C# ILEmitter.Ldloc方法代码示例

		/// <summary>
		/// Emits code that loads current <see cref="PHP.Core.ScriptContext"/> by calling
		/// <see cref="PHP.Core.ScriptContext.CurrentContext"/> and remembers it in a local.
		/// </summary>
		/// <param name="il"></param>
		public void EmitLoad(ILEmitter il)
		{
			if (localBuilder == null)
			{
				localBuilder = il.DeclareLocal(typeof(ScriptContext));
				il.EmitCall(OpCodes.Call, Methods.ScriptContext.GetCurrentContext, null);
				il.Stloc(localBuilder);
			}
			il.Ldloc(localBuilder);
		}

		public static void EmitArgFullPostCall(ILEmitter/*!*/ il, IPlace/*!*/ stack, LocalBuilder locArgsCount)
		{
			// args-aware:
			if (locArgsCount != null)
			{
				// CALL stack.RemoveArgsAwareFrame(count);
				stack.EmitLoad(il);
				il.Ldloc(locArgsCount);
				il.Emit(OpCodes.Call, Methods.PhpStack.RemoveArgsAwareFrame);
			}
		}

		/// <summary>
		/// Converts object to CLR type
		/// </summary>
		private static bool EmitConvertObjectToClr(ILEmitter il, PhpTypeCode typeCode, Type formalType, LocalBuilder strictnessLocal)
		{
			MethodInfo convert_method = null;
			switch (Type.GetTypeCode(formalType))
			{
				case TypeCode.Boolean: if (typeCode != PhpTypeCode.Boolean)
						convert_method = Methods.ConvertToClr.TryObjectToBoolean; break;
				case TypeCode.Int32: if (typeCode != PhpTypeCode.Integer)
						convert_method = Methods.ConvertToClr.TryObjectToInt32; break;
				case TypeCode.Int64: if (typeCode != PhpTypeCode.LongInteger)
						convert_method = Methods.ConvertToClr.TryObjectToInt64; break;
				case TypeCode.Double: if (typeCode != PhpTypeCode.Double)
						convert_method = Methods.ConvertToClr.TryObjectToDouble; break;
				case TypeCode.String: if (typeCode != PhpTypeCode.String)
						convert_method = Methods.ConvertToClr.TryObjectToString; break;

				case TypeCode.SByte: convert_method = Methods.ConvertToClr.TryObjectToInt8; break;
				case TypeCode.Int16: convert_method = Methods.ConvertToClr.TryObjectToInt16; break;
				case TypeCode.Byte: convert_method = Methods.ConvertToClr.TryObjectToUInt8; break;
				case TypeCode.UInt16: convert_method = Methods.ConvertToClr.TryObjectToUInt16; break;
				case TypeCode.UInt32: convert_method = Methods.ConvertToClr.TryObjectToUInt32; break;
				case TypeCode.UInt64: convert_method = Methods.ConvertToClr.TryObjectToUInt64; break;
				case TypeCode.Single: convert_method = Methods.ConvertToClr.TryObjectToSingle; break;
				case TypeCode.Decimal: convert_method = Methods.ConvertToClr.TryObjectToDecimal; break;
				case TypeCode.Char: convert_method = Methods.ConvertToClr.TryObjectToChar; break;
				case TypeCode.DateTime: convert_method = Methods.ConvertToClr.TryObjectToDateTime; break;
				case TypeCode.DBNull: convert_method = Methods.ConvertToClr.TryObjectToDBNull; break;

				case TypeCode.Object:
					{
						if (formalType.IsValueType)
						{
							if (formalType.IsGenericType && NullableType == formalType.GetGenericTypeDefinition())
							{
								// This is an ugly corner case (using generic TryObjectToStruct wouldn't work, because
								// for nullables .IsValueType returns true, but it doesn't match "T : struct" constraint)!
								// We have to try converting object to Nullable<T> first and then to T
								// (which requires a new call to 'EmitConvertObjectToClr') 
								Type nullableArg = formalType.GetGenericArguments()[0];
								Type nullableType = NullableType.MakeGenericType(nullableArg);
								
								LocalBuilder tmpVar = il.DeclareLocal(typeof(object));
								
								// This succeeds only for exact match
								il.Emit(OpCodes.Call, Methods.ConvertToClr.UnwrapNullable);
								il.Emit(OpCodes.Dup);
								il.Stloc(tmpVar);

								// <stack_0> = tmpVar = UnwrapNullable(...)
								// if (<stack_0> != null) 
								Label lblNull = il.DefineLabel(), lblDone = il.DefineLabel();
								il.Emit(OpCodes.Ldnull);
								il.Emit(OpCodes.Beq, lblNull);
								// {

								// Convert tmpVar to T and wrap it into Nullable<T>
								il.Ldloc(tmpVar);
								bool ret = EmitConvertObjectToClr(il, typeCode, nullableArg, strictnessLocal);
								// TODO: use reflection cache?
								il.Emit(OpCodes.Newobj, nullableType.GetConstructors()[0]);
								il.Emit(OpCodes.Br, lblDone);
								
								// } else /* == null */ {
								il.MarkLabel(lblNull);

								// return (T?)null;
								LocalBuilder tmpNull = il.DeclareLocal(nullableType);
								il.Ldloca(tmpNull);
								il.Emit(OpCodes.Initobj, nullableType);
								il.Ldloc(tmpNull);
								// }
								
								il.MarkLabel(lblDone);
								return ret;
							}
							else
								convert_method = Methods.ConvertToClr.TryObjectToStruct.MakeGenericMethod(formalType);
						}
						else
						{
							if (formalType.IsArray)
								convert_method = Methods.ConvertToClr.TryObjectToArray.MakeGenericMethod(formalType.GetElementType());
							else if (typeof(Delegate).IsAssignableFrom(formalType))
								convert_method = Methods.ConvertToClr.TryObjectToDelegate.MakeGenericMethod(formalType);
							else
								convert_method = Methods.ConvertToClr.TryObjectToClass.MakeGenericMethod(formalType);
						}
						break;
					}

				default:
					Debug.Fail();
					return true;
			}

			if (convert_method != null)
			{
//.........这里部分代码省略.........

		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 the value from this storage place.
		/// </summary>
		/// <param name="il">The <see cref="ILEmitter"/> to emit the code to.</param>
		public void EmitLoad(ILEmitter il)
		{
			switch (holder)
			{
				case PlaceHolder.Local: il.Ldloc(index); break;
				case PlaceHolder.Argument: il.Ldarg(index); break;
				case PlaceHolder.None: il.LdcI4(index); break;
			}
		}