Cosmos/source/Indy.IL2CPU.IL.X86/Castclass.cs

43 lines
No EOL
1.5 KiB
C#

using System;
using System.IO;
using Mono.Cecil;
using Mono.Cecil.Cil;
using CPU = Indy.IL2CPU.Assembler;
namespace Indy.IL2CPU.IL.X86 {
[OpCode(Code.Castclass, false)]
public class Castclass: Op {
private int mTypeId;
private string mThisLabel;
private string mNextOpLabel;
public Castclass(Mono.Cecil.Cil.Instruction aInstruction, MethodInformation aMethodInfo)
: base(aInstruction, aMethodInfo) {
TypeReference xType = aInstruction.Operand as TypeReference;
if(xType==null) {
throw new Exception("Unable to determine Type!");
}
TypeDefinition xTypeDef = Engine.GetDefinitionFromTypeReference(xType);
mTypeId = Engine.RegisterType(xTypeDef);
mThisLabel = GetInstructionLabel(aInstruction);
mNextOpLabel = GetInstructionLabel(aInstruction.Next);
}
public override void DoAssemble() {
// todo: throw an exception when the class does not support the cast!
string mReturnNullLabel = mThisLabel + "_ReturnNull";
Pop("eax");
Compare("eax", "0");
JumpIfZero(mReturnNullLabel);
Pushd("[eax]", "0" + mTypeId + "h");
MethodDefinition xMethodIsInstance = Engine.GetMethodDefinition(Engine.GetTypeDefinition("", "Indy.IL2CPU.VTablesImpl"), "IsInstance", "System.Int32", "System.Int32");
Engine.QueueMethod(xMethodIsInstance);
Call(new CPU.Label(xMethodIsInstance).Name);
Compare("eax", "0");
JumpIfEquals(mReturnNullLabel);
Pushd("eax");
JumpAlways(mNextOpLabel);
Label(mReturnNullLabel);
Pushd("0");
}
}
}