Copy string_view tests from libstdc++

This patch copies the string_view tests from the gcc repository (commit
02a4441f002c).

  ${gcc}/libstdc++-v3/testsuite/21_strings/basic_string_view ->
    ${binutils-gdb}/gdb/unittests/basic_string_view

The local modifications are done in the following patch, so that it's
easier to review them.

gdb/ChangeLog:

	* unittests/basic_string_view/capacity/1.cc: New file.
	* unittests/basic_string_view/capacity/empty_neg.cc: New file.
	* unittests/basic_string_view/cons/char/1.cc: New file.
	* unittests/basic_string_view/cons/char/2.cc: New file.
	* unittests/basic_string_view/cons/char/3.cc: New file.
	* unittests/basic_string_view/cons/wchar_t/1.cc: New file.
	* unittests/basic_string_view/cons/wchar_t/2.cc: New file.
	* unittests/basic_string_view/cons/wchar_t/3.cc: New file.
	* unittests/basic_string_view/element_access/char/1.cc: New file.
	* unittests/basic_string_view/element_access/char/2.cc: New file.
	* unittests/basic_string_view/element_access/char/empty.cc: New file.
	* unittests/basic_string_view/element_access/char/front_back.cc: New file.
	* unittests/basic_string_view/element_access/wchar_t/1.cc: New file.
	* unittests/basic_string_view/element_access/wchar_t/2.cc: New file.
	* unittests/basic_string_view/element_access/wchar_t/empty.cc: New file.
	* unittests/basic_string_view/element_access/wchar_t/front_back.cc: New file.
	* unittests/basic_string_view/include.cc: New file.
	* unittests/basic_string_view/inserters/char/1.cc: New file.
	* unittests/basic_string_view/inserters/char/2.cc: New file.
	* unittests/basic_string_view/inserters/char/3.cc: New file.
	* unittests/basic_string_view/inserters/pod/10081-out.cc: New file.
	* unittests/basic_string_view/inserters/wchar_t/1.cc: New file.
	* unittests/basic_string_view/inserters/wchar_t/2.cc: New file.
	* unittests/basic_string_view/inserters/wchar_t/3.cc: New file.
	* unittests/basic_string_view/literals/types.cc: New file.
	* unittests/basic_string_view/literals/values.cc: New file.
	* unittests/basic_string_view/modifiers/remove_prefix/char/1.cc: New file.
	* unittests/basic_string_view/modifiers/remove_prefix/wchar_t/1.cc: New file.
	* unittests/basic_string_view/modifiers/remove_suffix/char/1.cc: New file.
	* unittests/basic_string_view/modifiers/remove_suffix/wchar_t/1.cc: New file.
	* unittests/basic_string_view/modifiers/swap/char/1.cc: New file.
	* unittests/basic_string_view/modifiers/swap/wchar_t/1.cc: New file.
	* unittests/basic_string_view/operations/compare/char/1.cc: New file.
	* unittests/basic_string_view/operations/compare/char/13650.cc: New file.
	* unittests/basic_string_view/operations/compare/char/2.cc: New file.
	* unittests/basic_string_view/operations/compare/char/70483.cc: New file.
	* unittests/basic_string_view/operations/compare/wchar_t/1.cc: New file.
	* unittests/basic_string_view/operations/compare/wchar_t/13650.cc: New file.
	* unittests/basic_string_view/operations/compare/wchar_t/2.cc: New file.
	* unittests/basic_string_view/operations/copy/char/1.cc: New file.
	* unittests/basic_string_view/operations/copy/wchar_t/1.cc: New file.
	* unittests/basic_string_view/operations/data/char/1.cc: New file.
	* unittests/basic_string_view/operations/data/wchar_t/1.cc: New file.
	* unittests/basic_string_view/operations/find/char/1.cc: New file.
	* unittests/basic_string_view/operations/find/char/2.cc: New file.
	* unittests/basic_string_view/operations/find/char/3.cc: New file.
	* unittests/basic_string_view/operations/find/char/4.cc: New file.
	* unittests/basic_string_view/operations/find/wchar_t/1.cc: New file.
	* unittests/basic_string_view/operations/find/wchar_t/2.cc: New file.
	* unittests/basic_string_view/operations/find/wchar_t/3.cc: New file.
	* unittests/basic_string_view/operations/find/wchar_t/4.cc: New file.
	* unittests/basic_string_view/operations/rfind/char/1.cc: New file.
	* unittests/basic_string_view/operations/rfind/char/2.cc: New file.
	* unittests/basic_string_view/operations/rfind/char/3.cc: New file.
	* unittests/basic_string_view/operations/rfind/wchar_t/1.cc: New file.
	* unittests/basic_string_view/operations/rfind/wchar_t/2.cc: New file.
	* unittests/basic_string_view/operations/rfind/wchar_t/3.cc: New file.
	* unittests/basic_string_view/operations/string_conversion/1.cc: New file.
	* unittests/basic_string_view/operations/substr/char/1.cc: New file.
	* unittests/basic_string_view/operations/substr/wchar_t/1.cc: New file.
	* unittests/basic_string_view/operators/char/2.cc: New file.
	* unittests/basic_string_view/operators/wchar_t/2.cc: New file.
	* unittests/basic_string_view/range_access/char/1.cc: New file.
	* unittests/basic_string_view/range_access/wchar_t/1.cc: New file.
	* unittests/basic_string_view/requirements/explicit_instantiation/1.cc: New file.
	* unittests/basic_string_view/requirements/explicit_instantiation/char/1.cc: New file.
	* unittests/basic_string_view/requirements/explicit_instantiation/char16_t/1.cc: New file.
	* unittests/basic_string_view/requirements/explicit_instantiation/char32_t/1.cc: New file.
	* unittests/basic_string_view/requirements/explicit_instantiation/wchar_t/1.cc: New file.
	* unittests/basic_string_view/requirements/typedefs.cc: New file.
	* unittests/basic_string_view/typedefs.cc: New file.
	* unittests/basic_string_view/types/1.cc: New file.

1 files changed, 71 insertions, 0 deletions

diff --git a/gdb/unittests/basic_string_view/element_access/wchar_t/1.cc b/gdb/unittests/basic_string_view/element_access/wchar_t/1.cc
new file mode 100644
index 0000000..b74ee29
--- /dev/null
+++ b/gdb/unittests/basic_string_view/element_access/wchar_t/1.cc
@@ -0,0 +1,71 @@
+// { dg-options "-std=gnu++17" }
+
+// Copyright (C) 2013-2018 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// basic_string_view element access
+
+#include <string_view>
+#include <stdexcept>
+#include <testsuite_hooks.h>
+
+void
+test01()
+{
+  typedef std::wstring_view::size_type csize_type;
+  typedef std::wstring_view::const_reference cref;
+  typedef std::wstring_view::reference ref;
+  csize_type csz01, csz02;
+
+  const std::wstring_view str01(L"tamarindo, costa rica");
+  std::wstring_view str02(L"41st street beach, capitola, california");
+  std::wstring_view str03;
+
+  // const_reference operator[] (size_type pos) const;
+  csz01 = str01.size();
+  cref cref1 = str01[csz01 - 1];
+  VERIFY( cref1 == L'a' );
+  // Undefined behavior at size().
+  //cref cref2 = str01[csz01];
+  //VERIFY( cref2 == wchar_t() );
+
+  // const_reference at(size_type pos) const;
+  csz01 = str01.size();
+  cref cref3 = str01.at(csz01 - 1);
+  VERIFY( cref3 == L'a' );
+  try
+  {
+    str01.at(csz01);
+    VERIFY( false ); // Should not get here, as exception thrown.
+  }
+  catch (std::out_of_range& fail)
+  {
+    VERIFY( true );
+  }
+  catch (...)
+  {
+    VERIFY( false );
+  }
+}
+
+int
+main()
+{ 
+  test01();
+
+  return 0;
+}