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Re: [PING^3] [PATCH] Remove CANADIAN, that break compilation for foreign target


On 30/01/18 10:19 +0300, Petr Ovtchenkov wrote:
On Tue, 19 Dec 2017 11:37:43 +0300
Petr Ovtchenkov <ptr@void-ptr.info> wrote:

ping^3


I don't fully understand the consequences (or need) for this patch.

I asked some other people to look at it, and didn't get confirmation
it's OK. So I'm reluctant to make the change. Especially this late in
the GCC 8 cycle.


On Thu, 16 Nov 2017 20:55:37 +0300
Petr Ovtchenkov <ptr@void-ptr.info> wrote:

> On Wed, 20 Sep 2017 13:44:59 +0300
> Petr Ovtchenkov <ptr@void-ptr.info> wrote:
>
> > https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71212
> >
> > On Fri, 20 May 2016 16:10:50 +0300
> > Petr Ovtchenkov <ptr@void-ptr.info> wrote:
> >
> > > Some old ad-hoc (adding -I/usr/include to compiler
> > > flags) break compilation of libstdc++ for foreign
> > > target architecture (due to compiler see includes
> > > of native).
>
> Reference for terms:
>
> https://gcc.gnu.org/onlinedocs/gccint/Configure-Terms.html
>
> Present of "CANADIAN=yes" lead to inclusion of
> headers from build (-I/usr/include). "CANADIAN=yes" used _only_
> to set "-I/usr/include".
>
> Inclusion of build headers in cross-compilation
> process is not a mistake only in case of native (i.e. it is mistake
> for cross, for canadian, for crossed native and for crossback),
> but sometimes give "success".
>
> Note, that build/host/target may be different not only due to
> different architectures, but due to different sysroots
> (libc, kernel, binutils, etc.).
>
> CANADIAN is set to "yes" by code
>
> -  # If Canadian cross, then don't pick up tools from the build directory.
> -  # Used only in GLIBCXX_EXPORT_INCLUDES.
> -  if test -n "$with_cross_host" &&
> -     test x"$build_alias" != x"$with_cross_host" &&
> -     test x"$build" != x"$target";
> -  then
> -    CANADIAN=yes
> -  else
> -    CANADIAN=no
> -  fi
>
> and it add "-I/usr/include" to compiler flags for building libstdc++.
> This is wrong.
>
> Reference to patch:
> https://gcc.gnu.org/ml/gcc-patches/2017-09/msg01332.html


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