/*
* 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 javax.lang.model.element.ElementKind;
import com.sun.tools.javac.code.*;
import com.sun.tools.javac.code.Symbol.*;
import com.sun.tools.javac.tree.*;
import com.sun.tools.javac.tree.JCTree.*;
import com.sun.tools.javac.util.*;
import com.sun.tools.javac.util.JCDiagnostic.DiagnosticPosition;
import com.sun.tools.javac.util.List;
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 pass translates Generic Java to conventional Java.
*
* <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 TransTypes extends TreeTranslator {
/** The context key for the TransTypes phase. */
protected static final Context.Key<TransTypes> transTypesKey =
new Context.Key<TransTypes>();
/** Get the instance for this context. */
public static TransTypes instance(Context context) {
TransTypes instance = context.get(transTypesKey);
if (instance == null)
instance = new TransTypes(context);
return instance;
}
private Names names;
private Log log;
private Symtab syms;
private TreeMaker make;
private Enter enter;
private boolean allowEnums;
private Types types;
private final Resolve resolve;
/**
* Flag to indicate whether or not to generate bridge methods.
* For pre-Tiger source there is no need for bridge methods, so it
* can be skipped to get better performance for -source 1.4 etc.
*/
private final boolean addBridges;
protected TransTypes(Context context) {
context.put(transTypesKey, this);
names = Names.instance(context);
log = Log.instance(context);
syms = Symtab.instance(context);
enter = Enter.instance(context);
overridden = new HashMap<MethodSymbol,MethodSymbol>();
Source source = Source.instance(context);
allowEnums = source.allowEnums();
addBridges = source.addBridges();
types = Types.instance(context);
make = TreeMaker.instance(context);
resolve = Resolve.instance(context);
}
/** A hashtable mapping bridge methods to the methods they override after
* type erasure.
*/
Map<MethodSymbol,MethodSymbol> overridden;
/** Construct an attributed tree for a cast of expression to target type,
* unless it already has precisely that type.
* @param tree The expression tree.
* @param target The target type.
*/
JCExpression cast(JCExpression tree, Type target) {
int oldpos = make.pos;
make.at(tree.pos);
if (!types.isSameType(tree.type, target)) {
if (!resolve.isAccessible(env, target.tsym))
resolve.logAccessError(env, tree, target);
tree = make.TypeCast(make.Type(target), tree).setType(target);
}
make.pos = oldpos;
return tree;
}
/** Construct an attributed tree to coerce an expression to some erased
* target type, unless the expression is already assignable to that type.
* If target type is a constant type, use its base type instead.
* @param tree The expression tree.
* @param target The target type.
*/
JCExpression coerce(JCExpression tree, Type target) {
Type btarget = target.baseType();
if (tree.type.isPrimitive() == target.isPrimitive()) {
return types.isAssignable(tree.type, btarget, Warner.noWarnings)
? tree
: cast(tree, btarget);
}
return tree;
}
/** Given an erased reference type, assume this type as the tree's type.
* Then, coerce to some given target type unless target type is null.
* This operation is used in situations like the following:
*
* class Cell<A> { A value; }
* ...
* Cell<Integer> cell;
* Integer x = cell.value;
*
* Since the erasure of Cell.value is Object, but the type
* of cell.value in the assignment is Integer, we need to
* adjust the original type of cell.value to Object, and insert
* a cast to Integer. That is, the last assignment becomes:
*
* Integer x = (Integer)cell.value;
*
* @param tree The expression tree whose type might need adjustment.
* @param erasedType The expression's type after erasure.
* @param target The target type, which is usually the erasure of the
* expression's original type.
*/
JCExpression retype(JCExpression tree, Type erasedType, Type target) {
// System.err.println("retype " + tree + " to " + erasedType);//DEBUG
if (erasedType.tag > lastBaseTag) {
if (target != null && target.isPrimitive())
target = erasure(tree.type);
tree.type = erasedType;
if (target != null) return coerce(tree, target);
}
return tree;
}
/** Translate method argument list, casting each argument
* to its corresponding type in a list of target types.
* @param _args The method argument list.
* @param parameters The list of target types.
* @param varargsElement The erasure of the varargs element type,
* or null if translating a non-varargs invocation
*/
<T extends JCTree> List<T> translateArgs(List<T> _args,
List<Type> parameters,
Type varargsElement) {
if (parameters.isEmpty()) return _args;
List<T> args = _args;
while (parameters.tail.nonEmpty()) {
args.head = translate(args.head, parameters.head);
args = args.tail;
parameters = parameters.tail;
}
Type parameter = parameters.head;
Assert.check(varargsElement != null || args.length() == 1);
if (varargsElement != null) {
while (args.nonEmpty()) {
args.head = translate(args.head, varargsElement);
args = args.tail;
}
} else {
args.head = translate(args.head, parameter);
}
return _args;
}
/** Add a bridge definition and enter corresponding method symbol in
* local scope of origin.
*
* @param pos The source code position to be used for the definition.
* @param meth The method for which a bridge needs to be added
* @param impl That method's implementation (possibly the method itself)
* @param origin The class to which the bridge will be added
* @param hypothetical
* True if the bridge method is not strictly necessary in the
* binary, but is represented in the symbol table to detect
* erasure clashes.
* @param bridges The list buffer to which the bridge will be added
*/
void addBridge(DiagnosticPosition pos,
MethodSymbol meth,
MethodSymbol impl,
ClassSymbol origin,
boolean hypothetical,
ListBuffer<JCTree> bridges) {
make.at(pos);
Type origType = types.memberType(origin.type, meth);
Type origErasure = erasure(origType);
// Create a bridge method symbol and a bridge definition without a body.
Type bridgeType = meth.erasure(types);
long flags = impl.flags() & AccessFlags | SYNTHETIC | BRIDGE;
if (hypothetical) flags |= HYPOTHETICAL;
MethodSymbol bridge = new MethodSymbol(flags,
meth.name,
bridgeType,
origin);
if (!hypothetical) {
JCMethodDecl md = make.MethodDef(bridge, null);
// The bridge calls this.impl(..), if we have an implementation
// in the current class, super.impl(...) otherwise.
JCExpression receiver = (impl.owner == origin)
? make.This(origin.erasure(types))
: make.Super(types.supertype(origin.type).tsym.erasure(types), origin);
// The type returned from the original method.
Type calltype = erasure(impl.type.getReturnType());
// Construct a call of this.impl(params), or super.impl(params),
// casting params and possibly results as needed.
JCExpression call =
make.Apply(
null,
make.Select(receiver, impl).setType(calltype),
translateArgs(make.Idents(md.params), origErasure.getParameterTypes(), null))
.setType(calltype);
JCStatement stat = (origErasure.getReturnType().tag == VOID)
? make.Exec(call)
: make.Return(coerce(call, bridgeType.getReturnType()));
md.body = make.Block(0, List.of(stat));
// Add bridge to `bridges' buffer
bridges.append(md);
}
// Add bridge to scope of enclosing class and `overridden' table.
origin.members().enter(bridge);
overridden.put(bridge, meth);
}
/** Add bridge if given symbol is a non-private, non-static member
* of the given class, which is either defined in the class or non-final
* inherited, and one of the two following conditions holds:
* 1. The method's type changes in the given class, as compared to the
* class where the symbol was defined, (in this case
* we have extended a parameterized class with non-trivial parameters).
* 2. The method has an implementation with a different erased return type.
* (in this case we have used co-variant returns).
* If a bridge already exists in some other class, no new bridge is added.
* Instead, it is checked that the bridge symbol overrides the method symbol.
* (Spec ???).
* todo: what about bridges for privates???
*
* @param pos The source code position to be used for the definition.
* @param sym The symbol for which a bridge might have to be added.
* @param origin The class in which the bridge would go.
* @param bridges The list buffer to which the bridge would be added.
*/
void addBridgeIfNeeded(DiagnosticPosition pos,
Symbol sym,
ClassSymbol origin,
ListBuffer<JCTree> bridges) {
if (sym.kind == MTH &&
sym.name != names.init &&
(sym.flags() & (PRIVATE | STATIC)) == 0 &&
(sym.flags() & (SYNTHETIC | OVERRIDE_BRIDGE)) != SYNTHETIC &&
sym.isMemberOf(origin, types))
{
MethodSymbol meth = (MethodSymbol)sym;
MethodSymbol bridge = meth.binaryImplementation(origin, types);
MethodSymbol impl = meth.implementation(origin, types, true, overrideBridgeFilter);
if (bridge == null ||
bridge == meth ||
(impl != null && !bridge.owner.isSubClass(impl.owner, types))) {
// No bridge was added yet.
if (impl != null && isBridgeNeeded(meth, impl, origin.type)) {
addBridge(pos, meth, impl, origin, bridge==impl, bridges);
} else if (impl == meth
&& impl.owner != origin
&& (impl.flags() & FINAL) == 0
&& (meth.flags() & (ABSTRACT|PUBLIC)) == PUBLIC
&& (origin.flags() & PUBLIC) > (impl.owner.flags() & PUBLIC)) {
// this is to work around a horrible but permanent
// reflection design error.
addBridge(pos, meth, impl, origin, false, bridges);
}
} else if ((bridge.flags() & (SYNTHETIC | OVERRIDE_BRIDGE)) == SYNTHETIC) {
MethodSymbol other = overridden.get(bridge);
if (other != null && other != meth) {
if (impl == null || !impl.overrides(other, origin, types, true)) {
// Bridge for other symbol pair was added
log.error(pos, "name.clash.same.erasure.no.override",
other, other.location(origin.type, types),
meth, meth.location(origin.type, types));
}
}
} else if (!bridge.overrides(meth, origin, types, true)) {
// Accidental binary override without source override.
if (bridge.owner == origin ||
types.asSuper(bridge.owner.type, meth.owner) == null)
// Don't diagnose the problem if it would already
// have been reported in the superclass
log.error(pos, "name.clash.same.erasure.no.override",
bridge, bridge.location(origin.type, types),
meth, meth.location(origin.type, types));
}
}
}
// where
Filter<Symbol> overrideBridgeFilter = new Filter<Symbol>() {
public boolean accepts(Symbol s) {
return (s.flags() & (SYNTHETIC | OVERRIDE_BRIDGE)) != SYNTHETIC;
}
};
/**
* @param method The symbol for which a bridge might have to be added
* @param impl The implementation of method
* @param dest The type in which the bridge would go
*/
private boolean isBridgeNeeded(MethodSymbol method,
MethodSymbol impl,
Type dest) {
if (impl != method) {
// If either method or impl have different erasures as
// members of dest, a bridge is needed.
Type method_erasure = method.erasure(types);
if (!isSameMemberWhenErased(dest, method, method_erasure))
return true;
Type impl_erasure = impl.erasure(types);
if (!isSameMemberWhenErased(dest, impl, impl_erasure))
return true;
// If the erasure of the return type is different, a
// bridge is needed.
return !types.isSameType(impl_erasure.getReturnType(),
method_erasure.getReturnType());
} else {
// method and impl are the same...
if ((method.flags() & ABSTRACT) != 0) {
// ...and abstract so a bridge is not needed.
// Concrete subclasses will bridge as needed.
return false;
}
// The erasure of the return type is always the same
// for the same symbol. Reducing the three tests in
// the other branch to just one:
return !isSameMemberWhenErased(dest, method, method.erasure(types));
}
}
/**
* Lookup the method as a member of the type. Compare the
* erasures.
* @param type the class where to look for the method
* @param method the method to look for in class
* @param erasure the erasure of method
*/
private boolean isSameMemberWhenErased(Type type,
MethodSymbol method,
Type erasure) {
return types.isSameType(erasure(types.memberType(type, method)),
erasure);
}
void addBridges(DiagnosticPosition pos,
TypeSymbol i,
ClassSymbol origin,
ListBuffer<JCTree> bridges) {
for (Scope.Entry e = i.members().elems; e != null; e = e.sibling)
addBridgeIfNeeded(pos, e.sym, origin, bridges);
for (List<Type> l = types.interfaces(i.type); l.nonEmpty(); l = l.tail)
addBridges(pos, l.head.tsym, origin, bridges);
}
/** Add all necessary bridges to some class appending them to list buffer.
* @param pos The source code position to be used for the bridges.
* @param origin The class in which the bridges go.
* @param bridges The list buffer to which the bridges are added.
*/
void addBridges(DiagnosticPosition pos, ClassSymbol origin, ListBuffer<JCTree> bridges) {
Type st = types.supertype(origin.type);
while (st.tag == CLASS) {
// if (isSpecialization(st))
addBridges(pos, st.tsym, origin, bridges);
st = types.supertype(st);
}
for (List<Type> l = types.interfaces(origin.type); l.nonEmpty(); l = l.tail)
// if (isSpecialization(l.head))
addBridges(pos, l.head.tsym, origin, bridges);
}
/* ************************************************************************
* Visitor methods
*************************************************************************/
/** Visitor argument: proto-type.
*/
private Type pt;
/** Visitor method: perform a type translation on tree.
*/
public <T extends JCTree> T translate(T tree, Type pt) {
Type prevPt = this.pt;
try {
this.pt = pt;
return translate(tree);
} finally {
this.pt = prevPt;
}
}
/** Visitor method: perform a type translation on list of trees.
*/
public <T extends JCTree> List<T> translate(List<T> trees, Type pt) {
Type prevPt = this.pt;
List<T> res;
try {
this.pt = pt;
res = translate(trees);
} finally {
this.pt = prevPt;
}
return res;
}
public void visitClassDef(JCClassDecl tree) {
translateClass(tree.sym);
result = tree;
}
JCMethodDecl currentMethod = null;
public void visitMethodDef(JCMethodDecl tree) {
JCMethodDecl previousMethod = currentMethod;
try {
currentMethod = tree;
tree.restype = translate(tree.restype, null);
tree.typarams = List.nil();
tree.params = translateVarDefs(tree.params);
tree.thrown = translate(tree.thrown, null);
tree.body = translate(tree.body, tree.sym.erasure(types).getReturnType());
tree.type = erasure(tree.type);
result = tree;
} finally {
currentMethod = previousMethod;
}
// Check that we do not introduce a name clash by erasing types.
for (Scope.Entry e = tree.sym.owner.members().lookup(tree.name);
e.sym != null;
e = e.next()) {
if (e.sym != tree.sym &&
types.isSameType(erasure(e.sym.type), tree.type)) {
log.error(tree.pos(),
"name.clash.same.erasure", tree.sym,
e.sym);
return;
}
}
}
public void visitVarDef(JCVariableDecl tree) {
tree.vartype = translate(tree.vartype, null);
tree.init = translate(tree.init, tree.sym.erasure(types));
tree.type = erasure(tree.type);
result = tree;
}
public void visitDoLoop(JCDoWhileLoop tree) {
tree.body = translate(tree.body);
tree.cond = translate(tree.cond, syms.booleanType);
result = tree;
}
public void visitWhileLoop(JCWhileLoop tree) {
tree.cond = translate(tree.cond, syms.booleanType);
tree.body = translate(tree.body);
result = tree;
}
public void visitForLoop(JCForLoop tree) {
tree.init = translate(tree.init, null);
if (tree.cond != null)
tree.cond = translate(tree.cond, syms.booleanType);
tree.step = translate(tree.step, null);
tree.body = translate(tree.body);
result = tree;
}
public void visitForeachLoop(JCEnhancedForLoop tree) {
tree.var = translate(tree.var, null);
Type iterableType = tree.expr.type;
tree.expr = translate(tree.expr, erasure(tree.expr.type));
if (types.elemtype(tree.expr.type) == null)
tree.expr.type = iterableType; // preserve type for Lower
tree.body = translate(tree.body);
result = tree;
}
public void visitSwitch(JCSwitch tree) {
Type selsuper = types.supertype(tree.selector.type);
boolean enumSwitch = selsuper != null &&
selsuper.tsym == syms.enumSym;
Type target = enumSwitch ? erasure(tree.selector.type) : syms.intType;
tree.selector = translate(tree.selector, target);
tree.cases = translateCases(tree.cases);
result = tree;
}
public void visitCase(JCCase tree) {
tree.pat = translate(tree.pat, null);
tree.stats = translate(tree.stats);
result = tree;
}
public void visitSynchronized(JCSynchronized tree) {
tree.lock = translate(tree.lock, erasure(tree.lock.type));
tree.body = translate(tree.body);
result = tree;
}
public void visitTry(JCTry tree) {
tree.resources = translate(tree.resources, syms.autoCloseableType);
tree.body = translate(tree.body);
tree.catchers = translateCatchers(tree.catchers);
tree.finalizer = translate(tree.finalizer);
result = tree;
}
public void visitConditional(JCConditional tree) {
tree.cond = translate(tree.cond, syms.booleanType);
tree.truepart = translate(tree.truepart, erasure(tree.type));
tree.falsepart = translate(tree.falsepart, erasure(tree.type));
tree.type = erasure(tree.type);
result = retype(tree, tree.type, pt);
}
public void visitIf(JCIf tree) {
tree.cond = translate(tree.cond, syms.booleanType);
tree.thenpart = translate(tree.thenpart);
tree.elsepart = translate(tree.elsepart);
result = tree;
}
public void visitExec(JCExpressionStatement tree) {
tree.expr = translate(tree.expr, null);
result = tree;
}
public void visitReturn(JCReturn tree) {
tree.expr = translate(tree.expr, currentMethod.sym.erasure(types).getReturnType());
result = tree;
}
public void visitThrow(JCThrow tree) {
tree.expr = translate(tree.expr, erasure(tree.expr.type));
result = tree;
}
public void visitAssert(JCAssert tree) {
tree.cond = translate(tree.cond, syms.booleanType);
if (tree.detail != null)
tree.detail = translate(tree.detail, erasure(tree.detail.type));
result = tree;
}
public void visitApply(JCMethodInvocation tree) {
tree.meth = translate(tree.meth, null);
Symbol meth = TreeInfo.symbol(tree.meth);
Type mt = meth.erasure(types);
List<Type> argtypes = mt.getParameterTypes();
if (allowEnums &&
meth.name==names.init &&
meth.owner == syms.enumSym)
argtypes = argtypes.tail.tail;
if (tree.varargsElement != null)
tree.varargsElement = types.erasure(tree.varargsElement);
else
Assert.check(tree.args.length() == argtypes.length());
tree.args = translateArgs(tree.args, argtypes, tree.varargsElement);
// Insert casts of method invocation results as needed.
result = retype(tree, mt.getReturnType(), pt);
}
public void visitNewClass(JCNewClass tree) {
if (tree.encl != null)
tree.encl = translate(tree.encl, erasure(tree.encl.type));
tree.clazz = translate(tree.clazz, null);
if (tree.varargsElement != null)
tree.varargsElement = types.erasure(tree.varargsElement);
tree.args = translateArgs(
tree.args, tree.constructor.erasure(types).getParameterTypes(), tree.varargsElement);
tree.def = translate(tree.def, null);
tree.type = erasure(tree.type);
result = tree;
}
public void visitNewArray(JCNewArray tree) {
tree.elemtype = translate(tree.elemtype, null);
translate(tree.dims, syms.intType);
if (tree.type != null) {
tree.elems = translate(tree.elems, erasure(types.elemtype(tree.type)));
tree.type = erasure(tree.type);
} else {
tree.elems = translate(tree.elems, null);
}
result = tree;
}
public void visitParens(JCParens tree) {
tree.expr = translate(tree.expr, pt);
tree.type = erasure(tree.type);
result = tree;
}
public void visitAssign(JCAssign tree) {
tree.lhs = translate(tree.lhs, null);
tree.rhs = translate(tree.rhs, erasure(tree.lhs.type));
tree.type = erasure(tree.type);
result = tree;
}
public void visitAssignop(JCAssignOp tree) {
tree.lhs = translate(tree.lhs, null);
tree.rhs = translate(tree.rhs, tree.operator.type.getParameterTypes().tail.head);
tree.type = erasure(tree.type);
result = tree;
}
public void visitUnary(JCUnary tree) {
tree.arg = translate(tree.arg, tree.operator.type.getParameterTypes().head);
result = tree;
}
public void visitBinary(JCBinary tree) {
tree.lhs = translate(tree.lhs, tree.operator.type.getParameterTypes().head);
tree.rhs = translate(tree.rhs, tree.operator.type.getParameterTypes().tail.head);
result = tree;
}
public void visitTypeCast(JCTypeCast tree) {
tree.clazz = translate(tree.clazz, null);
tree.type = erasure(tree.type);
tree.expr = translate(tree.expr, tree.type);
result = tree;
}
public void visitTypeTest(JCInstanceOf tree) {
tree.expr = translate(tree.expr, null);
tree.clazz = translate(tree.clazz, null);
result = tree;
}
public void visitIndexed(JCArrayAccess tree) {
tree.indexed = translate(tree.indexed, erasure(tree.indexed.type));
tree.index = translate(tree.index, syms.intType);
// Insert casts of indexed expressions as needed.
result = retype(tree, types.elemtype(tree.indexed.type), pt);
}
// There ought to be nothing to rewrite here;
// we don't generate code.
public void visitAnnotation(JCAnnotation tree) {
result = tree;
}
public void visitIdent(JCIdent tree) {
Type et = tree.sym.erasure(types);
// Map type variables to their bounds.
if (tree.sym.kind == TYP && tree.sym.type.tag == TYPEVAR) {
result = make.at(tree.pos).Type(et);
} else
// Map constants expressions to themselves.
if (tree.type.constValue() != null) {
result = tree;
}
// Insert casts of variable uses as needed.
else if (tree.sym.kind == VAR) {
result = retype(tree, et, pt);
}
else {
tree.type = erasure(tree.type);
result = tree;
}
}
public void visitSelect(JCFieldAccess tree) {
Type t = tree.selected.type;
while (t.tag == TYPEVAR)
t = t.getUpperBound();
if (t.isCompound()) {
if ((tree.sym.flags() & IPROXY) != 0) {
tree.sym = ((MethodSymbol)tree.sym).
implemented((TypeSymbol)tree.sym.owner, types);
}
tree.selected = coerce(
translate(tree.selected, erasure(tree.selected.type)),
erasure(tree.sym.owner.type));
} else
tree.selected = translate(tree.selected, erasure(t));
// Map constants expressions to themselves.
if (tree.type.constValue() != null) {
result = tree;
}
// Insert casts of variable uses as needed.
else if (tree.sym.kind == VAR) {
result = retype(tree, tree.sym.erasure(types), pt);
}
else {
tree.type = erasure(tree.type);
result = tree;
}
}
public void visitTypeArray(JCArrayTypeTree tree) {
tree.elemtype = translate(tree.elemtype, null);
tree.type = erasure(tree.type);
result = tree;
}
/** Visitor method for parameterized types.
*/
public void visitTypeApply(JCTypeApply tree) {
JCTree clazz = translate(tree.clazz, null);
result = clazz;
}
/**************************************************************************
* utility methods
*************************************************************************/
private Type erasure(Type t) {
return types.erasure(t);
}
private boolean boundsRestricted(ClassSymbol c) {
Type st = types.supertype(c.type);
if (st.isParameterized()) {
List<Type> actuals = st.allparams();
List<Type> formals = st.tsym.type.allparams();
while (!actuals.isEmpty() && !formals.isEmpty()) {
Type actual = actuals.head;
Type formal = formals.head;
if (!types.isSameType(types.erasure(actual),
types.erasure(formal)))
return true;
actuals = actuals.tail;
formals = formals.tail;
}
}
return false;
}
private List<JCTree> addOverrideBridgesIfNeeded(DiagnosticPosition pos,
final ClassSymbol c) {
ListBuffer<JCTree> buf = ListBuffer.lb();
if (c.isInterface() || !boundsRestricted(c))
return buf.toList();
Type t = types.supertype(c.type);
Scope s = t.tsym.members();
if (s.elems != null) {
for (Symbol sym : s.getElements(new NeedsOverridBridgeFilter(c))) {
MethodSymbol m = (MethodSymbol)sym;
MethodSymbol member = (MethodSymbol)m.asMemberOf(c.type, types);
MethodSymbol impl = m.implementation(c, types, false);
if ((impl == null || impl.owner != c) &&
!types.isSameType(member.erasure(types), m.erasure(types))) {
addOverrideBridges(pos, m, member, c, buf);
}
}
}
return buf.toList();
}
// where
class NeedsOverridBridgeFilter implements Filter<Symbol> {
ClassSymbol c;
NeedsOverridBridgeFilter(ClassSymbol c) {
this.c = c;
}
public boolean accepts(Symbol s) {
return s.kind == MTH &&
!s.isConstructor() &&
s.isInheritedIn(c, types) &&
(s.flags() & FINAL) == 0 &&
(s.flags() & (SYNTHETIC | OVERRIDE_BRIDGE)) != SYNTHETIC;
}
}
private void addOverrideBridges(DiagnosticPosition pos,
MethodSymbol impl,
MethodSymbol member,
ClassSymbol c,
ListBuffer<JCTree> bridges) {
Type implErasure = impl.erasure(types);
long flags = (impl.flags() & AccessFlags) | SYNTHETIC | BRIDGE | OVERRIDE_BRIDGE;
member = new MethodSymbol(flags, member.name, member.type, c);
JCMethodDecl md = make.MethodDef(member, null);
JCExpression receiver = make.Super(types.supertype(c.type).tsym.erasure(types), c);
Type calltype = erasure(impl.type.getReturnType());
JCExpression call =
make.Apply(null,
make.Select(receiver, impl).setType(calltype),
translateArgs(make.Idents(md.params),
implErasure.getParameterTypes(), null))
.setType(calltype);
JCStatement stat = (member.getReturnType().tag == VOID)
? make.Exec(call)
: make.Return(coerce(call, member.erasure(types).getReturnType()));
md.body = make.Block(0, List.of(stat));
c.members().enter(member);
bridges.append(md);
}
/**************************************************************************
* main method
*************************************************************************/
private Env<AttrContext> env;
void translateClass(ClassSymbol c) {
Type st = types.supertype(c.type);
// process superclass before derived
if (st.tag == CLASS)
translateClass((ClassSymbol)st.tsym);
Env<AttrContext> myEnv = enter.typeEnvs.remove(c);
if (myEnv == null)
return;
Env<AttrContext> oldEnv = env;
try {
env = myEnv;
// class has not been translated yet
TreeMaker savedMake = make;
Type savedPt = pt;
make = make.forToplevel(env.toplevel);
pt = null;
try {
JCClassDecl tree = (JCClassDecl) env.tree;
tree.typarams = List.nil();
super.visitClassDef(tree);
make.at(tree.pos);
if (addBridges) {
ListBuffer<JCTree> bridges = new ListBuffer<JCTree>();
if (false) //see CR: 6996415
bridges.appendList(addOverrideBridgesIfNeeded(tree, c));
if ((tree.sym.flags() & INTERFACE) == 0)
addBridges(tree.pos(), tree.sym, bridges);
tree.defs = bridges.toList().prependList(tree.defs);
}
tree.type = erasure(tree.type);
} finally {
make = savedMake;
pt = savedPt;
}
} finally {
env = oldEnv;
}
}
/** Translate a toplevel class definition.
* @param cdef The definition to be translated.
*/
public JCTree translateTopLevelClass(JCTree cdef, TreeMaker make) {
// note that this method does NOT support recursion.
this.make = make;
pt = null;
return translate(cdef, null);
}
}