kbuild: rust: add rustc-min-version support function

Introduce `rustc-min-version` support function that mimics
`{gcc,clang}-min-version` ones, following commit 88b61e3bff93
("Makefile.compiler: replace cc-ifversion with compiler-specific macros").

In addition, use it in the first use case we have in the kernel (which
was done independently to minimize the changes needed for the fix).

Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Reviewed-by: Fiona Behrens <me@Kloenk.dev>
Reviewed-by: Nicolas Schier <n.schier@avm.de>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

diff --git a/Documentation/kbuild/makefiles.rst b/Documentation/kbuild/makefiles.rst
index 25e04e47fafff6b27cc0283a1d08e4e60c8fbc9a..3b9a8bc671e2e92126857059e985d6e5b2c43fd4 100644 (file)
--- a/Documentation/kbuild/makefiles.rst
+++ b/Documentation/kbuild/makefiles.rst
@@ -667,6 +667,20 @@ cc-cross-prefix
             endif
     endif
 
+$(RUSTC) support functions
+--------------------------
+
+rustc-min-version
+  rustc-min-version tests if the value of $(CONFIG_RUSTC_VERSION) is greater
+  than or equal to the provided value and evaluates to y if so.
+
+  Example::
+
+    rustflags-$(call rustc-min-version, 108500) := -Cfoo
+
+  In this example, rustflags-y will be assigned the value -Cfoo if
+  $(CONFIG_RUSTC_VERSION) is >= 1.85.0.
+
 $(LD) support functions
 -----------------------
 

diff --git a/arch/arm64/Makefile b/arch/arm64/Makefile
index 2b25d671365f290d42a7f10a09194b6c5a1215ae..1d5dfcd1c13ed2c535af5867eba1ebae9b33b64a 100644 (file)
--- a/arch/arm64/Makefile
+++ b/arch/arm64/Makefile
@@ -48,7 +48,7 @@ KBUILD_CFLAGS += $(CC_FLAGS_NO_FPU) \
 KBUILD_CFLAGS  += $(call cc-disable-warning, psabi)
 KBUILD_AFLAGS  += $(compat_vdso)
 
-ifeq ($(call test-ge, $(CONFIG_RUSTC_VERSION), 108500),y)
+ifeq ($(call rustc-min-version, 108500),y)
 KBUILD_RUSTFLAGS += --target=aarch64-unknown-none-softfloat
 else
 KBUILD_RUSTFLAGS += --target=aarch64-unknown-none -Ctarget-feature="-neon"

diff --git a/scripts/Makefile.compiler b/scripts/Makefile.compiler
index 8c1029687e2e4f67743dc28710a4abf81d7c6d85..8956587b85470ac5616822cabd795b80866057e5 100644 (file)
--- a/scripts/Makefile.compiler
+++ b/scripts/Makefile.compiler
@@ -67,6 +67,10 @@ gcc-min-version = $(call test-ge, $(CONFIG_GCC_VERSION), $1)
 # Usage: cflags-$(call clang-min-version, 110000) += -foo
 clang-min-version = $(call test-ge, $(CONFIG_CLANG_VERSION), $1)
 
+# rustc-min-version
+# Usage: rustc-$(call rustc-min-version, 108500) += -Cfoo
+rustc-min-version = $(call test-ge, $(CONFIG_RUSTC_VERSION), $1)
+
 # ld-option
 # Usage: KBUILD_LDFLAGS += $(call ld-option, -X, -Y)
 ld-option = $(call try-run, $(LD) $(KBUILD_LDFLAGS) $(1) -v,$(1),$(2),$(3))