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Re: [c++0x] nested_exception
2009/5/11 Paolo Carlini:
> The patch looks pretty good to me: since we are in Stage 1 and in any
> case you are not adding any new exported symbols, I think it would make
> sense to check in the patch as-is, or with small modifications, even if
> the specs are not finalised. I would only suggest double checking for
> overlong lines, that trivial functions are inline, and preparing a
> ChangeLog entry.
Hi Paolo, thanks for the review.
I'll commit the attached patch, which adds some 'inline' keywords,
fixes the overlong line and also adjusts the manual.
* libsupc++/exception: Include nested_exception.h in C++0x mode.
* libsupc++/nested_exception.h: New.
* libsupc++/Makefile.am: Add new header.
* libsupc++/Makefile.in: Regenerate.
* testsuite/18_support/nested_exception/rethrow_nested.cc: New.
* testsuite/18_support/nested_exception/throw_with_nested.cc: New.
* testsuite/18_support/nested_exception/cons.cc: New.
* testsuite/18_support/nested_exception/nested_ptr.cc: New.
* testsuite/18_support/nested_exception/rethrow_if_nested.cc: New.
* doc/xml/manual/status_cxx200x.xml: Adjust.
Cheers,
Jonathan
Index: libsupc++/Makefile.am
===================================================================
--- libsupc++/Makefile.am (revision 147392)
+++ libsupc++/Makefile.am (working copy)
@@ -33,7 +33,7 @@ noinst_LTLIBRARIES = libsupc++convenienc
headers = \
exception new typeinfo cxxabi.h cxxabi-forced.h exception_defines.h \
- initializer_list exception_ptr.h
+ initializer_list exception_ptr.h nested_exception.h
if GLIBCXX_HOSTED
c_sources = \
Index: libsupc++/Makefile.in
===================================================================
--- libsupc++/Makefile.in (revision 147392)
+++ libsupc++/Makefile.in (working copy)
@@ -367,7 +367,7 @@ toolexeclib_LTLIBRARIES = libsupc++.la
noinst_LTLIBRARIES = libsupc++convenience.la
headers = \
exception new typeinfo cxxabi.h cxxabi-forced.h exception_defines.h \
- initializer_list exception_ptr.h
+ initializer_list exception_ptr.h nested_exception.h
@GLIBCXX_HOSTED_TRUE@c_sources = \
@GLIBCXX_HOSTED_TRUE@ cp-demangle.c
Index: libsupc++/exception
===================================================================
--- libsupc++/exception (revision 147392)
+++ libsupc++/exception (working copy)
@@ -146,6 +146,7 @@ _GLIBCXX_END_NAMESPACE
#if (defined(__GXX_EXPERIMENTAL_CXX0X__) \
&& defined(_GLIBCXX_ATOMIC_BUILTINS_4))
#include <exception_ptr.h>
+#include <nested_exception.h>
#endif
#endif
Index: libsupc++/nested_exception.h
===================================================================
--- libsupc++/nested_exception.h (revision 0)
+++ libsupc++/nested_exception.h (revision 0)
@@ -0,0 +1,177 @@
+// Nested Exception support header (nested_exception class) for -*- C++ -*-
+
+// Copyright (C) 2009 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.
+
+// Under Section 7 of GPL version 3, you are granted additional
+// permissions described in the GCC Runtime Library Exception, version
+// 3.1, as published by the Free Software Foundation.
+
+// You should have received a copy of the GNU General Public License and
+// a copy of the GCC Runtime Library Exception along with this program;
+// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
+// <http://www.gnu.org/licenses/>.
+
+/** @file nested_exception.h
+ * This is an internal header file, included by other headers and the
+ * implementation. You should not attempt to use it directly.
+ */
+
+#ifndef _GLIBCXX_NESTED_EXCEPTION_H
+#define _GLIBCXX_NESTED_EXCEPTION_H 1
+
+#pragma GCC visibility push(default)
+
+#ifndef __GXX_EXPERIMENTAL_CXX0X__
+# include <c++0x_warning.h>
+#else
+
+#include <bits/c++config.h>
+
+#if !defined(_GLIBCXX_ATOMIC_BUILTINS_4)
+# error This platform does not support exception propagation.
+#endif
+
+extern "C++" {
+
+namespace std
+{
+ /**
+ * @addtogroup exceptions
+ * @{
+ */
+
+ /// nested_exception
+ class nested_exception
+ {
+ public:
+ nested_exception() throw() : _M_ptr(current_exception()) { }
+
+ nested_exception(const nested_exception&) throw() = default;
+
+ nested_exception& operator=(const nested_exception&) throw() = default;
+
+ virtual ~nested_exception() = default;
+
+ void
+ rethrow_nested() const __attribute__ ((__noreturn__))
+ { rethrow_exception(_M_ptr); }
+
+ exception_ptr
+ nested_ptr() const
+ { return _M_ptr; }
+
+ private:
+ exception_ptr _M_ptr;
+ };
+
+ template<typename _Except>
+ struct _Nested_exception : public _Except, public nested_exception
+ {
+ explicit
+ _Nested_exception(_Except&& __ex)
+ : _Except(static_cast<_Except&&>(__ex))
+ { }
+ };
+
+ template<typename _Ex>
+ struct __get_nested_helper
+ {
+ static const nested_exception*
+ _S_get(const _Ex& __ex)
+ {
+ return dynamic_cast<const nested_exception*>(&__ex);
+ }
+ };
+
+ template<typename _Ex>
+ struct __get_nested_helper<_Ex*>
+ {
+ static const nested_exception*
+ _S_get(const _Ex* __ex)
+ {
+ return dynamic_cast<const nested_exception*>(__ex);
+ }
+ };
+
+ template<typename _Ex>
+ inline const nested_exception*
+ __get_nested_exception(const _Ex& __ex)
+ {
+ return __get_nested_helper<_Ex>::_S_get(__ex);
+ }
+
+ template<typename _Ex>
+ void
+ __throw_with_nested(_Ex&&, const nested_exception* = 0)
+ __attribute__ ((__noreturn__));
+
+ template<typename _Ex>
+ void
+ __throw_with_nested(_Ex&&, ...) __attribute__ ((__noreturn__));
+
+ // This function should never be called, but is needed to avoid a warning
+ // about ambiguous base classes when instantiating throw_with_nested<_Ex>()
+ // with a type that has an accessible nested_exception base.
+ template<typename _Ex>
+ inline void
+ __throw_with_nested(_Ex&& __ex, const nested_exception* = 0)
+ {
+ throw __ex;
+ }
+
+ template<typename _Ex>
+ inline void
+ __throw_with_nested(_Ex&& __ex, ...)
+ {
+ throw _Nested_exception<_Ex>(static_cast<_Ex&&>(__ex));
+ }
+
+ template<typename _Ex>
+ void
+ throw_with_nested(_Ex __ex) __attribute__ ((__noreturn__));
+
+ template<typename _Ex>
+ inline void
+ throw_with_nested(_Ex __ex)
+ {
+ if (__get_nested_exception(__ex))
+ throw __ex;
+ __throw_with_nested(static_cast<_Ex&&>(__ex), &__ex);
+ }
+
+ template<typename _Ex>
+ inline void
+ rethrow_if_nested(const _Ex& __ex)
+ {
+ if (const nested_exception* __nested = __get_nested_exception(__ex))
+ __nested->rethrow_nested();
+ }
+
+ // see n2619
+ inline void
+ rethrow_if_nested(const nested_exception& __ex)
+ {
+ __ex.rethrow_nested();
+ }
+
+ // @} group exceptions
+} // namespace std
+
+} // extern "C++"
+
+#endif // __GXX_EXPERIMENTAL_CXX0X__
+
+#pragma GCC visibility pop
+
+#endif // _GLIBCXX_NESTED_EXCEPTION_H
Index: testsuite/18_support/nested_exception/rethrow_nested.cc
===================================================================
--- testsuite/18_support/nested_exception/rethrow_nested.cc (revision 0)
+++ testsuite/18_support/nested_exception/rethrow_nested.cc (revision 0)
@@ -0,0 +1,53 @@
+// { dg-options "-std=gnu++0x" }
+// { dg-require-atomic-builtins "" }
+
+// Copyright (C) 2009 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/>.
+
+#include <exception>
+#include <testsuite_hooks.h>
+
+void test01()
+{
+ bool test __attribute__((unused)) = false;
+
+ try
+ {
+ try
+ {
+ throw 42;
+ }
+ catch (...)
+ {
+ std::nested_exception e;
+ e.rethrow_nested();
+ }
+ }
+ catch(const int& i)
+ {
+ test = true;
+ VERIFY( i == 42 );
+ }
+
+ VERIFY( test );
+}
+
+int main()
+{
+ test01();
+ return 0;
+}
Index: testsuite/18_support/nested_exception/throw_with_nested.cc
===================================================================
--- testsuite/18_support/nested_exception/throw_with_nested.cc (revision 0)
+++ testsuite/18_support/nested_exception/throw_with_nested.cc (revision 0)
@@ -0,0 +1,79 @@
+// { dg-options "-std=gnu++0x" }
+// { dg-require-atomic-builtins "" }
+
+// Copyright (C) 2009 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/>.
+
+#include <exception>
+#include <testsuite_hooks.h>
+
+struct derived : std::nested_exception { };
+
+struct not_derived { virtual ~not_derived() = default; };
+
+void test01()
+{
+ bool test __attribute__((unused)) = false;
+
+ try
+ {
+ std::throw_with_nested(derived());
+ }
+ catch (const std::nested_exception& e)
+ {
+ VERIFY( !e.nested_ptr() );
+ try
+ {
+ throw;
+ }
+ catch (const derived&)
+ {
+ test = true;
+ }
+ }
+ VERIFY( test );
+}
+
+void test02()
+{
+ bool test __attribute__((unused)) = false;
+
+ try
+ {
+ std::throw_with_nested(not_derived());
+ }
+ catch (const std::nested_exception& e)
+ {
+ VERIFY( !e.nested_ptr() );
+ try
+ {
+ throw;
+ }
+ catch (const not_derived&)
+ {
+ test = true;
+ }
+ }
+ VERIFY( test );
+}
+
+int main()
+{
+ test01();
+ test02();
+ return 0;
+}
Index: testsuite/18_support/nested_exception/cons.cc
===================================================================
--- testsuite/18_support/nested_exception/cons.cc (revision 0)
+++ testsuite/18_support/nested_exception/cons.cc (revision 0)
@@ -0,0 +1,53 @@
+// { dg-options "-std=gnu++0x" }
+// { dg-require-atomic-builtins "" }
+
+// Copyright (C) 2009 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/>.
+
+#include <exception>
+#include <testsuite_hooks.h>
+
+void test01()
+{
+ bool test __attribute__((unused)) = true;
+
+ std::nested_exception e;
+
+ VERIFY( !e.nested_ptr() );
+}
+
+void test02()
+{
+ bool test __attribute__((unused)) = true;
+
+ try
+ {
+ throw 42;
+ }
+ catch (...)
+ {
+ std::nested_exception e;
+ VERIFY( e.nested_ptr() == std::current_exception() );
+ }
+}
+
+int main()
+{
+ test01();
+ test02();
+ return 0;
+}
Index: testsuite/18_support/nested_exception/nested_ptr.cc
===================================================================
--- testsuite/18_support/nested_exception/nested_ptr.cc (revision 0)
+++ testsuite/18_support/nested_exception/nested_ptr.cc (revision 0)
@@ -0,0 +1,71 @@
+// { dg-options "-std=gnu++0x" }
+// { dg-require-atomic-builtins "" }
+
+// Copyright (C) 2009 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/>.
+
+#include <exception>
+#include <testsuite_hooks.h>
+
+void test01()
+{
+ bool test __attribute__((unused)) = true;
+
+ try
+ {
+ throw std::nested_exception();
+ }
+ catch (const std::nested_exception& e)
+ {
+ VERIFY( !e.nested_ptr() );
+ }
+}
+
+void test02()
+{
+ bool test __attribute__((unused)) = true;
+
+ try
+ {
+ throw 42;
+ }
+ catch (...)
+ {
+ try
+ {
+ throw std::nested_exception();
+ }
+ catch (const std::nested_exception& e)
+ {
+ try
+ {
+ std::rethrow_exception( e.nested_ptr() );
+ }
+ catch(const int& i)
+ {
+ VERIFY( i == 42 );
+ }
+ }
+ }
+}
+
+int main()
+{
+ test01();
+ test02();
+ return 0;
+}
Index: testsuite/18_support/nested_exception/rethrow_if_nested.cc
===================================================================
--- testsuite/18_support/nested_exception/rethrow_if_nested.cc (revision 0)
+++ testsuite/18_support/nested_exception/rethrow_if_nested.cc (revision 0)
@@ -0,0 +1,110 @@
+// { dg-options "-std=gnu++0x" }
+// { dg-require-atomic-builtins "" }
+
+// Copyright (C) 2009 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/>.
+
+#include <exception>
+#include <testsuite_hooks.h>
+
+struct derived : std::nested_exception { };
+
+struct base { virtual ~base() = default; };
+
+struct derived2 : base, std::nested_exception { };
+
+void test01()
+{
+ bool test __attribute__((unused)) = false;
+
+ try
+ {
+ throw 42;
+ }
+ catch (...)
+ {
+ derived d;
+ try
+ {
+ std::rethrow_if_nested(d);
+ }
+ catch (const int& i)
+ {
+ test = true;
+ VERIFY( i == 42 );
+ }
+ }
+
+ VERIFY( test );
+}
+
+void test02()
+{
+ bool test __attribute__((unused)) = false;
+
+ try
+ {
+ throw base();
+ }
+ catch (const base& b)
+ {
+ std::rethrow_if_nested(b);
+ test = true;
+ }
+
+ VERIFY( test );
+}
+
+void test03()
+{
+ bool test __attribute__((unused)) = false;
+
+ try
+ {
+ throw 42;
+ }
+ catch (...)
+ {
+ try
+ {
+ throw derived2();
+ }
+ catch (const base& b)
+ {
+ try
+ {
+ std::rethrow_if_nested(b);
+ }
+ catch (const int& i)
+ {
+ VERIFY( i == 42 );
+ test = true;
+ }
+ }
+ }
+
+ VERIFY( test );
+}
+
+
+int main()
+{
+ test01();
+ test02();
+ test03();
+ return 0;
+}
Index: doc/xml/manual/status_cxx200x.xml
===================================================================
--- doc/xml/manual/status_cxx200x.xml (revision 147392)
+++ doc/xml/manual/status_cxx200x.xml (working copy)
@@ -235,10 +235,9 @@ particular release.
<entry></entry>
</row>
<row>
- <?dbhtml bgcolor="#C8B0B0" ?>
<entry>18.8.6</entry>
<entry>Class <code>nested_exception</code></entry>
- <entry>N</entry>
+ <entry>Y</entry>
<entry></entry>
</row>
<row>