[PATCH 27/30] [arm][fuchsia] Rework multilib support

[Richard Earnshaw <Richard dot Earnshaw at arm dot com>]

It looks like the fuchsia port relied on inheriting the multilib rules from
the bare-metal port (the t-arm-elf makefile fragment), but that has now been
rewritten on the assuption that the base architecture is ARMv4t; fuchsia
has a base architecture of ARMv7-a.

To account for this, I've cloned the original t-arm-elf rules into a
new makefile fragment t-fuchsia and arranged for that to be used when
targetting this system.

	* config/arm/t-fuchsia: New file.
	* config.gcc (arm*-*-fuchsia*): Use it.
---
 gcc/config.gcc           |  2 +-
 gcc/config/arm/t-fuchsia | 33 +++++++++++++++++++++++++++++++++
 2 files changed, 34 insertions(+), 1 deletion(-)
 create mode 100644 gcc/config/arm/t-fuchsia

diff --git a/gcc/config.gcc b/gcc/config.gcc
index b6dcbcd..967ea77 100644
--- a/gcc/config.gcc
+++ b/gcc/config.gcc
@@ -1158,7 +1158,7 @@ arm*-*-eabi* | arm*-*-symbianelf* | arm*-*-rtems* | arm*-*-fuchsia*)
 	  ;;
 	arm*-*-fuchsia*)
 	  tm_file="${tm_file} fuchsia.h arm/fuchsia-elf.h glibc-stdint.h"
-	  tmake_file="${tmake_file} arm/t-bpabi"
+	  tmake_file="${tmake_file} arm/t-bpabi arm/t-fuchsia"
 	  target_cpu_cname="generic-armv7-a"
 	  ;;
 	arm*-*-rtems*)
diff --git a/gcc/config/arm/t-fuchsia b/gcc/config/arm/t-fuchsia
new file mode 100644
index 0000000..18fc518
--- /dev/null
+++ b/gcc/config/arm/t-fuchsia
@@ -0,0 +1,33 @@
+# Copyright (C) 2017 Free Software Foundation, Inc.
+#
+# This file is part of GCC.
+#
+# GCC is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3, or (at your option)
+# any later version.
+#
+# GCC is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with GCC; see the file COPYING3.  If not see
+# <http://www.gnu.org/licenses/>.
+
+# Reset all the multilib variables.
+MULTILIB_OPTIONS	=
+MULTILIB_DIRNAMES	=
+MULTILIB_EXCEPTIONS	=
+MULTILIB_REUSE		=
+MULTILIB_MATCHES	=
+MULTILIB_REQUIRED	=
+
+# For compatibility with gcc-7 we build the following multilibs
+MULTILIB_OPTIONS	+= marm/mthumb
+MULTILIB_DIRNAMES	+= arm thumb
+
+MULTILIB_OPTIONS	+= mfloat-abi=hard
+MULTILIB_DIRNAMES	+= fpu
+MULTILIB_EXCEPTIONS	+= *mthumb/*mfloat-abi=hard*