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 parent 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;
39 // This flag on the method says `We found a match, but
40 // because it was private, we could not use the match
44 // If a method is defined here, then we always need to
45 // create a proxy for it. This is used when implementing
46 // an interface's indexer with a different IndexerName.
47 public MethodInfo [] need_proxy;
50 public class PendingImplementation {
52 /// The container for this PendingImplementation
54 TypeContainer container;
57 /// This filter is used by FindMembers, and it is used to
58 /// extract only virtual/abstract fields
60 static MemberFilter virtual_method_filter;
63 /// This is the array of TypeAndMethods that describes the pending implementations
64 /// (both interfaces and abstract methods in parent class)
66 TypeAndMethods [] pending_implementations;
68 static bool IsVirtualFilter (MemberInfo m, object filterCriteria)
70 MethodInfo mi = m as MethodInfo;
71 return (mi == null) ? false : mi.IsVirtual;
75 /// Inits the virtual_method_filter
77 static PendingImplementation ()
79 virtual_method_filter = new MemberFilter (IsVirtualFilter);
83 // Returns a list of the abstract methods that are exposed by all of our
84 // parents that we must implement. Notice that this `flattens' the
85 // method search space, and takes into account overrides.
87 static ArrayList GetAbstractMethods (Type t)
89 ArrayList list = null;
90 bool searching = true;
91 Type current_type = t;
96 mi = TypeContainer.FindMembers (
97 current_type, MemberTypes.Method,
98 BindingFlags.Public | BindingFlags.Instance |
99 BindingFlags.DeclaredOnly,
100 virtual_method_filter, null);
102 if (current_type == TypeManager.object_type)
105 current_type = current_type.BaseType;
106 if (!current_type.IsAbstract)
113 if (mi.Count == 1 && !(mi [0] is MethodBase))
116 list = TypeManager.CopyNewMethods (list, mi);
122 for (int i = 0; i < list.Count; i++){
123 while (list.Count > i && !((MethodInfo) list [i]).IsAbstract)
133 PendingImplementation (TypeContainer container, MissingInterfacesInfo [] missing_ifaces, ArrayList abstract_methods, int total)
135 TypeBuilder type_builder = container.TypeBuilder;
137 this.container = container;
138 pending_implementations = new TypeAndMethods [total];
141 foreach (MissingInterfacesInfo missing in missing_ifaces){
143 Type t = missing.Type;
145 if (t is TypeBuilder){
148 iface = TypeManager.LookupInterface (t);
150 mi = iface.GetMethods (container);
152 mi = t.GetMethods ();
154 int count = mi.Length;
155 pending_implementations [i].type = missing.Type;
156 pending_implementations [i].optional = missing.Optional;
157 pending_implementations [i].methods = mi;
158 pending_implementations [i].args = new Type [count][];
159 pending_implementations [i].found = new bool [count];
160 pending_implementations [i].need_proxy = new MethodInfo [count];
163 foreach (MethodInfo m in mi){
164 Type [] types = TypeManager.GetArgumentTypes (m);
166 pending_implementations [i].args [j] = types;
172 if (abstract_methods != null){
173 int count = abstract_methods.Count;
174 pending_implementations [i].methods = new MethodInfo [count];
175 pending_implementations [i].need_proxy = new MethodInfo [count];
177 abstract_methods.CopyTo (pending_implementations [i].methods, 0);
178 pending_implementations [i].found = new bool [count];
179 pending_implementations [i].args = new Type [count][];
180 pending_implementations [i].type = type_builder;
183 foreach (MemberInfo m in abstract_methods){
184 MethodInfo mi = (MethodInfo) m;
186 Type [] types = TypeManager.GetArgumentTypes (mi);
188 pending_implementations [i].args [j] = types;
194 struct MissingInterfacesInfo {
196 public bool Optional;
198 public MissingInterfacesInfo (Type t)
205 static MissingInterfacesInfo [] EmptyMissingInterfacesInfo = new MissingInterfacesInfo [0];
207 static MissingInterfacesInfo [] GetMissingInterfaces (TypeBuilder type_builder)
210 // Notice that TypeBuilders will only return the interfaces that the Type
211 // is supposed to implement, not all the interfaces that the type implements.
213 // Even better -- on MS it returns an empty array, no matter what.
215 // Completely broken. So we do it ourselves!
217 TypeExpr [] impl = TypeManager.GetExplicitInterfaces (type_builder);
219 if (impl == null || impl.Length == 0)
220 return EmptyMissingInterfacesInfo;
222 MissingInterfacesInfo [] ret = new MissingInterfacesInfo [impl.Length];
224 for (int i = 0; i < impl.Length; i++)
225 ret [i] = new MissingInterfacesInfo (impl [i].Type);
227 // we really should not get here because Object doesnt implement any
228 // interfaces. But it could implement something internal, so we have
229 // to handle that case.
230 if (type_builder.BaseType == null)
233 TypeExpr [] parent_impls = TypeManager.GetInterfaces (type_builder.BaseType);
235 foreach (TypeExpr te in parent_impls) {
238 for (int i = 0; i < ret.Length; i ++) {
239 if (t == ret [i].Type) {
240 ret [i].Optional = true;
249 // Factory method: if there are pending implementation methods, we return a PendingImplementation
250 // object, otherwise we return null.
252 // Register method implementations are either abstract methods
253 // flagged as such on the base class or interface methods
255 static public PendingImplementation GetPendingImplementations (TypeContainer container)
257 TypeBuilder type_builder = container.TypeBuilder;
258 MissingInterfacesInfo [] missing_interfaces;
259 Type b = type_builder.BaseType;
261 missing_interfaces = GetMissingInterfaces (type_builder);
264 // If we are implementing an abstract class, and we are not
265 // ourselves abstract, and there are abstract methods (C# allows
266 // abstract classes that have no abstract methods), then allocate
269 // We also pre-compute the methods.
271 bool implementing_abstract = ((b != null) && b.IsAbstract && !type_builder.IsAbstract);
272 ArrayList abstract_methods = null;
274 if (implementing_abstract){
275 abstract_methods = GetAbstractMethods (b);
277 if (abstract_methods == null)
278 implementing_abstract = false;
281 int total = missing_interfaces.Length + (implementing_abstract ? 1 : 0);
285 return new PendingImplementation (container, missing_interfaces, abstract_methods, total);
288 public enum Operation {
290 // If you change this, review the whole InterfaceMethod routine as there
291 // are a couple of assumptions on these three states
293 Lookup, ClearOne, ClearAll
297 /// Whether the specified method is an interface method implementation
299 public MethodInfo IsInterfaceMethod (Type t, string name, Type ret_type, Type [] args)
301 return InterfaceMethod (t, name, ret_type, args, Operation.Lookup, null);
304 public MethodInfo IsInterfaceIndexer (Type t, Type ret_type, Type [] args)
306 return InterfaceMethod (t, null, ret_type, args, Operation.Lookup, null);
309 public void ImplementMethod (Type t, string name, Type ret_type, Type [] args, bool clear_one)
311 InterfaceMethod (t, name, ret_type, args,
312 clear_one ? Operation.ClearOne : Operation.ClearAll, null);
315 public void ImplementIndexer (Type t, MethodInfo mi, Type ret_type, Type [] args, bool clear_one)
317 InterfaceMethod (t, mi.Name, ret_type, args,
318 clear_one ? Operation.ClearOne : Operation.ClearAll, mi);
322 /// If a method in Type `t' (or null to look in all interfaces
323 /// and the base abstract class) with name `Name', return type `ret_type' and
324 /// arguments `args' implements an interface, this method will
325 /// return the MethodInfo that this method implements.
327 /// If `name' is null, we operate solely on the method's signature. This is for
328 /// instance used when implementing indexers.
330 /// The `Operation op' controls whether to lookup, clear the pending bit, or clear
331 /// all the methods with the given signature.
333 /// The `MethodInfo need_proxy' is used when we're implementing an interface's
334 /// indexer in a class. If the new indexer's IndexerName does not match the one
335 /// that was used in the interface, then we always need to create a proxy for it.
338 public MethodInfo InterfaceMethod (Type t, string name, Type ret_type, Type [] args,
339 Operation op, MethodInfo need_proxy)
341 int arg_len = args.Length;
343 if (pending_implementations == null)
346 foreach (TypeAndMethods tm in pending_implementations){
347 if (!(t == null || tm.type == t))
350 int method_count = tm.methods.Length;
352 for (int i = 0; i < method_count; i++){
358 // `need_proxy' is not null when we're implementing an
359 // interface indexer and this is Clear(One/All) operation.
360 // If `name' is null, then we do a match solely based on the
361 // signature and not on the name (this is done in the Lookup
362 // for an interface indexer).
363 if ((name != null) && (need_proxy == null) && (name != m.Name))
366 if (ret_type != m.ReturnType){
367 if (!((ret_type == null && m.ReturnType == TypeManager.void_type) ||
368 (m.ReturnType == null && ret_type == TypeManager.void_type)))
373 // Check if we have the same parameters
375 if (tm.args [i].Length != arg_len)
378 int j, top = args.Length;
381 for (j = 0; j < top; j++){
382 if (tm.args [i][j] != args[j]){
390 if (op != Operation.Lookup){
391 // If `t != null', then this is an explicitly interface
392 // implementation and we can always clear the method.
393 // `need_proxy' is not null if we're implementing an
394 // interface indexer. In this case, we need to create
395 // a proxy if the implementation's IndexerName doesn't
396 // match the IndexerName in the interface.
397 if ((t == null) && (need_proxy != null) && (name != m.Name))
398 tm.need_proxy [i] = need_proxy;
400 tm.methods [i] = null;
405 // Lookups and ClearOne return
407 if (op != Operation.ClearAll)
411 // If a specific type was requested, we can stop now.
419 /// C# allows this kind of scenarios:
420 /// interface I { void M (); }
421 /// class X { public void M (); }
422 /// class Y : X, I { }
424 /// For that case, we create an explicit implementation function
427 void DefineProxy (Type iface, MethodInfo parent_method, MethodInfo iface_method,
432 string proxy_name = iface.Name + "." + iface_method.Name;
434 proxy = container.TypeBuilder.DefineMethod (
436 MethodAttributes.HideBySig |
437 MethodAttributes.NewSlot |
438 MethodAttributes.Virtual,
439 CallingConventions.Standard | CallingConventions.HasThis,
440 parent_method.ReturnType, args);
442 int top = args.Length;
443 ILGenerator ig = proxy.GetILGenerator ();
445 ig.Emit (OpCodes.Ldarg_0);
446 for (int i = 0; i < top; i++){
449 ig.Emit (OpCodes.Ldarg_1); break;
451 ig.Emit (OpCodes.Ldarg_2); break;
453 ig.Emit (OpCodes.Ldarg_3); break;
455 ig.Emit (OpCodes.Ldarg, i - 1); break;
458 ig.Emit (OpCodes.Call, parent_method);
459 ig.Emit (OpCodes.Ret);
461 container.TypeBuilder.DefineMethodOverride (proxy, iface_method);
465 /// This function tells whether one of our parent classes implements
466 /// the given method (which turns out, it is valid to have an interface
467 /// implementation in a parent
469 bool ParentImplements (Type iface_type, MethodInfo mi)
473 Type [] args = TypeManager.GetArgumentTypes (mi);
474 ms = new MethodSignature (mi.Name, mi.ReturnType, args);
475 MemberList list = TypeContainer.FindMembers (
476 container.TypeBuilder.BaseType, MemberTypes.Method | MemberTypes.Property,
477 BindingFlags.Public | BindingFlags.Instance,
478 MethodSignature.method_signature_filter, ms);
483 MethodInfo parent = (MethodInfo) list [0];
484 if (!parent.IsAbstract)
485 DefineProxy (iface_type, parent, mi, args);
490 /// Verifies that any pending abstract methods or interface methods
491 /// were implemented.
493 public bool VerifyPendingMethods ()
495 int top = pending_implementations.Length;
499 for (i = 0; i < top; i++){
500 Type type = pending_implementations [i].type;
503 foreach (MethodInfo mi in pending_implementations [i].methods){
507 if (type.IsInterface){
508 MethodInfo need_proxy =
509 pending_implementations [i].need_proxy [j];
511 if (need_proxy != null) {
512 Type [] args = TypeManager.GetArgumentTypes (mi);
513 DefineProxy (type, need_proxy, mi, args);
517 if (ParentImplements (type, mi))
520 if (pending_implementations [i].optional)
523 if (pending_implementations [i].found [j]) {
524 string[] methodLabel = TypeManager.CSharpSignature (mi).Split ('.');
525 Report.Error (536, container.Location, "'{0}' does not implement interface member '{1}'. '{2}.{3}' is either static, not public, or has the wrong return type",
526 container.Name, methodLabel, container.Name, methodLabel[methodLabel.Length - 1]);
529 Report.Error (535, container.Location, "'{0}' does not implement interface member '{1}'",
530 container.Name, TypeManager.CSharpSignature (mi));
533 Report.Error (534, container.Location, "'{0}' does not implement inherited abstract member '{1}'",
534 container.Name, TypeManager.CSharpSignature (mi));