[PATCH 03/12] Compiler Attributes: remove unneeded tests

From: Miguel Ojeda
Date: Mon Sep 03 2018 - 16:34:50 EST


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.

Cc: Rasmus Villemoes <linux@xxxxxxxxxxxxxxxxxx>
Cc: Luc Van Oostenryck <luc.vanoostenryck@xxxxxxxxx>
Cc: Eli Friedman <efriedma@xxxxxxxxxxxxxx>
Cc: Christopher Li <sparse@xxxxxxxxxxx>
Cc: Kees Cook <keescook@xxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
Cc: Arnd Bergmann <arnd@xxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx>
Cc: Joe Perches <joe@xxxxxxxxxxx>
Cc: Dominique Martinet <asmadeus@xxxxxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: linux-sparse@xxxxxxxxxxxxxxx
Reviewed-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>
Signed-off-by: Miguel Ojeda <miguel.ojeda.sandonis@xxxxxxxxx>
---
include/linux/compiler_types.h | 24 +++---------------------
1 file changed, 3 insertions(+), 21 deletions(-)

diff --git a/include/linux/compiler_types.h b/include/linux/compiler_types.h
index 2bc0f94df38e..759b3fea9216 100644
--- a/include/linux/compiler_types.h
+++ b/include/linux/compiler_types.h
@@ -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)))
@@ -211,7 +208,8 @@ struct ftrace_likely_data {
#define __alias(symbol) __attribute__((__alias__(#symbol)))
#define __cold __attribute__((__cold__))
#define __section(S) __attribute__((__section__(#S)))
-
+#define __gnu_inline __attribute__((__gnu_inline__))
+#define __always_inline inline __attribute__((__always_inline__))

#ifdef CONFIG_ENABLE_MUST_CHECK
#define __must_check __attribute__((__warn_unused_result__))
@@ -227,18 +225,6 @@ 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
@@ -263,10 +249,6 @@ 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.
--
2.17.1