Enable chained function calls in C++ expressions.

gdb/ChangeLog:

	* eval.c: Include gdbthread.h.
	(evaluate_subexp): Enable thread stack temporaries before
	evaluating a complete expression and clean them up after the
	evaluation is complete.
	* gdbthread.h: Include common/vec.h.
	(value_ptr): New typedef.
	(VEC (value_ptr)): New vector type.
	(value_vec): New typedef.
	(struct thread_info): Add new fields stack_temporaries_enabled
	and stack_temporaries.
	(enable_thread_stack_temporaries)
	(thread_stack_temporaries_enabled_p, push_thread_stack_temporary)
	(get_last_thread_stack_temporary)
	(value_in_thread_stack_temporaries): Declare.
	* gdbtypes.c (class_or_union_p): New function.
	* gdbtypes.h (class_or_union_p): Declare.
	* infcall.c (call_function_by_hand): Store return values of class
	type as	temporaries on stack.
	* thread.c (enable_thread_stack_temporaries): New function.
	(thread_stack_temporaries_enabled_p, push_thread_stack_temporary)
	(get_last_thread_stack_temporary): Likewise.
	(value_in_thread_stack_temporaries): Likewise.
	* value.c (value_force_lval): New function.
	* value.h (value_force_lval): Declare.

gdb/testsuite/ChangeLog:

	* gdb.cp/chained-calls.cc: New file.
	* gdb.cp/chained-calls.exp: New file.
	* gdb.cp/smartp.exp: Remove KFAIL for "p c2->inta".

gdb/thread.c

@@ -636,6 +636,108 @@ prune_threads (void)
     }
 }
 
+/* Disable storing stack temporaries for the thread whose id is
+   stored in DATA.  */
+
+static void
+disable_thread_stack_temporaries (void *data)
+{
+  ptid_t *pd = data;
+  struct thread_info *tp = find_thread_ptid (*pd);
+
+  if (tp != NULL)
+    {
+      tp->stack_temporaries_enabled = 0;
+      VEC_free (value_ptr, tp->stack_temporaries);
+    }
+
+  xfree (pd);
+}
+
+/* Enable storing stack temporaries for thread with id PTID and return a
+   cleanup which can disable and clear the stack temporaries.  */
+
+struct cleanup *
+enable_thread_stack_temporaries (ptid_t ptid)
+{
+  struct thread_info *tp = find_thread_ptid (ptid);
+  ptid_t  *data;
+  struct cleanup *c;
+
+  gdb_assert (tp != NULL);
+
+  tp->stack_temporaries_enabled = 1;
+  tp->stack_temporaries = NULL;
+  data = (ptid_t *) xmalloc (sizeof (ptid_t));
+  *data = ptid;
+  c = make_cleanup (disable_thread_stack_temporaries, data);
+
+  return c;
+}
+
+/* Return non-zero value if stack temporaies are enabled for the thread
+   with id PTID.  */
+
+int
+thread_stack_temporaries_enabled_p (ptid_t ptid)
+{
+  struct thread_info *tp = find_thread_ptid (ptid);
+
+  if (tp == NULL)
+    return 0;
+  else
+    return tp->stack_temporaries_enabled;
+}
+
+/* Push V on to the stack temporaries of the thread with id PTID.  */
+
+void
+push_thread_stack_temporary (ptid_t ptid, struct value *v)
+{
+  struct thread_info *tp = find_thread_ptid (ptid);
+
+  gdb_assert (tp != NULL && tp->stack_temporaries_enabled);
+  VEC_safe_push (value_ptr, tp->stack_temporaries, v);
+}
+
+/* Return 1 if VAL is among the stack temporaries of the thread
+   with id PTID.  Return 0 otherwise.  */
+
+int
+value_in_thread_stack_temporaries (struct value *val, ptid_t ptid)
+{
+  struct thread_info *tp = find_thread_ptid (ptid);
+
+  gdb_assert (tp != NULL && tp->stack_temporaries_enabled);
+  if (!VEC_empty (value_ptr, tp->stack_temporaries))
+    {
+      struct value *v;
+      int i;
+
+      for (i = 0; VEC_iterate (value_ptr, tp->stack_temporaries, i, v); i++)
+	if (v == val)
+	  return 1;
+    }
+
+  return 0;
+}
+
+/* Return the last of the stack temporaries for thread with id PTID.
+   Return NULL if there are no stack temporaries for the thread.  */
+
+struct value *
+get_last_thread_stack_temporary (ptid_t ptid)
+{
+  struct value *lastval = NULL;
+  struct thread_info *tp = find_thread_ptid (ptid);
+
+  gdb_assert (tp != NULL);
+  if (!VEC_empty (value_ptr, tp->stack_temporaries))
+    lastval = VEC_last (value_ptr, tp->stack_temporaries);
+
+  return lastval;
+}
+
 void
 thread_change_ptid (ptid_t old_ptid, ptid_t new_ptid)
 {