { |
| return tv1.tsym == tv2.tsym && checkSameBounds(tv1, tv2); |
| } |
| @Override |
| protected boolean containsTypes(List<Type> ts1, List<Type> ts2) { |
| return containsTypeEquivalent(ts1, ts2); |
| } |
| |
| /** |
| * Since type-variable bounds can be recursive, we need to protect against |
| * infinite loops - where the same bounds are checked over and over recursively. |
| */ |
| private boolean checkSameBounds(TypeVar tv1, TypeVar tv2) { |
| TypePair p = new TypePair(tv1, tv2, true); |
| if (cache.add(p)) { |
| try { |
| return visit(tv1.getUpperBound(), tv2.getUpperBound()); |
| } finally { |
| cache.remove(p); |
| } |
| } else { |
| return false; |
| } |
| } |
| }; |
| |
| /** |
| * Strict type-equality relation - type variables are considered |
| * equals if they share the same object identity. |
| */ |
| TypeRelation isSameTypeStrict = new SameTypeVisitor() { |
| @Override |
| boolean sameTypeVars(TypeVar tv1, TypeVar tv2) { |
| return tv1 == tv2; |
| } |
| @Override |
| protected boolean containsTypes(List<Type> ts1, List<Type> ts2) { |
| return isSameTypes(ts1, ts2, true); |
| } |
| |
| @Override |
| public Boolean visitWildcardType(WildcardType t, Type s) { |
| if (!s.hasTag(WILDCARD)) { |
| return false; |
| } else { |
| WildcardType t2 = (WildcardType)s; |
| return t.kind == t2.kind && |
| isSameType(t.type, t2.type, true); |
| } |
| } |
| }; |
| |
| // </editor-fold> |
| |
| // <editor-fold defaultstate="collapsed" desc="Contains Type"> |
| public boolean containedBy(Type t, Type s) { |
| switch (t.getTag()) { |
| case UNDETVAR: |
| if (s.hasTag(WILDCARD)) { |
| UndetVar undetvar = (UndetVar)t; |
| WildcardType wt = (WildcardType)s; |
| switch(wt.kind) { |
| case UNBOUND: |
| break; |
| case EXTENDS: { |
| Type bound = wildUpperBound(s); |
| undetvar.addBound(InferenceBound.UPPER, bound, this); |
| break; |
| } |
| case SUPER: { |
| Type bound = wildLowerBound(s); |
| undetvar.addBound(InferenceBound.LOWER, bound, this); |
| break; |
| } |
| } |
| return true; |
| } else { |
| return isSameType(t, s); |
| } |
| case ERROR: |
| return true; |
| default: |
| return containsType(s, t); |
| } |
| } |
| |
| boolean containsType(List<Type> ts, List<Type> ss) { |
| while (ts.nonEmpty() && ss.nonEmpty() |
| && containsType(ts.head, ss.head)) { |
| ts = ts.tail; |
| ss = ss.tail; |
| } |
| return ts.isEmpty() && ss.isEmpty(); |
| } |
| |
| /** |
| * Check if t contains s. |
| * |
| * <p>T contains S if: |
| * |
| * <p>{@code L(T) <: L(S) && U(S) <: U(T)} |
| * |
| * <p>This relation is only used by ClassType.isSubtype(), that |
| * is, |
| * |
| * <p>{@code C<S> <: C<T> if T contains S.} |
| * |
| * <p>Because of F-bounds, this relation can lead to infinite |
| * recursion. Thus we must somehow break that recursion. Notice |
| * that containsType() is only called from ClassType.isSubtype(). |
| * Since the arguments have already been checked against their |
| * bounds, we know: |
| * |
| * <p>{@code U(S) <: U(T) if T is "super" bound (U(T) *is* the bound)} |
| * |
| * <p>{@code L(T) <: L(S) if T is "extends" bound (L(T) is bottom)} |
| * |
| * @param t a type |
| * @param s a type |
| */ |
| public boolean containsType(Type t, Type s) { |
| return containsType.visit(t, s); |
| } |
| // where |
| private TypeRelation containsType = new TypeRelation() { |
| |
| public Boolean visitType(Type t, Type s) { |
| if (s.isPartial()) |
| return containedBy(s, t); |
| else |
| return isSameType(t, s); |
| } |
| |
| // void debugContainsType(WildcardType t, Type s) { |
| // System.err.println(); |
| // System.err.format(" does %s contain %s?%n", t, s); |
| // System.err.format(" %s U(%s) <: U(%s) %s = %s%n", |
| // wildUpperBound(s), s, t, wildUpperBound(t), |
| // t.isSuperBound() |
| // || isSubtypeNoCapture(wildUpperBound(s), wildUpperBound(t))); |
| // System.err.format(" %s L(%s) <: L(%s) %s = %s%n", |
| // wildLowerBound(t), t, s, wildLowerBound(s), |
| // t.isExtendsBound() |
| // || isSubtypeNoCapture(wildLowerBound(t), wildLowerBound(s))); |
| // System.err.println(); |
| // } |
| |
| @Override |
| public Boolean visitWildcardType(WildcardType t, Type s) { |
| if (s.isPartial()) |
| return containedBy(s, t); |
| else { |
| // debugContainsType(t, s); |
| return isSameWildcard(t, s) |
| || isCaptureOf(s, t) |
| || ((t.isExtendsBound() || isSubtypeNoCapture(wildLowerBound(t), wildLowerBound(s))) && |
| (t.isSuperBound() || isSubtypeNoCapture(wildUpperBound(s), wildUpperBound(t)))); |
| } |
| } |
| |
| @Override |
| public Boolean visitUndetVar(UndetVar t, Type s) { |
| if (!s.hasTag(WILDCARD)) { |
| return isSameType(t, s); |
| } else { |
| return false; |
| } |
| } |
| |
| @Override |
| public Boolean visitErrorType(ErrorType t, Type s) { |
| return true; |
| } |
| }; |
| |
| public boolean isCaptureOf(Type s, WildcardType t) { |
| if (!s.hasTag(TYPEVAR) || !((TypeVar)s).isCaptured()) |
| return false; |
| return isSameWildcard(t, ((CapturedType)s).wildcard); |
| } |
| |
| public boolean isSameWildcard(WildcardType t, Type s) { |
| if (!s.hasTag(WILDCARD)) |
| return false; |
| WildcardType w = (WildcardType)s; |
| return w.kind == t.kind && w.type == t.type; |
| } |
| |
| public boolean containsTypeEquivalent(List<Type> ts, List<Type> ss) { |
| while (ts.nonEmpty() && ss.nonEmpty() |
| && containsTypeEquivalent(ts.head, ss.head)) { |
| ts = ts.tail; |
| ss = ss.tail; |
| } |
| return ts.isEmpty() && ss.isEmpty(); |
| } |
| // </editor-fold> |
| |
| // <editor-fold defaultstate="collapsed" desc="isCastable"> |
| public boolean isCastable(Type t, Type s) { |
| return isCastable(t, s, noWarnings); |
| } |
| |
| /** |
| * Is t is castable to s?<br> |
| * s is assumed to be an erased type.<br> |
| * (not defined for Method and ForAll types). |
| */ |
| public boolean isCastable(Type t, Type s, Warner warn) { |
| if (t == s) |
| return true; |
| if (t.isPrimitive() != s.isPrimitive()) { |
| t = skipTypeVars(t, false); |
| return (isConvertible(t, s, warn) |
| || (allowObjectToPrimitiveCast && |
| s.isPrimitive() && |
| isSubtype(boxedClass(s).type, t))); |
| } |
| if (warn != warnStack.head) { |
| try { |
| warnStack = warnStack.prepend(warn); |
| checkUnsafeVarargsConversion(t, s, warn); |
| return isCastable.visit(t,s); |
| } finally { |
| warnStack = warnStack.tail; |
| } |
| } else { |
| return isCastable.visit(t,s); |
| } |
| } |
| // where |
| private TypeRelation isCastable = new TypeRelation() { |
| |
| public Boolean visitType(Type t, Type s) { |
| if (s.hasTag(ERROR)) |
| return true; |
| |
| switch (t.getTag()) { |
| case BYTE: case CHAR: case SHORT: case INT: case LONG: case FLOAT: |
| case DOUBLE: |
| return s.isNumeric(); |
| case BOOLEAN: |
| return s.hasTag(BOOLEAN); |
| case VOID: |
| return false; |
| case BOT: |
| return isSubtype(t, s); |
| default: |
| throw new AssertionError(); |
| } |
| } |
| |
| @Override |
| public Boolean visitWildcardType(WildcardType t, Type s) { |
| return isCastable(wildUpperBound(t), s, warnStack.head); |
| } |
| |
| @Override |
| public Boolean visitClassType(ClassType t, Type s) { |
| if (s.hasTag(ERROR) || s.hasTag(BOT)) |
| return true; |
| |
| if (s.hasTag(TYPEVAR)) { |
| if (isCastable(t, s.getUpperBound(), noWarnings)) { |
| warnStack.head.warn(LintCategory.UNCHECKED); |
| return true; |
| } else { |
| return false; |
| } |
| } |
| |
| if (t.isCompound() || s.isCompound()) { |
| return !t.isCompound() ? |
| visitCompoundType((ClassType)s, t, true) : |
| visitCompoundType(t, s, false); |
| } |
| |
| if (s.hasTag(CLASS) || s.hasTag(ARRAY)) { |
| boolean upcast; |
| if ((upcast = isSubtype(erasure(t), erasure(s))) |
| || isSubtype(erasure(s), erasure(t))) { |
| if (!upcast && s.hasTag(ARRAY)) { |
| if (!isReifiable(s)) |
| warnStack.head.warn(LintCategory.UNCHECKED); |
| return true; |
| } else if (s.isRaw()) { |
| return true; |
| } else if (t.isRaw()) { |
| if (!isUnbounded(s)) |
| warnStack.head.warn(LintCategory.UNCHECKED); |
| return true; |
| } |
| // Assume |a| <: |b| |
| final Type a = upcast ? t : s; |
| final Type b = upcast ? s : t; |
| final boolean HIGH = true; |
| final boolean LOW = false; |
| final boolean DONT_REWRITE_TYPEVARS = false; |
| Type aHigh = rewriteQuantifiers(a, HIGH, DONT_REWRITE_TYPEVARS); |
| Type aLow = rewriteQuantifiers(a, LOW, DONT_REWRITE_TYPEVARS); |
| Type bHigh = rewriteQuantifiers(b, HIGH, DONT_REWRITE_TYPEVARS); |
| Type bLow = rewriteQuantifiers(b, LOW, DONT_REWRITE_TYPEVARS); |
| Type lowSub = asSub(bLow, aLow.tsym); |
| Type highSub = (lowSub == null) ? null : asSub(bHigh, aHigh.tsym); |
| if (highSub == null) { |
| final boolean REWRITE_TYPEVARS = true; |
| aHigh = rewriteQuantifiers(a, HIGH, REWRITE_TYPEVARS); |
| aLow = rewriteQuantifiers(a, LOW, REWRITE_TYPEVARS); |
| bHigh = rewriteQuantifiers(b, HIGH, REWRITE_TYPEVARS); |
| bLow = rewriteQuantifiers(b, LOW, REWRITE_TYPEVARS); |
| lowSub = asSub(bLow, aLow.tsym); |
| highSub = (lowSub == null) ? null : asSub(bHigh, aHigh.tsym); |
| } |
| if (highSub != null) { |
| if (!(a.tsym == highSub.tsym && a.tsym == lowSub.tsym)) { |
| Assert.error(a.tsym + " != " + highSub.tsym + " != " + lowSub.tsym); |
| } |
| if (!disjointTypes(aHigh.allparams(), highSub.allparams()) |
| && !disjointTypes(aHigh.allparams(), lowSub.allparams()) |
| && !disjointTypes(aLow.allparams(), highSub.allparams()) |
| && !disjointTypes(aLow.allparams(), lowSub.allparams())) { |
| if (upcast ? giveWarning(a, b) : |
| giveWarning(b, a)) |
| warnStack.head.warn(LintCategory.UNCHECKED); |
| return true; |
| } |
| } |
| if (isReifiable(s)) |
| return isSubtypeUnchecked(a, b); |
| else |
| return isSubtypeUnchecked(a, b, warnStack.head); |
| } |
| |
| // Sidecast |
| if (s.hasTag(CLASS)) { |
| if ((s.tsym.flags() & INTERFACE) != 0) { |
| return ((t.tsym.flags() & FINAL) == 0) |
| ? sideCast(t, s, warnStack.head) |
| : sideCastFinal(t, s, warnStack.head); |
| } else if ((t.tsym.flags() & INTERFACE) != 0) { |
| return ((s.tsym.flags() & FINAL) == 0) |
| ? sideCast(t, s, warnStack.head) |
| : sideCastFinal(t, s, warnStack.head); |
| } else { |
| // unrelated class types |
| return false; |
| } |
| } |
| } |
| return false; |
| } |
| |
| boolean visitCompoundType(ClassType ct, Type s, boolean reverse) { |
| Warner warn = noWarnings; |
| for (Type c : directSupertypes(ct)) { |
| warn.clear(); |
| if (reverse ? !isCastable(s, c, warn) : !isCastable(c, s, warn)) |
| return false; |
| } |
| if (warn.hasLint(LintCategory.UNCHECKED)) |
| warnStack.head.warn(LintCategory.UNCHECKED); |
| return true; |
| } |
| |
| @Override |
| public Boolean visitArrayType(ArrayType t, Type s) { |
| switch (s.getTag()) { |
| case ERROR: |
| case BOT: |
| return true; |
| case TYPEVAR: |
| if (isCastable(s, t, noWarnings)) { |
| warnStack.head.warn(LintCategory.UNCHECKED); |
| return true; |
| } else { |
| return false; |
| } |
| case CLASS: |
| return isSubtype(t, s); |
| case ARRAY: |
| if (elemtype(t).isPrimitive() || elemtype(s).isPrimitive()) { |
| return elemtype(t).hasTag(elemtype(s).getTag()); |
| } else { |
| return visit(elemtype(t), elemtype(s)); |
| } |
| default: |
| return false; |
| } |
| } |
| |
| @Override |
| public Boolean visitTypeVar(TypeVar t, Type s) { |
| switch (s.getTag()) { |
| case ERROR: |
| case BOT: |
| return true; |
| case TYPEVAR: |
| if (isSubtype(t, s)) { |
| return true; |
| } else if (isCastable(t.bound, s, noWarnings)) { |
| warnStack.head.warn(LintCategory.UNCHECKED); |
| return true; |
| } else { |
| return false; |
| } |
| default: |
| return isCastable(t.bound, s, warnStack.head); |
| } |
| } |
| |
| @Override |
| public Boolean visitErrorType(ErrorType t, Type s) { |
| return true; |
| } |
| }; |
| // </editor-fold> |
| |
| // <editor-fold defaultstate="collapsed" desc="disjointTypes"> |
| public boolean disjointTypes(List<Type> ts, List<Type> ss) { |
| while (ts.tail != null && ss.tail != null) { |
| if (disjointType(ts.head, ss.head)) return true; |
| ts = ts.tail; |
| ss = ss.tail; |
| } |
| return false; |
| } |
| |
| /** |
| * Two types or wildcards are considered disjoint if it can be |
| * proven that no type can be contained in both. It is |
| * conservative in that it is allowed to say that two types are |
| * not disjoint, even though they actually are. |
| * |
| * The type {@code C<X>} is castable to {@code C<Y>} exactly if |
| * {@code X} and {@code Y} are not disjoint. |
| */ |
| public boolean disjointType(Type t, Type s) { |
| return disjointType.visit(t, s); |
| } |
| // where |
| private TypeRelation disjointType = new TypeRelation() { |
| |
| private Set<TypePair> cache = new HashSet<>(); |
| |
| @Override |
| public Boolean visitType(Type t, Type s) { |
| if (s.hasTag(WILDCARD)) |
| return visit(s, t); |
| else |
| return notSoftSubtypeRecursive(t, s) || notSoftSubtypeRecursive(s, t); |
| } |
| |
| private boolean isCastableRecursive(Type t, Type s) { |
| TypePair pair = new TypePair(t, s); |
| if (cache.add(pair)) { |
| try { |
| return Types.this.isCastable(t, s); |
| } finally { |
| cache.remove(pair); |
| } |
| } else { |
| return true; |
| } |
| } |
| |
| private boolean notSoftSubtypeRecursive(Type t, Type s) { |
| TypePair pair = new TypePair(t, s); |
| if (cache.add(pair)) { |
| try { |
| return Types.this.notSoftSubtype(t, s); |
| } finally { |
| cache.remove(pair); |
| } |
| } else { |
| return false; |
| } |
| } |
| |
| @Override |
| public Boolean visitWildcardType(WildcardType t, Type s) { |
| if (t.isUnbound()) |
| return false; |
| |
| if (!s.hasTag(WILDCARD)) { |
| if (t.isExtendsBound()) |
| return notSoftSubtypeRecursive(s, t.type); |
| else |
| return notSoftSubtypeRecursive(t.type, s); |
| } |
| |
| if (s.isUnbound()) |
| return false; |
| |
| if (t.isExtendsBound()) { |
| if (s.isExtendsBound()) |
| return !isCastableRecursive(t.type, wildUpperBound(s)); |
| else if (s.isSuperBound()) |
| return notSoftSubtypeRecursive(wildLowerBound(s), t.type); |
| } else if (t.isSuperBound()) { |
| if (s.isExtendsBound()) |
| return notSoftSubtypeRecursive(t.type, wildUpperBound(s)); |
| } |
| return false; |
| } |
| }; |
| // </editor-fold> |
| |
| // <editor-fold defaultstate="collapsed" desc="cvarLowerBounds"> |
| public List<Type> cvarLowerBounds(List<Type> ts) { |
| return ts.map(cvarLowerBoundMapping); |
| } |
| private final TypeMapping<Void> cvarLowerBoundMapping = new TypeMapping<Void>() { |
| @Override |
| public Type visitCapturedType(CapturedType t, Void _unused) { |
| return cvarLowerBound(t); |
| } |
| }; |
| // </editor-fold> |
| |
| // <editor-fold defaultstate="collapsed" desc="notSoftSubtype"> |
| /** |
| * This relation answers the question: is impossible that |
| * something of type `t' can be a subtype of `s'? This is |
| * different from the question "is `t' not a subtype of `s'?" |
| * when type variables are involved: Integer is not a subtype of T |
| * where {@code <T extends Number>} but it is not true that Integer cannot |
| * possibly be a subtype of T. |
| */ |
| public boolean notSoftSubtype(Type t, Type s) { |
| if (t == s) return false; |
| if (t.hasTag(TYPEVAR)) { |
| TypeVar tv = (TypeVar) t; |
| return !isCastable(tv.bound, |
| relaxBound(s), |
| noWarnings); |
| } |
| if (!s.hasTag(WILDCARD)) |
| s = cvarUpperBound(s); |
| |
| return !isSubtype(t, relaxBound(s)); |
| } |
| |
| private Type relaxBound(Type t) { |
| return (t.hasTag(TYPEVAR)) ? |
| rewriteQuantifiers(skipTypeVars(t, false), true, true) : |
| t; |
| } |
| // </editor-fold> |
| |
| // <editor-fold defaultstate="collapsed" desc="isReifiable"> |
| public boolean isReifiable(Type t) { |
| return isReifiable.visit(t); |
| } |
| // where |
| private UnaryVisitor<Boolean> isReifiable = new UnaryVisitor<Boolean>() { |
| |
| public Boolean visitType(Type t, Void ignored) { |
| return true; |
| } |
| |
| @Override |
| public Boolean visitClassType(ClassType t, Void ignored) { |
| if (t.isCompound()) |
| return false; |
| else { |
| if (!t.isParameterized()) |
| return true; |
| |
| for (Type param : t.allparams()) { |
| if (!param.isUnbound()) |
| return false; |
| } |
| return true; |
| } |
| } |
| |
| @Override |
| public Boolean visitArrayType(ArrayType t, Void ignored) { |
| return visit(t.elemtype); |
| } |
| |
| @Override |
| public Boolean visitTypeVar(TypeVar t, Void ignored) { |
| return false; |
| } |
| }; |
| // </editor-fold> |
| |
| // <editor-fold defaultstate="collapsed" desc="Array Utils"> |
| public boolean isArray(Type t) { |
| while (t.hasTag(WILDCARD)) |
| t = wildUpperBound(t); |
| return t.hasTag(ARRAY); |
| } |
| |
| /** |
| * The element type of an array. |
| */ |
| public Type elemtype(Type t) { |
| switch (t.getTag()) { |
| case WILDCARD: |
| return elemtype(wildUpperBound(t)); |
| case ARRAY: |
| return ((ArrayType)t).elemtype; |
| case FORALL: |
| return elemtype(((ForAll)t).qtype); |
| case ERROR: |
| return t; |
| default: |
| return null; |
| } |
| } |
| |
| public Type elemtypeOrType(Type t) { |
| Type elemtype = elemtype(t); |
| return elemtype != null ? |
| elemtype : |
| t; |
| } |
| |
| /** |
| * Mapping to take element type of an arraytype |
| */ |
| private TypeMapping<Void> elemTypeFun = new TypeMapping<Void>() { |
| @Override |
| public Type visitArrayType(ArrayType t, Void _unused) { |
| return t.elemtype; |
| } |
| |
| @Override |
| public Type visitTypeVar(TypeVar t, Void _unused) { |
| return visit(skipTypeVars(t, false)); |
| } |
| }; |
| |
| /** |
| * The number of dimensions of an array type. |
| */ |
| public int dimensions(Type t) { |
| int result = 0; |
| while (t.hasTag(ARRAY)) { |
| result++; |
| t = elemtype(t); |
| } |
| return result; |
| } |
| |
| /** |
| * Returns an ArrayType with the component type t |
| * |
| * @param t The component type of the ArrayType |
| * @return the ArrayType for the given component |
| */ |
| public ArrayType makeArrayType(Type t) { |
| if (t.hasTag(VOID) || t.hasTag(PACKAGE)) { |
| Assert.error("Type t must not be a VOID or PACKAGE type, " + t.toString()); |
| } |
| return new ArrayType(t, syms.arrayClass); |
| } |
| // </editor-fold> |
| |
| // <editor-fold defaultstate="collapsed" desc="asSuper"> |
| /** |
| * Return the (most specific) base type of t that starts with the |
| * given symbol. If none exists, return null. |
| * |
| * Caveat Emptor: Since javac represents the class of all arrays with a singleton |
| * symbol Symtab.arrayClass, which by being a singleton cannot hold any discriminant, |
| * this method could yield surprising answers when invoked on arrays. For example when |
| * invoked with t being byte [] and sym being t.sym itself, asSuper would answer null. |
| * |
| * @param t a type |
| * @param sym a symbol |
| */ |
| public Type asSuper(Type t, Symbol sym) { |
| /* Some examples: |
| * |
| * (Enum<E>, Comparable) => Comparable<E> |
| * (c.s.s.d.AttributeTree.ValueKind, Enum) => Enum<c.s.s.d.AttributeTree.ValueKind> |
| * (c.s.s.t.ExpressionTree, c.s.s.t.Tree) => c.s.s.t.Tree |
| * (j.u.List<capture#160 of ? extends c.s.s.d.DocTree>, Iterable) => |
| * Iterable<capture#160 of ? extends c.s.s.d.DocTree> |
| */ |
| if (sym.type == syms.objectType) { //optimization |
| return syms.objectType; |
| } |
| return asSuper.visit(t, sym); |
| } |
| // where |
| private SimpleVisitor<Type,Symbol> asSuper = new SimpleVisitor<Type,Symbol>() { |
| |
| public Type visitType(Type t, Symbol sym) { |
| return null; |
| } |
| |
| @Override |
| public Type visitClassType(ClassType t, Symbol sym) { |
| if (t.tsym == sym) |
| return t; |
| |
| Type st = supertype(t); |
| if (st.hasTag(CLASS) || st.hasTag(TYPEVAR)) { |
| Type x = asSuper(st, sym); |
| if (x != null) |
| return x; |
| } |
| if ((sym.flags() & INTERFACE) != 0) { |
| for (List<Type> l = interfaces(t); l.nonEmpty(); l = l.tail) { |
| if (!l.head.hasTag(ERROR)) { |
| Type x = asSuper(l.head, sym); |
| if (x != null) |
| return x; |
| } |
| } |
| } |
| return null; |
| } |
| |
| @Override |
| public Type visitArrayType(ArrayType t, Symbol sym) { |
| return isSubtype(t, sym.type) ? sym.type : null; |
| } |
| |
| @Override |
| public Type visitTypeVar(TypeVar t, Symbol sym) { |
| if (t.tsym == sym) |
| return t; |
| else |
| return asSuper(t.bound, sym); |
| } |
| |
| @Override |
| public Type visitErrorType(ErrorType t, Symbol sym) { |
| return t; |
| } |
| }; |
| |
| /** |
| * Return the base type of t or any of its outer types that starts |
| * with the given symbol. If none exists, return null. |
| * |
| * @param t a type |
| * @param sym a symbol |
| */ |
| public Type asOuterSuper(Type t, Symbol sym) { |
| switch (t.getTag()) { |
| case CLASS: |
| do { |
| Type s = asSuper(t, sym); |
| if (s != null) return s; |
| t = t.getEnclosingType(); |
| } while (t.hasTag(CLASS)); |
| return null; |
| case ARRAY: |
| return isSubtype(t, sym.type) ? sym.type : null; |
| case TYPEVAR: |
| return asSuper(t, sym); |
| case ERROR: |
| return t; |
| default: |
| return null; |
| } |
| } |
| |
| /** |
| * Return the base type of t or any of its enclosing types that |
| * starts with the given symbol. If none exists, return null. |
| * |
| * @param t a type |
| * @param sym a symbol |
| */ |
| public Type asEnclosingSuper(Type t, Symbol sym) { |
| switch (t.getTag()) { |
| case CLASS: |
| do { |
| Type s = asSuper(t, sym); |
| if (s != null) return s; |
| Type outer = t.getEnclosingType(); |
| t = (outer.hasTag(CLASS)) ? outer : |
| (t.tsym.owner.enclClass() != null) ? t.tsym.owner.enclClass().type : |
| Type.noType; |
| } while (t.hasTag(CLASS)); |
| return null; |
| case ARRAY: |
| return isSubtype(t, sym.type) ? sym.type : null; |
| case TYPEVAR: |
| return asSuper(t, sym); |
| case ERROR: |
| return t; |
| default: |
| return null; |
| } |
| } |
| // </editor-fold> |
| |
| // <editor-fold defaultstate="collapsed" desc="memberType"> |
| /** |
| * The type of given symbol, seen as a member of t. |
| * |
| * @param t a type |
| * @param sym a symbol |
| */ |
| public Type memberType(Type t, Symbol sym) { |
| return (sym.flags() & STATIC) != 0 |
| ? sym.type |
| : memberType.visit(t, sym); |
| } |
| // where |
| private SimpleVisitor<Type,Symbol> memberType = new SimpleVisitor<Type,Symbol>() { |
| |
| public Type visitType(Type t, Symbol sym) { |
| return sym.type; |
| } |
| |
| @Override |
| public Type visitWildcardType(WildcardType t, Symbol sym) { |
| return memberType(wildUpperBound(t), sym); |
| } |
| |
| @Override |
| public Type visitClassType(ClassType t, Symbol sym) { |
| Symbol owner = sym.owner; |
| long flags = sym.flags(); |
| if (((flags & STATIC) == 0) && owner.type.isParameterized()) { |
| Type base = asOuterSuper(t, owner); |
| //if t is an intersection type T = CT & I1 & I2 ... & In |
| //its supertypes CT, I1, ... In might contain wildcards |
| //so we need to go through capture conversion |
| base = t.isCompound() ? capture(base) : base; |
| if (base != null) { |
| List<Type> ownerParams = owner.type.allparams(); |
| List<Type> baseParams = base.allparams(); |
| if (ownerParams.nonEmpty()) { |
| if (baseParams.isEmpty()) { |
| // then base is a raw type |
| return erasure(sym.type); |
| } else { |
| return subst(sym.type, ownerParams, baseParams); |
| } |
| } |
| } |
| } |
| return sym.type; |
| } |
| |
| @Override |
| public Type visitTypeVar(TypeVar t, Symbol sym) { |
| return memberType(t.bound, sym); |
| } |
| |
| @Override |
| public Type visitErrorType(ErrorType t, Symbol sym) { |
| return t; |
| } |
| }; |
| // </editor-fold> |
| |
| // <editor-fold defaultstate="collapsed" desc="isAssignable"> |
| public boolean isAssignable(Type t, Type s) { |
| return isAssignable(t, s, noWarnings); |
| } |
| |
| /** |
| * Is t assignable to s?<br> |
| * Equivalent to subtype except for constant values and raw |
| * types.<br> |
| * (not defined for Method and ForAll types) |
| */ |
| public boolean isAssignable(Type t, Type s, Warner warn) { |
| if (t.hasTag(ERROR)) |
| return true; |
| if (t.getTag().isSubRangeOf(INT) && t.constValue() != null) { |
| int value = ((Number)t.constValue()).intValue(); |
| switch (s.getTag()) { |
| case BYTE: |
| if (Byte.MIN_VALUE <= value && value <= Byte.MAX_VALUE) |
| return true; |
| break; |
| case CHAR: |
| if (Character.MIN_VALUE <= value && value <= Character.MAX_VALUE) |
| return true; |
| break; |
| case SHORT: |
| if (Short.MIN_VALUE <= value && value <= Short.MAX_VALUE) |
| return true; |
| break; |
| case INT: |
| return true; |
| case CLASS: |
| switch (unboxedType(s).getTag()) { |
| case BYTE: |
| case CHAR: |
| case SHORT: |
| return isAssignable(t, unboxedType(s), warn); |
| } |
| break; |
| } |
| } |
| return isConvertible(t, s, warn); |
| } |
| // </editor-fold> |
| |
| // <editor-fold defaultstate="collapsed" desc="erasure"> |
| /** |
| * The erasure of t {@code |t|} -- the type that results when all |
| * type parameters in t are deleted. |
| */ |
| public Type erasure(Type t) { |
| return eraseNotNeeded(t) ? t : erasure(t, false); |
| } |
| //where |
| private boolean eraseNotNeeded(Type t) { |
| // We don't want to erase primitive types and String type as that |
| // operation is idempotent. Also, erasing these could result in loss |
| // of information such as constant values attached to such types. |
| return (t.isPrimitive()) || (syms.stringType.tsym == t.tsym); |
| } |
| |
| private Type erasure(Type t, boolean recurse) { |
| if (t.isPrimitive()) { |
| return t; /* fast special case */ |
| } else { |
| Type out = erasure.visit(t, recurse); |
| return out; |
| } |
| } |
| // where |
| private TypeMapping<Boolean> erasure = new TypeMapping<Boolean>() { |
| private Type combineMetadata(final Type s, |
| final Type t) { |
| if (t.getMetadata() != TypeMetadata.EMPTY) { |
| switch (s.getKind()) { |
| case OTHER: |
| case UNION: |
| case INTERSECTION: |
| case PACKAGE: |
| case EXECUTABLE: |
| case NONE: |
| case VOID: |
| case ERROR: |
| return s; |
| default: return s.cloneWithMetadata(s.getMetadata().without(Kind.ANNOTATIONS)); |
| } |
| } else { |
| return s; |
| } |
| } |
| |
| public Type visitType(Type t, Boolean recurse) { |
| if (t.isPrimitive()) |
| return t; /*fast special case*/ |
| else { |
| //other cases already handled |
| return combineMetadata(t, t); |
| } |
| } |
| |
| @Override |
| public Type visitWildcardType(WildcardType t, Boolean recurse) { |
| Type erased = erasure(wildUpperBound(t), recurse); |
| return combineMetadata(erased, t); |
| } |
| |
| @Override |
| public Type visitClassType(ClassType t, Boolean recurse) { |
| Type erased = t.tsym.erasure(Types.this); |
| if (recurse) { |
| erased = new ErasedClassType(erased.getEnclosingType(),erased.tsym, |
| t.getMetadata().without(Kind.ANNOTATIONS)); |
| return erased; |
| } else { |
| return combineMetadata(erased, t); |
| } |
| } |
| |
| @Override |
| public Type visitTypeVar(TypeVar t, Boolean recurse) { |
| Type erased = erasure(t.bound, recurse); |
| return combineMetadata(erased, t); |
| } |
| }; |
| |
| public List<Type> erasure(List<Type> ts) { |
| return erasure.visit(ts, false); |
| } |
| |
| public Type erasureRecursive(Type t) { |
| return erasure(t, true); |
| } |
| |
| public List<Type> erasureRecursive(List<Type> ts) { |
| return erasure.visit(ts, true); |
| } |
| // </editor-fold> |
| |
| // <editor-fold defaultstate="collapsed" desc="makeIntersectionType"> |
| /** |
| * Make an intersection type from non-empty list of types. The list should be ordered according to |
| * {@link TypeSymbol#precedes(TypeSymbol, Types)}. Note that this might cause a symbol completion. |
| * Hence, this version of makeIntersectionType may not be called during a classfile read. |
| * |
| * @param bounds the types from which the intersection type is formed |
| */ |
| public IntersectionClassType makeIntersectionType(List<Type> bounds) { |
| return makeIntersectionType(bounds, bounds.head.tsym.isInterface()); |
| } |
| |
| /** |
| * Make an intersection type from non-empty list of types. The list should be ordered according to |
| * {@link TypeSymbol#precedes(TypeSymbol, Types)}. This does not cause symbol completion as |
| * an extra parameter indicates as to whether all bounds are interfaces - in which case the |
| * supertype is implicitly assumed to be 'Object'. |
| * |
| * @param bounds the types from which the intersection type is formed |
| * @param allInterfaces are all bounds interface types? |
| */ |
| public IntersectionClassType makeIntersectionType(List<Type> bounds, boolean allInterfaces) { |
| Assert.check(bounds.nonEmpty()); |
| Type firstExplicitBound = bounds.head; |
| if (allInterfaces) { |
| bounds = bounds.prepend(syms.objectType); |
| } |
| ClassSymbol bc = |
| new ClassSymbol(ABSTRACT|PUBLIC|SYNTHETIC|COMPOUND|ACYCLIC, |
| Type.moreInfo |
| ? names.fromString(bounds.toString()) |
| : names.empty, |
| null, |
| syms.noSymbol); |
| IntersectionClassType intersectionType = new IntersectionClassType(bounds, bc, allInterfaces); |
| bc.type = intersectionType; |
| bc.erasure_field = (bounds.head.hasTag(TYPEVAR)) ? |
| syms.objectType : // error condition, recover |
| erasure(firstExplicitBound); |
| bc.members_field = WriteableScope.create(bc); |
| return intersectionType; |
| } |
| // </editor-fold> |
| |
| // <editor-fold defaultstate="collapsed" desc="supertype"> |
| public Type supertype(Type t) { |
| return supertype.visit(t); |
| } |
| // where |
| private UnaryVisitor<Type> supertype = new UnaryVisitor<Type>() { |
| |
| public Type visitType(Type t, Void ignored) { |
| // A note on wildcards: there is no good way to |
| // determine a supertype for a super bounded wildcard. |
| return Type.noType; |
| } |
| |
| @Override |
| public Type visitClassType(ClassType t, Void ignored) { |
| if (t.supertype_field == null) { |
| Type supertype = ((ClassSymbol)t.tsym).getSuperclass(); |
| // An interface has no superclass; its supertype is Object. |
| if (t.isInterface()) |
| supertype = ((ClassType)t.tsym.type).supertype_field; |
| if (t.supertype_field == null) { |
| List<Type> actuals = classBound(t).allparams(); |
| List<Type> formals = t.tsym.type.allparams(); |
| if (t.hasErasedSupertypes()) { |
| t.supertype_field = erasureRecursive(supertype); |
| } else if (formals.nonEmpty()) { |
| t.supertype_field = subst(supertype, formals, actuals); |
| } |
| else { |
| t.supertype_field = supertype; |
| } |
| } |
| } |
| return t.supertype_field; |
| } |
| |
| /** |
| * The supertype is always a class type. If the type |
| * variable's bounds start with a class type, this is also |
| * the supertype. Otherwise, the supertype is |
| * java.lang.Object. |
| */ |
| @Override |
| public Type visitTypeVar(TypeVar t, Void ignored) { |
| if (t.bound.hasTag(TYPEVAR) || |
| (!t.bound.isCompound() && !t.bound.isInterface())) { |
| return t.bound; |
| } else { |
| return supertype(t.bound); |
| } |
| } |
| |
| @Override |
| public Type visitArrayType(ArrayType t, Void ignored) { |
| if (t.elemtype.isPrimitive() || isSameType(t.elemtype, syms.objectType)) |
| return arraySuperType(); |
| else |
| return new ArrayType(supertype(t.elemtype), t.tsym); |
| } |
| |
| @Override |
| public Type visitErrorType(ErrorType t, Void ignored) { |
| return Type.noType; |
| } |
| }; |
| // </editor-fold> |
| |
| // <editor-fold defaultstate="collapsed" desc="interfaces"> |
| /** |
| * Return the interfaces implemented by this class. |
| */ |
| public List<Type> interfaces(Type t) { |
| return interfaces.visit(t); |
| } |
| // where |
| private UnaryVisitor<List<Type>> interfaces = new UnaryVisitor<List<Type>>() { |
| |
| public List<Type> visitType(Type t, Void ignored) { |
| return List.nil(); |
| } |
| |
| @Override |
| public List<Type> visitClassType(ClassType t, Void ignored) { |
| if (t.interfaces_field == null) { |
| List<Type> interfaces = ((ClassSymbol)t.tsym).getInterfaces(); |
| if (t.interfaces_field == null) { |
| // If t.interfaces_field is null, then t must |
| // be a parameterized type (not to be confused |
| // with a generic type declaration). |
| // Terminology: |
| // Parameterized type: List<String> |
| // Generic type declaration: class List<E> { ... } |
| // So t corresponds to List<String> and |
| // t.tsym.type corresponds to List<E>. |
| // The reason t must be parameterized type is |
| // that completion will happen as a side |
| // effect of calling |
| // ClassSymbol.getInterfaces. Since |
| // t.interfaces_field is null after |
| // completion, we can assume that t is not the |
| // type of a class/interface declaration. |
| Assert.check(t != t.tsym.type, t); |
| List<Type> actuals = t.allparams(); |
| List<Type> formals = t.tsym.type.allparams(); |
| if (t.hasErasedSupertypes()) { |
| t.interfaces_field = erasureRecursive(interfaces); |
| } else if (formals.nonEmpty()) { |
| t.interfaces_field = subst(interfaces, formals, actuals); |
| } |
| else { |
| t.interfaces_field = interfaces; |
| } |
| } |
| } |
| return t.interfaces_field; |
| } |
| |
| @Override |
| public List<Type> visitTypeVar(TypeVar t, Void ignored) { |
| if (t.bound.isCompound()) |
| return interfaces(t.bound); |
| |
| if (t.bound.isInterface()) |
| return List.of(t.bound); |
| |
| return List.nil(); |
| } |
| }; |
| |
| public List<Type> directSupertypes(Type t) { |
| return directSupertypes.visit(t); |
| } |
| // where |
| private final UnaryVisitor<List<Type>> directSupertypes = new UnaryVisitor<List<Type>>() { |
| |
| public List<Type> visitType(final Type type, final Void ignored) { |
| if (!type.isIntersection()) { |
| final Type sup = supertype(type); |
| return (sup == Type.noType || sup == type || sup == null) |
| ? interfaces(type) |
| : interfaces(type).prepend(sup); |
| } else { |
| return ((IntersectionClassType)type).getExplicitComponents(); |
| } |
| } |
| }; |
| |
| public boolean isDirectSuperInterface(TypeSymbol isym, TypeSymbol origin) { |
| for (Type i2 : interfaces(origin.type)) { |
| if (isym == i2.tsym) return true; |
| } |
| return false; |
| } |
| // </editor-fold> |
| |
| // <editor-fold defaultstate="collapsed" desc="isDerivedRaw"> |
| Map<Type,Boolean> isDerivedRawCache = new HashMap<>(); |
| |
| public boolean isDerivedRaw(Type t) { |
| Boolean result = isDerivedRawCache.get(t); |
| if (result == null) { |
| result = isDerivedRawInternal(t); |
| isDerivedRawCache.put(t, result); |
| } |
| return result; |
| } |
| |
| public boolean isDerivedRawInternal(Type t) { |
| if (t.isErroneous()) |
| return false; |
| return |
| t.isRaw() || |
| supertype(t) != Type.noType && isDerivedRaw(supertype(t)) || |
| isDerivedRaw(interfaces(t)); |
| } |
| |
| public boolean isDerivedRaw(List<Type> ts) { |
| List<Type> l = ts; |
| while (l.nonEmpty() && !isDerivedRaw(l.head)) l = l.tail; |
| return l.nonEmpty(); |
| } |
| // </editor-fold> |
| |
| // <editor-fold defaultstate="collapsed" desc="setBounds"> |
| /** |
| * Same as {@link Types#setBounds(TypeVar, List, boolean)}, except that third parameter is computed directly, |
| * as follows: if all all bounds are interface types, the computed supertype is Object,otherwise |
| * the supertype is simply left null (in this case, the supertype is assumed to be the head of |
| * the bound list passed as second argument). Note that this check might cause a symbol completion. |
| * Hence, this version of setBounds may not be called during a classfile read. |
| * |
| * @param t a type variable |
| * @param bounds the bounds, must be nonempty |
| */ |
| public void setBounds(TypeVar t, List<Type> bounds) { |
| setBounds(t, bounds, bounds.head.tsym.isInterface()); |
| } |
| |
| /** |
| * Set the bounds field of the given type variable to reflect a (possibly multiple) list of bounds. |
| * This does not cause symbol completion as an extra parameter indicates as to whether all bounds |
| * are interfaces - in which case the supertype is implicitly assumed to be 'Object'. |
| * |
| * @param t a type variable |
| * @param bounds the bounds, must be nonempty |
| * @param allInterfaces are all bounds interface types? |
| */ |
| public void setBounds(TypeVar t, List<Type> bounds, boolean allInterfaces) { |
| t.bound = bounds.tail.isEmpty() ? |
| bounds.head : |
| makeIntersectionType(bounds, allInterfaces); |
| t.rank_field = -1; |
| } |
| // </editor-fold> |
| |
| // <editor-fold defaultstate="collapsed" desc="getBounds"> |
| /** |
| * Return list of bounds of the given type variable. |
| */ |
| public List<Type> getBounds(TypeVar t) { |
| if (t.bound.hasTag(NONE)) |
| return List.nil(); |
| else if (t.bound.isErroneous() || !t.bound.isCompound()) |
| return List.of(t.bound); |
| else if ((erasure(t).tsym.flags() & INTERFACE) == 0) |
| return interfaces(t).prepend(supertype(t)); |
| else |
| // No superclass was given in bounds. |
| // In this case, supertype is Object, erasure is first interface. |
| return interfaces(t); |
| } |
| // </editor-fold> |
| |
| // <editor-fold defaultstate="collapsed" desc="classBound"> |
| /** |
| * If the given type is a (possibly selected) type variable, |
| * return the bounding class of this type, otherwise return the |
| * type itself. |
| */ |
| public Type classBound(Type t) { |
| return classBound.visit(t); |
| } |
| // where |
| private UnaryVisitor<Type> classBound = new UnaryVisitor<Type>() { |
| |
| public Type visitType(Type t, Void ignored) { |
| return t; |
| } |
| |
| @Override |
| public Type visitClassType(ClassType t, Void ignored) { |
| Type outer1 = classBound(t.getEnclosingType()); |
| if (outer1 != t.getEnclosingType()) |
| return new ClassType(outer1, t.getTypeArguments(), t.tsym, |
| t.getMetadata()); |
| else |
| return t; |
| } |
| |
| @Override |
| public Type visitTypeVar(TypeVar t, Void ignored) { |
| return classBound(supertype(t)); |
| } |
| |
| @Override |
| public Type visitErrorType(ErrorType t, Void ignored) { |
| return t; |
| } |
| }; |
| // </editor-fold> |
| |
| // <editor-fold defaultstate="collapsed" desc="sub signature / override equivalence"> |
| /** |
| * Returns true iff the first signature is a <em>sub |
| * signature</em> of the other. This is <b>not</b> an equivalence |
| * relation. |
| * |
| * @jls section 8.4.2. |
| * @see #overrideEquivalent(Type t, Type s) |
| * @param t first signature (possibly raw). |
| * @param s second signature (could be subjected to erasure). |
| * @return true if t is a sub signature of s. |
| */ |
| public boolean isSubSignature(Type t, Type s) { |
| return isSubSignature(t, s, true); |
| } |
| |
| public boolean isSubSignature(Type t, Type s, boolean strict) { |
| return hasSameArgs(t, s, strict) || hasSameArgs(t, erasure(s), strict); |
| } |
| |
| /** |
| * Returns true iff these signatures are related by <em>override |
| * equivalence</em>. This is the natural extension of |
| * isSubSignature to an equivalence relation. |
| * |
| * @jls section 8.4.2. |
| * @see #isSubSignature(Type t, Type s) |
| * @param t a signature (possible raw, could be subjected to |
| * erasure). |
| * @param s a signature (possible raw, could be subjected to |
| * erasure). |
| * @return true if either argument is a sub signature of the other. |
| */ |
| public boolean overrideEquivalent(Type t, Type s) { |
| return hasSameArgs(t, s) || |
| hasSameArgs(t, erasure(s)) || hasSameArgs(erasure(t), s); |
| } |
| |
| public boolean overridesObjectMethod(TypeSymbol origin, Symbol msym) { |
| for (Symbol sym : syms.objectType.tsym.members().getSymbolsByName(msym.name)) { |
| if (msym.overrides(sym, origin, Types.this, true)) { |
| return true; |
| } |
| } |
| return false; |
| } |
| |
| // <editor-fold defaultstate="collapsed" desc="Determining method implementation in given site"> |
| class ImplementationCache { |
| |
| private WeakHashMap<MethodSymbol, SoftReference<Map<TypeSymbol, Entry>>> _map = new WeakHashMap<>(); |
| |
| class Entry { |
| final MethodSymbol cachedImpl; |
| final Filter<Symbol> implFilter; |
| final boolean checkResult; |
| final int prevMark; |
| |
| public Entry(MethodSymbol cachedImpl, |
| Filter<Symbol> scopeFilter, |
| boolean checkResult, |
| int prevMark) { |
| this.cachedImpl = cachedImpl; |
| this.implFilter = scopeFilter; |
| this.checkResult = checkResult; |
| this.prevMark = prevMark; |
| } |
| |
| boolean matches(Filter<Symbol> scopeFilter, boolean checkResult, int mark) { |
| return this.implFilter == scopeFilter && |
| this.checkResult == checkResult && |
| this.prevMark == mark; |
| } |
| } |
| |
| MethodSymbol get(MethodSymbol ms, TypeSymbol origin, boolean checkResult, Filter<Symbol> implFilter) { |
| SoftReference<Map<TypeSymbol, Entry>> ref_cache = _map.get(ms); |
| Map<TypeSymbol, Entry> cache = ref_cache != null ? ref_cache.get() : null; |
| if (cache == null) { |
| cache = new HashMap<>(); |
| _map.put(ms, new SoftReference<>(cache)); |
| } |
| Entry e = cache.get(origin); |
| CompoundScope members = membersClosure(origin.type, true); |
| if (e == null || |
| !e.matches(implFilter, checkResult, members.getMark())) { |
| MethodSymbol impl = implementationInternal(ms, origin, checkResult, implFilter); |
| cache.put(origin, new Entry(impl, implFilter, checkResult, members.getMark())); |
| return impl; |
| } |
| else { |
| return e.cachedImpl; |
| } |
| } |
| |
| private MethodSymbol implementationInternal(MethodSymbol ms, TypeSymbol origin, boolean checkResult, Filter<Symbol> implFilter) { |
| for (Type t = origin.type; t.hasTag(CLASS) || t.hasTag(TYPEVAR); t = supertype(t)) { |
| t = skipTypeVars(t, false); |
| TypeSymbol c = t.tsym; |
| Symbol bestSoFar = null; |
| for (Symbol sym : c.members().getSymbolsByName(ms.name, implFilter)) { |
| if (sym != null && sym.overrides(ms, origin, Types.this, checkResult)) { |
| bestSoFar = sym; |
| if ((sym.flags() & ABSTRACT) == 0) { |
| //if concrete impl is found, exit immediately |
| break; |
| } |
| } |
| } |
| if (bestSoFar != null) { |
| //return either the (only) concrete implementation or the first abstract one |
| return (MethodSymbol)bestSoFar; |
| } |
| } |
| return null; |
| } |
| } |
| |
| private ImplementationCache implCache = new ImplementationCache(); |
| |
| public MethodSymbol implementation(MethodSymbol ms, TypeSymbol origin, boolean checkResult, Filter<Symbol> implFilter) { |
| return implCache.get(ms, origin, checkResult, implFilter); |
| } |
| // </editor-fold> |
| |
| // <editor-fold defaultstate="collapsed" desc="compute transitive closure of all members in given site"> |
| class MembersClosureCache extends SimpleVisitor<Scope.CompoundScope, Void> { |
| |
| private Map<TypeSymbol, CompoundScope> _map = new HashMap<>(); |
| |
| Set<TypeSymbol> seenTypes = new HashSet<>(); |
| |
| class MembersScope extends CompoundScope { |
| |
| CompoundScope scope; |
| |
| public MembersScope(CompoundScope scope) { |
| super(scope.owner); |
| this.scope = scope; |
| } |
| |
| Filter<Symbol> combine(Filter<Symbol> sf) { |
| return s -> !s.owner.isInterface() && (sf == null || sf.accepts(s)); |
| } |
| |
| @Override |
| public Iterable<Symbol> getSymbols(Filter<Symbol> sf, LookupKind lookupKind) { |
| return scope.getSymbols(combine(sf), lookupKind); |
| } |
| |
| @Override |
| public Iterable<Symbol> getSymbolsByName(Name name, Filter<Symbol> sf, LookupKind lookupKind) { |
| return scope.getSymbolsByName(name, combine(sf), lookupKind); |
| } |
| |
| @Override |
| public int getMark() { |
| return scope.getMark(); |
| } |
| } |
| |
| CompoundScope nilScope; |
| |
| /** members closure visitor methods **/ |
| |
| public CompoundScope visitType(Type t, Void _unused) { |
| if (nilScope == null) { |
| nilScope = new CompoundScope(syms.noSymbol); |
| } |
| return nilScope; |
| } |
| |
| @Override |
| public CompoundScope visitClassType(ClassType t, Void _unused) { |
| if (!seenTypes.add(t.tsym)) { |
| //this is possible when an interface is implemented in multiple |
| //superclasses, or when a class hierarchy is circular - in such |
| //cases we don't need to recurse (empty scope is returned) |
| return new CompoundScope(t.tsym); |
| } |
| try { |
| seenTypes.add(t.tsym); |
| ClassSymbol csym = (ClassSymbol)t.tsym; |
| CompoundScope membersClosure = _map.get(csym); |
| if (membersClosure == null) { |
| membersClosure = new CompoundScope(csym); |
| for (Type i : interfaces(t)) { |
| membersClosure.prependSubScope(visit(i, null)); |
| } |
| membersClosure.prependSubScope(visit(supertype(t), null)); |
| membersClosure.prependSubScope(csym.members()); |
| _map.put(csym, membersClosure); |
| } |
| return membersClosure; |
| } |
| finally { |
| seenTypes.remove(t.tsym); |
| } |
| } |
| |
| @Override |
| public CompoundScope visitTypeVar(TypeVar t, Void _unused) { |
| return visit(t.getUpperBound(), null); |
| } |
| } |
| |
| private MembersClosureCache membersCache = new MembersClosureCache(); |
| |
| public CompoundScope membersClosure(Type site, boolean skipInterface) { |
| CompoundScope cs = membersCache.visit(site, null); |
| Assert.checkNonNull(cs, () -> "type " + site); |
| return skipInterface ? membersCache.new MembersScope(cs) : cs; |
| } |
| // </editor-fold> |
| |
| |
| /** Return first abstract member of class `sym'. |
| */ |
| public MethodSymbol firstUnimplementedAbstract(ClassSymbol sym) { |
| try { |
| return firstUnimplementedAbstractImpl(sym, sym); |
| } catch (CompletionFailure ex) { |
| chk.completionError(enter.getEnv(sym).tree.pos(), ex); |
| return null; |
| } |
| } |
| //where: |
| private MethodSymbol firstUnimplementedAbstractImpl(ClassSymbol impl, ClassSymbol c) { |
| MethodSymbol undef = null; |
| // Do not bother to search in classes that are not abstract, |
| // since they cannot have abstract members. |
| if (c == impl || (c.flags() & (ABSTRACT | INTERFACE)) != 0) { |
| Scope s = c.members(); |
| for (Symbol sym : s.getSymbols(NON_RECURSIVE)) { |
| if (sym.kind == MTH && |
| (sym.flags() & (ABSTRACT|DEFAULT|PRIVATE)) == ABSTRACT) { |
| MethodSymbol absmeth = (MethodSymbol)sym; |
| MethodSymbol implmeth = absmeth.implementation(impl, this, true); |
| if (implmeth == null || implmeth == absmeth) { |
| //look for default implementations |
| if (allowDefaultMethods) { |
| MethodSymbol prov = interfaceCandidates(impl.type, absmeth).head; |
| if (prov != null && prov.overrides(absmeth, impl, this, true)) { |
| implmeth = prov; |
| } |
| } |
| } |
| if (implmeth == null || implmeth == absmeth) { |
| undef = absmeth; |
| break; |
| } |
| } |
| } |
| if (undef == null) { |
| Type st = supertype(c.type); |
| if (st.hasTag(CLASS)) |
| undef = firstUnimplementedAbstractImpl(impl, (ClassSymbol)st.tsym); |
| } |
| for (List<Type> l = interfaces(c.type); |
| undef == null && l.nonEmpty(); |
| l = l.tail) { |
| undef = firstUnimplementedAbstractImpl(impl, (ClassSymbol)l.head.tsym); |
| } |
| } |
| return undef; |
| } |
| |
| |
| //where |
| public List<MethodSymbol> interfaceCandidates(Type site, MethodSymbol ms) { |
| Filter<Symbol> filter = new MethodFilter(ms, site); |
| List<MethodSymbol> candidates = List.nil(); |
| for (Symbol s : membersClosure(site, false).getSymbols(filter)) { |
| if (!site.tsym.isInterface() && !s.owner.isInterface()) { |
| return List.of((MethodSymbol)s); |
| } else if (!candidates.contains(s)) { |
| candidates = candidates.prepend((MethodSymbol)s); |
| } |
| } |
| return prune(candidates); |
| } |
| |
| public List<MethodSymbol> prune(List<MethodSymbol> methods) { |
| ListBuffer<MethodSymbol> methodsMin = new ListBuffer<>(); |
| for (MethodSymbol m1 : methods) { |
| boolean isMin_m1 = true; |
| for (MethodSymbol m2 : methods) { |
| if (m1 == m2) continue; |
| if (m2.owner != m1.owner && |
| asSuper(m2.owner.type, m1.owner) != null) { |
| isMin_m1 = false; |
| break; |
| } |
| } |
| if (isMin_m1) |
| methodsMin.append(m1); |
| } |
| return methodsMin.toList(); |
| } |
| // where |
| private class MethodFilter implements Filter<Symbol> { |
| |
| Symbol msym; |
| Type site; |
| |
| MethodFilter(Symbol msym, Type site) { |
| this.msym = msym; |
| this.site = site; |
| } |
| |
| public boolean accepts(Symbol s) { |
| return s.kind == MTH && |
| s.name == msym.name && |
| (s.flags() & SYNTHETIC) == 0 && |
| s.isInheritedIn(site.tsym, Types.this) && |
| overrideEquivalent(memberType(site, s), memberType(site, msym)); |
| } |
| } |
| // </editor-fold> |
| |
| /** |
| * Does t have the same arguments as s? It is assumed that both |
| * types are (possibly polymorphic) method types. Monomorphic |
| * method types "have the same arguments", if their argument lists |
| * are equal. Polymorphic method types "have the same arguments", |
| * if they have the same arguments after renaming all type |
| * variables of one to corresponding type variables in the other, |
| * where correspondence is by position in the type parameter list. |
| */ |
| public boolean hasSameArgs(Type t, Type s) { |
| return hasSameArgs(t, s, true); |
| } |
| |
| public boolean hasSameArgs(Type t, Type s, boolean strict) { |
| return hasSameArgs(t, s, strict ? hasSameArgs_strict : hasSameArgs_nonstrict); |
| } |
| |
| private boolean hasSameArgs(Type t, Type s, TypeRelation hasSameArgs) { |
| return hasSameArgs.visit(t, s); |
| } |
| // where |
| private class HasSameArgs extends TypeRelation { |
| |
| boolean strict; |
| |
| public HasSameArgs(boolean strict) { |
| this.strict = strict; |
| } |
| |
| public Boolean visitType(Type t, Type s) { |
| throw new AssertionError(); |
| } |
| |
| @Override |
| public Boolean visitMethodType(MethodType t, Type s) { |
| return s.hasTag(METHOD) |
| && containsTypeEquivalent(t.argtypes, s.getParameterTypes()); |
| } |
| |
| @Override |
| public Boolean visitForAll(ForAll t, Type s) { |
| if (!s.hasTag(FORALL)) |
| return strict ? false : visitMethodType(t.asMethodType(), s); |
| |
| ForAll forAll = (ForAll)s; |
| return hasSameBounds(t, forAll) |
| && visit(t.qtype, subst(forAll.qtype, forAll.tvars, t.tvars)); |
| } |
| |
| @Override |
| public Boolean visitErrorType(ErrorType t, Type s) { |
| return false; |
| } |
| } |
| |
| TypeRelation hasSameArgs_strict = new HasSameArgs(true); |
| TypeRelation hasSameArgs_nonstrict = new HasSameArgs(false); |
| |
| // </editor-fold> |
| |
| // <editor-fold defaultstate="collapsed" desc="subst"> |
| public List<Type> subst(List<Type> ts, |
| List<Type> from, |
| List<Type> to) { |
| return ts.map(new Subst(from, to)); |
| } |
| |
| /** |
| * Substitute all occurrences of a type in `from' with the |
| * corresponding type in `to' in 't'. Match lists `from' and `to' |
| * from the right: If lists have different length, discard leading |
| * elements of the longer list. |
| */ |
| public Type subst(Type t, List<Type> from, List<Type> to) { |
| return t.map(new Subst(from, to)); |
| } |
| |
| private class Subst extends TypeMapping<Void> { |
| List<Type> from; |
| List<Type> to; |
| |
| public Subst(List<Type> from, List<Type> to) { |
| int fromLength = from.length(); |
| int toLength = to.length(); |
| while (fromLength > toLength) { |
| fromLength--; |
| from = from.tail; |
| } |
| while (fromLength < toLength) { |
| toLength--; |
| to = to.tail; |
| } |
| this.from = from; |
| this.to = to; |
| } |
| |
| @Override |
| public Type visitTypeVar(TypeVar t, Void ignored) { |
| for (List<Type> from = this.from, to = this.to; |
| from.nonEmpty(); |
| from = from.tail, to = to.tail) { |
| if (t.equalsIgnoreMetadata(from.head)) { |
| return to.head.withTypeVar(t); |
| } |
| } |
| return t; |
| } |
| |
| @Override |
| public Type visitClassType(ClassType t, Void ignored) { |
| if (!t.isCompound()) { |
| return super.visitClassType(t, ignored); |
| } else { |
| Type st = visit(supertype(t)); |
| List<Type> is = visit(interfaces(t), ignored); |
| if (st == supertype(t) && is == interfaces(t)) |
| return t; |
| else |
| return makeIntersectionType(is.prepend(st)); |
| } |
| } |
| |
| @Override |
| public Type visitWildcardType(WildcardType t, Void ignored) { |
| WildcardType t2 = (WildcardType)super.visitWildcardType(t, ignored); |
| if (t2 != t && t.isExtendsBound() && t2.type.isExtendsBound()) { |
| t2.type = wildUpperBound(t2.type); |
| } |
| return t2; |
| } |
| |
| @Override |
| public Type visitForAll(ForAll t, Void ignored) { |
| if (Type.containsAny(to, t.tvars)) { |
| //perform alpha-renaming of free-variables in 't' |
| //if 'to' types contain variables that are free in 't' |
| List<Type> freevars = newInstances(t.tvars); |
| t = new ForAll(freevars, |
| Types.this.subst(t.qtype, t.tvars, freevars)); |
| } |
| List<Type> tvars1 = substBounds(t.tvars, from, to); |
| Type qtype1 = visit(t.qtype); |
| if (tvars1 == t.tvars && qtype1 == t.qtype) { |
| return t; |
| } else if (tvars1 == t.tvars) { |
| return new ForAll(tvars1, qtype1) { |
| @Override |
| public boolean needsStripping() { |
| return true; |
| } |
| }; |
| } else { |
| return new ForAll(tvars1, Types.this.subst(qtype1, t.tvars, tvars1)) { |
| @Override |
| public boolean needsStripping() { |
| return true; |
| } |
| }; |
| } |
| } |
| } |
| |
| public List<Type> substBounds(List<Type> tvars, |
| List<Type> from, |
| List<Type> to) { |
| if (tvars.isEmpty()) |
| return tvars; |
| ListBuffer<Type> newBoundsBuf = new ListBuffer<>(); |
| boolean changed = false; |
| // calculate new bounds |
| for (Type t : tvars) { |
| TypeVar tv = (TypeVar) t; |
| Type bound = subst(tv.bound, from, to); |
| if (bound != tv.bound) |
| changed = true; |
| newBoundsBuf.append(bound); |
| } |
| if (!changed) |
| return tvars; |
| ListBuffer<Type> newTvars = new ListBuffer<>(); |
| // create new type variables without bounds |
| for (Type t : tvars) { |
| newTvars.append(new TypeVar(t.tsym, null, syms.botType, |
| t.getMetadata())); |
| } |
| // the new bounds should use the new type variables in place |
| // of the old |
| List<Type> newBounds = newBoundsBuf.toList(); |
| from = tvars; |
| to = newTvars.toList(); |
| for (; !newBounds.isEmpty(); newBounds = newBounds.tail) { |
| newBounds.head = subst(newBounds.head, from, to); |
| } |
| newBounds = newBoundsBuf.toList(); |
| // set the bounds of new type variables to the new bounds |
| for (Type t : newTvars.toList()) { |
| TypeVar tv = (TypeVar) t; |
| tv.bound = newBounds.head; |
| newBounds = newBounds.tail; |
| } |
| return newTvars.toList(); |
| } |
| |
| public TypeVar substBound(TypeVar t, List<Type> from, List<Type> to) { |
| Type bound1 = subst(t.bound, from, to); |
| if (bound1 == t.bound) |
| return t; |
| else { |
| // create new type variable without bounds |
| TypeVar tv = new TypeVar(t.tsym, null, syms.botType, |
| t.getMetadata()); |
| // the new bound should use the new type variable in place |
| // of the old |
| tv.bound = subst(bound1, List.<Type>of(t), List.<Type>of(tv)); |
| return tv; |
| } |
| } |
| // </editor-fold> |
| |
| // <editor-fold defaultstate="collapsed" desc="hasSameBounds"> |
| /** |
| * Does t have the same bounds for quantified variables as s? |
| */ |
| public boolean hasSameBounds(ForAll t, ForAll s) { |
| List<Type> l1 = t.tvars; |
| List<Type> l2 = s.tvars; |
| while (l1.nonEmpty() && l2.nonEmpty() && |
| isSameType(l1.head.getUpperBound(), |
| subst(l2.head.getUpperBound(), |
| s.tvars, |
| t.tvars))) { |
| l1 = l1.tail; |
| l2 = l2.tail; |
| } |
| return l1.isEmpty() && l2.isEmpty(); |
| } |
| // </editor-fold> |
| |
| // <editor-fold defaultstate="collapsed" desc="newInstances"> |
| /** Create new vector of type variables from list of variables |
| * changing all recursive bounds from old to new list. |
| */ |
| public List<Type> newInstances(List<Type> tvars) { |
| List<Type> tvars1 = tvars.map(newInstanceFun); |
| for (List<Type> l = tvars1; l.nonEmpty(); l = l.tail) { |
| TypeVar tv = (TypeVar) l.head; |
| tv.bound = subst(tv.bound, tvars, tvars1); |
| } |
| return tvars1; |
| } |
| private static final TypeMapping<Void> newInstanceFun = new TypeMapping<Void>() { |
| @Override |
| public TypeVar visitTypeVar(TypeVar t, Void _unused) { |
| return new TypeVar(t.tsym, t.getUpperBound(), t.getLowerBound(), t.getMetadata()); |
| } |
| }; |
| // </editor-fold> |
| |
| public Type createMethodTypeWithParameters(Type original, List<Type> newParams) { |
| return original.accept(methodWithParameters, newParams); |
| } |
| // where |
| private final MapVisitor<List<Type>> methodWithParameters = new MapVisitor<List<Type>>() { |
| public Type visitType(Type t, List<Type> newParams) { |
| throw new IllegalArgumentException("Not a method type: " + t); |
| } |
| public Type visitMethodType(MethodType t, List<Type> newParams) { |
| return new MethodType(newParams, t.restype, t.thrown, t.tsym); |
| } |
| public Type visitForAll(ForAll t, List<Type> newParams) { |
| return new ForAll(t.tvars, t.qtype.accept(this, newParams)); |
| } |
| }; |
| |
| public Type createMethodTypeWithThrown(Type original, List<Type> newThrown) { |
| return original.accept(methodWithThrown, newThrown); |
| } |
| // where |
| private final MapVisitor<List<Type>> methodWithThrown = new MapVisitor<List<Type>>() { |
| public Type visitType(Type t, List<Type> newThrown) { |
| throw new IllegalArgumentException("Not a method type: " + t); |
| } |
| public Type visitMethodType(MethodType t, List<Type> newThrown) { |
| return new MethodType(t.argtypes, t.restype, newThrown, t.tsym); |
| } |
| public Type visitForAll(ForAll t, List<Type> newThrown) { |
| return new ForAll(t.tvars, t.qtype.accept(this, newThrown)); |
| } |
| }; |
| |
| public Type createMethodTypeWithReturn(Type original, Type newReturn) { |
| return original.accept(methodWithReturn, newReturn); |
| } |
| // where |
| private final MapVisitor<Type> methodWithReturn = new MapVisitor<Type>() { |
| public Type visitType(Type t, Type newReturn) { |
| throw new IllegalArgumentException("Not a method type: " + t); |
| } |
| public Type visitMethodType(MethodType t, Type newReturn) { |
| return new MethodType(t.argtypes, newReturn, t.thrown, t.tsym) { |
| @Override |
| public Type baseType() { |
| return t; |
| } |
| }; |
| } |
| public Type visitForAll(ForAll t, Type newReturn) { |
| return new ForAll(t.tvars, t.qtype.accept(this, newReturn)) { |
| @Override |
| public Type baseType() { |
| return t; |
| } |
| }; |
| } |
| }; |
| |
| // <editor-fold defaultstate="collapsed" desc="createErrorType"> |
| public Type createErrorType(Type originalType) { |
| return new ErrorType(originalType, syms.errSymbol); |
| } |
| |
| public Type createErrorType(ClassSymbol c, Type originalType) { |
| return new ErrorType(c, originalType); |
| } |
| |
| public Type createErrorType(Name name, TypeSymbol container, Type originalType) { |
| return new ErrorType(name, container, originalType); |
| } |
| // </editor-fold> |
| |
| // <editor-fold defaultstate="collapsed" desc="rank"> |
| /** |
| * The rank of a class is the length of the longest path between |
| * the class and java.lang.Object in the class inheritance |
| * graph. Undefined for all but reference types. |
| */ |
| public int rank(Type t) { |
| switch(t.getTag()) { |
| case CLASS: { |
| ClassType cls = (ClassType)t; |
| if (cls.rank_field < 0) { |
| Name fullname = cls.tsym.getQualifiedName(); |
| if (fullname == names.java_lang_Object) |
| cls.rank_field = 0; |
| else { |
| int r = rank(supertype(cls)); |
| for (List<Type> l = interfaces(cls); |
| l.nonEmpty(); |
| l = l.tail) { |
| if (rank(l.head) > r) |
| r = rank(l.head); |
| } |
| cls.rank_field = r + 1; |
| } |
| } |
| return cls.rank_field; |
| } |
| case TYPEVAR: { |
| TypeVar tvar = (TypeVar)t; |
| if (tvar.rank_field < 0) { |
| int r = rank(supertype(tvar)); |
| for (List<Type> l = interfaces(tvar); |
| l.nonEmpty(); |
| l = l.tail) { |
| if (rank(l.head) > r) r = rank(l.head); |
| } |
| tvar.rank_field = r + 1; |
| } |
| return tvar.rank_field; |
| } |
| case ERROR: |
| case NONE: |
| return 0; |
| default: |
| throw new AssertionError(); |
| } |
| } |
| // </editor-fold> |
| |
| /** |
| * Helper method for generating a string representation of a given type |
| * accordingly to a given locale |
| */ |
| public String toString(Type t, Locale locale) { |
| return Printer.createStandardPrinter(messages).visit(t, locale); |
| } |
| |
| /** |
| * Helper method for generating a string representation of a given type |
| * accordingly to a given locale |
| */ |
| public String toString(Symbol t, Locale locale) { |
| return Printer.createStandardPrinter(messages).visit(t, locale); |
| } |
| |
| // <editor-fold defaultstate="collapsed" desc="toString"> |
| /** |
| * This toString is slightly more descriptive than the one on Type. |
| * |
| * @deprecated Types.toString(Type t, Locale l) provides better support |
| * for localization |
| */ |
| @Deprecated |
| public String toString(Type t) { |
| if (t.hasTag(FORALL)) { |
| ForAll forAll = (ForAll)t; |
| return typaramsString(forAll.tvars) + forAll.qtype; |
| } |
| return "" + t; |
| } |
| // where |
| private String typaramsString(List<Type> tvars) { |
| StringBuilder s = new StringBuilder(); |
| s.append('<'); |
| boolean first = true; |
| for (Type t : tvars) { |
| if (!first) s.append(", "); |
| first = false; |
| appendTyparamString(((TypeVar)t), s); |
| } |
| s.append('>'); |
| return s.toString(); |
| } |
| private void appendTyparamString(TypeVar t, StringBuilder buf) { |
| buf.append(t); |
| if (t.bound == null || |
| t.bound.tsym.getQualifiedName() == names.java_lang_Object) |
| return; |
| buf.append(" extends "); // Java syntax; no need for i18n |
| Type bound = t.bound; |
| if (!bound.isCompound()) { |
| buf.append(bound); |
| } else if ((erasure(t).tsym.flags() & INTERFACE) == 0) { |
| buf.append(supertype(t)); |
| for (Type intf : interfaces(t)) { |
| buf.append('&'); |
| buf.append(intf); |
| } |
| } else { |
| // No superclass was given in bounds. |
| // In this case, supertype is Object, erasure is first interface. |
| boolean first = true; |
| for (Type intf : interfaces(t)) { |
| if (!first) buf.append('&'); |
| first = false; |
| buf.append(intf); |
| } |
| } |
| } |
| // </editor-fold> |
| |
| // <editor-fold defaultstate="collapsed" desc="Determining least upper bounds of types"> |
| /** |
| * A cache for closures. |
| * |
| * <p>A closure is a list of all the supertypes and interfaces of |
| * a class or interface type, ordered by ClassSymbol.precedes |
| * (that is, subclasses come first, arbitrary but fixed |
| * otherwise). |
| */ |
| private Map<Type,List<Type>> closureCache = new HashMap<>(); |
| |
| /** |
| * Returns the closure of a class or interface type. |
| */ |
| public List<Type> closure(Type t) { |
| List<Type> cl = closureCache.get(t); |
| if (cl == null) { |
| Type st = supertype(t); |
| if (!t.isCompound()) { |
| if (st.hasTag(CLASS)) { |
| cl = insert(closure(st), t); |
| } else if (st.hasTag(TYPEVAR)) { |
| cl = closure(st).prepend(t); |
| } else { |
| cl = List.of(t); |
| } |
| } else { |
| cl = closure(supertype(t)); |
| } |
| for (List<Type> l = interfaces(t); l.nonEmpty(); l = l.tail) |
| cl = union(cl, closure(l.head)); |
| closureCache.put(t, cl); |
| } |
| return cl; |
| } |
| |
| /** |
| * Collect types into a new closure (using a @code{ClosureHolder}) |
| */ |
| public Collector<Type, ClosureHolder, List<Type>> closureCollector(boolean minClosure, BiPredicate<Type, Type> shouldSkip) { |
| return Collector.of(() -> new ClosureHolder(minClosure, shouldSkip), |
| ClosureHolder::add, |
| ClosureHolder::merge, |
| ClosureHolder::closure); |
| } |
| //where |
| class ClosureHolder { |
| List<Type> closure; |
| final boolean minClosure; |
| final BiPredicate<Type, Type> shouldSkip; |
| |
| ClosureHolder(boolean minClosure, BiPredicate<Type, Type> shouldSkip) { |
| this.closure = List.nil(); |
| this.minClosure = minClosure; |
| this.shouldSkip = shouldSkip; |
| } |
| |
| void add(Type type) { |
| closure = insert(closure, type, shouldSkip); |
| } |
| |
| ClosureHolder merge(ClosureHolder other) { |
| closure = union(closure, other.closure, shouldSkip); |
| return this; |
| } |
| |
| List<Type> closure() { |
| return minClosure ? closureMin(closure) : closure; |
| } |
| } |
| |
| BiPredicate<Type, Type> basicClosureSkip = (t1, t2) -> t1.tsym == t2.tsym; |
| |
| /** |
| * Insert a type in a closure |
| */ |
| public List<Type> insert(List<Type> cl, Type t, BiPredicate<Type, Type> shouldSkip) { |
| if (cl.isEmpty()) { |
| return cl.prepend(t); |
| } else if (shouldSkip.test(t, cl.head)) { |
| return cl; |
| } else if (t.tsym.precedes(cl.head.tsym, this)) { |
| return cl.prepend(t); |
| } else { |
| // t comes after head, or the two are unrelated |
| return insert(cl.tail, t, shouldSkip).prepend(cl.head); |
| } |
| } |
| |
| public List<Type> insert(List<Type> cl, Type t) { |
| return insert(cl, t, basicClosureSkip); |
| } |
| |
| /** |
| * Form the union of two closures |
| */ |
| public List<Type> union(List<Type> cl1, List<Type> cl2, BiPredicate<Type, Type> shouldSkip) { |
| if (cl1.isEmpty()) { |
| return cl2; |
| } else if (cl2.isEmpty()) { |
| return cl1; |
| } else if (shouldSkip.test(cl1.head, cl2.head)) { |
| return union(cl1.tail, cl2.tail, shouldSkip).prepend(cl1.head); |
| } else if (cl1.head.tsym.precedes(cl2.head.tsym, this)) { |
| return union(cl1.tail, cl2, shouldSkip).prepend(cl1.head); |
| } else if (cl2.head.tsym.precedes(cl1.head.tsym, this)) { |
| return union(cl1, cl2.tail, shouldSkip).prepend(cl2.head); |
| } else { |
| // unrelated types |
| return union(cl1.tail, cl2, shouldSkip).prepend(cl1.head); |
| } |
| } |
| |
| public List<Type> union(List<Type> cl1, List<Type> cl2) { |
| return union(cl1, cl2, basicClosureSkip); |
| } |
| |
| /** |
| * Intersect two closures |
| */ |
| public List<Type> intersect(List<Type> cl1, List<Type> cl2) { |
| if (cl1 == cl2) |
| return cl1; |
| if (cl1.isEmpty() || cl2.isEmpty()) |
| return List.nil(); |
| if (cl1.head.tsym.precedes(cl2.head.tsym, this)) |
| return intersect(cl1.tail, cl2); |
| if (cl2.head.tsym.precedes(cl1.head.tsym, this)) |
| return intersect(cl1, cl2.tail); |
| if (isSameType(cl1.head, cl2.head)) |
| return intersect(cl1.tail, cl2.tail).prepend(cl1.head); |
| if (cl1.head.tsym == cl2.head.tsym && |
| cl1.head.hasTag(CLASS) && cl2.head.hasTag(CLASS)) { |
| if (cl1.head.isParameterized() && cl2.head.isParameterized()) { |
| Type merge = merge(cl1.head,cl2.head); |
| return intersect(cl1.tail, cl2.tail).prepend(merge); |
| } |
| if (cl1.head.isRaw() || cl2.head.isRaw()) |
| return intersect(cl1.tail, cl2.tail).prepend(erasure(cl1.head)); |
| } |
| return intersect(cl1.tail, cl2.tail); |
| } |
| // where |
| class TypePair { |
| final Type t1; |
| final Type t2; |
| boolean strict; |
| |
| TypePair(Type t1, Type t2) { |
| this(t1, t2, false); |
| } |
| |
| TypePair(Type t1, Type t2, boolean strict) { |
| this.t1 = t1; |
| this.t2 = t2; |
| this.strict = strict; |
| } |
| @Override |
| public int hashCode() { |
| return 127 * Types.this.hashCode(t1) + Types.this.hashCode(t2); |
| } |
| @Override |
| public boolean equals(Object obj) { |
| if (!(obj instanceof TypePair)) |
| return false; |
| TypePair typePair = (TypePair)obj; |
| return isSameType(t1, typePair.t1, strict) |
| && isSameType(t2, typePair.t2, strict); |
| } |
| } |
| Set<TypePair> mergeCache = new HashSet<>(); |
| private Type merge(Type c1, Type c2) { |
| ClassType class1 = (ClassType) c1; |
| List<Type> act1 = class1.getTypeArguments(); |
| ClassType class2 = (ClassType) c2; |
| List<Type> act2 = class2.getTypeArguments(); |
| ListBuffer<Type> merged = new ListBuffer<>(); |
| List<Type> typarams = class1.tsym.type.getTypeArguments(); |
| |
| while (act1.nonEmpty() && act2.nonEmpty() && typarams.nonEmpty()) { |
| if (containsType(act1.head, act2.head)) { |
| merged.append(act1.head); |
| } else if (containsType(act2.head, act1.head)) { |
| merged.append(act2.head); |
| } else { |
| TypePair pair = new TypePair(c1, c2); |
| Type m; |
| if (mergeCache.add(pair)) { |
| m = new WildcardType(lub(wildUpperBound(act1.head), |
| wildUpperBound(act2.head)), |
| BoundKind.EXTENDS, |
| syms.boundClass); |
| mergeCache.remove(pair); |
| } else { |
| m = new WildcardType(syms.objectType, |
| BoundKind.UNBOUND, |
| syms.boundClass); |
| } |
| merged.append(m.withTypeVar(typarams.head)); |
| } |
| act1 = act1.tail; |
| act2 = act2.tail; |
| typarams = typarams.tail; |
| } |
| Assert.check(act1.isEmpty() && act2.isEmpty() && typarams.isEmpty()); |
| // There is no spec detailing how type annotations are to |
| // be inherited. So set it to noAnnotations for now |
| return new ClassType(class1.getEnclosingType(), merged.toList(), |
| class1.tsym); |
| } |
| |
| /** |
| * Return the minimum type of a closure, a compound type if no |
| * unique minimum exists. |
| */ |
| private Type compoundMin(List<Type> cl) { |
| if (cl.isEmpty()) return syms.objectType; |
| List<Type> compound = closureMin(cl); |
| if (compound.isEmpty()) |
| return null; |
| else if (compound.tail.isEmpty()) |
| return compound.head; |
| else |
| return makeIntersectionType(compound); |
| } |
| |
| /** |
| * Return the minimum types of a closure, suitable for computing |
| * compoundMin or glb. |
| */ |
| private List<Type> closureMin(List<Type> cl) { |
| ListBuffer<Type> classes = new ListBuffer<>(); |
| ListBuffer<Type> interfaces = new ListBuffer<>(); |
| Set<Type> toSkip = new HashSet<>(); |
| while (!cl.isEmpty()) { |
| Type current = cl.head; |
| boolean keep = !toSkip.contains(current); |
| if (keep && current.hasTag(TYPEVAR)) { |
| // skip lower-bounded variables with a subtype in cl.tail |
| for (Type t : cl.tail) { |
| if (isSubtypeNoCapture(t, current)) { |
| keep = false; |
| break; |
| } |
| } |
| } |
| if (keep) { |
| if (current.isInterface()) |
| interfaces.append(current); |
| else |
| classes.append(current); |
| for (Type t : cl.tail) { |
| // skip supertypes of 'current' in cl.tail |
| if (isSubtypeNoCapture(current, t)) |
| toSkip.add(t); |
| } |
| } |
| cl = cl.tail; |
| } |
| return classes.appendList(interfaces).toList(); |
| } |
| |
| /** |
| * Return the least upper bound of list of types. if the lub does |
| * not exist return null. |
| */ |
| public Type lub(List<Type> ts) { |
| return lub(ts.toArray(new Type[ts.length()])); |
| } |
| |
| /** |
| * Return the least upper bound (lub) of set of types. If the lub |
| * does not exist return the type of null (bottom). |
| */ |
| public Type lub(Type... ts) { |
| final int UNKNOWN_BOUND = 0; |
| final int ARRAY_BOUND = 1; |
| final int CLASS_BOUND = 2; |
| |
| int[] kinds = new int[ts.length]; |
| |
| int boundkind = UNKNOWN_BOUND; |
| for (int i = 0 ; i < ts.length ; i++) { |
| Type t = ts[i]; |
| switch (t.getTag()) { |
| case CLASS: |
| boundkind |= kinds[i] = CLASS_BOUND; |
| break; |
| case ARRAY: |
| boundkind |= kinds[i] = ARRAY_BOUND; |
| break; |
| case TYPEVAR: |
| do { |
| t = t.getUpperBound(); |
| } while (t.hasTag(TYPEVAR)); |
| if (t.hasTag(ARRAY)) { |
| boundkind |= kinds[i] = ARRAY_BOUND; |
| } else { |
| boundkind |= kinds[i] = CLASS_BOUND; |
| } |
| break; |
| default: |
| kinds[i] = UNKNOWN_BOUND; |
| if (t.isPrimitive()) |
| return syms.errType; |
| } |
| } |
| switch (boundkind) { |
| case 0: |
| return syms.botType; |
| |
| case ARRAY_BOUND: |
| // calculate lub(A[], B[]) |
| Type[] elements = new Type[ts.length]; |
| for (int i = 0 ; i < ts.length ; i++) { |
| Type elem = elements[i] = elemTypeFun.apply(ts[i]); |
| if (elem.isPrimitive()) { |
| // if a primitive type is found, then return |
| // arraySuperType unless all the types are the |
| // same |
| Type first = ts[0]; |
| for (int j = 1 ; j < ts.length ; j++) { |
| if (!isSameType(first, ts[j])) { |
| // lub(int[], B[]) is Cloneable & Serializable |
| return arraySuperType(); |
| } |
| } |
| // all the array types are the same, return one |
| // lub(int[], int[]) is int[] |
| return first; |
| } |
| } |
| // lub(A[], B[]) is lub(A, B)[] |
| return new ArrayType(lub(elements), syms.arrayClass); |
| |
| case CLASS_BOUND: |
| // calculate lub(A, B) |
| int startIdx = 0; |
| for (int i = 0; i < ts.length ; i++) { |
| Type t = ts[i]; |
| if (t.hasTag(CLASS) || t.hasTag(TYPEVAR)) { |
| break; |
| } else { |
| startIdx++; |
| } |
| } |
| Assert.check(startIdx < ts.length); |
| //step 1 - compute erased candidate set (EC) |
| List<Type> cl = erasedSupertypes(ts[startIdx]); |
| for (int i = startIdx + 1 ; i < ts.length ; i++) { |
| Type t = ts[i]; |
| if (t.hasTag(CLASS) || t.hasTag(TYPEVAR)) |
| cl = intersect(cl, erasedSupertypes(t)); |
| } |
| //step 2 - compute minimal erased candidate set (MEC) |
| List<Type> mec = closureMin(cl); |
| //step 3 - for each element G in MEC, compute lci(Inv(G)) |
| List<Type> candidates = List.nil(); |
| for (Type erasedSupertype : mec) { |
| List<Type> lci = List.of(asSuper(ts[startIdx], erasedSupertype.tsym)); |
| for (int i = startIdx + 1 ; i < ts.length ; i++) { |
| Type superType = asSuper(ts[i], erasedSupertype.tsym); |
| lci = intersect(lci, superType != null ? List.of(superType) : List.<Type>nil()); |
| } |
| candidates = candidates.appendList(lci); |
| } |
| //step 4 - let MEC be { G1, G2 ... Gn }, then we have that |
| //lub = lci(Inv(G1)) & lci(Inv(G2)) & ... & lci(Inv(Gn)) |
| return compoundMin(candidates); |
| |
| default: |
| // calculate lub(A, B[]) |
| List<Type> classes = List.of(arraySuperType()); |
| for (int i = 0 ; i < ts.length ; i++) { |
| if (kinds[i] != ARRAY_BOUND) // Filter out any arrays |
| classes = classes.prepend(ts[i]); |
| } |
| // lub(A, B[]) is lub(A, arraySuperType) |
| return lub(classes); |
| } |
| } |
| // where |
| List<Type> erasedSupertypes(Type t) { |
| ListBuffer<Type> buf = new ListBuffer<>(); |
| for (Type sup : closure(t)) { |
| if (sup.hasTag(TYPEVAR)) { |
| buf.append(sup); |
| } else { |
| buf.append(erasure(sup)); |
| } |
| } |
| return buf.toList(); |
| } |
| |
| private Type arraySuperType = null; |
| private Type arraySuperType() { |
| // initialized lazily to avoid problems during compiler startup |
| if (arraySuperType == null) { |
| synchronized (this) { |
| if (arraySuperType == null) { |
| // JLS 10.8: all arrays implement Cloneable and Serializable. |
| arraySuperType = makeIntersectionType(List.of(syms.serializableType, |
| syms.cloneableType), true); |
| } |
| } |
| } |
| return arraySuperType; |
| } |
| // </editor-fold> |
| |
| // <editor-fold defaultstate="collapsed" desc="Greatest lower bound"> |
| public Type glb(List<Type> ts) { |
| Type t1 = ts.head; |
| for (Type t2 : ts.tail) { |
| if (t1.isErroneous()) |
| return t1; |
| t1 = glb(t1, t2); |
| } |
| return t1; |
| } |
| //where |
| public Type glb(Type t, Type s) { |
| if (s == null) |
| return t; |
| else if (t.isPrimitive() || s.isPrimitive()) |
| return syms.errType; |
| else if (isSubtypeNoCapture(t, s)) |
| return t; |
| else if (isSubtypeNoCapture(s, t)) |
| return s; |
| |
| List<Type> closure = union(closure(t), closure(s)); |
| return glbFlattened(closure, t); |
| } |
| //where |
| /** |
| * Perform glb for a list of non-primitive, non-error, non-compound types; |
| * redundant elements are removed. Bounds should be ordered according to |
| * {@link Symbol#precedes(TypeSymbol,Types)}. |
| * |
| * @param flatBounds List of type to glb |
| * @param errT Original type to use if the result is an error type |
| */ |
| private Type glbFlattened(List<Type> flatBounds, Type errT) { |
| List<Type> bounds = closureMin(flatBounds); |
| |
| if (bounds.isEmpty()) { // length == 0 |
| return syms.objectType; |
| } else if (bounds.tail.isEmpty()) { // length == 1 |
| return bounds.head; |
| } else { // length > 1 |
| int classCount = 0; |
| List<Type> lowers = List.nil(); |
| for (Type bound : bounds) { |
| if (!bound.isInterface()) { |
| classCount++; |
| Type lower = cvarLowerBound(bound); |
| if (bound != lower && !lower.hasTag(BOT)) |
| lowers = insert(lowers, lower); |
| } |
| } |
| if (classCount > 1) { |
| if (lowers.isEmpty()) |
| return createErrorType(errT); |
| else |
| return glbFlattened(union(bounds, lowers), errT); |
| } |
| } |
| return makeIntersectionType(bounds); |
| } |
| // </editor-fold> |
| |
| // <editor-fold defaultstate="collapsed" desc="hashCode"> |
| /** |
| * Compute a hash code on a type. |
| */ |
| public int hashCode(Type t) { |
| return hashCode(t, false); |
| } |
| |
| public int hashCode(Type t, boolean strict) { |
| return strict ? |
| hashCodeStrictVisitor.visit(t) : |
| hashCodeVisitor.visit(t); |
| } |
| // where |
| private static final HashCodeVisitor hashCodeVisitor = new HashCodeVisitor(); |
| private static final HashCodeVisitor hashCodeStrictVisitor = new HashCodeVisitor() { |
| @Override |
| public Integer visitTypeVar(TypeVar t, Void ignored) { |
| return System.identityHashCode(t); |
| } |
| }; |
| |
| private static class HashCodeVisitor extends UnaryVisitor<Integer> { |
| public Integer visitType(Type t, Void ignored) { |
| return t.getTag().ordinal(); |
| } |
| |
| @Override |
| public Integer visitClassType(ClassType t, Void ignored) { |
| int result = visit(t.getEnclosingType()); |
| result *= 127; |
| result += t.tsym.flatName().hashCode(); |
| for (Type s : t.getTypeArguments()) { |
| result *= 127; |
| result += visit(s); |
| } |
| return result; |
| } |
| |
| @Override |
| public Integer visitMethodType(MethodType t, Void ignored) { |
| int h = METHOD.ordinal(); |
| for (List<Type> thisargs = t.argtypes; |
| thisargs.tail != null; |
| thisargs = thisargs.tail) |
| h = (h << 5) + visit(thisargs.head); |
| return (h << 5) + visit(t.restype); |
| } |
| |
| @Override |
| public Integer visitWildcardType(WildcardType t, Void ignored) { |
| int result = t.kind.hashCode(); |
| if (t.type != null) { |
| result *= 127; |
| result += visit(t.type); |
| } |
| return result; |
| } |
| |
| @Override |
| public Integer visitArrayType(ArrayType t, Void ignored) { |
| return visit(t.elemtype) + 12; |
| } |
| |
| @Override |
| public Integer visitTypeVar(TypeVar t, Void ignored) { |
| return System.identityHashCode(t); |
| } |
| |
| @Override |
| public Integer visitUndetVar(UndetVar t, Void ignored) { |
| return System.identityHashCode(t); |
| } |
| |
| @Override |
| public Integer visitErrorType(ErrorType t, Void ignored) { |
| return 0; |
| } |
| } |
| // </editor-fold> |
| |
| // <editor-fold defaultstate="collapsed" desc="Return-Type-Substitutable"> |
| /** |
| * Does t have a result that is a subtype of the result type of s, |
| * suitable for covariant returns? It is assumed that both types |
| * are (possibly polymorphic) method types. Monomorphic method |
| * types are handled in the obvious way. Polymorphic method types |
| * require renaming all type variables of one to corresponding |
| * type variables in the other, where correspondence is by |
| * position in the type parameter list. */ |
| public boolean resultSubtype(Type t, Type s, Warner warner) { |
| List<Type> tvars = t.getTypeArguments(); |
| List<Type> svars = s.getTypeArguments(); |
| Type tres = t.getReturnType(); |
| Type sres = subst(s.getReturnType(), svars, tvars); |
| return covariantReturnType(tres, sres, warner); |
| } |
| |
| /** |
| * Return-Type-Substitutable. |
| * @jls section 8.4.5 |
| */ |
| public boolean returnTypeSubstitutable(Type r1, Type r2) { |
| if (hasSameArgs(r1, r2)) |
| return resultSubtype(r1, r2, noWarnings); |
| else |
| return covariantReturnType(r1.getReturnType(), |
| erasure(r2.getReturnType()), |
| noWarnings); |
| } |
| |
| public boolean returnTypeSubstitutable(Type r1, |
| Type r2, Type r2res, |
| Warner warner) { |
| if (isSameType(r1.getReturnType(), r2res)) |
| return true; |
| if (r1.getReturnType().isPrimitive() || r2res.isPrimitive()) |
| return false; |
| |
| if (hasSameArgs(r1, r2)) |
| return covariantReturnType(r1.getReturnType(), r2res, warner); |
| if (isSubtypeUnchecked(r1.getReturnType(), r2res, warner)) |
| return true; |
| if (!isSubtype(r1.getReturnType(), erasure(r2res))) |
| return false; |
| warner.warn(LintCategory.UNCHECKED); |
| return true; |
| } |
| |
| /** |
| * Is t an appropriate return type in an overrider for a |
| * method that returns s? |
| */ |
| public boolean covariantReturnType(Type t, Type s, Warner warner) { |
| return |
| isSameType(t, s) || |
| !t.isPrimitive() && |
| !s.isPrimitive() && |
| isAssignable(t, s, warner); |
| } |
| // </editor-fold> |
| |
| // <editor-fold defaultstate="collapsed" desc="Box/unbox support"> |
| /** |
| * Return the class that boxes the given primitive. |
| */ |
| public ClassSymbol boxedClass(Type t) { |
| return syms.enterClass(syms.boxedName[t.getTag().ordinal()]); |
| } |
| |
| /** |
| * Return the boxed type if 't' is primitive, otherwise return 't' itself. |
| */ |
| public Type boxedTypeOrType(Type t) { |
| return t.isPrimitive() ? |
| boxedClass(t).type : |
| t; |
| } |
| |
| /** |
| * Return the primitive type corresponding to a boxed type. |
| */ |
| public Type unboxedType(Type t) { |
| for (int i=0; i<syms.boxedName.length; i++) { |
| Name box = syms.boxedName[i]; |
| if (box != null && |
| asSuper(t, syms.enterClass(box)) != null) |
| return syms.typeOfTag[i]; |
| } |
| return Type.noType; |
| } |
| |
| /** |
| * Return the unboxed type if 't' is a boxed class, otherwise return 't' itself. |
| */ |
| public Type unboxedTypeOrType(Type t) { |
| Type unboxedType = unboxedType(t); |
| return unboxedType.hasTag(NONE) ? t : unboxedType; |
| } |
| // </editor-fold> |
| |
| // <editor-fold defaultstate="collapsed" desc="Capture conversion"> |
| /* |
| * JLS 5.1.10 Capture Conversion: |
| * |
| * Let G name a generic type declaration with n formal type |
| * parameters A1 ... An with corresponding bounds U1 ... Un. There |
| * exists a capture conversion from G<T1 ... Tn> to G<S1 ... Sn>, |
| * where, for 1 <= i <= n: |
| * |
| * + If Ti is a wildcard type argument (4.5.1) of the form ? then |
| * Si is a fresh type variable whose upper bound is |
| * Ui[A1 := S1, ..., An := Sn] and whose lower bound is the null |
| * type. |
| * |
| * + If Ti is a wildcard type argument of the form ? extends Bi, |
| * then Si is a fresh type variable whose upper bound is |
| * glb(Bi, Ui[A1 := S1, ..., An := Sn]) and whose lower bound is |
| * the null type, where glb(V1,... ,Vm) is V1 & ... & Vm. It is |
| * a compile-time error if for any two classes (not interfaces) |
| * Vi and Vj,Vi is not a subclass of Vj or vice versa. |
| * |
| * + If Ti is a wildcard type argument of the form ? super Bi, |
| * then Si is a fresh type variable whose upper bound is |
| * Ui[A1 := S1, ..., An := Sn] and whose lower bound is Bi. |
| * |
| * + Otherwise, Si = Ti. |
| * |
| * Capture conversion on any type other than a parameterized type |
| * (4.5) acts as an identity conversion (5.1.1). Capture |
| * conversions never require a special action at run time and |
| * therefore never throw an exception at run time. |
| * |
| * Capture conversion is not applied recursively. |
| */ |
| /** |
| * Capture conversion as specified by the JLS. |
| */ |
| |
| public List<Type> capture(List<Type> ts) { |
| List<Type> buf = List.nil(); |
| for (Type t : ts) { |
| buf = buf.prepend(capture(t)); |
| } |
| return buf.reverse(); |
| } |
| |
| public Type capture(Type t) { |
| if (!t.hasTag(CLASS)) { |
| return t; |
| } |
| if (t.getEnclosingType() != Type.noType) { |
| Type capturedEncl = capture(t.getEnclosingType()); |
| if (capturedEncl != t.getEnclosingType()) { |
| Type type1 = memberType(capturedEncl, t.tsym); |
| t = subst(type1, t.tsym.type.getTypeArguments(), t.getTypeArguments()); |
| } |
| } |
| ClassType cls = (ClassType)t; |
| if (cls.isRaw() || !cls.isParameterized()) |
| return cls; |
| |
| ClassType G = (ClassType)cls.asElement().asType(); |
| List<Type> A = G.getTypeArguments(); |
| List<Type> T = cls.getTypeArguments(); |
| List<Type> S = freshTypeVariables(T); |
| |
| List<Type> currentA = A; |
| List<Type> currentT = T; |
| List<Type> currentS = S; |
| boolean captured = false; |
| while (!currentA.isEmpty() && |
| !currentT.isEmpty() && |
| !currentS.isEmpty()) { |
| if (currentS.head != currentT.head) { |
| captured = true; |
| WildcardType Ti = (WildcardType)currentT.head; |
| Type Ui = currentA.head.getUpperBound(); |
| CapturedType Si = (CapturedType)currentS.head; |
| if (Ui == null) |
| Ui = syms.objectType; |
| switch (Ti.kind) { |
| case UNBOUND: |
| Si.bound = subst(Ui, A, S); |
| Si.lower = syms.botType; |
| break; |
| case EXTENDS: |
| Si.bound = glb(Ti.getExtendsBound(), subst(Ui, A, S)); |
| Si.lower = syms.botType; |
| break; |
| case SUPER: |
| Si.bound = subst(Ui, A, S); |
| Si.lower = Ti.getSuperBound(); |
| break; |
| } |
| Type tmpBound = Si.bound.hasTag(UNDETVAR) ? ((UndetVar)Si.bound).qtype : Si.bound; |
| Type tmpLower = Si.lower.hasTag(UNDETVAR) ? ((UndetVar)Si.lower).qtype : Si.lower; |
| if (!Si.bound.hasTag(ERROR) && |
| !Si.lower.hasTag(ERROR) && |
| isSameType(tmpBound, tmpLower, false)) { |
| currentS.head = Si.bound; |
| } |
| } |
| currentA = currentA.tail; |
| currentT = currentT.tail; |
| currentS = currentS.tail; |
| } |
| if (!currentA.isEmpty() || !currentT.isEmpty() || !currentS.isEmpty()) |
| return erasure(t); // some "rare" type involved |
| |
| if (captured) |
| return new ClassType(cls.getEnclosingType(), S, cls.tsym, |
| cls.getMetadata()); |
| else |
| return t; |
| } |
| // where |
| public List<Type> freshTypeVariables(List<Type> types) { |
| ListBuffer<Type> result = new ListBuffer<>(); |
| for (Type t : types) { |
| if (t.hasTag(WILDCARD)) { |
| Type bound = ((WildcardType)t).getExtendsBound(); |
| if (bound == null) |
| bound = syms.objectType; |
| result.append(new CapturedType(capturedName, |
| syms.noSymbol, |
| bound, |
| syms.botType, |
| (WildcardType)t)); |
| } else { |
| result.append(t); |
| } |
| } |
| return result.toList(); |
| } |
| // </editor-fold> |
| |
| // <editor-fold defaultstate="collapsed" desc="Internal utility methods"> |
| private boolean sideCast(Type from, Type to, Warner warn) { |
| // We are casting from type $from$ to type $to$, which are |
| // non-final unrelated types. This method |
| // tries to reject a cast by transferring type parameters |
| // from $to$ to $from$ by common superinterfaces. |
| boolean reverse = false; |
| Type target = to; |
| if ((to.tsym.flags() & INTERFACE) == 0) { |
| Assert.check((from.tsym.flags() & INTERFACE) != 0); |
| reverse = true; |
| to = from; |
| from = target; |
| } |
| List<Type> commonSupers = superClosure(to, erasure(from)); |
| boolean giveWarning = commonSupers.isEmpty(); |
| // The arguments to the supers could be unified here to |
| // get a more accurate analysis |
| while (commonSupers.nonEmpty()) { |
| Type t1 = asSuper(from, commonSupers.head.tsym); |
| Type t2 = commonSupers.head; // same as asSuper(to, commonSupers.head.tsym); |
| if (disjointTypes(t1.getTypeArguments(), t2.getTypeArguments())) |
| return false; |
| giveWarning = giveWarning || (reverse ? giveWarning(t2, t1) : giveWarning(t1, t2)); |
| commonSupers = commonSupers.tail; |
| } |
| if (giveWarning && !isReifiable(reverse ? from : to)) |
| warn.warn(LintCategory.UNCHECKED); |
| return true; |
| } |
| |
| private boolean sideCastFinal(Type from, Type to, Warner warn) { |
| // We are casting from type $from$ to type $to$, which are |
| // unrelated types one of which is final and the other of |
| // which is an interface. This method |
| // tries to reject a cast by transferring type parameters |
| // from the final class to the interface. |
| boolean reverse = false; |
| Type target = to; |
| if ((to.tsym.flags() & INTERFACE) == 0) { |
| Assert.check((from.tsym.flags() & INTERFACE) != 0); |
| reverse = true; |
| to = from; |
| from = target; |
| } |
| Assert.check((from.tsym.flags() & FINAL) != 0); |
| Type t1 = asSuper(from, to.tsym); |
| if (t1 == null) return false; |
| Type t2 = to; |
| if (disjointTypes(t1.getTypeArguments(), t2.getTypeArguments())) |
| return false; |
| if (!isReifiable(target) && |
| (reverse ? giveWarning(t2, t1) : giveWarning(t1, t2))) |
| warn.warn(LintCategory.UNCHECKED); |
| return true; |
| } |
| |
| private boolean giveWarning(Type from, Type to) { |
| List<Type> bounds = to.isCompound() ? |
| directSupertypes(to) : List.of(to); |
| for (Type b : bounds) { |
| Type subFrom = asSub(from, b.tsym); |
| if (b.isParameterized() && |
| (!(isUnbounded(b) || |
| isSubtype(from, b) || |
| ((subFrom != null) && containsType(b.allparams(), subFrom.allparams()))))) { |
| return true; |
| } |
| } |
| return false; |
| } |
| |
| private List<Type> superClosure(Type t, Type s) { |
| List<Type> cl = List.nil(); |
| for (List<Type> l = interfaces(t); l.nonEmpty(); l = l.tail) { |
| if (isSubtype(s, erasure(l.head))) { |
| cl = insert(cl, l.head); |
| } else { |
| cl = union(cl, superClosure(l.head, s)); |
| } |
| } |
| return cl; |
| } |
| |
| private boolean containsTypeEquivalent(Type t, Type s) { |
| return isSameType(t, s) || // shortcut |
| containsType(t, s) && containsType(s, t); |
| } |
| |
| // <editor-fold defaultstate="collapsed" desc="adapt"> |
| /** |
| * Adapt a type by computing a substitution which maps a source |
| * type to a target type. |
| * |
| * @param source the source type |
| * @param target the target type |
| * @param from the type variables of the computed substitution |
| * @param to the types of the computed substitution. |
| */ |
| public void adapt(Type source, |
| Type target, |
| ListBuffer<Type> from, |
| ListBuffer<Type> to) throws AdaptFailure { |
| new Adapter(from, to).adapt(source, target); |
| } |
| |
| class Adapter extends SimpleVisitor<Void, Type> { |
| |
| ListBuffer<Type> from; |
| ListBuffer<Type> to; |
| Map<Symbol,Type> mapping; |
| |
| Adapter(ListBuffer<Type> from, ListBuffer<Type> to) { |
| this.from = from; |
| this.to = to; |
| mapping = new HashMap<>(); |
| } |
| |
| public void adapt(Type source, Type target) throws AdaptFailure { |
| visit(source, target); |
| List<Type> fromList = from.toList(); |
| List<Type> toList = to.toList(); |
| while (!fromList.isEmpty()) { |
| Type val = mapping.get(fromList.head.tsym); |
| if (toList.head != val) |
| toList.head = val; |
| fromList = fromList.tail; |
| toList = toList.tail; |
| } |
| } |
| |
| @Override |
| public Void visitClassType(ClassType source, Type target) throws AdaptFailure { |
| if (target.hasTag(CLASS)) |
| adaptRecursive(source.allparams(), target.allparams()); |
| return null; |
| } |
| |
| @Override |
| public Void visitArrayType(ArrayType source, Type target) throws AdaptFailure { |
| if (target.hasTag(ARRAY)) |
| adaptRecursive(elemtype(source), elemtype(target)); |
| return null; |
| } |
| |
| @Override |
| public Void visitWildcardType(WildcardType source, Type target) throws AdaptFailure { |
| if (source.isExtendsBound()) |
| adaptRecursive(wildUpperBound(source), wildUpperBound(target)); |
| else if (source.isSuperBound()) |
| adaptRecursive(wildLowerBound(source), wildLowerBound(target)); |
| return null; |
| } |
| |
| @Override |
| public Void visitTypeVar(TypeVar source, Type target) throws AdaptFailure { |
| // Check to see if there is |
| // already a mapping for $source$, in which case |
| // the old mapping will be merged with the new |
| Type val = mapping.get(source.tsym); |
| if (val != null) { |
| if (val.isSuperBound() && target.isSuperBound()) { |
| val = isSubtype(wildLowerBound(val), wildLowerBound(target)) |
| ? target : val; |
| } else if (val.isExtendsBound() && target.isExtendsBound()) { |
| val = isSubtype(wildUpperBound(val), wildUpperBound(target)) |
| ? val : target; |
| } else if (!isSameType(val, target)) { |
| throw new AdaptFailure(); |
| } |
| } else { |
| val = target; |
| from.append(source); |
| to.append(target); |
| } |
| mapping.put(source.tsym, val); |
| return null; |
| } |
| |
| @Override |
| public Void visitType(Type source, Type target) { |
| return null; |
| } |
| |
| private Set<TypePair> cache = new HashSet<>(); |
| |
| private void adaptRecursive(Type source, Type target) { |
| TypePair pair = new TypePair(source, target); |
| if (cache.add(pair)) { |
| try { |
| visit(source, target); |
| } finally { |
| cache.remove(pair); |
| } |
| } |
| } |
| |
| private void adaptRecursive(List<Type> source, List<Type> target) { |
| if (source.length() == target.length()) { |
| while (source.nonEmpty()) { |
| adaptRecursive(source.head, target.head); |
| source = source.tail; |
| target = target.tail; |
| } |
| } |
| } |
| } |
| |
| public static class AdaptFailure extends RuntimeException { |
| static final long serialVersionUID = -7490231548272701566L; |
| } |
| |
| private void adaptSelf(Type t, |
| ListBuffer<Type> from, |
| ListBuffer<Type> to) { |
| try { |
| //if (t.tsym.type != t) |
| adapt(t.tsym.type, t, from, to); |
| } catch (AdaptFailure ex) { |
| // Adapt should never fail calculating a mapping from |
| // t.tsym.type to t as there can be no merge problem. |
| throw new AssertionError(ex); |
| } |
| } |
| // </editor-fold> |
| |
| /** |
| * Rewrite all type variables (universal quantifiers) in the given |
| * type to wildcards (existential quantifiers). This is used to |
| * determine if a cast is allowed. For example, if high is true |
| * and {@code T <: Number}, then {@code List<T>} is rewritten to |
| * {@code List<? extends Number>}. Since {@code List<Integer> <: |
| * List<? extends Number>} a {@code List<T>} can be cast to {@code |
| * List<Integer>} with a warning. |
| * @param t a type |
| * @param high if true return an upper bound; otherwise a lower |
| * bound |
| * @param rewriteTypeVars only rewrite captured wildcards if false; |
| * otherwise rewrite all type variables |
| * @return the type rewritten with wildcards (existential |
| * quantifiers) only |
| */ |
| private Type rewriteQuantifiers(Type t, boolean high, boolean rewriteTypeVars) { |
| return new Rewriter(high, rewriteTypeVars).visit(t); |
| } |
| |
| class Rewriter extends UnaryVisitor<Type> { |
| |
| boolean high; |
| boolean rewriteTypeVars; |
| |
| Rewriter(boolean high, boolean rewriteTypeVars) { |
| this.high = high; |
| this.rewriteTypeVars = rewriteTypeVars; |
| } |
| |
| @Override |
| public Type visitClassType(ClassType t, Void s) { |
| ListBuffer<Type> rewritten = new ListBuffer<>(); |
| boolean changed = false; |
| for (Type arg : t.allparams()) { |
| Type bound = visit(arg); |
| if (arg != bound) { |
| changed = true; |
| } |
| rewritten.append(bound); |
| } |
| if (changed) |
| return subst(t.tsym.type, |
| t.tsym.type.allparams(), |
| rewritten.toList()); |
| else |
| return t; |
| } |
| |
| public Type visitType(Type t, Void s) { |
| return t; |
| } |
| |
| @Override |
| public Type visitCapturedType(CapturedType t, Void s) { |
| Type w_bound = t.wildcard.type; |
| Type bound = w_bound.contains(t) ? |
| erasure(w_bound) : |
| visit(w_bound); |
| return rewriteAsWildcardType(visit(bound), t.wildcard.bound, t.wildcard.kind); |
| } |
| |
| @Override |
| public Type visitTypeVar(TypeVar t, Void s) { |
| if (rewriteTypeVars) { |
| Type bound = t.bound.contains(t) ? |
| erasure(t.bound) : |
| visit(t.bound); |
| return rewriteAsWildcardType(bound, t, EXTENDS); |
| } else { |
| return t; |
| } |
| } |
| |
| @Override |
| public Type visitWildcardType(WildcardType t, Void s) { |
| Type bound2 = visit(t.type); |
| return t.type == bound2 ? t : rewriteAsWildcardType(bound2, t.bound, t.kind); |
| } |
| |
| private Type rewriteAsWildcardType(Type bound, TypeVar formal, BoundKind bk) { |
| switch (bk) { |
| case EXTENDS: return high ? |
| makeExtendsWildcard(B(bound), formal) : |
| makeExtendsWildcard(syms.objectType, formal); |
| case SUPER: return high ? |
| makeSuperWildcard(syms.botType, formal) : |
| makeSuperWildcard(B(bound), formal); |
| case UNBOUND: return makeExtendsWildcard(syms.objectType, formal); |
| default: |
| Assert.error("Invalid bound kind " + bk); |
| return null; |
| } |
| } |
| |
| Type B(Type t) { |
| while (t.hasTag(WILDCARD)) { |
| WildcardType w = (WildcardType)t; |
| t = high ? |
| w.getExtendsBound() : |
| w.getSuperBound(); |
| if (t == null) { |
| t = high ? syms.objectType : syms.botType; |
| } |
| } |
| return t; |
| } |
| } |
| |
| |
| /** |
| * Create a wildcard with the given upper (extends) bound; create |
| * an unbounded wildcard if bound is Object. |
| * |
| * @param bound the upper bound |
| * @param formal the formal type parameter that will be |
| * substituted by the wildcard |
| */ |
| private WildcardType makeExtendsWildcard(Type bound, TypeVar formal) { |
| if (bound == syms.objectType) { |
| return new WildcardType(syms.objectType, |
| BoundKind.UNBOUND, |
| syms.boundClass, |
| formal); |
| } else { |
| return new WildcardType(bound, |
| BoundKind.EXTENDS, |
| syms.boundClass, |
| formal); |
| } |
| } |
| |
| /** |
| * Create a wildcard with the given lower (super) bound; create an |
| * unbounded wildcard if bound is bottom (type of {@code null}). |
| * |
| * @param bound the lower bound |
| * @param formal the formal type parameter that will be |
| * substituted by the wildcard |
| */ |
| private WildcardType makeSuperWildcard(Type bound, TypeVar formal) { |
| if (bound.hasTag(BOT)) { |
| return new WildcardType(syms.objectType, |
| BoundKind.UNBOUND, |
| syms.boundClass, |
| formal); |
| } else { |
| return new WildcardType(bound, |
| BoundKind.SUPER, |
| syms.boundClass, |
| formal); |
| } |
| } |
| |
| /** |
| * A wrapper for a type that allows use in sets. |
| */ |
| public static class UniqueType { |
| public final Type type; |
| final Types types; |
| |
| public UniqueType(Type type, Types types) { |
| this.type = type; |
| this.types = types; |
| } |
| |
| public int hashCode() { |
| return types.hashCode(type); |
| } |
| |
| public boolean equals(Object obj) { |
| return (obj instanceof UniqueType) && |
| types.isSameType(type, ((UniqueType)obj).type); |
| } |
| |
| public String toString() { |
| return type.toString(); |
| } |
| |
| } |
| // </editor-fold> |
| |
| // <editor-fold defaultstate="collapsed" desc="Visitors"> |
| /** |
| * A default visitor for types. All visitor methods except |
| * visitType are implemented by delegating to visitType. Concrete |
| * subclasses must provide an implementation of visitType and can |
| * override other methods as needed. |
| * |
| * @param <R> the return type of the operation implemented by this |
| * visitor; use Void if no return type is needed. |
| * @param <S> the type of the second argument (the first being the |
| * type itself) of the operation implemented by this visitor; use |
| * Void if a second argument is not needed. |
| */ |
| public static abstract class DefaultTypeVisitor<R,S> implements Type.Visitor<R,S> { |
| final public R visit(Type t, S s) { return t.accept(this, s); } |
| public R visitClassType(ClassType t, S s) { return visitType(t, s); } |
| public R visitWildcardType(WildcardType t, S s) { return visitType(t, s); } |
| public R visitArrayType(ArrayType t, S s) { return visitType(t, s); } |
| public R visitMethodType(MethodType t, S s) { return visitType(t, s); } |
| public R visitPackageType(PackageType t, S s) { return visitType(t, s); } |
| public R visitTypeVar(TypeVar t, S s) { return visitType(t, s); } |
| public R visitCapturedType(CapturedType t, S s) { return visitType(t, s); } |
| public R visitForAll(ForAll t, S s) { return visitType(t, s); } |
| public R visitUndetVar(UndetVar t, S s) { return visitType(t, s); } |
| public R visitErrorType(ErrorType t, S s) { return visitType(t, s); } |
| } |
| |
| /** |
| * A default visitor for symbols. All visitor methods except |
| * visitSymbol are implemented by delegating to visitSymbol. Concrete |
| * subclasses must provide an implementation of visitSymbol and can |
| * override other methods as needed. |
| * |
| * @param <R> the return type of the operation implemented by this |
| * visitor; use Void if no return type is needed. |
| * @param <S> the type of the second argument (the first being the |
| * symbol itself) of the operation implemented by this visitor; use |
| * Void if a second argument is not needed. |
| */ |
| public static abstract class DefaultSymbolVisitor<R,S> implements Symbol.Visitor<R,S> { |
| final public R visit(Symbol s, S arg) { return s.accept(this, arg); } |
| public R visitClassSymbol(ClassSymbol s, S arg) { return visitSymbol(s, arg); } |
| public R visitMethodSymbol(MethodSymbol s, S arg) { return visitSymbol(s, arg); } |
| public R visitOperatorSymbol(OperatorSymbol s, S arg) { return visitSymbol(s, arg); } |
| public R visitPackageSymbol(PackageSymbol s, S arg) { return visitSymbol(s, arg); } |
| public R visitTypeSymbol(TypeSymbol s, S arg) { return visitSymbol(s, arg); } |
| public R visitVarSymbol(VarSymbol s, S arg) { return visitSymbol(s, arg); } |
| } |
| |
| /** |
| * A <em>simple</em> visitor for types. This visitor is simple as |
| * captured wildcards, for-all types (generic methods), and |
| * undetermined type variables (part of inference) are hidden. |
| * Captured wildcards are hidden by treating them as type |
| * variables and the rest are hidden by visiting their qtypes. |
| * |
| * @param <R> the return type of the operation implemented by this |
| * visitor; use Void if no return type is needed. |
| * @param <S> the type of the second argument (the first being the |
| * type itself) of the operation implemented by this visitor; use |
| * Void if a second argument is not needed. |
| */ |
| public static abstract class SimpleVisitor<R,S> extends DefaultTypeVisitor<R,S> { |
| @Override |
| public R visitCapturedType(CapturedType t, S s) { |
| return visitTypeVar(t, s); |
| } |
| @Override |
| public R visitForAll(ForAll t, S s) { |
| return visit(t.qtype, s); |
| } |
| @Override |
| public R visitUndetVar(UndetVar t, S s) { |
| return visit(t.qtype, s); |
| } |
| } |
| |
| /** |
| * A plain relation on types. That is a 2-ary function on the |
| * form Type × Type → Boolean. |
| * <!-- In plain text: Type x Type -> Boolean --> |
| */ |
| public static abstract class TypeRelation extends SimpleVisitor<Boolean,Type> {} |
| |
| /** |
| * A convenience visitor for implementing operations that only |
| * require one argument (the type itself), that is, unary |
| * operations. |
| * |
| * @param <R> the return type of the operation implemented by this |
| * visitor; use Void if no return type is needed. |
| */ |
| public static abstract class UnaryVisitor<R> extends SimpleVisitor<R,Void> { |
| final public R visit(Type t) { return t.accept(this, null); } |
| } |
| |
| /** |
| * A visitor for implementing a mapping from types to types. The |
| * default behavior of this class is to implement the identity |
| * mapping (mapping a type to itself). This can be overridden in |
| * subclasses. |
| * |
| * @param <S> the type of the second argument (the first being the |
| * type itself) of this mapping; use Void if a second argument is |
| * not needed. |
| */ |
| public static class MapVisitor<S> extends DefaultTypeVisitor<Type,S> { |
| final public Type visit(Type t) { return t.accept(this, null); } |
| public Type visitType(Type t, S s) { return t; } |
| } |
| // </editor-fold> |
| |
| |
| // <editor-fold defaultstate="collapsed" desc="Annotation support"> |
| |
| public RetentionPolicy getRetention(Attribute.Compound a) { |
| return getRetention(a.type.tsym); |
| } |
| |
| public RetentionPolicy getRetention(TypeSymbol sym) { |
| RetentionPolicy vis = RetentionPolicy.CLASS; // the default |
| Attribute.Compound c = sym.attribute(syms.retentionType.tsym); |
| if (c != null) { |
| Attribute value = c.member(names.value); |
| if (value != null && value instanceof Attribute.Enum) { |
| Name levelName = ((Attribute.Enum)value).value.name; |
| if (levelName == names.SOURCE) vis = RetentionPolicy.SOURCE; |
| else if (levelName == names.CLASS) vis = RetentionPolicy.CLASS; |
| else if (levelName == names.RUNTIME) vis = RetentionPolicy.RUNTIME; |
| else ;// /* fail soft */ throw new AssertionError(levelName); |
| } |
| } |
| return vis; |
| } |
| // </editor-fold> |
| |
| // <editor-fold defaultstate="collapsed" desc="Signature Generation"> |
| |
| public static abstract class SignatureGenerator { |
| |
| private final Types types; |
| |
| protected abstract void append(char ch); |
| protected abstract void append(byte[] ba); |
| protected abstract void append(Name name); |
| protected void classReference(ClassSymbol c) { /* by default: no-op */ } |
| |
| protected SignatureGenerator(Types types) { |
| this.types = types; |
| } |
| |
| /** |
| * Assemble signature of given type in string buffer. |
| */ |
| public void assembleSig(Type type) { |
| switch (type.getTag()) { |
| case BYTE: |
| append('B'); |
| break; |
| case SHORT: |
| append('S'); |
| break; |
| case CHAR: |
| append('C'); |
| break; |
| case INT: |
| append('I'); |
| break; |
| case LONG: |
| append('J'); |
| break; |
| case FLOAT: |
| append('F'); |
| break; |
| case DOUBLE: |
| append('D'); |
| break; |
| case BOOLEAN: |
| append('Z'); |
| break; |
| case VOID: |
| append('V'); |
| break; |
| case CLASS: |
| append('L'); |
| assembleClassSig(type); |
| append(';'); |
| break; |
| case ARRAY: |
| ArrayType at = (ArrayType) type; |
| append('['); |
| assembleSig(at.elemtype); |
| break; |
| case METHOD: |
| MethodType mt = (MethodType) type; |
| append('('); |
| assembleSig(mt.argtypes); |
| append(')'); |
| assembleSig(mt.restype); |
| if (hasTypeVar(mt.thrown)) { |
| for (List<Type> l = mt.thrown; l.nonEmpty(); l = l.tail) { |
| append('^'); |
| assembleSig(l.head); |
| } |
| } |
| break; |
| case WILDCARD: { |
| Type.WildcardType ta = (Type.WildcardType) type; |
| switch (ta.kind) { |
| case SUPER: |
| append('-'); |
| assembleSig(ta.type); |
| break; |
| case EXTENDS: |
| append('+'); |
| assembleSig(ta.type); |
| break; |
| case UNBOUND: |
| append('*'); |
| break; |
| default: |
| throw new AssertionError(ta.kind); |
| } |
| break; |
| } |
| case TYPEVAR: |
| append('T'); |
| append(type.tsym.name); |
| append(';'); |
| break; |
| case FORALL: |
| Type.ForAll ft = (Type.ForAll) type; |
| assembleParamsSig(ft.tvars); |
| assembleSig(ft.qtype); |
| break; |
| default: |
| throw new AssertionError("typeSig " + type.getTag()); |
| } |
| } |
| |
| public boolean hasTypeVar(List<Type> l) { |
| while (l.nonEmpty()) { |
| if (l.head.hasTag(TypeTag.TYPEVAR)) { |
| return true; |
| } |
| l = l.tail; |
| } |
| return false; |
| } |
| |
| public void assembleClassSig(Type type) { |
| ClassType ct = (ClassType) type; |
| ClassSymbol c = (ClassSymbol) ct.tsym; |
| classReference(c); |
| Type outer = ct.getEnclosingType(); |
| if (outer.allparams().nonEmpty()) { |
| boolean rawOuter = |
| c.owner.kind == MTH || // either a local class |
| c.name == types.names.empty; // or anonymous |
| assembleClassSig(rawOuter |
| ? types.erasure(outer) |
| : outer); |
| append(rawOuter ? '$' : '.'); |
| Assert.check(c.flatname.startsWith(c.owner.enclClass().flatname)); |
| append(rawOuter |
| ? c.flatname.subName(c.owner.enclClass().flatname.getByteLength() + 1, c.flatname.getByteLength()) |
| : c.name); |
| } else { |
| append(externalize(c.flatname)); |
| } |
| if (ct.getTypeArguments().nonEmpty()) { |
| append('<'); |
| assembleSig(ct.getTypeArguments()); |
| append('>'); |
| } |
| } |
| |
| public void assembleParamsSig(List<Type> typarams) { |
| append('<'); |
| for (List<Type> ts = typarams; ts.nonEmpty(); ts = ts.tail) { |
| Type.TypeVar tvar = (Type.TypeVar) ts.head; |
| append(tvar.tsym.name); |
| List<Type> bounds = types.getBounds(tvar); |
| if ((bounds.head.tsym.flags() & INTERFACE) != 0) { |
| append(':'); |
| } |
| for (List<Type> l = bounds; l.nonEmpty(); l = l.tail) { |
| append(':'); |
| assembleSig(l.head); |
| } |
| } |
| append('>'); |
| } |
| |
| private void assembleSig(List<Type> types) { |
| for (List<Type> ts = types; ts.nonEmpty(); ts = ts.tail) { |
| assembleSig(ts.head); |
| } |
| } |
| } |
| // </editor-fold> |
| |
| public void newRound() { |
| descCache._map.clear(); |
| isDerivedRawCache.clear(); |
| implCache._map.clear(); |
| membersCache._map.clear(); |
| closureCache.clear(); |
| } |
| } |