[PATCH] Fix handling of an empty filename at end of a path
Jonathan Wakely
jwakely@redhat.com
Wed May 23 16:10:00 GMT 2018
The C++17 std::filesystem::path grammar allows an empty filename as the
last component (to signify a trailing slash). The existing code does not
handle this consistently, sometimes an empty filename has type _Multi
and sometimes it has type _Filename. This can result in a non-empty
iterator range for an empty filename component.
This change ensures that empty paths always have type _Filename and will
yield an empty iterator range.
* include/bits/fs_path.h (path::_M_type): Change default member
initializer to _Filename.
(path::begin): Create past-the-end iterator for empty path.
* src/filesystem/std-path.cc (path::remove_filename()): Remove
debugging check.
(path::has_relative_path()): Return false for empty filenames.
(path::_M_split_cmpts): Set _M_type to _Filename for empty paths.
Fix offset of empty final component.
* testsuite/27_io/filesystem/path/itr/components.cc: New.
* testsuite/27_io/filesystem/path/itr/traversal.cc: Add new inputs.
Tested powerpc64le-linux, committed to trunk. I plan to backport this
to gcc-8-branch too.
-------------- next part --------------
commit ce947893c8e04ab3cde5f5dd3364a94a068b313c
Author: Jonathan Wakely <jwakely@redhat.com>
Date: Wed May 23 14:42:08 2018 +0100
Fix handling of an empty filename at end of a path
The C++17 std::filesystem::path grammar allows an empty filename as the
last component (to signify a trailing slash). The existing code does not
handle this consistently, sometimes an empty filename has type _Multi
and sometimes it has type _Filename. This can result in a non-empty
iterator range for an empty filename component.
This change ensures that empty paths always have type _Filename and will
yield an empty iterator range.
* include/bits/fs_path.h (path::_M_type): Change default member
initializer to _Filename.
(path::begin): Create past-the-end iterator for empty path.
* src/filesystem/std-path.cc (path::remove_filename()): Remove
debugging check.
(path::has_relative_path()): Return false for empty filenames.
(path::_M_split_cmpts): Set _M_type to _Filename for empty paths.
Fix offset of empty final component.
* testsuite/27_io/filesystem/path/itr/components.cc: New.
* testsuite/27_io/filesystem/path/itr/traversal.cc: Add new inputs.
diff --git a/libstdc++-v3/include/bits/fs_path.h b/libstdc++-v3/include/bits/fs_path.h
index 51af2891647..79a341830db 100644
--- a/libstdc++-v3/include/bits/fs_path.h
+++ b/libstdc++-v3/include/bits/fs_path.h
@@ -497,7 +497,7 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11
struct _Cmpt;
using _List = _GLIBCXX_STD_C::vector<_Cmpt>;
_List _M_cmpts; // empty unless _M_type == _Type::_Multi
- _Type _M_type = _Type::_Multi;
+ _Type _M_type = _Type::_Filename;
};
template<>
@@ -1076,7 +1076,7 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11
{
if (_M_type == _Type::_Multi)
return iterator(this, _M_cmpts.begin());
- return iterator(this, false);
+ return iterator(this, empty());
}
inline path::iterator
diff --git a/libstdc++-v3/src/filesystem/std-path.cc b/libstdc++-v3/src/filesystem/std-path.cc
index 6f594cec1d5..755cb7c883a 100644
--- a/libstdc++-v3/src/filesystem/std-path.cc
+++ b/libstdc++-v3/src/filesystem/std-path.cc
@@ -63,8 +63,6 @@ path::remove_filename()
}
else if (_M_type == _Type::_Filename)
clear();
- if (!empty() && _M_pathname.back() != '/')
- throw 1;
return *this;
}
@@ -292,7 +290,7 @@ path::has_root_path() const
bool
path::has_relative_path() const
{
- if (_M_type == _Type::_Filename)
+ if (_M_type == _Type::_Filename && !_M_pathname.empty())
return true;
if (!_M_cmpts.empty())
{
@@ -301,7 +299,7 @@ path::has_relative_path() const
++__it;
if (__it != _M_cmpts.end() && __it->_M_type == _Type::_Root_dir)
++__it;
- if (__it != _M_cmpts.end())
+ if (__it != _M_cmpts.end() && !__it->_M_pathname.empty())
return true;
}
return false;
@@ -514,11 +512,13 @@ path::_M_find_extension() const
void
path::_M_split_cmpts()
{
- _M_type = _Type::_Multi;
_M_cmpts.clear();
-
if (_M_pathname.empty())
- return;
+ {
+ _M_type = _Type::_Filename;
+ return;
+ }
+ _M_type = _Type::_Multi;
size_t pos = 0;
const size_t len = _M_pathname.size();
@@ -593,8 +593,7 @@ path::_M_split_cmpts()
// An empty element, if trailing non-root directory-separator present.
if (_M_cmpts.back()._M_type == _Type::_Filename)
{
- const auto& last = _M_cmpts.back();
- pos = last._M_pos + last._M_pathname.size();
+ pos = _M_pathname.size();
_M_cmpts.emplace_back(string_type(), _Type::_Filename, pos);
}
}
diff --git a/libstdc++-v3/testsuite/27_io/filesystem/path/itr/components.cc b/libstdc++-v3/testsuite/27_io/filesystem/path/itr/components.cc
new file mode 100644
index 00000000000..15736b22fd5
--- /dev/null
+++ b/libstdc++-v3/testsuite/27_io/filesystem/path/itr/components.cc
@@ -0,0 +1,51 @@
+// Copyright (C) 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/>.
+
+// { dg-options "-std=gnu++17 -lstdc++fs" }
+// { dg-do run { target c++17 } }
+// { dg-require-filesystem-ts "" }
+
+#include <filesystem>
+#include <iterator>
+#include <testsuite_hooks.h>
+#include <testsuite_fs.h>
+
+void
+test01()
+{
+ for (std::filesystem::path p : __gnu_test::test_paths)
+ {
+ if (p.empty())
+ VERIFY(std::distance(p.begin(), p.end()) == 0);
+ else
+ VERIFY(std::distance(p.begin(), p.end()) != 0);
+
+ for (const std::filesystem::path& cmpt : p)
+ {
+ if (cmpt.empty())
+ VERIFY(std::distance(cmpt.begin(), cmpt.end()) == 0);
+ else
+ VERIFY(std::distance(cmpt.begin(), cmpt.end()) == 1);
+ }
+ }
+}
+
+int
+main()
+{
+ test01();
+}
diff --git a/libstdc++-v3/testsuite/27_io/filesystem/path/itr/traversal.cc b/libstdc++-v3/testsuite/27_io/filesystem/path/itr/traversal.cc
index 3fc60d48d13..c23cb14fd73 100644
--- a/libstdc++-v3/testsuite/27_io/filesystem/path/itr/traversal.cc
+++ b/libstdc++-v3/testsuite/27_io/filesystem/path/itr/traversal.cc
@@ -104,7 +104,7 @@ test02()
void
test03()
{
- path paths[] = { "single", "multiple/elements" };
+ path paths[] = { "single", "multiple/elements", "trailing/slash/", "/." };
for (const path& p : paths)
for (auto iter = p.begin(); iter != p.end(); ++iter)
{
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