From e5c422b7d8af6f42f8ab230133210742b7ac5661 Mon Sep 17 00:00:00 2001 From: Jonathan Wakely Date: Fri, 25 Jun 2021 21:33:02 +0100 Subject: libstdc++: Implement LWG 415 for std::ws For C++11 std::ws changed to be an unformatted input function, meaning it constructs a sentry and sets badbit on exceptions. libstdc++-v3/ChangeLog: * doc/xml/manual/intro.xml: Document LWG 415 change. * doc/html/manual/bugs.html: Regenerate. * include/bits/istream.tcc (ws): Create sentry and catch exceptions. * testsuite/27_io/basic_istream/ws/char/lwg415.cc: New test. * testsuite/27_io/basic_istream/ws/wchar_t/lwg415.cc: New test. --- libstdc++-v3/doc/html/manual/bugs.html | 4 ++ libstdc++-v3/doc/xml/manual/intro.xml | 7 ++ libstdc++-v3/include/bits/istream.tcc | 46 ++++++++++--- .../27_io/basic_istream/ws/char/lwg415.cc | 77 ++++++++++++++++++++++ .../27_io/basic_istream/ws/wchar_t/lwg415.cc | 77 ++++++++++++++++++++++ 5 files changed, 201 insertions(+), 10 deletions(-) create mode 100644 libstdc++-v3/testsuite/27_io/basic_istream/ws/char/lwg415.cc create mode 100644 libstdc++-v3/testsuite/27_io/basic_istream/ws/wchar_t/lwg415.cc diff --git a/libstdc++-v3/doc/html/manual/bugs.html b/libstdc++-v3/doc/html/manual/bugs.html index 7b49e4a..38594a9 100644 --- a/libstdc++-v3/doc/html/manual/bugs.html +++ b/libstdc++-v3/doc/html/manual/bugs.html @@ -245,6 +245,10 @@

409: Closing an fstream should clear the error state

Have open clear the error flags. +

415: + Behavior of std::ws +

Change it to be an unformatted input function + (i.e. construct a sentry and catch exceptions).

431: Swapping containers with unequal allocators

Implement Option 3, as per N1599. diff --git a/libstdc++-v3/doc/xml/manual/intro.xml b/libstdc++-v3/doc/xml/manual/intro.xml index 45762ca..86ed696 100644 --- a/libstdc++-v3/doc/xml/manual/intro.xml +++ b/libstdc++-v3/doc/xml/manual/intro.xml @@ -634,6 +634,13 @@ requirements of the license of GCC. Have open clear the error flags. + 415: + Behavior of std::ws + + Change it to be an unformatted input function + (i.e. construct a sentry and catch exceptions). + + 431: Swapping containers with unequal allocators diff --git a/libstdc++-v3/include/bits/istream.tcc b/libstdc++-v3/include/bits/istream.tcc index 1b046be..2a153c2 100644 --- a/libstdc++-v3/include/bits/istream.tcc +++ b/libstdc++-v3/include/bits/istream.tcc @@ -1057,17 +1057,43 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION typedef typename __istream_type::int_type __int_type; typedef ctype<_CharT> __ctype_type; - const __ctype_type& __ct = use_facet<__ctype_type>(__in.getloc()); - const __int_type __eof = _Traits::eof(); - __streambuf_type* __sb = __in.rdbuf(); - __int_type __c = __sb->sgetc(); - - while (!_Traits::eq_int_type(__c, __eof) - && __ct.is(ctype_base::space, _Traits::to_char_type(__c))) - __c = __sb->snextc(); + // _GLIBCXX_RESOLVE_LIB_DEFECTS + // 451. behavior of std::ws + typename __istream_type::sentry __cerb(__in, true); + if (__cerb) + { + ios_base::iostate __err = ios_base::goodbit; + __try + { + const __ctype_type& __ct = use_facet<__ctype_type>(__in.getloc()); + const __int_type __eof = _Traits::eof(); + __streambuf_type* __sb = __in.rdbuf(); + __int_type __c = __sb->sgetc(); - if (_Traits::eq_int_type(__c, __eof)) - __in.setstate(ios_base::eofbit); + while (true) + { + if (_Traits::eq_int_type(__c, __eof)) + { + __err = ios_base::eofbit; + break; + } + if (!__ct.is(ctype_base::space, _Traits::to_char_type(__c))) + break; + __c = __sb->snextc(); + } + } + __catch (const __cxxabiv1::__forced_unwind&) + { + __in._M_setstate(ios_base::badbit); + __throw_exception_again; + } + __catch (...) + { + __in._M_setstate(ios_base::badbit); + } + if (__err) + __in.setstate(__err); + } return __in; } diff --git a/libstdc++-v3/testsuite/27_io/basic_istream/ws/char/lwg415.cc b/libstdc++-v3/testsuite/27_io/basic_istream/ws/char/lwg415.cc new file mode 100644 index 0000000..fe6980d --- /dev/null +++ b/libstdc++-v3/testsuite/27_io/basic_istream/ws/char/lwg415.cc @@ -0,0 +1,77 @@ +#include + +// C++11 27.7.2.4 Standard basic_istream manipulators [istream.manip] +// +// LWG 415. behavior of std::ws +// std::ws is an unformatted input function. + +#include +#include +#include + +void +test01() +{ + std::istream is(0); + VERIFY( is.rdstate() == std::ios_base::badbit ); + + is >> std::ws; // sentry should set failbit + VERIFY( is.rdstate() & std::ios_base::failbit ); +} + +void +test02() +{ + __gnu_test::sync_streambuf buf; + std::istream is(&buf); + + __gnu_test::sync_streambuf buf_tie; + std::ostream os_tie(&buf_tie); + + // A sentry should be constructed so is.tie()->flush() should be called. + // The standard allows the flush to be deferred because the put area of + // is_tie is empty, but libstdc++ doesn't defer it. + is.tie(&os_tie); + + is >> std::ws; + + VERIFY( is.eof() ); + VERIFY( !is.fail() ); + VERIFY( ! buf.sync_called() ); + VERIFY( buf_tie.sync_called() ); +} + +void +test03() +{ + __gnu_test::fail_streambuf buf; + std::istream is(&buf); + + char c; + is >> c >> std::ws; + VERIFY( is.rdstate() == std::ios_base::badbit ); + + is.clear(); + is.exceptions(std::ios_base::badbit); + + try + { + is >> std::ws; + VERIFY( false ); + } + catch (const __gnu_test::underflow_error&) + { + VERIFY( is.rdstate() == std::ios_base::badbit ); + } + catch (...) + { + VERIFY( false ); + } +} + +int main() +{ + test01(); + test02(); + test03(); +} diff --git a/libstdc++-v3/testsuite/27_io/basic_istream/ws/wchar_t/lwg415.cc b/libstdc++-v3/testsuite/27_io/basic_istream/ws/wchar_t/lwg415.cc new file mode 100644 index 0000000..fd04009 --- /dev/null +++ b/libstdc++-v3/testsuite/27_io/basic_istream/ws/wchar_t/lwg415.cc @@ -0,0 +1,77 @@ +#include + +// C++11 27.7.2.4 Standard basic_istream manipulators [istream.manip] +// +// LWG 415. behavior of std::ws +// std::ws is an unformatted input function. + +#include +#include +#include + +void +test01() +{ + std::wistream is(0); + VERIFY( is.rdstate() == std::ios_base::badbit ); + + is >> std::ws; // sentry should set failbit + VERIFY( is.rdstate() & std::ios_base::failbit ); +} + +void +test02() +{ + __gnu_test::sync_wstreambuf buf; + std::wistream is(&buf); + + __gnu_test::sync_wstreambuf buf_tie; + std::wostream os_tie(&buf_tie); + + // A sentry should be constructed so is.tie()->flush() should be called. + // The standard allows the flush to be deferred because the put area of + // is_tie is empty, but libstdc++ doesn't defer it. + is.tie(&os_tie); + + is >> std::ws; + + VERIFY( is.eof() ); + VERIFY( !is.fail() ); + VERIFY( ! buf.sync_called() ); + VERIFY( buf_tie.sync_called() ); +} + +void +test03() +{ + __gnu_test::fail_wstreambuf buf; + std::wistream is(&buf); + + wchar_t c; + is >> c >> std::ws; + VERIFY( is.rdstate() == std::ios_base::badbit ); + + is.clear(); + is.exceptions(std::ios_base::badbit); + + try + { + is >> std::ws; + VERIFY( false ); + } + catch (const __gnu_test::underflow_error&) + { + VERIFY( is.rdstate() == std::ios_base::badbit ); + } + catch (...) + { + VERIFY( false ); + } +} + +int main() +{ + test01(); + test02(); + test03(); +} -- cgit v1.1