[PATCH libstdc++] Fix for std::uncaught_exception (PR 62258)

[PATCH libstdc++] Fix for std::uncaught_exception (PR 62258)

[Michael Hanselmann]

Calls to `std::uncaught_exception` after calling
`std::rethrow_exception' always return `true' when
`std::uncaught_exception' should return `false' unless an exception is
in flight. `std::rethrow_exception' does not update
`__cxa_eh_globals::uncaughtExceptions' while the following call to
`__cxa_begin_catch' decrements it. This fixes PR 62258.

The original two-line patch was created by Dmitry Prokoptsev. Michael
Hanselmann implemented a testcase.

Signed-off-by: Michael Hanselmann <public@hansmi.ch>
---
 libstdc++-v3/libsupc++/eh_ptr.cc                   |  3 ++
 .../exception_ptr/62258-uncaught_exception.cc      | 63 ++++++++++++++++++++++
 2 files changed, 66 insertions(+)
 create mode 100644 libstdc++-v3/testsuite/18_support/exception_ptr/62258-uncaught_exception.cc

diff --git a/libstdc++-v3/libsupc++/eh_ptr.cc b/libstdc++-v3/libsupc++/eh_ptr.cc
index 685c9e0..dae9246 100644
--- a/libstdc++-v3/libsupc++/eh_ptr.cc
+++ b/libstdc++-v3/libsupc++/eh_ptr.cc
@@ -245,6 +245,9 @@ std::rethrow_exception(std::exception_ptr ep)
   __GXX_INIT_DEPENDENT_EXCEPTION_CLASS(dep->unwindHeader.exception_class);
   dep->unwindHeader.exception_cleanup = __gxx_dependent_exception_cleanup;
 
+  __cxa_eh_globals *globals = __cxa_get_globals ();
+  globals->uncaughtExceptions += 1;
+
 #ifdef _GLIBCXX_SJLJ_EXCEPTIONS
   _Unwind_SjLj_RaiseException (&dep->unwindHeader);
 #else
diff --git a/libstdc++-v3/testsuite/18_support/exception_ptr/62258-uncaught_exception.cc b/libstdc++-v3/testsuite/18_support/exception_ptr/62258-uncaught_exception.cc
new file mode 100644
index 0000000..dbb431e
--- /dev/null
+++ b/libstdc++-v3/testsuite/18_support/exception_ptr/62258-uncaught_exception.cc
@@ -0,0 +1,63 @@
+// { dg-options "-std=gnu++11" }
+// { dg-require-atomic-builtins "" }
+
+// 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/>.
+
+// PR libstdc++/62258
+
+#include <exception>
+#include <testsuite_hooks.h>
+
+struct check_on_destruct
+{
+  ~check_on_destruct();
+};
+
+check_on_destruct::~check_on_destruct()
+{
+  VERIFY(std::uncaught_exception());
+}
+
+int main ()
+{
+  VERIFY(!std::uncaught_exception());
+
+  try
+    {
+      check_on_destruct check;
+
+      try
+        {
+          throw 1;
+        }
+      catch (...)
+        {
+          VERIFY(!std::uncaught_exception());
+
+          std::rethrow_exception(std::current_exception());
+        }
+    }
+  catch (...)
+    {
+      VERIFY(!std::uncaught_exception());
+    }
+
+  VERIFY(!std::uncaught_exception());
+
+  return 0;
+}
-- 
2.1.4

Re: [PATCH libstdc++] Fix for std::uncaught_exception (PR 62258)

[Jonathan Wakely]

On 2 February 2015 at 02:37, Michael Hanselmann wrote:
> Calls to `std::uncaught_exception` after calling
> `std::rethrow_exception' always return `true' when
> `std::uncaught_exception' should return `false' unless an exception is
> in flight. `std::rethrow_exception' does not update
> `__cxa_eh_globals::uncaughtExceptions' while the following call to
> `__cxa_begin_catch' decrements it. This fixes PR 62258.

The patch looks correct, but I think it can wait until the trunk
reopens after the GCC 5 release.

Re: [PATCH libstdc++] Fix for std::uncaught_exception (PR 62258)

[Michael Hanselmann]

On 02.02.2015 12:03, Jonathan Wakely wrote:
> On 2 February 2015 at 02:37, Michael Hanselmann wrote:
>> Calls to `std::uncaught_exception` after calling
>> `std::rethrow_exception' always return `true' when
>> `std::uncaught_exception' should return `false' unless an exception is
>> in flight. `std::rethrow_exception' does not update
>> `__cxa_eh_globals::uncaughtExceptions' while the following call to
>> `__cxa_begin_catch' decrements it. This fixes PR 62258.
> 
> The patch looks correct, but I think it can wait until the trunk
> reopens after the GCC 5 release.

I presume that's the case now that the GCC 5 branch has been created.

Re: [PATCH libstdc++] Fix for std::uncaught_exception (PR 62258)

[Jonathan Wakely]

On 13 April 2015 at 13:13, Michael Hanselmann wrote:
> On 02.02.2015 12:03, Jonathan Wakely wrote:
>> On 2 February 2015 at 02:37, Michael Hanselmann wrote:
>>> Calls to `std::uncaught_exception` after calling
>>> `std::rethrow_exception' always return `true' when
>>> `std::uncaught_exception' should return `false' unless an exception is
>>> in flight. `std::rethrow_exception' does not update
>>> `__cxa_eh_globals::uncaughtExceptions' while the following call to
>>> `__cxa_begin_catch' decrements it. This fixes PR 62258.
>>
>> The patch looks correct, but I think it can wait until the trunk
>> reopens after the GCC 5 release.
>
> I presume that's the case now that the GCC 5 branch has been created.

Yes, thanks for the reminder. I plan to fix it some time this week.

Re: [PATCH libstdc++] Fix for std::uncaught_exception (PR 62258)

[Jonathan Wakely]

[-- Attachment #1: Type: text/plain, Size: 567 bytes --]

On 02/02/15 03:37 +0100, Michael Hanselmann wrote:
>Calls to `std::uncaught_exception` after calling
>`std::rethrow_exception' always return `true' when
>`std::uncaught_exception' should return `false' unless an exception is
>in flight. `std::rethrow_exception' does not update
>`__cxa_eh_globals::uncaughtExceptions' while the following call to
>`__cxa_begin_catch' decrements it. This fixes PR 62258.
>
>The original two-line patch was created by Dmitry Prokoptsev. Michael

>Hanselmann implemented a testcase.

Committed to trunk - thanks for the patch and test.


[-- Attachment #2: patch.txt --]
[-- Type: text/x-patch, Size: 2789 bytes --]

commit 1cfba1875f21f485fe82e8c118b2355c4714bcdc
Author: Jonathan Wakely <jwakely@redhat.com>
Date:   Mon Apr 27 13:48:23 2015 +0100

    2015-04-27  Dmitry Prokoptsev  <dprokoptsev@gmail.com>
    	    Michael Hanselmann  <public@hansmi.ch>
    
    	PR libstdc++/62258
    	* libsupc++/eh_ptr.cc (rethrow_exception): Increment count of
    	uncaught exceptions.
    	* testsuite/18_support/exception_ptr/62258.cc: New.

diff --git a/libstdc++-v3/libsupc++/eh_ptr.cc b/libstdc++-v3/libsupc++/eh_ptr.cc
index 685c9e0..dae9246 100644
--- a/libstdc++-v3/libsupc++/eh_ptr.cc
+++ b/libstdc++-v3/libsupc++/eh_ptr.cc
@@ -245,6 +245,9 @@ std::rethrow_exception(std::exception_ptr ep)
   __GXX_INIT_DEPENDENT_EXCEPTION_CLASS(dep->unwindHeader.exception_class);
   dep->unwindHeader.exception_cleanup = __gxx_dependent_exception_cleanup;
 
+  __cxa_eh_globals *globals = __cxa_get_globals ();
+  globals->uncaughtExceptions += 1;
+
 #ifdef _GLIBCXX_SJLJ_EXCEPTIONS
   _Unwind_SjLj_RaiseException (&dep->unwindHeader);
 #else
diff --git a/libstdc++-v3/testsuite/18_support/exception_ptr/62258.cc b/libstdc++-v3/testsuite/18_support/exception_ptr/62258.cc
new file mode 100644
index 0000000..3734f19
--- /dev/null
+++ b/libstdc++-v3/testsuite/18_support/exception_ptr/62258.cc
@@ -0,0 +1,61 @@
+// { dg-options "-std=gnu++11" }
+// { dg-require-atomic-builtins "" }
+
+// 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/>.
+
+// PR libstdc++/62258
+
+#include <exception>
+#include <testsuite_hooks.h>
+
+struct check_on_destruct
+{
+  ~check_on_destruct();
+};
+
+check_on_destruct::~check_on_destruct()
+{
+  VERIFY(std::uncaught_exception());
+}
+
+int main ()
+{
+  VERIFY(!std::uncaught_exception());
+
+  try
+    {
+      check_on_destruct check;
+
+      try
+        {
+          throw 1;
+        }
+      catch (...)
+        {
+          VERIFY(!std::uncaught_exception());
+
+          std::rethrow_exception(std::current_exception());
+        }
+    }
+  catch (...)
+    {
+      VERIFY(!std::uncaught_exception());
+    }
+
+  VERIFY(!std::uncaught_exception());
+}