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| author | Florian Weimer <fweimer@redhat.com> | 2024-05-18 09:33:19 +0200 |
|---|---|---|
| committer | Florian Weimer <fweimer@redhat.com> | 2024-05-18 09:33:19 +0200 |
| commit | 8d7b6b4cb27d4dec1dd5f7960298c1699275f962 (patch) | |
| tree | d3233e6a49dbde86dee8ea46920714a1adbbddb7 /misc | |
| parent | 2a99e2398d9d717c034e915f7846a49e623f5450 (diff) | |
| download | glibc-8d7b6b4cb27d4dec1dd5f7960298c1699275f962.tar.gz glibc-8d7b6b4cb27d4dec1dd5f7960298c1699275f962.tar.xz glibc-8d7b6b4cb27d4dec1dd5f7960298c1699275f962.zip | |
socket: Use may_alias on sockaddr structs (bug 19622)
This supports common coding patterns. The GCC C front end before version 7 rejects the may_alias attribute on a struct definition if it was not present in a previous forward declaration, so this attribute can only be conditionally applied. This implements the spirit of the change in Austin Group issue 1641. Suggested-by: Marek Polacek <polacek@redhat.com> Suggested-by: Jakub Jelinek <jakub@redhat.com> Reviewed-by: Sam James <sam@gentoo.org> Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Diffstat (limited to 'misc')
| -rw-r--r-- | misc/sys/cdefs.h | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/misc/sys/cdefs.h b/misc/sys/cdefs.h index 2e8279a2c7..ab9620bd0d 100644 --- a/misc/sys/cdefs.h +++ b/misc/sys/cdefs.h @@ -874,4 +874,13 @@ _Static_assert (0, "IEEE 128-bits long double requires redirection on this platf # define __attribute_returns_twice__ /* Ignore. */ #endif +/* Mark struct types as aliasable. Restricted to compilers that + support forward declarations of structs in the presence of the + attribute. */ +#if __GNUC_PREREQ (7, 1) || defined __clang__ +# define __attribute_struct_may_alias__ __attribute__ ((__may_alias__)) +#else +# define __attribute_struct_may_alias__ +#endif + #endif /* sys/cdefs.h */ |