| /* xalloc-oversized.h -- memory allocation size checking |

| |

| Copyright (C) 1990-2000, 2003-2004, 2006-2012 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 a 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_ */ |