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linux/scripts/as-version.sh
Nick Desaulniers d5c8d6e0fa kbuild: Update assembler calls to use proper flags and language target
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>
2023-01-26 12:41:38 +09:00

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#!/bin/sh
# SPDX-License-Identifier: GPL-2.0-only
#
# Print the assembler name and its version in a 5 or 6-digit form.
# Also, perform the minimum version check.
# (If it is the integrated assembler, return 0 as the version, and
# skip the version check.)
set -e
# Convert the version string x.y.z to a canonical 5 or 6-digit form.
get_canonical_version()
{
IFS=.
set -- $1
# If the 2nd or 3rd field is missing, fill it with a zero.
#
# The 4th field, if present, is ignored.
# This occurs in development snapshots as in 2.35.1.20201116
echo $((10000 * $1 + 100 * ${2:-0} + ${3:-0}))
}
# Clang fails to handle -Wa,--version unless -fno-integrated-as is given.
# We check -fintegrated-as, expecting it is explicitly passed in for the
# integrated assembler case.
check_integrated_as()
{
while [ $# -gt 0 ]; do
if [ "$1" = -fintegrated-as ]; then
# For the integrated assembler, we do not check the
# version here. It is the same as the clang version, and
# it has been already checked by scripts/cc-version.sh.
echo LLVM 0
exit 0
fi
shift
done
}
check_integrated_as "$@"
orig_args="$@"
# Get the first line of the --version output.
IFS='
'
set -- $(LC_ALL=C "$@" -Wa,--version -c -x assembler-with-cpp /dev/null -o /dev/null 2>/dev/null)
# Split the line on spaces.
IFS=' '
set -- $1
min_tool_version=$(dirname $0)/min-tool-version.sh
if [ "$1" = GNU -a "$2" = assembler ]; then
shift $(($# - 1))
version=$1
min_version=$($min_tool_version binutils)
name=GNU
else
echo "$orig_args: unknown assembler invoked" >&2
exit 1
fi
# Some distributions append a package release number, as in 2.34-4.fc32
# Trim the hyphen and any characters that follow.
version=${version%-*}
cversion=$(get_canonical_version $version)
min_cversion=$(get_canonical_version $min_version)
if [ "$cversion" -lt "$min_cversion" ]; then
echo >&2 "***"
echo >&2 "*** Assembler is too old."
echo >&2 "*** Your $name assembler version: $version"
echo >&2 "*** Minimum $name assembler version: $min_version"
echo >&2 "***"
exit 1
fi
echo $name $cversion