// Author:
// Miguel de Icaza (miguel@ximian.com)
// Martin Baulig (martin@ximian.com)
+// Marek Safar (marek.safar@gmail.com)
//
-// (C) 2001, 2002, 2003 Ximian, Inc.
-// (C) 2004 Novell, Inc
+// Dual licensed under the terms of the MIT X11 or GNU GPL
+//
+// Copyright 2001, 2002, 2003 Ximian, Inc.
+// Copyright 2004-2008 Novell, Inc
//
using System;
using System.Reflection;
using System.Reflection.Emit;
+using System.Collections;
namespace Mono.CSharp {
// end of the code generated for EmitAssign
//
void Emit (EmitContext ec, bool leave_copy);
-
+
//
// This method does the assignment
// `source' will be stored into the location specified by `this'
// for expressions like a [f ()] ++, where you can't call `f ()' twice.
//
void EmitAssign (EmitContext ec, Expression source, bool leave_copy, bool prepare_for_load);
-
+
/*
For simple assignments, this interface is very simple, EmitAssign is called with source
as the source expression and leave_copy and prepare_for_load false.
-
+
For compound assignments it gets complicated.
-
+
EmitAssign will be called as before, however, prepare_for_load will be
true. The @source expression will contain an expression
which calls Emit. So, the calls look like:
-
+
this.EmitAssign (ec, source, false, true) ->
source.Emit (ec); ->
[...] ->
end [...]
end source.Emit (ec);
end this.EmitAssign (ec, source, false, true)
-
-
+
+
When prepare_for_load is true, EmitAssign emits a `token' on the stack that
Emit will use for its state.
-
+
Let's take FieldExpr as an example. assume we are emitting f ().y += 1;
-
+
Here is the call tree again. This time, each call is annotated with the IL
it produces:
-
+
this.EmitAssign (ec, source, false, true)
call f
dup
-
+
Binary.Emit ()
this.Emit (ec, false);
ldfld y
end this.Emit (ec, false);
-
+
IntConstant.Emit ()
ldc.i4.1
end IntConstant.Emit
-
+
add
end Binary.Emit ()
-
+
stfld
end this.EmitAssign (ec, source, false, true)
-
+
Observe two things:
1) EmitAssign left a token on the stack. It was the result of f ().
2) This token was used by Emit
-
+
leave_copy (in both EmitAssign and Emit) tells the compiler to leave a copy
of the expression at that point in evaluation. This is used for pre/post inc/dec
and for a = x += y. Let's do the above example with leave_copy true in EmitAssign
-
+
this.EmitAssign (ec, source, true, true)
call f
dup
-
+
Binary.Emit ()
this.Emit (ec, false);
ldfld y
end this.Emit (ec, false);
-
+
IntConstant.Emit ()
ldc.i4.1
end IntConstant.Emit
-
+
add
end Binary.Emit ()
-
+
dup
stloc temp
stfld
ldloc temp
end this.EmitAssign (ec, source, true, true)
-
+
And with it true in Emit
-
+
this.EmitAssign (ec, source, false, true)
call f
dup
-
+
Binary.Emit ()
this.Emit (ec, true);
ldfld y
dup
stloc temp
end this.Emit (ec, true);
-
+
IntConstant.Emit ()
ldc.i4.1
end IntConstant.Emit
-
+
add
end Binary.Emit ()
-
+
stfld
ldloc temp
end this.EmitAssign (ec, source, false, true)
-
+
Note that these two examples are what happens for ++x and x++, respectively.
*/
}
/// code to access this value, return its address or save its value.
///
/// If `is_address' is true, then the value that we store is the address to the
- /// real value, and not the value itself.
+ /// real value, and not the value itself.
///
/// This is needed for a value type, because otherwise you just end up making a
/// copy of the value on the stack and modifying it. You really need a pointer
/// The `is_address' stuff is really just a hack. We need to come up with a better
/// way to handle it.
/// </remarks>
- public class LocalTemporary : Expression, IMemoryLocation {
+ public class LocalTemporary : Expression, IMemoryLocation, IAssignMethod {
LocalBuilder builder;
bool is_address;
-
- public LocalTemporary (EmitContext ec, Type t) : this (ec, t, false) {}
-
- public LocalTemporary (EmitContext ec, Type t, bool is_address)
+
+ public LocalTemporary (Type t) : this (t, false) {}
+
+ public LocalTemporary (Type t, bool is_address)
{
type = t;
eclass = ExprClass.Value;
- loc = Location.Null;
- builder = ec.GetTemporaryLocal (is_address ? TypeManager.GetReferenceType (t): t);
this.is_address = is_address;
}
ec.FreeTemporaryLocal (builder, type);
builder = null;
}
-
+
+ public override Expression CreateExpressionTree (EmitContext ec)
+ {
+ ArrayList args = new ArrayList (1);
+ args.Add (new Argument (this));
+ return CreateExpressionFactoryCall ("Constant", args);
+ }
+
public override Expression DoResolve (EmitContext ec)
{
return this;
}
+ public override Expression DoResolveLValue (EmitContext ec, Expression right_side)
+ {
+ return this;
+ }
+
public override void Emit (EmitContext ec)
{
ILGenerator ig = ec.ig;
-
+
+ if (builder == null)
+ throw new InternalErrorException ("Emit without Store, or after Release");
+
ig.Emit (OpCodes.Ldloc, builder);
// we need to copy from the pointer
if (is_address)
LoadFromPtr (ig, type);
}
+ #region IAssignMethod Members
+
+ public void Emit (EmitContext ec, bool leave_copy)
+ {
+ Emit (ec);
+
+ if (leave_copy)
+ Emit (ec);
+ }
+
+ public void EmitAssign (EmitContext ec, Expression source, bool leave_copy, bool prepare_for_load)
+ {
+ if (prepare_for_load)
+ throw new NotImplementedException ();
+
+ source.Emit (ec);
+
+ Store (ec);
+
+ if (leave_copy)
+ Emit (ec);
+ }
+
+ #endregion
+
+ public LocalBuilder Builder {
+ get { return builder; }
+ }
+
// NB: if you have `is_address' on the stack there must
// be a managed pointer. Otherwise, it is the type from
// the ctor.
public void Store (EmitContext ec)
{
ILGenerator ig = ec.ig;
+ if (builder == null)
+ builder = ec.GetTemporaryLocal (is_address ? TypeManager.GetReferenceType (type): type);
+
ig.Emit (OpCodes.Stloc, builder);
}
public void AddressOf (EmitContext ec, AddressOp mode)
{
+ if (builder == null)
+ builder = ec.GetTemporaryLocal (is_address ? TypeManager.GetReferenceType (type): type);
+
// if is_address, than this is just the address anyways,
// so we just return this.
ILGenerator ig = ec.ig;
-
+
if (is_address)
ig.Emit (OpCodes.Ldloc, builder);
else
ig.Emit (OpCodes.Ldloca, builder);
}
+ public override void MutateHoistedGenericType (AnonymousMethodStorey storey)
+ {
+ type = storey.MutateType (type);
+ }
+
public bool PointsToAddress {
get {
return is_address;
/// <summary>
/// The Assign node takes care of assigning the value of source into
- /// the expression represented by target.
+ /// the expression represented by target.
/// </summary>
public class Assign : ExpressionStatement {
- protected Expression target, source, real_source;
- protected LocalTemporary temp = null, real_temp = null;
- protected Assign embedded = null;
- protected bool is_embedded = false;
- protected bool must_free_temp = false;
+ protected Expression target, source;
- public Assign (Expression target, Expression source, Location l)
+ protected Assign (Expression target, Expression source, Location loc)
{
this.target = target;
- this.source = this.real_source = source;
- this.loc = l;
+ this.source = source;
+ this.loc = loc;
}
-
- protected Assign (Assign embedded, Location l)
- : this (embedded.target, embedded.source, l)
- {
- this.is_embedded = true;
- }
-
- protected virtual Assign GetEmbeddedAssign (Location loc)
+
+ public override Expression CreateExpressionTree (EmitContext ec)
{
- return new Assign (this, loc);
+ Report.Error (832, loc, "An expression tree cannot contain an assignment operator");
+ return null;
}
public Expression Target {
- get {
- return target;
- }
-
- set {
- target = value;
- }
+ get { return target; }
}
public Expression Source {
- get {
- return source;
- }
-
- set {
- source = value;
- }
+ get { return source; }
}
- public static void error70 (EventInfo ei, Location l)
- {
- Report.Error (70, l, "The event '" + ei.Name +
- "' can only appear on the left-side of a += or -= (except when" +
- " used from within the type '" + ei.DeclaringType + "')");
- }
-
- //
- // Will return either `this' or an instance of `New'.
- //
public override Expression DoResolve (EmitContext ec)
{
- // Create an embedded assignment if our source is an assignment.
- if (source is Assign)
- source = embedded = ((Assign) source).GetEmbeddedAssign (loc);
-
- real_source = source = source.Resolve (ec);
+ bool ok = true;
+ source = source.Resolve (ec);
+
if (source == null) {
- // Ensure that we don't propagate the error as spurious "uninitialized variable" errors.
- target = target.ResolveLValue (ec, EmptyExpression.Null);
- return null;
- }
-
- //
- // This is used in an embedded assignment.
- // As an example, consider the statement "A = X = Y = Z".
- //
- if (is_embedded && !(source is Constant)) {
- // If this is the innermost assignment (the "Y = Z" in our example),
- // create a new temporary local, otherwise inherit that variable
- // from our child (the "X = (Y = Z)" inherits the local from the
- // "Y = Z" assignment).
-
- if (embedded == null) {
- if (this is CompoundAssign)
- real_temp = temp = new LocalTemporary (ec, target.Type);
- else
- real_temp = temp = new LocalTemporary (ec, source.Type);
- } else
- temp = embedded.temp;
-
- // Set the source to the new temporary variable.
- // This means that the following target.ResolveLValue () will tell
- // the target to read it's source value from that variable.
- source = temp;
+ ok = false;
+ source = EmptyExpression.Null;
}
- // If we have an embedded assignment, use the embedded assignment's temporary
- // local variable as source.
- if (embedded != null)
- source = (embedded.temp != null) ? embedded.temp : embedded.source;
+ target = target.ResolveLValue (ec, source, Location);
- target = target.ResolveLValue (ec, source);
-
- if (target == null)
+ if (target == null || !ok)
return null;
- if (source.Equals (target)) {
- Report.Warning (1717, 3, loc, "Assignment made to same variable; did you mean to assign something else?");
- }
-
Type target_type = target.Type;
- Type source_type = real_source.Type;
+ Type source_type = source.Type;
- // If we're an embedded assignment, our parent will reuse our source as its
- // source, it won't read from our target.
- if (is_embedded)
- type = source_type;
- else
- type = target_type;
eclass = ExprClass.Value;
+ type = target_type;
-
- if (target is EventExpr) {
- EventInfo ei = ((EventExpr) target).EventInfo;
-
- Expression ml = MemberLookup (
- ec, ec.ContainerType, ei.Name,
- MemberTypes.Event, AllBindingFlags | BindingFlags.DeclaredOnly, loc);
-
- if (ml == null) {
- //
- // If this is the case, then the Event does not belong
- // to this Type and so, according to the spec
- // is allowed to only appear on the left hand of
- // the += and -= operators
- //
- // Note that target will not appear as an EventExpr
- // in the case it is being referenced within the same type container;
- // it will appear as a FieldExpr in that case.
- //
-
- if (!(source is BinaryDelegate)) {
- error70 (ei, loc);
- return null;
- }
- }
- }
-
- FieldExpr field_exp = target as FieldExpr;
- if (field_exp != null && field_exp.DeclaringType.IsValueType && !ec.IsConstructor && !ec.IsFieldInitializer) {
- field_exp = field_exp.InstanceExpression as FieldExpr;
- if (field_exp != null && field_exp.FieldInfo.IsInitOnly) {
- if (field_exp.IsStatic) {
- Report.Error (1650, loc, "Members of static readonly field '{0}' cannot be assigned to " +
- "(except in a static constructor or a variable initializer)", TypeManager.GetFullNameSignature (field_exp.FieldInfo));
- } else {
- Report.Error (1648, loc, "Members of readonly field '{0}' cannot be assigned to " +
- "(except in a constructor or a variable initializer)", TypeManager.GetFullNameSignature (field_exp.FieldInfo));
- }
- return null;
- }
- }
-
- if (!(target is IAssignMethod) && (target.eclass != ExprClass.EventAccess)) {
- Report.Error (131, loc,
- "Left hand of an assignment must be a variable, " +
- "a property or an indexer");
+ if (!(target is IAssignMethod)) {
+ Error_ValueAssignment (loc);
return null;
}
if ((source.eclass == ExprClass.Type) && (source is TypeExpr)) {
- source.Error_UnexpectedKind ("variable or value", loc);
+ source.Error_UnexpectedKind (ec.DeclContainer, "variable or value", loc);
return null;
} else if ((RootContext.Version == LanguageVersion.ISO_1) &&
(source is MethodGroupExpr)){
((MethodGroupExpr) source).ReportUsageError ();
return null;
-
}
- if (target_type == source_type){
- if (source is New && target_type.IsValueType &&
- (target.eclass != ExprClass.IndexerAccess) && (target.eclass != ExprClass.PropertyAccess)){
- New n = (New) source;
-
- if (n.SetValueTypeVariable (target))
- return n;
- else
- return null;
- }
-
- return this;
- }
-
- //
- // If this assignemnt/operator was part of a compound binary
- // operator, then we allow an explicit conversion, as detailed
- // in the spec.
- //
+ if (!TypeManager.IsEqual (target_type, source_type)){
+ Expression resolved = ResolveConversions (ec);
- if (this is CompoundAssign){
- CompoundAssign a = (CompoundAssign) this;
-
- Binary b = source as Binary;
- if (b != null){
- //
- // 1. if the source is explicitly convertible to the
- // target_type
- //
-
- source = Convert.ExplicitConversion (ec, source, target_type, loc);
- if (source == null){
- Convert.Error_CannotImplicitConversion (loc, source_type, target_type);
- return null;
- }
-
- //
- // 2. and the original right side is implicitly convertible to
- // the type of target
- //
- if (Convert.ImplicitStandardConversionExists (ec, a.original_source, target_type))
- return this;
-
- //
- // In the spec 2.4 they added: or if type of the target is int
- // and the operator is a shift operator...
- //
- if (source_type == TypeManager.int32_type &&
- (b.Oper == Binary.Operator.LeftShift || b.Oper == Binary.Operator.RightShift))
- return this;
-
- Convert.Error_CannotImplicitConversion (loc, a.original_source.Type, target_type);
- return null;
- }
+ if (resolved != this)
+ return resolved;
}
- source = Convert.ImplicitConversionRequired (ec, source, target_type, loc);
+ return this;
+ }
+
+ public override void MutateHoistedGenericType (AnonymousMethodStorey storey)
+ {
+ source.MutateHoistedGenericType (storey);
+ target.MutateHoistedGenericType (storey);
+ type = storey.MutateType (type);
+ }
+
+ protected virtual Expression ResolveConversions (EmitContext ec)
+ {
+ source = Convert.ImplicitConversionRequired (ec, source, target.Type, loc);
if (source == null)
return null;
- // If we're an embedded assignment, we need to create a new temporary variable
- // for the converted value. Our parent will use this new variable as its source.
- // The same applies when we have an embedded assignment - in this case, we need
- // to convert our embedded assignment's temporary local variable to the correct
- // type and store it in a new temporary local.
- if (is_embedded || embedded != null) {
- type = target_type;
- temp = new LocalTemporary (ec, type);
- must_free_temp = true;
- }
-
return this;
}
- Expression EmitEmbedded (EmitContext ec)
+ void Emit (EmitContext ec, bool is_statement)
{
- // Emit an embedded assignment.
+ IAssignMethod t = (IAssignMethod) target;
+ t.EmitAssign (ec, source, !is_statement, this is CompoundAssign);
+ }
- if (real_temp != null) {
- // If we're the innermost assignment, `real_source' is the right-hand
- // expression which gets assigned to all the variables left of it.
- // Emit this expression and store its result in real_temp.
- real_source.Emit (ec);
- real_temp.Store (ec);
- }
+ public override void Emit (EmitContext ec)
+ {
+ Emit (ec, false);
+ }
- if (embedded != null)
- embedded.EmitEmbedded (ec);
+ public override void EmitStatement (EmitContext ec)
+ {
+ Emit (ec, true);
+ }
- // This happens when we've done a type conversion, in this case source will be
- // the expression which does the type conversion from real_temp.
- // So emit it and store the result in temp; this is the var which will be read
- // by our parent.
- if (temp != real_temp) {
- source.Emit (ec);
- temp.Store (ec);
- }
+ protected override void CloneTo (CloneContext clonectx, Expression t)
+ {
+ Assign _target = (Assign) t;
- Expression temp_source = (temp != null) ? temp : source;
- ((IAssignMethod) target).EmitAssign (ec, temp_source, false, false);
- return temp_source;
+ _target.target = target.Clone (clonectx);
+ _target.source = source.Clone (clonectx);
}
+ }
- void ReleaseEmbedded (EmitContext ec)
+ class SimpleAssign : Assign {
+ public SimpleAssign (Expression target, Expression source)
+ : this (target, source, target.Location)
{
- if (embedded != null)
- embedded.ReleaseEmbedded (ec);
+ }
- if (real_temp != null)
- real_temp.Release (ec);
+ public SimpleAssign (Expression target, Expression source, Location loc)
+ : base (target, source, loc)
+ {
+ }
- if (must_free_temp)
- temp.Release (ec);
+ bool CheckEqualAssign (Expression t)
+ {
+ if (source is Assign) {
+ Assign a = (Assign) source;
+ if (t.Equals (a.Target))
+ return true;
+ return a is SimpleAssign && ((SimpleAssign) a).CheckEqualAssign (t);
+ }
+ return t.Equals (source);
}
- void Emit (EmitContext ec, bool is_statement)
+ public override Expression DoResolve (EmitContext ec)
{
- if (target is EventExpr) {
- ((EventExpr) target).EmitAddOrRemove (ec, source);
- return;
+ Expression e = base.DoResolve (ec);
+ if (e == null || e != this)
+ return e;
+
+ if (CheckEqualAssign (target))
+ Report.Warning (1717, 3, loc, "Assignment made to same variable; did you mean to assign something else?");
+
+ return this;
+ }
+ }
+
+ // This class implements fields and events class initializers
+ public class FieldInitializer : Assign
+ {
+ //
+ // Keep resolved value because field initializers have their own rules
+ //
+ ExpressionStatement resolved;
+ IResolveContext rc;
+
+ public FieldInitializer (FieldBuilder field, Expression expression, IResolveContext rc)
+ : base (new FieldExpr (field, expression.Location), expression, expression.Location)
+ {
+ this.rc = rc;
+ if (!field.IsStatic)
+ ((FieldExpr)target).InstanceExpression = CompilerGeneratedThis.Instance;
+ }
+
+ public override Expression DoResolve (EmitContext ec)
+ {
+ // Field initializer can be resolved (fail) many times
+ if (source == null)
+ return null;
+
+ if (resolved == null) {
+ //
+ // Field initializers are tricky for partial classes. They have to
+ // share same costructor (block) but they have they own resolve scope.
+ //
+
+ // TODO: Use ResolveContext only
+ EmitContext f_ec = new EmitContext (rc, rc.DeclContainer, loc, null, TypeManager.void_type, 0, true);
+ f_ec.IsStatic = ec.IsStatic;
+ f_ec.CurrentBlock = ec.CurrentBlock;
+
+ EmitContext.Flags flags = EmitContext.Flags.InFieldInitializer;
+ if (ec.IsInUnsafeScope)
+ flags |= EmitContext.Flags.InUnsafe;
+
+ f_ec.Set (flags);
+
+ resolved = base.DoResolve (f_ec) as ExpressionStatement;
}
-
- IAssignMethod am = (IAssignMethod) target;
- Expression temp_source;
- if (embedded != null) {
- temp_source = embedded.EmitEmbedded (ec);
+ return resolved;
+ }
- if (temp != null) {
- source.Emit (ec);
- temp.Store (ec);
- temp_source = temp;
- }
- } else
- temp_source = source;
+ public override void EmitStatement (EmitContext ec)
+ {
+ if (resolved == null)
+ return;
+
+ if (resolved != this)
+ resolved.EmitStatement (ec);
+ else
+ base.EmitStatement (ec);
+ }
- am.EmitAssign (ec, temp_source, !is_statement, this is CompoundAssign);
+ public bool IsComplexInitializer {
+ get { return !(source is Constant); }
+ }
+
+ public bool IsDefaultInitializer {
+ get {
+ Constant c = source as Constant;
+ if (c == null)
+ return false;
- if (embedded != null) {
- if (temp != null)
- temp.Release (ec);
- embedded.ReleaseEmbedded (ec);
+ FieldExpr fe = (FieldExpr)target;
+ return c.IsDefaultInitializer (fe.Type);
}
}
-
+ }
+
+ class EventAddOrRemove : ExpressionStatement {
+ EventExpr target;
+ Binary.Operator op;
+ Expression source;
+
+ public EventAddOrRemove (Expression target, Binary.Operator op, Expression source, Location loc)
+ {
+ this.target = target as EventExpr;
+ this.op = op;
+ this.source = source;
+ this.loc = loc;
+ }
+
+ public override Expression CreateExpressionTree (EmitContext ec)
+ {
+ return new SimpleAssign (target, source).CreateExpressionTree (ec);
+ }
+
+ public override Expression DoResolve (EmitContext ec)
+ {
+ source = source.Resolve (ec);
+ if (source == null)
+ return null;
+
+ source = Convert.ImplicitConversionRequired (ec, source, target.Type, loc);
+ if (source == null)
+ return null;
+
+ eclass = ExprClass.Value;
+ type = TypeManager.void_type;
+ return this;
+ }
+
public override void Emit (EmitContext ec)
{
- Emit (ec, false);
+ if (RootContext.EvalMode)
+ EmitStatement (ec);
+ else
+ throw new InternalErrorException ("don't know what to emit");
}
public override void EmitStatement (EmitContext ec)
{
- Emit (ec, true);
+ target.EmitAddOrRemove (ec, op == Binary.Operator.Addition, source);
}
}
-
//
- // This class is used for compound assignments.
+ // This class is used for compound assignments.
//
class CompoundAssign : Assign {
Binary.Operator op;
- public Expression original_source;
-
- public CompoundAssign (Binary.Operator op, Expression target, Expression source, Location l)
- : base (target, source, l)
+ Expression original_source;
+
+ public CompoundAssign (Binary.Operator op, Expression target, Expression source)
+ : base (target, source, target.Location)
{
original_source = source;
this.op = op;
}
- protected CompoundAssign (CompoundAssign embedded, Location l)
- : this (embedded.op, embedded.target, embedded.source, l)
- {
- this.is_embedded = true;
- }
+ public sealed class TargetExpression : Expression {
+ Expression child;
+ public TargetExpression (Expression child)
+ {
+ this.child = child;
+ this.loc = child.Location;
+ }
- protected override Assign GetEmbeddedAssign (Location loc)
- {
- return new CompoundAssign (this, loc);
- }
+ public override Expression CreateExpressionTree (EmitContext ec)
+ {
+ throw new NotSupportedException ("ET");
+ }
- public Expression ResolveSource (EmitContext ec)
- {
- return original_source.Resolve (ec);
+ public override Expression DoResolve (EmitContext ec)
+ {
+ child = child.Resolve (ec);
+ if (child == null)
+ return null;
+ type = child.Type;
+ eclass = ExprClass.Value;
+ return this;
+ }
+
+ public override void Emit (EmitContext ec)
+ {
+ child.Emit (ec);
+ }
}
public override Expression DoResolve (EmitContext ec)
if (original_source == null)
return null;
- target = target.Resolve (ec);
+ using (ec.Set (EmitContext.Flags.InCompoundAssignment)) {
+ target = target.Resolve (ec);
+ }
+
if (target == null)
return null;
-
+
+ if (target is MethodGroupExpr){
+ Error_CannotAssign (((MethodGroupExpr)target).Name, target.ExprClassName);
+ return null;
+ }
+
+ if (target is EventExpr)
+ return new EventAddOrRemove (target, op, original_source, loc).DoResolve (ec);
+
//
// Only now we can decouple the original source/target
// into a tree, to guarantee that we do not have side
// effects.
//
- source = new Binary (op, target, original_source, loc);
+ source = new Binary (op, new TargetExpression (target), original_source, true);
return base.DoResolve (ec);
}
- }
-}
+ protected override Expression ResolveConversions (EmitContext ec)
+ {
+ Type target_type = target.Type;
+ //
+ // 1. the return type is implicitly convertible to the type of target
+ //
+ if (Convert.ImplicitConversionExists (ec, source, target_type)) {
+ source = Convert.ImplicitConversion (ec, source, target_type, loc);
+ return this;
+ }
+ //
+ // Otherwise, if the selected operator is a predefined operator
+ //
+ Binary b = source as Binary;
+ if (b != null) {
+ //
+ // 2a. the operator is a shift operator
+ //
+ // 2b. the return type is explicitly convertible to the type of x, and
+ // y is implicitly convertible to the type of x
+ //
+ if ((b.Oper & Binary.Operator.ShiftMask) != 0 ||
+ Convert.ImplicitConversionExists (ec, original_source, target_type)) {
+ source = Convert.ExplicitConversion (ec, source, target_type, loc);
+ return this;
+ }
+ }
+
+ original_source.Error_ValueCannotBeConverted (ec, loc, target_type, false);
+ return null;
+ }
+
+ protected override void CloneTo (CloneContext clonectx, Expression t)
+ {
+ CompoundAssign ctarget = (CompoundAssign) t;
+ ctarget.original_source = ctarget.source = source.Clone (clonectx);
+ ctarget.target = target.Clone (clonectx);
+ }
+ }
+}
projects / mono.git / blobdiff