[PATCH] PR libstdc++/90454.cc path construction from void*

[Jonathan Wakely]

Make the filesystem::path constructors SFINAE away for void* arguments,
instead of giving an error due to iterator_traits<void*>::reference.

        PR libstdc++/90454.cc path construction from void*
        * include/bits/fs_path.h (path::_Path): Use remove_pointer so that
        pointers to void are rejected as well as void.
        * include/experimental/bits/fs_path.h (path::_Path): Likewise.
        * testsuite/27_io/filesystem/path/construct/80762.cc: Also check
        pointers to void.
        * testsuite/experimental/filesystem/path/construct/80762.cc: Likewise.

Tested powerpc64le-linux and x86_64-linux, committed to trunk.



commit 8f5ae78f657a521d506fd1d1ce6d70520461deb0
Author: Jonathan Wakely <jwak...@redhat.com>
Date:   Mon May 13 20:53:09 2019 +0100

    PR libstdc++/90454.cc path construction from void*
    
    Make the filesystem::path constructors SFINAE away for void* arguments,
    instead of giving an error due to iterator_traits<void*>::reference.
    
            PR libstdc++/90454.cc path construction from void*
            * include/bits/fs_path.h (path::_Path): Use remove_pointer so that
            pointers to void are rejected as well as void.
            * include/experimental/bits/fs_path.h (path::_Path): Likewise.
            * testsuite/27_io/filesystem/path/construct/80762.cc: Also check
            pointers to void.
            * testsuite/experimental/filesystem/path/construct/80762.cc: 
Likewise.

diff --git a/libstdc++-v3/include/bits/fs_path.h 
b/libstdc++-v3/include/bits/fs_path.h
index d1ad11a60c4..cec35614b42 100644
--- a/libstdc++-v3/include/bits/fs_path.h
+++ b/libstdc++-v3/include/bits/fs_path.h
@@ -115,7 +115,7 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11
     template<typename _Tp1, typename _Tp2 = void>
       using _Path = typename
        std::enable_if<__and_<__not_<is_same<remove_cv_t<_Tp1>, path>>,
-                             __not_<is_void<_Tp1>>,
+                             __not_<is_void<remove_pointer_t<_Tp1>>>,
                              __constructible_from<_Tp1, _Tp2>>::value,
                       path>::type;
 
diff --git a/libstdc++-v3/include/experimental/bits/fs_path.h 
b/libstdc++-v3/include/experimental/bits/fs_path.h
index f81f33ca161..588f06822be 100644
--- a/libstdc++-v3/include/experimental/bits/fs_path.h
+++ b/libstdc++-v3/include/experimental/bits/fs_path.h
@@ -128,11 +128,12 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11
       : decltype(__is_path_src(std::declval<_Source>(), 0))
       { };
 
-    template<typename _Tp1, typename _Tp2 = void>
+    template<typename _Tp1, typename _Tp2 = void,
+            typename _Tp1_nocv = typename remove_cv<_Tp1>::type,
+            typename _Tp1_noptr = typename remove_pointer<_Tp1>::type>
       using _Path = typename
-       std::enable_if<__and_<__not_<is_same<typename remove_cv<_Tp1>::type,
-                                            path>>,
-                             __not_<is_void<_Tp1>>,
+       std::enable_if<__and_<__not_<is_same<_Tp1_nocv, path>>,
+                             __not_<is_void<_Tp1_noptr>>,
                              __constructible_from<_Tp1, _Tp2>>::value,
                       path>::type;
 
diff --git a/libstdc++-v3/testsuite/27_io/filesystem/path/construct/80762.cc 
b/libstdc++-v3/testsuite/27_io/filesystem/path/construct/80762.cc
index 71cdaa9d969..e22e3deb56e 100644
--- a/libstdc++-v3/testsuite/27_io/filesystem/path/construct/80762.cc
+++ b/libstdc++-v3/testsuite/27_io/filesystem/path/construct/80762.cc
@@ -22,8 +22,18 @@
 
 using std::filesystem::path;
 
+// PR libstdc++/80762.cc
 static_assert( !std::is_constructible_v<path, void> );
 static_assert( !std::is_constructible_v<path, volatile path> );
 static_assert( !std::is_constructible_v<path, volatile path&> );
 static_assert( !std::is_constructible_v<path, const volatile path> );
 static_assert( !std::is_constructible_v<path, const volatile path&> );
+
+// PR libstdc++/90454.cc
+static_assert( !std::is_constructible_v<path, void*> );
+static_assert( !std::is_constructible_v<path, const void*> );
+static_assert( !std::is_constructible_v<path, volatile void*> );
+static_assert( !std::is_constructible_v<path, const volatile void*> );
+static_assert( !std::is_constructible_v<path, void*&> );
+static_assert( !std::is_constructible_v<path, void* const&> );
+static_assert( !std::is_constructible_v<path, const void* const&> );
diff --git 
a/libstdc++-v3/testsuite/experimental/filesystem/path/construct/80762.cc 
b/libstdc++-v3/testsuite/experimental/filesystem/path/construct/80762.cc
index fa4a64feb3e..98dadabcffb 100644
--- a/libstdc++-v3/testsuite/experimental/filesystem/path/construct/80762.cc
+++ b/libstdc++-v3/testsuite/experimental/filesystem/path/construct/80762.cc
@@ -22,8 +22,18 @@
 
 using std::experimental::filesystem::path;
 
+// PR libstdc++/80762.cc
 static_assert( !std::is_constructible<path, void>::value, "" );
 static_assert( !std::is_constructible<path, volatile path>::value, "" );
 static_assert( !std::is_constructible<path, volatile path&>::value, "" );
 static_assert( !std::is_constructible<path, const volatile path>::value, "" );
 static_assert( !std::is_constructible<path, const volatile path&>::value, "" );
+
+// PR libstdc++/90454.cc
+static_assert( !std::is_constructible<path, void*>::value, "" );
+static_assert( !std::is_constructible<path, const void*>::value, "" );
+static_assert( !std::is_constructible<path, volatile void*>::value, "" );
+static_assert( !std::is_constructible<path, const volatile void*>::value, "" );
+static_assert( !std::is_constructible<path, void*&>::value, "" );
+static_assert( !std::is_constructible<path, void* const&>::value, "" );
+static_assert( !std::is_constructible<path, const void* const&>::value, "" );