From: Paul Burton <paul.burton@mips.com>
Date: Tue, 7 Aug 2018 23:06:41 +0000 (-0700)
Subject: MIPS: Always specify -EB or -EL when using clang
X-Git-Url: http://git.cdn.openwrt.org/?a=commitdiff_plain;h=c6d6f4c55f5cda5a7fa5a08eede0eb289937c328;p=openwrt%2Fstaging%2Fblogic.git

MIPS: Always specify -EB or -EL when using clang

When building using clang, always specify -EB or -EL in order to ensure
we target the desired endianness.

Since clang cross compiles using a single compiler build with multiple
targets, our -dumpmachine tests which don't specify clang's --target
argument check output based upon the build machine rather than the
machine our build will target. This means our detection of whether to
specify -EB fails miserably & we never do. Providing the endianness flag
unconditionally for clang resolves this issue & simplifies the clang
path somewhat.

Signed-off-by: Paul Burton <paul.burton@mips.com>
---

diff --git a/arch/mips/Makefile b/arch/mips/Makefile
index 1e98d22ec119..5425df002a6b 100644
--- a/arch/mips/Makefile
+++ b/arch/mips/Makefile
@@ -122,12 +122,22 @@ cflags-y += -ffreestanding
 # are used, so we kludge that here.  A bug has been filed at
 # http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29413.
 #
+# clang doesn't suffer from these issues and our checks against -dumpmachine
+# don't work so well when cross compiling, since without providing --target
+# clang's output will be based upon the build machine. So for clang we simply
+# unconditionally specify -EB or -EL as appropriate.
+#
+ifeq ($(cc-name),clang)
+cflags-$(CONFIG_CPU_BIG_ENDIAN)		+= -EB
+cflags-$(CONFIG_CPU_LITTLE_ENDIAN)	+= -EL
+else
 undef-all += -UMIPSEB -U_MIPSEB -U__MIPSEB -U__MIPSEB__
 undef-all += -UMIPSEL -U_MIPSEL -U__MIPSEL -U__MIPSEL__
 predef-be += -DMIPSEB -D_MIPSEB -D__MIPSEB -D__MIPSEB__
 predef-le += -DMIPSEL -D_MIPSEL -D__MIPSEL -D__MIPSEL__
 cflags-$(CONFIG_CPU_BIG_ENDIAN)		+= $(shell $(CC) -dumpmachine |grep -q 'mips.*el-.*' && echo -EB $(undef-all) $(predef-be))
 cflags-$(CONFIG_CPU_LITTLE_ENDIAN)	+= $(shell $(CC) -dumpmachine |grep -q 'mips.*el-.*' || echo -EL $(undef-all) $(predef-le))
+endif
 
 cflags-$(CONFIG_SB1XXX_CORELIS)	+= $(call cc-option,-mno-sched-prolog) \
 				   -fno-omit-frame-pointer