Re: [PATCH] PR libstdc++/60555 std::system_category() should recognise POSIX errno values

[David Edelsohn <dje dot gcc at gmail dot com>]

On Thu, Aug 2, 2018 at 12:12 PM Jonathan Wakely <jwakely@redhat.com> wrote:
>
> On 02/08/18 11:32 -0400, David Edelsohn wrote:
> >Jonathan
> >
> >This patch broke AIX bootstrap.
> >
> >/nasfarm/edelsohn/src/src/libstdc++-v3/src/c++11/system_error.cc: In
> >member function 'virtual std::error_condition
> >{anonymous}::system_error_category::default_error_condition(int)
> >const':
> >/nasfarm/edelsohn/src/src/libstdc++-v3/src/c++11/system_error.cc:245:7:
> >error: duplicate case value
> >       case ENOTEMPTY:
> >       ^~~~
> >/nasfarm/edelsohn/src/src/libstdc++-v3/src/c++11/system_error.cc:136:7:
> >note: previously used here
> >       case EEXIST:
> >       ^~~~
> >
> >AIX errno.h
> >
> >/*
> > * AIX returns EEXIST where 4.3BSD used ENOTEMPTY;
> > * but, the standards insist on unique errno values for each errno.
> > * A unique value is reserved for users that want to code case
> > * statements for systems that return either EEXIST or ENOTEMPTY.
> > */
> >#if defined(_ALL_SOURCE) && !defined(_LINUX_SOURCE_COMPAT)
> >#define ENOTEMPTY       EEXIST  /* Directory not empty */
> >#else   /* not _ALL_SOURCE */
> >#define ENOTEMPTY       87
> >#endif  /* _ALL_SOURCE */
>
> Strange that "linux source compat" is required for POSIX conformance.
>
> >I will add _LINUX_SOURCE_COMPAT and see how bootstrap proceeds. If it
> >works, it also will be required in the backport.
>
> Let's just workaround the maybe-not-unique values instead:
>
> --- a/libstdc++-v3/src/c++11/system_error.cc
> +++ b/libstdc++-v3/src/c++11/system_error.cc
> @@ -241,7 +241,8 @@ namespace
>  #ifdef ENOTDIR
>        case ENOTDIR:
>  #endif
> -#ifdef ENOTEMPTY
> +#if defined ENOTEMPTY && (!defined EEXIST || ENOTEMPTY != EEXIST)
> +      // AIX sometimes uses the same value for EEXIST and ENOTEMPTY
>        case ENOTEMPTY:
>  #endif
>  #ifdef ENOTRECOVERABLE

Whatever you prefer.  _LINUX_SOURCE_COMPAT seems to be working for
bootstrap so far.

Thanks, David