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Diffstat (limited to 'scripts/dummy-tools/gcc')
| -rwxr-xr-x | scripts/dummy-tools/gcc | 116 |
1 files changed, 116 insertions, 0 deletions
diff --git a/scripts/dummy-tools/gcc b/scripts/dummy-tools/gcc new file mode 100755 index 000000000000..e6c41427c02f --- /dev/null +++ b/scripts/dummy-tools/gcc @@ -0,0 +1,116 @@ +#!/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 "$@"; then + # For scripts/cc-version.sh; This emulates GCC 20.0.0 + if arg_contain - "$@"; then + sed -n '/^GCC/{s/__GNUC__/20/; s/__GNUC_MINOR__/0/; s/__GNUC_PATCHLEVEL__/0/; p;}; s/__LONG_DOUBLE_128__/1/ p' + exit 0 + else + echo "no input files" >&2 + exit 1 + fi +fi + +# To set CONFIG_AS_IS_GNU +if arg_contain -Wa,--version "$@"; then + echo "GNU assembler (scripts/dummy-tools) 2.50" + exit 0 +fi + +if arg_contain -S "$@"; 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 "$@" && arg_contain -mprofile-kernel "$@"; then + if ! test -t 0 && ! grep -q notrace; then + echo "_mcount" + fi + exit 0 + fi + + # For arch/powerpc/tools/gcc-check-fpatchable-function-entry.sh + if arg_contain -m64 "$@" && arg_contain -fpatchable-function-entry=2 "$@"; then + echo "func:" + echo ".section __patchable_function_entries" + echo ".localentry" + echo " nop" + echo " nop" + exit 0 + fi +fi + +# To set GCC_PLUGINS +if arg_contain -print-file-name=plugin "$@"; then + # Use $0 to find the in-tree dummy directory + echo "$(dirname "$(readlink -f "$0")")/dummy-plugin-dir" + exit 0 +fi + +# inverted return value +if arg_contain -D__SIZEOF_INT128__=0 "$@"; then + exit 1 +fi |