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  #else
      44  # define xmalloca(N) \
      45    xmalloc (N)
      46  #endif
      47  
      48  /* xnmalloca(N,S) is an overflow-safe variant of xmalloca (N * S).
      49     It allocates an array of N objects, each with S bytes of memory,
      50     on the stack.  S must be positive and N must be nonnegative,
      51     and S and N should not have side effects.
      52     The array must be freed using freea() before the function returns.
      53     Upon failure, it exits with an error message.  */
      54  #if HAVE_ALLOCA
      55  /* Rely on xmalloca (SIZE_MAX) calling xalloc_die ().  */
      56  # define xnmalloca(n, s) \
      57      xmalloca (xalloc_oversized (n, s) ? (size_t) (-1) : (n) * (size_t) (s))
      58  #else
      59  # define xnmalloca(n, s) \
      60      xnmalloc (n, s)
      61  #endif
      62  
      63  
      64  #ifdef __cplusplus
      65  }
      66  #endif
      67  
      68  
      69  #endif /* _XMALLOCA_H */