[PATCH v2] toolchain-funcs.eclass: Set some Go arch-specific vars in tc-env_build

Some Go arch-specific variables can be set automatically based on the
tuple alone. Others cannot feasibly be determined automatically and must
therefore be set by the user. It is sometimes necessary to build Go code
for CBUILD, so use BUILD_GO* variables in case CHOST is a more advanced
model of CBUILD's architecture.

Signed-off-by: James Le Cuirot <[email protected]>
---
 eclass/toolchain-funcs.eclass | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/eclass/toolchain-funcs.eclass b/eclass/toolchain-funcs.eclass
index 2b57fc118705..8299c103c8dc 100644
--- a/eclass/toolchain-funcs.eclass
+++ b/eclass/toolchain-funcs.eclass
@@ -369,6 +369,13 @@ tc-export_build_env() {
 		: "${BUILD_CXXFLAGS:=${CXXFLAGS}}"
 		: "${BUILD_CPPFLAGS:=${CPPFLAGS}}"
 		: "${BUILD_LDFLAGS:=${LDFLAGS}}"
+
+		if has go-env ${INHERITED}; then
+			: "${BUILD_GOAMD64:=${GOAMD64}}"
+			: "${BUILD_GOARM64:=${GOARM64}}"
+			: "${BUILD_GOPPC64:=${GOPPC64}}"
+			: "${BUILD_GORISCV64:=${GORISCV64}}"
+		fi
 	fi
 	export BUILD_{C,CXX,CPP,LD}FLAGS

@@ -388,6 +395,13 @@ tc-export_build_env() {
 # the target build system does not check.
 tc-env_build() {
 	tc-export_build_env
+
+	has go-env ${INHERITED} && local -x \
+		GOAMD64=${BUILD_GOAMD64} \
+		GOARM64=${BUILD_GOARM64} \
+		GOPPC64=${BUILD_GOPPC64} \
+		GORISCV64=${BUILD_GORISCV64}
+
 	CFLAGS=${BUILD_CFLAGS} \
 	CXXFLAGS=${BUILD_CXXFLAGS} \
 	CPPFLAGS=${BUILD_CPPFLAGS} \
--
2.53.0