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Compiling a JNI file in Dev-C++ and Code::Blocks

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kostyabkg:
int i;
for (i = 0; i < 100; i++)
{
    printf("Thank you!\n");
}

 :D

Yes, it's important to get it working with GNU GCC, because I also want to produce .so files for other systems, than MS Windows. If a Java program loses its' interoperability, then what Java is for???

kostyabkg:
I have noticed that "def" files are different if it can help anyhow...

Michael:
Hello,

Yesterday night, I have worked to try solve this problem. Interesting challenge :). The problem of the java exception is not IMHO a C::B bug.

Several users have had such issue. Just look at here for descriptions and solutions (which could work or not :?):

http://forum.java.sun.com/thread.jspa?threadID=570194&tstart=29

The problem is that the GNU GCC generates a not correct def file. Therefore, the DLL is not create correctly. As a consequence, Java loads the library, but the method cannot be found (bad signature, I think). This generates the UnsatisfiedLinkError.

Instead MS Toolkit 2003 and (I have read) Borland compiler create a valid DLL (and a valid def/exp file).

In the Java thread mentioned above, a user suggests:


--- Quote ---GOTCHA: I found the option to solve the compiling problem with MinGW gcc. Use this command line:

gcc -shared -o bridgeC.dll bridgeC.o bridgeC.def

Inside the .def file, only describe the right function name:
--- bridgeC.def ----
EXPORT
sayHelloWorld
--- bridgeC.def ----

The compiler will say something like: Warning: linking sayHelloWorld to sayHelloWorld@2 , but the DLL will work.

--- End quote ---

This solution worked for me too, but only if I call gcc directly by using a command dos window. By using C::B, it did not work. I suppose that I could not configure C::B correctly or I have missed something. I have tried with C::B RC2 and SVN rev1447 with no positive results. I have also used MinGW that come with the release of C::B and another that I have installed with MSYS. Same result.

May be it could be possible to use a makefile, but I did not try it (sorry, but I am not a makefile expert :oops:).

You can try to look at wich compiler/link options use Dev-C++ and import them in C::B. You can also try the same MinGW that Dev-C++ uses.

Best wishes,
Michael

jschwarz0:

sorry I don't have this setup to try

from this link: http://forum.java.sun.com/thread.jspa?threadID=470937&messageID=2414695

you should be able to add:

--add-stdcall-alias to your gcc options

or

wrap all jni available calls with

extern C

jim

Michael:

--- Quote from: jschwarz0 on December 09, 2005, 12:22:37 am ---you should be able to add:

--add-stdcall-alias to your gcc options

--- End quote ---

I have already tried this option, but it did not work (at least for me)


--- Quote from: jschwarz0 on December 09, 2005, 12:22:37 am ---or

wrap all jni available calls with

extern C

jim

--- End quote ---

I will give it a try, thanks.

Michael

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