bc-abi2: large application handling

Mon Oct 11 16:41:00 GMT 2004

thank you Andrew for your replies so far.
Am Mon, den 11.10.2004 schrieb Andrew Haley um 17:29:
> > * what are shared object files / what are executables?
>> I don't understand this question.
>I simply asked myself when one should generate an executable and when a
shared object, in that sense that strictly speaking every java class can
be used as a library. So I meant that making a big executable out of
many jar files doesn't make much sense, given that there is pretty much
library reuse in java projects. (for instance most java apps link to
log4j or jakarta-commons)
> > in java every class can be mainable, so how do you go for that when
> > compiling so files - is the --main argument still the right method
> > should. 
>> Shared objects don't have a --main. You can invoke them with gij,
> which you give a class name whose main you wish to invoke.
>
ok. that's new to me.
how do you supply the so files then (using LD_LIRBARY_PATH?)
> > How about a generic app stub that is able to load a shared object
> > and call that static main. (so every class file resides inside a
> > so)
>> gij does that.

>> > * what is the way to use large interdependent jar files in compiling:
> > 
> > for instance, given 
> > - app.jar
> > - lib1.jar
> > - lib2.jar
> > 
> > app defining a mainable class as myapp.Main, which depends on lib1.jar
> > and lib2.jar, whats the best way to turn that into gcj form?
> > 
> > when using the idiom
> > 
> > gcj -findirect-dispatch -classpath app.jar:lib1.jar:lib2.jar
> > --main=myapp.Main -o app
>> gcj -findirect-dispatch -classpath app.jar:lib1.jar:lib2.jar -shared -o app.so
thanks for the info.
>> > with bigger classes, I get an internal compiler error. Is the usage
> > simply wrong, or is that a bug in the compiler?
>> That would be a bug. An ICE is always a bug.
ok.
The compiler failed only when generating an executable. Since the bug
was with a java.io class and read_zip_entry, I supplied the
$PREFIX/share/java/libgcj-3.5.0-abi.jar and it worked.
I am now wondering why it is searching for the core class
java.io.FilenameFilter in the system class path? Or does the compiler
need every class in .class format on the classpath?
>> > * is it better to compile the jar files separatly to so files and to
> > link them to app? - if so how is that expressed with gcj
>> I think so, but not everyone agrees.

Jakob