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|
//! A higher level attributes based on TokenTree, with also some shortcuts.
use std::{ops, sync::Arc};
use base_db::CrateId;
use cfg::{CfgExpr, CfgOptions};
use either::Either;
use hir_expand::{hygiene::Hygiene, name::AsName, AstId, InFile};
use itertools::Itertools;
use la_arena::ArenaMap;
use mbe::ast_to_token_tree;
use smallvec::{smallvec, SmallVec};
use syntax::{
ast::{self, AstNode, AttrsOwner},
match_ast, AstToken, SmolStr, SyntaxNode,
};
use tt::Subtree;
use crate::{
db::DefDatabase,
item_tree::{ItemTreeId, ItemTreeNode},
nameres::ModuleSource,
path::{ModPath, PathKind},
src::HasChildSource,
AdtId, AttrDefId, EnumId, GenericParamId, HasModule, LocalEnumVariantId, LocalFieldId, Lookup,
VariantId,
};
/// Holds documentation
#[derive(Debug, Clone, PartialEq, Eq, Hash)]
pub struct Documentation(String);
impl Documentation {
pub fn as_str(&self) -> &str {
&self.0
}
}
impl From<Documentation> for String {
fn from(Documentation(string): Documentation) -> Self {
string
}
}
/// Syntactical attributes, without filtering of `cfg_attr`s.
#[derive(Default, Debug, Clone, PartialEq, Eq)]
pub(crate) struct RawAttrs {
entries: Option<Arc<[Attr]>>,
}
#[derive(Default, Debug, Clone, PartialEq, Eq)]
pub struct Attrs(RawAttrs);
impl ops::Deref for RawAttrs {
type Target = [Attr];
fn deref(&self) -> &[Attr] {
match &self.entries {
Some(it) => &*it,
None => &[],
}
}
}
impl ops::Deref for Attrs {
type Target = [Attr];
fn deref(&self) -> &[Attr] {
match &self.0.entries {
Some(it) => &*it,
None => &[],
}
}
}
impl RawAttrs {
pub(crate) const EMPTY: Self = Self { entries: None };
pub(crate) fn new(owner: &dyn AttrsOwner, hygiene: &Hygiene) -> Self {
let attrs: Vec<_> = collect_attrs(owner).collect();
let entries = if attrs.is_empty() {
// Avoid heap allocation
None
} else {
Some(
attrs
.into_iter()
.enumerate()
.flat_map(|(i, attr)| match attr {
Either::Left(attr) => Attr::from_src(attr, hygiene).map(|attr| (i, attr)),
Either::Right(comment) => comment.doc_comment().map(|doc| {
(
i,
Attr {
index: 0,
input: Some(AttrInput::Literal(SmolStr::new(doc))),
path: ModPath::from(hir_expand::name!(doc)),
},
)
}),
})
.map(|(i, attr)| Attr { index: i as u32, ..attr })
.collect(),
)
};
Self { entries }
}
fn from_attrs_owner(db: &dyn DefDatabase, owner: InFile<&dyn AttrsOwner>) -> Self {
let hygiene = Hygiene::new(db.upcast(), owner.file_id);
Self::new(owner.value, &hygiene)
}
pub(crate) fn merge(&self, other: Self) -> Self {
match (&self.entries, &other.entries) {
(None, None) => Self::EMPTY,
(Some(entries), None) | (None, Some(entries)) => {
Self { entries: Some(entries.clone()) }
}
(Some(a), Some(b)) => {
Self { entries: Some(a.iter().chain(b.iter()).cloned().collect()) }
}
}
}
/// Processes `cfg_attr`s, returning the resulting semantic `Attrs`.
pub(crate) fn filter(self, db: &dyn DefDatabase, krate: CrateId) -> Attrs {
let has_cfg_attrs = self.iter().any(|attr| {
attr.path.as_ident().map_or(false, |name| *name == hir_expand::name![cfg_attr])
});
if !has_cfg_attrs {
return Attrs(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 == hir_expand::name![cfg_attr]);
if !is_cfg_attr {
return smallvec![attr.clone()];
}
let subtree = match &attr.input {
Some(AttrInput::TokenTree(it)) => it,
_ => return smallvec![attr.clone()],
};
// Input subtree is: `(cfg, $(attr),+)`
// Split it up into a `cfg` subtree and the `attr` subtrees.
// FIXME: There should be a common API for this.
let mut parts = subtree.token_trees.split(
|tt| matches!(tt, tt::TokenTree::Leaf(tt::Leaf::Punct(p)) if p.char == ','),
);
let cfg = parts.next().unwrap();
let cfg = Subtree { delimiter: subtree.delimiter, token_trees: cfg.to_vec() };
let cfg = CfgExpr::parse(&cfg);
let index = attr.index;
let attrs = parts.filter(|a| !a.is_empty()).filter_map(|attr| {
let tree = Subtree { delimiter: None, token_trees: attr.to_vec() };
let attr = ast::Attr::parse(&format!("#[{}]", tree)).ok()?;
// FIXME hygiene
let hygiene = Hygiene::new_unhygienic();
Attr::from_src(attr, &hygiene).map(|attr| Attr { index, ..attr })
});
let cfg_options = &crate_graph[krate].cfg_options;
if cfg_options.check(&cfg) == Some(false) {
smallvec![]
} else {
cov_mark::hit!(cfg_attr_active);
attrs.collect()
}
})
.collect();
Attrs(RawAttrs { entries: Some(new_attrs) })
}
}
impl Attrs {
pub const EMPTY: Self = Self(RawAttrs::EMPTY);
pub(crate) fn attrs_query(db: &dyn DefDatabase, def: AttrDefId) -> Attrs {
let raw_attrs = match def {
AttrDefId::ModuleId(module) => {
let def_map = module.def_map(db);
let mod_data = &def_map[module.local_id];
match mod_data.declaration_source(db) {
Some(it) => {
let raw_attrs = RawAttrs::from_attrs_owner(
db,
it.as_ref().map(|it| it as &dyn AttrsOwner),
);
match mod_data.definition_source(db) {
InFile { file_id, value: ModuleSource::SourceFile(file) } => raw_attrs
.merge(RawAttrs::from_attrs_owner(db, InFile::new(file_id, &file))),
_ => raw_attrs,
}
}
None => RawAttrs::from_attrs_owner(
db,
mod_data.definition_source(db).as_ref().map(|src| match src {
ModuleSource::SourceFile(file) => file as &dyn AttrsOwner,
ModuleSource::Module(module) => module as &dyn AttrsOwner,
ModuleSource::BlockExpr(block) => block as &dyn AttrsOwner,
}),
),
}
}
AttrDefId::FieldId(it) => {
return db.fields_attrs(it.parent)[it.local_id].clone();
}
AttrDefId::EnumVariantId(it) => {
return db.variants_attrs(it.parent)[it.local_id].clone();
}
AttrDefId::AdtId(it) => match it {
AdtId::StructId(it) => attrs_from_item_tree(it.lookup(db).id, db),
AdtId::EnumId(it) => attrs_from_item_tree(it.lookup(db).id, db),
AdtId::UnionId(it) => attrs_from_item_tree(it.lookup(db).id, db),
},
AttrDefId::TraitId(it) => attrs_from_item_tree(it.lookup(db).id, db),
AttrDefId::MacroDefId(it) => {
it.ast_id.map_or_else(Default::default, |ast_id| attrs_from_ast(ast_id, db))
}
AttrDefId::ImplId(it) => attrs_from_item_tree(it.lookup(db).id, db),
AttrDefId::ConstId(it) => attrs_from_item_tree(it.lookup(db).id, db),
AttrDefId::StaticId(it) => attrs_from_item_tree(it.lookup(db).id, db),
AttrDefId::FunctionId(it) => attrs_from_item_tree(it.lookup(db).id, db),
AttrDefId::TypeAliasId(it) => attrs_from_item_tree(it.lookup(db).id, db),
AttrDefId::GenericParamId(it) => match it {
GenericParamId::TypeParamId(it) => {
let src = it.parent.child_source(db);
RawAttrs::from_attrs_owner(
db,
src.with_value(
src.value[it.local_id].as_ref().either(|it| it as _, |it| it as _),
),
)
}
GenericParamId::LifetimeParamId(it) => {
let src = it.parent.child_source(db);
RawAttrs::from_attrs_owner(db, src.with_value(&src.value[it.local_id]))
}
GenericParamId::ConstParamId(it) => {
let src = it.parent.child_source(db);
RawAttrs::from_attrs_owner(db, src.with_value(&src.value[it.local_id]))
}
},
};
raw_attrs.filter(db, def.krate(db))
}
pub(crate) fn variants_attrs_query(
db: &dyn DefDatabase,
e: EnumId,
) -> Arc<ArenaMap<LocalEnumVariantId, Attrs>> {
let krate = e.lookup(db).container.krate;
let src = e.child_source(db);
let mut res = ArenaMap::default();
for (id, var) in src.value.iter() {
let attrs = RawAttrs::from_attrs_owner(db, src.with_value(var as &dyn AttrsOwner))
.filter(db, krate);
res.insert(id, attrs)
}
Arc::new(res)
}
pub(crate) fn fields_attrs_query(
db: &dyn DefDatabase,
v: VariantId,
) -> Arc<ArenaMap<LocalFieldId, Attrs>> {
let krate = v.module(db).krate;
let src = v.child_source(db);
let mut res = ArenaMap::default();
for (id, fld) in src.value.iter() {
let attrs = match fld {
Either::Left(_tuple) => Attrs::default(),
Either::Right(record) => {
RawAttrs::from_attrs_owner(db, src.with_value(record)).filter(db, krate)
}
};
res.insert(id, attrs);
}
Arc::new(res)
}
/// Constructs a map that maps the lowered `Attr`s in this `Attrs` back to its original syntax nodes.
///
/// `owner` must be the original owner of the attributes.
pub fn source_map(&self, owner: &dyn AttrsOwner) -> AttrSourceMap {
AttrSourceMap { attrs: collect_attrs(owner).collect() }
}
pub fn by_key(&self, key: &'static str) -> AttrQuery<'_> {
AttrQuery { attrs: self, key }
}
pub fn cfg(&self) -> Option<CfgExpr> {
let mut cfgs = self.by_key("cfg").tt_values().map(CfgExpr::parse).collect::<Vec<_>>();
match cfgs.len() {
0 => None,
1 => Some(cfgs.pop().unwrap()),
_ => Some(CfgExpr::All(cfgs)),
}
}
pub(crate) fn is_cfg_enabled(&self, cfg_options: &CfgOptions) -> bool {
match self.cfg() {
None => true,
Some(cfg) => cfg_options.check(&cfg) != Some(false),
}
}
pub fn docs(&self) -> Option<Documentation> {
let docs = self.by_key("doc").attrs().flat_map(|attr| match attr.input.as_ref()? {
AttrInput::Literal(s) => Some(s),
AttrInput::TokenTree(_) => None,
});
// FIXME: Replace `Itertools::intersperse` with `Iterator::intersperse[_with]` until the
// libstd api gets stabilized (https://github.com/rust-lang/rust/issues/79524).
let docs = Itertools::intersperse(docs, &SmolStr::new_inline("\n"))
.map(|it| it.as_str())
.collect::<String>();
if docs.is_empty() {
None
} else {
Some(Documentation(docs.into()))
}
}
}
fn inner_attributes(
syntax: &SyntaxNode,
) -> Option<(impl Iterator<Item = ast::Attr>, impl Iterator<Item = ast::Comment>)> {
let (attrs, docs) = match_ast! {
match syntax {
ast::SourceFile(it) => (it.attrs(), ast::CommentIter::from_syntax_node(it.syntax())),
ast::ExternBlock(it) => {
let extern_item_list = it.extern_item_list()?;
(extern_item_list.attrs(), ast::CommentIter::from_syntax_node(extern_item_list.syntax()))
},
ast::Fn(it) => {
let body = it.body()?;
(body.attrs(), ast::CommentIter::from_syntax_node(body.syntax()))
},
ast::Impl(it) => {
let assoc_item_list = it.assoc_item_list()?;
(assoc_item_list.attrs(), ast::CommentIter::from_syntax_node(assoc_item_list.syntax()))
},
ast::Module(it) => {
let item_list = it.item_list()?;
(item_list.attrs(), ast::CommentIter::from_syntax_node(item_list.syntax()))
},
// FIXME: BlockExpr's only accept inner attributes in specific cases
// Excerpt from the reference:
// 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.
ast::BlockExpr(_it) => return None,
_ => return None,
}
};
let attrs = attrs.filter(|attr| attr.excl_token().is_some());
let docs = docs.filter(|doc| doc.is_inner());
Some((attrs, docs))
}
pub struct AttrSourceMap {
attrs: Vec<Either<ast::Attr, ast::Comment>>,
}
impl AttrSourceMap {
/// Maps the lowered `Attr` back to its original syntax node.
///
/// `attr` must come from the `owner` used for AttrSourceMap
///
/// Note that the returned syntax node might be a `#[cfg_attr]`, or a doc comment, instead of
/// the attribute represented by `Attr`.
pub fn source_of(&self, attr: &Attr) -> &Either<ast::Attr, ast::Comment> {
self.attrs
.get(attr.index as usize)
.unwrap_or_else(|| panic!("cannot find `Attr` at index {}", attr.index))
}
}
#[derive(Debug, Clone, PartialEq, Eq)]
pub struct Attr {
index: u32,
pub(crate) path: ModPath,
pub(crate) input: Option<AttrInput>,
}
#[derive(Debug, Clone, PartialEq, Eq)]
pub enum AttrInput {
/// `#[attr = "string"]`
Literal(SmolStr),
/// `#[attr(subtree)]`
TokenTree(Subtree),
}
impl Attr {
fn from_src(ast: ast::Attr, hygiene: &Hygiene) -> Option<Attr> {
let path = ModPath::from_src(ast.path()?, hygiene)?;
let input = if let Some(lit) = ast.literal() {
let value = match lit.kind() {
ast::LiteralKind::String(string) => string.value()?.into(),
_ => lit.syntax().first_token()?.text().trim_matches('"').into(),
};
Some(AttrInput::Literal(value))
} else if let Some(tt) = ast.token_tree() {
Some(AttrInput::TokenTree(ast_to_token_tree(&tt)?.0))
} else {
None
};
Some(Attr { index: 0, path, input })
}
/// Maps this lowered `Attr` back to its original syntax node.
///
/// `owner` must be the original owner of the attribute.
///
/// Note that the returned syntax node might be a `#[cfg_attr]`, or a doc comment, instead of
/// the attribute represented by `Attr`.
pub fn to_src(&self, owner: &dyn AttrsOwner) -> Either<ast::Attr, ast::Comment> {
collect_attrs(owner).nth(self.index as usize).unwrap_or_else(|| {
panic!("cannot find `Attr` at index {} in {}", self.index, owner.syntax())
})
}
/// Parses this attribute as a `#[derive]`, returns an iterator that yields all contained paths
/// to derive macros.
///
/// Returns `None` when the attribute is not a well-formed `#[derive]` attribute.
pub(crate) fn parse_derive(&self) -> Option<impl Iterator<Item = ModPath>> {
if self.path.as_ident() != Some(&hir_expand::name![derive]) {
return None;
}
match &self.input {
Some(AttrInput::TokenTree(args)) => {
let mut counter = 0;
let paths = args
.token_trees
.iter()
.group_by(move |tt| {
match tt {
tt::TokenTree::Leaf(tt::Leaf::Punct(p)) if p.char == ',' => {
counter += 1;
}
_ => {}
}
counter
})
.into_iter()
.map(|(_, tts)| {
let segments = tts.filter_map(|tt| match tt {
tt::TokenTree::Leaf(tt::Leaf::Ident(id)) => Some(id.as_name()),
_ => None,
});
ModPath::from_segments(PathKind::Plain, segments)
})
.collect::<Vec<_>>();
Some(paths.into_iter())
}
_ => None,
}
}
pub fn string_value(&self) -> Option<&SmolStr> {
match self.input.as_ref()? {
AttrInput::Literal(it) => Some(it),
_ => None,
}
}
}
#[derive(Debug, Clone, Copy)]
pub struct AttrQuery<'a> {
attrs: &'a Attrs,
key: &'static str,
}
impl<'a> AttrQuery<'a> {
pub fn tt_values(self) -> impl Iterator<Item = &'a Subtree> {
self.attrs().filter_map(|attr| match attr.input.as_ref()? {
AttrInput::TokenTree(it) => Some(it),
_ => None,
})
}
pub fn string_value(self) -> Option<&'a SmolStr> {
self.attrs().find_map(|attr| match attr.input.as_ref()? {
AttrInput::Literal(it) => Some(it),
_ => None,
})
}
pub fn exists(self) -> bool {
self.attrs().next().is_some()
}
pub fn attrs(self) -> impl Iterator<Item = &'a Attr> {
let key = self.key;
self.attrs
.iter()
.filter(move |attr| attr.path.as_ident().map_or(false, |s| s.to_string() == key))
}
}
fn attrs_from_ast<N>(src: AstId<N>, db: &dyn DefDatabase) -> RawAttrs
where
N: ast::AttrsOwner,
{
let src = InFile::new(src.file_id, src.to_node(db.upcast()));
RawAttrs::from_attrs_owner(db, src.as_ref().map(|it| it as &dyn AttrsOwner))
}
fn attrs_from_item_tree<N: ItemTreeNode>(id: ItemTreeId<N>, db: &dyn DefDatabase) -> RawAttrs {
let tree = db.item_tree(id.file_id);
let mod_item = N::id_to_mod_item(id.value);
tree.raw_attrs(mod_item.into()).clone()
}
fn collect_attrs(owner: &dyn AttrsOwner) -> impl Iterator<Item = Either<ast::Attr, ast::Comment>> {
let (inner_attrs, inner_docs) = inner_attributes(owner.syntax())
.map_or((None, None), |(attrs, docs)| ((Some(attrs), Some(docs))));
let outer_attrs = owner.attrs().filter(|attr| attr.excl_token().is_none());
let attrs = outer_attrs
.chain(inner_attrs.into_iter().flatten())
.map(|attr| (attr.syntax().text_range().start(), Either::Left(attr)));
let outer_docs =
ast::CommentIter::from_syntax_node(owner.syntax()).filter(ast::Comment::is_outer);
let docs = outer_docs
.chain(inner_docs.into_iter().flatten())
.map(|docs_text| (docs_text.syntax().text_range().start(), Either::Right(docs_text)));
// sort here by syntax node offset because the source can have doc attributes and doc strings be interleaved
let attrs: Vec<_> = docs.chain(attrs).sorted_by_key(|&(offset, _)| offset).collect();
attrs.into_iter().map(|(_, attr)| attr)
}
|