gcj onLinux, 32 and 64 bit executables.

gcj onLinux, 32 and 64 bit executables.

[Me Myself and I]

If I successfully compile a Test.java program with gcj Test.java --main=Test -o Test.bin
on 64 bit linux, I then have a 64 bit Linux exectuable.

If I do similar on 32 bit Linux, I have a 32 bit Linux exectable.

If I am running 64 bit Linux, is there a way to use gcj on this to get a 32 bit Linux bin,
what should I do for this, where should I look, and can anyone give me any simple,
practical instructions on how to set it up? 		 	   		  

Re: gcj onLinux, 32 and 64 bit executables.

[Jonathan Wakely]

On 14 September 2011 04:41, Me Myself and I wrote:
>
> If I successfully compile a Test.java program with gcj Test.java --main=Test -o Test.bin
> on 64 bit linux, I then have a 64 bit Linux exectuable.
>
> If I do similar on 32 bit Linux, I have a 32 bit Linux exectable.
>
> If I am running 64 bit Linux, is there a way to use gcj on this to get a 32 bit Linux bin,
> what should I do for this, where should I look, and can anyone give me any simple,
> practical instructions on how to set it up?

Add -m32 to the gcj command.

Depending on your Linux distro you might need to install some
additional 32-bit packages.

Re: gcj onLinux, 32 and 64 bit executables.

[Andrew Haley]

On 11/12/2011 08:38 PM, Johann 'Myrkraverk' Oskarsson wrote:
> With GCC 4.6.2 on OpenIndiana 151a (Solaris) the boehm gc segfaults in
> os_dep.c:810 when JNI_CreateJavaVM() is called.  The attached
> invocation example (as small as I think I can make it) is a complete
> example.
>
> Is this the right place to discuss this issue?

Yes.

> I thought of merging boehm gc 7.1 into the gcc source tree, but this
> seems non-trivial.  In particular it's not possible just to make it
> a drop-in replacement.
>
> Is there a way to have GCJ use a system supplied boehm gc?

Not really, no.  GCC is in Stage 3, so the only reasonable way to get
this fixed is a self-contained patch.

Do you have any reason to suspect that merging gc 7.1 might help?

Andrew.

Re: Garbage collection segfault in OpenIndiana

[Johann 'Myrkraverk' Oskarsson]

Andrew Haley <aph@redhat.com> writes:

> On 11/12/2011 08:38 PM, Johann 'Myrkraverk' Oskarsson wrote:
>> With GCC 4.6.2 on OpenIndiana 151a (Solaris) the boehm gc segfaults
>> in os_dep.c:810 when JNI_CreateJavaVM() is called.
>
>> I thought of merging boehm gc 7.1 into the gcc source tree, but
>> this seems non-trivial.  In particular it's not possible just to
>> make it a drop-in replacement.
>
> Do you have any reason to suspect that merging gc 7.1 might help?

No concrete evidence.  In the past I was unable to use 6.x on it while
7.x worked in my own projects.  In 7.1 and 7.2alpha6 this function is
now called GC_find_limit_with_bound() instead of just GC_find_limit().
The relevant line number in 7.2alpha6 is os_dep.c:994.

I suppose the best way to be sure is to compare the output of gcc -E
for os_dep.c.

If you have any further ideas I can explore, please let me know.


-- 
   Johann Oskarsson                http://www.2ndquadrant.com/    |[]
   PostgreSQL Development, 24x7 Support, Training and Services  --+--
                                                                  |
   Blog: http://my.opera.com/myrkraverk/blog/

Garbage collection segfault in OpenIndiana

[Johann 'Myrkraverk' Oskarsson]

[-- Attachment #1: Type: text/plain, Size: 749 bytes --]

Hi all,

With GCC 4.6.2 on OpenIndiana 151a (Solaris) the boehm gc segfaults in
os_dep.c:810 when JNI_CreateJavaVM() is called.  The attached
invocation example (as small as I think I can make it) is a complete
example.

Is this the right place to discuss this issue?  I thought of merging
boehm gc 7.1 into the gcc source tree, but this seems non-trivial.  In
particular it's not possible just to make it a drop-in replacement.

Is there a way to have GCJ use a system supplied boehm gc?


-- 
   Johann Oskarsson                http://www.2ndquadrant.com/    |[]
   PostgreSQL Development, 24x7 Support, Training and Services  --+--
                                                                  |
   Blog: http://my.opera.com/myrkraverk/blog/

[-- Attachment #2: Invocation example --]
[-- Type: text/plain, Size: 804 bytes --]

// File: invoke.c

// Compile with:

// gcc -g -m64 -o inv inv.c -L<prefix>/lib/amd64/gcj-4.6.2-12 -ljvm \
// -R<prefix>/lib/amd64/gcj-4.6.2-12 \
// -R<prefix>/lib/gcc/i386-pc-solaris2.11/4.6.2/amd64

// The -g -m64 is optional, of course.  The last -R should not be
// neccesary but is on my install.

#include <jni.h>
 
int main( int argc, char *argv[] )
{
  JNIEnv *env;
  JavaVM *jvm;
  jint res;
 
  JavaVMInitArgs vm_args;
  JavaVMOption options[1];
  options[0].optionString =
    "-Djava.class.path=.";
  vm_args.version = 0x00010002;
  vm_args.options = options;
  vm_args.nOptions = 1;
  vm_args.ignoreUnrecognized = JNI_TRUE;

  // This segfaults in the Boehm GC, in
  // boehm-gc/os_dep.c:810
  res = JNI_CreateJavaVM(&jvm, (void**)&env, &vm_args);

  return 0;
}
/* End of file: invoke.c */