public void AddressOf(EmitContext ec, AddressOp mode)
{
IMemoryLocation ml;
if (temp_field != null) {
ml = temp_field as IMemoryLocation;
if (ml == null) {
var lt = new LocalTemporary (temp_field.Type);
temp_field.Emit (ec);
lt.Store (ec);
ml = lt;
}
} else {
ml = expr as VariableReference;
}
if (ml != null)
ml.AddressOf (ec, mode);
else
LocalVariable.AddressOf (ec, mode);
}
public void AddressOf (EmitContext ec, AddressOp Mode)
{
LocalTemporary value_target = new LocalTemporary (type);
value_target.AddressOf (ec, AddressOp.Store);
ec.Emit (OpCodes.Initobj, type);
((IMemoryLocation) value_target).AddressOf (ec, Mode);
}
public override void Emit (EmitContext ec)
{
// TODO: generate less temporary variables
LocalTemporary value_target = new LocalTemporary (type);
value_target.AddressOf (ec, AddressOp.Store);
ec.Emit (OpCodes.Initobj, type);
value_target.Emit (ec);
}
public override void Emit(EmitContext ec)
{
Label end_label = ec.DefineLabel();
if (unwrap != null)
{
Label is_null_label = ec.DefineLabel();
unwrap.EmitCheck(ec);
ec.Emit(OpCodes.Brfalse, is_null_label);
//
// When both expressions are nullable the unwrap
// is needed only for null check not for value uwrap
//
if (type.IsNullableType && TypeSpecComparer.IsEqual(NullableInfo.GetUnderlyingType(type), unwrap.Type))
{
unwrap.Load(ec);
}
else
{
left.Emit(ec);
}
ec.Emit(OpCodes.Br, end_label);
ec.MarkLabel(is_null_label);
right.Emit(ec);
ec.MarkLabel(end_label);
return;
}
//
// Null check is done on original expression not after expression is converted to
// result type. This is in most cases same but when user conversion is involved
// we can end up in situation when use operator does the null handling which is
// not what the operator is supposed to do
//
var op_expr = left as UserCast;
if (op_expr != null)
{
op_expr.Source.Emit(ec);
LocalTemporary temp;
// TODO: More load kinds can be special cased
if (!(op_expr.Source is VariableReference))
{
temp = new LocalTemporary(op_expr.Source.Type);
temp.Store(ec);
temp.Emit(ec);
op_expr.Source = temp;
}
else
{
temp = null;
}
var right_label = ec.DefineLabel();
ec.Emit(OpCodes.Brfalse_S, right_label);
left.Emit(ec);
ec.Emit(OpCodes.Br, end_label);
ec.MarkLabel(right_label);
if (temp != null)
{
temp.Release(ec);
}
}
else
{
//
// Common case where expression is not modified before null check and
// we generate better/smaller code
//
left.Emit(ec);
ec.Emit(OpCodes.Dup);
// Only to make verifier happy
if (left.Type.IsGenericParameter)
{
ec.Emit(OpCodes.Box, left.Type);
}
ec.Emit(OpCodes.Brtrue, end_label);
ec.Emit(OpCodes.Pop);
}
right.Emit(ec);
ec.MarkLabel(end_label);
}
//
// Emits optimized equality or inequality operator when possible
//
void EmitEquality(EmitContext ec)
{
//
// Either left or right is null
//
if (UnwrapLeft != null && Binary.Right.IsNull) // TODO: Optimize for EmitBranchable
//
// left.HasValue == false
//
{
UnwrapLeft.EmitCheck(ec);
if (Binary.Oper == Binary.Operator.Equality)
{
ec.EmitInt(0);
ec.Emit(OpCodes.Ceq);
}
return;
}
if (UnwrapRight != null && Binary.Left.IsNull)
{
//
// right.HasValue == false
//
UnwrapRight.EmitCheck(ec);
if (Binary.Oper == Binary.Operator.Equality)
{
ec.EmitInt(0);
ec.Emit(OpCodes.Ceq);
}
return;
}
Label dissimilar_label = ec.DefineLabel();
Label end_label = ec.DefineLabel();
if (UserOperator != null)
{
var left = Left;
if (UnwrapLeft != null)
{
UnwrapLeft.EmitCheck(ec);
}
else
{
// Keep evaluation order same
if (!(Left is VariableReference))
{
Left.Emit(ec);
var lt = new LocalTemporary(Left.Type);
lt.Store(ec);
left = lt;
}
}
if (UnwrapRight != null)
{
UnwrapRight.EmitCheck(ec);
if (UnwrapLeft != null)
{
ec.Emit(OpCodes.Bne_Un, dissimilar_label);
Label compare_label = ec.DefineLabel();
UnwrapLeft.EmitCheck(ec);
ec.Emit(OpCodes.Brtrue, compare_label);
if (Binary.Oper == Binary.Operator.Equality)
{
ec.EmitInt(1);
}
else
{
ec.EmitInt(0);
}
ec.Emit(OpCodes.Br, end_label);
ec.MarkLabel(compare_label);
}
else
{
ec.Emit(OpCodes.Brfalse, dissimilar_label);
}
}
else
{
ec.Emit(OpCodes.Brfalse, dissimilar_label);
}
var args = new Arguments(2);
args.Add(new Argument(left));
args.Add(new Argument(Right));
var call = new CallEmitter();
call.EmitPredefined(ec, UserOperator, args);
}
else
{
if (ec.HasSet(BuilderContext.Options.AsyncBody) && Binary.Right.ContainsEmitWithAwait())
{
Left = Left.EmitToField(ec);
Right = Right.EmitToField(ec);
}
//
// Emit underlying value comparison first.
//
// For this code: int? a = 1; bool b = a == 1;
//
// We emit something similar to this. Expressions with side effects have local
// variable created by Unwrap expression
//
// left.GetValueOrDefault ()
// right
// bne.un.s dissimilar_label
// left.HasValue
// br.s end_label
// dissimilar_label:
// ldc.i4.0
// end_label:
//
Left.Emit(ec);
Right.Emit(ec);
ec.Emit(OpCodes.Bne_Un_S, dissimilar_label);
//
// Check both left and right expressions for Unwrap call in which
// case we need to run get_HasValue() check because the type is
// nullable and could have null value
//
if (UnwrapLeft != null)
{
UnwrapLeft.EmitCheck(ec);
}
if (UnwrapRight != null)
{
UnwrapRight.EmitCheck(ec);
}
if (UnwrapLeft != null && UnwrapRight != null)
{
if (Binary.Oper == Binary.Operator.Inequality)
{
ec.Emit(OpCodes.Xor);
}
else
{
ec.Emit(OpCodes.Ceq);
}
}
else
{
if (Binary.Oper == Binary.Operator.Inequality)
{
ec.EmitInt(0);
ec.Emit(OpCodes.Ceq);
}
}
}
ec.Emit(OpCodes.Br_S, end_label);
ec.MarkLabel(dissimilar_label);
if (Binary.Oper == Binary.Operator.Inequality)
{
ec.EmitInt(1);
}
else
{
ec.EmitInt(0);
}
ec.MarkLabel(end_label);
}
//
// Emits optimized equality or inequality operator when possible
//
void EmitEquality (EmitContext ec)
{
//
// Either left or right is null
//
if (UnwrapLeft != null && Binary.Right.IsNull) { // TODO: Optimize for EmitBranchable
//
// left.HasValue == false
//
UnwrapLeft.EmitCheck (ec);
if (Binary.Oper == Binary.Operator.Equality) {
ec.EmitInt (0);
ec.Emit (OpCodes.Ceq);
}
return;
}
if (UnwrapRight != null && Binary.Left.IsNull) {
//
// right.HasValue == false
//
UnwrapRight.EmitCheck (ec);
if (Binary.Oper == Binary.Operator.Equality) {
ec.EmitInt (0);
ec.Emit (OpCodes.Ceq);
}
return;
}
Label dissimilar_label = ec.DefineLabel ();
Label end_label = ec.DefineLabel ();
if (UserOperator != null) {
var left = Left;
if (UnwrapLeft != null) {
UnwrapLeft.EmitCheck (ec);
} else {
// Keep evaluation order same
if (!(Left is VariableReference)) {
Left.Emit (ec);
var lt = new LocalTemporary (Left.Type);
lt.Store (ec);
left = lt;
}
}
if (UnwrapRight != null) {
UnwrapRight.EmitCheck (ec);
if (UnwrapLeft != null) {
ec.Emit (OpCodes.Bne_Un, dissimilar_label);
Label compare_label = ec.DefineLabel ();
UnwrapLeft.EmitCheck (ec);
ec.Emit (OpCodes.Brtrue, compare_label);
if (Binary.Oper == Binary.Operator.Equality)
ec.EmitInt (1);
else
ec.EmitInt (0);
ec.Emit (OpCodes.Br, end_label);
ec.MarkLabel (compare_label);
} else {
ec.Emit (OpCodes.Brfalse, dissimilar_label);
}
} else {
ec.Emit (OpCodes.Brfalse, dissimilar_label);
}
var args = new Arguments (2);
args.Add (new Argument (left));
args.Add (new Argument (Right));
var call = new CallEmitter ();
call.EmitPredefined (ec, UserOperator, args);
} else {
if (ec.HasSet (BuilderContext.Options.AsyncBody) && Binary.Right.ContainsEmitWithAwait ()) {
Left = Left.EmitToField (ec);
Right = Right.EmitToField (ec);
}
//
// Emit underlying value comparison first.
//
// For this code: int? a = 1; bool b = a == 1;
//
// We emit something similar to this. Expressions with side effects have local
// variable created by Unwrap expression
//
// left.GetValueOrDefault ()
// right
// bne.un.s dissimilar_label
// left.HasValue
// br.s end_label
// dissimilar_label:
// ldc.i4.0
// end_label:
//
Left.Emit (ec);
Right.Emit (ec);
ec.Emit (OpCodes.Bne_Un_S, dissimilar_label);
//
// Check both left and right expressions for Unwrap call in which
// case we need to run get_HasValue() check because the type is
// nullable and could have null value
//
if (UnwrapLeft != null)
UnwrapLeft.EmitCheck (ec);
if (UnwrapRight != null)
UnwrapRight.EmitCheck (ec);
if (UnwrapLeft != null && UnwrapRight != null) {
if (Binary.Oper == Binary.Operator.Inequality)
ec.Emit (OpCodes.Xor);
else
ec.Emit (OpCodes.Ceq);
} else {
if (Binary.Oper == Binary.Operator.Inequality) {
ec.EmitInt (0);
ec.Emit (OpCodes.Ceq);
}
}
}
ec.Emit (OpCodes.Br_S, end_label);
ec.MarkLabel (dissimilar_label);
if (Binary.Oper == Binary.Operator.Inequality)
ec.EmitInt (1);
else
ec.EmitInt (0);
ec.MarkLabel (end_label);
}
public void AddressOf (EmitContext ec, AddressOp mode)
{
IMemoryLocation ml;
if (temp_field != null) {
ml = temp_field as IMemoryLocation;
if (ml == null) {
var lt = new LocalTemporary (temp_field.Type);
temp_field.Emit (ec);
lt.Store (ec);
ml = lt;
}
} else {
ml = expr as VariableReference;
}
if (ml != null)
ml.AddressOf (ec, mode);
else
LocalVariable.AddressOf (ec, mode);
}
protected override void EmitOperation (EmitContext ec)
{
Label is_null_label = ec.DefineLabel ();
Label end_label = ec.DefineLabel ();
LocalTemporary lt = new LocalTemporary (type);
// Value is on the stack
lt.Store (ec);
var call = new CallEmitter ();
call.InstanceExpression = lt;
call.EmitPredefined (ec, NullableInfo.GetHasValue (expr.Type), null);
ec.Emit (OpCodes.Brfalse, is_null_label);
call = new CallEmitter ();
call.InstanceExpression = lt;
call.EmitPredefined (ec, NullableInfo.GetGetValueOrDefault (expr.Type), null);
lt.Release (ec);
base.EmitOperation (ec);
ec.Emit (OpCodes.Newobj, NullableInfo.GetConstructor (type));
ec.Emit (OpCodes.Br_S, end_label);
ec.MarkLabel (is_null_label);
LiftedNull.Create (type, loc).Emit (ec);
ec.MarkLabel (end_label);
}
public override void Emit (EmitContext ec)
{
Label end_label = ec.DefineLabel ();
if (unwrap != null) {
Label is_null_label = ec.DefineLabel ();
unwrap.EmitCheck (ec);
ec.Emit (OpCodes.Brfalse, is_null_label);
//
// When both expressions are nullable the unwrap
// is needed only for null check not for value uwrap
//
if (type.IsNullableType && TypeSpecComparer.IsEqual (NullableInfo.GetUnderlyingType (type), unwrap.Type))
unwrap.Load (ec);
else
left.Emit (ec);
ec.Emit (OpCodes.Br, end_label);
ec.MarkLabel (is_null_label);
right.Emit (ec);
ec.MarkLabel (end_label);
return;
}
//
// Null check is done on original expression not after expression is converted to
// result type. This is in most cases same but when user conversion is involved
// we can end up in situation when user operator does the null handling which is
// not what the operator is supposed to do.
// There is tricky case where cast of left expression is meant to be cast of
// whole source expression (null check is done on it) and cast from right-to-left
// conversion needs to do null check on unconverted source expression.
//
if (user_conversion_left) {
var op_expr = (UserCast) left;
op_expr.Source.Emit (ec);
LocalTemporary temp;
// TODO: More load kinds can be special cased
if (!(op_expr.Source is VariableReference)) {
temp = new LocalTemporary (op_expr.Source.Type);
temp.Store (ec);
temp.Emit (ec);
op_expr.Source = temp;
} else {
temp = null;
}
var right_label = ec.DefineLabel ();
ec.Emit (OpCodes.Brfalse_S, right_label);
left.Emit (ec);
ec.Emit (OpCodes.Br, end_label);
ec.MarkLabel (right_label);
if (temp != null)
temp.Release (ec);
} else {
//
// Common case where expression is not modified before null check and
// we generate better/smaller code
//
left.Emit (ec);
ec.Emit (OpCodes.Dup);
// Only to make verifier happy
if (left.Type.IsGenericParameter)
ec.Emit (OpCodes.Box, left.Type);
ec.Emit (OpCodes.Brtrue, end_label);
ec.Emit (OpCodes.Pop);
}
right.Emit (ec);
ec.MarkLabel (end_label);
}
