[PATCH 01/13] ldbl-128ibm-compat: PLT redirects for using ldbl redirects internally

[Paul E Murphy]

Ping?

On 3/6/20 2:37 PM, Paul E. Murphy wrote:
> Tweak the PLT bypass magic when building glibc with long double
> redirects.  This is made more difficult by the fact we only get
> one chance to redirect functions.  This happens via the public
> headers.
> 
> There are roughly three classes of redirect we need to attend to
> today:
> 
>   1. Simple redirects, redirected via cdef macro overrides and
>      and new libc_hidden_ldbl_proto macro.
>   2. Internal usage of internal API, e.g __snprintf, which has
>      no direct analogue.  This is bypassed directly on case-by-
>      case basis.
>   3. Double redirects, e.g sscanf and related.  These require
>      a heavier handed approach of macro renaming to existing
>      symbols.
> 
> Most simple redirects are handled via 1.  Ideally, the libc_*
> macro would live in libc-symbols.h, but in practice the macros
> needed for it to do anything useful live in cdefs.h, so they
> are defined in the local override.
> 
> Notably, the internal name of the asprintf generated for ieee ldbl
> redirects is renamed to work with internal prefixed usage.
> 
> This resolves the local plt usage introduced when building glibc
> with ldbl == ieee128 on ppc64le.
> ---
>   include/err.h                                 | 12 ++---
>   include/libc-symbols.h                        |  2 +
>   include/stdio.h                               | 52 +++++++++++++------
>   include/sys/cdefs.h                           | 20 +++++++
>   include/sys/syslog.h                          |  2 +-
>   include/wchar.h                               |  2 +-
>   .../ldbl-128ibm-compat/ieee128-asprintf.c     |  5 +-
>   .../ldbl-128ibm-compat/ieee128-dprintf.c      |  1 +
>   .../ieee754/ldbl-128ibm-compat/ieee128-err.c  |  7 +++
>   .../ldbl-128ibm-compat/ieee128-fprintf.c      |  1 +
>   .../ieee128-isoc99_sscanf.c                   |  1 +
>   .../ieee128-isoc99_vfscanf.c                  |  2 +
>   .../ieee128-isoc99_vsscanf.c                  |  1 +
>   .../ldbl-128ibm-compat/ieee128-sprintf.c      |  1 +
>   .../ldbl-128ibm-compat/ieee128-syslog.c       |  1 +
>   .../ldbl-128ibm-compat/ieee128-vfprintf.c     |  1 +
>   .../ldbl-128ibm/include/bits/iscanonical.h    |  2 +-
>   17 files changed, 87 insertions(+), 26 deletions(-)