On 23/02/19 01:26 +0000, Jonathan Wakely wrote:
On 23/02/19 02:06 +0100, Jakub Jelinek wrote:
On Sat, Feb 23, 2019 at 01:02:20AM +0000, Jonathan Wakely wrote:
PR libstdc++/89446
* include/bits/char_traits.h (__constant_char_array): Check index is
in range before dereferencing.
* testsuite/21_strings/basic_string_view/operators/char/89446.cc:
New test.
Tested x86_64-linux, committed to gcc-8-branch and gcc-7-branch.
And not trunk? The bug is still there, even when it should be usually
ifdefed out because __builtin_is_constexpr_evaluated() should be supported.
Yes, that's a bigger patch (with some cleanup) which is coming
shortly.
Here's the patch for trunk. When the size is zero we can just return,
we don't need to do the __builtin_constant_p checks.
Tested powerpc64le-linux, committed to trunk.
commit c1f64344793df8b29ccb27d06572ba8d5b51957b
Author: Jonathan Wakely <jwak...@redhat.com>
Date: Sat Feb 23 01:33:02 2019 +0000
PR libstdc++/89446 fix null pointer dereference in char_traits
PR libstdc++/89446
* include/bits/char_traits.h (__constant_char_array): Check index is
in range before dereferencing.
(char_traits<char>::compare, char_traits<char>::find)
(char_traits<char8_t>::compare, char_traits<char8_t>::find): Return
immediately if n is zero.
(char_traits<wchar_t>::compare, char_traits<wchar_t>::find): Likewise.
Remove workarounds for PR 67026.
* testsuite/21_strings/basic_string_view/operators/char/89446.cc:
New test.
* testsuite/21_strings/basic_string_view/operators/wchar_t/89446.cc:
New test.
diff --git a/libstdc++-v3/include/bits/char_traits.h b/libstdc++-v3/include/bits/char_traits.h
index 21099c36c3b..fd9a3c73930 100644
--- a/libstdc++-v3/include/bits/char_traits.h
+++ b/libstdc++-v3/include/bits/char_traits.h
@@ -260,7 +260,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
return __builtin_is_constant_evaluated();
#else
size_t __i = 0;
- while (__builtin_constant_p(__a[__i]) && __i < __n)
+ while (__i < __n && __builtin_constant_p(__a[__i]))
__i++;
return __i == __n;
#endif
@@ -314,14 +314,14 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
static _GLIBCXX17_CONSTEXPR int
compare(const char_type* __s1, const char_type* __s2, size_t __n)
{
+ if (__n == 0)
+ return 0;
#if __cplusplus >= 201703L
if (__builtin_constant_p(__n)
&& __constant_char_array_p(__s1, __n)
&& __constant_char_array_p(__s2, __n))
return __gnu_cxx::char_traits<char_type>::compare(__s1, __s2, __n);
#endif
- if (__n == 0)
- return 0;
return __builtin_memcmp(__s1, __s2, __n);
}
@@ -338,14 +338,14 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
static _GLIBCXX17_CONSTEXPR const char_type*
find(const char_type* __s, size_t __n, const char_type& __a)
{
+ if (__n == 0)
+ return 0;
#if __cplusplus >= 201703L
if (__builtin_constant_p(__n)
&& __builtin_constant_p(__a)
&& __constant_char_array_p(__s, __n))
return __gnu_cxx::char_traits<char_type>::find(__s, __n, __a);
#endif
- if (__n == 0)
- return 0;
return static_cast<const char_type*>(__builtin_memchr(__s, __a, __n));
}
@@ -423,16 +423,15 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
static _GLIBCXX17_CONSTEXPR int
compare(const char_type* __s1, const char_type* __s2, size_t __n)
{
+ if (__n == 0)
+ return 0;
#if __cplusplus >= 201703L
if (__builtin_constant_p(__n)
&& __constant_char_array_p(__s1, __n)
&& __constant_char_array_p(__s2, __n))
return __gnu_cxx::char_traits<char_type>::compare(__s1, __s2, __n);
#endif
- if (__n == 0)
- return 0;
- else
- return wmemcmp(__s1, __s2, __n);
+ return wmemcmp(__s1, __s2, __n);
}
static _GLIBCXX17_CONSTEXPR size_t
@@ -441,24 +440,22 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
#if __cplusplus >= 201703L
if (__constant_string_p(__s))
return __gnu_cxx::char_traits<char_type>::length(__s);
- else
#endif
- return wcslen(__s);
+ return wcslen(__s);
}
static _GLIBCXX17_CONSTEXPR const char_type*
find(const char_type* __s, size_t __n, const char_type& __a)
{
+ if (__n == 0)
+ return 0;
#if __cplusplus >= 201703L
if (__builtin_constant_p(__n)
&& __builtin_constant_p(__a)
&& __constant_char_array_p(__s, __n))
return __gnu_cxx::char_traits<char_type>::find(__s, __n, __a);
#endif
- if (__n == 0)
- return 0;
- else
- return wmemchr(__s, __a, __n);
+ return wmemchr(__s, __a, __n);
}
static char_type*
@@ -532,14 +529,14 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
static _GLIBCXX17_CONSTEXPR int
compare(const char_type* __s1, const char_type* __s2, size_t __n)
{
+ if (__n == 0)
+ return 0;
#if __cplusplus > 201402
if (__builtin_constant_p(__n)
&& __constant_char_array_p(__s1, __n)
&& __constant_char_array_p(__s2, __n))
return __gnu_cxx::char_traits<char_type>::compare(__s1, __s2, __n);
#endif
- if (__n == 0)
- return 0;
return __builtin_memcmp(__s1, __s2, __n);
}
@@ -559,14 +556,14 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
static _GLIBCXX17_CONSTEXPR const char_type*
find(const char_type* __s, size_t __n, const char_type& __a)
{
+ if (__n == 0)
+ return 0;
#if __cplusplus > 201402
if (__builtin_constant_p(__n)
&& __builtin_constant_p(__a)
&& __constant_char_array_p(__s, __n))
return __gnu_cxx::char_traits<char_type>::find(__s, __n, __a);
#endif
- if (__n == 0)
- return 0;
return static_cast<const char_type*>(__builtin_memchr(__s, __a, __n));
}
diff --git a/libstdc++-v3/testsuite/21_strings/basic_string_view/operators/char/89446.cc b/libstdc++-v3/testsuite/21_strings/basic_string_view/operators/char/89446.cc
new file mode 100644
index 00000000000..768ba63ddfe
--- /dev/null
+++ b/libstdc++-v3/testsuite/21_strings/basic_string_view/operators/char/89446.cc
@@ -0,0 +1,28 @@
+// 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 -fexceptions -fnon-call-exceptions -O1" }
+// { dg-do run { target { powerpc*-*-linux* i?86-*-linux* x86_64-*-linux* } } }
+// { dg-require-effective-target c++17 }
+
+#include <string_view>
+
+int main()
+{
+ std::string_view s1, s2;
+ return s1 != s2;
+}
diff --git a/libstdc++-v3/testsuite/21_strings/basic_string_view/operators/wchar_t/89446.cc b/libstdc++-v3/testsuite/21_strings/basic_string_view/operators/wchar_t/89446.cc
new file mode 100644
index 00000000000..a0ecbebea92
--- /dev/null
+++ b/libstdc++-v3/testsuite/21_strings/basic_string_view/operators/wchar_t/89446.cc
@@ -0,0 +1,28 @@
+// 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 -fexceptions -fnon-call-exceptions -O1" }
+// { dg-do run { target { powerpc*-*-linux* i?86-*-linux* x86_64-*-linux* } } }
+// { dg-require-effective-target c++17 }
+
+#include <string_view>
+
+int main()
+{
+ std::wstring_view s1, s2;
+ return s1 != s2;
+}
