Extracted QualifiedNameFinder.getQualifiedName() from PyQualifiedNameOwner implementations

python/src/com/jetbrains/python/psi/impl/PyClassImpl.java

@@ -20,7 +20,6 @@ import com.intellij.lang.ASTNode;
 import com.intellij.openapi.util.Comparing;
 import com.intellij.openapi.util.Key;
 import com.intellij.openapi.util.NotNullLazyValue;
-import com.intellij.openapi.vfs.VirtualFile;
 import com.intellij.psi.*;
 import com.intellij.psi.scope.PsiScopeProcessor;
 import com.intellij.psi.search.LocalSearchScope;
@@ -237,27 +236,7 @@ public class PyClassImpl extends PyPresentableElementImpl<PyClassStub> implement
 
   @Nullable
   public String getQualifiedName() {
-    String name = getName();
-    final PyClassStub stub = getStub();
-    PsiElement ancestor = stub != null ? stub.getParentStub().getPsi() : getParent();
-    while (!(ancestor instanceof PsiFile)) {
-      if (ancestor == null) return name;    // can this happen?
-      if (ancestor instanceof PyClass) {
-        name = ((PyClass)ancestor).getName() + "." + name;
-      }
-      ancestor = stub != null ? ((StubBasedPsiElement)ancestor).getStub().getParentStub().getPsi() : ancestor.getParent();
-    }
-
-    PsiFile psiFile = ((PsiFile)ancestor).getOriginalFile();
-    final PyFile builtins = PyBuiltinCache.getInstance(this).getBuiltinsFile();
-    if (!psiFile.equals(builtins)) {
-      VirtualFile vFile = psiFile.getVirtualFile();
-      if (vFile != null) {
-        final String packageName = QualifiedNameFinder.findShortestImportableName(this, vFile);
-        return packageName + "." + name;
-      }
-    }
-    return name;
+    return QualifiedNameFinder.getQualifiedName(this);
   }
 
   @Override

python/src/com/jetbrains/python/psi/impl/PyFunctionImpl.java

@@ -699,21 +699,6 @@ public class PyFunctionImpl extends PyPresentableElementImpl<PyFunctionStub> imp
   @Nullable
   @Override
   public String getQualifiedName() {
-    String name = getName();
-    if (name == null) {
-      return null;
-    }
-    PyClass containingClass = getContainingClass();
-    if (containingClass != null) {
-      return containingClass.getQualifiedName() + "." + name;
-    }
-    if (PsiTreeUtil.getStubOrPsiParent(this) instanceof PyFile) {
-      VirtualFile virtualFile = getContainingFile().getVirtualFile();
-      if (virtualFile != null) {
-        final String packageName = QualifiedNameFinder.findShortestImportableName(this, virtualFile);
-        return packageName + "." + name;
-      }
-    }
-    return null;
+    return QualifiedNameFinder.getQualifiedName(this);
   }
 }

python/src/com/jetbrains/python/psi/resolve/QualifiedNameFinder.java

@@ -24,10 +24,14 @@ import com.intellij.openapi.vfs.VfsUtilCore;
 import com.intellij.openapi.vfs.VirtualFile;
 import com.intellij.psi.*;
 import com.jetbrains.python.PyNames;
+import com.jetbrains.python.codeInsight.controlflow.ScopeOwner;
+import com.jetbrains.python.codeInsight.dataflow.scope.ScopeUtil;
 import com.jetbrains.python.psi.PyClass;
+import com.jetbrains.python.psi.PyElement;
 import com.jetbrains.python.psi.PyFile;
 import com.jetbrains.python.psi.PyFunction;
 import com.intellij.psi.util.QualifiedName;
+import com.jetbrains.python.psi.impl.PyBuiltinCache;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
@@ -156,6 +160,31 @@ public class QualifiedNameFinder {
     return qname;
   }
 
+  @Nullable
+  public static String getQualifiedName(@NotNull PyElement element) {
+    final String name = element.getName();
+    if (name != null) {
+      final ScopeOwner owner = ScopeUtil.getScopeOwner(element);
+      final PyBuiltinCache builtinCache = PyBuiltinCache.getInstance(element);
+      if (owner instanceof PyClass) {
+        final String classQName = ((PyClass)owner).getQualifiedName();
+        if (classQName != null) {
+          return classQName + "." + name;
+        }
+      }
+      else if (owner instanceof PyFile && !builtinCache.isBuiltin(element)) {
+        final VirtualFile virtualFile = ((PyFile)owner).getVirtualFile();
+        if (virtualFile != null) {
+          final String fileQName = findShortestImportableName(element, virtualFile);
+          if (fileQName != null) {
+            return fileQName + "." + name;
+          }
+        }
+      }
+    }
+    return null;
+  }
+
   /**
    * Tries to find roots that contain given vfile, and among them the root that contains at the smallest depth.
    * For equal depth source root is in preference to library.