GNU bug report logs - #9306
Java build errors due to trailing colon in CLASSPATH

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Message #5 received at submit <at> debbugs.gnu.org (full text, mbox):

From: "Daniel Richard G." <skunk <at> iSKUNK.ORG>
To: bug-automake <at> gnu.org
Subject: Java build errors due to trailing colon in CLASSPATH
Date: Mon, 15 Aug 2011 15:54:36 -0400

[Message part 1 (text/plain, inline)]

I am using Automake 1.11.1, and have recently encountered a subtle issue
that causes compilation of some Java programs to fail.

Here is a typical build failure, produced from a minimal test case I've
assembled, using OpenJDK on Ubuntu's Natty release:

make[3]: Entering directory `/tmp/automake-java-bug/org/gnu/bug'
CLASSPATH=../../..:./../../..:$CLASSPATH javac -d ../../..    Library.java Application.java
./Library.java:5: duplicate class: org.gnu.bug.Library
public class Library
       ^
Application.java:9: cannot access Library
bad class file: RegularFileObject[./Library.java]
file does not contain class Library
Please remove or make sure it appears in the correct subdirectory of the classpath.
		Library lib = new Library();
		^
2 errors
make[3]: *** [classdist_noinst.stamp] Error 1


If I copy-and-paste the javac invocation, edit it slightly, and run
it...

    env CLASSPATH=../../..:./../../..: javac -d ../../.. Library.java Application.java

...I get the same error. However, if I remove that trailing colon from
CLASSPATH, and try it again...

    env CLASSPATH=../../..:./../../.. javac -d ../../.. Library.java Application.java

...compilation succeeds. If I invoke the above build with

    env CLASSPATH=/does-not-exist make

then compilation likewise succeeds.

Note that I do not have CLASSPATH set in my environment. It would appear
that a trailing colon in the CLASSPATH environment variable has a
special meaning attached to it, which makes Automake's use of
CLASSPATH=mumblemumble:$$CLASSPATH in makefiles problematic.

(The straightforward solution would be to replace that construct with
CLASSPATH=mumblemumble$${CLASSPATH:+:$$CLASSPATH}, but whether all
shells can handle that is an open question.)

Attached is a tarball containing the minimal test case.


--Daniel


P.S.: Please Cc: any replies to me, as I am not subscribed to this list.


-- 
NAME = Daniel Richard G.     _\|/_    Remember, skunks
MAIL = skunk <at> iSKUNK.ORG     (/o|o\) _- don't smell bad---
MAIL+= skunk <at> alum.MIT.EDU   < (^),>     it's the people who
WWW  = (not there yet!)      /   \      annoy us that do!

[automake-java-bug.tar.gz (application/x-gzip, attachment)]

Message #8 received at submit <at> debbugs.gnu.org (full text, mbox):

From: Stefano Lattarini <stefano.lattarini <at> gmail.com>
To: bug-automake <at> gnu.org
Cc: 9306 <at> debbugs.gnu.org, "Daniel Richard G." <skunk <at> iskunk.org>
Subject: Re: bug#9306: Java build errors due to trailing colon in CLASSPATH
Date: Tue, 16 Aug 2011 15:30:59 +0200

[Message part 1 (text/plain, inline)]

Hi Daniel, thanks for the report.

On Monday 15 August 2011, Daniel Richard wrote:
> I am using Automake 1.11.1, and have recently encountered a subtle issue
> that causes compilation of some Java programs to fail.
> 
> Here is a typical build failure, produced from a minimal test case I've
> assembled, using OpenJDK on Ubuntu's Natty release:
> 
> make[3]: Entering directory `/tmp/automake-java-bug/org/gnu/bug'
> CLASSPATH=../../..:./../../..:$CLASSPATH javac -d ../../..    Library.java Application.java
> ./Library.java:5: duplicate class: org.gnu.bug.Library
> public class Library
>        ^
> Application.java:9: cannot access Library
> bad class file: RegularFileObject[./Library.java]
> file does not contain class Library
> Please remove or make sure it appears in the correct subdirectory of the classpath.
> 		Library lib = new Library();
> 		^
> 2 errors
> make[3]: *** [classdist_noinst.stamp] Error 1
> 
> 
> If I copy-and-paste the javac invocation, edit it slightly, and run
> it...
> 
>     env CLASSPATH=../../..:./../../..: javac -d ../../.. Library.java Application.java
> 
> ...I get the same error. However, if I remove that trailing colon from
> CLASSPATH, and try it again...
> 
>     env CLASSPATH=../../..:./../../.. javac -d ../../.. Library.java Application.java
> 
> ...compilation succeeds. If I invoke the above build with
> 
>     env CLASSPATH=/does-not-exist make
> 
> then compilation likewise succeeds.
> 
> Note that I do not have CLASSPATH set in my environment. It would appear
> that a trailing colon in the CLASSPATH environment variable has a
> special meaning attached to it, which makes Automake's use of
> CLASSPATH=mumblemumble:$$CLASSPATH in makefiles problematic.
> 
> (The straightforward solution would be to replace that construct with
> CLASSPATH=mumblemumble$${CLASSPATH:+:$$CLASSPATH}, but whether all
> shells can handle that is an open question.)
>
Luckily, as far as I know, the above construct should be portable to all
non-museum shells.  So I've used it with only a minor modification (with
the only purpose of making the contruct slighlty clearer):

  CLASSPATH=mumblemumble$${CLASSPATH:+":$$CLASSPATH"}

> Attached is a tarball containing the minimal test case.
> 
I can reproduce the problem using your test case, and fix it using your
suggestion.  I've preparad the attached patch, which I will push in a
couple of days if there are no further comments.

BTW, are you the same "Daniel Richard G." listed in THANKS with the address
"danielg <at> teragram.com"?  If yes, should I update your address there?

Thanks,
  Stefano

[0001-java-avoid-compilation-errors-when-CLASSPATH-is-empt.patch (text/x-patch, inline)]

From 7f1cf56ba7d1b36fb4c9464f8ed7d10ad44e65a9 Mon Sep 17 00:00:00 2001
Message-Id: <7f1cf56ba7d1b36fb4c9464f8ed7d10ad44e65a9.1313501403.git.stefano.lattarini <at> gmail.com>
From: Daniel Richard G <skunk <at> iskunk.org>
Date: Tue, 16 Aug 2011 15:19:14 +0200
Subject: [PATCH] java: avoid compilation errors when CLASSPATH is empty

* lib/am/java.am (CLASSPATH_ENV): When redefining `$CLASSPATH',
do not append an empty component in case the previous value of
CLASSPATH is empty or unset.
* tests/java-empty-classpath.test: New test.
* tests/Makefile.am (TESTS): Update.

Fixes automake bug#9306.
---
 ChangeLog                       |   11 +++++
 lib/am/java.am                  |    2 +-
 tests/java-empty-classpath.test |   90 +++++++++++++++++++++++++++++++++++++++
 3 files changed, 102 insertions(+), 1 deletions(-)
 create mode 100755 tests/java-empty-classpath.test

diff --git a/ChangeLog b/ChangeLog
index af2556f..c9ce830 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,14 @@
+2011-08-16  Daniel Richard G. <skunk <at> iskunk.org>  (tiny change)
+	    Stefano Lattarini  <stefano.lattarini <at> gmail.com>
+
+	java: avoid compilation errors when CLASSPATH is empty
+	* lib/am/java.am (CLASSPATH_ENV): When redefining `$CLASSPATH',
+	do not append an empty component in case the previous value of
+	CLASSPATH is empty or unset.
+	* tests/java-empty-classpath.test: New test.
+	* tests/Makefile.am (TESTS): Update.
+	Fixes automake bug#9306.
+
 2011-08-08  Stefano Lattarini  <stefano.lattarini <at> gmail.com>
 
 	test defs: more environment cleanup
diff --git a/lib/am/java.am b/lib/am/java.am
index d6eb455..604df22 100644
--- a/lib/am/java.am
+++ b/lib/am/java.am
@@ -21,7 +21,7 @@
 ## ---------- ##
 
 JAVAC = javac
-CLASSPATH_ENV = CLASSPATH=$(JAVAROOT):$(srcdir)/$(JAVAROOT):$$CLASSPATH
+CLASSPATH_ENV = CLASSPATH=$(JAVAROOT):$(srcdir)/$(JAVAROOT)$${CLASSPATH:+":$$CLASSPATH"}
 JAVAROOT = $(top_builddir)
 
 class%DIR%.stamp: $(%DIR%_JAVA)
diff --git a/tests/java-empty-classpath.test b/tests/java-empty-classpath.test
new file mode 100755
index 0000000..230bb7c
--- /dev/null
+++ b/tests/java-empty-classpath.test
@@ -0,0 +1,90 @@
+#! /bin/sh
+# Copyright (C) 2011 Free Software Foundation, Inc.
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2, or (at your option)
+# any later version.
+#
+# This program 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 for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+# Java compilation works also when CLASSPATH is unset or empty at
+# compilation time.  See automake bug#9306.
+
+required=javac
+. ./defs || Exit 1
+
+set -e
+
+cat >> configure.in <<'END'
+AC_CONFIG_SRCDIR([org/gnu/bug/Library.java])
+AC_CONFIG_FILES([
+    org/Makefile
+    org/gnu/Makefile
+    org/gnu/bug/Makefile
+])
+AC_OUTPUT
+END
+
+mkdir org org/gnu org/gnu/bug
+cat > Makefile.am <<END
+CLEANFILES = *.class
+SUBDIRS = org
+END
+echo SUBDIRS = gnu > org/Makefile.am 
+echo SUBDIRS = bug > org/gnu/Makefile.am 
+cat > org/gnu/bug/Makefile.am <<'END'
+JAVAROOT = ../../..
+dist_noinst_JAVA = Library.java Application.java
+END
+
+cat > org/gnu/bug/Library.java <<'END'
+package org.gnu.bug;
+public class Library
+{
+    public Library ()
+    {
+      // Nothing to do.
+    }
+    public static void doSomethingUseful (String arg)
+    {
+      System.out.println (arg);
+    }
+}
+END
+
+cat > org/gnu/bug/Application.java <<'END'
+import org.gnu.bug.*;
+public class Application
+{
+    public static void main (String args[])
+    {
+        Library lib = new Library ();
+        lib.doSomethingUseful ("PLUGH");
+    }
+}
+END
+
+$ACLOCAL
+$AUTOCONF
+$AUTOMAKE
+./configure
+
+unset CLASSPATH || :
+$MAKE
+$MAKE clean
+
+CLASSPATH=''; export CLASSPATH
+$MAKE
+$MAKE clean
+
+unset CLASSPATH || :
+$MAKE distcheck
+
+:
-- 
1.7.2.3

Message #16 received at submit <at> debbugs.gnu.org (full text, mbox):

From: "Daniel Richard G." <skunk <at> iSKUNK.ORG>
To: "Stefano Lattarini" <stefano.lattarini <at> gmail.com>, bug-automake <at> gnu.org
Cc: 9306 <at> debbugs.gnu.org
Subject: Re: bug#9306: Java build errors due to trailing colon in CLASSPATH
Date: Tue, 16 Aug 2011 15:10:11 -0400

On Tue, 2011 Aug 16 15:30+0200, Stefano Lattarini wrote:
>
> Luckily, as far as I know, the above construct should be portable to
> all non-museum shells.  So I've used it with only a minor modification
> (with the only purpose of making the contruct slighlty clearer):
>
>   CLASSPATH=mumblemumble$${CLASSPATH:+":$$CLASSPATH"}

The extra clarity is appreciated; I'm still not used to doing these
special variable dereferences :-)

> I can reproduce the problem using your test case, and fix it using
> your suggestion.  I've preparad the attached patch, which I will push
> in a couple of days if there are no further comments.

The patch works for me, and I defer to you on older shells being able to
handle this.

> BTW, are you the same "Daniel Richard G." listed in THANKS with the
> address "danielg <at> teragram.com"?  If yes, should I update your
> address there?

The same! That's my work address, and while it remains active, my
personal address (@iskunk.org) is the one I usually go by in this realm.
Please feel free to update the entry.


Regards,


--Daniel


-- 
NAME = Daniel Richard G.     _\|/_    Remember, skunks
MAIL = skunk <at> iSKUNK.ORG     (/o|o\) _- don't smell bad---
MAIL+= skunk <at> alum.MIT.EDU   < (^),>     it's the people who
WWW  = (not there yet!)      /   \      annoy us that do!

Message #22 received at submit <at> debbugs.gnu.org (full text, mbox):

From: Stefano Lattarini <stefano.lattarini <at> gmail.com>
To: "Daniel Richard G." <skunk <at> iskunk.org>
Cc: 9306 <at> debbugs.gnu.org, bug-automake <at> gnu.org
Subject: Re: bug#9306: Java build errors due to trailing colon in CLASSPATH
Date: Wed, 17 Aug 2011 09:54:12 +0200

[Message part 1 (text/plain, inline)]

On Tuesday 16 August 2011, Daniel Richard wrote:
> On Tue, 2011 Aug 16 15:30+0200, Stefano Lattarini wrote:
> > BTW, are you the same "Daniel Richard G." listed in THANKS with the
> > address "danielg <at> teragram.com"?  If yes, should I update your
> > address there?
> 
> The same! That's my work address, and while it remains active, my
> personal address (@iskunk.org) is the one I usually go by in this realm.
> Please feel free to update the entry.
> 
OK, will do with the attached trivial patch.

Thanks,
  Stefano

[0001-THANKS-Daniel-Richard-G.-Update-e-mail-address.patch (text/x-patch, inline)]

From 4eed80c1b8684ce924163f9b3aaae98ac6b3826e Mon Sep 17 00:00:00 2001
Message-Id: <4eed80c1b8684ce924163f9b3aaae98ac6b3826e.1313567598.git.stefano.lattarini <at> gmail.com>
From: Stefano Lattarini <stefano.lattarini <at> gmail.com>
Date: Wed, 17 Aug 2011 09:53:07 +0200
Subject: [PATCH] * THANKS (Daniel Richard G.): Update e-mail address.

---
 ChangeLog |    4 ++++
 THANKS    |    2 +-
 2 files changed, 5 insertions(+), 1 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index c9ce830..a124259 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+2011-08-17  Stefano Lattarini  <stefano.lattarini <at> gmail.com>
+
+	* THANKS (Daniel Richard G.): Update e-mail address.
+
 2011-08-16  Daniel Richard G. <skunk <at> iskunk.org>  (tiny change)
 	    Stefano Lattarini  <stefano.lattarini <at> gmail.com>
 
diff --git a/THANKS b/THANKS
index 3d71419..d91c5bb 100644
--- a/THANKS
+++ b/THANKS
@@ -67,7 +67,7 @@ Dalibor Topic		robilad <at> kaffe.org
 danbp			danpb <at> nospam.postmaster.co.uk
 Daniel Jacobowitz	drow <at> false.org
 Daniel Kahn Gillmor	dkg <at> fifthhorseman.net
-Daniel Richard G.	danielg <at> teragram.com
+Daniel Richard G.	skunk <at> iskunk.org
 Dave Brolley		brolley <at> redhat.com
 Dave Korn		dave.korn.cygwin <at> googlemail.com
 Dave Morrison		dave <at> bnl.gov
-- 
1.7.2.3

Message #30 received at 9306-done <at> debbugs.gnu.org (full text, mbox):

From: Stefano Lattarini <stefano.lattarini <at> gmail.com>
To: "Daniel Richard G." <skunk <at> iskunk.org>,
 9306-done <at> debbugs.gnu.org
Subject: Re: bug#9306: Java build errors due to trailing colon in CLASSPATH
Date: Thu, 18 Aug 2011 21:27:39 +0200

On Wednesday 17 August 2011, Stefano Lattarini wrote:
> On Tuesday 16 August 2011, Daniel Richard wrote:
> > On Tue, 2011 Aug 16 15:30+0200, Stefano Lattarini wrote:
> > > BTW, are you the same "Daniel Richard G." listed in THANKS with the
> > > address "danielg <at> teragram.com"?  If yes, should I update your
> > > address there?
> > 
> > The same! That's my work address, and while it remains active, my
> > personal address (@iskunk.org) is the one I usually go by in this realm.
> > Please feel free to update the entry.
> > 
> OK, will do with the attached trivial patch.
> 
I've pushed both the patches now, and I'm closing the bug report.

Thanks,
  Stefano

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