public inbox for gcc-cvs@sourceware.org
help / color / mirror / Atom feed
* [gcc r11-3711] libstdc++: Fix divide by zero in default template argument
@ 2020-10-07 23:45 Jonathan Wakely
0 siblings, 0 replies; only message in thread
From: Jonathan Wakely @ 2020-10-07 23:45 UTC (permalink / raw)
To: gcc-cvs, libstdc++-cvs
https://gcc.gnu.org/g:6ae17a3b6835b30102607d45ac89c7a668e2c8d4
commit r11-3711-g6ae17a3b6835b30102607d45ac89c7a668e2c8d4
Author: Jonathan Wakely <jwakely@redhat.com>
Date: Thu Oct 8 00:34:56 2020 +0100
libstdc++: Fix divide by zero in default template argument
libstdc++-v3/ChangeLog:
* include/bits/random.h (__detail::_Mod): Avoid divide by zero.
* testsuite/26_numerics/random/linear_congruential_engine/operators/call.cc:
New test.
Diff:
---
libstdc++-v3/include/bits/random.h | 2 +-
.../linear_congruential_engine/operators/call.cc | 27 ++++++++++++++++++++++
2 files changed, 28 insertions(+), 1 deletion(-)
diff --git a/libstdc++-v3/include/bits/random.h b/libstdc++-v3/include/bits/random.h
index 4a6558c966a..920f3d91513 100644
--- a/libstdc++-v3/include/bits/random.h
+++ b/libstdc++-v3/include/bits/random.h
@@ -109,7 +109,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
template<typename _Tp, _Tp __m, _Tp __a, _Tp __c,
bool __big_enough = (!(__m & (__m - 1))
|| (_Tp(-1) - __c) / __a >= __m - 1),
- bool __schrage_ok = __m % __a < __m / __a>
+ bool __schrage_ok = __a != 0 && __m % __a < __m / __a>
struct _Mod
{
typedef typename _Select_uint_least_t<std::__lg(__a)
diff --git a/libstdc++-v3/testsuite/26_numerics/random/linear_congruential_engine/operators/call.cc b/libstdc++-v3/testsuite/26_numerics/random/linear_congruential_engine/operators/call.cc
new file mode 100644
index 00000000000..d1fff6d0a5d
--- /dev/null
+++ b/libstdc++-v3/testsuite/26_numerics/random/linear_congruential_engine/operators/call.cc
@@ -0,0 +1,27 @@
+// Copyright (C) 2020 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 <random>
+
+unsigned
+test01()
+{
+ std::linear_congruential_engine<unsigned, 0, 0, 0> l;
+ return l(); // this used to result in divide by zero
+}
^ permalink raw reply [flat|nested] only message in thread
only message in thread, other threads:[~2020-10-07 23:45 UTC | newest]
Thread overview: (only message) (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-10-07 23:45 [gcc r11-3711] libstdc++: Fix divide by zero in default template argument Jonathan Wakely
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).