projects / deliverable / binutils-gdb.git / blame
| Commit | Line | Data |
|---|---|---|
| b0b92aeb PA |
1 | /* Poison symbols at compile time. |
| 2 | ||
| 3 | Copyright (C) 2017 Free Software Foundation, Inc. | |
| 4 | ||
| 5 | This file is part of GDB. | |
| 6 | ||
| 7 | This program is free software; you can redistribute it and/or modify | |
| 8 | it under the terms of the GNU General Public License as published by | |
| 9 | the Free Software Foundation; either version 3 of the License, or | |
| 10 | (at your option) any later version. | |
| 11 | ||
| 12 | This program is distributed in the hope that it will be useful, | |
| 13 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
| 14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
| 15 | GNU General Public License for more details. | |
| 16 | ||
| 17 | You should have received a copy of the GNU General Public License | |
| 18 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ | |
| 19 | ||
| 20 | #ifndef COMMON_POISON_H | |
| 21 | #define COMMON_POISON_H | |
| 22 | ||
| 23 | #include "traits.h" | |
| 24 | ||
| 25 | /* Poison memset of non-POD types. The idea is catching invalid | |
| 26 | initialization of non-POD structs that is easy to be introduced as | |
| 27 | side effect of refactoring. For example, say this: | |
| 28 | ||
| 29 | struct S { VEC(foo_s) *m_data; }; | |
| 30 | ||
| 31 | is converted to this at some point: | |
| 32 | ||
| 33 | struct S { | |
| 34 | S() { m_data.reserve (10); } | |
| 35 | std::vector<foo> m_data; | |
| 36 | }; | |
| 37 | ||
| 38 | and old code was initializing S objects like this: | |
| 39 | ||
| 40 | struct S s; | |
| 41 | memset (&s, 0, sizeof (S)); // whoops, now wipes vector. | |
| 42 | ||
| 43 | Declaring memset as deleted for non-POD types makes the memset above | |
| 44 | be a compile-time error. */ | |
| 45 | ||
| 46 | /* Helper for SFINAE. True if "T *" is memsettable. I.e., if T is | |
| 47 | either void, or POD. */ | |
| 48 | template<typename T> | |
| 49 | struct IsMemsettable | |
| 50 | : gdb::Or<std::is_void<T>, | |
| 51 | std::is_pod<T>> | |
| 52 | {}; | |
| 53 | ||
| 54 | template <typename T, | |
| 55 | typename = gdb::Requires<gdb::Not<IsMemsettable<T>>>> | |
| 56 | void *memset (T *s, int c, size_t n) = delete; | |
| 57 | ||
| 58 | /* Similarly, poison memcpy and memmove of non trivially-copyable | |
| 59 | types, which is undefined. */ | |
| 60 | ||
| 61 | /* True if "T *" is relocatable. I.e., copyable with memcpy/memmove. | |
| 62 | I.e., T is either trivially copyable, or void. */ | |
| 63 | template<typename T> | |
| 64 | struct IsRelocatable | |
| 65 | : gdb::Or<std::is_void<T>, | |
| 66 | std::is_trivially_copyable<T>> | |
| 67 | {}; | |
| 68 | ||
| 69 | /* True if both source and destination are relocatable. */ | |
| 70 | ||
| 71 | template <typename D, typename S> | |
| 72 | using BothAreRelocatable | |
| 73 | = gdb::And<IsRelocatable<D>, IsRelocatable<S>>; | |
| 74 | ||
| 75 | template <typename D, typename S, | |
| 76 | typename = gdb::Requires<gdb::Not<BothAreRelocatable<D, S>>>> | |
| 77 | void *memcpy (D *dest, const S *src, size_t n) = delete; | |
| 78 | ||
| 79 | template <typename D, typename S, | |
| 80 | typename = gdb::Requires<gdb::Not<BothAreRelocatable<D, S>>>> | |
| 81 | void *memmove (D *dest, const S *src, size_t n) = delete; | |
| 82 | ||
| 83 | #endif /* COMMON_POISON_H */ |