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Diffstat (limited to 'tests/xalloc-oversized.h')
-rw-r--r-- | tests/xalloc-oversized.h | 38 |
1 files changed, 38 insertions, 0 deletions
diff --git a/tests/xalloc-oversized.h b/tests/xalloc-oversized.h new file mode 100644 index 0000000..f0e9778 --- /dev/null +++ b/tests/xalloc-oversized.h @@ -0,0 +1,38 @@ +/* xalloc-oversized.h -- memory allocation size checking + + Copyright (C) 1990-2000, 2003-2004, 2006-2015 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_ */ |