Function detect_with_arm_paths 

pub fn detect_with_arm_paths(
    files: &[InputFile<'_>],
    arm_paths: &[Option<&[ArmPath]>],
    config: &EngineConfig,
) -> EngineReport

Detect clones while excluding pairs separated by C-family preprocessor arms.

arm_paths is parallel to files, and each path slice is parallel to its file’s token stream. Invalid metadata is ignored rather than causing an analysis failure; the ordinary Fast result is safer than trusting a partial conditional map.