Initial import of the CDE 2.1.30 sources from the Open Group.

cde/programs/dtinfo/DtMmdb/dti_excs/Jump_Environment.hh

@@ -0,0 +1,139 @@
+// $XConsortium: Jump_Environment.hh /main/6 1996/10/04 09:35:47 drk $
+#include <setjmp.h>
+
+#include "Unwind_Stack.hh"
+
+class Jump_Environment : public Destructable
+{
+public:
+  Jump_Environment();
+
+  // Only unregister the environment if it hasn't been unregistered.
+  // It is unregistered when an exception is thrown and stack unwound. 
+  ~Jump_Environment();
+
+  static void register_object (Destructable *object);
+  static void unregister_object (Destructable *object);
+
+  static void unwind_and_jump (Exception *current, int debugging)
+    { g_jump_env_stack->do_unwind_and_jump (current, debugging); }
+
+  // Must be public so setjmp can be called on it.  Can't use a
+  // method because of the way setjmp works. 
+  jmp_buf            f_env;
+#ifdef SVR4
+  // NOTE: this MUST follow f_env...mask bug in setjmp that overwrites our data
+  // 13:59 08/03/93 - jbm 
+  int		     f_filler[8] ;
+#endif
+
+private:
+  void longjmp()
+    { ::longjmp (f_env, 1); }
+  void do_register (Destructable *);
+  void do_unregister (Destructable *);
+  void do_unwind_and_jump (Exception *, int debugging);
+  void delete_active();
+  // The pending exception is the exception that is about to become
+  // the current exception.  It may be NULL if none has been thrown. 
+  static Exception *pending_exception()
+    { return (g_jump_env_stack->f_active_exception); }
+
+private: // variables
+  Exception         *f_active_exception;
+  Jump_Environment  *f_next;           // For Jump_Enviroment stacking.
+  unsigned char      f_unwinding;      // True when unwind in progress. 
+  Unwind_Stack       f_unwind_stack;   // Stack of objects to unwind.
+
+friend class Exceptions;
+  static Jump_Environment *g_jump_env_stack;
+  static Jump_Environment *g_used_jump_env_stack;
+#ifdef EXC_DEBUG
+  static int g_level;
+#endif
+};
+
+
+// /////////////////////////////////////////////////////////////////
+// do_register
+// /////////////////////////////////////////////////////////////////
+
+// Register the object if it isn't a member of another Destructable
+// object.  If it is a member of another, that object (or the object
+// that it's a member of) must be the last thing we registered.
+
+// First check for downward growing stack.  In this case the object
+// is part of another if it's address is greater than the start of
+// that other object.  If it wasn't a member of that object, it's
+// address would have to be lower than that object, having been 
+// created after that object.
+
+// Second check for upward growing stack.  In this case the object
+// is part of another if it's address is less than the end of that
+// other object.
+
+// If the stack is empty, it's the first object and can't be in another.
+
+inline void
+Jump_Environment::do_register (Destructable *object)
+{
+  PRINTF (("  Considering object %p: ", object));
+    
+  if (f_unwind_stack.empty() ||
+      (Destructable::stack_grows_down() ?
+       (unsigned long) object < f_unwind_stack.top().object_start() :
+       (unsigned long) object > f_unwind_stack.top().object_end()))
+    {
+      PRINTF ((" -- registered\n"));
+      f_unwind_stack.push (object, Destructable::g_size);
+    }
+#ifdef EXC_DEBUG
+  else
+    {
+      PRINTF ((" -- not registered\n"));
+    }
+#endif 
+}
+
+
+// /////////////////////////////////////////////////////////////////
+// unregister_object
+// /////////////////////////////////////////////////////////////////
+
+inline void
+Jump_Environment::do_unregister (Destructable *object)
+{
+  PRINTF (("  Unregister object @ %p:  ", object));
+  // Don't do anything it it wasn't on the stack.  It must have been
+  // part of another object or was never really constructed. 
+  if (!f_unwind_stack.empty() && f_unwind_stack.top().f_object == object)
+    {
+      PRINTF ((" -- removed\n"));
+      f_unwind_stack.pop();
+    }
+#ifdef EXC_DEBUG
+  else
+    {
+      PRINTF ((" -- never registered\n"));
+    }
+#endif
+}
+
+
+
+// /////////////////////////////////////////////////////////////////
+// register/unregister
+// /////////////////////////////////////////////////////////////////
+
+inline void
+Jump_Environment::register_object (Destructable *object)
+{
+  g_jump_env_stack->do_register (object);
+}
+
+inline void
+Jump_Environment::unregister_object (Destructable *object)
+{
+  g_jump_env_stack->do_unregister (object);
+}
+