Mercurial > lcfOS
annotate python/c3/typecheck.py @ 226:240111e0456f
Work on named types
| author | Windel Bouwman |
|---|---|
| date | Fri, 12 Jul 2013 17:25:31 +0200 |
| parents | 1c7364bd74c7 |
| children | 82dfe6a32717 |
| rev | line source |
|---|---|
| 163 | 1 from .astnodes import * |
| 2 from .scope import * | |
| 3 from .visitor import Visitor | |
| 4 | |
| 5 def equalTypes(a, b): | |
| 226 | 6 """ Compare types a and b for equality. Not equal until proven otherwise. """ |
| 7 # Recurse into named types: | |
| 8 if type(a) is DefinedType: | |
| 9 return equalTypes(a.typ, b) | |
| 10 if type(b) is DefinedType: | |
| 11 return equalTypes(a, b.typ) | |
| 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 | |
| 150 | 19 |
| 222 | 20 def canCast(fromT, toT): |
| 21 if isinstance(fromT, PointerType) and isinstance(toT, PointerType): | |
| 22 return True | |
| 23 elif fromT is intType and isinstance(toT, PointerType): | |
| 24 return True | |
| 25 return False | |
| 26 | |
| 150 | 27 class TypeChecker: |
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28 def __init__(self, diag): |
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29 self.diag = diag |
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30 |
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31 def error(self, msg, loc): |
| 186 | 32 """ Wrapper that registers the message and marks the result invalid """ |
| 33 self.diag.error(msg, loc) | |
| 34 self.ok = False | |
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35 |
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36 def checkPackage(self, pkg): |
| 186 | 37 self.ok = True |
| 215 | 38 visitor = Visitor() |
| 39 visitor.visit(pkg, f_post=self.check2) | |
| 186 | 40 return self.ok |
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41 |
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42 def check2(self, sym): |
| 225 | 43 if type(sym) in [IfStatement, WhileStatement]: |
| 44 if not equalTypes(sym.condition.typ, boolType): | |
| 45 self.error('Condition must be of type {0}'.format(boolType), sym.condition.loc) | |
| 46 elif type(sym) is Assignment: | |
| 221 | 47 if not equalTypes(sym.lval.typ, sym.rval.typ): |
| 48 self.error('Cannot assign {0} to {1}'.format(sym.rval.typ, sym.lval.typ), sym.loc) | |
| 49 if not sym.lval.lvalue: | |
| 50 self.error('No valid lvalue {}'.format(sym.lval), sym.lval.loc) | |
| 51 #if sym.rval.lvalue: | |
| 52 # self.error('Right hand side must be an rvalue', sym.rval.loc) | |
| 225 | 53 elif type(sym) is ReturnStatement: |
| 54 pass | |
| 55 elif type(sym) is FunctionCall: | |
| 166 | 56 if sym.proc: |
| 167 | 57 # Check arguments: |
| 58 ngiv = len(sym.args) | |
| 59 ptypes = sym.proc.typ.parametertypes | |
| 60 nreq = len(ptypes) | |
| 61 if ngiv != nreq: | |
| 186 | 62 self.error('Function {2}: {0} arguments required, {1} given'.format(nreq, ngiv, sym.proc.name), sym.loc) |
| 167 | 63 else: |
| 64 for a, at in zip(sym.args, ptypes): | |
| 65 if not equalTypes(a.typ, at): | |
| 186 | 66 self.error('Got {0}, expected {1}'.format(a.typ, at), a.loc) |
| 167 | 67 # determine return type: |
| 68 sym.typ = sym.proc.typ.returntype | |
| 69 else: | |
| 70 sym.typ = intType | |
| 225 | 71 elif type(sym) is VariableUse: |
| 221 | 72 sym.lvalue = True |
| 225 | 73 if type(sym.target) is Variable: |
| 221 | 74 sym.typ = sym.target.typ |
| 75 else: | |
| 225 | 76 print('warning {} has no target, defaulting to int'.format(sym)) |
| 221 | 77 sym.typ = intType |
| 225 | 78 elif type(sym) is Literal: |
| 221 | 79 sym.lvalue = False |
| 80 if type(sym.val) is int: | |
| 81 sym.typ = intType | |
| 82 elif type(sym.val) is float: | |
| 83 sym.typ = doubleType | |
| 84 elif type(sym.val) is bool: | |
| 85 sym.typ = boolType | |
| 86 else: | |
| 225 | 87 raise Exception('Unknown literal type'.format(sym.val)) |
| 88 elif type(sym) is Unop: | |
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89 if sym.op == '&': |
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90 sym.typ = PointerType(sym.a.typ) |
| 221 | 91 sym.lvalue = False |
| 225 | 92 else: |
| 93 raise Exception('Unknown unop {0}'.format(sym.op)) | |
| 94 elif type(sym) is Deref: | |
| 95 # pointer deref | |
| 96 sym.lvalue = True | |
| 97 # check if the to be dereferenced variable is a pointer type: | |
| 226 | 98 ptype = sym.ptr.typ |
| 99 if type(ptype) is DefinedType: | |
| 100 ptype = ptype.typ | |
| 101 if type(ptype) is PointerType: | |
| 102 sym.typ = ptype.ptype | |
| 225 | 103 else: |
| 226 | 104 self.error('Cannot dereference non-pointer type {}'.format(ptype), sym.loc) |
| 225 | 105 sym.typ = intType |
| 106 elif type(sym) is FieldRef: | |
| 107 basetype = sym.base.typ | |
| 108 sym.lvalue = True | |
| 226 | 109 if type(basetype) is DefinedType: |
| 110 basetype = basetype.typ | |
| 225 | 111 if type(basetype) is StructureType: |
| 112 if basetype.hasField(sym.field): | |
| 113 sym.typ = basetype.fieldType(sym.field) | |
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114 else: |
| 226 | 115 self.error('{} does not contain field {}'.format(basetype, sym.field), sym.loc) |
| 221 | 116 sym.typ = intType |
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parents:
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117 else: |
| 225 | 118 self.error('Cannot select field {} of non-structure type {}'.format(sym.field, basetype), sym.loc) |
| 119 sym.typ = intType | |
| 120 elif type(sym) is Binop: | |
| 221 | 121 sym.lvalue = False |
| 163 | 122 if sym.op in ['+', '-', '*', '/']: |
| 123 if equalTypes(sym.a.typ, sym.b.typ): | |
| 170 | 124 if equalTypes(sym.a.typ, intType): |
| 125 sym.typ = sym.a.typ | |
| 126 else: | |
| 186 | 127 self.error('Can only add integers', sym.loc) |
| 170 | 128 sym.typ = intType |
| 163 | 129 else: |
| 165 | 130 # assume void here? TODO: throw exception! |
| 131 sym.typ = intType | |
| 225 | 132 self.error('Types unequal {} != {}'.format(sym.a.typ, sym.b.typ), sym.loc) |
| 170 | 133 elif sym.op in ['>', '<', '==', '<=', '>=']: |
| 165 | 134 sym.typ = boolType |
| 135 if not equalTypes(sym.a.typ, sym.b.typ): | |
| 225 | 136 self.error('Types unequal {} != {}'.format(sym.a.typ, sym.b.typ), sym.loc) |
| 166 | 137 elif sym.op in ['or', 'and']: |
| 138 sym.typ = boolType | |
| 139 if not equalTypes(sym.a.typ, boolType): | |
| 186 | 140 self.error('Must be {0}'.format(boolType), sym.a.loc) |
| 166 | 141 if not equalTypes(sym.b.typ, boolType): |
| 186 | 142 self.error('Must be {0}'.format(boolType), sym.b.loc) |
| 221 | 143 elif sym.op in ['|', '&']: |
| 144 sym.typ = intType | |
| 225 | 145 raise Exception('Not implemented') |
| 221 | 146 # TODO: elaborate? |
| 163 | 147 else: |
| 225 | 148 raise Exception('Unknown binop {0}'.format(sym.op)) |
| 149 elif type(sym) is Variable: | |
| 165 | 150 # check initial value type: |
| 151 # TODO | |
| 152 pass | |
| 225 | 153 elif type(sym) is TypeCast: |
| 222 | 154 if canCast(sym.a.typ, sym.to_type): |
| 155 sym.typ = sym.to_type | |
| 156 else: | |
| 157 self.error('Cannot cast {} to {}'.format(sym.a.typ, sym.to_type)) | |
| 225 | 158 elif type(sym) is Constant: |
| 159 if not equalTypes(sym.typ, sym.value.typ): | |
| 160 self.error('Cannot assign {0} to {1}'.format(sym.value.typ, sym.typ), sym.loc) | |
| 161 elif type(sym) in [EmptyStatement, CompoundStatement, Package, Function, FunctionType, ExpressionStatement, DefinedType]: | |
| 165 | 162 pass |
| 225 | 163 else: |
| 186 | 164 raise Exception('Unknown type check {0}'.format(sym)) |
| 150 | 165 |