8231826: Implement javac changes for pattern matching for instanceof
Reviewed-by: mcimadamore
Contributed-by: brian.goetz@oracle.com, gavin.bierman@oracle.com, maurizio.cimadamore@oracle.com, srikanth.adayapalam@oracle.com, vicente.romero@oracle.com, jan.lahoda@oracle.com
/*
* Copyright (c) 1999, 2019, 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 com.sun.tools.javac.comp;
import java.util.*;
import java.util.function.BiConsumer;
import java.util.stream.Collectors;
import javax.lang.model.element.ElementKind;
import javax.tools.JavaFileObject;
import com.sun.source.tree.CaseTree;
import com.sun.source.tree.IdentifierTree;
import com.sun.source.tree.MemberReferenceTree.ReferenceMode;
import com.sun.source.tree.MemberSelectTree;
import com.sun.source.tree.TreeVisitor;
import com.sun.source.util.SimpleTreeVisitor;
import com.sun.tools.javac.code.*;
import com.sun.tools.javac.code.Lint.LintCategory;
import com.sun.tools.javac.code.Scope.WriteableScope;
import com.sun.tools.javac.code.Source.Feature;
import com.sun.tools.javac.code.Symbol.*;
import com.sun.tools.javac.code.Type.*;
import com.sun.tools.javac.code.TypeMetadata.Annotations;
import com.sun.tools.javac.code.Types.FunctionDescriptorLookupError;
import com.sun.tools.javac.comp.ArgumentAttr.LocalCacheContext;
import com.sun.tools.javac.comp.Check.CheckContext;
import com.sun.tools.javac.comp.DeferredAttr.AttrMode;
import com.sun.tools.javac.comp.MatchBindingsComputer.BindingSymbol;
import com.sun.tools.javac.jvm.*;
import static com.sun.tools.javac.resources.CompilerProperties.Fragments.Diamond;
import static com.sun.tools.javac.resources.CompilerProperties.Fragments.DiamondInvalidArg;
import static com.sun.tools.javac.resources.CompilerProperties.Fragments.DiamondInvalidArgs;
import com.sun.tools.javac.resources.CompilerProperties.Errors;
import com.sun.tools.javac.resources.CompilerProperties.Fragments;
import com.sun.tools.javac.resources.CompilerProperties.Warnings;
import com.sun.tools.javac.tree.*;
import com.sun.tools.javac.tree.JCTree.*;
import com.sun.tools.javac.tree.JCTree.JCPolyExpression.*;
import com.sun.tools.javac.util.*;
import com.sun.tools.javac.util.DefinedBy.Api;
import com.sun.tools.javac.util.JCDiagnostic.DiagnosticPosition;
import com.sun.tools.javac.util.JCDiagnostic.Error;
import com.sun.tools.javac.util.JCDiagnostic.Fragment;
import com.sun.tools.javac.util.JCDiagnostic.Warning;
import com.sun.tools.javac.util.List;
import static com.sun.tools.javac.code.Flags.*;
import static com.sun.tools.javac.code.Flags.ANNOTATION;
import static com.sun.tools.javac.code.Flags.BLOCK;
import static com.sun.tools.javac.code.Kinds.*;
import static com.sun.tools.javac.code.Kinds.Kind.*;
import static com.sun.tools.javac.code.TypeTag.*;
import static com.sun.tools.javac.code.TypeTag.WILDCARD;
import static com.sun.tools.javac.tree.JCTree.Tag.*;
import com.sun.tools.javac.util.JCDiagnostic.DiagnosticFlag;
/** This is the main context-dependent analysis phase in GJC. It
* encompasses name resolution, type checking and constant folding as
* subtasks. Some subtasks involve auxiliary classes.
* @see Check
* @see Resolve
* @see ConstFold
* @see Infer
*
* <p><b>This is NOT part of any supported API.
* If you write code that depends on this, you do so at your own risk.
* This code and its internal interfaces are subject to change or
* deletion without notice.</b>
*/
public class Attr extends JCTree.Visitor {
protected static final Context.Key<Attr> attrKey = new Context.Key<>();
final Names names;
final Log log;
final Symtab syms;
final Resolve rs;
final Operators operators;
final Infer infer;
final Analyzer analyzer;
final DeferredAttr deferredAttr;
final Check chk;
final Flow flow;
final MemberEnter memberEnter;
final TypeEnter typeEnter;
final TreeMaker make;
final ConstFold cfolder;
final Enter enter;
final Target target;
final Types types;
final Preview preview;
final JCDiagnostic.Factory diags;
final TypeAnnotations typeAnnotations;
final DeferredLintHandler deferredLintHandler;
final TypeEnvs typeEnvs;
final Dependencies dependencies;
final Annotate annotate;
final ArgumentAttr argumentAttr;
final MatchBindingsComputer matchBindingsComputer;
public static Attr instance(Context context) {
Attr instance = context.get(attrKey);
if (instance == null)
instance = new Attr(context);
return instance;
}
protected Attr(Context context) {
context.put(attrKey, this);
names = Names.instance(context);
log = Log.instance(context);
syms = Symtab.instance(context);
rs = Resolve.instance(context);
operators = Operators.instance(context);
chk = Check.instance(context);
flow = Flow.instance(context);
memberEnter = MemberEnter.instance(context);
typeEnter = TypeEnter.instance(context);
make = TreeMaker.instance(context);
enter = Enter.instance(context);
infer = Infer.instance(context);
analyzer = Analyzer.instance(context);
deferredAttr = DeferredAttr.instance(context);
cfolder = ConstFold.instance(context);
target = Target.instance(context);
types = Types.instance(context);
preview = Preview.instance(context);
diags = JCDiagnostic.Factory.instance(context);
annotate = Annotate.instance(context);
typeAnnotations = TypeAnnotations.instance(context);
deferredLintHandler = DeferredLintHandler.instance(context);
typeEnvs = TypeEnvs.instance(context);
dependencies = Dependencies.instance(context);
argumentAttr = ArgumentAttr.instance(context);
matchBindingsComputer = MatchBindingsComputer.instance(context);
Options options = Options.instance(context);
Source source = Source.instance(context);
allowPoly = Feature.POLY.allowedInSource(source);
allowTypeAnnos = Feature.TYPE_ANNOTATIONS.allowedInSource(source);
allowLambda = Feature.LAMBDA.allowedInSource(source);
allowDefaultMethods = Feature.DEFAULT_METHODS.allowedInSource(source);
allowStaticInterfaceMethods = Feature.STATIC_INTERFACE_METHODS.allowedInSource(source);
allowReifiableTypesInInstanceof =
Feature.REIFIABLE_TYPES_INSTANCEOF.allowedInSource(source) &&
(!preview.isPreview(Feature.REIFIABLE_TYPES_INSTANCEOF) || preview.isEnabled());
sourceName = source.name;
useBeforeDeclarationWarning = options.isSet("useBeforeDeclarationWarning");
statInfo = new ResultInfo(KindSelector.NIL, Type.noType);
varAssignmentInfo = new ResultInfo(KindSelector.ASG, Type.noType);
unknownExprInfo = new ResultInfo(KindSelector.VAL, Type.noType);
methodAttrInfo = new MethodAttrInfo();
unknownTypeInfo = new ResultInfo(KindSelector.TYP, Type.noType);
unknownTypeExprInfo = new ResultInfo(KindSelector.VAL_TYP, Type.noType);
recoveryInfo = new RecoveryInfo(deferredAttr.emptyDeferredAttrContext);
}
/** Switch: support target-typing inference
*/
boolean allowPoly;
/** Switch: support type annotations.
*/
boolean allowTypeAnnos;
/** Switch: support lambda expressions ?
*/
boolean allowLambda;
/** Switch: support default methods ?
*/
boolean allowDefaultMethods;
/** Switch: static interface methods enabled?
*/
boolean allowStaticInterfaceMethods;
/** Switch: reifiable types in instanceof enabled?
*/
boolean allowReifiableTypesInInstanceof;
/**
* Switch: warn about use of variable before declaration?
* RFE: 6425594
*/
boolean useBeforeDeclarationWarning;
/**
* Switch: name of source level; used for error reporting.
*/
String sourceName;
/** Check kind and type of given tree against protokind and prototype.
* If check succeeds, store type in tree and return it.
* If check fails, store errType in tree and return it.
* No checks are performed if the prototype is a method type.
* It is not necessary in this case since we know that kind and type
* are correct.
*
* @param tree The tree whose kind and type is checked
* @param found The computed type of the tree
* @param ownkind The computed kind of the tree
* @param resultInfo The expected result of the tree
*/
Type check(final JCTree tree,
final Type found,
final KindSelector ownkind,
final ResultInfo resultInfo) {
InferenceContext inferenceContext = resultInfo.checkContext.inferenceContext();
Type owntype;
boolean shouldCheck = !found.hasTag(ERROR) &&
!resultInfo.pt.hasTag(METHOD) &&
!resultInfo.pt.hasTag(FORALL);
if (shouldCheck && !ownkind.subset(resultInfo.pkind)) {
log.error(tree.pos(),
Errors.UnexpectedType(resultInfo.pkind.kindNames(),
ownkind.kindNames()));
owntype = types.createErrorType(found);
} else if (allowPoly && inferenceContext.free(found)) {
//delay the check if there are inference variables in the found type
//this means we are dealing with a partially inferred poly expression
owntype = shouldCheck ? resultInfo.pt : found;
if (resultInfo.checkMode.installPostInferenceHook()) {
inferenceContext.addFreeTypeListener(List.of(found),
instantiatedContext -> {
ResultInfo pendingResult =
resultInfo.dup(inferenceContext.asInstType(resultInfo.pt));
check(tree, inferenceContext.asInstType(found), ownkind, pendingResult);
});
}
} else {
owntype = shouldCheck ?
resultInfo.check(tree, found) :
found;
}
if (resultInfo.checkMode.updateTreeType()) {
tree.type = owntype;
}
return owntype;
}
/** Is given blank final variable assignable, i.e. in a scope where it
* may be assigned to even though it is final?
* @param v The blank final variable.
* @param env The current environment.
*/
boolean isAssignableAsBlankFinal(VarSymbol v, Env<AttrContext> env) {
Symbol owner = env.info.scope.owner;
// owner refers to the innermost variable, method or
// initializer block declaration at this point.
return
v.owner == owner
||
((owner.name == names.init || // i.e. we are in a constructor
owner.kind == VAR || // i.e. we are in a variable initializer
(owner.flags() & BLOCK) != 0) // i.e. we are in an initializer block
&&
v.owner == owner.owner
&&
((v.flags() & STATIC) != 0) == Resolve.isStatic(env));
}
/** Check that variable can be assigned to.
* @param pos The current source code position.
* @param v The assigned variable
* @param base If the variable is referred to in a Select, the part
* to the left of the `.', null otherwise.
* @param env The current environment.
*/
void checkAssignable(DiagnosticPosition pos, VarSymbol v, JCTree base, Env<AttrContext> env) {
if (v.name == names._this) {
log.error(pos, Errors.CantAssignValToThis);
} else if ((v.flags() & FINAL) != 0 &&
((v.flags() & HASINIT) != 0
||
!((base == null ||
TreeInfo.isThisQualifier(base)) &&
isAssignableAsBlankFinal(v, env)))) {
if (v.isResourceVariable()) { //TWR resource
log.error(pos, Errors.TryResourceMayNotBeAssigned(v));
} else if ((v.flags() & MATCH_BINDING) != 0) {
log.error(pos, Errors.PatternBindingMayNotBeAssigned(v));
} else {
log.error(pos, Errors.CantAssignValToFinalVar(v));
}
}
}
/** Does tree represent a static reference to an identifier?
* It is assumed that tree is either a SELECT or an IDENT.
* We have to weed out selects from non-type names here.
* @param tree The candidate tree.
*/
boolean isStaticReference(JCTree tree) {
if (tree.hasTag(SELECT)) {
Symbol lsym = TreeInfo.symbol(((JCFieldAccess) tree).selected);
if (lsym == null || lsym.kind != TYP) {
return false;
}
}
return true;
}
/** Is this symbol a type?
*/
static boolean isType(Symbol sym) {
return sym != null && sym.kind == TYP;
}
/** The current `this' symbol.
* @param env The current environment.
*/
Symbol thisSym(DiagnosticPosition pos, Env<AttrContext> env) {
return rs.resolveSelf(pos, env, env.enclClass.sym, names._this);
}
/** Attribute a parsed identifier.
* @param tree Parsed identifier name
* @param topLevel The toplevel to use
*/
public Symbol attribIdent(JCTree tree, JCCompilationUnit topLevel) {
Env<AttrContext> localEnv = enter.topLevelEnv(topLevel);
localEnv.enclClass = make.ClassDef(make.Modifiers(0),
syms.errSymbol.name,
null, null, null, null);
localEnv.enclClass.sym = syms.errSymbol;
return attribIdent(tree, localEnv);
}
/** Attribute a parsed identifier.
* @param tree Parsed identifier name
* @param env The env to use
*/
public Symbol attribIdent(JCTree tree, Env<AttrContext> env) {
return tree.accept(identAttributer, env);
}
// where
private TreeVisitor<Symbol,Env<AttrContext>> identAttributer = new IdentAttributer();
private class IdentAttributer extends SimpleTreeVisitor<Symbol,Env<AttrContext>> {
@Override @DefinedBy(Api.COMPILER_TREE)
public Symbol visitMemberSelect(MemberSelectTree node, Env<AttrContext> env) {
Symbol site = visit(node.getExpression(), env);
if (site.kind == ERR || site.kind == ABSENT_TYP || site.kind == HIDDEN)
return site;
Name name = (Name)node.getIdentifier();
if (site.kind == PCK) {
env.toplevel.packge = (PackageSymbol)site;
return rs.findIdentInPackage(null, env, (TypeSymbol)site, name,
KindSelector.TYP_PCK);
} else {
env.enclClass.sym = (ClassSymbol)site;
return rs.findMemberType(env, site.asType(), name, (TypeSymbol)site);
}
}
@Override @DefinedBy(Api.COMPILER_TREE)
public Symbol visitIdentifier(IdentifierTree node, Env<AttrContext> env) {
return rs.findIdent(null, env, (Name)node.getName(), KindSelector.TYP_PCK);
}
}
public Type coerce(Type etype, Type ttype) {
return cfolder.coerce(etype, ttype);
}
public Type attribType(JCTree node, TypeSymbol sym) {
Env<AttrContext> env = typeEnvs.get(sym);
Env<AttrContext> localEnv = env.dup(node, env.info.dup());
return attribTree(node, localEnv, unknownTypeInfo);
}
public Type attribImportQualifier(JCImport tree, Env<AttrContext> env) {
// Attribute qualifying package or class.
JCFieldAccess s = (JCFieldAccess)tree.qualid;
return attribTree(s.selected, env,
new ResultInfo(tree.staticImport ?
KindSelector.TYP : KindSelector.TYP_PCK,
Type.noType));
}
public Env<AttrContext> attribExprToTree(JCTree expr, Env<AttrContext> env, JCTree tree) {
return attribToTree(expr, env, tree, unknownExprInfo);
}
public Env<AttrContext> attribStatToTree(JCTree stmt, Env<AttrContext> env, JCTree tree) {
return attribToTree(stmt, env, tree, statInfo);
}
private Env<AttrContext> attribToTree(JCTree root, Env<AttrContext> env, JCTree tree, ResultInfo resultInfo) {
breakTree = tree;
JavaFileObject prev = log.useSource(env.toplevel.sourcefile);
try {
deferredAttr.attribSpeculative(root, env, resultInfo,
null, DeferredAttr.AttributionMode.ANALYZER,
argumentAttr.withLocalCacheContext());
} catch (BreakAttr b) {
return b.env;
} catch (AssertionError ae) {
if (ae.getCause() instanceof BreakAttr) {
return ((BreakAttr)(ae.getCause())).env;
} else {
throw ae;
}
} finally {
breakTree = null;
log.useSource(prev);
}
return env;
}
private JCTree breakTree = null;
private static class BreakAttr extends RuntimeException {
static final long serialVersionUID = -6924771130405446405L;
private transient Env<AttrContext> env;
private BreakAttr(Env<AttrContext> env) {
this.env = env;
}
}
/**
* Mode controlling behavior of Attr.Check
*/
enum CheckMode {
NORMAL,
/**
* Mode signalling 'fake check' - skip tree update. A side-effect of this mode is
* that the captured var cache in {@code InferenceContext} will be used in read-only
* mode when performing inference checks.
*/
NO_TREE_UPDATE {
@Override
public boolean updateTreeType() {
return false;
}
},
/**
* Mode signalling that caller will manage free types in tree decorations.
*/
NO_INFERENCE_HOOK {
@Override
public boolean installPostInferenceHook() {
return false;
}
};
public boolean updateTreeType() {
return true;
}
public boolean installPostInferenceHook() {
return true;
}
}
class ResultInfo {
final KindSelector pkind;
final Type pt;
final CheckContext checkContext;
final CheckMode checkMode;
ResultInfo(KindSelector pkind, Type pt) {
this(pkind, pt, chk.basicHandler, CheckMode.NORMAL);
}
ResultInfo(KindSelector pkind, Type pt, CheckMode checkMode) {
this(pkind, pt, chk.basicHandler, checkMode);
}
protected ResultInfo(KindSelector pkind,
Type pt, CheckContext checkContext) {
this(pkind, pt, checkContext, CheckMode.NORMAL);
}
protected ResultInfo(KindSelector pkind,
Type pt, CheckContext checkContext, CheckMode checkMode) {
this.pkind = pkind;
this.pt = pt;
this.checkContext = checkContext;
this.checkMode = checkMode;
}
/**
* Should {@link Attr#attribTree} use the {@ArgumentAttr} visitor instead of this one?
* @param tree The tree to be type-checked.
* @return true if {@ArgumentAttr} should be used.
*/
protected boolean needsArgumentAttr(JCTree tree) { return false; }
protected Type check(final DiagnosticPosition pos, final Type found) {
return chk.checkType(pos, found, pt, checkContext);
}
protected ResultInfo dup(Type newPt) {
return new ResultInfo(pkind, newPt, checkContext, checkMode);
}
protected ResultInfo dup(CheckContext newContext) {
return new ResultInfo(pkind, pt, newContext, checkMode);
}
protected ResultInfo dup(Type newPt, CheckContext newContext) {
return new ResultInfo(pkind, newPt, newContext, checkMode);
}
protected ResultInfo dup(Type newPt, CheckContext newContext, CheckMode newMode) {
return new ResultInfo(pkind, newPt, newContext, newMode);
}
protected ResultInfo dup(CheckMode newMode) {
return new ResultInfo(pkind, pt, checkContext, newMode);
}
@Override
public String toString() {
if (pt != null) {
return pt.toString();
} else {
return "";
}
}
}
class MethodAttrInfo extends ResultInfo {
public MethodAttrInfo() {
this(chk.basicHandler);
}
public MethodAttrInfo(CheckContext checkContext) {
super(KindSelector.VAL, Infer.anyPoly, checkContext);
}
@Override
protected boolean needsArgumentAttr(JCTree tree) {
return true;
}
protected ResultInfo dup(Type newPt) {
throw new IllegalStateException();
}
protected ResultInfo dup(CheckContext newContext) {
return new MethodAttrInfo(newContext);
}
protected ResultInfo dup(Type newPt, CheckContext newContext) {
throw new IllegalStateException();
}
protected ResultInfo dup(Type newPt, CheckContext newContext, CheckMode newMode) {
throw new IllegalStateException();
}
protected ResultInfo dup(CheckMode newMode) {
throw new IllegalStateException();
}
}
class RecoveryInfo extends ResultInfo {
public RecoveryInfo(final DeferredAttr.DeferredAttrContext deferredAttrContext) {
this(deferredAttrContext, Type.recoveryType);
}
public RecoveryInfo(final DeferredAttr.DeferredAttrContext deferredAttrContext, Type pt) {
super(KindSelector.VAL, pt, new Check.NestedCheckContext(chk.basicHandler) {
@Override
public DeferredAttr.DeferredAttrContext deferredAttrContext() {
return deferredAttrContext;
}
@Override
public boolean compatible(Type found, Type req, Warner warn) {
return true;
}
@Override
public void report(DiagnosticPosition pos, JCDiagnostic details) {
if (pt == Type.recoveryType) {
chk.basicHandler.report(pos, details);
}
}
});
}
}
final ResultInfo statInfo;
final ResultInfo varAssignmentInfo;
final ResultInfo methodAttrInfo;
final ResultInfo unknownExprInfo;
final ResultInfo unknownTypeInfo;
final ResultInfo unknownTypeExprInfo;
final ResultInfo recoveryInfo;
Type pt() {
return resultInfo.pt;
}
KindSelector pkind() {
return resultInfo.pkind;
}
/* ************************************************************************
* Visitor methods
*************************************************************************/
/** Visitor argument: the current environment.
*/
Env<AttrContext> env;
/** Visitor argument: the currently expected attribution result.
*/
ResultInfo resultInfo;
/** Visitor result: the computed type.
*/
Type result;
/** Visitor method: attribute a tree, catching any completion failure
* exceptions. Return the tree's type.
*
* @param tree The tree to be visited.
* @param env The environment visitor argument.
* @param resultInfo The result info visitor argument.
*/
Type attribTree(JCTree tree, Env<AttrContext> env, ResultInfo resultInfo) {
Env<AttrContext> prevEnv = this.env;
ResultInfo prevResult = this.resultInfo;
try {
this.env = env;
this.resultInfo = resultInfo;
if (resultInfo.needsArgumentAttr(tree)) {
result = argumentAttr.attribArg(tree, env);
} else {
tree.accept(this);
}
if (tree == breakTree &&
resultInfo.checkContext.deferredAttrContext().mode == AttrMode.CHECK) {
breakTreeFound(copyEnv(env));
}
return result;
} catch (CompletionFailure ex) {
tree.type = syms.errType;
return chk.completionError(tree.pos(), ex);
} finally {
this.env = prevEnv;
this.resultInfo = prevResult;
}
}
protected void breakTreeFound(Env<AttrContext> env) {
throw new BreakAttr(env);
}
Env<AttrContext> copyEnv(Env<AttrContext> env) {
Env<AttrContext> newEnv =
env.dup(env.tree, env.info.dup(copyScope(env.info.scope)));
if (newEnv.outer != null) {
newEnv.outer = copyEnv(newEnv.outer);
}
return newEnv;
}
WriteableScope copyScope(WriteableScope sc) {
WriteableScope newScope = WriteableScope.create(sc.owner);
List<Symbol> elemsList = List.nil();
for (Symbol sym : sc.getSymbols()) {
elemsList = elemsList.prepend(sym);
}
for (Symbol s : elemsList) {
newScope.enter(s);
}
return newScope;
}
/** Derived visitor method: attribute an expression tree.
*/
public Type attribExpr(JCTree tree, Env<AttrContext> env, Type pt) {
return attribTree(tree, env, new ResultInfo(KindSelector.VAL, !pt.hasTag(ERROR) ? pt : Type.noType));
}
/** Derived visitor method: attribute an expression tree with
* no constraints on the computed type.
*/
public Type attribExpr(JCTree tree, Env<AttrContext> env) {
return attribTree(tree, env, unknownExprInfo);
}
/** Derived visitor method: attribute a type tree.
*/
public Type attribType(JCTree tree, Env<AttrContext> env) {
Type result = attribType(tree, env, Type.noType);
return result;
}
/** Derived visitor method: attribute a type tree.
*/
Type attribType(JCTree tree, Env<AttrContext> env, Type pt) {
Type result = attribTree(tree, env, new ResultInfo(KindSelector.TYP, pt));
return result;
}
/** Derived visitor method: attribute a statement or definition tree.
*/
public Type attribStat(JCTree tree, Env<AttrContext> env) {
Env<AttrContext> analyzeEnv = analyzer.copyEnvIfNeeded(tree, env);
Type result = attribTree(tree, env, statInfo);
analyzer.analyzeIfNeeded(tree, analyzeEnv);
return result;
}
/** Attribute a list of expressions, returning a list of types.
*/
List<Type> attribExprs(List<JCExpression> trees, Env<AttrContext> env, Type pt) {
ListBuffer<Type> ts = new ListBuffer<>();
for (List<JCExpression> l = trees; l.nonEmpty(); l = l.tail)
ts.append(attribExpr(l.head, env, pt));
return ts.toList();
}
/** Attribute a list of statements, returning nothing.
*/
<T extends JCTree> void attribStats(List<T> trees, Env<AttrContext> env) {
for (List<T> l = trees; l.nonEmpty(); l = l.tail)
attribStat(l.head, env);
}
/** Attribute the arguments in a method call, returning the method kind.
*/
KindSelector attribArgs(KindSelector initialKind, List<JCExpression> trees, Env<AttrContext> env, ListBuffer<Type> argtypes) {
KindSelector kind = initialKind;
for (JCExpression arg : trees) {
Type argtype = chk.checkNonVoid(arg, attribTree(arg, env, allowPoly ? methodAttrInfo : unknownExprInfo));
if (argtype.hasTag(DEFERRED)) {
kind = KindSelector.of(KindSelector.POLY, kind);
}
argtypes.append(argtype);
}
return kind;
}
/** Attribute a type argument list, returning a list of types.
* Caller is responsible for calling checkRefTypes.
*/
List<Type> attribAnyTypes(List<JCExpression> trees, Env<AttrContext> env) {
ListBuffer<Type> argtypes = new ListBuffer<>();
for (List<JCExpression> l = trees; l.nonEmpty(); l = l.tail)
argtypes.append(attribType(l.head, env));
return argtypes.toList();
}
/** Attribute a type argument list, returning a list of types.
* Check that all the types are references.
*/
List<Type> attribTypes(List<JCExpression> trees, Env<AttrContext> env) {
List<Type> types = attribAnyTypes(trees, env);
return chk.checkRefTypes(trees, types);
}
/**
* Attribute type variables (of generic classes or methods).
* Compound types are attributed later in attribBounds.
* @param typarams the type variables to enter
* @param env the current environment
*/
void attribTypeVariables(List<JCTypeParameter> typarams, Env<AttrContext> env, boolean checkCyclic) {
for (JCTypeParameter tvar : typarams) {
TypeVar a = (TypeVar)tvar.type;
a.tsym.flags_field |= UNATTRIBUTED;
a.setUpperBound(Type.noType);
if (!tvar.bounds.isEmpty()) {
List<Type> bounds = List.of(attribType(tvar.bounds.head, env));
for (JCExpression bound : tvar.bounds.tail)
bounds = bounds.prepend(attribType(bound, env));
types.setBounds(a, bounds.reverse());
} else {
// if no bounds are given, assume a single bound of
// java.lang.Object.
types.setBounds(a, List.of(syms.objectType));
}
a.tsym.flags_field &= ~UNATTRIBUTED;
}
if (checkCyclic) {
for (JCTypeParameter tvar : typarams) {
chk.checkNonCyclic(tvar.pos(), (TypeVar)tvar.type);
}
}
}
/**
* Attribute the type references in a list of annotations.
*/
void attribAnnotationTypes(List<JCAnnotation> annotations,
Env<AttrContext> env) {
for (List<JCAnnotation> al = annotations; al.nonEmpty(); al = al.tail) {
JCAnnotation a = al.head;
attribType(a.annotationType, env);
}
}
/**
* Attribute a "lazy constant value".
* @param env The env for the const value
* @param variable The initializer for the const value
* @param type The expected type, or null
* @see VarSymbol#setLazyConstValue
*/
public Object attribLazyConstantValue(Env<AttrContext> env,
JCVariableDecl variable,
Type type) {
DiagnosticPosition prevLintPos
= deferredLintHandler.setPos(variable.pos());
final JavaFileObject prevSource = log.useSource(env.toplevel.sourcefile);
try {
Type itype = attribExpr(variable.init, env, type);
if (variable.isImplicitlyTyped()) {
//fixup local variable type
type = variable.type = variable.sym.type = chk.checkLocalVarType(variable, itype.baseType(), variable.name);
}
if (itype.constValue() != null) {
return coerce(itype, type).constValue();
} else {
return null;
}
} finally {
log.useSource(prevSource);
deferredLintHandler.setPos(prevLintPos);
}
}
/** Attribute type reference in an `extends' or `implements' clause.
* Supertypes of anonymous inner classes are usually already attributed.
*
* @param tree The tree making up the type reference.
* @param env The environment current at the reference.
* @param classExpected true if only a class is expected here.
* @param interfaceExpected true if only an interface is expected here.
*/
Type attribBase(JCTree tree,
Env<AttrContext> env,
boolean classExpected,
boolean interfaceExpected,
boolean checkExtensible) {
Type t = tree.type != null ?
tree.type :
attribType(tree, env);
return checkBase(t, tree, env, classExpected, interfaceExpected, checkExtensible);
}
Type checkBase(Type t,
JCTree tree,
Env<AttrContext> env,
boolean classExpected,
boolean interfaceExpected,
boolean checkExtensible) {
final DiagnosticPosition pos = tree.hasTag(TYPEAPPLY) ?
(((JCTypeApply) tree).clazz).pos() : tree.pos();
if (t.tsym.isAnonymous()) {
log.error(pos, Errors.CantInheritFromAnon);
return types.createErrorType(t);
}
if (t.isErroneous())
return t;
if (t.hasTag(TYPEVAR) && !classExpected && !interfaceExpected) {
// check that type variable is already visible
if (t.getUpperBound() == null) {
log.error(pos, Errors.IllegalForwardRef);
return types.createErrorType(t);
}
} else {
t = chk.checkClassType(pos, t, checkExtensible);
}
if (interfaceExpected && (t.tsym.flags() & INTERFACE) == 0) {
log.error(pos, Errors.IntfExpectedHere);
// return errType is necessary since otherwise there might
// be undetected cycles which cause attribution to loop
return types.createErrorType(t);
} else if (checkExtensible &&
classExpected &&
(t.tsym.flags() & INTERFACE) != 0) {
log.error(pos, Errors.NoIntfExpectedHere);
return types.createErrorType(t);
}
if (checkExtensible &&
((t.tsym.flags() & FINAL) != 0)) {
log.error(pos,
Errors.CantInheritFromFinal(t.tsym));
}
chk.checkNonCyclic(pos, t);
return t;
}
Type attribIdentAsEnumType(Env<AttrContext> env, JCIdent id) {
Assert.check((env.enclClass.sym.flags() & ENUM) != 0);
id.type = env.info.scope.owner.enclClass().type;
id.sym = env.info.scope.owner.enclClass();
return id.type;
}
public void visitClassDef(JCClassDecl tree) {
Optional<ArgumentAttr.LocalCacheContext> localCacheContext =
Optional.ofNullable(env.info.attributionMode.isSpeculative ?
argumentAttr.withLocalCacheContext() : null);
try {
// Local and anonymous classes have not been entered yet, so we need to
// do it now.
if (env.info.scope.owner.kind.matches(KindSelector.VAL_MTH)) {
enter.classEnter(tree, env);
} else {
// If this class declaration is part of a class level annotation,
// as in @MyAnno(new Object() {}) class MyClass {}, enter it in
// order to simplify later steps and allow for sensible error
// messages.
if (env.tree.hasTag(NEWCLASS) && TreeInfo.isInAnnotation(env, tree))
enter.classEnter(tree, env);
}
ClassSymbol c = tree.sym;
if (c == null) {
// exit in case something drastic went wrong during enter.
result = null;
} else {
// make sure class has been completed:
c.complete();
// If this class appears as an anonymous class
// in a superclass constructor call
// disable implicit outer instance from being passed.
// (This would be an illegal access to "this before super").
if (env.info.isSelfCall &&
env.tree.hasTag(NEWCLASS)) {
c.flags_field |= NOOUTERTHIS;
}
attribClass(tree.pos(), c);
result = tree.type = c.type;
}
} finally {
localCacheContext.ifPresent(LocalCacheContext::leave);
}
}
public void visitMethodDef(JCMethodDecl tree) {
MethodSymbol m = tree.sym;
boolean isDefaultMethod = (m.flags() & DEFAULT) != 0;
Lint lint = env.info.lint.augment(m);
Lint prevLint = chk.setLint(lint);
MethodSymbol prevMethod = chk.setMethod(m);
try {
deferredLintHandler.flush(tree.pos());
chk.checkDeprecatedAnnotation(tree.pos(), m);
// Create a new environment with local scope
// for attributing the method.
Env<AttrContext> localEnv = memberEnter.methodEnv(tree, env);
localEnv.info.lint = lint;
attribStats(tree.typarams, localEnv);
// If we override any other methods, check that we do so properly.
// JLS ???
if (m.isStatic()) {
chk.checkHideClashes(tree.pos(), env.enclClass.type, m);
} else {
chk.checkOverrideClashes(tree.pos(), env.enclClass.type, m);
}
chk.checkOverride(env, tree, m);
if (isDefaultMethod && types.overridesObjectMethod(m.enclClass(), m)) {
log.error(tree, Errors.DefaultOverridesObjectMember(m.name, Kinds.kindName(m.location()), m.location()));
}
// Enter all type parameters into the local method scope.
for (List<JCTypeParameter> l = tree.typarams; l.nonEmpty(); l = l.tail)
localEnv.info.scope.enterIfAbsent(l.head.type.tsym);
ClassSymbol owner = env.enclClass.sym;
if ((owner.flags() & ANNOTATION) != 0 &&
(tree.params.nonEmpty() ||
tree.recvparam != null))
log.error(tree.params.nonEmpty() ?
tree.params.head.pos() :
tree.recvparam.pos(),
Errors.IntfAnnotationMembersCantHaveParams);
// Attribute all value parameters.
for (List<JCVariableDecl> l = tree.params; l.nonEmpty(); l = l.tail) {
attribStat(l.head, localEnv);
}
chk.checkVarargsMethodDecl(localEnv, tree);
// Check that type parameters are well-formed.
chk.validate(tree.typarams, localEnv);
// Check that result type is well-formed.
if (tree.restype != null && !tree.restype.type.hasTag(VOID))
chk.validate(tree.restype, localEnv);
// Check that receiver type is well-formed.
if (tree.recvparam != null) {
// Use a new environment to check the receiver parameter.
// Otherwise I get "might not have been initialized" errors.
// Is there a better way?
Env<AttrContext> newEnv = memberEnter.methodEnv(tree, env);
attribType(tree.recvparam, newEnv);
chk.validate(tree.recvparam, newEnv);
}
// annotation method checks
if ((owner.flags() & ANNOTATION) != 0) {
// annotation method cannot have throws clause
if (tree.thrown.nonEmpty()) {
log.error(tree.thrown.head.pos(),
Errors.ThrowsNotAllowedInIntfAnnotation);
}
// annotation method cannot declare type-parameters
if (tree.typarams.nonEmpty()) {
log.error(tree.typarams.head.pos(),
Errors.IntfAnnotationMembersCantHaveTypeParams);
}
// validate annotation method's return type (could be an annotation type)
chk.validateAnnotationType(tree.restype);
// ensure that annotation method does not clash with members of Object/Annotation
chk.validateAnnotationMethod(tree.pos(), m);
}
for (List<JCExpression> l = tree.thrown; l.nonEmpty(); l = l.tail)
chk.checkType(l.head.pos(), l.head.type, syms.throwableType);
if (tree.body == null) {
// Empty bodies are only allowed for
// abstract, native, or interface methods, or for methods
// in a retrofit signature class.
if (tree.defaultValue != null) {
if ((owner.flags() & ANNOTATION) == 0)
log.error(tree.pos(),
Errors.DefaultAllowedInIntfAnnotationMember);
}
if (isDefaultMethod || (tree.sym.flags() & (ABSTRACT | NATIVE)) == 0)
log.error(tree.pos(), Errors.MissingMethBodyOrDeclAbstract);
} else if ((tree.sym.flags() & (ABSTRACT|DEFAULT|PRIVATE)) == ABSTRACT) {
if ((owner.flags() & INTERFACE) != 0) {
log.error(tree.body.pos(), Errors.IntfMethCantHaveBody);
} else {
log.error(tree.pos(), Errors.AbstractMethCantHaveBody);
}
} else if ((tree.mods.flags & NATIVE) != 0) {
log.error(tree.pos(), Errors.NativeMethCantHaveBody);
} else {
// Add an implicit super() call unless an explicit call to
// super(...) or this(...) is given
// or we are compiling class java.lang.Object.
if (tree.name == names.init && owner.type != syms.objectType) {
JCBlock body = tree.body;
if (body.stats.isEmpty() ||
!TreeInfo.isSelfCall(body.stats.head)) {
body.stats = body.stats.
prepend(typeEnter.SuperCall(make.at(body.pos),
List.nil(),
List.nil(),
false));
} else if ((env.enclClass.sym.flags() & ENUM) != 0 &&
(tree.mods.flags & GENERATEDCONSTR) == 0 &&
TreeInfo.isSuperCall(body.stats.head)) {
// enum constructors are not allowed to call super
// directly, so make sure there aren't any super calls
// in enum constructors, except in the compiler
// generated one.
log.error(tree.body.stats.head.pos(),
Errors.CallToSuperNotAllowedInEnumCtor(env.enclClass.sym));
}
}
// Attribute all type annotations in the body
annotate.queueScanTreeAndTypeAnnotate(tree.body, localEnv, m, null);
annotate.flush();
// Attribute method body.
attribStat(tree.body, localEnv);
}
localEnv.info.scope.leave();
result = tree.type = m.type;
} finally {
chk.setLint(prevLint);
chk.setMethod(prevMethod);
}
}
public void visitVarDef(JCVariableDecl tree) {
// Local variables have not been entered yet, so we need to do it now:
if (env.info.scope.owner.kind == MTH || env.info.scope.owner.kind == VAR) {
if (tree.sym != null) {
// parameters have already been entered
env.info.scope.enter(tree.sym);
} else {
if (tree.isImplicitlyTyped() && (tree.getModifiers().flags & PARAMETER) == 0) {
if (tree.init == null) {
//cannot use 'var' without initializer
log.error(tree, Errors.CantInferLocalVarType(tree.name, Fragments.LocalMissingInit));
tree.vartype = make.Erroneous();
} else {
Fragment msg = canInferLocalVarType(tree);
if (msg != null) {
//cannot use 'var' with initializer which require an explicit target
//(e.g. lambda, method reference, array initializer).
log.error(tree, Errors.CantInferLocalVarType(tree.name, msg));
tree.vartype = make.Erroneous();
}
}
}
try {
annotate.blockAnnotations();
memberEnter.memberEnter(tree, env);
} finally {
annotate.unblockAnnotations();
}
}
} else {
if (tree.init != null) {
// Field initializer expression need to be entered.
annotate.queueScanTreeAndTypeAnnotate(tree.init, env, tree.sym, tree.pos());
annotate.flush();
}
}
VarSymbol v = tree.sym;
Lint lint = env.info.lint.augment(v);
Lint prevLint = chk.setLint(lint);
// Check that the variable's declared type is well-formed.
boolean isImplicitLambdaParameter = env.tree.hasTag(LAMBDA) &&
((JCLambda)env.tree).paramKind == JCLambda.ParameterKind.IMPLICIT &&
(tree.sym.flags() & PARAMETER) != 0;
chk.validate(tree.vartype, env, !isImplicitLambdaParameter && !tree.isImplicitlyTyped());
try {
v.getConstValue(); // ensure compile-time constant initializer is evaluated
deferredLintHandler.flush(tree.pos());
chk.checkDeprecatedAnnotation(tree.pos(), v);
if (tree.init != null) {
if ((v.flags_field & FINAL) == 0 ||
!memberEnter.needsLazyConstValue(tree.init)) {
// Not a compile-time constant
// Attribute initializer in a new environment
// with the declared variable as owner.
// Check that initializer conforms to variable's declared type.
Env<AttrContext> initEnv = memberEnter.initEnv(tree, env);
initEnv.info.lint = lint;
// In order to catch self-references, we set the variable's
// declaration position to maximal possible value, effectively
// marking the variable as undefined.
initEnv.info.enclVar = v;
attribExpr(tree.init, initEnv, v.type);
if (tree.isImplicitlyTyped()) {
//fixup local variable type
v.type = chk.checkLocalVarType(tree, tree.init.type.baseType(), tree.name);
}
}
if (tree.isImplicitlyTyped()) {
setSyntheticVariableType(tree, v.type);
}
}
result = tree.type = v.type;
}
finally {
chk.setLint(prevLint);
}
}
Fragment canInferLocalVarType(JCVariableDecl tree) {
LocalInitScanner lis = new LocalInitScanner();
lis.scan(tree.init);
return lis.badInferenceMsg;
}
static class LocalInitScanner extends TreeScanner {
Fragment badInferenceMsg = null;
boolean needsTarget = true;
@Override
public void visitNewArray(JCNewArray tree) {
if (tree.elemtype == null && needsTarget) {
badInferenceMsg = Fragments.LocalArrayMissingTarget;
}
}
@Override
public void visitLambda(JCLambda tree) {
if (needsTarget) {
badInferenceMsg = Fragments.LocalLambdaMissingTarget;
}
}
@Override
public void visitTypeCast(JCTypeCast tree) {
boolean prevNeedsTarget = needsTarget;
try {
needsTarget = false;
super.visitTypeCast(tree);
} finally {
needsTarget = prevNeedsTarget;
}
}
@Override
public void visitReference(JCMemberReference tree) {
if (needsTarget) {
badInferenceMsg = Fragments.LocalMrefMissingTarget;
}
}
@Override
public void visitNewClass(JCNewClass tree) {
boolean prevNeedsTarget = needsTarget;
try {
needsTarget = false;
super.visitNewClass(tree);
} finally {
needsTarget = prevNeedsTarget;
}
}
@Override
public void visitApply(JCMethodInvocation tree) {
boolean prevNeedsTarget = needsTarget;
try {
needsTarget = false;
super.visitApply(tree);
} finally {
needsTarget = prevNeedsTarget;
}
}
}
public void visitSkip(JCSkip tree) {
result = null;
}
public void visitBlock(JCBlock tree) {
if (env.info.scope.owner.kind == TYP || env.info.scope.owner.kind == ERR) {
// Block is a static or instance initializer;
// let the owner of the environment be a freshly
// created BLOCK-method.
Symbol fakeOwner =
new MethodSymbol(tree.flags | BLOCK |
env.info.scope.owner.flags() & STRICTFP, names.empty, null,
env.info.scope.owner);
final Env<AttrContext> localEnv =
env.dup(tree, env.info.dup(env.info.scope.dupUnshared(fakeOwner)));
if ((tree.flags & STATIC) != 0) localEnv.info.staticLevel++;
// Attribute all type annotations in the block
annotate.queueScanTreeAndTypeAnnotate(tree, localEnv, localEnv.info.scope.owner, null);
annotate.flush();
attribStats(tree.stats, localEnv);
{
// Store init and clinit type annotations with the ClassSymbol
// to allow output in Gen.normalizeDefs.
ClassSymbol cs = (ClassSymbol)env.info.scope.owner;
List<Attribute.TypeCompound> tas = localEnv.info.scope.owner.getRawTypeAttributes();
if ((tree.flags & STATIC) != 0) {
cs.appendClassInitTypeAttributes(tas);
} else {
cs.appendInitTypeAttributes(tas);
}
}
} else {
// Create a new local environment with a local scope.
Env<AttrContext> localEnv =
env.dup(tree, env.info.dup(env.info.scope.dup()));
try {
attribStats(tree.stats, localEnv);
} finally {
localEnv.info.scope.leave();
}
}
result = null;
}
public void visitDoLoop(JCDoWhileLoop tree) {
attribStat(tree.body, env.dup(tree));
attribExpr(tree.cond, env, syms.booleanType);
if (!breaksOutOf(tree, tree.body)) {
//include condition's body when false after the while, if cannot get out of the loop
List<BindingSymbol> bindings = matchBindingsComputer.getMatchBindings(tree.cond, false);
bindings.forEach(env.info.scope::enter);
bindings.forEach(BindingSymbol::preserveBinding);
}
result = null;
}
public void visitWhileLoop(JCWhileLoop tree) {
attribExpr(tree.cond, env, syms.booleanType);
// include condition's bindings when true in the body:
Env<AttrContext> whileEnv = bindingEnv(env, matchBindingsComputer.getMatchBindings(tree.cond, true));
try {
attribStat(tree.body, whileEnv.dup(tree));
} finally {
whileEnv.info.scope.leave();
}
if (!breaksOutOf(tree, tree.body)) {
//include condition's bindings when false after the while, if cannot get out of the loop
List<BindingSymbol> bindings =
matchBindingsComputer.getMatchBindings(tree.cond, false);
bindings.forEach(env.info.scope::enter);
bindings.forEach(BindingSymbol::preserveBinding);
}
result = null;
}
private boolean breaksOutOf(JCTree loop, JCTree body) {
preFlow(body);
return flow.breaksOutOf(env, loop, body, make);
}
public void visitForLoop(JCForLoop tree) {
Env<AttrContext> loopEnv =
env.dup(env.tree, env.info.dup(env.info.scope.dup()));
try {
attribStats(tree.init, loopEnv);
List<BindingSymbol> matchBindings = List.nil();
if (tree.cond != null) {
attribExpr(tree.cond, loopEnv, syms.booleanType);
// include condition's bindings when true in the body and step:
matchBindings = matchBindingsComputer.getMatchBindings(tree.cond, true);
}
Env<AttrContext> bodyEnv = bindingEnv(loopEnv, matchBindings);
try {
bodyEnv.tree = tree; // before, we were not in loop!
attribStats(tree.step, bodyEnv);
attribStat(tree.body, bodyEnv);
} finally {
bodyEnv.info.scope.leave();
}
result = null;
}
finally {
loopEnv.info.scope.leave();
}
if (!breaksOutOf(tree, tree.body)) {
//include condition's body when false after the while, if cannot get out of the loop
List<BindingSymbol> bindings =
matchBindingsComputer.getMatchBindings(tree.cond, false);
bindings.forEach(env.info.scope::enter);
bindings.forEach(BindingSymbol::preserveBinding);
}
}
public void visitForeachLoop(JCEnhancedForLoop tree) {
Env<AttrContext> loopEnv =
env.dup(env.tree, env.info.dup(env.info.scope.dup()));
try {
//the Formal Parameter of a for-each loop is not in the scope when
//attributing the for-each expression; we mimick this by attributing
//the for-each expression first (against original scope).
Type exprType = types.cvarUpperBound(attribExpr(tree.expr, loopEnv));
chk.checkNonVoid(tree.pos(), exprType);
Type elemtype = types.elemtype(exprType); // perhaps expr is an array?
if (elemtype == null) {
// or perhaps expr implements Iterable<T>?
Type base = types.asSuper(exprType, syms.iterableType.tsym);
if (base == null) {
log.error(tree.expr.pos(),
Errors.ForeachNotApplicableToType(exprType,
Fragments.TypeReqArrayOrIterable));
elemtype = types.createErrorType(exprType);
} else {
List<Type> iterableParams = base.allparams();
elemtype = iterableParams.isEmpty()
? syms.objectType
: types.wildUpperBound(iterableParams.head);
}
}
if (tree.var.isImplicitlyTyped()) {
Type inferredType = chk.checkLocalVarType(tree.var, elemtype, tree.var.name);
setSyntheticVariableType(tree.var, inferredType);
}
attribStat(tree.var, loopEnv);
chk.checkType(tree.expr.pos(), elemtype, tree.var.sym.type);
loopEnv.tree = tree; // before, we were not in loop!
attribStat(tree.body, loopEnv);
result = null;
}
finally {
loopEnv.info.scope.leave();
}
}
public void visitLabelled(JCLabeledStatement tree) {
// Check that label is not used in an enclosing statement
Env<AttrContext> env1 = env;
while (env1 != null && !env1.tree.hasTag(CLASSDEF)) {
if (env1.tree.hasTag(LABELLED) &&
((JCLabeledStatement) env1.tree).label == tree.label) {
log.error(tree.pos(),
Errors.LabelAlreadyInUse(tree.label));
break;
}
env1 = env1.next;
}
attribStat(tree.body, env.dup(tree));
result = null;
}
public void visitSwitch(JCSwitch tree) {
handleSwitch(tree, tree.selector, tree.cases, (c, caseEnv) -> {
attribStats(c.stats, caseEnv);
});
result = null;
}
public void visitSwitchExpression(JCSwitchExpression tree) {
tree.polyKind = (pt().hasTag(NONE) && pt() != Type.recoveryType && pt() != Infer.anyPoly) ?
PolyKind.STANDALONE : PolyKind.POLY;
if (tree.polyKind == PolyKind.POLY && resultInfo.pt.hasTag(VOID)) {
//this means we are returning a poly conditional from void-compatible lambda expression
resultInfo.checkContext.report(tree, diags.fragment(Fragments.SwitchExpressionTargetCantBeVoid));
result = tree.type = types.createErrorType(resultInfo.pt);
return;
}
ResultInfo condInfo = tree.polyKind == PolyKind.STANDALONE ?
unknownExprInfo :
resultInfo.dup(switchExpressionContext(resultInfo.checkContext));
ListBuffer<DiagnosticPosition> caseTypePositions = new ListBuffer<>();
ListBuffer<Type> caseTypes = new ListBuffer<>();
handleSwitch(tree, tree.selector, tree.cases, (c, caseEnv) -> {
caseEnv.info.yieldResult = condInfo;
attribStats(c.stats, caseEnv);
new TreeScanner() {
@Override
public void visitYield(JCYield brk) {
if (brk.target == tree) {
caseTypePositions.append(brk.value != null ? brk.value.pos() : brk.pos());
caseTypes.append(brk.value != null ? brk.value.type : syms.errType);
}
super.visitYield(brk);
}
@Override public void visitClassDef(JCClassDecl tree) {}
@Override public void visitLambda(JCLambda tree) {}
}.scan(c.stats);
});
if (tree.cases.isEmpty()) {
log.error(tree.pos(),
Errors.SwitchExpressionEmpty);
} else if (caseTypes.isEmpty()) {
log.error(tree.pos(),
Errors.SwitchExpressionNoResultExpressions);
}
Type owntype = (tree.polyKind == PolyKind.STANDALONE) ? condType(caseTypePositions.toList(), caseTypes.toList()) : pt();
result = tree.type = check(tree, owntype, KindSelector.VAL, resultInfo);
}
//where:
CheckContext switchExpressionContext(CheckContext checkContext) {
return new Check.NestedCheckContext(checkContext) {
//this will use enclosing check context to check compatibility of
//subexpression against target type; if we are in a method check context,
//depending on whether boxing is allowed, we could have incompatibilities
@Override
public void report(DiagnosticPosition pos, JCDiagnostic details) {
enclosingContext.report(pos, diags.fragment(Fragments.IncompatibleTypeInSwitchExpression(details)));
}
};
}
private void handleSwitch(JCTree switchTree,
JCExpression selector,
List<JCCase> cases,
BiConsumer<JCCase, Env<AttrContext>> attribCase) {
Type seltype = attribExpr(selector, env);
Env<AttrContext> switchEnv =
env.dup(switchTree, env.info.dup(env.info.scope.dup()));
try {
boolean enumSwitch = (seltype.tsym.flags() & Flags.ENUM) != 0;
boolean stringSwitch = types.isSameType(seltype, syms.stringType);
if (!enumSwitch && !stringSwitch)
seltype = chk.checkType(selector.pos(), seltype, syms.intType);
// Attribute all cases and
// check that there are no duplicate case labels or default clauses.
Set<Object> labels = new HashSet<>(); // The set of case labels.
boolean hasDefault = false; // Is there a default label?
CaseTree.CaseKind caseKind = null;
boolean wasError = false;
for (List<JCCase> l = cases; l.nonEmpty(); l = l.tail) {
JCCase c = l.head;
if (caseKind == null) {
caseKind = c.caseKind;
} else if (caseKind != c.caseKind && !wasError) {
log.error(c.pos(),
Errors.SwitchMixingCaseTypes);
wasError = true;
}
if (c.getExpressions().nonEmpty()) {
for (JCExpression pat : c.getExpressions()) {
if (TreeInfo.isNull(pat)) {
log.error(pat.pos(),
Errors.SwitchNullNotAllowed);
} else if (enumSwitch) {
Symbol sym = enumConstant(pat, seltype);
if (sym == null) {
log.error(pat.pos(), Errors.EnumLabelMustBeUnqualifiedEnum);
} else if (!labels.add(sym)) {
log.error(c.pos(), Errors.DuplicateCaseLabel);
}
} else {
Type pattype = attribExpr(pat, switchEnv, seltype);
if (!pattype.hasTag(ERROR)) {
if (pattype.constValue() == null) {
log.error(pat.pos(),
(stringSwitch ? Errors.StringConstReq : Errors.ConstExprReq));
} else if (!labels.add(pattype.constValue())) {
log.error(c.pos(), Errors.DuplicateCaseLabel);
}
}
}
}
} else if (hasDefault) {
log.error(c.pos(), Errors.DuplicateDefaultLabel);
} else {
hasDefault = true;
}
Env<AttrContext> caseEnv =
switchEnv.dup(c, env.info.dup(switchEnv.info.scope.dup()));
try {
attribCase.accept(c, caseEnv);
} finally {
caseEnv.info.scope.leave();
}
addVars(c.stats, switchEnv.info.scope);
}
} finally {
switchEnv.info.scope.leave();
}
}
// where
/** Add any variables defined in stats to the switch scope. */
private static void addVars(List<JCStatement> stats, WriteableScope switchScope) {
for (;stats.nonEmpty(); stats = stats.tail) {
JCTree stat = stats.head;
if (stat.hasTag(VARDEF))
switchScope.enter(((JCVariableDecl) stat).sym);
}
}
// where
/** Return the selected enumeration constant symbol, or null. */
private Symbol enumConstant(JCTree tree, Type enumType) {
if (tree.hasTag(IDENT)) {
JCIdent ident = (JCIdent)tree;
Name name = ident.name;
for (Symbol sym : enumType.tsym.members().getSymbolsByName(name)) {
if (sym.kind == VAR) {
Symbol s = ident.sym = sym;
((VarSymbol)s).getConstValue(); // ensure initializer is evaluated
ident.type = s.type;
return ((s.flags_field & Flags.ENUM) == 0)
? null : s;
}
}
}
return null;
}
public void visitSynchronized(JCSynchronized tree) {
chk.checkRefType(tree.pos(), attribExpr(tree.lock, env));
attribStat(tree.body, env);
result = null;
}
public void visitTry(JCTry tree) {
// Create a new local environment with a local
Env<AttrContext> localEnv = env.dup(tree, env.info.dup(env.info.scope.dup()));
try {
boolean isTryWithResource = tree.resources.nonEmpty();
// Create a nested environment for attributing the try block if needed
Env<AttrContext> tryEnv = isTryWithResource ?
env.dup(tree, localEnv.info.dup(localEnv.info.scope.dup())) :
localEnv;
try {
// Attribute resource declarations
for (JCTree resource : tree.resources) {
CheckContext twrContext = new Check.NestedCheckContext(resultInfo.checkContext) {
@Override
public void report(DiagnosticPosition pos, JCDiagnostic details) {
chk.basicHandler.report(pos, diags.fragment(Fragments.TryNotApplicableToType(details)));
}
};
ResultInfo twrResult =
new ResultInfo(KindSelector.VAR,
syms.autoCloseableType,
twrContext);
if (resource.hasTag(VARDEF)) {
attribStat(resource, tryEnv);
twrResult.check(resource, resource.type);
//check that resource type cannot throw InterruptedException
checkAutoCloseable(resource.pos(), localEnv, resource.type);
VarSymbol var = ((JCVariableDecl) resource).sym;
var.setData(ElementKind.RESOURCE_VARIABLE);
} else {
attribTree(resource, tryEnv, twrResult);
}
}
// Attribute body
attribStat(tree.body, tryEnv);
} finally {
if (isTryWithResource)
tryEnv.info.scope.leave();
}
// Attribute catch clauses
for (List<JCCatch> l = tree.catchers; l.nonEmpty(); l = l.tail) {
JCCatch c = l.head;
Env<AttrContext> catchEnv =
localEnv.dup(c, localEnv.info.dup(localEnv.info.scope.dup()));
try {
Type ctype = attribStat(c.param, catchEnv);
if (TreeInfo.isMultiCatch(c)) {
//multi-catch parameter is implicitly marked as final
c.param.sym.flags_field |= FINAL | UNION;
}
if (c.param.sym.kind == VAR) {
c.param.sym.setData(ElementKind.EXCEPTION_PARAMETER);
}
chk.checkType(c.param.vartype.pos(),
chk.checkClassType(c.param.vartype.pos(), ctype),
syms.throwableType);
attribStat(c.body, catchEnv);
} finally {
catchEnv.info.scope.leave();
}
}
// Attribute finalizer
if (tree.finalizer != null) attribStat(tree.finalizer, localEnv);
result = null;
}
finally {
localEnv.info.scope.leave();
}
}
void checkAutoCloseable(DiagnosticPosition pos, Env<AttrContext> env, Type resource) {
if (!resource.isErroneous() &&
types.asSuper(resource, syms.autoCloseableType.tsym) != null &&
!types.isSameType(resource, syms.autoCloseableType)) { // Don't emit warning for AutoCloseable itself
Symbol close = syms.noSymbol;
Log.DiagnosticHandler discardHandler = new Log.DiscardDiagnosticHandler(log);
try {
close = rs.resolveQualifiedMethod(pos,
env,
types.skipTypeVars(resource, false),
names.close,
List.nil(),
List.nil());
}
finally {
log.popDiagnosticHandler(discardHandler);
}
if (close.kind == MTH &&
close.overrides(syms.autoCloseableClose, resource.tsym, types, true) &&
chk.isHandled(syms.interruptedExceptionType, types.memberType(resource, close).getThrownTypes()) &&
env.info.lint.isEnabled(LintCategory.TRY)) {
log.warning(LintCategory.TRY, pos, Warnings.TryResourceThrowsInterruptedExc(resource));
}
}
}
public void visitConditional(JCConditional tree) {
Type condtype = attribExpr(tree.cond, env, syms.booleanType);
tree.polyKind = (!allowPoly ||
pt().hasTag(NONE) && pt() != Type.recoveryType && pt() != Infer.anyPoly ||
isBooleanOrNumeric(env, tree)) ?
PolyKind.STANDALONE : PolyKind.POLY;
if (tree.polyKind == PolyKind.POLY && resultInfo.pt.hasTag(VOID)) {
//this means we are returning a poly conditional from void-compatible lambda expression
resultInfo.checkContext.report(tree, diags.fragment(Fragments.ConditionalTargetCantBeVoid));
result = tree.type = types.createErrorType(resultInfo.pt);
return;
}
ResultInfo condInfo = tree.polyKind == PolyKind.STANDALONE ?
unknownExprInfo :
resultInfo.dup(conditionalContext(resultInfo.checkContext));
// x ? y : z
// include x's bindings when true in y
// include x's bindings when false in z
Type truetype;
Env<AttrContext> trueEnv = bindingEnv(env, matchBindingsComputer.getMatchBindings(tree.cond, true));
try {
truetype = attribTree(tree.truepart, trueEnv, condInfo);
} finally {
trueEnv.info.scope.leave();
}
Type falsetype;
Env<AttrContext> falseEnv = bindingEnv(env, matchBindingsComputer.getMatchBindings(tree.cond, false));
try {
falsetype = attribTree(tree.falsepart, falseEnv, condInfo);
} finally {
falseEnv.info.scope.leave();
}
Type owntype = (tree.polyKind == PolyKind.STANDALONE) ?
condType(List.of(tree.truepart.pos(), tree.falsepart.pos()),
List.of(truetype, falsetype)) : pt();
if (condtype.constValue() != null &&
truetype.constValue() != null &&
falsetype.constValue() != null &&
!owntype.hasTag(NONE)) {
//constant folding
owntype = cfolder.coerce(condtype.isTrue() ? truetype : falsetype, owntype);
}
result = check(tree, owntype, KindSelector.VAL, resultInfo);
}
//where
private boolean isBooleanOrNumeric(Env<AttrContext> env, JCExpression tree) {
switch (tree.getTag()) {
case LITERAL: return ((JCLiteral)tree).typetag.isSubRangeOf(DOUBLE) ||
((JCLiteral)tree).typetag == BOOLEAN ||
((JCLiteral)tree).typetag == BOT;
case LAMBDA: case REFERENCE: return false;
case PARENS: return isBooleanOrNumeric(env, ((JCParens)tree).expr);
case CONDEXPR:
JCConditional condTree = (JCConditional)tree;
return isBooleanOrNumeric(env, condTree.truepart) &&
isBooleanOrNumeric(env, condTree.falsepart);
case APPLY:
JCMethodInvocation speculativeMethodTree =
(JCMethodInvocation)deferredAttr.attribSpeculative(
tree, env, unknownExprInfo,
argumentAttr.withLocalCacheContext());
Symbol msym = TreeInfo.symbol(speculativeMethodTree.meth);
Type receiverType = speculativeMethodTree.meth.hasTag(IDENT) ?
env.enclClass.type :
((JCFieldAccess)speculativeMethodTree.meth).selected.type;
Type owntype = types.memberType(receiverType, msym).getReturnType();
return primitiveOrBoxed(owntype);
case NEWCLASS:
JCExpression className =
removeClassParams.translate(((JCNewClass)tree).clazz);
JCExpression speculativeNewClassTree =
(JCExpression)deferredAttr.attribSpeculative(
className, env, unknownTypeInfo,
argumentAttr.withLocalCacheContext());
return primitiveOrBoxed(speculativeNewClassTree.type);
default:
Type speculativeType = deferredAttr.attribSpeculative(tree, env, unknownExprInfo,
argumentAttr.withLocalCacheContext()).type;
return primitiveOrBoxed(speculativeType);
}
}
//where
boolean primitiveOrBoxed(Type t) {
return (!t.hasTag(TYPEVAR) && types.unboxedTypeOrType(t).isPrimitive());
}
TreeTranslator removeClassParams = new TreeTranslator() {
@Override
public void visitTypeApply(JCTypeApply tree) {
result = translate(tree.clazz);
}
};
CheckContext conditionalContext(CheckContext checkContext) {
return new Check.NestedCheckContext(checkContext) {
//this will use enclosing check context to check compatibility of
//subexpression against target type; if we are in a method check context,
//depending on whether boxing is allowed, we could have incompatibilities
@Override
public void report(DiagnosticPosition pos, JCDiagnostic details) {
enclosingContext.report(pos, diags.fragment(Fragments.IncompatibleTypeInConditional(details)));
}
};
}
/** Compute the type of a conditional expression, after
* checking that it exists. See JLS 15.25. Does not take into
* account the special case where condition and both arms
* are constants.
*
* @param pos The source position to be used for error
* diagnostics.
* @param thentype The type of the expression's then-part.
* @param elsetype The type of the expression's else-part.
*/
Type condType(List<DiagnosticPosition> positions, List<Type> condTypes) {
if (condTypes.isEmpty()) {
return syms.objectType; //TODO: how to handle?
}
Type first = condTypes.head;
// If same type, that is the result
if (condTypes.tail.stream().allMatch(t -> types.isSameType(first, t)))
return first.baseType();
List<Type> unboxedTypes = condTypes.stream()
.map(t -> t.isPrimitive() ? t : types.unboxedType(t))
.collect(List.collector());
// Otherwise, if both arms can be converted to a numeric
// type, return the least numeric type that fits both arms
// (i.e. return larger of the two, or return int if one
// arm is short, the other is char).
if (unboxedTypes.stream().allMatch(t -> t.isPrimitive())) {
// If one arm has an integer subrange type (i.e., byte,
// short, or char), and the other is an integer constant
// that fits into the subrange, return the subrange type.
for (Type type : unboxedTypes) {
if (!type.getTag().isStrictSubRangeOf(INT)) {
continue;
}
if (unboxedTypes.stream().filter(t -> t != type).allMatch(t -> t.hasTag(INT) && types.isAssignable(t, type)))
return type.baseType();
}
for (TypeTag tag : primitiveTags) {
Type candidate = syms.typeOfTag[tag.ordinal()];
if (unboxedTypes.stream().allMatch(t -> types.isSubtype(t, candidate))) {
return candidate;
}
}
}
// Those were all the cases that could result in a primitive
condTypes = condTypes.stream()
.map(t -> t.isPrimitive() ? types.boxedClass(t).type : t)
.collect(List.collector());
for (Type type : condTypes) {
if (condTypes.stream().filter(t -> t != type).allMatch(t -> types.isAssignable(t, type)))
return type.baseType();
}
Iterator<DiagnosticPosition> posIt = positions.iterator();
condTypes = condTypes.stream()
.map(t -> chk.checkNonVoid(posIt.next(), t))
.collect(List.collector());
// both are known to be reference types. The result is
// lub(thentype,elsetype). This cannot fail, as it will
// always be possible to infer "Object" if nothing better.
return types.lub(condTypes.stream().map(t -> t.baseType()).collect(List.collector()));
}
final static TypeTag[] primitiveTags = new TypeTag[]{
BYTE,
CHAR,
SHORT,
INT,
LONG,
FLOAT,
DOUBLE,
BOOLEAN,
};
Env<AttrContext> bindingEnv(Env<AttrContext> env, List<BindingSymbol> bindings) {
Env<AttrContext> env1 = env.dup(env.tree, env.info.dup(env.info.scope.dup()));
bindings.forEach(env1.info.scope::enter);
return env1;
}
public void visitIf(JCIf tree) {
attribExpr(tree.cond, env, syms.booleanType);
// if (x) { y } [ else z ]
// include x's bindings when true in y
// include x's bindings when false in z
List<BindingSymbol> thenBindings = matchBindingsComputer.getMatchBindings(tree.cond, true);
Env<AttrContext> thenEnv = bindingEnv(env, thenBindings);
try {
attribStat(tree.thenpart, thenEnv);
} finally {
thenEnv.info.scope.leave();
}
preFlow(tree.thenpart);
boolean aliveAfterThen = flow.aliveAfter(env, tree.thenpart, make);
boolean aliveAfterElse;
List<BindingSymbol> elseBindings = matchBindingsComputer.getMatchBindings(tree.cond, false);
if (tree.elsepart != null) {
Env<AttrContext> elseEnv = bindingEnv(env, elseBindings);
try {
attribStat(tree.elsepart, elseEnv);
} finally {
elseEnv.info.scope.leave();
}
preFlow(tree.elsepart);
aliveAfterElse = flow.aliveAfter(env, tree.elsepart, make);
} else {
aliveAfterElse = true;
}
chk.checkEmptyIf(tree);
List<BindingSymbol> afterIfBindings = List.nil();
if (aliveAfterThen && !aliveAfterElse) {
afterIfBindings = thenBindings;
} else if (aliveAfterElse && !aliveAfterThen) {
afterIfBindings = elseBindings;
}
afterIfBindings.forEach(env.info.scope::enter);
afterIfBindings.forEach(BindingSymbol::preserveBinding);
result = null;
}
void preFlow(JCTree tree) {
new PostAttrAnalyzer() {
@Override
public void scan(JCTree tree) {
if (tree == null ||
(tree.type != null &&
tree.type == Type.stuckType)) {
//don't touch stuck expressions!
return;
}
super.scan(tree);
}
}.scan(tree);
}
public void visitExec(JCExpressionStatement tree) {
//a fresh environment is required for 292 inference to work properly ---
//see Infer.instantiatePolymorphicSignatureInstance()
Env<AttrContext> localEnv = env.dup(tree);
attribExpr(tree.expr, localEnv);
result = null;
}
public void visitBreak(JCBreak tree) {
tree.target = findJumpTarget(tree.pos(), tree.getTag(), tree.label, env);
result = null;
}
public void visitYield(JCYield tree) {
if (env.info.yieldResult != null) {
attribTree(tree.value, env, env.info.yieldResult);
tree.target = findJumpTarget(tree.pos(), tree.getTag(), names.empty, env);
} else {
log.error(tree.pos(), tree.value.hasTag(PARENS)
? Errors.NoSwitchExpressionQualify
: Errors.NoSwitchExpression);
attribTree(tree.value, env, unknownExprInfo);
}
result = null;
}
public void visitContinue(JCContinue tree) {
tree.target = findJumpTarget(tree.pos(), tree.getTag(), tree.label, env);
result = null;
}
//where
/** Return the target of a break, continue or yield statement,
* if it exists, report an error if not.
* Note: The target of a labelled break or continue is the
* (non-labelled) statement tree referred to by the label,
* not the tree representing the labelled statement itself.
*
* @param pos The position to be used for error diagnostics
* @param tag The tag of the jump statement. This is either
* Tree.BREAK or Tree.CONTINUE.
* @param label The label of the jump statement, or null if no
* label is given.
* @param env The environment current at the jump statement.
*/
private JCTree findJumpTarget(DiagnosticPosition pos,
JCTree.Tag tag,
Name label,
Env<AttrContext> env) {
Pair<JCTree, Error> jumpTarget = findJumpTargetNoError(tag, label, env);
if (jumpTarget.snd != null) {
log.error(pos, jumpTarget.snd);
}
return jumpTarget.fst;
}
/** Return the target of a break or continue statement, if it exists,
* report an error if not.
* Note: The target of a labelled break or continue is the
* (non-labelled) statement tree referred to by the label,
* not the tree representing the labelled statement itself.
*
* @param tag The tag of the jump statement. This is either
* Tree.BREAK or Tree.CONTINUE.
* @param label The label of the jump statement, or null if no
* label is given.
* @param env The environment current at the jump statement.
*/
private Pair<JCTree, JCDiagnostic.Error> findJumpTargetNoError(JCTree.Tag tag,
Name label,
Env<AttrContext> env) {
// Search environments outwards from the point of jump.
Env<AttrContext> env1 = env;
JCDiagnostic.Error pendingError = null;
LOOP:
while (env1 != null) {
switch (env1.tree.getTag()) {
case LABELLED:
JCLabeledStatement labelled = (JCLabeledStatement)env1.tree;
if (label == labelled.label) {
// If jump is a continue, check that target is a loop.
if (tag == CONTINUE) {
if (!labelled.body.hasTag(DOLOOP) &&
!labelled.body.hasTag(WHILELOOP) &&
!labelled.body.hasTag(FORLOOP) &&
!labelled.body.hasTag(FOREACHLOOP)) {
pendingError = Errors.NotLoopLabel(label);
}
// Found labelled statement target, now go inwards
// to next non-labelled tree.
return Pair.of(TreeInfo.referencedStatement(labelled), pendingError);
} else {
return Pair.of(labelled, pendingError);
}
}
break;
case DOLOOP:
case WHILELOOP:
case FORLOOP:
case FOREACHLOOP:
if (label == null) return Pair.of(env1.tree, pendingError);
break;
case SWITCH:
if (label == null && tag == BREAK) return Pair.of(env1.tree, null);
break;
case SWITCH_EXPRESSION:
if (tag == YIELD) {
return Pair.of(env1.tree, null);
} else if (tag == BREAK) {
pendingError = Errors.BreakOutsideSwitchExpression;
} else {
pendingError = Errors.ContinueOutsideSwitchExpression;
}
break;
case LAMBDA:
case METHODDEF:
case CLASSDEF:
break LOOP;
default:
}
env1 = env1.next;
}
if (label != null)
return Pair.of(null, Errors.UndefLabel(label));
else if (pendingError != null)
return Pair.of(null, pendingError);
else if (tag == CONTINUE)
return Pair.of(null, Errors.ContOutsideLoop);
else
return Pair.of(null, Errors.BreakOutsideSwitchLoop);
}
public void visitReturn(JCReturn tree) {
// Check that there is an enclosing method which is
// nested within than the enclosing class.
if (env.info.returnResult == null) {
log.error(tree.pos(), Errors.RetOutsideMeth);
} else if (env.info.yieldResult != null) {
log.error(tree.pos(), Errors.ReturnOutsideSwitchExpression);
} else {
// Attribute return expression, if it exists, and check that
// it conforms to result type of enclosing method.
if (tree.expr != null) {
if (env.info.returnResult.pt.hasTag(VOID)) {
env.info.returnResult.checkContext.report(tree.expr.pos(),
diags.fragment(Fragments.UnexpectedRetVal));
}
attribTree(tree.expr, env, env.info.returnResult);
} else if (!env.info.returnResult.pt.hasTag(VOID) &&
!env.info.returnResult.pt.hasTag(NONE)) {
env.info.returnResult.checkContext.report(tree.pos(),
diags.fragment(Fragments.MissingRetVal(env.info.returnResult.pt)));
}
}
result = null;
}
public void visitThrow(JCThrow tree) {
Type owntype = attribExpr(tree.expr, env, allowPoly ? Type.noType : syms.throwableType);
if (allowPoly) {
chk.checkType(tree, owntype, syms.throwableType);
}
result = null;
}
public void visitAssert(JCAssert tree) {
attribExpr(tree.cond, env, syms.booleanType);
if (tree.detail != null) {
chk.checkNonVoid(tree.detail.pos(), attribExpr(tree.detail, env));
}
result = null;
}
/** Visitor method for method invocations.
* NOTE: The method part of an application will have in its type field
* the return type of the method, not the method's type itself!
*/
public void visitApply(JCMethodInvocation tree) {
// The local environment of a method application is
// a new environment nested in the current one.
Env<AttrContext> localEnv = env.dup(tree, env.info.dup());
// The types of the actual method arguments.
List<Type> argtypes;
// The types of the actual method type arguments.
List<Type> typeargtypes = null;
Name methName = TreeInfo.name(tree.meth);
boolean isConstructorCall =
methName == names._this || methName == names._super;
ListBuffer<Type> argtypesBuf = new ListBuffer<>();
if (isConstructorCall) {
// We are seeing a ...this(...) or ...super(...) call.
// Check that this is the first statement in a constructor.
if (checkFirstConstructorStat(tree, env)) {
// Record the fact
// that this is a constructor call (using isSelfCall).
localEnv.info.isSelfCall = true;
// Attribute arguments, yielding list of argument types.
KindSelector kind = attribArgs(KindSelector.MTH, tree.args, localEnv, argtypesBuf);
argtypes = argtypesBuf.toList();
typeargtypes = attribTypes(tree.typeargs, localEnv);
// Variable `site' points to the class in which the called
// constructor is defined.
Type site = env.enclClass.sym.type;
if (methName == names._super) {
if (site == syms.objectType) {
log.error(tree.meth.pos(), Errors.NoSuperclass(site));
site = types.createErrorType(syms.objectType);
} else {
site = types.supertype(site);
}
}
if (site.hasTag(CLASS)) {
Type encl = site.getEnclosingType();
while (encl != null && encl.hasTag(TYPEVAR))
encl = encl.getUpperBound();
if (encl.hasTag(CLASS)) {
// we are calling a nested class
if (tree.meth.hasTag(SELECT)) {
JCTree qualifier = ((JCFieldAccess) tree.meth).selected;
// We are seeing a prefixed call, of the form
// <expr>.super(...).
// Check that the prefix expression conforms
// to the outer instance type of the class.
chk.checkRefType(qualifier.pos(),
attribExpr(qualifier, localEnv,
encl));
} else if (methName == names._super) {
// qualifier omitted; check for existence
// of an appropriate implicit qualifier.
rs.resolveImplicitThis(tree.meth.pos(),
localEnv, site, true);
}
} else if (tree.meth.hasTag(SELECT)) {
log.error(tree.meth.pos(),
Errors.IllegalQualNotIcls(site.tsym));
}
// if we're calling a java.lang.Enum constructor,
// prefix the implicit String and int parameters
if (site.tsym == syms.enumSym)
argtypes = argtypes.prepend(syms.intType).prepend(syms.stringType);
// Resolve the called constructor under the assumption
// that we are referring to a superclass instance of the
// current instance (JLS ???).
boolean selectSuperPrev = localEnv.info.selectSuper;
localEnv.info.selectSuper = true;
localEnv.info.pendingResolutionPhase = null;
Symbol sym = rs.resolveConstructor(
tree.meth.pos(), localEnv, site, argtypes, typeargtypes);
localEnv.info.selectSuper = selectSuperPrev;
// Set method symbol to resolved constructor...
TreeInfo.setSymbol(tree.meth, sym);
// ...and check that it is legal in the current context.
// (this will also set the tree's type)
Type mpt = newMethodTemplate(resultInfo.pt, argtypes, typeargtypes);
checkId(tree.meth, site, sym, localEnv,
new ResultInfo(kind, mpt));
}
// Otherwise, `site' is an error type and we do nothing
}
result = tree.type = syms.voidType;
} else {
// Otherwise, we are seeing a regular method call.
// Attribute the arguments, yielding list of argument types, ...
KindSelector kind = attribArgs(KindSelector.VAL, tree.args, localEnv, argtypesBuf);
argtypes = argtypesBuf.toList();
typeargtypes = attribAnyTypes(tree.typeargs, localEnv);
// ... and attribute the method using as a prototype a methodtype
// whose formal argument types is exactly the list of actual
// arguments (this will also set the method symbol).
Type mpt = newMethodTemplate(resultInfo.pt, argtypes, typeargtypes);
localEnv.info.pendingResolutionPhase = null;
Type mtype = attribTree(tree.meth, localEnv, new ResultInfo(kind, mpt, resultInfo.checkContext));
// Compute the result type.
Type restype = mtype.getReturnType();
if (restype.hasTag(WILDCARD))
throw new AssertionError(mtype);
Type qualifier = (tree.meth.hasTag(SELECT))
? ((JCFieldAccess) tree.meth).selected.type
: env.enclClass.sym.type;
Symbol msym = TreeInfo.symbol(tree.meth);
restype = adjustMethodReturnType(msym, qualifier, methName, argtypes, restype);
chk.checkRefTypes(tree.typeargs, typeargtypes);
// Check that value of resulting type is admissible in the
// current context. Also, capture the return type
Type capturedRes = resultInfo.checkContext.inferenceContext().cachedCapture(tree, restype, true);
result = check(tree, capturedRes, KindSelector.VAL, resultInfo);
}
chk.validate(tree.typeargs, localEnv);
}
//where
Type adjustMethodReturnType(Symbol msym, Type qualifierType, Name methodName, List<Type> argtypes, Type restype) {
if (msym != null &&
msym.owner == syms.objectType.tsym &&
methodName == names.getClass &&
argtypes.isEmpty()) {
// as a special case, x.getClass() has type Class<? extends |X|>
return new ClassType(restype.getEnclosingType(),
List.of(new WildcardType(types.erasure(qualifierType),
BoundKind.EXTENDS,
syms.boundClass)),
restype.tsym,
restype.getMetadata());
} else if (msym != null &&
msym.owner == syms.arrayClass &&
methodName == names.clone &&
types.isArray(qualifierType)) {
// as a special case, array.clone() has a result that is
// the same as static type of the array being cloned
return qualifierType;
} else {
return restype;
}
}
/** Check that given application node appears as first statement
* in a constructor call.
* @param tree The application node
* @param env The environment current at the application.
*/
boolean checkFirstConstructorStat(JCMethodInvocation tree, Env<AttrContext> env) {
JCMethodDecl enclMethod = env.enclMethod;
if (enclMethod != null && enclMethod.name == names.init) {
JCBlock body = enclMethod.body;
if (body.stats.head.hasTag(EXEC) &&
((JCExpressionStatement) body.stats.head).expr == tree)
return true;
}
log.error(tree.pos(),
Errors.CallMustBeFirstStmtInCtor(TreeInfo.name(tree.meth)));
return false;
}
/** Obtain a method type with given argument types.
*/
Type newMethodTemplate(Type restype, List<Type> argtypes, List<Type> typeargtypes) {
MethodType mt = new MethodType(argtypes, restype, List.nil(), syms.methodClass);
return (typeargtypes == null) ? mt : (Type)new ForAll(typeargtypes, mt);
}
public void visitNewClass(final JCNewClass tree) {
Type owntype = types.createErrorType(tree.type);
// The local environment of a class creation is
// a new environment nested in the current one.
Env<AttrContext> localEnv = env.dup(tree, env.info.dup());
// The anonymous inner class definition of the new expression,
// if one is defined by it.
JCClassDecl cdef = tree.def;
// If enclosing class is given, attribute it, and
// complete class name to be fully qualified
JCExpression clazz = tree.clazz; // Class field following new
JCExpression clazzid; // Identifier in class field
JCAnnotatedType annoclazzid; // Annotated type enclosing clazzid
annoclazzid = null;
if (clazz.hasTag(TYPEAPPLY)) {
clazzid = ((JCTypeApply) clazz).clazz;
if (clazzid.hasTag(ANNOTATED_TYPE)) {
annoclazzid = (JCAnnotatedType) clazzid;
clazzid = annoclazzid.underlyingType;
}
} else {
if (clazz.hasTag(ANNOTATED_TYPE)) {
annoclazzid = (JCAnnotatedType) clazz;
clazzid = annoclazzid.underlyingType;
} else {
clazzid = clazz;
}
}
JCExpression clazzid1 = clazzid; // The same in fully qualified form
if (tree.encl != null) {
// We are seeing a qualified new, of the form
// <expr>.new C <...> (...) ...
// In this case, we let clazz stand for the name of the
// allocated class C prefixed with the type of the qualifier
// expression, so that we can
// resolve it with standard techniques later. I.e., if
// <expr> has type T, then <expr>.new C <...> (...)
// yields a clazz T.C.
Type encltype = chk.checkRefType(tree.encl.pos(),
attribExpr(tree.encl, env));
// TODO 308: in <expr>.new C, do we also want to add the type annotations
// from expr to the combined type, or not? Yes, do this.
clazzid1 = make.at(clazz.pos).Select(make.Type(encltype),
((JCIdent) clazzid).name);
EndPosTable endPosTable = this.env.toplevel.endPositions;
endPosTable.storeEnd(clazzid1, tree.getEndPosition(endPosTable));
if (clazz.hasTag(ANNOTATED_TYPE)) {
JCAnnotatedType annoType = (JCAnnotatedType) clazz;
List<JCAnnotation> annos = annoType.annotations;
if (annoType.underlyingType.hasTag(TYPEAPPLY)) {
clazzid1 = make.at(tree.pos).
TypeApply(clazzid1,
((JCTypeApply) clazz).arguments);
}
clazzid1 = make.at(tree.pos).
AnnotatedType(annos, clazzid1);
} else if (clazz.hasTag(TYPEAPPLY)) {
clazzid1 = make.at(tree.pos).
TypeApply(clazzid1,
((JCTypeApply) clazz).arguments);
}
clazz = clazzid1;
}
// Attribute clazz expression and store
// symbol + type back into the attributed tree.
Type clazztype;
try {
env.info.isNewClass = true;
clazztype = TreeInfo.isEnumInit(env.tree) ?
attribIdentAsEnumType(env, (JCIdent)clazz) :
attribType(clazz, env);
} finally {
env.info.isNewClass = false;
}
clazztype = chk.checkDiamond(tree, clazztype);
chk.validate(clazz, localEnv);
if (tree.encl != null) {
// We have to work in this case to store
// symbol + type back into the attributed tree.
tree.clazz.type = clazztype;
TreeInfo.setSymbol(clazzid, TreeInfo.symbol(clazzid1));
clazzid.type = ((JCIdent) clazzid).sym.type;
if (annoclazzid != null) {
annoclazzid.type = clazzid.type;
}
if (!clazztype.isErroneous()) {
if (cdef != null && clazztype.tsym.isInterface()) {
log.error(tree.encl.pos(), Errors.AnonClassImplIntfNoQualForNew);
} else if (clazztype.tsym.isStatic()) {
log.error(tree.encl.pos(), Errors.QualifiedNewOfStaticClass(clazztype.tsym));
}
}
} else if (!clazztype.tsym.isInterface() &&
clazztype.getEnclosingType().hasTag(CLASS)) {
// Check for the existence of an apropos outer instance
rs.resolveImplicitThis(tree.pos(), env, clazztype);
}
// Attribute constructor arguments.
ListBuffer<Type> argtypesBuf = new ListBuffer<>();
final KindSelector pkind =
attribArgs(KindSelector.VAL, tree.args, localEnv, argtypesBuf);
List<Type> argtypes = argtypesBuf.toList();
List<Type> typeargtypes = attribTypes(tree.typeargs, localEnv);
if (clazztype.hasTag(CLASS) || clazztype.hasTag(ERROR)) {
// Enums may not be instantiated except implicitly
if ((clazztype.tsym.flags_field & Flags.ENUM) != 0 &&
(!env.tree.hasTag(VARDEF) ||
(((JCVariableDecl) env.tree).mods.flags & Flags.ENUM) == 0 ||
((JCVariableDecl) env.tree).init != tree))
log.error(tree.pos(), Errors.EnumCantBeInstantiated);
boolean isSpeculativeDiamondInferenceRound = TreeInfo.isDiamond(tree) &&
resultInfo.checkContext.deferredAttrContext().mode == DeferredAttr.AttrMode.SPECULATIVE;
boolean skipNonDiamondPath = false;
// Check that class is not abstract
if (cdef == null && !isSpeculativeDiamondInferenceRound && // class body may be nulled out in speculative tree copy
(clazztype.tsym.flags() & (ABSTRACT | INTERFACE)) != 0) {
log.error(tree.pos(),
Errors.AbstractCantBeInstantiated(clazztype.tsym));
skipNonDiamondPath = true;
} else if (cdef != null && clazztype.tsym.isInterface()) {
// Check that no constructor arguments are given to
// anonymous classes implementing an interface
if (!argtypes.isEmpty())
log.error(tree.args.head.pos(), Errors.AnonClassImplIntfNoArgs);
if (!typeargtypes.isEmpty())
log.error(tree.typeargs.head.pos(), Errors.AnonClassImplIntfNoTypeargs);
// Error recovery: pretend no arguments were supplied.
argtypes = List.nil();
typeargtypes = List.nil();
skipNonDiamondPath = true;
}
if (TreeInfo.isDiamond(tree)) {
ClassType site = new ClassType(clazztype.getEnclosingType(),
clazztype.tsym.type.getTypeArguments(),
clazztype.tsym,
clazztype.getMetadata());
Env<AttrContext> diamondEnv = localEnv.dup(tree);
diamondEnv.info.selectSuper = cdef != null || tree.classDeclRemoved();
diamondEnv.info.pendingResolutionPhase = null;
//if the type of the instance creation expression is a class type
//apply method resolution inference (JLS 15.12.2.7). The return type
//of the resolved constructor will be a partially instantiated type
Symbol constructor = rs.resolveDiamond(tree.pos(),
diamondEnv,
site,
argtypes,
typeargtypes);
tree.constructor = constructor.baseSymbol();
final TypeSymbol csym = clazztype.tsym;
ResultInfo diamondResult = new ResultInfo(pkind, newMethodTemplate(resultInfo.pt, argtypes, typeargtypes),
diamondContext(tree, csym, resultInfo.checkContext), CheckMode.NO_TREE_UPDATE);
Type constructorType = tree.constructorType = types.createErrorType(clazztype);
constructorType = checkId(tree, site,
constructor,
diamondEnv,
diamondResult);
tree.clazz.type = types.createErrorType(clazztype);
if (!constructorType.isErroneous()) {
tree.clazz.type = clazz.type = constructorType.getReturnType();
tree.constructorType = types.createMethodTypeWithReturn(constructorType, syms.voidType);
}
clazztype = chk.checkClassType(tree.clazz, tree.clazz.type, true);
}
// Resolve the called constructor under the assumption
// that we are referring to a superclass instance of the
// current instance (JLS ???).
else if (!skipNonDiamondPath) {
//the following code alters some of the fields in the current
//AttrContext - hence, the current context must be dup'ed in
//order to avoid downstream failures
Env<AttrContext> rsEnv = localEnv.dup(tree);
rsEnv.info.selectSuper = cdef != null;
rsEnv.info.pendingResolutionPhase = null;
tree.constructor = rs.resolveConstructor(
tree.pos(), rsEnv, clazztype, argtypes, typeargtypes);
if (cdef == null) { //do not check twice!
tree.constructorType = checkId(tree,
clazztype,
tree.constructor,
rsEnv,
new ResultInfo(pkind, newMethodTemplate(syms.voidType, argtypes, typeargtypes), CheckMode.NO_TREE_UPDATE));
if (rsEnv.info.lastResolveVarargs())
Assert.check(tree.constructorType.isErroneous() || tree.varargsElement != null);
}
}
if (cdef != null) {
visitAnonymousClassDefinition(tree, clazz, clazztype, cdef, localEnv, argtypes, typeargtypes, pkind);
return;
}
if (tree.constructor != null && tree.constructor.kind == MTH)
owntype = clazztype;
}
result = check(tree, owntype, KindSelector.VAL, resultInfo);
InferenceContext inferenceContext = resultInfo.checkContext.inferenceContext();
if (tree.constructorType != null && inferenceContext.free(tree.constructorType)) {
//we need to wait for inference to finish and then replace inference vars in the constructor type
inferenceContext.addFreeTypeListener(List.of(tree.constructorType),
instantiatedContext -> {
tree.constructorType = instantiatedContext.asInstType(tree.constructorType);
});
}
chk.validate(tree.typeargs, localEnv);
}
// where
private void visitAnonymousClassDefinition(JCNewClass tree, JCExpression clazz, Type clazztype,
JCClassDecl cdef, Env<AttrContext> localEnv,
List<Type> argtypes, List<Type> typeargtypes,
KindSelector pkind) {
// We are seeing an anonymous class instance creation.
// In this case, the class instance creation
// expression
//
// E.new <typeargs1>C<typargs2>(args) { ... }
//
// is represented internally as
//
// E . new <typeargs1>C<typargs2>(args) ( class <empty-name> { ... } ) .
//
// This expression is then *transformed* as follows:
//
// (1) add an extends or implements clause
// (2) add a constructor.
//
// For instance, if C is a class, and ET is the type of E,
// the expression
//
// E.new <typeargs1>C<typargs2>(args) { ... }
//
// is translated to (where X is a fresh name and typarams is the
// parameter list of the super constructor):
//
// new <typeargs1>X(<*nullchk*>E, args) where
// X extends C<typargs2> {
// <typarams> X(ET e, args) {
// e.<typeargs1>super(args)
// }
// ...
// }
InferenceContext inferenceContext = resultInfo.checkContext.inferenceContext();
final boolean isDiamond = TreeInfo.isDiamond(tree);
if (isDiamond
&& ((tree.constructorType != null && inferenceContext.free(tree.constructorType))
|| (tree.clazz.type != null && inferenceContext.free(tree.clazz.type)))) {
final ResultInfo resultInfoForClassDefinition = this.resultInfo;
inferenceContext.addFreeTypeListener(List.of(tree.constructorType, tree.clazz.type),
instantiatedContext -> {
tree.constructorType = instantiatedContext.asInstType(tree.constructorType);
tree.clazz.type = clazz.type = instantiatedContext.asInstType(clazz.type);
ResultInfo prevResult = this.resultInfo;
try {
this.resultInfo = resultInfoForClassDefinition;
visitAnonymousClassDefinition(tree, clazz, clazz.type, cdef,
localEnv, argtypes, typeargtypes, pkind);
} finally {
this.resultInfo = prevResult;
}
});
} else {
if (isDiamond && clazztype.hasTag(CLASS)) {
List<Type> invalidDiamondArgs = chk.checkDiamondDenotable((ClassType)clazztype);
if (!clazztype.isErroneous() && invalidDiamondArgs.nonEmpty()) {
// One or more types inferred in the previous steps is non-denotable.
Fragment fragment = Diamond(clazztype.tsym);
log.error(tree.clazz.pos(),
Errors.CantApplyDiamond1(
fragment,
invalidDiamondArgs.size() > 1 ?
DiamondInvalidArgs(invalidDiamondArgs, fragment) :
DiamondInvalidArg(invalidDiamondArgs, fragment)));
}
// For <>(){}, inferred types must also be accessible.
for (Type t : clazztype.getTypeArguments()) {
rs.checkAccessibleType(env, t);
}
}
// If we already errored, be careful to avoid a further avalanche. ErrorType answers
// false for isInterface call even when the original type is an interface.
boolean implementing = clazztype.tsym.isInterface() ||
clazztype.isErroneous() && !clazztype.getOriginalType().hasTag(NONE) &&
clazztype.getOriginalType().tsym.isInterface();
if (implementing) {
cdef.implementing = List.of(clazz);
} else {
cdef.extending = clazz;
}
if (resultInfo.checkContext.deferredAttrContext().mode == DeferredAttr.AttrMode.CHECK &&
isSerializable(clazztype)) {
localEnv.info.isSerializable = true;
}
attribStat(cdef, localEnv);
List<Type> finalargtypes;
// If an outer instance is given,
// prefix it to the constructor arguments
// and delete it from the new expression
if (tree.encl != null && !clazztype.tsym.isInterface()) {
finalargtypes = argtypes.prepend(tree.encl.type);
} else {
finalargtypes = argtypes;
}
// Reassign clazztype and recompute constructor. As this necessarily involves
// another attribution pass for deferred types in the case of <>, replicate
// them. Original arguments have right decorations already.
if (isDiamond && pkind.contains(KindSelector.POLY)) {
finalargtypes = finalargtypes.map(deferredAttr.deferredCopier);
}
clazztype = clazztype.hasTag(ERROR) ? types.createErrorType(cdef.sym.type)
: cdef.sym.type;
Symbol sym = tree.constructor = rs.resolveConstructor(
tree.pos(), localEnv, clazztype, finalargtypes, typeargtypes);
Assert.check(!sym.kind.isResolutionError());
tree.constructor = sym;
tree.constructorType = checkId(tree,
clazztype,
tree.constructor,
localEnv,
new ResultInfo(pkind, newMethodTemplate(syms.voidType, finalargtypes, typeargtypes), CheckMode.NO_TREE_UPDATE));
}
Type owntype = (tree.constructor != null && tree.constructor.kind == MTH) ?
clazztype : types.createErrorType(tree.type);
result = check(tree, owntype, KindSelector.VAL, resultInfo.dup(CheckMode.NO_INFERENCE_HOOK));
chk.validate(tree.typeargs, localEnv);
}
CheckContext diamondContext(JCNewClass clazz, TypeSymbol tsym, CheckContext checkContext) {
return new Check.NestedCheckContext(checkContext) {
@Override
public void report(DiagnosticPosition _unused, JCDiagnostic details) {
enclosingContext.report(clazz.clazz,
diags.fragment(Fragments.CantApplyDiamond1(Fragments.Diamond(tsym), details)));
}
};
}
/** Make an attributed null check tree.
*/
public JCExpression makeNullCheck(JCExpression arg) {
// optimization: new Outer() can never be null; skip null check
if (arg.getTag() == NEWCLASS)
return arg;
// optimization: X.this is never null; skip null check
Name name = TreeInfo.name(arg);
if (name == names._this || name == names._super) return arg;
JCTree.Tag optag = NULLCHK;
JCUnary tree = make.at(arg.pos).Unary(optag, arg);
tree.operator = operators.resolveUnary(arg, optag, arg.type);
tree.type = arg.type;
return tree;
}
public void visitNewArray(JCNewArray tree) {
Type owntype = types.createErrorType(tree.type);
Env<AttrContext> localEnv = env.dup(tree);
Type elemtype;
if (tree.elemtype != null) {
elemtype = attribType(tree.elemtype, localEnv);
chk.validate(tree.elemtype, localEnv);
owntype = elemtype;
for (List<JCExpression> l = tree.dims; l.nonEmpty(); l = l.tail) {
attribExpr(l.head, localEnv, syms.intType);
owntype = new ArrayType(owntype, syms.arrayClass);
}
} else {
// we are seeing an untyped aggregate { ... }
// this is allowed only if the prototype is an array
if (pt().hasTag(ARRAY)) {
elemtype = types.elemtype(pt());
} else {
if (!pt().hasTag(ERROR) &&
(env.info.enclVar == null || !env.info.enclVar.type.isErroneous())) {
log.error(tree.pos(),
Errors.IllegalInitializerForType(pt()));
}
elemtype = types.createErrorType(pt());
}
}
if (tree.elems != null) {
attribExprs(tree.elems, localEnv, elemtype);
owntype = new ArrayType(elemtype, syms.arrayClass);
}
if (!types.isReifiable(elemtype))
log.error(tree.pos(), Errors.GenericArrayCreation);
result = check(tree, owntype, KindSelector.VAL, resultInfo);
}
/*
* A lambda expression can only be attributed when a target-type is available.
* In addition, if the target-type is that of a functional interface whose
* descriptor contains inference variables in argument position the lambda expression
* is 'stuck' (see DeferredAttr).
*/
@Override
public void visitLambda(final JCLambda that) {
boolean wrongContext = false;
if (pt().isErroneous() || (pt().hasTag(NONE) && pt() != Type.recoveryType)) {
if (pt().hasTag(NONE) && (env.info.enclVar == null || !env.info.enclVar.type.isErroneous())) {
//lambda only allowed in assignment or method invocation/cast context
log.error(that.pos(), Errors.UnexpectedLambda);
}
resultInfo = recoveryInfo;
wrongContext = true;
}
//create an environment for attribution of the lambda expression
final Env<AttrContext> localEnv = lambdaEnv(that, env);
boolean needsRecovery =
resultInfo.checkContext.deferredAttrContext().mode == DeferredAttr.AttrMode.CHECK;
try {
if (needsRecovery && isSerializable(pt())) {
localEnv.info.isSerializable = true;
localEnv.info.isLambda = true;
}
List<Type> explicitParamTypes = null;
if (that.paramKind == JCLambda.ParameterKind.EXPLICIT) {
//attribute lambda parameters
attribStats(that.params, localEnv);
explicitParamTypes = TreeInfo.types(that.params);
}
TargetInfo targetInfo = getTargetInfo(that, resultInfo, explicitParamTypes);
Type currentTarget = targetInfo.target;
Type lambdaType = targetInfo.descriptor;
if (currentTarget.isErroneous()) {
result = that.type = currentTarget;
return;
}
setFunctionalInfo(localEnv, that, pt(), lambdaType, currentTarget, resultInfo.checkContext);
if (lambdaType.hasTag(FORALL)) {
//lambda expression target desc cannot be a generic method
Fragment msg = Fragments.InvalidGenericLambdaTarget(lambdaType,
kindName(currentTarget.tsym),
currentTarget.tsym);
resultInfo.checkContext.report(that, diags.fragment(msg));
result = that.type = types.createErrorType(pt());
return;
}
if (that.paramKind == JCLambda.ParameterKind.IMPLICIT) {
//add param type info in the AST
List<Type> actuals = lambdaType.getParameterTypes();
List<JCVariableDecl> params = that.params;
boolean arityMismatch = false;
while (params.nonEmpty()) {
if (actuals.isEmpty()) {
//not enough actuals to perform lambda parameter inference
arityMismatch = true;
}
//reset previously set info
Type argType = arityMismatch ?
syms.errType :
actuals.head;
if (params.head.isImplicitlyTyped()) {
setSyntheticVariableType(params.head, argType);
}
params.head.sym = null;
actuals = actuals.isEmpty() ?
actuals :
actuals.tail;
params = params.tail;
}
//attribute lambda parameters
attribStats(that.params, localEnv);
if (arityMismatch) {
resultInfo.checkContext.report(that, diags.fragment(Fragments.IncompatibleArgTypesInLambda));
result = that.type = types.createErrorType(currentTarget);
return;
}
}
//from this point on, no recovery is needed; if we are in assignment context
//we will be able to attribute the whole lambda body, regardless of errors;
//if we are in a 'check' method context, and the lambda is not compatible
//with the target-type, it will be recovered anyway in Attr.checkId
needsRecovery = false;
ResultInfo bodyResultInfo = localEnv.info.returnResult =
lambdaBodyResult(that, lambdaType, resultInfo);
if (that.getBodyKind() == JCLambda.BodyKind.EXPRESSION) {
attribTree(that.getBody(), localEnv, bodyResultInfo);
} else {
JCBlock body = (JCBlock)that.body;
if (body == breakTree &&
resultInfo.checkContext.deferredAttrContext().mode == AttrMode.CHECK) {
breakTreeFound(copyEnv(localEnv));
}
attribStats(body.stats, localEnv);
}
result = check(that, currentTarget, KindSelector.VAL, resultInfo);
boolean isSpeculativeRound =
resultInfo.checkContext.deferredAttrContext().mode == DeferredAttr.AttrMode.SPECULATIVE;
preFlow(that);
flow.analyzeLambda(env, that, make, isSpeculativeRound);
that.type = currentTarget; //avoids recovery at this stage
checkLambdaCompatible(that, lambdaType, resultInfo.checkContext);
if (!isSpeculativeRound) {
//add thrown types as bounds to the thrown types free variables if needed:
if (resultInfo.checkContext.inferenceContext().free(lambdaType.getThrownTypes())) {
List<Type> inferredThrownTypes = flow.analyzeLambdaThrownTypes(env, that, make);
if(!checkExConstraints(inferredThrownTypes, lambdaType.getThrownTypes(), resultInfo.checkContext.inferenceContext())) {
log.error(that, Errors.IncompatibleThrownTypesInMref(lambdaType.getThrownTypes()));
}
}
checkAccessibleTypes(that, localEnv, resultInfo.checkContext.inferenceContext(), lambdaType, currentTarget);
}
result = wrongContext ? that.type = types.createErrorType(pt())
: check(that, currentTarget, KindSelector.VAL, resultInfo);
} catch (Types.FunctionDescriptorLookupError ex) {
JCDiagnostic cause = ex.getDiagnostic();
resultInfo.checkContext.report(that, cause);
result = that.type = types.createErrorType(pt());
return;
} catch (CompletionFailure cf) {
chk.completionError(that.pos(), cf);
} catch (Throwable t) {
//when an unexpected exception happens, avoid attempts to attribute the same tree again
//as that would likely cause the same exception again.
needsRecovery = false;
throw t;
} finally {
localEnv.info.scope.leave();
if (needsRecovery) {
attribTree(that, env, recoveryInfo);
}
}
}
//where
class TargetInfo {
Type target;
Type descriptor;
public TargetInfo(Type target, Type descriptor) {
this.target = target;
this.descriptor = descriptor;
}
}
TargetInfo getTargetInfo(JCPolyExpression that, ResultInfo resultInfo, List<Type> explicitParamTypes) {
Type lambdaType;
Type currentTarget = resultInfo.pt;
if (resultInfo.pt != Type.recoveryType) {
/* We need to adjust the target. If the target is an
* intersection type, for example: SAM & I1 & I2 ...
* the target will be updated to SAM
*/
currentTarget = targetChecker.visit(currentTarget, that);
if (!currentTarget.isIntersection()) {
if (explicitParamTypes != null) {
currentTarget = infer.instantiateFunctionalInterface(that,
currentTarget, explicitParamTypes, resultInfo.checkContext);
}
currentTarget = types.removeWildcards(currentTarget);
lambdaType = types.findDescriptorType(currentTarget);
} else {
IntersectionClassType ict = (IntersectionClassType)currentTarget;
ListBuffer<Type> components = new ListBuffer<>();
for (Type bound : ict.getExplicitComponents()) {
if (explicitParamTypes != null) {
try {
bound = infer.instantiateFunctionalInterface(that,
bound, explicitParamTypes, resultInfo.checkContext);
} catch (FunctionDescriptorLookupError t) {
// do nothing
}
}
bound = types.removeWildcards(bound);
components.add(bound);
}
currentTarget = types.makeIntersectionType(components.toList());
currentTarget.tsym.flags_field |= INTERFACE;
lambdaType = types.findDescriptorType(currentTarget);
}
} else {
currentTarget = Type.recoveryType;
lambdaType = fallbackDescriptorType(that);
}
if (that.hasTag(LAMBDA) && lambdaType.hasTag(FORALL)) {
//lambda expression target desc cannot be a generic method
Fragment msg = Fragments.InvalidGenericLambdaTarget(lambdaType,
kindName(currentTarget.tsym),
currentTarget.tsym);
resultInfo.checkContext.report(that, diags.fragment(msg));
currentTarget = types.createErrorType(pt());
}
return new TargetInfo(currentTarget, lambdaType);
}
void preFlow(JCLambda tree) {
new PostAttrAnalyzer() {
@Override
public void scan(JCTree tree) {
if (tree == null ||
(tree.type != null &&
tree.type == Type.stuckType)) {
//don't touch stuck expressions!
return;
}
super.scan(tree);
}
@Override
public void visitClassDef(JCClassDecl that) {
// or class declaration trees!
}
public void visitLambda(JCLambda that) {
// or lambda expressions!
}
}.scan(tree.body);
}
Types.MapVisitor<DiagnosticPosition> targetChecker = new Types.MapVisitor<DiagnosticPosition>() {
@Override
public Type visitClassType(ClassType t, DiagnosticPosition pos) {
return t.isIntersection() ?
visitIntersectionClassType((IntersectionClassType)t, pos) : t;
}
public Type visitIntersectionClassType(IntersectionClassType ict, DiagnosticPosition pos) {
types.findDescriptorSymbol(makeNotionalInterface(ict, pos));
return ict;
}
private TypeSymbol makeNotionalInterface(IntersectionClassType ict, DiagnosticPosition pos) {
ListBuffer<Type> targs = new ListBuffer<>();
ListBuffer<Type> supertypes = new ListBuffer<>();
for (Type i : ict.interfaces_field) {
if (i.isParameterized()) {
targs.appendList(i.tsym.type.allparams());
}
supertypes.append(i.tsym.type);
}
IntersectionClassType notionalIntf = types.makeIntersectionType(supertypes.toList());
notionalIntf.allparams_field = targs.toList();
notionalIntf.tsym.flags_field |= INTERFACE;
return notionalIntf.tsym;
}
};
private Type fallbackDescriptorType(JCExpression tree) {
switch (tree.getTag()) {
case LAMBDA:
JCLambda lambda = (JCLambda)tree;
List<Type> argtypes = List.nil();
for (JCVariableDecl param : lambda.params) {
argtypes = param.vartype != null && param.vartype.type != null ?
argtypes.append(param.vartype.type) :
argtypes.append(syms.errType);
}
return new MethodType(argtypes, Type.recoveryType,
List.of(syms.throwableType), syms.methodClass);
case REFERENCE:
return new MethodType(List.nil(), Type.recoveryType,
List.of(syms.throwableType), syms.methodClass);
default:
Assert.error("Cannot get here!");
}
return null;
}
private void checkAccessibleTypes(final DiagnosticPosition pos, final Env<AttrContext> env,
final InferenceContext inferenceContext, final Type... ts) {
checkAccessibleTypes(pos, env, inferenceContext, List.from(ts));
}
private void checkAccessibleTypes(final DiagnosticPosition pos, final Env<AttrContext> env,
final InferenceContext inferenceContext, final List<Type> ts) {
if (inferenceContext.free(ts)) {
inferenceContext.addFreeTypeListener(ts,
solvedContext -> checkAccessibleTypes(pos, env, solvedContext, solvedContext.asInstTypes(ts)));
} else {
for (Type t : ts) {
rs.checkAccessibleType(env, t);
}
}
}
/**
* Lambda/method reference have a special check context that ensures
* that i.e. a lambda return type is compatible with the expected
* type according to both the inherited context and the assignment
* context.
*/
class FunctionalReturnContext extends Check.NestedCheckContext {
FunctionalReturnContext(CheckContext enclosingContext) {
super(enclosingContext);
}
@Override
public boolean compatible(Type found, Type req, Warner warn) {
//return type must be compatible in both current context and assignment context
return chk.basicHandler.compatible(inferenceContext().asUndetVar(found), inferenceContext().asUndetVar(req), warn);
}
@Override
public void report(DiagnosticPosition pos, JCDiagnostic details) {
enclosingContext.report(pos, diags.fragment(Fragments.IncompatibleRetTypeInLambda(details)));
}
}
class ExpressionLambdaReturnContext extends FunctionalReturnContext {
JCExpression expr;
boolean expStmtExpected;
ExpressionLambdaReturnContext(JCExpression expr, CheckContext enclosingContext) {
super(enclosingContext);
this.expr = expr;
}
@Override
public void report(DiagnosticPosition pos, JCDiagnostic details) {
if (expStmtExpected) {
enclosingContext.report(pos, diags.fragment(Fragments.StatExprExpected));
} else {
super.report(pos, details);
}
}
@Override
public boolean compatible(Type found, Type req, Warner warn) {
//a void return is compatible with an expression statement lambda
if (req.hasTag(VOID)) {
expStmtExpected = true;
return TreeInfo.isExpressionStatement(expr);
} else {
return super.compatible(found, req, warn);
}
}
}
ResultInfo lambdaBodyResult(JCLambda that, Type descriptor, ResultInfo resultInfo) {
FunctionalReturnContext funcContext = that.getBodyKind() == JCLambda.BodyKind.EXPRESSION ?
new ExpressionLambdaReturnContext((JCExpression)that.getBody(), resultInfo.checkContext) :
new FunctionalReturnContext(resultInfo.checkContext);
return descriptor.getReturnType() == Type.recoveryType ?
recoveryInfo :
new ResultInfo(KindSelector.VAL,
descriptor.getReturnType(), funcContext);
}
/**
* Lambda compatibility. Check that given return types, thrown types, parameter types
* are compatible with the expected functional interface descriptor. This means that:
* (i) parameter types must be identical to those of the target descriptor; (ii) return
* types must be compatible with the return type of the expected descriptor.
*/
void checkLambdaCompatible(JCLambda tree, Type descriptor, CheckContext checkContext) {
Type returnType = checkContext.inferenceContext().asUndetVar(descriptor.getReturnType());
//return values have already been checked - but if lambda has no return
//values, we must ensure that void/value compatibility is correct;
//this amounts at checking that, if a lambda body can complete normally,
//the descriptor's return type must be void
if (tree.getBodyKind() == JCLambda.BodyKind.STATEMENT && tree.canCompleteNormally &&
!returnType.hasTag(VOID) && returnType != Type.recoveryType) {
Fragment msg =
Fragments.IncompatibleRetTypeInLambda(Fragments.MissingRetVal(returnType));
checkContext.report(tree,
diags.fragment(msg));
}
List<Type> argTypes = checkContext.inferenceContext().asUndetVars(descriptor.getParameterTypes());
if (!types.isSameTypes(argTypes, TreeInfo.types(tree.params))) {
checkContext.report(tree, diags.fragment(Fragments.IncompatibleArgTypesInLambda));
}
}
/* Map to hold 'fake' clinit methods. If a lambda is used to initialize a
* static field and that lambda has type annotations, these annotations will
* also be stored at these fake clinit methods.
*
* LambdaToMethod also use fake clinit methods so they can be reused.
* Also as LTM is a phase subsequent to attribution, the methods from
* clinits can be safely removed by LTM to save memory.
*/
private Map<ClassSymbol, MethodSymbol> clinits = new HashMap<>();
public MethodSymbol removeClinit(ClassSymbol sym) {
return clinits.remove(sym);
}
/* This method returns an environment to be used to attribute a lambda
* expression.
*
* The owner of this environment is a method symbol. If the current owner
* is not a method, for example if the lambda is used to initialize
* a field, then if the field is:
*
* - an instance field, we use the first constructor.
* - a static field, we create a fake clinit method.
*/
public Env<AttrContext> lambdaEnv(JCLambda that, Env<AttrContext> env) {
Env<AttrContext> lambdaEnv;
Symbol owner = env.info.scope.owner;
if (owner.kind == VAR && owner.owner.kind == TYP) {
//field initializer
ClassSymbol enclClass = owner.enclClass();
Symbol newScopeOwner = env.info.scope.owner;
/* if the field isn't static, then we can get the first constructor
* and use it as the owner of the environment. This is what
* LTM code is doing to look for type annotations so we are fine.
*/
if ((owner.flags() & STATIC) == 0) {
for (Symbol s : enclClass.members_field.getSymbolsByName(names.init)) {
newScopeOwner = s;
break;
}
} else {
/* if the field is static then we need to create a fake clinit
* method, this method can later be reused by LTM.
*/
MethodSymbol clinit = clinits.get(enclClass);
if (clinit == null) {
Type clinitType = new MethodType(List.nil(),
syms.voidType, List.nil(), syms.methodClass);
clinit = new MethodSymbol(STATIC | SYNTHETIC | PRIVATE,
names.clinit, clinitType, enclClass);
clinit.params = List.nil();
clinits.put(enclClass, clinit);
}
newScopeOwner = clinit;
}
lambdaEnv = env.dup(that, env.info.dup(env.info.scope.dupUnshared(newScopeOwner)));
} else {
lambdaEnv = env.dup(that, env.info.dup(env.info.scope.dup()));
}
lambdaEnv.info.yieldResult = null;
return lambdaEnv;
}
@Override
public void visitReference(final JCMemberReference that) {
if (pt().isErroneous() || (pt().hasTag(NONE) && pt() != Type.recoveryType)) {
if (pt().hasTag(NONE) && (env.info.enclVar == null || !env.info.enclVar.type.isErroneous())) {
//method reference only allowed in assignment or method invocation/cast context
log.error(that.pos(), Errors.UnexpectedMref);
}
result = that.type = types.createErrorType(pt());
return;
}
final Env<AttrContext> localEnv = env.dup(that);
try {
//attribute member reference qualifier - if this is a constructor
//reference, the expected kind must be a type
Type exprType = attribTree(that.expr, env, memberReferenceQualifierResult(that));
if (that.getMode() == JCMemberReference.ReferenceMode.NEW) {
exprType = chk.checkConstructorRefType(that.expr, exprType);
if (!exprType.isErroneous() &&
exprType.isRaw() &&
that.typeargs != null) {
log.error(that.expr.pos(),
Errors.InvalidMref(Kinds.kindName(that.getMode()),
Fragments.MrefInferAndExplicitParams));
exprType = types.createErrorType(exprType);
}
}
if (exprType.isErroneous()) {
//if the qualifier expression contains problems,
//give up attribution of method reference
result = that.type = exprType;
return;
}
if (TreeInfo.isStaticSelector(that.expr, names)) {
//if the qualifier is a type, validate it; raw warning check is
//omitted as we don't know at this stage as to whether this is a
//raw selector (because of inference)
chk.validate(that.expr, env, false);
} else {
Symbol lhsSym = TreeInfo.symbol(that.expr);
localEnv.info.selectSuper = lhsSym != null && lhsSym.name == names._super;
}
//attrib type-arguments
List<Type> typeargtypes = List.nil();
if (that.typeargs != null) {
typeargtypes = attribTypes(that.typeargs, localEnv);
}
boolean isTargetSerializable =
resultInfo.checkContext.deferredAttrContext().mode == DeferredAttr.AttrMode.CHECK &&
isSerializable(pt());
TargetInfo targetInfo = getTargetInfo(that, resultInfo, null);
Type currentTarget = targetInfo.target;
Type desc = targetInfo.descriptor;
setFunctionalInfo(localEnv, that, pt(), desc, currentTarget, resultInfo.checkContext);
List<Type> argtypes = desc.getParameterTypes();
Resolve.MethodCheck referenceCheck = rs.resolveMethodCheck;
if (resultInfo.checkContext.inferenceContext().free(argtypes)) {
referenceCheck = rs.new MethodReferenceCheck(resultInfo.checkContext.inferenceContext());
}
Pair<Symbol, Resolve.ReferenceLookupHelper> refResult = null;
List<Type> saved_undet = resultInfo.checkContext.inferenceContext().save();
try {
refResult = rs.resolveMemberReference(localEnv, that, that.expr.type,
that.name, argtypes, typeargtypes, targetInfo.descriptor, referenceCheck,
resultInfo.checkContext.inferenceContext(), rs.basicReferenceChooser);
} finally {
resultInfo.checkContext.inferenceContext().rollback(saved_undet);
}
Symbol refSym = refResult.fst;
Resolve.ReferenceLookupHelper lookupHelper = refResult.snd;
/** this switch will need to go away and be replaced by the new RESOLUTION_TARGET testing
* JDK-8075541
*/
if (refSym.kind != MTH) {
boolean targetError;
switch (refSym.kind) {
case ABSENT_MTH:
case MISSING_ENCL:
targetError = false;
break;
case WRONG_MTH:
case WRONG_MTHS:
case AMBIGUOUS:
case HIDDEN:
case STATICERR:
targetError = true;
break;
default:
Assert.error("unexpected result kind " + refSym.kind);
targetError = false;
}
JCDiagnostic detailsDiag = ((Resolve.ResolveError)refSym.baseSymbol())
.getDiagnostic(JCDiagnostic.DiagnosticType.FRAGMENT,
that, exprType.tsym, exprType, that.name, argtypes, typeargtypes);
JCDiagnostic diag = diags.create(log.currentSource(), that,
targetError ?
Fragments.InvalidMref(Kinds.kindName(that.getMode()), detailsDiag) :
Errors.InvalidMref(Kinds.kindName(that.getMode()), detailsDiag));
if (targetError && currentTarget == Type.recoveryType) {
//a target error doesn't make sense during recovery stage
//as we don't know what actual parameter types are
result = that.type = currentTarget;
return;
} else {
if (targetError) {
resultInfo.checkContext.report(that, diag);
} else {
log.report(diag);
}
result = that.type = types.createErrorType(currentTarget);
return;
}
}
that.sym = refSym.isConstructor() ? refSym.baseSymbol() : refSym;
that.kind = lookupHelper.referenceKind(that.sym);
that.ownerAccessible = rs.isAccessible(localEnv, that.sym.enclClass());
if (desc.getReturnType() == Type.recoveryType) {
// stop here
result = that.type = currentTarget;
return;
}
if (!env.info.attributionMode.isSpeculative && that.getMode() == JCMemberReference.ReferenceMode.NEW) {
Type enclosingType = exprType.getEnclosingType();
if (enclosingType != null && enclosingType.hasTag(CLASS)) {
// Check for the existence of an apropriate outer instance
rs.resolveImplicitThis(that.pos(), env, exprType);
}
}
if (resultInfo.checkContext.deferredAttrContext().mode == AttrMode.CHECK) {
if (that.getMode() == ReferenceMode.INVOKE &&
TreeInfo.isStaticSelector(that.expr, names) &&
that.kind.isUnbound() &&
lookupHelper.site.isRaw()) {
chk.checkRaw(that.expr, localEnv);
}
if (that.sym.isStatic() && TreeInfo.isStaticSelector(that.expr, names) &&
exprType.getTypeArguments().nonEmpty()) {
//static ref with class type-args
log.error(that.expr.pos(),
Errors.InvalidMref(Kinds.kindName(that.getMode()),
Fragments.StaticMrefWithTargs));
result = that.type = types.createErrorType(currentTarget);
return;
}
if (!refSym.isStatic() && that.kind == JCMemberReference.ReferenceKind.SUPER) {
// Check that super-qualified symbols are not abstract (JLS)
rs.checkNonAbstract(that.pos(), that.sym);
}
if (isTargetSerializable) {
chk.checkAccessFromSerializableElement(that, true);
}
}
ResultInfo checkInfo =
resultInfo.dup(newMethodTemplate(
desc.getReturnType().hasTag(VOID) ? Type.noType : desc.getReturnType(),
that.kind.isUnbound() ? argtypes.tail : argtypes, typeargtypes),
new FunctionalReturnContext(resultInfo.checkContext), CheckMode.NO_TREE_UPDATE);
Type refType = checkId(that, lookupHelper.site, refSym, localEnv, checkInfo);
if (that.kind.isUnbound() &&
resultInfo.checkContext.inferenceContext().free(argtypes.head)) {
//re-generate inference constraints for unbound receiver
if (!types.isSubtype(resultInfo.checkContext.inferenceContext().asUndetVar(argtypes.head), exprType)) {
//cannot happen as this has already been checked - we just need
//to regenerate the inference constraints, as that has been lost
//as a result of the call to inferenceContext.save()
Assert.error("Can't get here");
}
}
if (!refType.isErroneous()) {
refType = types.createMethodTypeWithReturn(refType,
adjustMethodReturnType(refSym, lookupHelper.site, that.name, checkInfo.pt.getParameterTypes(), refType.getReturnType()));
}
//go ahead with standard method reference compatibility check - note that param check
//is a no-op (as this has been taken care during method applicability)
boolean isSpeculativeRound =
resultInfo.checkContext.deferredAttrContext().mode == DeferredAttr.AttrMode.SPECULATIVE;
that.type = currentTarget; //avoids recovery at this stage
checkReferenceCompatible(that, desc, refType, resultInfo.checkContext, isSpeculativeRound);
if (!isSpeculativeRound) {
checkAccessibleTypes(that, localEnv, resultInfo.checkContext.inferenceContext(), desc, currentTarget);
}
result = check(that, currentTarget, KindSelector.VAL, resultInfo);
} catch (Types.FunctionDescriptorLookupError ex) {
JCDiagnostic cause = ex.getDiagnostic();
resultInfo.checkContext.report(that, cause);
result = that.type = types.createErrorType(pt());
return;
}
}
//where
ResultInfo memberReferenceQualifierResult(JCMemberReference tree) {
//if this is a constructor reference, the expected kind must be a type
return new ResultInfo(tree.getMode() == ReferenceMode.INVOKE ?
KindSelector.VAL_TYP : KindSelector.TYP,
Type.noType);
}
@SuppressWarnings("fallthrough")
void checkReferenceCompatible(JCMemberReference tree, Type descriptor, Type refType, CheckContext checkContext, boolean speculativeAttr) {
InferenceContext inferenceContext = checkContext.inferenceContext();
Type returnType = inferenceContext.asUndetVar(descriptor.getReturnType());
Type resType;
switch (tree.getMode()) {
case NEW:
if (!tree.expr.type.isRaw()) {
resType = tree.expr.type;
break;
}
default:
resType = refType.getReturnType();
}
Type incompatibleReturnType = resType;
if (returnType.hasTag(VOID)) {
incompatibleReturnType = null;
}
if (!returnType.hasTag(VOID) && !resType.hasTag(VOID)) {
if (resType.isErroneous() ||
new FunctionalReturnContext(checkContext).compatible(resType, returnType,
checkContext.checkWarner(tree, resType, returnType))) {
incompatibleReturnType = null;
}
}
if (incompatibleReturnType != null) {
Fragment msg =
Fragments.IncompatibleRetTypeInMref(Fragments.InconvertibleTypes(resType, descriptor.getReturnType()));
checkContext.report(tree, diags.fragment(msg));
} else {
if (inferenceContext.free(refType)) {
// we need to wait for inference to finish and then replace inference vars in the referent type
inferenceContext.addFreeTypeListener(List.of(refType),
instantiatedContext -> {
tree.referentType = instantiatedContext.asInstType(refType);
});
} else {
tree.referentType = refType;
}
}
if (!speculativeAttr) {
if (!checkExConstraints(refType.getThrownTypes(), descriptor.getThrownTypes(), inferenceContext)) {
log.error(tree, Errors.IncompatibleThrownTypesInMref(refType.getThrownTypes()));
}
}
}
boolean checkExConstraints(
List<Type> thrownByFuncExpr,
List<Type> thrownAtFuncType,
InferenceContext inferenceContext) {
/** 18.2.5: Otherwise, let E1, ..., En be the types in the function type's throws clause that
* are not proper types
*/
List<Type> nonProperList = thrownAtFuncType.stream()
.filter(e -> inferenceContext.free(e)).collect(List.collector());
List<Type> properList = thrownAtFuncType.diff(nonProperList);
/** Let X1,...,Xm be the checked exception types that the lambda body can throw or
* in the throws clause of the invocation type of the method reference's compile-time
* declaration
*/
List<Type> checkedList = thrownByFuncExpr.stream()
.filter(e -> chk.isChecked(e)).collect(List.collector());
/** If n = 0 (the function type's throws clause consists only of proper types), then
* if there exists some i (1 <= i <= m) such that Xi is not a subtype of any proper type
* in the throws clause, the constraint reduces to false; otherwise, the constraint
* reduces to true
*/
ListBuffer<Type> uncaughtByProperTypes = new ListBuffer<>();
for (Type checked : checkedList) {
boolean isSubtype = false;
for (Type proper : properList) {
if (types.isSubtype(checked, proper)) {
isSubtype = true;
break;
}
}
if (!isSubtype) {
uncaughtByProperTypes.add(checked);
}
}
if (nonProperList.isEmpty() && !uncaughtByProperTypes.isEmpty()) {
return false;
}
/** If n > 0, the constraint reduces to a set of subtyping constraints:
* for all i (1 <= i <= m), if Xi is not a subtype of any proper type in the
* throws clause, then the constraints include, for all j (1 <= j <= n), <Xi <: Ej>
*/
List<Type> nonProperAsUndet = inferenceContext.asUndetVars(nonProperList);
uncaughtByProperTypes.forEach(checkedEx -> {
nonProperAsUndet.forEach(nonProper -> {
types.isSubtype(checkedEx, nonProper);
});
});
/** In addition, for all j (1 <= j <= n), the constraint reduces to the bound throws Ej
*/
nonProperAsUndet.stream()
.filter(t -> t.hasTag(UNDETVAR))
.forEach(t -> ((UndetVar)t).setThrow());
return true;
}
/**
* Set functional type info on the underlying AST. Note: as the target descriptor
* might contain inference variables, we might need to register an hook in the
* current inference context.
*/
private void setFunctionalInfo(final Env<AttrContext> env, final JCFunctionalExpression fExpr,
final Type pt, final Type descriptorType, final Type primaryTarget, final CheckContext checkContext) {
if (checkContext.inferenceContext().free(descriptorType)) {
checkContext.inferenceContext().addFreeTypeListener(List.of(pt, descriptorType),
inferenceContext -> setFunctionalInfo(env, fExpr, pt, inferenceContext.asInstType(descriptorType),
inferenceContext.asInstType(primaryTarget), checkContext));
} else {
if (pt.hasTag(CLASS)) {
fExpr.target = primaryTarget;
}
if (checkContext.deferredAttrContext().mode == DeferredAttr.AttrMode.CHECK &&
pt != Type.recoveryType) {
//check that functional interface class is well-formed
try {
/* Types.makeFunctionalInterfaceClass() may throw an exception
* when it's executed post-inference. See the listener code
* above.
*/
ClassSymbol csym = types.makeFunctionalInterfaceClass(env,
names.empty, fExpr.target, ABSTRACT);
if (csym != null) {
chk.checkImplementations(env.tree, csym, csym);
try {
//perform an additional functional interface check on the synthetic class,
//as there may be spurious errors for raw targets - because of existing issues
//with membership and inheritance (see JDK-8074570).
csym.flags_field |= INTERFACE;
types.findDescriptorType(csym.type);
} catch (FunctionDescriptorLookupError err) {
resultInfo.checkContext.report(fExpr,
diags.fragment(Fragments.NoSuitableFunctionalIntfInst(fExpr.target)));
}
}
} catch (Types.FunctionDescriptorLookupError ex) {
JCDiagnostic cause = ex.getDiagnostic();
resultInfo.checkContext.report(env.tree, cause);
}
}
}
}
public void visitParens(JCParens tree) {
Type owntype = attribTree(tree.expr, env, resultInfo);
result = check(tree, owntype, pkind(), resultInfo);
Symbol sym = TreeInfo.symbol(tree);
if (sym != null && sym.kind.matches(KindSelector.TYP_PCK))
log.error(tree.pos(), Errors.IllegalParenthesizedExpression);
}
public void visitAssign(JCAssign tree) {
Type owntype = attribTree(tree.lhs, env.dup(tree), varAssignmentInfo);
Type capturedType = capture(owntype);
attribExpr(tree.rhs, env, owntype);
result = check(tree, capturedType, KindSelector.VAL, resultInfo);
}
public void visitAssignop(JCAssignOp tree) {
// Attribute arguments.
Type owntype = attribTree(tree.lhs, env, varAssignmentInfo);
Type operand = attribExpr(tree.rhs, env);
// Find operator.
Symbol operator = tree.operator = operators.resolveBinary(tree, tree.getTag().noAssignOp(), owntype, operand);
if (operator != operators.noOpSymbol &&
!owntype.isErroneous() &&
!operand.isErroneous()) {
chk.checkDivZero(tree.rhs.pos(), operator, operand);
chk.checkCastable(tree.rhs.pos(),
operator.type.getReturnType(),
owntype);
}
result = check(tree, owntype, KindSelector.VAL, resultInfo);
}
public void visitUnary(JCUnary tree) {
// Attribute arguments.
Type argtype = (tree.getTag().isIncOrDecUnaryOp())
? attribTree(tree.arg, env, varAssignmentInfo)
: chk.checkNonVoid(tree.arg.pos(), attribExpr(tree.arg, env));
// Find operator.
Symbol operator = tree.operator = operators.resolveUnary(tree, tree.getTag(), argtype);
Type owntype = types.createErrorType(tree.type);
if (operator != operators.noOpSymbol &&
!argtype.isErroneous()) {
owntype = (tree.getTag().isIncOrDecUnaryOp())
? tree.arg.type
: operator.type.getReturnType();
int opc = ((OperatorSymbol)operator).opcode;
// If the argument is constant, fold it.
if (argtype.constValue() != null) {
Type ctype = cfolder.fold1(opc, argtype);
if (ctype != null) {
owntype = cfolder.coerce(ctype, owntype);
}
}
}
result = check(tree, owntype, KindSelector.VAL, resultInfo);
}
public void visitBinary(JCBinary tree) {
// Attribute arguments.
Type left = chk.checkNonVoid(tree.lhs.pos(), attribExpr(tree.lhs, env));
// x && y
// include x's bindings when true in y
// x || y
// include x's bindings when false in y
List<BindingSymbol> matchBindings;
switch (tree.getTag()) {
case AND:
matchBindings = matchBindingsComputer.getMatchBindings(tree.lhs, true);
break;
case OR:
matchBindings = matchBindingsComputer.getMatchBindings(tree.lhs, false);
break;
default:
matchBindings = List.nil();
break;
}
Env<AttrContext> rhsEnv = bindingEnv(env, matchBindings);
Type right;
try {
right = chk.checkNonVoid(tree.rhs.pos(), attribExpr(tree.rhs, rhsEnv));
} finally {
rhsEnv.info.scope.leave();
}
// Find operator.
Symbol operator = tree.operator = operators.resolveBinary(tree, tree.getTag(), left, right);
Type owntype = types.createErrorType(tree.type);
if (operator != operators.noOpSymbol &&
!left.isErroneous() &&
!right.isErroneous()) {
owntype = operator.type.getReturnType();
int opc = ((OperatorSymbol)operator).opcode;
// If both arguments are constants, fold them.
if (left.constValue() != null && right.constValue() != null) {
Type ctype = cfolder.fold2(opc, left, right);
if (ctype != null) {
owntype = cfolder.coerce(ctype, owntype);
}
}
// Check that argument types of a reference ==, != are
// castable to each other, (JLS 15.21). Note: unboxing
// comparisons will not have an acmp* opc at this point.
if ((opc == ByteCodes.if_acmpeq || opc == ByteCodes.if_acmpne)) {
if (!types.isCastable(left, right, new Warner(tree.pos()))) {
log.error(tree.pos(), Errors.IncomparableTypes(left, right));
}
}
chk.checkDivZero(tree.rhs.pos(), operator, right);
}
result = check(tree, owntype, KindSelector.VAL, resultInfo);
}
public void visitTypeCast(final JCTypeCast tree) {
Type clazztype = attribType(tree.clazz, env);
chk.validate(tree.clazz, env, false);
//a fresh environment is required for 292 inference to work properly ---
//see Infer.instantiatePolymorphicSignatureInstance()
Env<AttrContext> localEnv = env.dup(tree);
//should we propagate the target type?
final ResultInfo castInfo;
JCExpression expr = TreeInfo.skipParens(tree.expr);
boolean isPoly = allowPoly && (expr.hasTag(LAMBDA) || expr.hasTag(REFERENCE));
if (isPoly) {
//expression is a poly - we need to propagate target type info
castInfo = new ResultInfo(KindSelector.VAL, clazztype,
new Check.NestedCheckContext(resultInfo.checkContext) {
@Override
public boolean compatible(Type found, Type req, Warner warn) {
return types.isCastable(found, req, warn);
}
});
} else {
//standalone cast - target-type info is not propagated
castInfo = unknownExprInfo;
}
Type exprtype = attribTree(tree.expr, localEnv, castInfo);
Type owntype = isPoly ? clazztype : chk.checkCastable(tree.expr.pos(), exprtype, clazztype);
if (exprtype.constValue() != null)
owntype = cfolder.coerce(exprtype, owntype);
result = check(tree, capture(owntype), KindSelector.VAL, resultInfo);
if (!isPoly)
chk.checkRedundantCast(localEnv, tree);
}
public void visitTypeTest(JCInstanceOf tree) {
Type exprtype = chk.checkNullOrRefType(
tree.expr.pos(), attribExpr(tree.expr, env));
Type clazztype;
JCTree typeTree;
if (tree.pattern.getTag() == BINDINGPATTERN) {
attribTree(tree.pattern, env, unknownExprInfo);
clazztype = tree.pattern.type;
JCBindingPattern pattern = (JCBindingPattern) tree.pattern;
typeTree = pattern.vartype;
if (!clazztype.hasTag(TYPEVAR)) {
clazztype = chk.checkClassOrArrayType(pattern.vartype.pos(), clazztype);
}
} else {
clazztype = attribType(tree.pattern, env);
typeTree = tree.pattern;
}
if (!clazztype.hasTag(TYPEVAR)) {
clazztype = chk.checkClassOrArrayType(typeTree.pos(), clazztype);
}
if (!clazztype.isErroneous() && !types.isReifiable(clazztype)) {
boolean valid = false;
if (allowReifiableTypesInInstanceof) {
if (preview.isPreview(Feature.REIFIABLE_TYPES_INSTANCEOF)) {
preview.warnPreview(tree.expr.pos(), Feature.REIFIABLE_TYPES_INSTANCEOF);
}
Warner warner = new Warner();
if (!types.isCastable(exprtype, clazztype, warner)) {
chk.basicHandler.report(tree.expr.pos(),
diags.fragment(Fragments.InconvertibleTypes(exprtype, clazztype)));
} else if (warner.hasLint(LintCategory.UNCHECKED)) {
log.error(tree.expr.pos(),
Errors.InstanceofReifiableNotSafe(exprtype, clazztype));
} else {
valid = true;
}
} else {
log.error(typeTree.pos(), Errors.IllegalGenericTypeForInstof);
}
if (!valid) {
clazztype = types.createErrorType(clazztype);
}
}
chk.validate(typeTree, env, false);
chk.checkCastable(tree.expr.pos(), exprtype, clazztype);
result = check(tree, syms.booleanType, KindSelector.VAL, resultInfo);
}
public void visitBindingPattern(JCBindingPattern tree) {
ResultInfo varInfo = new ResultInfo(KindSelector.TYP, resultInfo.pt, resultInfo.checkContext);
tree.type = attribTree(tree.vartype, env, varInfo);
VarSymbol v = tree.symbol = new BindingSymbol(tree.name, tree.vartype.type, env.info.scope.owner);
if (chk.checkUnique(tree.pos(), v, env.info.scope)) {
chk.checkTransparentVar(tree.pos(), v, env.info.scope);
}
annotate.queueScanTreeAndTypeAnnotate(tree.vartype, env, v, tree.pos());
annotate.flush();
result = tree.type;
}
public void visitIndexed(JCArrayAccess tree) {
Type owntype = types.createErrorType(tree.type);
Type atype = attribExpr(tree.indexed, env);
attribExpr(tree.index, env, syms.intType);
if (types.isArray(atype))
owntype = types.elemtype(atype);
else if (!atype.hasTag(ERROR))
log.error(tree.pos(), Errors.ArrayReqButFound(atype));
if (!pkind().contains(KindSelector.VAL))
owntype = capture(owntype);
result = check(tree, owntype, KindSelector.VAR, resultInfo);
}
public void visitIdent(JCIdent tree) {
Symbol sym;
// Find symbol
if (pt().hasTag(METHOD) || pt().hasTag(FORALL)) {
// If we are looking for a method, the prototype `pt' will be a
// method type with the type of the call's arguments as parameters.
env.info.pendingResolutionPhase = null;
sym = rs.resolveMethod(tree.pos(), env, tree.name, pt().getParameterTypes(), pt().getTypeArguments());
} else if (tree.sym != null && tree.sym.kind != VAR) {
sym = tree.sym;
} else {
sym = rs.resolveIdent(tree.pos(), env, tree.name, pkind());
}
tree.sym = sym;
// (1) Also find the environment current for the class where
// sym is defined (`symEnv').
// Only for pre-tiger versions (1.4 and earlier):
// (2) Also determine whether we access symbol out of an anonymous
// class in a this or super call. This is illegal for instance
// members since such classes don't carry a this$n link.
// (`noOuterThisPath').
Env<AttrContext> symEnv = env;
boolean noOuterThisPath = false;
if (env.enclClass.sym.owner.kind != PCK && // we are in an inner class
sym.kind.matches(KindSelector.VAL_MTH) &&
sym.owner.kind == TYP &&
tree.name != names._this && tree.name != names._super) {
// Find environment in which identifier is defined.
while (symEnv.outer != null &&
!sym.isMemberOf(symEnv.enclClass.sym, types)) {
if ((symEnv.enclClass.sym.flags() & NOOUTERTHIS) != 0)
noOuterThisPath = false;
symEnv = symEnv.outer;
}
}
// If symbol is a variable, ...
if (sym.kind == VAR) {
VarSymbol v = (VarSymbol)sym;
// ..., evaluate its initializer, if it has one, and check for
// illegal forward reference.
checkInit(tree, env, v, false);
// If we are expecting a variable (as opposed to a value), check
// that the variable is assignable in the current environment.
if (KindSelector.ASG.subset(pkind()))
checkAssignable(tree.pos(), v, null, env);
}
// In a constructor body,
// if symbol is a field or instance method, check that it is
// not accessed before the supertype constructor is called.
if ((symEnv.info.isSelfCall || noOuterThisPath) &&
sym.kind.matches(KindSelector.VAL_MTH) &&
sym.owner.kind == TYP &&
(sym.flags() & STATIC) == 0) {
chk.earlyRefError(tree.pos(), sym.kind == VAR ?
sym : thisSym(tree.pos(), env));
}
Env<AttrContext> env1 = env;
if (sym.kind != ERR && sym.kind != TYP &&
sym.owner != null && sym.owner != env1.enclClass.sym) {
// If the found symbol is inaccessible, then it is
// accessed through an enclosing instance. Locate this
// enclosing instance:
while (env1.outer != null && !rs.isAccessible(env, env1.enclClass.sym.type, sym))
env1 = env1.outer;
}
if (env.info.isSerializable) {
chk.checkAccessFromSerializableElement(tree, env.info.isLambda);
}
result = checkId(tree, env1.enclClass.sym.type, sym, env, resultInfo);
}
public void visitSelect(JCFieldAccess tree) {
// Determine the expected kind of the qualifier expression.
KindSelector skind = KindSelector.NIL;
if (tree.name == names._this || tree.name == names._super ||
tree.name == names._class)
{
skind = KindSelector.TYP;
} else {
if (pkind().contains(KindSelector.PCK))
skind = KindSelector.of(skind, KindSelector.PCK);
if (pkind().contains(KindSelector.TYP))
skind = KindSelector.of(skind, KindSelector.TYP, KindSelector.PCK);
if (pkind().contains(KindSelector.VAL_MTH))
skind = KindSelector.of(skind, KindSelector.VAL, KindSelector.TYP);
}
// Attribute the qualifier expression, and determine its symbol (if any).
Type site = attribTree(tree.selected, env, new ResultInfo(skind, Type.noType));
if (!pkind().contains(KindSelector.TYP_PCK))
site = capture(site); // Capture field access
// don't allow T.class T[].class, etc
if (skind == KindSelector.TYP) {
Type elt = site;
while (elt.hasTag(ARRAY))
elt = ((ArrayType)elt).elemtype;
if (elt.hasTag(TYPEVAR)) {
log.error(tree.pos(), Errors.TypeVarCantBeDeref);
result = tree.type = types.createErrorType(tree.name, site.tsym, site);
tree.sym = tree.type.tsym;
return ;
}
}
// If qualifier symbol is a type or `super', assert `selectSuper'
// for the selection. This is relevant for determining whether
// protected symbols are accessible.
Symbol sitesym = TreeInfo.symbol(tree.selected);
boolean selectSuperPrev = env.info.selectSuper;
env.info.selectSuper =
sitesym != null &&
sitesym.name == names._super;
// Determine the symbol represented by the selection.
env.info.pendingResolutionPhase = null;
Symbol sym = selectSym(tree, sitesym, site, env, resultInfo);
if (sym.kind == VAR && sym.name != names._super && env.info.defaultSuperCallSite != null) {
log.error(tree.selected.pos(), Errors.NotEnclClass(site.tsym));
sym = syms.errSymbol;
}
if (sym.exists() && !isType(sym) && pkind().contains(KindSelector.TYP_PCK)) {
site = capture(site);
sym = selectSym(tree, sitesym, site, env, resultInfo);
}
boolean varArgs = env.info.lastResolveVarargs();
tree.sym = sym;
if (site.hasTag(TYPEVAR) && !isType(sym) && sym.kind != ERR) {
site = types.skipTypeVars(site, true);
}
// If that symbol is a variable, ...
if (sym.kind == VAR) {
VarSymbol v = (VarSymbol)sym;
// ..., evaluate its initializer, if it has one, and check for
// illegal forward reference.
checkInit(tree, env, v, true);
// If we are expecting a variable (as opposed to a value), check
// that the variable is assignable in the current environment.
if (KindSelector.ASG.subset(pkind()))
checkAssignable(tree.pos(), v, tree.selected, env);
}
if (sitesym != null &&
sitesym.kind == VAR &&
((VarSymbol)sitesym).isResourceVariable() &&
sym.kind == MTH &&
sym.name.equals(names.close) &&
sym.overrides(syms.autoCloseableClose, sitesym.type.tsym, types, true) &&
env.info.lint.isEnabled(LintCategory.TRY)) {
log.warning(LintCategory.TRY, tree, Warnings.TryExplicitCloseCall);
}
// Disallow selecting a type from an expression
if (isType(sym) && (sitesym == null || !sitesym.kind.matches(KindSelector.TYP_PCK))) {
tree.type = check(tree.selected, pt(),
sitesym == null ?
KindSelector.VAL : sitesym.kind.toSelector(),
new ResultInfo(KindSelector.TYP_PCK, pt()));
}
if (isType(sitesym)) {
if (sym.name == names._this) {
// If `C' is the currently compiled class, check that
// C.this' does not appear in a call to a super(...)
if (env.info.isSelfCall &&
site.tsym == env.enclClass.sym) {
chk.earlyRefError(tree.pos(), sym);
}
} else {
// Check if type-qualified fields or methods are static (JLS)
if ((sym.flags() & STATIC) == 0 &&
sym.name != names._super &&
(sym.kind == VAR || sym.kind == MTH)) {
rs.accessBase(rs.new StaticError(sym),
tree.pos(), site, sym.name, true);
}
}
if (!allowStaticInterfaceMethods && sitesym.isInterface() &&
sym.isStatic() && sym.kind == MTH) {
log.error(DiagnosticFlag.SOURCE_LEVEL, tree.pos(), Feature.STATIC_INTERFACE_METHODS_INVOKE.error(sourceName));
}
} else if (sym.kind != ERR &&
(sym.flags() & STATIC) != 0 &&
sym.name != names._class) {
// If the qualified item is not a type and the selected item is static, report
// a warning. Make allowance for the class of an array type e.g. Object[].class)
chk.warnStatic(tree, Warnings.StaticNotQualifiedByType(sym.kind.kindName(), sym.owner));
}
// If we are selecting an instance member via a `super', ...
if (env.info.selectSuper && (sym.flags() & STATIC) == 0) {
// Check that super-qualified symbols are not abstract (JLS)
rs.checkNonAbstract(tree.pos(), sym);
if (site.isRaw()) {
// Determine argument types for site.
Type site1 = types.asSuper(env.enclClass.sym.type, site.tsym);
if (site1 != null) site = site1;
}
}
if (env.info.isSerializable) {
chk.checkAccessFromSerializableElement(tree, env.info.isLambda);
}
env.info.selectSuper = selectSuperPrev;
result = checkId(tree, site, sym, env, resultInfo);
}
//where
/** Determine symbol referenced by a Select expression,
*
* @param tree The select tree.
* @param site The type of the selected expression,
* @param env The current environment.
* @param resultInfo The current result.
*/
private Symbol selectSym(JCFieldAccess tree,
Symbol location,
Type site,
Env<AttrContext> env,
ResultInfo resultInfo) {
DiagnosticPosition pos = tree.pos();
Name name = tree.name;
switch (site.getTag()) {
case PACKAGE:
return rs.accessBase(
rs.findIdentInPackage(pos, env, site.tsym, name, resultInfo.pkind),
pos, location, site, name, true);
case ARRAY:
case CLASS:
if (resultInfo.pt.hasTag(METHOD) || resultInfo.pt.hasTag(FORALL)) {
return rs.resolveQualifiedMethod(
pos, env, location, site, name, resultInfo.pt.getParameterTypes(), resultInfo.pt.getTypeArguments());
} else if (name == names._this || name == names._super) {
return rs.resolveSelf(pos, env, site.tsym, name);
} else if (name == names._class) {
// In this case, we have already made sure in
// visitSelect that qualifier expression is a type.
return syms.getClassField(site, types);
} else {
// We are seeing a plain identifier as selector.
Symbol sym = rs.findIdentInType(pos, env, site, name, resultInfo.pkind);
sym = rs.accessBase(sym, pos, location, site, name, true);
return sym;
}
case WILDCARD:
throw new AssertionError(tree);
case TYPEVAR:
// Normally, site.getUpperBound() shouldn't be null.
// It should only happen during memberEnter/attribBase
// when determining the super type which *must* beac
// done before attributing the type variables. In
// other words, we are seeing this illegal program:
// class B<T> extends A<T.foo> {}
Symbol sym = (site.getUpperBound() != null)
? selectSym(tree, location, capture(site.getUpperBound()), env, resultInfo)
: null;
if (sym == null) {
log.error(pos, Errors.TypeVarCantBeDeref);
return syms.errSymbol;
} else {
Symbol sym2 = (sym.flags() & Flags.PRIVATE) != 0 ?
rs.new AccessError(env, site, sym) :
sym;
rs.accessBase(sym2, pos, location, site, name, true);
return sym;
}
case ERROR:
// preserve identifier names through errors
return types.createErrorType(name, site.tsym, site).tsym;
default:
// The qualifier expression is of a primitive type -- only
// .class is allowed for these.
if (name == names._class) {
// In this case, we have already made sure in Select that
// qualifier expression is a type.
return syms.getClassField(site, types);
} else {
log.error(pos, Errors.CantDeref(site));
return syms.errSymbol;
}
}
}
/** Determine type of identifier or select expression and check that
* (1) the referenced symbol is not deprecated
* (2) the symbol's type is safe (@see checkSafe)
* (3) if symbol is a variable, check that its type and kind are
* compatible with the prototype and protokind.
* (4) if symbol is an instance field of a raw type,
* which is being assigned to, issue an unchecked warning if its
* type changes under erasure.
* (5) if symbol is an instance method of a raw type, issue an
* unchecked warning if its argument types change under erasure.
* If checks succeed:
* If symbol is a constant, return its constant type
* else if symbol is a method, return its result type
* otherwise return its type.
* Otherwise return errType.
*
* @param tree The syntax tree representing the identifier
* @param site If this is a select, the type of the selected
* expression, otherwise the type of the current class.
* @param sym The symbol representing the identifier.
* @param env The current environment.
* @param resultInfo The expected result
*/
Type checkId(JCTree tree,
Type site,
Symbol sym,
Env<AttrContext> env,
ResultInfo resultInfo) {
return (resultInfo.pt.hasTag(FORALL) || resultInfo.pt.hasTag(METHOD)) ?
checkMethodIdInternal(tree, site, sym, env, resultInfo) :
checkIdInternal(tree, site, sym, resultInfo.pt, env, resultInfo);
}
Type checkMethodIdInternal(JCTree tree,
Type site,
Symbol sym,
Env<AttrContext> env,
ResultInfo resultInfo) {
if (resultInfo.pkind.contains(KindSelector.POLY)) {
Type pt = resultInfo.pt.map(deferredAttr.new RecoveryDeferredTypeMap(AttrMode.SPECULATIVE, sym, env.info.pendingResolutionPhase));
Type owntype = checkIdInternal(tree, site, sym, pt, env, resultInfo);
resultInfo.pt.map(deferredAttr.new RecoveryDeferredTypeMap(AttrMode.CHECK, sym, env.info.pendingResolutionPhase));
return owntype;
} else {
return checkIdInternal(tree, site, sym, resultInfo.pt, env, resultInfo);
}
}
Type checkIdInternal(JCTree tree,
Type site,
Symbol sym,
Type pt,
Env<AttrContext> env,
ResultInfo resultInfo) {
if (pt.isErroneous()) {
return types.createErrorType(site);
}
Type owntype; // The computed type of this identifier occurrence.
switch (sym.kind) {
case TYP:
// For types, the computed type equals the symbol's type,
// except for two situations:
owntype = sym.type;
if (owntype.hasTag(CLASS)) {
chk.checkForBadAuxiliaryClassAccess(tree.pos(), env, (ClassSymbol)sym);
Type ownOuter = owntype.getEnclosingType();
// (a) If the symbol's type is parameterized, erase it
// because no type parameters were given.
// We recover generic outer type later in visitTypeApply.
if (owntype.tsym.type.getTypeArguments().nonEmpty()) {
owntype = types.erasure(owntype);
}
// (b) If the symbol's type is an inner class, then
// we have to interpret its outer type as a superclass
// of the site type. Example:
//
// class Tree<A> { class Visitor { ... } }
// class PointTree extends Tree<Point> { ... }
// ...PointTree.Visitor...
//
// Then the type of the last expression above is
// Tree<Point>.Visitor.
else if (ownOuter.hasTag(CLASS) && site != ownOuter) {
Type normOuter = site;
if (normOuter.hasTag(CLASS)) {
normOuter = types.asEnclosingSuper(site, ownOuter.tsym);
}
if (normOuter == null) // perhaps from an import
normOuter = types.erasure(ownOuter);
if (normOuter != ownOuter)
owntype = new ClassType(
normOuter, List.nil(), owntype.tsym,
owntype.getMetadata());
}
}
break;
case VAR:
VarSymbol v = (VarSymbol)sym;
if (env.info.enclVar != null
&& v.type.hasTag(NONE)) {
//self reference to implicitly typed variable declaration
log.error(TreeInfo.positionFor(v, env.enclClass), Errors.CantInferLocalVarType(v.name, Fragments.LocalSelfRef));
return v.type = types.createErrorType(v.type);
}
// Test (4): if symbol is an instance field of a raw type,
// which is being assigned to, issue an unchecked warning if
// its type changes under erasure.
if (KindSelector.ASG.subset(pkind()) &&
v.owner.kind == TYP &&
(v.flags() & STATIC) == 0 &&
(site.hasTag(CLASS) || site.hasTag(TYPEVAR))) {
Type s = types.asOuterSuper(site, v.owner);
if (s != null &&
s.isRaw() &&
!types.isSameType(v.type, v.erasure(types))) {
chk.warnUnchecked(tree.pos(), Warnings.UncheckedAssignToVar(v, s));
}
}
// The computed type of a variable is the type of the
// variable symbol, taken as a member of the site type.
owntype = (sym.owner.kind == TYP &&
sym.name != names._this && sym.name != names._super)
? types.memberType(site, sym)
: sym.type;
// If the variable is a constant, record constant value in
// computed type.
if (v.getConstValue() != null && isStaticReference(tree))
owntype = owntype.constType(v.getConstValue());
if (resultInfo.pkind == KindSelector.VAL) {
owntype = capture(owntype); // capture "names as expressions"
}
break;
case MTH: {
owntype = checkMethod(site, sym,
new ResultInfo(resultInfo.pkind, resultInfo.pt.getReturnType(), resultInfo.checkContext, resultInfo.checkMode),
env, TreeInfo.args(env.tree), resultInfo.pt.getParameterTypes(),
resultInfo.pt.getTypeArguments());
break;
}
case PCK: case ERR:
owntype = sym.type;
break;
default:
throw new AssertionError("unexpected kind: " + sym.kind +
" in tree " + tree);
}
// Emit a `deprecation' warning if symbol is deprecated.
// (for constructors (but not for constructor references), the error
// was given when the constructor was resolved)
if (sym.name != names.init || tree.hasTag(REFERENCE)) {
chk.checkDeprecated(tree.pos(), env.info.scope.owner, sym);
chk.checkSunAPI(tree.pos(), sym);
chk.checkProfile(tree.pos(), sym);
chk.checkPreview(tree.pos(), sym);
}
// If symbol is a variable, check that its type and
// kind are compatible with the prototype and protokind.
return check(tree, owntype, sym.kind.toSelector(), resultInfo);
}
/** Check that variable is initialized and evaluate the variable's
* initializer, if not yet done. Also check that variable is not
* referenced before it is defined.
* @param tree The tree making up the variable reference.
* @param env The current environment.
* @param v The variable's symbol.
*/
private void checkInit(JCTree tree,
Env<AttrContext> env,
VarSymbol v,
boolean onlyWarning) {
// A forward reference is diagnosed if the declaration position
// of the variable is greater than the current tree position
// and the tree and variable definition occur in the same class
// definition. Note that writes don't count as references.
// This check applies only to class and instance
// variables. Local variables follow different scope rules,
// and are subject to definite assignment checking.
Env<AttrContext> initEnv = enclosingInitEnv(env);
if (initEnv != null &&
(initEnv.info.enclVar == v || v.pos > tree.pos) &&
v.owner.kind == TYP &&
v.owner == env.info.scope.owner.enclClass() &&
((v.flags() & STATIC) != 0) == Resolve.isStatic(env) &&
(!env.tree.hasTag(ASSIGN) ||
TreeInfo.skipParens(((JCAssign) env.tree).lhs) != tree)) {
if (!onlyWarning || isStaticEnumField(v)) {
Error errkey = (initEnv.info.enclVar == v) ?
Errors.IllegalSelfRef : Errors.IllegalForwardRef;
log.error(tree.pos(), errkey);
} else if (useBeforeDeclarationWarning) {
Warning warnkey = (initEnv.info.enclVar == v) ?
Warnings.SelfRef(v) : Warnings.ForwardRef(v);
log.warning(tree.pos(), warnkey);
}
}
v.getConstValue(); // ensure initializer is evaluated
checkEnumInitializer(tree, env, v);
}
/**
* Returns the enclosing init environment associated with this env (if any). An init env
* can be either a field declaration env or a static/instance initializer env.
*/
Env<AttrContext> enclosingInitEnv(Env<AttrContext> env) {
while (true) {
switch (env.tree.getTag()) {
case VARDEF:
JCVariableDecl vdecl = (JCVariableDecl)env.tree;
if (vdecl.sym.owner.kind == TYP) {
//field
return env;
}
break;
case BLOCK:
if (env.next.tree.hasTag(CLASSDEF)) {
//instance/static initializer
return env;
}
break;
case METHODDEF:
case CLASSDEF:
case TOPLEVEL:
return null;
}
Assert.checkNonNull(env.next);
env = env.next;
}
}
/**
* Check for illegal references to static members of enum. In
* an enum type, constructors and initializers may not
* reference its static members unless they are constant.
*
* @param tree The tree making up the variable reference.
* @param env The current environment.
* @param v The variable's symbol.
* @jls 8.9 Enum Types
*/
private void checkEnumInitializer(JCTree tree, Env<AttrContext> env, VarSymbol v) {
// JLS:
//
// "It is a compile-time error to reference a static field
// of an enum type that is not a compile-time constant
// (15.28) from constructors, instance initializer blocks,
// or instance variable initializer expressions of that
// type. It is a compile-time error for the constructors,
// instance initializer blocks, or instance variable
// initializer expressions of an enum constant e to refer
// to itself or to an enum constant of the same type that
// is declared to the right of e."
if (isStaticEnumField(v)) {
ClassSymbol enclClass = env.info.scope.owner.enclClass();
if (enclClass == null || enclClass.owner == null)
return;
// See if the enclosing class is the enum (or a
// subclass thereof) declaring v. If not, this
// reference is OK.
if (v.owner != enclClass && !types.isSubtype(enclClass.type, v.owner.type))
return;
// If the reference isn't from an initializer, then
// the reference is OK.
if (!Resolve.isInitializer(env))
return;
log.error(tree.pos(), Errors.IllegalEnumStaticRef);
}
}
/** Is the given symbol a static, non-constant field of an Enum?
* Note: enum literals should not be regarded as such
*/
private boolean isStaticEnumField(VarSymbol v) {
return Flags.isEnum(v.owner) &&
Flags.isStatic(v) &&
!Flags.isConstant(v) &&
v.name != names._class;
}
/**
* Check that method arguments conform to its instantiation.
**/
public Type checkMethod(Type site,
final Symbol sym,
ResultInfo resultInfo,
Env<AttrContext> env,
final List<JCExpression> argtrees,
List<Type> argtypes,
List<Type> typeargtypes) {
// Test (5): if symbol is an instance method of a raw type, issue
// an unchecked warning if its argument types change under erasure.
if ((sym.flags() & STATIC) == 0 &&
(site.hasTag(CLASS) || site.hasTag(TYPEVAR))) {
Type s = types.asOuterSuper(site, sym.owner);
if (s != null && s.isRaw() &&
!types.isSameTypes(sym.type.getParameterTypes(),
sym.erasure(types).getParameterTypes())) {
chk.warnUnchecked(env.tree.pos(), Warnings.UncheckedCallMbrOfRawType(sym, s));
}
}
if (env.info.defaultSuperCallSite != null) {
for (Type sup : types.interfaces(env.enclClass.type).prepend(types.supertype((env.enclClass.type)))) {
if (!sup.tsym.isSubClass(sym.enclClass(), types) ||
types.isSameType(sup, env.info.defaultSuperCallSite)) continue;
List<MethodSymbol> icand_sup =
types.interfaceCandidates(sup, (MethodSymbol)sym);
if (icand_sup.nonEmpty() &&
icand_sup.head != sym &&
icand_sup.head.overrides(sym, icand_sup.head.enclClass(), types, true)) {
log.error(env.tree.pos(),
Errors.IllegalDefaultSuperCall(env.info.defaultSuperCallSite, Fragments.OverriddenDefault(sym, sup)));
break;
}
}
env.info.defaultSuperCallSite = null;
}
if (sym.isStatic() && site.isInterface() && env.tree.hasTag(APPLY)) {
JCMethodInvocation app = (JCMethodInvocation)env.tree;
if (app.meth.hasTag(SELECT) &&
!TreeInfo.isStaticSelector(((JCFieldAccess)app.meth).selected, names)) {
log.error(env.tree.pos(), Errors.IllegalStaticIntfMethCall(site));
}
}
// Compute the identifier's instantiated type.
// For methods, we need to compute the instance type by
// Resolve.instantiate from the symbol's type as well as
// any type arguments and value arguments.
Warner noteWarner = new Warner();
try {
Type owntype = rs.checkMethod(
env,
site,
sym,
resultInfo,
argtypes,
typeargtypes,
noteWarner);
DeferredAttr.DeferredTypeMap<Void> checkDeferredMap =
deferredAttr.new DeferredTypeMap<>(DeferredAttr.AttrMode.CHECK, sym, env.info.pendingResolutionPhase);
argtypes = argtypes.map(checkDeferredMap);
if (noteWarner.hasNonSilentLint(LintCategory.UNCHECKED)) {
chk.warnUnchecked(env.tree.pos(), Warnings.UncheckedMethInvocationApplied(kindName(sym),
sym.name,
rs.methodArguments(sym.type.getParameterTypes()),
rs.methodArguments(argtypes.map(checkDeferredMap)),
kindName(sym.location()),
sym.location()));
if (resultInfo.pt != Infer.anyPoly ||
!owntype.hasTag(METHOD) ||
!owntype.isPartial()) {
//if this is not a partially inferred method type, erase return type. Otherwise,
//erasure is carried out in PartiallyInferredMethodType.check().
owntype = new MethodType(owntype.getParameterTypes(),
types.erasure(owntype.getReturnType()),
types.erasure(owntype.getThrownTypes()),
syms.methodClass);
}
}
PolyKind pkind = (sym.type.hasTag(FORALL) &&
sym.type.getReturnType().containsAny(((ForAll)sym.type).tvars)) ?
PolyKind.POLY : PolyKind.STANDALONE;
TreeInfo.setPolyKind(env.tree, pkind);
return (resultInfo.pt == Infer.anyPoly) ?
owntype :
chk.checkMethod(owntype, sym, env, argtrees, argtypes, env.info.lastResolveVarargs(),
resultInfo.checkContext.inferenceContext());
} catch (Infer.InferenceException ex) {
//invalid target type - propagate exception outwards or report error
//depending on the current check context
resultInfo.checkContext.report(env.tree.pos(), ex.getDiagnostic());
return types.createErrorType(site);
} catch (Resolve.InapplicableMethodException ex) {
final JCDiagnostic diag = ex.getDiagnostic();
Resolve.InapplicableSymbolError errSym = rs.new InapplicableSymbolError(null) {
@Override
protected Pair<Symbol, JCDiagnostic> errCandidate() {
return new Pair<>(sym, diag);
}
};
List<Type> argtypes2 = argtypes.map(
rs.new ResolveDeferredRecoveryMap(AttrMode.CHECK, sym, env.info.pendingResolutionPhase));
JCDiagnostic errDiag = errSym.getDiagnostic(JCDiagnostic.DiagnosticType.ERROR,
env.tree, sym, site, sym.name, argtypes2, typeargtypes);
log.report(errDiag);
return types.createErrorType(site);
}
}
public void visitLiteral(JCLiteral tree) {
result = check(tree, litType(tree.typetag).constType(tree.value),
KindSelector.VAL, resultInfo);
}
//where
/** Return the type of a literal with given type tag.
*/
Type litType(TypeTag tag) {
return (tag == CLASS) ? syms.stringType : syms.typeOfTag[tag.ordinal()];
}
public void visitTypeIdent(JCPrimitiveTypeTree tree) {
result = check(tree, syms.typeOfTag[tree.typetag.ordinal()], KindSelector.TYP, resultInfo);
}
public void visitTypeArray(JCArrayTypeTree tree) {
Type etype = attribType(tree.elemtype, env);
Type type = new ArrayType(etype, syms.arrayClass);
result = check(tree, type, KindSelector.TYP, resultInfo);
}
/** Visitor method for parameterized types.
* Bound checking is left until later, since types are attributed
* before supertype structure is completely known
*/
public void visitTypeApply(JCTypeApply tree) {
Type owntype = types.createErrorType(tree.type);
// Attribute functor part of application and make sure it's a class.
Type clazztype = chk.checkClassType(tree.clazz.pos(), attribType(tree.clazz, env));
// Attribute type parameters
List<Type> actuals = attribTypes(tree.arguments, env);
if (clazztype.hasTag(CLASS)) {
List<Type> formals = clazztype.tsym.type.getTypeArguments();
if (actuals.isEmpty()) //diamond
actuals = formals;
if (actuals.length() == formals.length()) {
List<Type> a = actuals;
List<Type> f = formals;
while (a.nonEmpty()) {
a.head = a.head.withTypeVar(f.head);
a = a.tail;
f = f.tail;
}
// Compute the proper generic outer
Type clazzOuter = clazztype.getEnclosingType();
if (clazzOuter.hasTag(CLASS)) {
Type site;
JCExpression clazz = TreeInfo.typeIn(tree.clazz);
if (clazz.hasTag(IDENT)) {
site = env.enclClass.sym.type;
} else if (clazz.hasTag(SELECT)) {
site = ((JCFieldAccess) clazz).selected.type;
} else throw new AssertionError(""+tree);
if (clazzOuter.hasTag(CLASS) && site != clazzOuter) {
if (site.hasTag(CLASS))
site = types.asOuterSuper(site, clazzOuter.tsym);
if (site == null)
site = types.erasure(clazzOuter);
clazzOuter = site;
}
}
owntype = new ClassType(clazzOuter, actuals, clazztype.tsym,
clazztype.getMetadata());
} else {
if (formals.length() != 0) {
log.error(tree.pos(),
Errors.WrongNumberTypeArgs(Integer.toString(formals.length())));
} else {
log.error(tree.pos(), Errors.TypeDoesntTakeParams(clazztype.tsym));
}
owntype = types.createErrorType(tree.type);
}
}
result = check(tree, owntype, KindSelector.TYP, resultInfo);
}
public void visitTypeUnion(JCTypeUnion tree) {
ListBuffer<Type> multicatchTypes = new ListBuffer<>();
ListBuffer<Type> all_multicatchTypes = null; // lazy, only if needed
for (JCExpression typeTree : tree.alternatives) {
Type ctype = attribType(typeTree, env);
ctype = chk.checkType(typeTree.pos(),
chk.checkClassType(typeTree.pos(), ctype),
syms.throwableType);
if (!ctype.isErroneous()) {
//check that alternatives of a union type are pairwise
//unrelated w.r.t. subtyping
if (chk.intersects(ctype, multicatchTypes.toList())) {
for (Type t : multicatchTypes) {
boolean sub = types.isSubtype(ctype, t);
boolean sup = types.isSubtype(t, ctype);
if (sub || sup) {
//assume 'a' <: 'b'
Type a = sub ? ctype : t;
Type b = sub ? t : ctype;
log.error(typeTree.pos(), Errors.MulticatchTypesMustBeDisjoint(a, b));
}
}
}
multicatchTypes.append(ctype);
if (all_multicatchTypes != null)
all_multicatchTypes.append(ctype);
} else {
if (all_multicatchTypes == null) {
all_multicatchTypes = new ListBuffer<>();
all_multicatchTypes.appendList(multicatchTypes);
}
all_multicatchTypes.append(ctype);
}
}
Type t = check(tree, types.lub(multicatchTypes.toList()),
KindSelector.TYP, resultInfo.dup(CheckMode.NO_TREE_UPDATE));
if (t.hasTag(CLASS)) {
List<Type> alternatives =
((all_multicatchTypes == null) ? multicatchTypes : all_multicatchTypes).toList();
t = new UnionClassType((ClassType) t, alternatives);
}
tree.type = result = t;
}
public void visitTypeIntersection(JCTypeIntersection tree) {
attribTypes(tree.bounds, env);
tree.type = result = checkIntersection(tree, tree.bounds);
}
public void visitTypeParameter(JCTypeParameter tree) {
TypeVar typeVar = (TypeVar) tree.type;
if (tree.annotations != null && tree.annotations.nonEmpty()) {
annotate.annotateTypeParameterSecondStage(tree, tree.annotations);
}
if (!typeVar.getUpperBound().isErroneous()) {
//fixup type-parameter bound computed in 'attribTypeVariables'
typeVar.setUpperBound(checkIntersection(tree, tree.bounds));
}
}
Type checkIntersection(JCTree tree, List<JCExpression> bounds) {
Set<Type> boundSet = new HashSet<>();
if (bounds.nonEmpty()) {
// accept class or interface or typevar as first bound.
bounds.head.type = checkBase(bounds.head.type, bounds.head, env, false, false, false);
boundSet.add(types.erasure(bounds.head.type));
if (bounds.head.type.isErroneous()) {
return bounds.head.type;
}
else if (bounds.head.type.hasTag(TYPEVAR)) {
// if first bound was a typevar, do not accept further bounds.
if (bounds.tail.nonEmpty()) {
log.error(bounds.tail.head.pos(),
Errors.TypeVarMayNotBeFollowedByOtherBounds);
return bounds.head.type;
}
} else {
// if first bound was a class or interface, accept only interfaces
// as further bounds.
for (JCExpression bound : bounds.tail) {
bound.type = checkBase(bound.type, bound, env, false, true, false);
if (bound.type.isErroneous()) {
bounds = List.of(bound);
}
else if (bound.type.hasTag(CLASS)) {
chk.checkNotRepeated(bound.pos(), types.erasure(bound.type), boundSet);
}
}
}
}
if (bounds.length() == 0) {
return syms.objectType;
} else if (bounds.length() == 1) {
return bounds.head.type;
} else {
Type owntype = types.makeIntersectionType(TreeInfo.types(bounds));
// ... the variable's bound is a class type flagged COMPOUND
// (see comment for TypeVar.bound).
// In this case, generate a class tree that represents the
// bound class, ...
JCExpression extending;
List<JCExpression> implementing;
if (!bounds.head.type.isInterface()) {
extending = bounds.head;
implementing = bounds.tail;
} else {
extending = null;
implementing = bounds;
}
JCClassDecl cd = make.at(tree).ClassDef(
make.Modifiers(PUBLIC | ABSTRACT),
names.empty, List.nil(),
extending, implementing, List.nil());
ClassSymbol c = (ClassSymbol)owntype.tsym;
Assert.check((c.flags() & COMPOUND) != 0);
cd.sym = c;
c.sourcefile = env.toplevel.sourcefile;
// ... and attribute the bound class
c.flags_field |= UNATTRIBUTED;
Env<AttrContext> cenv = enter.classEnv(cd, env);
typeEnvs.put(c, cenv);
attribClass(c);
return owntype;
}
}
public void visitWildcard(JCWildcard tree) {
//- System.err.println("visitWildcard("+tree+");");//DEBUG
Type type = (tree.kind.kind == BoundKind.UNBOUND)
? syms.objectType
: attribType(tree.inner, env);
result = check(tree, new WildcardType(chk.checkRefType(tree.pos(), type),
tree.kind.kind,
syms.boundClass),
KindSelector.TYP, resultInfo);
}
public void visitAnnotation(JCAnnotation tree) {
Assert.error("should be handled in annotate");
}
public void visitAnnotatedType(JCAnnotatedType tree) {
attribAnnotationTypes(tree.annotations, env);
Type underlyingType = attribType(tree.underlyingType, env);
Type annotatedType = underlyingType.annotatedType(Annotations.TO_BE_SET);
if (!env.info.isNewClass)
annotate.annotateTypeSecondStage(tree, tree.annotations, annotatedType);
result = tree.type = annotatedType;
}
public void visitErroneous(JCErroneous tree) {
if (tree.errs != null)
for (JCTree err : tree.errs)
attribTree(err, env, new ResultInfo(KindSelector.ERR, pt()));
result = tree.type = syms.errType;
}
/** Default visitor method for all other trees.
*/
public void visitTree(JCTree tree) {
throw new AssertionError();
}
/**
* Attribute an env for either a top level tree or class or module declaration.
*/
public void attrib(Env<AttrContext> env) {
switch (env.tree.getTag()) {
case MODULEDEF:
attribModule(env.tree.pos(), ((JCModuleDecl)env.tree).sym);
break;
case TOPLEVEL:
attribTopLevel(env);
break;
case PACKAGEDEF:
attribPackage(env.tree.pos(), ((JCPackageDecl) env.tree).packge);
break;
default:
attribClass(env.tree.pos(), env.enclClass.sym);
}
}
/**
* Attribute a top level tree. These trees are encountered when the
* package declaration has annotations.
*/
public void attribTopLevel(Env<AttrContext> env) {
JCCompilationUnit toplevel = env.toplevel;
try {
annotate.flush();
} catch (CompletionFailure ex) {
chk.completionError(toplevel.pos(), ex);
}
}
public void attribPackage(DiagnosticPosition pos, PackageSymbol p) {
try {
annotate.flush();
attribPackage(p);
} catch (CompletionFailure ex) {
chk.completionError(pos, ex);
}
}
void attribPackage(PackageSymbol p) {
Env<AttrContext> env = typeEnvs.get(p);
chk.checkDeprecatedAnnotation(((JCPackageDecl) env.tree).pid.pos(), p);
}
public void attribModule(DiagnosticPosition pos, ModuleSymbol m) {
try {
annotate.flush();
attribModule(m);
} catch (CompletionFailure ex) {
chk.completionError(pos, ex);
}
}
void attribModule(ModuleSymbol m) {
// Get environment current at the point of module definition.
Env<AttrContext> env = enter.typeEnvs.get(m);
attribStat(env.tree, env);
}
/** Main method: attribute class definition associated with given class symbol.
* reporting completion failures at the given position.
* @param pos The source position at which completion errors are to be
* reported.
* @param c The class symbol whose definition will be attributed.
*/
public void attribClass(DiagnosticPosition pos, ClassSymbol c) {
try {
annotate.flush();
attribClass(c);
} catch (CompletionFailure ex) {
chk.completionError(pos, ex);
}
}
/** Attribute class definition associated with given class symbol.
* @param c The class symbol whose definition will be attributed.
*/
void attribClass(ClassSymbol c) throws CompletionFailure {
if (c.type.hasTag(ERROR)) return;
// Check for cycles in the inheritance graph, which can arise from
// ill-formed class files.
chk.checkNonCyclic(null, c.type);
Type st = types.supertype(c.type);
if ((c.flags_field & Flags.COMPOUND) == 0) {
// First, attribute superclass.
if (st.hasTag(CLASS))
attribClass((ClassSymbol)st.tsym);
// Next attribute owner, if it is a class.
if (c.owner.kind == TYP && c.owner.type.hasTag(CLASS))
attribClass((ClassSymbol)c.owner);
}
// The previous operations might have attributed the current class
// if there was a cycle. So we test first whether the class is still
// UNATTRIBUTED.
if ((c.flags_field & UNATTRIBUTED) != 0) {
c.flags_field &= ~UNATTRIBUTED;
// Get environment current at the point of class definition.
Env<AttrContext> env = typeEnvs.get(c);
// The info.lint field in the envs stored in typeEnvs is deliberately uninitialized,
// because the annotations were not available at the time the env was created. Therefore,
// we look up the environment chain for the first enclosing environment for which the
// lint value is set. Typically, this is the parent env, but might be further if there
// are any envs created as a result of TypeParameter nodes.
Env<AttrContext> lintEnv = env;
while (lintEnv.info.lint == null)
lintEnv = lintEnv.next;
// Having found the enclosing lint value, we can initialize the lint value for this class
env.info.lint = lintEnv.info.lint.augment(c);
Lint prevLint = chk.setLint(env.info.lint);
JavaFileObject prev = log.useSource(c.sourcefile);
ResultInfo prevReturnRes = env.info.returnResult;
try {
deferredLintHandler.flush(env.tree);
env.info.returnResult = null;
// java.lang.Enum may not be subclassed by a non-enum
if (st.tsym == syms.enumSym &&
((c.flags_field & (Flags.ENUM|Flags.COMPOUND)) == 0))
log.error(env.tree.pos(), Errors.EnumNoSubclassing);
// Enums may not be extended by source-level classes
if (st.tsym != null &&
((st.tsym.flags_field & Flags.ENUM) != 0) &&
((c.flags_field & (Flags.ENUM | Flags.COMPOUND)) == 0)) {
log.error(env.tree.pos(), Errors.EnumTypesNotExtensible);
}
if (isSerializable(c.type)) {
env.info.isSerializable = true;
}
attribClassBody(env, c);
chk.checkDeprecatedAnnotation(env.tree.pos(), c);
chk.checkClassOverrideEqualsAndHashIfNeeded(env.tree.pos(), c);
chk.checkFunctionalInterface((JCClassDecl) env.tree, c);
chk.checkLeaksNotAccessible(env, (JCClassDecl) env.tree);
} finally {
env.info.returnResult = prevReturnRes;
log.useSource(prev);
chk.setLint(prevLint);
}
}
}
public void visitImport(JCImport tree) {
// nothing to do
}
public void visitModuleDef(JCModuleDecl tree) {
tree.sym.completeUsesProvides();
ModuleSymbol msym = tree.sym;
Lint lint = env.outer.info.lint = env.outer.info.lint.augment(msym);
Lint prevLint = chk.setLint(lint);
chk.checkModuleName(tree);
chk.checkDeprecatedAnnotation(tree, msym);
try {
deferredLintHandler.flush(tree.pos());
} finally {
chk.setLint(prevLint);
}
}
/** Finish the attribution of a class. */
private void attribClassBody(Env<AttrContext> env, ClassSymbol c) {
JCClassDecl tree = (JCClassDecl)env.tree;
Assert.check(c == tree.sym);
// Validate type parameters, supertype and interfaces.
attribStats(tree.typarams, env);
if (!c.isAnonymous()) {
//already checked if anonymous
chk.validate(tree.typarams, env);
chk.validate(tree.extending, env);
chk.validate(tree.implementing, env);
}
c.markAbstractIfNeeded(types);
// If this is a non-abstract class, check that it has no abstract
// methods or unimplemented methods of an implemented interface.
if ((c.flags() & (ABSTRACT | INTERFACE)) == 0) {
chk.checkAllDefined(tree.pos(), c);
}
if ((c.flags() & ANNOTATION) != 0) {
if (tree.implementing.nonEmpty())
log.error(tree.implementing.head.pos(),
Errors.CantExtendIntfAnnotation);
if (tree.typarams.nonEmpty()) {
log.error(tree.typarams.head.pos(),
Errors.IntfAnnotationCantHaveTypeParams(c));
}
// If this annotation type has a @Repeatable, validate
Attribute.Compound repeatable = c.getAnnotationTypeMetadata().getRepeatable();
// If this annotation type has a @Repeatable, validate
if (repeatable != null) {
// get diagnostic position for error reporting
DiagnosticPosition cbPos = getDiagnosticPosition(tree, repeatable.type);
Assert.checkNonNull(cbPos);
chk.validateRepeatable(c, repeatable, cbPos);
}
} else {
// Check that all extended classes and interfaces
// are compatible (i.e. no two define methods with same arguments
// yet different return types). (JLS 8.4.6.3)
chk.checkCompatibleSupertypes(tree.pos(), c.type);
if (allowDefaultMethods) {
chk.checkDefaultMethodClashes(tree.pos(), c.type);
}
}
// Check that class does not import the same parameterized interface
// with two different argument lists.
chk.checkClassBounds(tree.pos(), c.type);
tree.type = c.type;
for (List<JCTypeParameter> l = tree.typarams;
l.nonEmpty(); l = l.tail) {
Assert.checkNonNull(env.info.scope.findFirst(l.head.name));
}
// Check that a generic class doesn't extend Throwable
if (!c.type.allparams().isEmpty() && types.isSubtype(c.type, syms.throwableType))
log.error(tree.extending.pos(), Errors.GenericThrowable);
// Check that all methods which implement some
// method conform to the method they implement.
chk.checkImplementations(tree);
//check that a resource implementing AutoCloseable cannot throw InterruptedException
checkAutoCloseable(tree.pos(), env, c.type);
for (List<JCTree> l = tree.defs; l.nonEmpty(); l = l.tail) {
// Attribute declaration
attribStat(l.head, env);
// Check that declarations in inner classes are not static (JLS 8.1.2)
// Make an exception for static constants.
if (c.owner.kind != PCK &&
((c.flags() & STATIC) == 0 || c.name == names.empty) &&
(TreeInfo.flags(l.head) & (STATIC | INTERFACE)) != 0) {
Symbol sym = null;
if (l.head.hasTag(VARDEF)) sym = ((JCVariableDecl) l.head).sym;
if (sym == null ||
sym.kind != VAR ||
((VarSymbol) sym).getConstValue() == null)
log.error(l.head.pos(), Errors.IclsCantHaveStaticDecl(c));
}
}
// Check for cycles among non-initial constructors.
chk.checkCyclicConstructors(tree);
// Check for cycles among annotation elements.
chk.checkNonCyclicElements(tree);
// Check for proper use of serialVersionUID
if (env.info.lint.isEnabled(LintCategory.SERIAL)
&& isSerializable(c.type)
&& (c.flags() & (Flags.ENUM | Flags.INTERFACE)) == 0
&& !c.isAnonymous()) {
checkSerialVersionUID(tree, c);
}
if (allowTypeAnnos) {
// Correctly organize the postions of the type annotations
typeAnnotations.organizeTypeAnnotationsBodies(tree);
// Check type annotations applicability rules
validateTypeAnnotations(tree, false);
}
}
// where
/** get a diagnostic position for an attribute of Type t, or null if attribute missing */
private DiagnosticPosition getDiagnosticPosition(JCClassDecl tree, Type t) {
for(List<JCAnnotation> al = tree.mods.annotations; !al.isEmpty(); al = al.tail) {
if (types.isSameType(al.head.annotationType.type, t))
return al.head.pos();
}
return null;
}
/** check if a type is a subtype of Serializable, if that is available. */
boolean isSerializable(Type t) {
try {
syms.serializableType.complete();
}
catch (CompletionFailure e) {
return false;
}
return types.isSubtype(t, syms.serializableType);
}
/** Check that an appropriate serialVersionUID member is defined. */
private void checkSerialVersionUID(JCClassDecl tree, ClassSymbol c) {
// check for presence of serialVersionUID
VarSymbol svuid = null;
for (Symbol sym : c.members().getSymbolsByName(names.serialVersionUID)) {
if (sym.kind == VAR) {
svuid = (VarSymbol)sym;
break;
}
}
if (svuid == null) {
log.warning(LintCategory.SERIAL,
tree.pos(), Warnings.MissingSVUID(c));
return;
}
// check that it is static final
if ((svuid.flags() & (STATIC | FINAL)) !=
(STATIC | FINAL))
log.warning(LintCategory.SERIAL,
TreeInfo.diagnosticPositionFor(svuid, tree), Warnings.ImproperSVUID(c));
// check that it is long
else if (!svuid.type.hasTag(LONG))
log.warning(LintCategory.SERIAL,
TreeInfo.diagnosticPositionFor(svuid, tree), Warnings.LongSVUID(c));
// check constant
else if (svuid.getConstValue() == null)
log.warning(LintCategory.SERIAL,
TreeInfo.diagnosticPositionFor(svuid, tree), Warnings.ConstantSVUID(c));
}
private Type capture(Type type) {
return types.capture(type);
}
private void setSyntheticVariableType(JCVariableDecl tree, Type type) {
if (type.isErroneous()) {
tree.vartype = make.at(Position.NOPOS).Erroneous();
} else {
tree.vartype = make.at(Position.NOPOS).Type(type);
}
}
public void validateTypeAnnotations(JCTree tree, boolean sigOnly) {
tree.accept(new TypeAnnotationsValidator(sigOnly));
}
//where
private final class TypeAnnotationsValidator extends TreeScanner {
private final boolean sigOnly;
public TypeAnnotationsValidator(boolean sigOnly) {
this.sigOnly = sigOnly;
}
public void visitAnnotation(JCAnnotation tree) {
chk.validateTypeAnnotation(tree, false);
super.visitAnnotation(tree);
}
public void visitAnnotatedType(JCAnnotatedType tree) {
if (!tree.underlyingType.type.isErroneous()) {
super.visitAnnotatedType(tree);
}
}
public void visitTypeParameter(JCTypeParameter tree) {
chk.validateTypeAnnotations(tree.annotations, true);
scan(tree.bounds);
// Don't call super.
// This is needed because above we call validateTypeAnnotation with
// false, which would forbid annotations on type parameters.
// super.visitTypeParameter(tree);
}
public void visitMethodDef(JCMethodDecl tree) {
if (tree.recvparam != null &&
!tree.recvparam.vartype.type.isErroneous()) {
checkForDeclarationAnnotations(tree.recvparam.mods.annotations,
tree.recvparam.vartype.type.tsym);
}
if (tree.restype != null && tree.restype.type != null) {
validateAnnotatedType(tree.restype, tree.restype.type);
}
if (sigOnly) {
scan(tree.mods);
scan(tree.restype);
scan(tree.typarams);
scan(tree.recvparam);
scan(tree.params);
scan(tree.thrown);
} else {
scan(tree.defaultValue);
scan(tree.body);
}
}
public void visitVarDef(final JCVariableDecl tree) {
//System.err.println("validateTypeAnnotations.visitVarDef " + tree);
if (tree.sym != null && tree.sym.type != null && !tree.isImplicitlyTyped())
validateAnnotatedType(tree.vartype, tree.sym.type);
scan(tree.mods);
scan(tree.vartype);
if (!sigOnly) {
scan(tree.init);
}
}
public void visitTypeCast(JCTypeCast tree) {
if (tree.clazz != null && tree.clazz.type != null)
validateAnnotatedType(tree.clazz, tree.clazz.type);
super.visitTypeCast(tree);
}
public void visitTypeTest(JCInstanceOf tree) {
if (tree.pattern != null && !(tree.pattern instanceof JCPattern) && tree.pattern.type != null)
validateAnnotatedType(tree.pattern, tree.pattern.type);
super.visitTypeTest(tree);
}
public void visitNewClass(JCNewClass tree) {
if (tree.clazz != null && tree.clazz.type != null) {
if (tree.clazz.hasTag(ANNOTATED_TYPE)) {
checkForDeclarationAnnotations(((JCAnnotatedType) tree.clazz).annotations,
tree.clazz.type.tsym);
}
if (tree.def != null) {
checkForDeclarationAnnotations(tree.def.mods.annotations, tree.clazz.type.tsym);
}
validateAnnotatedType(tree.clazz, tree.clazz.type);
}
super.visitNewClass(tree);
}
public void visitNewArray(JCNewArray tree) {
if (tree.elemtype != null && tree.elemtype.type != null) {
if (tree.elemtype.hasTag(ANNOTATED_TYPE)) {
checkForDeclarationAnnotations(((JCAnnotatedType) tree.elemtype).annotations,
tree.elemtype.type.tsym);
}
validateAnnotatedType(tree.elemtype, tree.elemtype.type);
}
super.visitNewArray(tree);
}
public void visitClassDef(JCClassDecl tree) {
//System.err.println("validateTypeAnnotations.visitClassDef " + tree);
if (sigOnly) {
scan(tree.mods);
scan(tree.typarams);
scan(tree.extending);
scan(tree.implementing);
}
for (JCTree member : tree.defs) {
if (member.hasTag(Tag.CLASSDEF)) {
continue;
}
scan(member);
}
}
public void visitBlock(JCBlock tree) {
if (!sigOnly) {
scan(tree.stats);
}
}
/* I would want to model this after
* com.sun.tools.javac.comp.Check.Validator.visitSelectInternal(JCFieldAccess)
* and override visitSelect and visitTypeApply.
* However, we only set the annotated type in the top-level type
* of the symbol.
* Therefore, we need to override each individual location where a type
* can occur.
*/
private void validateAnnotatedType(final JCTree errtree, final Type type) {
//System.err.println("Attr.validateAnnotatedType: " + errtree + " type: " + type);
if (type.isPrimitiveOrVoid()) {
return;
}
JCTree enclTr = errtree;
Type enclTy = type;
boolean repeat = true;
while (repeat) {
if (enclTr.hasTag(TYPEAPPLY)) {
List<Type> tyargs = enclTy.getTypeArguments();
List<JCExpression> trargs = ((JCTypeApply)enclTr).getTypeArguments();
if (trargs.length() > 0) {
// Nothing to do for diamonds
if (tyargs.length() == trargs.length()) {
for (int i = 0; i < tyargs.length(); ++i) {
validateAnnotatedType(trargs.get(i), tyargs.get(i));
}
}
// If the lengths don't match, it's either a diamond
// or some nested type that redundantly provides
// type arguments in the tree.
}
// Look at the clazz part of a generic type
enclTr = ((JCTree.JCTypeApply)enclTr).clazz;
}
if (enclTr.hasTag(SELECT)) {
enclTr = ((JCTree.JCFieldAccess)enclTr).getExpression();
if (enclTy != null &&
!enclTy.hasTag(NONE)) {
enclTy = enclTy.getEnclosingType();
}
} else if (enclTr.hasTag(ANNOTATED_TYPE)) {
JCAnnotatedType at = (JCTree.JCAnnotatedType) enclTr;
if (enclTy == null || enclTy.hasTag(NONE)) {
if (at.getAnnotations().size() == 1) {
log.error(at.underlyingType.pos(), Errors.CantTypeAnnotateScoping1(at.getAnnotations().head.attribute));
} else {
ListBuffer<Attribute.Compound> comps = new ListBuffer<>();
for (JCAnnotation an : at.getAnnotations()) {
comps.add(an.attribute);
}
log.error(at.underlyingType.pos(), Errors.CantTypeAnnotateScoping(comps.toList()));
}
repeat = false;
}
enclTr = at.underlyingType;
// enclTy doesn't need to be changed
} else if (enclTr.hasTag(IDENT)) {
repeat = false;
} else if (enclTr.hasTag(JCTree.Tag.WILDCARD)) {
JCWildcard wc = (JCWildcard) enclTr;
if (wc.getKind() == JCTree.Kind.EXTENDS_WILDCARD ||
wc.getKind() == JCTree.Kind.SUPER_WILDCARD) {
validateAnnotatedType(wc.getBound(), wc.getBound().type);
} else {
// Nothing to do for UNBOUND
}
repeat = false;
} else if (enclTr.hasTag(TYPEARRAY)) {
JCArrayTypeTree art = (JCArrayTypeTree) enclTr;
validateAnnotatedType(art.getType(), art.elemtype.type);
repeat = false;
} else if (enclTr.hasTag(TYPEUNION)) {
JCTypeUnion ut = (JCTypeUnion) enclTr;
for (JCTree t : ut.getTypeAlternatives()) {
validateAnnotatedType(t, t.type);
}
repeat = false;
} else if (enclTr.hasTag(TYPEINTERSECTION)) {
JCTypeIntersection it = (JCTypeIntersection) enclTr;
for (JCTree t : it.getBounds()) {
validateAnnotatedType(t, t.type);
}
repeat = false;
} else if (enclTr.getKind() == JCTree.Kind.PRIMITIVE_TYPE ||
enclTr.getKind() == JCTree.Kind.ERRONEOUS) {
repeat = false;
} else {
Assert.error("Unexpected tree: " + enclTr + " with kind: " + enclTr.getKind() +
" within: "+ errtree + " with kind: " + errtree.getKind());
}
}
}
private void checkForDeclarationAnnotations(List<? extends JCAnnotation> annotations,
Symbol sym) {
// Ensure that no declaration annotations are present.
// Note that a tree type might be an AnnotatedType with
// empty annotations, if only declaration annotations were given.
// This method will raise an error for such a type.
for (JCAnnotation ai : annotations) {
if (!ai.type.isErroneous() &&
typeAnnotations.annotationTargetType(ai.attribute, sym) == TypeAnnotations.AnnotationType.DECLARATION) {
log.error(ai.pos(), Errors.AnnotationTypeNotApplicableToType(ai.type));
}
}
}
}
// <editor-fold desc="post-attribution visitor">
/**
* Handle missing types/symbols in an AST. This routine is useful when
* the compiler has encountered some errors (which might have ended up
* terminating attribution abruptly); if the compiler is used in fail-over
* mode (e.g. by an IDE) and the AST contains semantic errors, this routine
* prevents NPE to be progagated during subsequent compilation steps.
*/
public void postAttr(JCTree tree) {
new PostAttrAnalyzer().scan(tree);
}
class PostAttrAnalyzer extends TreeScanner {
private void initTypeIfNeeded(JCTree that) {
if (that.type == null) {
if (that.hasTag(METHODDEF)) {
that.type = dummyMethodType((JCMethodDecl)that);
} else {
that.type = syms.unknownType;
}
}
}
/* Construct a dummy method type. If we have a method declaration,
* and the declared return type is void, then use that return type
* instead of UNKNOWN to avoid spurious error messages in lambda
* bodies (see:JDK-8041704).
*/
private Type dummyMethodType(JCMethodDecl md) {
Type restype = syms.unknownType;
if (md != null && md.restype != null && md.restype.hasTag(TYPEIDENT)) {
JCPrimitiveTypeTree prim = (JCPrimitiveTypeTree)md.restype;
if (prim.typetag == VOID)
restype = syms.voidType;
}
return new MethodType(List.nil(), restype,
List.nil(), syms.methodClass);
}
private Type dummyMethodType() {
return dummyMethodType(null);
}
@Override
public void scan(JCTree tree) {
if (tree == null) return;
if (tree instanceof JCExpression) {
initTypeIfNeeded(tree);
}
super.scan(tree);
}
@Override
public void visitIdent(JCIdent that) {
if (that.sym == null) {
that.sym = syms.unknownSymbol;
}
}
@Override
public void visitSelect(JCFieldAccess that) {
if (that.sym == null) {
that.sym = syms.unknownSymbol;
}
super.visitSelect(that);
}
@Override
public void visitClassDef(JCClassDecl that) {
initTypeIfNeeded(that);
if (that.sym == null) {
that.sym = new ClassSymbol(0, that.name, that.type, syms.noSymbol);
}
super.visitClassDef(that);
}
@Override
public void visitMethodDef(JCMethodDecl that) {
initTypeIfNeeded(that);
if (that.sym == null) {
that.sym = new MethodSymbol(0, that.name, that.type, syms.noSymbol);
}
super.visitMethodDef(that);
}
@Override
public void visitVarDef(JCVariableDecl that) {
initTypeIfNeeded(that);
if (that.sym == null) {
that.sym = new VarSymbol(0, that.name, that.type, syms.noSymbol);
that.sym.adr = 0;
}
if (that.vartype == null) {
that.vartype = make.at(Position.NOPOS).Erroneous();
}
super.visitVarDef(that);
}
@Override
public void visitBindingPattern(JCBindingPattern that) {
if (that.symbol == null) {
that.symbol = new BindingSymbol(that.name, that.type, syms.noSymbol);
that.symbol.adr = 0;
}
super.visitBindingPattern(that);
}
@Override
public void visitNewClass(JCNewClass that) {
if (that.constructor == null) {
that.constructor = new MethodSymbol(0, names.init,
dummyMethodType(), syms.noSymbol);
}
if (that.constructorType == null) {
that.constructorType = syms.unknownType;
}
super.visitNewClass(that);
}
@Override
public void visitAssignop(JCAssignOp that) {
if (that.operator == null) {
that.operator = new OperatorSymbol(names.empty, dummyMethodType(),
-1, syms.noSymbol);
}
super.visitAssignop(that);
}
@Override
public void visitBinary(JCBinary that) {
if (that.operator == null) {
that.operator = new OperatorSymbol(names.empty, dummyMethodType(),
-1, syms.noSymbol);
}
super.visitBinary(that);
}
@Override
public void visitUnary(JCUnary that) {
if (that.operator == null) {
that.operator = new OperatorSymbol(names.empty, dummyMethodType(),
-1, syms.noSymbol);
}
super.visitUnary(that);
}
@Override
public void visitReference(JCMemberReference that) {
super.visitReference(that);
if (that.sym == null) {
that.sym = new MethodSymbol(0, names.empty, dummyMethodType(),
syms.noSymbol);
}
}
}
// </editor-fold>
public void setPackageSymbols(JCExpression pid, Symbol pkg) {
new TreeScanner() {
Symbol packge = pkg;
@Override
public void visitIdent(JCIdent that) {
that.sym = packge;
}
@Override
public void visitSelect(JCFieldAccess that) {
that.sym = packge;
packge = packge.owner;
super.visitSelect(that);
}
}.scan(pid);
}
}