[libc++] Implement P0487R1 - Fixing operator>>(basic_istream&, CharT*)
Summary:
Avoid buffer overflow by replacing the pointer interface with an array reference interface in C++2a.
Tentatively ready on Batavia2018.
https://wg21.link/lwg2499
https://wg21.link/p0487
Reviewers: mclow.lists, ldionne, EricWF
Reviewed By: ldionne
Subscribers: libcxx-commits, cfe-commits, christof
Differential Revision: https://reviews.llvm.org/D51268
llvm-svn: 347377
Cr-Mirrored-From: sso://chromium.googlesource.com/_direct/external/github.com/llvm/llvm-project
Cr-Mirrored-Commit: 147b25b4a146be2a2b4d37c9388b7fb51d5508f4
diff --git a/include/istream b/include/istream
index e46881e..8487dbe 100644
--- a/include/istream
+++ b/include/istream
@@ -517,8 +517,9 @@
}
template<class _CharT, class _Traits>
+_LIBCPP_INLINE_VISIBILITY
basic_istream<_CharT, _Traits>&
-operator>>(basic_istream<_CharT, _Traits>& __is, _CharT* __s)
+__input_c_string(basic_istream<_CharT, _Traits>& __is, _CharT* __p, size_t __n)
{
#ifndef _LIBCPP_NO_EXCEPTIONS
try
@@ -527,13 +528,10 @@
typename basic_istream<_CharT, _Traits>::sentry __sen(__is);
if (__sen)
{
- streamsize __n = __is.width();
- if (__n <= 0)
- __n = numeric_limits<streamsize>::max() / sizeof(_CharT) - 1;
- streamsize __c = 0;
+ auto __s = __p;
const ctype<_CharT>& __ct = use_facet<ctype<_CharT> >(__is.getloc());
ios_base::iostate __err = ios_base::goodbit;
- while (__c < __n-1)
+ while (__s != __p + (__n-1))
{
typename _Traits::int_type __i = __is.rdbuf()->sgetc();
if (_Traits::eq_int_type(__i, _Traits::eof()))
@@ -545,12 +543,11 @@
if (__ct.is(__ct.space, __ch))
break;
*__s++ = __ch;
- ++__c;
__is.rdbuf()->sbumpc();
}
*__s = _CharT();
__is.width(0);
- if (__c == 0)
+ if (__s == __p)
__err |= ios_base::failbit;
__is.setstate(__err);
}
@@ -564,6 +561,48 @@
return __is;
}
+#if _LIBCPP_STD_VER > 17
+
+template<class _CharT, class _Traits, size_t _Np>
+inline _LIBCPP_INLINE_VISIBILITY
+basic_istream<_CharT, _Traits>&
+operator>>(basic_istream<_CharT, _Traits>& __is, _CharT (&__buf)[_Np])
+{
+ auto __n = _Np;
+ if (__is.width() > 0)
+ __n = _VSTD::min(size_t(__is.width()), _Np);
+ return _VSTD::__input_c_string(__is, __buf, __n);
+}
+
+template<class _Traits, size_t _Np>
+inline _LIBCPP_INLINE_VISIBILITY
+basic_istream<char, _Traits>&
+operator>>(basic_istream<char, _Traits>& __is, unsigned char (&__buf)[_Np])
+{
+ return __is >> (char(&)[_Np])__buf;
+}
+
+template<class _Traits, size_t _Np>
+inline _LIBCPP_INLINE_VISIBILITY
+basic_istream<char, _Traits>&
+operator>>(basic_istream<char, _Traits>& __is, signed char (&__buf)[_Np])
+{
+ return __is >> (char(&)[_Np])__buf;
+}
+
+#else
+
+template<class _CharT, class _Traits>
+inline _LIBCPP_INLINE_VISIBILITY
+basic_istream<_CharT, _Traits>&
+operator>>(basic_istream<_CharT, _Traits>& __is, _CharT* __s)
+{
+ streamsize __n = __is.width();
+ if (__n <= 0)
+ __n = numeric_limits<streamsize>::max() / sizeof(_CharT) - 1;
+ return _VSTD::__input_c_string(__is, __s, size_t(__n));
+}
+
template<class _Traits>
inline _LIBCPP_INLINE_VISIBILITY
basic_istream<char, _Traits>&
@@ -580,6 +619,8 @@
return __is >> (char*)__s;
}
+#endif // _LIBCPP_STD_VER > 17
+
template<class _CharT, class _Traits>
basic_istream<_CharT, _Traits>&
operator>>(basic_istream<_CharT, _Traits>& __is, _CharT& __c)