cleanup and more tests

TestSuite/errors/err0540_foreach_resolver.pas

@@ -0,0 +1,20 @@
+//!Невозможно выполнить оператор foreach или yield sequence по выражению типа c1
+
+uses System.Collections, System.Collections.Generic;
+
+type
+  c1 = class (IEnumerable<integer>, IEnumerable<string>)
+  public
+    function IEnumerable<string>.GetEnumerator: IEnumerator<string>;
+    begin end;
+    
+    function IEnumerable<integer>.GetEnumerator: IEnumerator<integer>;
+    begin end;
+    
+    function IEnumerable.GetEnumerator: IEnumerator;
+    begin end;
+  end;
+  
+begin
+  foreach var item in new c1 do ;
+end.

TestSuite/foreach_resolver2.pas

@@ -0,0 +1,67 @@
+uses System.Collections, System.Collections.Generic;
+
+type
+  c1 = class (IEnumerable<integer>)
+  public 
+  
+    function IEnumerable<integer>.GetEnumerator: IEnumerator<integer>;	
+    begin
+      Assert(false);
+    end;
+    
+    function GetEnumerator: IEnumerator;
+    begin
+      result:= Seq&<object>().GetEnumerator;
+    end;
+  end;
+  
+  c2<T1, T2> = class (IEnumerable<T2>)
+  public 
+    function GetEnumerator: IEnumerator<T2>;	
+    begin
+      result:= Seq&<T2>().GetEnumerator;
+    end;
+    
+    function IEnumerable.GetEnumerator: IEnumerator;
+    begin
+      Assert(false);
+    end;
+  end;
+  
+  c3 = class (IEnumerable<integer>, IEnumerable<string>)
+  public
+    function GetEnumerator: IEnumerator<string>;
+    begin
+      result:= Seq&<string>().GetEnumerator;
+    end;
+    
+    function IEnumerable<integer>.GetEnumerator: IEnumerator<integer>;
+    begin
+      Assert(false);
+    end;
+    
+    function IEnumerable.GetEnumerator: IEnumerator;
+    begin
+      Assert(false);
+    end;
+  end;
+  
+  c4 = class (c2<integer, int64>)
+  
+  end;
+  
+begin
+  
+  var v1:= new c1;
+  foreach var item in v1 do ;
+  
+  var v2:= new c2<byte, string>;
+  foreach var item in v2 do ;
+  
+  var v3:= new c3;
+  foreach var item in v3 do ;
+  
+  var v4:= new c4;
+  foreach var item in v4 do ;
+  
+end.

TreeConverter/TreeConversion/syntax_tree_visitor.cs

@@ -18577,7 +18577,7 @@ namespace PascalABCCompiler.TreeConverter
             }
         }
 
-        private bool IsIEnumerableInterface(ITypeNode t)
+        private bool IsIEnumerableInterface(type_node t)
         {
             compiled_type_node orig;
 
@@ -18594,7 +18594,7 @@ namespace PascalABCCompiler.TreeConverter
         /// <summary>
         /// Собирает интерфейсы, реализованные типом и его предками
         /// </summary>
-        private List<ITypeNode> CollectInterfacesFromTypeNode(type_node node)
+        private List<type_node> CollectInterfacesFromTypeNode(type_node node)
         {
             var result = new List<ITypeNode>();
             result.AddRange(node.ImplementingInterfaces);
@@ -18605,7 +18605,7 @@ namespace PascalABCCompiler.TreeConverter
                 result.AddRange(interfInBase);
             }
 
-            return result;
+            return result.Cast<type_node>().ToList();
         }
 
         private bool IsIEnumeratorInterface(type_node t)
@@ -18629,7 +18629,6 @@ namespace PascalABCCompiler.TreeConverter
 
             var filteredInterfaces = CollectInterfacesFromTypeNode(node)
                 .Where(item => IsIEnumerableInterface(item))
-                .Cast<type_node>()
                 .ToArray();
             
             var genericInterfaceCount = filteredInterfaces.Count(item => item.is_generic_type_instance);