rust: Add option to use sccache

Using sccache makes recompilation of rustc and Rust packages faster.

This also makes the rust package visible in menuconfig, in order for the
sccache options to be accessible.

Signed-off-by: Jeffery To <redacted>

diff --git a/lang/rust/Config.in b/lang/rust/Config.in
new file mode 100644 (file)
index 0000000..62051af
--- /dev/null
+++ b/lang/rust/Config.in
@@ -0,0 +1,15 @@
+menu "Configuration options (for developers)"
+
+config RUST_SCCACHE
+       bool "Use sccache"
+       help
+         Shared compilation cache; see https://github.com/mozilla/sccache
+
+config RUST_SCCACHE_DIR
+       string "Set sccache directory" if RUST_SCCACHE
+       default ""
+       help
+         Store sccache in this directory.
+         If not set, uses './.sccache'
+
+endmenu

diff --git a/lang/rust/Makefile b/lang/rust/Makefile
index d0a9ef48d5f0ce80d1d71755290fcceaf230fa34..7785e95f139f5dafa03d3a8a5299759d53689689 100644 (file)
--- a/lang/rust/Makefile
+++ b/lang/rust/Makefile
@@ -30,7 +30,6 @@ define Package/rust
   TITLE:=Rust Programming Language Compiler
   URL:=https://www.rust-lang.org/
   DEPENDS:=$(RUST_ARCH_DEPENDS)
-  BUILDONLY:=1
 endef
 
 define Package/rust/description
@@ -39,6 +38,10 @@ define Package/rust/description
   guarantee memory safety by using a borrow checker to validate references.
 endef
 
+define Package/rust/config
+  source "$(SOURCE)/Config.in"
+endef
+
 # Rust-lang has an uninstall script
 RUST_UNINSTALL:=$(STAGING_DIR)/host/lib/rustlib/uninstall.sh
 
@@ -80,6 +83,7 @@ define Host/Uninstall
 endef
 
 define Host/Compile
+       $(RUST_SCCACHE_VARS) \
        CARGO_HOME=$(CARGO_HOME) \
        OPENWRT_RUSTC_BOOTSTRAP_CACHE=$(DL_DIR)/rustc \
        $(PYTHON) $(HOST_BUILD_DIR)/x.py \

diff --git a/lang/rust/rust-values.mk b/lang/rust/rust-values.mk
index 8f2017af6b14e937bf2f6eb7636cb2ffd7231fbd..0a18cd17f4d0a03d9c735c4810ac160c676d13d6 100644 (file)
--- a/lang/rust/rust-values.mk
+++ b/lang/rust/rust-values.mk
@@ -62,12 +62,23 @@ endif
 # Support only a subset for now.
 RUST_ARCH_DEPENDS:=@(aarch64||arm||i386||i686||mips||mipsel||mips64||mips64el||mipsel||powerpc64||riscv64||x86_64)
 
+ifneq ($(CONFIG_RUST_SCCACHE),)
+  RUST_SCCACHE_DIR:=$(if $(call qstrip,$(CONFIG_RUST_SCCACHE_DIR)),$(call qstrip,$(CONFIG_RUST_SCCACHE_DIR)),$(TOPDIR)/.sccache)
+
+  RUST_SCCACHE_VARS:= \
+       CARGO_INCREMENTAL=0 \
+       RUSTC_WRAPPER=sccache \
+       SCCACHE_DIR=$(RUST_SCCACHE_DIR)
+endif
+
 CARGO_HOST_CONFIG_VARS= \
+       $(RUST_SCCACHE_VARS) \
        CARGO_HOME=$(CARGO_HOME)
 
 CARGO_HOST_PROFILE:=release
 
 CARGO_PKG_CONFIG_VARS= \
+       $(RUST_SCCACHE_VARS) \
        CARGO_BUILD_TARGET=$(RUSTC_TARGET_ARCH) \
        CARGO_HOME=$(CARGO_HOME) \
        CARGO_PROFILE_RELEASE_OPT_LEVEL=s \