As explained in the PR, we were incorrectly swallowing exceptions from
basic_filebuf::close(). They should propagate from that function, but
still be swallowed in the destructor.
PR libstdc++/81256
* include/bits/fstream.tcc (basic_filebuf::close): Do not swallow
exceptions from _M_terminate_output().
* include/std/fstream (basic_filebuf::~basic_filebuf): Swallow any
exceptions from close().
* testsuite/27_io/basic_filebuf/close/81256.cc: New.
Tested powerp64le-linux, committed to trunk.
commit adcfbaa7023dc8d2d5cfa0b6971a99d0ed33a1f5
Author: Jonathan Wakely <jwak...@redhat.com>
Date: Mon May 14 17:13:05 2018 +0100
PR libstdc++/81256 fix exception handling in basic_filebuf::close
PR libstdc++/81256
* include/bits/fstream.tcc (basic_filebuf::close): Do not swallow
exceptions from _M_terminate_output().
* include/std/fstream (basic_filebuf::~basic_filebuf): Swallow any
exceptions from close().
* testsuite/27_io/basic_filebuf/close/81256.cc: New.
diff --git a/libstdc++-v3/include/bits/fstream.tcc
b/libstdc++-v3/include/bits/fstream.tcc
index f23ff7af4eb..08cf189ee06 100644
--- a/libstdc++-v3/include/bits/fstream.tcc
+++ b/libstdc++-v3/include/bits/fstream.tcc
@@ -239,13 +239,11 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
if (!_M_terminate_output())
__testfail = true;
}
- __catch(__cxxabiv1::__forced_unwind&)
+ __catch(...)
{
_M_file.close();
__throw_exception_again;
}
- __catch(...)
- { __testfail = true; }
}
if (!_M_file.close())
diff --git a/libstdc++-v3/include/std/fstream b/libstdc++-v3/include/std/fstream
index 3a5895d68b0..05661d9d58f 100644
--- a/libstdc++-v3/include/std/fstream
+++ b/libstdc++-v3/include/std/fstream
@@ -244,7 +244,12 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
*/
virtual
~basic_filebuf()
- { this->close(); }
+ {
+ __try
+ { this->close(); }
+ __catch(...)
+ { }
+ }
#if __cplusplus >= 201103L
basic_filebuf& operator=(const basic_filebuf&) = delete;
diff --git a/libstdc++-v3/testsuite/27_io/basic_filebuf/close/81256.cc
b/libstdc++-v3/testsuite/27_io/basic_filebuf/close/81256.cc
new file mode 100644
index 00000000000..aef7364526b
--- /dev/null
+++ b/libstdc++-v3/testsuite/27_io/basic_filebuf/close/81256.cc
@@ -0,0 +1,109 @@
+// Copyright (C) 2018 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 run { target c++11 } }
+
+#include <fstream>
+#include <locale>
+#include <testsuite_hooks.h>
+
+struct E : std::runtime_error
+{
+ E() : runtime_error("") { }
+};
+
+struct Cvt : std::codecvt<wchar_t, char, std::mbstate_t>
+{
+ explicit Cvt(size_t refs) : codecvt(refs) { }
+
+ mutable int exceptions_thrown = 0;
+
+private:
+ int
+ do_encoding() const noexcept override
+ { return -1; }
+
+ bool
+ do_always_noconv() const noexcept override
+ { return false; }
+
+ result
+ do_unshift(state_type&, char*, char*, char*&) const override
+ {
+ ++exceptions_thrown;
+ throw E();
+ }
+};
+
+struct filebuf : std::basic_filebuf<wchar_t>
+{
+ explicit filebuf(Cvt* c)
+ {
+ std::locale loc(std::locale::classic(), c);
+ imbue(loc);
+ }
+};
+
+void
+test01()
+{
+ // This facet needs to still be valid when ~basic_filebuf runs:
+ Cvt conv{1};
+ {
+ filebuf fb(&conv);
+ fb.open("output.txt", std::wios::out);
+ fb.sputn(L"x", 1);
+
+ bool caught = false;
+ try
+ {
+ /* [filebuf.members] p7: If one of these calls throws an exception,
+ * the exception is caught and rethrown after closing the file. */
+ fb.close();
+ }
+ catch (const E&)
+ {
+ caught = true;
+ }
+ VERIFY( conv.exceptions_thrown == 1 );
+ VERIFY( caught );
+ }
+ VERIFY( conv.exceptions_thrown == 1 );
+}
+
+void
+test02()
+{
+ // This facet needs to still be valid when ~basic_filebuf runs:
+ Cvt conv{1};
+ {
+ filebuf fb(&conv);
+ fb.open("output.txt", std::wios::out);
+ fb.sputn(L"x", 1);
+ /* [filebuf.cons] p5: If an exception occurs during the destruction
+ * of the object, including the call to close(), the exception is
+ * caught but not rethrown. */
+ }
+ VERIFY( conv.exceptions_thrown == 1 );
+}
+
+int
+main()
+{
+ test01();
+ test02();
+}
