Here's a patch to replace the unsafe, unbounded operator>> with the
new one that only allows reading into a fixed-size array.
I think I'll sit on this until stage1 though.
The other options are to bump the libstdc++.so version and add it now,
or not bump the version and also add the new symbol on gcc-9-branch.
diff --git a/libstdc++-v3/config/abi/pre/gnu.ver b/libstdc++-v3/config/abi/pre/gnu.ver
index edf4485e607..00cae801dfc 100644
--- a/libstdc++-v3/config/abi/pre/gnu.ver
+++ b/libstdc++-v3/config/abi/pre/gnu.ver
@@ -2297,6 +2297,9 @@ GLIBCXX_3.4.28 {
_ZNSt3pmr25monotonic_buffer_resourceD[0125]Ev;
_ZT[ISV]NSt3pmr25monotonic_buffer_resourceE;
+ # std::__extract_to_array(std:istream&, char*, streamsize)
+ _ZSt18__extract_to_arrayRSiPc[ilx];
+
} GLIBCXX_3.4.27;
# Symbols in the support library (libsupc++) have their own tag.
diff --git a/libstdc++-v3/include/bits/istream.tcc b/libstdc++-v3/include/bits/istream.tcc
index c82da56b9f9..fb4a73a8539 100644
--- a/libstdc++-v3/include/bits/istream.tcc
+++ b/libstdc++-v3/include/bits/istream.tcc
@@ -958,9 +958,23 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
return __in;
}
+#if __cplusplus <= 201703L
template<typename _CharT, typename _Traits>
basic_istream<_CharT, _Traits>&
operator>>(basic_istream<_CharT, _Traits>& __in, _CharT* __s)
+#else
+ template<size_t _Num>
+ basic_istream<char>&
+ operator>>(basic_istream<char>& __in, char (&__s)[_Num])
+ {
+ static_assert(_Num <= __gnu_cxx::__numeric_traits<streamsize>::__max);
+ return std::__extract_to_array(__in, __s, _Num);
+ }
+
+ template<typename _CharT, typename _Traits, size_t _Num>
+ basic_istream<_CharT, _Traits>&
+ operator>>(basic_istream<_CharT, _Traits>& __in, _CharT (&__a)[_Num])
+#endif
{
typedef basic_istream<_CharT, _Traits> __istream_type;
typedef basic_streambuf<_CharT, _Traits> __streambuf_type;
@@ -977,8 +991,14 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
{
// Figure out how many characters to extract.
streamsize __num = __in.width();
+#if __cplusplus <= 201703L
if (__num <= 0)
__num = __gnu_cxx::__numeric_traits<streamsize>::__max;
+#else
+ if (__num <= 0 || (size_t)__num > _Num)
+ __num = _Num;
+ _CharT* __s = __a;
+#endif
const __ctype_type& __ct = use_facet<__ctype_type>(__in.getloc());
@@ -1048,11 +1068,13 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
extern template class basic_istream<char>;
extern template istream& ws(istream&);
extern template istream& operator>>(istream&, char&);
- extern template istream& operator>>(istream&, char*);
extern template istream& operator>>(istream&, unsigned char&);
extern template istream& operator>>(istream&, signed char&);
+#if __cplusplus <= 201703L
+ extern template istream& operator>>(istream&, char*);
extern template istream& operator>>(istream&, unsigned char*);
extern template istream& operator>>(istream&, signed char*);
+#endif
extern template istream& istream::_M_extract(unsigned short&);
extern template istream& istream::_M_extract(unsigned int&);
@@ -1074,7 +1096,9 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
extern template class basic_istream<wchar_t>;
extern template wistream& ws(wistream&);
extern template wistream& operator>>(wistream&, wchar_t&);
+#if __cplusplus <= 201703L
extern template wistream& operator>>(wistream&, wchar_t*);
+#endif
extern template wistream& wistream::_M_extract(unsigned short&);
extern template wistream& wistream::_M_extract(unsigned int&);
diff --git a/libstdc++-v3/include/std/istream b/libstdc++-v3/include/std/istream
index 407c1ccda49..47764604eff 100644
--- a/libstdc++-v3/include/std/istream
+++ b/libstdc++-v3/include/std/istream
@@ -789,6 +789,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
*
* If no characters are extracted, sets failbit.
*/
+#if __cplusplus <= 201703L
template<typename _CharT, typename _Traits>
basic_istream<_CharT, _Traits>&
operator>>(basic_istream<_CharT, _Traits>& __in, _CharT* __s);
@@ -807,6 +808,22 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
inline basic_istream<char, _Traits>&
operator>>(basic_istream<char, _Traits>& __in, signed char* __s)
{ return (__in >> reinterpret_cast<char*>(__s)); }
+
+#else // C++20
+ template<typename _CharT, typename _Traits, size_t _Num>
+ basic_istream<_CharT, _Traits>&
+ operator>>(basic_istream<_CharT, _Traits>& __in, _CharT (&__s)[_Num]);
+
+ template<class _Traits, size_t _Num>
+ inline basic_istream<char, _Traits>&
+ operator>>(basic_istream<char, _Traits>& __in, unsigned char (&__s)[_Num])
+ { return (__in >> reinterpret_cast<char(&)[_Num]>(__s)); }
+
+ template<class _Traits, size_t _Num>
+ inline basic_istream<char, _Traits>&
+ operator>>(basic_istream<char, _Traits>& __in, signed char (&__s)[_Num])
+ { return (__in >> reinterpret_cast<char(&)[_Num]>(__s)); }
+#endif
//@}
/**
diff --git a/libstdc++-v3/include/std/streambuf b/libstdc++-v3/include/std/streambuf
index f8e4cb9879c..89ccfe27e23 100644
--- a/libstdc++-v3/include/std/streambuf
+++ b/libstdc++-v3/include/std/streambuf
@@ -53,6 +53,9 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
__copy_streambufs_eof(basic_streambuf<_CharT, _Traits>*,
basic_streambuf<_CharT, _Traits>*, bool&);
+ basic_istream<char>&
+ __extract_to_array(basic_istream<char>&, char*, streamsize);
+
/**
* @brief The actual work of input and output (interface).
* @ingroup io
@@ -166,10 +169,6 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
void>::__type
advance(istreambuf_iterator<_CharT2>&, _Distance);
- template<typename _CharT2, typename _Traits2>
- friend basic_istream<_CharT2, _Traits2>&
- operator>>(basic_istream<_CharT2, _Traits2>&, _CharT2*);
-
template<typename _CharT2, typename _Traits2, typename _Alloc>
friend basic_istream<_CharT2, _Traits2>&
operator>>(basic_istream<_CharT2, _Traits2>&,
@@ -180,6 +179,9 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
getline(basic_istream<_CharT2, _Traits2>&,
basic_string<_CharT2, _Traits2, _Alloc>&, _CharT2);
+ friend basic_istream<char>&
+ __extract_to_array(basic_istream<char>&, char*, streamsize);
+
protected:
/*
* This is based on _IO_FILE, just reordered to be more consistent,
diff --git a/libstdc++-v3/src/c++98/istream.cc b/libstdc++-v3/src/c++98/istream.cc
index 79d829e23b4..27b1a3f0e64 100644
--- a/libstdc++-v3/src/c++98/istream.cc
+++ b/libstdc++-v3/src/c++98/istream.cc
@@ -192,85 +192,92 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
return *this;
}
+ basic_istream<char>&
+ __extract_to_array(basic_istream<char>& __in, char* __s, streamsize __maxnum)
+ {
+ typedef basic_istream<char> __istream_type;
+ typedef __istream_type::int_type __int_type;
+ typedef __istream_type::char_type __char_type;
+ typedef __istream_type::traits_type __traits_type;
+ typedef __istream_type::__streambuf_type __streambuf_type;
+ typedef __istream_type::__ctype_type __ctype_type;
+
+ streamsize __extracted = 0;
+ ios_base::iostate __err = ios_base::goodbit;
+ __istream_type::sentry __cerb(__in, false);
+ if (__cerb)
+ {
+ __try
+ {
+ // Figure out how many characters to extract.
+ streamsize __num = __in.width();
+ if (__num <= 0 || __num > __maxnum)
+ __num = __maxnum;
+
+ const __ctype_type& __ct = use_facet<__ctype_type>(__in.getloc());
+
+ const __int_type __eof = __traits_type::eof();
+ __streambuf_type* __sb = __in.rdbuf();
+ __int_type __c = __sb->sgetc();
+
+ while (__extracted < __num - 1
+ && !__traits_type::eq_int_type(__c, __eof)
+ && !__ct.is(ctype_base::space,
+ __traits_type::to_char_type(__c)))
+ {
+ streamsize __size = std::min(streamsize(__sb->egptr()
+ - __sb->gptr()),
+ streamsize(__num - __extracted
+ - 1));
+ if (__size > 1)
+ {
+ __size = (__ct.scan_is(ctype_base::space,
+ __sb->gptr() + 1,
+ __sb->gptr() + __size)
+ - __sb->gptr());
+ __traits_type::copy(__s, __sb->gptr(), __size);
+ __s += __size;
+ __sb->__safe_gbump(__size);
+ __extracted += __size;
+ __c = __sb->sgetc();
+ }
+ else
+ {
+ *__s++ = __traits_type::to_char_type(__c);
+ ++__extracted;
+ __c = __sb->snextc();
+ }
+ }
+
+ if (__traits_type::eq_int_type(__c, __eof))
+ __err |= ios_base::eofbit;
+
+ // _GLIBCXX_RESOLVE_LIB_DEFECTS
+ // 68. Extractors for char* should store null at end
+ *__s = __char_type();
+ __in.width(0);
+ }
+ __catch(__cxxabiv1::__forced_unwind&)
+ {
+ __in._M_setstate(ios_base::badbit);
+ __throw_exception_again;
+ }
+ __catch(...)
+ { __in._M_setstate(ios_base::badbit); }
+ }
+ if (!__extracted)
+ __err |= ios_base::failbit;
+ if (__err)
+ __in.setstate(__err);
+ return __in;
+ }
+
template<>
basic_istream<char>&
operator>>(basic_istream<char>& __in, char* __s)
{
- typedef basic_istream<char> __istream_type;
- typedef __istream_type::int_type __int_type;
- typedef __istream_type::char_type __char_type;
- typedef __istream_type::traits_type __traits_type;
- typedef __istream_type::__streambuf_type __streambuf_type;
- typedef __istream_type::__ctype_type __ctype_type;
-
- streamsize __extracted = 0;
- ios_base::iostate __err = ios_base::goodbit;
- __istream_type::sentry __cerb(__in, false);
- if (__cerb)
- {
- __try
- {
- // Figure out how many characters to extract.
- streamsize __num = __in.width();
- if (__num <= 0)
- __num = __gnu_cxx::__numeric_traits<streamsize>::__max;
-
- const __ctype_type& __ct = use_facet<__ctype_type>(__in.getloc());
-
- const __int_type __eof = __traits_type::eof();
- __streambuf_type* __sb = __in.rdbuf();
- __int_type __c = __sb->sgetc();
-
- while (__extracted < __num - 1
- && !__traits_type::eq_int_type(__c, __eof)
- && !__ct.is(ctype_base::space,
- __traits_type::to_char_type(__c)))
- {
- streamsize __size = std::min(streamsize(__sb->egptr()
- - __sb->gptr()),
- streamsize(__num - __extracted
- - 1));
- if (__size > 1)
- {
- __size = (__ct.scan_is(ctype_base::space,
- __sb->gptr() + 1,
- __sb->gptr() + __size)
- - __sb->gptr());
- __traits_type::copy(__s, __sb->gptr(), __size);
- __s += __size;
- __sb->__safe_gbump(__size);
- __extracted += __size;
- __c = __sb->sgetc();
- }
- else
- {
- *__s++ = __traits_type::to_char_type(__c);
- ++__extracted;
- __c = __sb->snextc();
- }
- }
-
- if (__traits_type::eq_int_type(__c, __eof))
- __err |= ios_base::eofbit;
-
- // _GLIBCXX_RESOLVE_LIB_DEFECTS
- // 68. Extractors for char* should store null at end
- *__s = __char_type();
- __in.width(0);
- }
- __catch(__cxxabiv1::__forced_unwind&)
- {
- __in._M_setstate(ios_base::badbit);
- __throw_exception_again;
- }
- __catch(...)
- { __in._M_setstate(ios_base::badbit); }
- }
- if (!__extracted)
- __err |= ios_base::failbit;
- if (__err)
- __in.setstate(__err);
- return __in;
+ return std::__extract_to_array(__in, __s,
+ __gnu_cxx::__numeric_traits<streamsize>::__max);
}
#ifdef _GLIBCXX_USE_WCHAR_T
