blob: 6a6213a871fdaa1aacba73f47d5b77a752666ba0 [file] [log] [blame]
//! cfg defines conditional compiling options, `cfg` attribute parser and evaluator
mod cfg_expr;
mod dnf;
#[cfg(test)]
mod tests;
use std::fmt;
use rustc_hash::FxHashSet;
use intern::{sym, Symbol};
pub use cfg_expr::{CfgAtom, CfgExpr};
pub use dnf::DnfExpr;
/// Configuration options used for conditional compilation 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(Clone, PartialEq, Eq)]
pub struct CfgOptions {
enabled: FxHashSet<CfgAtom>,
}
impl Default for CfgOptions {
fn default() -> Self {
Self { enabled: FxHashSet::from_iter([CfgAtom::Flag(sym::true_.clone())]) }
}
}
impl fmt::Debug for CfgOptions {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
let mut items = self
.enabled
.iter()
.map(|atom| match atom {
CfgAtom::Flag(it) => it.to_string(),
CfgAtom::KeyValue { key, value } => format!("{key}={value}"),
})
.collect::<Vec<_>>();
items.sort();
f.debug_tuple("CfgOptions").field(&items).finish()
}
}
impl CfgOptions {
pub fn check(&self, cfg: &CfgExpr) -> Option<bool> {
cfg.fold(&|atom| self.enabled.contains(atom))
}
pub fn check_atom(&self, cfg: &CfgAtom) -> bool {
self.enabled.contains(cfg)
}
pub fn insert_atom(&mut self, key: Symbol) {
self.insert_any_atom(CfgAtom::Flag(key));
}
pub fn insert_key_value(&mut self, key: Symbol, value: Symbol) {
self.insert_any_atom(CfgAtom::KeyValue { key, value });
}
pub fn apply_diff(&mut self, diff: CfgDiff) {
for atom in diff.enable {
self.insert_any_atom(atom);
}
for atom in diff.disable {
let (CfgAtom::Flag(sym) | CfgAtom::KeyValue { key: sym, .. }) = &atom;
if *sym == sym::true_ || *sym == sym::false_ {
tracing::error!("cannot remove `true` or `false` from cfg");
continue;
}
self.enabled.remove(&atom);
}
}
fn insert_any_atom(&mut self, atom: CfgAtom) {
let (CfgAtom::Flag(sym) | CfgAtom::KeyValue { key: sym, .. }) = &atom;
if *sym == sym::true_ || *sym == sym::false_ {
tracing::error!("cannot insert `true` or `false` to cfg");
return;
}
self.enabled.insert(atom);
}
pub fn get_cfg_keys(&self) -> impl Iterator<Item = &Symbol> {
self.enabled.iter().map(|it| match it {
CfgAtom::Flag(key) => key,
CfgAtom::KeyValue { key, .. } => key,
})
}
pub fn get_cfg_values<'a>(&'a self, cfg_key: &'a str) -> impl Iterator<Item = &'a Symbol> + 'a {
self.enabled.iter().filter_map(move |it| match it {
CfgAtom::KeyValue { key, value } if cfg_key == key.as_str() => Some(value),
_ => None,
})
}
}
impl Extend<CfgAtom> for CfgOptions {
fn extend<T: IntoIterator<Item = CfgAtom>>(&mut self, iter: T) {
iter.into_iter().for_each(|cfg_flag| self.insert_any_atom(cfg_flag));
}
}
impl IntoIterator for CfgOptions {
type Item = <FxHashSet<CfgAtom> as IntoIterator>::Item;
type IntoIter = <FxHashSet<CfgAtom> as IntoIterator>::IntoIter;
fn into_iter(self) -> Self::IntoIter {
<FxHashSet<CfgAtom> as IntoIterator>::into_iter(self.enabled)
}
}
impl<'a> IntoIterator for &'a CfgOptions {
type Item = <&'a FxHashSet<CfgAtom> as IntoIterator>::Item;
type IntoIter = <&'a FxHashSet<CfgAtom> as IntoIterator>::IntoIter;
fn into_iter(self) -> Self::IntoIter {
<&FxHashSet<CfgAtom> as IntoIterator>::into_iter(&self.enabled)
}
}
impl FromIterator<CfgAtom> for CfgOptions {
fn from_iter<T: IntoIterator<Item = CfgAtom>>(iter: T) -> Self {
let mut options = CfgOptions::default();
options.extend(iter);
options
}
}
#[derive(Default, Clone, Debug, PartialEq, Eq)]
pub struct CfgDiff {
// Invariants: No duplicates, no atom that's both in `enable` and `disable`.
enable: Vec<CfgAtom>,
disable: Vec<CfgAtom>,
}
impl CfgDiff {
/// Create a new CfgDiff. Will return None if the same item appears more than once in the set
/// of both.
pub fn new(enable: Vec<CfgAtom>, disable: Vec<CfgAtom>) -> Option<CfgDiff> {
let mut occupied = FxHashSet::default();
if enable.iter().chain(disable.iter()).any(|item| !occupied.insert(item)) {
// was present
return None;
}
Some(CfgDiff { enable, disable })
}
/// Returns the total number of atoms changed by this diff.
pub fn len(&self) -> usize {
self.enable.len() + self.disable.len()
}
pub fn is_empty(&self) -> bool {
self.len() == 0
}
}
impl fmt::Display for CfgDiff {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
if !self.enable.is_empty() {
f.write_str("enable ")?;
for (i, atom) in self.enable.iter().enumerate() {
let sep = match i {
0 => "",
_ if i == self.enable.len() - 1 => " and ",
_ => ", ",
};
f.write_str(sep)?;
atom.fmt(f)?;
}
if !self.disable.is_empty() {
f.write_str("; ")?;
}
}
if !self.disable.is_empty() {
f.write_str("disable ")?;
for (i, atom) in self.disable.iter().enumerate() {
let sep = match i {
0 => "",
_ if i == self.enable.len() - 1 => " and ",
_ => ", ",
};
f.write_str(sep)?;
atom.fmt(f)?;
}
}
Ok(())
}
}
pub struct InactiveReason {
enabled: Vec<CfgAtom>,
disabled: Vec<CfgAtom>,
}
impl fmt::Display for InactiveReason {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
if !self.enabled.is_empty() {
for (i, atom) in self.enabled.iter().enumerate() {
let sep = match i {
0 => "",
_ if i == self.enabled.len() - 1 => " and ",
_ => ", ",
};
f.write_str(sep)?;
atom.fmt(f)?;
}
let is_are = if self.enabled.len() == 1 { "is" } else { "are" };
write!(f, " {is_are} enabled")?;
if !self.disabled.is_empty() {
f.write_str(" and ")?;
}
}
if !self.disabled.is_empty() {
for (i, atom) in self.disabled.iter().enumerate() {
let sep = match i {
0 => "",
_ if i == self.disabled.len() - 1 => " and ",
_ => ", ",
};
f.write_str(sep)?;
atom.fmt(f)?;
}
let is_are = if self.disabled.len() == 1 { "is" } else { "are" };
write!(f, " {is_are} disabled")?;
}
Ok(())
}
}