From fde192511bdbff554320b31574bb8a9cb3275522 Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Sun, 2 Jun 2024 21:54:14 +0900 Subject: kconfig: remove tristate choice support I previously submitted a fix for a bug in the choice feature [1], where I mentioned, "Another (much cleaner) approach would be to remove the tristate choice support entirely". There are more issues in the tristate choice feature. For example, you can observe a couple of bugs in the following test code. [Test Code] config MODULES def_bool y modules choice prompt "tristate choice" default A config A tristate "A" config B tristate "B" endchoice Bug 1: the 'default' property is not correctly processed 'make alldefconfig' produces: CONFIG_MODULES=y # CONFIG_A is not set # CONFIG_B is not set However, the correct output should be: CONFIG_MODULES=y CONFIG_A=y # CONFIG_B is not set The unit test file, scripts/kconfig/tests/choice/alldef_expected_config, is wrong as well. Bug 2: choice members never get 'y' with randconfig For the test code above, the following combinations are possible: A B (1) y n (2) n y (3) m m (4) m n (5) n m (6) n n 'make randconfig' never produces (1) or (2). These bugs are fixable, but a more critical problem is the lack of a sensible syntax to specify the default for the tristate choice. The default for the choice must be one of the choice members, which cannot specify any of the patterns (3) through (6) above. In addition, I have never seen it being used in a useful way. The following commits removed unnecessary use of tristate choices: - df8df5e4bc37 ("usb: get rid of 'choice' for legacy gadget drivers") - bfb57ef0544a ("rapidio: remove choice for enumeration") This commit removes the tristate choice support entirely, which allows me to delete a lot of code, making further refactoring easier. Note: This includes the revert of commit fa64e5f6a35e ("kconfig/symbol.c: handle choice_values that depend on 'm' symbols"). It was suspicious because it did not address the root cause but introduced inconsistency in visibility between choice members and other symbols. [1]: https://lore.kernel.org/linux-kbuild/20240427104231.2728905-1-masahiroy@kernel.org/T/#m0a1bb6992581462ceca861b409bb33cb8fd7dbae Signed-off-by: Masahiro Yamada Reviewed-by: Nicolas Schier --- Documentation/kbuild/kconfig-language.rst | 13 +++---------- 1 file changed, 3 insertions(+), 10 deletions(-) (limited to 'Documentation') diff --git a/Documentation/kbuild/kconfig-language.rst b/Documentation/kbuild/kconfig-language.rst index 1fb3f5e6193c..71b38a7670f3 100644 --- a/Documentation/kbuild/kconfig-language.rst +++ b/Documentation/kbuild/kconfig-language.rst @@ -409,16 +409,9 @@ choices:: "endchoice" This defines a choice group and accepts any of the above attributes as -options. A choice can only be of type bool or tristate. If no type is -specified for a choice, its type will be determined by the type of -the first choice element in the group or remain unknown if none of the -choice elements have a type specified, as well. - -While a boolean choice only allows a single config entry to be -selected, a tristate choice also allows any number of config entries -to be set to 'm'. This can be used if multiple drivers for a single -hardware exists and only a single driver can be compiled/loaded into -the kernel, but all drivers can be compiled as modules. +options. + +A choice only allows a single config entry to be selected. comment:: -- cgit v1.2.3 From 5f99665ee8f4335f334a5292b6d5b41a577fc2c0 Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Thu, 4 Jul 2024 22:47:55 +0900 Subject: kbuild: raise the minimum GNU Make requirement to 4.0 RHEL/CentOS 7, popular distributions that install GNU Make 3.82, reached EOM/EOL on June 30, 2024. While you may get extended support, it is a good time to raise the minimum GNU Make version. The new requirement, GNU Make 4.0, was released in October, 2013. I did not touch the Makefiles under tools/ because I do not know the requirements for building tools. I do not find any GNU Make version checks under tools/. Signed-off-by: Masahiro Yamada Reviewed-by: Nathan Chancellor --- Documentation/process/changes.rst | 4 ++-- Makefile | 22 +++------------------- scripts/Kbuild.include | 2 +- 3 files changed, 6 insertions(+), 22 deletions(-) (limited to 'Documentation') diff --git a/Documentation/process/changes.rst b/Documentation/process/changes.rst index 5685d7bfe4d0..415ac8eeb46c 100644 --- a/Documentation/process/changes.rst +++ b/Documentation/process/changes.rst @@ -33,7 +33,7 @@ GNU C 5.1 gcc --version Clang/LLVM (optional) 13.0.1 clang --version Rust (optional) 1.78.0 rustc --version bindgen (optional) 0.65.1 bindgen --version -GNU make 3.82 make --version +GNU make 4.0 make --version bash 4.2 bash --version binutils 2.25 ld -v flex 2.5.35 flex --version @@ -111,7 +111,7 @@ It depends on ``libclang``. Make ---- -You will need GNU make 3.82 or later to build the kernel. +You will need GNU make 4.0 or later to build the kernel. Bash ---- diff --git a/Makefile b/Makefile index b25b5b44af10..7372ea45ed3f 100644 --- a/Makefile +++ b/Makefile @@ -11,8 +11,8 @@ NAME = Baby Opossum Posse # Comments in this file are targeted only to the developer, do not # expect to learn how to build the kernel reading this file. -ifeq ($(filter undefine,$(.FEATURES)),) -$(error GNU Make >= 3.82 is required. Your Make version is $(MAKE_VERSION)) +ifeq ($(filter output-sync,$(.FEATURES)),) +$(error GNU Make >= 4.0 is required. Your Make version is $(MAKE_VERSION)) endif $(if $(filter __%, $(MAKECMDGOALS)), \ @@ -93,15 +93,7 @@ endif # If the user is running make -s (silent mode), suppress echoing of # commands -# make-4.0 (and later) keep single letter options in the 1st word of MAKEFLAGS. - -ifeq ($(filter 3.%,$(MAKE_VERSION)),) -short-opts := $(firstword -$(MAKEFLAGS)) -else -short-opts := $(filter-out --%,$(MAKEFLAGS)) -endif - -ifneq ($(findstring s,$(short-opts)),) +ifneq ($(findstring s,$(firstword -$(MAKEFLAGS))),) quiet=silent_ override KBUILD_VERBOSE := endif @@ -201,14 +193,6 @@ ifneq ($(words $(subst :, ,$(abs_srctree))), 1) $(error source directory cannot contain spaces or colons) endif -ifneq ($(filter 3.%,$(MAKE_VERSION)),) -# 'MAKEFLAGS += -rR' does not immediately become effective for GNU Make 3.x -# We need to invoke sub-make to avoid implicit rules in the top Makefile. -need-sub-make := 1 -# Cancel implicit rules for this Makefile. -$(this-makefile): ; -endif - export sub_make_done := 1 endif # sub_make_done diff --git a/scripts/Kbuild.include b/scripts/Kbuild.include index faf37bafa3f8..ed8a7493524b 100644 --- a/scripts/Kbuild.include +++ b/scripts/Kbuild.include @@ -68,7 +68,7 @@ kbuild-file = $(or $(wildcard $(src)/Kbuild),$(src)/Makefile) # Read a file, replacing newlines with spaces # # Make 4.2 or later can read a file by using its builtin function. -ifneq ($(filter-out 3.% 4.0 4.1, $(MAKE_VERSION)),) +ifneq ($(filter-out 4.0 4.1, $(MAKE_VERSION)),) read-file = $(subst $(newline),$(space),$(file < $1)) else read-file = $(shell cat $1 2>/dev/null) -- cgit v1.2.3 From 13c239a2c088e91e453d26517b562c9a116444fa Mon Sep 17 00:00:00 2001 From: Ivan Davydov Date: Mon, 22 Jul 2024 08:57:31 +0300 Subject: kbuild: doc: gcc to CC change In this part of the documentation, $(CC) is meant, but gcc is written. Signed-off-by: Ivan Davydov Signed-off-by: Masahiro Yamada --- Documentation/kbuild/makefiles.rst | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'Documentation') diff --git a/Documentation/kbuild/makefiles.rst b/Documentation/kbuild/makefiles.rst index 991ce6081e35..be43990f1e7f 100644 --- a/Documentation/kbuild/makefiles.rst +++ b/Documentation/kbuild/makefiles.rst @@ -578,7 +578,7 @@ cc-option Note: cc-option uses KBUILD_CFLAGS for $(CC) options cc-option-yn - cc-option-yn is used to check if gcc supports a given option + cc-option-yn is used to check if $(CC) supports a given option and return "y" if supported, otherwise "n". Example:: @@ -596,7 +596,7 @@ cc-option-yn Note: cc-option-yn uses KBUILD_CFLAGS for $(CC) options cc-disable-warning - cc-disable-warning checks if gcc supports a given warning and returns + cc-disable-warning checks if $(CC) supports a given warning and returns the commandline switch to disable it. This special function is needed, because gcc 4.4 and later accept any unknown -Wno-* option and only warn about it if there is another warning in the source file. @@ -606,7 +606,7 @@ cc-disable-warning KBUILD_CFLAGS += $(call cc-disable-warning, unused-but-set-variable) In the above example, -Wno-unused-but-set-variable will be added to - KBUILD_CFLAGS only if gcc really accepts it. + KBUILD_CFLAGS only if $(CC) really accepts it. gcc-min-version gcc-min-version tests if the value of $(CONFIG_GCC_VERSION) is greater than -- cgit v1.2.3