/// <summary>
/// Emits assignment.
/// </summary>
/// <remarks>
/// Pattern: a op= b
///
/// PREPARE a (prepared)
/// LOAD a (prepared,a)
/// LOAD b (prepared,a,b)
/// OP (prepared,result)
/// *DUP (prepared,result,result)
/// *STORE tmp (prepared,result) must be this stack here!
/// STORE a ()
/// *LOAD tmp (result)
///
/// * only if the resulting value needs to be propagated to the right
///
/// Note: There is a possible improvement: some store operations (SetVariable) may return the value set
/// which would replace DUP and second temp op.
/// </remarks>
internal override PhpTypeCode Emit(CodeGenerator /*!*/ codeGenerator)
{
Debug.Assert(access == AccessType.Read || access == AccessType.None || access == AccessType.ReadRef ||
access == AccessType.ReadUnknown);
Statistics.AST.AddNode("Assign.Value");
ILEmitter il = codeGenerator.IL;
AccessType old_selector = codeGenerator.AccessSelector;
codeGenerator.ChainBuilder.Create();
PhpTypeCode result;
if (operation == Operations.AssignValue)
{
//
// Access Type = ReadRef/ReadUnknown
// ---------------------------------
//
// f(&$x) { }
//
// f($a = $b);
// f($a = $b =& $c);
//
// Destination variable $a is prepared for reference write.
// A new reference is created and its value set to a deep copy of the result of RHS ($b, $b =& $c).
// RHS has Read access => it has been dereferenced.
//
// PREPARE a:
codeGenerator.AccessSelector = AccessType.Write;
lvalue.Emit(codeGenerator);
codeGenerator.AccessSelector = AccessType.None;
PhpTypeCode src_type_code = EmitSourceValRead(codeGenerator);
// RHS should have Read access => should be dereferenced
Debug.Assert(src_type_code != PhpTypeCode.PhpReference);
// LOAD BOX b
codeGenerator.EmitBoxing(src_type_code);
// makes a copy if necessary:
if (PhpTypeCodeEnum.IsDeeplyCopied(src_type_code))
{
codeGenerator.EmitVariableCopy(CopyReason.Assigned, rvalue);
}
}
else
{
// PREPARE a:
codeGenerator.AccessSelector = AccessType.Write;
lvalue.Emit(codeGenerator);
codeGenerator.AccessSelector = AccessType.None;
// LOAD b,a (rvalue must be processed first, than +-*/ with lvalue, since lvalu can be changed by rvalue expression)
//must be the second operand// EmitDestVarRead(codeGenerator);
PhpTypeCode right_type = EmitSourceValRead(codeGenerator);
var rvalue_tmp = codeGenerator.IL.GetTemporaryLocal(PhpTypeCodeEnum.ToType(right_type), false);
codeGenerator.IL.Emit(OpCodes.Stloc, rvalue_tmp);
EmitDestVarRead(codeGenerator);
codeGenerator.IL.Emit(OpCodes.Ldloc, rvalue_tmp);
codeGenerator.IL.ReturnTemporaryLocal(rvalue_tmp);
switch (operation)
{
#region Arithmetic
case Operations.AssignAdd:
{
switch (right_type)
{
case PhpTypeCode.Integer:
result = codeGenerator.EmitMethodCall(Methods.Operators.Add.Object_Int32);
break;
case PhpTypeCode.Double:
result = codeGenerator.EmitMethodCall(Methods.Operators.Add.Object_Double);
break;
default:
codeGenerator.EmitBoxing(right_type);
result = codeGenerator.EmitMethodCall(Methods.Operators.Add.Object_Object);
break;
}
break;
}
case Operations.AssignSub:
{
switch (right_type)
{
case PhpTypeCode.Integer:
result = codeGenerator.EmitMethodCall(Methods.Operators.Subtract.Object_Int);
break;
default:
codeGenerator.EmitBoxing(right_type);
result = codeGenerator.EmitMethodCall(Methods.Operators.Subtract.Object_Object);
break;
}
break;
}
case Operations.AssignDiv:
{
switch (right_type)
{
case PhpTypeCode.Integer:
result = codeGenerator.EmitMethodCall(Methods.Operators.Divide.Object_Int32);
break;
case PhpTypeCode.Double:
result = codeGenerator.EmitMethodCall(Methods.Operators.Divide.Object_Double);
break;
default:
codeGenerator.EmitBoxing(right_type);
result = codeGenerator.EmitMethodCall(Methods.Operators.Divide.Object_Object);
break;
}
break;
}
case Operations.AssignMul:
{
switch (right_type)
{
case PhpTypeCode.Integer:
result = codeGenerator.EmitMethodCall(Methods.Operators.Multiply.Object_Int32);
break;
case PhpTypeCode.Double:
result = codeGenerator.EmitMethodCall(Methods.Operators.Multiply.Object_Double);
break;
default:
codeGenerator.EmitBoxing(right_type);
result = codeGenerator.EmitMethodCall(Methods.Operators.Multiply.Object_Object);
break;
}
break;
}
case Operations.AssignMod:
if (right_type == PhpTypeCode.Integer)
{
result = codeGenerator.EmitMethodCall(Methods.Operators.Remainder.Object_Int32);
}
else
{
codeGenerator.EmitBoxing(right_type);
result = codeGenerator.EmitMethodCall(Methods.Operators.Remainder.Object_Object);
}
break;
#endregion
#region Bitwise
case Operations.AssignAnd:
codeGenerator.EmitBoxing(right_type);
il.Emit(OpCodes.Ldc_I4, (int)Operators.BitOp.And);
result = codeGenerator.EmitMethodCall(Methods.Operators.BitOperation);
break;
case Operations.AssignOr:
codeGenerator.EmitBoxing(right_type);
il.Emit(OpCodes.Ldc_I4, (int)Operators.BitOp.Or);
result = codeGenerator.EmitMethodCall(Methods.Operators.BitOperation);
break;
case Operations.AssignXor:
codeGenerator.EmitBoxing(right_type);
il.Emit(OpCodes.Ldc_I4, (int)Operators.BitOp.Xor);
result = codeGenerator.EmitMethodCall(Methods.Operators.BitOperation);
break;
case Operations.AssignShiftLeft:
codeGenerator.EmitBoxing(right_type);
result = codeGenerator.EmitMethodCall(Methods.Operators.ShiftLeft);
break;
case Operations.AssignShiftRight:
codeGenerator.EmitBoxing(right_type);
result = codeGenerator.EmitMethodCall(Methods.Operators.ShiftRight);
break;
#endregion
#region String
case Operations.AssignAppend:
{
if (right_type == PhpTypeCode.String)
{
result = codeGenerator.EmitMethodCall(Methods.Operators.Append.Object_String);
}
else if (right_type == PhpTypeCode.PhpBytes)
{
result = codeGenerator.EmitMethodCall(Methods.PhpBytes.Append_Object_PhpBytes);
}
else
{
codeGenerator.EmitBoxing(right_type);
result = codeGenerator.EmitMethodCall(Methods.Operators.Append.Object_Object);
}
break;
}
case Operations.AssignPrepend:
{
if (right_type == PhpTypeCode.String)
{
result = codeGenerator.EmitMethodCall(Methods.Operators.Prepend.Object_String);
}
else
{
codeGenerator.EmitBoxing(right_type);
result = codeGenerator.EmitMethodCall(Methods.Operators.Prepend.Object_Object);
}
break;
}
#endregion
default:
Debug.Fail();
throw null;
}
il.EmitBoxing(result);
}
switch (access)
{
case AccessType.Read:
{
// DUP
il.Emit(OpCodes.Dup);
// STORE tmp
il.Stloc(il.GetAssignmentLocal());
// STORE prepared, result
codeGenerator.AccessSelector = AccessType.Write;
result = lvalue.EmitAssign(codeGenerator);
codeGenerator.AccessSelector = AccessType.None;
Debug.Assert(result == PhpTypeCode.Void);
// LOAD result
il.Ldloc(il.GetAssignmentLocal());
result = PhpTypeCode.Object;
break;
}
case AccessType.ReadRef:
case AccessType.ReadUnknown:
// STORE prepared,result
codeGenerator.AccessSelector = AccessType.Write;
result = lvalue.EmitAssign(codeGenerator);
codeGenerator.AccessSelector = AccessType.None;
Debug.Assert(result == PhpTypeCode.Void);
// loads a reference on the LHS variable:
codeGenerator.AccessSelector = access;
codeGenerator.ChainBuilder.Create();
result = lvalue.Emit(codeGenerator);
codeGenerator.ChainBuilder.EndRef();
codeGenerator.AccessSelector = AccessType.None;
break;
case AccessType.None:
// STORE a:
codeGenerator.AccessSelector = AccessType.Write;
result = lvalue.EmitAssign(codeGenerator);
codeGenerator.AccessSelector = AccessType.None;
Debug.Assert(result == PhpTypeCode.Void);
break;
default:
Debug.Fail("Invalid access type.");
result = PhpTypeCode.Invalid;
break;
}
codeGenerator.ChainBuilder.End();
codeGenerator.AccessSelector = old_selector;
return(result);
}