Re: [avr-libc-dev] [avr-gcc-list] [bug #28837] using PSTR with c++ produces warnings

[Volker Kuhlmann]

On Wed 02 Nov 2011 05:08:30 NZDT +1300, Joerg Wunsch wrote:

Thanks for posting some more info, much appreciated.

> If you look into the correct (out of the many ;) config.log files,
> you'll see the solution: the C compiler complains that it cannot find
> one of the shared object files (libmpc.so, IIRC).

The correct config.log file is easy to find straight away by looking at
the directory make exited just after the error, but it didn't tell me
anything much. The error was a missing input file, not a missing .so. I
gave up trying to understand the shell code of the corresponding
configure for a hint of why.

> All this happens if you compile the toolchain using some "esoteric"
> --prefix setting, where ${prefix} is not part of your normal
> LD_LIBRARY_PATH (or whatever your system uses as its default
> equivalent of that).

--prefix=/opt/cross/avr, because that's where the avr binutils and
libc are, in current versions, so no need to recompile those.
--prefix=/usr --with-sys-root=/opt/cross/avr seems more tricky, but can
be managed.

> libmpc (which has been recently added as a
> prerequisite to GCC) installs a shared library, and the target
> compiler wants to use it.

No problem at all (likewise for gmp, mpfr):

  ldconfig -p|grep mpc
        libmpc.so.2 (libc6,x86-64) => /usr/lib64/libmpc.so.2
        libmpc.so.2 (libc6) => /usr/lib/libmpc.so.2

There headers and libmpc.a are in the standard system paths.

But it's not good enough for cross-gcc, somehow it needs the sources in
its own source directory. Which can be managed.

The cross gcc instructions mention the optional libppl and libcloog.
Are they of any benefit to avr-gcc? Handling them in the same wash would
be no extra effort.

> Three possible solutions:

Thanks. I found some other relevant details too.

Thanks,

Volker

-- 
Volker Kuhlmann
http://volker.dnsalias.net/     Please do not CC list postings to me.