package/go: fixing host go cross compilation

Actually if GOHOSTOS == GOOS || GOHOSTARCH == GOARCH the go build system assume
it's not cross compiling and uses the same toolchain for both the host and the
target. This commit adds a patch to enable the explicit
GO_ASSUME_CROSSCOMPILING in go build system and updates to go package
accordingly.

Fixes:
http://autobuild.buildroot.net/results/3636b1ac5756a782fd7578186508aaf9d105e3e9/
http://autobuild.buildroot.net/results/25790dca7e19527bb360d7dfb325cd9cfc3b56cc/
and many more.

References:
https://github.com/golang/go/issues/25177
https://golang.org/cl/112156

Signed-off-by: Angelo Compagnucci <angelo@amarulasolutions.com>
Signed-off-by: Anisse Astier <anisse@astier.eu>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

diff --git a/package/go/0001-build.go-explicit-option-for-crosscompilation.patch b/package/go/0001-build.go-explicit-option-for-crosscompilation.patch
new file mode 100644 (file)
index 0000000..f76c5b1
--- /dev/null
+++ b/package/go/0001-build.go-explicit-option-for-crosscompilation.patch
@@ -0,0 +1,40 @@
+From e1382a731a726293e30901038c6870fa77ef6095 Mon Sep 17 00:00:00 2001
+From: Angelo Compagnucci <angelo@amarulasolutions.com>
+Date: Tue, 8 May 2018 16:08:44 +0200
+Subject: [PATCH] build.go: explicit option for crosscompilation
+
+Actually if GOHOSTOS == GOOS || GOHOSTARCH == GOARCH the go build system
+assume it's not cross compiling and uses the same toolchain also for the
+bootstrap.  This is a problem in case the cross compilation mandates a
+different toolchain for bootstrap and target.  This patch adds
+GO_ASSUME_CROSSCOMPILING varible to assure that in case of cross
+compilation CC_FOR_TARGET can be different from CC.
+
+Signed-off-by: Angelo Compagnucci <angelo@amarulasolutions.com>
+Signed-off-by: Anisse Astier <anisse@astier.eu>
+---
+ src/cmd/dist/build.go | 3 ++-
+ 1 file changed, 2 insertions(+), 1 deletion(-)
+
+diff --git a/src/cmd/dist/build.go b/src/cmd/dist/build.go
+index 99d1db5..eb4097f 100644
+--- a/src/cmd/dist/build.go
++++ b/src/cmd/dist/build.go
+@@ -252,12 +252,13 @@ func xinit() {
+ // $CC_FOR_goos_goarch, if set, applies only to goos/goarch.
+ func compilerEnv(envName, def string) map[string]string {
+       m := map[string]string{"": def}
++      crosscompiling := os.Getenv("GO_ASSUME_CROSSCOMPILING")
+ 
+       if env := os.Getenv(envName); env != "" {
+               m[""] = env
+       }
+       if env := os.Getenv(envName + "_FOR_TARGET"); env != "" {
+-              if gohostos != goos || gohostarch != goarch {
++              if gohostos != goos || gohostarch != goarch || crosscompiling == "1" {
+                       m[gohostos+"/"+gohostarch] = m[""]
+               }
+               m[""] = env
+-- 
+2.7.4
+

diff --git a/package/go/go.mk b/package/go/go.mk
index 4d55e16cc3e1acdf976ed72a992af3dbb246f3cb..6af58f04be54c3bf5d15c4242dc73d73b720e850 100644 (file)
--- a/package/go/go.mk
+++ b/package/go/go.mk
@@ -75,7 +75,8 @@ HOST_GO_MAKE_ENV = \
        $(if $(GO_GOARM),GOARM=$(GO_GOARM)) \
        GOOS=linux \
        CC=$(HOSTCC_NOCCACHE) \
-       CXX=$(HOSTCXX_NOCCACHE)
+       CXX=$(HOSTCXX_NOCCACHE) \
+       GO_ASSUME_CROSSCOMPILING=1
 
 HOST_GO_TARGET_CC = \
        CC_FOR_TARGET="$(TARGET_CC)" \