1  /* Safe automatic memory allocation with out of memory checking.
       2     Copyright (C) 2003, 2005, 2007, 2009-2023 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  /* This file uses _GL_ATTRIBUTE_ALLOC_SIZE, _GL_ATTRIBUTE_DEALLOC,
      22     _GL_ATTRIBUTE_MALLOC, _GL_ATTRIBUTE_RETURNS_NONNULL, HAVE_ALLOCA.  */
      23  #if !_GL_CONFIG_H_INCLUDED
      24   #error "Please include config.h first."
      25  #endif
      26  
      27  #include "malloca.h"
      28  #include "xalloc.h"
      29  #include "xalloc-oversized.h"
      30  
      31  
      32  #ifdef __cplusplus
      33  extern "C" {
      34  #endif
      35  
      36  
      37  /* xmalloca(N) is a checking safe variant of alloca(N).  It allocates N bytes
      38     of memory allocated on the stack, that must be freed using freea() before
      39     the function returns.  N should not have side effects.
      40     Upon failure, it exits with an error message.  */
      41  #if HAVE_ALLOCA
      42  # define xmalloca(N) \
      43    ((N) < 4032 - (2 * sa_alignment_max - 1)                                   \
      44     ? (void *) (((uintptr_t) (char *) alloca ((N) + 2 * sa_alignment_max - 1) \
      45                  + (2 * sa_alignment_max - 1))                                \
      46                 & ~(uintptr_t)(2 * sa_alignment_max - 1))                     \
      47     : xmmalloca (N))
      48  extern void * xmmalloca (size_t n)
      49    _GL_ATTRIBUTE_MALLOC _GL_ATTRIBUTE_DEALLOC (freea, 1)
      50    _GL_ATTRIBUTE_ALLOC_SIZE ((1)) _GL_ATTRIBUTE_RETURNS_NONNULL;
      51  #else
      52  # define xmalloca(N) \
      53    xmalloc (N)
      54  #endif
      55  
      56  /* xnmalloca(N,S) is an overflow-safe variant of xmalloca (N * S).
      57     It allocates an array of N objects, each with S bytes of memory,
      58     on the stack.  S must be positive and N must be nonnegative,
      59     and S and N should not have side effects.
      60     The array must be freed using freea() before the function returns.
      61     Upon failure, it exits with an error message.  */
      62  #if HAVE_ALLOCA
      63  /* Rely on xmalloca (SIZE_MAX) calling xalloc_die ().  */
      64  # define xnmalloca(n, s) \
      65      xmalloca (xalloc_oversized (n, s) ? (size_t) (-1) : (n) * (size_t) (s))
      66  #else
      67  # define xnmalloca(n, s) \
      68      xnmalloc (n, s)
      69  #endif
      70  
      71  
      72  #ifdef __cplusplus
      73  }
      74  #endif
      75  
      76  
      77  #endif /* _XMALLOCA_H */