Re: git: c27a89971805 - main - stdlib.h: add __noexcept to prototypes

On Fri, Feb 2, 2024 at 11:59 AM Konstantin Belousov <kostikbel@gmail.com>
wrote:

> On Fri, Feb 02, 2024 at 11:36:35AM -0700, Warner Losh wrote:
> > On Fri, Feb 2, 2024, 11:28 AM Konstantin Belousov <kostikbel@gmail.com>
> > wrote:
> >
> > > On Fri, Feb 02, 2024 at 06:16:59PM +0000, Warner Losh wrote:
> > > > The branch main has been updated by imp:
> > > >
> > > > URL:
> > >
> https://cgit.FreeBSD.org/src/commit/?id=c27a89971805b176dcfa5a234f2ea6f6109d0a70
> > > >
> > > > commit c27a89971805b176dcfa5a234f2ea6f6109d0a70
> > > > Author:     Lexi Winter <lexi@le-Fay.ORG>
> > > > AuthorDate: 2024-02-02 16:41:40 +0000
> > > > Commit:     Warner Losh <imp@FreeBSD.org>
> > > > CommitDate: 2024-02-02 18:11:17 +0000
> > > >
> > > >     stdlib.h: add __noexcept to prototypes
> > > >
> > > >     The noexcept specifier is required on these functions in C++:
> > > >     _Exit(), atexit(), quick_exit(), at_quick_exit(), abort().
> > > >
> > > >     MFC after:      2 weeks
> > > >
> > > >     Reviewed by: imp
> > > >     Pull Request: https://github.com/freebsd/freebsd-src/pull/1085
> > > > ---
> > > >  include/stdlib.h | 10 +++++-----
> > > >  1 file changed, 5 insertions(+), 5 deletions(-)
> > > >
> > > > diff --git a/include/stdlib.h b/include/stdlib.h
> > > > index ff8991d1fa94..f0687f01e6c7 100644
> > > > --- a/include/stdlib.h
> > > > +++ b/include/stdlib.h
> > > > @@ -84,9 +84,9 @@ extern int __mb_cur_max;
> > > >  extern int ___mb_cur_max(void);
> > > >  #define      MB_CUR_MAX      ((size_t)___mb_cur_max())
> > > >
> > > > -_Noreturn void        abort(void);
> > > > +_Noreturn void        abort(void) __noexcept;
> > > >  int   abs(int) __pure2;
> > > > -int   atexit(void (* _Nonnull)(void));
> > > > +int   atexit(void (* _Nonnull)(void)) __noexcept;
> > > >  double        atof(const char *);
> > > >  int   atoi(const char *);
> > > >  long  atol(const char *);
> > > > @@ -154,7 +154,7 @@ unsigned long long
> > > >        strtoull(const char * __restrict, char ** __restrict, int);
> > > >  #endif /* __LONG_LONG_SUPPORTED */
> > > >
> > > > -_Noreturn void        _Exit(int);
> > > > +_Noreturn void        _Exit(int) __noexcept;
> > > >  #endif /* __ISO_C_VISIBLE >= 1999 */
> > > >
> > > >  /*
> > > > @@ -163,9 +163,9 @@ _Noreturn void     _Exit(int);
> > > >  #if __ISO_C_VISIBLE >= 2011 || __cplusplus >= 201103L
> > > >  void *       aligned_alloc(size_t, size_t) __malloc_like
> > > __alloc_align(1)
> > > >           __alloc_size(2);
> > > > -int  at_quick_exit(void (*)(void));
> > > > +int  at_quick_exit(void (*)(void)) __noexcept;
> > > >  _Noreturn void
> > > > -     quick_exit(int);
> > > > +     quick_exit(int) __noexcept;
> > > This is wrong, libc quick_exit() does not provide such guarantees as
> > > implemented. More, being part of libc it cannot ever guarantee that
> ever
> > > (and call std::terminate if the requirement is violated).
> > >
> > > Making it such would require bringing some C++ ABI into libc which I
> > > object strongly.
> > >
> >
> > So is this just for quick_exit, or all the functions marked?
> Other functions are abort()/_Exit()/atexit(). No functions in this list
> call a user-provided functions, so they cannot raise exceptions.
>
> My objection is only against our quick_exit().
>

OK. I'll back that one out.

Warner