Re: [avr-libc-dev] avr-gcc, libgcc.a and libgcov.a

[Chris Marrin]

On May 4, 2011, at 10:24 AM, Weddington, Eric wrote:

> Hi Chris,
> 
> Mostly, yes.
> 
> Libgcc is absolutely needed as it contains certain math library routines and 
> other routines that gets used in the startup code. Libgcov is generally not 
> needed, and I'm not sure that it even works for the AVR.
> 
> Yes, the include files that GCC installs are useful. For example GCC installs 
> stdbool.h and stdint.h. I use bot of those extensively in an AVR application. 
> Other header files may not be used as much, but typically they are standard 
> files so should be available for any conforming target.
> 
> Yes, there is fixed point math available for the AVR via a patch from a 
> volunteer, and should be in the latest AVR Toolchain release from Atmel. 
> We're currently working on getting that patch committed upstream along with 
> some others.
> 
> So overall, yes most of them are absolutlely needed, or very useful to have. 
> Avr-libc does not provide everything. Sure there are some things that are 
> borderline, but at this point it hasn't been worth the time to go in and 
> pinpoint disable certain things. I know that there has been some recent work 
> on the GCC toplevel to reorganize how it works. Perhaps when this work is 
> done it might be easier to do that.

Thanks for the response. The problem with all this is that there is some 
overlapping functionality between avr-libc and libgcc. In fact each have a 
version of stdint.h. Which is the right one to use? It seems like it would be 
much better if avr-libc provided all the functionality from the libgcc files 
that can be used with avr-gcc. Or at least they should be at compatible places 
in the hierarchy. avr-libc includes are at "avr/include" while libgcc includes 
are at "lib/gcc/avr/4.5.2/include"! I was only able to find the libgcc files by 
scouring through the installed files.

-----
~Chris
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