//! Look up accessible paths for items.
use either::Either;
use hir::{AsAssocItem, AssocItemContainer, ModuleDef, Semantics};
use ide_db::{imports_locator, RootDatabase};
use rustc_hash::FxHashSet;
use syntax::{ast, AstNode, SyntaxNode};
use crate::assist_config::InsertUseConfig;
#[derive(Debug)]
pub(crate) enum ImportCandidate {
/// Simple name like 'HashMap'
UnqualifiedName(PathImportCandidate),
/// First part of the qualified name.
/// For 'std::collections::HashMap', that will be 'std'.
QualifierStart(PathImportCandidate),
/// A trait associated function (with no self parameter) or associated constant.
/// For 'test_mod::TestEnum::test_function', `ty` is the `test_mod::TestEnum` expression type
/// and `name` is the `test_function`
TraitAssocItem(TraitImportCandidate),
/// A trait method with self parameter.
/// For 'test_enum.test_method()', `ty` is the `test_enum` expression type
/// and `name` is the `test_method`
TraitMethod(TraitImportCandidate),
}
#[derive(Debug)]
pub(crate) struct TraitImportCandidate {
pub(crate) ty: hir::Type,
pub(crate) name: ast::NameRef,
}
#[derive(Debug)]
pub(crate) struct PathImportCandidate {
pub(crate) name: ast::NameRef,
}
#[derive(Debug)]
pub(crate) struct ImportAssets {
import_candidate: ImportCandidate,
module_with_name_to_import: hir::Module,
syntax_under_caret: SyntaxNode,
}
impl ImportAssets {
pub(crate) fn for_method_call(
method_call: ast::MethodCallExpr,
sema: &Semantics<RootDatabase>,
) -> Option<Self> {
let syntax_under_caret = method_call.syntax().to_owned();
let module_with_name_to_import = sema.scope(&syntax_under_caret).module()?;
Some(Self {
import_candidate: ImportCandidate::for_method_call(sema, &method_call)?,
module_with_name_to_import,
syntax_under_caret,
})
}
pub(crate) fn for_regular_path(
path_under_caret: ast::Path,
sema: &Semantics<RootDatabase>,
) -> Option<Self> {
let syntax_under_caret = path_under_caret.syntax().to_owned();
if syntax_under_caret.ancestors().find_map(ast::Use::cast).is_some() {
return None;
}
let module_with_name_to_import = sema.scope(&syntax_under_caret).module()?;
Some(Self {
import_candidate: ImportCandidate::for_regular_path(sema, &path_under_caret)?,
module_with_name_to_import,
syntax_under_caret,
})
}
pub(crate) fn syntax_under_caret(&self) -> &SyntaxNode {
&self.syntax_under_caret
}
pub(crate) fn import_candidate(&self) -> &ImportCandidate {
&self.import_candidate
}
fn get_search_query(&self) -> &str {
match &self.import_candidate {
ImportCandidate::UnqualifiedName(candidate)
| ImportCandidate::QualifierStart(candidate) => candidate.name.text(),
ImportCandidate::TraitAssocItem(candidate)
| ImportCandidate::TraitMethod(candidate) => candidate.name.text(),
}
}
pub(crate) fn search_for_imports(
&self,
sema: &Semantics<RootDatabase>,
config: &InsertUseConfig,
) -> Vec<(hir::ModPath, hir::ItemInNs)> {
let _p = profile::span("import_assists::search_for_imports");
self.search_for(sema, Some(config.prefix_kind))
}
/// This may return non-absolute paths if a part of the returned path is already imported into scope.
#[allow(dead_code)]
pub(crate) fn search_for_relative_paths(
&self,
sema: &Semantics<RootDatabase>,
) -> Vec<(hir::ModPath, hir::ItemInNs)> {
let _p = profile::span("import_assists::search_for_relative_paths");
self.search_for(sema, None)
}
fn search_for(
&self,
sema: &Semantics<RootDatabase>,
prefixed: Option<hir::PrefixKind>,
) -> Vec<(hir::ModPath, hir::ItemInNs)> {
let db = sema.db;
let mut trait_candidates = FxHashSet::default();
let current_crate = self.module_with_name_to_import.krate();
let filter = |candidate: Either<hir::ModuleDef, hir::MacroDef>| {
trait_candidates.clear();
match &self.import_candidate {
ImportCandidate::TraitAssocItem(trait_candidate) => {
let located_assoc_item = match candidate {
Either::Left(ModuleDef::Function(located_function)) => {
located_function.as_assoc_item(db)
}
Either::Left(ModuleDef::Const(located_const)) => {
located_const.as_assoc_item(db)
}
_ => None,
}
.map(|assoc| assoc.container(db))
.and_then(Self::assoc_to_trait)?;
trait_candidates.insert(located_assoc_item.into());
trait_candidate
.ty
.iterate_path_candidates(
db,
current_crate,
&trait_candidates,
None,
|_, assoc| Self::assoc_to_trait(assoc.container(db)),
)
.map(ModuleDef::from)
.map(Either::Left)
}
ImportCandidate::TraitMethod(trait_candidate) => {
let located_assoc_item =
if let Either::Left(ModuleDef::Function(located_function)) = candidate {
located_function
.as_assoc_item(db)
.map(|assoc| assoc.container(db))
.and_then(Self::assoc_to_trait)
} else {
None
}?;
trait_candidates.insert(located_assoc_item.into());
trait_candidate
.ty
.iterate_method_candidates(
db,
current_crate,
&trait_candidates,
None,
|_, function| {
Self::assoc_to_trait(function.as_assoc_item(db)?.container(db))
},
)
.map(ModuleDef::from)
.map(Either::Left)
}
_ => Some(candidate),
}
};
let mut res =
imports_locator::find_exact_imports(sema, current_crate, &self.get_search_query())
.filter_map(filter)
.filter_map(|candidate| {
let item: hir::ItemInNs = candidate.either(Into::into, Into::into);
if let Some(prefix_kind) = prefixed {
self.module_with_name_to_import.find_use_path_prefixed(
db,
item,
prefix_kind,
)
} else {
self.module_with_name_to_import.find_use_path(db, item)
}
.map(|path| (path, item))
})
.filter(|(use_path, _)| use_path.len() > 1)
.take(20)
.collect::<Vec<_>>();
res.sort_by_key(|(path, _)| path.clone());
res
}
fn assoc_to_trait(assoc: AssocItemContainer) -> Option<hir::Trait> {
if let AssocItemContainer::Trait(extracted_trait) = assoc {
Some(extracted_trait)
} else {
None
}
}
}
impl ImportCandidate {
fn for_method_call(
sema: &Semantics<RootDatabase>,
method_call: &ast::MethodCallExpr,
) -> Option<Self> {
match sema.resolve_method_call(method_call) {
Some(_) => None,
None => Some(Self::TraitMethod(TraitImportCandidate {
ty: sema.type_of_expr(&method_call.receiver()?)?,
name: method_call.name_ref()?,
})),
}
}
fn for_regular_path(
sema: &Semantics<RootDatabase>,
path_under_caret: &ast::Path,
) -> Option<Self> {
if sema.resolve_path(path_under_caret).is_some() {
return None;
}
let segment = path_under_caret.segment()?;
let candidate = if let Some(qualifier) = path_under_caret.qualifier() {
let qualifier_start = qualifier.syntax().descendants().find_map(ast::NameRef::cast)?;
let qualifier_start_path =
qualifier_start.syntax().ancestors().find_map(ast::Path::cast)?;
if let Some(qualifier_start_resolution) = sema.resolve_path(&qualifier_start_path) {
let qualifier_resolution = if qualifier_start_path == qualifier {
qualifier_start_resolution
} else {
sema.resolve_path(&qualifier)?
};
match qualifier_resolution {
hir::PathResolution::Def(hir::ModuleDef::Adt(assoc_item_path)) => {
ImportCandidate::TraitAssocItem(TraitImportCandidate {
ty: assoc_item_path.ty(sema.db),
name: segment.name_ref()?,
})
}
_ => return None,
}
} else {
ImportCandidate::QualifierStart(PathImportCandidate { name: qualifier_start })
}
} else {
ImportCandidate::UnqualifiedName(PathImportCandidate {
name: segment.syntax().descendants().find_map(ast::NameRef::cast)?,
})
};
Some(candidate)
}
}