michael@0: # Pretty-printers for SpiderMonkey JSObjects.
michael@0: 
michael@0: import gdb
michael@0: import mozilla.JSString
michael@0: import mozilla.prettyprinters as prettyprinters
michael@0: from mozilla.prettyprinters import ptr_pretty_printer, ref_pretty_printer
michael@0: from mozilla.Root import deref
michael@0: 
michael@0: prettyprinters.clear_module_printers(__name__)
michael@0: 
michael@0: class JSObjectTypeCache(object):
michael@0:     def __init__(self, value, cache):
michael@0:         # In GDB 7.4.50, with some programs, this first dummy gdb.lookup_type
michael@0:         # call is required to make the second lookup_type call succeed. A GDB
michael@0:         # built from the public sources as of 2012-12-12 did not require the
michael@0:         # dummy lookup.
michael@0:         gdb.lookup_type('js::BaseShape')
michael@0:         baseshape_flags = gdb.lookup_type('js::BaseShape::Flag')
michael@0:         self.flag_DELEGATE = prettyprinters.enum_value(baseshape_flags, 'js::BaseShape::DELEGATE')
michael@0:         self.func_ptr_type = gdb.lookup_type('JSFunction').pointer()
michael@0: 
michael@0: # There should be no need to register this for JSFunction as well, since we
michael@0: # search for pretty-printers under the names of base classes, and
michael@0: # JSFunction has JSObject as a base class.
michael@0: 
michael@0: @ptr_pretty_printer('JSObject')
michael@0: class JSObjectPtrOrRef(prettyprinters.Pointer):
michael@0:     def __init__(self, value, cache):
michael@0:         super(JSObjectPtrOrRef, self).__init__(value, cache)
michael@0:         if not cache.mod_JSObject:
michael@0:             cache.mod_JSObject = JSObjectTypeCache(value, cache)
michael@0:         self.otc = cache.mod_JSObject
michael@0: 
michael@0:     def summary(self):
michael@0:         shape = deref(self.value['shape_'])
michael@0:         baseshape = deref(shape['base_'])
michael@0:         otype = deref(self.value['type_'])
michael@0:         class_name = otype['clasp_']['name'].string()
michael@0:         flags = baseshape['flags']
michael@0:         is_delegate = bool(flags & self.otc.flag_DELEGATE)
michael@0:         name = None
michael@0:         if class_name == 'Function':
michael@0:             function = self.value
michael@0:             concrete_type = function.type.strip_typedefs()
michael@0:             if concrete_type.code == gdb.TYPE_CODE_REF:
michael@0:                 function = function.address
michael@0:             function = function.cast(self.otc.func_ptr_type)
michael@0:             atom = deref(function['atom_'])
michael@0:             name = str(atom) if atom else '<unnamed>'
michael@0:         return '[object %s%s]%s' % (class_name,
michael@0:                                     ' ' + name if name else '',
michael@0:                                     ' delegate' if is_delegate else '')
michael@0: 
michael@0: @ref_pretty_printer('JSObject')
michael@0: def JSObjectRef(value, cache): return JSObjectPtrOrRef(value, cache)