text: 
  from rpython.rtyper.lltypesystem.lltype import (Primitive, Ptr, typeOf,
      RuntimeTypeInfo, Struct, Array, FuncType, Void, ContainerType, OpaqueType,
      FixedSizeArray, Typedef)
  from rpython.rtyper.lltypesystem import lltype, rffi
  from rpython.rtyper.lltypesystem.llmemory import WeakRef, _WeakRefType, GCREF
  from rpython.rtyper.lltypesystem.rffi import CConstant
  from rpython.rtyper.lltypesystem import llgroup
  from rpython.tool.sourcetools import valid_identifier
  from rpython.translator.c.primitive import PrimitiveName, PrimitiveType
  from rpython.translator.c.node import StructDefNode, ArrayDefNode
  from rpython.translator.c.node import FixedSizeArrayDefNode, BareBoneArrayDefNode
  from rpython.translator.c.node import ContainerNodeFactory, ExtTypeOpaqueDefNode
  from rpython.translator.c.support import cdecl, CNameManager
  from rpython.translator.c.support import log, barebonearray
  from rpython.translator.c.extfunc import do_the_getting
  from rpython.translator.c import gc
  from rpython.tool.identity_dict import identity_dict
  
  
  class NoCorrespondingNode(Exception):
      pass
  
  # ____________________________________________________________
  
  class LowLevelDatabase(object):
      gctransformer = None
  
      def __init__(self, translator=None, standalone=False,
                   gcpolicyclass=None,
                   thread_enabled=False,
                   sandbox=False):
          self.translator = translator
          self.standalone = standalone
          self.sandbox    = sandbox
          if gcpolicyclass is None:
              gcpolicyclass = gc.RefcountingGcPolicy
          self.gcpolicy = gcpolicyclass(self, thread_enabled)
  
          self.structdefnodes = {}
          self.pendingsetupnodes = []
          self.containernodes = {}
          self.containerlist = []
          self.idelayedfunctionnames = identity_dict()
          self.delayedfunctionptrs = []
          self.completedcontainers = 0
          self.containerstats = {}
          self.externalfuncs = {}
          self.helper2ptr = {}
  
          # late_initializations is for when the value you want to
          # assign to a constant object is something C doesn't think is
          # constant
          self.late_initializations = []
          self.namespace = CNameManager()
  
          if translator is None or translator.rtyper is None:
              self.exctransformer = None
          else:
              self.exctransformer = translator.getexceptiontransformer()
          if translator is not None:
              self.gctransformer = self.gcpolicy.gettransformer()
          self.completed = False
  
          self.instrument_ncounter = 0
  
      def gettypedefnode(self, T, varlength=None):
          if varlength is None:
              key = T
          else:
              key = T, varlength
          try:
              node = self.structdefnodes[key]
          except KeyError:
              if isinstance(T, Struct):
                  if isinstance(T, FixedSizeArray):
                      node = FixedSizeArrayDefNode(self, T)
                  else:
                      node = StructDefNode(self, T, varlength)
              elif isinstance(T, Array):
                  if barebonearray(T):
                      node = BareBoneArrayDefNode(self, T, varlength)
                  else:
                      node = ArrayDefNode(self, T, varlength)
              elif isinstance(T, OpaqueType) and T.hints.get("render_structure", False):
                  node = ExtTypeOpaqueDefNode(self, T)
              elif T == WeakRef:
                  REALT = self.gcpolicy.get_real_weakref_type()
                  node = self.gettypedefnode(REALT)
              else:
                  raise NoCorrespondingNode("don't know about %r" % (T,))
              self.structdefnodes[key] = node
              self.pendingsetupnodes.append(node)
          return node
  
      def gettype(self, T, varlength=None, who_asks=None, argnames=[]):
          if isinstance(T, Primitive) or T == GCREF:
              return PrimitiveType[T]
          elif isinstance(T, Typedef):
              return '%s @' % T.c_name
          elif isinstance(T, Ptr):
              if (isinstance(T.TO, OpaqueType) and
                  T.TO.hints.get('c_pointer_typedef') is not None):
                  return '%s @' % T.TO.hints['c_pointer_typedef']
              try:
                  node = self.gettypedefnode(T.TO)
              except NoCorrespondingNode:
                  pass
              else:
                  if hasattr(node, 'getptrtype'):
                      return node.getptrtype()   # special-casing because of C
              typename = self.gettype(T.TO)   # who_asks not propagated
              return typename.replace('@', '*@')
          elif isinstance(T, (Struct, Array, _WeakRefType)):
              node = self.gettypedefnode(T, varlength=varlength)
              if who_asks is not None:
                  who_asks.dependencies.add(node)
              return node.gettype()
          elif isinstance(T, FuncType):
              resulttype = self.gettype(T.RESULT)
              argtypes = []
              for i in range(len(T.ARGS)):
                  if T.ARGS[i] is not Void:
                      argtype = self.gettype(T.ARGS[i])
                      try:
                          argname = argnames[i]
                      except IndexError:
                          argname = ''
                      argtypes.append(cdecl(argtype, argname))
              argtypes = ', '.join(argtypes) or 'void'
              return resulttype.replace('@', '(@)(%s)' % argtypes)
          elif isinstance(T, OpaqueType):
              if T == RuntimeTypeInfo:
                  return  self.gcpolicy.rtti_type()
              elif T.hints.get("render_structure", False):
                  node = self.gettypedefnode(T, varlength=varlength)
                  if who_asks is not None:
                      who_asks.dependencies.add(node)
                  return 'struct %s @' % node.name
              elif T.hints.get('external', None) == 'C':
                  return '%s @' % T.hints['c_name']
              else:
                  #raise Exception("don't know about opaque type %r" % (T,))
                  return 'struct %s @' % (
                      valid_identifier('pypy_opaque_' + T.tag),)
          elif isinstance(T, llgroup.GroupType):
              return "/*don't use me*/ void @"
          else:
              raise Exception("don't know about type %r" % (T,))
  
      def getcontainernode(self, container, _dont_write_c_code=True, **buildkwds):
          try:
              node = self.containernodes[container]
          except KeyError:
              T = typeOf(container)
              if isinstance(T, (lltype.Array, lltype.Struct)):
                  if hasattr(self.gctransformer, 'consider_constant'):
                      self.gctransformer.consider_constant(T, container)
              nodefactory = ContainerNodeFactory[T.__class__]
              node = nodefactory(self, T, container, **buildkwds)
              self.containernodes[container] = node
              # _dont_write_c_code should only be False for a hack in
              # weakrefnode_factory()
              if not _dont_write_c_code:
                  return node
              kind = getattr(node, 'nodekind', '?')
              self.containerstats[kind] = self.containerstats.get(kind, 0) + 1
              self.containerlist.append(node)
              if self.completed:
                  pass # we would like to fail here, but a few containers
                       # are found very late, e.g. _subarrays via addresses
                       # introduced by the GC transformer, or the type_info_table
          return node
  
      def get(self, obj, funcgen=None):
          if isinstance(obj, CConstant):
              return obj.c_name  # without further checks
          T = typeOf(obj)
          if isinstance(T, Primitive) or T == GCREF:
              return PrimitiveName[T](obj, self)
          elif isinstance(T, Ptr):
              if (isinstance(T.TO, OpaqueType) and
                  T.TO.hints.get('c_pointer_typedef') is not None):
                  if obj._obj is not None:
                      value = rffi.cast(rffi.SSIZE_T, obj)
                      return '((%s) %s)' % (cdecl(self.gettype(T), ''),
                                            self.get(value))
              if obj:   # test if the ptr is non-NULL
                  try:
                      container = obj._obj
                  except lltype.DelayedPointer:
                      # hack hack hack
                      name = obj._obj0
                      assert name.startswith('delayed!')
                      n = len('delayed!')
                      if len(name) == n:
                          raise
                      if isinstance(lltype.typeOf(obj).TO, lltype.FuncType):
                          if obj in self.idelayedfunctionnames:
                              return self.idelayedfunctionnames[obj][0]
                          funcname = name[n:]
                          funcname = self.namespace.uniquename('g_'+funcname)
                          self.idelayedfunctionnames[obj] = funcname, obj
                      else:
                          funcname = None      # can't use the name of a
                                               # delayed non-function ptr
                      self.delayedfunctionptrs.append(obj)
                      return funcname
                      # /hack hack hack
                  else:
                      # hack hack hack
                      if obj in self.idelayedfunctionnames:
                          # this used to be a delayed function,
                          # make sure we use the same name
                          forcename = self.idelayedfunctionnames[obj][0]
                          node = self.getcontainernode(container,
                                                       forcename=forcename)
                          assert node.getptrname() == forcename
                          return forcename
                      # /hack hack hack
  
                  if isinstance(container, int):
                      # special case for tagged odd-valued pointers
                      return '((%s) %d)' % (cdecl(self.gettype(T), ''),
                                            obj._obj)
                  node = self.getcontainernode(container)
                  if node._funccodegen_owner is None:
                      node._funccodegen_owner = funcgen
                  return node.getptrname()
              else:
                  return '((%s) NULL)' % (cdecl(self.gettype(T), ''), )
          else:
              raise Exception("don't know about %r" % (obj,))
  
      def complete(self, show_progress=True):
          assert not self.completed
          if self.translator and self.translator.rtyper:
              do_the_getting(self, self.translator.rtyper)
          def dump():
              lst = ['%s: %d' % keyvalue
                     for keyvalue in self.containerstats.items()]
              lst.sort()
              log.event('%8d nodes  [ %s ]' % (i, '  '.join(lst)))
          i = self.completedcontainers
          if show_progress:
              show_i = (i//1000 + 1) * 1000
          else:
              show_i = -1
  
          # The order of database completion is fragile with gc transformers.
          # Here is what occurs:
          #
          # 1. follow dependencies recursively from the entry point: data
          #    structures pointing to other structures or functions, and
          #    constants in functions pointing to other structures or functions.
          #    Because of the mixlevelannotator, this might find delayed
          #    (not-annotated-and-rtyped-yet) function pointers.  They are
          #    not followed at this point.  User finalizers (__del__) on the
          #    other hand are followed during this step too.
          #
          # 2. gctransformer.finish_helpers() - after this, all functions in
          #    the program have been rtyped.
          #
          # 3. follow new dependencies.  All previously delayed functions
          #    should have been resolved by 2 - they are gc helpers, like
          #    ll_finalize().  New FuncNodes are built for them.  No more
          #    FuncNodes can show up after this step.
          #
          # 4. gctransformer.finish_tables() - freeze the gc types table.
          #
          # 5. follow new dependencies (this should be only the gc type table,
          #    which contains only numbers and pointers to ll_finalizer
          #    functions seen in step 3).
          #
          # This is implemented by interleaving the follow-new-dependencies
          # steps with calls to the next 'finish' function from the following
          # list:
          finish_callbacks = []
          if self.gctransformer:
              finish_callbacks.append(('GC transformer: finished helpers',
                                       self.gctransformer.finish_helpers))
              finish_callbacks.append(('GC transformer: finished tables',
                                       self.gctransformer.get_finish_tables()))
  
          def add_dependencies(newdependencies, parent=None):
              for value in newdependencies:
                  #if isinstance(value, _uninitialized):
                  #    continue
                  if isinstance(value, lltype._uninitialized):
                      continue
                  if isinstance(typeOf(value), ContainerType):
                      node = self.getcontainernode(value)
                      if parent and node._funccodegen_owner is not None:
                          node._funccodegen_owner = parent._funccodegen_owner
                  else:
                      self.get(value, parent and parent._funccodegen_owner)
  
          while True:
              while True:
                  while self.pendingsetupnodes:
                      lst = self.pendingsetupnodes
                      self.pendingsetupnodes = []
                      for nodedef in lst:
                          nodedef.setup()
                  if i == len(self.containerlist):
                      break
                  node = self.containerlist[i]
                  add_dependencies(node.enum_dependencies(), node)
                  i += 1
                  self.completedcontainers = i
                  if i == show_i:
                      dump()
                      show_i += 1000
  
              if self.delayedfunctionptrs:
                  lst = self.delayedfunctionptrs
                  self.delayedfunctionptrs = []
                  progress = False
                  for fnptr in lst:
                      try:
                          fnptr._obj
                      except lltype.DelayedPointer:   # still not resolved
                          self.delayedfunctionptrs.append(fnptr)
                      else:
                          self.get(fnptr)
                          progress = True
                  if progress:
                      continue   # progress - follow all dependencies again
  
              if finish_callbacks:
                  logmsg, finish = finish_callbacks.pop(0)
                  if not hasattr(finish, 'next'):
                      newdependencies = finish()
                  else:
                      # if 'finish' is a generator, consume the next element
                      # and put the generator again in the queue
                      try:
                          newdependencies = finish.next()
                          finish_callbacks.insert(0, (None, finish))
                      except StopIteration:
                          newdependencies = None
                  if logmsg:
                      log.database(logmsg)
                  if newdependencies:
                      add_dependencies(newdependencies)
                  continue       # progress - follow all dependencies again
  
              break     # database is now complete
  
          assert not self.delayedfunctionptrs
          self.completed = True
          if show_progress:
              dump()
          log.database("Completed")
  
      def globalcontainers(self):
          for node in self.containerlist:
              if node.globalcontainer:
                  yield node
  
      def get_lltype_of_exception_value(self):
          exceptiondata = self.translator.rtyper.exceptiondata
          return exceptiondata.lltype_of_exception_value
  
      def getstructdeflist(self):
          # return the StructDefNodes sorted according to dependencies
          result = []
          seen = set()
          def produce(node):
              if node not in seen:
                  deps = list(node.dependencies)
                  deps.sort(key=lambda x: x.name)
                  for othernode in deps:
                      produce(othernode)
                  result.append(node)
                  seen.add(node)
          nodes = self.structdefnodes.values()
          nodes.sort(key=lambda x: x.name)
          for node in nodes:
              produce(node)
          return result
  
      def need_sandboxing(self, fnobj):
          if not self.sandbox:
              return False
          if hasattr(fnobj, '_safe_not_sandboxed'):
              return not fnobj._safe_not_sandboxed
          else:
              return "if_external"
  
      def prepare_inline_helpers(self):
          all_nodes = self.globalcontainers()
          funcnodes = [node for node in all_nodes if node.nodekind == 'func']
          graphs = []
          for node in funcnodes:
              for graph in node.graphs_to_patch():
                  graphs.append(graph)
          self.gctransformer.prepare_inline_helpers(graphs)
  
      def all_graphs(self):
          graphs = []
          for node in self.containerlist:
              if node.nodekind == 'func':
                  for graph in node.graphs_to_patch():
                      graphs.append(graph)
          return graphs
  