P0482R5 char8_t: Standard library support

gcc/cp:

2019-02-19  Tom Honermann  <tom@honermann.net>

	* name-lookup.c (get_std_name_hint): Added u8string as a name hint.

libstdc++:

2019-02-19  Tom Honermann  <tom@honermann.net>

	P0482R5 char8_t: Standard library support
	* config/abi/pre/gnu-versioned-namespace.ver (CXXABI_2.0): Add
	typeinfo symbols for char8_t.
	* config/abi/pre/gnu.ver: Add CXXABI_1.3.12.
	(GLIBCXX_3.4.26): Add symbols for specializations of
	numeric_limits and codecvt that involve char8_t.
	(CXXABI_1.3.12): Add typeinfo symbols for char8_t.
	* include/bits/atomic_base.h: Add atomic_char8_t.
	* include/bits/basic_string.h: Add std::hash<u8string> and
	operator""s(const char8_t*, size_t).
	* include/bits/c++config: Define _GLIBCXX_USE_CHAR8_T and
	__cpp_lib_char8_t.
	* include/bits/char_traits.h: Add char_traits<char8_t>.
	* include/bits/codecvt.h: Add
	codecvt<char16_t, char8_t, mbstate_t>,
	codecvt<char32_t, char8_t, mbstate_t>,
	codecvt_byname<char16_t, char8_t, mbstate_t>, and
	codecvt_byname<char32_t, char8_t, mbstate_t>.
	* include/bits/cpp_type_traits.h: Add __is_integer<char8_t> to
	recognize char8_t as an integral type.
	* include/bits/fs_path.h: (path::__is_encoded_char): Recognize
	char8_t.
	(path::u8string): Return std::u8string when char8_t support is
	enabled.
	(path::generic_u8string): Likewise.
	(path::_S_convert): Handle conversion from char8_t input.
	(path::_S_str_convert): Likewise.
	* include/bits/functional_hash.h: Add hash<char8_t>.
	* include/bits/locale_conv.h (__str_codecvt_out): Add overloads for
	char8_t.
	* include/bits/locale_facets.h (_GLIBCXX_NUM_UNICODE_FACETS): Bump
	for new char8_t specializations.
	* include/bits/localefwd.h: Add missing declarations of
	codecvt<char16_t, char, mbstate_t> and
	codecvt<char32_t, char, mbstate_t>.  Add char8_t declarations
	codecvt<char16_t, char8_t, mbstate_t> and
	codecvt<char32_t, char8_t, mbstate_t>.
	* include/bits/postypes.h: Add u8streampos
	* include/bits/stringfwd.h: Add declarations of
	char_traits<char8_t> and u8string.
	* include/c_global/cstddef: Add __byte_operand<char8_t>.
	* include/experimental/bits/fs_path.h (path::__is_encoded_char):
	Recognize char8_t.
	(path::u8string): Return std::u8string when char8_t support is
	enabled.
	(path::generic_u8string): Likewise.
	(path::_S_convert): Handle conversion from char8_t input.
	(path::_S_str_convert): Likewise.
	* include/experimental/string: Add u8string.
	* include/experimental/string_view: Add u8string_view,
	hash<experimental::u8string_view>, and
	operator""sv(const char8_t*, size_t).
	* include/std/atomic: Add atomic<char8_t> and atomic_char8_t.
	* include/std/charconv (__is_int_to_chars_type): Recognize char8_t
	as a character type.
	* include/std/limits: Add numeric_limits<char8_t>.
	* include/std/string_view: Add u8string_view,
	hash<experimental::u8string_view>, and
	operator""sv(const char8_t*, size_t).
	* include/std/type_traits: Add __is_integral_helper<char8_t>,
	__make_unsigned<char8_t>, and __make_signed<char8_t>.
	* libsupc++/atomic_lockfree_defines.h: Define
	ATOMIC_CHAR8_T_LOCK_FREE.
	* src/c++11/Makefile.am: Compile with -fchar8_t when compiling
	codecvt.cc and limits.cc so that char8_t specializations of
	numeric_limits and codecvt and emitted.
	* src/c++11/Makefile.in: Likewise.
	* src/c++11/codecvt.cc: Define members of
	codecvt<char16_t, char8_t, mbstate_t>,
	codecvt<char32_t, char8_t, mbstate_t>,
	codecvt_byname<char16_t, char8_t, mbstate_t>, and
	codecvt_byname<char32_t, char8_t, mbstate_t>.
	* src/c++11/limits.cc: Define members of
	numeric_limits<char8_t>.
	* src/c++98/Makefile.am: Compile with -fchar8_t when compiling
	locale_init.cc and localename.cc.
	* src/c++98/Makefile.in: Likewise.
	* src/c++98/locale_init.cc: Add initialization for the
	codecvt<char16_t, char8_t, mbstate_t> and
	codecvt<char32_t, char8_t, mbstate_t> facets.
	* src/c++98/localename.cc: Likewise.
	* testsuite/util/testsuite_abi.cc: Validate ABI bump.

From-SVN: r269004

3 files changed, 104 insertions, 16 deletions

diff --git a/libstdc++-v3/include/experimental/bits/fs_path.h b/libstdc++-v3/include/experimental/bits/fs_path.h
index 239776df313..ebd5072fc1a 100644
--- a/libstdc++-v3/include/experimental/bits/fs_path.h
+++ b/libstdc++-v3/include/experimental/bits/fs_path.h
@@ -82,8 +82,13 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11
     template<typename _CharT,
 	     typename _Ch = typename remove_const<_CharT>::type>
       using __is_encoded_char
-	= __or_<is_same<_Ch, char>, is_same<_Ch, wchar_t>,
-		is_same<_Ch, char16_t>, is_same<_Ch, char32_t>>;
+	= __or_<is_same<_Ch, char>,
+		is_same<_Ch, wchar_t>,
+#ifdef _GLIBCXX_USE_CHAR8_T
+		is_same<_Ch, char8_t>,
+#endif
+		is_same<_Ch, char16_t>,
+		is_same<_Ch, char32_t>>;
 
     template<typename _Iter,
 	     typename _Iter_traits = std::iterator_traits<_Iter>>
@@ -325,7 +330,12 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11
 #if _GLIBCXX_USE_WCHAR_T
     std::wstring   wstring() const;
 #endif
+#ifdef _GLIBCXX_USE_CHAR8_T
+    __attribute__((__abi_tag__("__u8")))
+    std::u8string  u8string() const;
+#else
     std::string    u8string() const;
+#endif // _GLIBCXX_USE_CHAR8_T
     std::u16string u16string() const;
     std::u32string u32string() const;
 
@@ -339,7 +349,12 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11
 #if _GLIBCXX_USE_WCHAR_T
     std::wstring   generic_wstring() const;
 #endif
+#ifdef _GLIBCXX_USE_CHAR8_T
+    __attribute__((__abi_tag__("__u8")))
+    std::u8string  generic_u8string() const;
+#else
     std::string    generic_u8string() const;
+#endif // _GLIBCXX_USE_CHAR8_T
     std::u16string generic_u16string() const;
     std::u32string generic_u32string() const;
 
@@ -674,10 +689,22 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11
       static string_type
       _S_convert(const _CharT* __f, const _CharT* __l)
       {
-	std::codecvt_utf8<_CharT> __cvt;
-	std::string __str;
-	if (__str_codecvt_out(__f, __l, __str, __cvt))
-	  return __str;
+#ifdef _GLIBCXX_USE_CHAR8_T
+	if constexpr (is_same<_CharT, char8_t>::value)
+	  {
+	    string_type __str(__f, __l);
+	    return __str;
+	  }
+	else
+	  {
+#endif
+	    std::codecvt_utf8<_CharT> __cvt;
+	    std::string __str;
+	    if (__str_codecvt_out(__f, __l, __str, __cvt))
+	      return __str;
+#ifdef _GLIBCXX_USE_CHAR8_T
+	  }
+#endif
 	_GLIBCXX_THROW_OR_ABORT(filesystem_error(
 	      "Cannot convert character sequence",
 	      std::make_error_code(errc::illegal_byte_sequence)));
@@ -867,12 +894,24 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11
 	    _WString*
 	    operator()(const _String& __from, _WString& __to, false_type)
 	    {
-	      // use codecvt_utf8<_CharT> to convert UTF-8 to wide string
-	      codecvt_utf8<_CharT> __cvt;
-	      const char* __f = __from.data();
-	      const char* __l = __f + __from.size();
-	      if (__str_codecvt_in(__f, __l, __to, __cvt))
-		return std::__addressof(__to);
+#ifdef _GLIBCXX_USE_CHAR8_T
+	      if constexpr (is_same<_CharT, char8_t>::value)
+	        {
+	          __to.assign(__from.begin(), __from.end());
+	          return std::__addressof(__to);
+	        }
+	      else
+	        {
+#endif
+	          // use codecvt_utf8<_CharT> to convert UTF-8 to wide string
+	          codecvt_utf8<_CharT> __cvt;
+	          const char* __f = __from.data();
+	          const char* __l = __f + __from.size();
+	          if (__str_codecvt_in(__f, __l, __to, __cvt))
+		    return std::__addressof(__to);
+#ifdef _GLIBCXX_USE_CHAR8_T
+	        }
+#endif
 	      return nullptr;
 	    }
 	  } __dispatch;
@@ -881,10 +920,22 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11
 	    return *__p;
 	}
 #else
-      codecvt_utf8<_CharT> __cvt;
-      basic_string<_CharT, _Traits, _Allocator> __wstr{__a};
-      if (__str_codecvt_in(__first, __last, __wstr, __cvt))
-	return __wstr;
+#ifdef _GLIBCXX_USE_CHAR8_T
+      if constexpr (is_same<_CharT, char8_t>::value)
+        {
+          basic_string<_CharT, _Traits, _Allocator> __wstr{__first, __last, __a};
+          return __wstr;
+        }
+      else
+        {
+#endif
+          codecvt_utf8<_CharT> __cvt;
+          basic_string<_CharT, _Traits, _Allocator> __wstr{__a};
+          if (__str_codecvt_in(__first, __last, __wstr, __cvt))
+	    return __wstr;
+#ifdef _GLIBCXX_USE_CHAR8_T
+        }
+#endif
 #endif
       _GLIBCXX_THROW_OR_ABORT(filesystem_error(
 	    "Cannot convert character sequence",
@@ -899,6 +950,10 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11
   path::wstring() const { return string<wchar_t>(); }
 #endif
 
+#ifdef _GLIBCXX_USE_CHAR8_T
+  inline std::u8string
+  path::u8string() const { return string<char8_t>(); }
+#else
   inline std::string
   path::u8string() const
   {
@@ -917,6 +972,7 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11
     return _M_pathname;
 #endif
   }
+#endif // _GLIBCXX_USE_CHAR8_T
 
   inline std::u16string
   path::u16string() const { return string<char16_t>(); }
@@ -938,8 +994,13 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11
   path::generic_wstring() const { return wstring(); }
 #endif
 
+#ifdef _GLIBCXX_USE_CHAR8_T
+  inline std::u8string
+  path::generic_u8string() const { return u8string(); }
+#else
   inline std::string
   path::generic_u8string() const { return u8string(); }
+#endif
 
   inline std::u16string
   path::generic_u16string() const { return u16string(); }
diff --git a/libstdc++-v3/include/experimental/string b/libstdc++-v3/include/experimental/string
index a8ab002d445..65bf2b8d009 100644
--- a/libstdc++-v3/include/experimental/string
+++ b/libstdc++-v3/include/experimental/string
@@ -73,6 +73,9 @@ inline namespace fundamentals_v2
     // basic_string typedef names using polymorphic allocator in namespace
     // std::experimental::pmr
     typedef basic_string<char> string;
+#ifdef _GLIBCXX_USE_CHAR8_T
+    typedef basic_string<char8_t> u8string;
+#endif
     typedef basic_string<char16_t> u16string;
     typedef basic_string<char32_t> u32string;
     typedef basic_string<wchar_t> wstring;
diff --git a/libstdc++-v3/include/experimental/string_view b/libstdc++-v3/include/experimental/string_view
index 8cc0e90246b..ce2c14cfe36 100644
--- a/libstdc++-v3/include/experimental/string_view
+++ b/libstdc++-v3/include/experimental/string_view
@@ -566,6 +566,9 @@ inline namespace fundamentals_v1
 #ifdef _GLIBCXX_USE_WCHAR_T
   using wstring_view = basic_string_view<wchar_t>;
 #endif
+#ifdef _GLIBCXX_USE_CHAR8_T
+  using u8string_view = basic_string_view<char8_t>;
+#endif
   using u16string_view = basic_string_view<char16_t>;
   using u32string_view = basic_string_view<char32_t>;
 } // namespace fundamentals_v1
@@ -605,6 +608,21 @@ inline namespace fundamentals_v1
     { };
 #endif
 
+#ifdef _GLIBCXX_USE_CHAR8_T
+  template<>
+    struct hash<experimental::u8string_view>
+    : public __hash_base<size_t, experimental::u8string_view>
+    {
+      size_t
+      operator()(const experimental::u8string_view& __s) const noexcept
+      { return std::_Hash_impl::hash(__s.data(), __s.length()); }
+    };
+
+  template<>
+    struct __is_fast_hash<hash<experimental::u8string_view>> : std::false_type
+    { };
+#endif
+
   template<>
     struct hash<experimental::u16string_view>
     : public __hash_base<size_t, experimental::u16string_view>
@@ -652,6 +670,12 @@ namespace experimental
     { return basic_string_view<wchar_t>{__str, __len}; }
 #endif
 
+#ifdef _GLIBCXX_USE_CHAR8_T
+    inline constexpr basic_string_view<char8_t>
+    operator""sv(const char8_t* __str, size_t __len) noexcept
+    { return basic_string_view<char8_t>{__str, __len}; }
+#endif
+
     inline constexpr basic_string_view<char16_t>
     operator""sv(const char16_t* __str, size_t __len) noexcept
     { return basic_string_view<char16_t>{__str, __len}; }