RES: Strange behavior when building

[Fabrício de Novaes Kucinskis]

Hi Joel,


I thought that a guard condition ("#ifndef CONFIG_H_ [...] #endif") was
enough, but I was wrong.

I changed the CONFIGURE_INIT definition as you said, and everything is ok
now.

Thank you very much!
Best regards,


Fabrício.


-----Mensagem original-----
De: Joel Sherrill <joel at OARcorp.com> [mailto:joel.sherrill at OARcorp.com]
Enviada em: terça-feira, 20 de dezembro de 2005 13:10
Para: Fabrício de Novaes Kucinskis
Cc: RTEMS - Mailing List
Assunto: Re: Strange behavior when building


Fabrício de Novaes Kucinskis wrote:
> Hello,
>
>
> I'm starting to develop some simple applications with RTEMS to an ERC32
BSP.
> The last one has some .c files and only one header, which I #included in
all
> source files (in a way similar to some of the RTEMS examples).
>
> Sometimes when trying to build, I got a "multiple definition" error. This
is
> not related to any specific change I made - I can change, for example, the
> text in a printf call and the error can happen.
>
> When the error happens, to build my application, I have to:
>
> 	1. execute a "make clean"
> 	2. comment the "confdefs.h" include
> 	3. execute make (different errors will happen, because there's no
confdefs
> inclusion)
> 	4. decomment the "confdefs.h" and
> 	5. execute make again (this time it'll work)
>
> If I change the includes over the source files (including bsp.h, stdio.h
and
> stdlib.h in each one) the problem stops. But I want to understand why this
> is happening, and I would like to avoid including the same set of headers
in
> each file.
>
> There is a snippet of the header:
>
> 	#ifndef CONFIG_H_ //guard
> 	#define CONFIG_H_
>
> 	#include <bsp.h>
> 	#include <stdio.h>
> 	#include <stdlib.h>
>
> 	//Prototypes
> 	rtems_task Interface[...]
> 	rtems_timer_service_routine Timer[...]
> 	boolean VerifyStatus[...]
>
> 	//RTEMS configuration
> 	#define CONFIGURE_TEST_NEEDS_CONSOLE_DRIVER
> 	[...]
>
> 	#define CONFIGURE_INIT
> 	#include <confdefs.h> //this is the line I have to comment when the error

Defining CONFIGURE_INIT actually instantiates data tables.  So it can
only happen  in one C file.  If you look at the tests and samples, they
are careful to define CONFIGURE_INIT in a single file (usually init.c)
and then everything is OK.  Otherwise, you get multiple definitions of
data objects.

I think this is what you are describing -- either no configuration table
or multiple definitions -- one per file the .h with CONFIGURE_INIT is
defined in.

> 	#endif /*CONFIG_H_*/
>
>
> Any comment will be very appreciated.
> Thank you in advance,
>
>
> Fabrício de Novaes Kucinskis - DEA / INPE
> -----------------------------------------
> Divisão de Eletrônica Aeroespacial
> Instituto Nacional de Pesquisas Espaciais
>


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Joel Sherrill, Ph.D.             Director of Research & Development
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