C# PhpTypeCode类代码示例

		public MethodInfo EmitLambda(string name, AST.DirectVarUse variable, AST.Expression/*!*/ expression,
			PhpTypeCode returnType)
		{
			MethodBuilder result = linqContextBuilder.DefineMethod(name, MethodAttributes.PrivateScope | MethodAttributes.SpecialName,
				PhpTypeCodeEnum.ToType(returnType), new Type[] { typeof(object) });

			ILEmitter il = new ILEmitter(result);

			EnterLambdaDeclaration(il);

			if (variable != null)
			{
				// <variable> = COPY(<argument>);
				variable.Emit(cg);
				il.Emit(OpCodes.Ldarg_1);
				cg.EmitVariableCopy(CopyReason.Assigned, null);
				variable.EmitAssign(cg);
			}

			cg.EmitConversion(expression, returnType);
			il.Emit(OpCodes.Ret);

			LeaveLambdaDeclaration();

			return result;
		}

        /// <summary>
        /// Emit <see cref="PhpVariable.Copy"/> if needed. It means <see cref="Expression.Access"/> has to be <see cref="AccessType.Read"/> and <paramref name="returnType"/> has to be copiable.
        /// </summary>
        /// <param name="il">The <see cref="ILEmitter"/>.</param>
        /// <param name="returnType"><see cref="PhpTypeCode"/> of function call return value.</param>
        protected void EmitReturnValueCopy(ILEmitter/*!*/il, PhpTypeCode returnType)
        {
            Debug.Assert(il != null);

            // copy only if we are reading the return value &&
            // only if return type is copiable:
            if (access != AccessType.None &&   // reading, not literals:
                PhpTypeCodeEnum.IsDeeplyCopied(returnType) &&
                returnType != PhpTypeCode.PhpReference) // PhpSmartReference can be an issue if method returns an object field (but this is handled by binders)
            {
                il.LdcI4((int)CopyReason.ReturnedByCopy);
                il.Emit(OpCodes.Call, Methods.PhpVariable.Copy);
            }
        }

		internal void EmitSetConversion(ILEmitter/*!*/ il, PhpTypeCode sourceTypeCode, Type/*!*/ targetType)
		{
			LocalBuilder strictness = il.GetTemporaryLocal(typeof(PHP.Core.ConvertToClr.ConversionStrictness));
			if (!ClrOverloadBuilder.EmitConvertToClr(il, sourceTypeCode, targetType, strictness))
			{
				Label label_ok = il.DefineLabel();

				il.Ldloc(strictness);
				il.LdcI4((int)PHP.Core.ConvertToClr.ConversionStrictness.Failed);
				il.Emit(OpCodes.Ceq);
				il.Emit(OpCodes.Brfalse, label_ok);

				il.Emit(OpCodes.Ldstr, Property.DeclaringType.FullName);
				il.Emit(OpCodes.Ldstr, Property.FullName);
				il.Emit(OpCodes.Call, Methods.PhpException.PropertyTypeMismatch);

				il.MarkLabel(label_ok, true);
			}
			il.ReturnTemporaryLocal(strictness);
		}

		/// <summary>
		/// Emits code that loads a specified parameter on the evaluation stack.
		/// </summary>
		/// <param name="paramInfo">The parameter to load.</param>
		/// <param name="requiredTypeCode">Specifies whether <see cref="PhpReference"/>
		/// (<see cref="PhpTypeCode.PhpReference"/>), <see cref="object"/> (<see cref="PhpTypeCode.Object"/>),
		/// or the most fitting of these two should be loaded.</param>
		public void EmitLoadClrParameter(ParameterInfo/*!*/ paramInfo, PhpTypeCode requiredTypeCode)
		{
			if (paramInfo.IsOut) il.Emit(OpCodes.Ldnull);
			else
			{
				il.Ldarg(paramInfo.Position + paramOffset);

				// dereference ref param
				Type param_type = paramInfo.ParameterType;
				if (param_type.IsByRef)
				{
					param_type = param_type.GetElementType();

					il.Ldind(param_type);
				}

				// convert the parameter to PHP type
				PhpTypeCode type_code = ClrOverloadBuilder.EmitConvertToPhp(
					il,
					param_type/*,
					scriptContextPlace*/);

				il.EmitBoxing(type_code);
			}

			// check whether we have to create a PhpReference
			if (requiredTypeCode == PhpTypeCode.Object ||
				(requiredTypeCode == PhpTypeCode.Unknown && !paramInfo.ParameterType.IsByRef)) return;

			if (paramInfo.ParameterType.IsByRef)
			{
				LocalBuilder ref_local = il.DeclareLocal(Types.PhpReference[0]);

				// remember the PhpReference in a local
				il.Emit(OpCodes.Newobj, Constructors.PhpReference_Object);
				il.Emit(OpCodes.Dup);
				il.Stloc(ref_local);

				referenceLocals[paramInfo.Position] = ref_local;
			}
			else
			{
				// no reference store-back is necessary
				il.Emit(OpCodes.Newobj, Constructors.PhpReference_Object);
			}
		}

		internal void EmitSetItem(PhpTypeCode keyTypeCode, Expression keyExpr, bool reference)
		{
			MethodInfo method;
			switch (keyTypeCode)
			{
				case PhpTypeCode.Integer:
					method = (reference) ? Methods.Operators.SetItemRef.Int32 : Methods.Operators.SetItem.Int32;
					break;

				case PhpTypeCode.String:
					if (reference)
					{
						method = Methods.Operators.SetItemRef.String;
					}
					else
					{					
						if (EmitExactStringKeyHash(keyTypeCode, keyExpr))
							method = Methods.Operators.SetItemExact;
						else
							method = Methods.Operators.SetItem.String;
					}
					break;

				case PhpTypeCode.Object:
					method = (reference) ? Methods.Operators.SetItemRef.Object : Methods.Operators.SetItem.Object;
					break;

				case PhpTypeCode.Invalid:
					method = Methods.Operators.SetItem.Keyless;
					break;

				default:
                    throw new ArgumentException();
			}
			il.Emit(OpCodes.Call, method);
		}

		public ExpressionPlace(CodeGenerator/*!*/ codeGenerator, Expression/*!*/ expression)
		{
			this.codeGenerator = codeGenerator;
			this.expression = expression;
			this.typeCode = PhpTypeCode.Invalid;
		}

		// Obsolete:
		// <summary>
		// A <see cref="Stack{T}"/> class that stores temporarily used variables. See Remarks for more information.
		// </summary>
		// <remarks>This stack stores locals that are used to obtain address of a variable stored in
		// a runtime variables table while calling methods from <see cref="PHP.Core.Operators"/> having
		// a <c>ref</c> argument. Those variables are not so short-live to be obtained by <see cref="GetTemporaryLocal"/>,
		// but can be reused within a defining scope under certain circumstances.
		// When <see cref="GetAddressStorageLocal"/> method is called, the temporary
		// local is either popped from the cache or a new local is defined if the cache is empty.
		// If the variable become useless, <see cref="ReturnAddressStorageLocal"/> method should
		// be called to push the variable back to cache. Once the variable is returned to cache it must not have
		// been used unless it is obtained again by <see cref="GetAddressStorageLocal"/> method.
		// The cache is created when the first local is returned.
		// </remarks>

		#endregion

		#region PHP Specific

		internal void EmitBoxing(PhpTypeCode type)
		{
			switch (type)
			{
				case PhpTypeCode.Integer:
					il.Emit(OpCodes.Box, typeof(Int32));
					break;

				case PhpTypeCode.LongInteger:
					il.Emit(OpCodes.Box, typeof(Int64));
					break;

				case PhpTypeCode.Double:
					il.Emit(OpCodes.Box, typeof(Double));
					break;

				case PhpTypeCode.Boolean:
					il.Emit(OpCodes.Box, typeof(Boolean));
					break;

				case PhpTypeCode.Void:
					il.Emit(OpCodes.Ldnull);
					break;
			}
		}

		/// <summary>
		/// Emits code to prepare an evaluation stack for storing a reference into a variable.
		/// Supports operators chaining. Store is finished by calling <see cref="EmitAssign"/>.
		/// </summary>
		/// <param name="codeGenerator"></param>
		private PhpTypeCode EmitNodeWriteRef(CodeGenerator codeGenerator)
		{
			ChainBuilder chain = codeGenerator.ChainBuilder;

			// Case 3: a_[x]_[x] never reached
			Debug.Assert(chain.IsArrayItem == false);

			// Case 4,5 never reached
			// 4: a[x]->...
			// 5: ...->a[]->...
			Debug.Assert(chain.IsMember == false);

			// 1, 2, 6, 7
			if (this.isMemberOf != null)
			{
				// 6, 7: ...->a[x]_[x]_
				chain.Create();
				chain.Begin();
				// Store isMemberOf for lazy emit
				chain.SetObjectForLazyEmit(this);
				chain.IsArrayItem = true;
				chain.IsLastMember = false;
				chain.Lengthen(); // for own []
				array.Emit(codeGenerator);
				indexTypeCode = codeGenerator.EmitArrayKey(chain, index);
							
				// Note that EmitAssign will finish the work (SetArrayItem or PhpArray.Add)
			}
			else
			{
				// 1, 2
				Debug.Assert(this.isMemberOf == null);

				if (array is ItemUse || array is DirectStFldUse || array is IndirectStFldUse /* ??? */)
				{
					// 2: a[]_[]_
					chain.Create();
					chain.Begin();
					chain.IsArrayItem = true;
					chain.IsLastMember = true;
					array.Emit(codeGenerator);
					indexTypeCode = codeGenerator.EmitArrayKey(chain, index);
							
					// Note that further work will be done by EmitAssign (SetArrayItem or PhpArray.Add)
				}
				// 1: a_[x]_
				// Do nothing now, let the work be done in EmitAssign()
				// Note further work will be done by EmitAssign (either SetItem or SetItemRef);	
			}
			return PhpTypeCode.Unknown;
		}

		private static void EmitCallSetObjectField(CodeGenerator/*!*/ codeGenerator, PhpTypeCode stackTypeCode)
		{
			// CALL Operators.SetObjectProperty(<STACK:instance>,<STACK:field name>,<STACK:field value>, <type desc>)
			codeGenerator.EmitLoadClassContext();

			codeGenerator.IL.Emit(OpCodes.Call, Methods.Operators.SetObjectProperty);
            
            //always when function with void return argument is called it's necesarry to add nop instruction due to debugger
            if (codeGenerator.Context.Config.Compiler.Debug)
            {
                codeGenerator.IL.Emit(OpCodes.Nop);
            }
		}

		/// <summary>
		/// Emits instructions to conform a required access type.
		/// </summary>
		/// <param name="callExpression">Expression emitting the call.</param>
		/// <param name="loadAddress">Whether to load an address of the return value.</param>
		/// <param name="result">The type code of a top item of the evaluation stack.</param>
		public void EmitReturnValueHandling(Expression/*!*/ callExpression, bool loadAddress, ref PhpTypeCode result)
		{
			Debug.Assert(callExpression != null);

			if (loadAddress)
			{
                if (result == PhpTypeCode.PhpReference)
				{
					// LOADADDR STACK.Value;
					il.Emit(OpCodes.Ldflda, Fields.PhpReference_Value);
				}
				else
				{
                    if (result == PhpTypeCode.Void)
                        il.Emit(OpCodes.Ldnull);
                    
                    // local = STACK; 
					// LOADADDR local;
					LocalBuilder local = il.GetTemporaryLocal(PhpTypeCodeEnum.ToType(result), true);
					il.Stloc(local);
					il.Ldloca(local);
				}
				result = PhpTypeCode.ObjectAddress;
				return;
			}

			switch (callExpression.GetAccess())
			{
				case AccessType.None:

					// return value is discarded:
					if (result != PhpTypeCode.Void)
					{
						il.Emit(OpCodes.Pop);
						result = PhpTypeCode.Void;
					}
					break;

				case AccessType.ReadUnknown:
				case AccessType.ReadRef:

					if (result != PhpTypeCode.PhpReference)
					{
						// return value is "boxed" to PhpReference:
						if (result != PhpTypeCode.Void)
						{
							EmitBoxing(result);
							EmitVariableCopy(CopyReason.ReturnedByCopy, callExpression);
							il.Emit(OpCodes.Newobj, Constructors.PhpReference_Object);
						}
						else
						{
							il.Emit(OpCodes.Newobj, Constructors.PhpReference_Void);
						}

						result = PhpTypeCode.PhpReference;
					}
					break;

				case AccessType.Read:

					if (result == PhpTypeCode.PhpReference)
					{
						// return value is dereferenced:
						il.Emit(OpCodes.Ldfld, Fields.PhpReference_Value);
						result = PhpTypeCode.Object;
					}
					else if (result == PhpTypeCode.Void)
					{
						// null value is loaded as a result:
						il.Emit(OpCodes.Ldnull);
						result = PhpTypeCode.Object;
					}
					break;

				default:
					Debug.Fail(null);
					break;
			}
		}

		/// <summary>
		/// Emits IL instructions that convert the top of evaluation stack to a specified type.
		/// </summary>
		/// <remarks>
		/// Emits a call to one of <see cref="PHP.Core.Convert"/> methods to do the conversion.
		/// The method result is left on the evaluation stack.
		/// </remarks>
		internal void EmitConversion(Expression/*!*/ expression, PhpTypeCode dst)
		{
			// expression is evaluable:
			if (expression.HasValue())
			{
				switch (dst)
				{
					case PhpTypeCode.String:
						il.Emit(OpCodes.Ldstr, PHP.Core.Convert.ObjectToString(expression.GetValue()));
						break;

					case PhpTypeCode.Boolean:
                        il.LdcI4(PHP.Core.Convert.ObjectToBoolean(expression.GetValue()) ? 1 : 0);
						break;

					case PhpTypeCode.Integer:
                        il.LdcI4(PHP.Core.Convert.ObjectToInteger(expression.GetValue()));
						break;

					case PhpTypeCode.Double:
                        il.Emit(OpCodes.Ldc_R8, PHP.Core.Convert.ObjectToDouble(expression.GetValue()));
						break;

					case PhpTypeCode.Object:
                        il.LoadLiteral(expression.GetValue());
						break;

					default:
						Debug.Fail("Conversion not implemented.");
						break;
				}
			}
			else
			{
				// emits the expression:
				PhpTypeCode src = expression.Emit(this);

				// emits no conversion if types are the same:
				if (src == dst) return;

				// emits boxing if needed (conversion methods takes object):
				EmitBoxing(src);

				switch (dst)
				{
					case PhpTypeCode.String:
						il.Emit(OpCodes.Call, Methods.Convert.ObjectToString);
						break;

					case PhpTypeCode.Boolean:
						il.Emit(OpCodes.Call, Methods.Convert.ObjectToBoolean);
						break;

					case PhpTypeCode.Integer:
						il.Emit(OpCodes.Call, Methods.Convert.ObjectToBoolean);
						break;

					case PhpTypeCode.Double:
						il.Emit(OpCodes.Call, Methods.Convert.ObjectToDouble);
						break;

					case PhpTypeCode.Object:
						// nop //
						break;

					default:
						Debug.Fail("Conversion is not implemented.");
						break;
				}
			}
		}

        /// <summary>
        /// Emits IL instructions to process the <B>echo</B> and <B>print</B> commands.
        /// </summary>
        /// <param name="expressions">List of expressions to be echoed. They will be evaluated first. The list cannot be null and it must contain at least one element.</param>
        public void EmitEcho(Expression[]/*!*/expressions)
        {
            Debug.Assert(expressions != null);
            Debug.Assert(expressions.Length > 0);

            // known types of resulting values
            PhpTypeCode[] types = new PhpTypeCode[expressions.Length];

            // construct the array with values
            // to preserve the proper order of evaluation and output
            il.LdcI4(expressions.Length);
            il.Emit(OpCodes.Newarr, typeof(object));

            for (int i = 0; i < expressions.Length; ++i)
            {
                // array[<i>] = <expressions[i]>;
                il.Emit(OpCodes.Dup);
                il.LdcI4(i);
                EmitBoxing(types[i] = expressions[i].Emit(this));
                il.Emit(OpCodes.Stelem_Ref);
            }

            // echo the values
            for (int i = 0; i < expressions.Length; ++i)
            {
                il.Emit(OpCodes.Dup);   // array
                il.LdcI4(i);            // <i>
                il.Emit(OpCodes.Ldelem_Ref);    // object array[<i>]
                il.EmitUnboxingForArg(types[i]);  // UnBox value type, if value-type was boxed here, prepared for method call argument
                // convert object to string or PhpBytes to hold the right type on the stack (valid IL)
                if (types[i] == PhpTypeCode.PhpBytes)   il.Emit(OpCodes.Castclass, Types.PhpBytes[0]);
                else if (types[i] == PhpTypeCode.String) il.Emit(OpCodes.Castclass, Types.String[0]);
                EmitLoadScriptContext();
                // CALL ScriptContext.Echo(<obj>, <ScriptContext>)
                EmitEchoStaticCall(types[i]);
            }

            il.Emit(OpCodes.Pop);// remove the array from the stack
        }

        internal void EmitName(string fullName, Expression nameExpr, bool createChain, PhpTypeCode dstType)
        {
            Debug.Assert(fullName != null ^ nameExpr != null);

            if (fullName != null)
            {
                il.Emit(OpCodes.Ldstr, fullName);
            }
            else
            {
                if (createChain) ChainBuilder.Create();
                EmitConversion(nameExpr, dstType);
                if (createChain) ChainBuilder.End();
            }
        }

        ///// <summary>
        ///// Emits IL instructions for calling the best overload of <see cref="PHP.Core.ScriptContext.Echo"/> method.
        ///// </summary>
        ///// <param name="typecode"><see cref="PHP.Core.PhpTypeCode"/> of the parameter.</param>
        ///// <remarks>GetUserEntryPoint parameters are expected on the evaluation stack. Nothing is left on the evaluation stack.</remarks>
        //private void EmitEchoCall(PhpTypeCode typecode)
        //{
        //    switch (typecode)
        //    {
        //        case PhpTypeCode.Object:
        //            il.Emit(OpCodes.Call, Methods.ScriptContext.Echo.Object);
        //            break;

        //        case PhpTypeCode.String:
        //            il.Emit(OpCodes.Call, Methods.ScriptContext.Echo.String);
        //            break;

        //        case PhpTypeCode.PhpBytes:
        //            il.Emit(OpCodes.Call, Methods.ScriptContext.Echo.PhpBytes);
        //            break;

        //        case PhpTypeCode.Integer:
        //            il.Emit(OpCodes.Call, Methods.ScriptContext.Echo.Int);
        //            break;

        //        case PhpTypeCode.LongInteger:
        //            il.Emit(OpCodes.Call, Methods.ScriptContext.Echo.LongInt);
        //            break;

        //        case PhpTypeCode.Double:
        //            il.Emit(OpCodes.Call, Methods.ScriptContext.Echo.Double);
        //            break;

        //        case PhpTypeCode.Boolean:
        //            il.Emit(OpCodes.Call, Methods.ScriptContext.Echo.Bool);
        //            break;

        //        default:
        //            il.Emit(OpCodes.Call, Methods.ScriptContext.Echo.Object);
        //            break;
        //    }
        //}

        /// <summary>
        /// Emits IL instructions for calling the best overload of <see cref="PHP.Core.ScriptContext.Echo"/> static method.
        /// </summary>
        /// <param name="typecode"><see cref="PHP.Core.PhpTypeCode"/> of the parameter.</param>
        /// <remarks>Nothing is left on the evaluation stack. Emitted method call expects two parameters on the evaluation stack: (value, ScriptContext).</remarks>
        private void EmitEchoStaticCall(PhpTypeCode typecode)
        {
            switch (typecode)
            {
                case PhpTypeCode.Object:
                    il.Emit(OpCodes.Call, Methods.ScriptContext.EchoStatic.Object);
                    break;

                case PhpTypeCode.String:
                    il.Emit(OpCodes.Call, Methods.ScriptContext.EchoStatic.String);
                    break;

                case PhpTypeCode.PhpBytes:
                    il.Emit(OpCodes.Call, Methods.ScriptContext.EchoStatic.PhpBytes);
                    break;

                case PhpTypeCode.Integer:
                    il.Emit(OpCodes.Call, Methods.ScriptContext.EchoStatic.Int);
                    break;

                case PhpTypeCode.LongInteger:
                    il.Emit(OpCodes.Call, Methods.ScriptContext.EchoStatic.LongInt);
                    break;

                case PhpTypeCode.Double:
                    il.Emit(OpCodes.Call, Methods.ScriptContext.EchoStatic.Double);
                    break;

                case PhpTypeCode.Boolean:
                    il.Emit(OpCodes.Call, Methods.ScriptContext.EchoStatic.Bool);
                    break;

                default:
                    il.Emit(OpCodes.Call, Methods.ScriptContext.EchoStatic.Object);
                    break;
            }
        }

		/// <summary>
		/// Emits IL instructions that sets the value to an <see cref="PHP.Core.PhpArray"/> item.
		/// </summary>
		/// <remarks>This method is used to set the item of an array having the index determined (not <B>null</B>).
		/// This method is called only in simple cases when operators chained are <b>not</b> involved.
		/// See short example of PHP code below.
		/// Expects that the reference to the object whose item should be set, the index and the value
		/// are loaded on the evaluation stack. Nothing is left on the evaluation stack.
		/// stack. 
		/// </remarks>
		/// <example>$a[3] = "foo"; $a[] = "foo";</example>
		/// <example>$x[y] =&amp; p; $x[] =&amp; p;</example>
		public void EmitSetItem(PhpTypeCode keyTypeCode, Expression index, bool reference)
		{
			codeGenerator.EmitSetItem(keyTypeCode, index, reference);
		}