diff options
Diffstat (limited to 'include/grub/safemath.h')
| -rw-r--r-- | include/grub/safemath.h | 37 |
1 files changed, 37 insertions, 0 deletions
diff --git a/include/grub/safemath.h b/include/grub/safemath.h new file mode 100644 index 0000000..c17b89b --- /dev/null +++ b/include/grub/safemath.h @@ -0,0 +1,37 @@ +/* + * GRUB -- GRand Unified Bootloader + * Copyright (C) 2020 Free Software Foundation, Inc. + * + * GRUB 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. + * + * GRUB 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 GRUB. If not, see <http://www.gnu.org/licenses/>. + * + * Arithmetic operations that protect against overflow. + */ + +#ifndef GRUB_SAFEMATH_H +#define GRUB_SAFEMATH_H 1 + +#include <grub/compiler.h> + +/* These appear in gcc 5.1 and clang 3.8. */ +#if GNUC_PREREQ(5, 1) || CLANG_PREREQ(3, 8) + +#define grub_add(a, b, res) __builtin_add_overflow(a, b, res) +#define grub_sub(a, b, res) __builtin_sub_overflow(a, b, res) +#define grub_mul(a, b, res) __builtin_mul_overflow(a, b, res) + +#else +#error gcc 5.1 or newer or clang 3.8 or newer is required +#endif + +#endif /* GRUB_SAFEMATH_H */ |