Commit c2c640aa authored by Miguel Ojeda's avatar Miguel Ojeda
Browse files

Compiler Attributes: remove unneeded tests 

Attributes const and always_inline have tests around them
which are unneeded, since they are supported by gcc >= 4.6,
clang >= 3 and icc >= 13. https://godbolt.org/z/DFPq37



In the case of gnu_inline, we do not need to test for
__GNUC_STDC_INLINE__ because, regardless of the current
inlining behavior, we can simply always force the old
GCC inlining behavior by using the attribute in all cases.

Tested-by: Sedat Dilek <sedat.dilek@gmail.com> # on top of v4.19-rc5, clang 7
Reviewed-by: default avatarNick Desaulniers <ndesaulniers@google.com>
Reviewed-by: default avatarLuc Van Oostenryck <luc.vanoostenryck@gmail.com>
Signed-off-by: default avatarMiguel Ojeda <miguel.ojeda.sandonis@gmail.com>
parent 5c67a52f

include/linux/compiler_types.h

+3 −20
Original line number Diff line number Diff line
@@ -158,10 +158,6 @@ struct ftrace_likely_data { 
	(sizeof(t) == sizeof(char) || sizeof(t) == sizeof(short) || \

	 sizeof(t) == sizeof(int) || sizeof(t) == sizeof(long))



#ifndef __attribute_const__

#define __attribute_const__	__attribute__((__const__))

#endif



#ifndef __noclone

#define __noclone

#endif
@@ -196,6 +192,7 @@ struct ftrace_likely_data { 
 * [...]

 */

#define __pure			__attribute__((__pure__))

#define __attribute_const__	__attribute__((__const__))

#define __aligned(x)		__attribute__((__aligned__(x)))

#define __aligned_largest	__attribute__((__aligned__))

#define __printf(a, b)		__attribute__((__format__(printf, a, b)))
@@ -211,6 +208,8 @@ struct ftrace_likely_data { 
#define __alias(symbol)		__attribute__((__alias__(#symbol)))

#define __cold			__attribute__((__cold__))

#define __section(S)		__attribute__((__section__(#S)))

#define __always_inline		inline __attribute__((__always_inline__))

#define __gnu_inline		__attribute__((__gnu_inline__))





#ifdef CONFIG_ENABLE_MUST_CHECK
@@ -235,18 +234,6 @@ struct ftrace_likely_data { 


#define __compiler_offsetof(a, b)	__builtin_offsetof(a, b)



/*

 * Feature detection for gnu_inline (gnu89 extern inline semantics). Either

 * __GNUC_STDC_INLINE__ is defined (not using gnu89 extern inline semantics,

 * and we opt in to the gnu89 semantics), or __GNUC_STDC_INLINE__ is not

 * defined so the gnu89 semantics are the default.

 */

#ifdef __GNUC_STDC_INLINE__

# define __gnu_inline	__attribute__((__gnu_inline__))

#else

# define __gnu_inline

#endif



/*

 * Force always-inline if the user requests it so via the .config.

 * GCC does not warn about unused static inline functions for
@@ -271,10 +258,6 @@ struct ftrace_likely_data { 
#define __inline inline

#define noinline	__attribute__((__noinline__))



#ifndef __always_inline

#define __always_inline inline __attribute__((__always_inline__))

#endif



/*

 * Rather then using noinline to prevent stack consumption, use

 * noinline_for_stack instead.  For documentation reasons.

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