[PATCH] 8133135: NPE on anonymous class defined by qualified instance creation expression with diamond

[Maurizio Cimadamore]

Thanks, I'll take a look.

Maurizio

On 31/08/15 14:40, bsrbnd wrote:
> Hi,
>
> As explained in issue 8133135, the following code produces a null
> pointer exception because the symbol of the anonymous class is not set
> during the attribute phase:
>
> class List<T> {}
>
> class ClassOut {
>      class ClassIn<T> { public ClassIn() {}}
> }
>
> public class TestBug {
>      public static <T> List<T> m(List<T> list, T item) {return list;}
>
>
>      public static void main(String[] args) {
>          m(new List<ClassOut.ClassIn<String>>(), new ClassOut().new
> ClassIn<>(){});
>      }
> }
>
> Method Attr.visitAnonymousClassDefinition() doesn't perform well type
> inference with diamond. Recurcivity condition on tree.clazz.type seems
> to be wrong because it never changes... instead, it should be made on
> clazz.type (or clazztype) to go deeper on the type resolution.
>
> The following patch shows a possible solution, I think (to be checked
> by someone who knows the code better than me...):
>
> diff --git a/src/jdk.compiler/share/classes/com/sun/tools/javac/comp/Attr.java
> b/src/jdk.compiler/share/classes/com/sun/tools/javac/comp/Attr.java
> --- a/src/jdk.compiler/share/classes/com/sun/tools/javac/comp/Attr.java
> +++ b/src/jdk.compiler/share/classes/com/sun/tools/javac/comp/Attr.java
> @@ -2173,7 +2173,7 @@
>               final boolean isDiamond = TreeInfo.isDiamond(tree);
>               if (isDiamond
>                       && ((tree.constructorType != null &&
> inferenceContext.free(tree.constructorType))
> -                    || (tree.clazz.type != null &&
> inferenceContext.free(tree.clazz.type)))) {
> +                    || (clazz.type != null &&
> inferenceContext.free(clazz.type)))) {
>                   final ResultInfo resultInfoForClassDefinition =
> this.resultInfo;
>
> inferenceContext.addFreeTypeListener(List.of(tree.constructorType,
> tree.clazz.type),
>                           instantiatedContext -> {
>
> Regards,
>
> bsrbnd