proposed java install and extensions directory change

Thu Feb 28 14:38:00 GMT 2002

On Thu, 2002年02月28日 at 11:51, Per Bothner wrote:
> These are some changes I feel it is important to make in gcc 3.1,
> so I'm hoping we can come to agreement quickly.

I am in favour of these changes. I think, for instance, it will make
using the packages in rhug much easier to use.
> * We agree to follow the proposed Debian Java policy, in that jar
> files should be installed as $(prefix)/share/java/LIBRARY-VERSION.jar.
> (This implies that RHUG and others packages need to be fixed.)

Happily.
> * libgcj.jar is installed in $(prefix)/share/java/libgcj-VERSION.jar,
> instead of $(prefix)/share/libgcj.jar. VERSION is the gcc version
> number string.

Or some mangling of the string. For instance, isn't it "3.1
experimental blah blah" right now?

> * We define an "extensions directory", which I propose should be
> $prefix/share/java/ext. Code that installs a library *may*
> add a link from $(prefix)/share/java/ext/LIBRARY.jar to
> $(prefix)/share/java/LIBRARY-VERSION.jar. Users *may* install
> libraries directly into $(prefix)/share/java/ext, but a Makefile
> or an install script *should* use a link instead.
>> * We (try to) get this added to the Debian Java policy.
>> * gcj gets an extra --extdirs (and for jdk compatibility -extdirs)
> option. If a class cannot be found otherwise, gcj searches every
> .jar in in the listed directories. (I.e. the extension directories
> are search *after* the bootclasspath.) The flag overrides (rather
> than adds to) the default extension directory $(prefix)/share/java/ext.

So the compiler always searches the extension directory, --extdirs= just
let the user override this? Does "--extdirs=" mean don't seach
anywhere?
> * The run-time classloader should do the same searching However,
this
> is not so critical for gcj, assuming .so files have been installed, but
> it is important if .jar files are installed without corresponding .so
> files.

I think this is important, especially if a package has a large number of
resource files you don't want to compile in.
Should there also be a default secondary /usr/local/share/java/ext?
If extdir searches end up being too slow, you can imagine speeding up
the search by having a single property file mapping class names to jar
files, which is refreshed at jar file installation time.
AG