Here is v2 to start to move compiler capability tests to Kconfig. V1: https://lkml.org/lkml/2018/2/16/610 I brushed up the implementation even more. Major changes for v2: [1] Environments and functions are expanded in the lexer (zconf.l) The parser (zconf.y) receives expanded tokens. This simplifies the implementation. [2] Implement only one built-in function 'shell'. This returns stdout from the command. We need something to return 'y' or 'n'. This is now implemented as a macro 'success'. [3] Macros (user-defined function) are defined by 'macro' keyword instead of string type symbol. ex1) macro success $(shell ($(1) && echo y) || echo n) ex2) macro cc-option $(success $CC -Werror $(1) -c -x c /dev/null -o /dev/null) My plan for v3 -------------- The MW is approaching, but I'd like to make it more lovely if I have some time. While I was writing these patches, I noticed a kind of similarity between Makefile and Kconfig. Makefile can define variables and functions to do text processing during the parse phase. After parsing, it builds up dependency graph, and moves on to the execution phase. Then, it generates objects as needed by checking time-stamps. [Makefile] OBJ := foo.o SRC := foo.c CC := gcc $(OBJ): $(SRC) $(CC) -c -o $(OBJ) $(SRC) [Makefile after text processing] foo.o: foo.c gcc -c -o foo.o foo.c Now, we are adding tools for text processing to Kconfig. Functions are statically expanded by the lexer. After all source files are parsed, Kconfig moves on to the evaluation phase. Then, users can tweak symbol values from menus. So, we should be able to describe Kconfig like follows: [Kconfig] MY_SYMBOL := CC_STACKPROTECTOR MY_PROMPT := "Stackprotector" success = $(shell ($(1) && echo y) || echo n) cc-option = $(success $CC -Werror $(1) -c -x c /dev/null -o /dev/null) config $(MY_SYMBOL) bool $(MY_PROMPT) depends on $(cc-option -fstack-protector) [Kconfig after text processing] config CC_STACKPROTECTOR bool "Stackptector" depends on y So, I think it is better to use '=' assignment for defining functions. I will remove the 'macro' keyword. Also, support variables. A variable is a function with no argument. So, it will be easy to implement it as a sub-set of function feature. It is better to support two flavors of assignments, '=' and ':=' as well. Masahiro Yamada (21): kbuild: remove kbuild cache kbuild: remove CONFIG_CROSS_COMPILE support kconfig: move and rename sym_expand_string_value() kconfig: reference environments directly and remove 'option env=' syntax kconfig: remove string expansion in file_lookup() kconfig: remove string expansion for mainmenu after yyparse() kconfig: add function support and implement 'shell' function kconfig: replace $UNAME_RELEASE with function call kconfig: add 'macro' keyword to support user-defined function kconfig: add 'success' and 'cc-option' macros stack-protector: test compiler capability in Kconfig and drop AUTO mode kconfig: show compiler version text in the top comment kconfig: add CC_IS_GCC and GCC_VERSION kconfig: add CC_IS_CLANG and CLANG_VERSION gcov: remove CONFIG_GCOV_FORMAT_AUTODETECT kcov: imply GCC_PLUGINS and GCC_PLUGIN_SANCOV instead of select'ing them gcc-plugins: always build plugins with C++ gcc-plugins: move GCC version check for PowerPC to Kconfig gcc-plugins: test GCC plugin support in Kconfig gcc-plugins: enable GCC_PLUGINS for COMPILE_TEST arm64: move GCC version check for ARCH_SUPPORTS_INT128 to Kconfig Documentation/kbuild/kconfig-language.txt | 8 -- Kconfig | 4 +- Makefile | 103 ++------------ arch/Kconfig | 37 ++--- arch/arm64/Kconfig | 1 + arch/arm64/Makefile | 2 - arch/powerpc/Kconfig | 2 +- arch/sh/Kconfig | 4 +- arch/sparc/Kconfig | 4 +- arch/tile/Kconfig | 2 +- arch/um/Kconfig.common | 4 - arch/x86/Kconfig | 12 +- arch/x86/um/Kconfig | 4 +- init/Kconfig | 44 +++--- kernel/gcov/Kconfig | 17 +-- kernel/gcov/Makefile | 2 - lib/Kconfig.debug | 7 +- scripts/Kbuild.include | 101 ++------------ scripts/Makefile.gcc-plugins | 95 ++++--------- scripts/clang-version.sh | 24 ++-- scripts/gcc-plugin.sh | 37 +---- scripts/gcc-plugins/Makefile | 15 +- scripts/gcc-x86_32-has-stack-protector.sh | 7 +- scripts/gcc-x86_64-has-stack-protector.sh | 5 - scripts/kconfig/confdata.c | 31 +--- scripts/kconfig/env.c | 95 +++++++++++++ scripts/kconfig/function.c | 225 ++++++++++++++++++++++++++++++ scripts/kconfig/kconf_id.c | 1 - scripts/kconfig/lkc.h | 9 +- scripts/kconfig/lkc_proto.h | 7 +- scripts/kconfig/menu.c | 3 - scripts/kconfig/symbol.c | 109 --------------- scripts/kconfig/util.c | 96 ++++++++++--- scripts/kconfig/zconf.l | 51 ++++++- scripts/kconfig/zconf.y | 35 ++--- 35 files changed, 608 insertions(+), 595 deletions(-) create mode 100644 scripts/kconfig/env.c create mode 100644 scripts/kconfig/function.c -- 2.7.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kbuild" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html