Mercurial > lcfOS
annotate python/c3/typecheck.py @ 249:e41e4109addd
Added current position arrow
| author | Windel Bouwman |
|---|---|
| date | Fri, 26 Jul 2013 20:26:05 +0200 |
| parents | e621e3ba78d2 |
| children | c4370696ccc7 |
| rev | line source |
|---|---|
| 163 | 1 from .astnodes import * |
| 2 from .scope import * | |
| 3 from .visitor import Visitor | |
| 4 | |
| 231 | 5 def theType(t): |
| 6 """ | |
| 7 Recurse until a 'real' type is found | |
| 8 """ | |
| 230 | 9 if type(t) is DefinedType: |
| 231 | 10 return theType(t.typ) |
| 230 | 11 return t |
| 12 | |
| 163 | 13 def equalTypes(a, b): |
| 230 | 14 """ |
| 228 | 15 Compare types a and b for equality. |
| 16 Not equal until proven otherwise. | |
| 17 """ | |
| 226 | 18 # Recurse into named types: |
| 231 | 19 a = theType(a) |
| 20 b = theType(b) | |
| 230 | 21 |
| 226 | 22 # Compare for structural equivalence: |
| 23 if type(a) is type(b): | |
| 24 if type(a) is BaseType: | |
| 25 return a.name == b.name | |
| 26 elif type(a) is PointerType: | |
| 27 return equalTypes(a.ptype, b.ptype) | |
| 227 | 28 elif type(a) is StructureType: |
| 29 if len(a.mems) != len(b.mems): | |
| 30 return False | |
| 31 for amem, bmem in zip(a.mems, b.mems): | |
| 32 if not equalTypes(amem.typ, bmem.typ): | |
| 33 return False | |
| 34 return True | |
| 35 else: | |
| 36 raise Exception('Type compare not implemented') | |
| 226 | 37 return False |
| 150 | 38 |
| 222 | 39 def canCast(fromT, toT): |
| 231 | 40 fromT = theType(fromT) |
| 41 toT = theType(toT) | |
| 222 | 42 if isinstance(fromT, PointerType) and isinstance(toT, PointerType): |
| 43 return True | |
| 44 elif fromT is intType and isinstance(toT, PointerType): | |
| 45 return True | |
| 46 return False | |
| 47 | |
| 230 | 48 def expectRval(s): |
| 49 # TODO: solve this better | |
| 50 s.expect_rvalue = True | |
| 51 | |
| 150 | 52 class TypeChecker: |
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53 def __init__(self, diag): |
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54 self.diag = diag |
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55 |
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56 def error(self, msg, loc): |
| 230 | 57 """ |
| 58 Wrapper that registers the message and marks the result invalid | |
| 228 | 59 """ |
| 186 | 60 self.diag.error(msg, loc) |
| 61 self.ok = False | |
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62 |
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63 def checkPackage(self, pkg): |
| 186 | 64 self.ok = True |
| 215 | 65 visitor = Visitor() |
| 66 visitor.visit(pkg, f_post=self.check2) | |
| 186 | 67 return self.ok |
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68 |
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69 def check2(self, sym): |
| 225 | 70 if type(sym) in [IfStatement, WhileStatement]: |
| 71 if not equalTypes(sym.condition.typ, boolType): | |
| 230 | 72 msg = 'Condition must be of type {}'.format(boolType) |
| 73 self.error(msg, sym.condition.loc) | |
| 225 | 74 elif type(sym) is Assignment: |
| 230 | 75 l, r = sym.lval, sym.rval |
| 76 if not equalTypes(l.typ, r.typ): | |
| 77 msg = 'Cannot assign {} to {}'.format(r.typ, l.typ) | |
| 78 self.error(msg, sym.loc) | |
| 79 if not l.lvalue: | |
| 80 self.error('No valid lvalue {}'.format(l), l.loc) | |
| 221 | 81 #if sym.rval.lvalue: |
| 82 # self.error('Right hand side must be an rvalue', sym.rval.loc) | |
| 230 | 83 expectRval(sym.rval) |
| 225 | 84 elif type(sym) is ReturnStatement: |
| 85 pass | |
| 86 elif type(sym) is FunctionCall: | |
| 167 | 87 # Check arguments: |
| 88 ngiv = len(sym.args) | |
| 89 ptypes = sym.proc.typ.parametertypes | |
| 90 nreq = len(ptypes) | |
| 91 if ngiv != nreq: | |
| 186 | 92 self.error('Function {2}: {0} arguments required, {1} given'.format(nreq, ngiv, sym.proc.name), sym.loc) |
| 167 | 93 else: |
| 94 for a, at in zip(sym.args, ptypes): | |
| 230 | 95 expectRval(a) |
| 167 | 96 if not equalTypes(a.typ, at): |
| 186 | 97 self.error('Got {0}, expected {1}'.format(a.typ, at), a.loc) |
| 167 | 98 # determine return type: |
| 99 sym.typ = sym.proc.typ.returntype | |
| 225 | 100 elif type(sym) is VariableUse: |
| 221 | 101 sym.lvalue = True |
| 225 | 102 if type(sym.target) is Variable: |
| 221 | 103 sym.typ = sym.target.typ |
| 104 else: | |
| 225 | 105 print('warning {} has no target, defaulting to int'.format(sym)) |
| 221 | 106 sym.typ = intType |
| 225 | 107 elif type(sym) is Literal: |
| 221 | 108 sym.lvalue = False |
| 109 if type(sym.val) is int: | |
| 110 sym.typ = intType | |
| 111 elif type(sym.val) is float: | |
| 112 sym.typ = doubleType | |
| 113 elif type(sym.val) is bool: | |
| 114 sym.typ = boolType | |
| 115 else: | |
| 225 | 116 raise Exception('Unknown literal type'.format(sym.val)) |
| 117 elif type(sym) is Unop: | |
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118 if sym.op == '&': |
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119 sym.typ = PointerType(sym.a.typ) |
| 221 | 120 sym.lvalue = False |
| 225 | 121 else: |
| 122 raise Exception('Unknown unop {0}'.format(sym.op)) | |
| 123 elif type(sym) is Deref: | |
| 124 # pointer deref | |
| 125 sym.lvalue = True | |
| 126 # check if the to be dereferenced variable is a pointer type: | |
| 231 | 127 ptype = theType(sym.ptr.typ) |
| 226 | 128 if type(ptype) is PointerType: |
| 129 sym.typ = ptype.ptype | |
| 225 | 130 else: |
| 226 | 131 self.error('Cannot dereference non-pointer type {}'.format(ptype), sym.loc) |
| 225 | 132 sym.typ = intType |
| 133 elif type(sym) is FieldRef: | |
| 134 basetype = sym.base.typ | |
| 230 | 135 sym.lvalue = sym.base.lvalue |
| 231 | 136 basetype = theType(basetype) |
| 225 | 137 if type(basetype) is StructureType: |
| 138 if basetype.hasField(sym.field): | |
| 139 sym.typ = basetype.fieldType(sym.field) | |
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140 else: |
| 226 | 141 self.error('{} does not contain field {}'.format(basetype, sym.field), sym.loc) |
| 221 | 142 sym.typ = intType |
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143 else: |
| 225 | 144 self.error('Cannot select field {} of non-structure type {}'.format(sym.field, basetype), sym.loc) |
| 145 sym.typ = intType | |
| 146 elif type(sym) is Binop: | |
| 227 | 147 sym.lvalue = False |
| 232 | 148 if sym.op in ['+', '-', '*', '/', '<<', '>>', '|', '&']: |
| 230 | 149 expectRval(sym.a) |
| 150 expectRval(sym.b) | |
| 227 | 151 if equalTypes(sym.a.typ, sym.b.typ): |
| 152 if equalTypes(sym.a.typ, intType): | |
| 153 sym.typ = sym.a.typ | |
| 154 else: | |
| 155 self.error('Can only add integers', sym.loc) | |
| 156 sym.typ = intType | |
| 157 else: | |
| 158 # assume void here? TODO: throw exception! | |
| 159 sym.typ = intType | |
| 160 self.error('Types unequal {} != {}'.format(sym.a.typ, sym.b.typ), sym.loc) | |
| 161 elif sym.op in ['>', '<', '==', '<=', '>=']: | |
| 162 sym.typ = boolType | |
| 163 if not equalTypes(sym.a.typ, sym.b.typ): | |
| 164 self.error('Types unequal {} != {}'.format(sym.a.typ, sym.b.typ), sym.loc) | |
| 165 elif sym.op in ['or', 'and']: | |
| 166 sym.typ = boolType | |
| 167 if not equalTypes(sym.a.typ, boolType): | |
| 168 self.error('Must be {0}'.format(boolType), sym.a.loc) | |
| 169 if not equalTypes(sym.b.typ, boolType): | |
| 170 self.error('Must be {0}'.format(boolType), sym.b.loc) | |
| 163 | 171 else: |
| 227 | 172 raise Exception('Unknown binop {0}'.format(sym.op)) |
| 225 | 173 elif type(sym) is Variable: |
| 231 | 174 # check initial value type: |
| 175 # TODO | |
| 176 pass | |
| 225 | 177 elif type(sym) is TypeCast: |
| 222 | 178 if canCast(sym.a.typ, sym.to_type): |
| 179 sym.typ = sym.to_type | |
| 180 else: | |
| 230 | 181 self.error('Cannot cast {} to {}'.format(sym.a.typ, sym.to_type), sym.loc) |
| 182 sym.typ = intType | |
| 225 | 183 elif type(sym) is Constant: |
| 184 if not equalTypes(sym.typ, sym.value.typ): | |
| 185 self.error('Cannot assign {0} to {1}'.format(sym.value.typ, sym.typ), sym.loc) | |
| 228 | 186 elif type(sym) in [CompoundStatement, Package, Function, FunctionType, ExpressionStatement, DefinedType]: |
| 230 | 187 pass |
| 225 | 188 else: |
| 186 | 189 raise Exception('Unknown type check {0}'.format(sym)) |
| 150 | 190 |