golang: Share build cache across package builds

This also adds a config option GOLANG_BUILD_CACHE_DIR to customize the
location of the build cache directory.

Signed-off-by: Jeffery To <jeffery.to@gmail.com>

lang/golang/golang-package.mk

@@ -123,11 +123,7 @@ GO_PKG_PATH:=/usr/share/gocode
 GO_PKG_BUILD_PKG?=$(strip $(GO_PKG))/...
 
 GO_PKG_WORK_DIR_NAME:=.go_work
-GO_PKG_WORK_DIR=$(PKG_BUILD_DIR)/$(GO_PKG_WORK_DIR_NAME)
-
-GO_PKG_BUILD_DIR=$(GO_PKG_WORK_DIR)/build
-GO_PKG_CACHE_DIR=$(GO_PKG_WORK_DIR)/cache
-
+GO_PKG_BUILD_DIR=$(PKG_BUILD_DIR)/$(GO_PKG_WORK_DIR_NAME)/build
 GO_PKG_BUILD_BIN_DIR=$(GO_PKG_BUILD_DIR)/bin$(if $(GO_HOST_TARGET_DIFFERENT),/$(GO_OS_ARCH))
 
 GO_PKG_BUILD_DEPENDS_SRC=$(STAGING_DIR)$(GO_PKG_PATH)/src
@@ -185,7 +181,7 @@ GO_PKG_TARGET_VARS= \
 
 GO_PKG_BUILD_VARS= \
 	GOPATH=$(GO_PKG_BUILD_DIR) \
-	GOCACHE=$(GO_PKG_CACHE_DIR) \
+	GOCACHE=$(GO_BUILD_CACHE_DIR) \
 	GOMODCACHE=$(GO_MOD_CACHE_DIR) \
 	GOENV=off
 
@@ -195,9 +191,6 @@ GO_PKG_DEFAULT_VARS= \
 
 GO_PKG_VARS=$(GO_PKG_DEFAULT_VARS)
 
-# do not use for new code; this will be removed after the next OpenWrt release
-GoPackage/Environment=$(GO_PKG_VARS)
-
 GO_PKG_DEFAULT_LDFLAGS= \
 	-buildid '$(SOURCE_DATE_EPOCH)' \
 	-linkmode external \
@@ -227,7 +220,9 @@ GoPackage/has_binaries=$(call GoPackage/is_dir_not_empty,$(GO_PKG_BUILD_BIN_DIR)
 define GoPackage/Build/Configure
 	( \
 		cd $(PKG_BUILD_DIR) ; \
-		mkdir -p $(GO_PKG_BUILD_DIR)/bin $(GO_PKG_BUILD_DIR)/src $(GO_PKG_CACHE_DIR) $(GO_MOD_CACHE_DIR) ; \
+		mkdir -p \
+			$(GO_PKG_BUILD_DIR)/bin $(GO_PKG_BUILD_DIR)/src \
+			$(GO_BUILD_CACHE_DIR) $(GO_MOD_CACHE_DIR) ; \
 		\
 		files=$$$$($(FIND) ./ \
 			-type d -a \( -path './.git' -o -path './$(GO_PKG_WORK_DIR_NAME)' \) -prune -o \
@@ -387,3 +382,10 @@ define GoSrcPackage
     Package/$(1)/install=$$(call GoPackage/Package/Install/Src,$$(1))
   endif
 endef
+
+
+# Deprecated variables - these will be removed after the next OpenWrt release
+GO_PKG_WORK_DIR=$(PKG_BUILD_DIR)/$(GO_PKG_WORK_DIR_NAME)
+GO_PKG_CACHE_DIR=$(GO_BUILD_CACHE_DIR)
+GoPackage/Environment=$(GO_PKG_VARS)
+# End of deprecated variables

lang/golang/golang-values.mk

@@ -223,6 +223,7 @@ endif
 
 # General build info
 
+GO_BUILD_CACHE_DIR:=$(or $(call qstrip,$(CONFIG_GOLANG_BUILD_CACHE_DIR)),$(TOPDIR)/.go-build)
 GO_MOD_CACHE_DIR:=$(DL_DIR)/go-mod-cache
 
 GO_MOD_ARGS= \

lang/golang/golang/Config.in

@@ -12,6 +12,13 @@ config GOLANG_EXTERNAL_BOOTSTRAP_ROOT
 
 	  Leave blank to compile the default bootstrap Go.
 
+config GOLANG_BUILD_CACHE_DIR
+	string "Go build cache directory"
+	default ""
+	help
+	  Store the Go build cache in this directory.
+	  If not set, uses './.go-build'.
+
 config GOLANG_MOD_CACHE_WORLD_READABLE
 	bool "Ensure Go module cache is world-readable"
 	default n

lang/golang/golang/Makefile

@@ -32,10 +32,6 @@ PKG_BUILD_DIR:=$(BUILD_DIR)/go-$(PKG_VERSION)
 PKG_BUILD_PARALLEL:=1
 PKG_USE_MIPS16:=0
 
-PKG_GO_WORK_DIR:=$(PKG_BUILD_DIR)/.go_work
-PKG_GO_HOST_CACHE_DIR:=$(PKG_GO_WORK_DIR)/host_cache
-PKG_GO_TARGET_CACHE_DIR:=$(PKG_GO_WORK_DIR)/target_cache
-
 PKG_GO_PREFIX:=/usr
 PKG_GO_VERSION_ID:=$(GO_VERSION_MAJOR_MINOR)
 PKG_GO_ROOT:=$(PKG_GO_PREFIX)/lib/go-$(PKG_GO_VERSION_ID)
@@ -43,9 +39,6 @@ PKG_GO_ROOT:=$(PKG_GO_PREFIX)/lib/go-$(PKG_GO_VERSION_ID)
 HOST_BUILD_DIR:=$(BUILD_DIR_HOST)/go-$(PKG_VERSION)
 HOST_BUILD_PARALLEL:=1
 
-HOST_GO_WORK_DIR:=$(HOST_BUILD_DIR)/.go_work
-HOST_GO_CACHE_DIR:=$(HOST_GO_WORK_DIR)/cache
-
 HOST_GO_PREFIX:=$(STAGING_DIR_HOSTPKG)
 HOST_GO_VERSION_ID:=cross
 HOST_GO_ROOT:=$(HOST_GO_PREFIX)/lib/go-$(HOST_GO_VERSION_ID)
@@ -78,8 +71,6 @@ BOOTSTRAP_SOURCE_URL:=$(GO_SOURCE_URLS)
 BOOTSTRAP_HASH:=f4ff5b5eb3a3cae1c993723f3eab519c5bae18866b5e5f96fe1102f0cb5c3e52
 
 BOOTSTRAP_BUILD_DIR:=$(HOST_BUILD_DIR)/.go_bootstrap
-BOOTSTRAP_WORK_DIR:=$(BOOTSTRAP_BUILD_DIR)/.go_work
-BOOTSTRAP_CACHE_DIR:=$(BOOTSTRAP_WORK_DIR)/cache
 
 BOOTSTRAP_GO_VALID_OS_ARCH:= \
   darwin_386     darwin_amd64 \
@@ -236,19 +227,16 @@ define Host/Compile
 	$(call GoCompiler/Bootstrap/CheckHost,$(BOOTSTRAP_GO_VALID_OS_ARCH))
 	$(call GoCompiler/Host/CheckHost,$(HOST_GO_VALID_OS_ARCH))
 
-	mkdir -p \
-		$(BOOTSTRAP_CACHE_DIR) \
-		$(HOST_GO_CACHE_DIR)
+	mkdir -p $(GO_BUILD_CACHE_DIR)
 
 	$(call GoCompiler/Bootstrap/Make, \
-		GOCACHE=$(BOOTSTRAP_CACHE_DIR) \
 		CC=$(HOSTCC_NOCACHE) \
 		CXX=$(HOSTCXX_NOCACHE) \
 	)
 
 	$(call GoCompiler/Host/Make, \
 		GOROOT_BOOTSTRAP=$(if $(USE_DEFAULT_BOOTSTRAP),$(BOOTSTRAP_BUILD_DIR),$(EXTERNAL_BOOTSTRAP_DIR)) \
-		GOCACHE=$(HOST_GO_CACHE_DIR) \
+		GOCACHE=$(GO_BUILD_CACHE_DIR) \
 		CC=$(HOSTCC_NOCACHE) \
 		CXX=$(HOSTCXX_NOCACHE) \
 	)
@@ -259,7 +247,7 @@ define Host/Compile
 	( \
 		cd $(HOST_BUILD_DIR)/bin ; \
 		$(CP) go go-nopie ; \
-		GOCACHE=$(HOST_GO_CACHE_DIR) \
+		GOCACHE=$(GO_BUILD_CACHE_DIR) \
 		GOENV=off \
 		CC=$(HOSTCC_NOCACHE) \
 		CXX=$(HOSTCXX_NOCACHE) \
@@ -299,15 +287,13 @@ define Host/Uninstall
 endef
 
 define Build/Compile
-	mkdir -p \
-		$(PKG_GO_HOST_CACHE_DIR) \
-		$(PKG_GO_TARGET_CACHE_DIR)
+	mkdir -p $(GO_BUILD_CACHE_DIR)
 
 	@echo "Building target Go first stage"
 
 	$(call GoCompiler/Package/Make, \
 		GOROOT_BOOTSTRAP=$(HOST_GO_ROOT) \
-		GOCACHE=$(PKG_GO_HOST_CACHE_DIR) \
+		GOCACHE=$(GO_BUILD_CACHE_DIR) \
 		GO_GCC_HELPER_CC="$(HOSTCC)" \
 		GO_GCC_HELPER_CXX="$(HOSTCXX)" \
 		GO_GCC_HELPER_PATH=$$$$PATH \
@@ -327,7 +313,7 @@ define Build/Compile
 		export $(GO_PKG_TARGET_VARS) ; \
 		$(CP) go go-host ; \
 		GOROOT_FINAL=$(PKG_GO_ROOT) \
-		GOCACHE=$(PKG_GO_TARGET_CACHE_DIR) \
+		GOCACHE=$(GO_BUILD_CACHE_DIR) \
 		GOENV=off \
 		GO_GCC_HELPER_CC="$(TARGET_CC)" \
 		GO_GCC_HELPER_CXX="$(TARGET_CXX)" \

utils/ctop/Makefile

@@ -35,12 +35,11 @@ endef
 MAKE_PATH:=$(GO_PKG_WORK_DIR_NAME)/build/src/$(GO_PKG)
 MAKE_VARS += \
 	GOPATH=$(GO_PKG_BUILD_DIR) \
-	GOCACHE=$(GO_PKG_CACHE_DIR) \
-	GOTMPDIR=$(GO_PKG_TMP_DIR) \
+	GOCACHE=$(GO_BUILD_CACHE_DIR) \
 	GOROOT_FINAL=$(GO_TARGET_ROOT) \
 	CC=$(TARGET_CC) \
 	CXX=$(TARGET_CXX) \
-	$(call GoPackage/Environment)
+	$(GO_PKG_VARS)
 MAKE_FLAGS += \
 	COMMIT=$(PKG_SOURCE_VERSION)
 

utils/docker-ce/Makefile

@@ -77,8 +77,7 @@ define Build/Configure
 	mkdir -p $(GO_PKG_BUILD_DIR)/bin \
 			 $(GO_PKG_BUILD_DIR)/src \
 			 $(GO_PKG_BUILD_DIR)/src/$(GO_PKG)/ \
-			 $(GO_PKG_CACHE_DIR) \
-			 $(GO_PKG_TMP_DIR)
+			 $(GO_BUILD_CACHE_DIR)
 	$(LN) $(PKG_BUILD_DIR)/cli $(GO_PKG_BUILD_DIR)/src/$(GO_PKG)/cli
 	$(LN) $(PKG_BUILD_DIR)/engine $(GO_PKG_BUILD_DIR)/src/$(GO_PKG)/docker
 endef