2005-01-31 Zoltan Varga <vargaz@freemail.hu>
[mono.git] / mcs / mcs / expression.cs
old mode 100755 (executable)
new mode 100644 (file)
index 7799ab9..7ea0a61
@@ -217,6 +217,10 @@ namespace Mono.CSharp {
                                e = new IntConstant (-((ShortConstant) expr).Value);
                        else if (expr is UShortConstant)
                                e = new IntConstant (-((UShortConstant) expr).Value);
+                       else if (expr is SByteConstant)
+                               e = new IntConstant (-((SByteConstant) expr).Value);
+                       else if (expr is ByteConstant)
+                               e = new IntConstant (-((ByteConstant) expr).Value);
                        return e;
                }
 
@@ -237,7 +241,7 @@ namespace Mono.CSharp {
                                
                        case Operator.UnaryNegation:
                                result = TryReduceNegative (e);
-                               return true;
+                               return result != null;
                                
                        case Operator.LogicalNot:
                                if (expr_type != TypeManager.bool_type) {
@@ -323,11 +327,22 @@ namespace Mono.CSharp {
 
                Expression ResolveOperator (EmitContext ec)
                {
-                       Type expr_type = Expr.Type;
+                       //
+                       // Step 1: Default operations on CLI native types.
+                       //
+
+                       // Attempt to use a constant folding operation.
+                       if (Expr is Constant){
+                               Expression result;
+                               
+                               if (Reduce (ec, (Constant) Expr, out result))
+                                       return result;
+                       }
 
                        //
-                       // Step 1: Perform Operator Overload location
+                       // Step 2: Perform Operator Overload location
                        //
+                       Type expr_type = Expr.Type;
                        Expression mg;
                        string op_name;
                        
@@ -353,18 +368,6 @@ namespace Mono.CSharp {
                        if (expr_type == null)
                                return null;
                        
-                       //
-                       // Step 2: Default operations on CLI native types.
-                       //
-
-                       // Attempt to use a constant folding operation.
-                       if (Expr is Constant){
-                               Expression result;
-                               
-                               if (Reduce (ec, (Constant) Expr, out result))
-                                       return result;
-                       }
-
                        switch (Oper){
                        case Operator.LogicalNot:
                                if (expr_type != TypeManager.bool_type) {
@@ -428,21 +431,34 @@ namespace Mono.CSharp {
                                }
 
                                IVariable variable = Expr as IVariable;
-                               if (!ec.InFixedInitializer && ((variable == null) || !variable.VerifyFixed (false))) {
+                               bool is_fixed = variable != null && variable.VerifyFixed (false);
+
+                               if (!ec.InFixedInitializer && !is_fixed) {
                                        Error (212, "You can only take the address of an unfixed expression inside " +
                                               "of a fixed statement initializer");
                                        return null;
                                }
-                               
-                               if (ec.InFixedInitializer && ((variable != null) && variable.VerifyFixed (false))) {
+
+                               if (ec.InFixedInitializer && is_fixed) {
                                        Error (213, "You can not fix an already fixed expression");
                                        return null;
                                }
 
+                               LocalVariableReference lr = Expr as LocalVariableReference;
+                               if (lr != null){
+                                       if (lr.local_info.IsCaptured){
+                                               AnonymousMethod.Error_AddressOfCapturedVar (lr.Name, loc);
+                                               return null;
+                                       }
+                                       lr.local_info.AddressTaken = true;
+                                       lr.local_info.Used = true;
+                               }
+
                                // According to the specs, a variable is considered definitely assigned if you take
                                // its address.
-                               if ((variable != null) && (variable.VariableInfo != null))
+                               if ((variable != null) && (variable.VariableInfo != null)){
                                        variable.VariableInfo.SetAssigned (ec);
+                               }
 
                                type = TypeManager.GetPointerType (Expr.Type);
                                return this;
@@ -645,7 +661,7 @@ namespace Mono.CSharp {
        // after semantic analysis (this is so we can take the address
        // of an indirection).
        //
-       public class Indirection : Expression, IMemoryLocation, IAssignMethod {
+       public class Indirection : Expression, IMemoryLocation, IAssignMethod, IVariable {
                Expression expr;
                LocalTemporary temporary;
                bool prepared;
@@ -719,6 +735,21 @@ namespace Mono.CSharp {
                {
                        return "*(" + expr + ")";
                }
+
+               #region IVariable Members
+
+               public VariableInfo VariableInfo {
+                       get {
+                               return null;
+                       }
+               }
+
+               public bool VerifyFixed (bool is_expression)
+               {
+                       return true;
+               }
+
+               #endregion
        }
        
        /// <summary>
@@ -2236,8 +2267,8 @@ namespace Mono.CSharp {
                        // Special cases: string comapred to null
                        //
                        if (oper == Operator.Equality || oper == Operator.Inequality){
-                               if ((!TypeManager.IsValueType (l) && (right is NullLiteral)) ||
-                                   (!TypeManager.IsValueType (r) && (left is NullLiteral))) {
+                               if ((!TypeManager.IsValueType (l) && r == TypeManager.null_type) ||
+                                   (!TypeManager.IsValueType (r) && l == TypeManager.null_type)) {
                                        Type = TypeManager.bool_type;
                                        
                                        return this;
@@ -2674,16 +2705,27 @@ namespace Mono.CSharp {
                                }
                        } else
                                left = left.Resolve (ec);
-                       right = right.Resolve (ec);
 
-                       if (left == null || right == null)
+                       if (left == null)
+                               return null;
+
+                       Constant lc = left as Constant;
+                       if (lc != null && lc.Type == TypeManager.bool_type && 
+                               ((oper == Operator.LogicalAnd && (bool)lc.GetValue () == false) ||
+                                (oper == Operator.LogicalOr && (bool)lc.GetValue () == true))) {
+
+                               // TODO: make a sense to resolve unreachable expression as we do for statement
+                               Report.Warning (429, 4, loc, "Unreachable expression code detected");
+                               return left;
+                       }
+
+                       right = right.Resolve (ec);
+                       if (right == null)
                                return null;
 
                        eclass = ExprClass.Value;
 
                        Constant rc = right as Constant;
-                       Constant lc = left as Constant;
-
                        if (rc != null & lc != null){
                                Expression e = ConstantFold.BinaryFold (
                                        ec, oper, lc, rc, loc);
@@ -3388,17 +3430,26 @@ namespace Mono.CSharp {
                                //
                                left.Emit (ec);
                                ig.Emit (OpCodes.Conv_I);
-                               right.Emit (ec);
-                               if (size != 1){
-                                       if (size == 0)
-                                               ig.Emit (OpCodes.Sizeof, element);
-                                       else 
-                                               IntLiteral.EmitInt (ig, size);
-                                       if (rtype == TypeManager.int64_type)
-                                               ig.Emit (OpCodes.Conv_I8);
-                                       else if (rtype == TypeManager.uint64_type)
-                                               ig.Emit (OpCodes.Conv_U8);
-                                       ig.Emit (OpCodes.Mul);
+
+                               Constant right_const = right as Constant;
+                               if (right_const != null && size != 0) {
+                                       Expression ex = ConstantFold.BinaryFold (ec, Binary.Operator.Multiply, new IntConstant (size), right_const, loc);
+                                       if (ex == null)
+                                               return;
+                                       ex.Emit (ec);
+                               } else {
+                                       right.Emit (ec);
+                                       if (size != 1){
+                                               if (size == 0)
+                                                       ig.Emit (OpCodes.Sizeof, element);
+                                               else 
+                                                       IntLiteral.EmitInt (ig, size);
+                                               if (rtype == TypeManager.int64_type)
+                                                       ig.Emit (OpCodes.Conv_I8);
+                                               else if (rtype == TypeManager.uint64_type)
+                                                       ig.Emit (OpCodes.Conv_U8);
+                                               ig.Emit (OpCodes.Mul);
+                                       }
                                }
                                
                                if (rtype == TypeManager.int64_type || rtype == TypeManager.uint64_type)
@@ -3465,9 +3516,6 @@ namespace Mono.CSharp {
                        if (trueExpr == null || falseExpr == null)
                                return null;
 
-                       if ((trueExpr is NullLiteral) && (falseExpr is NullLiteral))
-                               return trueExpr;
-
                        eclass = ExprClass.Value;
                        if (trueExpr.Type == falseExpr.Type)
                                type = trueExpr.Type;
@@ -3507,13 +3555,12 @@ namespace Mono.CSharp {
                                }
                        }
 
+                       // Dead code optimalization
                        if (expr is BoolConstant){
                                BoolConstant bc = (BoolConstant) expr;
 
-                               if (bc.Value)
-                                       return trueExpr;
-                               else
-                                       return falseExpr;
+                               Report.Warning (429, 4, bc.Value ? falseExpr.Location : trueExpr.Location, "Unreachable expression code detected");
+                               return bc.Value ? trueExpr : falseExpr;
                        }
 
                        return this;
@@ -3582,6 +3629,11 @@ namespace Mono.CSharp {
                {
                        if (local_info == null) {
                                local_info = Block.GetLocalInfo (Name);
+
+                               // is out param
+                               if (lvalue_right_side == EmptyExpression.Null)
+                                       local_info.Used = true;
+
                                is_readonly = local_info.ReadOnly;
                        }
 
@@ -3617,8 +3669,11 @@ namespace Mono.CSharp {
                                // flag it for capturing
                                //
                                if (local_info.Block.Toplevel != ec.CurrentBlock.Toplevel){
+                                       if (local_info.AddressTaken){
+                                               AnonymousMethod.Error_AddressOfCapturedVar (local_info.Name, loc);
+                                               return null;
+                                       }
                                        ec.CaptureVariable (local_info);
-                                       //Console.WriteLine ("Capturing at " + loc);
                                }
                        }
 
@@ -4132,8 +4187,9 @@ namespace Mono.CSharp {
 
                                        if (instance.GetType () != typeof (This)){
                                                if (fe.InstanceExpression.Type.IsSubclassOf (TypeManager.mbr_type)){
-                                                       Report.Error (197, loc,
-                                                                     "Can not pass a type that derives from MarshalByRefObject with out or ref");
+                                                       Report.SymbolRelatedToPreviousError (fe.InstanceExpression.Type);
+                                                       Report.Error (197, loc, "Cannot pass '{0}' as ref or out or take its address because it is a member of a marshal-by-reference class",
+                                                               fe.Name);
                                                        return false;
                                                }
                                        }
@@ -4185,7 +4241,14 @@ namespace Mono.CSharp {
                                                pr.AddressOf (ec, mode);
                                        }
                                } else {
-                                       ((IMemoryLocation)Expr).AddressOf (ec, mode);
+                                       if (Expr is IMemoryLocation)
+                                               ((IMemoryLocation) Expr).AddressOf (ec, mode);
+                                       else {
+                                               Report.Error (
+                                                       1510, Expr.Location,
+                                                       "An lvalue is required as an argument to out or ref");
+                                               return;
+                                       }
                                }
                        } else
                                Expr.Emit (ec);
@@ -4288,9 +4351,9 @@ namespace Mono.CSharp {
                                //   * There is no implicit conversion from type 'object' to other reference types
                                //  => Conversion of 'null' to a reference type is better than conversion to 'object'
                                //
-                               //  FIXME: This probably isn't necessary, since the type of a NullLiteral is 'System.Null'.
-                               //         I think it used to be 'object' and thus needed a special case to avoid the
-                               //         immediately following two checks.
+                               //  FIXME: This probably isn't necessary, since the type of a NullLiteral is the 
+                               //         null type. I think it used to be 'object' and thus needed a special 
+                               //         case to avoid the immediately following two checks.
                                //
                                if (!p.IsValueType && q == TypeManager.object_type)
                                        return p;
@@ -5137,6 +5200,9 @@ namespace Mono.CSharp {
                                }
                        }
 
+                       if (mg.InstanceExpression != null)
+                               mg.InstanceExpression.CheckMarshallByRefAccess (ec.ContainerType);
+
                        eclass = ExprClass.Value;
                        return this;
                }
@@ -5694,7 +5760,7 @@ namespace Mono.CSharp {
                        if (IsDelegate){
                                RequestedType = (new NewDelegate (type, Arguments, loc)).Resolve (ec);
                                if (RequestedType != null)
-                                       if (!(RequestedType is NewDelegate))
+                                       if (!(RequestedType is DelegateCreation))
                                                throw new Exception ("NewDelegate.Resolve returned a non NewDelegate: " + RequestedType.GetType ());
                                return RequestedType;
                        }
@@ -5744,11 +5810,16 @@ namespace Mono.CSharp {
                                }
 
                                method = Invocation.OverloadResolve (
-                                       ec, (MethodGroupExpr) ml, Arguments, false, loc);
+                                       ec, (MethodGroupExpr) ml, Arguments, true, loc);
                                
                        }
 
-                       if (method == null) { 
+                       if (method == null) {
+                               if (almostMatchedMembers.Count != 0) {
+                                       MemberLookupFailed (ec, type, type, ".ctor", null, loc);
+                                       return null;
+                               }
+
                                 if (!is_struct || Arguments.Count > 0) {
                                        Error (1501, String.Format (
                                            "New invocation: Can not find a constructor in `{0}' for this argument list",
@@ -7021,9 +7092,11 @@ namespace Mono.CSharp {
                        if (sn == null || left == null || left.Type.Name != sn.Name)
                                return false;
 
-                       return RootContext.LookupType (ec.DeclSpace, sn.Name, true, loc) != null;
+                       return ec.DeclSpace.LookupType (sn.Name, true, loc) != null;
                }
                
+               // TODO: possible optimalization
+               // Cache resolved constant result in FieldBuilder <-> expresion map
                public static Expression ResolveMemberAccess (EmitContext ec, Expression member_lookup,
                                                              Expression left, Location loc,
                                                              Expression left_original)
@@ -7049,7 +7122,10 @@ namespace Mono.CSharp {
                                FieldInfo fi = fe.FieldInfo;
                                Type decl_type = fi.DeclaringType;
 
-                               if (fi is FieldBuilder) {
+                               bool is_emitted = fi is FieldBuilder;
+                               Type t = fi.FieldType;
+
+                               if (is_emitted) {
                                        Const c = TypeManager.LookupConstant ((FieldBuilder) fi);
                                        
                                        if (c != null) {
@@ -7059,16 +7135,29 @@ namespace Mono.CSharp {
 
                                                object real_value = ((Constant) c.Expr).GetValue ();
 
-                                               return Constantify (real_value, fi.FieldType);
+                                               Expression exp = Constantify (real_value, t);
+
+                                               if (left_is_explicit && !left_is_type && !IdenticalNameAndTypeName (ec, left_original, left, loc)) {
+                                                       Report.SymbolRelatedToPreviousError (c);
+                                                       error176 (loc, c.GetSignatureForError ());
+                                                       return null;
+                                               }
+                                       
+                                               return exp;
                                        }
                                }
 
+                               // IsInitOnly is because of MS compatibility, I don't know why but they emit decimal constant as InitOnly
+                               if (fi.IsInitOnly && !is_emitted && t == TypeManager.decimal_type) {
+                                       object[] attrs = fi.GetCustomAttributes (TypeManager.decimal_constant_attribute_type, false);
+                                       if (attrs.Length == 1)
+                                               return new DecimalConstant (((System.Runtime.CompilerServices.DecimalConstantAttribute) attrs [0]).Value);
+                               }
+
                                if (fi.IsLiteral) {
-                                       Type t = fi.FieldType;
-                                       
                                        object o;
 
-                                       if (fi is FieldBuilder)
+                                       if (is_emitted)
                                                o = TypeManager.GetValue ((FieldBuilder) fi);
                                        else
                                                o = fi.GetValue (fi);
@@ -7105,7 +7194,7 @@ namespace Mono.CSharp {
                                        return exp;
                                }
 
-                               if (fi.FieldType.IsPointer && !ec.InUnsafe){
+                               if (t.IsPointer && !ec.InUnsafe){
                                        UnsafeError (loc);
                                        return null;
                                }
@@ -7230,12 +7319,12 @@ namespace Mono.CSharp {
                        if (expr == null)
                                return null;
 
-                       if (expr is SimpleName){
-                               SimpleName child_expr = (SimpleName) expr;
-
-                               Expression new_expr = new SimpleName (child_expr.Name, Identifier, loc);
-
-                               return new_expr.Resolve (ec, flags);
+                       if (expr is Namespace) {
+                               Namespace ns = (Namespace) expr;
+                               FullNamedExpression retval = ns.Lookup (ec.DeclSpace, Identifier, loc);
+                               if (retval == null)
+                                       Report.Error (234, loc, "The type or namespace name `{0}' could not be found in namespace `{1}'", Identifier, ns.FullName);
+                               return retval;
                        }
                                        
                        //
@@ -7299,7 +7388,8 @@ namespace Mono.CSharp {
                                return null;
 
                        if (member_lookup is TypeExpr) {
-                               if (!(expr is TypeExpr) && !(expr is SimpleName)) {
+                               if (!(expr is TypeExpr) && 
+                                   !IdenticalNameAndTypeName (ec, original, expr, loc)) {
                                        Error (572, "Can't reference type `" + Identifier + "' through an expression; try `" +
                                               member_lookup.Type + "' instead");
                                        return null;
@@ -7325,47 +7415,32 @@ namespace Mono.CSharp {
 
                public override Expression DoResolve (EmitContext ec)
                {
-                       return DoResolve (ec, null, ResolveFlags.VariableOrValue |
-                                         ResolveFlags.SimpleName | ResolveFlags.Type);
+                       return DoResolve (ec, null, ResolveFlags.VariableOrValue | ResolveFlags.Type);
                }
 
                public override Expression DoResolveLValue (EmitContext ec, Expression right_side)
                {
-                       return DoResolve (ec, right_side, ResolveFlags.VariableOrValue |
-                                         ResolveFlags.SimpleName | ResolveFlags.Type);
+                       return DoResolve (ec, right_side, ResolveFlags.VariableOrValue | ResolveFlags.Type);
                }
 
-               public override Expression ResolveAsTypeStep (EmitContext ec)
+               public override FullNamedExpression ResolveAsTypeStep (EmitContext ec)
                {
-                       string fname = null;
-                       MemberAccess full_expr = this;
-                       while (full_expr != null) {
-                               if (fname != null)
-                                       fname = String.Concat (full_expr.Identifier, ".", fname);
-                               else
-                                       fname = full_expr.Identifier;
-
-                               if (full_expr.Expr is SimpleName) {
-                                       string full_name = String.Concat (((SimpleName) full_expr.Expr).Name, ".", fname);
-                                       Type fully_qualified = ec.DeclSpace.FindType (loc, full_name);
-                                       if (fully_qualified != null)
-                                               return new TypeExpression (fully_qualified, loc);
-                               }
-
-                               full_expr = full_expr.Expr as MemberAccess;
-                       }
+                       return ResolveNamespaceOrType (ec, false);
+               }
 
-                       Expression new_expr = expr.ResolveAsTypeStep (ec);
+               public FullNamedExpression ResolveNamespaceOrType (EmitContext ec, bool silent)
+               {
+                       FullNamedExpression new_expr = expr.ResolveAsTypeStep (ec);
 
                        if (new_expr == null)
                                return null;
 
-                       if (new_expr is SimpleName){
-                               SimpleName child_expr = (SimpleName) new_expr;
-                               
-                               new_expr = new SimpleName (child_expr.Name, Identifier, loc);
-
-                               return new_expr.ResolveAsTypeStep (ec);
+                       if (new_expr is Namespace) {
+                               Namespace ns = (Namespace) new_expr;
+                               FullNamedExpression retval = ns.Lookup (ec.DeclSpace, Identifier, loc);
+                               if (!silent && retval == null)
+                                       Report.Error (234, loc, "The type or namespace name `{0}' could not be found in namespace `{1}'", Identifier, ns.FullName);
+                               return retval;
                        }
 
                        Type expr_type = new_expr.Type;
@@ -7376,17 +7451,21 @@ namespace Mono.CSharp {
                                return null;
                        }
                        
-                       Expression member_lookup;
-                       member_lookup = MemberLookupFinal (ec, expr_type, expr_type, Identifier, loc);
-                       if (member_lookup == null)
+                       Expression member_lookup = MemberLookupFinal (ec, expr_type, expr_type, Identifier, loc);
+                       if (!silent && member_lookup == null) {
+                               Report.Error (234, loc, "The type name `{0}' could not be found in type `{1}'", 
+                                             Identifier, new_expr.FullName);
                                return null;
+                       }
 
-                       if (member_lookup is TypeExpr){
-                               member_lookup.Resolve (ec, ResolveFlags.Type);
-                               return member_lookup;
+                       if (!(member_lookup is TypeExpr)) {
+                               Report.Error (118, loc, "'{0}.{1}' denotes a '{2}', where a type was expected",
+                                             new_expr.FullName, Identifier, member_lookup.ExprClassName ());
+                               return null;
                        } 
 
-                       return null;                    
+                       member_lookup = member_lookup.Resolve (ec, ResolveFlags.Type);
+                       return (member_lookup as TypeExpr);
                }
 
                public override void Emit (EmitContext ec)
@@ -8152,6 +8231,8 @@ namespace Mono.CSharp {
                                UnsafeError (loc);
                                return null;
                        }
+
+                       instance_expr.CheckMarshallByRefAccess (ec.ContainerType);
                        
                        eclass = ExprClass.IndexerAccess;
                        return this;
@@ -8222,6 +8303,8 @@ namespace Mono.CSharp {
                                }
                        }
                        
+                       instance_expr.CheckMarshallByRefAccess (ec.ContainerType);
+
                        eclass = ExprClass.IndexerAccess;
                        return this;
                }
@@ -8460,6 +8543,12 @@ namespace Mono.CSharp {
                        loc = l;
                }
 
+               public Expression Source {
+                       get {
+                               return source;
+                       }
+               }
+                       
                public override Expression DoResolve (EmitContext ec)
                {
                        //
@@ -8526,9 +8615,9 @@ namespace Mono.CSharp {
                                //
                                // For now, fall back to the full lookup in that case.
                                //
-                               type = RootContext.LookupType (
-                                       ec.DeclSpace, cname, false, loc);
-
+                               FullNamedExpression e = ec.DeclSpace.LookupType (cname, false, loc);
+                               if (e is TypeExpr)
+                                       type = ((TypeExpr) e).ResolveType (ec);
                                if (type == null)
                                        return null;
                        }
@@ -8537,6 +8626,12 @@ namespace Mono.CSharp {
                                UnsafeError (loc);
                                return null;
                        }
+
+                       if (type.IsArray && (type.GetElementType () == TypeManager.arg_iterator_type ||
+                               type.GetElementType () == TypeManager.typed_reference_type)) {
+                               Report.Error (611, loc, "Array elements cannot be of type '{0}'", TypeManager.CSharpName (type.GetElementType ()));
+                               return null;
+                       }
                        
                        eclass = ExprClass.Type;
                        return this;
@@ -8547,6 +8642,12 @@ namespace Mono.CSharp {
                                return left + dim;
                        }
                }
+
+               public override string FullName {
+                       get {
+                               return type.FullName;
+                       }
+               }
        }
 
        //