[OE-core] [v2][PATCH 1/2] go.bbclass: Export GOARM

[Mark Asselstine]

When building GO packages for ARM (v5, v6, v7) it is expected that the
GOARM env variable is set during the build. Not having GOARM exported
will result in GO binaries which can't be executed on the target
(terminate with segfault). Per https://github.com/golang/go/wiki/GoArm

We already have the logic in goarch.bbclass to determine the correct
value of GOARM (see GOARM_TARGET), but currently this is only used to
build go itself (go-cross_1.*.bb requires go-cross.inc --> export
GOARM = "${TARGET_GOARM}").

Here we export GOARM but we do it such that it is only exported if we
are building for 'arm' and only when recipes requiring/inheriting
go.bbclass are be used to build for the target.

Signed-off-by: Mark Asselstine <mark.asselstine at windriver.com>
---

V2
* Avoid potential undefined situations

 meta/classes/go.bbclass | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/meta/classes/go.bbclass b/meta/classes/go.bbclass
index af331f8..5af4c3e 100644
--- a/meta/classes/go.bbclass
+++ b/meta/classes/go.bbclass
@@ -8,6 +8,10 @@ GOROOT = "${STAGING_LIBDIR}/go"
 export GOROOT
 export GOROOT_FINAL = "${libdir}/go"
 
+GOARM[export] = "0"
+GOARM_arm_class-target = "${TARGET_GOARM}"
+GOARM_arm_class-target[export] = "1"
+
 DEPENDS_GOLANG_class-target = "virtual/${TUNE_PKGARCH}-go virtual/${TARGET_PREFIX}go-runtime"
 DEPENDS_GOLANG_class-native = "go-native"
 DEPENDS_GOLANG_class-nativesdk = "virtual/${TARGET_PREFIX}go-crosssdk virtual/${TARGET_PREFIX}go-runtime"
-- 
2.7.4