kc3-lang/gnulib/doc/posix-functions/aligned_alloc.texi

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• Hash : 69822de4
  Author :
  Date : 2022-01-27T11:36:00
  

  alignalloc: work around AddressSanitizer bug
  
  * doc/posix-functions/aligned_alloc.texi (aligned_alloc):
  Mention AddressSanitizer bug.
  * lib/alignalloc.h (ALIGNALLOC_VIA_ALIGNED_ALLOC):
  Define to 0 if AddressSanitizer is in use.
  * tests/test-alignalloc.c (test_alignalloc): New function,
  which tests for non-aligned sizes too.
  (main): Use it.  Don’t bother checking for alignments
  greater than 16 MiB, as this flummoxes AddressSanitizer
  and there seems little point to testing them.
  

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• doc/posix-functions/aligned_alloc.texi

• @node aligned_alloc
  @section @code{aligned_alloc}
  @findex aligned_alloc
  
  Documentation:@* @uref{https://www.kernel.org/doc/man-pages/online/pages/man3/aligned_alloc.3.html,,man aligned_alloc}
  
  Gnulib module: aligned_alloc
  
  Portability problems fixed by Gnulib:
  @itemize
  @item
  This function fails if the alignment argument is smaller than
  @code{sizeof (void *)} on some platforms:
  macOS 11.1, AIX 7.2.
  @end itemize
  
  Portability problems not fixed by Gnulib:
  @itemize
  @item
  On some platforms, @code{aligned_alloc} crashes if the requested size is
  not a multiple of the alignment:
  AddressSanitizer (gcc 11.2 or clang 13).
  
  @item
  This function is missing on many older platforms:
  glibc 2.15, macOS 10.13, FreeBSD 6.4, NetBSD 7.1, OpenBSD 6.0, Minix 3.1.8, AIX 7.1, HP-UX 11.31, IRIX 6.5, Solaris 11.3, Cygwin 1.7.x, mingw, MSVC 14, Android 8.1.
  @end itemize
  
  Gnulib has partial substitutes for @code{aligned_alloc}
  that do not crash even if the AddressSanitizer bug is present:
  
  @itemize
  @item
  The Gnulib module @code{alignalloc} provides a portable function
  @code{alignalloc} that is a near-substitute for for glibc
  @code{aligned_alloc}, except that the result must be freed
  with @code{alignfree} rather than plain @code{free}.
  
  @item
  The Gnulib module @code{aligned-malloc} provides functions for
  allocating and freeing blocks of suitably aligned memory.
  
  @item
  The Gnulib module @code{pagealign_alloc} provides a similar API for
  allocating and freeing blocks of memory aligned on a system page boundary.
  @end itemize
  

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