//! ra_cfg defines conditional compiling options, `cfg` attibute parser and evaluator mod cfg_expr; use ra_syntax::SmolStr; use rustc_hash::FxHashSet; pub use cfg_expr::{parse_cfg, CfgExpr}; /// Configuration options used for conditional compilition on items with `cfg` attributes. /// We have two kind of options in different namespaces: atomic options like `unix`, and /// key-value options like `target_arch="x86"`. /// /// Note that for key-value options, one key can have multiple values (but not none). /// `feature` is an example. We have both `feature="foo"` and `feature="bar"` if features /// `foo` and `bar` are both enabled. And here, we store key-value options as a set of tuple /// of key and value in `key_values`. /// /// See: https://doc.rust-lang.org/reference/conditional-compilation.html#set-configuration-options #[derive(Debug, Clone, PartialEq, Eq, Default)] pub struct CfgOptions { atoms: FxHashSet<SmolStr>, key_values: FxHashSet<(SmolStr, SmolStr)>, } impl CfgOptions { pub fn check(&self, cfg: &CfgExpr) -> Option<bool> { cfg.fold(&|key, value| match value { None => self.atoms.contains(key), Some(value) => self.key_values.contains(&(key.clone(), value.clone())), }) } pub fn is_cfg_enabled(&self, attr: &tt::Subtree) -> Option<bool> { self.check(&parse_cfg(attr)) } pub fn insert_atom(&mut self, key: SmolStr) { self.atoms.insert(key); } pub fn remove_atom(&mut self, name: &str) { self.atoms.remove(name); } pub fn insert_key_value(&mut self, key: SmolStr, value: SmolStr) { self.key_values.insert((key, value)); } pub fn append(&mut self, other: &CfgOptions) { for atom in &other.atoms { self.atoms.insert(atom.clone()); } for (key, value) in &other.key_values { self.key_values.insert((key.clone(), value.clone())); } } }