1/* Obstack wrapper for GDB.
2
3   Copyright (C) 2002-2020 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#if !defined (GDB_OBSTACK_H)
21#define GDB_OBSTACK_H 1
22
23#include "obstack.h"
24
25/* Utility macros - wrap obstack alloc into something more robust.  */
26
27template <typename T>
28static inline T*
29obstack_zalloc (struct obstack *ob)
30{
31  static_assert (IsMallocable<T>::value, "Trying to use OBSTACK_ZALLOC with a \
32non-POD data type.  Use obstack_new instead.");
33  return ((T *) memset (obstack_alloc (ob, sizeof (T)), 0, sizeof (T)));
34}
35
36#define OBSTACK_ZALLOC(OBSTACK,TYPE) obstack_zalloc<TYPE> ((OBSTACK))
37
38template <typename T>
39static inline T *
40obstack_calloc (struct obstack *ob, size_t number)
41{
42  static_assert (IsMallocable<T>::value, "Trying to use OBSTACK_CALLOC with a \
43non-POD data type.  Use obstack_new instead.");
44  return ((T *) memset (obstack_alloc (ob, number * sizeof (T)), 0,
45			number * sizeof (T)));
46}
47
48#define OBSTACK_CALLOC(OBSTACK,NUMBER,TYPE) \
49  obstack_calloc<TYPE> ((OBSTACK), (NUMBER))
50
51/* Allocate an object on OB and call its constructor.  */
52
53template <typename T, typename... Args>
54static inline T*
55obstack_new (struct obstack *ob, Args&&... args)
56{
57  T* object = (T *) obstack_alloc (ob, sizeof (T));
58  object = new (object) T (std::forward<Args> (args)...);
59  return object;
60}
61
62/* Unless explicitly specified, GDB obstacks always use xmalloc() and
63   xfree().  */
64/* Note: ezannoni 2004-02-09: One could also specify the allocation
65   functions using a special init function for each obstack,
66   obstack_specify_allocation.  However we just use obstack_init and
67   let these defines here do the job.  While one could argue the
68   superiority of one approach over the other, we just chose one
69   throughout.  */
70
71#define obstack_chunk_alloc xmalloc
72#define obstack_chunk_free xfree
73
74#define obstack_grow_str(OBSTACK,STRING) \
75  obstack_grow (OBSTACK, STRING, strlen (STRING))
76#define obstack_grow_str0(OBSTACK,STRING) \
77  obstack_grow0 (OBSTACK, STRING, strlen (STRING))
78
79#define obstack_grow_wstr(OBSTACK, WSTRING) \
80  obstack_grow (OBSTACK, WSTRING, sizeof (gdb_wchar_t) * gdb_wcslen (WSTRING))
81
82/* Concatenate NULL terminated variable argument list of `const char
83   *' strings; return the new string.  Space is found in the OBSTACKP.
84   Argument list must be terminated by a sentinel expression `(char *)
85   NULL'.  */
86
87extern char *obconcat (struct obstack *obstackp, ...) ATTRIBUTE_SENTINEL;
88
89/* Duplicate STRING, returning an equivalent string that's allocated on the
90   obstack OBSTACKP.  */
91
92static inline char *
93obstack_strdup (struct obstack *obstackp, const char *string)
94{
95  return (char *) obstack_copy0 (obstackp, string, strlen (string));
96}
97
98/* Duplicate STRING, returning an equivalent string that's allocated on the
99   obstack OBSTACKP.  */
100
101static inline char *
102obstack_strdup (struct obstack *obstackp, const std::string &string)
103{
104  return (char *) obstack_copy0 (obstackp, string.c_str (),
105				 string.size ());
106}
107
108/* Duplicate the first N characters of STRING, returning a
109   \0-terminated string that's allocated on the obstack OBSTACKP.
110   Note that exactly N characters are copied, even if STRING is
111   shorter.  */
112
113static inline char *
114obstack_strndup (struct obstack *obstackp, const char *string, size_t n)
115{
116  return (char *) obstack_copy0 (obstackp, string, n);
117}
118
119/* An obstack that frees itself on scope exit.  */
120struct auto_obstack : obstack
121{
122  auto_obstack ()
123  { obstack_init (this); }
124
125  ~auto_obstack ()
126  { obstack_free (this, NULL); }
127
128  DISABLE_COPY_AND_ASSIGN (auto_obstack);
129
130  /* Free all memory in the obstack but leave it valid for further
131     allocation.  */
132  void clear ()
133  { obstack_free (this, obstack_base (this)); }
134};
135
136/* Objects are allocated on obstack instead of heap.  */
137
138struct allocate_on_obstack
139{
140  allocate_on_obstack () = default;
141
142  void* operator new (size_t size, struct obstack *obstack)
143  {
144    return obstack_alloc (obstack, size);
145  }
146
147  void* operator new[] (size_t size, struct obstack *obstack)
148  {
149    return obstack_alloc (obstack, size);
150  }
151
152  void operator delete (void *memory) {}
153  void operator delete[] (void *memory) {}
154};
155
156#endif
157