glibc/termios
Adhemerval Zanella 6b7067460f Handle clang -Wignored-attributes on weak aliases
Clang issues a warning for double alias redirection, indicating that thei
original symbol is used even if a weak definition attempts to override it.

For instance, in the construction:

  int __internal_impl (...) {}
  weak_alias (__internal_impl, external_impl);
  #if SOMETHING
  weak_alias (external_impl, another_external_impl)
  #endif

Clang warns that another_external_impl always resolves to __internal_impl,
even if external_impl is a weak reference. Using the internal symbol for
both aliases resolves this warning.

This issue also occurs with certain libc_hidden_def usage:

  int __internal_impl (...) {}
  weak_alias (__internal_impl, __internal_alias)
  libc_hidden_weak (__internal_alias)

In this case, using a strong_alias is sufficient to avoid the warning
(since the alias is internal, there is no need to use a weak alias).

However, for the constructions like:

  int __internal_impl (...) {}
  weak_alias (__internal_impl, __internal_alias)
  libc_hidden_def (__internal_alias)
  weak_alias (__internal_impl, external_alias)
  libc_hidden_def (external_alias)

Clang warns that the internal external_alias will always resolve to
__GI___internal_impl, even if a weak definition of __GI_internal_impl is
overridden.  For this case, a new macro named static_weak_alias is used
to create a strong alias for SHARED, or a weak_alias otherwise.

With these changes, there is no need to check and enable the
-Wno-ignored-attributes suppression when using clang.

Checked with a build on affected ABIs, and a full check on aarch64,
armhf, i686, and x86_64.

Reviewed-by: Sam James <sam@gentoo.org>
2025-12-09 08:58:10 -03:00
..
sys hurd/termios: remove USE_OLD_TTY 2025-06-17 09:11:38 -03:00
Makefile Handle clang -Wignored-attributes on weak aliases 2025-12-09 08:58:10 -03:00
Versions termios: Move isatty, __isatty_nostatus from io 2025-07-11 16:04:07 +02:00
baud.c termios: add new baud_t interface, defined to be explicitly numeric 2025-06-17 09:11:38 -03:00
cfmakeraw.c Update copyright dates with scripts/update-copyrights 2025-01-01 11:22:09 -08:00
cfsetbaud.c termios: add new baud_t interface, defined to be explicitly numeric 2025-06-17 09:11:38 -03:00
cfsetspeed.c termios: add new baud_t interface, defined to be explicitly numeric 2025-06-17 09:11:38 -03:00
isatty.c termios: Move isatty, __isatty_nostatus from io 2025-07-11 16:04:07 +02:00
isatty_nostatus.c termios: Move isatty, __isatty_nostatus from io 2025-07-11 16:04:07 +02:00
speed.c termios: add new baud_t interface, defined to be explicitly numeric 2025-06-17 09:11:38 -03:00
tcdrain.c Update copyright dates with scripts/update-copyrights 2025-01-01 11:22:09 -08:00
tcflow.c Update copyright dates with scripts/update-copyrights 2025-01-01 11:22:09 -08:00
tcflush.c Update copyright dates with scripts/update-copyrights 2025-01-01 11:22:09 -08:00
tcgetattr.c Update copyright dates with scripts/update-copyrights 2025-01-01 11:22:09 -08:00
tcgetpgrp.c Update copyright dates with scripts/update-copyrights 2025-01-01 11:22:09 -08:00
tcgetsid.c Update copyright dates with scripts/update-copyrights 2025-01-01 11:22:09 -08:00
tcsendbrk.c Update copyright dates with scripts/update-copyrights 2025-01-01 11:22:09 -08:00
tcsetattr.c termios: make __tcsetattr() the internal interface 2025-06-17 09:11:38 -03:00
tcsetpgrp.c Update copyright dates with scripts/update-copyrights 2025-01-01 11:22:09 -08:00
termios.h termios: SPEED_MAX and BAUD_MAX constants 2025-07-20 17:17:41 +02:00