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af63ba4b JM |
1 | // Support routines for the -*- C++ -*- dynamic memory management. |
2 | ||
a5544970 | 3 | // Copyright (C) 1997-2019 Free Software Foundation, Inc. |
af63ba4b JM |
4 | // |
5 | // This file is part of GCC. | |
6 | // | |
7 | // GCC 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, or (at your option) | |
10 | // any later version. | |
11 | // | |
12 | // GCC 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 | // Under Section 7 of GPL version 3, you are granted additional | |
18 | // permissions described in the GCC Runtime Library Exception, version | |
19 | // 3.1, as published by the Free Software Foundation. | |
20 | ||
21 | // You should have received a copy of the GNU General Public License and | |
22 | // a copy of the GCC Runtime Library Exception along with this program; | |
23 | // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see | |
24 | // <http://www.gnu.org/licenses/>. | |
25 | ||
26 | #include <bits/c++config.h> | |
27 | #include <stdlib.h> | |
a8019919 | 28 | #include <stdint.h> |
af63ba4b | 29 | #include <bits/exception_defines.h> |
2383ed02 | 30 | #include <bit> |
af63ba4b JM |
31 | #include "new" |
32 | ||
a8019919 JW |
33 | #if !_GLIBCXX_HAVE_ALIGNED_ALLOC && !_GLIBCXX_HAVE__ALIGNED_MALLOC \ |
34 | && !_GLIBCXX_HAVE_POSIX_MEMALIGN && _GLIBCXX_HAVE_MEMALIGN | |
35 | # if _GLIBCXX_HOSTED && __has_include(<malloc.h>) | |
36 | // Some C libraries declare memalign in <malloc.h> | |
37 | # include <malloc.h> | |
38 | # else | |
39 | extern "C" void *memalign(std::size_t boundary, std::size_t size); | |
40 | # endif | |
41 | #endif | |
42 | ||
af63ba4b JM |
43 | using std::new_handler; |
44 | using std::bad_alloc; | |
45 | ||
a8019919 JW |
46 | namespace __gnu_cxx { |
47 | #if _GLIBCXX_HAVE_ALIGNED_ALLOC | |
48 | using ::aligned_alloc; | |
49 | #elif _GLIBCXX_HAVE__ALIGNED_MALLOC | |
50 | static inline void* | |
51 | aligned_alloc (std::size_t al, std::size_t sz) | |
52 | { return _aligned_malloc(sz, al); } | |
af63ba4b JM |
53 | #elif _GLIBCXX_HAVE_POSIX_MEMALIGN |
54 | static inline void* | |
55 | aligned_alloc (std::size_t al, std::size_t sz) | |
56 | { | |
57 | void *ptr; | |
1d1b7328 | 58 | // posix_memalign has additional requirement, not present on aligned_alloc: |
426042f5 JW |
59 | // The value of alignment shall be a power of two multiple of sizeof(void *). |
60 | if (al < sizeof(void*)) | |
61 | al = sizeof(void*); | |
af63ba4b JM |
62 | int ret = posix_memalign (&ptr, al, sz); |
63 | if (ret == 0) | |
64 | return ptr; | |
65 | return nullptr; | |
66 | } | |
67 | #elif _GLIBCXX_HAVE_MEMALIGN | |
1d1b7328 JW |
68 | static inline void* |
69 | aligned_alloc (std::size_t al, std::size_t sz) | |
70 | { | |
71 | #ifdef __sun | |
72 | // Solaris 10 memalign requires that alignment is greater than or equal to | |
73 | // the size of a word. | |
74 | if (al < sizeof(int)) | |
75 | al = sizeof(int); | |
76 | #endif | |
77 | return memalign (al, sz); | |
78 | } | |
79 | #else // !HAVE__ALIGNED_MALLOC && !HAVE_POSIX_MEMALIGN && !HAVE_MEMALIGN | |
bc9efeab JW |
80 | // The C library doesn't provide any aligned allocation functions, define one. |
81 | // This is a modified version of code from gcc/config/i386/gmm_malloc.h | |
82 | static inline void* | |
83 | aligned_alloc (std::size_t al, std::size_t sz) | |
84 | { | |
bc9efeab JW |
85 | // We need extra bytes to store the original value returned by malloc. |
86 | if (al < sizeof(void*)) | |
87 | al = sizeof(void*); | |
88 | void* const malloc_ptr = malloc(sz + al); | |
89 | if (!malloc_ptr) | |
90 | return nullptr; | |
91 | // Align to the requested value, leaving room for the original malloc value. | |
92 | void* const aligned_ptr = (void *) (((uintptr_t) malloc_ptr + al) & -al); | |
93 | ||
94 | // Store the original malloc value where it can be found by operator delete. | |
95 | ((void **) aligned_ptr)[-1] = malloc_ptr; | |
96 | ||
97 | return aligned_ptr; | |
98 | } | |
af63ba4b | 99 | #endif |
a8019919 | 100 | } // namespace __gnu_cxx |
af63ba4b JM |
101 | |
102 | _GLIBCXX_WEAK_DEFINITION void * | |
103 | operator new (std::size_t sz, std::align_val_t al) | |
104 | { | |
426042f5 | 105 | std::size_t align = (std::size_t)al; |
af63ba4b | 106 | |
1d1b7328 JW |
107 | /* Alignment must be a power of two. */ |
108 | /* XXX This should be checked by the compiler (PR 86878). */ | |
2383ed02 | 109 | if (__builtin_expect (!std::__ispow2(align), false)) |
1d1b7328 JW |
110 | _GLIBCXX_THROW_OR_ABORT(bad_alloc()); |
111 | ||
af63ba4b | 112 | /* malloc (0) is unpredictable; avoid it. */ |
1d1b7328 | 113 | if (__builtin_expect (sz == 0, false)) |
af63ba4b JM |
114 | sz = 1; |
115 | ||
426042f5 | 116 | #if _GLIBCXX_HAVE_ALIGNED_ALLOC |
1b3b888d JW |
117 | # ifdef _AIX |
118 | /* AIX 7.2.0.0 aligned_alloc incorrectly has posix_memalign's requirement | |
119 | * that alignment is a multiple of sizeof(void*). */ | |
120 | if (align < sizeof(void*)) | |
121 | align = sizeof(void*); | |
122 | # endif | |
426042f5 | 123 | /* C11: the value of size shall be an integral multiple of alignment. */ |
2383ed02 | 124 | sz = (sz + align - 1) & ~(align - 1); |
426042f5 JW |
125 | #endif |
126 | ||
b66e5a95 JW |
127 | void *p; |
128 | ||
129 | while ((p = __gnu_cxx::aligned_alloc (align, sz)) == nullptr) | |
af63ba4b JM |
130 | { |
131 | new_handler handler = std::get_new_handler (); | |
132 | if (! handler) | |
133 | _GLIBCXX_THROW_OR_ABORT(bad_alloc()); | |
134 | handler (); | |
135 | } | |
136 | ||
137 | return p; | |
138 | } |