The original implementation had multiple issues:
- Only worked when posix_memalign was available (Linux, RTEMS).
- Violated C11 link namespace rules by calling posix_memalign.
- Failed to set errno on error.
These can be fixed by essentially using the same implementation
for aligned_alloc as for memalign, i.e. simply calling _memalign_r
(which is always available and a "more reserved name" although
technically still not in the reserved link namespace, at least
code written in c cannot define a colliding symbol, newlib has
plenty such namespace issues so this is fine).
It is not clear what the right policy is when MALLOC_PROVIDED is set,
currently that does not cover aligned_alloc so it is kept that way.
Tested on aarch64-none-elf
aligned_alloc() is implemented in terms of posix_memalign() which is
only declared in <stdlib.h> but not defined in Newlib in general. At
least Linux and RTEMS implement this function.
newlib/ChangeLog
2015-10-14 Sebastian Huber <sebastian.huber@embedded-brains.de>
* libc/stdlib/Makefile.am (GENERAL_SOURCES): Add
alloc_aligned.c.c.
* libc/stdlib/Makefile.in: Regenerate.
* libc/stdlib/aligned_alloc.c: New.
Szabolcs Nagy
Sebastian Huber