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/*
* Copyright (c) 1999, 2017, 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
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package org.openjdk.tools.javac.comp;
import org.openjdk.tools.javac.api.Formattable.LocalizedString;
import org.openjdk.tools.javac.code.*;
import org.openjdk.tools.javac.code.Scope.WriteableScope;
import org.openjdk.tools.javac.code.Symbol.*;
import org.openjdk.tools.javac.code.Type.*;
import org.openjdk.tools.javac.comp.Attr.ResultInfo;
import org.openjdk.tools.javac.comp.Check.CheckContext;
import org.openjdk.tools.javac.comp.DeferredAttr.AttrMode;
import org.openjdk.tools.javac.comp.DeferredAttr.DeferredAttrContext;
import org.openjdk.tools.javac.comp.DeferredAttr.DeferredType;
import org.openjdk.tools.javac.comp.Infer.FreeTypeListener;
import org.openjdk.tools.javac.comp.Resolve.MethodResolutionContext.Candidate;
import org.openjdk.tools.javac.comp.Resolve.MethodResolutionDiagHelper.Template;
import org.openjdk.tools.javac.comp.Resolve.ReferenceLookupResult.StaticKind;
import org.openjdk.tools.javac.jvm.*;
import org.openjdk.tools.javac.main.Option;
import org.openjdk.tools.javac.resources.CompilerProperties.Fragments;
import org.openjdk.tools.javac.tree.*;
import org.openjdk.tools.javac.tree.JCTree.*;
import org.openjdk.tools.javac.tree.JCTree.JCMemberReference.ReferenceKind;
import org.openjdk.tools.javac.tree.JCTree.JCPolyExpression.*;
import org.openjdk.tools.javac.util.*;
import org.openjdk.tools.javac.util.DefinedBy.Api;
import org.openjdk.tools.javac.util.JCDiagnostic.DiagnosticFlag;
import org.openjdk.tools.javac.util.JCDiagnostic.DiagnosticPosition;
import org.openjdk.tools.javac.util.JCDiagnostic.DiagnosticType;
import java.util.Arrays;
import java.util.Collection;
import java.util.EnumSet;
import java.util.HashSet;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.Map;
import java.util.Set;
import java.util.function.BiFunction;
import java.util.function.BiPredicate;
import java.util.function.Function;
import java.util.function.Predicate;
import java.util.stream.Stream;
import javax.lang.model.element.ElementVisitor;
import static org.openjdk.tools.javac.code.Flags.*;
import static org.openjdk.tools.javac.code.Flags.BLOCK;
import static org.openjdk.tools.javac.code.Flags.STATIC;
import static org.openjdk.tools.javac.code.Kinds.*;
import static org.openjdk.tools.javac.code.Kinds.Kind.*;
import static org.openjdk.tools.javac.code.TypeTag.*;
import static org.openjdk.tools.javac.comp.Resolve.MethodResolutionPhase.*;
import static org.openjdk.tools.javac.tree.JCTree.Tag.*;
import static org.openjdk.tools.javac.util.Iterators.createCompoundIterator;
/** Helper class for name resolution, used mostly by the attribution phase.
*
* 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.
*/
public class Resolve {
protected static final Context.Key resolveKey = new Context.Key<>();
Names names;
Log log;
Symtab syms;
Attr attr;
DeferredAttr deferredAttr;
Check chk;
Infer infer;
ClassFinder finder;
ModuleFinder moduleFinder;
Types types;
JCDiagnostic.Factory diags;
public final boolean allowMethodHandles;
public final boolean allowFunctionalInterfaceMostSpecific;
public final boolean allowModules;
public final boolean checkVarargsAccessAfterResolution;
private final boolean compactMethodDiags;
final EnumSet verboseResolutionMode;
WriteableScope polymorphicSignatureScope;
protected Resolve(Context context) {
context.put(resolveKey, this);
syms = Symtab.instance(context);
varNotFound = new SymbolNotFoundError(ABSENT_VAR);
methodNotFound = new SymbolNotFoundError(ABSENT_MTH);
typeNotFound = new SymbolNotFoundError(ABSENT_TYP);
referenceNotFound = new ReferenceLookupResult(methodNotFound, null);
names = Names.instance(context);
log = Log.instance(context);
attr = Attr.instance(context);
deferredAttr = DeferredAttr.instance(context);
chk = Check.instance(context);
infer = Infer.instance(context);
finder = ClassFinder.instance(context);
moduleFinder = ModuleFinder.instance(context);
types = Types.instance(context);
diags = JCDiagnostic.Factory.instance(context);
Source source = Source.instance(context);
Options options = Options.instance(context);
compactMethodDiags = options.isSet(Option.XDIAGS, "compact") ||
options.isUnset(Option.XDIAGS) && options.isUnset("rawDiagnostics");
verboseResolutionMode = VerboseResolutionMode.getVerboseResolutionMode(options);
Target target = Target.instance(context);
allowMethodHandles = target.hasMethodHandles();
allowFunctionalInterfaceMostSpecific = source.allowFunctionalInterfaceMostSpecific();
checkVarargsAccessAfterResolution =
source.allowPostApplicabilityVarargsAccessCheck();
polymorphicSignatureScope = WriteableScope.create(syms.noSymbol);
inapplicableMethodException = new InapplicableMethodException(diags);
allowModules = source.allowModules();
}
/** error symbols, which are returned when resolution fails
*/
private final SymbolNotFoundError varNotFound;
private final SymbolNotFoundError methodNotFound;
private final SymbolNotFoundError typeNotFound;
/** empty reference lookup result */
private final ReferenceLookupResult referenceNotFound;
public static Resolve instance(Context context) {
Resolve instance = context.get(resolveKey);
if (instance == null)
instance = new Resolve(context);
return instance;
}
private static Symbol bestOf(Symbol s1,
Symbol s2) {
return s1.kind.betterThan(s2.kind) ? s1 : s2;
}
//
enum VerboseResolutionMode {
SUCCESS("success"),
FAILURE("failure"),
APPLICABLE("applicable"),
INAPPLICABLE("inapplicable"),
DEFERRED_INST("deferred-inference"),
PREDEF("predef"),
OBJECT_INIT("object-init"),
INTERNAL("internal");
final String opt;
private VerboseResolutionMode(String opt) {
this.opt = opt;
}
static EnumSet getVerboseResolutionMode(Options opts) {
String s = opts.get("debug.verboseResolution");
EnumSet res = EnumSet.noneOf(VerboseResolutionMode.class);
if (s == null) return res;
if (s.contains("all")) {
res = EnumSet.allOf(VerboseResolutionMode.class);
}
Collection args = Arrays.asList(s.split(","));
for (VerboseResolutionMode mode : values()) {
if (args.contains(mode.opt)) {
res.add(mode);
} else if (args.contains("-" + mode.opt)) {
res.remove(mode);
}
}
return res;
}
}
void reportVerboseResolutionDiagnostic(DiagnosticPosition dpos, Name name, Type site,
List argtypes, List typeargtypes, Symbol bestSoFar) {
boolean success = !bestSoFar.kind.isResolutionError();
if (success && !verboseResolutionMode.contains(VerboseResolutionMode.SUCCESS)) {
return;
} else if (!success && !verboseResolutionMode.contains(VerboseResolutionMode.FAILURE)) {
return;
}
if (bestSoFar.name == names.init &&
bestSoFar.owner == syms.objectType.tsym &&
!verboseResolutionMode.contains(VerboseResolutionMode.OBJECT_INIT)) {
return; //skip diags for Object constructor resolution
} else if (site == syms.predefClass.type &&
!verboseResolutionMode.contains(VerboseResolutionMode.PREDEF)) {
return; //skip spurious diags for predef symbols (i.e. operators)
} else if (currentResolutionContext.internalResolution &&
!verboseResolutionMode.contains(VerboseResolutionMode.INTERNAL)) {
return;
}
int pos = 0;
int mostSpecificPos = -1;
ListBuffer subDiags = new ListBuffer<>();
for (Candidate c : currentResolutionContext.candidates) {
if (currentResolutionContext.step != c.step ||
(c.isApplicable() && !verboseResolutionMode.contains(VerboseResolutionMode.APPLICABLE)) ||
(!c.isApplicable() && !verboseResolutionMode.contains(VerboseResolutionMode.INAPPLICABLE))) {
continue;
} else {
subDiags.append(c.isApplicable() ?
getVerboseApplicableCandidateDiag(pos, c.sym, c.mtype) :
getVerboseInapplicableCandidateDiag(pos, c.sym, c.details));
if (c.sym == bestSoFar)
mostSpecificPos = pos;
pos++;
}
}
String key = success ? "verbose.resolve.multi" : "verbose.resolve.multi.1";
List argtypes2 = argtypes.map(deferredAttr.new RecoveryDeferredTypeMap(AttrMode.SPECULATIVE, bestSoFar, currentResolutionContext.step));
JCDiagnostic main = diags.note(log.currentSource(), dpos, key, name,
site.tsym, mostSpecificPos, currentResolutionContext.step,
methodArguments(argtypes2),
methodArguments(typeargtypes));
JCDiagnostic d = new JCDiagnostic.MultilineDiagnostic(main, subDiags.toList());
log.report(d);
}
JCDiagnostic getVerboseApplicableCandidateDiag(int pos, Symbol sym, Type inst) {
JCDiagnostic subDiag = null;
if (sym.type.hasTag(FORALL)) {
subDiag = diags.fragment("partial.inst.sig", inst);
}
String key = subDiag == null ?
"applicable.method.found" :
"applicable.method.found.1";
return diags.fragment(key, pos, sym, subDiag);
}
JCDiagnostic getVerboseInapplicableCandidateDiag(int pos, Symbol sym, JCDiagnostic subDiag) {
return diags.fragment("not.applicable.method.found", pos, sym, subDiag);
}
//
/* ************************************************************************
* Identifier resolution
*************************************************************************/
/** An environment is "static" if its static level is greater than
* the one of its outer environment
*/
protected static boolean isStatic(Env env) {
return env.outer != null && env.info.staticLevel > env.outer.info.staticLevel;
}
/** An environment is an "initializer" if it is a constructor or
* an instance initializer.
*/
static boolean isInitializer(Env env) {
Symbol owner = env.info.scope.owner;
return owner.isConstructor() ||
owner.owner.kind == TYP &&
(owner.kind == VAR ||
owner.kind == MTH && (owner.flags() & BLOCK) != 0) &&
(owner.flags() & STATIC) == 0;
}
/** Is class accessible in given evironment?
* @param env The current environment.
* @param c The class whose accessibility is checked.
*/
public boolean isAccessible(Env env, TypeSymbol c) {
return isAccessible(env, c, false);
}
public boolean isAccessible(Env env, TypeSymbol c, boolean checkInner) {
/* 15.9.5.1: Note that it is possible for the signature of the anonymous constructor
to refer to an inaccessible type
*/
if (env.enclMethod != null && (env.enclMethod.mods.flags & ANONCONSTR) != 0)
return true;
if (env.info.visitingServiceImplementation &&
env.toplevel.modle == c.packge().modle) {
return true;
}
boolean isAccessible = false;
switch ((short)(c.flags() & AccessFlags)) {
case PRIVATE:
isAccessible =
env.enclClass.sym.outermostClass() ==
c.owner.outermostClass();
break;
case 0:
isAccessible =
env.toplevel.packge == c.owner // fast special case
||
env.toplevel.packge == c.packge();
break;
default: // error recovery
isAccessible = true;
break;
case PUBLIC:
if (allowModules) {
ModuleSymbol currModule = env.toplevel.modle;
currModule.complete();
PackageSymbol p = c.packge();
isAccessible =
(currModule == p.modle) || currModule.visiblePackages.get(p.fullname) == p || p == syms.rootPackage;
} else {
isAccessible = true;
}
break;
case PROTECTED:
isAccessible =
env.toplevel.packge == c.owner // fast special case
||
env.toplevel.packge == c.packge()
||
isInnerSubClass(env.enclClass.sym, c.owner);
break;
}
return (checkInner == false || c.type.getEnclosingType() == Type.noType) ?
isAccessible :
isAccessible && isAccessible(env, c.type.getEnclosingType(), checkInner);
}
//where
/** Is given class a subclass of given base class, or an inner class
* of a subclass?
* Return null if no such class exists.
* @param c The class which is the subclass or is contained in it.
* @param base The base class
*/
private boolean isInnerSubClass(ClassSymbol c, Symbol base) {
while (c != null && !c.isSubClass(base, types)) {
c = c.owner.enclClass();
}
return c != null;
}
boolean isAccessible(Env env, Type t) {
return isAccessible(env, t, false);
}
boolean isAccessible(Env env, Type t, boolean checkInner) {
return (t.hasTag(ARRAY))
? isAccessible(env, types.cvarUpperBound(types.elemtype(t)))
: isAccessible(env, t.tsym, checkInner);
}
/** Is symbol accessible as a member of given type in given environment?
* @param env The current environment.
* @param site The type of which the tested symbol is regarded
* as a member.
* @param sym The symbol.
*/
public boolean isAccessible(Env env, Type site, Symbol sym) {
return isAccessible(env, site, sym, false);
}
public boolean isAccessible(Env env, Type site, Symbol sym, boolean checkInner) {
if (sym.name == names.init && sym.owner != site.tsym) return false;
/* 15.9.5.1: Note that it is possible for the signature of the anonymous constructor
to refer to an inaccessible type
*/
if (env.enclMethod != null && (env.enclMethod.mods.flags & ANONCONSTR) != 0)
return true;
if (env.info.visitingServiceImplementation &&
env.toplevel.modle == sym.packge().modle) {
return true;
}
switch ((short)(sym.flags() & AccessFlags)) {
case PRIVATE:
return
(env.enclClass.sym == sym.owner // fast special case
||
env.enclClass.sym.outermostClass() ==
sym.owner.outermostClass())
&&
sym.isInheritedIn(site.tsym, types);
case 0:
return
(env.toplevel.packge == sym.owner.owner // fast special case
||
env.toplevel.packge == sym.packge())
&&
isAccessible(env, site, checkInner)
&&
sym.isInheritedIn(site.tsym, types)
&&
notOverriddenIn(site, sym);
case PROTECTED:
return
(env.toplevel.packge == sym.owner.owner // fast special case
||
env.toplevel.packge == sym.packge()
||
isProtectedAccessible(sym, env.enclClass.sym, site)
||
// OK to select instance method or field from 'super' or type name
// (but type names should be disallowed elsewhere!)
env.info.selectSuper && (sym.flags() & STATIC) == 0 && sym.kind != TYP)
&&
isAccessible(env, site, checkInner)
&&
notOverriddenIn(site, sym);
default: // this case includes erroneous combinations as well
return isAccessible(env, site, checkInner) && notOverriddenIn(site, sym);
}
}
//where
/* `sym' is accessible only if not overridden by
* another symbol which is a member of `site'
* (because, if it is overridden, `sym' is not strictly
* speaking a member of `site'). A polymorphic signature method
* cannot be overridden (e.g. MH.invokeExact(Object[])).
*/
private boolean notOverriddenIn(Type site, Symbol sym) {
if (sym.kind != MTH || sym.isConstructor() || sym.isStatic())
return true;
else {
Symbol s2 = ((MethodSymbol)sym).implementation(site.tsym, types, true);
return (s2 == null || s2 == sym || sym.owner == s2.owner ||
!types.isSubSignature(types.memberType(site, s2), types.memberType(site, sym)));
}
}
//where
/** Is given protected symbol accessible if it is selected from given site
* and the selection takes place in given class?
* @param sym The symbol with protected access
* @param c The class where the access takes place
* @site The type of the qualifier
*/
private
boolean isProtectedAccessible(Symbol sym, ClassSymbol c, Type site) {
Type newSite = site.hasTag(TYPEVAR) ? site.getUpperBound() : site;
while (c != null &&
!(c.isSubClass(sym.owner, types) &&
(c.flags() & INTERFACE) == 0 &&
// In JLS 2e 6.6.2.1, the subclass restriction applies
// only to instance fields and methods -- types are excluded
// regardless of whether they are declared 'static' or not.
((sym.flags() & STATIC) != 0 || sym.kind == TYP || newSite.tsym.isSubClass(c, types))))
c = c.owner.enclClass();
return c != null;
}
/**
* Performs a recursive scan of a type looking for accessibility problems
* from current attribution environment
*/
void checkAccessibleType(Env env, Type t) {
accessibilityChecker.visit(t, env);
}
/**
* Accessibility type-visitor
*/
Types.SimpleVisitor> accessibilityChecker =
new Types.SimpleVisitor>() {
void visit(List ts, Env env) {
for (Type t : ts) {
visit(t, env);
}
}
public Void visitType(Type t, Env env) {
return null;
}
@Override
public Void visitArrayType(ArrayType t, Env env) {
visit(t.elemtype, env);
return null;
}
@Override
public Void visitClassType(ClassType t, Env env) {
visit(t.getTypeArguments(), env);
if (!isAccessible(env, t, true)) {
accessBase(new AccessError(env, null, t.tsym), env.tree.pos(), env.enclClass.sym, t, t.tsym.name, true);
}
return null;
}
@Override
public Void visitWildcardType(WildcardType t, Env env) {
visit(t.type, env);
return null;
}
@Override
public Void visitMethodType(MethodType t, Env env) {
visit(t.getParameterTypes(), env);
visit(t.getReturnType(), env);
visit(t.getThrownTypes(), env);
return null;
}
};
/** Try to instantiate the type of a method so that it fits
* given type arguments and argument types. If successful, return
* the method's instantiated type, else return null.
* The instantiation will take into account an additional leading
* formal parameter if the method is an instance method seen as a member
* of an under determined site. In this case, we treat site as an additional
* parameter and the parameters of the class containing the method as
* additional type variables that get instantiated.
*
* @param env The current environment
* @param site The type of which the method is a member.
* @param m The method symbol.
* @param argtypes The invocation's given value arguments.
* @param typeargtypes The invocation's given type arguments.
* @param allowBoxing Allow boxing conversions of arguments.
* @param useVarargs Box trailing arguments into an array for varargs.
*/
Type rawInstantiate(Env env,
Type site,
Symbol m,
ResultInfo resultInfo,
List argtypes,
List typeargtypes,
boolean allowBoxing,
boolean useVarargs,
Warner warn) throws Infer.InferenceException {
Type mt = types.memberType(site, m);
// tvars is the list of formal type variables for which type arguments
// need to inferred.
List tvars = List.nil();
if (typeargtypes == null) typeargtypes = List.nil();
if (!mt.hasTag(FORALL) && typeargtypes.nonEmpty()) {
// This is not a polymorphic method, but typeargs are supplied
// which is fine, see JLS 15.12.2.1
} else if (mt.hasTag(FORALL) && typeargtypes.nonEmpty()) {
ForAll pmt = (ForAll) mt;
if (typeargtypes.length() != pmt.tvars.length())
// not enough args
throw inapplicableMethodException.setMessage("wrong.number.type.args", Integer.toString(pmt.tvars.length()));
// Check type arguments are within bounds
List formals = pmt.tvars;
List actuals = typeargtypes;
while (formals.nonEmpty() && actuals.nonEmpty()) {
List bounds = types.subst(types.getBounds((TypeVar)formals.head),
pmt.tvars, typeargtypes);
for (; bounds.nonEmpty(); bounds = bounds.tail) {
if (!types.isSubtypeUnchecked(actuals.head, bounds.head, warn))
throw inapplicableMethodException.setMessage("explicit.param.do.not.conform.to.bounds",actuals.head, bounds);
}
formals = formals.tail;
actuals = actuals.tail;
}
mt = types.subst(pmt.qtype, pmt.tvars, typeargtypes);
} else if (mt.hasTag(FORALL)) {
ForAll pmt = (ForAll) mt;
List tvars1 = types.newInstances(pmt.tvars);
tvars = tvars.appendList(tvars1);
mt = types.subst(pmt.qtype, pmt.tvars, tvars1);
}
// find out whether we need to go the slow route via infer
boolean instNeeded = tvars.tail != null; /*inlined: tvars.nonEmpty()*/
for (List l = argtypes;
l.tail != null/*inlined: l.nonEmpty()*/ && !instNeeded;
l = l.tail) {
if (l.head.hasTag(FORALL)) instNeeded = true;
}
if (instNeeded) {
return infer.instantiateMethod(env,
tvars,
(MethodType)mt,
resultInfo,
(MethodSymbol)m,
argtypes,
allowBoxing,
useVarargs,
currentResolutionContext,
warn);
}
DeferredAttr.DeferredAttrContext dc = currentResolutionContext.deferredAttrContext(m, infer.emptyContext, resultInfo, warn);
currentResolutionContext.methodCheck.argumentsAcceptable(env, dc,
argtypes, mt.getParameterTypes(), warn);
dc.complete();
return mt;
}
Type checkMethod(Env env,
Type site,
Symbol m,
ResultInfo resultInfo,
List argtypes,
List typeargtypes,
Warner warn) {
MethodResolutionContext prevContext = currentResolutionContext;
try {
currentResolutionContext = new MethodResolutionContext();
currentResolutionContext.attrMode = (resultInfo.pt == Infer.anyPoly) ?
AttrMode.SPECULATIVE : DeferredAttr.AttrMode.CHECK;
if (env.tree.hasTag(JCTree.Tag.REFERENCE)) {
//method/constructor references need special check class
//to handle inference variables in 'argtypes' (might happen
//during an unsticking round)
currentResolutionContext.methodCheck =
new MethodReferenceCheck(resultInfo.checkContext.inferenceContext());
}
MethodResolutionPhase step = currentResolutionContext.step = env.info.pendingResolutionPhase;
return rawInstantiate(env, site, m, resultInfo, argtypes, typeargtypes,
step.isBoxingRequired(), step.isVarargsRequired(), warn);
}
finally {
currentResolutionContext = prevContext;
}
}
/** Same but returns null instead throwing a NoInstanceException
*/
Type instantiate(Env env,
Type site,
Symbol m,
ResultInfo resultInfo,
List argtypes,
List typeargtypes,
boolean allowBoxing,
boolean useVarargs,
Warner warn) {
try {
return rawInstantiate(env, site, m, resultInfo, argtypes, typeargtypes,
allowBoxing, useVarargs, warn);
} catch (InapplicableMethodException ex) {
return null;
}
}
/**
* This interface defines an entry point that should be used to perform a
* method check. A method check usually consist in determining as to whether
* a set of types (actuals) is compatible with another set of types (formals).
* Since the notion of compatibility can vary depending on the circumstances,
* this interfaces allows to easily add new pluggable method check routines.
*/
interface MethodCheck {
/**
* Main method check routine. A method check usually consist in determining
* as to whether a set of types (actuals) is compatible with another set of
* types (formals). If an incompatibility is found, an unchecked exception
* is assumed to be thrown.
*/
void argumentsAcceptable(Env env,
DeferredAttrContext deferredAttrContext,
List argtypes,
List formals,
Warner warn);
/**
* Retrieve the method check object that will be used during a
* most specific check.
*/
MethodCheck mostSpecificCheck(List actuals);
}
/**
* Helper enum defining all method check diagnostics (used by resolveMethodCheck).
*/
enum MethodCheckDiag {
/**
* Actuals and formals differs in length.
*/
ARITY_MISMATCH("arg.length.mismatch", "infer.arg.length.mismatch"),
/**
* An actual is incompatible with a formal.
*/
ARG_MISMATCH("no.conforming.assignment.exists", "infer.no.conforming.assignment.exists"),
/**
* An actual is incompatible with the varargs element type.
*/
VARARG_MISMATCH("varargs.argument.mismatch", "infer.varargs.argument.mismatch"),
/**
* The varargs element type is inaccessible.
*/
INACCESSIBLE_VARARGS("inaccessible.varargs.type", "inaccessible.varargs.type");
final String basicKey;
final String inferKey;
MethodCheckDiag(String basicKey, String inferKey) {
this.basicKey = basicKey;
this.inferKey = inferKey;
}
String regex() {
return String.format("([a-z]*\\.)*(%s|%s)", basicKey, inferKey);
}
}
/**
* Dummy method check object. All methods are deemed applicable, regardless
* of their formal parameter types.
*/
MethodCheck nilMethodCheck = new MethodCheck() {
public void argumentsAcceptable(Env env, DeferredAttrContext deferredAttrContext, List argtypes, List formals, Warner warn) {
//do nothing - method always applicable regardless of actuals
}
public MethodCheck mostSpecificCheck(List actuals) {
return this;
}
};
/**
* Base class for 'real' method checks. The class defines the logic for
* iterating through formals and actuals and provides and entry point
* that can be used by subclasses in order to define the actual check logic.
*/
abstract class AbstractMethodCheck implements MethodCheck {
@Override
public void argumentsAcceptable(final Env env,
DeferredAttrContext deferredAttrContext,
List argtypes,
List formals,
Warner warn) {
//should we expand formals?
boolean useVarargs = deferredAttrContext.phase.isVarargsRequired();
JCTree callTree = treeForDiagnostics(env);
List trees = TreeInfo.args(callTree);
//inference context used during this method check
InferenceContext inferenceContext = deferredAttrContext.inferenceContext;
Type varargsFormal = useVarargs ? formals.last() : null;
if (varargsFormal == null &&
argtypes.size() != formals.size()) {
reportMC(callTree, MethodCheckDiag.ARITY_MISMATCH, inferenceContext); // not enough args
}
while (argtypes.nonEmpty() && formals.head != varargsFormal) {
DiagnosticPosition pos = trees != null ? trees.head : null;
checkArg(pos, false, argtypes.head, formals.head, deferredAttrContext, warn);
argtypes = argtypes.tail;
formals = formals.tail;
trees = trees != null ? trees.tail : trees;
}
if (formals.head != varargsFormal) {
reportMC(callTree, MethodCheckDiag.ARITY_MISMATCH, inferenceContext); // not enough args
}
if (useVarargs) {
//note: if applicability check is triggered by most specific test,
//the last argument of a varargs is _not_ an array type (see JLS 15.12.2.5)
final Type elt = types.elemtype(varargsFormal);
while (argtypes.nonEmpty()) {
DiagnosticPosition pos = trees != null ? trees.head : null;
checkArg(pos, true, argtypes.head, elt, deferredAttrContext, warn);
argtypes = argtypes.tail;
trees = trees != null ? trees.tail : trees;
}
}
}
// where
private JCTree treeForDiagnostics(Env env) {
return env.info.preferredTreeForDiagnostics != null ? env.info.preferredTreeForDiagnostics : env.tree;
}
/**
* Does the actual argument conforms to the corresponding formal?
*/
abstract void checkArg(DiagnosticPosition pos, boolean varargs, Type actual, Type formal, DeferredAttrContext deferredAttrContext, Warner warn);
protected void reportMC(DiagnosticPosition pos, MethodCheckDiag diag, InferenceContext inferenceContext, Object... args) {
boolean inferDiag = inferenceContext != infer.emptyContext;
InapplicableMethodException ex = inferDiag ?
infer.inferenceException : inapplicableMethodException;
if (inferDiag && (!diag.inferKey.equals(diag.basicKey))) {
Object[] args2 = new Object[args.length + 1];
System.arraycopy(args, 0, args2, 1, args.length);
args2[0] = inferenceContext.inferenceVars();
args = args2;
}
String key = inferDiag ? diag.inferKey : diag.basicKey;
throw ex.setMessage(diags.create(DiagnosticType.FRAGMENT, log.currentSource(), pos, key, args));
}
public MethodCheck mostSpecificCheck(List actuals) {
return nilMethodCheck;
}
}
/**
* Arity-based method check. A method is applicable if the number of actuals
* supplied conforms to the method signature.
*/
MethodCheck arityMethodCheck = new AbstractMethodCheck() {
@Override
void checkArg(DiagnosticPosition pos, boolean varargs, Type actual, Type formal, DeferredAttrContext deferredAttrContext, Warner warn) {
//do nothing - actual always compatible to formals
}
@Override
public String toString() {
return "arityMethodCheck";
}
};
List dummyArgs(int length) {
ListBuffer buf = new ListBuffer<>();
for (int i = 0 ; i < length ; i++) {
buf.append(Type.noType);
}
return buf.toList();
}
/**
* Main method applicability routine. Given a list of actual types A,
* a list of formal types F, determines whether the types in A are
* compatible (by method invocation conversion) with the types in F.
*
* Since this routine is shared between overload resolution and method
* type-inference, a (possibly empty) inference context is used to convert
* formal types to the corresponding 'undet' form ahead of a compatibility
* check so that constraints can be propagated and collected.
*
* Moreover, if one or more types in A is a deferred type, this routine uses
* DeferredAttr in order to perform deferred attribution. If one or more actual
* deferred types are stuck, they are placed in a queue and revisited later
* after the remainder of the arguments have been seen. If this is not sufficient
* to 'unstuck' the argument, a cyclic inference error is called out.
*
* A method check handler (see above) is used in order to report errors.
*/
MethodCheck resolveMethodCheck = new AbstractMethodCheck() {
@Override
void checkArg(DiagnosticPosition pos, boolean varargs, Type actual, Type formal, DeferredAttrContext deferredAttrContext, Warner warn) {
ResultInfo mresult = methodCheckResult(varargs, formal, deferredAttrContext, warn);
mresult.check(pos, actual);
}
@Override
public void argumentsAcceptable(final Env env,
DeferredAttrContext deferredAttrContext,
List argtypes,
List formals,
Warner warn) {
super.argumentsAcceptable(env, deferredAttrContext, argtypes, formals, warn);
// should we check varargs element type accessibility?
if (deferredAttrContext.phase.isVarargsRequired()) {
if (deferredAttrContext.mode == AttrMode.CHECK || !checkVarargsAccessAfterResolution) {
varargsAccessible(env, types.elemtype(formals.last()), deferredAttrContext.inferenceContext);
}
}
}
/**
* Test that the runtime array element type corresponding to 't' is accessible. 't' should be the
* varargs element type of either the method invocation type signature (after inference completes)
* or the method declaration signature (before inference completes).
*/
private void varargsAccessible(final Env env, final Type t, final InferenceContext inferenceContext) {
if (inferenceContext.free(t)) {
inferenceContext.addFreeTypeListener(List.of(t),
solvedContext -> varargsAccessible(env, solvedContext.asInstType(t), solvedContext));
} else {
if (!isAccessible(env, types.erasure(t))) {
Symbol location = env.enclClass.sym;
reportMC(env.tree, MethodCheckDiag.INACCESSIBLE_VARARGS, inferenceContext, t, Kinds.kindName(location), location);
}
}
}
private ResultInfo methodCheckResult(final boolean varargsCheck, Type to,
final DeferredAttr.DeferredAttrContext deferredAttrContext, Warner rsWarner) {
CheckContext checkContext = new MethodCheckContext(!deferredAttrContext.phase.isBoxingRequired(), deferredAttrContext, rsWarner) {
MethodCheckDiag methodDiag = varargsCheck ?
MethodCheckDiag.VARARG_MISMATCH : MethodCheckDiag.ARG_MISMATCH;
@Override
public void report(DiagnosticPosition pos, JCDiagnostic details) {
reportMC(pos, methodDiag, deferredAttrContext.inferenceContext, details);
}
};
return new MethodResultInfo(to, checkContext);
}
@Override
public MethodCheck mostSpecificCheck(List actuals) {
return new MostSpecificCheck(actuals);
}
@Override
public String toString() {
return "resolveMethodCheck";
}
};
/**
* This class handles method reference applicability checks; since during
* these checks it's sometime possible to have inference variables on
* the actual argument types list, the method applicability check must be
* extended so that inference variables are 'opened' as needed.
*/
class MethodReferenceCheck extends AbstractMethodCheck {
InferenceContext pendingInferenceContext;
MethodReferenceCheck(InferenceContext pendingInferenceContext) {
this.pendingInferenceContext = pendingInferenceContext;
}
@Override
void checkArg(DiagnosticPosition pos, boolean varargs, Type actual, Type formal, DeferredAttrContext deferredAttrContext, Warner warn) {
ResultInfo mresult = methodCheckResult(varargs, formal, deferredAttrContext, warn);
mresult.check(pos, actual);
}
private ResultInfo methodCheckResult(final boolean varargsCheck, Type to,
final DeferredAttr.DeferredAttrContext deferredAttrContext, Warner rsWarner) {
CheckContext checkContext = new MethodCheckContext(!deferredAttrContext.phase.isBoxingRequired(), deferredAttrContext, rsWarner) {
MethodCheckDiag methodDiag = varargsCheck ?
MethodCheckDiag.VARARG_MISMATCH : MethodCheckDiag.ARG_MISMATCH;
@Override
public boolean compatible(Type found, Type req, Warner warn) {
found = pendingInferenceContext.asUndetVar(found);
if (found.hasTag(UNDETVAR) && req.isPrimitive()) {
req = types.boxedClass(req).type;
}
return super.compatible(found, req, warn);
}
@Override
public void report(DiagnosticPosition pos, JCDiagnostic details) {
reportMC(pos, methodDiag, deferredAttrContext.inferenceContext, details);
}
};
return new MethodResultInfo(to, checkContext);
}
@Override
public MethodCheck mostSpecificCheck(List actuals) {
return new MostSpecificCheck(actuals);
}
@Override
public String toString() {
return "MethodReferenceCheck";
}
}
/**
* Check context to be used during method applicability checks. A method check
* context might contain inference variables.
*/
abstract class MethodCheckContext implements CheckContext {
boolean strict;
DeferredAttrContext deferredAttrContext;
Warner rsWarner;
public MethodCheckContext(boolean strict, DeferredAttrContext deferredAttrContext, Warner rsWarner) {
this.strict = strict;
this.deferredAttrContext = deferredAttrContext;
this.rsWarner = rsWarner;
}
public boolean compatible(Type found, Type req, Warner warn) {
InferenceContext inferenceContext = deferredAttrContext.inferenceContext;
return strict ?
types.isSubtypeUnchecked(inferenceContext.asUndetVar(found), inferenceContext.asUndetVar(req), warn) :
types.isConvertible(inferenceContext.asUndetVar(found), inferenceContext.asUndetVar(req), warn);
}
public void report(DiagnosticPosition pos, JCDiagnostic details) {
throw inapplicableMethodException.setMessage(details);
}
public Warner checkWarner(DiagnosticPosition pos, Type found, Type req) {
return rsWarner;
}
public InferenceContext inferenceContext() {
return deferredAttrContext.inferenceContext;
}
public DeferredAttrContext deferredAttrContext() {
return deferredAttrContext;
}
@Override
public String toString() {
return "MethodCheckContext";
}
}
/**
* ResultInfo class to be used during method applicability checks. Check
* for deferred types goes through special path.
*/
class MethodResultInfo extends ResultInfo {
public MethodResultInfo(Type pt, CheckContext checkContext) {
attr.super(KindSelector.VAL, pt, checkContext);
}
@Override
protected Type check(DiagnosticPosition pos, Type found) {
if (found.hasTag(DEFERRED)) {
DeferredType dt = (DeferredType)found;
return dt.check(this);
} else {
Type uResult = U(found);
Type capturedType = pos == null || pos.getTree() == null ?
types.capture(uResult) :
checkContext.inferenceContext()
.cachedCapture(pos.getTree(), uResult, true);
return super.check(pos, chk.checkNonVoid(pos, capturedType));
}
}
/**
* javac has a long-standing 'simplification' (see 6391995):
* given an actual argument type, the method check is performed
* on its upper bound. This leads to inconsistencies when an
* argument type is checked against itself. For example, given
* a type-variable T, it is not true that {@code U(T) <: T},
* so we need to guard against that.
*/
private Type U(Type found) {
return found == pt ?
found : types.cvarUpperBound(found);
}
@Override
protected MethodResultInfo dup(Type newPt) {
return new MethodResultInfo(newPt, checkContext);
}
@Override
protected ResultInfo dup(CheckContext newContext) {
return new MethodResultInfo(pt, newContext);
}
@Override
protected ResultInfo dup(Type newPt, CheckContext newContext) {
return new MethodResultInfo(newPt, newContext);
}
}
/**
* Most specific method applicability routine. Given a list of actual types A,
* a list of formal types F1, and a list of formal types F2, the routine determines
* as to whether the types in F1 can be considered more specific than those in F2 w.r.t.
* argument types A.
*/
class MostSpecificCheck implements MethodCheck {
List actuals;
MostSpecificCheck(List actuals) {
this.actuals = actuals;
}
@Override
public void argumentsAcceptable(final Env env,
DeferredAttrContext deferredAttrContext,
List formals1,
List formals2,
Warner warn) {
formals2 = adjustArgs(formals2, deferredAttrContext.msym, formals1.length(), deferredAttrContext.phase.isVarargsRequired());
while (formals2.nonEmpty()) {
ResultInfo mresult = methodCheckResult(formals2.head, deferredAttrContext, warn, actuals.head);
mresult.check(null, formals1.head);
formals1 = formals1.tail;
formals2 = formals2.tail;
actuals = actuals.isEmpty() ? actuals : actuals.tail;
}
}
/**
* Create a method check context to be used during the most specific applicability check
*/
ResultInfo methodCheckResult(Type to, DeferredAttr.DeferredAttrContext deferredAttrContext,
Warner rsWarner, Type actual) {
return attr.new ResultInfo(KindSelector.VAL, to,
new MostSpecificCheckContext(deferredAttrContext, rsWarner, actual));
}
/**
* Subclass of method check context class that implements most specific
* method conversion. If the actual type under analysis is a deferred type
* a full blown structural analysis is carried out.
*/
class MostSpecificCheckContext extends MethodCheckContext {
Type actual;
public MostSpecificCheckContext(DeferredAttrContext deferredAttrContext, Warner rsWarner, Type actual) {
super(true, deferredAttrContext, rsWarner);
this.actual = actual;
}
public boolean compatible(Type found, Type req, Warner warn) {
if (allowFunctionalInterfaceMostSpecific &&
unrelatedFunctionalInterfaces(found, req) &&
(actual != null && actual.getTag() == DEFERRED)) {
DeferredType dt = (DeferredType) actual;
JCTree speculativeTree = dt.speculativeTree(deferredAttrContext);
if (speculativeTree != deferredAttr.stuckTree) {
return functionalInterfaceMostSpecific(found, req, speculativeTree);
}
}
return compatibleBySubtyping(found, req);
}
private boolean compatibleBySubtyping(Type found, Type req) {
if (!strict && found.isPrimitive() != req.isPrimitive()) {
found = found.isPrimitive() ? types.boxedClass(found).type : types.unboxedType(found);
}
return types.isSubtypeNoCapture(found, deferredAttrContext.inferenceContext.asUndetVar(req));
}
/** Whether {@code t} and {@code s} are unrelated functional interface types. */
private boolean unrelatedFunctionalInterfaces(Type t, Type s) {
return types.isFunctionalInterface(t.tsym) &&
types.isFunctionalInterface(s.tsym) &&
unrelatedInterfaces(t, s);
}
/** Whether {@code t} and {@code s} are unrelated interface types; recurs on intersections. **/
private boolean unrelatedInterfaces(Type t, Type s) {
if (t.isCompound()) {
for (Type ti : types.interfaces(t)) {
if (!unrelatedInterfaces(ti, s)) {
return false;
}
}
return true;
} else if (s.isCompound()) {
for (Type si : types.interfaces(s)) {
if (!unrelatedInterfaces(t, si)) {
return false;
}
}
return true;
} else {
return types.asSuper(t, s.tsym) == null && types.asSuper(s, t.tsym) == null;
}
}
/** Parameters {@code t} and {@code s} are unrelated functional interface types. */
private boolean functionalInterfaceMostSpecific(Type t, Type s, JCTree tree) {
Type tDesc = types.findDescriptorType(types.capture(t));
Type tDescNoCapture = types.findDescriptorType(t);
Type sDesc = types.findDescriptorType(s);
final List tTypeParams = tDesc.getTypeArguments();
final List tTypeParamsNoCapture = tDescNoCapture.getTypeArguments();
final List sTypeParams = sDesc.getTypeArguments();
// compare type parameters
if (tDesc.hasTag(FORALL) && !types.hasSameBounds((ForAll) tDesc, (ForAll) tDescNoCapture)) {
return false;
}
// can't use Types.hasSameBounds on sDesc because bounds may have ivars
List tIter = tTypeParams;
List sIter = sTypeParams;
while (tIter.nonEmpty() && sIter.nonEmpty()) {
Type tBound = tIter.head.getUpperBound();
Type sBound = types.subst(sIter.head.getUpperBound(), sTypeParams, tTypeParams);
if (tBound.containsAny(tTypeParams) && inferenceContext().free(sBound)) {
return false;
}
if (!types.isSameType(tBound, inferenceContext().asUndetVar(sBound))) {
return false;
}
tIter = tIter.tail;
sIter = sIter.tail;
}
if (!tIter.isEmpty() || !sIter.isEmpty()) {
return false;
}
// compare parameters
List tParams = tDesc.getParameterTypes();
List tParamsNoCapture = tDescNoCapture.getParameterTypes();
List sParams = sDesc.getParameterTypes();
while (tParams.nonEmpty() && tParamsNoCapture.nonEmpty() && sParams.nonEmpty()) {
Type tParam = tParams.head;
Type tParamNoCapture = types.subst(tParamsNoCapture.head, tTypeParamsNoCapture, tTypeParams);
Type sParam = types.subst(sParams.head, sTypeParams, tTypeParams);
if (tParam.containsAny(tTypeParams) && inferenceContext().free(sParam)) {
return false;
}
if (!types.isSubtype(inferenceContext().asUndetVar(sParam), tParam)) {
return false;
}
if (!types.isSameType(tParamNoCapture, inferenceContext().asUndetVar(sParam))) {
return false;
}
tParams = tParams.tail;
tParamsNoCapture = tParamsNoCapture.tail;
sParams = sParams.tail;
}
if (!tParams.isEmpty() || !tParamsNoCapture.isEmpty() || !sParams.isEmpty()) {
return false;
}
// compare returns
Type tRet = tDesc.getReturnType();
Type sRet = types.subst(sDesc.getReturnType(), sTypeParams, tTypeParams);
if (tRet.containsAny(tTypeParams) && inferenceContext().free(sRet)) {
return false;
}
MostSpecificFunctionReturnChecker msc = new MostSpecificFunctionReturnChecker(tRet, sRet);
msc.scan(tree);
return msc.result;
}
/**
* Tests whether one functional interface type can be considered more specific
* than another unrelated functional interface type for the scanned expression.
*/
class MostSpecificFunctionReturnChecker extends DeferredAttr.PolyScanner {
final Type tRet;
final Type sRet;
boolean result;
/** Parameters {@code t} and {@code s} are unrelated functional interface types. */
MostSpecificFunctionReturnChecker(Type tRet, Type sRet) {
this.tRet = tRet;
this.sRet = sRet;
result = true;
}
@Override
void skip(JCTree tree) {
result &= false;
}
@Override
public void visitConditional(JCConditional tree) {
scan(asExpr(tree.truepart));
scan(asExpr(tree.falsepart));
}
@Override
public void visitReference(JCMemberReference tree) {
if (sRet.hasTag(VOID)) {
result &= true;
} else if (tRet.hasTag(VOID)) {
result &= false;
} else if (tRet.isPrimitive() != sRet.isPrimitive()) {
boolean retValIsPrimitive =
tree.refPolyKind == PolyKind.STANDALONE &&
tree.sym.type.getReturnType().isPrimitive();
result &= (retValIsPrimitive == tRet.isPrimitive()) &&
(retValIsPrimitive != sRet.isPrimitive());
} else {
result &= compatibleBySubtyping(tRet, sRet);
}
}
@Override
public void visitParens(JCParens tree) {
scan(asExpr(tree.expr));
}
@Override
public void visitLambda(JCLambda tree) {
if (sRet.hasTag(VOID)) {
result &= true;
} else if (tRet.hasTag(VOID)) {
result &= false;
} else {
List lambdaResults = lambdaResults(tree);
if (!lambdaResults.isEmpty() && unrelatedFunctionalInterfaces(tRet, sRet)) {
for (JCExpression expr : lambdaResults) {
result &= functionalInterfaceMostSpecific(tRet, sRet, expr);
}
} else if (!lambdaResults.isEmpty() && tRet.isPrimitive() != sRet.isPrimitive()) {
for (JCExpression expr : lambdaResults) {
boolean retValIsPrimitive = expr.isStandalone() && expr.type.isPrimitive();
result &= (retValIsPrimitive == tRet.isPrimitive()) &&
(retValIsPrimitive != sRet.isPrimitive());
}
} else {
result &= compatibleBySubtyping(tRet, sRet);
}
}
}
//where
private List lambdaResults(JCLambda lambda) {
if (lambda.getBodyKind() == JCTree.JCLambda.BodyKind.EXPRESSION) {
return List.of(asExpr((JCExpression) lambda.body));
} else {
final ListBuffer buffer = new ListBuffer<>();
DeferredAttr.LambdaReturnScanner lambdaScanner =
new DeferredAttr.LambdaReturnScanner() {
@Override
public void visitReturn(JCReturn tree) {
if (tree.expr != null) {
buffer.append(asExpr(tree.expr));
}
}
};
lambdaScanner.scan(lambda.body);
return buffer.toList();
}
}
private JCExpression asExpr(JCExpression expr) {
if (expr.type.hasTag(DEFERRED)) {
JCTree speculativeTree = ((DeferredType)expr.type).speculativeTree(deferredAttrContext);
if (speculativeTree != deferredAttr.stuckTree) {
expr = (JCExpression)speculativeTree;
}
}
return expr;
}
}
}
public MethodCheck mostSpecificCheck(List actuals) {
Assert.error("Cannot get here!");
return null;
}
}
public static class InapplicableMethodException extends RuntimeException {
private static final long serialVersionUID = 0;
JCDiagnostic diagnostic;
JCDiagnostic.Factory diags;
InapplicableMethodException(JCDiagnostic.Factory diags) {
this.diagnostic = null;
this.diags = diags;
}
InapplicableMethodException setMessage() {
return setMessage((JCDiagnostic)null);
}
InapplicableMethodException setMessage(String key) {
return setMessage(key != null ? diags.fragment(key) : null);
}
InapplicableMethodException setMessage(String key, Object... args) {
return setMessage(key != null ? diags.fragment(key, args) : null);
}
InapplicableMethodException setMessage(JCDiagnostic diag) {
this.diagnostic = diag;
return this;
}
public JCDiagnostic getDiagnostic() {
return diagnostic;
}
}
private final InapplicableMethodException inapplicableMethodException;
/* ***************************************************************************
* Symbol lookup
* the following naming conventions for arguments are used
*
* env is the environment where the symbol was mentioned
* site is the type of which the symbol is a member
* name is the symbol's name
* if no arguments are given
* argtypes are the value arguments, if we search for a method
*
* If no symbol was found, a ResolveError detailing the problem is returned.
****************************************************************************/
/** Find field. Synthetic fields are always skipped.
* @param env The current environment.
* @param site The original type from where the selection takes place.
* @param name The name of the field.
* @param c The class to search for the field. This is always
* a superclass or implemented interface of site's class.
*/
Symbol findField(Env env,
Type site,
Name name,
TypeSymbol c) {
while (c.type.hasTag(TYPEVAR))
c = c.type.getUpperBound().tsym;
Symbol bestSoFar = varNotFound;
Symbol sym;
for (Symbol s : c.members().getSymbolsByName(name)) {
if (s.kind == VAR && (s.flags_field & SYNTHETIC) == 0) {
return isAccessible(env, site, s)
? s : new AccessError(env, site, s);
}
}
Type st = types.supertype(c.type);
if (st != null && (st.hasTag(CLASS) || st.hasTag(TYPEVAR))) {
sym = findField(env, site, name, st.tsym);
bestSoFar = bestOf(bestSoFar, sym);
}
for (List l = types.interfaces(c.type);
bestSoFar.kind != AMBIGUOUS && l.nonEmpty();
l = l.tail) {
sym = findField(env, site, name, l.head.tsym);
if (bestSoFar.exists() && sym.exists() &&
sym.owner != bestSoFar.owner)
bestSoFar = new AmbiguityError(bestSoFar, sym);
else
bestSoFar = bestOf(bestSoFar, sym);
}
return bestSoFar;
}
/** Resolve a field identifier, throw a fatal error if not found.
* @param pos The position to use for error reporting.
* @param env The environment current at the method invocation.
* @param site The type of the qualifying expression, in which
* identifier is searched.
* @param name The identifier's name.
*/
public VarSymbol resolveInternalField(DiagnosticPosition pos, Env env,
Type site, Name name) {
Symbol sym = findField(env, site, name, site.tsym);
if (sym.kind == VAR) return (VarSymbol)sym;
else throw new FatalError(
diags.fragment("fatal.err.cant.locate.field",
name));
}
/** Find unqualified variable or field with given name.
* Synthetic fields always skipped.
* @param env The current environment.
* @param name The name of the variable or field.
*/
Symbol findVar(Env env, Name name) {
Symbol bestSoFar = varNotFound;
Env env1 = env;
boolean staticOnly = false;
while (env1.outer != null) {
Symbol sym = null;
if (isStatic(env1)) staticOnly = true;
for (Symbol s : env1.info.scope.getSymbolsByName(name)) {
if (s.kind == VAR && (s.flags_field & SYNTHETIC) == 0) {
sym = s;
break;
}
}
if (sym == null) {
sym = findField(env1, env1.enclClass.sym.type, name, env1.enclClass.sym);
}
if (sym.exists()) {
if (staticOnly &&
sym.kind == VAR &&
sym.owner.kind == TYP &&
(sym.flags() & STATIC) == 0)
return new StaticError(sym);
else
return sym;
} else {
bestSoFar = bestOf(bestSoFar, sym);
}
if ((env1.enclClass.sym.flags() & STATIC) != 0) staticOnly = true;
env1 = env1.outer;
}
Symbol sym = findField(env, syms.predefClass.type, name, syms.predefClass);
if (sym.exists())
return sym;
if (bestSoFar.exists())
return bestSoFar;
Symbol origin = null;
for (Scope sc : new Scope[] { env.toplevel.namedImportScope, env.toplevel.starImportScope }) {
for (Symbol currentSymbol : sc.getSymbolsByName(name)) {
if (currentSymbol.kind != VAR)
continue;
// invariant: sym.kind == Symbol.Kind.VAR
if (!bestSoFar.kind.isResolutionError() &&
currentSymbol.owner != bestSoFar.owner)
return new AmbiguityError(bestSoFar, currentSymbol);
else if (!bestSoFar.kind.betterThan(VAR)) {
origin = sc.getOrigin(currentSymbol).owner;
bestSoFar = isAccessible(env, origin.type, currentSymbol)
? currentSymbol : new AccessError(env, origin.type, currentSymbol);
}
}
if (bestSoFar.exists()) break;
}
if (bestSoFar.kind == VAR && bestSoFar.owner.type != origin.type)
return bestSoFar.clone(origin);
else
return bestSoFar;
}
Warner noteWarner = new Warner();
/** Select the best method for a call site among two choices.
* @param env The current environment.
* @param site The original type from where the
* selection takes place.
* @param argtypes The invocation's value arguments,
* @param typeargtypes The invocation's type arguments,
* @param sym Proposed new best match.
* @param bestSoFar Previously found best match.
* @param allowBoxing Allow boxing conversions of arguments.
* @param useVarargs Box trailing arguments into an array for varargs.
*/
@SuppressWarnings("fallthrough")
Symbol selectBest(Env env,
Type site,
List argtypes,
List typeargtypes,
Symbol sym,
Symbol bestSoFar,
boolean allowBoxing,
boolean useVarargs) {
if (sym.kind == ERR ||
!sym.isInheritedIn(site.tsym, types)) {
return bestSoFar;
} else if (useVarargs && (sym.flags() & VARARGS) == 0) {
return bestSoFar.kind.isResolutionError() ?
new BadVarargsMethod((ResolveError)bestSoFar.baseSymbol()) :
bestSoFar;
}
Assert.check(!sym.kind.isResolutionError());
try {
types.noWarnings.clear();
Type mt = rawInstantiate(env, site, sym, null, argtypes, typeargtypes,
allowBoxing, useVarargs, types.noWarnings);
currentResolutionContext.addApplicableCandidate(sym, mt);
} catch (InapplicableMethodException ex) {
currentResolutionContext.addInapplicableCandidate(sym, ex.getDiagnostic());
switch (bestSoFar.kind) {
case ABSENT_MTH:
return new InapplicableSymbolError(currentResolutionContext);
case WRONG_MTH:
bestSoFar = new InapplicableSymbolsError(currentResolutionContext);
default:
return bestSoFar;
}
}
if (!isAccessible(env, site, sym)) {
return (bestSoFar.kind == ABSENT_MTH)
? new AccessError(env, site, sym)
: bestSoFar;
}
return (bestSoFar.kind.isResolutionError() && bestSoFar.kind != AMBIGUOUS)
? sym
: mostSpecific(argtypes, sym, bestSoFar, env, site, useVarargs);
}
/* Return the most specific of the two methods for a call,
* given that both are accessible and applicable.
* @param m1 A new candidate for most specific.
* @param m2 The previous most specific candidate.
* @param env The current environment.
* @param site The original type from where the selection
* takes place.
* @param allowBoxing Allow boxing conversions of arguments.
* @param useVarargs Box trailing arguments into an array for varargs.
*/
Symbol mostSpecific(List argtypes, Symbol m1,
Symbol m2,
Env env,
final Type site,
boolean useVarargs) {
switch (m2.kind) {
case MTH:
if (m1 == m2) return m1;
boolean m1SignatureMoreSpecific =
signatureMoreSpecific(argtypes, env, site, m1, m2, useVarargs);
boolean m2SignatureMoreSpecific =
signatureMoreSpecific(argtypes, env, site, m2, m1, useVarargs);
if (m1SignatureMoreSpecific && m2SignatureMoreSpecific) {
Type mt1 = types.memberType(site, m1);
Type mt2 = types.memberType(site, m2);
if (!types.overrideEquivalent(mt1, mt2))
return ambiguityError(m1, m2);
// same signature; select (a) the non-bridge method, or
// (b) the one that overrides the other, or (c) the concrete
// one, or (d) merge both abstract signatures
if ((m1.flags() & BRIDGE) != (m2.flags() & BRIDGE))
return ((m1.flags() & BRIDGE) != 0) ? m2 : m1;
// if one overrides or hides the other, use it
TypeSymbol m1Owner = (TypeSymbol)m1.owner;
TypeSymbol m2Owner = (TypeSymbol)m2.owner;
if (types.asSuper(m1Owner.type, m2Owner) != null &&
((m1.owner.flags_field & INTERFACE) == 0 ||
(m2.owner.flags_field & INTERFACE) != 0) &&
m1.overrides(m2, m1Owner, types, false))
return m1;
if (types.asSuper(m2Owner.type, m1Owner) != null &&
((m2.owner.flags_field & INTERFACE) == 0 ||
(m1.owner.flags_field & INTERFACE) != 0) &&
m2.overrides(m1, m2Owner, types, false))
return m2;
boolean m1Abstract = (m1.flags() & ABSTRACT) != 0;
boolean m2Abstract = (m2.flags() & ABSTRACT) != 0;
if (m1Abstract && !m2Abstract) return m2;
if (m2Abstract && !m1Abstract) return m1;
// both abstract or both concrete
return ambiguityError(m1, m2);
}
if (m1SignatureMoreSpecific) return m1;
if (m2SignatureMoreSpecific) return m2;
return ambiguityError(m1, m2);
case AMBIGUOUS:
//compare m1 to ambiguous methods in m2
AmbiguityError e = (AmbiguityError)m2.baseSymbol();
boolean m1MoreSpecificThanAnyAmbiguous = true;
boolean allAmbiguousMoreSpecificThanM1 = true;
for (Symbol s : e.ambiguousSyms) {
Symbol moreSpecific = mostSpecific(argtypes, m1, s, env, site, useVarargs);
m1MoreSpecificThanAnyAmbiguous &= moreSpecific == m1;
allAmbiguousMoreSpecificThanM1 &= moreSpecific == s;
}
if (m1MoreSpecificThanAnyAmbiguous)
return m1;
//if m1 is more specific than some ambiguous methods, but other ambiguous methods are
//more specific than m1, add it as a new ambiguous method:
if (!allAmbiguousMoreSpecificThanM1)
e.addAmbiguousSymbol(m1);
return e;
default:
throw new AssertionError();
}
}
//where
private boolean signatureMoreSpecific(List actuals, Env env, Type site, Symbol m1, Symbol m2, boolean useVarargs) {
noteWarner.clear();
int maxLength = Math.max(
Math.max(m1.type.getParameterTypes().length(), actuals.length()),
m2.type.getParameterTypes().length());
MethodResolutionContext prevResolutionContext = currentResolutionContext;
try {
currentResolutionContext = new MethodResolutionContext();
currentResolutionContext.step = prevResolutionContext.step;
currentResolutionContext.methodCheck =
prevResolutionContext.methodCheck.mostSpecificCheck(actuals);
Type mst = instantiate(env, site, m2, null,
adjustArgs(types.cvarLowerBounds(types.memberType(site, m1).getParameterTypes()), m1, maxLength, useVarargs), null,
false, useVarargs, noteWarner);
return mst != null &&
!noteWarner.hasLint(Lint.LintCategory.UNCHECKED);
} finally {
currentResolutionContext = prevResolutionContext;
}
}
List adjustArgs(List args, Symbol msym, int length, boolean allowVarargs) {
if ((msym.flags() & VARARGS) != 0 && allowVarargs) {
Type varargsElem = types.elemtype(args.last());
if (varargsElem == null) {
Assert.error("Bad varargs = " + args.last() + " " + msym);
}
List newArgs = args.reverse().tail.prepend(varargsElem).reverse();
while (newArgs.length() < length) {
newArgs = newArgs.append(newArgs.last());
}
return newArgs;
} else {
return args;
}
}
//where
Symbol ambiguityError(Symbol m1, Symbol m2) {
if (((m1.flags() | m2.flags()) & CLASH) != 0) {
return (m1.flags() & CLASH) == 0 ? m1 : m2;
} else {
return new AmbiguityError(m1, m2);
}
}
Symbol findMethodInScope(Env env,
Type site,
Name name,
List argtypes,
List typeargtypes,
Scope sc,
Symbol bestSoFar,
boolean allowBoxing,
boolean useVarargs,
boolean abstractok) {
for (Symbol s : sc.getSymbolsByName(name, new LookupFilter(abstractok))) {
bestSoFar = selectBest(env, site, argtypes, typeargtypes, s,
bestSoFar, allowBoxing, useVarargs);
}
return bestSoFar;
}
//where
class LookupFilter implements Filter {
boolean abstractOk;
LookupFilter(boolean abstractOk) {
this.abstractOk = abstractOk;
}
public boolean accepts(Symbol s) {
long flags = s.flags();
return s.kind == MTH &&
(flags & SYNTHETIC) == 0 &&
(abstractOk ||
(flags & DEFAULT) != 0 ||
(flags & ABSTRACT) == 0);
}
}
/** Find best qualified method matching given name, type and value
* arguments.
* @param env The current environment.
* @param site The original type from where the selection
* takes place.
* @param name The method's name.
* @param argtypes The method's value arguments.
* @param typeargtypes The method's type arguments
* @param allowBoxing Allow boxing conversions of arguments.
* @param useVarargs Box trailing arguments into an array for varargs.
*/
Symbol findMethod(Env env,
Type site,
Name name,
List argtypes,
List typeargtypes,
boolean allowBoxing,
boolean useVarargs) {
Symbol bestSoFar = methodNotFound;
bestSoFar = findMethod(env,
site,
name,
argtypes,
typeargtypes,
site.tsym.type,
bestSoFar,
allowBoxing,
useVarargs);
return bestSoFar;
}
// where
private Symbol findMethod(Env env,
Type site,
Name name,
List argtypes,
List typeargtypes,
Type intype,
Symbol bestSoFar,
boolean allowBoxing,
boolean useVarargs) {
@SuppressWarnings({"unchecked","rawtypes"})
List[] itypes = (List[])new List[] { List.nil(), List.nil() };
InterfaceLookupPhase iphase = InterfaceLookupPhase.ABSTRACT_OK;
for (TypeSymbol s : superclasses(intype)) {
bestSoFar = findMethodInScope(env, site, name, argtypes, typeargtypes,
s.members(), bestSoFar, allowBoxing, useVarargs, true);
if (name == names.init) return bestSoFar;
iphase = (iphase == null) ? null : iphase.update(s, this);
if (iphase != null) {
for (Type itype : types.interfaces(s.type)) {
itypes[iphase.ordinal()] = types.union(types.closure(itype), itypes[iphase.ordinal()]);
}
}
}
Symbol concrete = bestSoFar.kind.isValid() &&
(bestSoFar.flags() & ABSTRACT) == 0 ?
bestSoFar : methodNotFound;
for (InterfaceLookupPhase iphase2 : InterfaceLookupPhase.values()) {
//keep searching for abstract methods
for (Type itype : itypes[iphase2.ordinal()]) {
if (!itype.isInterface()) continue; //skip j.l.Object (included by Types.closure())
if (iphase2 == InterfaceLookupPhase.DEFAULT_OK &&
(itype.tsym.flags() & DEFAULT) == 0) continue;
bestSoFar = findMethodInScope(env, site, name, argtypes, typeargtypes,
itype.tsym.members(), bestSoFar, allowBoxing, useVarargs, true);
if (concrete != bestSoFar &&
concrete.kind.isValid() &&
bestSoFar.kind.isValid() &&
types.isSubSignature(concrete.type, bestSoFar.type)) {
//this is an hack - as javac does not do full membership checks
//most specific ends up comparing abstract methods that might have
//been implemented by some concrete method in a subclass and,
//because of raw override, it is possible for an abstract method
//to be more specific than the concrete method - so we need
//to explicitly call that out (see CR 6178365)
bestSoFar = concrete;
}
}
}
return bestSoFar;
}
enum InterfaceLookupPhase {
ABSTRACT_OK() {
@Override
InterfaceLookupPhase update(Symbol s, Resolve rs) {
//We should not look for abstract methods if receiver is a concrete class
//(as concrete classes are expected to implement all abstracts coming
//from superinterfaces)
if ((s.flags() & (ABSTRACT | INTERFACE | ENUM)) != 0) {
return this;
} else {
return DEFAULT_OK;
}
}
},
DEFAULT_OK() {
@Override
InterfaceLookupPhase update(Symbol s, Resolve rs) {
return this;
}
};
abstract InterfaceLookupPhase update(Symbol s, Resolve rs);
}
/**
* Return an Iterable object to scan the superclasses of a given type.
* It's crucial that the scan is done lazily, as we don't want to accidentally
* access more supertypes than strictly needed (as this could trigger completion
* errors if some of the not-needed supertypes are missing/ill-formed).
*/
Iterable superclasses(final Type intype) {
return () -> new Iterator() {
List seen = List.nil();
TypeSymbol currentSym = symbolFor(intype);
TypeSymbol prevSym = null;
public boolean hasNext() {
if (currentSym == syms.noSymbol) {
currentSym = symbolFor(types.supertype(prevSym.type));
}
return currentSym != null;
}
public TypeSymbol next() {
prevSym = currentSym;
currentSym = syms.noSymbol;
Assert.check(prevSym != null || prevSym != syms.noSymbol);
return prevSym;
}
public void remove() {
throw new UnsupportedOperationException();
}
TypeSymbol symbolFor(Type t) {
if (!t.hasTag(CLASS) &&
!t.hasTag(TYPEVAR)) {
return null;
}
t = types.skipTypeVars(t, false);
if (seen.contains(t.tsym)) {
//degenerate case in which we have a circular
//class hierarchy - because of ill-formed classfiles
return null;
}
seen = seen.prepend(t.tsym);
return t.tsym;
}
};
}
/** Find unqualified method matching given name, type and value arguments.
* @param env The current environment.
* @param name The method's name.
* @param argtypes The method's value arguments.
* @param typeargtypes The method's type arguments.
* @param allowBoxing Allow boxing conversions of arguments.
* @param useVarargs Box trailing arguments into an array for varargs.
*/
Symbol findFun(Env env, Name name,
List argtypes, List typeargtypes,
boolean allowBoxing, boolean useVarargs) {
Symbol bestSoFar = methodNotFound;
Env env1 = env;
boolean staticOnly = false;
while (env1.outer != null) {
if (isStatic(env1)) staticOnly = true;
Assert.check(env1.info.preferredTreeForDiagnostics == null);
env1.info.preferredTreeForDiagnostics = env.tree;
try {
Symbol sym = findMethod(
env1, env1.enclClass.sym.type, name, argtypes, typeargtypes,
allowBoxing, useVarargs);
if (sym.exists()) {
if (staticOnly &&
sym.kind == MTH &&
sym.owner.kind == TYP &&
(sym.flags() & STATIC) == 0) return new StaticError(sym);
else return sym;
} else {
bestSoFar = bestOf(bestSoFar, sym);
}
} finally {
env1.info.preferredTreeForDiagnostics = null;
}
if ((env1.enclClass.sym.flags() & STATIC) != 0) staticOnly = true;
env1 = env1.outer;
}
Symbol sym = findMethod(env, syms.predefClass.type, name, argtypes,
typeargtypes, allowBoxing, useVarargs);
if (sym.exists())
return sym;
for (Symbol currentSym : env.toplevel.namedImportScope.getSymbolsByName(name)) {
Symbol origin = env.toplevel.namedImportScope.getOrigin(currentSym).owner;
if (currentSym.kind == MTH) {
if (currentSym.owner.type != origin.type)
currentSym = currentSym.clone(origin);
if (!isAccessible(env, origin.type, currentSym))
currentSym = new AccessError(env, origin.type, currentSym);
bestSoFar = selectBest(env, origin.type,
argtypes, typeargtypes,
currentSym, bestSoFar,
allowBoxing, useVarargs);
}
}
if (bestSoFar.exists())
return bestSoFar;
for (Symbol currentSym : env.toplevel.starImportScope.getSymbolsByName(name)) {
Symbol origin = env.toplevel.starImportScope.getOrigin(currentSym).owner;
if (currentSym.kind == MTH) {
if (currentSym.owner.type != origin.type)
currentSym = currentSym.clone(origin);
if (!isAccessible(env, origin.type, currentSym))
currentSym = new AccessError(env, origin.type, currentSym);
bestSoFar = selectBest(env, origin.type,
argtypes, typeargtypes,
currentSym, bestSoFar,
allowBoxing, useVarargs);
}
}
return bestSoFar;
}
/** Load toplevel or member class with given fully qualified name and
* verify that it is accessible.
* @param env The current environment.
* @param name The fully qualified name of the class to be loaded.
*/
Symbol loadClass(Env env, Name name, RecoveryLoadClass recoveryLoadClass) {
try {
ClassSymbol c = finder.loadClass(env.toplevel.modle, name);
return isAccessible(env, c) ? c : new AccessError(env, null, c);
} catch (ClassFinder.BadClassFile err) {
throw err;
} catch (CompletionFailure ex) {
Symbol candidate = recoveryLoadClass.loadClass(env, name);
if (candidate != null) {
return candidate;
}
return typeNotFound;
}
}
public interface RecoveryLoadClass {
Symbol loadClass(Env env, Name name);
}
private final RecoveryLoadClass noRecovery = (env, name) -> null;
private final RecoveryLoadClass doRecoveryLoadClass = new RecoveryLoadClass() {
@Override public Symbol loadClass(Env env, Name name) {
List candidates = Convert.classCandidates(name);
return lookupInvisibleSymbol(env, name,
n -> () -> createCompoundIterator(candidates,
c -> syms.getClassesForName(c)
.iterator()),
(ms, n) -> {
for (Name candidate : candidates) {
try {
return finder.loadClass(ms, candidate);
} catch (CompletionFailure cf) {
//ignore
}
}
return null;
}, sym -> sym.kind == Kind.TYP, false, typeNotFound);
}
};
private final RecoveryLoadClass namedImportScopeRecovery = (env, name) -> {
Scope importScope = env.toplevel.namedImportScope;
Symbol existing = importScope.findFirst(Convert.shortName(name),
sym -> sym.kind == TYP && sym.flatName() == name);
if (existing != null) {
return new InvisibleSymbolError(env, true, existing);
}
return null;
};
private final RecoveryLoadClass starImportScopeRecovery = (env, name) -> {
Scope importScope = env.toplevel.starImportScope;
Symbol existing = importScope.findFirst(Convert.shortName(name),
sym -> sym.kind == TYP && sym.flatName() == name);
if (existing != null) {
try {
existing = finder.loadClass(existing.packge().modle, name);
return new InvisibleSymbolError(env, true, existing);
} catch (CompletionFailure cf) {
//ignore
}
}
return null;
};
Symbol lookupPackage(Env env, Name name) {
PackageSymbol pack = syms.lookupPackage(env.toplevel.modle, name);
if (allowModules && isImportOnDemand(env, name)) {
pack.complete();
if (!pack.exists()) {
Name nameAndDot = name.append('.', names.empty);
boolean prefixOfKnown =
env.toplevel.modle.visiblePackages.values()
.stream()
.anyMatch(p -> p.fullname.startsWith(nameAndDot));
return lookupInvisibleSymbol(env, name, syms::getPackagesForName, syms::enterPackage, sym -> {
sym.complete();
return sym.exists();
}, prefixOfKnown, pack);
}
}
return pack;
}
private boolean isImportOnDemand(Env env, Name name) {
if (!env.tree.hasTag(IMPORT))
return false;
JCTree qualid = ((JCImport) env.tree).qualid;
if (!qualid.hasTag(SELECT))
return false;
if (TreeInfo.name(qualid) != names.asterisk)
return false;
return TreeInfo.fullName(((JCFieldAccess) qualid).selected) == name;
}
private Symbol lookupInvisibleSymbol(Env env,
Name name,
Function> get,
BiFunction load,
Predicate validate,
boolean suppressError,
Symbol defaultResult) {
//even if a class/package cannot be found in the current module and among packages in modules
//it depends on that are exported for any or this module, the class/package may exist internally
//in some of these modules, or may exist in a module on which this module does not depend.
//Provide better diagnostic in such cases by looking for the class in any module:
Iterable candidates = get.apply(name);
for (S sym : candidates) {
if (validate.test(sym))
return createInvisibleSymbolError(env, suppressError, sym);
}
Set recoverableModules = new HashSet<>(syms.getAllModules());
recoverableModules.remove(env.toplevel.modle);
for (ModuleSymbol ms : recoverableModules) {
//avoid overly eager completing classes from source-based modules, as those
//may not be completable with the current compiler settings:
if (ms.sourceLocation == null) {
if (ms.classLocation == null) {
ms = moduleFinder.findModule(ms);
}
if (ms.kind != ERR) {
S sym = load.apply(ms, name);
if (sym != null && validate.test(sym)) {
return createInvisibleSymbolError(env, suppressError, sym);
}
}
}
}
return defaultResult;
}
private Symbol createInvisibleSymbolError(Env env, boolean suppressError, Symbol sym) {
if (symbolPackageVisible(env, sym)) {
return new AccessError(env, null, sym);
} else {
return new InvisibleSymbolError(env, suppressError, sym);
}
}
private boolean symbolPackageVisible(Env env, Symbol sym) {
ModuleSymbol envMod = env.toplevel.modle;
PackageSymbol symPack = sym.packge();
return envMod == symPack.modle ||
envMod.visiblePackages.containsKey(symPack.fullname);
}
/**
* Find a type declared in a scope (not inherited). Return null
* if none is found.
* @param env The current environment.
* @param site The original type from where the selection takes
* place.
* @param name The type's name.
* @param c The class to search for the member type. This is
* always a superclass or implemented interface of
* site's class.
*/
Symbol findImmediateMemberType(Env env,
Type site,
Name name,
TypeSymbol c) {
for (Symbol sym : c.members().getSymbolsByName(name)) {
if (sym.kind == TYP) {
return isAccessible(env, site, sym)
? sym
: new AccessError(env, site, sym);
}
}
return typeNotFound;
}
/** Find a member type inherited from a superclass or interface.
* @param env The current environment.
* @param site The original type from where the selection takes
* place.
* @param name The type's name.
* @param c The class to search for the member type. This is
* always a superclass or implemented interface of
* site's class.
*/
Symbol findInheritedMemberType(Env env,
Type site,
Name name,
TypeSymbol c) {
Symbol bestSoFar = typeNotFound;
Symbol sym;
Type st = types.supertype(c.type);
if (st != null && st.hasTag(CLASS)) {
sym = findMemberType(env, site, name, st.tsym);
bestSoFar = bestOf(bestSoFar, sym);
}
for (List l = types.interfaces(c.type);
bestSoFar.kind != AMBIGUOUS && l.nonEmpty();
l = l.tail) {
sym = findMemberType(env, site, name, l.head.tsym);
if (!bestSoFar.kind.isResolutionError() &&
!sym.kind.isResolutionError() &&
sym.owner != bestSoFar.owner)
bestSoFar = new AmbiguityError(bestSoFar, sym);
else
bestSoFar = bestOf(bestSoFar, sym);
}
return bestSoFar;
}
/** Find qualified member type.
* @param env The current environment.
* @param site The original type from where the selection takes
* place.
* @param name The type's name.
* @param c The class to search for the member type. This is
* always a superclass or implemented interface of
* site's class.
*/
Symbol findMemberType(Env env,
Type site,
Name name,
TypeSymbol c) {
Symbol sym = findImmediateMemberType(env, site, name, c);
if (sym != typeNotFound)
return sym;
return findInheritedMemberType(env, site, name, c);
}
/** Find a global type in given scope and load corresponding class.
* @param env The current environment.
* @param scope The scope in which to look for the type.
* @param name The type's name.
*/
Symbol findGlobalType(Env env, Scope scope, Name name, RecoveryLoadClass recoveryLoadClass) {
Symbol bestSoFar = typeNotFound;
for (Symbol s : scope.getSymbolsByName(name)) {
Symbol sym = loadClass(env, s.flatName(), recoveryLoadClass);
if (bestSoFar.kind == TYP && sym.kind == TYP &&
bestSoFar != sym)
return new AmbiguityError(bestSoFar, sym);
else
bestSoFar = bestOf(bestSoFar, sym);
}
return bestSoFar;
}
Symbol findTypeVar(Env env, Name name, boolean staticOnly) {
for (Symbol sym : env.info.scope.getSymbolsByName(name)) {
if (sym.kind == TYP) {
if (staticOnly &&
sym.type.hasTag(TYPEVAR) &&
sym.owner.kind == TYP)
return new StaticError(sym);
return sym;
}
}
return typeNotFound;
}
/** Find an unqualified type symbol.
* @param env The current environment.
* @param name The type's name.
*/
Symbol findType(Env env, Name name) {
if (name == names.empty)
return typeNotFound; // do not allow inadvertent "lookup" of anonymous types
Symbol bestSoFar = typeNotFound;
Symbol sym;
boolean staticOnly = false;
for (Env env1 = env; env1.outer != null; env1 = env1.outer) {
if (isStatic(env1)) staticOnly = true;
// First, look for a type variable and the first member type
final Symbol tyvar = findTypeVar(env1, name, staticOnly);
sym = findImmediateMemberType(env1, env1.enclClass.sym.type,
name, env1.enclClass.sym);
// Return the type variable if we have it, and have no
// immediate member, OR the type variable is for a method.
if (tyvar != typeNotFound) {
if (env.baseClause || sym == typeNotFound ||
(tyvar.kind == TYP && tyvar.exists() &&
tyvar.owner.kind == MTH)) {
return tyvar;
}
}
// If the environment is a class def, finish up,
// otherwise, do the entire findMemberType
if (sym == typeNotFound)
sym = findInheritedMemberType(env1, env1.enclClass.sym.type,
name, env1.enclClass.sym);
if (staticOnly && sym.kind == TYP &&
sym.type.hasTag(CLASS) &&
sym.type.getEnclosingType().hasTag(CLASS) &&
env1.enclClass.sym.type.isParameterized() &&
sym.type.getEnclosingType().isParameterized())
return new StaticError(sym);
else if (sym.exists()) return sym;
else bestSoFar = bestOf(bestSoFar, sym);
JCClassDecl encl = env1.baseClause ? (JCClassDecl)env1.tree : env1.enclClass;
if ((encl.sym.flags() & STATIC) != 0)
staticOnly = true;
}
if (!env.tree.hasTag(IMPORT)) {
sym = findGlobalType(env, env.toplevel.namedImportScope, name, namedImportScopeRecovery);
if (sym.exists()) return sym;
else bestSoFar = bestOf(bestSoFar, sym);
sym = findGlobalType(env, env.toplevel.packge.members(), name, noRecovery);
if (sym.exists()) return sym;
else bestSoFar = bestOf(bestSoFar, sym);
sym = findGlobalType(env, env.toplevel.starImportScope, name, starImportScopeRecovery);
if (sym.exists()) return sym;
else bestSoFar = bestOf(bestSoFar, sym);
}
return bestSoFar;
}
/** Find an unqualified identifier which matches a specified kind set.
* @param env The current environment.
* @param name The identifier's name.
* @param kind Indicates the possible symbol kinds
* (a subset of VAL, TYP, PCK).
*/
Symbol findIdent(Env env, Name name, KindSelector kind) {
Symbol bestSoFar = typeNotFound;
Symbol sym;
if (kind.contains(KindSelector.VAL)) {
sym = findVar(env, name);
if (sym.exists()) return sym;
else bestSoFar = bestOf(bestSoFar, sym);
}
if (kind.contains(KindSelector.TYP)) {
sym = findType(env, name);
if (sym.exists()) return sym;
else bestSoFar = bestOf(bestSoFar, sym);
}
if (kind.contains(KindSelector.PCK))
return lookupPackage(env, name);
else return bestSoFar;
}
/** Find an identifier in a package which matches a specified kind set.
* @param env The current environment.
* @param name The identifier's name.
* @param kind Indicates the possible symbol kinds
* (a nonempty subset of TYP, PCK).
*/
Symbol findIdentInPackage(Env env, TypeSymbol pck,
Name name, KindSelector kind) {
Name fullname = TypeSymbol.formFullName(name, pck);
Symbol bestSoFar = typeNotFound;
if (kind.contains(KindSelector.TYP)) {
RecoveryLoadClass recoveryLoadClass =
allowModules && !kind.contains(KindSelector.PCK) &&
!pck.exists() && !env.info.isSpeculative ?
doRecoveryLoadClass : noRecovery;
Symbol sym = loadClass(env, fullname, recoveryLoadClass);
if (sym.exists()) {
// don't allow programs to use flatnames
if (name == sym.name) return sym;
}
else bestSoFar = bestOf(bestSoFar, sym);
}
if (kind.contains(KindSelector.PCK)) {
return lookupPackage(env, fullname);
}
return bestSoFar;
}
/** Find an identifier among the members of a given type `site'.
* @param env The current environment.
* @param site The type containing the symbol to be found.
* @param name The identifier's name.
* @param kind Indicates the possible symbol kinds
* (a subset of VAL, TYP).
*/
Symbol findIdentInType(Env env, Type site,
Name name, KindSelector kind) {
Symbol bestSoFar = typeNotFound;
Symbol sym;
if (kind.contains(KindSelector.VAL)) {
sym = findField(env, site, name, site.tsym);
if (sym.exists()) return sym;
else bestSoFar = bestOf(bestSoFar, sym);
}
if (kind.contains(KindSelector.TYP)) {
sym = findMemberType(env, site, name, site.tsym);
if (sym.exists()) return sym;
else bestSoFar = bestOf(bestSoFar, sym);
}
return bestSoFar;
}
/* ***************************************************************************
* Access checking
* The following methods convert ResolveErrors to ErrorSymbols, issuing
* an error message in the process
****************************************************************************/
/** If `sym' is a bad symbol: report error and return errSymbol
* else pass through unchanged,
* additional arguments duplicate what has been used in trying to find the
* symbol {@literal (--> flyweight pattern)}. This improves performance since we
* expect misses to happen frequently.
*
* @param sym The symbol that was found, or a ResolveError.
* @param pos The position to use for error reporting.
* @param location The symbol the served as a context for this lookup
* @param site The original type from where the selection took place.
* @param name The symbol's name.
* @param qualified Did we get here through a qualified expression resolution?
* @param argtypes The invocation's value arguments,
* if we looked for a method.
* @param typeargtypes The invocation's type arguments,
* if we looked for a method.
* @param logResolveHelper helper class used to log resolve errors
*/
Symbol accessInternal(Symbol sym,
DiagnosticPosition pos,
Symbol location,
Type site,
Name name,
boolean qualified,
List argtypes,
List typeargtypes,
LogResolveHelper logResolveHelper) {
if (sym.kind.isResolutionError()) {
ResolveError errSym = (ResolveError)sym.baseSymbol();
sym = errSym.access(name, qualified ? site.tsym : syms.noSymbol);
argtypes = logResolveHelper.getArgumentTypes(errSym, sym, name, argtypes);
if (logResolveHelper.resolveDiagnosticNeeded(site, argtypes, typeargtypes)) {
logResolveError(errSym, pos, location, site, name, argtypes, typeargtypes);
}
}
return sym;
}
/**
* Variant of the generalized access routine, to be used for generating method
* resolution diagnostics
*/
Symbol accessMethod(Symbol sym,
DiagnosticPosition pos,
Symbol location,
Type site,
Name name,
boolean qualified,
List argtypes,
List typeargtypes) {
return accessInternal(sym, pos, location, site, name, qualified, argtypes, typeargtypes, methodLogResolveHelper);
}
/** Same as original accessMethod(), but without location.
*/
Symbol accessMethod(Symbol sym,
DiagnosticPosition pos,
Type site,
Name name,
boolean qualified,
List argtypes,
List typeargtypes) {
return accessMethod(sym, pos, site.tsym, site, name, qualified, argtypes, typeargtypes);
}
/**
* Variant of the generalized access routine, to be used for generating variable,
* type resolution diagnostics
*/
Symbol accessBase(Symbol sym,
DiagnosticPosition pos,
Symbol location,
Type site,
Name name,
boolean qualified) {
return accessInternal(sym, pos, location, site, name, qualified, List.nil(), null, basicLogResolveHelper);
}
/** Same as original accessBase(), but without location.
*/
Symbol accessBase(Symbol sym,
DiagnosticPosition pos,
Type site,
Name name,
boolean qualified) {
return accessBase(sym, pos, site.tsym, site, name, qualified);
}
interface LogResolveHelper {
boolean resolveDiagnosticNeeded(Type site, List argtypes, List typeargtypes);
List getArgumentTypes(ResolveError errSym, Symbol accessedSym, Name name, List argtypes);
}
LogResolveHelper basicLogResolveHelper = new LogResolveHelper() {
public boolean resolveDiagnosticNeeded(Type site, List argtypes, List typeargtypes) {
return !site.isErroneous();
}
public List getArgumentTypes(ResolveError errSym, Symbol accessedSym, Name name, List argtypes) {
return argtypes;
}
};
LogResolveHelper methodLogResolveHelper = new LogResolveHelper() {
public boolean resolveDiagnosticNeeded(Type site, List argtypes, List typeargtypes) {
return !site.isErroneous() &&
!Type.isErroneous(argtypes) &&
(typeargtypes == null || !Type.isErroneous(typeargtypes));
}
public List getArgumentTypes(ResolveError errSym, Symbol accessedSym, Name name, List argtypes) {
return argtypes.map(new ResolveDeferredRecoveryMap(AttrMode.SPECULATIVE, accessedSym, currentResolutionContext.step));
}
};
class ResolveDeferredRecoveryMap extends DeferredAttr.RecoveryDeferredTypeMap {
public ResolveDeferredRecoveryMap(AttrMode mode, Symbol msym, MethodResolutionPhase step) {
deferredAttr.super(mode, msym, step);
}
@Override
protected Type typeOf(DeferredType dt) {
Type res = super.typeOf(dt);
if (!res.isErroneous()) {
switch (TreeInfo.skipParens(dt.tree).getTag()) {
case LAMBDA:
case REFERENCE:
return dt;
case CONDEXPR:
return res == Type.recoveryType ?
dt : res;
}
}
return res;
}
}
/** Check that sym is not an abstract method.
*/
void checkNonAbstract(DiagnosticPosition pos, Symbol sym) {
if ((sym.flags() & ABSTRACT) != 0 && (sym.flags() & DEFAULT) == 0)
log.error(pos, "abstract.cant.be.accessed.directly",
kindName(sym), sym, sym.location());
}
/* ***************************************************************************
* Name resolution
* Naming conventions are as for symbol lookup
* Unlike the find... methods these methods will report access errors
****************************************************************************/
/** Resolve an unqualified (non-method) identifier.
* @param pos The position to use for error reporting.
* @param env The environment current at the identifier use.
* @param name The identifier's name.
* @param kind The set of admissible symbol kinds for the identifier.
*/
Symbol resolveIdent(DiagnosticPosition pos, Env env,
Name name, KindSelector kind) {
return accessBase(
findIdent(env, name, kind),
pos, env.enclClass.sym.type, name, false);
}
/** Resolve an unqualified method identifier.
* @param pos The position to use for error reporting.
* @param env The environment current at the method invocation.
* @param name The identifier's name.
* @param argtypes The types of the invocation's value arguments.
* @param typeargtypes The types of the invocation's type arguments.
*/
Symbol resolveMethod(DiagnosticPosition pos,
Env env,
Name name,
List argtypes,
List typeargtypes) {
return lookupMethod(env, pos, env.enclClass.sym, resolveMethodCheck,
new BasicLookupHelper(name, env.enclClass.sym.type, argtypes, typeargtypes) {
@Override
Symbol doLookup(Env env, MethodResolutionPhase phase) {
return findFun(env, name, argtypes, typeargtypes,
phase.isBoxingRequired(),
phase.isVarargsRequired());
}});
}
/** Resolve a qualified method identifier
* @param pos The position to use for error reporting.
* @param env The environment current at the method invocation.
* @param site The type of the qualifying expression, in which
* identifier is searched.
* @param name The identifier's name.
* @param argtypes The types of the invocation's value arguments.
* @param typeargtypes The types of the invocation's type arguments.
*/
Symbol resolveQualifiedMethod(DiagnosticPosition pos, Env env,
Type site, Name name, List argtypes,
List typeargtypes) {
return resolveQualifiedMethod(pos, env, site.tsym, site, name, argtypes, typeargtypes);
}
Symbol resolveQualifiedMethod(DiagnosticPosition pos, Env env,
Symbol location, Type site, Name name, List argtypes,
List typeargtypes) {
return resolveQualifiedMethod(new MethodResolutionContext(), pos, env, location, site, name, argtypes, typeargtypes);
}
private Symbol resolveQualifiedMethod(MethodResolutionContext resolveContext,
DiagnosticPosition pos, Env env,
Symbol location, Type site, Name name, List argtypes,
List typeargtypes) {
return lookupMethod(env, pos, location, resolveContext, new BasicLookupHelper(name, site, argtypes, typeargtypes) {
@Override
Symbol doLookup(Env env, MethodResolutionPhase phase) {
return findMethod(env, site, name, argtypes, typeargtypes,
phase.isBoxingRequired(),
phase.isVarargsRequired());
}
@Override
Symbol access(Env env, DiagnosticPosition pos, Symbol location, Symbol sym) {
if (sym.kind.isResolutionError()) {
sym = super.access(env, pos, location, sym);
} else if (allowMethodHandles) {
MethodSymbol msym = (MethodSymbol)sym;
if ((msym.flags() & SIGNATURE_POLYMORPHIC) != 0) {
return findPolymorphicSignatureInstance(env, sym, argtypes);
}
}
return sym;
}
});
}
/** Find or create an implicit method of exactly the given type (after erasure).
* Searches in a side table, not the main scope of the site.
* This emulates the lookup process required by JSR 292 in JVM.
* @param env Attribution environment
* @param spMethod signature polymorphic method - i.e. MH.invokeExact
* @param argtypes The required argument types
*/
Symbol findPolymorphicSignatureInstance(Env env,
final Symbol spMethod,
List argtypes) {
Type mtype = infer.instantiatePolymorphicSignatureInstance(env,
(MethodSymbol)spMethod, currentResolutionContext, argtypes);
for (Symbol sym : polymorphicSignatureScope.getSymbolsByName(spMethod.name)) {
// Check that there is already a method symbol for the method
// type and owner
if (types.isSameType(mtype, sym.type) &&
spMethod.owner == sym.owner) {
return sym;
}
}
// Create the desired method
// Retain static modifier is to support invocations to
// MethodHandle.linkTo* methods
long flags = ABSTRACT | HYPOTHETICAL |
spMethod.flags() & (Flags.AccessFlags | Flags.STATIC);
Symbol msym = new MethodSymbol(flags, spMethod.name, mtype, spMethod.owner) {
@Override
public Symbol baseSymbol() {
return spMethod;
}
};
if (!mtype.isErroneous()) { // Cache only if kosher.
polymorphicSignatureScope.enter(msym);
}
return msym;
}
/** Resolve a qualified method identifier, throw a fatal error if not
* found.
* @param pos The position to use for error reporting.
* @param env The environment current at the method invocation.
* @param site The type of the qualifying expression, in which
* identifier is searched.
* @param name The identifier's name.
* @param argtypes The types of the invocation's value arguments.
* @param typeargtypes The types of the invocation's type arguments.
*/
public MethodSymbol resolveInternalMethod(DiagnosticPosition pos, Env env,
Type site, Name name,
List argtypes,
List typeargtypes) {
MethodResolutionContext resolveContext = new MethodResolutionContext();
resolveContext.internalResolution = true;
Symbol sym = resolveQualifiedMethod(resolveContext, pos, env, site.tsym,
site, name, argtypes, typeargtypes);
if (sym.kind == MTH) return (MethodSymbol)sym;
else throw new FatalError(
diags.fragment("fatal.err.cant.locate.meth",
name));
}
/** Resolve constructor.
* @param pos The position to use for error reporting.
* @param env The environment current at the constructor invocation.
* @param site The type of class for which a constructor is searched.
* @param argtypes The types of the constructor invocation's value
* arguments.
* @param typeargtypes The types of the constructor invocation's type
* arguments.
*/
Symbol resolveConstructor(DiagnosticPosition pos,
Env env,
Type site,
List argtypes,
List typeargtypes) {
return resolveConstructor(new MethodResolutionContext(), pos, env, site, argtypes, typeargtypes);
}
private Symbol resolveConstructor(MethodResolutionContext resolveContext,
final DiagnosticPosition pos,
Env env,
Type site,
List argtypes,
List typeargtypes) {
return lookupMethod(env, pos, site.tsym, resolveContext, new BasicLookupHelper(names.init, site, argtypes, typeargtypes) {
@Override
Symbol doLookup(Env env, MethodResolutionPhase phase) {
return findConstructor(pos, env, site, argtypes, typeargtypes,
phase.isBoxingRequired(),
phase.isVarargsRequired());
}
});
}
/** Resolve a constructor, throw a fatal error if not found.
* @param pos The position to use for error reporting.
* @param env The environment current at the method invocation.
* @param site The type to be constructed.
* @param argtypes The types of the invocation's value arguments.
* @param typeargtypes The types of the invocation's type arguments.
*/
public MethodSymbol resolveInternalConstructor(DiagnosticPosition pos, Env env,
Type site,
List argtypes,
List typeargtypes) {
MethodResolutionContext resolveContext = new MethodResolutionContext();
resolveContext.internalResolution = true;
Symbol sym = resolveConstructor(resolveContext, pos, env, site, argtypes, typeargtypes);
if (sym.kind == MTH) return (MethodSymbol)sym;
else throw new FatalError(
diags.fragment("fatal.err.cant.locate.ctor", site));
}
Symbol findConstructor(DiagnosticPosition pos, Env env,
Type site, List argtypes,
List typeargtypes,
boolean allowBoxing,
boolean useVarargs) {
Symbol sym = findMethod(env, site,
names.init, argtypes,
typeargtypes, allowBoxing,
useVarargs);
chk.checkDeprecated(pos, env.info.scope.owner, sym);
return sym;
}
/** Resolve constructor using diamond inference.
* @param pos The position to use for error reporting.
* @param env The environment current at the constructor invocation.
* @param site The type of class for which a constructor is searched.
* The scope of this class has been touched in attribution.
* @param argtypes The types of the constructor invocation's value
* arguments.
* @param typeargtypes The types of the constructor invocation's type
* arguments.
*/
Symbol resolveDiamond(DiagnosticPosition pos,
Env env,
Type site,
List argtypes,
List typeargtypes) {
return lookupMethod(env, pos, site.tsym, resolveMethodCheck,
new BasicLookupHelper(names.init, site, argtypes, typeargtypes) {
@Override
Symbol doLookup(Env env, MethodResolutionPhase phase) {
return findDiamond(env, site, argtypes, typeargtypes,
phase.isBoxingRequired(),
phase.isVarargsRequired());
}
@Override
Symbol access(Env env, DiagnosticPosition pos, Symbol location, Symbol sym) {
if (sym.kind.isResolutionError()) {
if (sym.kind != WRONG_MTH &&
sym.kind != WRONG_MTHS) {
sym = super.access(env, pos, location, sym);
} else {
final JCDiagnostic details = sym.kind == WRONG_MTH ?
((InapplicableSymbolError)sym.baseSymbol()).errCandidate().snd :
null;
sym = new DiamondError(sym, currentResolutionContext);
sym = accessMethod(sym, pos, site, names.init, true, argtypes, typeargtypes);
env.info.pendingResolutionPhase = currentResolutionContext.step;
}
}
return sym;
}});
}
/** This method scans all the constructor symbol in a given class scope -
* assuming that the original scope contains a constructor of the kind:
* {@code Foo(X x, Y y)}, where X,Y are class type-variables declared in Foo,
* a method check is executed against the modified constructor type:
* {@code Foo(X x, Y y)}. This is crucial in order to enable diamond
* inference. The inferred return type of the synthetic constructor IS
* the inferred type for the diamond operator.
*/
private Symbol findDiamond(Env env,
Type site,
List argtypes,
List typeargtypes,
boolean allowBoxing,
boolean useVarargs) {
Symbol bestSoFar = methodNotFound;
TypeSymbol tsym = site.tsym.isInterface() ? syms.objectType.tsym : site.tsym;
for (final Symbol sym : tsym.members().getSymbolsByName(names.init)) {
//- System.out.println(" e " + e.sym);
if (sym.kind == MTH &&
(sym.flags_field & SYNTHETIC) == 0) {
List oldParams = sym.type.hasTag(FORALL) ?
((ForAll)sym.type).tvars :
List.nil();
Type constrType = new ForAll(site.tsym.type.getTypeArguments().appendList(oldParams),
types.createMethodTypeWithReturn(sym.type.asMethodType(), site));
MethodSymbol newConstr = new MethodSymbol(sym.flags(), names.init, constrType, site.tsym) {
@Override
public Symbol baseSymbol() {
return sym;
}
};
bestSoFar = selectBest(env, site, argtypes, typeargtypes,
newConstr,
bestSoFar,
allowBoxing,
useVarargs);
}
}
return bestSoFar;
}
Symbol getMemberReference(DiagnosticPosition pos,
Env env,
JCMemberReference referenceTree,
Type site,
Name name) {
site = types.capture(site);
ReferenceLookupHelper lookupHelper = makeReferenceLookupHelper(
referenceTree, site, name, List.nil(), null, VARARITY);
Env newEnv = env.dup(env.tree, env.info.dup());
Symbol sym = lookupMethod(newEnv, env.tree.pos(), site.tsym,
nilMethodCheck, lookupHelper);
env.info.pendingResolutionPhase = newEnv.info.pendingResolutionPhase;
return sym;
}
ReferenceLookupHelper makeReferenceLookupHelper(JCMemberReference referenceTree,
Type site,
Name name,
List argtypes,
List typeargtypes,
MethodResolutionPhase maxPhase) {
if (!name.equals(names.init)) {
//method reference
return new MethodReferenceLookupHelper(referenceTree, name, site, argtypes, typeargtypes, maxPhase);
} else if (site.hasTag(ARRAY)) {
//array constructor reference
return new ArrayConstructorReferenceLookupHelper(referenceTree, site, argtypes, typeargtypes, maxPhase);
} else {
//class constructor reference
return new ConstructorReferenceLookupHelper(referenceTree, site, argtypes, typeargtypes, maxPhase);
}
}
/**
* Resolution of member references is typically done as a single
* overload resolution step, where the argument types A are inferred from
* the target functional descriptor.
*
* If the member reference is a method reference with a type qualifier,
* a two-step lookup process is performed. The first step uses the
* expected argument list A, while the second step discards the first
* type from A (which is treated as a receiver type).
*
* There are two cases in which inference is performed: (i) if the member
* reference is a constructor reference and the qualifier type is raw - in
* which case diamond inference is used to infer a parameterization for the
* type qualifier; (ii) if the member reference is an unbound reference
* where the type qualifier is raw - in that case, during the unbound lookup
* the receiver argument type is used to infer an instantiation for the raw
* qualifier type.
*
* When a multi-step resolution process is exploited, the process of picking
* the resulting symbol is delegated to an helper class {@link com.sun.tools.javac.comp.Resolve.ReferenceChooser}.
*
* This routine returns a pair (T,S), where S is the member reference symbol,
* and T is the type of the class in which S is defined. This is necessary as
* the type T might be dynamically inferred (i.e. if constructor reference
* has a raw qualifier).
*/
Pair resolveMemberReference(Env env,
JCMemberReference referenceTree,
Type site,
Name name,
List argtypes,
List typeargtypes,
MethodCheck methodCheck,
InferenceContext inferenceContext,
ReferenceChooser referenceChooser) {
//step 1 - bound lookup
ReferenceLookupHelper boundLookupHelper = makeReferenceLookupHelper(
referenceTree, site, name, argtypes, typeargtypes, VARARITY);
Env boundEnv = env.dup(env.tree, env.info.dup());
MethodResolutionContext boundSearchResolveContext = new MethodResolutionContext();
boundSearchResolveContext.methodCheck = methodCheck;
Symbol boundSym = lookupMethod(boundEnv, env.tree.pos(),
site.tsym, boundSearchResolveContext, boundLookupHelper);
ReferenceLookupResult boundRes = new ReferenceLookupResult(boundSym, boundSearchResolveContext);
//step 2 - unbound lookup
Symbol unboundSym = methodNotFound;
Env unboundEnv = env.dup(env.tree, env.info.dup());
ReferenceLookupHelper unboundLookupHelper = boundLookupHelper.unboundLookup(inferenceContext);
ReferenceLookupResult unboundRes = referenceNotFound;
if (unboundLookupHelper != null) {
MethodResolutionContext unboundSearchResolveContext =
new MethodResolutionContext();
unboundSearchResolveContext.methodCheck = methodCheck;
unboundSym = lookupMethod(unboundEnv, env.tree.pos(),
site.tsym, unboundSearchResolveContext, unboundLookupHelper);
unboundRes = new ReferenceLookupResult(unboundSym, unboundSearchResolveContext);
}
//merge results
Pair res;
Symbol bestSym = referenceChooser.result(boundRes, unboundRes);
res = new Pair<>(bestSym,
bestSym == unboundSym ? unboundLookupHelper : boundLookupHelper);
env.info.pendingResolutionPhase = bestSym == unboundSym ?
unboundEnv.info.pendingResolutionPhase :
boundEnv.info.pendingResolutionPhase;
return res;
}
/**
* This class is used to represent a method reference lookup result. It keeps track of two
* things: (i) the symbol found during a method reference lookup and (ii) the static kind
* of the lookup (see {@link com.sun.tools.javac.comp.Resolve.ReferenceLookupResult.StaticKind}).
*/
static class ReferenceLookupResult {
/**
* Static kind associated with a method reference lookup. Erroneous lookups end up with
* the UNDEFINED kind; successful lookups will end up with either STATIC, NON_STATIC,
* depending on whether all applicable candidates are static or non-static methods,
* respectively. If a successful lookup has both static and non-static applicable methods,
* its kind is set to BOTH.
*/
enum StaticKind {
STATIC,
NON_STATIC,
BOTH,
UNDEFINED;
/**
* Retrieve the static kind associated with a given (method) symbol.
*/
static StaticKind from(Symbol s) {
return s.isStatic() ?
STATIC : NON_STATIC;
}
/**
* Merge two static kinds together.
*/
static StaticKind reduce(StaticKind sk1, StaticKind sk2) {
if (sk1 == UNDEFINED) {
return sk2;
} else if (sk2 == UNDEFINED) {
return sk1;
} else {
return sk1 == sk2 ? sk1 : BOTH;
}
}
}
/** The static kind. */
StaticKind staticKind;
/** The lookup result. */
Symbol sym;
ReferenceLookupResult(Symbol sym, MethodResolutionContext resolutionContext) {
this.staticKind = staticKind(sym, resolutionContext);
this.sym = sym;
}
private StaticKind staticKind(Symbol sym, MethodResolutionContext resolutionContext) {
switch (sym.kind) {
case MTH:
case AMBIGUOUS:
return resolutionContext.candidates.stream()
.filter(c -> c.isApplicable() && c.step == resolutionContext.step)
.map(c -> StaticKind.from(c.sym))
.reduce(StaticKind::reduce)
.orElse(StaticKind.UNDEFINED);
default:
return StaticKind.UNDEFINED;
}
}
/**
* Does this result corresponds to a successful lookup (i.e. one where a method has been found?)
*/
boolean isSuccess() {
return staticKind != StaticKind.UNDEFINED;
}
/**
* Does this result have given static kind?
*/
boolean hasKind(StaticKind sk) {
return this.staticKind == sk;
}
/**
* Error recovery helper: can this lookup result be ignored (for the purpose of returning
* some 'better' result) ?
*/
boolean canIgnore() {
switch (sym.kind) {
case ABSENT_MTH:
return true;
case WRONG_MTH:
InapplicableSymbolError errSym =
(InapplicableSymbolError)sym.baseSymbol();
return new Template(MethodCheckDiag.ARITY_MISMATCH.regex())
.matches(errSym.errCandidate().snd);
case WRONG_MTHS:
InapplicableSymbolsError errSyms =
(InapplicableSymbolsError)sym.baseSymbol();
return errSyms.filterCandidates(errSyms.mapCandidates()).isEmpty();
default:
return false;
}
}
}
/**
* This abstract class embodies the logic that converts one (bound lookup) or two (unbound lookup)
* {@code ReferenceLookupResult} objects into a (@code Symbol), which is then regarded as the
* result of method reference resolution.
*/
abstract class ReferenceChooser {
/**
* Generate a result from a pair of lookup result objects. This method delegates to the
* appropriate result generation routine.
*/
Symbol result(ReferenceLookupResult boundRes, ReferenceLookupResult unboundRes) {
return unboundRes != referenceNotFound ?
unboundResult(boundRes, unboundRes) :
boundResult(boundRes);
}
/**
* Generate a symbol from a given bound lookup result.
*/
abstract Symbol boundResult(ReferenceLookupResult boundRes);
/**
* Generate a symbol from a pair of bound/unbound lookup results.
*/
abstract Symbol unboundResult(ReferenceLookupResult boundRes, ReferenceLookupResult unboundRes);
}
/**
* This chooser implements the selection strategy used during a full lookup; this logic
* is described in JLS SE 8 (15.3.2).
*/
ReferenceChooser basicReferenceChooser = new ReferenceChooser() {
@Override
Symbol boundResult(ReferenceLookupResult boundRes) {
return !boundRes.isSuccess() || boundRes.hasKind(StaticKind.NON_STATIC) ?
boundRes.sym : //the search produces a non-static method
new BadMethodReferenceError(boundRes.sym, false);
}
@Override
Symbol unboundResult(ReferenceLookupResult boundRes, ReferenceLookupResult unboundRes) {
if (boundRes.hasKind(StaticKind.STATIC) &&
(!unboundRes.isSuccess() || unboundRes.hasKind(StaticKind.STATIC))) {
//the first search produces a static method and no non-static method is applicable
//during the second search
return boundRes.sym;
} else if (unboundRes.hasKind(StaticKind.NON_STATIC) &&
(!boundRes.isSuccess() || boundRes.hasKind(StaticKind.NON_STATIC))) {
//the second search produces a non-static method and no static method is applicable
//during the first search
return unboundRes.sym;
} else if (boundRes.isSuccess() && unboundRes.isSuccess()) {
//both searches produce some result; ambiguity (error recovery)
return ambiguityError(boundRes.sym, unboundRes.sym);
} else if (boundRes.isSuccess() || unboundRes.isSuccess()) {
//Both searches failed to produce a result with correct staticness (i.e. first search
//produces an non-static method). Alternatively, a given search produced a result
//with the right staticness, but the other search has applicable methods with wrong
//staticness (error recovery)
return new BadMethodReferenceError(boundRes.isSuccess() ? boundRes.sym : unboundRes.sym, true);
} else {
//both searches fail to produce a result - pick 'better' error using heuristics (error recovery)
return (boundRes.canIgnore() && !unboundRes.canIgnore()) ?
unboundRes.sym : boundRes.sym;
}
}
};
/**
* This chooser implements the selection strategy used during an arity-based lookup; this logic
* is described in JLS SE 8 (15.12.2.1).
*/
ReferenceChooser structuralReferenceChooser = new ReferenceChooser() {
@Override
Symbol boundResult(ReferenceLookupResult boundRes) {
return (!boundRes.isSuccess() || !boundRes.hasKind(StaticKind.STATIC)) ?
boundRes.sym : //the search has at least one applicable non-static method
new BadMethodReferenceError(boundRes.sym, false);
}
@Override
Symbol unboundResult(ReferenceLookupResult boundRes, ReferenceLookupResult unboundRes) {
if (boundRes.isSuccess() && !boundRes.hasKind(StaticKind.NON_STATIC)) {
//the first serach has at least one applicable static method
return boundRes.sym;
} else if (unboundRes.isSuccess() && !unboundRes.hasKind(StaticKind.STATIC)) {
//the second search has at least one applicable non-static method
return unboundRes.sym;
} else if (boundRes.isSuccess() || unboundRes.isSuccess()) {
//either the first search produces a non-static method, or second search produces
//a non-static method (error recovery)
return new BadMethodReferenceError(boundRes.isSuccess() ? boundRes.sym : unboundRes.sym, true);
} else {
//both searches fail to produce a result - pick 'better' error using heuristics (error recovery)
return (boundRes.canIgnore() && !unboundRes.canIgnore()) ?
unboundRes.sym : boundRes.sym;
}
}
};
/**
* Helper for defining custom method-like lookup logic; a lookup helper
* provides hooks for (i) the actual lookup logic and (ii) accessing the
* lookup result (this step might result in compiler diagnostics to be generated)
*/
abstract class LookupHelper {
/** name of the symbol to lookup */
Name name;
/** location in which the lookup takes place */
Type site;
/** actual types used during the lookup */
List argtypes;
/** type arguments used during the lookup */
List typeargtypes;
/** Max overload resolution phase handled by this helper */
MethodResolutionPhase maxPhase;
LookupHelper(Name name, Type site, List argtypes, List typeargtypes, MethodResolutionPhase maxPhase) {
this.name = name;
this.site = site;
this.argtypes = argtypes;
this.typeargtypes = typeargtypes;
this.maxPhase = maxPhase;
}
/**
* Should lookup stop at given phase with given result
*/
final boolean shouldStop(Symbol sym, MethodResolutionPhase phase) {
return phase.ordinal() > maxPhase.ordinal() ||
!sym.kind.isResolutionError() || sym.kind == AMBIGUOUS;
}
/**
* Search for a symbol under a given overload resolution phase - this method
* is usually called several times, once per each overload resolution phase
*/
abstract Symbol lookup(Env env, MethodResolutionPhase phase);
/**
* Dump overload resolution info
*/
void debug(DiagnosticPosition pos, Symbol sym) {
//do nothing
}
/**
* Validate the result of the lookup
*/
abstract Symbol access(Env env, DiagnosticPosition pos, Symbol location, Symbol sym);
}
abstract class BasicLookupHelper extends LookupHelper {
BasicLookupHelper(Name name, Type site, List argtypes, List typeargtypes) {
this(name, site, argtypes, typeargtypes, MethodResolutionPhase.VARARITY);
}
BasicLookupHelper(Name name, Type site, List argtypes, List typeargtypes, MethodResolutionPhase maxPhase) {
super(name, site, argtypes, typeargtypes, maxPhase);
}
@Override
final Symbol lookup(Env env, MethodResolutionPhase phase) {
Symbol sym = doLookup(env, phase);
if (sym.kind == AMBIGUOUS) {
AmbiguityError a_err = (AmbiguityError)sym.baseSymbol();
sym = a_err.mergeAbstracts(site);
}
return sym;
}
abstract Symbol doLookup(Env env, MethodResolutionPhase phase);
@Override
Symbol access(Env env, DiagnosticPosition pos, Symbol location, Symbol sym) {
if (sym.kind.isResolutionError()) {
//if nothing is found return the 'first' error
sym = accessMethod(sym, pos, location, site, name, true, argtypes, typeargtypes);
}
return sym;
}
@Override
void debug(DiagnosticPosition pos, Symbol sym) {
reportVerboseResolutionDiagnostic(pos, name, site, argtypes, typeargtypes, sym);
}
}
/**
* Helper class for member reference lookup. A reference lookup helper
* defines the basic logic for member reference lookup; a method gives
* access to an 'unbound' helper used to perform an unbound member
* reference lookup.
*/
abstract class ReferenceLookupHelper extends LookupHelper {
/** The member reference tree */
JCMemberReference referenceTree;
ReferenceLookupHelper(JCMemberReference referenceTree, Name name, Type site,
List argtypes, List typeargtypes, MethodResolutionPhase maxPhase) {
super(name, site, argtypes, typeargtypes, maxPhase);
this.referenceTree = referenceTree;
}
/**
* Returns an unbound version of this lookup helper. By default, this
* method returns an dummy lookup helper.
*/
ReferenceLookupHelper unboundLookup(InferenceContext inferenceContext) {
return null;
}
/**
* Get the kind of the member reference
*/
abstract JCMemberReference.ReferenceKind referenceKind(Symbol sym);
Symbol access(Env env, DiagnosticPosition pos, Symbol location, Symbol sym) {
if (sym.kind == AMBIGUOUS) {
AmbiguityError a_err = (AmbiguityError)sym.baseSymbol();
sym = a_err.mergeAbstracts(site);
}
//skip error reporting
return sym;
}
}
/**
* Helper class for method reference lookup. The lookup logic is based
* upon Resolve.findMethod; in certain cases, this helper class has a
* corresponding unbound helper class (see UnboundMethodReferenceLookupHelper).
* In such cases, non-static lookup results are thrown away.
*/
class MethodReferenceLookupHelper extends ReferenceLookupHelper {
/** The original method reference lookup site. */
Type originalSite;
MethodReferenceLookupHelper(JCMemberReference referenceTree, Name name, Type site,
List argtypes, List typeargtypes, MethodResolutionPhase maxPhase) {
super(referenceTree, name, types.skipTypeVars(site, true), argtypes, typeargtypes, maxPhase);
this.originalSite = site;
}
@Override
final Symbol lookup(Env env, MethodResolutionPhase phase) {
return findMethod(env, site, name, argtypes, typeargtypes,
phase.isBoxingRequired(), phase.isVarargsRequired());
}
@Override
ReferenceLookupHelper unboundLookup(InferenceContext inferenceContext) {
if (TreeInfo.isStaticSelector(referenceTree.expr, names)) {
if (argtypes.nonEmpty() &&
(argtypes.head.hasTag(NONE) ||
types.isSubtypeUnchecked(inferenceContext.asUndetVar(argtypes.head), originalSite))) {
return new UnboundMethodReferenceLookupHelper(referenceTree, name,
originalSite, argtypes, typeargtypes, maxPhase);
} else {
return new ReferenceLookupHelper(referenceTree, name, site, argtypes, typeargtypes, maxPhase) {
@Override
ReferenceLookupHelper unboundLookup(InferenceContext inferenceContext) {
return this;
}
@Override
Symbol lookup(Env env, MethodResolutionPhase phase) {
return methodNotFound;
}
@Override
ReferenceKind referenceKind(Symbol sym) {
Assert.error();
return null;
}
};
}
} else {
return super.unboundLookup(inferenceContext);
}
}
@Override
ReferenceKind referenceKind(Symbol sym) {
if (sym.isStatic()) {
return ReferenceKind.STATIC;
} else {
Name selName = TreeInfo.name(referenceTree.getQualifierExpression());
return selName != null && selName == names._super ?
ReferenceKind.SUPER :
ReferenceKind.BOUND;
}
}
}
/**
* Helper class for unbound method reference lookup. Essentially the same
* as the basic method reference lookup helper; main difference is that static
* lookup results are thrown away. If qualifier type is raw, an attempt to
* infer a parameterized type is made using the first actual argument (that
* would otherwise be ignored during the lookup).
*/
class UnboundMethodReferenceLookupHelper extends MethodReferenceLookupHelper {
UnboundMethodReferenceLookupHelper(JCMemberReference referenceTree, Name name, Type site,
List argtypes, List typeargtypes, MethodResolutionPhase maxPhase) {
super(referenceTree, name, site, argtypes.tail, typeargtypes, maxPhase);
if (site.isRaw() && !argtypes.head.hasTag(NONE)) {
Type asSuperSite = types.asSuper(argtypes.head, site.tsym);
this.site = types.skipTypeVars(asSuperSite, true);
}
}
@Override
ReferenceLookupHelper unboundLookup(InferenceContext inferenceContext) {
return this;
}
@Override
ReferenceKind referenceKind(Symbol sym) {
return ReferenceKind.UNBOUND;
}
}
/**
* Helper class for array constructor lookup; an array constructor lookup
* is simulated by looking up a method that returns the array type specified
* as qualifier, and that accepts a single int parameter (size of the array).
*/
class ArrayConstructorReferenceLookupHelper extends ReferenceLookupHelper {
ArrayConstructorReferenceLookupHelper(JCMemberReference referenceTree, Type site, List argtypes,
List typeargtypes, MethodResolutionPhase maxPhase) {
super(referenceTree, names.init, site, argtypes, typeargtypes, maxPhase);
}
@Override
protected Symbol lookup(Env env, MethodResolutionPhase phase) {
WriteableScope sc = WriteableScope.create(syms.arrayClass);
MethodSymbol arrayConstr = new MethodSymbol(PUBLIC, name, null, site.tsym);
arrayConstr.type = new MethodType(List.of(syms.intType), site, List.nil(), syms.methodClass);
sc.enter(arrayConstr);
return findMethodInScope(env, site, name, argtypes, typeargtypes, sc, methodNotFound, phase.isBoxingRequired(), phase.isVarargsRequired(), false);
}
@Override
ReferenceKind referenceKind(Symbol sym) {
return ReferenceKind.ARRAY_CTOR;
}
}
/**
* Helper class for constructor reference lookup. The lookup logic is based
* upon either Resolve.findMethod or Resolve.findDiamond - depending on
* whether the constructor reference needs diamond inference (this is the case
* if the qualifier type is raw). A special erroneous symbol is returned
* if the lookup returns the constructor of an inner class and there's no
* enclosing instance in scope.
*/
class ConstructorReferenceLookupHelper extends ReferenceLookupHelper {
boolean needsInference;
ConstructorReferenceLookupHelper(JCMemberReference referenceTree, Type site, List argtypes,
List typeargtypes, MethodResolutionPhase maxPhase) {
super(referenceTree, names.init, site, argtypes, typeargtypes, maxPhase);
if (site.isRaw()) {
this.site = new ClassType(site.getEnclosingType(), site.tsym.type.getTypeArguments(), site.tsym, site.getMetadata());
needsInference = true;
}
}
@Override
protected Symbol lookup(Env env, MethodResolutionPhase phase) {
Symbol sym = needsInference ?
findDiamond(env, site, argtypes, typeargtypes, phase.isBoxingRequired(), phase.isVarargsRequired()) :
findMethod(env, site, name, argtypes, typeargtypes,
phase.isBoxingRequired(), phase.isVarargsRequired());
return enclosingInstanceMissing(env, site) ? new BadConstructorReferenceError(sym) : sym;
}
@Override
ReferenceKind referenceKind(Symbol sym) {
return site.getEnclosingType().hasTag(NONE) ?
ReferenceKind.TOPLEVEL : ReferenceKind.IMPLICIT_INNER;
}
}
/**
* Main overload resolution routine. On each overload resolution step, a
* lookup helper class is used to perform the method/constructor lookup;
* at the end of the lookup, the helper is used to validate the results
* (this last step might trigger overload resolution diagnostics).
*/
Symbol lookupMethod(Env env, DiagnosticPosition pos, Symbol location, MethodCheck methodCheck, LookupHelper lookupHelper) {
MethodResolutionContext resolveContext = new MethodResolutionContext();
resolveContext.methodCheck = methodCheck;
return lookupMethod(env, pos, location, resolveContext, lookupHelper);
}
Symbol lookupMethod(Env env, DiagnosticPosition pos, Symbol location,
MethodResolutionContext resolveContext, LookupHelper lookupHelper) {
MethodResolutionContext prevResolutionContext = currentResolutionContext;
try {
Symbol bestSoFar = methodNotFound;
currentResolutionContext = resolveContext;
for (MethodResolutionPhase phase : methodResolutionSteps) {
if (lookupHelper.shouldStop(bestSoFar, phase))
break;
MethodResolutionPhase prevPhase = currentResolutionContext.step;
Symbol prevBest = bestSoFar;
currentResolutionContext.step = phase;
Symbol sym = lookupHelper.lookup(env, phase);
lookupHelper.debug(pos, sym);
bestSoFar = phase.mergeResults(bestSoFar, sym);
env.info.pendingResolutionPhase = (prevBest == bestSoFar) ? prevPhase : phase;
}
return lookupHelper.access(env, pos, location, bestSoFar);
} finally {
currentResolutionContext = prevResolutionContext;
}
}
/**
* Resolve `c.name' where name == this or name == super.
* @param pos The position to use for error reporting.
* @param env The environment current at the expression.
* @param c The qualifier.
* @param name The identifier's name.
*/
Symbol resolveSelf(DiagnosticPosition pos,
Env env,
TypeSymbol c,
Name name) {
Env env1 = env;
boolean staticOnly = false;
while (env1.outer != null) {
if (isStatic(env1)) staticOnly = true;
if (env1.enclClass.sym == c) {
Symbol sym = env1.info.scope.findFirst(name);
if (sym != null) {
if (staticOnly) sym = new StaticError(sym);
return accessBase(sym, pos, env.enclClass.sym.type,
name, true);
}
}
if ((env1.enclClass.sym.flags() & STATIC) != 0) staticOnly = true;
env1 = env1.outer;
}
if (c.isInterface() &&
name == names._super && !isStatic(env) &&
types.isDirectSuperInterface(c, env.enclClass.sym)) {
//this might be a default super call if one of the superinterfaces is 'c'
for (Type t : pruneInterfaces(env.enclClass.type)) {
if (t.tsym == c) {
env.info.defaultSuperCallSite = t;
return new VarSymbol(0, names._super,
types.asSuper(env.enclClass.type, c), env.enclClass.sym);
}
}
//find a direct super type that is a subtype of 'c'
for (Type i : types.directSupertypes(env.enclClass.type)) {
if (i.tsym.isSubClass(c, types) && i.tsym != c) {
log.error(pos, "illegal.default.super.call", c,
diags.fragment("redundant.supertype", c, i));
return syms.errSymbol;
}
}
Assert.error();
}
log.error(pos, "not.encl.class", c);
return syms.errSymbol;
}
//where
private List pruneInterfaces(Type t) {
ListBuffer result = new ListBuffer<>();
for (Type t1 : types.interfaces(t)) {
boolean shouldAdd = true;
for (Type t2 : types.directSupertypes(t)) {
if (t1 != t2 && types.isSubtypeNoCapture(t2, t1)) {
shouldAdd = false;
}
}
if (shouldAdd) {
result.append(t1);
}
}
return result.toList();
}
/**
* Resolve `c.this' for an enclosing class c that contains the
* named member.
* @param pos The position to use for error reporting.
* @param env The environment current at the expression.
* @param member The member that must be contained in the result.
*/
Symbol resolveSelfContaining(DiagnosticPosition pos,
Env env,
Symbol member,
boolean isSuperCall) {
Symbol sym = resolveSelfContainingInternal(env, member, isSuperCall);
if (sym == null) {
log.error(pos, "encl.class.required", member);
return syms.errSymbol;
} else {
return accessBase(sym, pos, env.enclClass.sym.type, sym.name, true);
}
}
boolean enclosingInstanceMissing(Env env, Type type) {
if (type.hasTag(CLASS) && type.getEnclosingType().hasTag(CLASS)) {
Symbol encl = resolveSelfContainingInternal(env, type.tsym, false);
return encl == null || encl.kind.isResolutionError();
}
return false;
}
private Symbol resolveSelfContainingInternal(Env env,
Symbol member,
boolean isSuperCall) {
Name name = names._this;
Env env1 = isSuperCall ? env.outer : env;
boolean staticOnly = false;
if (env1 != null) {
while (env1 != null && env1.outer != null) {
if (isStatic(env1)) staticOnly = true;
if (env1.enclClass.sym.isSubClass(member.owner.enclClass(), types)) {
Symbol sym = env1.info.scope.findFirst(name);
if (sym != null) {
if (staticOnly) sym = new StaticError(sym);
return sym;
}
}
if ((env1.enclClass.sym.flags() & STATIC) != 0)
staticOnly = true;
env1 = env1.outer;
}
}
return null;
}
/**
* Resolve an appropriate implicit this instance for t's container.
* JLS 8.8.5.1 and 15.9.2
*/
Type resolveImplicitThis(DiagnosticPosition pos, Env env, Type t) {
return resolveImplicitThis(pos, env, t, false);
}
Type resolveImplicitThis(DiagnosticPosition pos, Env