build warning with gcc 12

[richardlau]

We recently switched to build with gcc 12 on RHEL (other platforms to follow) in nodejs/build#3886.
This is causing ubi81_sharedlibs_openssl111fips_x64 to fail as it builds with --error-on-warn.

e.g. https://ci.nodejs.org/job/node-test-commit-linux-containered/45894/nodes=ubi81_sharedlibs_openssl111fips_x64/

07:14:38 In file included from /opt/rh/gcc-toolset-12/root/usr/include/c++/12/string:40,
07:14:38                  from /opt/rh/gcc-toolset-12/root/usr/include/c++/12/bits/locale_classes.h:40,
07:14:38                  from /opt/rh/gcc-toolset-12/root/usr/include/c++/12/locale:39,
07:14:38                  from ../src/util-inl.h:29,
07:14:38                  from ../src/node_dotenv.h:6,
07:14:38                  from ../src/node_dotenv.cc:1:
07:14:38 In static member function 'static constexpr std::char_traits<char>::char_type* std::char_traits<char>::copy(char_type*, const char_type*, std::size_t)',
07:14:38     inlined from 'static constexpr void std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::_S_copy(_CharT*, const _CharT*, size_type) [with _CharT = char; _Traits = std::char_traits<char>; _Alloc = std::allocator<char>]' at /opt/rh/gcc-toolset-12/root/usr/include/c++/12/bits/basic_string.h:423:21,
07:14:38     inlined from 'constexpr std::__cxx11::basic_string<_CharT, _Traits, _Allocator>& std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::_M_replace(size_type, size_type, const _CharT*, size_type) [with _CharT = char; _Traits = std::char_traits<char>; _Alloc = std::allocator<char>]' at /opt/rh/gcc-toolset-12/root/usr/include/c++/12/bits/basic_string.tcc:532:22,
07:14:38     inlined from 'constexpr std::__cxx11::basic_string<_CharT, _Traits, _Alloc>& std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::replace(size_type, size_type, const _CharT*, size_type) [with _CharT = char; _Traits = std::char_traits<char>; _Alloc = std::allocator<char>]' at /opt/rh/gcc-toolset-12/root/usr/include/c++/12/bits/basic_string.h:2171:19,
07:14:38     inlined from 'constexpr std::__cxx11::basic_string<_CharT, _Traits, _Alloc>& std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::replace(size_type, size_type, const _CharT*) [with _CharT = char; _Traits = std::char_traits<char>; _Alloc = std::allocator<char>]' at /opt/rh/gcc-toolset-12/root/usr/include/c++/12/bits/basic_string.h:2196:22,
07:14:38     inlined from 'void node::Dotenv::ParseContent(std::string_view)' at ../src/node_dotenv.cc:164:35:
07:14:38 /opt/rh/gcc-toolset-12/root/usr/include/c++/12/bits/char_traits.h:431:56: error: 'void* __builtin_memcpy(void*, const void*, long unsigned int)' accessing 9223372036854775810 or more bytes at offsets [2, 9223372036854775807] and 1 may overlap up to 9223372036854775813 bytes at offset -3 [-Werror=restrict]
07:14:38   431 |         return static_cast<char_type*>(__builtin_memcpy(__s1, __s2, __n));
07:14:38       |                                        ~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~
07:14:38 cc1plus: all warnings being treated as errors
07:14:38 make[2]: *** [libnode.target.mk:445: /home/iojs/build/workspace/node-test-commit-linux-containered/out/Release/obj.target/libnode/src/node_dotenv.o] Error 1

[richardlau]

If we look at a rhel8-x64 build (where we haven't enabled --error-on-warn) we can see several instances of this warning being emitted, e.g. https://ci.nodejs.org/job/node-test-commit-linux/nodes=rhel8-x64/60200/consoleFull.

[richardlau]

Could be related to

• https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105651
• https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105329

[richardlau]

Other examples
https://ci.nodejs.org/job/node-test-commit-linux/nodes=rhel8-x64/60200/consoleFull

15:21:13     inlined from ‘void node::Dotenv::ParseContent(std::string_view)’ at ../src/node_dotenv.cc:164:35:
15:21:13 /opt/rh/gcc-toolset-12/root/usr/include/c++/12/bits/char_traits.h:431:56: warning: ‘void* __builtin_memcpy(void*, const void*, long unsigned int)’ accessing 9223372036854775810 or more bytes at offsets [2, 9223372036854775807] and 1 may overlap up to 9223372036854775813 bytes at offset -3 [-Wrestrict]
15:21:13   431 |         return static_cast<char_type*>(__builtin_memcpy(__s1, __s2, __n));
15:21:13       |                                        ~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~

15:21:16     inlined from ‘virtual std::string node::SocketAddressBlockList::SocketAddressMaskRule::ToString()’ at ../src/node_sockaddr.cc:500:14:
15:21:16 /opt/rh/gcc-toolset-12/root/usr/include/c++/12/bits/char_traits.h:431:56: warning: ‘void* __builtin_memcpy(void*, const void*, long unsigned int)’ accessing 9223372036854775810 or more bytes at offsets [2, 9223372036854775807] and 1 may overlap up to 9223372036854775813 bytes at offset -3 [-Wrestrict]
15:21:16   431 |         return static_cast<char_type*>(__builtin_memcpy(__s1, __s2, __n));
15:21:16       |                                        ~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~

15:21:16     inlined from ‘node::task_runner::ProcessRunner::ProcessRunner(std::shared_ptr<node::InitializationResultImpl>, const std::filesystem::__cxx11::path&, std::string_view, std::string_view, std::string_view, const node::task_runner::PositionalArgs&)’ at ../src/node_task_runner.cc:58:26:
15:21:16 /opt/rh/gcc-toolset-12/root/usr/include/c++/12/bits/char_traits.h:431:56: warning: ‘void* __builtin_memcpy(void*, const void*, long unsigned int)’ accessing 9223372036854775810 or more bytes at offsets [2, 9223372036854775807] and 1 may overlap up to 9223372036854775813 bytes at offset -3 [-Wrestrict]
15:21:16   431 |         return static_cast<char_type*>(__builtin_memcpy(__s1, __s2, __n));
15:21:16       |                                        ~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~

15:21:16     inlined from ‘static void node::url::BindingData::Format(const v8::FunctionCallbackInfo<v8::Value>&)’ at ../src/node_url.cc:228:38:
15:21:16 /opt/rh/gcc-toolset-12/root/usr/include/c++/12/bits/char_traits.h:431:56: warning: ‘void* __builtin_memcpy(void*, const void*, long unsigned int)’ accessing 9223372036854775810 or more bytes at offsets [2, 9223372036854775807] and 1 may overlap up to 9223372036854775813 bytes at offset -3 [-Wrestrict]
15:21:16   431 |         return static_cast<char_type*>(__builtin_memcpy(__s1, __s2, __n));
15:21:16       |                                        ~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~

15:21:20     inlined from ‘void node::crypto::LogSecret(const SSLPointer&, const char*, const unsigned char*, std::size_t)’ at ../src/crypto/crypto_common.cc:61:15:
15:21:20 /opt/rh/gcc-toolset-12/root/usr/include/c++/12/bits/char_traits.h:431:56: warning: ‘void* __builtin_memcpy(void*, const void*, long unsigned int)’ accessing 9223372036854775810 or more bytes at offsets [2, 9223372036854775807] and 1 may overlap up to 9223372036854775813 bytes at offset -3 [-Wrestrict]
15:21:20   431 |         return static_cast<char_type*>(__builtin_memcpy(__s1, __s2, __n));
15:21:20       |                                        ~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~

15:21:20     inlined from ‘void node::crypto::LogSecret(const SSLPointer&, const char*, const unsigned char*, std::size_t)’ at ../src/crypto/crypto_common.cc:64:11:
15:21:20 /opt/rh/gcc-toolset-12/root/usr/include/c++/12/bits/char_traits.h:431:56: warning: ‘void* __builtin_memcpy(void*, const void*, long unsigned int)’ accessing 9223372036854775810 or more bytes at offsets [2, 9223372036854775807] and 1 may overlap up to 9223372036854775813 bytes at offset -3 [-Wrestrict]
15:21:20   431 |         return static_cast<char_type*>(__builtin_memcpy(__s1, __s2, __n));
15:21:20       |                                        ~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~

[richardlau]

I've opened #54737 to turn off -Wrestrict (i.e. -Wno-restrict).