rust/ql/src/queries/unusedentities/UnusedVariable.ql

/**
 * @name Unused variable
 * @description Unused variables may be an indication that the code is incomplete or has a typo.
 * @kind problem
 * @problem.severity recommendation
 * @precision high
 * @id rust/unused-variable
 * @tags maintainability
 *       quality
 */

import rust
import UnusedVariable

from Variable v
where
  isUnused(v) and
  not isAllowableUnused(v) and
  not v instanceof DiscardVariable
select v, "Variable '" + v + "' is not used."