Commit af0121c2 authored by Gary Guo's avatar Gary Guo Committed by Miguel Ojeda
Browse files

kbuild: rust: add `CONFIG_RUSTC_LLVM_VERSION` 

Each version of Rust supports a range of LLVM versions. There are cases where
we want to gate a config on the LLVM version instead of the Rust version.
Normalized cfi integer tags are one example [1].

The invocation of rustc-version is being moved from init/Kconfig to
scripts/Kconfig.include for consistency with cc-version.

Link: https://lore.kernel.org/all/20240925-cfi-norm-kasan-fix-v1-1-0328985cdf33@google.com/

 [1]
Signed-off-by: default avatarGary Guo <gary@garyguo.net>
Link: https://lore.kernel.org/r/20241011114040.3900487-1-gary@garyguo.net


[ Added missing `-llvm` to the Usage documentation. - Miguel ]
Signed-off-by: default avatarMiguel Ojeda <ojeda@kernel.org>
parent e72a076c

init/Kconfig

+5 −1
Original line number Diff line number Diff line
@@ -62,7 +62,7 @@ config LLD_VERSION 


config RUSTC_VERSION

	int

	default $(shell,$(srctree)/scripts/rustc-version.sh $(RUSTC))

	default $(rustc-version)

	help

	  It does not depend on `RUST` since that one may need to use the version

	  in a `depends on`.
@@ -78,6 +78,10 @@ config RUST_IS_AVAILABLE 
	  In particular, the Makefile target 'rustavailable' is useful to check

	  why the Rust toolchain is not being detected.



config RUSTC_LLVM_VERSION

	int

	default $(rustc-llvm-version)



config CC_CAN_LINK

	bool

	default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(CLANG_FLAGS) $(USERCFLAGS) $(USERLDFLAGS) $(m64-flag)) if 64BIT

scripts/Kconfig.include

+3 −0
Original line number Diff line number Diff line
@@ -65,6 +65,9 @@ cc-option-bit = $(if-success,$(CC) -Werror $(1) -E -x c /dev/null -o /dev/null,$ 
m32-flag := $(cc-option-bit,-m32)

m64-flag := $(cc-option-bit,-m64)



rustc-version := $(shell,$(srctree)/scripts/rustc-version.sh $(RUSTC))

rustc-llvm-version := $(shell,$(srctree)/scripts/rustc-llvm-version.sh $(RUSTC))



# $(rustc-option,<flag>)

# Return y if the Rust compiler supports <flag>, n otherwise

# Calls to this should be guarded so that they are not evaluated if

scripts/rustc-llvm-version.sh

0 → 100755
+22 −0
Original line number Diff line number Diff line 
#!/bin/sh

# SPDX-License-Identifier: GPL-2.0

#

# Usage: $ ./rustc-llvm-version.sh rustc

#

# Print the LLVM version that the Rust compiler uses in a 6 digit form.



# Convert the version string x.y.z to a canonical up-to-6-digits form.

get_canonical_version()

{

	IFS=.

	set -- $1

	echo $((10000 * $1 + 100 * $2 + $3))

}



if output=$("$@" --version --verbose 2>/dev/null | grep LLVM); then

	set -- $output

	get_canonical_version $3

else

	echo 0

	exit 1

fi