[PATCH v2 3/6] compiler_types.h: don't #define __inline

From: Rasmus Villemoes
Date: Fri Aug 30 2019 - 19:15:50 EST


The spellings __inline and __inline__ should be reserved for uses
where one really wants to refer to the inline keyword, regardless of
whether or not the spelling "inline" has been #defined to something
else. Due to use of __inline__ in uapi headers, we can't easily get
rid of the definition of __inline__. However, almost all users of
__inline has been converted to inline, so we can get rid of that
#define.

The exception is include/acpi/platform/acintel.h. However, that header
is only included when using the intel compiler (does anybody actually
build the kernel with that?), and the ACPI_INLINE macro is only used
in the definition of utterly trivial stub functions, where I doubt a
small change of semantics (lack of __gnu_inline) changes anything.

Signed-off-by: Rasmus Villemoes <linux@xxxxxxxxxxxxxxxxxx>
---
include/linux/compiler_types.h | 11 ++++++++++-
1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/include/linux/compiler_types.h b/include/linux/compiler_types.h
index 599c27b56c29..ee49be6d6088 100644
--- a/include/linux/compiler_types.h
+++ b/include/linux/compiler_types.h
@@ -150,8 +150,17 @@ struct ftrace_likely_data {
__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

/*
* Rather then using noinline to prevent stack consumption, use
--
2.20.1