// Author:
// Miguel de Icaza (miguel@ximian.com)
//
-// (C) 2001 Ximian, Inc.
+// (C) 2001, 2002 Ximian, Inc.
//
using System;
using System.Reflection;
/// invoking this method.
/// </remarks>
public interface IAssignMethod {
+ //
+ // This method will emit the code for the actual assignment
+ //
void EmitAssign (EmitContext ec, Expression source);
+
+ //
+ // This method is invoked before any code generation takes
+ // place, and it is a mechanism to inform that the expression
+ // will be invoked more than once, and that the method should
+ // use temporary values to avoid having side effects
+ //
+ // Example: a [ g () ] ++
+ //
+ void CacheTemporaries (EmitContext ec);
}
/// <summary>
builder = null;
}
- Public LocalTemporary (LocalBuilder b, Type t)
+ public LocalTemporary (LocalBuilder b, Type t)
{
type = t;
eclass = ExprClass.Value;
ec.ig.Emit (OpCodes.Stloc, builder);
}
- public void AddressOf (EmitContext ec)
+ public void AddressOf (EmitContext ec, AddressOp mode)
{
ec.ig.Emit (OpCodes.Ldloca, builder);
}
/// the expression represented by target.
/// </summary>
public class Assign : ExpressionStatement {
- Expression target, source;
- Location l;
+ protected Expression target, source;
+ public Location l;
public Assign (Expression target, Expression source, Location l)
{
" used from within the type '" + ei.DeclaringType + "')");
}
+ //
+ // Will return either `this' or an instance of `New'.
+ //
public override Expression DoResolve (EmitContext ec)
{
source = source.Resolve (ec);
type = target_type;
eclass = ExprClass.Value;
-
+
//
// If we are doing a property assignment, then
// set the `value' field on the property, and Resolve
if (target is PropertyExpr){
PropertyExpr property_assign = (PropertyExpr) target;
+ if (source_type != target_type){
+ source = ConvertImplicitRequired (ec, source, target_type, l);
+ if (source == null)
+ return null;
+ }
+
//
// FIXME: Maybe handle this in the LValueResolve
//
}
if (target is IndexerAccess){
- IndexerAccess ia = (IndexerAccess) target;
-
+ if (source_type != target_type){
+ source = ConvertImplicitRequired (ec, source, target_type, l);
+ if (source == null)
+ return null;
+ }
+
return this;
}
Expression ml = MemberLookup (
- ec, ec.TypeContainer.TypeBuilder, ei.Name,
+ ec, ec.ContainerType, ei.Name,
MemberTypes.Event, AllBindingFlags, l);
if (ml == null) {
return n;
}
- if (target_type != source_type){
- source = ConvertImplicitRequired (ec, source, target_type, l);
- if (source == null)
- return null;
- }
-
if (target.eclass != ExprClass.Variable && target.eclass != ExprClass.EventAccess){
Report.Error (131, l,
"Left hand of an assignment must be a variable, " +
return null;
}
+ if (target_type == source_type)
+ 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 (this is CompoundAssign){
+ CompoundAssign a = (CompoundAssign) this;
+
+ Binary b = source as Binary;
+ if (b != null && b.IsBuiltinOperator){
+ //
+ // 1. if the source is explicitly convertible to the
+ // target_type
+ //
+
+ source = ConvertExplicit (ec, source, target_type, l);
+ if (source == null){
+ Error_CannotConvertImplicit (l, source_type, target_type);
+ return null;
+ }
+
+ //
+ // 2. and the original right side is implicitly convertible to
+ // the type of target_type.
+ //
+ if (StandardConversionExists (a.original_source, target_type))
+ return this;
+
+ Error_CannotConvertImplicit (l, a.original_source.Type, target_type);
+ return null;
+ }
+ }
+
+ source = ConvertImplicitRequired (ec, source, target_type, l);
+ if (source == null)
+ return null;
+
return this;
}
// just use `dup' to propagate the result
//
IAssignMethod am = (IAssignMethod) target;
+
+ if (this is CompoundAssign){
+ am.CacheTemporaries (ec);
+ }
if (is_statement)
am.EmitAssign (ec, source);
Emit (ec, true);
}
}
+
+
+ //
+ // 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)
+ {
+ original_source = source;
+ this.op = op;
+ }
+
+ public Expression ResolveSource (EmitContext ec)
+ {
+ return original_source.Resolve (ec);
+ }
+
+ public override Expression DoResolve (EmitContext ec)
+ {
+ target = target.ResolveLValue (ec, source);
+ if (target == null)
+ return null;
+
+ original_source = original_source.Resolve (ec);
+ if (original_source == null)
+ return null;
+
+ //
+ // 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, l);
+ return base.DoResolve (ec);
+ }
+ }
}
projects / mono.git / blobdiff