| Message ID | 20150929151541.GZ12094@redhat.com |
|---|---|
| State | New |
| Headers | show |
On Tue, Sep 29, 2015 at 04:15:41PM +0100, Jonathan Wakely wrote: > We set errno=0 in __gnu_cxx::__stoa in order to reliably detect when > it gets set to ERANGE. This restores the previous value when the > conversion is successful. > > Tested powerpc64le-linux, committed to trunk. > commit 412f75dc37b1048e14996c9caafa46c00db8eb30 > Author: Jonathan Wakely <jwakely@redhat.com> > Date: Tue Sep 29 15:09:23 2015 +0100 > > Leave errno unchanged by successful std::stoi etc > > * include/ext/string_conversions.h (__stoa): Save and restore errno. > * testsuite/21_strings/basic_string/numeric_conversions/char/errno.cc: > New. > > diff --git a/libstdc++-v3/include/ext/string_conversions.h b/libstdc++-v3/include/ext/string_conversions.h > index f4648a8..58387a2 100644 > --- a/libstdc++-v3/include/ext/string_conversions.h > +++ b/libstdc++-v3/include/ext/string_conversions.h > @@ -58,6 +58,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION > _Ret __ret; > > _CharT* __endptr; > + const int __saved_errno = errno; > errno = 0; > const _TRet __tmp = __convf(__str, &__endptr, __base...); > > @@ -70,6 +71,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION > std::__throw_out_of_range(__name); > else > __ret = __tmp; > + errno = __saved_errno; That looks wrong to me, you only restore errno if you don't throw :(. If you throw, then errno might remain 0, which is IMHO undesirable. So, I'd say you want to restore it earlier, right after __convf, and immediately before that copy the current errno to some other temporary for the use in the condition? Or restore errno = __saved_errno; in all the 3 spots instead of just one. Jakub
commit 412f75dc37b1048e14996c9caafa46c00db8eb30
Author: Jonathan Wakely <jwakely@redhat.com>
Date: Tue Sep 29 15:09:23 2015 +0100
Leave errno unchanged by successful std::stoi etc
* include/ext/string_conversions.h (__stoa): Save and restore errno.
* testsuite/21_strings/basic_string/numeric_conversions/char/errno.cc:
New.
diff --git a/libstdc++-v3/include/ext/string_conversions.h b/libstdc++-v3/include/ext/string_conversions.h
index f4648a8..58387a2 100644
--- a/libstdc++-v3/include/ext/string_conversions.h
+++ b/libstdc++-v3/include/ext/string_conversions.h
@@ -58,6 +58,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
_Ret __ret;
_CharT* __endptr;
+ const int __saved_errno = errno;
errno = 0;
const _TRet __tmp = __convf(__str, &__endptr, __base...);
@@ -70,6 +71,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
std::__throw_out_of_range(__name);
else
__ret = __tmp;
+ errno = __saved_errno;
if (__idx)
*__idx = __endptr - __str;
diff --git a/libstdc++-v3/testsuite/21_strings/basic_string/numeric_conversions/char/errno.cc b/libstdc++-v3/testsuite/21_strings/basic_string/numeric_conversions/char/errno.cc
new file mode 100644
index 0000000..4079744
--- /dev/null
+++ b/libstdc++-v3/testsuite/21_strings/basic_string/numeric_conversions/char/errno.cc
@@ -0,0 +1,36 @@
+// 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" }
+// { dg-require-string-conversions "" }
+
+#include <string>
+#include <testsuite_hooks.h>
+
+void
+test01()
+{
+ errno = ERANGE;
+ std::stoi("42");
+ VERIFY( errno == ERANGE ); // errno should not be altered by successful call
+}
+
+int
+main()
+{
+ test01();
+}