/// <summary>
/// Generate code for the entrypoint function
/// </summary>
public void GenerateCode(ASTNode node)
{
#region Early testing
//MethodInfo stringtoint = typeof(Convert).GetMethod("ToInt32", new[] { typeof(string) });
//ILGenerator generator = EntryPoint.GetILGenerator();
#region Testing built in functions
#region testing print
//generator.Emit(OpCodes.Ldstr, "Hello World");
//generator.Emit(OpCodes.Call, BuiltInFunctiontoBuilder["print"]);
#endregion
#region testing printi
//generator.Emit(OpCodes.Ldc_I4, 255);
//generator.Emit(OpCodes.Call,BuiltInFunctiontoBuilder["printi"]);
#endregion
#region testing printline
//generator.Emit(OpCodes.Ldstr, "Hello World");
//generator.Emit(OpCodes.Call, BuiltInFunctiontoBuilder["printline"]);
#endregion
#region testing flush
//generator.Emit(OpCodes.Call, BuiltInFunctiontoBuilder["flush"]);
#endregion
#region testing getchar
//generator.Emit(OpCodes.Call, BuiltInFunctiontoBuilder["getchar"]);
//generator.DeclareLocal(typeof (string));
//generator.Emit(OpCodes.Stloc_0);
//generator.Emit(OpCodes.Ldloc_0);
//generator.Emit(OpCodes.Call, typeof(Console).GetMethod("WriteLine", new Type[]{typeof(string)},null));
#endregion
#region testing getline
//generator.Emit(OpCodes.Call, BuiltInFunctiontoBuilder["getline"]);
//generator.Emit(OpCodes.Call, BuiltInFunctiontoBuilder["printline"]);
#endregion
#region testing ord
//generator.Emit(OpCodes.Call, BuiltInFunctiontoBuilder["getline"]);
//generator.Emit(OpCodes.Call, BuiltInFunctiontoBuilder["ord"]);
//generator.Emit(OpCodes.Call, BuiltInFunctiontoBuilder["printi"]);
#endregion
#region testing chr
//generator.Emit(OpCodes.Call, BuiltInFunctiontoBuilder["getline"]);
//generator.Emit(OpCodes.Call, stringtoint);
//generator.Emit(OpCodes.Call, BuiltInFunctiontoBuilder["chr"]);
//generator.Emit(OpCodes.Call, BuiltInFunctiontoBuilder["printline"]);
#endregion
#region testing size
//generator.Emit(OpCodes.Call, BuiltInFunctiontoBuilder["getline"]);
//generator.Emit(OpCodes.Call, BuiltInFunctiontoBuilder["size"]);
//generator.Emit(OpCodes.Call, BuiltInFunctiontoBuilder["printi"]);
#endregion
#region testing substring
//generator.Emit(OpCodes.Call, BuiltInFunctiontoBuilder["getline"]);
//generator.Emit(OpCodes.Ldc_I4_0);
//generator.Emit(OpCodes.Ldc_I4_2);
//generator.Emit(OpCodes.Call, BuiltInFunctiontoBuilder["substring"]);
//generator.Emit(OpCodes.Call, BuiltInFunctiontoBuilder["printline"]);
#endregion
#region testing concat
//generator.Emit(OpCodes.Call, BuiltInFunctiontoBuilder["getline"]);
//generator.Emit(OpCodes.Call, BuiltInFunctiontoBuilder["getline"]);
//generator.Emit(OpCodes.Call, BuiltInFunctiontoBuilder["concat"]);
//generator.Emit(OpCodes.Call, BuiltInFunctiontoBuilder["printline"]);
#endregion
#region testing not
//generator.Emit(OpCodes.Ldc_I4_0);
//generator.Emit(OpCodes.Call, BuiltInFunctiontoBuilder["not"]);
//generator.Emit(OpCodes.Call, BuiltInFunctiontoBuilder["printi"]);
//generator.Emit(OpCodes.Ldc_I4_2);
//generator.Emit(OpCodes.Call, BuiltInFunctiontoBuilder["not"]);
//generator.Emit(OpCodes.Call, BuiltInFunctiontoBuilder["printi"]);
#endregion
#region testing exit
//generator.Emit(OpCodes.Ldc_I4_0);
//generator.Emit(OpCodes.Call, BuiltInFunctiontoBuilder["exit"]);
#endregion
#endregion
#region Testing Type and Array Creation
//TypeBuilder builder = ILModule.DefineType("Person");
//FieldBuilder fieldBuilder0 = builder.DefineField("Name", typeof(string), FieldAttributes.Public);
//FieldBuilder fieldBuilder1 = builder.DefineField("Age", typeof(int), FieldAttributes.Public);
//ConstructorBuilder ctor = builder.DefineConstructor(MethodAttributes.Public, CallingConventions.Standard,
// new Type[] { typeof(string), typeof(int) });
//ILGenerator ctorIlgen = ctor.GetILGenerator();
//ctorIlgen.Emit(OpCodes.Ldarg_0);
//ctorIlgen.Emit(OpCodes.Ldarg_1);
//ctorIlgen.Emit(OpCodes.Stfld, fieldBuilder0);
//ctorIlgen.Emit(OpCodes.Ldarg_0);
//ctorIlgen.Emit(OpCodes.Ldarg_2);
//ctorIlgen.Emit(OpCodes.Stfld, fieldBuilder1);
//ctorIlgen.Emit(OpCodes.Ret);
//builder.CreateType();
//LocalBuilder person = IlGenerator.DeclareLocal(builder);
//LocalBuilder arrayofperson = IlGenerator.DeclareLocal(builder.MakeArrayType());
//IlGenerator.Emit(OpCodes.Ldstr, "Frank");
//IlGenerator.Emit(OpCodes.Ldc_I4, 22);
//IlGenerator.Emit(OpCodes.Newobj, ctor);
//IlGenerator.Emit(OpCodes.Stloc_0);
//IlGenerator.Emit(OpCodes.Ldloc_0);
//IlGenerator.Emit(OpCodes.Ldfld, fieldBuilder0);
//IlGenerator.Emit(OpCodes.Call, BuiltInFunctiontoBuilder["printline"]);
//IlGenerator.Emit(OpCodes.Ldc_I4_1);
//IlGenerator.Emit(OpCodes.Newarr, builder);
//IlGenerator.Emit(OpCodes.Stloc_1);
//IlGenerator.Emit(OpCodes.Ldloc_1);
//IlGenerator.Emit(OpCodes.Ldc_I4_0);
//IlGenerator.Emit(OpCodes.Ldloc_0);
//IlGenerator.Emit(OpCodes.Stelem, builder);
//IlGenerator.Emit(OpCodes.Ldloc_1);
//IlGenerator.Emit(OpCodes.Ldc_I4_0);
//IlGenerator.Emit(OpCodes.Ldelem, builder);
//IlGenerator.Emit(OpCodes.Ldfld, fieldBuilder0);
//IlGenerator.Emit(OpCodes.Call, BuiltInFunctiontoBuilder["printline"]);
#endregion
#region Testing Field Acces an Store
#endregion
#endregion
//All the needed resources to handle exceptions
Type exception = typeof(Exception);
MethodInfo geterroroutput = typeof(Console).GetProperty("Error").GetGetMethod();
MethodInfo writeline = typeof(TextWriter).GetMethod("WriteLine", new [] { typeof(string), typeof(object) });
MethodInfo readline = typeof(Console).GetMethod("ReadLine");
MethodInfo gettype = typeof(Exception).GetMethod("GetType");
MethodInfo exit = typeof(Environment).GetMethod("Exit", new [] { typeof(int) });
LocalBuilder exceptioninstance = IlGenerator.DeclareLocal(exception);
//To enclose all the generated code in an enormous try
IlGenerator.BeginExceptionBlock();
node.GenerateCode(this);
// To handle exceptions thrown by IL execution code
IlGenerator.BeginCatchBlock(exception);
//the launched exception will be in the top of the stack so we must store it
IlGenerator.Emit(OpCodes.Stloc, exceptioninstance);
//Getting the std error output
IlGenerator.Emit(OpCodes.Call, geterroroutput);
//Get the parameters to report to the error output
IlGenerator.Emit(OpCodes.Ldstr, "\nException of type '{0}' was thrown");
IlGenerator.Emit(OpCodes.Ldloc, exceptioninstance);
IlGenerator.Emit(OpCodes.Call, gettype);
//Calling the writeline method of the error output
IlGenerator.Emit(OpCodes.Call, writeline);
// Set a readline son the user can see the exception thrown, comment this line if there is any problem
//IlGenerator.EmitCall(OpCodes.Call, readline, null);
//Exiting with code 1
IlGenerator.Emit(OpCodes.Ldc_I4_1);
IlGenerator.Emit(OpCodes.Call, exit);
//Exception management is done
IlGenerator.EndExceptionBlock();
// No exception was thrown finish with exit code 0
IlGenerator.Emit(OpCodes.Ldc_I4_0);
IlGenerator.Emit(OpCodes.Call, exit);
// Don't forget the ret
IlGenerator.Emit(OpCodes.Ret);
Program.CreateType();
}