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[libc++] Refactor iostream.cpp #121116

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[libc++] Refactor iostream.cpp #121116

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145 changes: 54 additions & 91 deletions libcxx/src/iostream.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -8,91 +8,67 @@

#include "std_stream.h"
#include <__locale>
#include <new>
#include <string>

#define _str(s) #s
#define str(s) _str(s)
#define _LIBCPP_ABI_NAMESPACE_STR str(_LIBCPP_ABI_NAMESPACE)

_LIBCPP_BEGIN_NAMESPACE_STD

alignas(istream) _LIBCPP_EXPORTED_FROM_ABI char cin[sizeof(istream)]
#if defined(_LIBCPP_ABI_MICROSOFT) && defined(__clang__)
__asm__("?cin@" _LIBCPP_ABI_NAMESPACE_STR "@std@@3V?$basic_istream@DU?$char_traits@D@" _LIBCPP_ABI_NAMESPACE_STR
"@std@@@12@A")
#endif
;
alignas(__stdinbuf<char>) static char __cin[sizeof(__stdinbuf<char>)];
static mbstate_t mb_cin;
static mbstate_t mb_cout;
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constinit?

static mbstate_t mb_cerr;

#if _LIBCPP_HAS_WIDE_CHARACTERS
alignas(wistream) _LIBCPP_EXPORTED_FROM_ABI char wcin[sizeof(wistream)]
# if defined(_LIBCPP_ABI_MICROSOFT) && defined(__clang__)
__asm__("?wcin@" _LIBCPP_ABI_NAMESPACE_STR "@std@@3V?$basic_istream@_WU?$char_traits@_W@" _LIBCPP_ABI_NAMESPACE_STR
"@std@@@12@A")
# endif
;
alignas(__stdinbuf<wchar_t>) static char __wcin[sizeof(__stdinbuf<wchar_t>)];
static mbstate_t mb_wcin;
#endif // _LIBCPP_HAS_WIDE_CHARACTERS

alignas(ostream) _LIBCPP_EXPORTED_FROM_ABI char cout[sizeof(ostream)]
#if defined(_LIBCPP_ABI_MICROSOFT) && defined(__clang__)
__asm__("?cout@" _LIBCPP_ABI_NAMESPACE_STR "@std@@3V?$basic_ostream@DU?$char_traits@D@" _LIBCPP_ABI_NAMESPACE_STR
"@std@@@12@A")
static mbstate_t mb_wcout;
static mbstate_t mb_wcerr;
#endif
;
alignas(__stdoutbuf<char>) static char __cout[sizeof(__stdoutbuf<char>)];
static mbstate_t mb_cout;

#if _LIBCPP_HAS_WIDE_CHARACTERS
alignas(wostream) _LIBCPP_EXPORTED_FROM_ABI char wcout[sizeof(wostream)]
# if defined(_LIBCPP_ABI_MICROSOFT) && defined(__clang__)
__asm__("?wcout@" _LIBCPP_ABI_NAMESPACE_STR "@std@@3V?$basic_ostream@_WU?$char_traits@_W@" _LIBCPP_ABI_NAMESPACE_STR
"@std@@@12@A")
# endif
;
alignas(__stdoutbuf<wchar_t>) static char __wcout[sizeof(__stdoutbuf<wchar_t>)];
static mbstate_t mb_wcout;
#endif // _LIBCPP_HAS_WIDE_CHARACTERS
#if __has_cpp_attribute(clang::no_destroy)
template <class T>
using no_destroy_t = T;

alignas(ostream) _LIBCPP_EXPORTED_FROM_ABI char cerr[sizeof(ostream)]
#if defined(_LIBCPP_ABI_MICROSOFT) && defined(__clang__)
__asm__("?cerr@" _LIBCPP_ABI_NAMESPACE_STR "@std@@3V?$basic_ostream@DU?$char_traits@D@" _LIBCPP_ABI_NAMESPACE_STR
"@std@@@12@A")
# define STREAM_ATTRS [[clang::no_destroy]] _LIBCPP_INIT_PRIORITY_MAX
#else
template <class T>
using no_destroy_t = __no_destroy<T>;

# define STREAM_ATTRS _LIBCPP_INIT_PRIORITY_MAX
#endif
;
alignas(__stdoutbuf<char>) static char __cerr[sizeof(__stdoutbuf<char>)];
static mbstate_t mb_cerr;

#if _LIBCPP_HAS_WIDE_CHARACTERS
alignas(wostream) _LIBCPP_EXPORTED_FROM_ABI char wcerr[sizeof(wostream)]
# if defined(_LIBCPP_ABI_MICROSOFT) && defined(__clang__)
__asm__("?wcerr@" _LIBCPP_ABI_NAMESPACE_STR "@std@@3V?$basic_ostream@_WU?$char_traits@_W@" _LIBCPP_ABI_NAMESPACE_STR
"@std@@@12@A")
# endif
;
alignas(__stdoutbuf<wchar_t>) static char __wcerr[sizeof(__stdoutbuf<wchar_t>)];
static mbstate_t mb_wcerr;
#endif // _LIBCPP_HAS_WIDE_CHARACTERS
auto&& unwrap(auto& val) { return val; }
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Suggested change
auto&& unwrap(auto& val) { return val; }
inline auto&& unwrap(auto& val) { return val; }

If you decide to write this as an auto function, let's make the linkage clear by using inline.


alignas(ostream) _LIBCPP_EXPORTED_FROM_ABI char clog[sizeof(ostream)]
#if defined(_LIBCPP_ABI_MICROSOFT) && defined(__clang__)
__asm__("?clog@" _LIBCPP_ABI_NAMESPACE_STR "@std@@3V?$basic_ostream@DU?$char_traits@D@" _LIBCPP_ABI_NAMESPACE_STR
"@std@@@12@A")
#endif
;
template <class T>
auto&& unwrap(__no_destroy<T>& val) {
return val.__get();
}

# 43 __FILE__ 3 // FIXME: Remove this (and the one below) once https://llvm.org/PR121108 is fixed.

STREAM_ATTRS static no_destroy_t<__stdinbuf<char>> cin_stdbuf(stdin, &mb_cin);
STREAM_ATTRS _LIBCPP_EXPORTED_FROM_ABI no_destroy_t<istream> cin(&unwrap(cin_stdbuf));

STREAM_ATTRS static no_destroy_t<__stdoutbuf<char>> cout_stdbuf(stdout, &mb_cout);
STREAM_ATTRS _LIBCPP_EXPORTED_FROM_ABI no_destroy_t<ostream> cout(&unwrap(cout_stdbuf));

STREAM_ATTRS static no_destroy_t<__stdoutbuf<char>> cerr_stdbuf(stderr, &mb_cerr);
STREAM_ATTRS _LIBCPP_EXPORTED_FROM_ABI no_destroy_t<ostream> cerr(&unwrap(cerr_stdbuf));

STREAM_ATTRS _LIBCPP_EXPORTED_FROM_ABI no_destroy_t<ostream> clog(&unwrap(cerr_stdbuf));

#if _LIBCPP_HAS_WIDE_CHARACTERS
alignas(wostream) _LIBCPP_EXPORTED_FROM_ABI char wclog[sizeof(wostream)]
# if defined(_LIBCPP_ABI_MICROSOFT) && defined(__clang__)
__asm__("?wclog@" _LIBCPP_ABI_NAMESPACE_STR "@std@@3V?$basic_ostream@_WU?$char_traits@_W@" _LIBCPP_ABI_NAMESPACE_STR
"@std@@@12@A")
# endif
;
STREAM_ATTRS static __stdinbuf<wchar_t> wcin_stdbuf(stdin, &mb_wcin);
STREAM_ATTRS _LIBCPP_EXPORTED_FROM_ABI wistream wcin(&unwrap(wcin_stdbuf));

STREAM_ATTRS static no_destroy_t<__stdoutbuf<wchar_t>> wcout_stdbuf(stdout, &mb_wcout);
STREAM_ATTRS _LIBCPP_EXPORTED_FROM_ABI no_destroy_t<wostream> wcout(&unwrap(wcout_stdbuf));

STREAM_ATTRS static no_destroy_t<__stdoutbuf<wchar_t>> wcerr_stdbuf(stderr, &mb_wcerr);
STREAM_ATTRS _LIBCPP_EXPORTED_FROM_ABI no_destroy_t<wostream> wcerr(&unwrap(wcerr_stdbuf));

STREAM_ATTRS _LIBCPP_EXPORTED_FROM_ABI no_destroy_t<wostream> wclog(&unwrap(wcerr_stdbuf));

#endif // _LIBCPP_HAS_WIDE_CHARACTERS

# 70 __FILE__ 1

// 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"
Comment on lines 72 to 74
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You could move the contents of that file inside the # __FILE__ directive and get rid of the header.

_LIBCPP_HIDDEN ios_base::Init __start_std_streams _LIBCPP_INIT_PRIORITY_MAX;

# 70 __FILE__ 1

Expand Down Expand Up @@ -124,37 +100,24 @@ class DoIOSInit {
DoIOSInit::DoIOSInit() {
force_locale_initialization();

istream* cin_ptr = ::new (cin) istream(::new (__cin) __stdinbuf<char>(stdin, &mb_cin));
ostream* cout_ptr = ::new (cout) ostream(::new (__cout) __stdoutbuf<char>(stdout, &mb_cout));
ostream* cerr_ptr = ::new (cerr) ostream(::new (__cerr) __stdoutbuf<char>(stderr, &mb_cerr));
::new (clog) ostream(cerr_ptr->rdbuf());
cin_ptr->tie(cout_ptr);
std::unitbuf(*cerr_ptr);
cerr_ptr->tie(cout_ptr);
unwrap(cin).tie(&unwrap(cout));
std::unitbuf(unwrap(cerr));
unwrap(cerr).tie(&unwrap(cout));

#if _LIBCPP_HAS_WIDE_CHARACTERS
wistream* wcin_ptr = ::new (wcin) wistream(::new (__wcin) __stdinbuf<wchar_t>(stdin, &mb_wcin));
wostream* wcout_ptr = ::new (wcout) wostream(::new (__wcout) __stdoutbuf<wchar_t>(stdout, &mb_wcout));
wostream* wcerr_ptr = ::new (wcerr) wostream(::new (__wcerr) __stdoutbuf<wchar_t>(stderr, &mb_wcerr));
::new (wclog) wostream(wcerr_ptr->rdbuf());

wcin_ptr->tie(wcout_ptr);
std::unitbuf(*wcerr_ptr);
wcerr_ptr->tie(wcout_ptr);
unwrap(wcin).tie(&unwrap(wcout));
std::unitbuf(unwrap(wcerr));
unwrap(wcerr).tie(&unwrap(wcout));
#endif
}

DoIOSInit::~DoIOSInit() {
ostream* cout_ptr = reinterpret_cast<ostream*>(cout);
cout_ptr->flush();
ostream* clog_ptr = reinterpret_cast<ostream*>(clog);
clog_ptr->flush();
unwrap(cout).flush();
unwrap(clog).flush();

#if _LIBCPP_HAS_WIDE_CHARACTERS
wostream* wcout_ptr = reinterpret_cast<wostream*>(wcout);
wcout_ptr->flush();
wostream* wclog_ptr = reinterpret_cast<wostream*>(wclog);
wclog_ptr->flush();
unwrap(wcout).flush();
unwrap(wclog).flush();
#endif
}

Expand Down
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