From 104daea149c45cc84842ce77a9bd6436d19f3dd8 Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Mon, 28 May 2018 18:21:40 +0900 Subject: kconfig: reference environment variables directly and remove 'option env=' To get access to environment variables, Kconfig needs to define a symbol using "option env=" syntax. It is tedious to add a symbol entry for each environment variable given that we need to define much more such as 'CC', 'AS', 'srctree' etc. to evaluate the compiler capability in Kconfig. Adding '$' for symbol references is grammatically inconsistent. Looking at the code, the symbols prefixed with 'S' are expanded by: - conf_expand_value() This is used to expand 'arch/$ARCH/defconfig' and 'defconfig_list' - sym_expand_string_value() This is used to expand strings in 'source' and 'mainmenu' All of them are fixed values independent of user configuration. So, they can be changed into the direct expansion instead of symbols. This change makes the code much cleaner. The bounce symbols 'SRCARCH', 'ARCH', 'SUBARCH', 'KERNELVERSION' are gone. sym_init() hard-coding 'UNAME_RELEASE' is also gone. 'UNAME_RELEASE' should be replaced with an environment variable. ARCH_DEFCONFIG is a normal symbol, so it should be simply referenced without '$' prefix. The new syntax is addicted by Make. The variable reference needs parentheses, like $(FOO), but you can omit them for single-letter variables, like $F. Yet, in Makefiles, people tend to use the parenthetical form for consistency / clarification. At this moment, only the environment variable is supported, but I will extend the concept of 'variable' later on. The variables are expanded in the lexer so we can simplify the token handling on the parser side. For example, the following code works. [Example code] config MY_TOOLCHAIN_LIST string default "My tools: CC=$(CC), AS=$(AS), CPP=$(CPP)" [Result] $ make -s alldefconfig && tail -n 1 .config CONFIG_MY_TOOLCHAIN_LIST="My tools: CC=gcc, AS=as, CPP=gcc -E" Signed-off-by: Masahiro Yamada Reviewed-by: Kees Cook --- arch/x86/um/Kconfig | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'arch/x86/um') diff --git a/arch/x86/um/Kconfig b/arch/x86/um/Kconfig index 13ed827c7c66..6a15c4dcc746 100644 --- a/arch/x86/um/Kconfig +++ b/arch/x86/um/Kconfig @@ -1,5 +1,5 @@ # SPDX-License-Identifier: GPL-2.0 -mainmenu "User Mode Linux/$SUBARCH $KERNELVERSION Kernel Configuration" +mainmenu "User Mode Linux/$(SUBARCH) $(KERNELVERSION) Kernel Configuration" source "arch/um/Kconfig.common" @@ -16,8 +16,8 @@ config UML_X86 select GENERIC_FIND_FIRST_BIT config 64BIT - bool "64-bit kernel" if SUBARCH = "x86" - default SUBARCH != "i386" + bool "64-bit kernel" if "$(SUBARCH)" = "x86" + default "$(SUBARCH)" != "i386" config X86_32 def_bool !64BIT -- cgit v1.2.3 From 21c54b774744719c386fbdc829b0e7759edb8ece Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Mon, 28 May 2018 18:21:58 +0900 Subject: kconfig: show compiler version text in the top comment The kernel configuration phase is now tightly coupled with the compiler in use. It will be nice to show the compiler information in Kconfig. The compiler information will be displayed like this: $ make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- config scripts/kconfig/conf --oldaskconfig Kconfig * * Linux/arm64 4.16.0-rc1 Kernel Configuration * * * Compiler: aarch64-linux-gnu-gcc (Linaro GCC 7.2-2017.11) 7.2.1 20171011 * * * General setup * Compile also drivers which will not load (COMPILE_TEST) [N/y/?] If you use GUI methods such as menuconfig, it will be displayed in the top menu. This is simply implemented by using the 'comment' statement. So, it will be saved into the .config file as well. This commit has a very important meaning. If the compiler is upgraded, Kconfig must be re-run since different compilers have different sets of supported options. All referenced environments are written to include/config/auto.conf.cmd so that any environment change triggers syncconfig, and prompt the user to input new values if needed. With this commit, something like follows will be added to include/config/auto.conf.cmd ifneq "$(CC_VERSION_TEXT)" "aarch64-linux-gnu-gcc (Linaro GCC 7.2-2017.11) 7.2.1 20171011" include/config/auto.conf: FORCE endif Signed-off-by: Masahiro Yamada Reviewed-by: Kees Cook --- arch/x86/um/Kconfig | 2 ++ 1 file changed, 2 insertions(+) (limited to 'arch/x86/um') diff --git a/arch/x86/um/Kconfig b/arch/x86/um/Kconfig index 6a15c4dcc746..a992f8e94887 100644 --- a/arch/x86/um/Kconfig +++ b/arch/x86/um/Kconfig @@ -1,6 +1,8 @@ # SPDX-License-Identifier: GPL-2.0 mainmenu "User Mode Linux/$(SUBARCH) $(KERNELVERSION) Kernel Configuration" +comment "Compiler: $(CC_VERSION_TEXT)" + source "arch/um/Kconfig.common" menu "UML-specific options" -- cgit v1.2.3 From e1cfdc0e72fc9ad7c04ad6329acb92876e062849 Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Mon, 28 May 2018 18:21:59 +0900 Subject: kconfig: add basic helper macros to scripts/Kconfig.include Kconfig got text processing tools like we see in Make. Add Kconfig helper macros to scripts/Kconfig.include like we collect Makefile macros in scripts/Kbuild.include. Signed-off-by: Masahiro Yamada Reviewed-by: Kees Cook Reviewed-by: Ulf Magnusson --- arch/x86/um/Kconfig | 2 ++ 1 file changed, 2 insertions(+) (limited to 'arch/x86/um') diff --git a/arch/x86/um/Kconfig b/arch/x86/um/Kconfig index a992f8e94887..9d529f22fd9d 100644 --- a/arch/x86/um/Kconfig +++ b/arch/x86/um/Kconfig @@ -3,6 +3,8 @@ mainmenu "User Mode Linux/$(SUBARCH) $(KERNELVERSION) Kernel Configuration" comment "Compiler: $(CC_VERSION_TEXT)" +source "scripts/Kconfig.include" + source "arch/um/Kconfig.common" menu "UML-specific options" -- cgit v1.2.3