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

[Jonathan Wakely]

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