Re: Android port

[Arsen Arsenović]

Hi,

I encountered another one:

  javac -classpath 
"/home/arsen/Android/Sdk/platforms/android-Tiramisu/android.jar:." -target 1.7 
-source 1.7 -Xlint:d
  eprecation org/gnu/emacs/EmacsContextMenu.java
  warning: [options] bootstrap class path not set in conjunction with -source 7
  warning: [options] source value 7 is obsolete and will be removed in a future 
release
  warning: [options] target value 7 is obsolete and will be removed in a future 
release
  warning: [options] To suppress warnings about obsolete options, use 
-Xlint:-options.
  org/gnu/emacs/EmacsContextMenu.java:265: error: cannot find symbol
      final Holder<Boolean> rc;
            ^
    symbol:   class Holder
    location: class EmacsContextMenu
  org/gnu/emacs/EmacsContextMenu.java:267: error: cannot find symbol
      rc = new Holder<Boolean> ();
               ^
    symbol:   class Holder
    location: class EmacsContextMenu
  2 errors
  4 warnings
  make[2]: *** [Makefile:261: org/gnu/emacs/EmacsContextMenu.class] Error 1 
shuffle=2758590628

I tried replicating with that shuffle= value, but it seems that I did
not get lucky twice.  However, I believe I have the reason why:

  ~/gnu/emacs-android2 130 $ grep -r --include='*.java' Holder
  java/org/gnu/emacs/EmacsService.java:class Holder<T>
  java/org/gnu/emacs/EmacsService.java:    final Holder<EmacsView> view;
  java/org/gnu/emacs/EmacsService.java:    view = new Holder<EmacsView> ();
  java/org/gnu/emacs/EmacsService.java:    final Holder<ClipboardManager> 
manager;
  java/org/gnu/emacs/EmacsService.java:    manager = new 
Holder<ClipboardManager> ();
  java/org/gnu/emacs/EmacsDialog.java:    final Holder<Boolean> rc;
  java/org/gnu/emacs/EmacsDialog.java:    rc = new Holder<Boolean> ();
  java/org/gnu/emacs/EmacsContextMenu.java:    final Holder<Boolean> rc;
  java/org/gnu/emacs/EmacsContextMenu.java:    rc = new Holder<Boolean> ();

There is no dependency between these Holder<T> users and the .java that
provides it:

  ~/gnu/emacs-android2/java$ rm org/gnu/emacs/EmacsDialog.class
  ~/gnu/emacs-android2/java$ make org/gnu/emacs/EmacsDialog.class
    JAVAC    org/gnu/emacs/EmacsDialog.class
  warning: [options] bootstrap class path not set in conjunction with -source 7
  warning: [options] source value 7 is obsolete and will be removed in a future 
release
  warning: [options] target value 7 is obsolete and will be removed in a future 
release
  warning: [options] To suppress warnings about obsolete options, use 
-Xlint:-options.
  org/gnu/emacs/EmacsDialog.java:302: error: cannot find symbol
      final Holder<Boolean> rc;
            ^
    symbol:   class Holder
    location: class EmacsDialog
  org/gnu/emacs/EmacsDialog.java:304: error: cannot find symbol
      rc = new Holder<Boolean> ();
               ^
    symbol:   class Holder
    location: class EmacsDialog
  2 errors
  4 warnings
  make: *** [Makefile:261: org/gnu/emacs/EmacsDialog.class] Error 1
  ~/gnu/emacs-android2/java 2 $ rm org/gnu/emacs/EmacsService.class; make 
org/gnu/emacs/EmacsService.class
    JAVAC    org/gnu/emacs/EmacsService.class
  warning: [options] bootstrap class path not set in conjunction with -source 7
  warning: [options] source value 7 is obsolete and will be removed in a future 
release
  warning: [options] target value 7 is obsolete and will be removed in a future 
release
  warning: [options] To suppress warnings about obsolete options, use 
-Xlint:-options.
  4 warnings
  ~/gnu/emacs-android2/java$ make org/gnu/emacs/EmacsDialog.class
    JAVAC    org/gnu/emacs/EmacsDialog.class
  warning: [options] bootstrap class path not set in conjunction with -source 7
  warning: [options] source value 7 is obsolete and will be removed in a future 
release
  warning: [options] target value 7 is obsolete and will be removed in a future 
release
  warning: [options] To suppress warnings about obsolete options, use 
-Xlint:-options.
  4 warnings
  ~/gnu/emacs-android2/java$ 

The simplest way to fix it is probably to break out Holder<T> into
Holder.java, as that won't require manually bookkeeping the
dependencies.  I attached a patch, which builds on x86_64-pc-linux-gnu.

From faf8fc54ad1d835d843e33833715eed2af83d517 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Arsen=20Arsenovi=C4=87?= <arsen@aarsen.me>
Date: Sun, 19 Feb 2023 16:21:02 +0100
Subject: [PATCH] java: Resolve possible parallelism error across Holder class

* java/org/gnu/emacs/EmacsService.java (Holder): Move from here
to...
* java/org/gnu/emacs/Holder.java: ... here.  New file.
---
 java/org/gnu/emacs/EmacsService.java | 5 -----
 java/org/gnu/emacs/Holder.java       | 6 ++++++
 2 files changed, 6 insertions(+), 5 deletions(-)
 create mode 100644 java/org/gnu/emacs/Holder.java

diff --git a/java/org/gnu/emacs/EmacsService.java 
b/java/org/gnu/emacs/EmacsService.java
index ba6ec485d62..18cbb06eaa8 100644
--- a/java/org/gnu/emacs/EmacsService.java
+++ b/java/org/gnu/emacs/EmacsService.java
@@ -62,11 +62,6 @@
 
 import android.hardware.input.InputManager;
 
-class Holder<T>
-{
-  T thing;
-};
-
 /* EmacsService is the service that starts the thread running Emacs
    and handles requests by that Emacs instance.  */
 
diff --git a/java/org/gnu/emacs/Holder.java b/java/org/gnu/emacs/Holder.java
new file mode 100644
index 00000000000..41866084ab9
--- /dev/null
+++ b/java/org/gnu/emacs/Holder.java
@@ -0,0 +1,6 @@
+package org.gnu.emacs;
+
+class Holder<T>
+{
+  T thing;
+};
-- 
2.39.2

I also tested the above by making EmacsDialog.class on a clean
configure, triggering the edge case.

Thanks in advance.
-- 
Arsen Arsenović

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