X-Git-Url: http://wien.tomnetworks.com/gitweb/?a=blobdiff_plain;f=mcs%2Fgmcs%2Fiterators.cs;h=82250f6bb91c6a674bb7c893de85283e02c8d181;hb=8a0c60914e6a8dffa512d9b0c1c1cb155df90f5f;hp=6f2d32ab29e6e92160953a52c4ef0f8e690c3238;hpb=84b709f11124509f2268722945b803ee7e631d93;p=mono.git diff --git a/mcs/gmcs/iterators.cs b/mcs/gmcs/iterators.cs index 6f2d32ab29e..82250f6bb91 100644 --- a/mcs/gmcs/iterators.cs +++ b/mcs/gmcs/iterators.cs @@ -8,7 +8,7 @@ // // TODO: // Flow analysis for Yield. -// Emit calls to parent object constructor. +// Emit calls to base object constructor. // // Generics note: // Current should be defined to return T, and IEnumerator.Current returns object @@ -30,33 +30,42 @@ namespace Mono.CSharp { } public class Yield : Statement { - public Expression expr; - bool in_exc; - + Expression expr; + ArrayList finally_blocks; + public Yield (Expression expr, Location l) { this.expr = expr; loc = l; } - public static bool CheckContext (EmitContext ec, Location loc) + public static bool CheckContext (EmitContext ec, Location loc, bool isYieldBreak) { - if (ec.CurrentBranching.InFinally (true)){ - Report.Error (-208, loc, "yield statement can not appear in finally clause"); + if (ec.InFinally) { + Report.Error (1625, loc, "Cannot yield in the body of a " + + "finally clause"); return false; - } - if (ec.CurrentBranching.InCatch ()){ - Report.Error (-209, loc, "yield statement can not appear in the catch clause"); + } + + if (ec.InUnsafe) { + Report.Error (1629, loc, "Unsafe code may not appear in iterators"); return false; } - if (ec.InAnonymousMethod){ - Report.Error (-209, loc, "yield statement can not appear inside an anonymoud method"); + + AnonymousContainer am = ec.CurrentAnonymousMethod; + if ((am != null) && !am.IsIterator){ + Report.Error (1621, loc, "The yield statement cannot be used inside anonymous method blocks"); return false; } - // - // FIXME: Missing check for Yield inside try block that contains catch clauses - // + if (ec.CurrentBranching.InTryWithCatch () && (!isYieldBreak || !ec.InCatch)) { + if (!ec.InCatch) + Report.Error (1626, loc, "Cannot yield a value in the body of a " + + "try block with a catch clause"); + else + Report.Error (1631, loc, "Cannot yield a value in the body of a catch clause"); + return false; + } return true; } @@ -65,22 +74,26 @@ namespace Mono.CSharp { expr = expr.Resolve (ec); if (expr == null) return false; - if (!CheckContext (ec, loc)) + + if (!CheckContext (ec, loc, false)) return false; - in_exc = ec.CurrentBranching.InTryOrCatch (false); - Type iterator_type = IteratorHandler.Current.IteratorType; - if (expr.Type != iterator_type){ - expr = Convert.ImplicitConversionRequired (ec, expr, iterator_type, loc); + Iterator iterator = ec.CurrentIterator; + + if (expr.Type != iterator.IteratorType){ + expr = Convert.ImplicitConversionRequired ( + ec, expr, iterator.IteratorType, loc); if (expr == null) return false; } + + ec.CurrentBranching.StealFinallyClauses (ref finally_blocks); return true; } protected override void DoEmit (EmitContext ec) { - IteratorHandler.Current.MarkYield (ec, expr, in_exc); + ec.CurrentIterator.MarkYield (ec, expr, finally_blocks); } } @@ -93,7 +106,7 @@ namespace Mono.CSharp { public override bool Resolve (EmitContext ec) { - if (!Yield.CheckContext (ec, loc)) + if (!Yield.CheckContext (ec, loc, true)) return false; ec.CurrentBranching.CurrentUsageVector.Goto (); @@ -102,592 +115,1161 @@ namespace Mono.CSharp { protected override void DoEmit (EmitContext ec) { - IteratorHandler.Current.EmitYieldBreak (ec.ig, true); + ec.CurrentIterator.EmitYieldBreak (ec.ig); } } - public class IteratorHandler { - // - // Points to the current iterator handler, will be probed by - // Yield and YieldBreak to get their context information - // - public static IteratorHandler Current; - - // - // The typebuilder to the proxy class we create - // - TypeBuilder enumerator_proxy_class; - TypeBuilder enumerable_proxy_class; - - // - // The type of this iterator, object by default. - // - public Type IteratorType; - - // - // The members we create on the proxy class - // - MethodBuilder move_next_method; - MethodBuilder reset_method; - MethodBuilder get_current_method; - MethodBuilder dispose_method; - MethodBuilder getenumerator_method; - PropertyBuilder current_property; - ConstructorBuilder enumerator_proxy_constructor; - ConstructorBuilder enumerable_proxy_constructor; - - // - // The PC for the state machine. - // - FieldBuilder pc_field; - - // - // The value computed for Current - // - FieldBuilder current_field; - - // - // Used to reference fields on the container class (instance methods) - // - public FieldBuilder this_field; - public FieldBuilder enumerable_this_field; + public class Iterator : Class { + protected ToplevelBlock original_block; + protected ToplevelBlock block; - // - // References the parameters - // + Type original_iterator_type; + TypeExpr iterator_type_expr; + bool is_enumerable; + public readonly bool IsStatic; - public FieldBuilder [] parameter_fields; - FieldBuilder [] enumerable_parameter_fields; - // // The state as we generate the iterator // - ArrayList resume_labels = new ArrayList (); + Label move_next_ok, move_next_error; + ArrayList resume_points = new ArrayList (); int pc; // // Context from the original method // - string name; + GenericMethod generic_method; TypeContainer container; - Type return_type; - Type [] param_types; - InternalParameters parameters; - Block original_block; - Location loc; - int modifiers; + TypeExpr current_type; + Type this_type; + Parameters parameters; + Parameters original_parameters; + IMethodData orig_method; + + MethodInfo dispose_method; + MoveNextMethod move_next_method; + Constructor ctor; + CaptureContext cc; + + Expression enumerator_type; + Expression enumerable_type; + Expression generic_enumerator_type; + Expression generic_enumerable_type; + TypeArguments generic_args; + EmitContext ec; + + protected enum State { + Uninitialized = -2, + After, + Running + } static int proxy_count; - public void EmitYieldBreak (ILGenerator ig, bool add_return) + public void EmitYieldBreak (ILGenerator ig) { ig.Emit (OpCodes.Ldarg_0); - IntConstant.EmitInt (ig, -1); - ig.Emit (OpCodes.Stfld, pc_field); - if (add_return){ - ig.Emit (OpCodes.Ldc_I4_0); - ig.Emit (OpCodes.Ret); - } + IntConstant.EmitInt (ig, (int) State.After); + ig.Emit (OpCodes.Stfld, pc_field.FieldBuilder); + ig.Emit (OpCodes.Br, move_next_error); } - void EmitThrowInvalidOp (ILGenerator ig) + public void EmitMoveNext (EmitContext ec) { - ig.Emit (OpCodes.Newobj, TypeManager.invalid_operation_ctor); - ig.Emit (OpCodes.Throw); - } - - void Create_MoveNext () - { - move_next_method = enumerator_proxy_class.DefineMethod ( - "System.IEnumerator.MoveNext", - MethodAttributes.HideBySig | MethodAttributes.NewSlot | - MethodAttributes.Virtual, - CallingConventions.HasThis, TypeManager.bool_type, TypeManager.NoTypes); - enumerator_proxy_class.DefineMethodOverride (move_next_method, TypeManager.bool_movenext_void); + ILGenerator ig = ec.ig; + + move_next_ok = ig.DefineLabel (); + move_next_error = ig.DefineLabel (); - ILGenerator ig = move_next_method.GetILGenerator (); - EmitContext ec = new EmitContext ( - container, loc, ig, - TypeManager.void_type, modifiers); + LocalBuilder retval = ec.GetTemporaryLocal (TypeManager.int32_type); + + ig.BeginExceptionBlock (); Label dispatcher = ig.DefineLabel (); ig.Emit (OpCodes.Br, dispatcher); - Label entry_point = ig.DefineLabel (); - ig.MarkLabel (entry_point); - resume_labels.Add (entry_point); - - Current = this; - SymbolWriter sw = CodeGen.SymbolWriter; - if ((sw != null) && !Location.IsNull (loc) && !Location.IsNull (original_block.EndLocation)) { - sw.OpenMethod (container, move_next_method, loc, original_block.EndLocation); - ec.EmitTopBlock (original_block, parameters, loc); + ResumePoint entry_point = new ResumePoint (null); + resume_points.Add (entry_point); + entry_point.Define (ig); - sw.CloseMethod (); - } else { - ec.EmitTopBlock (original_block, parameters, loc); - } - Current = null; + ec.EmitTopBlock (orig_method, original_block); - EmitYieldBreak (ig, true); + EmitYieldBreak (ig); - // - // FIXME: Split the switch in blocks that can be consumed by switch. - // ig.MarkLabel (dispatcher); - - Label [] labels = new Label [resume_labels.Count]; - resume_labels.CopyTo (labels); + + Label [] labels = new Label [resume_points.Count]; + for (int i = 0; i < labels.Length; i++) + labels [i] = ((ResumePoint) resume_points [i]).Label; + ig.Emit (OpCodes.Ldarg_0); - ig.Emit (OpCodes.Ldfld, pc_field); + ig.Emit (OpCodes.Ldfld, pc_field.FieldBuilder); ig.Emit (OpCodes.Switch, labels); - ig.Emit (OpCodes.Ldc_I4_0); - ig.Emit (OpCodes.Ret); - } - // - // Invoked when a local variable declaration needs to be mapped to - // a field in our proxy class - // - // Prefixes registered: - // v_ for EmitContext.MapVariable - // s_ for Storage - // - public FieldBuilder MapVariable (string pfx, string name, Type t) - { - return enumerator_proxy_class.DefineField (pfx + name, t, FieldAttributes.Public); - } - - void Create_Reset () - { - reset_method = enumerator_proxy_class.DefineMethod ( - "System.IEnumerator.Reset", - MethodAttributes.HideBySig | MethodAttributes.NewSlot | - MethodAttributes.Virtual, - CallingConventions.HasThis, TypeManager.void_type, TypeManager.NoTypes); - enumerator_proxy_class.DefineMethodOverride (reset_method, TypeManager.void_reset_void); - ILGenerator ig = reset_method.GetILGenerator (); - EmitThrowInvalidOp (ig); + Label end = ig.DefineLabel (); + + ig.MarkLabel (move_next_error); + ig.Emit (OpCodes.Ldc_I4_0); + ig.Emit (OpCodes.Stloc, retval); + ig.Emit (OpCodes.Leave, end); + + ig.MarkLabel (move_next_ok); + ig.Emit (OpCodes.Ldc_I4_1); + ig.Emit (OpCodes.Stloc, retval); + ig.Emit (OpCodes.Leave, end); + + ig.BeginFaultBlock (); + + ig.Emit (OpCodes.Ldarg_0); + ig.Emit (OpCodes.Callvirt, dispose_method); + + ig.EndExceptionBlock (); + + ig.MarkLabel (end); + ig.Emit (OpCodes.Ldloc, retval); + ig.Emit (OpCodes.Ret); } - void Create_Current () + public void EmitDispose (EmitContext ec) { - get_current_method = enumerator_proxy_class.DefineMethod ( - "System.IEnumerator.get_Current", - MethodAttributes.HideBySig | MethodAttributes.SpecialName | - MethodAttributes.NewSlot | MethodAttributes.Virtual, - CallingConventions.HasThis, TypeManager.object_type, TypeManager.NoTypes); - enumerator_proxy_class.DefineMethodOverride (get_current_method, TypeManager.object_getcurrent_void); + ILGenerator ig = ec.ig; - current_property = enumerator_proxy_class.DefineProperty ( - "Current", - PropertyAttributes.RTSpecialName | PropertyAttributes.SpecialName, - TypeManager.object_type, null); + Label end = ig.DefineLabel (); + Label dispatcher = ig.DefineLabel (); + ig.Emit (OpCodes.Br, dispatcher); - current_property.SetGetMethod (get_current_method); - - ILGenerator ig = get_current_method.GetILGenerator (); + Label [] labels = new Label [resume_points.Count]; + for (int i = 0; i < labels.Length; i++) { + ResumePoint point = (ResumePoint) resume_points [i]; + + if (point.FinallyBlocks == null) { + labels [i] = end; + continue; + } + + labels [i] = ig.DefineLabel (); + ig.MarkLabel (labels [i]); + + ig.BeginExceptionBlock (); + ig.BeginFinallyBlock (); + foreach (ExceptionStatement stmt in point.FinallyBlocks) { + if (stmt != null) + stmt.EmitFinally (ec); + } + + ig.EndExceptionBlock (); + ig.Emit (OpCodes.Br, end); + } + + ig.MarkLabel (dispatcher); ig.Emit (OpCodes.Ldarg_0); - ig.Emit (OpCodes.Ldfld, pc_field); - ig.Emit (OpCodes.Ldc_I4_0); - Label return_current = ig.DefineLabel (); - ig.Emit (OpCodes.Bgt, return_current); - EmitThrowInvalidOp (ig); - - ig.MarkLabel (return_current); + ig.Emit (OpCodes.Ldfld, pc_field.FieldBuilder); + ig.Emit (OpCodes.Switch, labels); + ig.Emit (OpCodes.Ldarg_0); - ig.Emit (OpCodes.Ldfld, current_field); - ig.Emit (OpCodes.Ret); + IntConstant.EmitInt (ig, (int) State.After); + ig.Emit (OpCodes.Stfld, pc_field.FieldBuilder); + + ig.MarkLabel (end); } - void Create_Dispose () + protected class ResumePoint { - dispose_method = enumerator_proxy_class.DefineMethod ( - "System.IDisposable.Dispose", - MethodAttributes.HideBySig | MethodAttributes.SpecialName | - MethodAttributes.NewSlot | MethodAttributes.Virtual, - CallingConventions.HasThis, TypeManager.void_type, TypeManager.NoTypes); - enumerator_proxy_class.DefineMethodOverride (dispose_method, TypeManager.void_dispose_void); - ILGenerator ig = dispose_method.GetILGenerator (); + public Label Label; + public readonly ExceptionStatement[] FinallyBlocks; - EmitYieldBreak (ig, false); - ig.Emit (OpCodes.Ret); - } - - void Create_GetEnumerator () - { - getenumerator_method = enumerable_proxy_class.DefineMethod ( - "IEnumerable.GetEnumerator", - MethodAttributes.HideBySig | MethodAttributes.SpecialName | - MethodAttributes.NewSlot | MethodAttributes.Virtual, - CallingConventions.HasThis, TypeManager.ienumerator_type, TypeManager.NoTypes); - - enumerable_proxy_class.DefineMethodOverride (getenumerator_method, TypeManager.ienumerable_getenumerator_void); - ILGenerator ig = getenumerator_method.GetILGenerator (); - - ig.Emit (OpCodes.Newobj, (ConstructorInfo) enumerator_proxy_constructor); - if (enumerable_this_field != null || parameters.Count > 0){ - LocalBuilder obj = ig.DeclareLocal (enumerator_proxy_class); - ig.Emit (OpCodes.Stloc, obj); - if (enumerable_this_field != null){ - ig.Emit (OpCodes.Ldloc, obj); - ig.Emit (OpCodes.Ldarg_0); - ig.Emit (OpCodes.Ldfld, enumerable_this_field); - ig.Emit (OpCodes.Stfld, this_field); - } - - for (int i = 0; i < parameters.Count; i++){ - ig.Emit (OpCodes.Ldloc, obj); - ig.Emit (OpCodes.Ldarg_0); - ig.Emit (OpCodes.Ldfld, enumerable_parameter_fields [i]); - ig.Emit (OpCodes.Stfld, parameter_fields [i]); + public ResumePoint (ArrayList list) + { + if (list != null) { + FinallyBlocks = new ExceptionStatement [list.Count]; + list.CopyTo (FinallyBlocks, 0); } - ig.Emit (OpCodes.Ldloc, obj); } - - ig.Emit (OpCodes.Ret); + + public void Define (ILGenerator ig) + { + Label = ig.DefineLabel (); + ig.MarkLabel (Label); + } } // // Called back from Yield // - public void MarkYield (EmitContext ec, Expression expr, bool in_exc) + public void MarkYield (EmitContext ec, Expression expr, + ArrayList finally_blocks) { ILGenerator ig = ec.ig; // Store the new current ig.Emit (OpCodes.Ldarg_0); expr.Emit (ec); - ig.Emit (OpCodes.Stfld, current_field); + ig.Emit (OpCodes.Stfld, current_field.FieldBuilder); // increment pc pc++; ig.Emit (OpCodes.Ldarg_0); IntConstant.EmitInt (ig, pc); - ig.Emit (OpCodes.Stfld, pc_field); + ig.Emit (OpCodes.Stfld, pc_field.FieldBuilder); // Return ok - ig.Emit (OpCodes.Ldc_I4_1); - - // Find out how to "leave" - if (in_exc || !ec.IsLastStatement){ - Type old = ec.ReturnType; - ec.ReturnType = TypeManager.int32_type; - ig.Emit (OpCodes.Stloc, ec.TemporaryReturn ()); - ec.ReturnType = old; - } - - if (in_exc){ - ec.NeedReturnLabel (); - ig.Emit (OpCodes.Leave, ec.ReturnLabel); - } else if (ec.IsLastStatement){ - ig.Emit (OpCodes.Ret); - } else { - ec.NeedReturnLabel (); - ig.Emit (OpCodes.Br, ec.ReturnLabel); - } - - Label resume_point = ig.DefineLabel (); - ig.MarkLabel (resume_point); - resume_labels.Add (resume_point); + ig.Emit (OpCodes.Br, move_next_ok); + + ResumePoint point = new ResumePoint (finally_blocks); + resume_points.Add (point); + point.Define (ig); + } + + public void MarkFinally (EmitContext ec, ArrayList finally_blocks) + { + ILGenerator ig = ec.ig; + + // increment pc + pc++; + ig.Emit (OpCodes.Ldarg_0); + IntConstant.EmitInt (ig, pc); + ig.Emit (OpCodes.Stfld, pc_field.FieldBuilder); + + ResumePoint point = new ResumePoint (finally_blocks); + resume_points.Add (point); + point.Define (ig); + } + + private static MemberName MakeProxyName (string name, GenericMethod generic, Location loc) + { + int pos = name.LastIndexOf ('.'); + if (pos > 0) + name = name.Substring (pos + 1); + + string proxy_name = "<" + name + ">__" + (proxy_count++); + + if (generic != null) { + TypeArguments args = new TypeArguments (loc); + foreach (TypeParameter tparam in generic.CurrentTypeParameters) + args.Add (new SimpleName (tparam.Name, loc)); + return new MemberName (proxy_name, args, loc); + } else + return new MemberName (proxy_name, loc); } // - // Creates the IEnumerator Proxy class + // Our constructor // - void MakeEnumeratorProxy () + public Iterator (IMethodData m_container, DeclSpace parent, GenericMethod generic, + int modifiers) + : base (parent.NamespaceEntry, parent, + MakeProxyName (m_container.MethodName.Name, generic, m_container.Location), + (modifiers & Modifiers.UNSAFE) | Modifiers.PRIVATE, null) { - TypeExpr [] proxy_base_interfaces = new TypeExpr [2]; - proxy_base_interfaces [0] = new TypeExpression (TypeManager.ienumerator_type, loc); - proxy_base_interfaces [1] = new TypeExpression (TypeManager.idisposable_type, loc); - Type [] proxy_base_itypes = new Type [2]; - proxy_base_itypes [0] = TypeManager.ienumerator_type; - proxy_base_itypes [1] = TypeManager.idisposable_type; - TypeBuilder container_builder = container.TypeBuilder; + this.orig_method = m_container; - // - // Create the class - // - enumerator_proxy_class = container_builder.DefineNestedType ( - "", - TypeAttributes.AutoLayout | TypeAttributes.Class |TypeAttributes.NestedPrivate, - TypeManager.object_type, proxy_base_itypes); + this.generic_method = generic; + this.container = parent.PartialContainer; + this.original_parameters = m_container.ParameterInfo; + this.original_block = orig_method.Block; + this.block = new ToplevelBlock (orig_method.Block, parameters, orig_method.Location); - TypeManager.RegisterBuilder (enumerator_proxy_class, proxy_base_interfaces); + if (generic != null) { + ArrayList constraints = new ArrayList (); + foreach (TypeParameter tparam in generic.TypeParameters) + constraints.Add (tparam.Constraints); - // - // Define our fields - // - pc_field = enumerator_proxy_class.DefineField ("PC", TypeManager.int32_type, FieldAttributes.Assembly); - current_field = enumerator_proxy_class.DefineField ("current", IteratorType, FieldAttributes.Assembly); - if ((modifiers & Modifiers.STATIC) == 0) - this_field = enumerator_proxy_class.DefineField ("THIS", container.TypeBuilder, FieldAttributes.Assembly); + SetParameterInfo (constraints); + } + + IsStatic = (modifiers & Modifiers.STATIC) != 0; + } + + public AnonymousContainer Host { + get { return move_next_method; } + } - parameter_fields = new FieldBuilder [parameters.Count]; - for (int i = 0; i < parameters.Count; i++){ - parameter_fields [i] = enumerator_proxy_class.DefineField ( - String.Format ("tor{0}_{1}", i, parameters.ParameterName (i)), - parameters.ParameterType (i), FieldAttributes.Assembly); + public bool DefineIterator () + { + ec = new EmitContext (this, this, Location, null, null, ModFlags); + ec.CurrentAnonymousMethod = move_next_method; + ec.InIterator = true; + + if (!CheckType ()) { + Report.Error (1624, Location, + "The body of `{0}' cannot be an iterator block because `{1}' is not an iterator interface type", + orig_method.GetSignatureForError (), TypeManager.CSharpName (orig_method.ReturnType)); + return false; } - - // - // Define a constructor - // - enumerator_proxy_constructor = enumerator_proxy_class.DefineConstructor ( - MethodAttributes.Public | MethodAttributes.HideBySig | - MethodAttributes.SpecialName | MethodAttributes.RTSpecialName, - CallingConventions.HasThis, TypeManager.NoTypes); - InternalParameters parameter_info = new InternalParameters ( - TypeManager.NoTypes, Parameters.EmptyReadOnlyParameters); - TypeManager.RegisterMethod (enumerator_proxy_constructor, parameter_info, TypeManager.NoTypes); + for (int i = 0; i < original_parameters.Count; i++){ + Parameter.Modifier mod = original_parameters.ParameterModifier (i); + if ((mod & (Parameter.Modifier.REF | Parameter.Modifier.OUT)) != 0){ + Report.Error ( + 1623, Location, + "Iterators cannot have ref or out parameters"); + return false; + } - // - // Our constructor - // - ILGenerator ig = enumerator_proxy_constructor.GetILGenerator (); - ig.Emit (OpCodes.Ldarg_0); - ig.Emit (OpCodes.Call, TypeManager.object_ctor); + if ((mod & Parameter.Modifier.ARGLIST) != 0) { + Report.Error (1636, Location, "__arglist is not allowed in parameter list of iterators"); + return false; + } - ig.Emit (OpCodes.Ret); + if (original_parameters.ParameterType (i).IsPointer) { + Report.Error (1637, Location, "Iterators cannot have unsafe parameters or yield types"); + return false; + } + } + + if (container.CurrentType != null) + this_type = container.CurrentType; + else + this_type = container.TypeBuilder; + + container.AddIterator (this); + + orig_method.Block = block; + return true; } - // - // Creates the IEnumerable proxy class - // - void MakeEnumerableProxy () + MethodInfo FetchMethodDispose () { - TypeBuilder container_builder = container.TypeBuilder; - Type [] proxy_base_interfaces = new Type [1]; - proxy_base_interfaces [0] = TypeManager.ienumerable_type; + MemberList dispose_list; - // - // Creates the Enumerable proxy class. - // - enumerable_proxy_class = container_builder.DefineNestedType ( - "", - TypeAttributes.AutoLayout | TypeAttributes.Class |TypeAttributes.NestedPublic, - TypeManager.object_type, proxy_base_interfaces); + dispose_list = FindMembers ( + current_type.Type, + MemberTypes.Method, BindingFlags.Public | BindingFlags.Instance, + Type.FilterName, "Dispose"); - // - // Constructor - // - if ((modifiers & Modifiers.STATIC) == 0){ - enumerable_this_field = enumerable_proxy_class.DefineField ( - "THIS", container.TypeBuilder, FieldAttributes.Assembly); + if (dispose_list.Count != 1) + throw new InternalErrorException ("Cannot find Dipose() method."); + + return (MethodInfo) dispose_list [0]; + } + + protected override bool DoDefineMembers () + { + ec.InIterator = true; + ec.CurrentAnonymousMethod = move_next_method; + ec.capture_context = cc; + + if (!base.DoDefineMembers ()) + return false; + + dispose_method = FetchMethodDispose (); + if (dispose_method == null) + return false; + + return true; + } + + public override bool Define () + { + if (!base.Define ()) + return false; + + ec.InIterator = true; + ec.CurrentAnonymousMethod = move_next_method; + ec.capture_context = cc; + + ec.TypeContainer = ec.TypeContainer.Parent; + + if (ec.TypeContainer.CurrentType != null) + ec.ContainerType = ec.TypeContainer.CurrentType; + else + ec.ContainerType = ec.TypeContainer.TypeBuilder; + + ec.ig = move_next_method.method.MethodBuilder.GetILGenerator (); + + if (!ctor.Define ()) + return false; + + bool unreachable; + + if (!ec.ResolveTopBlock (null, original_block, parameters, orig_method, out unreachable)) + return false; + + if (!ec.ResolveTopBlock (null, block, parameters, orig_method, out unreachable)) + return false; + + original_block.CompleteContexts (); + + cc.EmitAnonymousHelperClasses (ec); + + return true; + } + + TypeExpr InflateType (Type it) + { + if (generic_method == null) + return new TypeExpression (it, Location); + + if (it.IsGenericParameter && (it.DeclaringMethod != null)) { + int pos = it.GenericParameterPosition; + it = CurrentTypeParameters [pos].Type; + } else if (it.IsGenericType) { + Type[] args = it.GetGenericArguments (); + + TypeArguments inflated = new TypeArguments (Location); + foreach (Type t in args) + inflated.Add (InflateType (t)); + + return new ConstructedType (it, inflated, Location); + } else if (it.IsArray) { + TypeExpr et_expr = InflateType (it.GetElementType ()); + int rank = it.GetArrayRank (); + + Type et = et_expr.ResolveAsTypeTerminal (ec, false).Type; + it = et.MakeArrayType (rank); } - enumerable_parameter_fields = new FieldBuilder [parameters.Count]; - for (int i = 0; i < parameters.Count; i++){ - enumerable_parameter_fields [i] = enumerable_proxy_class.DefineField ( - String.Format ("able{0}_{1}", i, parameters.ParameterName (i)), - parameters.ParameterType (i), FieldAttributes.Assembly); + + return new TypeExpression (it, Location); + } + + Parameter InflateParameter (Parameter param) + { + TypeExpr te = InflateType (param.ParameterType); + return new Parameter ( + te, param.Name, param.ModFlags, param.OptAttributes, param.Location); + } + + Parameters InflateParameters (Parameters parameters, EmitContext ec) + { + int count = parameters.FixedParameters.Length; + if (count == 0) + return Parameters.EmptyReadOnlyParameters; + Parameter[] fixed_params = new Parameter [count]; + for (int i = 0; i < count; i++) + fixed_params [i] = InflateParameter (parameters.FixedParameters [i]); + + return new Parameters (fixed_params, parameters.HasArglist); + } + + public override TypeExpr [] GetClassBases (out TypeExpr base_class) + { + iterator_type_expr = InflateType (original_iterator_type); + + generic_args = new TypeArguments (Location); + generic_args.Add (iterator_type_expr); + + ArrayList list = new ArrayList (); + if (is_enumerable) { + enumerable_type = new TypeExpression ( + TypeManager.ienumerable_type, Location); + list.Add (enumerable_type); + + generic_enumerable_type = new ConstructedType ( + TypeManager.generic_ienumerable_type, + generic_args, Location); + list.Add (generic_enumerable_type); } - - enumerable_proxy_constructor = enumerable_proxy_class.DefineConstructor ( - MethodAttributes.Public | MethodAttributes.HideBySig | - MethodAttributes.SpecialName | MethodAttributes.RTSpecialName, - CallingConventions.HasThis, TypeManager.NoTypes); - InternalParameters parameter_info = new InternalParameters ( - TypeManager.NoTypes, Parameters.EmptyReadOnlyParameters); - TypeManager.RegisterMethod (enumerable_proxy_constructor, parameter_info, TypeManager.NoTypes); - - ILGenerator ig = enumerable_proxy_constructor.GetILGenerator (); - ig.Emit (OpCodes.Ldarg_0); - ig.Emit (OpCodes.Call, TypeManager.object_ctor); - ig.Emit (OpCodes.Ret); + enumerator_type = new TypeExpression ( + TypeManager.ienumerator_type, Location); + list.Add (enumerator_type); + + list.Add (new TypeExpression (TypeManager.idisposable_type, Location)); + + generic_enumerator_type = new ConstructedType ( + TypeManager.generic_ienumerator_type, + generic_args, Location); + list.Add (generic_enumerator_type); + + Bases = list; + + return base.GetClassBases (out base_class); } // - // Populates the Enumerator Proxy class + // Returns the new block for the method, or null on failure // - void PopulateProxy () + protected override bool DefineNestedTypes () { - RootContext.RegisterHelperClass (enumerator_proxy_class); - - Create_MoveNext (); - Create_Reset (); - Create_Current (); - Create_Dispose (); + if (CurrentType != null) + current_type = new TypeExpression (CurrentType, Location); + else + current_type = new TypeExpression (TypeBuilder, Location); + + if (IsGeneric) { + foreach (TypeParameter tparam in TypeParameters) + tparam.InflateConstraints (current_type.Type); + } + + parameters = InflateParameters (original_parameters, ec); + if (!parameters.Resolve (ec)) { + // TODO: + } - if (IsIEnumerable (return_type)){ - Create_GetEnumerator (); - RootContext.RegisterHelperClass (enumerable_proxy_class); + Define_Fields (); + Define_Current (false); + Define_Current (true); + Define_MoveNext (); + Define_Reset (); + Define_Dispose (); + + Define_Constructor (); + + Create_Block (); + + if (is_enumerable) { + Define_GetEnumerator (false); + Define_GetEnumerator (true); } + + return base.DefineNestedTypes (); } - - // - // This is invoked by the EmitCode hook - // - void SetupIterator () + Field pc_field; + Field current_field; + Method dispose; + + void Create_Block () { - PopulateProxy (); + original_block.SetHaveAnonymousMethods (Location, move_next_method); + block.SetHaveAnonymousMethods (Location, move_next_method); + + cc = original_block.CaptureContext; + + int first = IsStatic ? 0 : 1; + + ArrayList args = new ArrayList (); + if (!IsStatic) { + Type t = this_type; + args.Add (new Argument ( + new ThisParameterReference (t, Location))); + cc.CaptureThis (move_next_method); + } + + args.Add (new Argument (new BoolLiteral (false, Location))); + + for (int i = 0; i < parameters.Count; i++) { + Type t = original_parameters.ParameterType (i); + Type inflated = parameters.ParameterType (i); + string name = parameters.ParameterName (i); + + args.Add (new Argument ( + new SimpleParameterReference (t, first + i, Location))); + + cc.AddParameterToContext (move_next_method, name, inflated, first + i); + } + + TypeExpr proxy_type; + if (generic_method != null) { + TypeArguments new_args = new TypeArguments (Location); + if (Parent.IsGeneric) { + foreach (TypeParameter tparam in Parent.TypeParameters) + new_args.Add (new TypeParameterExpr (tparam, Location)); + } + foreach (TypeParameter tparam in generic_method.TypeParameters) + new_args.Add (new TypeParameterExpr (tparam, Location)); + ConstructedType ct = new ConstructedType (CurrentType, new_args, Location); + proxy_type = ct.ResolveAsTypeTerminal (ec, false); + } else + proxy_type = current_type; + + Expression new_expr = new New (proxy_type, args, Location); + block.AddStatement (new NoCheckReturn (new_expr, Location)); } - // - // Our constructor - // - public IteratorHandler (string name, TypeContainer container, Type return_type, Type [] param_types, - InternalParameters parameters, int modifiers, Location loc) - { - this.name = name; - this.container = container; - this.return_type = return_type; - this.param_types = param_types; - this.parameters = parameters; - this.modifiers = modifiers; - this.loc = loc; - - IteratorType = TypeManager.object_type; - - RootContext.EmitCodeHook += new RootContext.Hook (SetupIterator); + void Define_Fields () + { + pc_field = new Field ( + this, TypeManager.system_int32_expr, Modifiers.PRIVATE, "$PC", + null, Location); + AddField (pc_field); + + current_field = new Field ( + this, iterator_type_expr, Modifiers.PRIVATE, "$current", + null, Location); + AddField (current_field); } - // - // This class is just an expression that evaluates to a type, and the - // type is our internal proxy class. Used in the generated new body - // of the original method - // - class NewInnerType : Expression { - IteratorHandler handler; - - public NewInnerType (IteratorHandler handler, Location l) + void Define_Constructor () + { + Parameters ctor_params; + + ArrayList list = new ArrayList (); + + if (!IsStatic) + list.Add (new Parameter ( + new TypeExpression (this_type, Location), + "this", Parameter.Modifier.NONE, + null, Location)); + list.Add (new Parameter ( + TypeManager.bool_type, "initialized", + Parameter.Modifier.NONE, null, Location)); + + Parameter[] old_fixed = parameters.FixedParameters; + list.AddRange (old_fixed); + + Parameter[] fixed_params = new Parameter [list.Count]; + list.CopyTo (fixed_params); + + ctor_params = new Parameters (fixed_params); + + ctor = new Constructor ( + this, MemberName.Name, Modifiers.PUBLIC, ctor_params, + new GeneratedBaseInitializer (Location), + Location); + AddConstructor (ctor); + + ctor.Block = new ToplevelBlock (block, parameters, Location); + + int first = IsStatic ? 2 : 3; + + State initial = is_enumerable ? State.Uninitialized : State.Running; + ctor.Block.AddStatement (new SetState (this, initial, Location)); + + ctor.Block.AddStatement (new If ( + new SimpleParameterReference ( + TypeManager.bool_type, first - 1, Location), + new SetState (this, State.Running, Location), + Location)); + + ctor.Block.AddStatement (new InitScope (this, Location)); + } + + Statement Create_ThrowInvalidOperation () + { + TypeExpr ex_type = new TypeExpression ( + TypeManager.invalid_operation_exception_type, Location); + + return new Throw (new New (ex_type, null, Location), Location); + } + + Statement Create_ThrowNotSupported () + { + TypeExpr ex_type = new TypeExpression ( + TypeManager.not_supported_exception_type, Location); + + return new Throw (new New (ex_type, null, Location), Location); + } + + void Define_Current (bool is_generic) + { + MemberName left; + Expression type; + if (is_generic) { + left = new MemberName ( + "System.Collections.Generic.IEnumerator", + generic_args, Location); + type = iterator_type_expr; + } else { + left = new MemberName ("System.Collections.IEnumerator", Location); + type = TypeManager.system_object_expr; + } + + MemberName name = new MemberName (left, "Current", null, Location); + + ToplevelBlock get_block = new ToplevelBlock ( + block, parameters, Location); + + get_block.AddStatement (new If ( + new Binary ( + Binary.Operator.LessThanOrEqual, + new FieldExpression (this, pc_field), + new IntLiteral ((int) State.Running, pc_field.Location)), + Create_ThrowInvalidOperation (), + new Return ( + new FieldExpression (this, current_field), Location), + Location)); + + Accessor getter = new Accessor (get_block, 0, null, Location); + + Property current = new Property ( + this, type, 0, false, name, null, getter, null); + AddProperty (current); + } + + void Define_MoveNext () + { + move_next_method = new MoveNextMethod (this, Location); + + original_block.ReParent (block, move_next_method); + + move_next_method.CreateMethod (ec); + + AddMethod (move_next_method.method); + } + + void Define_GetEnumerator (bool is_generic) + { + MemberName left; + Expression type; + if (is_generic) { + left = new MemberName ( + "System.Collections.Generic.IEnumerable", + generic_args, Location); + type = generic_enumerator_type; + } else { + left = new MemberName ("System.Collections.IEnumerable", Location); + type = enumerator_type; + } + + MemberName name = new MemberName (left, "GetEnumerator", Location); + + Method get_enumerator = new Method ( + this, null, type, 0, false, name, + Parameters.EmptyReadOnlyParameters, null); + + // + // We call append instead of add, as we need to make sure that + // this method is resolved after the MoveNext method, as that one + // triggers the computation of the AnonymousMethod Scope, which is + // required during the code generation of the enumerator + // + AppendMethod (get_enumerator); + + get_enumerator.Block = new ToplevelBlock ( + block, parameters, Location); + + get_enumerator.Block.SetHaveAnonymousMethods (Location, move_next_method); + + Expression ce = new MemberAccess ( + new SimpleName ("System.Threading.Interlocked", Location), + "CompareExchange"); + + Expression pc = new FieldExpression (this, pc_field); + Expression before = new IntLiteral ((int) State.Running, Location); + Expression uninitialized = new IntLiteral ((int) State.Uninitialized, Location); + + ArrayList args = new ArrayList (); + args.Add (new Argument (pc, Argument.AType.Ref)); + args.Add (new Argument (before, Argument.AType.Expression)); + args.Add (new Argument (uninitialized, Argument.AType.Expression)); + + get_enumerator.Block.AddStatement (new If ( + new Binary ( + Binary.Operator.Equality, + new Invocation (ce, args), + uninitialized), + new Return (new ThisParameterReference (type.Type, Location), + Location), + Location)); + + args = new ArrayList (); + if (!IsStatic) { + args.Add (new Argument (new CapturedThisReference (this, Location))); + } + + args.Add (new Argument (new BoolLiteral (true, Location))); + + for (int i = 0; i < parameters.Count; i++) { + Expression cp = new CapturedParameterReference ( + this, parameters.ParameterType (i), + parameters.ParameterName (i), Location); + args.Add (new Argument (cp)); + } + + Expression new_expr = new New (current_type, args, Location); + get_enumerator.Block.AddStatement (new Return (new_expr, Location)); + } + + protected class SimpleParameterReference : Expression + { + int idx; + + public SimpleParameterReference (Type type, int idx, Location loc) { - this.handler = handler; - eclass = ExprClass.Value; - loc = l; + this.idx = idx; + this.loc = loc; + this.type = type; + eclass = ExprClass.Variable; } public override Expression DoResolve (EmitContext ec) { - // Create the proxy class type. - handler.MakeEnumeratorProxy (); + return this; + } - if (IsIEnumerable (handler.return_type)) - handler.MakeEnumerableProxy (); + public override void Emit (EmitContext ec) + { + DoEmit (ec); + } - type = handler.return_type; - return this; + protected virtual void DoEmit (EmitContext ec) + { + ParameterReference.EmitLdArg (ec.ig, idx); + } + } + + protected class ThisParameterReference : SimpleParameterReference, IMemoryLocation + { + public ThisParameterReference (Type type, Location loc) + : base (type, 0, loc) + { } + + protected override void DoEmit (EmitContext ec) + { + base.DoEmit (ec); + if (ec.TypeContainer is Struct) + ec.ig.Emit (OpCodes.Ldobj, type); + } + + public void AddressOf (EmitContext ec, AddressOp mode) + { + if (ec.TypeContainer is Struct) + ec.ig.Emit (OpCodes.Ldarga, 0); + else + ec.ig.Emit (OpCodes.Ldarg, 0); + } + } + + protected class CapturedParameterReference : Expression + { + Iterator iterator; + string name; + + public CapturedParameterReference (Iterator iterator, Type type, + string name, Location loc) + { + this.iterator = iterator; + this.loc = loc; + this.type = type; + this.name = name; + eclass = ExprClass.Variable; } - public override Expression ResolveAsTypeStep (EmitContext ec) + public override Expression DoResolve (EmitContext ec) { - return DoResolve (ec); + return this; } public override void Emit (EmitContext ec) { - ILGenerator ig = ec.ig; - FieldBuilder this_field = null; - bool is_ienumerable = IsIEnumerable (handler.return_type); - Type temp_type; - - if (is_ienumerable){ - temp_type = handler.enumerable_proxy_class; - ig.Emit (OpCodes.Newobj, (ConstructorInfo) handler.enumerable_proxy_constructor); - this_field = handler.enumerable_this_field; - } else { - temp_type = handler.enumerator_proxy_class; - ig.Emit (OpCodes.Newobj, (ConstructorInfo) handler.enumerator_proxy_constructor); - this_field = handler.this_field; - } + ec.CurrentAnonymousMethod = iterator.move_next_method; - if (this_field == null && handler.parameters.Count == 0) - return; + LocalTemporary dummy = null; - LocalBuilder temp = ec.GetTemporaryLocal (temp_type); - - ig.Emit (OpCodes.Stloc, temp); - // - // Initialize This - // - int first = 0; - if (this_field != null){ - ig.Emit (OpCodes.Ldloc, temp); - ig.Emit (OpCodes.Ldarg_0); - if (handler.container is Struct) - ig.Emit (OpCodes.Ldobj, handler.container.TypeBuilder); - ig.Emit (OpCodes.Stfld, this_field); - first = 1; - } + iterator.cc.EmitParameter (ec, name, false, false, ref dummy); + } + } - for (int i = 0; i < handler.parameters.Count; i++){ - ig.Emit (OpCodes.Ldloc, temp); - ParameterReference.EmitLdArg (ig, i + first); - if (is_ienumerable) - ig.Emit (OpCodes.Stfld, handler.enumerable_parameter_fields [i]); - else - ig.Emit (OpCodes.Stfld, handler.parameter_fields [i]); - } - - // - // Initialize fields - // - ig.Emit (OpCodes.Ldloc, temp); - ec.FreeTemporaryLocal (temp, handler.container.TypeBuilder); + protected class CapturedThisReference : Expression + { + public CapturedThisReference (Iterator iterator, Location loc) + { + this.loc = loc; + this.type = iterator.this_type; + eclass = ExprClass.Variable; + } + + public override Expression DoResolve (EmitContext ec) + { + return this; + } + + public override void Emit (EmitContext ec) + { + ec.EmitThis (false); } } - // - // This return statement tricks return into not flagging an error for being - // used in a Yields method - // - class NoCheckReturn : Return { - public NoCheckReturn (Expression expr, Location loc) : base (expr, loc) + protected class FieldExpression : Expression + { + Iterator iterator; + Field field; + + public FieldExpression (Iterator iterator, Field field) + { + this.iterator = iterator; + this.field = field; + this.loc = iterator.Location; + } + + public override Expression DoResolveLValue (EmitContext ec, Expression right_side) + { + FieldExpr fexpr = new FieldExpr (field.FieldBuilder, loc); + fexpr.InstanceExpression = new ThisParameterReference ( + iterator.this_type, loc); + return fexpr.ResolveLValue (ec, right_side, loc); + } + + public override Expression DoResolve (EmitContext ec) + { + FieldExpr fexpr = new FieldExpr (field.FieldBuilder, loc); + fexpr.InstanceExpression = new ThisParameterReference ( + iterator.this_type, loc); + return fexpr.Resolve (ec); + } + + public override void Emit (EmitContext ec) + { + throw new InvalidOperationException (); + } + } + + protected class MoveNextMethod : AnonymousContainer + { + Iterator iterator; + + public MoveNextMethod (Iterator iterator, Location loc) + : base (iterator.parameters, iterator.original_block, loc) + { + this.iterator = iterator; + } + + protected override bool CreateMethodHost (EmitContext ec) + { + method = new Method ( + iterator, null, TypeManager.system_boolean_expr, + Modifiers.PUBLIC, false, new MemberName ("MoveNext", loc), + Parameters.EmptyReadOnlyParameters, null); + + method.Block = Block; + + MoveNextStatement inline = new MoveNextStatement (iterator, loc); + Block.AddStatement (inline); + + return true; + } + + public bool CreateMethod (EmitContext ec) { + return CreateMethodHost (ec); + } + + public override Iterator Iterator { + get { return iterator; } + } + + public void ComputeHost () + { + ComputeMethodHost (); } + public override bool IsIterator { + get { return true; } + } + + public override void CreateScopeType (EmitContext ec, ScopeInfo scope) + { + scope.ScopeTypeBuilder = iterator.TypeBuilder; + scope.ScopeConstructor = iterator.ctor.ConstructorBuilder; + } + + public override void Emit (EmitContext ec) + { + throw new InternalErrorException (); + } + } + + protected class MoveNextStatement : Statement { + Iterator iterator; + + public MoveNextStatement (Iterator iterator, Location loc) + { + this.loc = loc; + this.iterator = iterator; + } + public override bool Resolve (EmitContext ec) { - ec.InIterator = false; - bool ret_val = base.Resolve (ec); + return true; + } + + protected override void DoEmit (EmitContext ec) + { + iterator.move_next_method.ComputeHost (); + ec.CurrentAnonymousMethod = iterator.move_next_method; ec.InIterator = true; - return ret_val; + iterator.EmitMoveNext (ec); + } + } + + protected class DisposeMethod : Statement { + Iterator iterator; + + public DisposeMethod (Iterator iterator, Location loc) + { + this.loc = loc; + this.iterator = iterator; + } + + public override bool Resolve (EmitContext ec) + { + return true; + } + + protected override void DoEmit (EmitContext ec) + { + iterator.EmitDispose (ec); + } + } + + protected class StatementList : Statement { + ArrayList statements; + + public StatementList (Location loc) + { + this.loc = loc; + statements = new ArrayList (); + } + + public void Add (Statement statement) + { + statements.Add (statement); + } + + public override bool Resolve (EmitContext ec) + { + foreach (Statement stmt in statements) { + if (!stmt.Resolve (ec)) + return false; + } + + return true; + } + + protected override void DoEmit (EmitContext ec) + { + foreach (Statement stmt in statements) + stmt.Emit (ec); + } + } + + protected class SetState : Statement + { + Iterator iterator; + State state; + + public SetState (Iterator iterator, State state, Location loc) + { + this.iterator = iterator; + this.state = state; + this.loc = loc; + } + + public override bool Resolve (EmitContext ec) + { + return true; + } + + protected override void DoEmit (EmitContext ec) + { + ec.ig.Emit (OpCodes.Ldarg_0); + IntConstant.EmitInt (ec.ig, (int) state); + ec.ig.Emit (OpCodes.Stfld, iterator.pc_field.FieldBuilder); + } + } + + protected class InitScope : Statement + { + Iterator iterator; + + public InitScope (Iterator iterator, Location loc) + { + this.iterator = iterator; + this.loc = loc; + } + + public override bool Resolve (EmitContext ec) + { + return true; + } + + protected override void DoEmit (EmitContext ec) + { + iterator.cc.EmitInitScope (ec); } } - static bool IsIEnumerable (Type t) + void Define_Reset () { - return t == TypeManager.ienumerable_type || TypeManager.ImplementsInterface (t, TypeManager.ienumerable_type); + Method reset = new Method ( + this, null, TypeManager.system_void_expr, Modifiers.PUBLIC, + false, new MemberName ("Reset", Location), + Parameters.EmptyReadOnlyParameters, null); + AddMethod (reset); + + reset.Block = new ToplevelBlock (Location); + reset.Block = new ToplevelBlock (block, parameters, Location); + reset.Block.SetHaveAnonymousMethods (Location, move_next_method); + + reset.Block.AddStatement (Create_ThrowNotSupported ()); } - static bool IsIEnumerator (Type t) + void Define_Dispose () { - return t == TypeManager.ienumerator_type || TypeManager.ImplementsInterface (t, TypeManager.ienumerator_type); + dispose = new Method ( + this, null, TypeManager.system_void_expr, Modifiers.PUBLIC, + false, new MemberName ("Dispose", Location), + Parameters.EmptyReadOnlyParameters, null); + AddMethod (dispose); + + dispose.Block = new ToplevelBlock (block, parameters, Location); + dispose.Block.SetHaveAnonymousMethods (Location, move_next_method); + + dispose.Block.AddStatement (new DisposeMethod (this, Location)); } - + + public Type IteratorType { + get { return iterator_type_expr.Type; } + } + // - // Returns the new block for the method, or null on failure + // This return statement tricks return into not flagging an error for being + // used in a Yields method // - public Block Setup (Block block) - { - if (!(IsIEnumerator (return_type) || IsIEnumerable (return_type))){ - Report.Error ( - -205, loc, String.Format ( - "The method `{0}' contains a yield statement, but has an invalid return type for an iterator `{1}'", - name, TypeManager.CSharpName (return_type))); - return null; + class NoCheckReturn : Statement { + public Expression Expr; + + public NoCheckReturn (Expression expr, Location l) + { + Expr = expr; + loc = l; } - for (int i = 0; i < parameters.Count; i++){ - Parameter.Modifier mod = parameters.ParameterModifier (i); - if ((mod & (Parameter.Modifier.REF | Parameter.Modifier.OUT)) != 0){ - Report.Error (-207, loc, String.Format ( - "Parameter {0} of `{1}' is {2} and not allowed for an iterator method", - i+1, name, parameters.ParameterDesc (i))); - return null; - } + public override bool Resolve (EmitContext ec) + { + Expr = Expr.Resolve (ec); + if (Expr == null) + return false; + + ec.CurrentBranching.CurrentUsageVector.Return (); + + return true; + } + + protected override void DoEmit (EmitContext ec) + { + Expr.Emit (ec); + ec.ig.Emit (OpCodes.Ret); } + } + + bool CheckType () + { + Type ret = orig_method.ReturnType; - original_block = block; - Block b = new Block (null); + if (ret == TypeManager.ienumerable_type) { + original_iterator_type = TypeManager.object_type; + is_enumerable = true; + return true; + } + if (ret == TypeManager.ienumerator_type) { + original_iterator_type = TypeManager.object_type; + is_enumerable = false; + return true; + } + + if (!ret.IsGenericType) + return false; + + Type[] args = TypeManager.GetTypeArguments (ret); + if (args.Length != 1) + return false; + + Type gt = ret.GetGenericTypeDefinition (); + if (gt == TypeManager.generic_ienumerable_type) { + original_iterator_type = args [0]; + is_enumerable = true; + return true; + } else if (gt == TypeManager.generic_ienumerator_type) { + original_iterator_type = args [0]; + is_enumerable = false; + return true; + } - // return new InnerClass () - b.AddStatement (new NoCheckReturn (new NewInnerType (this, loc), loc)); - return b; + return false; } } }