// option. This file may not be copied, modified, or distributed
// except according to those terms.
-use attr::{AttrMetaMethods, HasAttrs};
+use attr::HasAttrs;
use feature_gate::{emit_feature_err, EXPLAIN_STMT_ATTR_SYNTAX, Features, get_features, GateIssue};
-use fold::Folder;
use {fold, attr};
use ast;
use codemap::{Spanned, respan};
-use parse::{ParseSess, token};
+use parse::ParseSess;
use ptr::P;
use util::small_vector::SmallVector;
pub features: Option<&'a Features>,
}
+// `cfg_attr`-process the crate's attributes and compute the crate's features.
+pub fn features(mut krate: ast::Crate, sess: &ParseSess, should_test: bool)
+ -> (ast::Crate, Features) {
+ let features;
+ {
+ let mut strip_unconfigured = StripUnconfigured {
+ config: &krate.config.clone(),
+ should_test: should_test,
+ sess: sess,
+ features: None,
+ };
+
+ let unconfigured_attrs = krate.attrs.clone();
+ let err_count = sess.span_diagnostic.err_count();
+ if let Some(attrs) = strip_unconfigured.configure(krate.attrs) {
+ krate.attrs = attrs;
+ } else { // the entire crate is unconfigured
+ krate.attrs = Vec::new();
+ krate.module.items = Vec::new();
+ return (krate, Features::new());
+ }
+
+ features = get_features(&sess.span_diagnostic, &krate.attrs);
+
+ // Avoid reconfiguring malformed `cfg_attr`s
+ if err_count == sess.span_diagnostic.err_count() {
+ strip_unconfigured.features = Some(&features);
+ strip_unconfigured.configure(unconfigured_attrs);
+ }
+ }
+
+ (krate, features)
+}
+
+macro_rules! configure {
+ ($this:ident, $node:ident) => {
+ match $this.configure($node) {
+ Some(node) => node,
+ None => return Default::default(),
+ }
+ }
+}
+
impl<'a> StripUnconfigured<'a> {
- fn configure<T: HasAttrs>(&mut self, node: T) -> Option<T> {
+ pub fn configure<T: HasAttrs>(&mut self, node: T) -> Option<T> {
let node = self.process_cfg_attrs(node);
if self.in_cfg(node.attrs()) { Some(node) } else { None }
}
return None;
}
};
+
let (cfg, mi) = match (attr_list.len(), attr_list.get(0), attr_list.get(1)) {
(2, Some(cfg), Some(mi)) => (cfg, mi),
_ => {
}
};
- if attr::cfg_matches(self.config, &cfg, self.sess, self.features) {
- self.process_cfg_attr(respan(mi.span, ast::Attribute_ {
- id: attr::mk_attr_id(),
- style: attr.node.style,
- value: mi.clone(),
- is_sugared_doc: false,
- }))
- } else {
- None
+ use attr::cfg_matches;
+ match (cfg.meta_item(), mi.meta_item()) {
+ (Some(cfg), Some(mi)) =>
+ if cfg_matches(self.config, &cfg, self.sess, self.features) {
+ self.process_cfg_attr(respan(mi.span, ast::Attribute_ {
+ id: attr::mk_attr_id(),
+ style: attr.node.style,
+ value: mi.clone(),
+ is_sugared_doc: false,
+ }))
+ } else {
+ None
+ },
+ _ => {
+ let msg = "unexpected literal(s) in `#[cfg_attr(<cfg pattern>, <attr>)]`";
+ self.sess.span_diagnostic.span_err(attr.span, msg);
+ None
+ }
}
}
// Determine if a node with the given attributes should be included in this configuation.
- fn in_cfg(&mut self, attrs: &[ast::Attribute]) -> bool {
+ pub fn in_cfg(&mut self, attrs: &[ast::Attribute]) -> bool {
attrs.iter().all(|attr| {
// When not compiling with --test we should not compile the #[test] functions
if !self.should_test && is_test_or_bench(attr) {
return true;
}
- attr::cfg_matches(self.config, &mis[0], self.sess, self.features)
+ if !mis[0].is_meta_item() {
+ self.sess.span_diagnostic.span_err(mis[0].span, "unexpected literal");
+ return true;
+ }
+
+ attr::cfg_matches(self.config, mis[0].meta_item().unwrap(), self.sess, self.features)
})
}
// Visit attributes on expression and statements (but not attributes on items in blocks).
- fn visit_stmt_or_expr_attrs(&mut self, attrs: &[ast::Attribute]) {
+ fn visit_expr_attrs(&mut self, attrs: &[ast::Attribute]) {
// flag the offending attributes
for attr in attrs.iter() {
if !self.features.map(|features| features.stmt_expr_attributes).unwrap_or(true) {
- emit_feature_err(&self.sess.span_diagnostic,
+ emit_feature_err(&self.sess,
"stmt_expr_attributes",
attr.span,
GateIssue::Language,
}
}
}
-}
-
-// Support conditional compilation by transforming the AST, stripping out
-// any items that do not belong in the current configuration
-pub fn strip_unconfigured_items(mut krate: ast::Crate, sess: &ParseSess, should_test: bool)
- -> (ast::Crate, Features) {
- let features;
- {
- let mut strip_unconfigured = StripUnconfigured {
- config: &krate.config.clone(),
- should_test: should_test,
- sess: sess,
- features: None,
- };
-
- let err_count = sess.span_diagnostic.err_count();
- let krate_attrs = strip_unconfigured.configure(krate.attrs.clone()).unwrap_or_default();
- features = get_features(&sess.span_diagnostic, &krate_attrs);
- if err_count < sess.span_diagnostic.err_count() {
- krate.attrs = krate_attrs.clone(); // Avoid reconfiguring malformed `cfg_attr`s
- }
-
- strip_unconfigured.features = Some(&features);
- krate = strip_unconfigured.fold_crate(krate);
- krate.attrs = krate_attrs;
- }
- (krate, features)
-}
-
-impl<'a> fold::Folder for StripUnconfigured<'a> {
- fn fold_foreign_mod(&mut self, foreign_mod: ast::ForeignMod) -> ast::ForeignMod {
+ pub fn configure_foreign_mod(&mut self, foreign_mod: ast::ForeignMod) -> ast::ForeignMod {
ast::ForeignMod {
abi: foreign_mod.abi,
- items: foreign_mod.items.into_iter().filter_map(|item| {
- self.configure(item).map(|item| fold::noop_fold_foreign_item(item, self))
- }).collect(),
+ items: foreign_mod.items.into_iter().filter_map(|item| self.configure(item)).collect(),
}
}
- fn fold_item_kind(&mut self, item: ast::ItemKind) -> ast::ItemKind {
- let fold_struct = |this: &mut Self, vdata| match vdata {
+ fn configure_variant_data(&mut self, vdata: ast::VariantData) -> ast::VariantData {
+ match vdata {
ast::VariantData::Struct(fields, id) => {
- let fields = fields.into_iter().filter_map(|field| this.configure(field));
+ let fields = fields.into_iter().filter_map(|field| self.configure(field));
ast::VariantData::Struct(fields.collect(), id)
}
ast::VariantData::Tuple(fields, id) => {
- let fields = fields.into_iter().filter_map(|field| this.configure(field));
+ let fields = fields.into_iter().filter_map(|field| self.configure(field));
ast::VariantData::Tuple(fields.collect(), id)
}
ast::VariantData::Unit(id) => ast::VariantData::Unit(id)
- };
+ }
+ }
- let item = match item {
+ pub fn configure_item_kind(&mut self, item: ast::ItemKind) -> ast::ItemKind {
+ match item {
ast::ItemKind::Struct(def, generics) => {
- ast::ItemKind::Struct(fold_struct(self, def), generics)
+ ast::ItemKind::Struct(self.configure_variant_data(def), generics)
+ }
+ ast::ItemKind::Union(def, generics) => {
+ ast::ItemKind::Union(self.configure_variant_data(def), generics)
}
ast::ItemKind::Enum(def, generics) => {
let variants = def.variants.into_iter().filter_map(|v| {
node: ast::Variant_ {
name: v.node.name,
attrs: v.node.attrs,
- data: fold_struct(self, v.node.data),
+ data: self.configure_variant_data(v.node.data),
disr_expr: v.node.disr_expr,
},
span: v.span
}, generics)
}
item => item,
- };
+ }
+ }
- fold::noop_fold_item_kind(item, self)
+ pub fn configure_expr_kind(&mut self, expr_kind: ast::ExprKind) -> ast::ExprKind {
+ if let ast::ExprKind::Match(m, arms) = expr_kind {
+ let arms = arms.into_iter().filter_map(|a| self.configure(a)).collect();
+ ast::ExprKind::Match(m, arms)
+ } else {
+ expr_kind
+ }
}
-
fn fold_expr(&mut self, expr: P<ast::Expr>) -> P<ast::Expr> {
- self.visit_stmt_or_expr_attrs(expr.attrs());
+
pub fn configure_expr(&mut self, expr: P<ast::Expr>) -> P<ast::Expr> {
+ self.visit_expr_attrs(expr.attrs());
// If an expr is valid to cfg away it will have been removed by the
// outer stmt or expression folder before descending in here.
self.sess.span_diagnostic.span_err(attr.span, msg);
}
- let expr = self.process_cfg_attrs(expr);
- fold_expr(self, expr)
+ self.process_cfg_attrs(expr)
}
- fn fold_opt_expr(&mut self, expr: P<ast::Expr>) -> Option<P<ast::Expr>> {
- self.configure(expr).map(|expr| fold_expr(self, expr))
+ pub fn configure_stmt(&mut self, stmt: ast::Stmt) -> Option<ast::Stmt> {
+ self.configure(stmt)
}
+}
- fn fold_stmt(&mut self, stmt: ast::Stmt) -> SmallVector<ast::Stmt> {
- self.visit_stmt_or_expr_attrs(stmt.attrs());
- self.configure(stmt).map(|stmt| fold::noop_fold_stmt(stmt, self))
- .unwrap_or(SmallVector::zero())
+impl<'a> fold::Folder for StripUnconfigured<'a> {
+ fn fold_foreign_mod(&mut self, foreign_mod: ast::ForeignMod) -> ast::ForeignMod {
+ let foreign_mod = self.configure_foreign_mod(foreign_mod);
+ fold::noop_fold_foreign_mod(foreign_mod, self)
}
- fn fold_mac(&mut self, mac: ast::Mac) -> ast::Mac {
- fold::noop_fold_mac(mac, self)
+ fn fold_item_kind(&mut self, item: ast::ItemKind) -> ast::ItemKind {
+ let item = self.configure_item_kind(item);
+ fold::noop_fold_item_kind(item, self)
+ }
+
+ fn fold_expr(&mut self, expr: P<ast::Expr>) -> P<ast::Expr> {
+ let mut expr = self.configure_expr(expr).unwrap();
+ expr.node = self.configure_expr_kind(expr.node);
+ P(fold::noop_fold_expr(expr, self))
+ }
+
+ fn fold_opt_expr(&mut self, expr: P<ast::Expr>) -> Option<P<ast::Expr>> {
+ let mut expr = configure!(self, expr).unwrap();
+ expr.node = self.configure_expr_kind(expr.node);
+ Some(P(fold::noop_fold_expr(expr, self)))
+ }
+
+ fn fold_stmt(&mut self, stmt: ast::Stmt) -> SmallVector<ast::Stmt> {
+ match self.configure_stmt(stmt) {
+ Some(stmt) => fold::noop_fold_stmt(stmt, self),
+ None => return SmallVector::zero(),
+ }
}
fn fold_item(&mut self, item: P<ast::Item>) -> SmallVector<P<ast::Item>> {
- self.configure(item).map(|item| fold::noop_fold_item(item, self))
- .unwrap_or(SmallVector::zero())
+ fold::noop_fold_item(configure!(self, item), self)
}
fn fold_impl_item(&mut self, item: ast::ImplItem) -> SmallVector<ast::ImplItem> {
- self.configure(item).map(|item| fold::noop_fold_impl_item(item, self))
- .unwrap_or(SmallVector::zero())
+ fold::noop_fold_impl_item(configure!(self, item), self)
}
fn fold_trait_item(&mut self, item: ast::TraitItem) -> SmallVector<ast::TraitItem> {
- self.configure(item).map(|item| fold::noop_fold_trait_item(item, self))
- .unwrap_or(SmallVector::zero())
+ fold::noop_fold_trait_item(configure!(self, item), self)
}
- fn fold_interpolated(&mut self, nt: token::Nonterminal) -> token::Nonterminal {
+ fn fold_mac(&mut self, mac: ast::Mac) -> ast::Mac {
// Don't configure interpolated AST (c.f. #34171).
// Interpolated AST will get configured once the surrounding tokens are parsed.
- nt
+ mac
}
}
-fn fold_expr(folder: &mut StripUnconfigured, expr: P<ast::Expr>) -> P<ast::Expr> {
- expr.map(|ast::Expr {id, span, node, attrs}| {
- fold::noop_fold_expr(ast::Expr {
- id: id,
- node: match node {
- ast::ExprKind::Match(m, arms) => {
- ast::ExprKind::Match(m, arms.into_iter()
- .filter_map(|a| folder.configure(a))
- .collect())
- }
- _ => node
- },
- span: span,
- attrs: attrs,
- }, folder)
- })
-}
-
fn is_cfg(attr: &ast::Attribute) -> bool {
attr.check_name("cfg")
}
projects / rustc.git / blobdiff