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android / platform / libcore / bd9526ecbe5 / . / langtools / src / share / classes / com / sun / tools / javac / comp / Attr.java
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/*
* Copyright (c) 1999, 2011, 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 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.Lint.LintCategory;
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
*
* <p><b>This is NOT part of any supported API.
* If you write code that depends on this, you do so at your own risk.
* This code and its internal interfaces are subject to change or
* deletion without notice.</b>
*/
public class Attr extends JCTree.Visitor {
protected static final Context.Key<Attr> attrKey =
new Context.Key<Attr>();
final Names names;
final Log log;
final Symtab syms;
final Resolve rs;
final Infer infer;
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;
final DeferredLintHandler deferredLintHandler;
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);
infer = Infer.instance(context);
cfolder = ConstFold.instance(context);
target = Target.instance(context);
types = Types.instance(context);
diags = JCDiagnostic.Factory.instance(context);
annotate = Annotate.instance(context);
deferredLintHandler = DeferredLintHandler.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.isSet("-retrofit") ||
options.isSet("-relax"));
findDiamonds = options.get("findDiamond") != null &&
source.allowDiamond();
useBeforeDeclarationWarning = options.isSet("useBeforeDeclarationWarning");
}
/** 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: generates a warning if diamond can be safely applied
* to a given new expression
*/
boolean findDiamonds;
/**
* Internally enables/disables diamond finder feature
*/
static final boolean allowDiamondFinder = true;
/**
* 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 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, errKey);
} 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<AttrContext> env) {
Symbol owner = env.info.scope.owner;
// owner refers to the innermost variable, method or
// initializer block declaration at this point.
return
v.owner == owner
||
((owner.name == names.init || // i.e. we are in a constructor
owner.kind == VAR || // i.e. we are in a variable initializer
(owner.flags() & BLOCK) != 0) // i.e. we are in an initializer block
&&
v.owner == owner.owner
&&
((v.flags() & STATIC) != 0) == Resolve.isStatic(env));
}
/** Check that variable can be assigned to.
* @param pos The current source code position.
* @param v The assigned 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<AttrContext> env) {
if ((v.flags() & FINAL) != 0 &&
((v.flags() & HASINIT) != 0
||
!((base == null ||
(base.getTag() == JCTree.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);
}
} else if ((v.flags() & EFFECTIVELY_FINAL) != 0) {
v.flags_field &= ~EFFECTIVELY_FINAL;
}
}
/** 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<AttrContext> env) {
return rs.resolveSelf(pos, env, env.enclClass.sym, names._this);
}
/** Attribute a parsed identifier.
* @param tree Parsed identifier name
* @param topLevel The toplevel to use
*/
public Symbol attribIdent(JCTree tree, JCCompilationUnit topLevel) {
Env<AttrContext> localEnv = enter.topLevelEnv(topLevel);
localEnv.enclClass = make.ClassDef(make.Modifiers(0),
syms.errSymbol.name,
null, null, null, null);
localEnv.enclClass.sym = syms.errSymbol;
return tree.accept(identAttributer, localEnv);
}
// where
private TreeVisitor<Symbol,Env<AttrContext>> identAttributer = new IdentAttributer();
private class IdentAttributer extends SimpleTreeVisitor<Symbol,Env<AttrContext>> {
@Override
public Symbol visitMemberSelect(MemberSelectTree node, Env<AttrContext> 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<AttrContext> 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<AttrContext> env = enter.typeEnvs.get(sym);
Env<AttrContext> localEnv = env.dup(node, env.info.dup());
return attribTree(node, localEnv, Kinds.TYP, Type.noType);
}
public Env<AttrContext> attribExprToTree(JCTree expr, Env<AttrContext> 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<AttrContext> attribStatToTree(JCTree stmt, Env<AttrContext> 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<AttrContext> env;
private BreakAttr(Env<AttrContext> env) {
this.env = env;
}
}
/* ************************************************************************
* Visitor methods
*************************************************************************/
/** Visitor argument: the current environment.
*/
Env<AttrContext> env;
/** Visitor argument: the currently expected proto-kind.
*/
int pkind;
/** Visitor argument: the currently expected proto-type.
*/
Type pt;
/** Visitor argument: the error key to be generated when a type error occurs
*/
String errKey;
/** 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<AttrContext> env, int pkind, Type pt) {
return attribTree(tree, env, pkind, pt, "incompatible.types");
}
Type attribTree(JCTree tree, Env<AttrContext> env, int pkind, Type pt, String errKey) {
Env<AttrContext> prevEnv = this.env;
int prevPkind = this.pkind;
Type prevPt = this.pt;
String prevErrKey = this.errKey;
try {
this.env = env;
this.pkind = pkind;
this.pt = pt;
this.errKey = errKey;
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;
this.errKey = prevErrKey;
}
}
/** Derived visitor method: attribute an expression tree.
*/
public Type attribExpr(JCTree tree, Env<AttrContext> env, Type pt) {
return attribTree(tree, env, VAL, pt.tag != ERROR ? pt : Type.noType);
}
public Type attribExpr(JCTree tree, Env<AttrContext> env, Type pt, String key) {
return attribTree(tree, env, VAL, pt.tag != ERROR ? pt : Type.noType, key);
}
/** Derived visitor method: attribute an expression tree with
* no constraints on the computed type.
*/
Type attribExpr(JCTree tree, Env<AttrContext> env) {
return attribTree(tree, env, VAL, Type.noType);
}
/** Derived visitor method: attribute a type tree.
*/
Type attribType(JCTree tree, Env<AttrContext> env) {
Type result = attribType(tree, env, Type.noType);
return result;
}
/** Derived visitor method: attribute a type tree.
*/
Type attribType(JCTree tree, Env<AttrContext> env, Type pt) {
Type result = attribTree(tree, env, TYP, pt);
return result;
}
/** Derived visitor method: attribute a statement or definition tree.
*/
public Type attribStat(JCTree tree, Env<AttrContext> env) {
return attribTree(tree, env, NIL, Type.noType);
}
/** Attribute a list of expressions, returning a list of types.
*/
List<Type> attribExprs(List<JCExpression> trees, Env<AttrContext> env, Type pt) {
ListBuffer<Type> ts = new ListBuffer<Type>();
for (List<JCExpression> l = trees; l.nonEmpty(); l = l.tail)
ts.append(attribExpr(l.head, env, pt));
return ts.toList();
}
/** Attribute a list of statements, returning nothing.
*/
<T extends JCTree> void attribStats(List<T> trees, Env<AttrContext> env) {
for (List<T> l = trees; l.nonEmpty(); l = l.tail)
attribStat(l.head, env);
}
/** Attribute the arguments in a method call, returning a list of types.
*/
List<Type> attribArgs(List<JCExpression> trees, Env<AttrContext> env) {
ListBuffer<Type> argtypes = new ListBuffer<Type>();
for (List<JCExpression> 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<Type> attribAnyTypes(List<JCExpression> trees, Env<AttrContext> env) {
ListBuffer<Type> argtypes = new ListBuffer<Type>();
for (List<JCExpression> l = trees; l.nonEmpty(); l = l.tail)
argtypes.append(attribType(l.head, env));
return argtypes.toList();
}
/** Attribute a type argument list, returning a list of types.
* Check that all the types are references.
*/
List<Type> attribTypes(List<JCExpression> trees, Env<AttrContext> env) {
List<Type> types = attribAnyTypes(trees, env);
return chk.checkRefTypes(trees, types);
}
/**
* Attribute type variables (of generic classes or methods).
* Compound types are attributed later in attribBounds.
* @param typarams the type variables to enter
* @param env the current environment
*/
void attribTypeVariables(List<JCTypeParameter> typarams, Env<AttrContext> env) {
for (JCTypeParameter tvar : typarams) {
TypeVar a = (TypeVar)tvar.type;
a.tsym.flags_field |= UNATTRIBUTED;
a.bound = Type.noType;
if (!tvar.bounds.isEmpty()) {
List<Type> bounds = List.of(attribType(tvar.bounds.head, env));
for (JCExpression bound : tvar.bounds.tail)
bounds = bounds.prepend(attribType(bound, env));
types.setBounds(a, bounds.reverse());
} else {
// if no bounds are given, assume a single bound of
// java.lang.Object.
types.setBounds(a, List.of(syms.objectType));
}
a.tsym.flags_field &= ~UNATTRIBUTED;
}
for (JCTypeParameter tvar : typarams)
chk.checkNonCyclic(tvar.pos(), (TypeVar)tvar.type);
attribStats(typarams, env);
}
void attribBounds(List<JCTypeParameter> 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.check((c.flags_field & UNATTRIBUTED) != 0, c);
attribClass(typaram.pos(), c);
}
}
}
}
/**
* Attribute the type references in a list of annotations.
*/
void attribAnnotationTypes(List<JCAnnotation> annotations,
Env<AttrContext> env) {
for (List<JCAnnotation> al = annotations; al.nonEmpty(); al = al.tail) {
JCAnnotation a = al.head;
attribType(a.annotationType, env);
}
}
/**
* Attribute a "lazy constant value".
* @param env The env for the const value
* @param initializer The initializer for the const value
* @param type The expected type, or null
* @see VarSymbol#setlazyConstValue
*/
public Object attribLazyConstantValue(Env<AttrContext> env,
JCTree.JCExpression initializer,
Type type) {
// in case no lint value has been set up for this env, scan up
// env stack looking for smallest enclosing env for which it is set.
Env<AttrContext> lintEnv = env;
while (lintEnv.info.lint == null)
lintEnv = lintEnv.next;
// Having found the enclosing lint value, we can initialize the lint value for this class
env.info.lint = lintEnv.info.lint.augment(env.info.enclVar.attributes_field, env.info.enclVar.flags());
Lint prevLint = chk.setLint(env.info.lint);
JavaFileObject prevSource = log.useSource(env.toplevel.sourcefile);
try {
Type itype = attribExpr(initializer, env, type);
if (itype.constValue() != null)
return coerce(itype, type).constValue();
else
return null;
} finally {
env.info.lint = prevLint;
log.useSource(prevSource);
}
}
/** Attribute type reference in an `extends' or `implements' clause.
* Supertypes of anonymous inner classes are usually already attributed.
*
* @param tree The tree making up the type reference.
* @param env The environment current at the reference.
* @param classExpected true if only a class is expected here.
* @param interfaceExpected true if only an interface is expected here.
*/
Type attribBase(JCTree tree,
Env<AttrContext> env,
boolean classExpected,
boolean interfaceExpected,
boolean checkExtensible) {
Type t = tree.type != null ?
tree.type :
attribType(tree, env);
return checkBase(t, tree, env, classExpected, interfaceExpected, checkExtensible);
}
Type checkBase(Type t,
JCTree tree,
Env<AttrContext> env,
boolean classExpected,
boolean interfaceExpected,
boolean checkExtensible) {
if (t.isErroneous())
return t;
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);
MethodSymbol prevMethod = chk.setMethod(m);
try {
deferredLintHandler.flush(tree.pos());
chk.checkDeprecatedAnnotation(tree.pos(), m);
attribBounds(tree.typarams);
// 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(tree, m);
// Create a new environment with local scope
// for attributing the method.
Env<AttrContext> localEnv = memberEnter.methodEnv(tree, env);
localEnv.info.lint = lint;
// Enter all type parameters into the local method scope.
for (List<JCTypeParameter> l = tree.typarams; l.nonEmpty(); l = l.tail)
localEnv.info.scope.enterIfAbsent(l.head.type.tsym);
ClassSymbol owner = env.enclClass.sym;
if ((owner.flags() & ANNOTATION) != 0 &&
tree.params.nonEmpty())
log.error(tree.params.head.pos(),
"intf.annotation.members.cant.have.params");
// Attribute all value parameters.
for (List<JCVariableDecl> l = tree.params; l.nonEmpty(); l = l.tail) {
attribStat(l.head, localEnv);
}
chk.checkVarargsMethodDecl(localEnv, tree);
// Check that type parameters are well-formed.
chk.validate(tree.typarams, localEnv);
// Check that result type is well-formed.
chk.validate(tree.restype, localEnv);
// 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);
if (tree.defaultValue != null) {
// if default value is an annotation, check it is a well-formed
// annotation value (e.g. no duplicate values, no missing values, etc.)
chk.validateAnnotationTree(tree.defaultValue);
}
}
for (List<JCExpression> l = tree.thrown; l.nonEmpty(); l = l.tail)
chk.checkType(l.head.pos(), l.head.type, syms.throwableType);
if (tree.body == null) {
// Empty bodies are only allowed for
// abstract, native, or interface methods, or for methods
// in a retrofit signature class.
if ((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.<Type>nil(),
List.<JCVariableDecl>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);
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 {
memberEnter.memberEnter(tree, env);
annotate.flush();
}
tree.sym.flags_field |= EFFECTIVELY_FINAL;
}
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);
deferredLintHandler.flush(tree.pos());
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<AttrContext> initEnv = memberEnter.initEnv(tree, env);
initEnv.info.lint = lint;
// In order to catch self-references, we set the variable's
// declaration position to maximal possible value, effectively
// marking the variable as undefined.
initEnv.info.enclVar = v;
attribExpr(tree.init, initEnv, v.type);
}
}
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<AttrContext> 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<AttrContext> 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<AttrContext> 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<AttrContext> 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<T>?
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<Type> 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<AttrContext> 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<AttrContext> 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<Object> labels = new HashSet<Object>(); // The set of case labels.
boolean hasDefault = false; // Is there a default label?
for (List<JCCase> l = tree.cases; l.nonEmpty(); l = l.tail) {
JCCase c = l.head;
Env<AttrContext> 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.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.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<JCStatement> 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) {
// Create a new local environment with a local
Env<AttrContext> localEnv = env.dup(tree, env.info.dup(env.info.scope.dup()));
boolean isTryWithResource = tree.resources.nonEmpty();
// Create a nested environment for attributing the try block if needed
Env<AttrContext> tryEnv = isTryWithResource ?
env.dup(tree, localEnv.info.dup(localEnv.info.scope.dup())) :
localEnv;
// Attribute resource declarations
for (JCTree resource : tree.resources) {
if (resource.getTag() == JCTree.VARDEF) {
attribStat(resource, tryEnv);
chk.checkType(resource, resource.type, syms.autoCloseableType, "try.not.applicable.to.type");
VarSymbol var = (VarSymbol)TreeInfo.symbolFor(resource);
var.setData(ElementKind.RESOURCE_VARIABLE);
} else {
attribExpr(resource, tryEnv, syms.autoCloseableType, "try.not.applicable.to.type");
}
}
// Attribute body
attribStat(tree.body, tryEnv);
if (isTryWithResource)
tryEnv.info.scope.leave();
// Attribute catch clauses
for (List<JCCatch> l = tree.catchers; l.nonEmpty(); l = l.tail) {
JCCatch c = l.head;
Env<AttrContext> catchEnv =
localEnv.dup(c, localEnv.info.dup(localEnv.info.scope.dup()));
Type ctype = attribStat(c.param, catchEnv);
if (TreeInfo.isMultiCatch(c)) {
//multi-catch parameter is implicitly marked as final
c.param.sym.flags_field |= FINAL | DISJUNCTION;
}
if (c.param.sym.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, localEnv);
localEnv.info.scope.leave();
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) {
//a fresh environment is required for 292 inference to work properly ---
//see Infer.instantiatePolymorphicSignatureInstance()
Env<AttrContext> localEnv = env.dup(tree);
attribExpr(tree.expr, localEnv);
result = null;
}
public void visitBreak(JCBreak tree) {
tree.target = findJumpTarget(tree.pos(), tree.getTag(), tree.label, env);
result = null;
}
public void 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<AttrContext> env) {
// Search environments outwards from the point of jump.
Env<AttrContext> 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<AttrContext> localEnv = env.dup(tree, env.info.dup());
// The types of the actual method arguments.
List<Type> argtypes;
// The types of the actual method type arguments.
List<Type> typeargtypes = null;
Name methName = TreeInfo.name(tree.meth);
boolean isConstructorCall =
methName == names._this || methName == names._super;
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
// <expr>.super(...).
// Check that the prefix expression conforms
// to the outer instance type of the class.
chk.checkRefType(qualifier.pos(),
attribExpr(qualifier, localEnv,
encl));
} else if (methName == names._super) {
// qualifier omitted; check for existence
// of an appropriate implicit qualifier.
rs.resolveImplicitThis(tree.meth.pos(),
localEnv, site, true);
}
} else if (tree.meth.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.check(mtype.isErroneous() || tree.varargsElement != null);
// Compute the result type.
Type restype = mtype.getReturnType();
if (restype.tag == WILDCARD)
throw new AssertionError(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<? extends |X|>
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.<Type>of(new WildcardType(types.erasure(qualifier),
BoundKind.EXTENDS,
syms.boundClass)),
restype.tsym);
}
chk.checkRefTypes(tree.typeargs, typeargtypes);
// Check that value of resulting type is admissible in the
// current context. Also, capture the return type
result = check(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<AttrContext> 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<Type> argtypes, List<Type> 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<AttrContext> localEnv = env.dup(tree, env.info.dup());
// The anonymous inner class definition of the new expression,
// if one is defined by it.
JCClassDecl cdef = tree.def;
// If enclosing class is given, attribute it, and
// complete class name to be fully qualified
JCExpression clazz = tree.clazz; // Class field following new
JCExpression clazzid = // Identifier in class field
(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
// <expr>.new C <...> (...) ...
// In this case, we let clazz stand for the name of the
// allocated class C prefixed with the type of the qualifier
// expression, so that we can
// resolve it with standard techniques later. I.e., if
// <expr> has type T, then <expr>.new C <...> (...)
// yields a clazz T.C.
Type encltype = chk.checkRefType(tree.encl.pos(),
attribExpr(tree.encl, env));
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;
}
// Attribute clazz expression and store
// symbol + type back into the attributed tree.
Type clazztype = attribType(clazz, env);
Pair<Scope,Scope> mapping = getSyntheticScopeMapping(clazztype);
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 (!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<Type> argtypes = attribArgs(tree.args, localEnv);
List<Type> typeargtypes = attribTypes(tree.typeargs, localEnv);
if (TreeInfo.isDiamond(tree) && !clazztype.isErroneous()) {
clazztype = attribDiamond(localEnv, tree, clazztype, mapping, argtypes, typeargtypes);
clazz.type = clazztype;
} else if (allowDiamondFinder &&
tree.def == null &&
!clazztype.isErroneous() &&
clazztype.getTypeArguments().nonEmpty() &&
findDiamonds) {
boolean prevDeferDiags = log.deferDiagnostics;
Queue<JCDiagnostic> prevDeferredDiags = log.deferredDiagnostics;
Type inferred = null;
try {
//disable diamond-related diagnostics
log.deferDiagnostics = true;
log.deferredDiagnostics = ListBuffer.lb();
inferred = attribDiamond(localEnv,
tree,
clazztype,
mapping,
argtypes,
typeargtypes);
}
finally {
log.deferDiagnostics = prevDeferDiags;
log.deferredDiagnostics = prevDeferredDiags;
}
if (inferred != null &&
!inferred.isErroneous() &&
inferred.tag == CLASS &&
types.isAssignable(inferred, pt.tag == NONE ? clazztype : pt, Warner.noWarnings)) {
String key = types.isSameType(clazztype, inferred) ?
"diamond.redundant.args" :
"diamond.redundant.args.1";
log.warning(tree.clazz.pos(), key, clazztype, inferred);
}
}
// 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 = tree.constructor.type.isErroneous() ?
syms.errType :
checkMethod(clazztype,
tree.constructor,
localEnv,
tree.args,
argtypes,
typeargtypes,
localEnv.info.varArgs);
if (localEnv.info.varArgs)
Assert.check(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 <typeargs1>C<typargs2>(args) { ... }
//
// is represented internally as
//
// E . new <typeargs1>C<typargs2>(args) ( class <empty-name> { ... } ) .
//
// This expression is then *transformed* as follows:
//
// (1) add 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 <typeargs1>C<typargs2>(args) { ... }
//
// is translated to (where X is a fresh name and typarams is the
// parameter list of the super constructor):
//
// new <typeargs1>X(<*nullchk*>E, args) where
// X extends C<typargs2> {
// <typarams> X(ET e, args) {
// e.<typeargs1>super(args)
// }
// ...
// }
if (Resolve.isStatic(env)) cdef.mods.flags |= STATIC;
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.check(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);
}
Type attribDiamond(Env<AttrContext> env,
JCNewClass tree,
Type clazztype,
Pair<Scope, Scope> mapping,
List<Type> argtypes,
List<Type> typeargtypes) {
if (clazztype.isErroneous() ||
clazztype.isInterface() ||
mapping == erroneousMapping) {
//if the type of the instance creation expression is erroneous,
//or if it's an interface, or if something prevented us to form a valid
//mapping, return the (possibly erroneous) type unchanged
return clazztype;
}
//dup attribution environment and augment the set of inference variables
Env<AttrContext> localEnv = env.dup(tree);
localEnv.info.tvars = clazztype.tsym.type.getTypeArguments();
//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
((ClassSymbol) clazztype.tsym).members_field = mapping.snd;
Symbol constructor;
try {
constructor = rs.resolveDiamond(tree.pos(),
localEnv,
clazztype.tsym.type,
argtypes,
typeargtypes);
} finally {
((ClassSymbol) clazztype.tsym).members_field = mapping.fst;
}
if (constructor.kind == MTH) {
ClassType ct = new ClassType(clazztype.getEnclosingType(),
clazztype.tsym.type.getTypeArguments(),
clazztype.tsym);
clazztype = checkMethod(ct,
constructor,
localEnv,
tree.args,
argtypes,
typeargtypes,
localEnv.info.varArgs).getReturnType();
} else {
clazztype = syms.errType;
}
if (clazztype.tag == FORALL && !pt.isErroneous()) {
//if the resolved constructor's return type has some uninferred
//type-variables, infer them using the expected type and declared
//bounds (JLS 15.12.2.8).
try {
clazztype = infer.instantiateExpr((ForAll) clazztype,
pt.tag == NONE ? syms.objectType : pt,
Warner.noWarnings);
} catch (Infer.InferenceException ex) {
//an error occurred while inferring uninstantiated type-variables
log.error(tree.clazz.pos(),
"cant.apply.diamond.1",
diags.fragment("diamond", clazztype.tsym),
ex.diagnostic);
}
}
return chk.checkClassType(tree.clazz.pos(),
clazztype,
true);
}
/** Creates a synthetic scope containing fake generic constructors.
* Assuming that the original scope contains a constructor of the kind:
* Foo(X x, Y y), where X,Y are class type-variables declared in Foo,
* the synthetic scope is added a generic constructor of the kind:
* <X,Y>Foo<X,Y>(X x, Y y). This is crucial in order to enable diamond
* inference. The inferred return type of the synthetic constructor IS
* the inferred type for the diamond operator.
*/
private Pair<Scope, Scope> getSyntheticScopeMapping(Type ctype) {
if (ctype.tag != CLASS) {
return erroneousMapping;
}
Pair<Scope, Scope> mapping =
new Pair<Scope, Scope>(ctype.tsym.members(), new Scope(ctype.tsym));
//for each constructor in the original scope, create a synthetic constructor
//whose return type is the type of the class in which the constructor is
//declared, and insert it into the new scope.
for (Scope.Entry e = mapping.fst.lookup(names.init);
e.scope != null;
e = e.next()) {
Type synthRestype = new ClassType(ctype.getEnclosingType(),
ctype.tsym.type.getTypeArguments(),
ctype.tsym);
MethodSymbol synhConstr = new MethodSymbol(e.sym.flags(),
names.init,
types.createMethodTypeWithReturn(e.sym.type, synthRestype),
e.sym.owner);
mapping.snd.enter(synhConstr);
}
return mapping;
}
private final Pair<Scope,Scope> erroneousMapping = new Pair<Scope,Scope>(null, null);
/** 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<JCExpression> 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 &&
!owntype.isErroneous() &&
!operand.isErroneous()) {
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 &&
!argtype.isErroneous()) {
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 &&
!left.isErroneous() &&
!right.isErroneous()) {
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, false);
//a fresh environment is required for 292 inference to work properly ---
//see Infer.instantiatePolymorphicSignatureInstance()
Env<AttrContext> localEnv = env.dup(tree);
Type exprtype = attribExpr(tree.expr, localEnv, 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, false);
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<AttrContext> 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<AttrContext> env1 = env;
if (sym.kind != ERR && sym.kind != TYP && sym.owner != null && sym.owner != env1.enclClass.sym) {
// If the found symbol is inaccessible, then it is
// accessed through an enclosing instance. Locate this
// enclosing instance:
while (env1.outer != null && !rs.isAccessible(env, env1.enclClass.sym.type, sym))
env1 = env1.outer;
}
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, sitesym, site, env, pt, pkind);
if (sym.exists() && !isType(sym) && (pkind & (PCK | TYP)) != 0) {
site = capture(site);
sym = selectSym(tree, sitesym, 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);
}
if (sitesym != null &&
sitesym.kind == VAR &&
((VarSymbol)sitesym).isResourceVariable() &&
sym.kind == MTH &&
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&(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);
}
}
} 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", Kinds.kindName(sym.kind), 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;
}
}
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<AttrContext> env,
Type pt,
int pkind) {
return selectSym(tree, site.tsym, site, env, pt, pkind);
}
private Symbol selectSym(JCFieldAccess tree,
Symbol location,
Type site,
Env<AttrContext> 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, location, site, name, true);
case ARRAY:
case CLASS:
if (pt.tag == METHOD || pt.tag == FORALL) {
return rs.resolveQualifiedMethod(
pos, env, location, 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<Type> typeargs = allowGenerics
? List.of(types.erasure(site))
: List.<Type>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, location, site, name, true);
return sym;
}
case WILDCARD:
throw new AssertionError(tree);
case TYPEVAR:
// Normally, site.getUpperBound() shouldn't be null.
// It should only happen during memberEnter/attribBase
// when determining the super type which *must* beac
// done before attributing the type variables. In
// other words, we are seeing this illegal program:
// class B<T> extends A<T.foo> {}
Symbol sym = (site.getUpperBound() != null)
? selectSym(tree, location, capture(site.getUpperBound()), env, 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, 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 pkind The set of expected kinds.
* @param pt The expected type.
*/
Type checkId(JCTree tree,
Type site,
Symbol sym,
Env<AttrContext> 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<A> { class Visitor { ... } }
// class PointTree extends Tree<Point> { ... }
// ...PointTree.Visitor...
//
// Then the type of the last expression above is
// Tree<Point>.Visitor.
else if (ownOuter.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.<Type>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<Type> 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) {
chk.checkDeprecated(tree.pos(), env.info.scope.owner, sym);
chk.checkSunAPI(tree.pos(), 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<AttrContext> 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<AttrContext> 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<AttrContext> env,
final List<JCExpression> argtrees,
List<Type> argtypes,
List<Type> 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.clear();
Type owntype = rs.instantiate(env,
site,
sym,
argtypes,
typeargtypes,
true,
useVarargs,
noteWarner);
boolean warned = noteWarner.hasNonSilentLint(LintCategory.UNCHECKED);
// 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<Type> formals = owntype.getParameterTypes();
Type last = useVarargs ? formals.last() : null;
if (sym.name==names.init &&
sym.owner == syms.enumSym)
formals = formals.tail.tail;
List<JCExpression> 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.hasNonSilentLint(LintCategory.UNCHECKED);
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.hasNonSilentLint(LintCategory.UNCHECKED);
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()),
types.erasure(owntype.getThrownTypes()),
syms.methodClass);
}
if (useVarargs) {
JCTree tree = env.tree;
Type argtype = owntype.getParameterTypes().last();
if (owntype.getReturnType().tag != FORALL || warned) {
chk.checkVararg(env.tree.pos(), owntype.getParameterTypes(), sym);
}
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<Type> actuals = attribTypes(tree.arguments, env);
if (clazztype.tag == CLASS) {
List<Type> formals = clazztype.tsym.type.getTypeArguments();
if (actuals.length() == formals.length() || actuals.length() == 0) {
List<Type> a = actuals;
List<Type> f = formals;
while (a.nonEmpty()) {
a.head = a.head.withTypeVar(f.head);
a = a.tail;
f = f.tail;
}
// Compute the proper generic outer
Type clazzOuter = clazztype.getEnclosingType();
if (clazzOuter.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;
}
}
owntype = new ClassType(clazzOuter, actuals, clazztype.tsym);
} 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 visitTypeDisjunction(JCTypeDisjunction tree) {
ListBuffer<Type> multicatchTypes = ListBuffer.lb();
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 disjunctive 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);
}
}
tree.type = result = check(tree, types.lub(multicatchTypes.toList()), TYP, pkind, pt);
}
public void visitTypeParameter(JCTypeParameter tree) {
TypeVar a = (TypeVar)tree.type;
Set<Type> boundSet = new HashSet<Type>();
if (a.bound.isErroneous())
return;
List<Type> 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, ...
JCExpression extending;
List<JCExpression> 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.<JCTypeParameter>nil(),
extending, implementing, List.<JCTree>nil());
ClassSymbol c = (ClassSymbol)a.getUpperBound().tsym;
Assert.check((c.flags() & COMPOUND) != 0);
cd.sym = c;
c.sourcefile = env.toplevel.sourcefile;
// ... and attribute the bound class
c.flags_field |= UNATTRIBUTED;
Env<AttrContext> cenv = enter.classEnv(cd, env);
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 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();
}
/**
* Attribute an env for either a top level tree or class declaration.
*/
public void attrib(Env<AttrContext> env) {
if (env.tree.getTag() == JCTree.TOPLEVEL)
attribTopLevel(env);
else
attribClass(env.tree.pos(), env.enclClass.sym);
}
/**
* Attribute a top level tree. These trees are encountered when the
* package declaration has annotations.
*/
public void attribTopLevel(Env<AttrContext> env) {
JCCompilationUnit toplevel = env.toplevel;
try {
annotate.flush();
chk.validateAnnotations(toplevel.packageAnnotations, toplevel.packge);
} catch (CompletionFailure ex) {
chk.completionError(toplevel.pos(), ex);
}
}
/** 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<AttrContext> 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<AttrContext> lintEnv = env;
while (lintEnv.info.lint == null)
lintEnv = lintEnv.next;
// Having found the enclosing lint value, we can initialize the lint value for this class
env.info.lint = lintEnv.info.lint.augment(c.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<AttrContext> env, ClassSymbol c) {
JCClassDecl tree = (JCClassDecl)env.tree;
Assert.check(c == tree.sym);
// Validate annotations
chk.validateAnnotations(tree.mods.annotations, c);
// Validate type parameters, supertype and interfaces.
attribBounds(tree.typarams);
if (!c.isAnonymous()) {
//already checked if anonymous
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;
for (List<JCTypeParameter> l = tree.typarams;
l.nonEmpty(); l = l.tail) {
Assert.checkNonNull(env.info.scope.lookup(l.head.name).scope);
}
// 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<JCTree> l = tree.defs; l.nonEmpty(); l = l.tail) {
// Attribute declaration
attribStat(l.head, env);
// Check that declarations in inner classes are not static (JLS 8.1.2)
// Make an exception for static constants.
if (c.owner.kind != PCK &&
((c.flags() & STATIC) == 0 || c.name == names.empty) &&
(TreeInfo.flags(l.head) & (STATIC | INTERFACE)) != 0) {
Symbol sym = null;
if (l.head.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", 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) &&
(c.flags() & Flags.ENUM) == 0 &&
(c.flags() & ABSTRACT) == 0) {
checkSerialVersionUID(tree, c);
}
}
// 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(LintCategory.SERIAL,
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(LintCategory.SERIAL,
TreeInfo.diagnosticPositionFor(svuid, tree), "improper.SVUID", c);
// check that it is long
else if (svuid.type.tag != TypeTags.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);
}
// <editor-fold desc="post-attribution visitor">
/**
* Handle missing types/symbols in an AST. This routine is useful when
* the compiler has encountered some errors (which might have ended up
* terminating attribution abruptly); if the compiler is used in fail-over
* mode (e.g. by an IDE) and the AST contains semantic errors, this routine
* prevents NPE to be progagated during subsequent compilation steps.
*/
public void postAttr(Env<AttrContext> env) {
new PostAttrAnalyzer().scan(env.tree);
}
class PostAttrAnalyzer extends TreeScanner {
private void initTypeIfNeeded(JCTree that) {
if (that.type == null) {
that.type = syms.unknownType;
}
}
@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, syms.unknownType, syms.noSymbol);
}
if (that.constructorType == null) {
that.constructorType = syms.unknownType;
}
super.visitNewClass(that);
}
@Override
public void visitBinary(JCBinary that) {
if (that.operator == null)
that.operator = new OperatorSymbol(names.empty, syms.unknownType, -1, syms.noSymbol);
super.visitBinary(that);
}
@Override
public void visitUnary(JCUnary that) {
if (that.operator == null)
that.operator = new OperatorSymbol(names.empty, syms.unknownType, -1, syms.noSymbol);
super.visitUnary(that);
}
}
// </editor-fold>
}