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comparison python/c3/typecheck.py @ 226:240111e0456f

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Work on named types
author Windel Bouwman
date Fri, 12 Jul 2013 17:25:31 +0200
parents 1c7364bd74c7
children 82dfe6a32717
comparison
equal deleted inserted replaced
225:1c7364bd74c7 226:240111e0456f
1 from .astnodes import * 1 from .astnodes import *
2 from .scope import * 2 from .scope import *
3 from .visitor import Visitor 3 from .visitor import Visitor
4 4
5 def equalTypes(a, b): 5 def equalTypes(a, b):
6 """ Compare types a and b for equality. Not equal until proven otherwise. """ 6 """ Compare types a and b for equality. Not equal until proven otherwise. """
7 if type(a) is type(b): 7 # Recurse into named types:
8 if type(a) is BaseType: 8 if type(a) is DefinedType:
9 return a.name == b.name 9 return equalTypes(a.typ, b)
10 elif type(a) is PointerType: 10 if type(b) is DefinedType:
11 return equalTypes(a.ptype, b.ptype) 11 return equalTypes(a, b.typ)
12 return False 12 # Compare for structural equivalence:
13 if type(a) is type(b):
14 if type(a) is BaseType:
15 return a.name == b.name
16 elif type(a) is PointerType:
17 return equalTypes(a.ptype, b.ptype)
18 return False
13 19
14 def canCast(fromT, toT): 20 def canCast(fromT, toT):
15 if isinstance(fromT, PointerType) and isinstance(toT, PointerType): 21 if isinstance(fromT, PointerType) and isinstance(toT, PointerType):
16 return True 22 return True
17 elif fromT is intType and isinstance(toT, PointerType): 23 elif fromT is intType and isinstance(toT, PointerType):
87 raise Exception('Unknown unop {0}'.format(sym.op)) 93 raise Exception('Unknown unop {0}'.format(sym.op))
88 elif type(sym) is Deref: 94 elif type(sym) is Deref:
89 # pointer deref 95 # pointer deref
90 sym.lvalue = True 96 sym.lvalue = True
91 # check if the to be dereferenced variable is a pointer type: 97 # check if the to be dereferenced variable is a pointer type:
92 if type(sym.ptr.typ) is PointerType: 98 ptype = sym.ptr.typ
93 sym.typ = sym.ptr.typ.ptype 99 if type(ptype) is DefinedType:
100 ptype = ptype.typ
101 if type(ptype) is PointerType:
102 sym.typ = ptype.ptype
94 else: 103 else:
95 self.error('Cannot dereference non-pointer type {}'.format(sym.ptr.typ), sym.loc) 104 self.error('Cannot dereference non-pointer type {}'.format(ptype), sym.loc)
96 sym.typ = intType 105 sym.typ = intType
97 elif type(sym) is FieldRef: 106 elif type(sym) is FieldRef:
98 basetype = sym.base.typ 107 basetype = sym.base.typ
99 sym.lvalue = True 108 sym.lvalue = True
109 if type(basetype) is DefinedType:
110 basetype = basetype.typ
100 if type(basetype) is StructureType: 111 if type(basetype) is StructureType:
101 if basetype.hasField(sym.field): 112 if basetype.hasField(sym.field):
102 sym.typ = basetype.fieldType(sym.field) 113 sym.typ = basetype.fieldType(sym.field)
103 else: 114 else:
104 self.error('{} does not contain field {}'.format(basetype, symfield), sym.loc) 115 self.error('{} does not contain field {}'.format(basetype, sym.field), sym.loc)
105 sym.typ = intType 116 sym.typ = intType
106 else: 117 else:
107 self.error('Cannot select field {} of non-structure type {}'.format(sym.field, basetype), sym.loc) 118 self.error('Cannot select field {} of non-structure type {}'.format(sym.field, basetype), sym.loc)
108 sym.typ = intType 119 sym.typ = intType
109 elif type(sym) is Binop: 120 elif type(sym) is Binop: