Compiler: lookup for abstract def implementation in all ancestors. Fixes

#4052
crystal-lang · Mar 3, 2017 · 812223f · 812223f · luislavena · Mar 3, 2017
1 parent e1cdde8
commit 812223f
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Showing 2 changed files with 23 additions and 7 deletions.
diff --git a/spec/compiler/semantic/abstract_def_spec.cr b/spec/compiler/semantic/abstract_def_spec.cr
@@ -375,4 +375,23 @@ describe "Semantic: abstract def" do
       end
       )
   end
+
+  it "finds implements in included module in disorder (#4052)" do
+    semantic %(
+      module B
+        abstract def x
+      end
+
+      module C
+        def x
+          :x
+        end
+      end
+
+      class A
+        include C
+        include B
+      end
+      )
+  end
 end
diff --git a/src/compiler/crystal/semantic/abstract_def_checker.cr b/src/compiler/crystal/semantic/abstract_def_checker.cr
@@ -74,7 +74,7 @@ class Crystal::AbstractDefChecker
                end
 
     subtypes.try &.each do |subtype|
-      next if implements_with_parents?(subtype, method, base)
+      next if implements_with_ancestors?(subtype, method, base)
 
       # Union doesn't need a hash, dup, to_s, etc., methods because it's special
       next if subtype == @program.union
@@ -87,15 +87,12 @@ class Crystal::AbstractDefChecker
     end
   end
 
-  def implements_with_parents?(type : Type, method : Def, base)
+  def implements_with_ancestors?(type : Type, method : Def, base)
     return true if implements?(type, method, base)
 
-    type.parents.try &.each do |parent|
-      break if parent == base
-      return true if implements?(parent, method, base)
+    type.ancestors.any? do |ancestor|
+      implements?(ancestor, method, base)
     end
-
-    return false
   end
 
   def implements?(type : Type, method : Def, base)