[PATCH 06/18] rust: kbuild: support per-target environment variables

[Miguel Ojeda <ojeda@kernel.org>]

Certain vendored crates, like the upcoming `zerocopy`, use extra
environment variables (e.g. via `env!`).

Thus add support to easily specify those.

Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
---
 rust/Makefile | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/rust/Makefile b/rust/Makefile
index df90fabefb70..61f07b1303ce 100644
--- a/rust/Makefile
+++ b/rust/Makefile
@@ -144,6 +144,7 @@ doctests_modifiers_workaround := $(rustdoc_modifiers_workaround)$(if $(call rust
 
 quiet_cmd_rustdoc = RUSTDOC $(if $(rustdoc_host),H, ) $<
       cmd_rustdoc = \
+	$(rustc_target_envs) \
 	OBJTREE=$(abspath $(objtree)) \
 	$(RUSTDOC) $(filter-out $(skip_flags) --remap-path-scope=%,$(if $(rustdoc_host),$(rust_common_flags),$(rust_flags))) \
 		$(rustc_target_flags) -L$(objtree)/$(obj) \
@@ -250,6 +251,7 @@ rustdoc-clean: FORCE
 
 quiet_cmd_rustc_test_library = $(RUSTC_OR_CLIPPY_QUIET) TL $<
       cmd_rustc_test_library = \
+	$(rustc_target_envs) \
 	OBJTREE=$(abspath $(objtree)) \
 	$(RUSTC_OR_CLIPPY) $(filter-out $(skip_flags),$(rust_common_flags) $(rustc_target_flags)) \
 		@$(objtree)/include/generated/rustc_cfg \
@@ -567,6 +569,7 @@ $(obj)/$(libpin_init_internal_name): $(src)/pin-init/internal/src/lib.rs \
 # since Rust 1.95.0 (https://github.com/rust-lang/rust/pull/151534).
 quiet_cmd_rustc_library = $(if $(skip_clippy),RUSTC,$(RUSTC_OR_CLIPPY_QUIET)) L $@
       cmd_rustc_library = \
+	$(rustc_target_envs) \
 	OBJTREE=$(abspath $(objtree)) \
 	$(if $(skip_clippy),$(RUSTC),$(RUSTC_OR_CLIPPY)) \
 		$(filter-out $(skip_flags),$(rust_flags)) $(rustc_target_flags) \
-- 
2.54.0