//--- determine if name is already in scope.
public bool IsDefined(String name)
{
bool defined = symbols.IsDefined(name); // look in current symbol table.
if (defined || outer == null)
{
// either name is found in current symbol table or there is no outer table - so return what we've got.
return(defined);
}
else
{
return(outer.IsDefined(name)); // not found so search recursively through outer scope.
}
} // end IsDefined method.
public bool IsDefinedInParent(String name)
{
ISymbolTable scopeRef = parent;
while (scopeRef != null)
{
if (scopeRef.IsDefined(name))
{
return(true);
}
scopeRef = scopeRef.Parent;
}
return(false);
}
public override bool VisitAssignmentExpression(AssignmentExpression assignExp)
{
if (assignExp.Target.NodeType == NodeType.VariableRefExpression)
{
// Convert to declaration if not found on the scope
VariableReferenceExpression varRef = (VariableReferenceExpression)assignExp.Target;
ISymbolTable scope = varRef.SymbolTable;
System.Diagnostics.Debug.Assert(scope != null);
String name = varRef.Identifier.Name;
if (!scope.IsDefined(name)) // TODO: The rules are slighly more complicated than that.
{
errorReport.Disable();
SingleVariableDeclarationStatement varDecl = new SingleVariableDeclarationStatement(varRef.Identifier);
IStatement stmt = ASTUtils.GetParentStatement(varRef);
System.Diagnostics.Debug.Assert(stmt != null);
IStatementContainer stmts = stmt.Parent as IStatementContainer;
int index = stmts.Statements.IndexOf(stmt);
varDecl.InitExp = assignExp.Value;
// stmts.Statements.Insert(index, varDecl);
stmts.Statements.Replace(stmt, varDecl);
if (!ApplyDeclarationRules(varRef.Identifier, scope, varDecl, stmt))
{
stmts.Statements.Remove(varDecl);
}
errorReport.Enable();
}
}
return(base.VisitAssignmentExpression(assignExp));
}
public override bool VisitParameterIdentifier(ParameterIdentifier parameterIdentifier)
{
ISymbolTable namescope = parameterIdentifier.Parent.SymbolTable;
System.Diagnostics.Debug.Assert(namescope != null);
System.Diagnostics.Debug.Assert(namescope.ScopeType == ScopeType.Method || namescope.ScopeType == ScopeType.Block);
if (!identifierService.IsValidFormatParameterName(parameterIdentifier.Name))
{
errorReport.Error("TODOFILENAME", parameterIdentifier.Position, "'{0}' is an invalid parameter name.", parameterIdentifier.Name);
return(false);
}
System.Diagnostics.Debug.Assert(!namescope.IsDefined(parameterIdentifier.Name));
namescope.AddVariable(parameterIdentifier);
return(base.VisitParameterIdentifier(parameterIdentifier));
}
private void EnsureTypeDeclarationsBelongsToThisScope(MultipleVariableDeclarationStatement varDecl, IList stmts)
{
ISymbolTable namescope = varDecl.Parent.SymbolTable;
System.Diagnostics.Debug.Assert(namescope != null);
foreach (SingleVariableDeclarationStatement typeDecl in stmts)
{
Identifier ident = typeDecl.Identifier;
// Most simple of cases: duplicated declaration
if (namescope.IsDefined(ident.Name))
{
errorReport.Error("TODOFILENAME", typeDecl.Position, "Sorry but '{0}' is already defined.", ident.Name);
continue;
}
ApplyDeclarationRules(ident, namescope, typeDecl, varDecl);
}
}
private bool ApplyDeclarationRules(Identifier ident, ISymbolTable namescope, SingleVariableDeclarationStatement typeDecl, IStatement statem)
{
// Second simple case: a local var and we are on the right place to
// declare it
if (ident.Type == IdentifierType.Local &&
(namescope.ScopeType == ScopeType.Method ||
namescope.ScopeType == ScopeType.Compound ||
namescope.ScopeType == ScopeType.Block))
{
namescope.AddVariable(ident);
return(true);
}
// More complex: a block or compound tries to redefine a variable
if (ident.Type == IdentifierType.Local &&
(namescope.ScopeType == ScopeType.Compound ||
namescope.ScopeType == ScopeType.Block))
{
if (namescope.Parent.IsDefined(ident.Name))
{
errorReport.Error("TODOFILENAME", typeDecl.Position, "Sorry but '{0}' is already defined in a parent scope.", ident.Name);
return(false);
}
}
// Local variables at class level?
// We will support that as a type initializer, but not now.
if (ident.Type == IdentifierType.Local && namescope.ScopeType == ScopeType.Type)
{
errorReport.Error("TODOFILENAME", typeDecl.Position, "At type level, just instance or static fields are allowed (yet)");
return(false);
}
// Static or instance in a method/block/compound are moved
// to the parent class or source unit level
if (ident.Type == IdentifierType.InstanceField ||
ident.Type == IdentifierType.StaticField)
{
if (namescope.ScopeType == ScopeType.SourceUnit ||
namescope.ScopeType == ScopeType.Type)
{
namescope.AddVariable(ident);
}
else if (namescope.ScopeType == ScopeType.Method ||
namescope.ScopeType == ScopeType.Compound ||
namescope.ScopeType == ScopeType.Block)
{
IASTNode node = statem.Parent;
while (node != null &&
node.NodeType != NodeType.TypeDefinition &&
node.NodeType != NodeType.SourceUnit)
{
node = node.Parent;
}
if (node == null || node.SymbolTable == null)
{
errorReport.Error("TODOFILENAME", typeDecl.Position,
"Compiler error: The instance of static declaration '{0}' could not be mapped to a parent type", ident.Name);
return(false);
}
ISymbolTable parentScope = node.SymbolTable;
IStatementContainer typeStmtsContainer = node as IStatementContainer;
System.Diagnostics.Debug.Assert(parentScope != null);
System.Diagnostics.Debug.Assert(typeStmtsContainer != null);
if (parentScope.IsDefined(ident.Name))
{
errorReport.Error("TODOFILENAME", typeDecl.Position,
"Sorry but '{0}' is already defined.", ident.Name);
return(false);
}
else
{
parentScope.AddVariable(ident);
// We can replace the declaration on the method
// body with an assignment if and only if this type decl has
// an init expression, so CreateAssignmentFromTypeDecl can return null
AssignmentExpression assignExp = CreateAssignmentFromTypeDecl(typeDecl);
ExpressionStatement assignExpStmt = new ExpressionStatement(assignExp);
typeDecl.ConvertInitExpressionToDependency();
// Replace the declaration with an assignment
(statem.Parent as IStatementContainer).Statements.Replace(typeDecl, assignExpStmt);
// Add the member/field declaration to the parent
typeStmtsContainer.Statements.Add(typeDecl);
// TODO: Link assignment expression and typeDecl to help
// find out the type of the field later
return(true);
}
}
}
return(false);
}
