1 // Protocol Buffers - Google's data interchange format
2 // Copyright 2017 Google Inc. All rights reserved.
3 // https://developers.google.com/protocol-buffers/
4 //
5 // Redistribution and use in source and binary forms, with or without
6 // modification, are permitted provided that the following conditions are
7 // met:
8 //
9 // * Redistributions of source code must retain the above copyright
10 // notice, this list of conditions and the following disclaimer.
11 // * Redistributions in binary form must reproduce the above
12 // copyright notice, this list of conditions and the following disclaimer
13 // in the documentation and/or other materials provided with the
14 // distribution.
15 // * Neither the name of Google Inc. nor the names of its
16 // contributors may be used to endorse or promote products derived from
17 // this software without specific prior written permission.
18 //
19 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
20 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
21 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
22 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
23 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
24 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
25 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
26 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
27 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
28 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
29 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30
31 #include <string.h>
32
33 // On x86-64 Linux with glibc, we link against the 2.2.5 version of memcpy so
34 // that we avoid depending on the 2.14 version of the symbol. This way,
35 // distributions that are using pre-2.14 versions of glibc can successfully use
36 // the gem we distribute (https://github.com/protocolbuffers/protobuf/issues/2783).
37 //
38 // This wrapper is enabled by passing the linker flags -Wl,-wrap,memcpy in
39 // extconf.rb.
40 #ifdef __linux__
41 #if defined(__x86_64__) && defined(__GNU_LIBRARY__)
42 __asm__(".symver memcpy,memcpy@GLIBC_2.2.5");
__wrap_memcpy(void * dest,const void * src,size_t n)43 void *__wrap_memcpy(void *dest, const void *src, size_t n) {
44 return memcpy(dest, src, n);
45 }
46 #else
__wrap_memcpy(void * dest,const void * src,size_t n)47 void *__wrap_memcpy(void *dest, const void *src, size_t n) {
48 return memmove(dest, src, n);
49 }
50 #endif
51 #endif
52