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

[Petr Ovtchenkov]

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