//! Functions dealing with attributes and meta items mod builtin; pub use builtin::{ cfg_matches, contains_feature_attr, eval_condition, find_crate_name, find_deprecation, find_repr_attrs, find_stability, find_unwind_attr, Deprecation, InlineAttr, OptimizeAttr, IntType, ReprAttr, RustcDeprecation, Stability, StabilityLevel, UnwindAttr, }; pub use IntType::*; pub use ReprAttr::*; pub use StabilityLevel::*; use crate::ast; use crate::ast::{AttrId, Attribute, AttrStyle, Name, Ident, Path, PathSegment}; use crate::ast::{MetaItem, MetaItemKind, NestedMetaItem}; use crate::ast::{Lit, LitKind, Expr, Item, Local, Stmt, StmtKind, GenericParam}; use crate::mut_visit::visit_clobber; use crate::source_map::{BytePos, Spanned, dummy_spanned}; use crate::parse::lexer::comments::{doc_comment_style, strip_doc_comment_decoration}; use crate::parse::parser::Parser; use crate::parse::{self, ParseSess, PResult}; use crate::parse::token::{self, Token}; use crate::ptr::P; use crate::symbol::{keywords, LocalInternedString, Symbol}; use crate::ThinVec; use crate::tokenstream::{TokenStream, TokenTree, DelimSpan}; use crate::GLOBALS; use log::debug; use syntax_pos::{FileName, Span}; use std::iter; use std::ops::DerefMut; pub fn mark_used(attr: &Attribute) { debug!("Marking {:?} as used.", attr); GLOBALS.with(|globals| { globals.used_attrs.lock().insert(attr.id); }); } pub fn is_used(attr: &Attribute) -> bool { GLOBALS.with(|globals| { globals.used_attrs.lock().contains(attr.id) }) } pub fn mark_known(attr: &Attribute) { debug!("Marking {:?} as known.", attr); GLOBALS.with(|globals| { globals.known_attrs.lock().insert(attr.id); }); } pub fn is_known(attr: &Attribute) -> bool { GLOBALS.with(|globals| { globals.known_attrs.lock().contains(attr.id) }) } pub fn is_known_lint_tool(m_item: Ident) -> bool { ["clippy"].contains(&m_item.as_str().as_ref()) } impl NestedMetaItem { /// Returns the MetaItem if self is a NestedMetaItem::MetaItem. pub fn meta_item(&self) -> Option<&MetaItem> { match *self { NestedMetaItem::MetaItem(ref item) => Some(item), _ => None } } /// Returns the Lit if self is a NestedMetaItem::Literal. pub fn literal(&self) -> Option<&Lit> { match *self { NestedMetaItem::Literal(ref lit) => Some(lit), _ => None } } /// Returns `true` if this list item is a MetaItem with a name of `name`. pub fn check_name(&self, name: Symbol) -> bool { self.meta_item().map_or(false, |meta_item| meta_item.check_name(name)) } /// For a single-segment meta-item returns its name, otherwise returns `None`. pub fn ident(&self) -> Option { self.meta_item().and_then(|meta_item| meta_item.ident()) } pub fn name_or_empty(&self) -> LocalInternedString { self.ident().unwrap_or(keywords::Invalid.ident()).name.as_str() } /// Gets the string value if self is a MetaItem and the MetaItem is a /// MetaItemKind::NameValue variant containing a string, otherwise None. pub fn value_str(&self) -> Option { self.meta_item().and_then(|meta_item| meta_item.value_str()) } /// Returns a name and single literal value tuple of the MetaItem. pub fn name_value_literal(&self) -> Option<(Name, &Lit)> { self.meta_item().and_then( |meta_item| meta_item.meta_item_list().and_then( |meta_item_list| { if meta_item_list.len() == 1 { if let Some(ident) = meta_item.ident() { if let Some(lit) = meta_item_list[0].literal() { return Some((ident.name, lit)); } } } None })) } /// Gets a list of inner meta items from a list MetaItem type. pub fn meta_item_list(&self) -> Option<&[NestedMetaItem]> { self.meta_item().and_then(|meta_item| meta_item.meta_item_list()) } /// Returns `true` if the variant is MetaItem. pub fn is_meta_item(&self) -> bool { self.meta_item().is_some() } /// Returns `true` if the variant is Literal. pub fn is_literal(&self) -> bool { self.literal().is_some() } /// Returns `true` if self is a MetaItem and the meta item is a word. pub fn is_word(&self) -> bool { self.meta_item().map_or(false, |meta_item| meta_item.is_word()) } /// Returns `true` if self is a MetaItem and the meta item is a ValueString. pub fn is_value_str(&self) -> bool { self.value_str().is_some() } /// Returns `true` if self is a MetaItem and the meta item is a list. pub fn is_meta_item_list(&self) -> bool { self.meta_item_list().is_some() } } impl Attribute { /// Returns `true` if the attribute's path matches the argument. If it matches, then the /// attribute is marked as used. /// /// To check the attribute name without marking it used, use the `path` field directly. pub fn check_name(&self, name: Symbol) -> bool { let matches = self.path == name; if matches { mark_used(self); } matches } /// For a single-segment attribute returns its name, otherwise returns `None`. pub fn ident(&self) -> Option { if self.path.segments.len() == 1 { Some(self.path.segments[0].ident) } else { None } } pub fn name_or_empty(&self) -> LocalInternedString { self.ident().unwrap_or(keywords::Invalid.ident()).name.as_str() } pub fn value_str(&self) -> Option { self.meta().and_then(|meta| meta.value_str()) } pub fn meta_item_list(&self) -> Option> { match self.meta() { Some(MetaItem { node: MetaItemKind::List(list), .. }) => Some(list), _ => None } } pub fn is_word(&self) -> bool { self.tokens.is_empty() } pub fn is_meta_item_list(&self) -> bool { self.meta_item_list().is_some() } /// Indicates if the attribute is a Value String. pub fn is_value_str(&self) -> bool { self.value_str().is_some() } } impl MetaItem { /// For a single-segment meta-item returns its name, otherwise returns `None`. pub fn ident(&self) -> Option { if self.path.segments.len() == 1 { Some(self.path.segments[0].ident) } else { None } } pub fn name_or_empty(&self) -> LocalInternedString { self.ident().unwrap_or(keywords::Invalid.ident()).name.as_str() } // #[attribute(name = "value")] // ^^^^^^^^^^^^^^ pub fn name_value_literal(&self) -> Option<&Lit> { match &self.node { MetaItemKind::NameValue(v) => Some(v), _ => None, } } pub fn value_str(&self) -> Option { match self.node { MetaItemKind::NameValue(ref v) => { match v.node { LitKind::Str(ref s, _) => Some(*s), _ => None, } }, _ => None } } pub fn meta_item_list(&self) -> Option<&[NestedMetaItem]> { match self.node { MetaItemKind::List(ref l) => Some(&l[..]), _ => None } } pub fn is_word(&self) -> bool { match self.node { MetaItemKind::Word => true, _ => false, } } pub fn check_name(&self, name: Symbol) -> bool { self.path == name } pub fn is_value_str(&self) -> bool { self.value_str().is_some() } pub fn is_meta_item_list(&self) -> bool { self.meta_item_list().is_some() } } impl Attribute { /// Extracts the MetaItem from inside this Attribute. pub fn meta(&self) -> Option { let mut tokens = self.tokens.trees().peekable(); Some(MetaItem { path: self.path.clone(), node: if let Some(node) = MetaItemKind::from_tokens(&mut tokens) { if tokens.peek().is_some() { return None; } node } else { return None; }, span: self.span, }) } pub fn parse<'a, T, F>(&self, sess: &'a ParseSess, mut f: F) -> PResult<'a, T> where F: FnMut(&mut Parser<'a>) -> PResult<'a, T>, { let mut parser = Parser::new(sess, self.tokens.clone(), None, false, false); let result = f(&mut parser)?; if parser.token != token::Eof { parser.unexpected()?; } Ok(result) } pub fn parse_list<'a, T, F>(&self, sess: &'a ParseSess, mut f: F) -> PResult<'a, Vec> where F: FnMut(&mut Parser<'a>) -> PResult<'a, T>, { if self.tokens.is_empty() { return Ok(Vec::new()); } self.parse(sess, |parser| { parser.expect(&token::OpenDelim(token::Paren))?; let mut list = Vec::new(); while !parser.eat(&token::CloseDelim(token::Paren)) { list.push(f(parser)?); if !parser.eat(&token::Comma) { parser.expect(&token::CloseDelim(token::Paren))?; break } } Ok(list) }) } pub fn parse_meta<'a>(&self, sess: &'a ParseSess) -> PResult<'a, MetaItem> { Ok(MetaItem { path: self.path.clone(), node: self.parse(sess, |parser| parser.parse_meta_item_kind())?, span: self.span, }) } /// Converts self to a normal #[doc="foo"] comment, if it is a /// comment like `///` or `/** */`. (Returns self unchanged for /// non-sugared doc attributes.) pub fn with_desugared_doc(&self, f: F) -> T where F: FnOnce(&Attribute) -> T, { if self.is_sugared_doc { let comment = self.value_str().unwrap(); let meta = mk_name_value_item_str( Ident::from_str("doc"), dummy_spanned(Symbol::intern(&strip_doc_comment_decoration(&comment.as_str())))); let mut attr = if self.style == ast::AttrStyle::Outer { mk_attr_outer(self.span, self.id, meta) } else { mk_attr_inner(self.span, self.id, meta) }; attr.is_sugared_doc = true; f(&attr) } else { f(self) } } } /* Constructors */ pub fn mk_name_value_item_str(ident: Ident, value: Spanned) -> MetaItem { let lit_kind = LitKind::Str(value.node, ast::StrStyle::Cooked); mk_name_value_item(ident.span.to(value.span), ident, lit_kind, value.span) } pub fn mk_name_value_item(span: Span, ident: Ident, lit_kind: LitKind, lit_span: Span) -> MetaItem { let lit = Lit::from_lit_kind(lit_kind, lit_span); MetaItem { path: Path::from_ident(ident), span, node: MetaItemKind::NameValue(lit) } } pub fn mk_list_item(span: Span, ident: Ident, items: Vec) -> MetaItem { MetaItem { path: Path::from_ident(ident), span, node: MetaItemKind::List(items) } } pub fn mk_word_item(ident: Ident) -> MetaItem { MetaItem { path: Path::from_ident(ident), span: ident.span, node: MetaItemKind::Word } } pub fn mk_nested_word_item(ident: Ident) -> NestedMetaItem { NestedMetaItem::MetaItem(mk_word_item(ident)) } pub fn mk_attr_id() -> AttrId { use std::sync::atomic::AtomicUsize; use std::sync::atomic::Ordering; static NEXT_ATTR_ID: AtomicUsize = AtomicUsize::new(0); let id = NEXT_ATTR_ID.fetch_add(1, Ordering::SeqCst); assert!(id != ::std::usize::MAX); AttrId(id) } /// Returns an inner attribute with the given value. pub fn mk_attr_inner(span: Span, id: AttrId, item: MetaItem) -> Attribute { mk_spanned_attr_inner(span, id, item) } /// Returns an inner attribute with the given value and span. pub fn mk_spanned_attr_inner(sp: Span, id: AttrId, item: MetaItem) -> Attribute { Attribute { id, style: ast::AttrStyle::Inner, path: item.path, tokens: item.node.tokens(item.span), is_sugared_doc: false, span: sp, } } /// Returns an outer attribute with the given value. pub fn mk_attr_outer(span: Span, id: AttrId, item: MetaItem) -> Attribute { mk_spanned_attr_outer(span, id, item) } /// Returns an outer attribute with the given value and span. pub fn mk_spanned_attr_outer(sp: Span, id: AttrId, item: MetaItem) -> Attribute { Attribute { id, style: ast::AttrStyle::Outer, path: item.path, tokens: item.node.tokens(item.span), is_sugared_doc: false, span: sp, } } pub fn mk_sugared_doc_attr(id: AttrId, text: Symbol, span: Span) -> Attribute { let style = doc_comment_style(&text.as_str()); let lit_kind = LitKind::Str(text, ast::StrStyle::Cooked); let lit = Lit::from_lit_kind(lit_kind, span); Attribute { id, style, path: Path::from_ident(Ident::from_str("doc").with_span_pos(span)), tokens: MetaItemKind::NameValue(lit).tokens(span), is_sugared_doc: true, span, } } pub fn list_contains_name(items: &[NestedMetaItem], name: Symbol) -> bool { items.iter().any(|item| { item.check_name(name) }) } pub fn contains_name(attrs: &[Attribute], name: Symbol) -> bool { attrs.iter().any(|item| { item.check_name(name) }) } pub fn find_by_name<'a>(attrs: &'a [Attribute], name: Symbol) -> Option<&'a Attribute> { attrs.iter().find(|attr| attr.check_name(name)) } pub fn filter_by_name<'a>(attrs: &'a [Attribute], name: Symbol) -> impl Iterator { attrs.iter().filter(move |attr| attr.check_name(name)) } pub fn first_attr_value_str_by_name(attrs: &[Attribute], name: Symbol) -> Option { attrs.iter() .find(|at| at.check_name(name)) .and_then(|at| at.value_str()) } impl MetaItem { fn tokens(&self) -> TokenStream { let mut idents = vec![]; let mut last_pos = BytePos(0 as u32); for (i, segment) in self.path.segments.iter().enumerate() { let is_first = i == 0; if !is_first { let mod_sep_span = Span::new(last_pos, segment.ident.span.lo(), segment.ident.span.ctxt()); idents.push(TokenTree::Token(mod_sep_span, Token::ModSep).into()); } idents.push(TokenTree::Token(segment.ident.span, Token::from_ast_ident(segment.ident)).into()); last_pos = segment.ident.span.hi(); } self.node.tokens(self.span).append_to_tree_and_joint_vec(&mut idents); TokenStream::new(idents) } fn from_tokens(tokens: &mut iter::Peekable) -> Option where I: Iterator, { // FIXME: Share code with `parse_path`. let path = match tokens.next() { Some(TokenTree::Token(span, token @ Token::Ident(..))) | Some(TokenTree::Token(span, token @ Token::ModSep)) => 'arm: { let mut segments = if let Token::Ident(ident, _) = token { if let Some(TokenTree::Token(_, Token::ModSep)) = tokens.peek() { tokens.next(); vec![PathSegment::from_ident(ident.with_span_pos(span))] } else { break 'arm Path::from_ident(ident.with_span_pos(span)); } } else { vec![PathSegment::path_root(span)] }; loop { if let Some(TokenTree::Token(span, Token::Ident(ident, _))) = tokens.next() { segments.push(PathSegment::from_ident(ident.with_span_pos(span))); } else { return None; } if let Some(TokenTree::Token(_, Token::ModSep)) = tokens.peek() { tokens.next(); } else { break; } } let span = span.with_hi(segments.last().unwrap().ident.span.hi()); Path { span, segments } } Some(TokenTree::Token(_, Token::Interpolated(nt))) => match *nt { token::Nonterminal::NtIdent(ident, _) => Path::from_ident(ident), token::Nonterminal::NtMeta(ref meta) => return Some(meta.clone()), token::Nonterminal::NtPath(ref path) => path.clone(), _ => return None, }, _ => return None, }; let list_closing_paren_pos = tokens.peek().map(|tt| tt.span().hi()); let node = MetaItemKind::from_tokens(tokens)?; let hi = match node { MetaItemKind::NameValue(ref lit) => lit.span.hi(), MetaItemKind::List(..) => list_closing_paren_pos.unwrap_or(path.span.hi()), _ => path.span.hi(), }; let span = path.span.with_hi(hi); Some(MetaItem { path, node, span }) } } impl MetaItemKind { pub fn tokens(&self, span: Span) -> TokenStream { match *self { MetaItemKind::Word => TokenStream::empty(), MetaItemKind::NameValue(ref lit) => { let mut vec = vec![TokenTree::Token(span, Token::Eq).into()]; lit.tokens().append_to_tree_and_joint_vec(&mut vec); TokenStream::new(vec) } MetaItemKind::List(ref list) => { let mut tokens = Vec::new(); for (i, item) in list.iter().enumerate() { if i > 0 { tokens.push(TokenTree::Token(span, Token::Comma).into()); } item.tokens().append_to_tree_and_joint_vec(&mut tokens); } TokenTree::Delimited( DelimSpan::from_single(span), token::Paren, TokenStream::new(tokens).into(), ).into() } } } fn from_tokens(tokens: &mut iter::Peekable) -> Option where I: Iterator, { let delimited = match tokens.peek().cloned() { Some(TokenTree::Token(_, token::Eq)) => { tokens.next(); return if let Some(TokenTree::Token(span, token)) = tokens.next() { Lit::from_token(&token, span, None).map(MetaItemKind::NameValue) } else { None }; } Some(TokenTree::Delimited(_, delim, ref tts)) if delim == token::Paren => { tokens.next(); tts.clone() } _ => return Some(MetaItemKind::Word), }; let mut tokens = delimited.into_trees().peekable(); let mut result = Vec::new(); while let Some(..) = tokens.peek() { let item = NestedMetaItem::from_tokens(&mut tokens)?; result.push(item); match tokens.next() { None | Some(TokenTree::Token(_, Token::Comma)) => {} _ => return None, } } Some(MetaItemKind::List(result)) } } impl NestedMetaItem { pub fn span(&self) -> Span { match *self { NestedMetaItem::MetaItem(ref item) => item.span, NestedMetaItem::Literal(ref lit) => lit.span, } } fn tokens(&self) -> TokenStream { match *self { NestedMetaItem::MetaItem(ref item) => item.tokens(), NestedMetaItem::Literal(ref lit) => lit.tokens(), } } fn from_tokens(tokens: &mut iter::Peekable) -> Option where I: Iterator, { if let Some(TokenTree::Token(span, token)) = tokens.peek().cloned() { if let Some(lit) = Lit::from_token(&token, span, None) { tokens.next(); return Some(NestedMetaItem::Literal(lit)); } } MetaItem::from_tokens(tokens).map(NestedMetaItem::MetaItem) } } pub trait HasAttrs: Sized { fn attrs(&self) -> &[ast::Attribute]; fn visit_attrs)>(&mut self, f: F); } impl HasAttrs for Spanned { fn attrs(&self) -> &[ast::Attribute] { self.node.attrs() } fn visit_attrs)>(&mut self, f: F) { self.node.visit_attrs(f); } } impl HasAttrs for Vec { fn attrs(&self) -> &[Attribute] { self } fn visit_attrs)>(&mut self, f: F) { f(self) } } impl HasAttrs for ThinVec { fn attrs(&self) -> &[Attribute] { self } fn visit_attrs)>(&mut self, f: F) { visit_clobber(self, |this| { let mut vec = this.into(); f(&mut vec); vec.into() }); } } impl HasAttrs for P { fn attrs(&self) -> &[Attribute] { (**self).attrs() } fn visit_attrs)>(&mut self, f: F) { (**self).visit_attrs(f); } } impl HasAttrs for StmtKind { fn attrs(&self) -> &[Attribute] { match *self { StmtKind::Local(ref local) => local.attrs(), StmtKind::Item(..) => &[], StmtKind::Expr(ref expr) | StmtKind::Semi(ref expr) => expr.attrs(), StmtKind::Mac(ref mac) => { let (_, _, ref attrs) = **mac; attrs.attrs() } } } fn visit_attrs)>(&mut self, f: F) { match self { StmtKind::Local(local) => local.visit_attrs(f), StmtKind::Item(..) => {} StmtKind::Expr(expr) => expr.visit_attrs(f), StmtKind::Semi(expr) => expr.visit_attrs(f), StmtKind::Mac(mac) => { let (_mac, _style, attrs) = mac.deref_mut(); attrs.visit_attrs(f); } } } } impl HasAttrs for Stmt { fn attrs(&self) -> &[ast::Attribute] { self.node.attrs() } fn visit_attrs)>(&mut self, f: F) { self.node.visit_attrs(f); } } impl HasAttrs for GenericParam { fn attrs(&self) -> &[ast::Attribute] { &self.attrs } fn visit_attrs)>(&mut self, f: F) { self.attrs.visit_attrs(f); } } macro_rules! derive_has_attrs { ($($ty:path),*) => { $( impl HasAttrs for $ty { fn attrs(&self) -> &[Attribute] { &self.attrs } fn visit_attrs)>(&mut self, f: F) { self.attrs.visit_attrs(f); } } )* } } derive_has_attrs! { Item, Expr, Local, ast::ForeignItem, ast::StructField, ast::ImplItem, ast::TraitItem, ast::Arm, ast::Field, ast::FieldPat, ast::Variant_ } pub fn inject(mut krate: ast::Crate, parse_sess: &ParseSess, attrs: &[String]) -> ast::Crate { for raw_attr in attrs { let mut parser = parse::new_parser_from_source_str( parse_sess, FileName::cli_crate_attr_source_code(&raw_attr), raw_attr.clone(), ); let start_span = parser.span; let (path, tokens) = panictry!(parser.parse_meta_item_unrestricted()); let end_span = parser.span; if parser.token != token::Eof { parse_sess.span_diagnostic .span_err(start_span.to(end_span), "invalid crate attribute"); continue; } krate.attrs.push(Attribute { id: mk_attr_id(), style: AttrStyle::Inner, path, tokens, is_sugared_doc: false, span: start_span.to(end_span), }); } krate }