kc3-lang/gnulib/lib/xalloc-oversized.h

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• Hash : bf18c9b4
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  Date : 2011-04-27T15:54:30
  

  xalloc-oversized: new module
  
  Due to inline functions, mere inclusion of xalloc.h can result
  in a link dependency on xalloc_die() on some platforms.  However,
  there are several modules that want to use just xalloc_oversized
  in order to short-circuit the potential to call xalloc_die.
  Splitting the macro into a new header and module makes this easy.
  
  * modules/xalloc-oversized: New module.
  * modules/xalloc (Depends-on): Add it.
  * lib/xalloc.h (xalloc_oversized): Move...
  * lib/xalloc-oversized.h: ...into new file.
  
  Signed-off-by: Eric Blake <eblake@redhat.com>
  

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• lib/xalloc-oversized.h

• /* xalloc-oversized.h -- memory allocation size checking
  
     Copyright (C) 1990-2000, 2003-2004, 2006-2011 Free Software Foundation, Inc.
  
     This program is free software: you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
     the Free Software Foundation; either version 3 of the License, or
     (at your option) any later version.
  
     This program 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 General Public License for more details.
  
     You should have received a copy of the GNU General Public License
     along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  
  #ifndef XALLOC_OVERSIZED_H_
  # define XALLOC_OVERSIZED_H_
  
  # include <stddef.h>
  
  /* Return 1 if an array of N objects, each of size S, cannot exist due
     to size arithmetic overflow.  S must be positive and N must be
     nonnegative.  This is a macro, not an inline function, so that it
     works correctly even when SIZE_MAX < N.
  
     By gnulib convention, SIZE_MAX represents overflow in size
     calculations, so the conservative dividend to use here is
     SIZE_MAX - 1, since SIZE_MAX might represent an overflowed value.
     However, malloc (SIZE_MAX) fails on all known hosts where
     sizeof (ptrdiff_t) <= sizeof (size_t), so do not bother to test for
     exactly-SIZE_MAX allocations on such hosts; this avoids a test and
     branch when S is known to be 1.  */
  # define xalloc_oversized(n, s) \
      ((size_t) (sizeof (ptrdiff_t) <= sizeof (size_t) ? -1 : -2) / (s) < (n))
  
  #endif /* !XALLOC_OVERSIZED_H_ */
  

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