Swift: improve print-cfg query

Author: aibaars

…ide-contextual-queries/IDEContextual.qll swift/ql/lib/codeql/IDEContextual.qllswift/ql/src/queries/ide-contextual-queries/IDEContextual.qll renamed to swift/ql/lib/codeql/IDEContextual.qll swift/ql/src/queries/ide-contextual-queries/IDEContextual.qll renamed to swift/ql/lib/codeql/IDEContextual.qll

@@ -7,9 +7,52 @@
  * @tags ide-contextual-queries/print-cfg
  */
 
+private import codeql.IDEContextual
 private import codeql.swift.controlflow.ControlFlowGraph
 private import codeql.swift.controlflow.internal.ControlFlowGraphImpl::TestOutput
 
+/**
+ * Gets the source file to generate a CFG from.
+ */
+external string selectedSourceFile();
+
+/**
+ * Gets the source line to generate a CFG from.
+ */
+external string selectedSourceLine();
+
+/**
+ * Gets the source column to generate a CFG from.
+ */
+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() { any() }
+  MyRelevantNode() {
+    this.getScope() =
+      smallestEnclosingScope(getFileBySourceArchiveName(selectedSourceFile()),
+        selectedSourceLine().toInt(), selectedSourceColumn().toInt())
+  }
 }

swift/ql/lib/codeql/swift/controlflow/internal/PrintCFG.ql

@@ -9,7 +9,7 @@
 
 import swift
 import codeql.swift.printast.PrintAst
-import IDEContextual
+import codeql.IDEContextual
 import codeql.swift.generated.ParentChild
 
 /**