Fix -Wunused warnings in libstdc++ headers

	* config/io/basic_file_stdio.h (__basic_file): Remove name of unused
	parameter.
	* include/bits/boost_concept_check.h: Add pragmas to disable
	-Wunused-local-typedef warnings.
	* include/bits/codecvt.h (codecvt_byname<char16_t, char, mbstate_t>)
	(codecvt_byname<char32_t, char, mbstate_t>): Remove name of unused
	parameter.
	* include/bits/locale_facets_nonio.tcc (time_get::do_get_weekday)
	(time_get::do_get_monthname, time_get::do_get_year): Remove unused
	variables.
	* include/std/bitset (_Base_bitset<0>::_M_getword): Remove name of
	unused parameter.
	* include/std/streambuf (_IsUnused): Define.
	(basic_streambuf::imbue, basic_streambuf::pbackfail)
	(basic_streambuf::overflow): Add macro to unused parameters.
	* testsuite/24_iterators/operations/prev_neg.cc: Adjust dg-error.

From-SVN: r255391

libstdc++-v3/ChangeLog

+2017-12-04  Jonathan Wakely  <jwakely@redhat.com>
+
+	* config/io/basic_file_stdio.h (__basic_file): Remove name of unused
+	parameter.
+	* include/bits/boost_concept_check.h: Add pragmas to disable
+	-Wunused-local-typedef warnings.
+	* include/bits/codecvt.h (codecvt_byname<char16_t, char, mbstate_t>)
+	(codecvt_byname<char32_t, char, mbstate_t>): Remove name of unused
+	parameter.
+	* include/bits/locale_facets_nonio.tcc (time_get::do_get_weekday)
+	(time_get::do_get_monthname, time_get::do_get_year): Remove unused
+	variables.
+	* include/std/bitset (_Base_bitset<0>::_M_getword): Remove name of
+	unused parameter.
+	* include/std/streambuf (_IsUnused): Define.
+	(basic_streambuf::imbue, basic_streambuf::pbackfail)
+	(basic_streambuf::overflow): Add macro to unused parameters.
+	* testsuite/24_iterators/operations/prev_neg.cc: Adjust dg-error.
+
 2017-12-01  Jonathan Wakely  <jwakely@redhat.com>
 
 	* include/experimental/string_view (basic_string_view::_S_compare):

libstdc++-v3/config/io/basic_file_stdio.h

@@ -63,7 +63,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       __basic_file(__c_lock* __lock = 0) throw ();
 
 #if __cplusplus >= 201103L
-      __basic_file(__basic_file&& __rv, __c_lock* __lock = 0) noexcept
+      __basic_file(__basic_file&& __rv, __c_lock* = 0) noexcept
       : _M_cfile(__rv._M_cfile), _M_cfile_created(__rv._M_cfile_created)
       {
 	__rv._M_cfile = nullptr;

libstdc++-v3/include/bits/boost_concept_check.h

@@ -48,6 +48,9 @@ namespace __gnu_cxx _GLIBCXX_VISIBILITY(default)
 {
 _GLIBCXX_BEGIN_NAMESPACE_VERSION
 
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wunused-local-typedefs"
+
 #define _IsUnused __attribute__ ((__unused__))
 
 // When the C-C code is in use, we would like this function to do as little
@@ -783,6 +786,7 @@ struct _Aux_require_same<_Tp,_Tp> { typedef _Tp _Type; };
 _GLIBCXX_END_NAMESPACE_VERSION
 } // namespace
 
+#pragma GCC diagnostic pop
 #undef _IsUnused
 
 #endif // _GLIBCXX_BOOST_CONCEPT_CHECK

libstdc++-v3/include/bits/codecvt.h

@@ -612,7 +612,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     {
     public:
       explicit
-      codecvt_byname(const char* __s, size_t __refs = 0)
+      codecvt_byname(const char*, size_t __refs = 0)
       : codecvt<char16_t, char, mbstate_t>(__refs) { }
 
       explicit
@@ -630,7 +630,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     {
     public:
       explicit
-      codecvt_byname(const char* __s, size_t __refs = 0)
+      codecvt_byname(const char*, size_t __refs = 0)
       : codecvt<char32_t, char, mbstate_t>(__refs) { }
 
       explicit

libstdc++-v3/include/bits/locale_facets_nonio.tcc

@@ -1096,7 +1096,6 @@ _GLIBCXX_END_NAMESPACE_LDBL_OR_CXX11
     {
       const locale& __loc = __io._M_getloc();
       const __timepunct<_CharT>& __tp = use_facet<__timepunct<_CharT> >(__loc);
-      const ctype<_CharT>& __ctype = use_facet<ctype<_CharT> >(__loc);
       const char_type* __days[14];
       __tp._M_days_abbreviated(__days);
       __tp._M_days(__days + 7);
@@ -1123,7 +1122,6 @@ _GLIBCXX_END_NAMESPACE_LDBL_OR_CXX11
     {
       const locale& __loc = __io._M_getloc();
       const __timepunct<_CharT>& __tp = use_facet<__timepunct<_CharT> >(__loc);
-      const ctype<_CharT>& __ctype = use_facet<ctype<_CharT> >(__loc);
       const char_type*  __months[24];
       __tp._M_months_abbreviated(__months);
       __tp._M_months(__months + 12);
@@ -1148,8 +1146,6 @@ _GLIBCXX_END_NAMESPACE_LDBL_OR_CXX11
     do_get_year(iter_type __beg, iter_type __end, ios_base& __io,
 		ios_base::iostate& __err, tm* __tm) const
     {
-      const locale& __loc = __io._M_getloc();
-      const ctype<_CharT>& __ctype = use_facet<ctype<_CharT> >(__loc);
       int __tmpyear;
       ios_base::iostate __tmperr = ios_base::goodbit;
 

libstdc++-v3/include/std/bitset

@@ -561,7 +561,7 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
       }
 
       _GLIBCXX_CONSTEXPR _WordT
-      _M_getword(size_t __pos) const _GLIBCXX_NOEXCEPT
+      _M_getword(size_t) const _GLIBCXX_NOEXCEPT
       { return 0; }
 
       _GLIBCXX_CONSTEXPR _WordT

libstdc++-v3/include/std/streambuf

@@ -46,6 +46,8 @@ namespace std _GLIBCXX_VISIBILITY(default)
 {
 _GLIBCXX_BEGIN_NAMESPACE_VERSION
 
+#define _IsUnused __attribute__ ((__unused__))
+
   template<typename _CharT, typename _Traits>
     streamsize
     __copy_streambufs_eof(basic_streambuf<_CharT, _Traits>*,
@@ -578,7 +580,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
        *  @note  Base class version does nothing.
       */
       virtual void
-      imbue(const locale& __loc)
+      imbue(const locale& __loc _IsUnused)
       { }
 
       // [27.5.2.4.2] buffer management and positioning
@@ -726,7 +728,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
        *  @note  Base class version does nothing, returns eof().
       */
       virtual int_type
-      pbackfail(int_type __c  = traits_type::eof())
+      pbackfail(int_type __c _IsUnused  = traits_type::eof())
       { return traits_type::eof(); }
 
       // Put area:
@@ -770,7 +772,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
        *  @note  Base class version does nothing, returns eof().
       */
       virtual int_type
-      overflow(int_type __c  = traits_type::eof())
+      overflow(int_type __c _IsUnused  = traits_type::eof())
       { return traits_type::eof(); }
 
 #if _GLIBCXX_USE_DEPRECATED && __cplusplus <= 201402L
@@ -852,6 +854,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 			  basic_streambuf<wchar_t>* __sbout, bool& __ineof);
 #endif
 
+#undef _IsUnused
+
 _GLIBCXX_END_NAMESPACE_VERSION
 } // namespace
 

libstdc++-v3/testsuite/24_iterators/operations/prev_neg.cc

@@ -38,5 +38,5 @@ test02()
 {
   const Y array[1] = { };
   std::prev(array + 1);
-  // { dg-error "forward_iterator" "" { target *-*-* } 220 }
+  // { dg-error "forward_iterator" "" { target *-*-* } 223 }
 }