2 This module contains helper classes for structure fields and length expressions.
6 Represents a field of a structure.
8 type is the datatype object for the field.
9 field_type is the name of the type (string tuple)
10 field_name is the name of the structure field.
11 visible is true iff the field should be in the request API.
12 wire is true iff the field should be in the request structure.
13 auto is true iff the field is on the wire but not in the request API (e.g. opcode)
14 enum is the enum name this field refers to, if any.
16 def __init__(self, type, field_type, field_name, visible, wire, auto, enum=None, isfd=False):
18 self.field_type = field_type
19 self.field_name = field_name
21 self.visible = visible
28 class Expression(object):
30 Represents a mathematical expression for a list length or exprfield.
33 op is the operation (text +,*,/,<<,~) or None.
34 lhs and rhs are the sub-Expressions if op is set.
35 lenfield_name is the name of the length field, or None for request lists.
36 lenfield is the Field object for the length field, or None.
37 bitfield is True if the length field is a bitmask instead of a number.
38 nmemb is the fixed size (value)of the expression, or None
40 def __init__(self, elt, parent):
45 self.lenfield_name = None
46 self.lenfield_type = None
47 self.lenfield_parent = None
56 self.contains_listelement_ref = False
59 # List going into a request, which has no length field (inferred by server)
60 self.lenfield_name = elt.get('name') + '_len'
61 self.lenfield_type = 'CARD32'
63 elif elt.tag == 'fieldref':
64 # Standard list with a fieldref
65 self.lenfield_name = elt.text
67 elif elt.tag == 'valueparam':
68 # Value-mask. The length bitmask is described by attributes.
69 self.lenfield_name = elt.get('value-mask-name')
70 self.lenfield_type = elt.get('value-mask-type')
75 # Op field. Need to recurse.
76 self.op = elt.get('op')
77 self.lhs = Expression(list(elt)[0], parent)
78 self.rhs = Expression(list(elt)[1], parent)
80 # Hopefully we don't have two separate length fields...
81 self.lenfield_name = self.lhs.lenfield_name
82 if self.lenfield_name == None:
83 self.lenfield_name = self.rhs.lenfield_name
85 elif elt.tag == 'unop':
86 # Op field. Need to recurse.
87 self.op = elt.get('op')
88 self.rhs = Expression(list(elt)[0], parent)
90 self.lenfield_name = self.rhs.lenfield_name
92 elif elt.tag == 'value':
94 self.nmemb = int(elt.text, 0)
96 elif elt.tag == 'popcount':
98 self.rhs = Expression(list(elt)[0], parent)
99 self.lenfield_name = self.rhs.lenfield_name
100 # xcb_popcount returns 'int' - handle the type in the language-specific part
102 elif elt.tag == 'enumref':
104 self.lenfield_name = (elt.get('ref'), elt.text)
106 elif elt.tag == 'sumof':
108 self.lenfield_name = elt.get('ref')
109 subexpressions = list(elt)
110 if len(subexpressions) > 0:
111 # sumof with a nested expression which is to be evaluated
112 # for each list-element in the context of that list-element.
113 # sumof then returns the sum of the results of these evaluations
114 self.rhs = Expression(subexpressions[0], parent)
116 elif elt.tag == 'listelement-ref':
117 # current list element inside iterating expressions such as sumof
118 self.op = 'listelement-ref'
119 self.contains_listelement_ref = True
123 raise Exception("undefined tag '%s'" % elt.tag)
125 def fixed_size(self):
126 return self.nmemb != None
128 def recursive_resolve_tasks(self, module, parents):
129 for subexpr in (self.lhs, self.rhs):
131 subexpr.recursive_resolve_tasks(module, parents)
132 self.contains_listelement_ref |= subexpr.contains_listelement_ref
134 def resolve(self, module, parents):
135 if self.op == 'enumref':
136 self.lenfield_type = module.get_type(self.lenfield_name[0])
137 self.lenfield_name = self.lenfield_name[1]
138 elif self.op == 'sumof':
139 # need to find the field with lenfield_name
140 for p in reversed(parents):
141 fields = dict([(f.field_name, f) for f in p.fields])
142 if self.lenfield_name in fields.keys():
143 if p.is_case_or_bitcase:
144 # switch is the anchestor
145 self.lenfield_parent = p.parents[-1]
147 self.lenfield_parent = p
148 self.lenfield_type = fields[self.lenfield_name].field_type
151 self.recursive_resolve_tasks(module, parents)