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| author | Jonathan Wakely <jwakely@redhat.com> | 2019-04-05 17:56:14 +0100 |
|---|---|---|
| committer | Jonathan Wakely <redi@gcc.gnu.org> | 2019-04-05 17:56:14 +0100 |
| commit | d96f11a2720c8ddfc3d181b181cfaadd888323cd (patch) | |
| tree | afbf6b6816e29fd29cd900906f354e82fde3df91 | |
| parent | 10f26de9155b71a2bd5055060004420939cf7a2d (diff) | |
| download | gcc-d96f11a2720c8ddfc3d181b181cfaadd888323cd.zip gcc-d96f11a2720c8ddfc3d181b181cfaadd888323cd.tar.gz gcc-d96f11a2720c8ddfc3d181b181cfaadd888323cd.tar.bz2 | |
Make filesystem::path safe for self assignment
The standard says "If *this and p are the same object, has no effect."
Previously we ended up clearing the path.
* include/bits/fs_path.h (path::operator=(path&&)): Check for self
assignment.
* src/c++17/fs_path.cc (path::operator=(const path&)): Likewise.
* testsuite/27_io/filesystem/path/assign/copy.cc: Test self
assignment.
From-SVN: r270171
| -rw-r--r-- | libstdc++-v3/ChangeLog | 6 | ||||
| -rw-r--r-- | libstdc++-v3/include/bits/fs_path.h | 3 | ||||
| -rw-r--r-- | libstdc++-v3/src/c++17/fs_path.cc | 3 | ||||
| -rw-r--r-- | libstdc++-v3/testsuite/27_io/filesystem/path/assign/copy.cc | 18 |
4 files changed, 30 insertions, 0 deletions
diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog index a34428f..4275142 100644 --- a/libstdc++-v3/ChangeLog +++ b/libstdc++-v3/ChangeLog @@ -1,5 +1,11 @@ 2019-04-05 Jonathan Wakely <jwakely@redhat.com> + * include/bits/fs_path.h (path::operator=(path&&)): Check for self + assignment. + * src/c++17/fs_path.cc (path::operator=(const path&)): Likewise. + * testsuite/27_io/filesystem/path/assign/copy.cc: Test self + assignment. + PR libstdc++/87431 (again) * include/bits/basic_string.h (__variant::_Never_valueless_alt): Define partial specialization for basic_string. diff --git a/libstdc++-v3/include/bits/fs_path.h b/libstdc++-v3/include/bits/fs_path.h index 96033f6..bf7c65c 100644 --- a/libstdc++-v3/include/bits/fs_path.h +++ b/libstdc++-v3/include/bits/fs_path.h @@ -877,6 +877,9 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11 inline path& path::operator=(path&& __p) noexcept { + if (&__p == this) [[__unlikely__]] + return *this; + _M_pathname = std::move(__p._M_pathname); _M_cmpts = std::move(__p._M_cmpts); __p.clear(); diff --git a/libstdc++-v3/src/c++17/fs_path.cc b/libstdc++-v3/src/c++17/fs_path.cc index 268b562..605f62c 100644 --- a/libstdc++-v3/src/c++17/fs_path.cc +++ b/libstdc++-v3/src/c++17/fs_path.cc @@ -444,6 +444,9 @@ path::_List::reserve(int newcap, bool exact = false) path& path::operator=(const path& p) { + if (&p == this) [[__unlikely__]] + return *this; + _M_pathname.reserve(p._M_pathname.length()); _M_cmpts = p._M_cmpts; // might throw _M_pathname = p._M_pathname; // won't throw because we reserved enough space diff --git a/libstdc++-v3/testsuite/27_io/filesystem/path/assign/copy.cc b/libstdc++-v3/testsuite/27_io/filesystem/path/assign/copy.cc index 6c24e3a..775dbff 100644 --- a/libstdc++-v3/testsuite/27_io/filesystem/path/assign/copy.cc +++ b/libstdc++-v3/testsuite/27_io/filesystem/path/assign/copy.cc @@ -20,6 +20,7 @@ #include <filesystem> #include <testsuite_fs.h> +#include <testsuite_hooks.h> using std::filesystem::path; using __gnu_test::compare_paths; @@ -47,9 +48,26 @@ test02() } } +void +test03() +{ + // self assignment should have no effect + const path orig = "foo/bar/baz"; + path p = orig; + const auto ptr1 = p.c_str(); + const auto ptr2 = p.begin()->c_str(); + p = std::move(p); + __gnu_test::compare_paths(p, orig); + p = p; + __gnu_test::compare_paths(p, orig); + VERIFY( ptr1 == p.c_str() ); + VERIFY( ptr2 == p.begin()->c_str() ); +} + int main() { test01(); test02(); + test03(); } |