//
// delegate.cs: Delegate Handler
//
// Authors:
// Ravi Pratap (ravi@ximian.com)
// Miguel de Icaza (miguel@ximian.com)
// Marek Safar (marek.safar@gmail.com)
//
// Dual licensed under the terms of the MIT X11 or GNU GPL
//
// Copyright 2001 Ximian, Inc (http://www.ximian.com)
// Copyright 2003-2008 Novell, Inc (http://www.ximian.com)
//
using System;
using System.Collections;
using System.Reflection;
using System.Reflection.Emit;
using System.Text;
namespace Mono.CSharp {
///
/// Holds Delegates
///
public class Delegate : DeclSpace, IMemberContainer
{
FullNamedExpression ReturnType;
public Parameters Parameters;
public ConstructorBuilder ConstructorBuilder;
public MethodBuilder InvokeBuilder;
public MethodBuilder BeginInvokeBuilder;
public MethodBuilder EndInvokeBuilder;
Type ret_type;
static string[] attribute_targets = new string [] { "type", "return" };
Expression instance_expr;
MethodBase delegate_method;
ReturnParameter return_attributes;
MemberCache member_cache;
const MethodAttributes mattr = MethodAttributes.Public | MethodAttributes.HideBySig |
MethodAttributes.Virtual | MethodAttributes.NewSlot;
const int AllowedModifiers =
Modifiers.NEW |
Modifiers.PUBLIC |
Modifiers.PROTECTED |
Modifiers.INTERNAL |
Modifiers.UNSAFE |
Modifiers.PRIVATE;
public Delegate (NamespaceEntry ns, DeclSpace parent, FullNamedExpression type,
int mod_flags, MemberName name, Parameters param_list,
Attributes attrs)
: base (ns, parent, name, attrs)
{
this.ReturnType = type;
ModFlags = Modifiers.Check (AllowedModifiers, mod_flags,
IsTopLevel ? Modifiers.INTERNAL :
Modifiers.PRIVATE, name.Location);
Parameters = param_list;
}
public override void ApplyAttributeBuilder(Attribute a, CustomAttributeBuilder cb)
{
if (a.Target == AttributeTargets.ReturnValue) {
if (return_attributes == null)
return_attributes = new ReturnParameter (InvokeBuilder, Location);
return_attributes.ApplyAttributeBuilder (a, cb);
return;
}
base.ApplyAttributeBuilder (a, cb);
}
public override TypeBuilder DefineType ()
{
if (TypeBuilder != null)
return TypeBuilder;
if (IsTopLevel) {
if (TypeManager.NamespaceClash (Name, Location))
return null;
ModuleBuilder builder = CodeGen.Module.Builder;
TypeBuilder = builder.DefineType (
Name, TypeAttr, TypeManager.multicast_delegate_type);
} else {
TypeBuilder builder = Parent.TypeBuilder;
string name = Name.Substring (1 + Name.LastIndexOf ('.'));
TypeBuilder = builder.DefineNestedType (
name, TypeAttr, TypeManager.multicast_delegate_type);
}
TypeManager.AddUserType (this);
#if GMCS_SOURCE
if (IsGeneric) {
string[] param_names = new string [TypeParameters.Length];
for (int i = 0; i < TypeParameters.Length; i++)
param_names [i] = TypeParameters [i].Name;
GenericTypeParameterBuilder[] gen_params;
gen_params = TypeBuilder.DefineGenericParameters (param_names);
int offset = CountTypeParameters - CurrentTypeParameters.Length;
for (int i = offset; i < gen_params.Length; i++)
CurrentTypeParameters [i - offset].Define (gen_params [i]);
foreach (TypeParameter type_param in CurrentTypeParameters) {
if (!type_param.Resolve (this))
return null;
}
Expression current = new SimpleName (
MemberName.Basename, TypeParameters, Location);
current = current.ResolveAsTypeTerminal (this, false);
if (current == null)
return null;
CurrentType = current.Type;
}
#endif
return TypeBuilder;
}
public override bool Define ()
{
#if GMCS_SOURCE
if (IsGeneric) {
foreach (TypeParameter type_param in TypeParameters) {
if (!type_param.Resolve (this))
return false;
}
foreach (TypeParameter type_param in TypeParameters) {
if (!type_param.DefineType (this))
return false;
}
foreach (TypeParameter type_param in TypeParameters) {
if (!type_param.CheckDependencies ())
return false;
}
}
#endif
member_cache = new MemberCache (TypeManager.multicast_delegate_type, this);
// FIXME: POSSIBLY make this static, as it is always constant
//
Type [] const_arg_types = new Type [2];
const_arg_types [0] = TypeManager.object_type;
const_arg_types [1] = TypeManager.intptr_type;
const MethodAttributes ctor_mattr = MethodAttributes.RTSpecialName | MethodAttributes.SpecialName |
MethodAttributes.HideBySig | MethodAttributes.Public;
ConstructorBuilder = TypeBuilder.DefineConstructor (ctor_mattr,
CallingConventions.Standard,
const_arg_types);
ConstructorBuilder.DefineParameter (1, ParameterAttributes.None, "object");
ConstructorBuilder.DefineParameter (2, ParameterAttributes.None, "method");
//
// HACK because System.Reflection.Emit is lame
//
Parameter [] fixed_pars = new Parameter [2];
fixed_pars [0] = new Parameter (TypeManager.object_type, "object",
Parameter.Modifier.NONE, null, Location);
fixed_pars [1] = new Parameter (TypeManager.intptr_type, "method",
Parameter.Modifier.NONE, null, Location);
Parameters const_parameters = new Parameters (fixed_pars);
const_parameters.Resolve (null);
TypeManager.RegisterMethod (ConstructorBuilder, const_parameters);
member_cache.AddMember (ConstructorBuilder, this);
ConstructorBuilder.SetImplementationFlags (MethodImplAttributes.Runtime);
//
// Here the various methods like Invoke, BeginInvoke etc are defined
//
// First, call the `out of band' special method for
// defining recursively any types we need:
if (!Parameters.Resolve (this))
return false;
//
// Invoke method
//
// Check accessibility
foreach (Type partype in Parameters.Types){
if (!IsAccessibleAs (partype)) {
Report.SymbolRelatedToPreviousError (partype);
Report.Error (59, Location,
"Inconsistent accessibility: parameter type `" +
TypeManager.CSharpName (partype) + "' is less " +
"accessible than delegate `" + GetSignatureForError () + "'");
return false;
}
}
ReturnType = ReturnType.ResolveAsTypeTerminal (this, false);
if (ReturnType == null)
return false;
ret_type = ReturnType.Type;
if (!IsAccessibleAs (ret_type)) {
Report.SymbolRelatedToPreviousError (ret_type);
Report.Error (58, Location,
"Inconsistent accessibility: return type `" +
TypeManager.CSharpName (ret_type) + "' is less " +
"accessible than delegate `" + GetSignatureForError () + "'");
return false;
}
CheckProtectedModifier ();
if (RootContext.StdLib && (ret_type == TypeManager.arg_iterator_type || ret_type == TypeManager.typed_reference_type)) {
Method.Error1599 (Location, ret_type);
return false;
}
//
// We don't have to check any others because they are all
// guaranteed to be accessible - they are standard types.
//
CallingConventions cc = Parameters.CallingConvention;
InvokeBuilder = TypeBuilder.DefineMethod ("Invoke",
mattr,
cc,
ret_type,
Parameters.Types);
InvokeBuilder.SetImplementationFlags (MethodImplAttributes.Runtime);
TypeManager.RegisterMethod (InvokeBuilder, Parameters);
member_cache.AddMember (InvokeBuilder, this);
if (TypeManager.iasyncresult_type != null && TypeManager.asynccallback_type != null) {
DefineAsyncMethods (cc);
}
return true;
}
void DefineAsyncMethods (CallingConventions cc)
{
//
// BeginInvoke
//
Parameters async_parameters = Parameters.MergeGenerated (Parameters,
new Parameter (TypeManager.asynccallback_type, "callback", Parameter.Modifier.NONE, null, Location),
new Parameter (TypeManager.object_type, "object", Parameter.Modifier.NONE, null, Location));
BeginInvokeBuilder = TypeBuilder.DefineMethod ("BeginInvoke",
mattr, cc, TypeManager.iasyncresult_type, async_parameters.Types);
BeginInvokeBuilder.SetImplementationFlags (MethodImplAttributes.Runtime);
TypeManager.RegisterMethod (BeginInvokeBuilder, async_parameters);
member_cache.AddMember (BeginInvokeBuilder, this);
//
// EndInvoke is a bit more interesting, all the parameters labeled as
// out or ref have to be duplicated here.
//
//
// Define parameters, and count out/ref parameters
//
Parameters end_parameters;
int out_params = 0;
foreach (Parameter p in Parameters.FixedParameters) {
if ((p.ModFlags & Parameter.Modifier.ISBYREF) != 0)
++out_params;
}
if (out_params > 0) {
Type [] end_param_types = new Type [out_params];
Parameter [] end_params = new Parameter [out_params];
int param = 0;
for (int i = 0; i < Parameters.FixedParameters.Length; ++i) {
Parameter p = Parameters.FixedParameters [i];
if ((p.ModFlags & Parameter.Modifier.ISBYREF) == 0)
continue;
end_param_types [param] = p.ExternalType ();
end_params [param] = p;
++param;
}
end_parameters = Parameters.CreateFullyResolved (end_params, end_param_types);
} else {
end_parameters = Parameters.EmptyReadOnlyParameters;
}
end_parameters = Parameters.MergeGenerated (end_parameters,
new Parameter (TypeManager.iasyncresult_type, "result", Parameter.Modifier.NONE, null, Location));
//
// Create method, define parameters, register parameters with type system
//
EndInvokeBuilder = TypeBuilder.DefineMethod ("EndInvoke", mattr, cc, ret_type, end_parameters.Types);
EndInvokeBuilder.SetImplementationFlags (MethodImplAttributes.Runtime);
end_parameters.ApplyAttributes (EndInvokeBuilder);
TypeManager.RegisterMethod (EndInvokeBuilder, end_parameters);
member_cache.AddMember (EndInvokeBuilder, this);
}
public override void Emit ()
{
Parameters.ApplyAttributes (InvokeBuilder);
if (BeginInvokeBuilder != null) {
Parameters p = (Parameters) TypeManager.GetParameterData (BeginInvokeBuilder);
p.ApplyAttributes (BeginInvokeBuilder);
}
if (OptAttributes != null) {
OptAttributes.Emit ();
}
base.Emit ();
}
protected override TypeAttributes TypeAttr {
get {
return Modifiers.TypeAttr (ModFlags, IsTopLevel) |
TypeAttributes.Class | TypeAttributes.Sealed |
base.TypeAttr;
}
}
public override string[] ValidAttributeTargets {
get {
return attribute_targets;
}
}
//TODO: duplicate
protected override bool VerifyClsCompliance ()
{
if (!base.VerifyClsCompliance ()) {
return false;
}
Parameters.VerifyClsCompliance ();
if (!AttributeTester.IsClsCompliant (ReturnType.Type)) {
Report.Error (3002, Location, "Return type of `{0}' is not CLS-compliant", GetSignatureForError ());
}
return true;
}
public static ConstructorInfo GetConstructor (Type container_type, Type delegate_type)
{
Type dt = delegate_type;
#if GMCS_SOURCE
Type[] g_args = null;
if (delegate_type.IsGenericType) {
g_args = delegate_type.GetGenericArguments ();
delegate_type = delegate_type.GetGenericTypeDefinition ();
}
#endif
Delegate d = TypeManager.LookupDelegate (delegate_type);
if (d != null) {
#if GMCS_SOURCE
if (g_args != null)
return TypeBuilder.GetConstructor (dt, d.ConstructorBuilder);
#endif
return d.ConstructorBuilder;
}
Expression ml = Expression.MemberLookup (container_type,
null, dt, ConstructorInfo.ConstructorName, MemberTypes.Constructor,
BindingFlags.Public | BindingFlags.Instance | BindingFlags.DeclaredOnly, Location.Null);
MethodGroupExpr mg = ml as MethodGroupExpr;
if (mg == null) {
Report.Error (-100, Location.Null, "Internal error: could not find delegate constructor!");
// FIXME: null will cause a crash later
return null;
}
return (ConstructorInfo) mg.Methods[0];
}
//
// Returns the MethodBase for "Invoke" from a delegate type, this is used
// to extract the signature of a delegate.
//
public static MethodInfo GetInvokeMethod (Type container_type, Type delegate_type)
{
Type dt = delegate_type;
#if GMCS_SOURCE
Type[] g_args = null;
if (delegate_type.IsGenericType) {
g_args = delegate_type.GetGenericArguments ();
delegate_type = delegate_type.GetGenericTypeDefinition ();
}
#endif
Delegate d = TypeManager.LookupDelegate (delegate_type);
if (d != null) {
#if GMCS_SOURCE
if (g_args != null) {
MethodInfo invoke = TypeBuilder.GetMethod (dt, d.InvokeBuilder);
#if MS_COMPATIBLE
Parameters p = (Parameters) d.Parameters.InflateTypes (g_args, g_args);
TypeManager.RegisterMethod (invoke, p);
#endif
return invoke;
}
#endif
return d.InvokeBuilder;
}
Expression ml = Expression.MemberLookup (container_type, null, dt,
"Invoke", Location.Null);
MethodGroupExpr mg = ml as MethodGroupExpr;
if (mg == null) {
Report.Error (-100, Location.Null, "Internal error: could not find Invoke method!");
// FIXME: null will cause a crash later
return null;
}
return (MethodInfo) mg.Methods[0];
}
public static bool IsTypeCovariant (Expression a, Type b)
{
Type a_type = a.Type;
if (a_type == b)
return true;
if (RootContext.Version == LanguageVersion.ISO_1)
return false;
if (a.Type.IsValueType)
return false;
return Convert.ImplicitReferenceConversionCore (
a, b);
}
///
/// Verifies whether the method in question is compatible with the delegate
/// Returns the method itself if okay and null if not.
///
public static MethodBase VerifyMethod (Type container_type, Type delegate_type,
MethodGroupExpr old_mg, MethodBase mb,
Location loc)
{
MethodInfo invoke_mb = GetInvokeMethod (container_type, delegate_type);
if (invoke_mb == null)
return null;
ParameterData invoke_pd = TypeManager.GetParameterData (invoke_mb);
#if GMCS_SOURCE
if (old_mg.type_arguments == null &&
!TypeManager.InferTypeArguments (invoke_pd, ref mb))
return null;
#endif
ParameterData pd = TypeManager.GetParameterData (mb);
if (invoke_pd.Count != pd.Count)
return null;
for (int i = pd.Count; i > 0; ) {
i--;
Type invoke_pd_type = invoke_pd.ParameterType (i);
Type pd_type = pd.ParameterType (i);
Parameter.Modifier invoke_pd_type_mod = invoke_pd.ParameterModifier (i);
Parameter.Modifier pd_type_mod = pd.ParameterModifier (i);
invoke_pd_type_mod &= ~Parameter.Modifier.PARAMS;
pd_type_mod &= ~Parameter.Modifier.PARAMS;
if (invoke_pd_type_mod != pd_type_mod)
return null;
if (invoke_pd_type == pd_type)
continue;
//if (!IsTypeCovariant (invoke_pd_type, pd_type))
// return null;
if (RootContext.Version == LanguageVersion.ISO_1)
return null;
}
Type invoke_mb_retval = ((MethodInfo) invoke_mb).ReturnType;
Type mb_retval = ((MethodInfo) mb).ReturnType;
if (TypeManager.TypeToCoreType (invoke_mb_retval) == TypeManager.TypeToCoreType (mb_retval))
return mb;
//if (!IsTypeCovariant (mb_retval, invoke_mb_retval))
// return null;
if (RootContext.Version == LanguageVersion.ISO_1)
return null;
return mb;
}
//
// Verifies whether the invocation arguments are compatible with the
// delegate's target method
//
public static bool VerifyApplicability (EmitContext ec, Type delegate_type,
ArrayList args, Location loc)
{
int arg_count;
if (args == null)
arg_count = 0;
else
arg_count = args.Count;
Expression ml = Expression.MemberLookup (
ec.ContainerType, delegate_type, "Invoke", loc);
MethodGroupExpr me = ml as MethodGroupExpr;
if (me == null) {
Report.Error (-100, loc, "Internal error: could not find Invoke method!" + delegate_type);
return false;
}
MethodBase mb = GetInvokeMethod (ec.ContainerType, delegate_type);
ParameterData pd = TypeManager.GetParameterData (mb);
int pd_count = pd.Count;
bool params_method = pd.HasParams;
bool is_params_applicable = false;
me.DelegateType = delegate_type;
bool is_applicable = me.IsApplicable (ec, args, arg_count, ref mb, ref is_params_applicable) == 0;
if (!is_applicable && !params_method && arg_count != pd_count) {
Report.Error (1593, loc, "Delegate `{0}' does not take `{1}' arguments",
TypeManager.CSharpName (delegate_type), arg_count.ToString ());
return false;
}
return me.VerifyArgumentsCompat (
ec, ref args, arg_count, mb,
is_params_applicable || (!is_applicable && params_method),
false, loc);
}
public static string FullDelegateDesc (MethodBase invoke_method)
{
return TypeManager.GetFullNameSignature (invoke_method).Replace (".Invoke", "");
}
public override MemberCache MemberCache {
get {
return member_cache;
}
}
public Expression InstanceExpression {
get {
return instance_expr;
}
set {
instance_expr = value;
}
}
public MethodBase TargetMethod {
get {
return delegate_method;
}
set {
delegate_method = value;
}
}
public Type TargetReturnType {
get {
return ret_type;
}
}
public override AttributeTargets AttributeTargets {
get {
return AttributeTargets.Delegate;
}
}
//
// Represents header string for documentation comment.
//
public override string DocCommentHeader {
get { return "T:"; }
}
#region IMemberContainer Members
string IMemberContainer.Name
{
get { throw new NotImplementedException (); }
}
Type IMemberContainer.Type
{
get { throw new NotImplementedException (); }
}
MemberCache IMemberContainer.BaseCache
{
get { throw new NotImplementedException (); }
}
bool IMemberContainer.IsInterface {
get {
return false;
}
}
MemberList IMemberContainer.GetMembers (MemberTypes mt, BindingFlags bf)
{
throw new NotImplementedException ();
}
#endregion
}
//
// Base class for `NewDelegate' and `ImplicitDelegateCreation'
//
public abstract class DelegateCreation : Expression, MethodGroupExpr.IErrorHandler
{
protected ConstructorInfo constructor_method;
protected MethodInfo delegate_method;
// We keep this to handle IsBase only
protected MethodGroupExpr method_group;
protected Expression delegate_instance_expression;
public static ArrayList CreateDelegateMethodArguments (MethodInfo invoke_method, Location loc)
{
ParameterData pd = TypeManager.GetParameterData (invoke_method);
ArrayList delegate_arguments = new ArrayList (pd.Count);
for (int i = 0; i < pd.Count; ++i) {
Argument.AType atype_modifier;
Type atype = pd.Types [i];
switch (pd.ParameterModifier (i)) {
case Parameter.Modifier.REF:
atype_modifier = Argument.AType.Ref;
atype = atype.GetElementType ();
break;
case Parameter.Modifier.OUT:
atype_modifier = Argument.AType.Out;
atype = atype.GetElementType ();
break;
case Parameter.Modifier.ARGLIST:
// __arglist is not valid
throw new InternalErrorException ("__arglist modifier");
default:
atype_modifier = Argument.AType.Expression;
break;
}
delegate_arguments.Add (new Argument (new TypeExpression (atype, loc), atype_modifier));
}
return delegate_arguments;
}
public override Expression CreateExpressionTree (EmitContext ec)
{
MemberAccess ma = new MemberAccess (new MemberAccess (new QualifiedAliasMember ("global", "System", loc), "Delegate", loc), "CreateDelegate", loc);
ArrayList args = new ArrayList (3);
args.Add (new Argument (new TypeOf (new TypeExpression (type, loc), loc)));
args.Add (new Argument (new NullLiteral (loc)));
args.Add (new Argument (new TypeOfMethodInfo (delegate_method, loc)));
Expression e = new Invocation (ma, args).Resolve (ec);
if (e == null)
return null;
e = Convert.ExplicitConversion (ec, e, type, loc);
if (e == null)
return null;
return e.CreateExpressionTree (ec);
}
public override Expression DoResolve (EmitContext ec)
{
constructor_method = Delegate.GetConstructor (ec.ContainerType, type);
MethodInfo invoke_method = Delegate.GetInvokeMethod (ec.ContainerType, type);
method_group.DelegateType = type;
method_group.CustomErrorHandler = this;
ArrayList arguments = CreateDelegateMethodArguments (invoke_method, loc);
method_group = method_group.OverloadResolve (ec, ref arguments, false, loc);
if (method_group == null)
return null;
delegate_method = (MethodInfo) method_group;
ExtensionMethodGroupExpr emg = method_group as ExtensionMethodGroupExpr;
if (emg != null) {
delegate_instance_expression = emg.ExtensionExpression;
Type e_type = delegate_instance_expression.Type;
if (TypeManager.IsValueType (e_type)) {
Report.Error (1113, loc, "Extension method `{0}' of value type `{1}' cannot be used to create delegates",
TypeManager.CSharpSignature (delegate_method), TypeManager.CSharpName (e_type));
}
}
Type rt = TypeManager.TypeToCoreType (delegate_method.ReturnType);
Expression ret_expr = new TypeExpression (rt, loc);
if (!Delegate.IsTypeCovariant (ret_expr, (TypeManager.TypeToCoreType (invoke_method.ReturnType)))) {
Error_ConversionFailed (ec, delegate_method, ret_expr);
}
DoResolveInstanceExpression (ec);
eclass = ExprClass.Value;
return this;
}
void DoResolveInstanceExpression (EmitContext ec)
{
//
// Argument is another delegate
//
if (delegate_instance_expression != null)
return;
if (method_group.InstanceExpression != null)
delegate_instance_expression = method_group.InstanceExpression;
else if (!delegate_method.IsStatic && !ec.IsStatic)
delegate_instance_expression = ec.GetThis (loc);
if (delegate_instance_expression != null && delegate_instance_expression.Type.IsValueType)
delegate_instance_expression = new BoxedCast (
delegate_instance_expression, TypeManager.object_type);
}
public override void Emit (EmitContext ec)
{
if (delegate_instance_expression == null)
ec.ig.Emit (OpCodes.Ldnull);
else
delegate_instance_expression.Emit (ec);
if (!delegate_method.DeclaringType.IsSealed && delegate_method.IsVirtual && !method_group.IsBase) {
ec.ig.Emit (OpCodes.Dup);
ec.ig.Emit (OpCodes.Ldvirtftn, (MethodInfo) delegate_method);
} else
ec.ig.Emit (OpCodes.Ldftn, (MethodInfo) delegate_method);
ec.ig.Emit (OpCodes.Newobj, constructor_method);
}
void Error_ConversionFailed (EmitContext ec, MethodBase method, Expression return_type)
{
MethodInfo invoke_method = Delegate.GetInvokeMethod (ec.ContainerType, type);
string member_name = delegate_instance_expression != null ?
Delegate.FullDelegateDesc (method) :
TypeManager.GetFullNameSignature (method);
Report.SymbolRelatedToPreviousError (type);
Report.SymbolRelatedToPreviousError (method);
if (RootContext.Version == LanguageVersion.ISO_1) {
Report.Error (410, loc, "A method or delegate `{0} {1}' parameters and return type must be same as delegate `{2} {3}' parameters and return type",
TypeManager.CSharpName (((MethodInfo) method).ReturnType), member_name,
TypeManager.CSharpName (invoke_method.ReturnType), Delegate.FullDelegateDesc (invoke_method));
return;
}
if (return_type == null) {
Report.Error (123, loc, "A method or delegate `{0}' parameters do not match delegate `{1}' parameters",
member_name, Delegate.FullDelegateDesc (invoke_method));
return;
}
Report.Error (407, loc, "A method or delegate `{0} {1}' return type does not match delegate `{2} {3}' return type",
return_type.GetSignatureForError (), member_name,
TypeManager.CSharpName (invoke_method.ReturnType), Delegate.FullDelegateDesc (invoke_method));
}
public static MethodBase ImplicitStandardConversionExists (MethodGroupExpr mg, Type target_type)
{
if (target_type == TypeManager.delegate_type || target_type == TypeManager.multicast_delegate_type)
return null;
foreach (MethodInfo mi in mg.Methods){
MethodBase mb = Delegate.VerifyMethod (mg.DeclaringType, target_type, mg, mi, Location.Null);
if (mb != null)
return mb;
}
return null;
}
#region IErrorHandler Members
public bool NoExactMatch (EmitContext ec, MethodBase method)
{
if (TypeManager.IsGenericMethod (method))
return false;
Error_ConversionFailed (ec, method, null);
return true;
}
#endregion
}
//
// Created from the conversion code
//
public class ImplicitDelegateCreation : DelegateCreation
{
ImplicitDelegateCreation (Type t, MethodGroupExpr mg, Location l)
{
type = t;
this.method_group = mg;
loc = l;
}
static public Expression Create (EmitContext ec, MethodGroupExpr mge,
Type target_type, Location loc)
{
ImplicitDelegateCreation d = new ImplicitDelegateCreation (target_type, mge, loc);
return d.DoResolve (ec);
}
}
//
// A delegate-creation-expression, invoked from the `New' class
//
public class NewDelegate : DelegateCreation
{
public ArrayList Arguments;
//
// This constructor is invoked from the `New' expression
//
public NewDelegate (Type type, ArrayList Arguments, Location loc)
{
this.type = type;
this.Arguments = Arguments;
this.loc = loc;
}
public override Expression DoResolve (EmitContext ec)
{
if (Arguments == null) {
Error_InvalidDelegateArgument ();
return null;
}
Argument a = (Argument) Arguments [0];
if (!a.ResolveMethodGroup (ec))
return null;
Expression e = a.Expr;
if (e is AnonymousMethodExpression && RootContext.Version != LanguageVersion.ISO_1) {
e = ((AnonymousMethodExpression) e).Compatible (ec, type);
if (e == null)
return null;
return e.Resolve (ec);
}
method_group = e as MethodGroupExpr;
if (method_group == null) {
if (!TypeManager.IsDelegateType (e.Type)) {
Report.Error (149, loc, "Method name expected");
return null;
}
//
// An argument is not a method but another delegate
//
delegate_instance_expression = e;
method_group = new MethodGroupExpr (new MemberInfo [] {
Delegate.GetInvokeMethod (ec.ContainerType, e.Type) }, e.Type, loc);
}
if (base.DoResolve (ec) == null)
return null;
if (TypeManager.IsNullableType (method_group.DeclaringType)) {
Report.Error (1728, loc, "Cannot use method `{0}' as delegate creation expression because it is member of Nullable type",
TypeManager.GetFullNameSignature (delegate_method));
}
if (Invocation.IsMethodExcluded (delegate_method)) {
Report.SymbolRelatedToPreviousError (delegate_method);
Report.Error (1618, loc, "Cannot create delegate with `{0}' because it has a Conditional attribute",
TypeManager.CSharpSignature (delegate_method));
}
return this;
}
void Error_InvalidDelegateArgument ()
{
Report.Error (149, loc, "Method name expected");
}
}
public class DelegateInvocation : ExpressionStatement {
readonly Expression InstanceExpr;
readonly ArrayList Arguments;
MethodBase method;
public DelegateInvocation (Expression instance_expr, ArrayList args, Location loc)
{
this.InstanceExpr = instance_expr;
this.Arguments = args;
this.loc = loc;
}
public override Expression CreateExpressionTree (EmitContext ec)
{
ArrayList args;
if (Arguments == null)
args = new ArrayList (1);
else
args = new ArrayList (Arguments.Count + 1);
args.Add (new Argument (InstanceExpr.CreateExpressionTree (ec)));
if (Arguments != null) {
foreach (Argument a in Arguments)
args.Add (new Argument (a.Expr.CreateExpressionTree (ec)));
}
return CreateExpressionFactoryCall ("Invoke", args);
}
public override Expression DoResolve (EmitContext ec)
{
if (InstanceExpr is EventExpr) {
((EventExpr) InstanceExpr).Error_CannotAssign ();
return null;
}
Type del_type = InstanceExpr.Type;
if (del_type == null)
return null;
if (Arguments != null){
foreach (Argument a in Arguments){
if (!a.Resolve (ec, loc))
return null;
}
}
if (!Delegate.VerifyApplicability (ec, del_type, Arguments, loc))
return null;
method = Delegate.GetInvokeMethod (ec.ContainerType, del_type);
type = ((MethodInfo) method).ReturnType;
type = TypeManager.TypeToCoreType (type);
eclass = ExprClass.Value;
return this;
}
public override void Emit (EmitContext ec)
{
//
// Invocation on delegates call the virtual Invoke member
// so we are always `instance' calls
//
Invocation.EmitCall (ec, false, InstanceExpr, method, Arguments, loc);
}
public override void EmitStatement (EmitContext ec)
{
Emit (ec);
//
// Pop the return value if there is one
//
if (method is MethodInfo){
Type ret = ((MethodInfo)method).ReturnType;
if (TypeManager.TypeToCoreType (ret) != TypeManager.void_type)
ec.ig.Emit (OpCodes.Pop);
}
}
}
}