6 public class SemanticCheck {
10 public SemanticCheck(State state, TypeUtil tu) {
15 public void semanticCheck() {
16 SymbolTable classtable=state.getClassSymbolTable();
17 Iterator it=classtable.getDescriptorsIterator();
18 // Do descriptors first
20 ClassDescriptor cd=(ClassDescriptor)it.next();
21 System.out.println("Checking class: "+cd);
22 //Set superclass link up
23 if (cd.getSuper()!=null) {
24 cd.setSuper(typeutil.getClass(cd.getSuper()));
25 // Link together Field and Method tables
26 cd.getFieldTable().setParent(cd.getSuperDesc().getFieldTable());
27 cd.getMethodTable().setParent(cd.getSuperDesc().getMethodTable());
30 for(Iterator field_it=cd.getFields();field_it.hasNext();) {
31 FieldDescriptor fd=(FieldDescriptor)field_it.next();
32 System.out.println("Checking field: "+fd);
35 for(Iterator method_it=cd.getMethods();method_it.hasNext();) {
36 MethodDescriptor md=(MethodDescriptor)method_it.next();
41 it=classtable.getDescriptorsIterator();
42 // Do descriptors first
44 ClassDescriptor cd=(ClassDescriptor)it.next();
45 for(Iterator method_it=cd.getMethods();method_it.hasNext();) {
46 MethodDescriptor md=(MethodDescriptor)method_it.next();
47 checkMethodBody(cd,md);
52 public void checkTypeDescriptor(TypeDescriptor td) {
56 String name=td.toString();
57 ClassDescriptor field_cd=(ClassDescriptor)state.getClassSymbolTable().get(name);
59 throw new Error("Undefined class "+name);
60 td.setClassDescriptor(field_cd);
66 public void checkField(ClassDescriptor cd, FieldDescriptor fd) {
67 checkTypeDescriptor(fd.getType());
70 public void checkMethod(ClassDescriptor cd, MethodDescriptor md) {
71 /* Check return type */
72 if (!md.getReturnType().isVoid())
73 checkTypeDescriptor(md.getReturnType());
74 for(int i=0;i<md.numParameters();i++) {
75 TypeDescriptor param_type=md.getParamType(i);
76 checkTypeDescriptor(param_type);
78 /* Link the naming environments */
79 md.getParameterTable().setParent(cd.getFieldTable());
82 public void checkMethodBody(ClassDescriptor cd, MethodDescriptor md) {
83 BlockNode bn=state.getMethodBody(md);
84 checkBlockNode(md, md.getParameterTable(),bn);
87 public void checkBlockNode(MethodDescriptor md, SymbolTable nametable, BlockNode bn) {
88 /* Link in the naming environment */
89 bn.getVarTable().setParent(nametable);
90 for(int i=0;i<bn.size();i++) {
91 BlockStatementNode bsn=bn.get(i);
92 checkBlockStatementNode(md, bn.getVarTable(),bsn);
96 public void checkBlockStatementNode(MethodDescriptor md, SymbolTable nametable, BlockStatementNode bsn) {
98 case Kind.BlockExpressionNode:
99 checkBlockExpressionNode(md, nametable,(BlockExpressionNode)bsn);
102 case Kind.DeclarationNode:
103 checkDeclarationNode(md, nametable, (DeclarationNode)bsn);
106 case Kind.IfStatementNode:
107 checkIfStatementNode(md, nametable, (IfStatementNode)bsn);
111 checkLoopNode(md, nametable, (LoopNode)bsn);
114 case Kind.ReturnNode:
115 checkReturnNode(md, nametable, (ReturnNode)bsn);
118 case Kind.SubBlockNode:
119 checkSubBlockNode(md, nametable, (SubBlockNode)bsn);
125 void checkBlockExpressionNode(MethodDescriptor md, SymbolTable nametable, BlockExpressionNode ben) {
126 checkExpressionNode(md, nametable, ben.getExpression(), null);
129 void checkDeclarationNode(MethodDescriptor md, SymbolTable nametable, DeclarationNode dn) {
130 VarDescriptor vd=dn.getVarDescriptor();
131 checkTypeDescriptor(vd.getType());
132 Descriptor d=nametable.get(vd.getSymbol());
134 (d instanceof FieldDescriptor)) {
137 throw new Error(vd.getSymbol()+" defined a second time");
138 if (dn.getExpression()!=null)
139 checkExpressionNode(md, nametable, dn.getExpression(), vd.getType());
142 void checkSubBlockNode(MethodDescriptor md, SymbolTable nametable, SubBlockNode sbn) {
143 checkBlockNode(md, nametable, sbn.getBlockNode());
146 void checkReturnNode(MethodDescriptor md, SymbolTable nametable, ReturnNode rn) {
147 checkExpressionNode(md, nametable, rn.getReturnExpression(), md.getReturnType());
150 void checkIfStatementNode(MethodDescriptor md, SymbolTable nametable, IfStatementNode isn) {
151 checkExpressionNode(md, nametable, isn.getCondition(), new TypeDescriptor(TypeDescriptor.BOOLEAN));
152 checkBlockNode(md, nametable, isn.getTrueBlock());
153 checkBlockNode(md, nametable, isn.getFalseBlock());
156 void checkExpressionNode(MethodDescriptor md, SymbolTable nametable, ExpressionNode en, TypeDescriptor td) {
158 case Kind.AssignmentNode:
159 checkAssignmentNode(md,nametable,(AssignmentNode)en,td);
162 checkCastNode(md,nametable,(CastNode)en,td);
164 case Kind.CreateObjectNode:
165 checkCreateObjectNode(md,nametable,(CreateObjectNode)en,td);
167 case Kind.FieldAccessNode:
168 checkFieldAccessNode(md,nametable,(FieldAccessNode)en,td);
170 case Kind.LiteralNode:
171 checkLiteralNode(md,nametable,(LiteralNode)en,td);
173 case Kind.MethodInvokeNode:
174 checkMethodInvokeNode(md,nametable,(MethodInvokeNode)en,td);
177 checkNameNode(md,nametable,(NameNode)en,td);
180 checkOpNode(md,nametable,(OpNode)en,td);
186 void checkCastNode(MethodDescriptor md, SymbolTable nametable, CastNode cn, TypeDescriptor td) {
187 /* Get type descriptor */
188 if (cn.getType()==null) {
189 NameDescriptor typenamed=cn.getTypeName().getName();
190 String typename=typenamed.toString();
191 TypeDescriptor ntd=new TypeDescriptor(typeutil.getClass(typename));
195 /* Check the type descriptor */
196 TypeDescriptor cast_type=cn.getType();
197 checkTypeDescriptor(cast_type);
201 if (!typeutil.isSuperorType(td,cast_type))
202 throw new Error("Cast node returns "+cast_type+", but need "+td);
205 ExpressionNode en=cn.getExpression();
206 checkExpressionNode(md, nametable, en, null);
207 TypeDescriptor etd=en.getType();
208 if (typeutil.isSuperorType(cast_type,etd)) /* Cast trivially succeeds */
211 if (typeutil.isSuperorType(etd,cast_type)) /* Cast may succeed */
214 /* Different branches */
215 /* TODO: change if add interfaces */
216 throw new Error("Cast will always fail\n"+cn.printNode(0));
219 void checkFieldAccessNode(MethodDescriptor md, SymbolTable nametable, FieldAccessNode fan, TypeDescriptor td) {
220 ExpressionNode left=fan.getExpression();
221 checkExpressionNode(md,nametable,left,null);
222 TypeDescriptor ltd=left.getType();
223 String fieldname=fan.getFieldName();
224 FieldDescriptor fd=(FieldDescriptor) ltd.getClassDesc().getFieldTable().get(fieldname);
226 throw new Error("Unknown field "+fieldname);
229 if (!typeutil.isSuperorType(td,fan.getType()))
230 throw new Error("Field node returns "+fan.getType()+", but need "+td);
233 void checkLiteralNode(MethodDescriptor md, SymbolTable nametable, LiteralNode ln, TypeDescriptor td) {
234 /* Resolve the type */
235 Object o=ln.getValue();
236 if (ln.getTypeString().equals("null")) {
237 ln.setType(new TypeDescriptor(TypeDescriptor.NULL));
238 } else if (o instanceof Integer) {
239 ln.setType(new TypeDescriptor(TypeDescriptor.INT));
240 } else if (o instanceof Long) {
241 ln.setType(new TypeDescriptor(TypeDescriptor.LONG));
242 } else if (o instanceof Float) {
243 ln.setType(new TypeDescriptor(TypeDescriptor.FLOAT));
244 } else if (o instanceof Double) {
245 ln.setType(new TypeDescriptor(TypeDescriptor.DOUBLE));
246 } else if (o instanceof Character) {
247 ln.setType(new TypeDescriptor(TypeDescriptor.CHAR));
248 } else if (o instanceof String) {
249 ln.setType(new TypeDescriptor(typeutil.getClass(TypeUtil.StringClass)));
253 if (!typeutil.isSuperorType(td,ln.getType()))
254 throw new Error("Field node returns "+ln.getType()+", but need "+td);
257 void checkNameNode(MethodDescriptor md, SymbolTable nametable, NameNode nn, TypeDescriptor td) {
258 NameDescriptor nd=nn.getName();
259 String varname=nd.toString();
260 VarDescriptor vd=(VarDescriptor)nametable.get(varname);
262 throw new Error("Variable "+varname+" undefined");
266 if (!typeutil.isSuperorType(td,nn.getType()))
267 throw new Error("Field node returns "+nn.getType()+", but need "+td);
270 void checkAssignmentNode(MethodDescriptor md, SymbolTable nametable, AssignmentNode an, TypeDescriptor td) {
271 checkExpressionNode(md, nametable, an.getSrc() ,td);
272 //TODO: Need check on validity of operation here
273 if (!((an.getDest() instanceof FieldAccessNode)||
274 (an.getDest() instanceof NameNode)))
275 throw new Error("Bad lside in "+an.printNode(0));
276 checkExpressionNode(md, nametable, an.getDest(), null);
277 if (!typeutil.isSuperorType(an.getDest().getType(),an.getSrc().getType()))
278 throw new Error("Type of rside not compatible with type of lside"+an.printNode(0));
281 void checkLoopNode(MethodDescriptor md, SymbolTable nametable, LoopNode ln) {
282 if (ln.getType()==LoopNode.WHILELOOP||ln.getType()==LoopNode.DOWHILELOOP) {
283 checkExpressionNode(md, nametable, ln.getCondition(), new TypeDescriptor(TypeDescriptor.BOOLEAN));
284 checkBlockNode(md, nametable, ln.getBody());
287 /* Link in the initializer naming environment */
288 BlockNode bn=ln.getInitializer();
289 bn.getVarTable().setParent(nametable);
290 for(int i=0;i<bn.size();i++) {
291 BlockStatementNode bsn=bn.get(i);
292 checkBlockStatementNode(md, bn.getVarTable(),bsn);
294 //check the condition
295 checkExpressionNode(md, bn.getVarTable(), ln.getCondition(), new TypeDescriptor(TypeDescriptor.BOOLEAN));
296 checkBlockNode(md, bn.getVarTable(), ln.getBody());
297 checkBlockNode(md, bn.getVarTable(), ln.getUpdate());
302 void checkCreateObjectNode(MethodDescriptor md, SymbolTable nametable, CreateObjectNode con, TypeDescriptor td) {
307 void checkMethodInvokeNode(MethodDescriptor md, SymbolTable nametable, MethodInvokeNode min, TypeDescriptor td) {
312 void checkOpNode(MethodDescriptor md, SymbolTable nametable, OpNode on,TypeDescriptor td) {