|
public LookupExtensionMethod ( System.TypeSpec extensionType, string name, int arity, |
||
| extensionType | System.TypeSpec | |
| name | string | |
| arity | int | |
| scope | ||
| return | IList |
|
protected override Expression DoResolve(ResolveContext ec)
{
eclass = ExprClass.PropertyAccess;
bool must_do_cs1540_check = false;
ec.Report.DisableReporting ();
bool res = ResolveGetter (ec, ref must_do_cs1540_check);
ec.Report.EnableReporting ();
if (!res) {
if (InstanceExpression != null) {
TypeSpec expr_type = InstanceExpression.Type;
ExtensionMethodGroupExpr ex_method_lookup = ec.LookupExtensionMethod (expr_type, Name, 0, loc);
if (ex_method_lookup != null) {
ex_method_lookup.ExtensionExpression = InstanceExpression;
ex_method_lookup.SetTypeArguments (ec, targs);
return ex_method_lookup.Resolve (ec);
}
}
ResolveGetter (ec, ref must_do_cs1540_check);
return null;
}
if (!InstanceResolve (ec, false, must_do_cs1540_check))
return null;
//
// Only base will allow this invocation to happen.
//
if (IsBase && spec.IsAbstract) {
Error_CannotCallAbstractBase (ec, TypeManager.GetFullNameSignature (spec));
}
if (spec.MemberType.IsPointer && !ec.IsUnsafe){
UnsafeError (ec, loc);
}
if (!ec.IsObsolete) {
ObsoleteAttribute oa = spec.GetAttributeObsolete ();
if (oa != null)
AttributeTester.Report_ObsoleteMessage (oa, GetSignatureForError (), loc, ec.Report);
}
return this;
}
/// <summary>
/// Find the Applicable Function Members (7.4.2.1)
///
/// me: Method Group expression with the members to select.
/// it might contain constructors or methods (or anything
/// that maps to a method).
///
/// Arguments: ArrayList containing resolved Argument objects.
///
/// loc: The location if we want an error to be reported, or a Null
/// location for "probing" purposes.
///
/// Returns: The MethodBase (either a ConstructorInfo or a MethodInfo)
/// that is the best match of me on Arguments.
///
/// </summary>
public virtual MethodGroupExpr OverloadResolve(ResolveContext ec, ref Arguments Arguments,
bool may_fail, Location loc)
{
var candidates = new List<MethodSpec> (2);
List<MethodSpec> params_candidates = null;
int arg_count = Arguments != null ? Arguments.Count : 0;
Dictionary<MethodSpec, Arguments> candidates_expanded = null;
Arguments candidate_args = Arguments;
if (RootContext.Version == LanguageVersion.ISO_1 && Name == "Invoke" && TypeManager.IsDelegateType (DeclaringType)) {
if (!may_fail)
ec.Report.Error (1533, loc, "Invoke cannot be called directly on a delegate");
return null;
}
//
// Enable message recording, it's used mainly by lambda expressions
//
var msg_recorder = new SessionReportPrinter ();
var prev_recorder = ec.Report.SetPrinter (msg_recorder);
do {
//
// Methods in a base class are not candidates if any method in a derived
// class is applicable
//
int best_candidate_rate = int.MaxValue;
foreach (var member in Methods) {
var m = member as MethodSpec;
if (m == null) {
// TODO: It's wrong when non-member is before applicable method
// TODO: Should report only when at least 1 from the batch is applicable
if (candidates.Count != 0) {
ec.Report.SymbolRelatedToPreviousError (candidates [0]);
ec.Report.SymbolRelatedToPreviousError (member);
ec.Report.Warning (467, 2, loc, "Ambiguity between method `{0}' and non-method `{1}'. Using method `{0}'",
candidates[0].GetSignatureForError (), member.GetSignatureForError ());
}
continue;
}
//
// Check if candidate is applicable (section 14.4.2.1)
//
bool params_expanded_form = false;
int candidate_rate = IsApplicable (ec, ref candidate_args, arg_count, ref m, ref params_expanded_form);
if (candidate_rate < best_candidate_rate) {
best_candidate_rate = candidate_rate;
best_candidate = m;
}
if (params_expanded_form) {
if (params_candidates == null)
params_candidates = new List<MethodSpec> (2);
params_candidates.Add (m);
}
if (candidate_args != Arguments) {
if (candidates_expanded == null)
candidates_expanded = new Dictionary<MethodSpec, Arguments> (2);
candidates_expanded.Add (m, candidate_args);
candidate_args = Arguments;
}
if (candidate_rate != 0 || has_inaccessible_candidates_only) {
if (msg_recorder != null)
msg_recorder.EndSession ();
continue;
}
msg_recorder = null;
candidates.Add (m);
}
} while (candidates.Count == 0 && GetBaseTypeMethods (ec));
ec.Report.SetPrinter (prev_recorder);
if (msg_recorder != null && !msg_recorder.IsEmpty) {
if (!may_fail)
msg_recorder.Merge (prev_recorder);
return null;
}
int candidate_top = candidates.Count;
if (candidate_top == 0) {
//
// When we found a top level method which does not match and it's
// not an extension method. We start extension methods lookup from here
//
if (InstanceExpression != null) {
var first = Methods.First ();
var arity = type_arguments == null ? -1 : type_arguments.Count;
ExtensionMethodGroupExpr ex_method_lookup = ec.LookupExtensionMethod (type, first.Name, arity, loc);
if (ex_method_lookup != null) {
ex_method_lookup.ExtensionExpression = InstanceExpression;
ex_method_lookup.SetTypeArguments (ec, type_arguments);
return ex_method_lookup.OverloadResolve (ec, ref Arguments, may_fail, loc);
}
}
if (may_fail)
return null;
//
// Okay so we have failed to find exact match so we
// return error info about the closest match
//
if (best_candidate != null) {
if (CustomErrorHandler != null && !has_inaccessible_candidates_only && CustomErrorHandler.NoExactMatch (ec, best_candidate))
return null;
bool params_expanded = params_candidates != null && params_candidates.Contains (best_candidate);
if (NoExactMatch (ec, ref Arguments, params_expanded))
return null;
}
//
// We failed to find any method with correct argument count
//
if (Methods.First ().Kind == MemberKind.Constructor) {
ec.Report.SymbolRelatedToPreviousError (queried_type);
ec.Report.Error (1729, loc,
"The type `{0}' does not contain a constructor that takes `{1}' arguments",
TypeManager.CSharpName (queried_type), arg_count.ToString ());
} else {
Error_ArgumentCountWrong (ec, arg_count);
}
return null;
}
if (arg_count != 0 && Arguments.HasDynamic) {
best_candidate = null;
return this;
}
//
// Now we actually find the best method
//
best_candidate = candidates [0];
bool method_params = params_candidates != null && params_candidates.Contains (best_candidate);
for (int ix = 1; ix < candidate_top; ix++) {
var candidate = candidates [ix];
if (candidate == best_candidate)
continue;
bool cand_params = params_candidates != null && params_candidates.Contains (candidate);
if (candidates_expanded != null && candidates_expanded.ContainsKey (candidate)) {
candidate_args = candidates_expanded[candidate];
arg_count = candidate_args.Count;
}
if (BetterFunction (ec, candidate_args, arg_count,
candidate, cand_params,
best_candidate, method_params)) {
best_candidate = candidate;
method_params = cand_params;
}
if (candidate_args != Arguments) {
candidate_args = Arguments;
arg_count = candidate_args != null ? candidate_args.Count : 0;
}
}
if (candidates_expanded != null && candidates_expanded.ContainsKey (best_candidate)) {
candidate_args = candidates_expanded[best_candidate];
arg_count = candidate_args.Count;
}
//
// Now check that there are no ambiguities i.e the selected method
// should be better than all the others
//
MethodSpec ambiguous = null;
for (int ix = 1; ix < candidate_top; ix++) {
var candidate = candidates [ix];
if (candidate == best_candidate)
continue;
bool cand_params = params_candidates != null && params_candidates.Contains (candidate);
if (!BetterFunction (ec, candidate_args, arg_count,
best_candidate, method_params,
candidate, cand_params))
{
if (!may_fail)
ec.Report.SymbolRelatedToPreviousError (candidate);
ambiguous = candidate;
}
}
if (ambiguous != null) {
Error_AmbiguousCall (ec, ambiguous);
return this;
}
//
// And now check if the arguments are all
// compatible, perform conversions if
// necessary etc. and return if everything is
// all right
//
if (!VerifyArgumentsCompat (ec, ref candidate_args, arg_count, best_candidate,
method_params, may_fail, loc))
return null;
if (best_candidate == null)
return null;
if (best_candidate.IsGeneric) {
ConstraintChecker.CheckAll (best_candidate.GetGenericMethodDefinition (), best_candidate.TypeArguments,
best_candidate.Constraints, loc, ec.Report);
}
//
// Check ObsoleteAttribute on the best method
//
ObsoleteAttribute oa = best_candidate.GetAttributeObsolete ();
if (oa != null && !ec.IsObsolete)
AttributeTester.Report_ObsoleteMessage (oa, GetSignatureForError (), loc, ec.Report);
best_candidate.MemberDefinition.SetIsUsed ();
Arguments = candidate_args;
return this;
}
public override Expression DoResolve (ResolveContext ec)
{
// Don't resolve already resolved expression
if (eclass != ExprClass.Invalid)
return this;
Expression expr_resolved = expr.Resolve (ec, ResolveFlags.VariableOrValue | ResolveFlags.MethodGroup);
if (expr_resolved == null)
return null;
//
// Next, evaluate all the expressions in the argument list
//
bool dynamic_arg = false;
if (arguments != null && !arguments_resolved)
arguments.Resolve (ec, out dynamic_arg);
Type expr_type = expr_resolved.Type;
mg = expr_resolved as MethodGroupExpr;
if (dynamic_arg || TypeManager.IsDynamicType (expr_type)) {
Arguments args;
DynamicMemberBinder dmb = expr_resolved as DynamicMemberBinder;
if (dmb != null) {
args = dmb.Arguments;
if (arguments != null)
args.AddRange (arguments);
} else if (mg == null) {
if (arguments == null)
args = new Arguments (1);
else
args = arguments;
args.Insert (0, new Argument (expr_resolved));
expr = null;
} else {
if (mg.IsBase) {
ec.Report.Error (1971, loc,
"The base call to method `{0}' cannot be dynamically dispatched. Consider casting the dynamic arguments or eliminating the base access",
mg.Name);
return null;
}
args = arguments;
if (mg.IsStatic != mg.IsInstance) {
if (args == null)
args = new Arguments (1);
if (mg.IsStatic) {
args.Insert (0, new Argument (new TypeOf (new TypeExpression (mg.DeclaringType, loc), loc).Resolve (ec), Argument.AType.DynamicStatic));
} else {
MemberAccess ma = expr as MemberAccess;
if (ma != null)
args.Insert (0, new Argument (ma.Left.Resolve (ec)));
else
args.Insert (0, new Argument (new This (loc).Resolve (ec)));
}
}
}
return new DynamicInvocation (expr as ATypeNameExpression, args, loc).Resolve (ec);
}
if (mg == null) {
if (expr_type != null && TypeManager.IsDelegateType (expr_type)){
return (new DelegateInvocation (
expr_resolved, arguments, loc)).Resolve (ec);
}
MemberExpr me = expr_resolved as MemberExpr;
if (me == null) {
expr_resolved.Error_UnexpectedKind (ec, ResolveFlags.MethodGroup, loc);
return null;
}
mg = ec.LookupExtensionMethod (me.Type, me.Name, loc);
if (mg == null) {
ec.Report.Error (1955, loc, "The member `{0}' cannot be used as method or delegate",
expr_resolved.GetSignatureForError ());
return null;
}
((ExtensionMethodGroupExpr)mg).ExtensionExpression = me.InstanceExpression;
}
mg = DoResolveOverload (ec);
if (mg == null)
return null;
MethodInfo method = (MethodInfo)mg;
if (method != null) {
type = TypeManager.TypeToCoreType (method.ReturnType);
// TODO: this is a copy of mg.ResolveMemberAccess method
Expression iexpr = mg.InstanceExpression;
if (method.IsStatic) {
if (iexpr == null ||
iexpr is This || iexpr is EmptyExpression ||
mg.IdenticalTypeName) {
mg.InstanceExpression = null;
} else {
MemberExpr.error176 (ec, loc, mg.GetSignatureForError ());
return null;
}
} else {
if (iexpr == null || iexpr == EmptyExpression.Null) {
SimpleName.Error_ObjectRefRequired (ec, loc, mg.GetSignatureForError ());
}
}
}
if (type.IsPointer){
if (!ec.IsUnsafe){
UnsafeError (ec, loc);
return null;
}
}
//
// Only base will allow this invocation to happen.
//
if (mg.IsBase && method.IsAbstract){
Error_CannotCallAbstractBase (ec, TypeManager.CSharpSignature (method));
return null;
}
if (arguments == null && method.DeclaringType == TypeManager.object_type && method.Name == Destructor.MetadataName) {
if (mg.IsBase)
ec.Report.Error (250, loc, "Do not directly call your base class Finalize method. It is called automatically from your destructor");
else
ec.Report.Error (245, loc, "Destructors and object.Finalize cannot be called directly. Consider calling IDisposable.Dispose if available");
return null;
}
IsSpecialMethodInvocation (ec, method, loc);
if (mg.InstanceExpression != null)
mg.InstanceExpression.CheckMarshalByRefAccess (ec);
eclass = ExprClass.Value;
return this;
}
Expression DoResolve (ResolveContext ec, Expression right_side)
{
if (type != null)
throw new Exception ();
//
// Resolve the expression with flow analysis turned off, we'll do the definite
// assignment checks later. This is because we don't know yet what the expression
// will resolve to - it may resolve to a FieldExpr and in this case we must do the
// definite assignment check on the actual field and not on the whole struct.
//
SimpleName original = expr as SimpleName;
Expression expr_resolved = expr.Resolve (ec,
ResolveFlags.VariableOrValue | ResolveFlags.Type |
ResolveFlags.Intermediate | ResolveFlags.DisableStructFlowAnalysis);
if (expr_resolved == null)
return null;
string LookupIdentifier = MemberName.MakeName (Name, targs);
Namespace ns = expr_resolved as Namespace;
if (ns != null) {
FullNamedExpression retval = ns.Lookup (ec.Compiler, LookupIdentifier, loc);
if (retval == null)
ns.Error_NamespaceDoesNotExist (loc, LookupIdentifier, ec.Report);
else if (targs != null)
retval = new GenericTypeExpr (retval.Type, targs, loc).ResolveAsTypeStep (ec, false);
return retval;
}
Type expr_type = expr_resolved.Type;
if (TypeManager.IsDynamicType (expr_type)) {
Arguments args = new Arguments (2);
args.Add (new Argument (expr_resolved.Resolve (ec)));
if (right_side != null)
args.Add (new Argument (right_side));
return new DynamicMemberBinder (right_side != null, Name, args, loc).Resolve (ec);
}
if (expr_type.IsPointer || expr_type == TypeManager.void_type ||
expr_type == TypeManager.null_type || expr_type == InternalType.AnonymousMethod) {
Unary.Error_OperatorCannotBeApplied (ec, loc, ".", expr_type);
return null;
}
Constant c = expr_resolved as Constant;
if (c != null && c.GetValue () == null) {
ec.Report.Warning (1720, 1, loc, "Expression will always cause a `{0}'",
"System.NullReferenceException");
}
if (targs != null) {
if (!targs.Resolve (ec))
return null;
}
Expression member_lookup;
member_lookup = MemberLookup (ec.Compiler,
ec.CurrentType, expr_type, expr_type, Name, loc);
if (member_lookup == null && targs != null) {
member_lookup = MemberLookup (ec.Compiler,
ec.CurrentType, expr_type, expr_type, LookupIdentifier, loc);
}
if (member_lookup == null) {
ExprClass expr_eclass = expr_resolved.eclass;
//
// Extension methods are not allowed on all expression types
//
if (expr_eclass == ExprClass.Value || expr_eclass == ExprClass.Variable ||
expr_eclass == ExprClass.IndexerAccess || expr_eclass == ExprClass.PropertyAccess ||
expr_eclass == ExprClass.EventAccess) {
ExtensionMethodGroupExpr ex_method_lookup = ec.LookupExtensionMethod (expr_type, Name, loc);
if (ex_method_lookup != null) {
ex_method_lookup.ExtensionExpression = expr_resolved;
if (targs != null) {
ex_method_lookup.SetTypeArguments (ec, targs);
}
return ex_method_lookup.DoResolve (ec);
}
}
expr = expr_resolved;
member_lookup = Error_MemberLookupFailed (ec,
ec.CurrentType, expr_type, expr_type, Name, null,
AllMemberTypes, AllBindingFlags);
if (member_lookup == null)
return null;
}
TypeExpr texpr = member_lookup as TypeExpr;
if (texpr != null) {
if (!(expr_resolved is TypeExpr) &&
(original == null || !original.IdenticalNameAndTypeName (ec, expr_resolved, loc))) {
ec.Report.Error (572, loc, "`{0}': cannot reference a type through an expression; try `{1}' instead",
Name, member_lookup.GetSignatureForError ());
return null;
}
if (!texpr.CheckAccessLevel (ec.MemberContext)) {
ec.Report.SymbolRelatedToPreviousError (member_lookup.Type);
ErrorIsInaccesible (loc, TypeManager.CSharpName (member_lookup.Type), ec.Report);
return null;
}
GenericTypeExpr ct = expr_resolved as GenericTypeExpr;
if (ct != null) {
//
// When looking up a nested type in a generic instance
// via reflection, we always get a generic type definition
// and not a generic instance - so we have to do this here.
//
// See gtest-172-lib.cs and gtest-172.cs for an example.
//
TypeArguments nested_targs;
if (HasTypeArguments) {
nested_targs = ct.TypeArguments.Clone ();
nested_targs.Add (targs);
} else {
nested_targs = ct.TypeArguments;
}
ct = new GenericTypeExpr (member_lookup.Type, nested_targs, loc);
return ct.ResolveAsTypeStep (ec, false);
}
return member_lookup;
}
MemberExpr me = (MemberExpr) member_lookup;
me = me.ResolveMemberAccess (ec, expr_resolved, loc, original);
if (me == null)
return null;
if (targs != null) {
me.SetTypeArguments (ec, targs);
}
if (original != null && !TypeManager.IsValueType (expr_type)) {
if (me.IsInstance) {
LocalVariableReference var = expr_resolved as LocalVariableReference;
if (var != null && !var.VerifyAssigned (ec))
return null;
}
}
// The following DoResolve/DoResolveLValue will do the definite assignment
// check.
if (right_side != null)
return me.DoResolveLValue (ec, right_side);
else
return me.DoResolve (ec);
}
/// <summary>
/// Find the Applicable Function Members (7.4.2.1)
///
/// me: Method Group expression with the members to select.
/// it might contain constructors or methods (or anything
/// that maps to a method).
///
/// Arguments: ArrayList containing resolved Argument objects.
///
/// loc: The location if we want an error to be reported, or a Null
/// location for "probing" purposes.
///
/// Returns: The MethodBase (either a ConstructorInfo or a MethodInfo)
/// that is the best match of me on Arguments.
///
/// </summary>
public virtual MethodGroupExpr OverloadResolve (ResolveContext ec, ref Arguments Arguments,
bool may_fail, Location loc)
{
bool method_params = false;
Type applicable_type = null;
ArrayList candidates = new ArrayList (2);
ArrayList candidate_overrides = null;
//
// Used to keep a map between the candidate
// and whether it is being considered in its
// normal or expanded form
//
// false is normal form, true is expanded form
//
Hashtable candidate_to_form = null;
Hashtable candidates_expanded = null;
Arguments candidate_args = Arguments;
int arg_count = Arguments != null ? Arguments.Count : 0;
if (RootContext.Version == LanguageVersion.ISO_1 && Name == "Invoke" && TypeManager.IsDelegateType (DeclaringType)) {
if (!may_fail)
ec.Report.Error (1533, loc, "Invoke cannot be called directly on a delegate");
return null;
}
int nmethods = Methods.Length;
if (!IsBase) {
//
// Methods marked 'override' don't take part in 'applicable_type'
// computation, nor in the actual overload resolution.
// However, they still need to be emitted instead of a base virtual method.
// So, we salt them away into the 'candidate_overrides' array.
//
// In case of reflected methods, we replace each overriding method with
// its corresponding base virtual method. This is to improve compatibility
// with non-C# libraries which change the visibility of overrides (#75636)
//
int j = 0;
for (int i = 0; i < Methods.Length; ++i) {
MethodBase m = Methods [i];
if (TypeManager.IsOverride (m)) {
if (candidate_overrides == null)
candidate_overrides = new ArrayList ();
candidate_overrides.Add (m);
m = TypeManager.TryGetBaseDefinition (m);
}
if (m != null)
Methods [j++] = m;
}
nmethods = j;
}
//
// Enable message recording, it's used mainly by lambda expressions
//
SessionReportPrinter msg_recorder = new SessionReportPrinter ();
ReportPrinter prev_recorder = ec.Report.SetPrinter (msg_recorder);
//
// First we construct the set of applicable methods
//
bool is_sorted = true;
int best_candidate_rate = int.MaxValue;
for (int i = 0; i < nmethods; i++) {
Type decl_type = Methods [i].DeclaringType;
//
// If we have already found an applicable method
// we eliminate all base types (Section 14.5.5.1)
//
if (applicable_type != null && IsAncestralType (decl_type, applicable_type))
continue;
//
// Check if candidate is applicable (section 14.4.2.1)
//
bool params_expanded_form = false;
int candidate_rate = IsApplicable (ec, ref candidate_args, arg_count, ref Methods [i], ref params_expanded_form);
if (candidate_rate < best_candidate_rate) {
best_candidate_rate = candidate_rate;
best_candidate = Methods [i];
}
if (params_expanded_form) {
if (candidate_to_form == null)
candidate_to_form = new PtrHashtable ();
MethodBase candidate = Methods [i];
candidate_to_form [candidate] = candidate;
}
if (candidate_args != Arguments) {
if (candidates_expanded == null)
candidates_expanded = new Hashtable (2);
candidates_expanded.Add (Methods [i], candidate_args);
candidate_args = Arguments;
}
if (candidate_rate != 0 || has_inaccessible_candidates_only) {
if (msg_recorder != null)
msg_recorder.EndSession ();
continue;
}
msg_recorder = null;
candidates.Add (Methods [i]);
if (applicable_type == null)
applicable_type = decl_type;
else if (applicable_type != decl_type) {
is_sorted = false;
if (IsAncestralType (applicable_type, decl_type))
applicable_type = decl_type;
}
}
ec.Report.SetPrinter (prev_recorder);
if (msg_recorder != null && !msg_recorder.IsEmpty) {
if (!may_fail)
msg_recorder.Merge (prev_recorder);
return null;
}
int candidate_top = candidates.Count;
if (applicable_type == null) {
//
// When we found a top level method which does not match and it's
// not an extension method. We start extension methods lookup from here
//
if (InstanceExpression != null) {
ExtensionMethodGroupExpr ex_method_lookup = ec.LookupExtensionMethod (type, Name, loc);
if (ex_method_lookup != null) {
ex_method_lookup.ExtensionExpression = InstanceExpression;
ex_method_lookup.SetTypeArguments (ec, type_arguments);
return ex_method_lookup.OverloadResolve (ec, ref Arguments, may_fail, loc);
}
}
if (may_fail)
return null;
//
// Okay so we have failed to find exact match so we
// return error info about the closest match
//
if (best_candidate != null) {
if (CustomErrorHandler != null && !has_inaccessible_candidates_only && CustomErrorHandler.NoExactMatch (ec, best_candidate))
return null;
AParametersCollection pd = TypeManager.GetParameterData (best_candidate);
bool cand_params = candidate_to_form != null && candidate_to_form.Contains (best_candidate);
if (arg_count == pd.Count || pd.HasParams) {
if (TypeManager.IsGenericMethodDefinition (best_candidate)) {
if (type_arguments == null) {
ec.Report.Error (411, loc,
"The type arguments for method `{0}' cannot be inferred from " +
"the usage. Try specifying the type arguments explicitly",
TypeManager.CSharpSignature (best_candidate));
return null;
}
Type[] g_args = TypeManager.GetGenericArguments (best_candidate);
if (type_arguments.Count != g_args.Length) {
ec.Report.SymbolRelatedToPreviousError (best_candidate);
ec.Report.Error (305, loc, "Using the generic method `{0}' requires `{1}' type argument(s)",
TypeManager.CSharpSignature (best_candidate),
g_args.Length.ToString ());
return null;
}
} else {
if (type_arguments != null && !TypeManager.IsGenericMethod (best_candidate)) {
Namespace.Error_TypeArgumentsCannotBeUsed (best_candidate, loc);
return null;
}
}
if (has_inaccessible_candidates_only) {
if (InstanceExpression != null && type != ec.CurrentType && TypeManager.IsNestedFamilyAccessible (ec.CurrentType, best_candidate.DeclaringType)) {
// Although a derived class can access protected members of
// its base class it cannot do so through an instance of the
// base class (CS1540). If the qualifier_type is a base of the
// ec.CurrentType and the lookup succeeds with the latter one,
// then we are in this situation.
Error_CannotAccessProtected (ec, loc, best_candidate, queried_type, ec.CurrentType);
} else {
ec.Report.SymbolRelatedToPreviousError (best_candidate);
ErrorIsInaccesible (loc, GetSignatureForError (), ec.Report);
}
}
if (!VerifyArgumentsCompat (ec, ref Arguments, arg_count, best_candidate, cand_params, may_fail, loc))
return null;
if (has_inaccessible_candidates_only)
return null;
throw new InternalErrorException ("VerifyArgumentsCompat didn't find any problem with rejected candidate " + best_candidate);
}
}
//
// We failed to find any method with correct argument count
//
if (Name == ConstructorInfo.ConstructorName) {
ec.Report.SymbolRelatedToPreviousError (queried_type);
ec.Report.Error (1729, loc,
"The type `{0}' does not contain a constructor that takes `{1}' arguments",
TypeManager.CSharpName (queried_type), arg_count);
} else {
Error_ArgumentCountWrong (ec, arg_count);
}
return null;
}
if (!is_sorted) {
//
// At this point, applicable_type is _one_ of the most derived types
// in the set of types containing the methods in this MethodGroup.
// Filter the candidates so that they only contain methods from the
// most derived types.
//
int finalized = 0; // Number of finalized candidates
do {
// Invariant: applicable_type is a most derived type
// We'll try to complete Section 14.5.5.1 for 'applicable_type' by
// eliminating all it's base types. At the same time, we'll also move
// every unrelated type to the end of the array, and pick the next
// 'applicable_type'.
Type next_applicable_type = null;
int j = finalized; // where to put the next finalized candidate
int k = finalized; // where to put the next undiscarded candidate
for (int i = finalized; i < candidate_top; ++i) {
MethodBase candidate = (MethodBase) candidates [i];
Type decl_type = candidate.DeclaringType;
if (decl_type == applicable_type) {
candidates [k++] = candidates [j];
candidates [j++] = candidates [i];
continue;
}
if (IsAncestralType (decl_type, applicable_type))
continue;
if (next_applicable_type != null &&
IsAncestralType (decl_type, next_applicable_type))
continue;
candidates [k++] = candidates [i];
if (next_applicable_type == null ||
IsAncestralType (next_applicable_type, decl_type))
next_applicable_type = decl_type;
}
applicable_type = next_applicable_type;
finalized = j;
candidate_top = k;
} while (applicable_type != null);
}
//
// Now we actually find the best method
//
best_candidate = (MethodBase) candidates [0];
method_params = candidate_to_form != null && candidate_to_form.Contains (best_candidate);
//
// TODO: Broken inverse order of candidates logic does not work with optional
// parameters used for method overrides and I am not going to fix it for SRE
//
if (candidates_expanded != null && candidates_expanded.Contains (best_candidate)) {
candidate_args = (Arguments) candidates_expanded [best_candidate];
arg_count = candidate_args.Count;
}
for (int ix = 1; ix < candidate_top; ix++) {
MethodBase candidate = (MethodBase) candidates [ix];
if (candidate == best_candidate)
continue;
bool cand_params = candidate_to_form != null && candidate_to_form.Contains (candidate);
if (BetterFunction (ec, candidate_args, arg_count,
candidate, cand_params,
best_candidate, method_params)) {
best_candidate = candidate;
method_params = cand_params;
}
}
//
// Now check that there are no ambiguities i.e the selected method
// should be better than all the others
//
MethodBase ambiguous = null;
for (int ix = 1; ix < candidate_top; ix++) {
MethodBase candidate = (MethodBase) candidates [ix];
if (candidate == best_candidate)
continue;
bool cand_params = candidate_to_form != null && candidate_to_form.Contains (candidate);
if (!BetterFunction (ec, candidate_args, arg_count,
best_candidate, method_params,
candidate, cand_params))
{
if (!may_fail)
ec.Report.SymbolRelatedToPreviousError (candidate);
ambiguous = candidate;
}
}
if (ambiguous != null) {
Error_AmbiguousCall (ec, ambiguous);
return this;
}
//
// If the method is a virtual function, pick an override closer to the LHS type.
//
if (!IsBase && best_candidate.IsVirtual) {
if (TypeManager.IsOverride (best_candidate))
throw new InternalErrorException (
"Should not happen. An 'override' method took part in overload resolution: " + best_candidate);
if (candidate_overrides != null) {
Type[] gen_args = null;
bool gen_override = false;
if (TypeManager.IsGenericMethod (best_candidate))
gen_args = TypeManager.GetGenericArguments (best_candidate);
foreach (MethodBase candidate in candidate_overrides) {
if (TypeManager.IsGenericMethod (candidate)) {
if (gen_args == null)
continue;
if (gen_args.Length != TypeManager.GetGenericArguments (candidate).Length)
continue;
} else {
if (gen_args != null)
continue;
}
if (IsOverride (candidate, best_candidate)) {
gen_override = true;
best_candidate = candidate;
}
}
if (gen_override && gen_args != null) {
#if GMCS_SOURCE
best_candidate = ((MethodInfo) best_candidate).MakeGenericMethod (gen_args);
#endif
}
}
}
//
// And now check if the arguments are all
// compatible, perform conversions if
// necessary etc. and return if everything is
// all right
//
if (!VerifyArgumentsCompat (ec, ref candidate_args, arg_count, best_candidate,
method_params, may_fail, loc))
return null;
if (best_candidate == null)
return null;
MethodBase the_method = TypeManager.DropGenericMethodArguments (best_candidate);
if (TypeManager.IsGenericMethodDefinition (the_method) &&
!ConstraintChecker.CheckConstraints (ec, the_method, best_candidate, loc))
return null;
//
// Check ObsoleteAttribute on the best method
//
ObsoleteAttribute oa = AttributeTester.GetMethodObsoleteAttribute (the_method);
if (oa != null && !ec.IsObsolete)
AttributeTester.Report_ObsoleteMessage (oa, GetSignatureForError (), loc, ec.Report);
IMethodData data = TypeManager.GetMethod (the_method);
if (data != null)
data.SetMemberIsUsed ();
Arguments = candidate_args;
return this;
}
