[RFC PATCH v3 09/22] rust: Kbuild: enable `capnp`

[Ariel Miculas <amiculas@xxxxxxxxx>]

With all the new files in place for capnp, this patch adds support
for it in the build system.

Signed-off-by: Ariel Miculas <amiculas@xxxxxxxxx>
---
 rust/Makefile          | 23 ++++++++++++++++++++---
 scripts/Makefile.build |  2 +-
 2 files changed, 21 insertions(+), 4 deletions(-)

diff --git a/rust/Makefile b/rust/Makefile
index fef8e38fbebd..f088ff4bdd34 100644
--- a/rust/Makefile
+++ b/rust/Makefile
@@ -15,7 +15,7 @@ always-$(CONFIG_RUST) += libmacros.so
 no-clean-files += libmacros.so
 
 always-$(CONFIG_RUST) += bindings/bindings_generated.rs bindings/bindings_helpers_generated.rs
-obj-$(CONFIG_RUST) += alloc.o bindings.o hex.o kernel.o
+obj-$(CONFIG_RUST) += alloc.o bindings.o hex.o capnp.o kernel.o
 always-$(CONFIG_RUST) += exports_alloc_generated.h exports_bindings_generated.h \
     exports_kernel_generated.h
 
@@ -74,6 +74,16 @@ hex-flags := \
     --edition=2018 \
     -Amissing_docs
 
+capnp-skip_flags := \
+    -Drust_2018_idioms \
+    -Dunsafe_op_in_unsafe_fn \
+    -Dunreachable_pub
+
+capnp-flags := \
+    -Amissing_docs \
+    --cfg 'feature="kernel"' \
+    --cfg 'feature="sync_reader"'
+
 quiet_cmd_rustdoc = RUSTDOC $(if $(rustdoc_host),H, ) $<
       cmd_rustdoc = \
 	OBJTREE=$(abspath $(objtree)) \
@@ -470,11 +480,18 @@ $(obj)/hex.o: private rustc_target_flags = $(hex-flags)
 $(obj)/hex.o: $(src)/hex/lib.rs $(obj)/compiler_builtins.o FORCE
 	$(call if_changed_dep,rustc_library)
 
+$(obj)/canpproto.o: private skip_clippy = 1
+$(obj)/capnp.o: private skip_flags = $(capnp-skip_flags)
+$(obj)/capnp.o: private rustc_target_flags = $(capnp-flags)
+$(obj)/capnp.o: $(src)/capnp/lib.rs $(obj)/compiler_builtins.o FORCE
+	$(call if_changed_dep,rustc_library)
+
 $(obj)/kernel.o: private rustc_target_flags = --extern alloc \
     --extern build_error --extern macros --extern bindings --extern uapi \
-    --extern hex
+    --extern hex --extern capnp
 $(obj)/kernel.o: $(src)/kernel/lib.rs $(obj)/alloc.o $(obj)/build_error.o \
-    $(obj)/libmacros.so $(obj)/bindings.o $(obj)/uapi.o $(obj)/hex.o FORCE
+    $(obj)/libmacros.so $(obj)/bindings.o $(obj)/uapi.o $(obj)/hex.o \
+    $(obj)/capnp.o FORCE
 	$(call if_changed_dep,rustc_library)
 
 endif # CONFIG_RUST
diff --git a/scripts/Makefile.build b/scripts/Makefile.build
index 2e9a64224c51..8a500593ea05 100644
--- a/scripts/Makefile.build
+++ b/scripts/Makefile.build
@@ -273,7 +273,7 @@ rust_common_cmd = \
 	-Zallow-features=$(rust_allowed_features) \
 	-Zcrate-attr=no_std \
 	-Zcrate-attr='feature($(rust_allowed_features))' \
-	--extern alloc --extern kernel --extern hex \
+	--extern alloc --extern kernel --extern hex --extern capnp \
 	--crate-type rlib -L $(objtree)/rust/ \
 	--crate-name $(basename $(notdir $@)) \
 	--sysroot=/dev/null \
-- 
2.34.1