PR libstdc++/65049

	* include/bits/char_traits.h (char_traits<char>::compare,
	char_traits<char>::find, char_traits<char>::move,
	char_traits<char>::copy, char_traits<char>::assign): Check for zero
	length.
	(char_traits<wchar_t>::compare, char_traits<wchar_t>::find,
	char_traits<wchar_t>::move, char_traits<wchar_t>::copy,
	char_traits<wchar_t>::assign): Likewise.
	(char_traits<char16_t>::move, char_traits<char16_t>::copy): Likewise.
	(char_traits<char32_t>::move, char_traits<char32_t>::copy): Likewise.
	* include/ext/pod_char_traits.h (char_traits<character<>>::move,
	char_traits<character<>>::copy): Likewise.
	* testsuite/21_strings/char_traits/requirements/char/65049.cc: New.
	* testsuite/21_strings/char_traits/requirements/char16_t/65049.cc:
	New.
	* testsuite/21_strings/char_traits/requirements/char32_t/65049.cc:
	New.
	* testsuite/21_strings/char_traits/requirements/wchar_t/65049.cc:
	New.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@227127 138bc75d-0d04-0410-961f-82ee72b054a4

7 files changed, 274 insertions, 10 deletions

diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog
index 090e8e3373a..f6f68a81301 100644
--- a/libstdc++-v3/ChangeLog
+++ b/libstdc++-v3/ChangeLog
@@ -1,5 +1,25 @@
 2015-08-24  Jonathan Wakely  <jwakely@redhat.com>
 
+	PR libstdc++/65049
+	* include/bits/char_traits.h (char_traits<char>::compare,
+	char_traits<char>::find, char_traits<char>::move,
+	char_traits<char>::copy, char_traits<char>::assign): Check for zero
+	length.
+	(char_traits<wchar_t>::compare, char_traits<wchar_t>::find,
+	char_traits<wchar_t>::move, char_traits<wchar_t>::copy,
+	char_traits<wchar_t>::assign): Likewise.
+	(char_traits<char16_t>::move, char_traits<char16_t>::copy): Likewise.
+	(char_traits<char32_t>::move, char_traits<char32_t>::copy): Likewise.
+	* include/ext/pod_char_traits.h (char_traits<character<>>::move,
+	char_traits<character<>>::copy): Likewise.
+	* testsuite/21_strings/char_traits/requirements/char/65049.cc: New.
+	* testsuite/21_strings/char_traits/requirements/char16_t/65049.cc:
+	New.
+	* testsuite/21_strings/char_traits/requirements/char32_t/65049.cc:
+	New.
+	* testsuite/21_strings/char_traits/requirements/wchar_t/65049.cc:
+	New.
+
 	PR libstdc++/67309
 	* include/bits/random.tcc
 	(poisson_distribution::param_type::_M_initialize): Use max<double>.
diff --git a/libstdc++-v3/include/bits/char_traits.h b/libstdc++-v3/include/bits/char_traits.h
index 369c636d8fd..0d0063bcee6 100644
--- a/libstdc++-v3/include/bits/char_traits.h
+++ b/libstdc++-v3/include/bits/char_traits.h
@@ -256,7 +256,11 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 
       static int
       compare(const char_type* __s1, const char_type* __s2, size_t __n)
-      { return __builtin_memcmp(__s1, __s2, __n); }
+      {
+	if (__n == 0)
+	  return 0;
+	return __builtin_memcmp(__s1, __s2, __n);
+      }
 
       static size_t
       length(const char_type* __s)
@@ -264,19 +268,35 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 
       static const char_type*
       find(const char_type* __s, size_t __n, const char_type& __a)
-      { return static_cast<const char_type*>(__builtin_memchr(__s, __a, __n)); }
+      {
+	if (__n == 0)
+	  return 0;
+	return static_cast<const char_type*>(__builtin_memchr(__s, __a, __n));
+      }
 
       static char_type*
       move(char_type* __s1, const char_type* __s2, size_t __n)
-      { return static_cast<char_type*>(__builtin_memmove(__s1, __s2, __n)); }
+      {
+	if (__n == 0)
+	  return __s1;
+	return static_cast<char_type*>(__builtin_memmove(__s1, __s2, __n));
+      }
 
       static char_type*
       copy(char_type* __s1, const char_type* __s2, size_t __n)
-      { return static_cast<char_type*>(__builtin_memcpy(__s1, __s2, __n)); }
+      {
+	if (__n == 0)
+	  return __s1;
+	return static_cast<char_type*>(__builtin_memcpy(__s1, __s2, __n));
+      }
 
       static char_type*
       assign(char_type* __s, size_t __n, char_type __a)
-      { return static_cast<char_type*>(__builtin_memset(__s, __a, __n)); }
+      {
+	if (__n == 0)
+	  return __s;
+	return static_cast<char_type*>(__builtin_memset(__s, __a, __n));
+      }
 
       static _GLIBCXX_CONSTEXPR char_type
       to_char_type(const int_type& __c) _GLIBCXX_NOEXCEPT
@@ -327,7 +347,11 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 
       static int
       compare(const char_type* __s1, const char_type* __s2, size_t __n)
-      { return wmemcmp(__s1, __s2, __n); }
+      {
+	if (__n == 0)
+	  return 0;
+	return wmemcmp(__s1, __s2, __n);
+      }
 
       static size_t
       length(const char_type* __s)
@@ -335,19 +359,35 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 
       static const char_type*
       find(const char_type* __s, size_t __n, const char_type& __a)
-      { return wmemchr(__s, __a, __n); }
+      {
+	if (__n == 0)
+	  return 0;
+	return wmemchr(__s, __a, __n);
+      }
 
       static char_type*
       move(char_type* __s1, const char_type* __s2, size_t __n)
-      { return wmemmove(__s1, __s2, __n); }
+      {
+	if (__n == 0)
+	  return __s1;
+	return wmemmove(__s1, __s2, __n);
+      }
 
       static char_type*
       copy(char_type* __s1, const char_type* __s2, size_t __n)
-      { return wmemcpy(__s1, __s2, __n); }
+      {
+	if (__n == 0)
+	  return __s1;
+	return wmemcpy(__s1, __s2, __n);
+      }
 
       static char_type*
       assign(char_type* __s, size_t __n, char_type __a)
-      { return wmemset(__s, __a, __n); }
+      {
+	if (__n == 0)
+	  return __s;
+	return wmemset(__s, __a, __n);
+      }
 
       static _GLIBCXX_CONSTEXPR char_type
       to_char_type(const int_type& __c) _GLIBCXX_NOEXCEPT
@@ -436,6 +476,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       static char_type*
       move(char_type* __s1, const char_type* __s2, size_t __n)
       {
+	if (__n == 0)
+	  return __s1;
 	return (static_cast<char_type*>
 		(__builtin_memmove(__s1, __s2, __n * sizeof(char_type))));
       }
@@ -443,6 +485,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       static char_type*
       copy(char_type* __s1, const char_type* __s2, size_t __n)
       {
+	if (__n == 0)
+	  return __s1;
 	return (static_cast<char_type*>
 		(__builtin_memcpy(__s1, __s2, __n * sizeof(char_type))));
       }
@@ -529,6 +573,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       static char_type*
       move(char_type* __s1, const char_type* __s2, size_t __n)
       {
+	if (__n == 0)
+	  return __s1;
 	return (static_cast<char_type*>
 		(__builtin_memmove(__s1, __s2, __n * sizeof(char_type))));
       }
@@ -536,6 +582,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       static char_type*
       copy(char_type* __s1, const char_type* __s2, size_t __n)
       { 
+	if (__n == 0)
+	  return __s1;
 	return (static_cast<char_type*>
 		(__builtin_memcpy(__s1, __s2, __n * sizeof(char_type))));
       }
diff --git a/libstdc++-v3/include/ext/pod_char_traits.h b/libstdc++-v3/include/ext/pod_char_traits.h
index c941080f54a..38a84c80d5b 100644
--- a/libstdc++-v3/include/ext/pod_char_traits.h
+++ b/libstdc++-v3/include/ext/pod_char_traits.h
@@ -144,6 +144,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       static char_type*
       move(char_type* __s1, const char_type* __s2, size_t __n)
       { 
+	if (__n == 0)
+	  return __s1;
 	return static_cast<char_type*>
 	  (__builtin_memmove(__s1, __s2, __n * sizeof(char_type)));
       }
@@ -151,6 +153,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       static char_type*
       copy(char_type* __s1, const char_type* __s2, size_t __n)
       {
+	if (__n == 0)
+	  return __s1;
 	std::copy(__s2, __s2 + __n, __s1);
 	return __s1;
       }
diff --git a/libstdc++-v3/testsuite/21_strings/char_traits/requirements/char/65049.cc b/libstdc++-v3/testsuite/21_strings/char_traits/requirements/char/65049.cc
new file mode 100644
index 00000000000..1aa00ddc1fc
--- /dev/null
+++ b/libstdc++-v3/testsuite/21_strings/char_traits/requirements/char/65049.cc
@@ -0,0 +1,48 @@
+// Copyright (C) 2015 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++11" }
+
+// libstdc++/65049
+
+#include <string>
+#include <testsuite_hooks.h>
+
+using C = char;
+
+void
+test01()
+{
+  const C* p = 0;
+  C* q = 0;
+  auto c = std::char_traits<C>::compare(p, q, 0);
+  VERIFY( c == 0 );
+  auto r = std::char_traits<C>::find(p, 0, '0');
+  VERIFY( r == nullptr );
+  r = std::char_traits<C>::move(q, p, 0);
+  VERIFY( r == q );
+  r = std::char_traits<C>::copy(q, p, 0);
+  VERIFY( r == q );
+  r = std::char_traits<C>::assign(q, 0, '0');
+  VERIFY( r == q );
+}
+
+int
+main()
+{
+  test01();
+}
diff --git a/libstdc++-v3/testsuite/21_strings/char_traits/requirements/char16_t/65049.cc b/libstdc++-v3/testsuite/21_strings/char_traits/requirements/char16_t/65049.cc
new file mode 100644
index 00000000000..7af6db3ff42
--- /dev/null
+++ b/libstdc++-v3/testsuite/21_strings/char_traits/requirements/char16_t/65049.cc
@@ -0,0 +1,48 @@
+// Copyright (C) 2015 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++11" }
+
+// libstdc++/65049
+
+#include <string>
+#include <testsuite_hooks.h>
+
+using C = char16_t;
+
+void
+test01()
+{
+  const C* p = 0;
+  C* q = 0;
+  auto c = std::char_traits<C>::compare(p, q, 0);
+  VERIFY( c == 0 );
+  auto r = std::char_traits<C>::find(p, 0, '0');
+  VERIFY( r == nullptr );
+  r = std::char_traits<C>::move(q, p, 0);
+  VERIFY( r == q );
+  r = std::char_traits<C>::copy(q, p, 0);
+  VERIFY( r == q );
+  r = std::char_traits<C>::assign(q, 0, '0');
+  VERIFY( r == q );
+}
+
+int
+main()
+{
+  test01();
+}
diff --git a/libstdc++-v3/testsuite/21_strings/char_traits/requirements/char32_t/65049.cc b/libstdc++-v3/testsuite/21_strings/char_traits/requirements/char32_t/65049.cc
new file mode 100644
index 00000000000..a7730ec2582
--- /dev/null
+++ b/libstdc++-v3/testsuite/21_strings/char_traits/requirements/char32_t/65049.cc
@@ -0,0 +1,48 @@
+// Copyright (C) 2015 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++11" }
+
+// libstdc++/65049
+
+#include <string>
+#include <testsuite_hooks.h>
+
+using C = char32_t;
+
+void
+test01()
+{
+  const C* p = 0;
+  C* q = 0;
+  auto c = std::char_traits<C>::compare(p, q, 0);
+  VERIFY( c == 0 );
+  auto r = std::char_traits<C>::find(p, 0, '0');
+  VERIFY( r == nullptr );
+  r = std::char_traits<C>::move(q, p, 0);
+  VERIFY( r == q );
+  r = std::char_traits<C>::copy(q, p, 0);
+  VERIFY( r == q );
+  r = std::char_traits<C>::assign(q, 0, '0');
+  VERIFY( r == q );
+}
+
+int
+main()
+{
+  test01();
+}
diff --git a/libstdc++-v3/testsuite/21_strings/char_traits/requirements/wchar_t/65049.cc b/libstdc++-v3/testsuite/21_strings/char_traits/requirements/wchar_t/65049.cc
new file mode 100644
index 00000000000..22dfdf03513
--- /dev/null
+++ b/libstdc++-v3/testsuite/21_strings/char_traits/requirements/wchar_t/65049.cc
@@ -0,0 +1,48 @@
+// Copyright (C) 2015 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++11" }
+
+// libstdc++/65049
+
+#include <string>
+#include <testsuite_hooks.h>
+
+using C = wchar_t;
+
+void
+test01()
+{
+  const C* p = 0;
+  C* q = 0;
+  auto c = std::char_traits<C>::compare(p, q, 0);
+  VERIFY( c == 0 );
+  auto r = std::char_traits<C>::find(p, 0, '0');
+  VERIFY( r == nullptr );
+  r = std::char_traits<C>::move(q, p, 0);
+  VERIFY( r == q );
+  r = std::char_traits<C>::copy(q, p, 0);
+  VERIFY( r == q );
+  r = std::char_traits<C>::assign(q, 0, '0');
+  VERIFY( r == q );
+}
+
+int
+main()
+{
+  test01();
+}