Re: [gentoo-dev] Re: GCC upgrades, FUD and gentoo documentation

[Mike Frysinger]

On Wednesday 12 October 2011 15:38:47 Matt Turner wrote:
> On Wed, Oct 12, 2011 at 3:13 PM, Mike Frysinger wrote:
> > On Saturday 08 October 2011 11:07:49 Diego Elio Pettenò wrote:
> >> Il giorno sab, 08/10/2011 alle 11.33 +0000, Sven Vermeulen ha scritto:
> >> > - The fix_libtool_files.sh command is now part of the toolchain
> >> > eclass, so
> >> >
> >> >   doesn't need to be ran by users anymore
> >>
> >> Moreover, that should only be needed for very old installs: libstdc++.la
> >> that caused the trouble in the first place hasn't been around for over
> >> an year (maybe two? I lost count), and the auto-fix of .la files in
> >> recent Portage versions make it even less necessary.
> >
> > well, that's not entirely accurate.  like libtool, now that we've dropped
> > libstdc++.la, the majority of issues have "gone away".  but we still
> > install .la files for the other (much more infrequently used) internal
> > gcc libraries.
> >
> > although this might be something we want to address in gcc.  i was fine
> > with dropping the libstdc++.la even though it listed things in
> > dependency_libs because the only correct way (imo) to link C++ code is
> > with `g++`.  using `gcc -lstdc++` is not supported.
> >
> > i think cases can be made for the other internal gcc libraries:
> >  - libgomp.la: build/link with -fopenmp, not -lgomp
> >  - libgfortran*.la: build/link with `gfortran`, not `gcc -lgfortran`
> >  - libgcj*.la: build/link with `gcj`, not `gcc -lgcj`
> >  - libobjc.la: use -lobjc to link, but dependency_libs=''
> >  - libffi.la: use -lffi to link, but dependency_libs=''
> >  - libmudflap.la: build/link with `gcc -fmudflap`, not `gcc -lmudflap`
> >  - libgij.la: build/link with `gij`, not `gcc -lgij`
> >  - libquadmath.la: only used by fortran, and dependency_libs=''
>
> gcc's Optimize Options page
> (http://gcc.gnu.org/onlinedocs/gcc/Optimize-Options.html) has an
> example of linking C, C++, and FORTRAN code together, where it uses
> g++ -lgfortran. Just thought I'd mention it.

hmm, unusual, but good point.  their example breaks when linking statically as 
fortran (always?) needs -lm, and with newer versions, -lquadmath.  not sure 
how to address that other than leaving libgfortran.la in place :(.
-mike