2018-05-28 21:23 GMT+09:00 Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx>: > 2018-05-28 18:21 GMT+09:00 Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx>: >> >> [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. By moving the >> compiler capability tests to Kconfig, Kconfig entries will be visible >> only when they are available. >> >> [Major Changes in V5] >> >> V5 removed the complexity unnecessary for Kconfig. >> >> - In order to make the implementation simpler, I drop the lazy >> argument expansion. >> In V5, parameters are expanded before passed to a function. >> (the same behavior as v3) >> >> - Replace 'warning', 'error' functions with 'warning-if', >> 'error-if' functions. The new functions are effective >> only when the condition part is 'y'. >> >> - In V4, '$' must be followed by '$' or '('. >> '$$' meant an escaped '$'. >> >> V4 caused a build error for ARC architecture due to the >> following line: >> https://github.com/torvalds/linux/blob/v4.17-rc4/arch/arc/Kconfig#L252 >> >> Of course, we could rephrase "D$" to "D cache", but >> I treaked the grammar a little bit. >> >> Kconfig decided to not support single-letter variable as in "$X". >> Nor curly braces as in "${CC}" are not supported. >> This means variable/function references in Kconfig always start >> with "$(". >> We can use '$' not followed by '(' as-is. >> We do not need the "$$" escape sequence. >> If necessary, we can use a trick to print '$(' verbatim. See below. >> >> - Fix a wrong behavior of simply expanded variables. >> V4 expanded simply expanded variables when used, but it should not. >> >> For example, >> >> dollar := $ >> X := 1 >> Y := $(dollar)(X) >> $(info,$(Y)) >> >> V5 prints '$(X)', not '1'. >> >> - Remove a space after a comma is $( ) context. >> Actually, spaces do not matter in most cases. >> >> You can write either >> >> $(cc-option,-fstack-protector) >> >> or >> >> $(cc-option, -fstack-protector) >> >> In fact, both style co-exist in our Makefiles too. >> However, there are some cases where they do matter. >> >> I remove spaces after commas for consistency. >> If you are unsure, no-space-after-comma is always safe. >> >> [Major Changes in V4] >> >> - In V4, I slightly change the syntax of a function call. >> I chose grammatical consistency and simplicity. >> Anyway, Kconfig is deviating from Make behavior already. >> >> In v3, a function call looked like this: >> >> $(func-name arg1,arg2,arg3) >> >> In v4, a function is invoked like follows: >> >> $(func-name,arg1,arg2,arg3) >> >> The difference is that the function name and the first argument >> are separated by a comma. >> >> - V3 supported single-letter variable like $X. >> V4 dropped it because we do not need multiple ways to do the >> same thing. >> You must always enclose a variable name like $(X). >> >> - Support lazy argument expansion. This is necessary for implementing >> 'if', 'and', 'or' functions as in Make. >> >> - Add more built-in functions: >> 'if', 'error', 'filename', 'lineno' >> >> - Error out if a recursive variable references itself eventually. >> For example, X = $(X) >> ends up with a circular expansion. It must be terminated >> since the expansion would continue eternally. >> >> - Update Documentation and unit-tests, accordingly. >> >> [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 >> >> [Old Versions] >> >> V4: https://lkml.org/lkml/2018/5/17/97 >> V3: https://lkml.org/lkml/2018/4/13/37 >> 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 (31): >> 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: make default prompt of mainmenu less specific >> 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 user-defined function and recursively expanded >> variable >> kconfig: support simply expanded variable >> kconfig: support append assignment operator >> kconfig: expand lefthand side of assignment statement >> kconfig: add 'info', 'warning-if', and 'error-if' built-in functions >> kconfig: add 'filename' and 'lineno' built-in variables >> kconfig: error out if a recursive variable references itself >> Documentation: kconfig: document a new Kconfig macro language >> kconfig: test: add Kconfig macro language tests >> 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 >> Documentation: kconfig: add recommended way to describe compiler >> support >> >> Documentation/kbuild/kconfig-language.txt | 26 +- >> Documentation/kbuild/kconfig-macro-language.txt | 242 +++++++++ >> Kconfig | 10 +- >> MAINTAINERS | 3 +- >> Makefile | 105 +--- >> arch/Kconfig | 49 +- >> 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 | 10 +- >> init/Kconfig | 40 +- >> kernel/gcov/Kconfig | 17 +- >> kernel/gcov/Makefile | 2 - >> lib/Kconfig.debug | 11 +- >> scripts/Kbuild.include | 101 +--- >> scripts/Kconfig.include | 30 ++ >> 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 | 33 +- >> scripts/kconfig/kconf_id.c | 1 - >> scripts/kconfig/lkc.h | 5 +- >> scripts/kconfig/lkc_proto.h | 15 +- >> scripts/kconfig/menu.c | 3 - >> scripts/kconfig/preprocess.c | 572 +++++++++++++++++++++ >> scripts/kconfig/symbol.c | 109 ---- >> .../tests/no_write_if_dep_unmet/expected_config | 2 +- >> .../kconfig/tests/preprocess/builtin_func/Kconfig | 27 + >> .../tests/preprocess/builtin_func/__init__.py | 9 + >> .../tests/preprocess/builtin_func/expected_stderr | 5 + >> .../tests/preprocess/builtin_func/expected_stdout | 1 + >> .../tests/preprocess/circular_expansion/Kconfig | 5 + >> .../preprocess/circular_expansion/__init__.py | 11 + >> .../preprocess/circular_expansion/expected_stderr | 1 + >> scripts/kconfig/tests/preprocess/escape/Kconfig | 44 ++ >> .../kconfig/tests/preprocess/escape/__init__.py | 8 + >> .../tests/preprocess/escape/expected_stderr | 10 + >> scripts/kconfig/tests/preprocess/variable/Kconfig | 53 ++ >> .../kconfig/tests/preprocess/variable/__init__.py | 8 + >> .../tests/preprocess/variable/expected_stderr | 9 + >> scripts/kconfig/util.c | 33 +- >> scripts/kconfig/zconf.l | 95 +++- >> scripts/kconfig/zconf.y | 46 +- >> 48 files changed, 1345 insertions(+), 567 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/circular_expansion/Kconfig >> create mode 100644 scripts/kconfig/tests/preprocess/circular_expansion/__init__.py >> create mode 100644 scripts/kconfig/tests/preprocess/circular_expansion/expected_stderr >> 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/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 >> > > > > I pushed this series to > > git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild.git > kconfig-shell-v5 > I pushed this series to the for-next branch. Unless a significant problem is reported, I'd like to merge this series in the upcoming MW. At least, I need to keep it in linux-next for a while. Your comments and tags are still appreciated. I will add tags (or replace patches if necessary) later, but I want this series tested in linux-next to expose to more developers' eyes. It passed my local test. O-day bot did not report anything so far. -- Best Regards Masahiro Yamada -- 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