//
// delegate.cs: Delegate Handler
//
// Authors:
// Ravi Pratap (ravi@ximian.com)
// Miguel de Icaza (miguel@ximian.com)
//
// Licensed under the terms of the GNU GPL
//
// (C) 2001 Ximian, 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 {
public Expression 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;
const int AllowedModifiers =
Modifiers.NEW |
Modifiers.PUBLIC |
Modifiers.PROTECTED |
Modifiers.INTERNAL |
Modifiers.UNSAFE |
Modifiers.PRIVATE;
public Delegate (NamespaceEntry ns, DeclSpace parent, Expression 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 (TypeManager.multicast_delegate_type == null && !RootContext.StdLib) {
Namespace system = RootNamespace.Global.GetNamespace ("System", true);
TypeExpr expr = system.Lookup (this, "MulticastDelegate", Location) as TypeExpr;
TypeManager.multicast_delegate_type = expr.Type;
}
if (TypeManager.multicast_delegate_type == null)
Report.Error (-100, Location, "Internal error: delegate used before " +
"System.MulticastDelegate is resolved. This can only " +
"happen during corlib compilation, when using a delegate " +
"in any of the `core' classes. See bug #72015 for details.");
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
// 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);
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 (!Parent.AsAccessible (partype, ModFlags)) {
Report.Error (59, Location,
"Inconsistent accessibility: parameter type `" +
TypeManager.CSharpName (partype) + "' is less " +
"accessible than delegate `" + Name + "'");
return false;
}
}
ReturnType = ReturnType.ResolveAsTypeTerminal (this, false);
if (ReturnType == null)
return false;
ret_type = ReturnType.Type;
if (!Parent.AsAccessible (ret_type, ModFlags)) {
Report.Error (58, Location,
"Inconsistent accessibility: return type `" +
TypeManager.CSharpName (ret_type) + "' is less " +
"accessible than delegate `" + Name + "'");
return false;
}
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;
const MethodAttributes mattr = MethodAttributes.Public | MethodAttributes.HideBySig | MethodAttributes.Virtual | MethodAttributes.NewSlot;
InvokeBuilder = TypeBuilder.DefineMethod ("Invoke",
mattr,
cc,
ret_type,
Parameters.Types);
InvokeBuilder.SetImplementationFlags (MethodImplAttributes.Runtime);
TypeManager.RegisterMethod (InvokeBuilder, Parameters);
//
// 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);
//
// 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);
return true;
}
public override void Emit ()
{
Parameters.ApplyAttributes (InvokeBuilder);
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;
}
//
// Returns the MethodBase for "Invoke" from a delegate type, this is used
// to extract the signature of a delegate.
//
public static MethodGroupExpr GetInvokeMethod (Type container_type, Type delegate_type, Location loc)
{
Expression ml = Expression.MemberLookup (container_type, null, delegate_type,
"Invoke", loc);
MethodGroupExpr mg = ml as MethodGroupExpr;
if (mg == null) {
Report.Error (-100, loc, "Internal error: could not find Invoke method!");
return null;
}
return mg;
}
///
/// 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)
{
MethodGroupExpr mg = GetInvokeMethod (container_type, delegate_type, loc);
if (mg == null)
return null;
if (old_mg.HasTypeArguments)
mg.HasTypeArguments = true;
MethodBase invoke_mb = mg.Methods [0];
ParameterData invoke_pd = TypeManager.GetParameterData (invoke_mb);
#if GMCS_SOURCE
if (!mg.HasTypeArguments &&
!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 (!Convert.ImplicitReferenceConversionExists (new EmptyExpression (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 (invoke_mb_retval == mb_retval)
return mb;
if (!Convert.ImplicitReferenceConversionExists (new EmptyExpression (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 = me.Methods [0];
ParameterData pd = TypeManager.GetParameterData (mb);
int pd_count = pd.Count;
bool params_method = pd.HasParams;
bool is_params_applicable = false;
bool is_applicable = Invocation.IsApplicable (ec, me, args, arg_count, ref mb);
if (!is_applicable && params_method &&
Invocation.IsParamsMethodApplicable (ec, me, args, arg_count, ref mb))
is_applicable = is_params_applicable = true;
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 Invocation.VerifyArgumentsCompat (
ec, args, arg_count, mb,
is_params_applicable || (!is_applicable && params_method),
delegate_type, false, loc);
}
///
/// Verifies whether the delegate in question is compatible with this one in
/// order to determine if instantiation from the same is possible.
///
public static bool VerifyDelegate (EmitContext ec, Type delegate_type, Location loc)
{
Expression ml = Expression.MemberLookup (
ec.ContainerType, delegate_type, "Invoke", loc);
if (!(ml is MethodGroupExpr)) {
Report.Error (-100, loc, "Internal error: could not find Invoke method!");
return false;
}
MethodBase mb = ((MethodGroupExpr) ml).Methods [0];
ParameterData pd = TypeManager.GetParameterData (mb);
Expression probe_ml = Expression.MemberLookup (
ec.ContainerType, delegate_type, "Invoke", loc);
if (!(probe_ml is MethodGroupExpr)) {
Report.Error (-100, loc, "Internal error: could not find Invoke method!");
return false;
}
MethodBase probe_mb = ((MethodGroupExpr) probe_ml).Methods [0];
ParameterData probe_pd = TypeManager.GetParameterData (probe_mb);
if (((MethodInfo) mb).ReturnType != ((MethodInfo) probe_mb).ReturnType)
return false;
if (pd.Count != probe_pd.Count)
return false;
for (int i = pd.Count; i > 0; ) {
i--;
if (pd.ParameterType (i) != probe_pd.ParameterType (i) ||
pd.ParameterModifier (i) != probe_pd.ParameterModifier (i))
return false;
}
return true;
}
public static string FullDelegateDesc (Type del_type, MethodBase mb, ParameterData pd)
{
StringBuilder sb = new StringBuilder ();
sb.Append (TypeManager.CSharpName (((MethodInfo) mb).ReturnType));
sb.Append (" ");
sb.Append (TypeManager.CSharpName (del_type));
sb.Append (pd.GetSignatureForError ());
return sb.ToString ();
}
// Hack around System.Reflection as found everywhere else
public override MemberList FindMembers (MemberTypes mt, BindingFlags bf,
MemberFilter filter, object criteria)
{
ArrayList members = new ArrayList (2);
if ((mt & MemberTypes.Constructor) != 0) {
if (ConstructorBuilder != null && filter (ConstructorBuilder, criteria))
members.Add (ConstructorBuilder);
}
if ((mt & MemberTypes.Method) != 0) {
if (InvokeBuilder != null)
if (filter (InvokeBuilder, criteria))
members.Add (InvokeBuilder);
if (BeginInvokeBuilder != null)
if (filter (BeginInvokeBuilder, criteria))
members.Add (BeginInvokeBuilder);
if (EndInvokeBuilder != null)
if (filter (EndInvokeBuilder, criteria))
members.Add (EndInvokeBuilder);
}
return new MemberList (members);
}
public override MemberCache MemberCache {
get {
return null;
}
}
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:"; }
}
}
//
// Base class for `NewDelegate' and `ImplicitDelegateCreation'
//
public abstract class DelegateCreation : Expression {
protected MethodBase constructor_method;
protected MethodBase delegate_method;
protected MethodGroupExpr method_group;
protected Expression delegate_instance_expression;
protected DelegateCreation () {}
public static void Error_NoMatchingMethodForDelegate (EmitContext ec, MethodGroupExpr mg, Type type, Location loc)
{
string method_desc;
MethodBase found_method = mg.Methods [0];
if (mg.Methods.Length > 1)
method_desc = found_method.Name;
else
method_desc = Invocation.FullMethodDesc (found_method);
Expression invoke_method = Expression.MemberLookup (
ec.ContainerType, type, "Invoke", MemberTypes.Method,
Expression.AllBindingFlags, loc);
MethodInfo method = ((MethodGroupExpr) invoke_method).Methods [0] as MethodInfo;
ParameterData param = TypeManager.GetParameterData (method);
string delegate_desc = Delegate.FullDelegateDesc (type, method, param);
#if GMCS_SOURCE
if (!mg.HasTypeArguments &&
!TypeManager.InferTypeArguments (param, ref found_method)) {
Report.Error (411, loc, "The type arguments for " +
"method `{0}' cannot be inferred from " +
"the usage. Try specifying the type " +
"arguments explicitly.", method_desc);
return;
}
#endif
Report.SymbolRelatedToPreviousError (found_method);
if (RootContext.Version == LanguageVersion.ISO_1) {
Report.Error (410, loc, "The method `{0}' parameters and return type must be same as delegate `{1}' parameters and return type",
method_desc, delegate_desc);
return;
}
Type delegateType = method.ReturnType;
Type methodType = ((MethodInfo) found_method).ReturnType;
if (delegateType != methodType &&
!Convert.ImplicitReferenceConversionExists (new EmptyExpression (methodType), delegateType)) {
Report.Error (407, loc, "`{0}' has the wrong return type to match the delegate `{1}'", method_desc, delegate_desc);
} else {
Report.Error (123, loc, "The method `{0}' parameters do not match delegate `{1}' parameters",
TypeManager.CSharpSignature (found_method), delegate_desc);
}
}
public override void Emit (EmitContext ec)
{
if (delegate_instance_expression == null || delegate_method.IsStatic)
ec.ig.Emit (OpCodes.Ldnull);
else
delegate_instance_expression.Emit (ec);
if (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, (ConstructorInfo) constructor_method);
}
protected bool ResolveConstructorMethod (EmitContext ec)
{
Expression ml = Expression.MemberLookupFinal(ec,
null, type, ".ctor", MemberTypes.Constructor, AllBindingFlags | BindingFlags.DeclaredOnly, loc);
if (!(ml is MethodGroupExpr)) {
Report.Error (-100, loc, "Internal error: Could not find delegate constructor!");
return false;
}
constructor_method = ((MethodGroupExpr) ml).Methods [0];
return true;
}
public static MethodBase ImplicitStandardConversionExists (MethodGroupExpr mg, Type targetType)
{
foreach (MethodInfo mi in mg.Methods){
MethodBase mb = Delegate.VerifyMethod (mg.DeclaringType, targetType, mg, mi, Location.Null);
if (mb != null)
return mb;
}
return null;
}
protected Expression ResolveMethodGroupExpr (EmitContext ec, MethodGroupExpr mg)
{
delegate_method = ImplicitStandardConversionExists (mg, type);
if (delegate_method == null) {
Error_NoMatchingMethodForDelegate (ec, mg, type, loc);
return null;
}
//
// Check safe/unsafe of the delegate
//
if (!ec.InUnsafe){
ParameterData param = TypeManager.GetParameterData (delegate_method);
int count = param.Count;
for (int i = 0; i < count; i++){
if (param.ParameterType (i).IsPointer){
Expression.UnsafeError (loc);
return null;
}
}
}
//TODO: implement caching when performance will be low
IMethodData md = TypeManager.GetMethod (
TypeManager.DropGenericMethodArguments (delegate_method));
if (md == null) {
if (System.Attribute.GetCustomAttribute (delegate_method, TypeManager.conditional_attribute_type) != null) {
Report.SymbolRelatedToPreviousError (delegate_method);
Report.Error (1618, loc, "Cannot create delegate with `{0}' because it has a Conditional attribute", TypeManager.CSharpSignature (delegate_method));
return null;
}
} else {
md.SetMemberIsUsed ();
if (md.OptAttributes != null && md.OptAttributes.Search (TypeManager.conditional_attribute_type) != null) {
Report.SymbolRelatedToPreviousError (delegate_method);
Report.Error (1618, loc, "Cannot create delegate with `{0}' because it has a Conditional attribute", TypeManager.CSharpSignature (delegate_method));
return null;
}
}
if (mg.InstanceExpression != null)
delegate_instance_expression = mg.InstanceExpression.Resolve (ec);
else if (ec.IsStatic) {
if (!delegate_method.IsStatic) {
Report.Error (120, loc, "`{0}': An object reference is required for the nonstatic field, method or property",
TypeManager.CSharpSignature (delegate_method));
return null;
}
delegate_instance_expression = null;
} else
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);
method_group = mg;
eclass = ExprClass.Value;
return this;
}
}
//
// Created from the conversion code
//
public class ImplicitDelegateCreation : DelegateCreation {
ImplicitDelegateCreation (Type t, Location l)
{
type = t;
loc = l;
}
public override Expression DoResolve (EmitContext ec)
{
return this;
}
static public Expression Create (EmitContext ec, MethodGroupExpr mge,
Type target_type, Location loc)
{
ImplicitDelegateCreation d = new ImplicitDelegateCreation (target_type, loc);
if (!d.ResolveConstructorMethod (ec))
return null;
return d.ResolveMethodGroupExpr (ec, mge);
}
}
//
// 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) {
Invocation.Error_WrongNumArguments (loc, GetSignatureForError (), 0);
return null;
}
if (!ResolveConstructorMethod (ec))
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)
return ((AnonymousMethodExpression) e).Compatible (ec, type);
MethodGroupExpr mg = e as MethodGroupExpr;
if (mg != null) {
if (TypeManager.IsNullableType (mg.DeclaringType)) {
Report.Error (1728, loc, "Cannot use method `{0}' as delegate creation expression because it is member of Nullable type",
mg.GetSignatureForError ());
return null;
}
return ResolveMethodGroupExpr (ec, mg);
}
if (!TypeManager.IsDelegateType (e.Type)) {
Report.Error (149, loc, "Method name expected");
return null;
}
method_group = Expression.MemberLookup (
ec.ContainerType, type, "Invoke", MemberTypes.Method,
Expression.AllBindingFlags, loc) as MethodGroupExpr;
if (method_group == null) {
Report.Error (-200, loc, "Internal error ! Could not find Invoke method!");
return null;
}
// This is what MS' compiler reports. We could always choose
// to be more verbose and actually give delegate-level specifics
if (!Delegate.VerifyDelegate (ec, type, loc)) {
Report.Error (29, loc, "Cannot implicitly convert type '" + e.Type + "' " +
"to type '" + type + "'");
return null;
}
delegate_instance_expression = e;
delegate_method = method_group.Methods [0];
eclass = ExprClass.Value;
return this;
}
}
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 DoResolve (EmitContext ec)
{
if (InstanceExpr is EventExpr) {
EventInfo ei = ((EventExpr) InstanceExpr).EventInfo;
Expression ml = MemberLookup (
ec.ContainerType, 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
// cannot be accessed directly
//
// 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.
//
Assign.error70 (ei, loc);
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;
Expression lookup = Expression.MemberLookup (ec.ContainerType, del_type, "Invoke", loc);
if (!(lookup is MethodGroupExpr)) {
Report.Error (-100, loc, "Internal error: could not find Invoke method!");
return null;
}
method = ((MethodGroupExpr) lookup).Methods [0];
type = ((MethodInfo) method).ReturnType;
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);
}
}
}
}