Re: [Mingw-users] Linking to Java's jvm.lib with mingw

[Earnie B. <ear...@ya...>]

Mo DeJong wrote:
> Hi all
> 
> I recently was able to link to a Java VM lib file using mingw and I figured
> others might want to see this post so they don't end up wasting time like I did.
> I was using mingw 1.1, msys 1.0.8, and IBM JDK 1.3 for Win32.
> 
> The problem I was running into looked like this:
> 
> gcc -o jni.exe -I../../ibmjdk13/include ../../ibmjdk13/lib/jvm.lib jni.c
> c:\windows\TEMP\ccn1jhgb.o(.text+0x17):jni.c: undefined reference to `_imp__JNI_GetCreatedJavaVMs@12'
> 
> If you do some searching on the web, you might come across info like
> the following:
> 
> http://www.inonit.com/cygwin/jni/invocationApi/archive.html
> 
> This page states that you need to create your own .a file and link
> to that instead of the .lib file that comes with the JDK. Perhaps this
> was an issue in older versions of mingw, but this actually had
> nothing to do with the problem.
> 

Yes, early versions of bin utils didn't like to find .lib files.

> What actually fixed it, was to put the .lib file after the .c file on
> the compile line.
> 
> gcc -o jni.exe -I../../ibmjdk13/include jni.c ../../ibmjdk13/lib/jvm.lib
> 

It is known that command line order matters when placing objects for 
linking.

> The above command compiled and linked just fine. I know, I know,
> it was a silly mistake. I hope this post keeps others from making
> the same mistake.
> 

IIRC it should work like this as well:
gcc -o jni.exe -I../../ibmjdk13/include jni.c -L../../ibmjdk13/lib -ljvm

Earnie