/* * Copyright 1999-2009 Sun Microsystems, Inc. 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. Sun designates this * particular file as subject to the "Classpath" exception as provided * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, * CA 95054 USA or visit www.sun.com if you need additional information or * have any questions. */ package com.sun.tools.javac.comp; import java.util.*; import java.util.Set; import javax.lang.model.element.ElementKind; import javax.tools.JavaFileObject; import com.sun.tools.javac.code.*; import com.sun.tools.javac.jvm.*; import com.sun.tools.javac.tree.*; import com.sun.tools.javac.util.*; import com.sun.tools.javac.util.JCDiagnostic.DiagnosticPosition; import com.sun.tools.javac.util.List; import com.sun.tools.javac.jvm.Target; import com.sun.tools.javac.code.Symbol.*; import com.sun.tools.javac.tree.JCTree.*; import com.sun.tools.javac.code.Type.*; import com.sun.source.tree.IdentifierTree; import com.sun.source.tree.MemberSelectTree; import com.sun.source.tree.TreeVisitor; import com.sun.source.util.SimpleTreeVisitor; import static com.sun.tools.javac.code.Flags.*; import static com.sun.tools.javac.code.Kinds.*; import static com.sun.tools.javac.code.TypeTags.*; /** 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 API supported by Sun Microsystems. 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 Check chk; final MemberEnter memberEnter; final TreeMaker make; final ConstFold cfolder; final Enter enter; final Target target; final Types types; final JCDiagnostic.Factory diags; final Annotate annotate; 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); chk = Check.instance(context); memberEnter = MemberEnter.instance(context); make = TreeMaker.instance(context); enter = Enter.instance(context); cfolder = ConstFold.instance(context); target = Target.instance(context); types = Types.instance(context); diags = JCDiagnostic.Factory.instance(context); annotate = Annotate.instance(context); Options options = Options.instance(context); Source source = Source.instance(context); allowGenerics = source.allowGenerics(); allowVarargs = source.allowVarargs(); allowEnums = source.allowEnums(); allowBoxing = source.allowBoxing(); allowCovariantReturns = source.allowCovariantReturns(); allowAnonOuterThis = source.allowAnonOuterThis(); allowStringsInSwitch = source.allowStringsInSwitch(); sourceName = source.name; relax = (options.get("-retrofit") != null || options.get("-relax") != null); useBeforeDeclarationWarning = options.get("useBeforeDeclarationWarning") != null; allowInvokedynamic = options.get("invokedynamic") != null; enableSunApiLintControl = options.get("enableSunApiLintControl") != null; } /** Switch: relax some constraints for retrofit mode. */ boolean relax; /** Switch: support generics? */ boolean allowGenerics; /** Switch: allow variable-arity methods. */ boolean allowVarargs; /** Switch: support enums? */ boolean allowEnums; /** Switch: support boxing and unboxing? */ boolean allowBoxing; /** Switch: support covariant result types? */ boolean allowCovariantReturns; /** Switch: allow references to surrounding object from anonymous * objects during constructor call? */ boolean allowAnonOuterThis; /** Switch: allow invokedynamic syntax */ boolean allowInvokedynamic; /** * Switch: warn about use of variable before declaration? * RFE: 6425594 */ boolean useBeforeDeclarationWarning; /** * Switch: allow lint infrastructure to control Sun proprietary * API warnings. */ boolean enableSunApiLintControl; /** * 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 owntype The computed type of the tree * @param ownkind The computed kind of the tree * @param pkind The expected kind (or: protokind) of the tree * @param pt The expected type (or: prototype) of the tree */ Type check(JCTree tree, Type owntype, int ownkind, int pkind, Type pt) { if (owntype.tag != ERROR && pt.tag != METHOD && pt.tag != FORALL) { if ((ownkind & ~pkind) == 0) { owntype = chk.checkType(tree.pos(), owntype, pt); } else { log.error(tree.pos(), "unexpected.type", kindNames(pkind), kindName(ownkind)); owntype = types.createErrorType(owntype); } } tree.type = owntype; return owntype; } Type checkReturn(JCTree tree, Type owntype, int ownkind, int pkind, Type pt) { if (owntype.tag != ERROR && pt.tag != METHOD && pt.tag != FORALL) { if ((ownkind & ~pkind) == 0) { owntype = chk.checkReturnType(tree.pos(), owntype, pt); } else { log.error(tree.pos(), "unexpected.type", kindNames(pkind), kindName(ownkind)); owntype = types.createErrorType(owntype); } } 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 varaible * @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.flags() & FINAL) != 0 && ((v.flags() & HASINIT) != 0 || !((base == null || (base.getTag() == JCTree.IDENT && TreeInfo.name(base) == names._this)) && isAssignableAsBlankFinal(v, env)))) { 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.getTag() == JCTree.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 tree.accept(identAttributer, localEnv); } // where private TreeVisitor> identAttributer = new IdentAttributer(); private class IdentAttributer extends SimpleTreeVisitor> { @Override public Symbol visitMemberSelect(MemberSelectTree node, Env env) { Symbol site = visit(node.getExpression(), env); if (site.kind == ERR) return site; Name name = (Name)node.getIdentifier(); if (site.kind == PCK) { env.toplevel.packge = (PackageSymbol)site; return rs.findIdentInPackage(env, (TypeSymbol)site, name, TYP | PCK); } else { env.enclClass.sym = (ClassSymbol)site; return rs.findMemberType(env, site.asType(), name, (TypeSymbol)site); } } @Override public Symbol visitIdentifier(IdentifierTree node, Env env) { return rs.findIdent(env, (Name)node.getName(), TYP | PCK); } } public Type coerce(Type etype, Type ttype) { return cfolder.coerce(etype, ttype); } public Type attribType(JCTree node, TypeSymbol sym) { Env env = enter.typeEnvs.get(sym); Env localEnv = env.dup(node, env.info.dup()); return attribTree(node, localEnv, Kinds.TYP, 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; } 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; } 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; } } /* ************************************************************************ * Visitor methods *************************************************************************/ /** Visitor argument: the current environment. */ Env env; /** Visitor argument: the currently expected proto-kind. */ int pkind; /** Visitor argument: the currently expected proto-type. */ Type pt; /** 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 pkind The protokind visitor argument. * @param pt The prototype visitor argument. */ Type attribTree(JCTree tree, Env env, int pkind, Type pt) { Env prevEnv = this.env; int prevPkind = this.pkind; Type prevPt = this.pt; try { this.env = env; this.pkind = pkind; this.pt = pt; tree.accept(this); if (tree == breakTree) throw new BreakAttr(env); return result; } catch (CompletionFailure ex) { tree.type = syms.errType; return chk.completionError(tree.pos(), ex); } finally { this.env = prevEnv; this.pkind = prevPkind; this.pt = prevPt; } } /** Derived visitor method: attribute an expression tree. */ public Type attribExpr(JCTree tree, Env env, Type pt) { return attribTree(tree, env, VAL, pt.tag != ERROR ? pt : Type.noType); } /** Derived visitor method: attribute an expression tree with * no constraints on the computed type. */ Type attribExpr(JCTree tree, Env env) { return attribTree(tree, env, VAL, Type.noType); } /** Derived visitor method: attribute a type tree. */ 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, TYP, pt); return result; } /** Derived visitor method: attribute a statement or definition tree. */ public Type attribStat(JCTree tree, Env env) { return attribTree(tree, env, NIL, Type.noType); } /** 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 a list of types. */ List attribArgs(List trees, Env env) { ListBuffer argtypes = new ListBuffer(); for (List l = trees; l.nonEmpty(); l = l.tail) argtypes.append(chk.checkNonVoid( l.head.pos(), types.upperBound(attribTree(l.head, env, VAL, Infer.anyPoly)))); return argtypes.toList(); } /** 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); attribStats(typarams, env); } void attribBounds(List typarams) { for (JCTypeParameter typaram : typarams) { Type bound = typaram.type.getUpperBound(); if (bound != null && bound.tsym instanceof ClassSymbol) { ClassSymbol c = (ClassSymbol)bound.tsym; if ((c.flags_field & COMPOUND) != 0) { assert (c.flags_field & UNATTRIBUTED) != 0 : c; attribClass(typaram.pos(), c); } } } } /** * 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 type reference in an `extends' or `implements' clause. * * @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 = 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) { if (t.tag == TYPEVAR && !classExpected && !interfaceExpected) { // check that type variable is already visible if (t.getUpperBound() == null) { log.error(tree.pos(), "illegal.forward.ref"); return types.createErrorType(t); } } else { t = chk.checkClassType(tree.pos(), t, checkExtensible|!allowGenerics); } if (interfaceExpected && (t.tsym.flags() & INTERFACE) == 0) { log.error(tree.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(tree.pos(), "no.intf.expected.here"); return types.createErrorType(t); } if (checkExtensible && ((t.tsym.flags() & FINAL) != 0)) { log.error(tree.pos(), "cant.inherit.from.final", t.tsym); } chk.checkNonCyclic(tree.pos(), t); return t; } public void visitClassDef(JCClassDecl tree) { // Local classes have not been entered yet, so we need to do it now: if ((env.info.scope.owner.kind & (VAR | MTH)) != 0) 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.getTag() == JCTree.NEWCLASS && ((JCNewClass) env.tree).encl == null) { c.flags_field |= NOOUTERTHIS; } attribClass(tree.pos(), c); result = tree.type = c.type; } } public void visitMethodDef(JCMethodDecl tree) { MethodSymbol m = tree.sym; Lint lint = env.info.lint.augment(m.attributes_field, m.flags()); Lint prevLint = chk.setLint(lint); try { chk.checkDeprecatedAnnotation(tree.pos(), m); attribBounds(tree.typarams); // If we override any other methods, check that we do so properly. // JLS ??? chk.checkOverride(tree, m); // Create a new environment with local scope // for attributing the method. Env localEnv = memberEnter.methodEnv(tree, env); localEnv.info.lint = lint; // 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); } // Check that type parameters are well-formed. chk.validate(tree.typarams, localEnv); if ((owner.flags() & ANNOTATION) != 0 && tree.typarams.nonEmpty()) log.error(tree.typarams.head.pos(), "intf.annotation.members.cant.have.type.params"); // Check that result type is well-formed. chk.validate(tree.restype, localEnv); if ((owner.flags() & ANNOTATION) != 0) chk.validateAnnotationType(tree.restype); if ((owner.flags() & ANNOTATION) != 0) chk.validateAnnotationMethod(tree.pos(), m); // Check that all exceptions mentioned in the throws clause extend // java.lang.Throwable. if ((owner.flags() & ANNOTATION) != 0 && tree.thrown.nonEmpty()) log.error(tree.thrown.head.pos(), "throws.not.allowed.in.intf.annotation"); 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 ((owner.flags() & INTERFACE) == 0 && (tree.mods.flags & (ABSTRACT | NATIVE)) == 0 && !relax) log.error(tree.pos(), "missing.meth.body.or.decl.abstract"); if (tree.defaultValue != null) { if ((owner.flags() & ANNOTATION) == 0) log.error(tree.pos(), "default.allowed.in.intf.annotation.member"); } } else if ((owner.flags() & INTERFACE) != 0) { log.error(tree.body.pos(), "intf.meth.cant.have.body"); } else if ((tree.mods.flags & ABSTRACT) != 0) { 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(memberEnter.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 method body. attribStat(tree.body, localEnv); } localEnv.info.scope.leave(); result = tree.type = m.type; chk.validateAnnotations(tree.mods.annotations, m); } finally { chk.setLint(prevLint); } } 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 { memberEnter.memberEnter(tree, env); annotate.flush(); } } VarSymbol v = tree.sym; Lint lint = env.info.lint.augment(v.attributes_field, v.flags()); Lint prevLint = chk.setLint(lint); // Check that the variable's declared type is well-formed. chk.validate(tree.vartype, env); try { chk.checkDeprecatedAnnotation(tree.pos(), v); if (tree.init != null) { if ((v.flags_field & FINAL) != 0 && tree.init.getTag() != JCTree.NEWCLASS) { // In this case, `v' is final. Ensure that it's initializer is // evaluated. v.getConstValue(); // ensure initializer is evaluated } else { // 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; chk.validateAnnotations(tree.mods.annotations, v); } 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. Env localEnv = env.dup(tree, env.info.dup(env.info.scope.dupUnshared())); localEnv.info.scope.owner = new MethodSymbol(tree.flags | BLOCK, names.empty, null, env.info.scope.owner); if ((tree.flags & STATIC) != 0) localEnv.info.staticLevel++; attribStats(tree.stats, localEnv); } else { // Create a new local environment with a local scope. Env localEnv = env.dup(tree, env.info.dup(env.info.scope.dup())); attribStats(tree.stats, localEnv); 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())); 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); loopEnv.info.scope.leave(); result = null; } public void visitForeachLoop(JCEnhancedForLoop tree) { Env loopEnv = env.dup(env.tree, env.info.dup(env.info.scope.dup())); attribStat(tree.var, loopEnv); Type exprType = types.upperBound(attribExpr(tree.expr, loopEnv)); chk.checkNonVoid(tree.pos(), exprType); Type elemtype = types.elemtype(exprType); // perhaps expr is an array? if (elemtype == null) { // or perhaps expr implements Iterable? Type base = types.asSuper(exprType, syms.iterableType.tsym); if (base == null) { log.error(tree.expr.pos(), "foreach.not.applicable.to.type"); elemtype = types.createErrorType(exprType); } else { List iterableParams = base.allparams(); elemtype = iterableParams.isEmpty() ? syms.objectType : types.upperBound(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); loopEnv.info.scope.leave(); result = null; } public void visitLabelled(JCLabeledStatement tree) { // Check that label is not used in an enclosing statement Env env1 = env; while (env1 != null && env1.tree.getTag() != JCTree.CLASSDEF) { if (env1.tree.getTag() == JCTree.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())); boolean enumSwitch = allowEnums && (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; Env caseEnv = switchEnv.dup(c, env.info.dup(switchEnv.info.scope.dup())); if (c.pat != null) { if (enumSwitch) { Symbol sym = enumConstant(c.pat, seltype); if (sym == null) { log.error(c.pat.pos(), "enum.const.req"); } else if (!labels.add(sym)) { log.error(c.pos(), "duplicate.case.label"); } } else { Type pattype = attribExpr(c.pat, switchEnv, seltype); if (pattype.tag != ERROR) { if (pattype.constValue() == null) { log.error(c.pat.pos(), (stringSwitch ? "string.const.req" : "const.expr.req")); } else if (labels.contains(pattype.constValue())) { log.error(c.pos(), "duplicate.case.label"); } else { labels.add(pattype.constValue()); } } } } else if (hasDefault) { log.error(c.pos(), "duplicate.default.label"); } else { hasDefault = true; } attribStats(c.stats, caseEnv); caseEnv.info.scope.leave(); addVars(c.stats, switchEnv.info.scope); } switchEnv.info.scope.leave(); result = null; } // where /** Add any variables defined in stats to the switch scope. */ private static void addVars(List stats, Scope switchScope) { for (;stats.nonEmpty(); stats = stats.tail) { JCTree stat = stats.head; if (stat.getTag() == JCTree.VARDEF) switchScope.enter(((JCVariableDecl) stat).sym); } } // where /** Return the selected enumeration constant symbol, or null. */ private Symbol enumConstant(JCTree tree, Type enumType) { if (tree.getTag() != JCTree.IDENT) { log.error(tree.pos(), "enum.label.must.be.unqualified.enum"); return syms.errSymbol; } JCIdent ident = (JCIdent)tree; Name name = ident.name; for (Scope.Entry e = enumType.tsym.members().lookup(name); e.scope != null; e = e.next()) { if (e.sym.kind == VAR) { Symbol s = ident.sym = e.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) { // Attribute body attribStat(tree.body, env.dup(tree, env.info.dup())); // Attribute catch clauses for (List l = tree.catchers; l.nonEmpty(); l = l.tail) { JCCatch c = l.head; Env catchEnv = env.dup(c, env.info.dup(env.info.scope.dup())); Type ctype = attribStat(c.param, catchEnv); if (c.param.type.tsym.kind == Kinds.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); catchEnv.info.scope.leave(); } // Attribute finalizer if (tree.finalizer != null) attribStat(tree.finalizer, env); result = null; } public void visitConditional(JCConditional tree) { attribExpr(tree.cond, env, syms.booleanType); attribExpr(tree.truepart, env); attribExpr(tree.falsepart, env); result = check(tree, capture(condType(tree.pos(), tree.cond.type, tree.truepart.type, tree.falsepart.type)), VAL, pkind, pt); } //where /** Compute the type of a conditional expression, after * checking that it exists. See Spec 15.25. * * @param pos The source position to be used for * error diagnostics. * @param condtype The type of the expression's condition. * @param thentype The type of the expression's then-part. * @param elsetype The type of the expression's else-part. */ private Type condType(DiagnosticPosition pos, Type condtype, Type thentype, Type elsetype) { Type ctype = condType1(pos, condtype, thentype, elsetype); // If condition and both arms are numeric constants, // evaluate at compile-time. return ((condtype.constValue() != null) && (thentype.constValue() != null) && (elsetype.constValue() != null)) ? cfolder.coerce(condtype.isTrue()?thentype:elsetype, ctype) : ctype; } /** Compute the type of a conditional expression, after * checking that it exists. 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 condtype The type of the expression's condition. * @param thentype The type of the expression's then-part. * @param elsetype The type of the expression's else-part. */ private Type condType1(DiagnosticPosition pos, Type condtype, Type thentype, Type elsetype) { // If same type, that is the result if (types.isSameType(thentype, elsetype)) return thentype.baseType(); Type thenUnboxed = (!allowBoxing || thentype.isPrimitive()) ? thentype : types.unboxedType(thentype); Type elseUnboxed = (!allowBoxing || 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.tag < INT && elseUnboxed.tag == INT && types.isAssignable(elseUnboxed, thenUnboxed)) return thenUnboxed.baseType(); if (elseUnboxed.tag < INT && thenUnboxed.tag == INT && types.isAssignable(thenUnboxed, elseUnboxed)) return elseUnboxed.baseType(); for (int i = BYTE; i < VOID; i++) { Type candidate = syms.typeOfTag[i]; if (types.isSubtype(thenUnboxed, candidate) && types.isSubtype(elseUnboxed, candidate)) return candidate; } } // Those were all the cases that could result in a primitive if (allowBoxing) { 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 (!allowBoxing || thentype.tag == VOID || elsetype.tag == 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()); } 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) { attribExpr(tree.expr, env); 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, int 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 JCTree.LABELLED: JCLabeledStatement labelled = (JCLabeledStatement)env1.tree; if (label == labelled.label) { // If jump is a continue, check that target is a loop. if (tag == JCTree.CONTINUE) { if (labelled.body.getTag() != JCTree.DOLOOP && labelled.body.getTag() != JCTree.WHILELOOP && labelled.body.getTag() != JCTree.FORLOOP && labelled.body.getTag() != JCTree.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 JCTree.DOLOOP: case JCTree.WHILELOOP: case JCTree.FORLOOP: case JCTree.FOREACHLOOP: if (label == null) return env1.tree; break; case JCTree.SWITCH: if (label == null && tag == JCTree.BREAK) return env1.tree; break; case JCTree.METHODDEF: case JCTree.CLASSDEF: break LOOP; default: } env1 = env1.next; } if (label != null) log.error(pos, "undef.label", label); else if (tag == JCTree.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.enclMethod == null || env.enclMethod.sym.owner != env.enclClass.sym) { 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. Symbol m = env.enclMethod.sym; if (m.type.getReturnType().tag == VOID) { if (tree.expr != null) log.error(tree.expr.pos(), "cant.ret.val.from.meth.decl.void"); } else if (tree.expr == null) { log.error(tree.pos(), "missing.ret.val"); } else { attribExpr(tree.expr, env, m.type.getReturnType()); } } result = null; } public void visitThrow(JCThrow tree) { attribExpr(tree.expr, env, 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; boolean typeargtypesNonRefOK = false; Name methName = TreeInfo.name(tree.meth); boolean isConstructorCall = methName == names._this || methName == names._super; 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. argtypes = attribArgs(tree.args, localEnv); 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.tag == CLASS) { Type encl = site.getEnclosingType(); while (encl != null && encl.tag == TYPEVAR) encl = encl.getUpperBound(); if (encl.tag == CLASS) { // we are calling a nested class if (tree.meth.getTag() == JCTree.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); } } else if (tree.meth.getTag() == JCTree.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 && allowEnums) 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.varArgs = false; 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 = newMethTemplate(argtypes, typeargtypes); checkId(tree.meth, site, sym, localEnv, MTH, mpt, tree.varargsElement != null); } // 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, ... argtypes = attribArgs(tree.args, localEnv); 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 = newMethTemplate(argtypes, typeargtypes); localEnv.info.varArgs = false; Type mtype = attribExpr(tree.meth, localEnv, mpt); if (localEnv.info.varArgs) assert mtype.isErroneous() || tree.varargsElement != null; // Compute the result type. Type restype = mtype.getReturnType(); assert restype.tag != WILDCARD : mtype; // as a special case, array.clone() has a result that is // the same as static type of the array being cloned if (tree.meth.getTag() == JCTree.SELECT && allowCovariantReturns && methName == names.clone && types.isArray(((JCFieldAccess) tree.meth).selected.type)) restype = ((JCFieldAccess) tree.meth).selected.type; // as a special case, x.getClass() has type Class if (allowGenerics && methName == names.getClass && tree.args.isEmpty()) { Type qualifier = (tree.meth.getTag() == JCTree.SELECT) ? ((JCFieldAccess) tree.meth).selected.type : env.enclClass.sym.type; restype = new ClassType(restype.getEnclosingType(), List.of(new WildcardType(types.erasure(qualifier), BoundKind.EXTENDS, syms.boundClass)), restype.tsym); } // as a special case, MethodHandle.invoke(abc) and InvokeDynamic.foo(abc) // has type , and T can be a primitive type. if (tree.meth.getTag() == JCTree.SELECT && !typeargtypes.isEmpty()) { Type selt = ((JCFieldAccess) tree.meth).selected.type; if ((selt == syms.methodHandleType && methName == names.invoke) || selt == syms.invokeDynamicType) { assert types.isSameType(restype, typeargtypes.head) : mtype; typeargtypesNonRefOK = true; } } if (!typeargtypesNonRefOK) { chk.checkRefTypes(tree.typeargs, typeargtypes); } // Check that value of resulting type is admissible in the // current context. Also, capture the return type result = checkReturn(tree, capture(restype), VAL, pkind, pt); } chk.validate(tree.typeargs, localEnv); } //where /** 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.getTag() == JCTree.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 newMethTemplate(List argtypes, List typeargtypes) { MethodType mt = new MethodType(argtypes, null, null, syms.methodClass); return (typeargtypes == null) ? mt : (Type)new ForAll(typeargtypes, mt); } public void visitNewClass(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 (clazz.getTag() == JCTree.TYPEAPPLY) ? ((JCTypeApply) clazz).clazz : 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)); clazzid1 = make.at(clazz.pos).Select(make.Type(encltype), ((JCIdent) clazzid).name); if (clazz.getTag() == JCTree.TYPEAPPLY) clazz = make.at(tree.pos). TypeApply(clazzid1, ((JCTypeApply) clazz).arguments); else clazz = clazzid1; // System.out.println(clazz + " generated.");//DEBUG } // Attribute clazz expression and store // symbol + type back into the attributed tree. Type clazztype = attribType(clazz, env); chk.validate(clazz, localEnv); clazztype = chk.checkNewClassType(clazz.pos(), clazztype, true, pt); 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 (!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().tag == CLASS) { // Check for the existence of an apropos outer instance rs.resolveImplicitThis(tree.pos(), env, clazztype); } // Attribute constructor arguments. List argtypes = attribArgs(tree.args, localEnv); List typeargtypes = attribTypes(tree.typeargs, localEnv); // If we have made no mistakes in the class type... if (clazztype.tag == CLASS) { // Enums may not be instantiated except implicitly if (allowEnums && (clazztype.tsym.flags_field&Flags.ENUM) != 0 && (env.tree.getTag() != JCTree.VARDEF || (((JCVariableDecl) env.tree).mods.flags&Flags.ENUM) == 0 || ((JCVariableDecl) env.tree).init != tree)) log.error(tree.pos(), "enum.cant.be.instantiated"); // Check that class is not abstract if (cdef == null && (clazztype.tsym.flags() & (ABSTRACT | INTERFACE)) != 0) { log.error(tree.pos(), "abstract.cant.be.instantiated", clazztype.tsym); } 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(); } // Resolve the called constructor under the assumption // that we are referring to a superclass instance of the // current instance (JLS ???). else { localEnv.info.selectSuper = cdef != null; localEnv.info.varArgs = false; tree.constructor = rs.resolveConstructor( tree.pos(), localEnv, clazztype, argtypes, typeargtypes); tree.constructorType = checkMethod(clazztype, tree.constructor, localEnv, tree.args, argtypes, typeargtypes, localEnv.info.varArgs); if (localEnv.info.varArgs) assert tree.constructorType.isErroneous() || tree.varargsElement != null; } if (cdef != null) { // 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 a STATIC flag to the class definition // if the current environment is static // (2) add an extends or implements clause // (3) 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) // } // ... // } if (Resolve.isStatic(env)) cdef.mods.flags |= STATIC; clazz = TreeInfo.isDiamond(tree) ? make.Type(clazztype) : clazz; if (clazztype.tsym.isInterface()) { cdef.implementing = List.of(clazz); } else { cdef.extending = clazz; } attribStat(cdef, localEnv); // 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)); argtypes = argtypes.prepend(tree.encl.type); tree.encl = null; } // Reassign clazztype and recompute constructor. clazztype = cdef.sym.type; Symbol sym = rs.resolveConstructor( tree.pos(), localEnv, clazztype, argtypes, typeargtypes, true, tree.varargsElement != null); assert sym.kind < AMBIGUOUS || tree.constructor.type.isErroneous(); tree.constructor = sym; if (tree.constructor.kind > ERRONEOUS) { tree.constructorType = syms.errType; } else { tree.constructorType = checkMethod(clazztype, tree.constructor, localEnv, tree.args, argtypes, typeargtypes, localEnv.info.varArgs); } } if (tree.constructor != null && tree.constructor.kind == MTH) owntype = clazztype; } result = check(tree, owntype, VAL, pkind, pt); chk.validate(tree.typeargs, localEnv); } /** 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; int optag = JCTree.NULLCHK; JCUnary tree = make.at(arg.pos).Unary(optag, arg); tree.operator = syms.nullcheck; tree.type = arg.type; return tree; } public void visitNewArray(JCNewArray tree) { Type owntype = types.createErrorType(tree.type); Type elemtype; if (tree.elemtype != null) { elemtype = attribType(tree.elemtype, env); chk.validate(tree.elemtype, env); owntype = elemtype; for (List l = tree.dims; l.nonEmpty(); l = l.tail) { attribExpr(l.head, env, 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.tag == ARRAY) { elemtype = types.elemtype(pt); } else { if (pt.tag != ERROR) { log.error(tree.pos(), "illegal.initializer.for.type", pt); } elemtype = types.createErrorType(pt); } } if (tree.elems != null) { attribExprs(tree.elems, env, elemtype); owntype = new ArrayType(elemtype, syms.arrayClass); } if (!types.isReifiable(elemtype)) log.error(tree.pos(), "generic.array.creation"); result = check(tree, owntype, VAL, pkind, pt); } public void visitParens(JCParens tree) { Type owntype = attribTree(tree.expr, env, pkind, pt); result = check(tree, owntype, pkind, pkind, pt); Symbol sym = TreeInfo.symbol(tree); if (sym != null && (sym.kind&(TYP|PCK)) != 0) log.error(tree.pos(), "illegal.start.of.type"); } public void visitAssign(JCAssign tree) { Type owntype = attribTree(tree.lhs, env.dup(tree), VAR, Type.noType); Type capturedType = capture(owntype); attribExpr(tree.rhs, env, owntype); result = check(tree, capturedType, VAL, pkind, pt); } public void visitAssignop(JCAssignOp tree) { // Attribute arguments. Type owntype = attribTree(tree.lhs, env, VAR, Type.noType); Type operand = attribExpr(tree.rhs, env); // Find operator. Symbol operator = tree.operator = rs.resolveBinaryOperator( tree.pos(), tree.getTag() - JCTree.ASGOffset, env, owntype, operand); if (operator.kind == MTH) { chk.checkOperator(tree.pos(), (OperatorSymbol)operator, tree.getTag() - JCTree.ASGOffset, owntype, operand); chk.checkDivZero(tree.rhs.pos(), operator, operand); chk.checkCastable(tree.rhs.pos(), operator.type.getReturnType(), owntype); } result = check(tree, owntype, VAL, pkind, pt); } public void visitUnary(JCUnary tree) { // Attribute arguments. Type argtype = (JCTree.PREINC <= tree.getTag() && tree.getTag() <= JCTree.POSTDEC) ? attribTree(tree.arg, env, VAR, Type.noType) : chk.checkNonVoid(tree.arg.pos(), attribExpr(tree.arg, env)); // Find operator. Symbol operator = tree.operator = rs.resolveUnaryOperator(tree.pos(), tree.getTag(), env, argtype); Type owntype = types.createErrorType(tree.type); if (operator.kind == MTH) { owntype = (JCTree.PREINC <= tree.getTag() && tree.getTag() <= JCTree.POSTDEC) ? 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); // Remove constant types from arguments to // conserve space. The parser will fold concatenations // of string literals; the code here also // gets rid of intermediate results when some of the // operands are constant identifiers. if (tree.arg.type.tsym == syms.stringType.tsym) { tree.arg.type = syms.stringType; } } } } result = check(tree, owntype, VAL, pkind, pt); } public void visitBinary(JCBinary tree) { // Attribute arguments. Type left = chk.checkNonVoid(tree.lhs.pos(), attribExpr(tree.lhs, env)); Type right = chk.checkNonVoid(tree.lhs.pos(), attribExpr(tree.rhs, env)); // Find operator. Symbol operator = tree.operator = rs.resolveBinaryOperator(tree.pos(), tree.getTag(), env, left, right); Type owntype = types.createErrorType(tree.type); if (operator.kind == MTH) { owntype = operator.type.getReturnType(); int opc = chk.checkOperator(tree.lhs.pos(), (OperatorSymbol)operator, tree.getTag(), left, right); // 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); // Remove constant types from arguments to // conserve space. The parser will fold concatenations // of string literals; the code here also // gets rid of intermediate results when some of the // operands are constant identifiers. if (tree.lhs.type.tsym == syms.stringType.tsym) { tree.lhs.type = syms.stringType; } if (tree.rhs.type.tsym == syms.stringType.tsym) { tree.rhs.type = syms.stringType; } } } // Check that argument types of a reference ==, != are // castable to each other, (JLS???). 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, VAL, pkind, pt); } public void visitTypeCast(JCTypeCast tree) { Type clazztype = attribType(tree.clazz, env); chk.validate(tree.clazz, env); Type exprtype = attribExpr(tree.expr, env, Infer.anyPoly); Type owntype = chk.checkCastable(tree.expr.pos(), exprtype, clazztype); if (exprtype.constValue() != null) owntype = cfolder.coerce(exprtype, owntype); result = check(tree, capture(owntype), VAL, pkind, pt); } public void visitTypeTest(JCInstanceOf tree) { Type exprtype = chk.checkNullOrRefType( tree.expr.pos(), attribExpr(tree.expr, env)); Type clazztype = chk.checkReifiableReferenceType( tree.clazz.pos(), attribType(tree.clazz, env)); chk.validate(tree.clazz, env); chk.checkCastable(tree.expr.pos(), exprtype, clazztype); result = check(tree, syms.booleanType, VAL, pkind, pt); } 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.tag != ERROR) log.error(tree.pos(), "array.req.but.found", atype); if ((pkind & VAR) == 0) owntype = capture(owntype); result = check(tree, owntype, VAR, pkind, pt); } public void visitIdent(JCIdent tree) { Symbol sym; boolean varArgs = false; // Find symbol if (pt.tag == METHOD || pt.tag == 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.varArgs = false; sym = rs.resolveMethod(tree.pos(), env, tree.name, pt.getParameterTypes(), pt.getTypeArguments()); varArgs = env.info.varArgs; } 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 & (VAR | MTH | TYP)) != 0 && 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 = !allowAnonOuterThis; 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 symbol is a local variable accessed from an embedded // inner class check that it is final. if (v.owner.kind == MTH && v.owner != env.info.scope.owner && (v.flags_field & FINAL) == 0) { log.error(tree.pos(), "local.var.accessed.from.icls.needs.final", v); } // If we are expecting a variable (as opposed to a value), check // that the variable is assignable in the current environment. if (pkind == VAR) 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 & (VAR | MTH)) != 0 && 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; } result = checkId(tree, env1.enclClass.sym.type, sym, env, pkind, pt, varArgs); } public void visitSelect(JCFieldAccess tree) { // Determine the expected kind of the qualifier expression. int skind = 0; if (tree.name == names._this || tree.name == names._super || tree.name == names._class) { skind = TYP; } else { if ((pkind & PCK) != 0) skind = skind | PCK; if ((pkind & TYP) != 0) skind = skind | TYP | PCK; if ((pkind & (VAL | MTH)) != 0) skind = skind | VAL | TYP; } // Attribute the qualifier expression, and determine its symbol (if any). Type site = attribTree(tree.selected, env, skind, Infer.anyPoly); if ((pkind & (PCK | TYP)) == 0) site = capture(site); // Capture field access // don't allow T.class T[].class, etc if (skind == TYP) { Type elt = site; while (elt.tag == ARRAY) elt = ((ArrayType)elt).elemtype; if (elt.tag == TYPEVAR) { log.error(tree.pos(), "type.var.cant.be.deref"); result = types.createErrorType(tree.type); 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; // If selected expression is polymorphic, strip // type parameters and remember in env.info.tvars, so that // they can be added later (in Attr.checkId and Infer.instantiateMethod). if (tree.selected.type.tag == FORALL) { ForAll pstype = (ForAll)tree.selected.type; env.info.tvars = pstype.tvars; site = tree.selected.type = pstype.qtype; } // Determine the symbol represented by the selection. env.info.varArgs = false; Symbol sym = selectSym(tree, site, env, pt, pkind); if (sym.exists() && !isType(sym) && (pkind & (PCK | TYP)) != 0) { site = capture(site); sym = selectSym(tree, site, env, pt, pkind); } boolean varArgs = env.info.varArgs; tree.sym = sym; if (site.tag == TYPEVAR && !isType(sym) && sym.kind != ERR) { while (site.tag == TYPEVAR) site = site.getUpperBound(); site = capture(site); } // 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 (pkind == VAR) checkAssignable(tree.pos(), v, tree.selected, env); } // Disallow selecting a type from an expression if (isType(sym) && (sitesym==null || (sitesym.kind&(TYP|PCK)) == 0)) { tree.type = check(tree.selected, pt, sitesym == null ? VAL : sitesym.kind, 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.access(rs.new StaticError(sym), tree.pos(), site, sym.name, true); } } } // 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; } } env.info.selectSuper = selectSuperPrev; result = checkId(tree, site, sym, env, pkind, pt, varArgs); env.info.tvars = List.nil(); } //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 pt The current prototype. * @param pkind The expected kind(s) of the Select expression. */ private Symbol selectSym(JCFieldAccess tree, Type site, Env env, Type pt, int pkind) { DiagnosticPosition pos = tree.pos(); Name name = tree.name; switch (site.tag) { case PACKAGE: return rs.access( rs.findIdentInPackage(env, site.tsym, name, pkind), pos, site, name, true); case ARRAY: case CLASS: if (pt.tag == METHOD || pt.tag == FORALL) { return rs.resolveQualifiedMethod( pos, env, site, name, pt.getParameterTypes(), 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 = allowGenerics ? List.of(types.erasure(site)) : List.nil(); 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, pkind); if ((pkind & ERRONEOUS) == 0) sym = rs.access(sym, pos, 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* be // 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, capture(site.getUpperBound()), env, pt, pkind) : 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.access(sym2, pos, 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 pkind The set of expected kinds. * @param pt The expected type. */ Type checkId(JCTree tree, Type site, Symbol sym, Env env, int pkind, Type pt, boolean useVarargs) { 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.tag == CLASS) { 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.tag == CLASS && site != ownOuter) { Type normOuter = site; if (normOuter.tag == 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); } } 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 (allowGenerics && pkind == VAR && v.owner.kind == TYP && (v.flags() & STATIC) == 0 && (site.tag == CLASS || site.tag == 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 (env.info.tvars.nonEmpty()) { Type owntype1 = new ForAll(env.info.tvars, owntype); for (List l = env.info.tvars; l.nonEmpty(); l = l.tail) if (!owntype.contains(l.head)) { log.error(tree.pos(), "undetermined.type", owntype1); owntype1 = types.createErrorType(owntype1); } owntype = owntype1; } // If the variable is a constant, record constant value in // computed type. if (v.getConstValue() != null && isStaticReference(tree)) owntype = owntype.constType(v.getConstValue()); if (pkind == VAL) { owntype = capture(owntype); // capture "names as expressions" } break; case MTH: { JCMethodInvocation app = (JCMethodInvocation)env.tree; owntype = checkMethod(site, sym, env, app.args, pt.getParameterTypes(), pt.getTypeArguments(), env.info.varArgs); break; } case PCK: case ERR: owntype = sym.type; break; default: throw new AssertionError("unexpected kind: " + sym.kind + " in tree " + tree); } // Test (1): emit a `deprecation' warning if symbol is deprecated. // (for constructors, the error was given when the constructor was // resolved) if (sym.name != names.init && (sym.flags() & DEPRECATED) != 0 && (env.info.scope.owner.flags() & DEPRECATED) == 0 && sym.outermostClass() != env.info.scope.owner.outermostClass()) chk.warnDeprecated(tree.pos(), sym); if ((sym.flags() & PROPRIETARY) != 0) { if (enableSunApiLintControl) chk.warnSunApi(tree.pos(), "sun.proprietary", sym); else log.strictWarning(tree.pos(), "sun.proprietary", sym); } // Test (3): if symbol is a variable, check that its type and // kind are compatible with the prototype and protokind. return check(tree, owntype, sym.kind, pkind, pt); } /** 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) { // System.err.println(v + " " + ((v.flags() & STATIC) != 0) + " " + // tree.pos + " " + v.pos + " " + // Resolve.isStatic(env));//DEBUG // 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. if ((env.info.enclVar == v || v.pos > tree.pos) && v.owner.kind == TYP && canOwnInitializer(env.info.scope.owner) && v.owner == env.info.scope.owner.enclClass() && ((v.flags() & STATIC) != 0) == Resolve.isStatic(env) && (env.tree.getTag() != JCTree.ASSIGN || TreeInfo.skipParens(((JCAssign) env.tree).lhs) != tree)) { String suffix = (env.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); } /** * 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. * @see JLS 3rd Ed. (8.9 Enums) */ private void checkEnumInitializer(JCTree tree, Env env, VarSymbol v) { // JLS 3rd Ed.: // // "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; } /** Can the given symbol be the owner of code which forms part * if class initialization? This is the case if the symbol is * a type or field, or if the symbol is the synthetic method. * owning a block. */ private boolean canOwnInitializer(Symbol sym) { return (sym.kind & (VAR | TYP)) != 0 || (sym.kind == MTH && (sym.flags() & BLOCK) != 0); } Warner noteWarner = new Warner(); /** * Check that method arguments conform to its instantation. **/ public Type checkMethod(Type site, Symbol sym, Env env, final List argtrees, List argtypes, List typeargtypes, boolean useVarargs) { // Test (5): if symbol is an instance method of a raw type, issue // an unchecked warning if its argument types change under erasure. if (allowGenerics && (sym.flags() & STATIC) == 0 && (site.tag == CLASS || site.tag == 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); } } // 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. noteWarner.warned = false; Type owntype = rs.instantiate(env, site, sym, argtypes, typeargtypes, true, useVarargs, noteWarner); boolean warned = noteWarner.warned; // If this fails, something went wrong; we should not have // found the identifier in the first place. if (owntype == null) { if (!pt.isErroneous()) log.error(env.tree.pos(), "internal.error.cant.instantiate", sym, site, Type.toString(pt.getParameterTypes())); owntype = types.createErrorType(site); } else { // System.out.println("call : " + env.tree); // System.out.println("method : " + owntype); // System.out.println("actuals: " + argtypes); List formals = owntype.getParameterTypes(); Type last = useVarargs ? formals.last() : null; if (sym.name==names.init && sym.owner == syms.enumSym) formals = formals.tail.tail; List args = argtrees; while (formals.head != last) { JCTree arg = args.head; Warner warn = chk.convertWarner(arg.pos(), arg.type, formals.head); assertConvertible(arg, arg.type, formals.head, warn); warned |= warn.warned; args = args.tail; formals = formals.tail; } if (useVarargs) { Type varArg = types.elemtype(last); while (args.tail != null) { JCTree arg = args.head; Warner warn = chk.convertWarner(arg.pos(), arg.type, varArg); assertConvertible(arg, arg.type, varArg, warn); warned |= warn.warned; args = args.tail; } } else if ((sym.flags() & VARARGS) != 0 && allowVarargs) { // non-varargs call to varargs method Type varParam = owntype.getParameterTypes().last(); Type lastArg = argtypes.last(); if (types.isSubtypeUnchecked(lastArg, types.elemtype(varParam)) && !types.isSameType(types.erasure(varParam), types.erasure(lastArg))) log.warning(argtrees.last().pos(), "inexact.non-varargs.call", types.elemtype(varParam), varParam); } if (warned && sym.type.tag == FORALL) { chk.warnUnchecked(env.tree.pos(), "unchecked.meth.invocation.applied", kindName(sym), sym.name, rs.methodArguments(sym.type.getParameterTypes()), rs.methodArguments(argtypes), kindName(sym.location()), sym.location()); owntype = new MethodType(owntype.getParameterTypes(), types.erasure(owntype.getReturnType()), owntype.getThrownTypes(), syms.methodClass); } if (useVarargs) { JCTree tree = env.tree; Type argtype = owntype.getParameterTypes().last(); if (!types.isReifiable(argtype)) chk.warnUnchecked(env.tree.pos(), "unchecked.generic.array.creation", argtype); Type elemtype = types.elemtype(argtype); switch (tree.getTag()) { case JCTree.APPLY: ((JCMethodInvocation) tree).varargsElement = elemtype; break; case JCTree.NEWCLASS: ((JCNewClass) tree).varargsElement = elemtype; break; default: throw new AssertionError(""+tree); } } } return owntype; } private void assertConvertible(JCTree tree, Type actual, Type formal, Warner warn) { if (types.isConvertible(actual, formal, warn)) return; if (formal.isCompound() && types.isSubtype(actual, types.supertype(formal)) && types.isSubtypeUnchecked(actual, types.interfaces(formal), warn)) return; if (false) { // TODO: make assertConvertible work chk.typeError(tree.pos(), diags.fragment("incompatible.types"), actual, formal); throw new AssertionError("Tree: " + tree + " actual:" + actual + " formal: " + formal); } } public void visitLiteral(JCLiteral tree) { result = check( tree, litType(tree.typetag).constType(tree.value), VAL, pkind, pt); } //where /** Return the type of a literal with given type tag. */ Type litType(int tag) { return (tag == TypeTags.CLASS) ? syms.stringType : syms.typeOfTag[tag]; } public void visitTypeIdent(JCPrimitiveTypeTree tree) { result = check(tree, syms.typeOfTag[tree.typetag], TYP, pkind, pt); } public void visitTypeArray(JCArrayTypeTree tree) { Type etype = attribType(tree.elemtype, env); Type type = new ArrayType(etype, syms.arrayClass); result = check(tree, type, TYP, pkind, pt); } /** 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.tag == CLASS) { List formals = clazztype.tsym.type.getTypeArguments(); if (actuals.length() == formals.length() || actuals.isEmpty()) { 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.tag == CLASS) { Type site; JCExpression clazz = TreeInfo.typeIn(tree.clazz); if (clazz.getTag() == JCTree.IDENT) { site = env.enclClass.sym.type; } else if (clazz.getTag() == JCTree.SELECT) { site = ((JCFieldAccess) clazz).selected.type; } else throw new AssertionError(""+tree); if (clazzOuter.tag == CLASS && site != clazzOuter) { if (site.tag == CLASS) site = types.asOuterSuper(site, clazzOuter.tsym); if (site == null) site = types.erasure(clazzOuter); clazzOuter = site; } } if (actuals.nonEmpty()) { owntype = new ClassType(clazzOuter, actuals, clazztype.tsym); } else if (TreeInfo.isDiamond(tree)) { //a type apply with no explicit type arguments - diamond operator //the result type is a forall F where F's tvars are the type-variables //that will be inferred when F is checked against the expected type List ftvars = clazztype.tsym.type.getTypeArguments(); List new_tvars = types.newInstances(ftvars); clazztype = new ClassType(clazzOuter, new_tvars, clazztype.tsym); owntype = new ForAll(new_tvars, clazztype); } } 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, TYP, pkind, pt); } public void visitTypeParameter(JCTypeParameter tree) { TypeVar a = (TypeVar)tree.type; Set boundSet = new HashSet(); if (a.bound.isErroneous()) return; List bs = types.getBounds(a); if (tree.bounds.nonEmpty()) { // accept class or interface or typevar as first bound. Type b = checkBase(bs.head, tree.bounds.head, env, false, false, false); boundSet.add(types.erasure(b)); if (b.isErroneous()) { a.bound = b; } else if (b.tag == TYPEVAR) { // if first bound was a typevar, do not accept further bounds. if (tree.bounds.tail.nonEmpty()) { log.error(tree.bounds.tail.head.pos(), "type.var.may.not.be.followed.by.other.bounds"); tree.bounds = List.of(tree.bounds.head); a.bound = bs.head; } } else { // if first bound was a class or interface, accept only interfaces // as further bounds. for (JCExpression bound : tree.bounds.tail) { bs = bs.tail; Type i = checkBase(bs.head, bound, env, false, true, false); if (i.isErroneous()) a.bound = i; else if (i.tag == CLASS) chk.checkNotRepeated(bound.pos(), types.erasure(i), boundSet); } } } bs = types.getBounds(a); // in case of multiple bounds ... if (bs.length() > 1) { // ... 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, ... JCTree extending; List implementing; if ((bs.head.tsym.flags() & INTERFACE) == 0) { extending = tree.bounds.head; implementing = tree.bounds.tail; } else { extending = null; implementing = tree.bounds; } JCClassDecl cd = make.at(tree.pos).ClassDef( make.Modifiers(PUBLIC | ABSTRACT), tree.name, List.nil(), extending, implementing, List.nil()); ClassSymbol c = (ClassSymbol)a.getUpperBound().tsym; assert (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); enter.typeEnvs.put(c, cenv); } } 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), TYP, pkind, pt); } public void visitAnnotation(JCAnnotation tree) { log.error(tree.pos(), "annotation.not.valid.for.type", pt); result = tree.type = syms.errType; } public void visitAnnotatedType(JCAnnotatedType tree) { result = tree.type = attribType(tree.getUnderlyingType(), env); } public void visitErroneous(JCErroneous tree) { if (tree.errs != null) for (JCTree err : tree.errs) attribTree(err, env, ERR, pt); result = tree.type = syms.errType; } /** Default visitor method for all other trees. */ public void visitTree(JCTree tree) { throw new AssertionError(); } /** 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.tag == 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.tag == CLASS) attribClass((ClassSymbol)st.tsym); // Next attribute owner, if it is a class. if (c.owner.kind == TYP && c.owner.type.tag == 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 = enter.typeEnvs.get(c); // The info.lint field in the envs stored in enter.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.attributes_field, c.flags()); Lint prevLint = chk.setLint(env.info.lint); JavaFileObject prev = log.useSource(c.sourcefile); try { // 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) && !target.compilerBootstrap(c)) { log.error(env.tree.pos(), "enum.types.not.extensible"); } attribClassBody(env, c); chk.checkDeprecatedAnnotation(env.tree.pos(), c); } finally { log.useSource(prev); chk.setLint(prevLint); } } } public void visitImport(JCImport tree) { // nothing to do } /** Finish the attribution of a class. */ private void attribClassBody(Env env, ClassSymbol c) { JCClassDecl tree = (JCClassDecl)env.tree; assert c == tree.sym; // Validate annotations chk.validateAnnotations(tree.mods.annotations, c); // Validate type parameters, supertype and interfaces. attribBounds(tree.typarams); chk.validate(tree.typarams, env); chk.validate(tree.extending, env); chk.validate(tree.implementing, env); // 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) { if (!relax) 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"); } 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); } // 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; boolean assertsEnabled = false; assert assertsEnabled = true; if (assertsEnabled) { for (List l = tree.typarams; l.nonEmpty(); l = l.tail) assert env.info.scope.lookup(l.head.name).scope != null; } // 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); 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.getTag() == JCTree.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"); } } // 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(Lint.LintCategory.SERIAL) && isSerializable(c) && (c.flags() & Flags.ENUM) == 0 && (c.flags() & ABSTRACT) == 0) { checkSerialVersionUID(tree, c); } // Check type annotations applicability rules validateTypeAnnotations(tree); } // where /** check if a class is a subtype of Serializable, if that is available. */ private boolean isSerializable(ClassSymbol c) { try { syms.serializableType.complete(); } catch (CompletionFailure e) { return false; } return types.isSubtype(c.type, syms.serializableType); } /** Check that an appropriate serialVersionUID member is defined. */ private void checkSerialVersionUID(JCClassDecl tree, ClassSymbol c) { // check for presence of serialVersionUID Scope.Entry e = c.members().lookup(names.serialVersionUID); while (e.scope != null && e.sym.kind != VAR) e = e.next(); if (e.scope == null) { log.warning(tree.pos(), "missing.SVUID", c); return; } // check that it is static final VarSymbol svuid = (VarSymbol)e.sym; if ((svuid.flags() & (STATIC | FINAL)) != (STATIC | FINAL)) log.warning(TreeInfo.diagnosticPositionFor(svuid, tree), "improper.SVUID", c); // check that it is long else if (svuid.type.tag != TypeTags.LONG) log.warning(TreeInfo.diagnosticPositionFor(svuid, tree), "long.SVUID", c); // check constant else if (svuid.getConstValue() == null) log.warning(TreeInfo.diagnosticPositionFor(svuid, tree), "constant.SVUID", c); } private Type capture(Type type) { return types.capture(type); } private void validateTypeAnnotations(JCTree tree) { tree.accept(typeAnnotationsValidator); } //where private final JCTree.Visitor typeAnnotationsValidator = new TreeScanner() { public void visitAnnotation(JCAnnotation tree) { if (tree instanceof JCTypeAnnotation) { chk.validateTypeAnnotation((JCTypeAnnotation)tree, false); } super.visitAnnotation(tree); } public void visitTypeParameter(JCTypeParameter tree) { chk.validateTypeAnnotations(tree.annotations, true); // don't call super. skip type annotations scan(tree.bounds); } public void visitMethodDef(JCMethodDecl tree) { // need to check static methods if ((tree.sym.flags() & Flags.STATIC) != 0) { for (JCTypeAnnotation a : tree.receiverAnnotations) { if (chk.isTypeAnnotation(a, false)) log.error(a.pos(), "annotation.type.not.applicable"); } } super.visitMethodDef(tree); } }; }