ecore.cs

C#编译器源代码。Micorsoft开放源代码

			StringBuilder sb = new StringBuilder (valid [0]);
			for (int i = 1; i < count - 1; i++) {
				sb.Append ("', `");
				sb.Append (valid [i]);
			}
			if (count > 1) {
				sb.Append ("' or `");
				sb.Append (valid [count - 1]);
			}

			Report.Error (119, loc, 
				"Expression denotes a `{0}', where a `{1}' was expected", ExprClassName, sb);
		}
		
		public static void UnsafeError (Location loc)
		{
			Report.Error (214, loc, "Pointers and fixed size buffers may only be used in an unsafe context");
		}

		//
		// Load the object from the pointer.  
		//
		public static void LoadFromPtr (ILGenerator ig, Type t)
		{
			if (t == TypeManager.int32_type)
				ig.Emit (OpCodes.Ldind_I4);
			else if (t == TypeManager.uint32_type)
				ig.Emit (OpCodes.Ldind_U4);
			else if (t == TypeManager.short_type)
				ig.Emit (OpCodes.Ldind_I2);
			else if (t == TypeManager.ushort_type)
				ig.Emit (OpCodes.Ldind_U2);
			else if (t == TypeManager.char_type)
				ig.Emit (OpCodes.Ldind_U2);
			else if (t == TypeManager.byte_type)
				ig.Emit (OpCodes.Ldind_U1);
			else if (t == TypeManager.sbyte_type)
				ig.Emit (OpCodes.Ldind_I1);
			else if (t == TypeManager.uint64_type)
				ig.Emit (OpCodes.Ldind_I8);
			else if (t == TypeManager.int64_type)
				ig.Emit (OpCodes.Ldind_I8);
			else if (t == TypeManager.float_type)
				ig.Emit (OpCodes.Ldind_R4);
			else if (t == TypeManager.double_type)
				ig.Emit (OpCodes.Ldind_R8);
			else if (t == TypeManager.bool_type)
				ig.Emit (OpCodes.Ldind_I1);
			else if (t == TypeManager.intptr_type)
				ig.Emit (OpCodes.Ldind_I);
			else if (TypeManager.IsEnumType (t)) {
				if (t == TypeManager.enum_type)
					ig.Emit (OpCodes.Ldind_Ref);
				else
					LoadFromPtr (ig, TypeManager.EnumToUnderlying (t));
			} else if (t.IsValueType)
				ig.Emit (OpCodes.Ldobj, t);
			else if (t.IsPointer)
				ig.Emit (OpCodes.Ldind_I);
			else 
				ig.Emit (OpCodes.Ldind_Ref);
		}

		//
		// The stack contains the pointer and the value of type `type'
		//
		public static void StoreFromPtr (ILGenerator ig, Type type)
		{
			if (TypeManager.IsEnumType (type))
				type = TypeManager.EnumToUnderlying (type);
			if (type == TypeManager.int32_type || type == TypeManager.uint32_type)
				ig.Emit (OpCodes.Stind_I4);
			else if (type == TypeManager.int64_type || type == TypeManager.uint64_type)
				ig.Emit (OpCodes.Stind_I8);
			else if (type == TypeManager.char_type || type == TypeManager.short_type ||
				 type == TypeManager.ushort_type)
				ig.Emit (OpCodes.Stind_I2);
			else if (type == TypeManager.float_type)
				ig.Emit (OpCodes.Stind_R4);
			else if (type == TypeManager.double_type)
				ig.Emit (OpCodes.Stind_R8);
			else if (type == TypeManager.byte_type || type == TypeManager.sbyte_type ||
				 type == TypeManager.bool_type)
				ig.Emit (OpCodes.Stind_I1);
			else if (type == TypeManager.intptr_type)
				ig.Emit (OpCodes.Stind_I);
			else if (type.IsValueType)
				ig.Emit (OpCodes.Stobj, type);
			else
				ig.Emit (OpCodes.Stind_Ref);
		}
		
		//
		// Returns the size of type `t' if known, otherwise, 0
		//
		public static int GetTypeSize (Type t)
		{
			t = TypeManager.TypeToCoreType (t);
			if (t == TypeManager.int32_type ||
			    t == TypeManager.uint32_type ||
			    t == TypeManager.float_type)
			        return 4;
			else if (t == TypeManager.int64_type ||
				 t == TypeManager.uint64_type ||
				 t == TypeManager.double_type)
			        return 8;
			else if (t == TypeManager.byte_type ||
				 t == TypeManager.sbyte_type ||
				 t == TypeManager.bool_type) 	
			        return 1;
			else if (t == TypeManager.short_type ||
				 t == TypeManager.char_type ||
				 t == TypeManager.ushort_type)
				return 2;
			else if (t == TypeManager.decimal_type)
				return 16;
			else
				return 0;
		}

		public static void Error_NegativeArrayIndex (Location loc)
		{
			Report.Error (248, loc, "Cannot create an array with a negative size");
		}

		protected void Error_CannotCallAbstractBase (string name)
		{
			Report.Error (205, loc, "Cannot call an abstract base member `{0}'", name);
		}
		
		//
		// Converts `source' to an int, uint, long or ulong.
		//
		public Expression ExpressionToArrayArgument (EmitContext ec, Expression source, Location loc)
		{
			Expression target;
			
			bool old_checked = ec.CheckState;
			ec.CheckState = true;
			
			target = Convert.ImplicitConversion (ec, source, TypeManager.int32_type, loc);
			if (target == null){
				target = Convert.ImplicitConversion (ec, source, TypeManager.uint32_type, loc);
				if (target == null){
					target = Convert.ImplicitConversion (ec, source, TypeManager.int64_type, loc);
					if (target == null){
						target = Convert.ImplicitConversion (ec, source, TypeManager.uint64_type, loc);
						if (target == null)
							source.Error_ValueCannotBeConverted (loc, TypeManager.int32_type, false);
					}
				}
			} 
			ec.CheckState = old_checked;

			//
			// Only positive constants are allowed at compile time
			//
			if (target is Constant){
				if (target is IntConstant){
					if (((IntConstant) target).Value < 0){
						Error_NegativeArrayIndex (loc);
						return null;
					}
				}

				if (target is LongConstant){
					if (((LongConstant) target).Value < 0){
						Error_NegativeArrayIndex (loc);
						return null;
					}
				}
				
			}

			return target;
		}
		
	}

	/// <summary>
	///   This is just a base class for expressions that can
	///   appear on statements (invocations, object creation,
	///   assignments, post/pre increment and decrement).  The idea
	///   being that they would support an extra Emition interface that
	///   does not leave a result on the stack.
	/// </summary>
	public abstract class ExpressionStatement : Expression {

		public virtual ExpressionStatement ResolveStatement (EmitContext ec)
		{
			Expression e = Resolve (ec);
			if (e == null)
				return null;

			ExpressionStatement es = e as ExpressionStatement;
			if (es == null)
				Error (201, "Only assignment, call, increment, decrement and new object " +
				       "expressions can be used as a statement");

			return es;
		}

		/// <summary>
		///   Requests the expression to be emitted in a `statement'
		///   context.  This means that no new value is left on the
		///   stack after invoking this method (constrasted with
		///   Emit that will always leave a value on the stack).
		/// </summary>
		public abstract void EmitStatement (EmitContext ec);
	}

	/// <summary>
	///   This kind of cast is used to encapsulate the child
	///   whose type is child.Type into an expression that is
	///   reported to return "return_type".  This is used to encapsulate
	///   expressions which have compatible types, but need to be dealt
	///   at higher levels with.
	///
	///   For example, a "byte" expression could be encapsulated in one
	///   of these as an "unsigned int".  The type for the expression
	///   would be "unsigned int".
	///
	/// </summary>
	public class EmptyCast : Expression {
		protected Expression child;

		public Expression Child {
			get {
				return child;
			}
		}		

		public EmptyCast (Expression child, Type return_type)
		{
			eclass = child.eclass;
			loc = child.Location;
			type = return_type;
			this.child = child;
		}

		public override Expression DoResolve (EmitContext ec)
		{
			// This should never be invoked, we are born in fully
			// initialized state.

			return this;
		}

		public override void Emit (EmitContext ec)
		{
			child.Emit (ec);
		}
	}
	/// <summary>
	/// 	This is a numeric cast to a Decimal
	/// </summary>
	public class CastToDecimal : EmptyCast {

		MethodInfo conversion_operator;

		public CastToDecimal (Expression child)
			: this (child, false)
		{
		}

		public CastToDecimal (Expression child, bool find_explicit)
			: base (child, TypeManager.decimal_type)
		{
			conversion_operator = GetConversionOperator (find_explicit);

			if (conversion_operator == null)
				throw new InternalErrorException ("Outer conversion routine is out of sync");
		}

		// Returns the implicit operator that converts from
		// 'child.Type' to System.Decimal.
		MethodInfo GetConversionOperator (bool find_explicit)
		{
			string operator_name = find_explicit ? "op_Explicit" : "op_Implicit";
			
			MemberInfo [] mi = TypeManager.MemberLookup (type, type, type, MemberTypes.Method,
				BindingFlags.Static | BindingFlags.Public, operator_name, null);

			foreach (MethodInfo oper in mi) {
				ParameterData pd = TypeManager.GetParameterData (oper);

				if (pd.ParameterType (0) == child.Type && oper.ReturnType == type)
					return oper;
			}

			return null;
		}
		public override void Emit (EmitContext ec)
		{
			ILGenerator ig = ec.ig;
			child.Emit (ec);

			ig.Emit (OpCodes.Call, conversion_operator);
		}
	}

	/// <summary>
	/// 	This is an explicit numeric cast from a Decimal
	/// </summary>
	public class CastFromDecimal : EmptyCast
	{
		static IDictionary operators;

		public CastFromDecimal (Expression child, Type return_type)
			: base (child, return_type)
		{
			if (child.Type != TypeManager.decimal_type)
				throw new InternalErrorException (
					"The expected type is Decimal, instead it is " + child.Type.FullName);
		}

		// Returns the explicit operator that converts from an
		// express of type System.Decimal to 'type'.
		public Expression Resolve ()
		{
			if (operators == null) {
				 MemberInfo[] all_oper = TypeManager.MemberLookup (TypeManager.decimal_type,
					TypeManager.decimal_type, TypeManager.decimal_type, MemberTypes.Method,
					BindingFlags.Static | BindingFlags.Public, "op_Explicit", null);

				operators = new System.Collections.Specialized.HybridDictionary ();
				foreach (MethodInfo oper in all_oper) {
					ParameterData pd = TypeManager.GetParameterData (oper);
					if (pd.ParameterType (0) == TypeManager.decimal_type)
						operators.Add (oper.ReturnType, oper);
				}
			}

			return operators.Contains (type) ? this : null;
		}

		public override void Emit (EmitContext ec)
		{
			ILGenerator ig = ec.ig;
			child.Emit (ec);

			ig.Emit (OpCodes.Call, (MethodInfo)operators [type]);
		}
	}

        //
	// We need to special case this since an empty cast of
	// a NullLiteral is still a Constant
	//
	public class NullCast : Constant {
		public Constant child;
				
		public NullCast (Constant child, Type return_type):
			base (Location.Null)
		{
			eclass = child.eclass;
			type = return_type;
			this.child = child;
		}

		override public string AsString ()
		{
			return "null";
		}

		public override object GetValue ()
		{
			return null;
		}

		public override Expression DoResolve (EmitContext ec)
		{
			// This should never be invoked, we are born in fully
			// initialized state.

			return this;
		}

		public override void Emit (EmitContext ec)
		{
			child.Emit (ec);
		}

		public override Constant Increment ()
		{
			throw new NotSupportedException ();
		}

		public override bool IsDefaultValue {
			get {
				throw new NotImplementedException ();
			}
		}

		public override bool IsNegative {
			get {
				return false;
			}
		}

		public override Constant Reduce (EmitContext ec, Type target_type)
		{
			if (type == target_type)
				return child.Reduce (ec, target_type);

			return null;
		}

	}


	/// <summary>
	///  This class is used to wrap literals which belong inside Enums
	/// </summary>
	public class EnumConstant : Constant {
		public Constant Child;

		public EnumConstant (Constant child, Type enum_type):
			base (child.Location)
		{
			eclass = child.eclass;
			this.Child = child;
			type = enum_type;
		}
		
		public override Expression DoResolve (EmitContext ec)
		{
			// This should never be invoked, we are born in fully
			// initialized state.

			return this;
		}

		public override void Emit (EmitContext ec)
		{
			Child.Emit (ec);
		}

		public override string GetSignatureForError()
		{
			return TypeManager.CSharpName (Type);
		}

		public override object GetValue ()
		{
			return Child.GetValue ();
		}

		public override object GetTypedValue ()
		{
			// FIXME: runtime is not ready to work with just emited enums
			if (!RootContext.StdLib) {
				return Child.GetValue ();