6369605: Unconstrained type variables fails to include bounds
Summary: unconstrained type-variables with recursive bounds are not inferred properly
Reviewed-by: jjg
--- a/langtools/src/share/classes/com/sun/tools/javac/code/Type.java Mon Aug 16 14:56:23 2010 +0100
+++ b/langtools/src/share/classes/com/sun/tools/javac/code/Type.java Mon Aug 16 14:58:10 2010 +0100
@@ -347,11 +347,17 @@
return false;
}
- /** Does this type contain an occurrence of some type in `elems'?
+ /** Does this type contain an occurrence of some type in 'ts'?
*/
- public boolean containsSome(List<Type> ts) {
- for (List<Type> l = ts; l.nonEmpty(); l = l.tail)
- if (this.contains(ts.head)) return true;
+ public boolean containsAny(List<Type> ts) {
+ for (Type t : ts)
+ if (this.contains(t)) return true;
+ return false;
+ }
+
+ public static boolean containsAny(List<Type> ts1, List<Type> ts2) {
+ for (Type t : ts1)
+ if (t.containsAny(ts2)) return true;
return false;
}
@@ -431,6 +437,10 @@
this.bound = bound;
}
+ public boolean contains(Type t) {
+ return kind != UNBOUND && type.contains(t);
+ }
+
public boolean isSuperBound() {
return kind == SUPER ||
kind == UNBOUND;
@@ -681,7 +691,9 @@
return
elem == this
|| (isParameterized()
- && (getEnclosingType().contains(elem) || contains(getTypeArguments(), elem)));
+ && (getEnclosingType().contains(elem) || contains(getTypeArguments(), elem)))
+ || (isCompound()
+ && (supertype_field.contains(elem) || contains(interfaces_field, elem)));
}
public void complete() {
--- a/langtools/src/share/classes/com/sun/tools/javac/comp/Infer.java Mon Aug 16 14:56:23 2010 +0100
+++ b/langtools/src/share/classes/com/sun/tools/javac/comp/Infer.java Mon Aug 16 14:58:10 2010 +0100
@@ -138,24 +138,73 @@
/** A mapping that returns its type argument with every UndetVar replaced
* by its `inst' field. Throws a NoInstanceException
* if this not possible because an `inst' field is null.
+ * Note: mutually referring undertvars will be left uninstantiated
+ * (that is, they will be replaced by the underlying type-variable).
*/
+
Mapping getInstFun = new Mapping("getInstFun") {
public Type apply(Type t) {
switch (t.tag) {
- case UNKNOWN:
- throw ambiguousNoInstanceException
- .setMessage("undetermined.type");
- case UNDETVAR:
- UndetVar that = (UndetVar) t;
- if (that.inst == null)
+ case UNKNOWN:
throw ambiguousNoInstanceException
- .setMessage("type.variable.has.undetermined.type",
- that.qtype);
- return apply(that.inst);
- default:
- return t.map(this);
+ .setMessage("undetermined.type");
+ case UNDETVAR:
+ UndetVar that = (UndetVar) t;
+ if (that.inst == null)
+ throw ambiguousNoInstanceException
+ .setMessage("type.variable.has.undetermined.type",
+ that.qtype);
+ return isConstraintCyclic(that) ?
+ that.qtype :
+ apply(that.inst);
+ default:
+ return t.map(this);
}
}
+
+ private boolean isConstraintCyclic(UndetVar uv) {
+ Types.UnaryVisitor<Boolean> constraintScanner =
+ new Types.UnaryVisitor<Boolean>() {
+
+ List<Type> seen = List.nil();
+
+ Boolean visit(List<Type> ts) {
+ for (Type t : ts) {
+ if (visit(t)) return true;
+ }
+ return false;
+ }
+
+ public Boolean visitType(Type t, Void ignored) {
+ return false;
+ }
+
+ @Override
+ public Boolean visitClassType(ClassType t, Void ignored) {
+ if (t.isCompound()) {
+ return visit(types.supertype(t)) ||
+ visit(types.interfaces(t));
+ } else {
+ return visit(t.getTypeArguments());
+ }
+ }
+ @Override
+ public Boolean visitWildcardType(WildcardType t, Void ignored) {
+ return visit(t.type);
+ }
+
+ @Override
+ public Boolean visitUndetVar(UndetVar t, Void ignored) {
+ if (seen.contains(t)) {
+ return true;
+ } else {
+ seen = seen.prepend(t);
+ return visit(t.inst);
+ }
+ }
+ };
+ return constraintScanner.visit(uv);
+ }
};
/***************************************************************************
@@ -257,10 +306,9 @@
TypeVar tv = (TypeVar)uv.qtype;
ListBuffer<Type> hibounds = new ListBuffer<Type>();
for (Type t : that.getConstraints(tv, ConstraintKind.EXTENDS)) {
- if (!t.containsSome(that.tvars) && t.tag != BOT) {
- hibounds.append(t);
- }
+ hibounds.append(types.subst(t, that.tvars, undetvars));
}
+
List<Type> inst = that.getConstraints(tv, ConstraintKind.EQUAL);
if (inst.nonEmpty() && inst.head.tag != BOT) {
uv.inst = inst.head;
@@ -279,9 +327,32 @@
// check bounds
List<Type> targs = Type.map(undetvars, getInstFun);
- targs = types.subst(targs, that.tvars, targs);
+ if (Type.containsAny(targs, that.tvars)) {
+ //replace uninferred type-vars
+ targs = types.subst(targs,
+ that.tvars,
+ instaniateAsUninferredVars(undetvars, that.tvars));
+ }
return chk.checkType(warn.pos(), that.inst(targs, types), to);
}
+ //where
+ private List<Type> instaniateAsUninferredVars(List<Type> undetvars, List<Type> tvars) {
+ ListBuffer<Type> new_targs = ListBuffer.lb();
+ //step 1 - create syntethic captured vars
+ for (Type t : undetvars) {
+ UndetVar uv = (UndetVar)t;
+ Type newArg = new CapturedType(t.tsym.name, t.tsym, uv.inst, syms.botType, null);
+ new_targs = new_targs.append(newArg);
+ }
+ //step 2 - replace synthetic vars in their bounds
+ for (Type t : new_targs.toList()) {
+ CapturedType ct = (CapturedType)t;
+ ct.bound = types.subst(ct.bound, tvars, new_targs.toList());
+ WildcardType wt = new WildcardType(ct.bound, BoundKind.EXTENDS, syms.boundClass);
+ ct.wildcard = wt;
+ }
+ return new_targs.toList();
+ }
/** Instantiate method type `mt' by finding instantiations of
* `tvars' so that method can be applied to `argtypes'.
--- a/langtools/test/tools/javac/Diagnostics/6862608/T6862608a.out Mon Aug 16 14:56:23 2010 +0100
+++ b/langtools/test/tools/javac/Diagnostics/6862608/T6862608a.out Mon Aug 16 14:58:10 2010 +0100
@@ -1,3 +1,3 @@
-T6862608a.java:19:41: compiler.err.invalid.inferred.types: T, (compiler.misc.inferred.do.not.conform.to.params: java.lang.Iterable<? extends java.util.Comparator<? super java.lang.String>>, java.util.List<java.util.Comparator<?>>)
+T6862608a.java:19:41: compiler.err.prob.found.req: (compiler.misc.incompatible.types.1: (compiler.misc.no.conforming.instance.exists: T, java.util.Comparator<T>, java.util.Comparator<java.lang.String>)), <T>java.util.Comparator<T>, java.util.Comparator<java.lang.String>
- compiler.misc.where.description.typevar: T,{(compiler.misc.where.typevar: T, java.lang.Object, kindname.method, <T>compound(java.lang.Iterable<? extends java.util.Comparator<? super T>>))}
1 error
--- a/langtools/test/tools/javac/diags/examples.not-yet.txt Mon Aug 16 14:56:23 2010 +0100
+++ b/langtools/test/tools/javac/diags/examples.not-yet.txt Mon Aug 16 14:58:10 2010 +0100
@@ -64,6 +64,7 @@
compiler.misc.fatal.err.cant.locate.meth # Resolve, from Lower
compiler.misc.file.does.not.contain.package
compiler.misc.illegal.start.of.class.file
+compiler.misc.inferred.do.not.conform.to.params # UNUSED (hard to see if very complex inference scenario might require this though, so leaving it in, as per JLS3)
compiler.misc.kindname.annotation
compiler.misc.kindname.enum
compiler.misc.kindname.package
--- a/langtools/test/tools/javac/diags/examples/InvalidInferredTypes.java Mon Aug 16 14:56:23 2010 +0100
+++ b/langtools/test/tools/javac/diags/examples/InvalidInferredTypes.java Mon Aug 16 14:58:10 2010 +0100
@@ -22,17 +22,17 @@
*/
// key: compiler.err.invalid.inferred.types
-// key: compiler.misc.inferred.do.not.conform.to.params
+// key: compiler.misc.inferred.do.not.conform.to.bounds
import java.util.*;
class InvalidInferredTypes {
- <T> Comparator<T> compound(Iterable<? extends Comparator<? super T>> it) {
+ <T extends List<? super T>> T makeList() {
return null;
}
- public void test(List<Comparator<?>> x) {
- Comparator<String> c3 = compound(x);
+ public void test() {
+ List<? super String> l = makeList();
}
}
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/langtools/test/tools/javac/generics/inference/6369605/T6369605a.java Mon Aug 16 14:58:10 2010 +0100
@@ -0,0 +1,50 @@
+/*
+ * Copyright (c) 2010, 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.
+ *
+ * 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.
+ */
+
+/**
+ * @test
+ * @bug 6369605
+ * @summary Unconstrained type variables fails to include bounds
+ * @author mcimadamore
+ * @compile T6369605a.java
+ */
+import java.util.List;
+
+class T6369605a {
+ static <T extends List<T>> T m1() {
+ return null;
+ }
+
+ static <T extends List<U>, U extends List<T>> T m2() {
+ return null;
+ }
+
+ static <T extends List<U>, U extends List<V>, V extends List<T>> T m3() {
+ return null;
+ }
+
+ List<?> l1 = m1();
+ List<?> l2 = m2();
+ List<?> l3 = m3();
+}
+
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/langtools/test/tools/javac/generics/inference/6369605/T6369605b.java Mon Aug 16 14:58:10 2010 +0100
@@ -0,0 +1,49 @@
+/*
+ * Copyright (c) 2010, 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.
+ *
+ * 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.
+ */
+
+/**
+ * @test
+ * @bug 6369605
+ * @summary Unconstrained type variables fails to include bounds
+ * @author mcimadamore
+ * @compile T6369605b.java
+ */
+import java.util.List;
+
+class T6369605b {
+ static <T extends List<X>, X> List<T> m1() {
+ return null;
+ }
+
+ static <T extends List<U>, U extends List<X>, X> List<T> m2() {
+ return null;
+ }
+
+ static <T extends List<U>, U extends List<V>, V extends List<X>, X> List<T> m3() {
+ return null;
+ }
+
+ List<?> l1 = m1();
+ List<?> l2 = m2();
+ List<?> l3 = m3();
+}
--- a/langtools/test/tools/javac/generics/inference/6638712/T6638712a.out Mon Aug 16 14:56:23 2010 +0100
+++ b/langtools/test/tools/javac/generics/inference/6638712/T6638712a.out Mon Aug 16 14:58:10 2010 +0100
@@ -1,2 +1,2 @@
-T6638712a.java:16:41: compiler.err.invalid.inferred.types: T, (compiler.misc.inferred.do.not.conform.to.params: java.lang.Iterable<? extends java.util.Comparator<? super java.lang.String>>, java.util.List<java.util.Comparator<?>>)
+T6638712a.java:16:41: compiler.err.prob.found.req: (compiler.misc.incompatible.types.1: (compiler.misc.no.conforming.instance.exists: T, java.util.Comparator<T>, java.util.Comparator<java.lang.String>)), <T>java.util.Comparator<T>, java.util.Comparator<java.lang.String>
1 error