Static build for linux only

Makefile

@@ -4,24 +4,32 @@ GOBUILD=$(GOCMD) build
 GOCLEAN=$(GOCMD) clean
 VERSION=$(shell git describe --tags)
 DEBUG_LDFLAGS=''
-RELEASE_LDFLAGS='-s -w -X main.version=$(VERSION) -extldflags "-static"'
+RELEASE_LDFLAGS='-s -w -X main.version=$(VERSION)'
+STATIC_RELEASE_LDFLAGS='-s -w -X main.version=$(VERSION) -extldflags "-static"'
 BUILD_TAGS?=socks
 BUILDDIR=$(shell pwd)/build
 CMDDIR=$(shell pwd)/cmd/tun2socks
 PROGRAM=tun2socks
 
 BUILD_CMD="cd $(CMDDIR) && $(GOBUILD) -ldflags $(RELEASE_LDFLAGS) -o $(BUILDDIR)/$(PROGRAM) -v -tags '$(BUILD_TAGS)'"
-XBUILD_CMD="cd $(BUILDDIR) && $(XGOCMD) -ldflags $(RELEASE_LDFLAGS) -tags '$(BUILD_TAGS)' --targets=*/* $(CMDDIR)"
+XBUILD_LINUX_CMD="cd $(BUILDDIR) && $(XGOCMD) -ldflags $(STATIC_RELEASE_LDFLAGS) -tags '$(BUILD_TAGS)' --targets=linux/* $(CMDDIR)"
+XBUILD_OTHERS_CMD="cd $(BUILDDIR) && $(XGOCMD) -ldflags $(RELEASE_LDFLAGS) -tags '$(BUILD_TAGS)' --targets=darwin/*,windows/*,android/*,ios/* $(CMDDIR)"
 
 all: build
 
 build:
 	mkdir -p $(BUILDDIR)
 	eval $(BUILD_CMD)
 
-xbuild:
+xbuild_linux:
 	mkdir -p $(BUILDDIR)
-	eval $(XBUILD_CMD)
+	eval $(XBUILD_LINUX_CMD)
+
+xbuild_others:
+	mkdir -p $(BUILDDIR)
+	eval $(XBUILD_OTHERS_CMD)
+
+xbuild: xbuild_linux xbuild_others
 
 travisbuild: xbuild