From eb5c2d4b45e3d2d5d052ea6b8f1463976b1020d5 Mon Sep 17 00:00:00 2001 From: Will Deacon Date: Tue, 21 Jul 2020 09:54:15 +0100 Subject: compiler.h: Move compiletime_assert() macros into compiler_types.h The kernel test robot reports that moving READ_ONCE() out into its own header breaks a W=1 build for parisc, which is relying on the definition of compiletime_assert() being available: | In file included from ./arch/parisc/include/generated/asm/rwonce.h:1, | from ./include/asm-generic/barrier.h:16, | from ./arch/parisc/include/asm/barrier.h:29, | from ./arch/parisc/include/asm/atomic.h:11, | from ./include/linux/atomic.h:7, | from kernel/locking/percpu-rwsem.c:2: | ./arch/parisc/include/asm/atomic.h: In function 'atomic_read': | ./include/asm-generic/rwonce.h:36:2: error: implicit declaration of function 'compiletime_assert' [-Werror=implicit-function-declaration] | 36 | compiletime_assert(__native_word(t) || sizeof(t) == sizeof(long long), \ | | ^~~~~~~~~~~~~~~~~~ | ./include/asm-generic/rwonce.h:49:2: note: in expansion of macro 'compiletime_assert_rwonce_type' | 49 | compiletime_assert_rwonce_type(x); \ | | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ | ./arch/parisc/include/asm/atomic.h:73:9: note: in expansion of macro 'READ_ONCE' | 73 | return READ_ONCE((v)->counter); | | ^~~~~~~~~ Move these macros into compiler_types.h, so that they are available to READ_ONCE() and friends. Link: http://lists.infradead.org/pipermail/linux-arm-kernel/2020-July/587094.html Reported-by: kernel test robot Signed-off-by: Will Deacon --- include/linux/compiler_types.h | 41 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 41 insertions(+) (limited to 'include/linux/compiler_types.h') diff --git a/include/linux/compiler_types.h b/include/linux/compiler_types.h index c3bf7710f69a..d9bbb62a3e2a 100644 --- a/include/linux/compiler_types.h +++ b/include/linux/compiler_types.h @@ -300,6 +300,47 @@ struct ftrace_likely_data { (sizeof(t) == sizeof(char) || sizeof(t) == sizeof(short) || \ sizeof(t) == sizeof(int) || sizeof(t) == sizeof(long)) +/* Compile time object size, -1 for unknown */ +#ifndef __compiletime_object_size +# define __compiletime_object_size(obj) -1 +#endif +#ifndef __compiletime_warning +# define __compiletime_warning(message) +#endif +#ifndef __compiletime_error +# define __compiletime_error(message) +#endif + +#ifdef __OPTIMIZE__ +# define __compiletime_assert(condition, msg, prefix, suffix) \ + do { \ + extern void prefix ## suffix(void) __compiletime_error(msg); \ + if (!(condition)) \ + prefix ## suffix(); \ + } while (0) +#else +# define __compiletime_assert(condition, msg, prefix, suffix) do { } while (0) +#endif + +#define _compiletime_assert(condition, msg, prefix, suffix) \ + __compiletime_assert(condition, msg, prefix, suffix) + +/** + * compiletime_assert - break build and emit msg if condition is false + * @condition: a compile-time constant condition to check + * @msg: a message to emit if condition is false + * + * In tradition of POSIX assert, this macro will break the build if the + * supplied condition is *false*, emitting the supplied error message if the + * compiler has support to do so. + */ +#define compiletime_assert(condition, msg) \ + _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__) + +#define compiletime_assert_atomic_type(t) \ + compiletime_assert(__native_word(t), \ + "Need native word sized stores/loads for atomicity.") + /* Helpers for emitting diagnostics in pragmas. */ #ifndef __diag #define __diag(string) -- cgit