Re: [Discuss-gnuradio] Quesition Signal Processing Block: Compilation Errors Regarding Multiple Definition

[George Nychis]

You need to understand the basics of compiling and linking.  Otherwise 
you're going to keep taking blind shots in the dark that won't work. 
You could spend an hour learning and understanding it, or hours on top 
of hours guessing and waiting for others to attempt to fix things for 
you.... which many people won't have the patience or will to do :)

At the very least, you could simply look at some of the other code in 
GNU Radio and follow the guides.  There are many, many examples.  You 
don't include .cc files, you include header files.  Then you must link 
properly.  If you don't understand what I mean by this, take Eric's 
suggestion and start reading up on shared libraries, compiling, and 
linking.  Once you do this, you will understand why you keep getting 
multiple definition errors.

- George


Jonas wrote:
> By the way, when I defined divcom_shared_func.cc in only ONE of the
> files, the other files won't compile successfully complaining that
> some functions are NOT yet defined.
>
> And so I'm forced to define divcom_shared_func.cc in all the other
> files. Doing this results in my original problem... So what do I do?
>
> On 1/15/08, Jonas <address@hidden> wrote:
> > I still have the same problem. Actually, I am just including header
> > files of my own design. And as par your suggesstion, I decided to
> > include them in a file called divcom_shared_func.cc.
> >
> > In short divcom_shared_func.cc contains only the following lines that
> > are needed by my other signal processing blocks:
> >
> > #include "others.cc"
> > #include "elem_matrix.cc"
> > using elem_matrix_jonas::elem_matrix;
> >
> > And the functions defined in these files are all repeatedly used.
> >
> > Unfortunately, I still get the same errors regarding multiple definitions.
> >
> > So what do I do now?
> >
> > =)
> >
> > On 1/15/08, Jonas <address@hidden> wrote:
> > > Thanks!
> > >
> > > I'll try this.
> > >
> > > =)
> > >
> > > On 1/15/08, Eric Blossom <address@hidden> wrote:
> > > > On Mon, Jan 14, 2008 at 07:40:26PM +0800, Jonas wrote:
> > > > > I have a question.
> > > > >
> > > > > I am trying to make 4 signal processing blocks wherein some of the
> > > > > definitions for its computations will be REPEATEDLY defined. I really
> > > > intend
> > > > > this. However, basing from the gr-howto module (of which I used the
> > > > built-in
> > > > > dependencies there), the compiler ALWAYS COMPLAINS of a multiple
> > > > definition
> > > > > of something that I REALLY INTEND to define repeatedly. This is due to
> > > the
> > > > > fact that the four signal processing blocks that I made share some
> > > COMMON
> > > > > signal processing manipulations.
> > > > >
> > > > > I want to be able to ignore this error and compile the four signal
> > > > > processing blocks simultaneously. Is this possible with GNU Radio?
> > > > >
> > > > > Thanks!
> > > > Don't define the function multiple times, define it once, and include
> > > > it in the shared library that you build for the swig module.
> > > > E.g., in the "howto" example, create a new file
> > > > my_shared_functions.cc, and add it to _howto_la_SOURCES.
> > > >
> > > > If this doesn't make sense, you may want to read up on shared
> > > > libraries, automake and libtool.
> > > >
> > > > Eric
>
>
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