From 3eccbd53df3c51c1c6ece217d19f1d01eb9575a7 Mon Sep 17 00:00:00 2001
From: Peter Korsgaard <peter@korsgaard.com>
Date: Fri, 2 Aug 2019 15:53:16 +0200
Subject: [PATCH] configure.ac: fixup $CC --print-multiarch output for
 musl/uclibc GCC 8+ toolchains

GCC commit 6834b83784dcf0364eb820e8 (multiarch support for non-glibc linux
systems), which is part of GCC 8+, changed the multiarch logic to use
$arch-linux-musl / $arch-linux-uclibc rather than $arch-linux-gnu.

This then causes the python3 configure script to error out:

checking for the platform triplet based on compiler characteristics... powerpc-linux-gnu
configure: error: internal configure error for the platform triplet, please file a bug report

http://autobuild.buildroot.net/results/cb4/cb49c539501342e45cbe5ade82e588fcdf51f05b

As it requires that the --print-multiarch output (if not empty) matches the
deduced triplet (which always uses -linux-gnu).

It isn't quite clear why --print-multiarch returns something for a
non-multiarch toolchain on some architectures (E.G.  PowerPC), but as a
workaround, rewrite the --print-multiarch output to match older GCC versions
to keep the configure script happy.

Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
[Peter: updated for 3.10.2]
Signed-off-by: Vincent Fazio <vfazio@gmail.com>
[Vincent: fixup offsets for 3.12.4]
---
 configure.ac | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/configure.ac b/configure.ac
index 1cb95f41fd..d142af404a 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1128,7 +1128,11 @@ AC_MSG_CHECKING([for multiarch])
 AS_CASE([$ac_sys_system],
   [Darwin*], [MULTIARCH=""],
   [FreeBSD*], [MULTIARCH=""],
-  [MULTIARCH=$($CC --print-multiarch 2>/dev/null)]
+  [
+  # GCC 8+ returns $arch-linux-{musl,uclibc} for musl/uClibc based
+  # toolchains confusing python. Fix that up
+  MULTIARCH=$($CC --print-multiarch 2>/dev/null | sed -E 's/-linux-(musl|uclibc)*$/-linux-gnu/')
+  ]
 )
 AC_SUBST([MULTIARCH])
 AC_MSG_RESULT([$MULTIARCH])
-- 
2.34.1