rust/crates/ide_db/src/search.rs
2021-05-08 23:35:18 +02:00

587 lines
21 KiB
Rust

//! Implementation of find-usages functionality.
//!
//! It is based on the standard ide trick: first, we run a fast text search to
//! get a super-set of matches. Then, we we confirm each match using precise
//! name resolution.
use std::{convert::TryInto, mem};
use base_db::{FileId, FileRange, SourceDatabase, SourceDatabaseExt};
use hir::{
DefWithBody, HasAttrs, HasSource, InFile, ModuleDef, ModuleSource, Semantics, Visibility,
};
use once_cell::unsync::Lazy;
use rustc_hash::FxHashMap;
use syntax::{ast, match_ast, AstNode, TextRange, TextSize};
use crate::{
defs::{Definition, NameClass, NameRefClass},
RootDatabase,
};
#[derive(Debug, Default, Clone)]
pub struct UsageSearchResult {
pub references: FxHashMap<FileId, Vec<FileReference>>,
}
impl UsageSearchResult {
pub fn is_empty(&self) -> bool {
self.references.is_empty()
}
pub fn len(&self) -> usize {
self.references.len()
}
pub fn iter(&self) -> impl Iterator<Item = (&FileId, &Vec<FileReference>)> + '_ {
self.references.iter()
}
pub fn file_ranges(&self) -> impl Iterator<Item = FileRange> + '_ {
self.references.iter().flat_map(|(&file_id, refs)| {
refs.iter().map(move |&FileReference { range, .. }| FileRange { file_id, range })
})
}
}
impl IntoIterator for UsageSearchResult {
type Item = (FileId, Vec<FileReference>);
type IntoIter = <FxHashMap<FileId, Vec<FileReference>> as IntoIterator>::IntoIter;
fn into_iter(self) -> Self::IntoIter {
self.references.into_iter()
}
}
#[derive(Debug, Clone)]
pub struct FileReference {
pub range: TextRange,
pub name: ast::NameLike,
pub access: Option<ReferenceAccess>,
}
#[derive(Debug, Copy, Clone, PartialEq)]
pub enum ReferenceAccess {
Read,
Write,
}
/// Generally, `search_scope` returns files that might contain references for the element.
/// For `pub(crate)` things it's a crate, for `pub` things it's a crate and dependant crates.
/// In some cases, the location of the references is known to within a `TextRange`,
/// e.g. for things like local variables.
pub struct SearchScope {
entries: FxHashMap<FileId, Option<TextRange>>,
}
impl SearchScope {
fn new(entries: FxHashMap<FileId, Option<TextRange>>) -> SearchScope {
SearchScope { entries }
}
fn crate_graph(db: &RootDatabase) -> SearchScope {
let mut entries = FxHashMap::default();
let graph = db.crate_graph();
for krate in graph.iter() {
let root_file = graph[krate].root_file_id;
let source_root_id = db.file_source_root(root_file);
let source_root = db.source_root(source_root_id);
entries.extend(source_root.iter().map(|id| (id, None)));
}
SearchScope { entries }
}
fn reverse_dependencies(db: &RootDatabase, of: hir::Crate) -> SearchScope {
let mut entries = FxHashMap::default();
for rev_dep in of.transitive_reverse_dependencies(db) {
let root_file = rev_dep.root_file(db);
let source_root_id = db.file_source_root(root_file);
let source_root = db.source_root(source_root_id);
entries.extend(source_root.iter().map(|id| (id, None)));
}
SearchScope { entries }
}
fn krate(db: &RootDatabase, of: hir::Crate) -> SearchScope {
let root_file = of.root_file(db);
let source_root_id = db.file_source_root(root_file);
let source_root = db.source_root(source_root_id);
SearchScope {
entries: source_root.iter().map(|id| (id, None)).collect::<FxHashMap<_, _>>(),
}
}
fn module(db: &RootDatabase, module: hir::Module) -> SearchScope {
let mut entries = FxHashMap::default();
let mut to_visit = vec![module];
let mut is_first = true;
while let Some(module) = to_visit.pop() {
let src = module.definition_source(db);
let file_id = src.file_id.original_file(db);
match src.value {
ModuleSource::Module(m) => {
if is_first {
let range = Some(m.syntax().text_range());
entries.insert(file_id, range);
} else {
// We have already added the enclosing file to the search scope,
// so do nothing.
}
}
ModuleSource::BlockExpr(b) => {
if is_first {
let range = Some(b.syntax().text_range());
entries.insert(file_id, range);
} else {
// We have already added the enclosing file to the search scope,
// so do nothing.
}
}
ModuleSource::SourceFile(_) => {
entries.insert(file_id, None);
}
};
is_first = false;
to_visit.extend(module.children(db));
}
SearchScope { entries }
}
pub fn empty() -> SearchScope {
SearchScope::new(FxHashMap::default())
}
pub fn single_file(file: FileId) -> SearchScope {
SearchScope::new(std::iter::once((file, None)).collect())
}
pub fn file_range(range: FileRange) -> SearchScope {
SearchScope::new(std::iter::once((range.file_id, Some(range.range))).collect())
}
pub fn files(files: &[FileId]) -> SearchScope {
SearchScope::new(files.iter().map(|f| (*f, None)).collect())
}
pub fn intersection(&self, other: &SearchScope) -> SearchScope {
let (mut small, mut large) = (&self.entries, &other.entries);
if small.len() > large.len() {
mem::swap(&mut small, &mut large)
}
let res = small
.iter()
.filter_map(|(file_id, r1)| {
let r2 = large.get(file_id)?;
let r = intersect_ranges(*r1, *r2)?;
Some((*file_id, r))
})
.collect();
return SearchScope::new(res);
fn intersect_ranges(
r1: Option<TextRange>,
r2: Option<TextRange>,
) -> Option<Option<TextRange>> {
match (r1, r2) {
(None, r) | (r, None) => Some(r),
(Some(r1), Some(r2)) => {
let r = r1.intersect(r2)?;
Some(Some(r))
}
}
}
}
}
impl IntoIterator for SearchScope {
type Item = (FileId, Option<TextRange>);
type IntoIter = std::collections::hash_map::IntoIter<FileId, Option<TextRange>>;
fn into_iter(self) -> Self::IntoIter {
self.entries.into_iter()
}
}
impl Definition {
fn search_scope(&self, db: &RootDatabase) -> SearchScope {
let _p = profile::span("search_scope");
if let Definition::ModuleDef(hir::ModuleDef::BuiltinType(_)) = self {
return SearchScope::crate_graph(db);
}
let module = match self.module(db) {
Some(it) => it,
None => return SearchScope::empty(),
};
let InFile { file_id, value: module_source } = module.definition_source(db);
let file_id = file_id.original_file(db);
if let Definition::Local(var) = self {
let range = match var.parent(db) {
DefWithBody::Function(f) => f.source(db).map(|src| src.value.syntax().text_range()),
DefWithBody::Const(c) => c.source(db).map(|src| src.value.syntax().text_range()),
DefWithBody::Static(s) => s.source(db).map(|src| src.value.syntax().text_range()),
};
return match range {
Some(range) => SearchScope::file_range(FileRange { file_id, range }),
None => SearchScope::single_file(file_id),
};
}
if let Definition::SelfType(impl_) = self {
return match impl_.source(db).map(|src| src.value.syntax().text_range()) {
Some(range) => SearchScope::file_range(FileRange { file_id, range }),
None => SearchScope::single_file(file_id),
};
}
if let Definition::GenericParam(hir::GenericParam::LifetimeParam(param)) = self {
let range = match param.parent(db) {
hir::GenericDef::Function(it) => {
it.source(db).map(|src| src.value.syntax().text_range())
}
hir::GenericDef::Adt(it) => match it {
hir::Adt::Struct(it) => {
it.source(db).map(|src| src.value.syntax().text_range())
}
hir::Adt::Union(it) => it.source(db).map(|src| src.value.syntax().text_range()),
hir::Adt::Enum(it) => it.source(db).map(|src| src.value.syntax().text_range()),
},
hir::GenericDef::Trait(it) => {
it.source(db).map(|src| src.value.syntax().text_range())
}
hir::GenericDef::TypeAlias(it) => {
it.source(db).map(|src| src.value.syntax().text_range())
}
hir::GenericDef::Impl(it) => {
it.source(db).map(|src| src.value.syntax().text_range())
}
hir::GenericDef::Variant(it) => {
it.source(db).map(|src| src.value.syntax().text_range())
}
hir::GenericDef::Const(it) => {
it.source(db).map(|src| src.value.syntax().text_range())
}
};
return match range {
Some(range) => SearchScope::file_range(FileRange { file_id, range }),
None => SearchScope::single_file(file_id),
};
}
if let Definition::Macro(macro_def) = self {
if macro_def.kind() == hir::MacroKind::Declarative {
return if macro_def.attrs(db).by_key("macro_export").exists() {
SearchScope::reverse_dependencies(db, module.krate())
} else {
SearchScope::krate(db, module.krate())
};
}
}
let vis = self.visibility(db);
if let Some(Visibility::Public) = vis {
return SearchScope::reverse_dependencies(db, module.krate());
}
if let Some(Visibility::Module(module)) = vis {
return SearchScope::module(db, module.into());
}
let range = match module_source {
ModuleSource::Module(m) => Some(m.syntax().text_range()),
ModuleSource::BlockExpr(b) => Some(b.syntax().text_range()),
ModuleSource::SourceFile(_) => None,
};
match range {
Some(range) => SearchScope::file_range(FileRange { file_id, range }),
None => SearchScope::single_file(file_id),
}
}
pub fn usages<'a>(&'a self, sema: &'a Semantics<RootDatabase>) -> FindUsages<'a> {
FindUsages { def: self, sema, scope: None, include_self_kw_refs: None }
}
}
pub struct FindUsages<'a> {
def: &'a Definition,
sema: &'a Semantics<'a, RootDatabase>,
scope: Option<SearchScope>,
include_self_kw_refs: Option<hir::Type>,
}
impl<'a> FindUsages<'a> {
/// Enable searching for `Self` when the definition is a type.
pub fn include_self_refs(mut self) -> FindUsages<'a> {
self.include_self_kw_refs = def_to_ty(self.sema, self.def);
self
}
pub fn in_scope(self, scope: SearchScope) -> FindUsages<'a> {
self.set_scope(Some(scope))
}
pub fn set_scope(mut self, scope: Option<SearchScope>) -> FindUsages<'a> {
assert!(self.scope.is_none());
self.scope = scope;
self
}
pub fn at_least_one(self) -> bool {
let mut found = false;
self.search(&mut |_, _| {
found = true;
true
});
found
}
pub fn all(self) -> UsageSearchResult {
let mut res = UsageSearchResult::default();
self.search(&mut |file_id, reference| {
res.references.entry(file_id).or_default().push(reference);
false
});
res
}
fn search(self, sink: &mut dyn FnMut(FileId, FileReference) -> bool) {
let _p = profile::span("FindUsages:search");
let sema = self.sema;
let search_scope = {
let base = self.def.search_scope(sema.db);
match &self.scope {
None => base,
Some(scope) => base.intersection(scope),
}
};
let name = self.def.name(sema.db).or_else(|| {
self.include_self_kw_refs.as_ref().and_then(|ty| {
ty.as_adt()
.map(|adt| adt.name(self.sema.db))
.or_else(|| ty.as_builtin().map(|builtin| builtin.name()))
})
});
let name = match name {
Some(name) => name.to_string(),
None => return,
};
let name = name.as_str();
for (file_id, search_range) in search_scope {
let text = sema.db.file_text(file_id);
let search_range =
search_range.unwrap_or_else(|| TextRange::up_to(TextSize::of(text.as_str())));
let tree = Lazy::new(|| sema.parse(file_id).syntax().clone());
for (idx, _) in text.match_indices(name) {
let offset: TextSize = idx.try_into().unwrap();
if !search_range.contains_inclusive(offset) {
continue;
}
if let Some(name) = sema.find_node_at_offset_with_descend(&tree, offset) {
if match name {
ast::NameLike::NameRef(name_ref) => self.found_name_ref(&name_ref, sink),
ast::NameLike::Name(name) => self.found_name(&name, sink),
ast::NameLike::Lifetime(lifetime) => self.found_lifetime(&lifetime, sink),
} {
return;
}
}
}
if let Some(self_ty) = &self.include_self_kw_refs {
for (idx, _) in text.match_indices("Self") {
let offset: TextSize = idx.try_into().unwrap();
if !search_range.contains_inclusive(offset) {
continue;
}
if let Some(ast::NameLike::NameRef(name_ref)) =
sema.find_node_at_offset_with_descend(&tree, offset)
{
if self.found_self_ty_name_ref(&self_ty, &name_ref, sink) {
return;
}
}
}
}
}
}
fn found_self_ty_name_ref(
&self,
self_ty: &hir::Type,
name_ref: &ast::NameRef,
sink: &mut dyn FnMut(FileId, FileReference) -> bool,
) -> bool {
match NameRefClass::classify(self.sema, &name_ref) {
Some(NameRefClass::Definition(Definition::SelfType(impl_)))
if impl_.self_ty(self.sema.db) == *self_ty =>
{
let FileRange { file_id, range } = self.sema.original_range(name_ref.syntax());
let reference = FileReference {
range,
name: ast::NameLike::NameRef(name_ref.clone()),
access: None,
};
sink(file_id, reference)
}
_ => false,
}
}
fn found_lifetime(
&self,
lifetime: &ast::Lifetime,
sink: &mut dyn FnMut(FileId, FileReference) -> bool,
) -> bool {
match NameRefClass::classify_lifetime(self.sema, lifetime) {
Some(NameRefClass::Definition(def)) if &def == self.def => {
let FileRange { file_id, range } = self.sema.original_range(lifetime.syntax());
let reference = FileReference {
range,
name: ast::NameLike::Lifetime(lifetime.clone()),
access: None,
};
sink(file_id, reference)
}
_ => false,
}
}
fn found_name_ref(
&self,
name_ref: &ast::NameRef,
sink: &mut dyn FnMut(FileId, FileReference) -> bool,
) -> bool {
match NameRefClass::classify(self.sema, &name_ref) {
Some(NameRefClass::Definition(def)) if &def == self.def => {
let FileRange { file_id, range } = self.sema.original_range(name_ref.syntax());
let reference = FileReference {
range,
name: ast::NameLike::NameRef(name_ref.clone()),
access: reference_access(&def, &name_ref),
};
sink(file_id, reference)
}
Some(NameRefClass::Definition(def)) if self.include_self_kw_refs.is_some() => {
if self.include_self_kw_refs == def_to_ty(self.sema, &def) {
let FileRange { file_id, range } = self.sema.original_range(name_ref.syntax());
let reference = FileReference {
range,
name: ast::NameLike::NameRef(name_ref.clone()),
access: reference_access(&def, &name_ref),
};
sink(file_id, reference)
} else {
false
}
}
Some(NameRefClass::FieldShorthand { local_ref: local, field_ref: field }) => {
let FileRange { file_id, range } = self.sema.original_range(name_ref.syntax());
let access = match self.def {
Definition::Field(_) if &field == self.def => {
reference_access(&field, &name_ref)
}
Definition::Local(l) if &local == l => {
reference_access(&Definition::Local(local), &name_ref)
}
_ => return false,
};
let reference =
FileReference { range, name: ast::NameLike::NameRef(name_ref.clone()), access };
sink(file_id, reference)
}
_ => false,
}
}
fn found_name(
&self,
name: &ast::Name,
sink: &mut dyn FnMut(FileId, FileReference) -> bool,
) -> bool {
match NameClass::classify(self.sema, name) {
Some(NameClass::PatFieldShorthand { local_def: _, field_ref })
if matches!(
self.def, Definition::Field(_) if &field_ref == self.def
) =>
{
let FileRange { file_id, range } = self.sema.original_range(name.syntax());
let reference = FileReference {
range,
name: ast::NameLike::Name(name.clone()),
// FIXME: mutable patterns should have `Write` access
access: Some(ReferenceAccess::Read),
};
sink(file_id, reference)
}
Some(NameClass::ConstReference(def)) if *self.def == def => {
let FileRange { file_id, range } = self.sema.original_range(name.syntax());
let reference =
FileReference { range, name: ast::NameLike::Name(name.clone()), access: None };
sink(file_id, reference)
}
_ => false,
}
}
}
fn def_to_ty(sema: &Semantics<RootDatabase>, def: &Definition) -> Option<hir::Type> {
match def {
Definition::ModuleDef(def) => match def {
ModuleDef::Adt(adt) => Some(adt.ty(sema.db)),
ModuleDef::TypeAlias(it) => Some(it.ty(sema.db)),
ModuleDef::BuiltinType(it) => {
let graph = sema.db.crate_graph();
let krate = graph.iter().next()?;
let root_file = graph[krate].root_file_id;
let module = sema.to_module_def(root_file)?;
Some(it.ty(sema.db, module))
}
_ => None,
},
Definition::SelfType(it) => Some(it.self_ty(sema.db)),
_ => None,
}
}
fn reference_access(def: &Definition, name_ref: &ast::NameRef) -> Option<ReferenceAccess> {
// Only Locals and Fields have accesses for now.
if !matches!(def, Definition::Local(_) | Definition::Field(_)) {
return None;
}
let mode = name_ref.syntax().ancestors().find_map(|node| {
match_ast! {
match (node) {
ast::BinExpr(expr) => {
if expr.op_kind()?.is_assignment() {
// If the variable or field ends on the LHS's end then it's a Write (covers fields and locals).
// FIXME: This is not terribly accurate.
if let Some(lhs) = expr.lhs() {
if lhs.syntax().text_range().end() == name_ref.syntax().text_range().end() {
return Some(ReferenceAccess::Write);
}
}
}
Some(ReferenceAccess::Read)
},
_ => None
}
}
});
// Default Locals and Fields to read
mode.or(Some(ReferenceAccess::Read))
}