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c0a0aba8e4
The use of config_enabled() is ambiguous. For config options, IS_ENABLED(), IS_REACHABLE(), etc. will make intention clearer. Sometimes config_enabled() has been used for non-config options because it is useful to check whether the given symbol is defined or not. I have been tackling on deprecating config_enabled(), and now is the time to finish this work. Some new users have appeared for v4.9-rc1, but it is trivial to replace them: - arch/x86/mm/kaslr.c replace config_enabled() with IS_ENABLED() because CONFIG_X86_ESPFIX64 and CONFIG_EFI are boolean. - include/asm-generic/export.h replace config_enabled() with __is_defined(). Then, config_enabled() can be removed now. Going forward, please use IS_ENABLED(), IS_REACHABLE(), etc. for config options, and __is_defined() for non-config symbols. Link: http://lkml.kernel.org/r/1476616078-32252-1-git-send-email-yamada.masahiro@socionext.com Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Acked-by: Ingo Molnar <mingo@kernel.org> Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org> Cc: Peter Oberparleiter <oberpar@linux.vnet.ibm.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Kees Cook <keescook@chromium.org> Cc: Michal Marek <mmarek@suse.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Thomas Garnier <thgarnie@google.com> Cc: Paul Bolle <pebolle@tiscali.nl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
66 lines
2.3 KiB
C
66 lines
2.3 KiB
C
#ifndef __LINUX_KCONFIG_H
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#define __LINUX_KCONFIG_H
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#include <generated/autoconf.h>
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#define __ARG_PLACEHOLDER_1 0,
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#define __take_second_arg(__ignored, val, ...) val
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/*
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* The use of "&&" / "||" is limited in certain expressions.
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* The followings enable to calculate "and" / "or" with macro expansion only.
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*/
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#define __and(x, y) ___and(x, y)
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#define ___and(x, y) ____and(__ARG_PLACEHOLDER_##x, y)
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#define ____and(arg1_or_junk, y) __take_second_arg(arg1_or_junk y, 0)
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#define __or(x, y) ___or(x, y)
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#define ___or(x, y) ____or(__ARG_PLACEHOLDER_##x, y)
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#define ____or(arg1_or_junk, y) __take_second_arg(arg1_or_junk 1, y)
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/*
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* Helper macros to use CONFIG_ options in C/CPP expressions. Note that
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* these only work with boolean and tristate options.
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*/
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/*
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* Getting something that works in C and CPP for an arg that may or may
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* not be defined is tricky. Here, if we have "#define CONFIG_BOOGER 1"
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* we match on the placeholder define, insert the "0," for arg1 and generate
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* the triplet (0, 1, 0). Then the last step cherry picks the 2nd arg (a one).
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* When CONFIG_BOOGER is not defined, we generate a (... 1, 0) pair, and when
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* the last step cherry picks the 2nd arg, we get a zero.
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*/
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#define __is_defined(x) ___is_defined(x)
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#define ___is_defined(val) ____is_defined(__ARG_PLACEHOLDER_##val)
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#define ____is_defined(arg1_or_junk) __take_second_arg(arg1_or_junk 1, 0)
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/*
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* IS_BUILTIN(CONFIG_FOO) evaluates to 1 if CONFIG_FOO is set to 'y', 0
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* otherwise. For boolean options, this is equivalent to
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* IS_ENABLED(CONFIG_FOO).
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*/
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#define IS_BUILTIN(option) __is_defined(option)
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/*
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* IS_MODULE(CONFIG_FOO) evaluates to 1 if CONFIG_FOO is set to 'm', 0
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* otherwise.
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*/
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#define IS_MODULE(option) __is_defined(option##_MODULE)
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/*
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* IS_REACHABLE(CONFIG_FOO) evaluates to 1 if the currently compiled
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* code can call a function defined in code compiled based on CONFIG_FOO.
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* This is similar to IS_ENABLED(), but returns false when invoked from
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* built-in code when CONFIG_FOO is set to 'm'.
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*/
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#define IS_REACHABLE(option) __or(IS_BUILTIN(option), \
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__and(IS_MODULE(option), __is_defined(MODULE)))
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/*
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* IS_ENABLED(CONFIG_FOO) evaluates to 1 if CONFIG_FOO is set to 'y' or 'm',
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* 0 otherwise.
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*/
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#define IS_ENABLED(option) __or(IS_BUILTIN(option), IS_MODULE(option))
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#endif /* __LINUX_KCONFIG_H */
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