kbuild: add dummy toolchains to enable all cc-option etc. in Kconfig

#!/bin/sh

# SPDX-License-Identifier: GPL-2.0-only

#

# Staring v4.18, Kconfig evaluates compiler capabilities, and hides CONFIG

# options your compiler does not support. This works well if you configure and

# build the kernel on the same host machine.

#

# It is inconvenient if you prepare the .config that is carried to a different

# build environment (typically this happens when you package the kernel for

# distros) because using a different compiler potentially produces different

# CONFIG options than the real build environment. So, you probably want to make

# as many options visible as possible. In other words, you need to create a

# super-set of CONFIG options that cover any build environment. If some of the

# CONFIG options turned out to be unsupported on the build machine, they are

# automatically disabled by the nature of Kconfig.

#

# However, it is not feasible to get a full-featured compiler for every arch.

# Hence these dummy toolchains to make all compiler tests pass.

#

# Usage:

#

# From the top directory of the source tree, run

#

#   $ make CROSS_COMPILE=scripts/dummy-tools/ oldconfig

#

# Most of compiler features are tested by cc-option, which simply checks the

# exit code of $(CC). This script does nothing and just exits with 0 in most

# cases. So, $(cc-option, ...) is evaluated as 'y'.

#

# This scripts caters to more checks; handle --version and pre-process __GNUC__

# etc. to pretend to be GCC, and also do right things to satisfy some scripts.

# Check if the first parameter appears in the rest. Succeeds if found.

# This helper is useful if a particular option was passed to this script.

# Typically used like this:

#   arg_contain <word-you-are-searching-for> "$@"

arg_contain ()

{

	search="$1"

	shift

	while [ $# -gt 0 ]

	do

		if [ "$search" = "$1" ]; then

			return 0

		fi

		shift

	done

	return 1

}

# To set CONFIG_CC_IS_GCC=y

if arg_contain --version "$@"; then

	echo "gcc (scripts/dummy-tools/gcc)"

	exit 0

fi

if arg_contain -E "$@"; then

	# For scripts/gcc-version.sh; This emulates GCC 20.0.0

	if arg_contain - "$@"; then

		sed 's/^__GNUC__$/20/; s/^__GNUC_MINOR__$/0/; s/^__GNUC_PATCHLEVEL__$/0/'

		exit 0

	else

		echo "no input files" >&2

		exit 1

	fi

fi

if arg_contain -S "$@"; then

	# For scripts/gcc-x86-*-has-stack-protector.sh

	if arg_contain -fstack-protector "$@"; then

		echo "%gs"

		exit 0

	fi

fi

# For scripts/gcc-plugin.sh

if arg_contain -print-file-name=plugin "$@"; then

	plugin_dir=$(mktemp -d)

	sed -n 's/.*#include "\(.*\)"/\1/p' $(dirname $0)/../gcc-plugins/gcc-common.h |

	while read header

	do

		mkdir -p $plugin_dir/include/$(dirname $header)

		touch $plugin_dir/include/$header

	done

	echo $plugin_dir

	exit 0

fi

#!/bin/sh

# SPDX-License-Identifier: GPL-2.0-only

# Dummy script that always succeeds.

# Check if the first parameter appears in the rest. Succeeds if found.

# This helper is useful if a particular option was passed to this script.

# Typically used like this:

#   arg_contain <word-you-are-searching-for> "$@"

arg_contain ()

{

	search="$1"

	shift

	while [ $# -gt 0 ]

	do

		if [ "$search" = "$1" ]; then

			return 0

		fi

		shift

	done

	return 1

}

if arg_contain --version "$@" || arg_contain -v "$@"; then

	progname=$(basename $0)

	echo "GNU $progname (scripts/dummy-tools/$progname) 2.50"

	exit 0

fi

ld

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ld

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