glibc/sysdeps/powerpc/powerpc64/le/no_ldbl_gnu_attribute.c
Paul E. Murphy 4531ba8ebf powerpc64le: enforce non-specific long double in .gnu.attributes section
We turn off this feature to avoid polluting our shared libary with
a specific value.  However, static libgcc is not under our control,
and has enabled this for ibm128 routines.  This pollutes the
resulting shared libraries with it.

Attach a post-linking hook to replace this section with one crafted
as hard-float + indeterminate ldbl.  This allows IEEE ldbl users to
avoid having to disable the gnu attributes feature which should
protect them from linking ibm ldbl libraries using the gnu attributes
feature.

Currently, this only replaces libc and libm which support both ldbl
formats and rely on application code to explicitly determine which
is to be used.

Strictly speaking, the section could be deleted with minimal lost value.
However correctly set attributes could prove useful for some future change,
and similarly missing attributes.

Reviewed-by: Tulio Magno Quites Machado Filho <tuliom@linux.ibm.com>
2020-04-06 10:23:58 -05:00

31 lines
1.1 KiB
C

/* File to generate desired .gnu.attribute section
Copyright (C) 2020 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library. If not, see
<https://www.gnu.org/licenses/>. */
/* This generates a .gnu.attributes sections with
the default toolchain settings and an indeterminate
long double format. */
long double _not_used;
/* Some older GCC versions need a little more convincing to
generate .gnu.attributes. */
double
foo (double d)
{
return d;
}