re PR libstdc++/59476 (gdb pretty-printer cannot print C++11 _Rb_tree_iterator)

	PR libstdc++/59476
	* python/libstdcxx/v6/printers.py (get_value_from_Rb_tree_node): New
	function to handle both C++03 and C++11 _Rb_tree_node implementations.
	(StdRbtreeIteratorPrinter, StdMapPrinter, StdSetPrinter): Use it.
	* testsuite/libstdc++-prettyprinters/simple.cc: Update comment to
	refer to...
	* testsuite/libstdc++-prettyprinters/simple11.cc: New.

From-SVN: r210008

1 files changed, 22 insertions, 3 deletions

diff --git a/libstdc++-v3/python/libstdcxx/v6/printers.py b/libstdc++-v3/python/libstdcxx/v6/printers.py
index 05da17b..1f1f860 100644
--- a/libstdc++-v3/python/libstdcxx/v6/printers.py
+++ b/libstdc++-v3/python/libstdcxx/v6/printers.py
@@ -375,6 +375,22 @@ class RbtreeIterator:
             self.node = node
         return result
 
+def get_value_from_Rb_tree_node(node):
+    """Returns the value held in an _Rb_tree_node<_Val>"""
+    try:
+        member = node.type.fields()[1].name
+        if member == '_M_value_field':
+            # C++03 implementation, node contains the value as a member
+            return node['_M_value_field']
+        elif member == '_M_storage':
+            # C++11 implementation, node stores value in __aligned_buffer
+            p = node['_M_storage']['_M_storage'].address
+            p = p.cast(node.type.template_argument(0).pointer())
+            return p.dereference()
+    except:
+        pass
+    raise ValueError, "Unsupported implementation for %s" % str(node.type)
+
 # This is a pretty printer for std::_Rb_tree_iterator (which is
 # std::map::iterator), and has nothing to do with the RbtreeIterator
 # class above.
@@ -387,7 +403,8 @@ class StdRbtreeIteratorPrinter:
     def to_string (self):
         typename = str(self.val.type.strip_typedefs()) + '::_Link_type'
         nodetype = gdb.lookup_type(typename).strip_typedefs()
-        return self.val.cast(nodetype).dereference()['_M_value_field']
+        node = self.val.cast(nodetype).dereference()
+        return get_value_from_Rb_tree_node(node)
 
 class StdDebugIteratorPrinter:
     "Print a debug enabled version of an iterator"
@@ -417,7 +434,8 @@ class StdMapPrinter:
         def next(self):
             if self.count % 2 == 0:
                 n = self.rbiter.next()
-                n = n.cast(self.type).dereference()['_M_value_field']
+                n = n.cast(self.type).dereference()
+                n = get_value_from_Rb_tree_node(n)
                 self.pair = n
                 item = n['first']
             else:
@@ -458,7 +476,8 @@ class StdSetPrinter:
 
         def next(self):
             item = self.rbiter.next()
-            item = item.cast(self.type).dereference()['_M_value_field']
+            item = item.cast(self.type).dereference()
+            item = get_value_from_Rb_tree_node(item)
             # FIXME: this is weird ... what to do?
             # Maybe a 'set' display hint?
             result = ('[%d]' % self.count, item)