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: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
Signed-off-by: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>

diff --git a/include/linux/compiler_types.h b/include/linux/compiler_types.h
index 8fbdd47dd3d0ddf966970ae6cc0ebe8f3e8f6999..5ff9cda893f4a637b0ce001adeed42740a838b56 100644 (file)
--- 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)))
@@ -211,6 +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.