null qualifying inner instance creation should be error.

Name: boT120536 Date: 01/22/2001


java version "1.3.0"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.3.0-C)
Java HotSpot(TM) Client VM (build 1.3.0-C, mixed mode)


According to JLS 15.9.1, sub-bullet 2 of second paragraph, "It is a compile-time
error if Identifier is not the simple name of an accessible non-abstract inner
class T that is a member of the compile-time type of the Primary." Then, in
4.1, it reads "There is also a special null type, the type of the expression
null." Since the null literal is its own type, and not a reference type, and
since it has no inner classes, this code should fail to compile:

class Outer {
    class Inner{}
    Object o = null.new Inner();
    public static void main(String[] args) {
        System.out.println(new Outer().o);
    }
}

But javac 1.3 compiles it, with no second thoughts. Even weirder, when I
execute, I would expect a null-pointer exception according to 15.9.4, but
instead I get some nice output confirming an inner class instance was created.

So, I next tried this modification:

class Outer {
    class Inner {}
    Object o = null.new Inner(){};
}

Lo and behold, it only gets more interesting:

An exception has occurred in the compiler (1.3.0). Please file a bug at the Java
 Developer Connection (http://java.sun.com/cgi-bin/bugreport.cgi). Include your
 program and the following diagnostic in your report. Thank you.
java.lang.InternalError: unexpected type: <null>
        at com.sun.tools.javac.v8.tree.TreeMaker.Type(TreeMaker.java:399)
        at com.sun.tools.javac.v8.tree.TreeMaker.VarDef(TreeMaker.java:437)
        at com.sun.tools.javac.v8.tree.TreeMaker.Param(TreeMaker.java:463)
        at com.sun.tools.javac.v8.tree.TreeMaker.Params(TreeMaker.java:474)
        at com.sun.tools.javac.v8.comp.Enter.DefaultConstructor(Enter.java:170)
        at com.sun.tools.javac.v8.comp.Enter$CompleteEnter.complete(Enter.java:8
34)
        at com.sun.tools.javac.v8.code.Symbol.complete(Symbol.java:366)
        at com.sun.tools.javac.v8.comp.Attr._case(Attr.java:341)
        at com.sun.tools.javac.v8.tree.Tree$ClassDef.visit(Tree.java:402)
        at com.sun.tools.javac.v8.comp.Attr.attribTree(Attr.java:234)
        at com.sun.tools.javac.v8.comp.Attr.attribStat(Attr.java:276)
        at com.sun.tools.javac.v8.comp.Attr._case(Attr.java:871)
        at com.sun.tools.javac.v8.tree.Tree$NewClass.visit(Tree.java:810)
        at com.sun.tools.javac.v8.comp.Attr.attribTree(Attr.java:234)
        at com.sun.tools.javac.v8.comp.Attr.attribExpr(Attr.java:254)
        at com.sun.tools.javac.v8.comp.Attr._case(Attr.java:402)
        at com.sun.tools.javac.v8.tree.Tree$VarDef.visit(Tree.java:470)
        at com.sun.tools.javac.v8.comp.Attr.attribTree(Attr.java:234)
        at com.sun.tools.javac.v8.comp.Attr.attribStat(Attr.java:276)
        at com.sun.tools.javac.v8.comp.Attr.attribClass(Attr.java:1415)
        at com.sun.tools.javac.v8.JavaCompiler.compile(JavaCompiler.java:378)
        at com.sun.tools.javac.v8.Main.compile(Main.java:247)
        at com.sun.tools.javac.Main.main(Main.java:16)
(Review ID: 115114)
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