//
// 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 Attributes OptAttributes;
public ConstructorBuilder ConstructorBuilder;
public MethodBuilder InvokeBuilder;
public MethodBuilder BeginInvokeBuilder;
public MethodBuilder EndInvokeBuilder;
Type [] param_types;
Type ret_type;
Expression instance_expr;
MethodBase delegate_method;
const int AllowedModifiers =
Modifiers.NEW |
Modifiers.PUBLIC |
Modifiers.PROTECTED |
Modifiers.INTERNAL |
Modifiers.UNSAFE |
Modifiers.PRIVATE;
public Delegate (NamespaceEntry ns, TypeContainer parent, Expression type,
int mod_flags, string name, Parameters param_list,
Attributes attrs, Location l)
: base (ns, parent, name, l)
{
this.ReturnType = type;
ModFlags = Modifiers.Check (AllowedModifiers, mod_flags,
IsTopLevel ? Modifiers.INTERNAL :
Modifiers.PRIVATE, l);
Parameters = param_list;
OptAttributes = attrs;
}
public override TypeBuilder DefineType ()
{
if (TypeBuilder != null)
return TypeBuilder;
TypeAttributes attr = Modifiers.TypeAttr (ModFlags, IsTopLevel) |
TypeAttributes.Class | TypeAttributes.Sealed;
if (IsTopLevel) {
if (TypeManager.NamespaceClash (Name, Location))
return null;
ModuleBuilder builder = CodeGen.ModuleBuilder;
TypeBuilder = builder.DefineType (
Name, attr, TypeManager.multicast_delegate_type);
} else {
TypeBuilder builder = Parent.TypeBuilder;
string name = Name.Substring (1 + Name.LastIndexOf ('.'));
TypeBuilder = builder.DefineNestedType (
name, attr, TypeManager.multicast_delegate_type);
}
TypeManager.AddDelegateType (Name, TypeBuilder, this);
return TypeBuilder;
}
public override bool DefineMembers (TypeContainer container)
{
return true;
}
public override bool Define (TypeContainer container)
{
MethodAttributes mattr;
int i;
ParameterBuilder pb;
Attributes cattr;
EmitContext ec = new EmitContext (this, this, Location, null,
null, ModFlags, false);
// 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;
mattr = MethodAttributes.RTSpecialName | MethodAttributes.SpecialName |
MethodAttributes.HideBySig | MethodAttributes.Public;
ConstructorBuilder = TypeBuilder.DefineConstructor (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
//
//
// FIXME: POSSIBLY make these static, as they are always the same
Parameter [] fixed_pars = new Parameter [2];
fixed_pars [0] = new Parameter (null, null, Parameter.Modifier.NONE, null);
fixed_pars [1] = new Parameter (null, null, Parameter.Modifier.NONE, null);
Parameters const_parameters = new Parameters (fixed_pars, null, Location);
TypeManager.RegisterMethod (
ConstructorBuilder,
new InternalParameters (const_arg_types, const_parameters),
const_arg_types);
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.ComputeAndDefineParameterTypes (this))
return false;
param_types = Parameters.GetParameterInfo (this);
if (param_types == null)
return false;
//
// Invoke method
//
// Check accessibility
foreach (Type partype in param_types){
if (!container.AsAccessible (partype, ModFlags)) {
Report.Error (59, Location,
"Inconsistent accessibility: parameter type `" +
TypeManager.CSharpName (partype) + "` is less " +
"accessible than delegate `" + Name + "'");
return false;
}
if (partype.IsPointer && !UnsafeOK (container))
return false;
}
ReturnType = ResolveTypeExpr (ReturnType, false, Location);
ret_type = ReturnType.Type;
if (ret_type == null)
return false;
if (!container.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 (ret_type.IsPointer && !UnsafeOK (container))
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.GetCallingConvention ();
mattr = MethodAttributes.Public | MethodAttributes.HideBySig | MethodAttributes.Virtual;
InvokeBuilder = TypeBuilder.DefineMethod ("Invoke",
mattr,
cc,
ret_type,
param_types);
//
// Define parameters, and count out/ref parameters
//
int out_params = 0;
i = 0;
if (Parameters.FixedParameters != null){
int top = Parameters.FixedParameters.Length;
Parameter p;
for (; i < top; i++) {
p = Parameters.FixedParameters [i];
pb = InvokeBuilder.DefineParameter (i+1, p.Attributes, p.Name);
cattr = p.OptAttributes;
if (cattr != null)
Attribute.ApplyAttributes (ec, pb, pb, cattr);
if ((p.ModFlags & Parameter.Modifier.ISBYREF) != 0)
out_params++;
}
}
if (Parameters.ArrayParameter != null){
Parameter p = Parameters.ArrayParameter;
pb = InvokeBuilder.DefineParameter (
i+1, p.Attributes, p.Name);
cattr = p.OptAttributes;
if (cattr != null)
Attribute.ApplyAttributes (ec, pb, pb, cattr);
}
InvokeBuilder.SetImplementationFlags (MethodImplAttributes.Runtime);
TypeManager.RegisterMethod (InvokeBuilder,
new InternalParameters (container, Parameters),
param_types);
//
// BeginInvoke
//
int params_num = param_types.Length;
Type [] async_param_types = new Type [params_num + 2];
param_types.CopyTo (async_param_types, 0);
async_param_types [params_num] = TypeManager.asynccallback_type;
async_param_types [params_num + 1] = TypeManager.object_type;
mattr = MethodAttributes.Public | MethodAttributes.HideBySig |
MethodAttributes.Virtual | MethodAttributes.NewSlot;
BeginInvokeBuilder = TypeBuilder.DefineMethod ("BeginInvoke",
mattr,
cc,
TypeManager.iasyncresult_type,
async_param_types);
i = 0;
if (Parameters.FixedParameters != null){
int top = Parameters.FixedParameters.Length;
Parameter p;
for (i = 0 ; i < top; i++) {
p = Parameters.FixedParameters [i];
pb = BeginInvokeBuilder.DefineParameter (i+1, p.Attributes, p.Name);
cattr = p.OptAttributes;
if (cattr != null)
Attribute.ApplyAttributes (ec, pb, pb, cattr);
}
}
if (Parameters.ArrayParameter != null){
Parameter p = Parameters.ArrayParameter;
pb = BeginInvokeBuilder.DefineParameter (i+1, p.Attributes, p.Name);
cattr = p.OptAttributes;
if (cattr != null)
Attribute.ApplyAttributes (ec, pb, pb, cattr);
i++;
}
BeginInvokeBuilder.DefineParameter (i + 1, ParameterAttributes.None, "callback");
BeginInvokeBuilder.DefineParameter (i + 2, ParameterAttributes.None, "object");
BeginInvokeBuilder.SetImplementationFlags (MethodImplAttributes.Runtime);
Parameter [] async_params = new Parameter [params_num + 2];
int n = 0;
if (Parameters.FixedParameters != null){
Parameters.FixedParameters.CopyTo (async_params, 0);
n = Parameters.FixedParameters.Length;
}
if (Parameters.ArrayParameter != null)
async_params [n] = Parameters.ArrayParameter;
async_params [params_num] = new Parameter (
TypeManager.system_asynccallback_expr, "callback",
Parameter.Modifier.NONE, null);
async_params [params_num + 1] = new Parameter (
TypeManager.system_object_expr, "object",
Parameter.Modifier.NONE, null);
Parameters async_parameters = new Parameters (async_params, null, Location);
async_parameters.ComputeAndDefineParameterTypes (this);
async_parameters.ComputeAndDefineParameterTypes (this);
TypeManager.RegisterMethod (BeginInvokeBuilder,
new InternalParameters (container, async_parameters),
async_param_types);
//
// EndInvoke is a bit more interesting, all the parameters labeled as
// out or ref have to be duplicated here.
//
Type [] end_param_types = new Type [out_params + 1];
Parameter [] end_params = new Parameter [out_params + 1];
int param = 0;
if (out_params > 0){
int top = Parameters.FixedParameters.Length;
for (i = 0; i < top; i++){
Parameter p = Parameters.FixedParameters [i];
if ((p.ModFlags & Parameter.Modifier.ISBYREF) == 0)
continue;
end_param_types [param] = param_types [i];
end_params [param] = p;
param++;
}
}
end_param_types [out_params] = TypeManager.iasyncresult_type;
end_params [out_params] = new Parameter (TypeManager.system_iasyncresult_expr, "result", Parameter.Modifier.NONE, null);
//
// Create method, define parameters, register parameters with type system
//
EndInvokeBuilder = TypeBuilder.DefineMethod ("EndInvoke", mattr, cc, ret_type, end_param_types);
EndInvokeBuilder.SetImplementationFlags (MethodImplAttributes.Runtime);
//
// EndInvoke: Label the parameters
//
EndInvokeBuilder.DefineParameter (out_params + 1, ParameterAttributes.None, "result");
for (i = 0; i < end_params.Length-1; i++){
EndInvokeBuilder.DefineParameter (i + 1, end_params [i].Attributes, end_params [i].Name);
}
Parameters end_parameters = new Parameters (end_params, null, Location);
end_parameters.ComputeAndDefineParameterTypes (this);
TypeManager.RegisterMethod (
EndInvokeBuilder,
new InternalParameters (container, end_parameters),
end_param_types);
return true;
}
///
/// 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 (EmitContext ec, Type delegate_type, MethodBase mb,
Location loc)
{
ParameterData pd = Invocation.GetParameterData (mb);
int pd_count = pd.Count;
Expression ml = Expression.MemberLookup (
ec, delegate_type, "Invoke", loc);
if (!(ml is MethodGroupExpr)) {
Report.Error (-100, loc, "Internal error: could not find Invoke method!");
return null;
}
MethodBase invoke_mb = ((MethodGroupExpr) ml).Methods [0];
ParameterData invoke_pd = Invocation.GetParameterData (invoke_mb);
if (invoke_pd.Count != pd_count)
return null;
for (int i = pd_count; i > 0; ) {
i--;
if (invoke_pd.ParameterType (i) == pd.ParameterType (i) &&
invoke_pd.ParameterModifier (i) == pd.ParameterModifier (i))
continue;
else {
return null;
}
}
if (((MethodInfo) invoke_mb).ReturnType == ((MethodInfo) mb).ReturnType)
return mb;
else
return null;
}
//
// 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, delegate_type, "Invoke", loc);
if (!(ml is MethodGroupExpr)) {
Report.Error (-100, loc, "Internal error: could not find Invoke method!" + delegate_type);
return false;
}
MethodBase mb = ((MethodGroupExpr) ml).Methods [0];
ParameterData pd = Invocation.GetParameterData (mb);
int pd_count = pd.Count;
bool not_params_method = (pd_count == 0) ||
(pd.ParameterModifier (pd_count - 1) != Parameter.Modifier.PARAMS);
if (not_params_method && pd_count != arg_count) {
Report.Error (1593, loc,
"Delegate '" + delegate_type.ToString ()
+ "' does not take '" + arg_count + "' arguments");
return false;
}
return Invocation.VerifyArgumentsCompat (ec, args, arg_count, mb, !not_params_method,
delegate_type, 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, Type probe_type, Location loc)
{
Expression ml = Expression.MemberLookup (
ec, 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 = Invocation.GetParameterData (mb);
Expression probe_ml = Expression.MemberLookup (
ec, 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 = Invocation.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 (TypeManager.CSharpName (((MethodInfo) mb).ReturnType));
sb.Append (" " + del_type.ToString ());
sb.Append (" (");
int length = pd.Count;
for (int i = length; i > 0; ) {
i--;
sb.Append (pd.ParameterDesc (length - i - 1));
if (i != 0)
sb.Append (", ");
}
sb.Append (")");
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 ();
if ((mt & MemberTypes.Method) != 0) {
if (ConstructorBuilder != null)
if (filter (ConstructorBuilder, criteria))
members.Add (ConstructorBuilder);
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 Type [] ParameterTypes {
get {
return param_types;
}
}
}
public class NewDelegate : Expression {
public ArrayList Arguments;
MethodBase constructor_method;
MethodBase delegate_method;
Expression delegate_instance_expr;
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 || Arguments.Count != 1) {
Report.Error (149, loc,
"Method name expected");
return null;
}
Expression ml = Expression.MemberLookup (
ec, type, ".ctor", loc);
if (!(ml is MethodGroupExpr)) {
Report.Error (-100, loc, "Internal error: Could not find delegate constructor!");
return null;
}
constructor_method = ((MethodGroupExpr) ml).Methods [0];
Argument a = (Argument) Arguments [0];
if (!a.ResolveMethodGroup (ec, Location))
return null;
Expression e = a.Expr;
Expression invoke_method = Expression.MemberLookup (
ec, type, "Invoke", MemberTypes.Method,
Expression.AllBindingFlags, loc);
if (invoke_method == null) {
Report.Error (-200, loc, "Internal error ! Could not find Invoke method!");
return null;
}
if (e is MethodGroupExpr) {
MethodGroupExpr mg = (MethodGroupExpr) e;
foreach (MethodInfo mi in mg.Methods){
delegate_method = Delegate.VerifyMethod (ec, type, mi, loc);
if (delegate_method != null)
break;
}
if (delegate_method == null) {
string method_desc;
if (mg.Methods.Length > 1)
method_desc = mg.Methods [0].Name;
else
method_desc = Invocation.FullMethodDesc (mg.Methods [0]);
MethodBase dm = ((MethodGroupExpr) invoke_method).Methods [0];
ParameterData param = Invocation.GetParameterData (dm);
string delegate_desc = Delegate.FullDelegateDesc (type, dm, param);
Report.Error (123, loc, "Method '" + method_desc + "' does not " +
"match delegate '" + delegate_desc + "'");
return null;
}
//
// Check safe/unsafe of the delegate
//
if (!ec.InUnsafe){
ParameterData param = Invocation.GetParameterData (delegate_method);
int count = param.Count;
for (int i = 0; i < count; i++){
if (param.ParameterType (i).IsPointer){
Expression.UnsafeError (loc);
return null;
}
}
}
if (mg.InstanceExpression != null)
delegate_instance_expr = mg.InstanceExpression.Resolve (ec);
else {
if (ec.IsStatic){
if (!delegate_method.IsStatic){
Report.Error (120, loc,
"An object reference is required for the non-static method " +
delegate_method.Name);
return null;
}
delegate_instance_expr = null;
} else
delegate_instance_expr = ec.GetThis (loc);
}
if (delegate_instance_expr != null)
if (delegate_instance_expr.Type.IsValueType)
delegate_instance_expr = new BoxedCast (delegate_instance_expr);
eclass = ExprClass.Value;
return this;
}
Type e_type = e.Type;
if (!TypeManager.IsDelegateType (e_type)) {
e.Error_UnexpectedKind ("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, e_type, loc)) {
Report.Error (29, loc, "Cannot implicitly convert type '" + e_type + "' " +
"to type '" + type + "'");
return null;
}
delegate_instance_expr = e;
delegate_method = ((MethodGroupExpr) invoke_method).Methods [0];
eclass = ExprClass.Value;
return this;
}
public override void Emit (EmitContext ec)
{
if (delegate_instance_expr == null ||
delegate_method.IsStatic)
ec.ig.Emit (OpCodes.Ldnull);
else
delegate_instance_expr.Emit (ec);
if (delegate_method.IsVirtual) {
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);
}
}
public class DelegateInvocation : ExpressionStatement {
public Expression InstanceExpr;
public 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, 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, 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)
{
Delegate del = TypeManager.LookupDelegate (InstanceExpr.Type);
//
// Invocation on delegates call the virtual Invoke member
// so we are always `instance' calls
//
Invocation.EmitCall (ec, false, 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){
if (((MethodInfo) method).ReturnType != TypeManager.void_type)
ec.ig.Emit (OpCodes.Pop);
}
}
}
}