https://gcc.gnu.org/bugzilla/show_bug.cgi?id=123815
Bug ID: 123815
Summary: Possible false positive -Wattributes for internal
linkage functions marked always_inline
Product: gcc
Version: 15.2.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: diagnostics
Assignee: dmalcolm at redhat dot com
Reporter: janschultke at googlemail dot com
Target Milestone: ---
https://godbolt.org/z/81xP5nb1G
[[gnu::always_inline]]
static void f() {}
<source>:2:13: warning: 'always_inline' function might not be inlinable unless
also declared 'inline' [-Wattributes]
2 | static void f() {}
| ^
Is this warning actually correct? My intuition is that [[gnu::always_inline]]
is meant to warn the user about misuses of the attribute, where they've applied
the attribute to a function that cannot be inlined because its definition is
not visible (in some contexts).
However, it is seemingly nonsensical to trigger the warning for a function with
internal linkage whose body is visible. Why would such a function ever not be
inlinable unless declared inline? The end result is that MANY correct (or
harmless in practice) uses of [[gnu::always_inline]] are being flagged on -Wall
when updating to GCC 15.
