#!/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" = "$1" ]; then			return 0		fi		shift	done 	return 1} # To set CONFIG_CC_IS_GCC=yif arg_contain --version "$@"; then	echo "gcc (scripts/dummy-tools/gcc)"	exit 0fi if arg_contain -E "$@"; then	# For scripts/cc-version.sh; This emulates GCC 20.0.0	if arg_contain - "$@"; then		sed -n '/^GCC/{s/__GNUC__/20/; s/__GNUC_MINOR__/0/; s/__GNUC_PATCHLEVEL__/0/; p;}'		exit 0	else		echo "no input files" >&2		exit 1	fifi # To set CONFIG_AS_IS_GNUif arg_contain -Wa,--version "$@"; then	echo "GNU assembler (scripts/dummy-tools) 2.50"	exit 0fi if arg_contain -S "$@"; then	# For scripts/gcc-x86-*-has-stack-protector.sh	if arg_contain -fstack-protector "$@"; then		if arg_contain -mstack-protector-guard-reg=fs "$@"; then			echo "%fs"		else			echo "%gs"		fi		exit 0	fi 	# For arch/powerpc/tools/gcc-check-mprofile-kernel.sh	if arg_contain -m64 "$@" && arg_contain -mlittle-endian "$@" &&		arg_contain -mprofile-kernel "$@"; then		if ! test -t 0 && ! grep -q notrace; then			echo "_mcount"		fi		exit 0	fifi # To set GCC_PLUGINSif arg_contain -print-file-name=plugin "$@"; then	plugin_dir=$(mktemp -d) 	mkdir -p $plugin_dir/include	touch $plugin_dir/include/plugin-version.h 	echo $plugin_dir	exit 0fi # inverted return valueif arg_contain -D__SIZEOF_INT128__=0 "$@"; then	exit 1fi