Separate Simple Backend creation from initialization.
[chromium-blink-merge.git] / third_party / tcmalloc / chromium / src / libc_override_glibc.h
blob7cdbe976339e16a2974afa6b6d0866cbb3ae9fe8
1 // Copyright (c) 2011, Google Inc.
2 // All rights reserved.
3 //
4 // Redistribution and use in source and binary forms, with or without
5 // modification, are permitted provided that the following conditions are
6 // met:
7 //
8 // * Redistributions of source code must retain the above copyright
9 // notice, this list of conditions and the following disclaimer.
10 // * Redistributions in binary form must reproduce the above
11 // copyright notice, this list of conditions and the following disclaimer
12 // in the documentation and/or other materials provided with the
13 // distribution.
14 // * Neither the name of Google Inc. nor the names of its
15 // contributors may be used to endorse or promote products derived from
16 // this software without specific prior written permission.
18 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
19 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
20 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
21 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
22 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
23 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
24 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
28 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30 // ---
31 // Author: Craig Silverstein <opensource@google.com>
33 // Used to override malloc routines on systems that are using glibc.
35 #ifndef TCMALLOC_LIBC_OVERRIDE_GLIBC_INL_H_
36 #define TCMALLOC_LIBC_OVERRIDE_GLIBC_INL_H_
38 // MALLOC_HOOK_MAYBE_VOLATILE is defined at config.h in the original gperftools.
39 // Chromium does this check with the macro __MALLOC_HOOK_VOLATILE.
40 // GLibc 2.14+ requires the hook functions be declared volatile, based on the
41 // value of the define __MALLOC_HOOK_VOLATILE. For compatibility with
42 // older/non-GLibc implementations, provide an empty definition.
43 #if !defined(__MALLOC_HOOK_VOLATILE)
44 #define MALLOC_HOOK_MAYBE_VOLATILE /**/
45 #else
46 #define MALLOC_HOOK_MAYBE_VOLATILE __MALLOC_HOOK_VOLATILE
47 #endif
49 #include <config.h>
50 #include <features.h> // for __GLIBC__
51 #ifdef HAVE_SYS_CDEFS_H
52 #include <sys/cdefs.h> // for __THROW
53 #endif
54 #include <gperftools/tcmalloc.h>
56 #ifndef __GLIBC__
57 # error libc_override_glibc.h is for glibc distributions only.
58 #endif
60 // In glibc, the memory-allocation methods are weak symbols, so we can
61 // just override them with our own. If we're using gcc, we can use
62 // __attribute__((alias)) to do the overriding easily (exception:
63 // Mach-O, which doesn't support aliases). Otherwise we have to use a
64 // function call.
65 #if !defined(__GNUC__) || defined(__MACH__)
67 // This also defines ReplaceSystemAlloc().
68 # include "libc_override_redefine.h" // defines functions malloc()/etc
70 #else // #if !defined(__GNUC__) || defined(__MACH__)
72 // If we get here, we're a gcc system, so do all the overriding we do
73 // with gcc. This does the overriding of all the 'normal' memory
74 // allocation. This also defines ReplaceSystemAlloc().
75 # include "libc_override_gcc_and_weak.h"
77 // We also have to do some glibc-specific overriding. Some library
78 // routines on RedHat 9 allocate memory using malloc() and free it
79 // using __libc_free() (or vice-versa). Since we provide our own
80 // implementations of malloc/free, we need to make sure that the
81 // __libc_XXX variants (defined as part of glibc) also point to the
82 // same implementations. Since it only matters for redhat, we
83 // do it inside the gcc #ifdef, since redhat uses gcc.
84 // TODO(csilvers): only do this if we detect we're an old enough glibc?
86 #define ALIAS(tc_fn) __attribute__ ((alias (#tc_fn)))
87 extern "C" {
88 void* __libc_malloc(size_t size) ALIAS(tc_malloc);
89 void __libc_free(void* ptr) ALIAS(tc_free);
90 void* __libc_realloc(void* ptr, size_t size) ALIAS(tc_realloc);
91 void* __libc_calloc(size_t n, size_t size) ALIAS(tc_calloc);
92 void __libc_cfree(void* ptr) ALIAS(tc_cfree);
93 void* __libc_memalign(size_t align, size_t s) ALIAS(tc_memalign);
94 void* __libc_valloc(size_t size) ALIAS(tc_valloc);
95 void* __libc_pvalloc(size_t size) ALIAS(tc_pvalloc);
96 int __posix_memalign(void** r, size_t a, size_t s) ALIAS(tc_posix_memalign);
97 } // extern "C"
98 #undef ALIAS
100 #endif // #if defined(__GNUC__) && !defined(__MACH__)
103 // We also have to hook libc malloc. While our work with weak symbols
104 // should make sure libc malloc is never called in most situations, it
105 // can be worked around by shared libraries with the DEEPBIND
106 // environment variable set. The below hooks libc to call our malloc
107 // routines even in that situation. In other situations, this hook
108 // should never be called.
109 extern "C" {
110 static void* glibc_override_malloc(size_t size, const void *caller) {
111 return tc_malloc(size);
113 static void* glibc_override_realloc(void *ptr, size_t size,
114 const void *caller) {
115 return tc_realloc(ptr, size);
117 static void glibc_override_free(void *ptr, const void *caller) {
118 tc_free(ptr);
120 static void* glibc_override_memalign(size_t align, size_t size,
121 const void *caller) {
122 return tc_memalign(align, size);
125 // We should be using __malloc_initialize_hook here, like the #if 0
126 // code below. (See http://swoolley.org/man.cgi/3/malloc_hook.)
127 // However, this causes weird linker errors with programs that link
128 // with -static, so instead we just assign the vars directly at
129 // static-constructor time. That should serve the same effect of
130 // making sure the hooks are set before the first malloc call the
131 // program makes.
132 #if 0
133 #include <malloc.h> // for __malloc_hook, etc.
134 void glibc_override_malloc_init_hook(void) {
135 __malloc_hook = glibc_override_malloc;
136 __realloc_hook = glibc_override_realloc;
137 __free_hook = glibc_override_free;
138 __memalign_hook = glibc_override_memalign;
141 void (* MALLOC_HOOK_MAYBE_VOLATILE __malloc_initialize_hook)(void)
142 = &glibc_override_malloc_init_hook;
143 #endif
145 void* (* MALLOC_HOOK_MAYBE_VOLATILE __malloc_hook)(size_t, const void*)
146 = &glibc_override_malloc;
147 void* (* MALLOC_HOOK_MAYBE_VOLATILE __realloc_hook)(void*, size_t, const void*)
148 = &glibc_override_realloc;
149 void (* MALLOC_HOOK_MAYBE_VOLATILE __free_hook)(void*, const void*)
150 = &glibc_override_free;
151 void* (* MALLOC_HOOK_MAYBE_VOLATILE __memalign_hook)(size_t,size_t, const void*)
152 = &glibc_override_memalign;
154 } // extern "C"
156 // No need to write ReplaceSystemAlloc(); one of the #includes above
157 // did it for us.
159 #endif // TCMALLOC_LIBC_OVERRIDE_GLIBC_INL_H_