[PATCH] MIPS: fix building on multiarch platform

[YunQiang Su <yunqiang.su@cipunited.com>]

On platforms that support multiarch, such as Debian,
the filesystem hierarchy doesn't fellow the old Irix style:
	lib & lib/<multiarch> for native
	lib64 for N64 on N32/O32 systems
	lib32 for N32 on N64/O32 systems
	libo32 for O32 on N64/N32 systems

Thus we cannot
 #define STANDARD_STARTFILE_PREFIX_1
 #define STANDARD_STARTFILE_PREFIX_2
on N32 or N64 systems, else collect2 won't look for libraries
on /lib/<multiarch>.

gcc/ChangeLog:
	* configure.ac: AC_DEFINE(ENABLE_MULTIARCH, 1)
	* configure: Regenerated.
	* config.in: Regenerated.
	* config/mips/mips.h: don't define STANDARD_STARTFILE_PREFIX_1
	  if ENABLE_MULTIARCH is defined.
	* config/mips/t-linux64: define correct multiarch path when
	  multiarch is enabled.
---
 gcc/config.in             |  6 ++++++
 gcc/config/mips/mips.h    |  2 ++
 gcc/config/mips/t-linux64 | 21 ++++++++++++++++++++-
 gcc/configure             |  4 ++++
 gcc/configure.ac          |  3 +++
 5 files changed, 35 insertions(+), 1 deletion(-)

diff --git a/gcc/config.in b/gcc/config.in
index 6ac17be189e..b2ce6361327 100644
--- a/gcc/config.in
+++ b/gcc/config.in
@@ -2312,6 +2312,12 @@
 #endif
 
 
+/* Specify if mutliarch is enabled. */
+#ifndef USED_FOR_TARGET
+#undef ENABLE_MULTIARCH
+#endif
+
+
 /* The size of `dev_t', as computed by sizeof. */
 #ifndef USED_FOR_TARGET
 #undef SIZEOF_DEV_T
diff --git a/gcc/config/mips/mips.h b/gcc/config/mips/mips.h
index 74b6e11aabb..fe7f5b274b9 100644
--- a/gcc/config/mips/mips.h
+++ b/gcc/config/mips/mips.h
@@ -3427,6 +3427,7 @@ struct GTY(())  machine_function {
 
 /* If we are *not* using multilibs and the default ABI is not ABI_32 we
    need to change these from /lib and /usr/lib.  */
+#ifndef ENABLE_MULTIARCH
 #if MIPS_ABI_DEFAULT == ABI_N32
 #define STANDARD_STARTFILE_PREFIX_1 "/lib32/"
 #define STANDARD_STARTFILE_PREFIX_2 "/usr/lib32/"
@@ -3434,6 +3435,7 @@ struct GTY(())  machine_function {
 #define STANDARD_STARTFILE_PREFIX_1 "/lib64/"
 #define STANDARD_STARTFILE_PREFIX_2 "/usr/lib64/"
 #endif
+#endif
 
 /* Load store bonding is not supported by micromips and fix_24k.  The
    performance can be degraded for those targets.  Hence, do not bond for
diff --git a/gcc/config/mips/t-linux64 b/gcc/config/mips/t-linux64
index 2fdd8e00407..37d176ea309 100644
--- a/gcc/config/mips/t-linux64
+++ b/gcc/config/mips/t-linux64
@@ -20,7 +20,26 @@ MULTILIB_OPTIONS = mabi=n32/mabi=32/mabi=64
 MULTILIB_DIRNAMES = n32 32 64
 MIPS_EL = $(if $(filter %el, $(firstword $(subst -, ,$(target)))),el)
 MIPS_SOFT = $(if $(strip $(filter MASK_SOFT_FLOAT_ABI, $(target_cpu_default)) $(filter soft, $(with_float))),soft)
-MULTILIB_OSDIRNAMES = \
+ifeq (yes,$(enable_multiarch))
+  ifneq (,$(findstring gnuabi64,$(target)))
+    MULTILIB_OSDIRNAMES = \
+	../lib32$(call if_multiarch,:mips64$(MIPS_EL)-linux-gnuabin32$(MIPS_SOFT)) \
+	../libo32$(call if_multiarch,:mips$(MIPS_EL)-linux-gnu$(MIPS_SOFT)) \
+	../lib$(call if_multiarch,:mips64$(MIPS_EL)-linux-gnuabi64$(MIPS_SOFT))
+  else ifneq (,$(findstring gnuabin32,$(target)))
+    MULTILIB_OSDIRNAMES = \
+	../lib$(call if_multiarch,:mips64$(MIPS_EL)-linux-gnuabin32$(MIPS_SOFT)) \
+	../libo32$(call if_multiarch,:mips$(MIPS_EL)-linux-gnu$(MIPS_SOFT)) \
+	../lib64$(call if_multiarch,:mips64$(MIPS_EL)-linux-gnuabi64$(MIPS_SOFT))
+  else
+    MULTILIB_OSDIRNAMES = \
+	../lib32$(call if_multiarch,:mips64$(MIPS_EL)-linux-gnuabin32$(MIPS_SOFT)) \
+	../lib$(call if_multiarch,:mips$(MIPS_EL)-linux-gnu$(MIPS_SOFT)) \
+	../lib64$(call if_multiarch,:mips64$(MIPS_EL)-linux-gnuabi64$(MIPS_SOFT))
+  endif
+else
+  MULTILIB_OSDIRNAMES = \
 	../lib32$(call if_multiarch,:mips64$(MIPS_EL)-linux-gnuabin32$(MIPS_SOFT)) \
 	../lib$(call if_multiarch,:mips$(MIPS_EL)-linux-gnu$(MIPS_SOFT)) \
 	../lib64$(call if_multiarch,:mips64$(MIPS_EL)-linux-gnuabi64$(MIPS_SOFT))
+endif
diff --git a/gcc/configure b/gcc/configure
index 817d765568e..f9a796d6bb4 100755
--- a/gcc/configure
+++ b/gcc/configure
@@ -7841,6 +7841,10 @@ if test x${enable_multiarch} = xauto; then
     enable_multiarch=no
   fi
 fi
+if test x${enable_multiarch} = xyes; then
+  $as_echo "#define ENABLE_MULTIARCH 1" >>confdefs.h
+
+fi
 { $as_echo "$as_me:${as_lineno-$LINENO}: checking for multiarch configuration" >&5
 $as_echo_n "checking for multiarch configuration... " >&6; }
 
diff --git a/gcc/configure.ac b/gcc/configure.ac
index 59f205a1781..44631e23033 100644
--- a/gcc/configure.ac
+++ b/gcc/configure.ac
@@ -886,6 +886,9 @@ if test x${enable_multiarch} = xauto; then
     enable_multiarch=no
   fi
 fi
+if test x${enable_multiarch} = xyes; then
+  AC_DEFINE(ENABLE_MULTIARCH, 1)
+fi
 AC_MSG_CHECKING(for multiarch configuration)
 AC_SUBST(enable_multiarch)
 AC_MSG_RESULT($enable_multiarch$ma_msg_suffix)
-- 
2.30.2