[Introduction] The motivation of this work is to move the compiler option tests to Kconfig from Makefile. A number of kernel features require the compiler support. Enabling such features blindly in Kconfig ends up with a lot of nasty build-time testing in Makefiles. If a chosen feature turns out unsupported by the compiler, what the build system can do is either to disable it (silently!) or to forcibly break the build, despite Kconfig has let the user to enable it. [Major Changes in V3] This version looks more like Make. - Use = operator instead of 'macro' keyword to define a user-defined function. - 'Recursively expanded variable' is implemented as a side-effect. A variable is a function with zero argument. - Support simply expanded variable which is defined by := operator - Support += operator. Probably, this feature will be useful to accumulate compiler flags. At least, Clang needs some prerequisite flags such as triplet to test other compiler flags. - Support $(info ...) and $(warning ...) built-in functions, which were useful while I was debugging this. - Add documentation - Add unit tests - Collect helpers to scripts/Kconfig.include [TODO items] I have not been able to finish this. Maybe aiming for v4.18-rc1. - The text expansion should be able to defer argument expansion. This is necessary if we want to implement $(if ...) built-in function. - Error out recursive expansion of itself. For example, X = $(X) refers itself. If referenced, the expansion continues eternally. This must be terminated. - More compatible behavior? Kconfig works mostly like Make, but there are naive cases where the behavior is different. [Old Versions] V2: https://lkml.org/lkml/2018/2/16/610 V1: https://lkml.org/lkml/2018/2/16/610 RFC: https://lkml.org/lkml/2018/2/8/429 Masahiro Yamada (30): gcc-plugins: fix build condition of SANCOV plugin kbuild: remove kbuild cache kbuild: remove CONFIG_CROSS_COMPILE support kconfig: reference environment variables directly and remove 'option env=' kconfig: remove string expansion in file_lookup() kconfig: remove string expansion for mainmenu after yyparse() kconfig: remove sym_expand_string_value() kconfig: add built-in function support kconfig: add 'shell' built-in function kconfig: replace $(UNAME_RELEASE) with function call kconfig: begin PARAM state only when seeing a command keyword kconfig: support variable and user-defined function kconfig: support simply expanded variable kconfig: support append assignment operator kconfig: expand lefthand side of assignment statement kconfig: add 'info' and 'warning' built-in functions Documentation: kconfig: document a new Kconfig macro language kconfig: test: test text expansion kconfig: show compiler version text in the top comment kconfig: add basic helper macros to scripts/Kconfig.include stack-protector: test compiler capability in Kconfig and drop AUTO mode kconfig: add CC_IS_GCC and GCC_VERSION kconfig: add CC_IS_CLANG and CLANG_VERSION gcov: remove CONFIG_GCOV_FORMAT_AUTODETECT kcov: test compiler capability in Kconfig and correct dependency gcc-plugins: move GCC version check for PowerPC to Kconfig gcc-plugins: test plugin support in Kconfig and clean up Makefile gcc-plugins: allow to enable GCC_PLUGINS for COMPILE_TEST arm64: move GCC version check for ARCH_SUPPORTS_INT128 to Kconfig kbuild: test dead code/data elimination support in Kconfig Documentation/kbuild/kconfig-language.txt | 8 - Documentation/kbuild/kconfig-macro-language.txt | 179 +++++++ Kconfig | 10 +- MAINTAINERS | 3 +- Makefile | 113 +--- arch/Kconfig | 53 +- arch/arm64/Kconfig | 1 + arch/arm64/Makefile | 2 - arch/powerpc/Kconfig | 2 +- arch/sh/Kconfig | 4 +- arch/sparc/Kconfig | 4 +- arch/um/Kconfig.common | 4 - arch/x86/Kconfig | 15 +- arch/x86/um/Kconfig | 6 +- init/Kconfig | 40 +- kernel/gcov/Kconfig | 17 +- kernel/gcov/Makefile | 2 - lib/Kconfig.debug | 11 +- scripts/Kbuild.include | 101 +--- scripts/Kconfig.include | 20 + scripts/Makefile.gcc-plugins | 91 +--- scripts/Makefile.kcov | 10 +- scripts/clang-version.sh | 18 +- scripts/gcc-plugins/Makefile | 1 + 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/kconf_id.c | 1 - scripts/kconfig/lkc.h | 4 - scripts/kconfig/lkc_proto.h | 15 +- scripts/kconfig/menu.c | 3 - scripts/kconfig/preprocess.c | 594 +++++++++++++++++++++ scripts/kconfig/symbol.c | 109 ---- .../kconfig/tests/preprocess/builtin_func/Kconfig | 19 + .../tests/preprocess/builtin_func/__init__.py | 8 + .../tests/preprocess/builtin_func/expected_stderr | 4 + .../tests/preprocess/builtin_func/expected_stdout | 1 + scripts/kconfig/tests/preprocess/escape/Kconfig | 49 ++ .../kconfig/tests/preprocess/escape/__init__.py | 9 + .../tests/preprocess/escape/expected_stderr | 10 + scripts/kconfig/tests/preprocess/user_func/Kconfig | 19 + .../kconfig/tests/preprocess/user_func/__init__.py | 7 + .../tests/preprocess/user_func/expected_stderr | 5 + scripts/kconfig/tests/preprocess/variable/Kconfig | 39 ++ .../kconfig/tests/preprocess/variable/__init__.py | 7 + .../tests/preprocess/variable/expected_stderr | 7 + scripts/kconfig/util.c | 22 +- scripts/kconfig/zconf.l | 95 +++- scripts/kconfig/zconf.y | 48 +- 49 files changed, 1259 insertions(+), 574 deletions(-) create mode 100644 Documentation/kbuild/kconfig-macro-language.txt create mode 100644 scripts/Kconfig.include create mode 100644 scripts/kconfig/preprocess.c create mode 100644 scripts/kconfig/tests/preprocess/builtin_func/Kconfig create mode 100644 scripts/kconfig/tests/preprocess/builtin_func/__init__.py create mode 100644 scripts/kconfig/tests/preprocess/builtin_func/expected_stderr create mode 100644 scripts/kconfig/tests/preprocess/builtin_func/expected_stdout create mode 100644 scripts/kconfig/tests/preprocess/escape/Kconfig create mode 100644 scripts/kconfig/tests/preprocess/escape/__init__.py create mode 100644 scripts/kconfig/tests/preprocess/escape/expected_stderr create mode 100644 scripts/kconfig/tests/preprocess/user_func/Kconfig create mode 100644 scripts/kconfig/tests/preprocess/user_func/__init__.py create mode 100644 scripts/kconfig/tests/preprocess/user_func/expected_stderr create mode 100644 scripts/kconfig/tests/preprocess/variable/Kconfig create mode 100644 scripts/kconfig/tests/preprocess/variable/__init__.py create mode 100644 scripts/kconfig/tests/preprocess/variable/expected_stderr -- 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