From: Matthias Maier <tamiko@43-1.org>
Date: Fri, 15 Jun 2018 19:54:05 +0000 (-0500)
Subject: Exceptions: Do not set verbose terminate handler
X-Git-Tag: v9.1.0-rc1~1024^2
X-Git-Url: https://gitweb.dealii.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=refs%2Fpull%2F6776%2Fhead;p=dealii.git

Exceptions: Do not set verbose terminate handler

All of this is entirely redundant nowadays. libstdc++ defaults to
setting the verbose terminate handler since (almost) forever. So all we
end up doing is setting something that is already the default.

Remove it.

Rationale:

 - libstdc++ (gcc) switched to __gnu_cxx::__verbose_terminate_handler a
   long time ago [1].

 - libc++ (clang) has its own verbose terminate handler. And above code
   snippet never worked there [2]:

Example:

```

struct my_exception : public std::runtime_error {
  my_exception() : std::runtime_error("Nope, not with me") {}
};

int main() { throw my_exception(); }
```

libstdc++:
terminate called after throwing an instance of 'my_exception'
  what():  Nope, not with me
zsh: abort (core dumped)  ./a.out

libc++:
terminating with uncaught exception of type my_exception: Nope, not with me

[1] https://gcc.gnu.org/onlinedocs/libstdc++/manual/termination.html

[2] The DEAL_II_HAVE_VERBOSE_TERMINATE check fails for libc++ because
    (of course) no __gnu_cxx:: namespace is available...
---

diff --git a/cmake/checks/check_02_compiler_features.cmake b/cmake/checks/check_02_compiler_features.cmake
index 9046f50d22..a2b90d1c4c 100644
--- a/cmake/checks/check_02_compiler_features.cmake
+++ b/cmake/checks/check_02_compiler_features.cmake
@@ -25,7 +25,6 @@
 #   DEAL_II_COMPILER_USE_VECTOR_ARITHMETICS
 #   DEAL_II_VECTOR_ITERATOR_IS_POINTER
 #   DEAL_II_HAVE_BUILTIN_EXPECT
-#   DEAL_II_HAVE_VERBOSE_TERMINATE
 #   DEAL_II_HAVE_GLIBC_STACKTRACE
 #   DEAL_II_HAVE_LIBSTDCXX_DEMANGLER
 #   DEAL_II_COMPILER_HAS_ATTRIBUTE_PRETTY_FUNCTION
@@ -125,41 +124,6 @@ CHECK_CXX_SOURCE_COMPILES(
   DEAL_II_HAVE_BUILTIN_EXPECT)
 
 
-#
-# Newer versions of GCC have a very nice feature: you can set
-# a verbose terminate handler, that not only aborts a program
-# when an exception is thrown and not caught somewhere, but
-# before aborting it prints that an exception has been thrown,
-# and possibly what the std::exception::what() function has to
-# say. Since many people run into the trap of not having a
-# catch clause in main(), they wonder where that abort may be
-# coming from.  The terminate handler then at least says what is
-# missing in their program.
-#
-# This test checks whether this feature is available.
-#
-# - Matthias Maier, rewritten 2012
-#
-CHECK_CXX_SOURCE_COMPILES(
-  "
-  #include <exception>
-  namespace __gnu_cxx
-  {
-    extern void __verbose_terminate_handler ();
-  }
-  struct preload_terminate_dummy
-  {
-    preload_terminate_dummy()
-    {
-      std::set_terminate (__gnu_cxx::__verbose_terminate_handler);
-    }
-  };
-  static preload_terminate_dummy dummy;
-  int main() { throw 1; return 0; }
-  "
-  DEAL_II_HAVE_VERBOSE_TERMINATE)
-
-
 #
 # Check whether glibc-like stacktrace information is available
 # for the Exception class. If it is, then try to also determine
diff --git a/include/deal.II/base/config.h.in b/include/deal.II/base/config.h.in
index d66211ef98..9b4a45be3e 100644
--- a/include/deal.II/base/config.h.in
+++ b/include/deal.II/base/config.h.in
@@ -88,7 +88,6 @@
 #cmakedefine DEAL_II_COMPILER_USE_VECTOR_ARITHMETICS
 #cmakedefine DEAL_II_VECTOR_ITERATOR_IS_POINTER
 #cmakedefine DEAL_II_HAVE_BUILTIN_EXPECT
-#cmakedefine DEAL_II_HAVE_VERBOSE_TERMINATE
 #cmakedefine DEAL_II_HAVE_GLIBC_STACKTRACE
 #cmakedefine DEAL_II_HAVE_LIBSTDCXX_DEMANGLER
 #cmakedefine __PRETTY_FUNCTION__ @__PRETTY_FUNCTION__@
diff --git a/source/base/exceptions.cc b/source/base/exceptions.cc
index 5f869b9153..c9f83a897a 100644
--- a/source/base/exceptions.cc
+++ b/source/base/exceptions.cc
@@ -572,34 +572,3 @@ namespace deal_II_exceptions
 
 
 DEAL_II_NAMESPACE_CLOSE
-
-
-
-// Newer versions of gcc have a very nice feature: you can set a verbose
-// terminate handler, that not only aborts a program when an exception is
-// thrown and not caught somewhere, but before aborting it prints that an
-// exception has been thrown, and possibly what the std::exception::what()
-// function has to say. Since many people run into the trap of not having a
-// catch clause in main(), they wonder where that abort may be coming from.
-// The terminate handler then at least says what is missing in their
-// program.
-#ifdef DEAL_II_HAVE_VERBOSE_TERMINATE
-namespace __gnu_cxx
-{
-  extern void
-  __verbose_terminate_handler();
-}
-
-namespace
-{
-  struct preload_terminate_dummy
-  {
-    preload_terminate_dummy()
-    {
-      std::set_terminate(__gnu_cxx::__verbose_terminate_handler);
-    }
-  };
-
-  static preload_terminate_dummy dummy;
-} // namespace
-#endif