maint/gnulib/lib/xmalloca.h

/* */
   1 /* Safe automatic memory allocation with out of memory checking.
   2    Copyright (C) 2003, 2005, 2007, 2009-2021 Free Software Foundation, Inc.
   3    Written by Bruno Haible <bruno@clisp.org>, 2003.
   4 
   5    This program is free software: you can redistribute it and/or modify
   6    it under the terms of the GNU General Public License as published by
   7    the Free Software Foundation; either version 3 of the License, or
   8    (at your option) any later version.
   9 
  10    This program is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13    GNU General Public License for more details.
  14 
  15    You should have received a copy of the GNU General Public License
  16    along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
  17 
  18 #ifndef _XMALLOCA_H
  19 #define _XMALLOCA_H
  20 
  21 #include "malloca.h"
  22 #include "xalloc.h"
  23 #include "xalloc-oversized.h"
  24 
  25 
  26 #ifdef __cplusplus
  27 extern "C" {
  28 #endif
  29 
  30 
  31 /* xmalloca(N) is a checking safe variant of alloca(N).  It allocates N bytes
  32    of memory allocated on the stack, that must be freed using freea() before
  33    the function returns.  N should not have side effects.
  34    Upon failure, it exits with an error message.  */
  35 #if HAVE_ALLOCA
  36 # define xmalloca(N) \
  37   ((N) < 4032 - (2 * sa_alignment_max - 1)                                   \
  38    ? (void *) (((uintptr_t) (char *) alloca ((N) + 2 * sa_alignment_max - 1) \
  39                 + (2 * sa_alignment_max - 1))                                \
  40                & ~(uintptr_t)(2 * sa_alignment_max - 1))                     \
  41    : xmmalloca (N))
  42 extern void * xmmalloca (size_t n)
  43   _GL_ATTRIBUTE_MALLOC _GL_ATTRIBUTE_DEALLOC (freea, 1)
  44   _GL_ATTRIBUTE_ALLOC_SIZE ((1)) _GL_ATTRIBUTE_RETURNS_NONNULL;
  45 #else
  46 # define xmalloca(N) \
  47   xmalloc (N)
  48 #endif
  49 
  50 /* xnmalloca(N,S) is an overflow-safe variant of xmalloca (N * S).
  51    It allocates an array of N objects, each with S bytes of memory,
  52    on the stack.  S must be positive and N must be nonnegative,
  53    and S and N should not have side effects.
  54    The array must be freed using freea() before the function returns.
  55    Upon failure, it exits with an error message.  */
  56 #if HAVE_ALLOCA
  57 /* Rely on xmalloca (SIZE_MAX) calling xalloc_die ().  */
  58 # define xnmalloca(n, s) \
  59     xmalloca (xalloc_oversized (n, s) ? (size_t) (-1) : (n) * (size_t) (s))
  60 #else
  61 # define xnmalloca(n, s) \
  62     xnmalloc (n, s)
  63 #endif
  64 
  65 
  66 #ifdef __cplusplus
  67 }
  68 #endif
  69 
  70 
  71 #endif /* _XMALLOCA_H */
/* */
root/maint/gnulib/lib/xmalloca.h

INCLUDED FROM
