Merge tag 'compiler-attributes-for-linus-v5.4' of git://github.com/ojeda/linux

[sfrench/cifs-2.6.git] / include / linux / compiler_types.h

diff --git a/include/linux/compiler_types.h b/include/linux/compiler_types.h
index 599c27b56c29a9674bc8b189c4200c3c0fbed58c..72393a8c1a6c5daeab6bb6403252daeb2aecdb93 100644 (file)
--- a/include/linux/compiler_types.h
+++ b/include/linux/compiler_types.h
@@ -130,10 +130,6 @@ struct ftrace_likely_data {
 
 /*
  * Force always-inline if the user requests it so via the .config.
- * GCC does not warn about unused static inline functions for
- * -Wunused-function.  This turns out to avoid the need for complex #ifdef
- * directives.  Suppress the warning in clang as well by using "unused"
- * function attribute, which is redundant but not harmful for gcc.
  * Prefer gnu_inline, so that extern inline functions do not emit an
  * externally visible function. This makes extern inline behave as per gnu89
  * semantics rather than c99. This prevents multiple symbol definition errors
@@ -144,14 +140,35 @@ struct ftrace_likely_data {
  */
 #if !defined(CONFIG_OPTIMIZE_INLINING)
 #define inline inline __attribute__((__always_inline__)) __gnu_inline \
-       __maybe_unused notrace
+       __inline_maybe_unused notrace
 #else
 #define inline inline                                    __gnu_inline \
-       __maybe_unused notrace
+       __inline_maybe_unused notrace
 #endif
 
+/*
+ * gcc provides both __inline__ and __inline as alternate spellings of
+ * the inline keyword, though the latter is undocumented. New kernel
+ * code should only use the inline spelling, but some existing code
+ * uses __inline__. Since we #define inline above, to ensure
+ * __inline__ has the same semantics, we need this #define.
+ *
+ * However, the spelling __inline is strictly reserved for referring
+ * to the bare keyword.
+ */
 #define __inline__ inline
-#define __inline   inline
+
+/*
+ * GCC does not warn about unused static inline functions for -Wunused-function.
+ * Suppress the warning in clang as well by using __maybe_unused, but enable it
+ * for W=1 build. This will allow clang to find unused functions. Remove the
+ * __inline_maybe_unused entirely after fixing most of -Wunused-function warnings.
+ */
+#ifdef KBUILD_EXTRA_WARN1
+#define __inline_maybe_unused
+#else
+#define __inline_maybe_unused __maybe_unused
+#endif
 
 /*
  * Rather then using noinline to prevent stack consumption, use
@@ -189,6 +206,12 @@ struct ftrace_likely_data {
 #define asm_volatile_goto(x...) asm goto(x)
 #endif
 
+#ifdef CONFIG_CC_HAS_ASM_INLINE
+#define asm_inline asm __inline
+#else
+#define asm_inline asm
+#endif
+
 #ifndef __no_fgcse
 # define __no_fgcse
 #endif