changeset 634:dc550520ed6f

6369605: Unconstrained type variables fails to include bounds Summary: unconstrained type-variables with recursive bounds are not inferred properly Reviewed-by: jjg
author mcimadamore
date Mon, 16 Aug 2010 14:58:10 +0100
parents 27bae58329d5
children a31c511db424
files src/share/classes/com/sun/tools/javac/code/Type.java src/share/classes/com/sun/tools/javac/comp/Infer.java test/tools/javac/Diagnostics/6862608/T6862608a.out test/tools/javac/diags/examples.not-yet.txt test/tools/javac/diags/examples/InvalidInferredTypes.java test/tools/javac/generics/inference/6369605/T6369605a.java test/tools/javac/generics/inference/6369605/T6369605b.java test/tools/javac/generics/inference/6638712/T6638712a.out
diffstat 8 files changed, 209 insertions(+), 26 deletions(-) [+]
line wrap: on
line diff
--- a/src/share/classes/com/sun/tools/javac/code/Type.java	Mon Aug 16 14:56:23 2010 +0100
+++ b/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/src/share/classes/com/sun/tools/javac/comp/Infer.java	Mon Aug 16 14:56:23 2010 +0100
+++ b/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/test/tools/javac/Diagnostics/6862608/T6862608a.out	Mon Aug 16 14:56:23 2010 +0100
+++ b/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/test/tools/javac/diags/examples.not-yet.txt	Mon Aug 16 14:56:23 2010 +0100
+++ b/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/test/tools/javac/diags/examples/InvalidInferredTypes.java	Mon Aug 16 14:56:23 2010 +0100
+++ b/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/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/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/test/tools/javac/generics/inference/6638712/T6638712a.out	Mon Aug 16 14:56:23 2010 +0100
+++ b/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