[PATCH] PR libstdc++/89164 enforce constraints for uninitialized algos
Jonathan Wakely
jwakely@redhat.com
Wed Feb 6 20:52:00 GMT 2019
The memmove optimizations for std::uninitialized_copy/fill/_n will
compile even if the type is not copy constructible, because std::copy
doesn't require copy construction to work. But the uninitialized
algorithms do require it.
This adds explicit static assertions to ensure we don't allow ill-formed
initializations.
PR libstdc++/89164
* include/bits/stl_uninitialized.h (uninitialized_copy): Add static
assertion.
* testsuite/20_util/specialized_algorithms/uninitialized_copy/89164.cc:
New test.
* testsuite/20_util/specialized_algorithms/uninitialized_copy_n/
89164.cc: New test.
* testsuite/20_util/specialized_algorithms/uninitialized_fill/89164.cc:
New test.
* testsuite/20_util/specialized_algorithms/uninitialized_fill_n/
89164.cc: New test.
* testsuite/23_containers/vector/cons/89164.cc: New test.
This fixes an accepts-invalid bug in vector (and probably other
containers, I didn't check) but I don't see any great urgency to fix
this now. I'll wait for stage 1.
-------------- next part --------------
commit 6f61f77f40546fdf47aaf6320d141f380a0c7d49
Author: Jonathan Wakely <jwakely@redhat.com>
Date: Tue Feb 5 14:12:27 2019 +0000
PR libstdc++/89164 enforce constraints for uninitialized algos
The memmove optimizations for std::uninitialized_copy/fill/_n will
compile even if the type is not copy constructible, because std::copy
doesn't require copy construction to work. But the uninitialized
algorithms do require it.
This adds explicit static assertions to ensure we don't allow ill-formed
initializations.
PR libstdc++/89164
* include/bits/stl_uninitialized.h (uninitialized_copy): Add static
assertion.
* testsuite/20_util/specialized_algorithms/uninitialized_copy/89164.cc:
New test.
* testsuite/20_util/specialized_algorithms/uninitialized_copy_n/
89164.cc: New test.
* testsuite/20_util/specialized_algorithms/uninitialized_fill/89164.cc:
New test.
* testsuite/20_util/specialized_algorithms/uninitialized_fill_n/
89164.cc: New test.
* testsuite/23_containers/vector/cons/89164.cc: New test.
diff --git a/libstdc++-v3/include/bits/stl_algobase.h b/libstdc++-v3/include/bits/stl_algobase.h
index 2b69e658fe8..646d15b2164 100644
--- a/libstdc++-v3/include/bits/stl_algobase.h
+++ b/libstdc++-v3/include/bits/stl_algobase.h
@@ -301,7 +301,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
// (2) If we're using random access iterators, then write the loop as
// a for loop with an explicit count.
- template<bool, bool, typename>
+ template<bool _IsMove, bool _IsSimple, typename _Category>
struct __copy_move
{
template<typename _II, typename _OI>
diff --git a/libstdc++-v3/include/bits/stl_uninitialized.h b/libstdc++-v3/include/bits/stl_uninitialized.h
index 0d42b253df1..f5ca74329e2 100644
--- a/libstdc++-v3/include/bits/stl_uninitialized.h
+++ b/libstdc++-v3/include/bits/stl_uninitialized.h
@@ -122,9 +122,15 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
#if __cplusplus < 201103L
const bool __assignable = true;
#else
- // trivial types can have deleted assignment
+ // Trivial types can have deleted copy constructor, but the std::copy
+ // optimization that uses memmove would happily "copy" them anyway.
+ static_assert(is_constructible<_ValueType2, decltype(*__first)>::value,
+ "result type must be constructible from value type of input range");
+
typedef typename iterator_traits<_InputIterator>::reference _RefType1;
typedef typename iterator_traits<_ForwardIterator>::reference _RefType2;
+ // Trivial types can have deleted assignment, so using std::copy
+ // would be ill-formed. Require assignability before using std::copy:
const bool __assignable = is_assignable<_RefType2, _RefType1>::value;
#endif
@@ -186,7 +192,13 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
#if __cplusplus < 201103L
const bool __assignable = true;
#else
- // trivial types can have deleted assignment
+ // Trivial types can have deleted copy constructor, but the std::fill
+ // optimization that uses memmove would happily "copy" them anyway.
+ static_assert(is_constructible<_ValueType, const _Tp&>::value,
+ "result type must be constructible from input type");
+
+ // Trivial types can have deleted assignment, so using std::fill
+ // would be ill-formed. Require assignability before using std::fill:
const bool __assignable = is_copy_assignable<_ValueType>::value;
#endif
@@ -248,7 +260,13 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
#if __cplusplus < 201103L
const bool __assignable = true;
#else
- // trivial types can have deleted assignment
+ // Trivial types can have deleted copy constructor, but the std::fill
+ // optimization that uses memmove would happily "copy" them anyway.
+ static_assert(is_constructible<_ValueType, const _Tp&>::value,
+ "result type must be constructible from input type");
+
+ // Trivial types can have deleted assignment, so using std::fill
+ // would be ill-formed. Require assignability before using std::fill:
const bool __assignable = is_copy_assignable<_ValueType>::value;
#endif
return __uninitialized_fill_n<__is_trivial(_ValueType) && __assignable>::
diff --git a/libstdc++-v3/testsuite/20_util/specialized_algorithms/uninitialized_copy/89164.cc b/libstdc++-v3/testsuite/20_util/specialized_algorithms/uninitialized_copy/89164.cc
new file mode 100644
index 00000000000..0221c018362
--- /dev/null
+++ b/libstdc++-v3/testsuite/20_util/specialized_algorithms/uninitialized_copy/89164.cc
@@ -0,0 +1,37 @@
+// Copyright (C) 2019 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-do compile { target c++11 } }
+
+#include <vector>
+
+// PR libstdc++/89164
+
+struct X
+{
+ X() = default;
+ X(const X&) = delete;
+};
+
+void test01()
+{
+ X x[1];
+ alignas(X) unsigned char buf[sizeof(X)];
+ X* p = (X*)buf;
+
+ std::uninitialized_copy(x, x+1, p); // { dg-error "must be constructible" }
+}
diff --git a/libstdc++-v3/testsuite/20_util/specialized_algorithms/uninitialized_copy_n/89164.cc b/libstdc++-v3/testsuite/20_util/specialized_algorithms/uninitialized_copy_n/89164.cc
new file mode 100644
index 00000000000..c0f94d4fe5e
--- /dev/null
+++ b/libstdc++-v3/testsuite/20_util/specialized_algorithms/uninitialized_copy_n/89164.cc
@@ -0,0 +1,34 @@
+// Copyright (C) 2019 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-do compile { target c++11 } }
+
+#include <vector>
+
+struct X {
+ X() = default;
+ X(const X&) = delete;
+};
+
+void test01()
+{
+ X x[1];
+ alignas(X) unsigned char buf[sizeof(X)];
+ X* p = (X*)buf;
+
+ std::uninitialized_copy_n(x, 1, p); // { dg-error "must be constructible" }
+}
diff --git a/libstdc++-v3/testsuite/20_util/specialized_algorithms/uninitialized_fill/89164.cc b/libstdc++-v3/testsuite/20_util/specialized_algorithms/uninitialized_fill/89164.cc
new file mode 100644
index 00000000000..7b4d2a29b6a
--- /dev/null
+++ b/libstdc++-v3/testsuite/20_util/specialized_algorithms/uninitialized_fill/89164.cc
@@ -0,0 +1,34 @@
+// Copyright (C) 2019 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-do compile { target c++11 } }
+
+#include <vector>
+
+struct X {
+ X() = default;
+ X(const X&) = delete;
+};
+
+void f()
+{
+ X x;
+ alignas(X) unsigned char buf[sizeof(X)];
+ X* p = (X*)buf;
+
+ std::uninitialized_fill(p, p+1, x); // { dg-error "must be constructible" }
+}
diff --git a/libstdc++-v3/testsuite/20_util/specialized_algorithms/uninitialized_fill_n/89164.cc b/libstdc++-v3/testsuite/20_util/specialized_algorithms/uninitialized_fill_n/89164.cc
new file mode 100644
index 00000000000..f251cb7ebd2
--- /dev/null
+++ b/libstdc++-v3/testsuite/20_util/specialized_algorithms/uninitialized_fill_n/89164.cc
@@ -0,0 +1,34 @@
+// Copyright (C) 2019 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-do compile { target c++11 } }
+
+#include <vector>
+
+struct X {
+ X() = default;
+ X(const X&) = delete;
+};
+
+void test01()
+{
+ X x;
+ alignas(X) unsigned char buf[sizeof(X)];
+ X* p = (X*)buf;
+
+ std::uninitialized_fill_n(p, 1, x); // { dg-error "must be constructible" }
+}
diff --git a/libstdc++-v3/testsuite/23_containers/vector/cons/89164.cc b/libstdc++-v3/testsuite/23_containers/vector/cons/89164.cc
new file mode 100644
index 00000000000..c5c1ca1432b
--- /dev/null
+++ b/libstdc++-v3/testsuite/23_containers/vector/cons/89164.cc
@@ -0,0 +1,44 @@
+// Copyright (C) 2019 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-do compile { target c++11 } }
+
+#include <vector>
+
+// PR libstdc++/89164
+
+struct X
+{
+ X() = default;
+ X(const X&) = delete;
+};
+
+void test01()
+{
+ X x[1];
+ // Should not be able to create vector using uninitialized_copy:
+ std::vector<X> v1{x, x+1}; // { dg-error "constructible from value" }
+
+ // Should not be able to create vector using uninitialized_fill_n:
+ std::vector<X> v2{2u, X{}}; // { dg-error "constructible from input" }
+
+#if __cplusplus >= 201703L
+ // Can create initializer_list<X> with C++17 guaranteed copy elision,
+ // but shouldn't be able to copy from it with uninitialized_copy:
+ std::vector<X> v3{X{}, X{}, X{}}; // { dg-error "constructible from value" }
+#endif
+}
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