Merge tag 'rust-fixes-6.12-2' of https://github.com/Rust-for-Linux/linux

Pull rust fixes from Miguel Ojeda:
 "Toolchain and infrastructure:

   - Fix several issues with the 'rustc-option' macro. It includes a
     refactor from Masahiro of three '{cc,rust}-*' macros, which is not
     a fix but avoids repeating the same commands (which would be
     several lines in the case of 'rustc-option').

   - Fix conditions for 'CONFIG_HAVE_CFI_ICALL_NORMALIZE_INTEGERS'. It
     includes the addition of 'CONFIG_RUSTC_LLVM_VERSION', which is not
     a fix but is needed for the actual fix.

  And a trivial grammar fix"

* tag 'rust-fixes-6.12-2' of https://github.com/Rust-for-Linux/linux:
  cfi: fix conditions for HAVE_CFI_ICALL_NORMALIZE_INTEGERS
  kbuild: rust: add `CONFIG_RUSTC_LLVM_VERSION`
  kbuild: fix issues with rustc-option
  kbuild: refactor cc-option-yn, cc-disable-warning, rust-option-yn macros
  lib/Kconfig.debug: fix grammar in RUST_BUILD_ASSERT_ALLOW

3 files changed, 32 insertions, 7 deletions

diff --git a/scripts/Kconfig.include b/scripts/Kconfig.include
index 785a491e5996..33193ca6e803 100644
--- a/scripts/Kconfig.include
+++ b/scripts/Kconfig.include
@@ -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
diff --git a/scripts/Makefile.compiler b/scripts/Makefile.compiler
index 057305eae85c..e0842496d26e 100644
--- a/scripts/Makefile.compiler
+++ b/scripts/Makefile.compiler
@@ -53,13 +53,11 @@ cc-option = $(call __cc-option, $(CC),\
 
 # cc-option-yn
 # Usage: flag := $(call cc-option-yn,-march=winchip-c6)
-cc-option-yn = $(call try-run,\
-	$(CC) -Werror $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) $(1) -c -x c /dev/null -o "$$TMP",y,n)
+cc-option-yn = $(if $(call cc-option,$1),y,n)
 
 # cc-disable-warning
 # Usage: cflags-y += $(call cc-disable-warning,unused-but-set-variable)
-cc-disable-warning = $(call try-run,\
-	$(CC) -Werror $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) -W$(strip $(1)) -c -x c /dev/null -o "$$TMP",-Wno-$(strip $(1)))
+cc-disable-warning = $(if $(call cc-option,-W$(strip $1)),-Wno-$(strip $1))
 
 # gcc-min-version
 # Usage: cflags-$(call gcc-min-version, 70100) += -foo
@@ -75,8 +73,11 @@ ld-option = $(call try-run, $(LD) $(KBUILD_LDFLAGS) $(1) -v,$(1),$(2),$(3))
 
 # __rustc-option
 # Usage: MY_RUSTFLAGS += $(call __rustc-option,$(RUSTC),$(MY_RUSTFLAGS),-Cinstrument-coverage,-Zinstrument-coverage)
+# TODO: remove RUSTC_BOOTSTRAP=1 when we raise the minimum GNU Make version to 4.4
 __rustc-option = $(call try-run,\
-	$(1) $(2) $(3) --crate-type=rlib /dev/null --out-dir=$$TMPOUT -o "$$TMP",$(3),$(4))
+	echo '#![allow(missing_docs)]#![feature(no_core)]#![no_core]' | RUSTC_BOOTSTRAP=1\
+	$(1) --sysroot=/dev/null $(filter-out --sysroot=/dev/null,$(2)) $(3)\
+	--crate-type=rlib --out-dir=$(TMPOUT) --emit=obj=- - >/dev/null,$(3),$(4))
 
 # rustc-option
 # Usage: rustflags-y += $(call rustc-option,-Cinstrument-coverage,-Zinstrument-coverage)
@@ -85,5 +86,4 @@ rustc-option = $(call __rustc-option, $(RUSTC),\
 
 # rustc-option-yn
 # Usage: flag := $(call rustc-option-yn,-Cinstrument-coverage)
-rustc-option-yn = $(call try-run,\
-	$(RUSTC) $(KBUILD_RUSTFLAGS) $(1) --crate-type=rlib /dev/null --out-dir=$$TMPOUT -o "$$TMP",y,n)
+rustc-option-yn = $(if $(call rustc-option,$1),y,n)
diff --git a/scripts/rustc-llvm-version.sh b/scripts/rustc-llvm-version.sh
new file mode 100755
index 000000000000..b6063cbe5bdc
--- /dev/null
+++ b/scripts/rustc-llvm-version.sh
@@ -0,0 +1,22 @@
+#!/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