rust: refactor build helper

Added new RustBinPackage, RustBinHostBuild wrapper.
Added new RUST_PKG_FEATURES flag.
Moved CARGO_HOME to STAGING_DIR_HOSTPKG.
Overrode default Build/Compile and Host/Compile to Cargo build.

Signed-off-by: Tianling Shen <cnsztl@immortalwrt.org>

lang/rust/Makefile

@@ -20,9 +20,9 @@ PKG_LICENSE_FILES:=LICENSE-APACHE LICENSE-MIT
 HOST_BUILD_DEPENDS:=python3/host
 PKG_HOST_ONLY:=1
 
-include $(INCLUDE_DIR)/package.mk
 include $(INCLUDE_DIR)/host-build.mk
-include ./rust-host.mk
+include $(INCLUDE_DIR)/package.mk
+include ./rust-values.mk
 
 define Package/rust
   SECTION:=lang

lang/rust/rust-host-build.mk

@@ -0,0 +1,45 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# Copyright (C) 2023 Luca Barbato and Donald Hoskins
+
+ifeq ($(origin RUST_INCLUDE_DIR),undefined)
+  RUST_INCLUDE_DIR:=$(dir $(lastword $(MAKEFILE_LIST)))
+endif
+include $(RUST_INCLUDE_DIR)/rust-values.mk
+
+# $(1) path to the package (optional)
+# $(2) additional arguments to cargo (optional)
+define Host/Compile/Cargo
+	( \
+		cd $(HOST_BUILD_DIR) ; \
+		export PATH="$(CARGO_HOME)/bin:$(PATH)" ; \
+		CARGO_HOME=$(CARGO_HOME) \
+		CC=$(HOSTCC_NOCACHE) \
+		cargo install -v \
+			--profile stripped \
+			$(if $(RUST_PKG_FEATURES),--features "$(RUST_PKG_FEATURES)") \
+			--root $(HOST_INSTALL_DIR) \
+			--path "$(if $(strip $(1)),$(strip $(1)),.)" $(2) ; \
+	)
+endef
+
+define Host/Uninstall/Cargo
+	( \
+		cd $(HOST_BUILD_DIR) ; \
+		export PATH="$(CARGO_HOME)/bin:$(PATH)" ; \
+		CARGO_HOME=$(CARGO_HOME) \
+		CC=$(HOSTCC_NOCACHE) \
+		cargo uninstall -v \
+			--root $(HOST_INSTALL_DIR) || true ; \
+	)
+endef
+
+define RustBinHostBuild
+  define Host/Install
+	$(INSTALL_DIR) $(STAGING_DIR_HOSTPKG)/bin
+	$(INSTALL_BIN) $(HOST_INSTALL_DIR)/bin/* $(STAGING_DIR_HOSTPKG)/bin/
+  endef
+endef
+
+Host/Compile=$(call Host/Compile/Cargo)
+Host/Uninstall=$(call Host/Uninstall/Cargo)

lang/rust/rust-package.mk

@@ -2,27 +2,49 @@
 #
 # Copyright (C) 2023 Luca Barbato and Donald Hoskins
 
-rust_mk_path:=$(dir $(lastword $(MAKEFILE_LIST)))
+# Variables (all optional) to be set in package Makefiles:
-include $(rust_mk_path)rust-host.mk
+#
+# RUST_PKG_FEATURES - list of options, default empty
+#
+#   Space or comma separated list of features to activate
+#
+#   e.g. RUST_PKG_FEATURES:=enable-foo,with-bar
 
-# $(1) path to the package
+ifeq ($(origin RUST_INCLUDE_DIR),undefined)
-# $(2) additional arguments to cargo
+  RUST_INCLUDE_DIR:=$(dir $(lastword $(MAKEFILE_LIST)))
-define Host/Compile/Cargo
+endif
-	( \
+include $(RUST_INCLUDE_DIR)/rust-values.mk
-		cd $(HOST_BUILD_DIR) ; \
-		export PATH="$(CARGO_HOME)/bin:$(PATH)" ; \
-		CARGO_HOME=$(CARGO_HOME) CC=$(HOSTCC) \
-			cargo install -v --profile stripped --root $(HOST_INSTALL_DIR) --path "$(if $(strip $(1)),$(strip $(1)),.)" $(2) ; \
-	)
-endef
 
-# $(1) path to the package
+# Support only a subset for now.
-# $(2) additional arguments to cargo
+RUST_ARCH_DEPENDS:=@(aarch64||arm||i386||i686||mips||mipsel||mips64||mips64el||mipsel||powerpc64||x86_64)
+
+# $(1) path to the package (optional)
+# $(2) additional arguments to cargo (optional)
 define Build/Compile/Cargo
 	( \
 		cd $(PKG_BUILD_DIR) ; \
 		export PATH="$(CARGO_HOME)/bin:$(PATH)" ; \
-		CARGO_HOME=$(CARGO_HOME) TARGET_CFLAGS="$(TARGET_CFLAGS) $(RUST_CFLAGS)" TARGET_CC=$(TARGET_CC_NOCACHE) CC=cc \
+		CARGO_HOME=$(CARGO_HOME) \
-			cargo install -v --profile stripped --target $(RUSTC_TARGET_ARCH) --root $(PKG_INSTALL_DIR) --path "$(if $(strip $(1)),$(strip $(1)),.)" $(2) ; \
+		TARGET_CFLAGS="$(TARGET_CFLAGS) $(RUST_CFLAGS)" \
+		TARGET_CC=$(TARGET_CC_NOCACHE) \
+		CC=$(HOSTCC) \
+		cargo install -v \
+			--profile stripped \
+			--target $(RUSTC_TARGET_ARCH) \
+			$(if $(strip $(RUST_PKG_FEATURES)),--features "$(strip $(RUST_PKG_FEATURES))") \
+			--root $(PKG_INSTALL_DIR) \
+			--path "$(if $(strip $(1)),$(strip $(1)),.)" \
+			$(2) ; \
 	)
 endef
+
+define RustBinPackage
+  ifndef Package/$(1)/install
+    define Package/$(1)/install
+	$$(INSTALL_DIR) $$(1)/usr/bin/
+	$$(INSTALL_BIN) $$(PKG_INSTALL_DIR)/bin/* $$(1)/usr/bin/
+    endef
+  endif
+endef
+
+Build/Compile=$(call Build/Compile/Cargo)

lang/rust/rust-values.mk

@@ -5,17 +5,7 @@
 # Rust Environmental Vars
 CONFIG_HOST_SUFFIX:=$(word 4, $(subst -, ,$(GNU_HOST_NAME)))
 RUSTC_HOST_ARCH:=$(HOST_ARCH)-unknown-linux-$(CONFIG_HOST_SUFFIX)
-CARGO_HOME:=$(STAGING_DIR_HOST)/cargo
+CARGO_HOME:=$(STAGING_DIR_HOSTPKG)/cargo
-
-# Support only a subset for now.
-RUST_ARCH_DEPENDS:=@(aarch64||arm||i386||i686||mips||mipsel||mips64||mips64el||mipsel||powerpc64||x86_64)
-
-# Common Build Flags
-RUST_BUILD_FLAGS = \
-  CARGO_HOME="$(CARGO_HOME)"
-
-# This adds the rust environmental variables to Make calls
-MAKE_FLAGS += $(RUST_BUILD_FLAGS)
 
 # Force linking of the SSP library
 ifdef CONFIG_PKG_CC_STACKPROTECTOR_REGULAR