use rustc_ast::NodeId;
use rustc_ast::{self as ast, AttrStyle, Attribute, HasAttrs, HasTokens, MetaItem};
use rustc_attr as attr;
+use rustc_data_structures::flat_map_in_place::FlatMapInPlace;
use rustc_data_structures::fx::FxHashMap;
-use rustc_data_structures::map_in_place::MapInPlace;
use rustc_feature::{Feature, Features, State as FeatureState};
use rustc_feature::{
ACCEPTED_FEATURES, ACTIVE_FEATURES, REMOVED_FEATURES, STABLE_REMOVED_FEATURES,
use rustc_span::edition::{Edition, ALL_EDITIONS};
use rustc_span::symbol::{sym, Symbol};
use rustc_span::{Span, DUMMY_SP};
-use thin_vec::ThinVec;
/// A folder that strips out items that do not belong in the current configuration.
pub struct StripUnconfigured<'a> {
pub lint_node_id: NodeId,
}
-fn get_features(sess: &Session, krate_attrs: &[ast::Attribute]) -> Features {
+pub fn features(sess: &Session, krate_attrs: &[Attribute]) -> Features {
fn feature_removed(sess: &Session, span: Span, reason: Option<&str>) {
sess.emit_err(FeatureRemoved {
span,
features
}
-/// `cfg_attr`-process the crate's attributes and compute the crate's features.
-pub fn features(
- sess: &Session,
- mut krate: ast::Crate,
- lint_node_id: NodeId,
-) -> (ast::Crate, Features) {
- let mut strip_unconfigured =
- StripUnconfigured { sess, features: None, config_tokens: false, lint_node_id };
-
- let unconfigured_attrs = krate.attrs.clone();
- let diag = &sess.parse_sess.span_diagnostic;
- let err_count = diag.err_count();
- let features = match strip_unconfigured.configure_krate_attrs(krate.attrs) {
- None => {
- // The entire crate is unconfigured.
- krate.attrs = ast::AttrVec::new();
- krate.items = ThinVec::new();
- Features::default()
- }
- Some(attrs) => {
- krate.attrs = attrs;
- let features = get_features(sess, &krate.attrs);
- if err_count == diag.err_count() {
- // Avoid reconfiguring malformed `cfg_attr`s.
- strip_unconfigured.features = Some(&features);
- // Run configuration again, this time with features available
- // so that we can perform feature-gating.
- strip_unconfigured.configure_krate_attrs(unconfigured_attrs);
- }
- features
- }
+pub fn pre_configure_attrs(sess: &Session, attrs: &[Attribute]) -> ast::AttrVec {
+ let strip_unconfigured = StripUnconfigured {
+ sess,
+ features: None,
+ config_tokens: false,
+ lint_node_id: ast::CRATE_NODE_ID,
};
- (krate, features)
+ let attrs: ast::AttrVec =
+ attrs.iter().flat_map(|attr| strip_unconfigured.process_cfg_attr(attr)).collect();
+ if strip_unconfigured.in_cfg(&attrs) { attrs } else { ast::AttrVec::new() }
}
#[macro_export]
}
}
- fn configure_krate_attrs(&self, mut attrs: ast::AttrVec) -> Option<ast::AttrVec> {
- attrs.flat_map_in_place(|attr| self.process_cfg_attr(attr));
- self.in_cfg(&attrs).then_some(attrs)
- }
-
/// Performs cfg-expansion on `stream`, producing a new `AttrTokenStream`.
/// This is only used during the invocation of `derive` proc-macros,
/// which require that we cfg-expand their entire input.
.iter()
.flat_map(|tree| match tree.clone() {
AttrTokenTree::Attributes(mut data) => {
- data.attrs.flat_map_in_place(|attr| self.process_cfg_attr(attr));
+ data.attrs.flat_map_in_place(|attr| self.process_cfg_attr(&attr));
if self.in_cfg(&data.attrs) {
data.tokens = LazyAttrTokenStream::new(
/// the syntax of any `cfg_attr` is incorrect.
fn process_cfg_attrs<T: HasAttrs>(&self, node: &mut T) {
node.visit_attrs(|attrs| {
- attrs.flat_map_in_place(|attr| self.process_cfg_attr(attr));
+ attrs.flat_map_in_place(|attr| self.process_cfg_attr(&attr));
});
}
- fn process_cfg_attr(&self, attr: Attribute) -> Vec<Attribute> {
- if attr.has_name(sym::cfg_attr) { self.expand_cfg_attr(attr, true) } else { vec![attr] }
+ fn process_cfg_attr(&self, attr: &Attribute) -> Vec<Attribute> {
+ if attr.has_name(sym::cfg_attr) {
+ self.expand_cfg_attr(attr, true)
+ } else {
+ vec![attr.clone()]
+ }
}
/// Parse and expand a single `cfg_attr` attribute into a list of attributes
/// Gives a compiler warning when the `cfg_attr` contains no attributes and
/// is in the original source file. Gives a compiler error if the syntax of
/// the attribute is incorrect.
- pub(crate) fn expand_cfg_attr(&self, attr: Attribute, recursive: bool) -> Vec<Attribute> {
+ pub(crate) fn expand_cfg_attr(&self, attr:
&Attribute, recursive: bool) -> Vec<Attribute> {
let Some((cfg_predicate, expanded_attrs)) =
- rustc_parse::parse_cfg_attr(&attr, &self.sess.parse_sess) else {
+ rustc_parse::parse_cfg_attr(attr, &self.sess.parse_sess) else {
return vec![];
};
// `#[cfg_attr(false, cfg_attr(true, some_attr))]`.
expanded_attrs
.into_iter()
- .flat_map(|item| self.process_cfg_attr(self.expand_cfg_attr_item(&attr, item)))
+ .flat_map(|item| self.process_cfg_attr(&self.expand_cfg_attr_item(attr, item)))
.collect()
} else {
- expanded_attrs.into_iter().map(|item| self.expand_cfg_attr_item(&attr, item)).collect()
+ expanded_attrs.into_iter().map(|item| self.expand_cfg_attr_item(attr, item)).collect()
}
}
//
// N.B., this is intentionally not part of the visit_expr() function
// in order for filter_map_expr() to be able to avoid this check
- if let Some(attr) = expr.attrs().iter().find(|a| is_cfg(*a)) {
+ if let Some(attr) = expr.attrs().iter().find(|a| is_cfg(a)) {
self.sess.emit_err(RemoveExprNotSupported { span: attr.span });
}
projects / rustc.git / blobdiff