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	as-instr uses KBUILD_AFLAGS, but as-option uses KBUILD_CFLAGS. This can
cause as-option to fail unexpectedly when CONFIG_WERROR is set, because
clang will emit -Werror,-Wunused-command-line-argument for various -m
and -f flags in KBUILD_CFLAGS for assembler sources.
Callers of as-option and as-instr should be adding flags to
KBUILD_AFLAGS / aflags-y, not KBUILD_CFLAGS / cflags-y. Use
KBUILD_AFLAGS in all macros to clear up the initial problem.
Unfortunately, -Wunused-command-line-argument can still be triggered
with clang by the presence of warning flags or macro definitions because
'-x assembler' is used, instead of '-x assembler-with-cpp', which will
consume these flags. Switch to '-x assembler-with-cpp' in places where
'-x assembler' is used, as the compiler is always used as the driver for
out of line assembler sources in the kernel.
Finally, add -Werror to these macros so that they behave consistently
whether or not CONFIG_WERROR is set.
[nathan: Reworded and expanded on problems in commit message
         Use '-x assembler-with-cpp' in a couple more places]
Link: https://github.com/ClangBuiltLinux/linux/issues/1699
Suggested-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Linux Kernel Functional Testing <lkft@linaro.org>
Tested-by: Anders Roxell <anders.roxell@linaro.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
		
	
			
		
			
				
	
	
		
			82 lines
		
	
	
	
		
			2 KiB
		
	
	
	
		
			Bash
		
	
	
		
			Executable file
		
	
	
	
	
			
		
		
	
	
			82 lines
		
	
	
	
		
			2 KiB
		
	
	
	
		
			Bash
		
	
	
		
			Executable file
		
	
	
	
	
#!/bin/sh
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# SPDX-License-Identifier: GPL-2.0-only
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#
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# Print the assembler name and its version in a 5 or 6-digit form.
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# Also, perform the minimum version check.
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# (If it is the integrated assembler, return 0 as the version, and
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# skip the version check.)
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set -e
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# Convert the version string x.y.z to a canonical 5 or 6-digit form.
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get_canonical_version()
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{
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	IFS=.
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	set -- $1
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	# If the 2nd or 3rd field is missing, fill it with a zero.
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	#
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	# The 4th field, if present, is ignored.
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	# This occurs in development snapshots as in 2.35.1.20201116
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	echo $((10000 * $1 + 100 * ${2:-0} + ${3:-0}))
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}
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# Clang fails to handle -Wa,--version unless -fno-integrated-as is given.
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# We check -fintegrated-as, expecting it is explicitly passed in for the
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# integrated assembler case.
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check_integrated_as()
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{
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	while [ $# -gt 0 ]; do
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		if [ "$1" = -fintegrated-as ]; then
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			# For the integrated assembler, we do not check the
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			# version here. It is the same as the clang version, and
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			# it has been already checked by scripts/cc-version.sh.
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			echo LLVM 0
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			exit 0
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		fi
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		shift
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	done
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}
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check_integrated_as "$@"
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orig_args="$@"
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# Get the first line of the --version output.
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IFS='
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'
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set -- $(LC_ALL=C "$@" -Wa,--version -c -x assembler-with-cpp /dev/null -o /dev/null 2>/dev/null)
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# Split the line on spaces.
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IFS=' '
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set -- $1
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min_tool_version=$(dirname $0)/min-tool-version.sh
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if [ "$1" = GNU -a "$2" = assembler ]; then
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	shift $(($# - 1))
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	version=$1
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	min_version=$($min_tool_version binutils)
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	name=GNU
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else
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	echo "$orig_args: unknown assembler invoked" >&2
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	exit 1
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fi
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# Some distributions append a package release number, as in 2.34-4.fc32
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# Trim the hyphen and any characters that follow.
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version=${version%-*}
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cversion=$(get_canonical_version $version)
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min_cversion=$(get_canonical_version $min_version)
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if [ "$cversion" -lt "$min_cversion" ]; then
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	echo >&2 "***"
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	echo >&2 "*** Assembler is too old."
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	echo >&2 "***   Your $name assembler version:    $version"
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	echo >&2 "***   Minimum $name assembler version: $min_version"
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	echo >&2 "***"
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	exit 1
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fi
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echo $name $cversion
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