diff options
Diffstat (limited to 'src/tools/rust-analyzer/crates/hir-expand/src/attrs.rs')
| -rw-r--r-- | src/tools/rust-analyzer/crates/hir-expand/src/attrs.rs | 349 |
1 files changed, 349 insertions, 0 deletions
diff --git a/src/tools/rust-analyzer/crates/hir-expand/src/attrs.rs b/src/tools/rust-analyzer/crates/hir-expand/src/attrs.rs new file mode 100644 index 000000000..5c04f8e8b --- /dev/null +++ b/src/tools/rust-analyzer/crates/hir-expand/src/attrs.rs @@ -0,0 +1,349 @@ +//! A higher level attributes based on TokenTree, with also some shortcuts. +use std::{fmt, ops, sync::Arc}; + +use base_db::CrateId; +use cfg::CfgExpr; +use either::Either; +use intern::Interned; +use mbe::{syntax_node_to_token_tree, DelimiterKind, Punct}; +use smallvec::{smallvec, SmallVec}; +use syntax::{ast, match_ast, AstNode, SmolStr, SyntaxNode}; + +use crate::{ + db::AstDatabase, + hygiene::Hygiene, + mod_path::{ModPath, PathKind}, + name::AsName, + tt::{self, Subtree}, + InFile, +}; + +/// Syntactical attributes, without filtering of `cfg_attr`s. +#[derive(Default, Debug, Clone, PartialEq, Eq)] +pub struct RawAttrs { + entries: Option<Arc<[Attr]>>, +} + +impl ops::Deref for RawAttrs { + type Target = [Attr]; + + fn deref(&self) -> &[Attr] { + match &self.entries { + Some(it) => &*it, + None => &[], + } + } +} + +impl RawAttrs { + pub const EMPTY: Self = Self { entries: None }; + + pub fn new(db: &dyn AstDatabase, owner: &dyn ast::HasAttrs, hygiene: &Hygiene) -> Self { + let entries = collect_attrs(owner) + .filter_map(|(id, attr)| match attr { + Either::Left(attr) => { + attr.meta().and_then(|meta| Attr::from_src(db, meta, hygiene, id)) + } + Either::Right(comment) => comment.doc_comment().map(|doc| Attr { + id, + input: Some(Interned::new(AttrInput::Literal(SmolStr::new(doc)))), + path: Interned::new(ModPath::from(crate::name!(doc))), + }), + }) + .collect::<Arc<_>>(); + + Self { entries: if entries.is_empty() { None } else { Some(entries) } } + } + + pub fn from_attrs_owner(db: &dyn AstDatabase, owner: InFile<&dyn ast::HasAttrs>) -> Self { + let hygiene = Hygiene::new(db, owner.file_id); + Self::new(db, owner.value, &hygiene) + } + + pub fn merge(&self, other: Self) -> Self { + match (&self.entries, other.entries) { + (None, None) => Self::EMPTY, + (None, entries @ Some(_)) => Self { entries }, + (Some(entries), None) => Self { entries: Some(entries.clone()) }, + (Some(a), Some(b)) => { + let last_ast_index = a.last().map_or(0, |it| it.id.ast_index() + 1) as u32; + Self { + entries: Some( + a.iter() + .cloned() + .chain(b.iter().map(|it| { + let mut it = it.clone(); + it.id.id = it.id.ast_index() as u32 + last_ast_index + | (it.id.cfg_attr_index().unwrap_or(0) as u32) + << AttrId::AST_INDEX_BITS; + it + })) + .collect(), + ), + } + } + } + } + + /// Processes `cfg_attr`s, returning the resulting semantic `Attrs`. + // FIXME: This should return a different type + pub fn filter(self, db: &dyn AstDatabase, krate: CrateId) -> RawAttrs { + let has_cfg_attrs = self + .iter() + .any(|attr| attr.path.as_ident().map_or(false, |name| *name == crate::name![cfg_attr])); + if !has_cfg_attrs { + return self; + } + + let crate_graph = db.crate_graph(); + let new_attrs = self + .iter() + .flat_map(|attr| -> SmallVec<[_; 1]> { + let is_cfg_attr = + attr.path.as_ident().map_or(false, |name| *name == crate::name![cfg_attr]); + if !is_cfg_attr { + return smallvec![attr.clone()]; + } + + let subtree = match attr.token_tree_value() { + Some(it) => it, + _ => return smallvec![attr.clone()], + }; + + let (cfg, parts) = match parse_cfg_attr_input(subtree) { + Some(it) => it, + None => return smallvec![attr.clone()], + }; + let index = attr.id; + let attrs = + parts.enumerate().take(1 << AttrId::CFG_ATTR_BITS).filter_map(|(idx, attr)| { + let tree = Subtree { + delimiter: tt::Delimiter::unspecified(), + token_trees: attr.to_vec(), + }; + // FIXME hygiene + let hygiene = Hygiene::new_unhygienic(); + Attr::from_tt(db, &tree, &hygiene, index.with_cfg_attr(idx)) + }); + + let cfg_options = &crate_graph[krate].cfg_options; + let cfg = Subtree { delimiter: subtree.delimiter, token_trees: cfg.to_vec() }; + let cfg = CfgExpr::parse(&cfg); + if cfg_options.check(&cfg) == Some(false) { + smallvec![] + } else { + cov_mark::hit!(cfg_attr_active); + + attrs.collect() + } + }) + .collect(); + + RawAttrs { entries: Some(new_attrs) } + } +} + +#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)] +pub struct AttrId { + id: u32, +} + +// FIXME: This only handles a single level of cfg_attr nesting +// that is `#[cfg_attr(all(), cfg_attr(all(), cfg(any())))]` breaks again +impl AttrId { + const CFG_ATTR_BITS: usize = 7; + const AST_INDEX_MASK: usize = 0x00FF_FFFF; + const AST_INDEX_BITS: usize = Self::AST_INDEX_MASK.count_ones() as usize; + const CFG_ATTR_SET_BITS: u32 = 1 << 31; + + pub fn ast_index(&self) -> usize { + self.id as usize & Self::AST_INDEX_MASK + } + + pub fn cfg_attr_index(&self) -> Option<usize> { + if self.id & Self::CFG_ATTR_SET_BITS == 0 { + None + } else { + Some(self.id as usize >> Self::AST_INDEX_BITS) + } + } + + pub fn with_cfg_attr(self, idx: usize) -> AttrId { + AttrId { id: self.id | (idx as u32) << Self::AST_INDEX_BITS | Self::CFG_ATTR_SET_BITS } + } +} + +#[derive(Debug, Clone, PartialEq, Eq)] +pub struct Attr { + pub id: AttrId, + pub path: Interned<ModPath>, + pub input: Option<Interned<AttrInput>>, +} + +#[derive(Debug, Clone, PartialEq, Eq, Hash)] +pub enum AttrInput { + /// `#[attr = "string"]` + Literal(SmolStr), + /// `#[attr(subtree)]` + TokenTree(tt::Subtree, mbe::TokenMap), +} + +impl fmt::Display for AttrInput { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + match self { + AttrInput::Literal(lit) => write!(f, " = \"{}\"", lit.escape_debug()), + AttrInput::TokenTree(subtree, _) => subtree.fmt(f), + } + } +} + +impl Attr { + fn from_src( + db: &dyn AstDatabase, + ast: ast::Meta, + hygiene: &Hygiene, + id: AttrId, + ) -> Option<Attr> { + let path = Interned::new(ModPath::from_src(db, ast.path()?, hygiene)?); + let input = if let Some(ast::Expr::Literal(lit)) = ast.expr() { + let value = match lit.kind() { + ast::LiteralKind::String(string) => string.value()?.into(), + _ => lit.syntax().first_token()?.text().trim_matches('"').into(), + }; + Some(Interned::new(AttrInput::Literal(value))) + } else if let Some(tt) = ast.token_tree() { + let (tree, map) = syntax_node_to_token_tree(tt.syntax()); + Some(Interned::new(AttrInput::TokenTree(tree, map))) + } else { + None + }; + Some(Attr { id, path, input }) + } + + fn from_tt( + db: &dyn AstDatabase, + tt: &tt::Subtree, + hygiene: &Hygiene, + id: AttrId, + ) -> Option<Attr> { + let (parse, _) = mbe::token_tree_to_syntax_node(tt, mbe::TopEntryPoint::MetaItem); + let ast = ast::Meta::cast(parse.syntax_node())?; + + Self::from_src(db, ast, hygiene, id) + } + + pub fn path(&self) -> &ModPath { + &self.path + } +} + +impl Attr { + /// #[path = "string"] + pub fn string_value(&self) -> Option<&SmolStr> { + match self.input.as_deref()? { + AttrInput::Literal(it) => Some(it), + _ => None, + } + } + + /// #[path(ident)] + pub fn single_ident_value(&self) -> Option<&tt::Ident> { + match self.input.as_deref()? { + AttrInput::TokenTree(subtree, _) => match &*subtree.token_trees { + [tt::TokenTree::Leaf(tt::Leaf::Ident(ident))] => Some(ident), + _ => None, + }, + _ => None, + } + } + + /// #[path TokenTree] + pub fn token_tree_value(&self) -> Option<&Subtree> { + match self.input.as_deref()? { + AttrInput::TokenTree(subtree, _) => Some(subtree), + _ => None, + } + } + + /// Parses this attribute as a token tree consisting of comma separated paths. + pub fn parse_path_comma_token_tree(&self) -> Option<impl Iterator<Item = ModPath> + '_> { + let args = self.token_tree_value()?; + + if args.delimiter.kind != DelimiterKind::Parenthesis { + return None; + } + let paths = args + .token_trees + .split(|tt| matches!(tt, tt::TokenTree::Leaf(tt::Leaf::Punct(Punct { char: ',', .. })))) + .filter_map(|tts| { + if tts.is_empty() { + return None; + } + let segments = tts.iter().filter_map(|tt| match tt { + tt::TokenTree::Leaf(tt::Leaf::Ident(id)) => Some(id.as_name()), + _ => None, + }); + Some(ModPath::from_segments(PathKind::Plain, segments)) + }); + + Some(paths) + } +} + +pub fn collect_attrs( + owner: &dyn ast::HasAttrs, +) -> impl Iterator<Item = (AttrId, Either<ast::Attr, ast::Comment>)> { + let inner_attrs = inner_attributes(owner.syntax()).into_iter().flatten(); + let outer_attrs = + ast::AttrDocCommentIter::from_syntax_node(owner.syntax()).filter(|el| match el { + Either::Left(attr) => attr.kind().is_outer(), + Either::Right(comment) => comment.is_outer(), + }); + outer_attrs.chain(inner_attrs).enumerate().map(|(id, attr)| (AttrId { id: id as u32 }, attr)) +} + +fn inner_attributes( + syntax: &SyntaxNode, +) -> Option<impl Iterator<Item = Either<ast::Attr, ast::Comment>>> { + let node = match_ast! { + match syntax { + ast::SourceFile(_) => syntax.clone(), + ast::ExternBlock(it) => it.extern_item_list()?.syntax().clone(), + ast::Fn(it) => it.body()?.stmt_list()?.syntax().clone(), + ast::Impl(it) => it.assoc_item_list()?.syntax().clone(), + ast::Module(it) => it.item_list()?.syntax().clone(), + ast::BlockExpr(it) => { + use syntax::SyntaxKind::{BLOCK_EXPR , EXPR_STMT}; + // Block expressions accept outer and inner attributes, but only when they are the outer + // expression of an expression statement or the final expression of another block expression. + let may_carry_attributes = matches!( + it.syntax().parent().map(|it| it.kind()), + Some(BLOCK_EXPR | EXPR_STMT) + ); + if !may_carry_attributes { + return None + } + syntax.clone() + }, + _ => return None, + } + }; + + let attrs = ast::AttrDocCommentIter::from_syntax_node(&node).filter(|el| match el { + Either::Left(attr) => attr.kind().is_inner(), + Either::Right(comment) => comment.is_inner(), + }); + Some(attrs) +} + +// Input subtree is: `(cfg, $(attr),+)` +// Split it up into a `cfg` subtree and the `attr` subtrees. +pub fn parse_cfg_attr_input( + subtree: &Subtree, +) -> Option<(&[tt::TokenTree], impl Iterator<Item = &[tt::TokenTree]>)> { + let mut parts = subtree + .token_trees + .split(|tt| matches!(tt, tt::TokenTree::Leaf(tt::Leaf::Punct(Punct { char: ',', .. })))); + let cfg = parts.next()?; + Some((cfg, parts.filter(|it| !it.is_empty()))) +} |