Debug: fixes for Nuttx.py debug gdb add-ons

also fixed preceding mask calculation in show heaps

Debug/Nuttx.py

@@ -306,12 +306,15 @@ class NX_show_heap (gdb.Command):
 
  def __init__(self):
  super(NX_show_heap, self).__init__('show heap', gdb.COMMAND_USER)
- if gdb.lookup_type('struct mm_allocnode_s').sizeof == 8:
- self._allocflag = 0x80000000
- self._allocnodesize = 8
- else:
+ struct_mm_allocnode_s = gdb.lookup_type('struct mm_allocnode_s')
+ preceding_size = struct_mm_allocnode_s['preceding'].type.sizeof
+ if preceding_size == 2:
  self._allocflag = 0x8000
- self._allocnodesize = 4
+ elif preceding_size == 4:
+ self._allocflag = 0x80000000
+ else:
+ raise gdb.GdbError('invalid mm_allocnode_s.preceding size %u' % preceding_size)
+ self._allocnodesize = struct_mm_allocnode_s.sizeof
 
  def _node_allocated(self, allocnode):
  if allocnode['preceding'] & self._allocflag:
@@ -333,7 +336,8 @@ def _print_allocations(self, region_start, region_end):
  state = ''
  else:
  state = '(free)'
- print ' {} {} {}'.format(allocnode.address + 8, self._node_size(allocnode), state)
+ print ' {} {} {}'.format(allocnode.address + self._allocnodesize,
+ self._node_size(allocnode), state)
  cursor += self._node_size(allocnode) / self._allocnodesize
 
  def invoke(self, args, from_tty):