Ruby: printCfg: only show graph for selected CfgScope

ruby/ql/lib/ide-contextual-queries/printCfg.ql

@@ -9,14 +9,45 @@
 
 private import codeql.ruby.controlflow.internal.ControlFlowGraphImplShared::TestOutput
 private import codeql.IDEContextual
+private import codeql.Locations
+private import codeql.ruby.controlflow.ControlFlowGraph
 
 /**
  * Gets the source file to generate a CFG from.
  */
 external string selectedSourceFile();
 
+external string selectedSourceLine();
+
+external string selectedSourceColumn();
+
+bindingset[file, line, column]
+private CfgScope smallestEnclosingScope(File file, int line, int column) {
+  result =
+    min(Location loc, CfgScope scope |
+      loc = scope.getLocation() and
+      (
+        loc.getStartLine() < line
+        or
+        loc.getStartLine() = line and loc.getStartColumn() <= column
+      ) and
+      (
+        loc.getEndLine() > line
+        or
+        loc.getEndLine() = line and loc.getEndColumn() >= column
+      ) and
+      loc.getFile() = file
+    |
+      scope
+      order by
+        loc.getStartLine() desc, loc.getStartColumn() desc, loc.getEndLine(), loc.getEndColumn()
+    )
+}
+
 class MyRelevantNode extends RelevantNode {
   MyRelevantNode() {
-    this.getScope().getLocation().getFile() = getFileBySourceArchiveName(selectedSourceFile())
+    this.getScope() =
+      smallestEnclosingScope(getFileBySourceArchiveName(selectedSourceFile()),
+        selectedSourceLine().toInt(), selectedSourceColumn().toInt())
   }
 }