Message-id: <4B7DAEF1.2090202@cygwin.com>
Date: Thu, 18 Feb 2010 16:19:45 -0500
From: "Larry Hall (Cygwin)" <reply-to-list-only-lh AT cygwin DOT com>
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Subject: Re: "undefined reference to `_JNI_CreateJavaVM'"
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On 02/18/2010 03:50 PM, Gary wrote:
> On Thu, Feb 18, 2010 at 11:47:13AM -0500, Larry Hall (Cygwin) wrote:
>> On 02/18/2010 05:43 AM, Gary wrote:
>>> I've basically followed along with what is written at
>>> http://www.inonit.com/cygwin/jni/invocationApi/  (built an import
>>> library, passed ld the "-L. -ljvm" parameters, and so on). One difference
>>> is that gcc no longer supports -mno-cygwin, but I'm not convinced that
>>> is the cause.
>>
>> Since the above site isn't cygwin.com, this list really can't support the
>> process they've outlined.
>
> I'm not asking you to.

My point is that if you're having trouble with a procedure/instructions you
found on another site, your best bet is to query the authors first.

>> if you really need '-mno-cygwin', then you're not building for
>> Cygwin,
>
> With or without is irrelevant to me. Since I am using Cygwin tools I am
> perfectly happy to not have the '-mno-cygwin'.

OK, if you prefer Cygwin and the DLL that comes with it (licensing and all),
then you can certainly experiment.  You need to be conscious of differences
between POSIX and Windows though.  However, if you are, you want to
build as if you're in a POSIX environment (because you are).  You should
avoid using the "win32" includes.  Your undefined reference is likely coming
about because of a mixture of calling conventions though.  You need to
look at the calling convention that the JNI stuff uses.  Compiling with Cygwin
for Cygwin is going to get you the C calling convention, which is what you
see for the undefined reference above.  My guess is the Windows JNI
interface you're linking against uses stdcall.  If so, you'd need your
declarations of the functions you're going to call there to match.  This
would be another reason to not use Cygwin's gcc since doing so would
make more work for you.

-- 
Larry Hall                              http://www.rfk.com
RFK Partners, Inc.                      (508) 893-9779 - RFK Office
216 Dalton Rd.                          (508) 893-9889 - FAX
Holliston, MA 01746

_____________________________________________________________________

A: Yes.
 > Q: Are you sure?
 >> A: Because it reverses the logical flow of conversation.
 >>> Q: Why is top posting annoying in email?

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