PR libstdc++/67214 Avoid signed overflow in num_get::_M_extract_int

2017-05-23  Xi Ruoyao  <ryxi@stu.xidian.edu.cn>

	PR libstdc++/67214
	* include/bits/locale_facets.tcc (num_get::_M_extract_int): Add
	explicit conversion to avoid signed overflow.

From-SVN: r248362

diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog
index ef4e3839faf419204d4131ec2e6a7468c0977b76..5b34ccf1166928be75abbcf4b50023d905e30cc9 100644 (file)
--- a/libstdc++-v3/ChangeLog
+++ b/libstdc++-v3/ChangeLog
@@ -1,3 +1,9 @@
+2017-05-23  Xi Ruoyao  <ryxi@stu.xidian.edu.cn>
+
+       PR libstdc++/67214
+       * include/bits/locale_facets.tcc (num_get::_M_extract_int): Add
+       explicit conversion to avoid signed overflow.
+
 2017-05-19  Jonathan Wakely  <jwakely@redhat.com>
 
        PR libstdc++/80796

diff --git a/libstdc++-v3/include/bits/locale_facets.tcc b/libstdc++-v3/include/bits/locale_facets.tcc
index 351190ccb004f4c44d65709682c01ddfd3eff932..d7710e6bb32bd1ada47c56b19b38c6f26c55d481 100644 (file)
--- a/libstdc++-v3/include/bits/locale_facets.tcc
+++ b/libstdc++-v3/include/bits/locale_facets.tcc
@@ -375,10 +375,10 @@ _GLIBCXX_BEGIN_NAMESPACE_LDBL
       _M_extract_int(_InIter __beg, _InIter __end, ios_base& __io,
                     ios_base::iostate& __err, _ValueT& __v) const
       {
-        typedef char_traits<_CharT>                         __traits_type;
+        typedef char_traits<_CharT>                        __traits_type;
        using __gnu_cxx::__add_unsigned;
-       typedef typename __add_unsigned<_ValueT>::__type __unsigned_type;
-       typedef __numpunct_cache<_CharT>                     __cache_type;
+       typedef typename __add_unsigned<_ValueT>::__type    __unsigned_type;
+       typedef __numpunct_cache<_CharT>                    __cache_type;
        __use_cache<__cache_type> __uc;
        const locale& __loc = __io._M_getloc();
        const __cache_type* __lc = __uc(__loc);
@@ -463,15 +463,16 @@ _GLIBCXX_BEGIN_NAMESPACE_LDBL
                              - __num_base::_S_izero : __base);
 
        // Extract.
+       typedef __gnu_cxx::__numeric_traits<_ValueT> __num_traits;
        string __found_grouping;
        if (__lc->_M_use_grouping)
          __found_grouping.reserve(32);
        bool __testfail = false;
        bool __testoverflow = false;
        const __unsigned_type __max =
-         (__negative && __gnu_cxx::__numeric_traits<_ValueT>::__is_signed)
-         ? -__gnu_cxx::__numeric_traits<_ValueT>::__min
-         : __gnu_cxx::__numeric_traits<_ValueT>::__max;
+         (__negative && __num_traits::__is_signed)
+         ? -static_cast<__unsigned_type>(__num_traits::__min)
+         : __num_traits::__max;
        const __unsigned_type __smax = __max / __base;
        __unsigned_type __result = 0;
        int __digit = 0;
@@ -572,11 +573,10 @@ _GLIBCXX_BEGIN_NAMESPACE_LDBL
          }
        else if (__testoverflow)
          {
-           if (__negative
-               && __gnu_cxx::__numeric_traits<_ValueT>::__is_signed)
-             __v = __gnu_cxx::__numeric_traits<_ValueT>::__min;
+           if (__negative && __num_traits::__is_signed)
+             __v = __num_traits::__min;
            else
-             __v = __gnu_cxx::__numeric_traits<_ValueT>::__max;
+             __v = __num_traits::__max;
            __err = ios_base::failbit;
          }
        else