cmd/go, cmd/cgo, make.bash: cross compiling with cgo enabled
Introduce two new environment variables, CC_FOR_TARGET and CXX_FOR_TARGET.
CC_FOR_TARGET defaults to CC and is used when compiling for GOARCH, while
CC remains for compiling for GOHOSTARCH.
CXX_FOR_TARGET defaults to CXX and is used when compiling C++ code for
GOARCH.
CGO_ENABLED defaults to disabled when cross compiling and has to be
explicitly enabled.
Update #4714
LGTM=minux.ma, iant
R=golang-codereviews, minux.ma, iant, rsc, dominik.honnef
CC=golang-codereviews
https://golang.org/cl/57100043
diff --git a/src/make.bash b/src/make.bash
index 877d1e5..bfcb5d5 100755
--- a/src/make.bash
+++ b/src/make.bash
@@ -35,10 +35,15 @@
# controls the default behavior of the linker's -linkmode option. The
# default value depends on the system.
#
-# CC: Command line to run to get at host C compiler.
+# CC: Command line to run to compile C code for GOHOSTARCH.
# Default is "gcc". Also supported: "clang".
-# CXX: Command line to run to get at host C++ compiler, only recorded
-# for cgo use. Default is "g++". Also supported: "clang++".
+#
+# CC_FOR_TARGET: Command line to run to compile C code for GOARCH.
+# This is used by cgo. Default is CC.
+#
+# CXX_FOR_TARGET: Command line to run to compile C++ code for GOARCH.
+# This is used by cgo. Default is CXX, or, if that is not set,
+# "g++" or "clang++".
#
# GO_DISTFLAGS: extra flags to provide to "dist bootstrap". Use "-s"
# to build a statically linked toolchain.
@@ -153,13 +158,15 @@
if [ "$GOHOSTARCH" != "$GOARCH" -o "$GOHOSTOS" != "$GOOS" ]; then
echo "# Building packages and commands for host, $GOHOSTOS/$GOHOSTARCH."
- GOOS=$GOHOSTOS GOARCH=$GOHOSTARCH \
+ # CC_FOR_TARGET is recorded as the default compiler for the go tool. When building for the host, however,
+ # use the host compiler, CC, from `cmd/dist/dist env` instead.
+ CC=$CC GOOS=$GOHOSTOS GOARCH=$GOHOSTARCH \
"$GOTOOLDIR"/go_bootstrap install -ccflags "$GO_CCFLAGS" -gcflags "$GO_GCFLAGS" -ldflags "$GO_LDFLAGS" -v std
echo
fi
echo "# Building packages and commands for $GOOS/$GOARCH."
-"$GOTOOLDIR"/go_bootstrap install $GO_FLAGS -ccflags "$GO_CCFLAGS" -gcflags "$GO_GCFLAGS" -ldflags "$GO_LDFLAGS" -v std
+CC=$CC_FOR_TARGET "$GOTOOLDIR"/go_bootstrap install $GO_FLAGS -ccflags "$GO_CCFLAGS" -gcflags "$GO_GCFLAGS" -ldflags "$GO_LDFLAGS" -v std
echo
rm -f "$GOTOOLDIR"/go_bootstrap
