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_algobase.h (__copy_move): Give descriptive names
	to template parameters.
	* include/bits/stl_uninitialized.h (uninitialized_copy)
	(uninitialized_fill, uninitialized_fill_n): Add static assertions to
	diagnose invalid uses.
	* testsuite/20_util/specialized_algorithms/uninitialized_copy/1.cc:
	Adjust expected error.
	* 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.
	* testsuite/23_containers/vector/cons/89164_c++17.cc: New test.

From-SVN: r275177

libstdc++-v3/ChangeLog

+2019-08-30  Jonathan Wakely  <jwakely@redhat.com>
+
+	PR libstdc++/89164
+	* include/bits/stl_algobase.h (__copy_move): Give descriptive names
+	to template parameters.
+	* include/bits/stl_uninitialized.h (uninitialized_copy)
+	(uninitialized_fill, uninitialized_fill_n): Add static assertions to
+	diagnose invalid uses.
+	* testsuite/20_util/specialized_algorithms/uninitialized_copy/1.cc:
+	Adjust expected error.
+	* 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.
+	* testsuite/23_containers/vector/cons/89164_c++17.cc: New test.
+
 2019-08-29  Jonathan Wakely  <jwakely@redhat.com>
 
 	PR libstdc++/91067

libstdc++-v3/include/bits/stl_algobase.h

@@ -359,7 +359,7 @@ _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>

libstdc++-v3/include/bits/stl_uninitialized.h

@@ -130,9 +130,15 @@ _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
 
@@ -197,7 +203,13 @@ _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
 
@@ -262,7 +274,13 @@ _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>::

libstdc++-v3/testsuite/20_util/specialized_algorithms/uninitialized_copy/1.cc

@@ -34,4 +34,4 @@ test01(T* result)
   T t[1];
   std::uninitialized_copy(t, t+1, result); // { dg-error "here" }
 }
-// { dg-prune-output "use of deleted function" }
+// { dg-error "constructible from value" "" { target *-*-* } 0 }

libstdc++-v3/testsuite/20_util/specialized_algorithms/uninitialized_copy/89164.cc

+// 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 "here" }
+}
+// { dg-error "must be constructible" "" { target *-*-* } 0 }

libstdc++-v3/testsuite/20_util/specialized_algorithms/uninitialized_copy_n/89164.cc

+// 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 "here" }
+}
+// { dg-error "must be constructible" "" { target *-*-* } 0 }

libstdc++-v3/testsuite/20_util/specialized_algorithms/uninitialized_fill/89164.cc

+// 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 "here" }
+}
+// { dg-error "must be constructible" "" { target *-*-* } 0 }

libstdc++-v3/testsuite/20_util/specialized_algorithms/uninitialized_fill_n/89164.cc

+// 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 "here" }
+}
+// { dg-error "must be constructible" "" { target *-*-* } 0 }

libstdc++-v3/testsuite/23_containers/vector/cons/89164.cc

+// 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 "here" }
+
+  // Should not be able to create vector using uninitialized_fill_n:
+  std::vector<X> v2{2u, X{}};	// { dg-error "here" }
+}
+// { dg-error "constructible from value" "" { target *-*-* } 0 }
+// { dg-error "constructible from input" "" { target *-*-* } 0 }

libstdc++-v3/testsuite/23_containers/vector/cons/89164_c++17.cc

+// 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-options "-std=gnu++17" }
+// { dg-do compile { target c++17 } }
+
+#include <vector>
+
+// PR libstdc++/89164
+
+void test01()
+{
+  X x[1];
+  // Should not be able to create vector using uninitialized_copy:
+  std::vector<X> v1{x, x+1};	// { dg-error "here" }
+
+  // Should not be able to create vector using uninitialized_fill_n:
+  std::vector<X> v2{2u, X{}};	// { dg-error "here" }
+}
+
+void test02()
+{
+#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 "here" }
+#endif
+}
+// { dg-error "constructible from value" "" { target *-*-* } 0 }
+// { dg-error "constructible from input" "" { target *-*-* } 0 }