/*
* @(#)Check.java 1.169 07/03/21
*
* Copyright (c) 2007 Sun Microsystems, Inc. All Rights Reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Sun designates this
* particular file as subject to the "Classpath" exception as provided
* by Sun in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
* CA 95054 USA or visit www.sun.com if you need additional information or
* have any questions.
*/
package com.sun.tools.javac.comp;
import java.util.*;
import java.util.Set;
import 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.tree.JCTree.*;
import com.sun.tools.javac.code.Lint;
import com.sun.tools.javac.code.Lint.LintCategory;
import com.sun.tools.javac.code.Type.*;
import com.sun.tools.javac.code.Symbol.*;
import static com.sun.tools.javac.code.Flags.*;
import static com.sun.tools.javac.code.Kinds.*;
import static com.sun.tools.javac.code.TypeTags.*;
/** Type checking helper class for the attribution phase.
*
* <p><b>This is NOT part of any API supported by Sun Microsystems. If
* you write code that depends on this, you do so at your own risk.
* This code and its internal interfaces are subject to change or
* deletion without notice.</b>
*/
@Version("@(#)Check.java 1.169 07/03/21")
public class Check {
private static my.Debug DEBUG=new my.Debug(my.Debug.Check);//我加上的
protected static final Context.Key<Check> checkKey =
new Context.Key<Check>();
private final Name.Table names;
private final Log log;
private final Symtab syms;
private final Infer infer;
private final Target target;
private final Source source;
private final Types types;
private final boolean skipAnnotations;
private final TreeInfo treeinfo;
// The set of lint options currently in effect. It is initialized
// from the context, and then is set/reset as needed by Attr as it
// visits all the various parts of the trees during attribution.
private Lint lint;
public static Check instance(Context context) {
Check instance = context.get(checkKey);
if (instance == null)
instance = new Check(context);
return instance;
}
protected Check(Context context) {
DEBUG.P(this,"Check(1)");
context.put(checkKey, this);
names = Name.Table.instance(context);
log = Log.instance(context);
syms = Symtab.instance(context);
infer = Infer.instance(context);
this.types = Types.instance(context);
Options options = Options.instance(context);
target = Target.instance(context);
source = Source.instance(context);
lint = Lint.instance(context);
treeinfo = TreeInfo.instance(context);
Source source = Source.instance(context);
allowGenerics = source.allowGenerics();
allowAnnotations = source.allowAnnotations();
complexInference = options.get("-complexinference") != null;
skipAnnotations = options.get("skipAnnotations") != null;
boolean verboseDeprecated = lint.isEnabled(LintCategory.DEPRECATION);
boolean verboseUnchecked = lint.isEnabled(LintCategory.UNCHECKED);
deprecationHandler = new MandatoryWarningHandler(log,verboseDeprecated, "deprecated");
uncheckedHandler = new MandatoryWarningHandler(log, verboseUnchecked, "unchecked");
DEBUG.P(0,this,"Check(1)");
}
/** Switch: generics enabled?
*/
boolean allowGenerics;
/** Switch: annotations enabled?
*/
boolean allowAnnotations;
/** Switch: -complexinference option set?
*/
boolean complexInference;
/** A table mapping flat names of all compiled classes in this run to their
* symbols; maintained from outside.
*/
public Map<Name,ClassSymbol> compiled = new HashMap<Name, ClassSymbol>();
/** A handler for messages about deprecated usage.
*/
private MandatoryWarningHandler deprecationHandler;
/** A handler for messages about unchecked or unsafe usage.
*/
private MandatoryWarningHandler uncheckedHandler;
/* *************************************************************************
* Errors and Warnings
**************************************************************************/
Lint setLint(Lint newLint) {
Lint prev = lint;
lint = newLint;
return prev;
}
/** Warn about deprecated symbol.
* @param pos Position to be used for error reporting.
* @param sym The deprecated symbol.
*/
void warnDeprecated(DiagnosticPosition pos, Symbol sym) {
if (!lint.isSuppressed(LintCategory.DEPRECATION))
deprecationHandler.report(pos, "has.been.deprecated", sym, sym.location());
}
/** Warn about unchecked operation.
* @param pos Position to be used for error reporting.
* @param msg A string describing the problem.
*/
public void warnUnchecked(DiagnosticPosition pos, String msg, Object... args) {
if (!lint.isSuppressed(LintCategory.UNCHECKED))
uncheckedHandler.report(pos, msg, args);
}
/**
* Report any deferred diagnostics.
*/
public void reportDeferredDiagnostics() {
deprecationHandler.reportDeferredDiagnostic();
uncheckedHandler.reportDeferredDiagnostic();
}
/** Report a failure to complete a class.
* @param pos Position to be used for error reporting.
* @param ex The failure to report.
*/
public Type completionError(DiagnosticPosition pos, CompletionFailure ex) {
log.error(pos, "cant.access", ex.sym, ex.errmsg);
//com.sun.tools.javac.jvm.ClassReader.BadClassFile继承自
//com.sun.tools.javac.code.Symbol.CompletionFailure
if (ex instanceof ClassReader.BadClassFile) throw new Abort();
else return syms.errType;
}
/** Report a type error.
* @param pos Position to be used for error reporting.
* @param problem A string describing the error.
* @param found The type that was found.
* @param req The type that was required.
*/
Type typeError(DiagnosticPosition pos, Object problem, Type found, Type req) {
log.error(pos, "prob.found.req",
problem, found, req);
return syms.errType;
}
Type typeError(DiagnosticPosition pos, String problem, Type found, Type req, Object explanation) {
log.error(pos, "prob.found.req.1", problem, found, req, explanation);
return syms.errType;
}
/** Report an error that wrong type tag was found.
* @param pos Position to be used for error reporting.
* @param required An internationalized string describing the type tag
* required.
* @param found The type that was found.
*/
Type typeTagError(DiagnosticPosition pos, Object required, Object found) {
log.error(pos, "type.found.req", found, required);
return syms.errType;
}
/** Report an error that symbol cannot be referenced before super
* has been called.
* @param pos Position to be used for error reporting.
* @param sym The referenced symbol.
*/
void earlyRefError(DiagnosticPosition pos, Symbol sym) {
log.error(pos, "cant.ref.before.ctor.called", sym);
}
/** Report duplicate declaration error.
*/
void duplicateError(DiagnosticPosition pos, Symbol sym) {
DEBUG.P(this,"duplicateError(2)");
DEBUG.P("sym="+sym);
if (!sym.type.isErroneous()) {
log.error(pos, "already.defined", sym, sym.location());
}
DEBUG.P(0,this,"duplicateError(2)");
}
/** Report array/varargs duplicate declaration
*/
void varargsDuplicateError(DiagnosticPosition pos, Symbol sym1, Symbol sym2) {
DEBUG.P(this,"varargsDuplicateError(3)");
DEBUG.P("sym1="+sym1+" sym2="+sym2);
if (!sym1.type.isErroneous() && !sym2.type.isErroneous()) {
log.error(pos, "array.and.varargs", sym1, sym2, sym2.location());
}
DEBUG.P(this,"varargsDuplicateError(3)");
}
/* ************************************************************************
* duplicate declaration checking
*************************************************************************/
/** Check that variable does not hide variable with same name in
* immediately enclosing local scope.
* @param pos Position for error reporting.
* @param v The symbol.
* @param s The scope.
*/
void checkTransparentVar(DiagnosticPosition pos, VarSymbol v, Scope s) {
try {//我加上的
DEBUG.P(this,"checkTransparentVar(3)");
DEBUG.P("VarSymbol v="+v);
DEBUG.P("Scope s="+s);
DEBUG.P("s.next="+s.next);
if (s.next != null) {
Scope.Entry e2 = s.next.lookup(v.name);
DEBUG.P("e2.scope="+e2.scope);
if(e2.scope != null) {
DEBUG.P("e.sym.owner="+e2.sym.owner);
DEBUG.P("v.owner="+v.owner);
}
for (Scope.Entry e = s.next.lookup(v.name);
e.scope != null && e.sym.owner == v.owner;
e = e.next()) {
if (e.sym.kind == VAR &&
(e.sym.owner.kind & (VAR | MTH)) != 0 &&
v.name != names.error) {
//如:void methodD(int i) { int i; }
duplicateError(pos, e.sym);
return;
}
}
}
}finally{//我加上的
DEBUG.P(0,this,"checkTransparentVar(3)");
}
}
/** Check that a class or interface does not hide a class or
* interface with same name in immediately enclosing local scope.
* @param pos Position for error reporting.
* @param c The symbol.
* @param s The scope.
*/
void checkTransparentClass(DiagnosticPosition pos, ClassSymbol c, Scope s) {
try {//我加上的
DEBUG.P(this,"checkTransparentClass(3)");
DEBUG.P("c="+c);
DEBUG.P("s="+s);
DEBUG.P("s.next="+s.next);
/*例:这个例子不对
class EnterTest {
void methodA() {
class EnterTest{}
}
}*/
if (s.next != null) {
for (Scope.Entry e = s.next.lookup(c.name);
e.scope != null && e.sym.owner == c.owner;
e = e.next()) {
if (e.sym.kind == TYP &&
(e.sym.owner.kind & (VAR | MTH)) != 0 &&
c.name != names.error) {
duplicateError(pos, e.sym);
return;
}
}
}
}finally{//我加上的
DEBUG.P(0,this,"checkTransparentClass(3)");
}
}
/** Check that class does not have the same name as one of
* its enclosing classes, or as a class defined in its enclosing scope.
* return true if class is unique in its enclosing scope.
* @param pos Position for error reporting.
* @param name The class name.
* @param s The enclosing scope.
*/
boolean checkUniqueClassName(DiagnosticPosition pos, Name name, Scope s) {
try {//我加上的
DEBUG.P(this,"checkUniqueClassName(3)");
DEBUG.P("name="+name);
DEBUG.P("Scope s="+s);
//各成员名不能重复
for (Scope.Entry e = s.lookup(name); e.scope == s; e = e.next()) {
if (e.sym.kind == TYP && e.sym.name != names.error) {
duplicateError(pos, e.sym);
return false;
}
}
//各成员名不能与此成员的直接或间接owner有相同名称
for (Symbol sym = s.owner; sym != null; sym = sym.owner) {
if (sym.kind == TYP && sym.name == name && sym.name != names.error) {
duplicateError(pos, sym);
return true;
}
}
return true;
}finally{//我加上的
DEBUG.P(0,this,"checkUniqueClassName(3)");
}
}
/* *************************************************************************
* Class name generation
**************************************************************************/
/** Return name of local class.
* This is of the form <enclClass> $ n <classname>
* where
* enclClass is the flat name of the enclosing class,
* classname is the simple name of the local class
*/
Name localClassName(ClassSymbol c) {
for (int i=1; ; i++) {
Name flatname = names.
fromString("" + c.owner.enclClass().flatname +
target.syntheticNameChar() + i +
c.name);
if (compiled.get(flatname) == null) return flatname;
}
}
/* *************************************************************************
* Type Checking
**************************************************************************/
/** Check that a given type is assignable to a given proto-type.
* If it is, return the type, otherwise return errType.
* @param pos Position to be used for error reporting.
* @param found The type that was found.
* @param req The type that was required.
*/
Type checkType(DiagnosticPosition pos, Type found, Type req) {
try {//我加上的
DEBUG.P(this,"checkType(3)");
DEBUG.P("found.tag="+TypeTags.toString(found.tag));
DEBUG.P("req.tag="+TypeTags.toString(req.tag));
if (req.tag == ERROR)
return req;
if (found.tag == FORALL)
return instantiatePoly(pos, (ForAll)found, req, convertWarner(pos, found, req));
if (req.tag == NONE)
return found;
if (types.isAssignable(found, req, convertWarner(pos, found, req)))
return found;
if (found.tag <= DOUBLE && req.tag <= DOUBLE)
return typeError(pos, JCDiagnostic.fragment("possible.loss.of.precision"), found, req);
if (found.isSuperBound()) {
log.error(pos, "assignment.from.super-bound", found);
return syms.errType;
}
if (req.isExtendsBound()) {
log.error(pos, "assignment.to.extends-bound", req);
return syms.errType;
}
return typeError(pos, JCDiagnostic.fragment("incompatible.types"), found, req);
}finally{//我加上的
DEBUG.P(0,this,"checkType(3)");
}
}
/** Instantiate polymorphic type to some prototype, unless
* prototype is `anyPoly' in which case polymorphic type
* is returned unchanged.
*/
Type instantiatePoly(DiagnosticPosition pos, ForAll t, Type pt, Warner warn) {
if (pt == Infer.anyPoly && complexInference) {
return t;
} else if (pt == Infer.anyPoly || pt.tag == NONE) {
Type newpt = t.qtype.tag <= VOID ? t.qtype : syms.objectType;
return instantiatePoly(pos, t, newpt, warn);
} else if (pt.tag == ERROR) {
return pt;
} else {
try {
return infer.instantiateExpr(t, pt, warn);
} catch (Infer.NoInstanceException ex) {
if (ex.isAmbiguous) {
JCDiagnostic d = ex.getDiagnostic();
log.error(pos,
"undetermined.type" + (d!=null ? ".1" : ""),
t, d);
return syms.errType;
} else {
JCDiagnostic d = ex.getDiagnostic();
return typeError(pos,
JCDiagnostic.fragment("incompatible.types" + (d!=null ? ".1" : ""), d),
t, pt);
}
}
}
}
/** Check that a given type can be cast to a given target type.
* Return the result of the cast.
* @param pos Position to be used for error reporting.
* @param found The type that is being cast.
* @param req The target type of the cast.
*/
Type checkCastable(DiagnosticPosition pos, Type found, Type req) {
if (found.tag == FORALL) {
instantiatePoly(pos, (ForAll) found, req, castWarner(pos, found, req));
return req;
} else if (types.isCastable(found, req, castWarner(pos, found, req))) {
return req;
} else {
return typeError(pos,
JCDiagnostic.fragment("inconvertible.types"),
found, req);
}
}
//where
/** Is type a type variable, or a (possibly multi-dimensional) array of
* type variables?
*/
boolean isTypeVar(Type t) {
return t.tag == TYPEVAR || t.tag == ARRAY && isTypeVar(types.elemtype(t));
}
/** Check that a type is within some bounds.
*
* Used in TypeApply to verify that, e.g., X in V<X> is a valid
* type argument.
* @param pos Position to be used for error reporting.
* @param a The type that should be bounded by bs.
* @param bs The bound.
*/
private void checkExtends(DiagnosticPosition pos, Type a, TypeVar bs) {
try {//我加上的
DEBUG.P(this,"checkExtends(3)");
DEBUG.P("a="+a);
DEBUG.P("a.tag="+TypeTags.toString(a.tag));
DEBUG.P("a.isUnbound()="+a.isUnbound());
DEBUG.P("a.isExtendsBound()="+a.isExtendsBound());
DEBUG.P("a.isSuperBound()="+a.isSuperBound());
DEBUG.P("bs="+bs);
//测试upperBound与lowerBound
//types.upperBound(a);
//types.lowerBound(a);
if (a.isUnbound()) {
return;
} else if (a.tag != WILDCARD) {
a = types.upperBound(a);
for (List<Type> l = types.getBounds(bs); l.nonEmpty(); l = l.tail) {
if (!types.isSubtype(a, l.head)) {
log.error(pos, "not.within.bounds", a);
return;
}
}
} else if (a.isExtendsBound()) {
if (!types.isCastable(bs.getUpperBound(), types.upperBound(a), Warner.noWarnings))
log.error(pos, "not.within.bounds", a);
} else if (a.isSuperBound()) {
if (types.notSoftSubtype(types.lowerBound(a), bs.getUpperBound()))
log.error(pos, "not.within.bounds", a);
}
}finally{//我加上的
DEBUG.P(1,this,"checkExtends(3)");
}
}
/** Check that type is different from 'void'.
* @param pos Position to be used for error reporting.
* @param t The type to be checked.
*/
Type checkNonVoid(DiagnosticPosition pos, Type t) {
if (t.tag == VOID) {
log.error(pos, "void.not.allowed.here");
return syms.errType;
} else {
return t;
}
}
/** Check that type is a class or interface type.
* @param pos Position to be used for error reporting.
* @param t The type to be checked.
*/
Type checkClassType(DiagnosticPosition pos, Type t) {
try {//我加上的
DEBUG.P(this,"checkClassType(2)");
DEBUG.P("t="+t+" t.tag="+TypeTags.toString(t.tag));
/*src/my/test/EnterTest.java:23: 意外的类型
找到： 类型参数 T
需要： 类
public class EnterTest<T,S> extends T implements EnterTestInterfaceA,EnterTestInterfaceB { ^
*/
if (t.tag != CLASS && t.tag != ERROR)
return typeTagError(pos,
JCDiagnostic.fragment("type.req.class"),
(t.tag == TYPEVAR)
? JCDiagnostic.fragment("type.parameter", t)
: t);
else
return t;
}finally{//我加上的
DEBUG.P(0,this,"checkClassType(2)");
}
}
/** Check that type is a class or interface type.
* @param pos Position to be used for error reporting.
* @param t The type to be checked.
* @param noBounds True if type bounds are illegal here.
*/
Type checkClassType(DiagnosticPosition pos, Type t, boolean noBounds) {
try {//我加上的
DEBUG.P(this,"checkClassType(3)");
DEBUG.P("t="+t);
DEBUG.P("t.tag="+TypeTags.toString(t.tag));
DEBUG.P("t.isParameterized()="+t.isParameterized());
DEBUG.P("noBounds="+noBounds);
t = checkClassType(pos, t);
DEBUG.P("t="+t);
DEBUG.P("t.tag="+TypeTags.toString(t.tag));
DEBUG.P("t.isParameterized()="+t.isParameterized());
DEBUG.P("noBounds="+noBounds);
//noBounds为true时表示t的类型参数不能是WILDCARD(即: <?>、<? extends ...>、<? super ...>)
if (noBounds && t.isParameterized()) {
List<Type> args = t.getTypeArguments();
while (args.nonEmpty()) {
DEBUG.P("args.head.tag="+TypeTags.toString(args.head.tag));
/*报错如下:
bin\mysrc\my\test\Test.java:85: unexpected type
found : ?
required: class or interface without bounds
public class Test<S,T> extends TestOhter<?,String> implements MyInterfaceA,MyInterfaceB { ^
1 error
*/
if (args.head.tag == WILDCARD)
return typeTagError(pos,
log.getLocalizedString("type.req.exact"),
args.head);
args = args.tail;
}
}
return t;
}finally{//我加上的
DEBUG.P(0,this,"checkClassType(3)");
}
}
/** Check that type is a reifiable class, interface or array type.
* @param pos Position to be used for error reporting.
* @param t The type to be checked.
*/
Type checkReifiableReferenceType(DiagnosticPosition pos, Type t) {
if (t.tag != CLASS && t.tag != ARRAY && t.tag != ERROR) {
return typeTagError(pos,
JCDiagnostic.fragment("type.req.class.array"),
t);
} else if (!types.isReifiable(t)) {
log.error(pos, "illegal.generic.type.for.instof");
return syms.errType;
} else {
return t;
}
}
/** Check that type is a reference type, i.e. a class, interface or array type
* or a type variable.
* @param pos Position to be used for error reporting.
* @param t The type to be checked.
*/
Type checkRefType(DiagnosticPosition pos, Type t) {
try {//我加上的
DEBUG.P(this,"checkRefType(2)");
DEBUG.P("t="+t+" t.tag="+TypeTags.toString(t.tag));
switch (t.tag) {
case CLASS:
case ARRAY:
case TYPEVAR:
case WILDCARD:
case ERROR:
return t;
default:
/*例子:
bin\mysrc\my\test\Test.java:8: 意外的类型
找到： int
需要： 引用
MyTestInnerClass<Z extends ExtendsTest<int,? super ExtendsTest>>
^
*/
return typeTagError(pos,
JCDiagnostic.fragment("type.req.ref"),
t);
}
}finally{//我加上的
DEBUG.P(0,this,"checkRefType(2)");
}
}
/** Check that type is a null or reference type.
* @param pos Position to be used for error reporting.
* @param t The type to be checked.
*/
Type checkNullOrRefType(DiagnosticPosition pos, Type t) {
switch (t.tag) {
case CLASS:
case ARRAY:
case TYPEVAR:
case WILDCARD:
case BOT:
case ERROR:
return t;
default:
return typeTagError(pos,
JCDiagnostic.fragment("type.req.ref"),
t);
}
}
/** Check that flag set does not contain elements of two conflicting sets. s
* Return true if it doesn't.
* @param pos Position to be used for error reporting.
* @param flags The set of flags to be checked.
* @param set1 Conflicting flags set #1.
* @param set2 Conflicting flags set #2.
*/
boolean checkDisjoint(DiagnosticPosition pos, long flags, long set1, long set2) {
if ((flags & set1) != 0 && (flags & set2) != 0) {
log.error(pos,
"illegal.combination.of.modifiers",
TreeInfo.flagNames(TreeInfo.firstFlag(flags & set1)),
TreeInfo.flagNames(TreeInfo.firstFlag(flags & set2)));
return false;
} else
return true;
}
/** Check that given modifiers are legal for given symbol and
* return modifiers together with any implicit modififiers for that symbol.
* Warning: we can't use flags() here since this method
* is called during class enter, when flags() would cause a premature
* completion.
* @param pos Position to be used for error reporting.
* @param flags The set of modifiers given in a definition.
* @param sym The defined symbol.
*/
long checkFlags(DiagnosticPosition pos, long flags, Symbol sym, JCTree tree) {
DEBUG.P(this,"checkFlags(4)");
DEBUG.P("flags="+Flags.toString(flags));
DEBUG.P("sym.kind="+Kinds.toString(sym.kind));
long mask;
long implicit = 0;
switch (sym.kind) {
case VAR:
if (sym.owner.kind != TYP)
mask = LocalVarFlags; //本地变量
else if ((sym.owner.flags_field & INTERFACE) != 0)
mask = implicit = InterfaceVarFlags; //接口中定义的字段
else
mask = VarFlags; //类中定义的字段
break;
case MTH:
DEBUG.P("sym.name="+sym.name);
DEBUG.P("if (sym.name == names.init)="+(sym.name == names.init));
DEBUG.P("sym.owner.flags_field="+Flags.toString(sym.owner.flags_field));
if (sym.name == names.init) {
if ((sym.owner.flags_field & ENUM) != 0) {
/*错误例子:
bin\mysrc\my\test\Test.java:16: 此处不允许使用修饰符 public
public MyInnerEnum() {}
^
bin\mysrc\my\test\Test.java:16: 此处不允许使用修饰符 protected
protected MyInnerEnum() {}
^
*/
// enum constructors cannot be declared public or
// protected and must be implicitly or explicitly
// private
implicit = PRIVATE;
mask = PRIVATE;
} else
mask = ConstructorFlags;
} else if ((sym.owner.flags_field & INTERFACE) != 0)
mask = implicit = InterfaceMethodFlags;
else {
mask = MethodFlags;
}
//如果方法不是抽象的(abstract)，
//并且定义方法的类型含有strictfp修饰符，
//则此方法也默认含有strictfp修饰符
//接口方法默认是public abstract，不会有strictfp修饰符
DEBUG.P("((flags|implicit) & Flags.ABSTRACT)="+Flags.toString(((flags|implicit) & Flags.ABSTRACT)));
// Imply STRICTFP if owner has STRICTFP set.
if (((flags|implicit) & Flags.ABSTRACT) == 0) //参考<<深入java虚拟机>>P290
implicit |= sym.owner.flags_field & STRICTFP;
DEBUG.P("implicit="+Flags.toString(implicit));
break;
case TYP:
DEBUG.P("sym.isLocal()="+sym.isLocal());
DEBUG.P("sym.owner.kind="+Kinds.toString(sym.owner.kind));
if (sym.isLocal()) {
mask = LocalClassFlags;
if (sym.name.len == 0) { // Anonymous class
// Anonymous classes in static methods are themselves static;
// that's why we admit STATIC here.
mask |= STATIC;
// JLS: Anonymous classes are final.
implicit |= FINAL;
}
if ((sym.owner.flags_field & STATIC) == 0 &&
(flags & ENUM) != 0)
log.error(pos, "enums.must.be.static");
} else if (sym.owner.kind == TYP) {
mask = MemberClassFlags;
if (sym.owner.owner.kind == PCK ||
(sym.owner.flags_field & STATIC) != 0)
mask |= STATIC;
/*源码例子:
public class Test {
public class MyInnerClass {
public enum MyInnerEnum2{}
}
}
错误提示:
bin\mysrc\my\test\Test.java:11: 只有在静态上下文中才允许使用枚举声明
public enum MyInnerEnum2{}
^
*/
else if ((flags & ENUM) != 0)
log.error(pos, "enums.must.be.static");
// Nested interfaces and enums are always STATIC (Spec ???)
if ((flags & (INTERFACE | ENUM)) != 0 ) implicit = STATIC;
} else {
mask = ClassFlags;
}
// Interfaces are always ABSTRACT
if ((flags & INTERFACE) != 0) implicit |= ABSTRACT;
if ((flags & ENUM) != 0) {
// enums can't be declared abstract or final
mask &= ~(ABSTRACT | FINAL);
implicit |= implicitEnumFinalFlag(tree);
}
// Imply STRICTFP if owner has STRICTFP set.
implicit |= sym.owner.flags_field & STRICTFP;
break;
default:
throw new AssertionError();
}
//mask的值表示能用在VAR、MTH、TYP前的所有修饰符的集合(见Flags类中的Modifier masks)
//如果在一个接口中这样定义一个方法:strictfp void methodA();
//因为mask = InterfaceMethodFlags = ABSTRACT | PUBLIC
//所以就会报错:此处不允许使用修饰符 strictfp
long illegal = flags & StandardFlags & ~mask;
if (illegal != 0) {
if ((illegal & INTERFACE) != 0) {
log.error(pos, "intf.not.allowed.here");
mask |= INTERFACE;
}
else {
log.error(pos, "mod.not.allowed.here", TreeInfo.flagNames(illegal));
}
}
else if ((sym.kind == TYP ||
// ISSUE: Disallowing abstract&private is no longer appropriate
// in the presence of inner classes. Should it be deleted here?
checkDisjoint(pos, flags,
ABSTRACT, //ABSTRACT与"PRIVATE,STATIC"其中之一不能同时出现
PRIVATE | STATIC))//如static abstract void methodC();非法的修饰符组合 abstract 和 static
&& //下面的checkDisjoint同上，都是第三个参数与第四个参数中所含的修饰符不能同时出现在flags中
checkDisjoint(pos, flags,
ABSTRACT | INTERFACE,
FINAL | NATIVE | SYNCHRONIZED)
&&
checkDisjoint(pos, flags,
PUBLIC,
PRIVATE | PROTECTED)
&&
checkDisjoint(pos, flags,
PRIVATE,
PUBLIC | PROTECTED)
&&
checkDisjoint(pos, flags,
FINAL,
VOLATILE)
&&
(sym.kind == TYP ||
checkDisjoint(pos, flags,
ABSTRACT | NATIVE,
STRICTFP))) {
// skip
}
DEBUG.P("flags="+Flags.toString(flags));
DEBUG.P("mask="+Flags.toString(mask));
DEBUG.P("implicit="+Flags.toString(implicit));
DEBUG.P("returnFlags="+(flags & (mask | ~StandardFlags) | implicit)+"("+Flags.toString((flags & (mask | ~StandardFlags) | implicit))+")");
DEBUG.P(0,this,"checkFlags(4)");
return flags & (mask | ~StandardFlags) | implicit;
}
/** Determine if this enum should be implicitly final.
*
* If the enum has no specialized enum contants, it is final.
*
* If the enum does have specialized enum contants, it is
* <i>not</i> final.
*/
private long implicitEnumFinalFlag(JCTree tree) {
if (tree.tag != JCTree.CLASSDEF) return 0;
class SpecialTreeVisitor extends JCTree.Visitor {
boolean specialized;
SpecialTreeVisitor() {
this.specialized = false;
};
public void visitTree(JCTree tree) { /* no-op */ }
public void visitVarDef(JCVariableDecl tree) {
if ((tree.mods.flags & ENUM) != 0) {
if (tree.init instanceof JCNewClass &&
((JCNewClass) tree.init).def != null) {
specialized = true;
}
}
}
}
SpecialTreeVisitor sts = new SpecialTreeVisitor();
JCClassDecl cdef = (JCClassDecl) tree;
for (JCTree defs: cdef.defs) {
defs.accept(sts);
if (sts.specialized) return 0;
}
return FINAL;
}
/* *************************************************************************
* Type Validation
**************************************************************************/
/** Validate a type expression. That is,
* check that all type arguments of a parametric type are within
* their bounds. This must be done in a second phase after type attributon
* since a class might have a subclass as type parameter bound. E.g:
*
* class B<A extends C> { ... }
* class C extends B<C> { ... }
*
* and we can't make sure that the bound is already attributed because
* of possible cycles.
*/
private Validator validator = new Validator();
/** Visitor method: Validate a type expression, if it is not null, catching
* and reporting any completion failures.
*/
void validate(JCTree tree) {
DEBUG.P(this,"validate(JCTree tree)");
if (tree != null) {
//DEBUG.P("tree.type="+tree.type);
DEBUG.P("tree.tag="+tree.myTreeTag());
}else DEBUG.P("tree=null");
try {
if (tree != null) tree.accept(validator);
} catch (CompletionFailure ex) {
completionError(tree.pos(), ex);
}
DEBUG.P(1,this,"validate(JCTree tree)");
}
/** Visitor method: Validate a list of type expressions.
*/
void validate(List<? extends JCTree> trees) {
DEBUG.P(this,"validate(List<? extends JCTree> trees)");
DEBUG.P("trees.size="+trees.size());
DEBUG.P("trees="+trees);
for (List<? extends JCTree> l = trees; l.nonEmpty(); l = l.tail)
validate(l.head);
DEBUG.P(1,this,"validate(List<? extends JCTree> trees)");
}
/** Visitor method: Validate a list of type parameters.
*/
void validateTypeParams(List<JCTypeParameter> trees) {
DEBUG.P(this,"validateTypeParams(1)");
DEBUG.P("trees="+trees);
for (List<JCTypeParameter> l = trees; l.nonEmpty(); l = l.tail)
validate(l.head);
DEBUG.P(1,this,"validateTypeParams(1)");
}
/** A visitor class for type validation.
*/
class Validator extends JCTree.Visitor {
public void visitTypeArray(JCArrayTypeTree tree) {
DEBUG.P(this,"visitTypeArray(1)");
DEBUG.P("tree="+tree);
validate(tree.elemtype);
DEBUG.P(0,this,"visitTypeArray(1)");
}
public void visitTypeApply(JCTypeApply tree) {
DEBUG.P(this,"visitTypeApply(1)");
DEBUG.P("tree="+tree);
DEBUG.P("tree.type="+tree.type);
DEBUG.P("tree.type.tag="+TypeTags.toString(tree.type.tag));
if (tree.type.tag == CLASS) {
List<Type> formals = tree.type.tsym.type.getTypeArguments();
List<Type> actuals = tree.type.getTypeArguments();
List<JCExpression> args = tree.arguments;
List<Type> forms = formals;
ListBuffer<TypeVar> tvars_buf = new ListBuffer<TypeVar>();
DEBUG.P("formals="+formals);
DEBUG.P("actuals="+actuals);
DEBUG.P("args="+args);
// For matching pairs of actual argument types `a' and
// formal type parameters with declared bound `b' ...
while (args.nonEmpty() && forms.nonEmpty()) {
validate(args.head);
// exact type arguments needs to know their
// bounds (for upper and lower bound
// calculations). So we create new TypeVars with
// bounds substed with actuals.
tvars_buf.append(types.substBound(((TypeVar)forms.head),
formals,
Type.removeBounds(actuals)));
args = args.tail;
forms = forms.tail;
}
args = tree.arguments;
List<TypeVar> tvars = tvars_buf.toList();
DEBUG.P("");
DEBUG.P("tvars="+tvars);
DEBUG.P("args ="+args);
while (args.nonEmpty() && tvars.nonEmpty()) {
DEBUG.P("");
DEBUG.P("args.head.type="+args.head.type);
DEBUG.P("args.head.type.tag="+TypeTags.toString(args.head.type.tag));
// Let the actual arguments know their bound
args.head.type.withTypeVar(tvars.head);
args = args.tail;
tvars = tvars.tail;
}
args = tree.arguments;
tvars = tvars_buf.toList();
while (args.nonEmpty() && tvars.nonEmpty()) {
checkExtends(args.head.pos(),
args.head.type,
tvars.head);
args = args.tail;
tvars = tvars.tail;
}
DEBUG.P("");
DEBUG.P("tree.type="+tree.type);
DEBUG.P("tree.type.getEnclosingType()="+tree.type.getEnclosingType());
DEBUG.P("tree.type.getEnclosingType().isRaw()="+tree.type.getEnclosingType().isRaw());
DEBUG.P("tree.clazz="+tree.clazz);
DEBUG.P("tree.clazz.tag="+tree.clazz.myTreeTag());
// Check that this type is either fully parameterized, or
// not parameterized at all.
/*错误例子:
bin\mysrc\my\test\Test.java:47: 类型的格式不正确，给出了普通类型的类型参数
Test.MyTestInnerClass<?> myTestInnerClass =
^
bin\mysrc\my\test\Test.java:47: improperly formed type, type parameters given on a raw type
Test.MyTestInnerClass<?> myTestInnerClass =
^
*/
if (tree.type.getEnclosingType().isRaw())
log.error(tree.pos(), "improperly.formed.type.inner.raw.param");
if (tree.clazz.tag == JCTree.SELECT)
visitSelectInternal((JCFieldAccess)tree.clazz);
}
DEBUG.P(0,this,"visitTypeApply(1)");
}
public void visitTypeParameter(JCTypeParameter tree) {
DEBUG.P(this,"visitTypeParameter(1)");
DEBUG.P("tree="+tree);
validate(tree.bounds);
checkClassBounds(tree.pos(), tree.type);
DEBUG.P(0,this,"visitTypeParameter(1)");
}
@Override
public void visitWildcard(JCWildcard tree) {
DEBUG.P(this,"visitWildcard(1)");
DEBUG.P("tree="+tree);
if (tree.inner != null)
validate(tree.inner);
DEBUG.P(0,this,"visitWildcard(1)");
}
public void visitSelect(JCFieldAccess tree) {
DEBUG.P(this,"visitSelect(1)");
DEBUG.P("tree="+tree);
DEBUG.P("tree.type.tag="+TypeTags.toString(tree.type.tag));
if (tree.type.tag == CLASS) {
visitSelectInternal(tree);
// Check that this type is either fully parameterized, or
// not parameterized at all.
DEBUG.P("tree.selected.type.isParameterized()="+tree.selected.type.isParameterized());
DEBUG.P("tree.type.tsym.type.getTypeArguments().nonEmpty()="+tree.type.tsym.type.getTypeArguments().nonEmpty());
if (tree.selected.type.isParameterized() && tree.type.tsym.type.getTypeArguments().nonEmpty())
log.error(tree.pos(), "improperly.formed.type.param.missing");
}
DEBUG.P(0,this,"visitSelect(1)");
}
public void visitSelectInternal(JCFieldAccess tree) {
DEBUG.P(this,"visitSelectInternal(1)");
DEBUG.P("tree.type.getEnclosingType().tag="+TypeTags.toString(tree.type.getEnclosingType().tag));
DEBUG.P("tree.selected.type.isParameterized()="+tree.selected.type.isParameterized());
DEBUG.P("tree.selected.type.allparams()="+tree.selected.type.allparams());
if (tree.type.getEnclosingType().tag != CLASS &&
tree.selected.type.isParameterized()) {
/*错误例子:
bin\mysrc\my\test\Test.java:7: 无法从参数化的类型中选择静态类
public class Test<S,T extends ExtendsTest,E extends ExtendsTest & MyInterfaceA>
extends my.ExtendsTest<String>.MyInnerClassStatic {
^
1 错误
打印结果:
com.sun.tools.javac.comp.Check$Validator===>visitSelect(1)
-------------------------------------------------------------------------
tree=my.ExtendsTest<String>.MyInnerClassStatic
tree.type.tag=CLASS
com.sun.tools.javac.comp.Check$Validator===>visitSelectInternal(1)
-------------------------------------------------------------------------
tree.type.getEnclosingType().tag=NONE
tree.selected.type.isParameterized()=true
tree.selected.type.allparams()=java.lang.String
com.sun.tools.javac.comp.Check$Validator===>visitSelectInternal(1) END
-------------------------------------------------------------------------
com.sun.tools.javac.comp.Check$Validator===>visitSelect(1) END
-------------------------------------------------------------------------
*/
// The enclosing type is not a class, so we are
// looking at a static member type. However, the
// qualifying expression is parameterized.
log.error(tree.pos(), "cant.select.static.class.from.param.type");
} else {
// otherwise validate the rest of the expression
validate(tree.selected);
}
DEBUG.P(0,this,"visitSelectInternal(1)");
}
/** Default visitor method: do nothing.
*/
public void visitTree(JCTree tree) {
DEBUG.P(this,"visitTree(1)");
DEBUG.P("tree="+tree);
DEBUG.P("do nothing");
DEBUG.P(0,this,"visitTree(1)");
}
}
/* *************************************************************************
* Exception checking
**************************************************************************/
/* The following methods treat classes as sets that contain
* the class itself and all their subclasses
*/
/** Is given type a subtype of some of the types in given list?
*/
boolean subset(Type t, List<Type> ts) {
for (List<Type> l = ts; l.nonEmpty(); l = l.tail)
if (types.isSubtype(t, l.head)) return true;
return false;
}
/** Is given type a subtype or supertype of
* some of the types in given list?
*/
boolean intersects(Type t, List<Type> ts) {
for (List<Type> l = ts; l.nonEmpty(); l = l.tail)
if (types.isSubtype(t, l.head) || types.isSubtype(l.head, t)) return true;
return false;
}
/** Add type set to given type list, unless it is a subclass of some class
* in the list.
*/
List<Type> incl(Type t, List<Type> ts) {
return subset(t, ts) ? ts : excl(t, ts).prepend(t);
}
/** Remove type set from type set list.
*/
List<Type> excl(Type t, List<Type> ts) {
if (ts.isEmpty()) {
return ts;
} else {
List<Type> ts1 = excl(t, ts.tail);
if (types.isSubtype(ts.head, t)) return ts1;
else if (ts1 == ts.tail) return ts;
else return ts1.prepend(ts.head);
}
}
/** Form the union of two type set lists.
*/
List<Type> union(List<Type> ts1, List<Type> ts2) {
DEBUG.P(this,"union(2)");
List<Type> ts = ts1;
for (List<Type> l = ts2; l.nonEmpty(); l = l.tail)
ts = incl(l.head, ts);
DEBUG.P(0,this,"union(2)");
return ts;
}
/** Form the difference of two type lists.
*/
List<Type> diff(List<Type> ts1, List<Type> ts2) {
List<Type> ts = ts1;
for (List<Type> l = ts2; l.nonEmpty(); l = l.tail)
ts = excl(l.head, ts);
return ts;
}
/** Form the intersection of two type lists.
*/
public List<Type> intersect(List<Type> ts1, List<Type> ts2) {
DEBUG.P(this,"intersect(2)");
List<Type> ts = List.nil();
for (List<Type> l = ts1; l.nonEmpty(); l = l.tail)
if (subset(l.head, ts2)) ts = incl(l.head, ts);
for (List<Type> l = ts2; l.nonEmpty(); l = l.tail)
if (subset(l.head, ts1)) ts = incl(l.head, ts);
DEBUG.P(0,this,"intersect(2)");
return ts;
}
/** Is exc an exception symbol that need not be declared?
*/
//平常所说的未检查异常:
//就是java.lang.Error与java.lang.RuntimeException及这两者的子类
//所谓“未检查”就是说编译器不会在源代码中检查哪些地方使用到了上面所说的
//异常，即使你在方法中用throws或throw抛出了上面所说的异常，
//当前方法或别的方法用到这样的异常也不需要用try/catch捕获或重新抛出
//除了上面所说的异常之外的异常都是“已检查异常”，
//只要方法中用throws或throw抛出了“已检查异常”，
//那么当前方法或别的方法用到这样的异常就必需用try/catch捕获或重新抛出
boolean isUnchecked(ClassSymbol exc) {
return
exc.kind == ERR ||
exc.isSubClass(syms.errorType.tsym, types) ||
exc.isSubClass(syms.runtimeExceptionType.tsym, types);
}
/** Is exc an exception type that need not be declared?
*/
boolean isUnchecked(Type exc) {
return
(exc.tag == TYPEVAR) ? isUnchecked(types.supertype(exc)) :
(exc.tag == CLASS) ? isUnchecked((ClassSymbol)exc.tsym) :
exc.tag == BOT;
}
/** Same, but handling completion failures.
*/
boolean isUnchecked(DiagnosticPosition pos, Type exc) {
try {
return isUnchecked(exc);
} catch (CompletionFailure ex) {
completionError(pos, ex);
return true;
}
}
/** Is exc handled by given exception list?
*/
boolean isHandled(Type exc, List<Type> handled) {
return isUnchecked(exc) || subset(exc, handled);
}
/** Return all exceptions in thrown list that are not in handled list.
* @param thrown The list of thrown exceptions.
* @param handled The list of handled exceptions.
*/
List<Type> unHandled(List<Type> thrown, List<Type> handled) {
DEBUG.P(this,"unHandled(2)");
DEBUG.P("thrown="+thrown);
DEBUG.P("handled="+handled);
List<Type> unhandled = List.nil();
for (List<Type> l = thrown; l.nonEmpty(); l = l.tail)
if (!isHandled(l.head, handled)) unhandled = unhandled.prepend(l.head);
DEBUG.P("unhandled="+unhandled);
DEBUG.P(0,this,"unHandled(2)");
return unhandled;
}
/* *************************************************************************
* Overriding/Implementation checking
**************************************************************************/
/** The level of access protection given by a flag set,
* where PRIVATE is highest and PUBLIC is lowest.
*/
static int protection(long flags) {
//当(flags & AccessFlags)是0时，表示的是“包访问级别”，
//“包访问级别”比“PROTECTED”的限制还大，所以数字也大
switch ((short)(flags & AccessFlags)) {
case PRIVATE: return 3;
case PROTECTED: return 1;
default:
case PUBLIC: return 0;
case 0: return 2;
}
}
/** A string describing the access permission given by a flag set.
* This always returns a space-separated list of Java Keywords.
*/
private static String protectionString(long flags) {
long flags1 = flags & AccessFlags;
return (flags1 == 0) ? "package" : TreeInfo.flagNames(flags1);
}
/** A customized "cannot override" error message.
* @param m The overriding method.
* @param other The overridden method.
* @return An internationalized string.
*/
static Object cannotOverride(MethodSymbol m, MethodSymbol other) {
String key;
if ((other.owner.flags() & INTERFACE) == 0)
key = "cant.override";
else if ((m.owner.flags() & INTERFACE) == 0)
key = "cant.implement";
else
key = "clashes.with";
return JCDiagnostic.fragment(key, m, m.location(), other, other.location());
}
/** A customized "override" warning message.
* @param m The overriding method.
* @param other The overridden method.
* @return An internationalized string.
*/
static Object uncheckedOverrides(MethodSymbol m, MethodSymbol other) {
String key;
if ((other.owner.flags() & INTERFACE) == 0)
key = "unchecked.override";
else if ((m.owner.flags() & INTERFACE) == 0)
key = "unchecked.implement";
else
key = "unchecked.clash.with";
return JCDiagnostic.fragment(key, m, m.location(), other, other.location());
}
/** A customized "override" warning message.
* @param m The overriding method.
* @param other The overridden method.
* @return An internationalized string.
*/
static Object varargsOverrides(MethodSymbol m, MethodSymbol other) {
String key;
if ((other.owner.flags() & INTERFACE) == 0)
key = "varargs.override";
else if ((m.owner.flags() & INTERFACE) == 0)
key = "varargs.implement";
else
key = "varargs.clash.with";
return JCDiagnostic.fragment(key, m, m.location(), other, other.location());
}
/** Check that this method conforms with overridden method 'other'.
* where `origin' is the class where checking started.
* Complications:
* (1) Do not check overriding of synthetic methods
* (reason: they might be final).
* todo: check whether this is still necessary.
* (2) Admit the case where an interface proxy throws fewer exceptions
* than the method it implements. Augment the proxy methods with the
* undeclared exceptions in this case.
* (3) When generics are enabled, admit the case where an interface proxy
* has a result type
* extended by the result type of the method it implements.
* Change the proxies result type to the smaller type in this case.
*
* @param tree The tree from which positions
* are extracted for errors.
* @param m The overriding method.
* @param other The overridden method.
* @param origin The class of which the overriding method
* is a member.
*/
void checkOverride(JCTree tree,
MethodSymbol m,
MethodSymbol other,
ClassSymbol origin) {
try {//我加上的
DEBUG.P(this,"checkOverride(4)");
DEBUG.P("m="+m+" m.owner="+m.owner);
DEBUG.P("m.flags()="+Flags.toString(m.flags()));
DEBUG.P("other="+other+" other.owner="+other.owner);
DEBUG.P("other.flags()="+Flags.toString(other.flags()));
DEBUG.P("origin="+origin);
DEBUG.P("origin.flags()="+Flags.toString(origin.flags()));
// Don't check overriding of synthetic methods or by bridge methods.
if ((m.flags() & (SYNTHETIC|BRIDGE)) != 0 || (other.flags() & SYNTHETIC) != 0) {
return;
}
// Error if static method overrides instance method (JLS 8.4.6.2).
if ((m.flags() & STATIC) != 0 &&
(other.flags() & STATIC) == 0) {
log.error(TreeInfo.diagnosticPositionFor(m, tree), "override.static",
cannotOverride(m, other));
return;
}
// Error if instance method overrides static or final
// method (JLS 8.4.6.1).
if ((other.flags() & FINAL) != 0 ||
(m.flags() & STATIC) == 0 &&
(other.flags() & STATIC) != 0) {
log.error(TreeInfo.diagnosticPositionFor(m, tree), "override.meth",
cannotOverride(m, other),
TreeInfo.flagNames(other.flags() & (FINAL | STATIC)));
return;
}
if ((m.owner.flags() & ANNOTATION) != 0) {
// handled in validateAnnotationMethod
return;
}
// Error if overriding method has weaker access (JLS 8.4.6.3).
if ((origin.flags() & INTERFACE) == 0 &&
protection(m.flags()) > protection(other.flags())) {
log.error(TreeInfo.diagnosticPositionFor(m, tree), "override.weaker.access",
cannotOverride(m, other),
protectionString(other.flags()));
return;
}
Type mt = types.memberType(origin.type, m);
Type ot = types.memberType(origin.type, other);
// Error if overriding result type is different
// (or, in the case of generics mode, not a subtype) of
// overridden result type. We have to rename any type parameters
// before comparing types.
List<Type> mtvars = mt.getTypeArguments();
List<Type> otvars = ot.getTypeArguments();
Type mtres = mt.getReturnType();
DEBUG.P("mtvars="+mtvars);
DEBUG.P("otvars="+otvars);
DEBUG.P("mtres="+mtres);
Type otres = types.subst(ot.getReturnType(), otvars, mtvars);
overrideWarner.warned = false;
boolean resultTypesOK =
types.returnTypeSubstitutable(mt, ot, otres, overrideWarner);
DEBUG.P("resultTypesOK="+resultTypesOK);
DEBUG.P("overrideWarner.warned="+overrideWarner.warned);
if (!resultTypesOK) {
if (!source.allowCovariantReturns() &&
m.owner != origin &&
m.owner.isSubClass(other.owner, types)) {
// allow limited interoperability with covariant returns
} else {
typeError(TreeInfo.diagnosticPositionFor(m, tree),
JCDiagnostic.fragment("override.incompatible.ret",
cannotOverride(m, other)),
mtres, otres);
return;
}
} else if (overrideWarner.warned) {
warnUnchecked(TreeInfo.diagnosticPositionFor(m, tree),
"prob.found.req",
JCDiagnostic.fragment("override.unchecked.ret",
uncheckedOverrides(m, other)),
mtres, otres);
}
// Error if overriding method throws an exception not reported
// by overridden method.
List<Type> otthrown = types.subst(ot.getThrownTypes(), otvars, mtvars);
List<Type> unhandled = unHandled(mt.getThrownTypes(), otthrown);
DEBUG.P("unhandled="+unhandled);
if (unhandled.nonEmpty()) {
log.error(TreeInfo.diagnosticPositionFor(m, tree),
"override.meth.doesnt.throw",
cannotOverride(m, other),
unhandled.head);
return;
}
DEBUG.P("m.flags()="+Flags.toString(m.flags()));
DEBUG.P("other.flags()="+Flags.toString(other.flags()));
DEBUG.P("(m.flags() ^ other.flags())="+Flags.toString((m.flags() ^ other.flags())));
DEBUG.P("lint.isEnabled(Lint.LintCategory.OVERRIDES)="+lint.isEnabled(Lint.LintCategory.OVERRIDES));
// Optional warning if varargs don't agree
if ((((m.flags() ^ other.flags()) & Flags.VARARGS) != 0)
&& lint.isEnabled(Lint.LintCategory.OVERRIDES)) {
log.warning(TreeInfo.diagnosticPositionFor(m, tree),
((m.flags() & Flags.VARARGS) != 0)
? "override.varargs.missing"
: "override.varargs.extra",
varargsOverrides(m, other));
}
// Warn if instance method overrides bridge method (compiler spec ??)
if ((other.flags() & BRIDGE) != 0) {
log.warning(TreeInfo.diagnosticPositionFor(m, tree), "override.bridge",
uncheckedOverrides(m, other));
}
// Warn if a deprecated method overridden by a non-deprecated one.
if ((other.flags() & DEPRECATED) != 0
&& (m.flags() & DEPRECATED) == 0
&& m.outermostClass() != other.outermostClass()
&& !isDeprecatedOverrideIgnorable(other, origin)) {
warnDeprecated(TreeInfo.diagnosticPositionFor(m, tree), other);
}
}finally{//我加上的
DEBUG.P(0,this,"checkOverride(4)");
}
}
// where
private boolean isDeprecatedOverrideIgnorable(MethodSymbol m, ClassSymbol origin) {
try {//我加上的
DEBUG.P(this,"isDeprecatedOverrideIgnorable(2)");
DEBUG.P("m="+m);
DEBUG.P("origin="+origin);
// If the method, m, is defined in an interface, then ignore the issue if the method
// is only inherited via a supertype and also implemented in the supertype,
// because in that case, we will rediscover the issue when examining the method
// in the supertype.
// If the method, m, is not defined in an interface, then the only time we need to
// address the issue is when the method is the supertype implemementation: any other
// case, we will have dealt with when examining the supertype classes
ClassSymbol mc = m.enclClass();
Type st = types.supertype(origin.type);
DEBUG.P("st="+st+" st.tag="+TypeTags.toString(st.tag));
if (st.tag != CLASS)
return true;
MethodSymbol stimpl = m.implementation((ClassSymbol)st.tsym, types, false);
if (mc != null && ((mc.flags() & INTERFACE) != 0)) {
List<Type> intfs = types.interfaces(origin.type);
return (intfs.contains(mc.type) ? false : (stimpl != null));
}
else
return (stimpl != m);
}finally{//我加上的
DEBUG.P(0,this,"isDeprecatedOverrideIgnorable(2)");
}
}
// used to check if there were any unchecked conversions
Warner overrideWarner = new Warner();
/** Check that a class does not inherit two concrete methods
* with the same signature.
* @param pos Position to be used for error reporting.
* @param site The class type to be checked.
*/
public void checkCompatibleConcretes(DiagnosticPosition pos, Type site) {
try {//我加上的
DEBUG.P(this,"checkCompatibleConcretes(2)");
DEBUG.P("site="+site);
Type sup = types.supertype(site);
DEBUG.P("sup="+sup);
DEBUG.P("sup.tag="+TypeTags.toString(sup.tag));
if (sup.tag != CLASS) return;
for (Type t1 = sup;
t1.tsym.type.isParameterized();
t1 = types.supertype(t1)) {
for (Scope.Entry e1 = t1.tsym.members().elems;
e1 != null;
e1 = e1.sibling) {
Symbol s1 = e1.sym;
if (s1.kind != MTH ||
(s1.flags() & (STATIC|SYNTHETIC|BRIDGE)) != 0 ||
!s1.isInheritedIn(site.tsym, types) ||
((MethodSymbol)s1).implementation(site.tsym,
types,
true) != s1)
continue;
Type st1 = types.memberType(t1, s1);
int s1ArgsLength = st1.getParameterTypes().length();
if (st1 == s1.type) continue;
for (Type t2 = sup;
t2.tag == CLASS;
t2 = types.supertype(t2)) {
for (Scope.Entry e2 = t1.tsym.members().lookup(s1.name);
e2.scope != null;
e2 = e2.next()) {
Symbol s2 = e2.sym;
if (s2 == s1 ||
s2.kind != MTH ||
(s2.flags() & (STATIC|SYNTHETIC|BRIDGE)) != 0 ||
s2.type.getParameterTypes().length() != s1ArgsLength ||
!s2.isInheritedIn(site.tsym, types) ||
((MethodSymbol)s2).implementation(site.tsym,
types,
true) != s2)
continue;
Type st2 = types.memberType(t2, s2);
if (types.overrideEquivalent(st1, st2))
log.error(pos, "concrete.inheritance.conflict",
s1, t1, s2, t2, sup);
}
}
}
}
}finally{//我加上的
DEBUG.P(0,this,"checkCompatibleConcretes(2)");
}
}
/** Check that classes (or interfaces) do not each define an abstract
* method with same name and arguments but incompatible return types.
* @param pos Position to be used for error reporting.
* @param t1 The first argument type.
* @param t2 The second argument type.
*/
public boolean checkCompatibleAbstracts(DiagnosticPosition pos,
Type t1,
Type t2) {
try {//我加上的
DEBUG.P(this,"checkCompatibleAbstracts(3)");
DEBUG.P("t1="+t1);
DEBUG.P("t2="+t2);
return checkCompatibleAbstracts(pos, t1, t2,
types.makeCompoundType(t1, t2));
}finally{//我加上的
DEBUG.P(0,this,"checkCompatibleAbstracts(3)");
}
}
public boolean checkCompatibleAbstracts(DiagnosticPosition pos,
Type t1,
Type t2,
Type site) {
boolean checkCompatibleAbstracts=false;//我加上的
try {//我加上的
DEBUG.P(this,"checkCompatibleAbstracts(4)");
DEBUG.P("t1="+t1);
DEBUG.P("t2="+t2);
DEBUG.P("site="+site);
Symbol sym = firstIncompatibility(t1, t2, site);
DEBUG.P("");DEBUG.P("sym="+sym);
if (sym != null) {
log.error(pos, "types.incompatible.diff.ret",
t1, t2, sym.name +
"(" + types.memberType(t2, sym).getParameterTypes() + ")");
return false;
}
checkCompatibleAbstracts=true;//我加上的
return true;
}finally{//我加上的
DEBUG.P("checkCompatibleAbstracts="+checkCompatibleAbstracts);
DEBUG.P(0,this,"checkCompatibleAbstracts(4)");
}
}
/** Return the first method which is defined with same args
* but different return types in two given interfaces, or null if none
* exists.
* @param t1 The first type.
* @param t2 The second type.
* @param site The most derived type.
* @returns symbol from t2 that conflicts with one in t1.
*/
private Symbol firstIncompatibility(Type t1, Type t2, Type site) {
try {//我加上的
DEBUG.P(this,"firstIncompatibility(3)");
DEBUG.P("t1="+t1);
DEBUG.P("t2="+t2);
DEBUG.P("site="+site);
Map<TypeSymbol,Type> interfaces1 = new HashMap<TypeSymbol,Type>();
closure(t1, interfaces1);
Map<TypeSymbol,Type> interfaces2;
if (t1 == t2)
interfaces2 = interfaces1;
else
closure(t2, interfaces1, interfaces2 = new HashMap<TypeSymbol,Type>());
DEBUG.P("");
DEBUG.P("site="+site);
DEBUG.P("interfaces1="+interfaces1);
DEBUG.P("interfaces2="+interfaces2);
for (Type t3 : interfaces1.values()) {
for (Type t4 : interfaces2.values()) {
Symbol s = firstDirectIncompatibility(t3, t4, site);
if (s != null) return s;
}
}
return null;
}finally{//我加上的
DEBUG.P(0,this,"firstIncompatibility(3)");
}
}
/** Compute all the supertypes of t, indexed by type symbol. */
private void closure(Type t, Map<TypeSymbol,Type> typeMap) {
try {//我加上的
DEBUG.P(this,"closure(2)");
DEBUG.P("t="+t+" t.tag="+TypeTags.toString(t.tag));
DEBUG.P("typeMap="+typeMap);
if (t.tag != CLASS) return;
if (typeMap.put(t.tsym, t) == null) {
closure(types.supertype(t), typeMap);
for (Type i : types.interfaces(t))
closure(i, typeMap);
}
}finally{//我加上的
DEBUG.P(0,this,"closure(2)");
}
}
/** Compute all the supertypes of t, indexed by type symbol (except thise in typesSkip). */
private void closure(Type t, Map<TypeSymbol,Type> typesSkip, Map<TypeSymbol,Type> typeMap) {
try {//我加上的
DEBUG.P(this,"closure(3)");
DEBUG.P("t="+t+" t.tag="+TypeTags.toString(t.tag));
DEBUG.P("typesSkip="+typesSkip);
DEBUG.P("typeMap="+typeMap);
if (t.tag != CLASS) return;
if (typesSkip.get(t.tsym) != null) return;
if (typeMap.put(t.tsym, t) == null) {
closure(types.supertype(t), typesSkip, typeMap);
for (Type i : types.interfaces(t))
closure(i, typesSkip, typeMap);
}
}finally{//我加上的
DEBUG.P(0,this,"closure(3)");
}
}
/** Return the first method in t2 that conflicts with a method from t1. */
private Symbol firstDirectIncompatibility(Type t1, Type t2, Type site) {
try {//我加上的
DEBUG.P(this,"firstDirectIncompatibility(3)");
DEBUG.P("t1="+t1);
DEBUG.P("t2="+t2);
DEBUG.P("site="+site);
DEBUG.P("t1.tsym.members()="+t1.tsym.members());
DEBUG.P("t2.tsym.members()="+t2.tsym.members());
for (Scope.Entry e1 = t1.tsym.members().elems; e1 != null; e1 = e1.sibling) {
Symbol s1 = e1.sym;
Type st1 = null;
DEBUG.P("s1.name="+s1.name);
DEBUG.P("s1.kind="+Kinds.toString(s1.kind));
if (s1.kind != MTH || !s1.isInheritedIn(site.tsym, types)) continue;
Symbol impl = ((MethodSymbol)s1).implementation(site.tsym, types, false);
//if (impl != null && (impl.flags() & ABSTRACT) == 0) continue;
if (impl != null && (impl.flags() & ABSTRACT) == 0) {
DEBUG.P("");
DEBUG.P("***********************");
DEBUG.P("site="+site);
DEBUG.P("与下面的type中的方法( "+s1.name+" )兼容");
DEBUG.P("t1="+t1);
DEBUG.P("所以不再与下面的type比较");
DEBUG.P("t2="+t2);
DEBUG.P("***********************");
DEBUG.P("");
continue;
}
DEBUG.P("");DEBUG.P("for.......................");
for (Scope.Entry e2 = t2.tsym.members().lookup(s1.name); e2.scope != null; e2 = e2.next()) {
Symbol s2 = e2.sym;
DEBUG.P("s2.name="+s2.name);
DEBUG.P("s2.kind="+Kinds.toString(s2.kind));
if (s1 == s2) continue;
if (s2.kind != MTH || !s2.isInheritedIn(site.tsym, types)) continue;
if (st1 == null) st1 = types.memberType(t1, s1);
Type st2 = types.memberType(t2, s2);
if (types.overrideEquivalent(st1, st2)) {
List<Type> tvars1 = st1.getTypeArguments();
List<Type> tvars2 = st2.getTypeArguments();
Type rt1 = st1.getReturnType();
Type rt2 = types.subst(st2.getReturnType(), tvars2, tvars1);
boolean compat =
types.isSameType(rt1, rt2) ||
rt1.tag >= CLASS && rt2.tag >= CLASS &&
(types.covariantReturnType(rt1, rt2, Warner.noWarnings) ||
types.covariantReturnType(rt2, rt1, Warner.noWarnings));
if (!compat) return s2;
}
}
}
return null;
}finally{//我加上的
DEBUG.P(0,this,"firstDirectIncompatibility(3)");
}
}
/** Check that a given method conforms with any method it overrides.
* @param tree The tree from which positions are extracted
* for errors.
* @param m The overriding method.
*/
void checkOverride(JCTree tree, MethodSymbol m) {
try {//我加上的
DEBUG.P(this,"checkOverride(2)");
DEBUG.P("MethodSymbol m.name="+m.name);
ClassSymbol origin = (ClassSymbol)m.owner;
DEBUG.P("origin.name="+origin.name);
DEBUG.P("origin.flags_field="+Flags.toString(origin.flags_field));
if ((origin.flags() & ENUM) != 0 && names.finalize.equals(m.name))
if (m.overrides(syms.enumFinalFinalize, origin, types, false)) {
log.error(tree.pos(), "enum.no.finalize");
return;
}
for (Type t = types.supertype(origin.type); t.tag == CLASS;
t = types.supertype(t)) {
TypeSymbol c = t.tsym;
Scope.Entry e = c.members().lookup(m.name);
DEBUG.P("e.scope="+e.scope);
while (e.scope != null) {
if (m.overrides(e.sym, origin, types, false))
checkOverride(tree, m, (MethodSymbol)e.sym, origin);
e = e.next();
}
}
}finally{//我加上的
DEBUG.P(1,this,"checkOverride(2)");
}
}
/** Check that all abstract members of given class have definitions.
* @param pos Position to be used for error reporting.
* @param c The class.
*/
void checkAllDefined(DiagnosticPosition pos, ClassSymbol c) {
DEBUG.P(this,"checkAllDefined(2)");
try {
MethodSymbol undef = firstUndef(c, c);
if (undef != null) {
if ((c.flags() & ENUM) != 0 &&
types.supertype(c.type).tsym == syms.enumSym &&
(c.flags() & FINAL) == 0) {
// add the ABSTRACT flag to an enum
c.flags_field |= ABSTRACT;
} else {
MethodSymbol undef1 =
new MethodSymbol(undef.flags(), undef.name,
types.memberType(c.type, undef), undef.owner);
log.error(pos, "does.not.override.abstract",
c, undef1, undef1.location());
}
}
} catch (CompletionFailure ex) {
completionError(pos, ex);
}
DEBUG.P(2,this,"checkAllDefined(2)");
}
//where
/** Return first abstract member of class `c' that is not defined
* in `impl', null if there is none.
*/
//impl是一个实现类，c是一个假定被impl实现的类(抽象或非抽象类、接口)
//只要在c中找到第一个没有被impl实现的抽象方法，就马上返回它，否则返回null
private MethodSymbol firstUndef(ClassSymbol impl, ClassSymbol c) {
DEBUG.P(this,"firstUndef(2)");
MethodSymbol undef = null;
DEBUG.P("ClassSymbol impl="+impl);
DEBUG.P("ClassSymbol c ="+c);
DEBUG.P("c.flags()="+Flags.toString(c.flags_field));
// Do not bother to search in classes that are not abstract,
// since they cannot have abstract members.
//c == impl这个条件用于检查非abstract类中, 含有abstract方法的情况
if (c == impl || (c.flags() & (ABSTRACT | INTERFACE)) != 0) {
Scope s = c.members();
DEBUG.P("Scope s="+s);
DEBUG.P("");
DEBUG.P("for........................开始");
for (Scope.Entry e = s.elems;
undef == null && e != null;
e = e.sibling) {
DEBUG.P("");
DEBUG.P("e.sym.name="+e.sym.name);
DEBUG.P("e.sym.kind="+Kinds.toString(e.sym.kind));
DEBUG.P("e.sym.flags()="+Flags.toString(e.sym.flags_field));
if (e.sym.kind == MTH &&
(e.sym.flags() & (ABSTRACT|IPROXY)) == ABSTRACT) {
MethodSymbol absmeth = (MethodSymbol)e.sym;
DEBUG.P("absmeth="+absmeth);
MethodSymbol implmeth = absmeth.implementation(impl, types, true);
DEBUG.P("implmeth="+implmeth);
/*
implmeth == absmeth这个条件用于检查非abstract类中,
含有abstract方法的情况
例子:
------------------------------------------------------
public class Test {
public abstract void abstractMethod();
}
错误提示:
bin\mysrc\my\test\Test.java:1: Test 不是抽象的，并且未覆盖 Test 中的抽象方法 abstractMethod()
public class Test {
^
1 错误
------------------------------------------------------
或者是在实现类impl中没有定义absmeth这个方法，
absmeth只在超类中定义，如:
------------------------------------------------------
abstract class ExtendsTestt{
public abstract void extendsTestAbstractMethod();
}
public class Test extends ExtendsTest {}
------------------------------------------------------
这时:implmeth = absmeth = extendsTestAbstractMethod()
*/
if (implmeth == null || implmeth == absmeth)
undef = absmeth;
}
}
DEBUG.P("for........................结束");
DEBUG.P("");
DEBUG.P("undef="+undef);
DEBUG.P("搜索超类........................开始");
if (undef == null) {
Type st = types.supertype(c.type);
DEBUG.P("st.tag="+TypeTags.toString(st.tag));
if (st.tag == CLASS)
undef = firstUndef(impl, (ClassSymbol)st.tsym);
}
DEBUG.P("搜索超类........................结束");
DEBUG.P("");
DEBUG.P("undef="+undef);
DEBUG.P("搜索接口........................开始");
//在for之前可以多加个if (undef == null)，这样当
//undef!=null时就不用找c.type的interfaces。
//源代码在这没加，可能是作者考虑到用户写程序时
//抽象方法没有实现的情况比已实现的情况多，也就是undef!=null
//这种情况很少出现，大多数情况下还是undef == null
for (List<Type> l = types.interfaces(c.type);
undef == null && l.nonEmpty();
l = l.tail) {
undef = firstUndef(impl, (ClassSymbol)l.head.tsym);
}
DEBUG.P("搜索接口........................结束");
}
DEBUG.P("");
DEBUG.P("undef="+undef);
DEBUG.P(0,this,"firstUndef(2)");
return undef;
}
/** Check for cyclic references. Issue an error if the
* symbol of the type referred to has a LOCKED flag set.
*
* @param pos Position to be used for error reporting.
* @param t The type referred to.
*/
void checkNonCyclic(DiagnosticPosition pos, Type t) {
DEBUG.P(this,"checkNonCyclic(2)");
checkNonCyclicInternal(pos, t);
DEBUG.P(1,this,"checkNonCyclic(2)");
}
//b10新增
void checkNonCyclic(DiagnosticPosition pos, TypeVar t) {
DEBUG.P(this,"checkNonCyclic(DiagnosticPosition pos, TypeVar t)");
checkNonCyclic1(pos, t, new HashSet<TypeVar>());
DEBUG.P(1,this,"checkNonCyclic(DiagnosticPosition pos, TypeVar t)");
}
//b10新增
private void checkNonCyclic1(DiagnosticPosition pos, Type t, Set<TypeVar> seen) {
DEBUG.P(this,"checkNonCyclic1(3)");
DEBUG.P("t="+t+" seen="+seen);
final TypeVar tv;
if (seen.contains(t)) {
tv = (TypeVar)t;
tv.bound = new ErrorType();
//循环继承 如:<V extends T,T extends V>
log.error(pos, "cyclic.inheritance", t);
} else if (t.tag == TYPEVAR) {
tv = (TypeVar)t;
seen.add(tv);
for (Type b : types.getBounds(tv))
checkNonCyclic1(pos, b, seen);
}
DEBUG.P(0,this,"checkNonCyclic1(3)");
}
/** Check for cyclic references. Issue an error if the
* symbol of the type referred to has a LOCKED flag set.
*
* @param pos Position to be used for error reporting.
* @param t The type referred to.
* @returns True if the check completed on all attributed classes
*/
private boolean checkNonCyclicInternal(DiagnosticPosition pos, Type t) {
boolean complete = true; // was the check complete?
//- System.err.println("checkNonCyclicInternal("+t+");");//DEBUG
Symbol c = t.tsym;
try {//我加上的
DEBUG.P(this,"checkNonCyclicInternal(2)");
DEBUG.P("Symbol c="+c);
DEBUG.P("c.flags_field="+Flags.toString(c.flags_field));
DEBUG.P("c.type.tag="+TypeTags.toString(c.type.tag));
DEBUG.P("c.type.isErroneous()="+c.type.isErroneous());
DEBUG.P("c.completer="+c.completer);
//flags_field是一个复合标志位,凡是出现下面的情况(先&再与0进行!=比较)
//都是用来判断flags_field是否包含所要比较的标志位,包含则为true,否则为false
//例:如果c.flags_field=public unattributed,那么if ((c.flags_field & ACYCLIC) != 0)=false
if ((c.flags_field & ACYCLIC) != 0) {
DEBUG.P(c+" 已确认不存在循环，所以不再检测，直接返回。");
return true;
}
//当同一个Symbol的flags_field在前一次置过LOCKED时,第二次checkNonCyclicInternal时
//又是同一个Symbol,说明肯定存在循环继承
if ((c.flags_field & LOCKED) != 0) {
noteCyclic(pos, (ClassSymbol)c);
} else if (!c.type.isErroneous()) {
try {
c.flags_field |= LOCKED;//加锁
if (c.type.tag == CLASS) {
ClassType clazz = (ClassType)c.type;
//检查所有实现的接口
DEBUG.P("检查 "+clazz+" 的所有接口: "+clazz.interfaces_field);
if (clazz.interfaces_field != null)
for (List<Type> l=clazz.interfaces_field; l.nonEmpty(); l=l.tail)
complete &= checkNonCyclicInternal(pos, l.head);
//检查超类
DEBUG.P("检查 "+clazz+" 的超类: "+clazz.supertype_field);
if (clazz.supertype_field != null) {
Type st = clazz.supertype_field;
if (st != null && st.tag == CLASS)
complete &= checkNonCyclicInternal(pos, st);
}
//检查外部类(通常是在Symbol c为一个内部类时，c.owner.kind == TYP)
DEBUG.P("检查 "+clazz+" 的owner: "+c.owner.type);
DEBUG.P("c.owner.kind="+Kinds.toString(c.owner.kind));
if (c.owner.kind == TYP)
complete &= checkNonCyclicInternal(pos, c.owner.type);
}
} finally {
c.flags_field &= ~LOCKED;//解锁
}
}
if (complete)
//((c.flags_field & UNATTRIBUTED) == 0)当flags_field不包含UNATTRIBUTED时为true
complete = ((c.flags_field & UNATTRIBUTED) == 0) && c.completer == null;
if (complete) c.flags_field |= ACYCLIC;
return complete;
}finally{//我加上的
DEBUG.P("");
DEBUG.P("complete="+complete);
DEBUG.P(c+".flags_field="+Flags.toString(c.flags_field));
DEBUG.P(0,this,"checkNonCyclicInternal(2)");
}
}
/** Note that we found an inheritance cycle. */
private void noteCyclic(DiagnosticPosition pos, ClassSymbol c) {
DEBUG.P(this,"noteCyclic(2)");
DEBUG.P("ClassSymbol c="+c);
log.error(pos, "cyclic.inheritance", c);
for (List<Type> l=types.interfaces(c.type); l.nonEmpty(); l=l.tail)
l.head = new ErrorType((ClassSymbol)l.head.tsym);
Type st = types.supertype(c.type);
if (st.tag == CLASS)
((ClassType)c.type).supertype_field = new ErrorType((ClassSymbol)st.tsym);
c.type = new ErrorType(c);
c.flags_field |= ACYCLIC;
DEBUG.P("c.flags_field="+Flags.toString(c.flags_field));
DEBUG.P(0,this,"noteCyclic(2)");
}
/** Check that all methods which implement some
* method conform to the method they implement.
* @param tree The class definition whose members are checked.
*/
void checkImplementations(JCClassDecl tree) {
DEBUG.P(this,"checkImplementations(1)");
checkImplementations(tree, tree.sym);
DEBUG.P(1,this,"checkImplementations(1)");
}
//where
/** Check that all methods which implement some
* method in `ic' conform to the method they implement.
*/
void checkImplementations(JCClassDecl tree, ClassSymbol ic) {
DEBUG.P(this,"checkImplementations(2)");
DEBUG.P("ClassSymbol ic="+ic);
DEBUG.P("tree.sym="+tree.sym);
ClassSymbol origin = tree.sym;
for (List<Type> l = types.closure(ic.type); l.nonEmpty(); l = l.tail) {
ClassSymbol lc = (ClassSymbol)l.head.tsym;
DEBUG.P("origin="+origin);
DEBUG.P("lc="+lc);
if ((allowGenerics || origin != lc) && (lc.flags() & ABSTRACT) != 0) {
for (Scope.Entry e=lc.members().elems; e != null; e=e.sibling) {
DEBUG.P("e.sym.name="+e.sym.name);
DEBUG.P("e.sym.kind="+com.sun.tools.javac.code.Kinds.toString(e.sym.kind));
if (e.sym.kind == MTH &&
(e.sym.flags() & (STATIC|ABSTRACT)) == ABSTRACT) {
MethodSymbol absmeth = (MethodSymbol)e.sym;
MethodSymbol implmeth = absmeth.implementation(origin, types, false);
DEBUG.P("implmeth="+implmeth);
DEBUG.P("absmeth="+absmeth);
DEBUG.P("(implmeth != absmeth)="+(implmeth != absmeth));
if (implmeth != null && implmeth != absmeth &&
(implmeth.owner.flags() & INTERFACE) ==
(origin.flags() & INTERFACE)) {
// don't check if implmeth is in a class, yet
// origin is an interface. This case arises only
// if implmeth is declared in Object. The reason is
// that interfaces really don't inherit from
// Object it's just that the compiler represents
// things that way.
checkOverride(tree, implmeth, absmeth, origin);
}
}
}
}
}
DEBUG.P(0,this,"checkImplementations(2)");
}
/** Check that all abstract methods implemented by a class are
* mutually compatible.
* @param pos Position to be used for error reporting.
* @param c The class whose interfaces are checked.
*/
void checkCompatibleSupertypes(DiagnosticPosition pos, Type c) {
try {//我加上的
DEBUG.P(this,"checkCompatibleSupertypes(2)");
DEBUG.P("c="+c);
List<Type> supertypes = types.interfaces(c);
Type supertype = types.supertype(c);
if (supertype.tag == CLASS &&
(supertype.tsym.flags() & ABSTRACT) != 0)
supertypes = supertypes.prepend(supertype);
DEBUG.P("supertypes="+supertypes);
DEBUG.P("");
for (List<Type> l = supertypes; l.nonEmpty(); l = l.tail) {
DEBUG.P("allowGenerics="+allowGenerics);
DEBUG.P("l.head.getTypeArguments()="+l.head.getTypeArguments());
if (allowGenerics && !l.head.getTypeArguments().isEmpty() &&
!checkCompatibleAbstracts(pos, l.head, l.head, c))
return;
for (List<Type> m = supertypes; m != l; m = m.tail)
if (!checkCompatibleAbstracts(pos, l.head, m.head, c))
return;
}
checkCompatibleConcretes(pos, c);
}finally{//我加上的
DEBUG.P(2,this,"checkCompatibleSupertypes(2)");
}
}
/** Check that class c does not implement directly or indirectly
* the same parameterized interface with two different argument lists.
* @param pos Position to be used for error reporting.
* @param type The type whose interfaces are checked.
*/
void checkClassBounds(DiagnosticPosition pos, Type type) {
DEBUG.P(this,"checkClassBounds(2)");
DEBUG.P("type="+type);
checkClassBounds(pos, new HashMap<TypeSymbol,Type>(), type);
DEBUG.P(0,this,"checkClassBounds(2)");
}
//where
/** Enter all interfaces of type `type' into the hash table `seensofar'
* with their class symbol as key and their type as value. Make
* sure no class is entered with two different types.
*/
void checkClassBounds(DiagnosticPosition pos,
Map<TypeSymbol,Type> seensofar,
Type type) {
try {//我加上的
DEBUG.P(this,"checkClassBounds(3)");
DEBUG.P("seensofar="+seensofar);
DEBUG.P("type="+type);
if (type.isErroneous()) return;
for (List<Type> l = types.interfaces(type); l.nonEmpty(); l = l.tail) {
Type it = l.head;
Type oldit = seensofar.put(it.tsym, it);
DEBUG.P("Type it="+it);
DEBUG.P("Type oldit="+oldit);
if (oldit != null) {
/*错误例子:
bin\mysrc\my\test\Test.java:7: 接口重复
public class Test<S,T extends ExtendsTest,E extends ExtendsTest & MyInterfaceA>
extends my.ExtendsTest.MyInnerClassStatic implements InterfaceTest<ExtendsTest,M
yInterfaceA>, InterfaceTest<ExtendsTest,Test> {
^
bin\mysrc\my\test\Test.java:7: 无法使用以下不同的参数继承 my.InterfaceTest：<my.
ExtendsTest,my.test.MyInterfaceA> 和 <my.ExtendsTest,my.test.Test>
public class Test<S,T extends ExtendsTest,E extends ExtendsTest & MyInterfaceA>
extends my.ExtendsTest.MyInnerClassStatic implements InterfaceTest<ExtendsTest,M
yInterfaceA>, InterfaceTest<ExtendsTest,Test> {
^
2 错误
打印输出:
Type it=my.InterfaceTest<my.ExtendsTest,my.test.Test>
Type oldit=my.InterfaceTest<my.ExtendsTest,my.test.MyInterfaceA>
oldparams=my.ExtendsTest,my.test.MyInterfaceA
newparams=my.ExtendsTest,my.test.Test
*/
List<Type> oldparams = oldit.allparams();
List<Type> newparams = it.allparams();
DEBUG.P("oldparams="+oldparams);
DEBUG.P("newparams="+newparams);
if (!types.containsTypeEquivalent(oldparams, newparams))
log.error(pos, "cant.inherit.diff.arg",
it.tsym, Type.toString(oldparams),
Type.toString(newparams));
}
checkClassBounds(pos, seensofar, it);
}
Type st = types.supertype(type);
DEBUG.P("st="+st);
if (st != null) checkClassBounds(pos, seensofar, st);
}finally{//我加上的
DEBUG.P(0,this,"checkClassBounds(3)");
}
}
/** Enter interface into into set.
* If it existed already, issue a "repeated interface" error.
*/
void checkNotRepeated(DiagnosticPosition pos, Type it, Set<Type> its) {
DEBUG.P(this,"checkNotRepeated(3)");
DEBUG.P("it="+it);
DEBUG.P("its="+its);
/*
bin\mysrc\my\test\Test.java:8: 接口重复
public class Test<S extends TestBound & MyInterfaceA, T> extends TestOhter<Integ
er,String> implements MyInterfaceA,MyInterfaceA,MyInterfaceB {
^
1 错误
*/
if (its.contains(it))
log.error(pos, "repeated.interface");
else {
its.add(it);
}
DEBUG.P(0,this,"checkNotRepeated(3)");
}
/* *************************************************************************
* Check annotations
**************************************************************************/
/** Annotation types are restricted to primitives, String, an
* enum, an annotation, Class, Class<?>, Class<? extends
* Anything>, arrays of the preceding.
*/
void validateAnnotationType(JCTree restype) {
// restype may be null if an error occurred, so don't bother validating it
if (restype != null) {
validateAnnotationType(restype.pos(), restype.type);
}
}
void validateAnnotationType(DiagnosticPosition pos, Type type) {
if (type.isPrimitive()) return;
if (types.isSameType(type, syms.stringType)) return;
if ((type.tsym.flags() & Flags.ENUM) != 0) return;
if ((type.tsym.flags() & Flags.ANNOTATION) != 0) return;
if (types.lowerBound(type).tsym == syms.classType.tsym) return;
//不可以是二维(多维)数组
if (types.isArray(type) && !types.isArray(types.elemtype(type))) {
validateAnnotationType(pos, types.elemtype(type));
return;
}
log.error(pos, "invalid.annotation.member.type");
}
/**
* "It is also a compile-time error if any method declared in an
* annotation type has a signature that is override-equivalent to
* that of any public or protected method declared in class Object
* or in the interface annotation.Annotation."
*
* @jls3 9.6 Annotation Types
*/
void validateAnnotationMethod(DiagnosticPosition pos, MethodSymbol m) {
DEBUG.P(this,"validateAnnotationMethod(2)");
DEBUG.P("m="+m);
/* 如:
@interface IA {
boolean equals();
int hashCode();
String toString();
}
*/
for (Type sup = syms.annotationType; sup.tag == CLASS; sup = types.supertype(sup)) {
Scope s = sup.tsym.members();
DEBUG.P("s="+s);
for (Scope.Entry e = s.lookup(m.name); e.scope != null; e = e.next()) {
if (e.sym.kind == MTH &&
(e.sym.flags() & (PUBLIC | PROTECTED)) != 0 &&
types.overrideEquivalent(m.type, e.sym.type))
log.error(pos, "intf.annotation.member.clash", e.sym, sup);
}
}
DEBUG.P(0,this,"validateAnnotationMethod(2)");
}
/** Check the annotations of a symbol.
*/
public void validateAnnotations(List<JCAnnotation> annotations, Symbol s) {
try {//我加上的
DEBUG.P(this,"validateAnnotations(2)");
//DEBUG.P("暂时跳过注释，不检测");
DEBUG.P("annotations="+annotations);
DEBUG.P("s="+s);
DEBUG.P("skipAnnotations="+skipAnnotations);
if (skipAnnotations) return;
for (JCAnnotation a : annotations)
validateAnnotation(a, s);
}finally{//我加上的
DEBUG.P(2,this,"validateAnnotations(2)");
}
}
/** Check an annotation of a symbol.
*/
public void validateAnnotation(JCAnnotation a, Symbol s) {
DEBUG.P(this,"validateAnnotation(2)");
DEBUG.P("a="+a);
DEBUG.P("s="+s);
validateAnnotation(a);
/*
if (!annotationApplicable(a, s))
log.error(a.pos(), "annotation.type.not.applicable");
if (a.annotationType.type.tsym == syms.overrideType.tsym) {
if (!isOverrider(s))
log.error(a.pos(), "method.does.not.override.superclass");
}
*/
//下面两个log.error()的位置都是a.pos()，所以当两个同时出现时，只报告一个错误
boolean annotationApplicableFlag=annotationApplicable(a, s);
DEBUG.P("annotationApplicableFlag="+annotationApplicableFlag);
if (!annotationApplicableFlag)
log.error(a.pos(), "annotation.type.not.applicable");
DEBUG.P("a.annotationType.type.tsym="+a.annotationType.type.tsym);
DEBUG.P("syms.overrideType.tsym="+syms.overrideType.tsym);
if (a.annotationType.type.tsym == syms.overrideType.tsym) {
boolean isOverriderFlag=isOverrider(s);
DEBUG.P("isOverriderFlag="+isOverriderFlag);
if (!isOverriderFlag)
log.error(a.pos(), "method.does.not.override.superclass");
}
DEBUG.P(1,this,"validateAnnotation(2)");
}
/** Is s a method symbol that overrides a method in a superclass? */
boolean isOverrider(Symbol s) {
try {//我加上的
DEBUG.P(this,"isOverrider(Symbol s)");
DEBUG.P("s="+s+" s.kind="+Kinds.toString(s.kind)+" s.isStatic()="+s.isStatic());
if (s.kind != MTH || s.isStatic()) //静态方法永远不会覆盖超类中的静态方法
return false;
MethodSymbol m = (MethodSymbol)s;
TypeSymbol owner = (TypeSymbol)m.owner;
DEBUG.P("m="+m);
DEBUG.P("owner="+owner);
for (Type sup : types.closure(owner.type)) {
if (sup == owner.type)
continue; // skip "this"
Scope scope = sup.tsym.members();
DEBUG.P("scope="+scope);
for (Scope.Entry e = scope.lookup(m.name); e.scope != null; e = e.next()) {
if (!e.sym.isStatic() && m.overrides(e.sym, owner, types, true))
return true;
}
}
return false;
}finally{//我加上的
DEBUG.P(1,this,"isOverrider(Symbol s)");
}
}
/** Is the annotation applicable to the symbol? */
boolean annotationApplicable(JCAnnotation a, Symbol s) {
try {//我加上的
DEBUG.P(this,"annotationApplicable(2)");
DEBUG.P("a="+a);
DEBUG.P("s="+s+" s.kind="+Kinds.toString(s.kind)+" s.isStatic()="+s.isStatic());
Attribute.Compound atTarget =
a.annotationType.type.tsym.attribute(syms.annotationTargetType.tsym);
DEBUG.P("atTarget="+atTarget);
if (atTarget == null) return true;
Attribute atValue = atTarget.member(names.value);
DEBUG.P("atValue="+atValue);
DEBUG.P("(!(atValue instanceof Attribute.Array))="+(!(atValue instanceof Attribute.Array)));
if (!(atValue instanceof Attribute.Array)) return true; // error recovery
Attribute.Array arr = (Attribute.Array) atValue;
for (Attribute app : arr.values) {
DEBUG.P("(!(app instanceof Attribute.Enum))="+(!(app instanceof Attribute.Enum)));
if (!(app instanceof Attribute.Enum)) return true; // recovery
Attribute.Enum e = (Attribute.Enum) app;
DEBUG.P("s.kind="+Kinds.toString(s.kind));
DEBUG.P("s.owner.kind="+Kinds.toString(s.owner.kind));
DEBUG.P("s.flags()="+Flags.toString(s.flags()));
DEBUG.P("e.value.name="+e.value.name);
if (e.value.name == names.TYPE)
{ if (s.kind == TYP) return true; }
else if (e.value.name == names.FIELD)
{ if (s.kind == VAR && s.owner.kind != MTH) return true; }
else if (e.value.name == names.METHOD)
{ if (s.kind == MTH && !s.isConstructor()) return true; }
else if (e.value.name == names.PARAMETER)
{
if (s.kind == VAR &&
s.owner.kind == MTH &&
(s.flags() & PARAMETER) != 0)
return true;
}
else if (e.value.name == names.CONSTRUCTOR)
{ if (s.kind == MTH && s.isConstructor()) return true; }
else if (e.value.name == names.LOCAL_VARIABLE)
{ if (s.kind == VAR && s.owner.kind == MTH &&
(s.flags() & PARAMETER) == 0)
return true;
}
else if (e.value.name == names.ANNOTATION_TYPE)
{ if (s.kind == TYP && (s.flags() & ANNOTATION) != 0)
return true;
}
else if (e.value.name == names.PACKAGE)
{ if (s.kind == PCK) return true; }
else
//在Annotate解析Target时发生了错误，导致e.value.name不是以上各项
return true; // recovery
}
return false;
}finally{//我加上的
DEBUG.P(0,this,"annotationApplicable(2)");
}
}
/** Check an annotation value.
*/
public void validateAnnotation(JCAnnotation a) {
try {//我加上的
DEBUG.P(this,"validateAnnotation(1)");
DEBUG.P("a="+a);
DEBUG.P("a.type="+a.type);
DEBUG.P("a.type.isErroneous()="+a.type.isErroneous());
if (a.type.isErroneous()) return;
DEBUG.P("");
DEBUG.P("a.annotationType.type.tsym="+a.annotationType.type.tsym);
DEBUG.P("a.annotationType.type.tsym.members()="+a.annotationType.type.tsym.members());
// collect an inventory of the members
Set<MethodSymbol> members = new HashSet<MethodSymbol>();
for (Scope.Entry e = a.annotationType.type.tsym.members().elems;
e != null;
e = e.sibling)
if (e.sym.kind == MTH)
members.add((MethodSymbol) e.sym);
DEBUG.P("members="+members);
DEBUG.P("");
DEBUG.P("a.args="+a.args);
DEBUG.P("for...............开始");
// count them off as they're annotated
for (JCTree arg : a.args) {
DEBUG.P("arg.tag="+arg.myTreeTag());
if (arg.tag != JCTree.ASSIGN) continue; // recovery
JCAssign assign = (JCAssign) arg;
Symbol m = TreeInfo.symbol(assign.lhs);
DEBUG.P("m="+m);
if (m == null || m.type.isErroneous()) continue;
/*
检查注释成员值是否有重复，有重复，
则编译器会报一个关键字为“duplicate.annotation.member.value”的错误。
如下源代码:
--------------------------------------------------------------------
package my.error;
@interface MyAnnotation {
String value();
}
@MyAnnotation(value="testA",value="testB")
public class duplicate_annotation_member_value {}
--------------------------------------------------------------------
编译错误提示信息如下:
--------------------------------------------------------------------
bin\mysrc\my\error\duplicate_annotation_member_value.java:5: my.error.MyAnnotation 中的注释成员值 value 重复
@MyAnnotation(value="testA",value="testB")
^
1 错误
--------------------------------------------------------------------
因为members=[value()]，a.args却有两个value，
所以第二次members.remove(m)时将返回false
(也就是value()在第一次for循环时已删除，在第二次for循环时已不存在)
*/
if (!members.remove(m))
log.error(arg.pos(), "duplicate.annotation.member.value",
m.name, a.type);
DEBUG.P("assign.rhs.tag="+assign.rhs.myTreeTag());
if (assign.rhs.tag == ANNOTATION)
validateAnnotation((JCAnnotation)assign.rhs);
}
DEBUG.P("for...............结束");
DEBUG.P("");
DEBUG.P("members="+members);
// all the remaining ones better have default values
for (MethodSymbol m : members)
if (m.defaultValue == null && !m.type.isErroneous())
log.error(a.pos(), "annotation.missing.default.value",
a.type, m.name);
DEBUG.P("a.annotationType.type.tsym="+a.annotationType.type.tsym);
DEBUG.P("syms.annotationTargetType.tsym="+syms.annotationTargetType.tsym);
DEBUG.P("a.args.tail="+a.args.tail);
// special case: java.lang.annotation.Target must not have
// repeated values in its value member
if (a.annotationType.type.tsym != syms.annotationTargetType.tsym ||
a.args.tail == null) //a.args.tail == null是@Target不加参数的情况
return;
DEBUG.P("a.args.head.tag="+a.args.head.myTreeTag());
if (a.args.head.tag != JCTree.ASSIGN) return; // error recovery
JCAssign assign = (JCAssign) a.args.head;
Symbol m = TreeInfo.symbol(assign.lhs);
DEBUG.P("m.name="+m.name);
if (m.name != names.value) return;
JCTree rhs = assign.rhs;
DEBUG.P("rhs.tag="+rhs.myTreeTag());
if (rhs.tag != JCTree.NEWARRAY) return;
JCNewArray na = (JCNewArray) rhs;
Set<Symbol> targets = new HashSet<Symbol>();
for (JCTree elem : na.elems) {
if (!targets.add(TreeInfo.symbol(elem))) {
log.error(elem.pos(), "repeated.annotation.target");
}
}
}finally{//我加上的
DEBUG.P(1,this,"validateAnnotation(1)");
}
}
void checkDeprecatedAnnotation(DiagnosticPosition pos, Symbol s) {
/*
当在javac命令行中启用“-Xlint:dep-ann”选项时，
如果javadoc文档中有@deprecated，
但是没有加“@Deprecated ”这个注释标记时，编译器就会发出警告
注意是:“-Xlint:dep-ann”选项，而不是-Xlint:deprecation
*/
DEBUG.P(this,"checkDeprecatedAnnotation(2)");
if (allowAnnotations &&
lint.isEnabled(Lint.LintCategory.DEP_ANN) &&
(s.flags() & DEPRECATED) != 0 &&
!syms.deprecatedType.isErroneous() &&
s.attribute(syms.deprecatedType.tsym) == null) {
log.warning(pos, "missing.deprecated.annotation");
}
DEBUG.P(0,this,"checkDeprecatedAnnotation(2)");
}
/* *************************************************************************
* Check for recursive annotation elements.
**************************************************************************/
/** Check for cycles in the graph of annotation elements.
*/
void checkNonCyclicElements(JCClassDecl tree) {
try {//我加上的
DEBUG.P(this,"checkNonCyclicElements(JCClassDecl tree)");
DEBUG.P("tree.sym.flags_field="+Flags.toString(tree.sym.flags_field));
if ((tree.sym.flags_field & ANNOTATION) == 0) return;
assert (tree.sym.flags_field & LOCKED) == 0;
try {
tree.sym.flags_field |= LOCKED;
for (JCTree def : tree.defs) {
if (def.tag != JCTree.METHODDEF) continue;
JCMethodDecl meth = (JCMethodDecl)def;
checkAnnotationResType(meth.pos(), meth.restype.type);
}
} finally {
tree.sym.flags_field &= ~LOCKED;
tree.sym.flags_field |= ACYCLIC_ANN;
}
}finally{//我加上的
DEBUG.P(1,this,"checkNonCyclicElements(JCClassDecl tree)");
}
}
void checkNonCyclicElementsInternal(DiagnosticPosition pos, TypeSymbol tsym) {
if ((tsym.flags_field & ACYCLIC_ANN) != 0)
return;
if ((tsym.flags_field & LOCKED) != 0) {
log.error(pos, "cyclic.annotation.element");
return;
}
try {
tsym.flags_field |= LOCKED;
for (Scope.Entry e = tsym.members().elems; e != null; e = e.sibling) {
Symbol s = e.sym;
if (s.kind != Kinds.MTH)
continue;
checkAnnotationResType(pos, ((MethodSymbol)s).type.getReturnType());
}
} finally {
tsym.flags_field &= ~LOCKED;
tsym.flags_field |= ACYCLIC_ANN;
}
}
void checkAnnotationResType(DiagnosticPosition pos, Type type) {
switch (type.tag) {
case TypeTags.CLASS:
if ((type.tsym.flags() & ANNOTATION) != 0)
checkNonCyclicElementsInternal(pos, type.tsym);
break;
case TypeTags.ARRAY:
checkAnnotationResType(pos, types.elemtype(type));
break;
default:
break; // int etc
}
}
/* *************************************************************************
* Check for cycles in the constructor call graph.
**************************************************************************/
/** Check for cycles in the graph of constructors calling other
* constructors.
*/
void checkCyclicConstructors(JCClassDecl tree) {
DEBUG.P(this,"checkCyclicConstructors(JCClassDecl tree)");
Map<Symbol,Symbol> callMap = new HashMap<Symbol, Symbol>();
// enter each constructor this-call into the map
for (List<JCTree> l = tree.defs; l.nonEmpty(); l = l.tail) {
JCMethodInvocation app = TreeInfo.firstConstructorCall(l.head);
if (app == null) continue;
JCMethodDecl meth = (JCMethodDecl) l.head;
if (TreeInfo.name(app.meth) == names._this) {
callMap.put(meth.sym, TreeInfo.symbol(app.meth));
} else {
meth.sym.flags_field |= ACYCLIC;
}
}
// Check for cycles in the map
Symbol[] ctors = new Symbol[0];
ctors = callMap.keySet().toArray(ctors);
for (Symbol caller : ctors) {
checkCyclicConstructor(tree, caller, callMap);
}
DEBUG.P(1,this,"checkCyclicConstructors(JCClassDecl tree)");
}
/** Look in the map to see if the given constructor is part of a
* call cycle.
*/
private void checkCyclicConstructor(JCClassDecl tree, Symbol ctor,
Map<Symbol,Symbol> callMap) {
if (ctor != null && (ctor.flags_field & ACYCLIC) == 0) {
if ((ctor.flags_field & LOCKED) != 0) {
log.error(TreeInfo.diagnosticPositionFor(ctor, tree),
"recursive.ctor.invocation");
} else {
ctor.flags_field |= LOCKED;
checkCyclicConstructor(tree, callMap.remove(ctor), callMap);
ctor.flags_field &= ~LOCKED;
}
ctor.flags_field |= ACYCLIC;
}
}
/* *************************************************************************
* Miscellaneous
**************************************************************************/
/**
* Return the opcode of the operator but emit an error if it is an
* error.
* @param pos position for error reporting.
* @param operator an operator
* @param tag a tree tag
* @param left type of left hand side
* @param right type of right hand side
*/
int checkOperator(DiagnosticPosition pos,
OperatorSymbol operator,
int tag,
Type left,
Type right) {
if (operator.opcode == ByteCodes.error) {
log.error(pos,
"operator.cant.be.applied",
treeinfo.operatorName(tag),
left + "," + right);
}
return operator.opcode;
}
/**
* Check for division by integer constant zero
* @param pos Position for error reporting.
* @param operator The operator for the expression
* @param operand The right hand operand for the expression
*/
void checkDivZero(DiagnosticPosition pos, Symbol operator, Type operand) {
if (operand.constValue() != null
&& lint.isEnabled(Lint.LintCategory.DIVZERO)
&& operand.tag <= LONG
&& ((Number) (operand.constValue())).longValue() == 0) {
int opc = ((OperatorSymbol)operator).opcode;
if (opc == ByteCodes.idiv || opc == ByteCodes.imod
|| opc == ByteCodes.ldiv || opc == ByteCodes.lmod) {
log.warning(pos, "div.zero");
}
}
}
/**
* Check for empty statements after if
*/
void checkEmptyIf(JCIf tree) {
if (tree.thenpart.tag == JCTree.SKIP && tree.elsepart == null && lint.isEnabled(Lint.LintCategory.EMPTY))
log.warning(tree.thenpart.pos(), "empty.if");
}
/** Check that symbol is unique in given scope.
* @param pos Position for error reporting.
* @param sym The symbol.
* @param s The scope.
*/
boolean checkUnique(DiagnosticPosition pos, Symbol sym, Scope s) {
try {//我加上的
DEBUG.P(this,"checkUnique(3)");
DEBUG.P("Scope s="+s);
DEBUG.P("sym.name="+sym.name);
DEBUG.P("sym.type.isErroneous()="+sym.type.isErroneous());
if (sym.type.isErroneous())
return true;
DEBUG.P("sym.owner.name="+sym.owner.name);
if (sym.owner.name == names.any) return false;//errSymbol见Symtab类
/*
注意这里for的结束条件不能是e.scope != null，例如在MemberEnter===>methodEnv(2)中
方法对应的scope的next指向类的scope，如果类中定义了与方法相同名称的类型变量
如:
class VisitMethodDefTest<T> {
<T> void m1(int i1,int i2) throws T{}
}
就会出现错误:
test\memberEnter\VisitMethodDefTest.java:13: 已在 test.memberEnter.VisitMethodDefTest 中定义 T
这是因为s.lookup(sym.name)会查找完所有的scope链表
*/
//for (Scope.Entry e = s.lookup(sym.name); e.scope != null; e = e.next()) {
for (Scope.Entry e = s.lookup(sym.name); e.scope == s; e = e.next()) {
DEBUG.P("e.scope="+e.scope);
DEBUG.P("e.sym="+e.sym);
if (sym != e.sym &&
sym.kind == e.sym.kind &&
sym.name != names.error &&
/*
//两个方法，不管是不是范型方法，也不管两个方法的返回值是否一样，
//只要方法名一样，参数类型一样，就认为是错误的
例如:
void m2(int[] i1) {}
<T> void m2(int... i1) {}
或
void m2(int[] i1) {}
<T> int m2(int... i1) {}
错误:
test\memberEnter\VisitMethodDefTest.java:22: 无法在 test.memberEnter.VisitMethod
DefTest 中同时声明 <T {bound=Object}>m2(int...) 和 m2(int[])
<T> int m2(int... i1) {}
^
1 错误
*/
(sym.kind != MTH || types.overrideEquivalent(sym.type, e.sym.type))) {
if ((sym.flags() & VARARGS) != (e.sym.flags() & VARARGS))
varargsDuplicateError(pos, sym, e.sym);
else
duplicateError(pos, e.sym);
return false;
}
}
return true;
}finally{//我加上的
DEBUG.P(0,this,"checkUnique(3)");
}
}
/** Check that single-type import is not already imported or top-level defined,
* but make an exception for two single-type imports which denote the same type.
* @param pos Position for error reporting.
* @param sym The symbol.
* @param s The scope
*/
boolean checkUniqueImport(DiagnosticPosition pos, Symbol sym, Scope s) {
return checkUniqueImport(pos, sym, s, false);
}
/** Check that static single-type import is not already imported or top-level defined,
* but make an exception for two single-type imports which denote the same type.
* @param pos Position for error reporting.
* @param sym The symbol.
* @param s The scope
* @param staticImport Whether or not this was a static import
*/
boolean checkUniqueStaticImport(DiagnosticPosition pos, Symbol sym, Scope s) {
try {//我加上的
DEBUG.P(this,"checkUniqueStaticImport(3)");
return checkUniqueImport(pos, sym, s, true);
}finally{//我加上的
DEBUG.P(0,this,"checkUniqueStaticImport(3)");
}
}
/** Check that single-type import is not already imported or top-level defined,
* but make an exception for two single-type imports which denote the same type.
* @param pos Position for error reporting.
* @param sym The symbol.
* @param s The scope.
* @param staticImport Whether or not this was a static import
*/
private boolean checkUniqueImport(DiagnosticPosition pos, Symbol sym, Scope s, boolean staticImport) {
try {//我加上的
DEBUG.P(this,"checkUniqueImport(4)");
DEBUG.P("Symbol sym="+sym);
DEBUG.P("Scope s="+s);
DEBUG.P("staticImport="+staticImport);
for (Scope.Entry e = s.lookup(sym.name); e.scope != null; e = e.next()) {
// is encountered class entered via a class declaration?
boolean isClassDecl = e.scope == s;
DEBUG.P("e.scope="+e.scope);
DEBUG.P("isClassDecl="+isClassDecl);
DEBUG.P("(sym != e.sym)="+(sym != e.sym));
if ((isClassDecl || sym != e.sym) &&
sym.kind == e.sym.kind &&
sym.name != names.error) {
if (!e.sym.type.isErroneous()) {
String what = e.sym.toString();
if (!isClassDecl) {
/*如:
import static my.StaticImportTest.MyInnerClassStaticPublic;
import static my.ExtendsTest.MyInnerClassStaticPublic;
import java.util.Date;
import java.sql.Date;
bin\mysrc\my\test\Test.java:5: 已在静态 single-type 导入中定义 my.StaticImportTest.MyInnerClassStaticPublic
import static my.ExtendsTest.MyInnerClassStaticPublic;
^
bin\mysrc\my\test\Test.java:7: 已在 single-type 导入中定义 java.util.Date
import java.sql.Date;
^
2 错误
*/
if (staticImport)
log.error(pos, "already.defined.static.single.import", what);
else
log.error(pos, "already.defined.single.import", what);
}
/*
src/my/test/EnterTest.java:9: 已在该编译单元中定义 my.test.InnerInterface
import static my.test.EnterTest.InnerInterface;
^
源码：
import static my.test.EnterTest.InnerInterface;
interface InnerInterface{}
public class EnterTest {
public static interface InnerInterface<T extends EnterTest> {}
public void m() {
class LocalClass{}
}
}*/
//如果是import static my.test.InnerInterface就不会报错
//因为此时sym == e.sym，虽然没报错，但是还是返回false，指明不用
//把这个sym加入env.toplevel.namedImportScope
else if (sym != e.sym)
log.error(pos, "already.defined.this.unit", what);//已在该编译单元中定义
}
return false;
}
}
return true;
}finally{//我加上的
DEBUG.P(0,this,"checkUniqueImport(4)");
}
}
/** Check that a qualified name is in canonical form (for import decls).
*/
public void checkCanonical(JCTree tree) {
DEBUG.P(this,"checkCanonical(1)");
DEBUG.P("tree="+tree);
if (!isCanonical(tree))
log.error(tree.pos(), "import.requires.canonical",
TreeInfo.symbol(tree));
DEBUG.P(0,this,"checkCanonical(1)");
}
// where
private boolean isCanonical(JCTree tree) {
while (tree.tag == JCTree.SELECT) {
JCFieldAccess s = (JCFieldAccess) tree;
DEBUG.P("s.selected="+s.selected);
DEBUG.P("s.sym.owner="+s.sym.owner);
DEBUG.P("TreeInfo.symbol(tree)="+TreeInfo.symbol(tree));
DEBUG.P("TreeInfo.symbol(s.selected)="+TreeInfo.symbol(s.selected));
if (s.sym.owner != TreeInfo.symbol(s.selected))
return false;
tree = s.selected;
}
return true;
}
private class ConversionWarner extends Warner {
final String key;
final Type found;
final Type expected;
public ConversionWarner(DiagnosticPosition pos, String key, Type found, Type expected) {
super(pos);
this.key = key;
this.found = found;
this.expected = expected;
}
public void warnUnchecked() {
boolean warned = this.warned;
super.warnUnchecked();
if (warned) return; // suppress redundant diagnostics
Object problem = JCDiagnostic.fragment(key);
Check.this.warnUnchecked(pos(), "prob.found.req", problem, found, expected);
}
}
public Warner castWarner(DiagnosticPosition pos, Type found, Type expected) {
return new ConversionWarner(pos, "unchecked.cast.to.type", found, expected);
}
public Warner convertWarner(DiagnosticPosition pos, Type found, Type expected) {
return new ConversionWarner(pos, "unchecked.assign", found, expected);
}
}