2 // pending.cs: Pending method implementation
5 // Miguel de Icaza (miguel@gnu.org)
7 // Licensed under the terms of the GNU GPL
9 // (C) 2001, 2002 Ximian, Inc (http://www.ximian.com)
14 using System.Collections;
15 using System.Reflection;
16 using System.Reflection.Emit;
18 namespace Mono.CSharp {
20 struct TypeAndMethods {
22 public MethodInfo [] methods;
25 // Whether it is optional, this is used to allow the explicit/implicit
26 // implementation when a base class already implements an interface.
30 // class X : IA { } class Y : X, IA { IA.Explicit (); }
34 // Far from ideal, but we want to avoid creating a copy
36 public Type [][] args;
38 //This is used to store the modifiers of arguments
39 public Parameter.Modifier [][] mods;
42 // This flag on the method says `We found a match, but
43 // because it was private, we could not use the match
47 // If a method is defined here, then we always need to
48 // create a proxy for it. This is used when implementing
49 // an interface's indexer with a different IndexerName.
50 public MethodInfo [] need_proxy;
53 // The name of the indexer (if it exists), precompute set/get, because
54 // they would be recomputed many times inside a loop later on.
56 public string set_indexer_name;
57 public string get_indexer_name;
60 public class PendingImplementation {
62 /// The container for this PendingImplementation
64 TypeContainer container;
67 /// This filter is used by FindMembers, and it is used to
68 /// extract only virtual/abstract fields
70 static MemberFilter virtual_method_filter;
73 /// This is the array of TypeAndMethods that describes the pending implementations
74 /// (both interfaces and abstract methods in base class)
76 TypeAndMethods [] pending_implementations;
78 static bool IsVirtualFilter (MemberInfo m, object filterCriteria)
80 MethodInfo mi = m as MethodInfo;
81 return (mi == null) ? false : mi.IsVirtual;
85 /// Inits the virtual_method_filter
87 static PendingImplementation ()
89 virtual_method_filter = new MemberFilter (IsVirtualFilter);
93 // Returns a list of the abstract methods that are exposed by all of our
94 // bases that we must implement. Notice that this `flattens' the
95 // method search space, and takes into account overrides.
97 static ArrayList GetAbstractMethods (Type t)
99 ArrayList list = null;
100 bool searching = true;
101 Type current_type = t;
106 mi = TypeContainer.FindMembers (
107 current_type, MemberTypes.Method,
108 BindingFlags.Public | BindingFlags.NonPublic |
109 BindingFlags.Instance | BindingFlags.DeclaredOnly,
110 virtual_method_filter, null);
112 if (current_type == TypeManager.object_type)
115 current_type = current_type.BaseType;
116 if (!current_type.IsAbstract)
123 if (mi.Count == 1 && !(mi [0] is MethodBase))
126 list = TypeManager.CopyNewMethods (list, mi);
132 for (int i = 0; i < list.Count; i++){
133 while (list.Count > i && !((MethodInfo) list [i]).IsAbstract)
143 PendingImplementation (TypeContainer container, MissingInterfacesInfo [] missing_ifaces, ArrayList abstract_methods, int total)
145 TypeBuilder type_builder = container.TypeBuilder;
147 this.container = container;
148 pending_implementations = new TypeAndMethods [total];
151 if (abstract_methods != null) {
152 int count = abstract_methods.Count;
153 pending_implementations [i].methods = new MethodInfo [count];
154 pending_implementations [i].need_proxy = new MethodInfo [count];
156 abstract_methods.CopyTo (pending_implementations [i].methods, 0);
157 pending_implementations [i].found = new bool [count];
158 pending_implementations [i].args = new Type [count][];
159 pending_implementations [i].mods = new Parameter.Modifier [count][];
160 pending_implementations [i].type = type_builder;
162 string indexer_name = TypeManager.IndexerPropertyName (type_builder);
163 pending_implementations [i].set_indexer_name = "set_" + indexer_name;
164 pending_implementations [i].get_indexer_name = "get_" + indexer_name;
167 foreach (MemberInfo m in abstract_methods) {
168 MethodInfo mi = (MethodInfo) m;
170 ParameterData pd = TypeManager.GetParameterData (mi);
171 Type [] types = pd.Types;
173 pending_implementations [i].args [j] = types;
174 pending_implementations [i].mods [j] = null;
176 Parameter.Modifier [] pm = new Parameter.Modifier [pd.Count];
177 for (int k = 0; k < pd.Count; k++)
178 pm [k] = pd.ParameterModifier (k);
179 pending_implementations [i].mods [j] = pm;
187 foreach (MissingInterfacesInfo missing in missing_ifaces) {
189 Type t = missing.Type;
194 if (t is TypeBuilder){
197 iface = TypeManager.LookupInterface (t);
199 mi = iface.GetMethods ();
201 mi = t.GetMethods ();
203 int count = mi.Length;
204 pending_implementations [i].type = t;
205 pending_implementations [i].optional = missing.Optional;
206 pending_implementations [i].methods = mi;
207 pending_implementations [i].args = new Type [count][];
208 pending_implementations [i].mods = new Parameter.Modifier [count][];
209 pending_implementations [i].found = new bool [count];
210 pending_implementations [i].need_proxy = new MethodInfo [count];
211 string indexer_name = TypeManager.IndexerPropertyName (t);
213 pending_implementations [i].set_indexer_name = "set_" + indexer_name;
214 pending_implementations [i].get_indexer_name = "get_" + indexer_name;
217 foreach (MethodInfo m in mi){
218 pending_implementations [i].args [j] = Type.EmptyTypes;
219 pending_implementations [i].mods [j] = null;
221 // If there is a previous error, just ignore
225 ParameterData pd = TypeManager.GetParameterData (m);
226 pending_implementations [i].args [j] = pd.Types;
229 Parameter.Modifier [] pm = new Parameter.Modifier [pd.Count];
230 for (int k = 0; k < pd.Count; k++)
231 pm [k] = pd.ParameterModifier (k);
232 pending_implementations [i].mods [j] = pm;
241 struct MissingInterfacesInfo {
243 public bool Optional;
245 public MissingInterfacesInfo (Type t)
252 static MissingInterfacesInfo [] EmptyMissingInterfacesInfo = new MissingInterfacesInfo [0];
254 static MissingInterfacesInfo [] GetMissingInterfaces (TypeBuilder type_builder)
257 // Notice that TypeBuilders will only return the interfaces that the Type
258 // is supposed to implement, not all the interfaces that the type implements.
260 // Even better -- on MS it returns an empty array, no matter what.
262 // Completely broken. So we do it ourselves!
264 Type [] impl = TypeManager.GetExplicitInterfaces (type_builder);
266 if (impl == null || impl.Length == 0)
267 return EmptyMissingInterfacesInfo;
269 MissingInterfacesInfo [] ret = new MissingInterfacesInfo [impl.Length];
271 for (int i = 0; i < impl.Length; i++)
272 ret [i] = new MissingInterfacesInfo (impl [i]);
274 // we really should not get here because Object doesnt implement any
275 // interfaces. But it could implement something internal, so we have
276 // to handle that case.
277 if (type_builder.BaseType == null)
280 Type [] base_impls = TypeManager.GetInterfaces (type_builder.BaseType);
282 foreach (Type t in base_impls) {
283 for (int i = 0; i < ret.Length; i ++) {
284 if (t == ret [i].Type) {
285 ret [i].Optional = true;
294 // Factory method: if there are pending implementation methods, we return a PendingImplementation
295 // object, otherwise we return null.
297 // Register method implementations are either abstract methods
298 // flagged as such on the base class or interface methods
300 static public PendingImplementation GetPendingImplementations (TypeContainer container)
302 TypeBuilder type_builder = container.TypeBuilder;
303 MissingInterfacesInfo [] missing_interfaces;
304 Type b = type_builder.BaseType;
306 missing_interfaces = GetMissingInterfaces (type_builder);
309 // If we are implementing an abstract class, and we are not
310 // ourselves abstract, and there are abstract methods (C# allows
311 // abstract classes that have no abstract methods), then allocate
314 // We also pre-compute the methods.
316 bool implementing_abstract = ((b != null) && b.IsAbstract && !type_builder.IsAbstract);
317 ArrayList abstract_methods = null;
319 if (implementing_abstract){
320 abstract_methods = GetAbstractMethods (b);
322 if (abstract_methods == null)
323 implementing_abstract = false;
326 int total = missing_interfaces.Length + (implementing_abstract ? 1 : 0);
330 return new PendingImplementation (container, missing_interfaces, abstract_methods, total);
333 public enum Operation {
335 // If you change this, review the whole InterfaceMethod routine as there
336 // are a couple of assumptions on these three states
338 Lookup, ClearOne, ClearAll
342 /// Whether the specified method is an interface method implementation
344 public MethodInfo IsInterfaceMethod (Type t, string name, Type ret_type, ParameterData args)
346 return InterfaceMethod (t, name, ret_type, args, Operation.Lookup, null);
349 public MethodInfo IsInterfaceIndexer (Type t, Type ret_type, ParameterData args)
351 return InterfaceMethod (t, null, ret_type, args, Operation.Lookup, null);
354 public void ImplementMethod (Type t, string name, Type ret_type, ParameterData args, bool clear_one)
356 InterfaceMethod (t, name, ret_type, args,
357 clear_one ? Operation.ClearOne : Operation.ClearAll, null);
360 public void ImplementIndexer (Type t, MethodInfo mi, Type ret_type, ParameterData args, bool clear_one)
362 InterfaceMethod (t, null, ret_type, args,
363 clear_one ? Operation.ClearOne : Operation.ClearAll, mi);
367 /// If a method in Type `t' (or null to look in all interfaces
368 /// and the base abstract class) with name `Name', return type `ret_type' and
369 /// arguments `args' implements an interface, this method will
370 /// return the MethodInfo that this method implements.
372 /// If `name' is null, we operate solely on the method's signature. This is for
373 /// instance used when implementing indexers.
375 /// The `Operation op' controls whether to lookup, clear the pending bit, or clear
376 /// all the methods with the given signature.
378 /// The `MethodInfo need_proxy' is used when we're implementing an interface's
379 /// indexer in a class. If the new indexer's IndexerName does not match the one
380 /// that was used in the interface, then we always need to create a proxy for it.
383 public MethodInfo InterfaceMethod (Type t, string name, Type ret_type, ParameterData args,
384 Operation op, MethodInfo need_proxy)
386 int arg_len = args.Count;
388 if (pending_implementations == null)
391 foreach (TypeAndMethods tm in pending_implementations){
392 if (!(t == null || tm.type == t))
395 int method_count = tm.methods.Length;
397 for (int i = 0; i < method_count; i++){
403 string mname = TypeManager.GetMethodName (m);
406 // `need_proxy' is not null when we're implementing an
407 // interface indexer and this is Clear(One/All) operation.
409 // If `name' is null, then we do a match solely based on the
410 // signature and not on the name (this is done in the Lookup
411 // for an interface indexer).
414 if (mname != tm.get_indexer_name && mname != tm.set_indexer_name)
416 } else if ((need_proxy == null) && (name != mname))
419 if (!TypeManager.IsEqual (ret_type, m.ReturnType) &&
420 !(ret_type == null && m.ReturnType == TypeManager.void_type) &&
421 !(m.ReturnType == null && ret_type == TypeManager.void_type))
425 // Check if we have the same parameters
428 if (tm.args [i] == null && arg_len != 0)
430 if (tm.args [i] != null && tm.args [i].Length != arg_len)
435 for (j = 0; j < arg_len; j++) {
436 if (!TypeManager.IsEqual (tm.args [i][j], args.ParameterType (j)))
438 if (tm.mods [i][j] == args.ParameterModifier (j))
440 // The modifiers are different, but if one of them
441 // is a PARAMS modifier, and the other isn't, ignore
443 if (tm.mods [i][j] != Parameter.Modifier.PARAMS &&
444 args.ParameterModifier (j) != Parameter.Modifier.PARAMS)
450 if (op != Operation.Lookup){
451 // If `t != null', then this is an explicitly interface
452 // implementation and we can always clear the method.
453 // `need_proxy' is not null if we're implementing an
454 // interface indexer. In this case, we need to create
455 // a proxy if the implementation's IndexerName doesn't
456 // match the IndexerName in the interface.
457 bool name_matches = false;
458 if (name == mname || mname == tm.get_indexer_name || mname == tm.set_indexer_name)
461 if ((t == null) && (need_proxy != null) && !name_matches)
462 tm.need_proxy [i] = need_proxy;
464 tm.methods [i] = null;
469 // Lookups and ClearOne return
471 if (op != Operation.ClearAll)
475 // If a specific type was requested, we can stop now.
483 /// C# allows this kind of scenarios:
484 /// interface I { void M (); }
485 /// class X { public void M (); }
486 /// class Y : X, I { }
488 /// For that case, we create an explicit implementation function
491 void DefineProxy (Type iface, MethodInfo base_method, MethodInfo iface_method,
496 string proxy_name = SimpleName.RemoveGenericArity (iface.Name) + '.' + iface_method.Name;
498 proxy = container.TypeBuilder.DefineMethod (
500 MethodAttributes.HideBySig |
501 MethodAttributes.NewSlot |
502 MethodAttributes.Virtual,
503 CallingConventions.Standard | CallingConventions.HasThis,
504 base_method.ReturnType, args);
506 ParameterData pd = TypeManager.GetParameterData (iface_method);
507 proxy.DefineParameter (0, ParameterAttributes.None, "");
508 for (int i = 0; i < pd.Count; i++) {
509 string name = pd.ParameterName (i);
510 ParameterAttributes attr = Parameter.GetParameterAttributes (pd.ParameterModifier (i));
511 proxy.DefineParameter (i + 1, attr, name);
514 int top = args.Length;
515 ILGenerator ig = proxy.GetILGenerator ();
517 for (int i = 0; i <= top; i++)
518 ParameterReference.EmitLdArg (ig, i);
520 ig.Emit (OpCodes.Call, base_method);
521 ig.Emit (OpCodes.Ret);
523 container.TypeBuilder.DefineMethodOverride (proxy, iface_method);
527 /// This function tells whether one of our base classes implements
528 /// the given method (which turns out, it is valid to have an interface
529 /// implementation in a base
531 bool BaseImplements (Type iface_type, MethodInfo mi)
535 Type [] args = TypeManager.GetParameterData (mi).Types;
536 ms = new MethodSignature (mi.Name, mi.ReturnType, args);
537 MemberList list = TypeContainer.FindMembers (
538 container.TypeBuilder.BaseType, MemberTypes.Method | MemberTypes.Property,
539 BindingFlags.Public | BindingFlags.Instance,
540 MethodSignature.method_signature_filter, ms);
545 if (TypeManager.ImplementsInterface (container.TypeBuilder.BaseType, iface_type))
549 // FIXME: We should be creating fewer proxies. The runtime can handle most cases.
550 // At worst, if we can't avoid creating the proxy, we may need to make the
551 // proxy use Callvirt.
553 MethodInfo base_method = (MethodInfo) list [0];
555 if (base_method.DeclaringType.IsInterface)
558 if (!base_method.IsAbstract && !base_method.IsVirtual)
559 DefineProxy (iface_type, base_method, mi, args);
565 /// Verifies that any pending abstract methods or interface methods
566 /// were implemented.
568 public bool VerifyPendingMethods ()
570 int top = pending_implementations.Length;
574 for (i = 0; i < top; i++){
575 Type type = pending_implementations [i].type;
578 bool base_implements_type = type.IsInterface &&
579 container.TypeBuilder.BaseType != null &&
580 TypeManager.ImplementsInterface (container.TypeBuilder.BaseType, type);
582 foreach (MethodInfo mi in pending_implementations [i].methods){
586 if (type.IsInterface){
587 MethodInfo need_proxy =
588 pending_implementations [i].need_proxy [j];
590 if (need_proxy != null) {
591 Type [] args = TypeManager.GetParameterData (mi).Types;
592 DefineProxy (type, need_proxy, mi, args);
596 if (base_implements_type || BaseImplements (type, mi))
599 if (pending_implementations [i].optional)
602 Report.SymbolRelatedToPreviousError (mi);
603 if (pending_implementations [i].found [j]) {
604 if (mi.IsSpecialName) {
605 string name = TypeManager.CSharpName (mi.DeclaringType) + '.' + mi.Name.Substring (4);
606 Report.Error (551, container.Location, "Explicit interface implementation `{0}.{1}' is missing accessor `{2}'",
607 container.GetSignatureForError (), name, TypeManager.CSharpSignature (mi, true));
609 string[] methodLabel = TypeManager.CSharpSignature (mi).Split ('.');
610 Report.Error (536, container.Location,
611 "`{0}' does not implement interface member `{1}'. `{2}.{3}' " +
612 "is either static, not public, or has the wrong return type",
613 container.Name, TypeManager.CSharpSignature (mi),
614 container.Name, methodLabel[methodLabel.Length - 1]);
618 Report.Error (535, container.Location, "`{0}' does not implement interface member `{1}'",
619 container.GetSignatureForError (), TypeManager.CSharpSignature (mi));
622 Report.Error (534, container.Location, "`{0}' does not implement inherited abstract member `{1}'",
623 container.GetSignatureForError (), TypeManager.CSharpSignature (mi, true));