[gcc(refs/vendors/redhat/heads/gcc-10-branch)] libstdc++: Handle type-changing path concatenations (PR 94063)
Jakub Jelinek
jakub@gcc.gnu.org
Wed Mar 11 23:11:35 GMT 2020
https://gcc.gnu.org/g:ea182fe63634bb5b7913b3f1b6846e1900c5e0c4
commit ea182fe63634bb5b7913b3f1b6846e1900c5e0c4
Author: Jonathan Wakely <jwakely@redhat.com>
Date: Mon Mar 9 23:22:57 2020 +0000
libstdc++: Handle type-changing path concatenations (PR 94063)
The filesystem::path::operator+= and filesystem::path::concat functions
operate directly on the native format of the path and so can cause a
path to mutate to a completely different type.
For Windows combining a filename "x" with a filename ":" produces a
root-name "x:". Similarly, a Cygwin root-directory "/" combined with a
root-directory and filename "/x" produces a root-name "//x".
Before this patch the implemenation didn't support those kind of
mutations, assuming that concatenating two filenames would always
produce a filename and concatenating with a root-dir would still have a
root-dir.
This patch fixes it simply by checking for the problem cases and
creating a new path by re-parsing the result of the string
concatenation. This is slightly suboptimal because the argument has
already been parsed if it's a path, but more importantly it doesn't
reuse any excess capacity that the path object being modified might
already have allocated. That can be fixed later though.
PR libstdc++/94063
* src/c++17/fs_path.cc (path::operator+=(const path&)): Add kluge to
handle concatenations that change the type of the first component.
(path::operator+=(basic_string_view<value_type>)): Likewise.
* testsuite/27_io/filesystem/path/concat/94063.cc: New test.
Diff:
---
libstdc++-v3/ChangeLog | 8 ++
libstdc++-v3/src/c++17/fs_path.cc | 40 ++++++++
.../27_io/filesystem/path/concat/94063.cc | 111 +++++++++++++++++++++
3 files changed, 159 insertions(+)
diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog
index b3e8b9a25d2..be382dc4e63 100644
--- a/libstdc++-v3/ChangeLog
+++ b/libstdc++-v3/ChangeLog
@@ -1,3 +1,11 @@
+2020-03-09 Jonathan Wakely <jwakely@redhat.com>
+
+ PR libstdc++/94063
+ * src/c++17/fs_path.cc (path::operator+=(const path&)): Add kluge to
+ handle concatenations that change the type of the first component.
+ (path::operator+=(basic_string_view<value_type>)): Likewise.
+ * testsuite/27_io/filesystem/path/concat/94063.cc: New test.
+
2020-03-06 Patrick Palka <ppalka@redhat.com>
* include/std/ranges (join_view::_Sentinel<_Const>): Befriend
diff --git a/libstdc++-v3/src/c++17/fs_path.cc b/libstdc++-v3/src/c++17/fs_path.cc
index 73071d8d052..5ff17741f81 100644
--- a/libstdc++-v3/src/c++17/fs_path.cc
+++ b/libstdc++-v3/src/c++17/fs_path.cc
@@ -852,6 +852,26 @@ path::operator+=(const path& p)
return *this;
}
+#if _GLIBCXX_FILESYSTEM_IS_WINDOWS
+ if (_M_type() == _Type::_Root_name
+ || (_M_type() == _Type::_Filename && _M_pathname.size() == 1))
+ {
+ // Handle path("C") += path(":") and path("C:") += path("/x")
+ // FIXME: do this more efficiently
+ *this = path(_M_pathname + p._M_pathname);
+ return *this;
+ }
+#endif
+#if SLASHSLASH_IS_ROOTNAME
+ if (_M_type() == _Type::_Root_dir)
+ {
+ // Handle path("/") += path("/x") and path("//") += path("x")
+ // FIXME: do this more efficiently
+ *this = path(_M_pathname + p._M_pathname);
+ return *this;
+ }
+#endif
+
const auto orig_pathlen = _M_pathname.length();
const auto orig_type = _M_type();
const auto orig_size = _M_cmpts.size();
@@ -1038,6 +1058,26 @@ path::_M_concat(basic_string_view<value_type> s)
return;
}
+#if _GLIBCXX_FILESYSTEM_IS_WINDOWS
+ if (_M_type() == _Type::_Root_name
+ || (_M_type() == _Type::_Filename && _M_pathname.size() == 1))
+ {
+ // Handle path("C") += ":" and path("C:") += "/x"
+ // FIXME: do this more efficiently
+ *this = path(_M_pathname + string_type(s));
+ return;
+ }
+#endif
+#if SLASHSLASH_IS_ROOTNAME
+ if (_M_type() == _Type::_Root_dir)
+ {
+ // Handle path("/") += "/x" and path("//") += "x"
+ // FIXME: do this more efficiently
+ *this = path(_M_pathname + string_type(s));
+ return;
+ }
+#endif
+
const auto orig_pathlen = _M_pathname.length();
const auto orig_type = _M_type();
const auto orig_size = _M_cmpts.size();
diff --git a/libstdc++-v3/testsuite/27_io/filesystem/path/concat/94063.cc b/libstdc++-v3/testsuite/27_io/filesystem/path/concat/94063.cc
new file mode 100644
index 00000000000..9f4c9c0aa08
--- /dev/null
+++ b/libstdc++-v3/testsuite/27_io/filesystem/path/concat/94063.cc
@@ -0,0 +1,111 @@
+// Copyright (C) 2020 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" }
+// { dg-do run { target { *-*-*mingw* || *-*-cygwin } } }
+// { dg-require-effective-target c++17 }
+
+#include <filesystem>
+#include <testsuite_hooks.h>
+
+void
+test01()
+{
+ using std::filesystem::path;
+ path p;
+
+ // PR libstdc++/94063
+#ifdef _GLIBCXX_FILESYSTEM_IS_WINDOWS
+ p = L"C";
+ p += path(L":");
+ VERIFY( p.has_root_name() );
+ VERIFY( p.root_name() == p );
+ p += path(L"\\");
+ VERIFY( p.has_root_name() );
+ VERIFY( p.has_root_directory() );
+ VERIFY( p.root_name() == L"C:" );
+ VERIFY( p.root_directory() == L"\\" );
+
+ p = L"C";
+ p += L':';
+ VERIFY( p.has_root_name() );
+ VERIFY( p.root_name() == p );
+ p += L'\\';
+ VERIFY( p.has_root_name() );
+ VERIFY( p.has_root_directory() );
+ VERIFY( p.root_name() == L"C:" );
+ VERIFY( p.root_directory() == L"\\" );
+
+ p = L"C:";
+ p += path(L"/foo");
+ VERIFY( p.has_root_name() );
+ VERIFY( p.has_root_directory() );
+ VERIFY( p.root_name() == L"C:" );
+ VERIFY( p.root_directory() == L"/" );
+ VERIFY( p.filename() == L"foo" );
+
+ p = L"C:";
+ p += L"/foo";
+ VERIFY( p.has_root_name() );
+ VERIFY( p.has_root_directory() );
+ VERIFY( p.root_name() == L"C:" );
+ VERIFY( p.root_directory() == L"/" );
+ VERIFY( p.filename() == L"foo" );
+
+ p = L"C";
+ p += path(L":/foo");
+ VERIFY( p.has_root_name() );
+ VERIFY( p.has_root_directory() );
+ VERIFY( p.root_name() == L"C:" );
+ VERIFY( p.root_directory() == L"/" );
+ VERIFY( p.filename() == L"foo" );
+
+ p = L"C";
+ p += L":/foo";
+ VERIFY( p.has_root_name() );
+ VERIFY( p.has_root_directory() );
+ VERIFY( p.root_name() == L"C:" );
+ VERIFY( p.root_directory() == L"/" );
+ VERIFY( p.filename() == L"foo" );
+#elif defined __CYGWIN__
+ p = "/";
+ p += path("/x");
+ VERIFY( p.has_root_name() );
+ VERIFY( p.root_name() == p );
+
+ p = "/";
+ p += "/x";
+ VERIFY( p.has_root_name() );
+ VERIFY( p.root_name() == p );
+
+ p = "/";
+ p += path("/");
+ VERIFY( !p.has_root_name() );
+ VERIFY( p.has_root_directory() );
+
+ p = "/";
+ p += "/";
+ VERIFY( !p.has_root_name() );
+ VERIFY( p.has_root_directory() );
+#endif
+}
+
+int
+main()
+{
+ test01();
+}
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