Re: [PATCH v4] Introduce attribute sym

[Fangrui Song <maskray@google.com>]

On Wed, Jul 19, 2023 at 4:12 PM Alexandre Oliva via Gcc-patches
<gcc-patches@gcc.gnu.org> wrote:
>
> On Jul 18, 2023, Richard Biener <richard.guenther@gmail.com> wrote:
>
> > I think the __symver__ attribute does something similar already so
> > maybe use __attribute__((__sym__("foo")))?
>
> Cool, thanks, that will do.  Regstrapped on x86_64-linux-gnu.  Ok to
> install?
>
>
> This patch introduces an attribute to add extra asm names (aliases)
> for a decl when its definition is output.  The main goal is to ease
> interfacing C++ with Ada, as C++ mangled names have to be named, and
> in some cases (e.g. when using stdint.h typedefs in function
> arguments) the symbol names may vary across platforms.
>
> The attribute is usable in C and C++, presumably in all C-family
> languages.  It can be attached to global variables and functions.  In
> C++, it can also be attached to class types, namespace-scoped
> variables and functions, static data members, member functions,
> explicit instantiations and specializations of template functions,
> members and classes.
>
> When applied to constructors or destructor, additional sym aliases
> with _Base and _Del suffixes are defined for variants other than
> complete-object ones.  This changes the assumption that clones always
> carry the same attributes as their abstract declarations, so there is
> now a function to adjust them.

I wonder whether this attribute can be named "alias" without arguments.
alias ("target") is an existing attribute that applies to a
declaration. The new "alias" without arguments can apply to
definitions.

I am just thinking that the semantics of "sym" may confuse users who
are familiar with "alias" :)