private ArrayList refReferences = new ArrayList(3); // GENERICS: <LocalBuilder>
#endregion
#region Call Switch Emitter
/// <summary>
/// Emits calls to specified overloads and a switch statement which calls appropriate overload
/// according to the current value of <see cref="PhpStack.ArgCount"/> field of the current stack.
/// </summary>
/// <param name="thisRef">Reference to self.</param>
/// <param name="script_context">Current script context.</param>
/// <param name="rtVariables">
/// Place where a run-time variables table can be loaded from.
/// </param>
/// <param name="namingContext">Naming context load-from place.</param>
/// <param name="classContext">Class context load.</param>
/// <param name="overloads">The overload list.</param>
/// <remarks>
/// Example: given overloads (2,5,7,9+), i.e. there are four overloads having 2, 5, 7 and 9 PHP parameters,
/// respectively, and the last overload is marked as vararg,
/// the method emits the following code:
/// <code>
/// switch(ArgCount - 2) // 2 = minimum { arg count of overload }
/// {
/// case 0: return call #2; // call to the 2nd overload with appropriate arg. and return value handling
/// case 1: goto case error;
/// case 2: goto case error;
/// case 3: return call #5;
/// case 4: goto case error;
/// case 5: return call #7;
/// case 6: goto case error;
///
/// #if vararg
/// case 7: goto default;
/// default: return call #vararg (9 mandatory args,optional args);break;
/// #elif
/// case 7: return call #9;
/// default: goto case error;
/// #endif
///
/// case error: PhpException.InvalidArgumentCount(null, functionName); break;
/// }
/// </code>
/// </remarks>
public void EmitCallSwitch(IPlace /*!*/ thisRef, IPlace /*!*/ script_context, IPlace /*!*/ rtVariables, IPlace /*!*/ namingContext, IPlace /*!*/ classContext, List <PhpLibraryFunction.Overload> /*!!*/ overloads)
{
DebugHelper.AssertAllNonNull(overloads);
int last = overloads.Count - 1;
int min = overloads[0].ParamCount;
int max = overloads[last].ParamCount;
var flags = overloads[last].Flags;
// if function is not supported, just throw the warning:
if ((flags & PhpLibraryFunction.OverloadFlags.NotSupported) != 0)
{
// stack.RemoveFrame();
if (stack != null)
{
stack.EmitLoad(il);
il.Emit(OpCodes.Call, Methods.PhpStack.RemoveFrame);
}
// PhpException.FunctionNotSupported( <FullName> );
il.Emit(OpCodes.Ldstr, FunctionName.Value);
il.Emit(OpCodes.Call, Methods.PhpException.FunctionNotSupported_String);
if (debug)
{
il.Emit(OpCodes.Nop);
}
// load methods default value
il.EmitBoxing(OverloadsBuilder.EmitLoadDefault(il, overloads[last].Method));
return;
}
bool is_vararg = (flags & PhpLibraryFunction.OverloadFlags.IsVararg) != 0;
if ((flags & PhpLibraryFunction.OverloadFlags.NeedsScriptContext) == 0)
{
script_context = null;
}
if ((flags & PhpLibraryFunction.OverloadFlags.NeedsThisReference) == 0)
{
thisRef = null;
}
if ((flags & PhpLibraryFunction.OverloadFlags.NeedsVariables) == 0)
{
rtVariables = null;
}
if ((flags & PhpLibraryFunction.OverloadFlags.NeedsNamingContext) == 0)
{
namingContext = null;
}
if ((flags & (PhpLibraryFunction.OverloadFlags.NeedsClassContext | PhpLibraryFunction.OverloadFlags.NeedsLateStaticBind)) == 0)
{
classContext = null;
}
Label end_label = il.DefineLabel();
Label error_label = il.DefineLabel();
Label[] cases = new Label[max - min + 1];
MethodInfo method;
// fills cases with "goto case error":
for (int i = 0; i < cases.Length; i++)
{
cases[i] = error_label;
}
// define labels for valid cases:
for (int i = 0; i < overloads.Count; i++)
{
int count = overloads[i].ParamCount;
cases[count - min] = il.DefineLabel();
}
// LOAD(stack.ArgCount - min);
stack.EmitLoad(il);
il.Emit(OpCodes.Ldfld, Fields.PhpStack_ArgCount);
il.LdcI4(min);
il.Emit(OpCodes.Sub);
// SWITCH(tmp)
il.Emit(OpCodes.Switch, cases);
// CASE >=N or <0 (underflows);
// if the last overload is vararg:
if (is_vararg)
{
LocalBuilder opt_arg_count_local = il.DeclareLocal(typeof(int));
// CASE N:
il.MarkLabel(cases[cases.Length - 1]);
// opt_arg_count = stack.ArgCount - max;
stack.EmitLoad(il);
il.Emit(OpCodes.Ldfld, Fields.PhpStack_ArgCount);
il.LdcI4(max);
il.Emit(OpCodes.Sub);
il.Stloc(opt_arg_count_local);
// IF(tmp<0) GOTO CASE error;
il.Ldloc(opt_arg_count_local);
il.Emit(OpCodes.Ldc_I4_0);
il.Emit(OpCodes.Blt, error_label);
// emits argument loading, stack frame removal, method call, return value conversion:
method = overloads[last].Method;
Type return_type = EmitOverloadCall(method, overloads[last].RealParameters, max, script_context,
rtVariables, namingContext, classContext, new Place(opt_arg_count_local), thisRef, false);
// loads boxed return value:
if (return_type != Types.Void)
{
//il.LoadBoxed(return_value);
if (return_type.IsValueType)
{
il.Emit(OpCodes.Box, return_type);
}
}
else
{
il.Emit(OpCodes.Ldnull);
}
// RETURN;
il.Emit(OpCodes.Ret); //bug in Reflector: il.Emit(OpCodes.Br,end_label);
}
else
{
// GOTO CASE error;
il.Emit(OpCodes.Br, error_label);
}
// emits all valid cases which are not vararg:
int j = 0;
for (int i = min; i <= max - (is_vararg ? 1 : 0); i++)
{
if (overloads[j].ParamCount == i)
{
// CASE <i>;
il.MarkLabel(cases[i - min]);
// emits argument loading, stack frame removal, method call, return value conversion:
method = overloads[j].Method;
Type return_type = EmitOverloadCall(method, overloads[j].RealParameters, i, script_context, rtVariables, namingContext, classContext, null, thisRef, false);
// loads boxed return value:
if (return_type != Types.Void)
{
//il.LoadBoxed(return_value);
if (return_type.IsValueType)
{
il.Emit(OpCodes.Box, return_type);
}
}
else
{
il.Emit(OpCodes.Ldnull);
}
// RETURN;
il.Emit(OpCodes.Ret); //bug in Reflector: il.Emit(OpCodes.Br,end_label);
j++;
}
}
Debug.Assert(j + (is_vararg ? 1 : 0) == overloads.Count);
// ERROR:
il.MarkLabel(error_label);
il.Emit(OpCodes.Ldnull);
il.Emit(OpCodes.Ldstr, this.functionName.ToString());
il.Emit(OpCodes.Call, Methods.PhpException.InvalidArgumentCount);
if (debug)
{
il.Emit(OpCodes.Nop);
}
// RETURN null:
il.Emit(OpCodes.Ldnull);
il.MarkLabel(end_label);
}
