This is the mail archive of the mailing list for the GCC project.

Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

Re: [PATCH] libstdc++-v3: Have aligned_alloc() on Newlib

On 08/08/18 13:18, Jonathan Wakely wrote:
On 08/08/18 10:52 +0200, Sebastian Huber wrote:
While building for Newlib, some configure checks must be hard coded.
The aligned_alloc() is supported since 2015 in Newlib.


    PR target/85904
    * Define HAVE_ALIGNED_ALLOC if building for

There's a stray closing parenthesis here.

    * configure: Regnerate.

Typo "Regnerate".

But the patch itself is fine - OK for trunk.

Oh, sorry, for all the typos.

I'm ambivalent about this being backported to gcc-7 and gcc-8 branches
(gcc-6 is unaffected as it doesn't use aligned_alloc).

It's strictly speaking an ABI change, because HAVE_ALIGNED_ALLOC
affects the memory layout for allocations from operator new(size_t,
align_val_t) (in which needs to agree with the
corresponding operator delete (in Using static linking it
might be possible to create a binary that has operator new using
aligned_alloc, but operator delete expecting to do ((void**)ptr)[-1],
which would be bad.

Those operators are C++17, so "experimental", but maybe we shouldn't
make the change on release branches.

I was able to build a GCC 7.3.0 compiler, but now the build fails on the GCC 7 branch.

Sebastian Huber, embedded brains GmbH

Address : Dornierstr. 4, D-82178 Puchheim, Germany
Phone   : +49 89 189 47 41-16
Fax     : +49 89 189 47 41-09
E-Mail  :
PGP     : Public key available on request.

Diese Nachricht ist keine geschäftliche Mitteilung im Sinne des EHUG.

Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]