示例#1
0
        protected override void EmitMarshalFieldNativeToManaged()
        {
            ILEmitter    emitter    = _ilCodeStreams.Emitter;
            ILCodeStream codeStream = _ilCodeStreams.UnmarshallingCodestream;

            // It generates the following IL:
            //  ManagedArg.s = new ElementType[Length];
            //
            //    for (uint index = 0u; index < Length; index += 1u)
            //    {
            //        ManagedArg.s[index] = NativeArg.s[index];
            //    }
            //

            ILCodeLabel lRangeCheck = emitter.NewCodeLabel();
            ILCodeLabel lLoopHeader = emitter.NewCodeLabel();

            Debug.Assert(ManagedType is ArrayType);

            var nativeArrayType = NativeType as InlineArrayType;

            Debug.Assert(nativeArrayType != null);

            var managedElementType = ((ArrayType)ManagedType).ElementType;

            ILLocalVariable vLength = emitter.NewLocal(Context.GetWellKnownType(WellKnownType.Int32));

            codeStream.EmitLdArg(1);
            // load the length
            EmitElementCount(codeStream, MarshalDirection.Reverse);
            codeStream.EmitStLoc(vLength);

            codeStream.EmitLdLoc(vLength);
            codeStream.Emit(ILOpcode.newarr, emitter.NewToken(managedElementType));
            codeStream.Emit(ILOpcode.stfld, emitter.NewToken(_managedField));


            var vIndex = emitter.NewLocal(Context.GetWellKnownType(WellKnownType.Int32));

            // index = 0
            codeStream.EmitLdc(0);
            codeStream.EmitStLoc(vIndex);
            codeStream.Emit(ILOpcode.br, lRangeCheck);

            codeStream.EmitLabel(lLoopHeader);

            // load managed type
            codeStream.EmitLdArg(1);
            codeStream.Emit(ILOpcode.ldfld, emitter.NewToken(_managedField));

            codeStream.EmitLdLoc(vIndex);

            // load native type
            codeStream.EmitLdArg(0);
            codeStream.Emit(ILOpcode.ldflda, emitter.NewToken(_nativeField));
            codeStream.EmitLdLoc(vIndex);

            codeStream.Emit(ILOpcode.call, emitter.NewToken(
                                nativeArrayType.GetInlineArrayMethod(InlineArrayMethodKind.Getter)));

            // generate marshalling IL for the element
            GetElementMarshaller(MarshalDirection.Reverse)
            .EmitMarshallingIL(new PInvokeILCodeStreams(_ilCodeStreams.Emitter, codeStream));

            codeStream.EmitStElem(managedElementType);

            codeStream.EmitLdLoc(vIndex);
            codeStream.EmitLdc(1);
            codeStream.Emit(ILOpcode.add);
            codeStream.EmitStLoc(vIndex);

            codeStream.EmitLabel(lRangeCheck);

            codeStream.EmitLdLoc(vIndex);
            codeStream.EmitLdLoc(vLength);
            codeStream.Emit(ILOpcode.blt, lLoopHeader);
        }