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new-op.c
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1 /* Replace operator new/new[], for GDB, the GNU debugger.
2
3 Copyright (C) 2016-2018 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 /* GCC does not understand __has_feature. */
21 #if !defined(__has_feature)
22 # define __has_feature(x) 0
23 #endif
24
25 #if !__has_feature(address_sanitizer) && !defined(__SANITIZE_ADDRESS__)
26 #include "common-defs.h"
27 #include "host-defs.h"
28 #include <new>
29
30 /* Override operator new / operator new[], in order to internal_error
31 on allocation failure and thus query the user for abort/core
32 dump/continue, just like xmalloc does. We don't do this from a
33 new-handler function instead (std::set_new_handler) because we want
34 to catch allocation errors from within global constructors too.
35
36 Skip overriding if building with -fsanitize=address though.
37 Address sanitizer wants to override operator new/delete too in
38 order to detect malloc+delete and new+free mismatches. Our
39 versions would mask out ASan's, with the result of losing that
40 useful mismatch detection.
41
42 Note that C++ implementations could either have their throw
43 versions call the nothrow versions (libstdc++), or the other way
44 around (clang/libc++). For that reason, we replace both throw and
45 nothrow variants and call malloc directly. */
46
47 void *
48 operator new (std::size_t sz)
49 {
50 /* malloc (0) is unpredictable; avoid it. */
51 if (sz == 0)
52 sz = 1;
53
54 void *p = malloc (sz); /* ARI: malloc */
55 if (p == NULL)
56 {
57 /* If the user decides to continue debugging, throw a
58 gdb_quit_bad_alloc exception instead of a regular QUIT
59 gdb_exception. The former extends both std::bad_alloc and a
60 QUIT gdb_exception. This is necessary because operator new
61 can only ever throw std::bad_alloc, or something that extends
62 it. */
63 TRY
64 {
65 malloc_failure (sz);
66 }
67 CATCH (ex, RETURN_MASK_ALL)
68 {
69 do_cleanups (all_cleanups ());
70
71 throw gdb_quit_bad_alloc (ex);
72 }
73 END_CATCH
74 }
75 return p;
76 }
77
78 void *
79 operator new (std::size_t sz, const std::nothrow_t&) noexcept
80 {
81 /* malloc (0) is unpredictable; avoid it. */
82 if (sz == 0)
83 sz = 1;
84 return malloc (sz); /* ARI: malloc */
85 }
86
87 void *
88 operator new[] (std::size_t sz)
89 {
90 return ::operator new (sz);
91 }
92
93 void*
94 operator new[] (std::size_t sz, const std::nothrow_t&) noexcept
95 {
96 return ::operator new (sz, std::nothrow);
97 }
98 #endif
RETURN_MASK_ALL
Definition: common-exceptions.h:44
host-defs.h
END_CATCH
#define END_CATCH
Definition: common-exceptions.h:259
all_cleanups
struct cleanup * all_cleanups(void)
Definition: cleanups.c:165
TRY
#define TRY
Definition: common-exceptions.h:246
CATCH
#define CATCH(EXCEPTION, MASK)
Definition: common-exceptions.h:254
common-defs.h
gdb_quit_bad_alloc
Definition: common-exceptions.h:299
malloc_failure
void malloc_failure(long size) ATTRIBUTE_NORETURN
Definition: utils.c:773
do_cleanups
void do_cleanups(struct cleanup *old_chain)
Definition: cleanups.c:174