//
// assign.cs: Assignments.
//
-// Author:
+// Authors:
// Miguel de Icaza (miguel@ximian.com)
+// Martin Baulig (martin@gnome.org)
//
// (C) 2001, 2002 Ximian, Inc.
//
+// This program is free software; you can redistribute it and/or
+// modify it under the terms of the GNU General Public License
+// as published by the Free Software Foundation; either version 2
+// of the License, or (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program; if not, write to the Free Software
+// Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+
using System;
+using System.Collections;
using System.Reflection;
using System.Reflection.Emit;
-namespace Mono.CSharp {
+namespace Mono.MonoBASIC {
/// <summary>
/// This interface is implemented by expressions that can be assigned to.
{
type = t;
eclass = ExprClass.Value;
+ loc = Location.Null;
builder = ec.GetTemporaryStorage (t);
}
{
type = t;
eclass = ExprClass.Value;
+ loc = Location.Null;
builder = b;
}
/// the expression represented by target.
/// </summary>
public class Assign : ExpressionStatement {
- protected Expression target, source;
- public Location l;
+ 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;
public Assign (Expression target, Expression source, Location l)
{
this.target = target;
- this.source = source;
- this.l = l;
+ this.source = this.real_source = source;
+ this.loc = l;
+ }
+
+ protected Assign (Assign embedded, Location l)
+ : this (embedded.target, embedded.source, l)
+ {
+ this.is_embedded = true;
}
public Expression Target {
" used from within the type '" + ei.DeclaringType + "')");
}
+ bool IsLateIndexSet(Expression target, EmitContext ec)
+ {
+ if (target is Invocation)
+ {
+ Invocation i = (Invocation) target;
+ if (i.Expr is MethodGroupExpr)
+ {
+ MethodGroupExpr mg = (MethodGroupExpr) i.Expr;
+ if (mg.Name == "LateIndexSet")
+ return true;
+ }
+ }
+ return false;
+ }
+
//
// Will return either `this' or an instance of `New'.
//
public override Expression DoResolve (EmitContext ec)
{
- source = source.Resolve (ec);
+ // Create an embedded assignment if our source is an assignment.
+ if (source is Assign)
+ source = embedded = new Assign ((Assign) source, loc);
+
+ real_source = source = source.Resolve (ec);
if (source == 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)
+ 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;
+ }
+
+ // 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);
-
+
if (target == null)
return null;
Type target_type = target.Type;
- Type source_type = source.Type;
-
- type = target_type;
+ Type source_type = real_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;
//
PropertyExpr property_assign = (PropertyExpr) target;
if (source_type != target_type){
- source = ConvertImplicitRequired (ec, source, target_type, l);
+ source = ConvertImplicitRequired (ec, source, target_type, loc);
if (source == null)
return null;
}
//
if (!property_assign.VerifyAssignable ())
return null;
-
+
return this;
}
- if (target is IndexerAccess)
+ if (target is IndexerAccess) {
return this;
+ }
if (target is EventExpr) {
-
- Binary tmp;
EventInfo ei = ((EventExpr) target).EventInfo;
-
Expression ml = MemberLookup (
ec, ec.ContainerType, ei.Name,
- MemberTypes.Event, AllBindingFlags, l);
+ MemberTypes.Event, AllBindingFlags | BindingFlags.DeclaredOnly, loc);
if (ml == null) {
//
// If this is the case, then the Event does not belong
- // to this TypeContainer and so, according to the spec
+ // to this Type and so, according to the spec
// is allowed to only appear on the left hand of
// the += and -= operators
//
- // Note that if target will not appear as an EventExpr
+ // 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 Binary)) {
- error70 (ei, l);
+ error70 (ei, loc);
return null;
} else {
- tmp = ((Binary) source);
+ Binary tmp = ((Binary) source);
if (tmp.Oper != Binary.Operator.Addition &&
tmp.Oper != Binary.Operator.Subtraction) {
- error70 (ei, l);
+ error70 (ei, loc);
return null;
}
}
}
}
- if (source is New && target_type.IsSubclassOf (TypeManager.value_type)){
+ if (source is New && target_type.IsValueType){
New n = (New) source;
n.ValueTypeVariable = target;
}
if (target.eclass != ExprClass.Variable && target.eclass != ExprClass.EventAccess){
- Report.Error (131, l,
+ Report.Error (30074, loc,
"Left hand of an assignment must be a variable, " +
"a property or an indexer");
return null;
}
+ if ((source.eclass == ExprClass.Type) && (source is TypeExpr)) {
+ source.Error118 ("variable or value");
+ return null;
+ } else if (source is MethodGroupExpr){
+ ((MethodGroupExpr) source).ReportUsageError ();
+ return null;
+ }
+
if (target_type == source_type)
return this;
// target_type
//
- source = ConvertExplicit (ec, source, target_type, l);
+ source = ConvertExplicit (ec, source, target_type, false, loc);
if (source == null){
- Error_CannotConvertImplicit (l, source_type, target_type);
+ Error_CannotConvertImplicit (loc, source_type, target_type);
return null;
}
if (StandardConversionExists (a.original_source, target_type))
return this;
- Error_CannotConvertImplicit (l, a.original_source.Type, target_type);
+ Error_CannotConvertImplicit (loc, a.original_source.Type, target_type);
return null;
}
}
-
- source = ConvertImplicitRequired (ec, source, target_type, l);
+ if (IsLateIndexSet(target, ec))
+ {
+ // then we must rewrite the whole expression, since
+ // THIS assign is no longer valid/needed
+ Invocation i = (Invocation) target;
+ return i;
+ }
+ source = ConvertImplicitRequired (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)
+ {
+ // Emit an embedded assignment.
+
+ 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);
+ }
+
+ if (embedded != null)
+ embedded.EmitEmbedded (ec);
+
+ // 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);
+ }
+
+ Expression temp_source = (temp != null) ? temp : source;
+ ((IAssignMethod) target).EmitAssign (ec, temp_source);
+ return temp_source;
+ }
+
+ void ReleaseEmbedded (EmitContext ec)
+ {
+ if (embedded != null)
+ embedded.ReleaseEmbedded (ec);
+
+ if (real_temp != null)
+ real_temp.Release (ec);
+
+ if (must_free_temp)
+ temp.Release (ec);
+ }
+
void Emit (EmitContext ec, bool is_statement)
{
if (target is EventExpr) {
if (this is CompoundAssign){
am.CacheTemporaries (ec);
}
-
+
+ Expression temp_source;
+ if (embedded != null) {
+ temp_source = embedded.EmitEmbedded (ec);
+
+ if (temp != null) {
+ source.Emit (ec);
+ temp.Store (ec);
+ temp_source = temp;
+ }
+ } else
+ temp_source = source;
+
if (is_statement)
- am.EmitAssign (ec, source);
+ am.EmitAssign (ec, temp_source);
else {
LocalTemporary tempo;
-
+
tempo = new LocalTemporary (ec, source.Type);
-
- source.Emit (ec);
+
+ temp_source.Emit (ec);
tempo.Store (ec);
am.EmitAssign (ec, tempo);
tempo.Emit (ec);
tempo.Release (ec);
}
+
+ if (embedded != null) {
+ if (temp != null)
+ temp.Release (ec);
+ embedded.ReleaseEmbedded (ec);
+ }
}
public override void Emit (EmitContext ec)
// into a tree, to guarantee that we do not have side
// effects.
//
- source = new Binary (op, target, original_source, l);
+ source = new Binary (op, target, original_source, loc);
return base.DoResolve (ec);
}
}
}
-
-
-
-
projects / mono.git / blobdiff