c6d95c441a
Asan reports it after #124103. It's know case of false positive for Asan. https://github.com/google/sanitizers/wiki/AddressSanitizerInitializationOrderFiasco#false-positives It's can be avoided with `constexpr` constructors. In general order global constructors in different modules is undefined. If global constructor uses external global, they can be not constructed yet. However, implementation may contain workaround for that, or the state of non-constructed global can be still valid. Asan will still falsely report such cases, as it has no machinery to detect correctness of such cases. We need to fix/workaround the issue in libc++, as it will affect many libc++ with Asan users.
139 lines
4.3 KiB
C++
139 lines
4.3 KiB
C++
//===----------------------------------------------------------------------===//
|
|
//
|
|
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
|
|
// See https://llvm.org/LICENSE.txt for license information.
|
|
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#include "std_stream.h"
|
|
|
|
#include <__memory/construct_at.h>
|
|
#include <__ostream/basic_ostream.h>
|
|
#include <istream>
|
|
|
|
#define ABI_NAMESPACE_STR _LIBCPP_TOSTRING(_LIBCPP_ABI_NAMESPACE)
|
|
|
|
_LIBCPP_BEGIN_NAMESPACE_STD
|
|
|
|
template <class StreamT, class BufferT>
|
|
union stream_data {
|
|
constexpr stream_data() {}
|
|
constexpr ~stream_data() {}
|
|
struct {
|
|
// The stream has to be the first element, since that's referenced by the stream declarations in <iostream>
|
|
StreamT stream;
|
|
BufferT buffer;
|
|
mbstate_t mb;
|
|
};
|
|
|
|
void init(FILE* stdstream) {
|
|
mb = {};
|
|
std::construct_at(&buffer, stdstream, &mb);
|
|
std::construct_at(&stream, &buffer);
|
|
}
|
|
};
|
|
|
|
#define CHAR_MANGLING_char "D"
|
|
#define CHAR_MANGLING_wchar_t "_W"
|
|
#define CHAR_MANGLING(CharT) CHAR_MANGLING_##CharT
|
|
|
|
#ifdef _LIBCPP_COMPILER_CLANG_BASED
|
|
# define STRING_DATA_CONSTINIT constinit
|
|
#else
|
|
# define STRING_DATA_CONSTINIT
|
|
#endif
|
|
|
|
#ifdef _LIBCPP_ABI_MICROSOFT
|
|
# define STREAM(StreamT, BufferT, CharT, var) \
|
|
STRING_DATA_CONSTINIT stream_data<StreamT<CharT>, BufferT<CharT>> var __asm__( \
|
|
"?" #var "@" ABI_NAMESPACE_STR "@std@@3V?$" #StreamT \
|
|
"@" CHAR_MANGLING(CharT) "U?$char_traits@" CHAR_MANGLING(CharT) "@" ABI_NAMESPACE_STR "@std@@@12@A")
|
|
#else
|
|
# define STREAM(StreamT, BufferT, CharT, var) STRING_DATA_CONSTINIT stream_data<StreamT<CharT>, BufferT<CharT>> var
|
|
#endif
|
|
|
|
// These definitions and the declarations in <iostream> technically cause ODR violations, since they have different
|
|
// types (stream_data and {i,o}stream respectively). This means that <iostream> should never be included in this TU.
|
|
|
|
_LIBCPP_EXPORTED_FROM_ABI STREAM(basic_istream, __stdinbuf, char, cin);
|
|
_LIBCPP_EXPORTED_FROM_ABI STREAM(basic_ostream, __stdoutbuf, char, cout);
|
|
_LIBCPP_EXPORTED_FROM_ABI STREAM(basic_ostream, __stdoutbuf, char, cerr);
|
|
_LIBCPP_EXPORTED_FROM_ABI STREAM(basic_ostream, __stdoutbuf, char, clog);
|
|
#if _LIBCPP_HAS_WIDE_CHARACTERS
|
|
_LIBCPP_EXPORTED_FROM_ABI STREAM(basic_istream, __stdinbuf, wchar_t, wcin);
|
|
_LIBCPP_EXPORTED_FROM_ABI STREAM(basic_ostream, __stdoutbuf, wchar_t, wcout);
|
|
_LIBCPP_EXPORTED_FROM_ABI STREAM(basic_ostream, __stdoutbuf, wchar_t, wcerr);
|
|
_LIBCPP_EXPORTED_FROM_ABI STREAM(basic_ostream, __stdoutbuf, wchar_t, wclog);
|
|
#endif // _LIBCPP_HAS_WIDE_CHARACTERS
|
|
|
|
// Pretend we're inside a system header so the compiler doesn't flag the use of the init_priority
|
|
// attribute with a value that's reserved for the implementation (we're the implementation).
|
|
#include "iostream_init.h"
|
|
|
|
// On Windows the TLS storage for locales needs to be initialized before we create
|
|
// the standard streams, otherwise it may not be alive during program termination
|
|
// when we flush the streams.
|
|
static void force_locale_initialization() {
|
|
#if defined(_LIBCPP_MSVCRT_LIKE)
|
|
static bool once = []() {
|
|
auto loc = __locale::__newlocale(_LIBCPP_ALL_MASK, "C", 0);
|
|
{
|
|
__locale::__locale_guard g(loc); // forces initialization of locale TLS
|
|
((void)g);
|
|
}
|
|
__locale::__freelocale(loc);
|
|
return true;
|
|
}();
|
|
((void)once);
|
|
#endif
|
|
}
|
|
|
|
class DoIOSInit {
|
|
public:
|
|
DoIOSInit();
|
|
~DoIOSInit();
|
|
};
|
|
|
|
DoIOSInit::DoIOSInit() {
|
|
force_locale_initialization();
|
|
|
|
cin.init(stdin);
|
|
cout.init(stdout);
|
|
cerr.init(stderr);
|
|
clog.init(stderr);
|
|
|
|
cin.stream.tie(&cout.stream);
|
|
std::unitbuf(cerr.stream);
|
|
cerr.stream.tie(&cout.stream);
|
|
|
|
#if _LIBCPP_HAS_WIDE_CHARACTERS
|
|
wcin.init(stdin);
|
|
wcout.init(stdout);
|
|
wcerr.init(stderr);
|
|
wclog.init(stderr);
|
|
|
|
wcin.stream.tie(&wcout.stream);
|
|
std::unitbuf(wcerr.stream);
|
|
wcerr.stream.tie(&wcout.stream);
|
|
#endif
|
|
}
|
|
|
|
DoIOSInit::~DoIOSInit() {
|
|
cout.stream.flush();
|
|
clog.stream.flush();
|
|
|
|
#if _LIBCPP_HAS_WIDE_CHARACTERS
|
|
wcout.stream.flush();
|
|
wclog.stream.flush();
|
|
#endif
|
|
}
|
|
|
|
ios_base::Init::Init() {
|
|
static DoIOSInit init_the_streams; // gets initialized once
|
|
}
|
|
|
|
ios_base::Init::~Init() {}
|
|
|
|
_LIBCPP_END_NAMESPACE_STD
|