Add recursive_directory_iterator::pop(error_code&)

* include/experimental/bits/fs_dir.h (recursive_directory_iterator):
	Overload pop (LWG 2706).
	* src/filesystem/dir.cc (recursive_directory_iterator::pop): Define
	new overload.
	* testsuite/experimental/filesystem/iterators/pop.cc: New test.

From-SVN: r241559

libstdc++-v3/ChangeLog

@@ -1,5 +1,11 @@
 2016-10-26  Jonathan Wakely  <jwakely@redhat.com>
 
+	* include/experimental/bits/fs_dir.h (recursive_directory_iterator):
+	Overload pop (LWG 2706).
+	* src/filesystem/dir.cc (recursive_directory_iterator::pop): Define
+	new overload.
+	* testsuite/experimental/filesystem/iterators/pop.cc: New test.
+
 	* src/filesystem/dir.cc (recursive_directory_iterator::increment):
 	Reset state on error.
 	* testsuite/experimental/filesystem/iterators/

libstdc++-v3/include/experimental/bits/fs_dir.h

@@ -312,6 +312,7 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11
     }
 
     void pop();
+    void pop(error_code&);
 
     void disable_recursion_pending() { _M_pending = false; }
 

libstdc++-v3/src/filesystem/dir.cc

@@ -364,19 +364,33 @@ fs::recursive_directory_iterator::increment(error_code& ec) noexcept
 }
 
 void
-fs::recursive_directory_iterator::pop()
+fs::recursive_directory_iterator::pop(error_code& ec)
 {
   if (!_M_dirs)
-    _GLIBCXX_THROW_OR_ABORT(filesystem_error(
-	  "cannot pop non-dereferenceable recursive directory iterator",
-	  std::make_error_code(errc::invalid_argument)));
+    {
+      ec = std::make_error_code(errc::invalid_argument);
+      return;
+    }
 
   do {
     _M_dirs->pop();
     if (_M_dirs->empty())
       {
 	_M_dirs.reset();
+	ec.clear();
 	return;
       }
-  } while (!_M_dirs->top().advance(nullptr, _M_options));
+  } while (!_M_dirs->top().advance(&ec, _M_options));
+}
+
+void
+fs::recursive_directory_iterator::pop()
+{
+  error_code ec;
+  pop(ec);
+  if (ec)
+    _GLIBCXX_THROW_OR_ABORT(filesystem_error(_M_dirs
+	  ? "recursive directory iterator cannot pop"
+	  : "non-dereferenceable recursive directory iterator cannot pop",
+	  ec));
 }

libstdc++-v3/testsuite/experimental/filesystem/iterators/pop.cc

@@ -0,0 +1,115 @@
+// Copyright (C) 2016 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/>.
+
+// { dg-options "-lstdc++fs" }
+// { dg-do run { target c++11 } }
+// { dg-require-filesystem-ts "" }
+
+#include <experimental/filesystem>
+#include <testsuite_hooks.h>
+#include <testsuite_fs.h>
+
+namespace fs = std::experimental::filesystem;
+
+void
+test01()
+{
+  std::error_code ec;
+  fs::recursive_directory_iterator dir;
+  dir.pop(ec);  // This is undefined, but our implementation
+  VERIFY( ec ); // checks and returns an error.
+  VERIFY( dir == end(dir) );
+
+  std::error_code ec2;
+  try
+  {
+    dir.pop();
+  }
+  catch (const fs::filesystem_error& ex)
+  {
+    ec2 = ex.code();
+  }
+  VERIFY( ec2 == ec );
+}
+
+void
+test02()
+{
+  std::error_code ec = make_error_code(std::errc::interrupted);
+  const auto p = __gnu_test::nonexistent_path();
+  create_directories(p / "d1/d2/d3");
+  for (int i = 0; i < 3; ++i)
+  {
+    fs::recursive_directory_iterator dir(p);
+    std::advance(dir, i);
+    VERIFY( dir.depth() == i );
+    dir.pop(ec);
+    VERIFY( !ec );
+    VERIFY( dir == end(dir) );
+
+    dir = fs::recursive_directory_iterator(p);
+    std::advance(dir, i);
+    VERIFY( dir.depth() == i );
+    dir.pop();
+    VERIFY( dir == end(dir) );
+  }
+  remove_all(p, ec);
+}
+
+void
+test03()
+{
+  std::error_code ec = make_error_code(std::errc::interrupted);
+  const auto p = __gnu_test::nonexistent_path();
+  create_directories(p / "d1/d2/d3");
+  create_directories(p / "d1/d2/e3");
+  create_directories(p / "d1/e2/d3");
+  create_directories(p / "e1");
+  __gnu_test::scoped_file f(p / "d1/d2/d3/f");
+  for (int i = 0; i < 4; ++i)
+  {
+    fs::recursive_directory_iterator dir(p);
+    std::advance(dir, i);
+    int expected_depth = std::min(i, 3); // fourth entry is a file, not dir
+    VERIFY( dir.depth() == expected_depth );
+    __builtin_printf("%d %d %s\n", i, dir.depth(), dir->path().c_str());
+    dir.pop(ec);
+    VERIFY( !ec );
+    if (dir != end(dir))
+    {
+    __builtin_printf("%d %d %s\n", i, dir.depth(), dir->path().c_str());
+      VERIFY( dir.depth() == (expected_depth - 1) );
+    }
+
+    dir = fs::recursive_directory_iterator(p);
+    std::advance(dir, i);
+    VERIFY( dir.depth() == i );
+    dir.pop();
+    if (dir != end(dir))
+      VERIFY( dir.depth() == (i -1) );
+  }
+  f.path.clear();
+  remove_all(p, ec);
+}
+
+int
+main()
+{
+  test01();
+  test02();
+  test03();
+}