From javran.c at gmail.com  Wed Mar 17 09:20:23 2021
From: javran.c at gmail.com (Javran Cheng)
Date: Wed, 17 Mar 2021 09:20:23 -0000
Subject: A question regarding handling consecutive '>' characters in "3.2.
 Lexical Translations"
Message-ID: <CA+TfdNZaj8P-KcHuabYSR5zybQwH+nZ6YVR4p_mgAmJFcTUhxA@mail.gmail.com>

Hello Java SE Spec authors,

I'm recently reading Java SE 16 spec (this is also present in many other
recent versions) and there is one part in "3.2. Lexical Translations" that
I would want some clarification:

> ... There is one exception: if lexical translation occurs in a type
context (?4.11) and the input stream has two or more consecutive >
characters ...

Here I want to know how can I tell whether it is in a type context when the
lexical analysis is not done - does this sentence just want to make sure
readers are aware of this ambiguity when it comes to consecutive >
characters (so how exactly this is done is up to implementor) or is there
somewhere explained in the spec regarding how to tell a type context during
lexical analysis?

Thanks!
Javran (Fang) Cheng

From x4e_x4e at protonmail.com  Fri Mar 12 12:33:23 2021
From: x4e_x4e at protonmail.com (x4e_x4e)
Date: Fri, 12 Mar 2021 12:33:23 -0000
Subject: JVMS conflicting rules on interface methods
Message-ID: <xpaHo2dCqepqVqCQUCwHeqO_rkkjy8jQlZ0KgrVsbdC-YFpNbMhmLr8VRG6XCst9vFLFqbvRf9plguQxk2eMDWCrK5mA1oRZ0kMZlDYZ7p0=@protonmail.com>

Hello,

JVMS 4.2.2 states:

> Note that a field name or interface method name may be `<init>` or `<clinit>`, but no method invocation instruction may reference `<clinit>` and only the invokespecial instruction (?invokespecial) may reference `<init>`.

(Interface's may have an <init> method). This seems in contradiction with 2.9.1 which states:

> In a class, any non-`void` method named `<init>` is not an instance initialization method. In an interface, any method named `<init>` is not an instance initialization method. Such methods cannot be invoked by any Java Virtual Machine instruction (?4.4.2, ?4.9.2) and are rejected by format checking (?4.6, ?4.8).

(<init> methods in interfaces are rejected by format checking).

I think it should be clarified whether an <init> method is allowed in an interface classfile.
Since Java 9 the verifier rejects an <init> method in an interface, so it seems like 2.9.1 is the intended behaviour.

Related links:
https://bugs.openjdk.java.net/browse/JDK-8122940
https://bugs.openjdk.java.net/browse/JDK-8135265

Thanks,
x4e