[v3] Fix cross compilation to Solaris

[Jonathan Wakely]

On 30/05/17 15:10 +0200, Rainer Orth wrote:
>I recently tried a cross-build from sparc-sun-solaris2.12 to
>i386-pc-solaris2.12 (with cross-binutils and gas, but the native ld
>which has been a cross-linker for quite some time).  The build failed in
>libstdc++-v3 like this:
>
>/vol/gcc/src/hg/trunk/local/libstdc++-v3/libsupc++/new_opa.cc:62:46: error: ‘void* aligned_alloc(std::size_t, std::size_t)’ conflicts with a previous declaration
> aligned_alloc (std::size_t al, std::size_t sz)
>                                              ^
>In file included from /var/gcc/sysroot/i386/usr/include/stdlib.h:13:0,
>                 from /var/gcc/cross/i386-pc-solaris2.12/obj/gcc-8.0.0-20170516/12-gcc-gas/i386-pc-solaris2.12/libstdc++-v3/include/cstdlib:75,
>                 from /var/gcc/cross/i386-pc-solaris2.12/obj/gcc-8.0.0-20170516/12-gcc-gas/i386-pc-solaris2.12/libstdc++-v3/include/stdlib.h:36,
>                 from /vol/gcc/src/hg/trunk/local/libstdc++-v3/libsupc++/new_opa.cc:27:
>/var/gcc/sysroot/i386/usr/include/iso/stdlib_c99.h:79:14: note: previous declaration ‘void* std::aligned_alloc(std::size_t, std::size_t)’
> extern void *aligned_alloc(size_t, size_t);
>              ^~~~~~~~~~~~~
>/vol/gcc/src/hg/trunk/local/libstdc++-v3/libsupc++/new_opa.cc: In function ‘void* operator new(std::size_t, std::align_val_t)’:
>/vol/gcc/src/hg/trunk/local/libstdc++-v3/libsupc++/new_opa.cc:103:57: error: call of overloaded ‘aligned_alloc(std::size_t&, std::size_t&)’ is ambiguous
>   while (__builtin_expect ((p = aligned_alloc (align, sz)) == 0, false))
>                                                         ^
>In file included from /var/gcc/sysroot/i386/usr/include/stdlib.h:13:0,
>                 from /var/gcc/cross/i386-pc-solaris2.12/obj/gcc-8.0.0-20170516/12-gcc-gas/i386-pc-solaris2.12/libstdc++-v3/include/cstdlib:75,
>                 from /var/gcc/cross/i386-pc-solaris2.12/obj/gcc-8.0.0-20170516/12-gcc-gas/i386-pc-solaris2.12/libstdc++-v3/include/stdlib.h:36,
>                 from /vol/gcc/src/hg/trunk/local/libstdc++-v3/libsupc++/new_opa.cc:27:
>/var/gcc/sysroot/i386/usr/include/iso/stdlib_c99.h:79:14: note: candidate: ‘void* std::aligned_alloc(std::size_t, std::size_t)’
> extern void *aligned_alloc(size_t, size_t);
>              ^~~~~~~~~~~~~
>/vol/gcc/src/hg/trunk/local/libstdc++-v3/libsupc++/new_opa.cc:62:1: note: candidate: ‘void* aligned_alloc(std::size_t, std::size_t)’
> aligned_alloc (std::size_t al, std::size_t sz)
> ^~~~~~~~~~~~~
>make[4]: *** [Makefile:936: new_opa.lo] Error 1
>
>It turns out that currently crossconfig.m4 has a static list of
>AC_DEFINEs for *-solaris*, which is obviously incomplete compared to the
>target's features.  Instead of manually fixing this, it seems the way to
>go is follow the lead of the Linux etc. targets and just perform the
>link tests which are skipped in configure.ac for the !GLIBCXX_IS_NATIVE
>case since they *do* work reliably in this case.  This is just what this
>patch does: treat Solaris like the Linux targets and remove the
>hardcoded feature list from crossconfig.m4.
>
>This way, config.h is identical between a native build and the cross
>above, with the exception of HAVE_SETENV which is equally guarded with
>GLIBCXX_IS_NATIVE in acinclude.m4 (GLIBCXX_CONFIGURE_TESTSUITE).  Maybe
>it's time to somehow refine the GLIBCXX_IS_NATIVE check to allow cross
>configurations that *can* perform link tests to run them?

Sounds like a good idea, although I don't know how to do that.


>With the patch, the cross-build succeeded without issues.
>
>Ok for mainline?

OK, thanks.