libstdc++: Deprecate std::unexpected and handler functions

These functions have been deprecated since C++11, and were removed in
C++17. The proposal P0323 wants to reuse the name std::unexpected for a
class template, so we will need to stop defining the current function
for C++23 anyway.

This marks them as deprecated for C++11 and up, to warn users they won't
continue to be available. It disables them for C++17 and up, unless the
_GLIBCXX_USE_DEPRECATED macro is defined.

The <unwind-cxx.h> header uses std::unexpected_handler in the public
API, but since that type is the same as std::terminate_handler we can
just use that instead, to avoid warnings about it being deprecated.

libstdc++-v3/ChangeLog:

	* doc/xml/manual/evolution.xml: Document deprecations.
	* doc/html/*: Regenerate.
	* libsupc++/exception (unexpected_handler, unexpected)
	(get_unexpected, set_unexpected): Add deprecated attribute.
	Do not define without _GLIBCXX_USE_DEPRECATED for C++17 and up.
	* libsupc++/eh_personality.cc (PERSONALITY_FUNCTION): Disable
	deprecated warnings.
	* libsupc++/eh_ptr.cc (std::rethrow_exception): Likewise.
	* libsupc++/eh_terminate.cc: Likewise.
	* libsupc++/eh_throw.cc (__cxa_init_primary_exception):
	Likewise.
	* libsupc++/unwind-cxx.h (struct __cxa_exception): Use
	terminate_handler instead of unexpected_handler.
	(struct __cxa_dependent_exception): Likewise.
	(__unexpected): Likewise.
	* testsuite/18_support/headers/exception/synopsis.cc: Add
	dg-warning for deprecated warning.
	* testsuite/18_support/exception_ptr/60612-unexpected.cc:
	Disable deprecated warnings.
	* testsuite/18_support/set_unexpected.cc: Likewise.
	* testsuite/18_support/unexpected_handler.cc: Likewise.

gcc/testsuite/ChangeLog:

	* g++.dg/cpp0x/lambda/lambda-eh2.C: Add dg-warning for new
	deprecation warnings.
	* g++.dg/cpp0x/noexcept06.C: Likewise.
	* g++.dg/cpp0x/noexcept07.C: Likewise.
	* g++.dg/eh/forced3.C: Likewise.
	* g++.dg/eh/unexpected1.C: Likewise.
	* g++.old-deja/g++.eh/spec1.C: Likewise.
	* g++.old-deja/g++.eh/spec2.C: Likewise.
	* g++.old-deja/g++.eh/spec3.C: Likewise.
	* g++.old-deja/g++.eh/spec4.C: Likewise.
	* g++.old-deja/g++.mike/eh33.C: Likewise.
	* g++.old-deja/g++.mike/eh34.C: Likewise.
	* g++.old-deja/g++.mike/eh50.C: Likewise.
	* g++.old-deja/g++.mike/eh51.C: Likewise.

6 files changed, 38 insertions, 13 deletions

diff --git a/libstdc++-v3/libsupc++/eh_personality.cc b/libstdc++-v3/libsupc++/eh_personality.cc
index 33c3cc3..edd5f6a 100644
--- a/libstdc++-v3/libsupc++/eh_personality.cc
+++ b/libstdc++-v3/libsupc++/eh_personality.cc
@@ -673,10 +673,13 @@ PERSONALITY_FUNCTION (int version,
 	std::terminate ();
       else if (handler_switch_value < 0)
 	{
-	  __try 
-	    { std::unexpected (); } 
-	  __catch(...) 
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wdeprecated-declarations"
+	  __try
+	    { std::unexpected (); }
+	  __catch(...)
 	    { std::terminate (); }
+#pragma GCC diagnostic pop
 	}
     }
   else
diff --git a/libstdc++-v3/libsupc++/eh_ptr.cc b/libstdc++-v3/libsupc++/eh_ptr.cc
index 5c46856..9f47b666 100644
--- a/libstdc++-v3/libsupc++/eh_ptr.cc
+++ b/libstdc++-v3/libsupc++/eh_ptr.cc
@@ -198,7 +198,10 @@ std::rethrow_exception(std::exception_ptr ep)
   dep->primaryException = obj;
   __gnu_cxx::__eh_atomic_inc (&eh->referenceCount);
 
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wdeprecated-declarations"
   dep->unexpectedHandler = get_unexpected ();
+#pragma GCC diagnostic pop
   dep->terminateHandler = get_terminate ();
   __GXX_INIT_DEPENDENT_EXCEPTION_CLASS(dep->unwindHeader.exception_class);
   dep->unwindHeader.exception_cleanup = __gxx_dependent_exception_cleanup;
diff --git a/libstdc++-v3/libsupc++/eh_terminate.cc b/libstdc++-v3/libsupc++/eh_terminate.cc
index af257b6..a94f173 100644
--- a/libstdc++-v3/libsupc++/eh_terminate.cc
+++ b/libstdc++-v3/libsupc++/eh_terminate.cc
@@ -58,6 +58,7 @@ std::terminate () throw()
   __cxxabiv1::__terminate (get_terminate ());
 }
 
+#pragma GCC diagnostic ignored "-Wdeprecated-declarations"
 void
 __cxxabiv1::__unexpected (std::unexpected_handler handler)
 {
diff --git a/libstdc++-v3/libsupc++/eh_throw.cc b/libstdc++-v3/libsupc++/eh_throw.cc
index 765a6c1..51cbbc9 100644
--- a/libstdc++-v3/libsupc++/eh_throw.cc
+++ b/libstdc++-v3/libsupc++/eh_throw.cc
@@ -63,7 +63,10 @@ _GLIBCXX_NOTHROW
   header->referenceCount = 0;
   header->exc.exceptionType = tinfo;
   header->exc.exceptionDestructor = dest;
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wdeprecated-declarations"
   header->exc.unexpectedHandler = std::get_unexpected ();
+#pragma GCC diagnostic pop
   header->exc.terminateHandler = std::get_terminate ();
   __GXX_INIT_PRIMARY_EXCEPTION_CLASS(header->exc.unwindHeader.exception_class);
   header->exc.unwindHeader.exception_cleanup = __gxx_exception_cleanup;
diff --git a/libstdc++-v3/libsupc++/exception b/libstdc++-v3/libsupc++/exception
index a023e22..5088681 100644
--- a/libstdc++-v3/libsupc++/exception
+++ b/libstdc++-v3/libsupc++/exception
@@ -67,9 +67,6 @@ namespace std
   /// If you write a replacement %terminate handler, it must be of this type.
   typedef void (*terminate_handler) ();
 
-  /// If you write a replacement %unexpected handler, it must be of this type.
-  typedef void (*unexpected_handler) ();
-
   /// Takes a new handler function as an argument, returns the old function.
   terminate_handler set_terminate(terminate_handler) _GLIBCXX_USE_NOEXCEPT;
 
@@ -82,17 +79,35 @@ namespace std
    *  abandoned for any reason.  It can also be called by the user.  */
   void terminate() _GLIBCXX_USE_NOEXCEPT __attribute__ ((__noreturn__));
 
-  /// Takes a new handler function as an argument, returns the old function.
+#if __cplusplus < 201703L || _GLIBCXX_USE_DEPRECATED
+  /// If you write a replacement %unexpected handler, it must be of this type.
+  typedef void (*_GLIBCXX11_DEPRECATED unexpected_handler) ();
+
+  /** Takes a new handler function as an argument, returns the old function.
+   *
+   * @deprecated Removed from the C++ standard in C++17
+   */
+  _GLIBCXX11_DEPRECATED
   unexpected_handler set_unexpected(unexpected_handler) _GLIBCXX_USE_NOEXCEPT;
 
 #if __cplusplus >= 201103L
-  /// Return the current unexpected handler.
+  /** Return the current unexpected handler.
+   *
+   * @since C++11
+   * @deprecated Removed from the C++ standard in C++17
+   */
+  _GLIBCXX11_DEPRECATED
   unexpected_handler get_unexpected() noexcept;
 #endif
 
   /** The runtime will call this function if an %exception is thrown which
-   *  violates the function's %exception specification.  */
+   *  violates the function's %exception specification.
+   *
+   * @deprecated Removed from the C++ standard in C++17
+   */
+  _GLIBCXX11_DEPRECATED
   void unexpected() __attribute__ ((__noreturn__));
+#endif
 
   /** [18.6.4]/1:  'Returns true after completing evaluation of a
    *  throw-expression until either completing initialization of the
diff --git a/libstdc++-v3/libsupc++/unwind-cxx.h b/libstdc++-v3/libsupc++/unwind-cxx.h
index 65fd530..96d50ea 100644
--- a/libstdc++-v3/libsupc++/unwind-cxx.h
+++ b/libstdc++-v3/libsupc++/unwind-cxx.h
@@ -67,7 +67,7 @@ struct __cxa_exception
 
   // The C++ standard has entertaining rules wrt calling set_terminate
   // and set_unexpected in the middle of the exception cleanup process.
-  std::unexpected_handler unexpectedHandler;
+  std::terminate_handler unexpectedHandler;
   std::terminate_handler terminateHandler;
 
   // The caught exception stack threads through here.
@@ -121,7 +121,7 @@ struct __cxa_dependent_exception
 
   // The C++ standard has entertaining rules wrt calling set_terminate
   // and set_unexpected in the middle of the exception cleanup process.
-  std::unexpected_handler unexpectedHandler;
+  std::terminate_handler unexpectedHandler;
   std::terminate_handler terminateHandler;
 
   // The caught exception stack threads through here.
@@ -191,12 +191,12 @@ extern "C" void __cxa_tm_cleanup (void *, void *, unsigned int) throw();
 // so inconsiderate as to return.
 extern void __terminate(std::terminate_handler) throw () 
   __attribute__((__noreturn__));
-extern void __unexpected(std::unexpected_handler)
+extern void __unexpected(std::terminate_handler)
   __attribute__((__noreturn__));
 
 // The current installed user handlers.
 extern std::terminate_handler __terminate_handler;
-extern std::unexpected_handler __unexpected_handler;
+extern std::terminate_handler __unexpected_handler;
 
 // These are explicitly GNU C++ specific.