C# PHP.EmitBoxing方法代码示例

        /// <summary>
        /// Emit the target of instance method invocation.
        /// </summary>
        /// <param name="cg"></param>
        /// <param name="targetExpr"></param>
        private static void EmitMethodTargetExpr(PHP.Core.CodeGenerator/*!*/cg, Expression/*!*/targetExpr)
        {
            // start a new operators chain (as the rest of chain is read)
            cg.ChainBuilder.Create();
            cg.ChainBuilder.Begin();
            cg.ChainBuilder.Lengthen(); // for hop over ->

            // prepare for operator invocation
            cg.EmitBoxing(targetExpr.Emit(cg));
            cg.ChainBuilder.End();
        }

        /// <summary>
        /// Create and call <see cref="CallSite"/> for getting property.
        /// </summary>
        /// <param name="cg"><see cref="CodeGenerator"/>.</param>
        /// <param name="wantRef">Wheter <see cref="PhpReference"/> is expected as the result.</param>
        /// <param name="targetExpr">The expression representing the target (object).</param>
        /// <param name="targetObjectPlace">The place representing the target (<see cref="DObject"/>) iff <paramref name="targetExpr"/> is not provided.</param>
        /// <param name="targetPlace">The place representing the target (object) iff <paramref name="targetExpr"/> and <paramref name="targetObjectPlace"/> are not provided.</param>
        /// <param name="targetType">Type of target iff we are getting property statically.</param>
        /// <param name="fieldName">The name of the field. Can be null if the name is not known at compile time (indirect).</param>
        /// <param name="fieldNameExpr">The expression used to get field name in run time (iff <paramref name="fieldName"/> is <c>null</c>.</param>
        /// <param name="issetSemantics">Wheter we are only checking if the property exists. If true, no warnings are thrown during run time.</param>
        /// <returns>Type code of the value that is pushed onto the top of the evaluation stack.</returns>
        public PhpTypeCode EmitGetProperty(
            PHP.Core.CodeGenerator/*!*/cg, bool wantRef,
            Expression targetExpr, IPlace targetObjectPlace, IPlace targetPlace, DType targetType,
            string fieldName, Expression fieldNameExpr,
            bool issetSemantics)
        {
            Debug.Assert(fieldName != null ^ fieldNameExpr != null);
            Debug.Assert(targetExpr != null || targetObjectPlace != null || targetPlace != null || targetType != null);
            
            //
            bool staticCall = (targetExpr == null && targetObjectPlace == null && targetPlace == null); // we are going to access static property
            bool fieldNameIsKnown = (fieldName != null);
            bool classContextIsKnown = (this.classContextPlace != null);

            //
            // binder flags:
            //
            Type returnType = wantRef ? Types.PhpReference[0] : Types.Object[0];
            
            //
            // define the call site:
            //

            //
            List<Type> additionalArgs = new List<Type>();
            if (!classContextIsKnown) additionalArgs.Add(Types.DTypeDesc[0]);
            if (!fieldNameIsKnown) additionalArgs.Add(Types.String[0]);

            var delegateTypeArgs = GetPropertyDelegateTypeArgs(
                staticCall ? Types.DTypeDesc[0] : ((targetObjectPlace != null) ? Types.DObject[0] : Types.Object[0]),   // DTypeDesc of static field's declaring type || DObject if field called on DObject known at compile time || otherwise object
                additionalArgs.ToArray(),
                returnType);

            var delegateType = /*System.Linq.Expressions.Expression.*/delegateBuilder.GetDelegateType(delegateTypeArgs, callSitesCount);    // (J) do not create dynamic delegates in dynamic modules, so they can be referenced from non-transient assemblies

            //
            var field = DefineCallSite(cg.IL, string.Format("get{0}_{1}", wantRef ? "ref" : string.Empty, fieldName ?? "$"), delegateType, (il) =>
            {
                // <LOAD> Binder.{GetProperty|GetStaticProperty}( fieldName, classContext, issetSemantics, <returnType> )
                if (fieldName != null) il.Emit(OpCodes.Ldstr, fieldName); else il.Emit(OpCodes.Ldnull);
                if (this.classContextPlace != null) this.classContextPlace.EmitLoad(il); else il.Emit(OpCodes.Ldsfld, Fields.UnknownTypeDesc.Singleton);
                il.LoadBool(issetSemantics);

                il.Emit(OpCodes.Ldtoken, returnType);
                il.Emit(OpCodes.Call, Methods.GetTypeFromHandle);

                il.Emit(OpCodes.Call, staticCall ? Methods.Binder.StaticGetProperty : Methods.Binder.GetProperty);
            });

            //
            // call the CallSite:
            //

            // <field>.Target( <field>, <targetExpr|targetType>, (classContext)?, <methodNameExpr>? ):

            cg.IL.Emit(OpCodes.Ldsfld, field);
            cg.IL.Emit(OpCodes.Ldfld, field.FieldType.GetField("Target"));
            cg.IL.Emit(OpCodes.Ldsfld, field);
            if (staticCall) targetType.EmitLoadTypeDesc(cg, ResolveTypeFlags.UseAutoload | ResolveTypeFlags.ThrowErrors);
            else if (targetExpr != null)
            {
                cg.ChainBuilder.Lengthen(); // for hop over ->
                cg.EmitBoxing(targetExpr.Emit(cg)); // prepare for operator invocation
            }
            else if (targetObjectPlace != null) targetObjectPlace.EmitLoad(cg.IL);
            else if (targetPlace != null) targetPlace.EmitLoad(cg.IL);
            else Debug.Fail();
            if (!classContextIsKnown) cg.EmitLoadClassContext();
            if (!fieldNameIsKnown) cg.EmitName(fieldName/*null*/, fieldNameExpr, true, PhpTypeCode.String);

            cg.MarkTransientSequencePoint();
            cg.IL.Emit(OpCodes.Callvirt, delegateType.GetMethod("Invoke"));

            cg.MarkTransientSequencePoint();
            
            //
            return PhpTypeCodeEnum.FromType(returnType);
        }

 /// <summary>
 /// Helper method, loads parameters onto evaluation stack.
 /// </summary>
 private static void EmitMethodCallParameters(PHP.Core.CodeGenerator/*!*/cg, CallSignature callSignature)
 {
     foreach (var t in callSignature.GenericParams) t.EmitLoadTypeDesc(cg, ResolveTypeFlags.UseAutoload | ResolveTypeFlags.ThrowErrors); // load DTypeDescs on the stack
     foreach (var p in callSignature.Parameters) { cg.EmitBoxing(p.Emit(cg)); }  // load boxed args on the stack            
 }