aboutsummaryrefslogtreecommitdiff
path: root/gdbsupport/poison.h
blob: 0d0159eb7f8145f27bb277c9f9b795da460bb72c (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
/* Poison symbols at compile time.

   Copyright (C) 2017-2024 Free Software Foundation, Inc.

   This file is part of GDB.

   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 COMMON_POISON_H
#define COMMON_POISON_H

#include "traits.h"
#include "obstack.h"

/* Poison memset of non-POD types.  The idea is catching invalid
   initialization of non-POD structs that is easy to be introduced as
   side effect of refactoring.  For example, say this:

 struct S { VEC(foo_s) *m_data; };

is converted to this at some point:

 struct S {
   S() { m_data.reserve (10); }
   std::vector<foo> m_data;
 };

and old code was initializing S objects like this:

 struct S s;
 memset (&s, 0, sizeof (S)); // whoops, now wipes vector.

Declaring memset as deleted for non-POD types makes the memset above
be a compile-time error.  */

/* Helper for SFINAE.  True if "T *" is memsettable.  I.e., if T is
   either void, or POD.  */
template<typename T>
struct IsMemsettable
  : gdb::Or<std::is_void<T>,
	    gdb::And<std::is_standard_layout<T>, std::is_trivial<T>>>
{};

template <typename T,
	  typename = gdb::Requires<gdb::Not<IsMemsettable<T>>>>
void *memset (T *s, int c, size_t n) = delete;

#if HAVE_IS_TRIVIALLY_COPYABLE

/* Similarly, poison memcpy and memmove of non trivially-copyable
   types, which is undefined.  */

/* True if "T *" is relocatable.  I.e., copyable with memcpy/memmove.
   I.e., T is either trivially copyable, or void.  */
template<typename T>
struct IsRelocatable
  : gdb::Or<std::is_void<T>,
	    std::is_trivially_copyable<T>>
{};

/* True if both source and destination are relocatable.  */

template <typename D, typename S>
using BothAreRelocatable
  = gdb::And<IsRelocatable<D>, IsRelocatable<S>>;

template <typename D, typename S,
	  typename = gdb::Requires<gdb::Not<BothAreRelocatable<D, S>>>>
void *memcpy (D *dest, const S *src, size_t n) = delete;

template <typename D, typename S,
	  typename = gdb::Requires<gdb::Not<BothAreRelocatable<D, S>>>>
void *memmove (D *dest, const S *src, size_t n) = delete;

#endif /* HAVE_IS_TRIVIALLY_COPYABLE */

/* Poison XNEW and friends to catch usages of malloc-style allocations on
   objects that require new/delete.  */

template<typename T>
#if HAVE_IS_TRIVIALLY_CONSTRUCTIBLE
using IsMallocable = std::is_trivially_constructible<T>;
#else
using IsMallocable = std::true_type;
#endif

template<typename T>
using IsFreeable = gdb::Or<std::is_trivially_destructible<T>, std::is_void<T>>;

template <typename T, typename = gdb::Requires<gdb::Not<IsFreeable<T>>>>
void free (T *ptr) = delete;

template<typename T>
static T *
xnew ()
{
  static_assert (IsMallocable<T>::value, "Trying to use XNEW with a non-POD \
data type.  Use operator new instead.");
  return XNEW (T);
}

#undef XNEW
#define XNEW(T) xnew<T>()

template<typename T>
static T *
xcnew ()
{
  static_assert (IsMallocable<T>::value, "Trying to use XCNEW with a non-POD \
data type.  Use operator new instead.");
  return XCNEW (T);
}

#undef XCNEW
#define XCNEW(T) xcnew<T>()

template<typename T>
static void
xdelete (T *p)
{
  static_assert (IsFreeable<T>::value, "Trying to use XDELETE with a non-POD \
data type.  Use operator delete instead.");
  XDELETE (p);
}

#undef XDELETE
#define XDELETE(P) xdelete (P)

template<typename T>
static T *
xnewvec (size_t n)
{
  static_assert (IsMallocable<T>::value, "Trying to use XNEWVEC with a \
non-POD data type.  Use operator new[] (or std::vector) instead.");
  return XNEWVEC (T, n);
}

#undef XNEWVEC
#define XNEWVEC(T, N) xnewvec<T> (N)

template<typename T>
static T *
xcnewvec (size_t n)
{
  static_assert (IsMallocable<T>::value, "Trying to use XCNEWVEC with a \
non-POD data type.  Use operator new[] (or std::vector) instead.");
  return XCNEWVEC (T, n);
}

#undef XCNEWVEC
#define XCNEWVEC(T, N) xcnewvec<T> (N)

template<typename T>
static T *
xresizevec (T *p, size_t n)
{
  static_assert (IsMallocable<T>::value, "Trying to use XRESIZEVEC with a \
non-POD data type.");
  return XRESIZEVEC (T, p, n);
}

#undef XRESIZEVEC
#define XRESIZEVEC(T, P, N) xresizevec<T> (P, N)

template<typename T>
static void
xdeletevec (T *p)
{
  static_assert (IsFreeable<T>::value, "Trying to use XDELETEVEC with a \
non-POD data type.  Use operator delete[] (or std::vector) instead.");
  XDELETEVEC (p);
}

#undef XDELETEVEC
#define XDELETEVEC(P) xdeletevec (P)

template<typename T>
static T *
xnewvar (size_t s)
{
  static_assert (IsMallocable<T>::value, "Trying to use XNEWVAR with a \
non-POD data type.");
  return XNEWVAR (T, s);;
}

#undef XNEWVAR
#define XNEWVAR(T, S) xnewvar<T> (S)

template<typename T>
static T *
xcnewvar (size_t s)
{
  static_assert (IsMallocable<T>::value, "Trying to use XCNEWVAR with a \
non-POD data type.");
  return XCNEWVAR (T, s);
}

#undef XCNEWVAR
#define XCNEWVAR(T, S) xcnewvar<T> (S)

template<typename T>
static T *
xresizevar (T *p, size_t s)
{
  static_assert (IsMallocable<T>::value, "Trying to use XRESIZEVAR with a \
non-POD data type.");
  return XRESIZEVAR (T, p, s);
}

#undef XRESIZEVAR
#define XRESIZEVAR(T, P, S) xresizevar<T> (P, S)

template<typename T>
static T *
xobnew (obstack *ob)
{
  static_assert (IsMallocable<T>::value, "Trying to use XOBNEW with a \
non-POD data type.");
  return XOBNEW (ob, T);
}

#undef XOBNEW
#define XOBNEW(O, T) xobnew<T> (O)

template<typename T>
static T *
xobnewvec (obstack *ob, size_t n)
{
  static_assert (IsMallocable<T>::value, "Trying to use XOBNEWVEC with a \
non-POD data type.");
  return XOBNEWVEC (ob, T, n);
}

#undef XOBNEWVEC
#define XOBNEWVEC(O, T, N) xobnewvec<T> (O, N)

#endif /* COMMON_POISON_H */