/* * Copyright (c) 1999, 2016, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ package com.sun.tools.javac.comp; import java.util.*; import javax.lang.model.element.ElementKind; import javax.tools.JavaFileObject; 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.Directive.RequiresFlag; import com.sun.tools.javac.code.Lint.LintCategory; import com.sun.tools.javac.code.Scope.WriteableScope; 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.Infer.FreeTypeListener; 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.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.Fragment; 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.*; /** 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 * *

This is NOT part of any supported API. * If you write code that depends on this, you do so at your own risk. * This code and its internal interfaces are subject to change or * deletion without notice. */ public class Attr extends JCTree.Visitor { protected static final Context.Key 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 JCDiagnostic.Factory diags; final TypeAnnotations typeAnnotations; final DeferredLintHandler deferredLintHandler; final TypeEnvs typeEnvs; final Dependencies dependencies; final Annotate annotate; final ArgumentAttr argumentAttr; 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); 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); Options options = Options.instance(context); Source source = Source.instance(context); allowStringsInSwitch = source.allowStringsInSwitch(); allowPoly = source.allowPoly(); allowTypeAnnos = source.allowTypeAnnotations(); allowLambda = source.allowLambda(); allowDefaultMethods = source.allowDefaultMethods(); allowStaticInterfaceMethods = source.allowStaticInterfaceMethods(); 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: warn about use of variable before declaration? * RFE: 6425594 */ boolean useBeforeDeclarationWarning; /** * Switch: allow strings in switch? */ boolean allowStringsInSwitch; /** * 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(), "unexpected.type", 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 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 env) { if (v.name == names._this) { log.error(pos, Errors.CantAssignValToThis); } else if ((v.flags() & FINAL) != 0 && ((v.flags() & HASINIT) != 0 || !((base == null || (base.hasTag(IDENT) && TreeInfo.name(base) == names._this)) && isAssignableAsBlankFinal(v, env)))) { if (v.isResourceVariable()) { //TWR resource log.error(pos, "try.resource.may.not.be.assigned", v); } else { log.error(pos, "cant.assign.val.to.final.var", 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 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 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 env) { return tree.accept(identAttributer, env); } // where private TreeVisitor> identAttributer = new IdentAttributer(); private class IdentAttributer extends SimpleTreeVisitor> { @Override @DefinedBy(Api.COMPILER_TREE) public Symbol visitMemberSelect(MemberSelectTree node, Env env) { Symbol site = visit(node.getExpression(), env); if (site.kind == ERR || site.kind == ABSENT_TYP) return site; Name name = (Name)node.getIdentifier(); if (site.kind == PCK) { env.toplevel.packge = (PackageSymbol)site; return rs.findIdentInPackage(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 env) { return rs.findIdent(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 env = typeEnvs.get(sym); Env localEnv = env.dup(node, env.info.dup()); return attribTree(node, localEnv, unknownTypeInfo); } public Type attribImportQualifier(JCImport tree, Env 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 attribExprToTree(JCTree expr, Env env, JCTree tree) { breakTree = tree; JavaFileObject prev = log.useSource(env.toplevel.sourcefile); try { attribExpr(expr, env); } 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; } public Env attribStatToTree(JCTree stmt, Env env, JCTree tree) { breakTree = tree; JavaFileObject prev = log.useSource(env.toplevel.sourcefile); try { attribStat(stmt, env); } 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 Env env; private BreakAttr(Env env) { this.env = env; } } /** * Mode controlling behavior of Attr.Check */ enum CheckMode { NORMAL, NO_TREE_UPDATE { // Mode signalling 'fake check' - skip tree update @Override public boolean updateTreeType() { return false; } }, NO_INFERENCE_HOOK { // Mode signalling that caller will manage free types in tree decorations. @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; } protected void attr(JCTree tree, Env env) { tree.accept(Attr.this); } 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 void attr(JCTree tree, Env env) { result = argumentAttr.attribArg(tree, env); } 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) { super(KindSelector.VAL, Type.recoveryType, 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) { 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 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 env, ResultInfo resultInfo) { Env prevEnv = this.env; ResultInfo prevResult = this.resultInfo; try { this.env = env; this.resultInfo = resultInfo; resultInfo.attr(tree, env); if (tree == breakTree && resultInfo.checkContext.deferredAttrContext().mode == AttrMode.CHECK) { throw new BreakAttr(copyEnv(env)); } return result; } catch (CompletionFailure ex) { tree.type = syms.errType; return chk.completionError(tree.pos(), ex); } finally { this.env = prevEnv; this.resultInfo = prevResult; } } Env copyEnv(Env env) { Env 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 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 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 env) { return attribTree(tree, env, unknownExprInfo); } /** Derived visitor method: attribute a type tree. */ public Type attribType(JCTree tree, Env env) { Type result = attribType(tree, env, Type.noType); return result; } /** Derived visitor method: attribute a type tree. */ Type attribType(JCTree tree, Env 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 env) { Env analyzeEnv = env.dup(tree, env.info.dup(env.info.scope.dupUnshared(env.info.scope.owner))); try { return attribTree(tree, env, statInfo); } finally { analyzer.analyzeIfNeeded(tree, analyzeEnv); } } /** Attribute a list of expressions, returning a list of types. */ List attribExprs(List trees, Env env, Type pt) { ListBuffer ts = new ListBuffer<>(); for (List l = trees; l.nonEmpty(); l = l.tail) ts.append(attribExpr(l.head, env, pt)); return ts.toList(); } /** Attribute a list of statements, returning nothing. */ void attribStats(List trees, Env env) { for (List 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 trees, Env env, ListBuffer 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 attribAnyTypes(List trees, Env env) { ListBuffer argtypes = new ListBuffer<>(); for (List 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 attribTypes(List trees, Env env) { List 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 typarams, Env env) { for (JCTypeParameter tvar : typarams) { TypeVar a = (TypeVar)tvar.type; a.tsym.flags_field |= UNATTRIBUTED; a.bound = Type.noType; if (!tvar.bounds.isEmpty()) { List 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; } for (JCTypeParameter tvar : typarams) { chk.checkNonCyclic(tvar.pos(), (TypeVar)tvar.type); } } /** * Attribute the type references in a list of annotations. */ void attribAnnotationTypes(List annotations, Env env) { for (List 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 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 (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 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 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, "cant.inherit.from.anon"); 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, "illegal.forward.ref"); return types.createErrorType(t); } } else { t = chk.checkClassType(pos, t, checkExtensible); } if (interfaceExpected && (t.tsym.flags() & INTERFACE) == 0) { log.error(pos, "intf.expected.here"); // 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, "no.intf.expected.here"); return types.createErrorType(t); } if (checkExtensible && ((t.tsym.flags() & FINAL) != 0)) { log.error(pos, "cant.inherit.from.final", t.tsym); } chk.checkNonCyclic(pos, t); return t; } Type attribIdentAsEnumType(Env 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 localCacheContext = Optional.ofNullable(env.info.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 where // no explicit outer instance is given, // 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) && ((JCNewClass)env.tree).encl == null) { 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 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, "default.overrides.object.member", m.name, Kinds.kindName(m.location()), m.location()); } // Enter all type parameters into the local method scope. for (List 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()) log.error(tree.params.head.pos(), "intf.annotation.members.cant.have.params"); // Attribute all value parameters. for (List 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 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(), "throws.not.allowed.in.intf.annotation"); } // annotation method cannot declare type-parameters if (tree.typarams.nonEmpty()) { log.error(tree.typarams.head.pos(), "intf.annotation.members.cant.have.type.params"); } // 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 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(), "default.allowed.in.intf.annotation.member"); } if (isDefaultMethod || (tree.sym.flags() & (ABSTRACT | NATIVE)) == 0) log.error(tree.pos(), "missing.meth.body.or.decl.abstract"); } else if ((tree.sym.flags() & (ABSTRACT|DEFAULT|PRIVATE)) == ABSTRACT) { if ((owner.flags() & INTERFACE) != 0) { log.error(tree.body.pos(), "intf.meth.cant.have.body"); } else { log.error(tree.pos(), "abstract.meth.cant.have.body"); } } else if ((tree.mods.flags & NATIVE) != 0) { log.error(tree.pos(), "native.meth.cant.have.body"); } 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(), "call.to.super.not.allowed.in.enum.ctor", 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) { if (tree.sym != null) { // parameters have already been entered env.info.scope.enter(tree.sym); } else { 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); 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 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); } } result = tree.type = v.type; } finally { chk.setLint(prevLint); } } public void visitSkip(JCSkip tree) { result = null; } public void visitBlock(JCBlock tree) { if (env.info.scope.owner.kind == TYP) { // 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 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 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 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); result = null; } public void visitWhileLoop(JCWhileLoop tree) { attribExpr(tree.cond, env, syms.booleanType); attribStat(tree.body, env.dup(tree)); result = null; } public void visitForLoop(JCForLoop tree) { Env loopEnv = env.dup(env.tree, env.info.dup(env.info.scope.dup())); try { attribStats(tree.init, loopEnv); if (tree.cond != null) attribExpr(tree.cond, loopEnv, syms.booleanType); loopEnv.tree = tree; // before, we were not in loop! attribStats(tree.step, loopEnv); attribStat(tree.body, loopEnv); result = null; } finally { loopEnv.info.scope.leave(); } } public void visitForeachLoop(JCEnhancedForLoop tree) { Env 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)); attribStat(tree.var, loopEnv); chk.checkNonVoid(tree.pos(), exprType); Type elemtype = types.elemtype(exprType); // perhaps expr is an array? if (elemtype == null) { // or perhaps expr implements Iterable? Type base = types.asSuper(exprType, syms.iterableType.tsym); if (base == null) { log.error(tree.expr.pos(), "foreach.not.applicable.to.type", exprType, diags.fragment("type.req.array.or.iterable")); elemtype = types.createErrorType(exprType); } else { List iterableParams = base.allparams(); elemtype = iterableParams.isEmpty() ? syms.objectType : types.wildUpperBound(iterableParams.head); } } 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 env1 = env; while (env1 != null && !env1.tree.hasTag(CLASSDEF)) { if (env1.tree.hasTag(LABELLED) && ((JCLabeledStatement) env1.tree).label == tree.label) { log.error(tree.pos(), "label.already.in.use", tree.label); break; } env1 = env1.next; } attribStat(tree.body, env.dup(tree)); result = null; } public void visitSwitch(JCSwitch tree) { Type seltype = attribExpr(tree.selector, env); Env switchEnv = env.dup(tree, env.info.dup(env.info.scope.dup())); try { boolean enumSwitch = (seltype.tsym.flags() & Flags.ENUM) != 0; boolean stringSwitch = false; if (types.isSameType(seltype, syms.stringType)) { if (allowStringsInSwitch) { stringSwitch = true; } else { log.error(tree.selector.pos(), "string.switch.not.supported.in.source", sourceName); } } if (!enumSwitch && !stringSwitch) seltype = chk.checkType(tree.selector.pos(), seltype, syms.intType); // Attribute all cases and // check that there are no duplicate case labels or default clauses. Set labels = new HashSet<>(); // The set of case labels. boolean hasDefault = false; // Is there a default label? for (List l = tree.cases; l.nonEmpty(); l = l.tail) { JCCase c = l.head; if (c.pat != null) { if (enumSwitch) { Symbol sym = enumConstant(c.pat, seltype); if (sym == null) { log.error(c.pat.pos(), "enum.label.must.be.unqualified.enum"); } else if (!labels.add(sym)) { log.error(c.pos(), "duplicate.case.label"); } } else { Type pattype = attribExpr(c.pat, switchEnv, seltype); if (!pattype.hasTag(ERROR)) { if (pattype.constValue() == null) { log.error(c.pat.pos(), (stringSwitch ? "string.const.req" : "const.expr.req")); } else if (!labels.add(pattype.constValue())) { log.error(c.pos(), "duplicate.case.label"); } } } } else if (hasDefault) { log.error(c.pos(), "duplicate.default.label"); } else { hasDefault = true; } Env caseEnv = switchEnv.dup(c, env.info.dup(switchEnv.info.scope.dup())); try { attribStats(c.stats, caseEnv); } finally { caseEnv.info.scope.leave(); addVars(c.stats, switchEnv.info.scope); } } result = null; } finally { switchEnv.info.scope.leave(); } } // where /** Add any variables defined in stats to the switch scope. */ private static void addVars(List 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 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 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("try.not.applicable.to.type", 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 l = tree.catchers; l.nonEmpty(); l = l.tail) { JCCatch c = l.head; Env 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 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, resource, 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, "try.resource.throws.interrupted.exc", 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("conditional.target.cant.be.void")); result = tree.type = types.createErrorType(resultInfo.pt); return; } ResultInfo condInfo = tree.polyKind == PolyKind.STANDALONE ? unknownExprInfo : resultInfo.dup(conditionalContext(resultInfo.checkContext)); Type truetype = attribTree(tree.truepart, env, condInfo); Type falsetype = attribTree(tree.falsepart, env, condInfo); Type owntype = (tree.polyKind == PolyKind.STANDALONE) ? condType(tree, 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 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); 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); return primitiveOrBoxed(speculativeNewClassTree.type); default: Type speculativeType = deferredAttr.attribSpeculative(tree, env, unknownExprInfo).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("incompatible.type.in.conditional", 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(DiagnosticPosition pos, Type thentype, Type elsetype) { // If same type, that is the result if (types.isSameType(thentype, elsetype)) return thentype.baseType(); Type thenUnboxed = (thentype.isPrimitive()) ? thentype : types.unboxedType(thentype); Type elseUnboxed = (elsetype.isPrimitive()) ? elsetype : types.unboxedType(elsetype); // 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 (thenUnboxed.isPrimitive() && elseUnboxed.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. if (thenUnboxed.getTag().isStrictSubRangeOf(INT) && elseUnboxed.hasTag(INT) && types.isAssignable(elseUnboxed, thenUnboxed)) { return thenUnboxed.baseType(); } if (elseUnboxed.getTag().isStrictSubRangeOf(INT) && thenUnboxed.hasTag(INT) && types.isAssignable(thenUnboxed, elseUnboxed)) { return elseUnboxed.baseType(); } for (TypeTag tag : primitiveTags) { Type candidate = syms.typeOfTag[tag.ordinal()]; if (types.isSubtype(thenUnboxed, candidate) && types.isSubtype(elseUnboxed, candidate)) { return candidate; } } } // Those were all the cases that could result in a primitive if (thentype.isPrimitive()) thentype = types.boxedClass(thentype).type; if (elsetype.isPrimitive()) elsetype = types.boxedClass(elsetype).type; if (types.isSubtype(thentype, elsetype)) return elsetype.baseType(); if (types.isSubtype(elsetype, thentype)) return thentype.baseType(); if (thentype.hasTag(VOID) || elsetype.hasTag(VOID)) { log.error(pos, "neither.conditional.subtype", thentype, elsetype); return thentype.baseType(); } // 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(thentype.baseType(), elsetype.baseType()); } final static TypeTag[] primitiveTags = new TypeTag[]{ BYTE, CHAR, SHORT, INT, LONG, FLOAT, DOUBLE, BOOLEAN, }; public void visitIf(JCIf tree) { attribExpr(tree.cond, env, syms.booleanType); attribStat(tree.thenpart, env); if (tree.elsepart != null) attribStat(tree.elsepart, env); chk.checkEmptyIf(tree); result = null; } public void visitExec(JCExpressionStatement tree) { //a fresh environment is required for 292 inference to work properly --- //see Infer.instantiatePolymorphicSignatureInstance() Env 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 visitContinue(JCContinue tree) { tree.target = findJumpTarget(tree.pos(), tree.getTag(), tree.label, env); result = null; } //where /** 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 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 env) { // Search environments outwards from the point of jump. Env env1 = env; 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)) log.error(pos, "not.loop.label", label); // Found labelled statement target, now go inwards // to next non-labelled tree. return TreeInfo.referencedStatement(labelled); } else { return labelled; } } break; case DOLOOP: case WHILELOOP: case FORLOOP: case FOREACHLOOP: if (label == null) return env1.tree; break; case SWITCH: if (label == null && tag == BREAK) return env1.tree; break; case LAMBDA: case METHODDEF: case CLASSDEF: break LOOP; default: } env1 = env1.next; } if (label != null) log.error(pos, "undef.label", label); else if (tag == CONTINUE) log.error(pos, "cont.outside.loop"); else log.error(pos, "break.outside.switch.loop"); return null; } 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(), "ret.outside.meth"); } 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("unexpected.ret.val")); } 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("missing.ret.val")); } } 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 localEnv = env.dup(tree, env.info.dup()); // The types of the actual method arguments. List argtypes; // The types of the actual method type arguments. List typeargtypes = null; Name methName = TreeInfo.name(tree.meth); boolean isConstructorCall = methName == names._this || methName == names._super; ListBuffer 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(), "no.superclass", 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 // .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(), "illegal.qual.not.icls", 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; restype = adjustMethodReturnType(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(Type qualifierType, Name methodName, List argtypes, Type restype) { if (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 if (methodName == names.getClass && argtypes.isEmpty()) { // as a special case, x.getClass() has type Class return new ClassType(restype.getEnclosingType(), List.of(new WildcardType(types.erasure(qualifierType), BoundKind.EXTENDS, syms.boundClass)), restype.tsym, restype.getMetadata()); } 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 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(),"call.must.be.first.stmt.in.ctor", TreeInfo.name(tree.meth)); return false; } /** Obtain a method type with given argument types. */ Type newMethodTemplate(Type restype, List argtypes, List 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 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 // .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 // has type T, then .new C <...> (...) // yields a clazz T.C. Type encltype = chk.checkRefType(tree.encl.pos(), attribExpr(tree.encl, env)); // TODO 308: in .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 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(), "anon.class.impl.intf.no.qual.for.new"); } else if (clazztype.tsym.isStatic()) { log.error(tree.encl.pos(), "qualified.new.of.static.class", 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 argtypesBuf = new ListBuffer<>(); final KindSelector pkind = attribArgs(KindSelector.VAL, tree.args, localEnv, argtypesBuf); List argtypes = argtypesBuf.toList(); List typeargtypes = attribTypes(tree.typeargs, localEnv); // If we have made no mistakes in the class type... if (clazztype.hasTag(CLASS)) { // 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(), "enum.cant.be.instantiated"); 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(), "abstract.cant.be.instantiated", 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(), "anon.class.impl.intf.no.args"); if (!typeargtypes.isEmpty()) log.error(tree.typeargs.head.pos(), "anon.class.impl.intf.no.typeargs"); // 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 diamondEnv = localEnv.dup(tree); diamondEnv.info.selectSuper = cdef != null; 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 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 localEnv, List argtypes, List typeargtypes, KindSelector pkind) { // We are seeing an anonymous class instance creation. // In this case, the class instance creation // expression // // E.new C(args) { ... } // // is represented internally as // // E . new C(args) ( class { ... } ) . // // 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 C(args) { ... } // // is translated to (where X is a fresh name and typarams is the // parameter list of the super constructor): // // new X(<*nullchk*>E, args) where // X extends C { // X(ET e, args) { // e.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 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().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 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()) { tree.args = tree.args.prepend(makeNullCheck(tree.encl)); finalargtypes = argtypes.prepend(tree.encl.type); tree.encl = null; } 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 = 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("cant.apply.diamond.1", diags.fragment("diamond", tsym), details)); } }; } /** Make an attributed null check tree. */ public JCExpression makeNullCheck(JCExpression 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 localEnv = env.dup(tree); Type elemtype; if (tree.elemtype != null) { elemtype = attribType(tree.elemtype, localEnv); chk.validate(tree.elemtype, localEnv); owntype = elemtype; for (List 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)) { log.error(tree.pos(), "illegal.initializer.for.type", 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(), "generic.array.creation"); 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) { if (pt().isErroneous() || (pt().hasTag(NONE) && pt() != Type.recoveryType)) { if (pt().hasTag(NONE)) { //lambda only allowed in assignment or method invocation/cast context log.error(that.pos(), "unexpected.lambda"); } result = that.type = types.createErrorType(pt()); return; } //create an environment for attribution of the lambda expression final Env localEnv = lambdaEnv(that, env); boolean needsRecovery = resultInfo.checkContext.deferredAttrContext().mode == DeferredAttr.AttrMode.CHECK; try { if (needsRecovery && isSerializable(pt())) { localEnv.info.isSerializable = true; } List 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 resultInfo.checkContext.report(that, diags.fragment("invalid.generic.lambda.target", lambdaType, kindName(currentTarget.tsym), currentTarget.tsym)); result = that.type = types.createErrorType(pt()); return; } if (that.paramKind == JCLambda.ParameterKind.IMPLICIT) { //add param type info in the AST List actuals = lambdaType.getParameterTypes(); List 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; params.head.vartype = make.at(params.head).Type(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("incompatible.arg.types.in.lambda")); 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; 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 inferredThrownTypes = flow.analyzeLambdaThrownTypes(env, that, make); List thrownTypes = resultInfo.checkContext.inferenceContext().asUndetVars(lambdaType.getThrownTypes()); chk.unhandled(inferredThrownTypes, thrownTypes); } checkAccessibleTypes(that, localEnv, resultInfo.checkContext.inferenceContext(), lambdaType, 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; } 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 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 (explicitParamTypes != null) { currentTarget = infer.instantiateFunctionalInterface(that, currentTarget, explicitParamTypes, resultInfo.checkContext); } currentTarget = types.removeWildcards(currentTarget); 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 resultInfo.checkContext.report(that, diags.fragment("invalid.generic.lambda.target", lambdaType, kindName(currentTarget.tsym), currentTarget.tsym)); 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); } }.scan(tree); } Types.MapVisitor targetChecker = new Types.MapVisitor() { @Override public Type visitClassType(ClassType t, DiagnosticPosition pos) { return t.isIntersection() ? visitIntersectionClassType((IntersectionClassType)t, pos) : t; } public Type visitIntersectionClassType(IntersectionClassType ict, DiagnosticPosition pos) { Symbol desc = types.findDescriptorSymbol(makeNotionalInterface(ict)); Type target = null; for (Type bound : ict.getExplicitComponents()) { TypeSymbol boundSym = bound.tsym; if (types.isFunctionalInterface(boundSym) && types.findDescriptorSymbol(boundSym) == desc) { target = bound; } else if (!boundSym.isInterface() || (boundSym.flags() & ANNOTATION) != 0) { //bound must be an interface reportIntersectionError(pos, "not.an.intf.component", boundSym); } } return target != null ? target : ict.getExplicitComponents().head; //error recovery } private TypeSymbol makeNotionalInterface(IntersectionClassType ict) { ListBuffer targs = new ListBuffer<>(); ListBuffer 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 void reportIntersectionError(DiagnosticPosition pos, String key, Object... args) { resultInfo.checkContext.report(pos, diags.fragment("bad.intersection.target.for.functional.expr", diags.fragment(key, args))); } }; private Type fallbackDescriptorType(JCExpression tree) { switch (tree.getTag()) { case LAMBDA: JCLambda lambda = (JCLambda)tree; List argtypes = List.nil(); for (JCVariableDecl param : lambda.params) { argtypes = param.vartype != 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 env, final InferenceContext inferenceContext, final Type... ts) { checkAccessibleTypes(pos, env, inferenceContext, List.from(ts)); } private void checkAccessibleTypes(final DiagnosticPosition pos, final Env env, final InferenceContext inferenceContext, final List ts) { if (inferenceContext.free(ts)) { inferenceContext.addFreeTypeListener(ts, new FreeTypeListener() { @Override public void typesInferred(InferenceContext inferenceContext) { checkAccessibleTypes(pos, env, inferenceContext, inferenceContext.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("incompatible.ret.type.in.lambda", 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) { checkContext.report(tree, diags.fragment("incompatible.ret.type.in.lambda", diags.fragment("missing.ret.val", returnType))); } List argTypes = checkContext.inferenceContext().asUndetVars(descriptor.getParameterTypes()); if (!types.isSameTypes(argTypes, TreeInfo.types(tree.params))) { checkContext.report(tree, diags.fragment("incompatible.arg.types.in.lambda")); } } /* 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 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 lambdaEnv(JCLambda that, Env env) { Env 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())); } return lambdaEnv; } @Override public void visitReference(final JCMemberReference that) { if (pt().isErroneous() || (pt().hasTag(NONE) && pt() != Type.recoveryType)) { if (pt().hasTag(NONE)) { //method reference only allowed in assignment or method invocation/cast context log.error(that.pos(), "unexpected.mref"); } result = that.type = types.createErrorType(pt()); return; } final Env 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(), "invalid.mref", Kinds.kindName(that.getMode()), diags.fragment("mref.infer.and.explicit.params")); 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 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 argtypes = desc.getParameterTypes(); Resolve.MethodCheck referenceCheck = rs.resolveMethodCheck; if (resultInfo.checkContext.inferenceContext().free(argtypes)) { referenceCheck = rs.new MethodReferenceCheck(resultInfo.checkContext.inferenceContext()); } Pair refResult = null; List saved_undet = resultInfo.checkContext.inferenceContext().save(); try { refResult = rs.resolveMemberReference(localEnv, that, that.expr.type, that.name, argtypes, typeargtypes, 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.DiagnosticType diagKind = targetError ? JCDiagnostic.DiagnosticType.FRAGMENT : JCDiagnostic.DiagnosticType.ERROR; JCDiagnostic diag = diags.create(diagKind, log.currentSource(), that, "invalid.mref", 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.baseSymbol(); 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 (resultInfo.checkContext.deferredAttrContext().mode == AttrMode.CHECK) { if (that.getMode() == ReferenceMode.INVOKE && TreeInfo.isStaticSelector(that.expr, names) && that.kind.isUnbound() && !desc.getParameterTypes().head.isParameterized()) { 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(), "invalid.mref", Kinds.kindName(that.getMode()), diags.fragment("static.mref.with.targs")); 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.checkElemAccessFromSerializableLambda(that); } } 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(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, types.noWarnings)) { incompatibleReturnType = null; } } if (incompatibleReturnType != null) { checkContext.report(tree, diags.fragment("incompatible.ret.type.in.mref", diags.fragment("inconvertible.types", resType, descriptor.getReturnType()))); } 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) { List thrownTypes = inferenceContext.asUndetVars(descriptor.getThrownTypes()); if (chk.unhandled(refType.getThrownTypes(), thrownTypes).nonEmpty()) { log.error(tree, "incompatible.thrown.types.in.mref", refType.getThrownTypes()); } } } /** * 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 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), new FreeTypeListener() { public void typesInferred(InferenceContext inferenceContext) { setFunctionalInfo(env, fExpr, pt, inferenceContext.asInstType(descriptorType), inferenceContext.asInstType(primaryTarget), checkContext); } }); } else { ListBuffer targets = new ListBuffer<>(); if (pt.hasTag(CLASS)) { if (pt.isCompound()) { targets.append(types.removeWildcards(primaryTarget)); //this goes first for (Type t : ((IntersectionClassType)pt()).interfaces_field) { if (t != primaryTarget) { targets.append(types.removeWildcards(t)); } } } else { targets.append(types.removeWildcards(primaryTarget)); } } fExpr.targets = targets.toList(); 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, List.of(fExpr.targets.head), 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.targets.head))); } } } 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(), "illegal.start.of.type"); } 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.kind == MTH && !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.kind == MTH && !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)); Type right = chk.checkNonVoid(tree.rhs.pos(), attribExpr(tree.rhs, env)); // Find operator. Symbol operator = tree.operator = operators.resolveBinary(tree, tree.getTag(), left, right); Type owntype = types.createErrorType(tree.type); if (operator.kind == MTH && !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(), "incomparable.types", 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 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 = attribType(tree.clazz, env); if (!clazztype.hasTag(TYPEVAR)) { clazztype = chk.checkClassOrArrayType(tree.clazz.pos(), clazztype); } if (!clazztype.isErroneous() && !types.isReifiable(clazztype)) { log.error(tree.clazz.pos(), "illegal.generic.type.for.instof"); clazztype = types.createErrorType(clazztype); } chk.validate(tree.clazz, env, false); chk.checkCastable(tree.expr.pos(), exprtype, clazztype); result = check(tree, syms.booleanType, KindSelector.VAL, resultInfo); } 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(), "array.req.but.found", 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 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 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.checkElemAccessFromSerializableLambda(tree); } 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(), "type.var.cant.be.deref"); 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(), "not.encl.class", 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, "try.explicit.close.call"); } // 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(tree.pos(), "static.intf.method.invoke.not.supported.in.source", 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, "static.not.qualified.by.type", 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.checkElemAccessFromSerializableLambda(tree); } 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 env, ResultInfo resultInfo) { DiagnosticPosition pos = tree.pos(); Name name = tree.name; switch (site.getTag()) { case PACKAGE: return rs.accessBase( rs.findIdentInPackage(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. Type t = syms.classType; List typeargs = List.of(types.erasure(site)); t = new ClassType(t.getEnclosingType(), typeargs, t.tsym); return new VarSymbol( STATIC | PUBLIC | FINAL, names._class, t, site.tsym); } else { // We are seeing a plain identifier as selector. Symbol sym = rs.findIdentInType(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 extends A {} Symbol sym = (site.getUpperBound() != null) ? selectSym(tree, location, capture(site.getUpperBound()), env, resultInfo) : null; if (sym == null) { log.error(pos, "type.var.cant.be.deref"); 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. Type t = syms.classType; Type arg = types.boxedClass(site).type; t = new ClassType(t.getEnclosingType(), List.of(arg), t.tsym); return new VarSymbol( STATIC | PUBLIC | FINAL, names._class, t, site.tsym); } else { log.error(pos, "cant.deref", 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 env, ResultInfo resultInfo) { return (resultInfo.pt.hasTag(FORALL) || resultInfo.pt.hasTag(METHOD)) ? checkMethodId(tree, site, sym, env, resultInfo) : checkIdInternal(tree, site, sym, resultInfo.pt, env, resultInfo); } Type checkMethodId(JCTree tree, Type site, Symbol sym, Env env, ResultInfo resultInfo) { boolean isPolymorhicSignature = (sym.baseSymbol().flags() & SIGNATURE_POLYMORPHIC) != 0; return isPolymorhicSignature ? checkSigPolyMethodId(tree, site, sym, env, resultInfo) : checkMethodIdInternal(tree, site, sym, env, resultInfo); } Type checkSigPolyMethodId(JCTree tree, Type site, Symbol sym, Env env, ResultInfo resultInfo) { //recover original symbol for signature polymorphic methods checkMethodIdInternal(tree, site, sym.baseSymbol(), env, resultInfo); env.info.pendingResolutionPhase = Resolve.MethodResolutionPhase.BASIC; return sym.type; } Type checkMethodIdInternal(JCTree tree, Type site, Symbol sym, Env 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 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 { class Visitor { ... } } // class PointTree extends Tree { ... } // ...PointTree.Visitor... // // Then the type of the last expression above is // Tree.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; // 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(), "unchecked.assign.to.var", 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), 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); } // 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 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 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)) { String suffix = (initEnv.info.enclVar == v) ? "self.ref" : "forward.ref"; if (!onlyWarning || isStaticEnumField(v)) { log.error(tree.pos(), "illegal." + suffix); } else if (useBeforeDeclarationWarning) { log.warning(tree.pos(), suffix, v); } } 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 enclosingInitEnv(Env 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 section 8.9 Enums */ private void checkEnumInitializer(JCTree tree, Env 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(), "illegal.enum.static.ref"); } } /** 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 env, final List argtrees, List argtypes, List 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(), "unchecked.call.mbr.of.raw.type", 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 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(), "illegal.default.super.call", env.info.defaultSuperCallSite, diags.fragment("overridden.default", 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(), "illegal.static.intf.meth.call", 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 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(), "unchecked.meth.invocation.applied", kindName(sym), sym.name, rs.methodArguments(sym.type.getParameterTypes()), rs.methodArguments(argtypes.map(checkDeferredMap)), kindName(sym.location()), sym.location()); 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 errCandidate() { return new Pair<>(sym, diag); } }; List 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 actuals = attribTypes(tree.arguments, env); if (clazztype.hasTag(CLASS)) { List formals = clazztype.tsym.type.getTypeArguments(); if (actuals.isEmpty()) //diamond actuals = formals; if (actuals.length() == formals.length()) { List a = actuals; List 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(), "wrong.number.type.args", Integer.toString(formals.length())); } else { log.error(tree.pos(), "type.doesnt.take.params", clazztype.tsym); } owntype = types.createErrorType(tree.type); } } result = check(tree, owntype, KindSelector.TYP, resultInfo); } public void visitTypeUnion(JCTypeUnion tree) { ListBuffer multicatchTypes = new ListBuffer<>(); ListBuffer 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(), "multicatch.types.must.be.disjoint", 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 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.bound.isErroneous()) { //fixup type-parameter bound computed in 'attribTypeVariables' typeVar.bound = checkIntersection(tree, tree.bounds); } } Type checkIntersection(JCTree tree, List bounds) { Set 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(), "type.var.may.not.be.followed.by.other.bounds"); 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 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 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 env) { switch (env.tree.getTag()) { case MODULEDEF: attribModule(env.tree.pos(), ((JCModuleDecl)env.tree).sym); break; case TOPLEVEL: attribTopLevel(env); 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 env) { JCCompilationUnit toplevel = env.toplevel; try { annotate.flush(); } catch (CompletionFailure ex) { chk.completionError(toplevel.pos(), ex); } } 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 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 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 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(), "enum.no.subclassing"); // 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(), "enum.types.not.extensible"); } 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(); } /** Finish the attribution of a class. */ private void attribClassBody(Env 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(), "cant.extend.intf.annotation"); if (tree.typarams.nonEmpty()) log.error(tree.typarams.head.pos(), "intf.annotation.cant.have.type.params"); // 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 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(), "generic.throwable"); // 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 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(), "icls.cant.have.static.decl", 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) == 0 && !c.isAnonymous() && checkForSerial(c)) { 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 boolean checkForSerial(ClassSymbol c) { if ((c.flags() & ABSTRACT) == 0) { return true; } else { return c.members().anyMatch(anyNonAbstractOrDefaultMethod); } } public static final Filter anyNonAbstractOrDefaultMethod = new Filter() { @Override public boolean accepts(Symbol s) { return s.kind == MTH && (s.flags() & (DEFAULT | ABSTRACT)) != ABSTRACT; } }; /** get a diagnostic position for an attribute of Type t, or null if attribute missing */ private DiagnosticPosition getDiagnosticPosition(JCClassDecl tree, Type t) { for(List 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(), "missing.SVUID", c); return; } // check that it is static final if ((svuid.flags() & (STATIC | FINAL)) != (STATIC | FINAL)) log.warning(LintCategory.SERIAL, TreeInfo.diagnosticPositionFor(svuid, tree), "improper.SVUID", c); // check that it is long else if (!svuid.type.hasTag(LONG)) log.warning(LintCategory.SERIAL, TreeInfo.diagnosticPositionFor(svuid, tree), "long.SVUID", c); // check constant else if (svuid.getConstValue() == null) log.warning(LintCategory.SERIAL, TreeInfo.diagnosticPositionFor(svuid, tree), "constant.SVUID", c); } private Type capture(Type type) { return types.capture(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) 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.clazz != null && tree.clazz.type != null) validateAnnotatedType(tree.clazz, tree.clazz.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 tyargs = enclTy.getTypeArguments(); List 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(), "cant.type.annotate.scoping.1", at.getAnnotations().head.attribute); } else { ListBuffer comps = new ListBuffer<>(); for (JCAnnotation an : at.getAnnotations()) { comps.add(an.attribute); } log.error(at.underlyingType.pos(), "cant.type.annotate.scoping", 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) { validateAnnotatedType(wc.getBound(), ((WildcardType)enclTy).getExtendsBound()); } else if (wc.getKind() == JCTree.Kind.SUPER_WILDCARD) { validateAnnotatedType(wc.getBound(), ((WildcardType)enclTy).getSuperBound()); } else { // Nothing to do for UNBOUND } repeat = false; } else if (enclTr.hasTag(TYPEARRAY)) { JCArrayTypeTree art = (JCArrayTypeTree) enclTr; validateAnnotatedType(art.getType(), ((ArrayType)enclTy).getComponentType()); 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 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)); } } } } // /** * 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.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; } super.visitVarDef(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 visitLambda(JCLambda that) { super.visitLambda(that); if (that.targets == null) { that.targets = List.nil(); } } @Override public void visitReference(JCMemberReference that) { super.visitReference(that); if (that.sym == null) { that.sym = new MethodSymbol(0, names.empty, dummyMethodType(), syms.noSymbol); } if (that.targets == null) { that.targets = List.nil(); } } } // 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); } }