766 lines
19 KiB
Rust

//! Completion of paths, i.e. `some::prefix::$0`.
use std::iter;
use hir::{ScopeDef, Trait};
use rustc_hash::FxHashSet;
use syntax::{ast, AstNode};
use crate::{
context::{PathCompletionContext, PathKind},
patterns::ImmediateLocation,
CompletionContext, Completions,
};
pub(crate) fn complete_qualified_path(acc: &mut Completions, ctx: &CompletionContext) {
if ctx.is_path_disallowed() || ctx.has_impl_or_trait_prev_sibling() {
return;
}
let (path, use_tree_parent, kind) = match ctx.path_context {
// let ... else, syntax would come in really handy here right now
Some(PathCompletionContext {
qualifier: Some(ref qualifier),
use_tree_parent,
kind,
..
}) => (qualifier, use_tree_parent, kind),
_ => return,
};
// special case `<_>::$0` as this doesn't resolve to anything.
if path.qualifier().is_none() {
if matches!(
path.segment().and_then(|it| it.kind()),
Some(ast::PathSegmentKind::Type {
type_ref: Some(ast::Type::InferType(_)),
trait_ref: None,
})
) {
cov_mark::hit!(completion_type_anchor_empty);
ctx.scope
.visible_traits()
.into_iter()
.flat_map(|it| Trait::from(it).items(ctx.sema.db))
.for_each(|item| add_assoc_item(acc, ctx, item));
return;
}
}
let resolution = match ctx.sema.resolve_path(path) {
Some(res) => res,
None => return,
};
let context_module = ctx.module;
match ctx.completion_location {
Some(ImmediateLocation::ItemList | ImmediateLocation::Trait | ImmediateLocation::Impl) => {
if let hir::PathResolution::Def(hir::ModuleDef::Module(module)) = resolution {
for (name, def) in module.scope(ctx.db, context_module) {
if let ScopeDef::MacroDef(macro_def) = def {
if macro_def.is_fn_like() {
acc.add_macro(ctx, Some(name.clone()), macro_def);
}
}
if let ScopeDef::ModuleDef(hir::ModuleDef::Module(_)) = def {
acc.add_resolution(ctx, name, def);
}
}
}
return;
}
_ => (),
}
match kind {
Some(PathKind::Vis { .. }) => {
if let hir::PathResolution::Def(hir::ModuleDef::Module(module)) = resolution {
if let Some(current_module) = ctx.module {
if let Some(next) = current_module
.path_to_root(ctx.db)
.into_iter()
.take_while(|&it| it != module)
.next()
{
if let Some(name) = next.name(ctx.db) {
acc.add_resolution(ctx, name, ScopeDef::ModuleDef(next.into()));
}
}
}
}
return;
}
Some(PathKind::Attr) => {
if let hir::PathResolution::Def(hir::ModuleDef::Module(module)) = resolution {
for (name, def) in module.scope(ctx.db, context_module) {
let add_resolution = match def {
ScopeDef::MacroDef(mac) => mac.is_attr(),
ScopeDef::ModuleDef(hir::ModuleDef::Module(_)) => true,
_ => false,
};
if add_resolution {
acc.add_resolution(ctx, name, def);
}
}
}
return;
}
Some(PathKind::Use) => {
if iter::successors(Some(path.clone()), |p| p.qualifier())
.all(|p| p.segment().and_then(|s| s.super_token()).is_some())
{
acc.add_keyword(ctx, "super::");
}
// only show `self` in a new use-tree when the qualifier doesn't end in self
if use_tree_parent
&& !matches!(
path.segment().and_then(|it| it.kind()),
Some(ast::PathSegmentKind::SelfKw)
)
{
acc.add_keyword(ctx, "self");
}
}
_ => (),
}
if !matches!(kind, Some(PathKind::Pat)) {
// Add associated types on type parameters and `Self`.
resolution.assoc_type_shorthand_candidates(ctx.db, |_, alias| {
acc.add_type_alias(ctx, alias);
None::<()>
});
}
match resolution {
hir::PathResolution::Def(hir::ModuleDef::Module(module)) => {
let module_scope = module.scope(ctx.db, context_module);
for (name, def) in module_scope {
if let Some(PathKind::Use) = kind {
if let ScopeDef::Unknown = def {
if let Some(ast::NameLike::NameRef(name_ref)) = ctx.name_syntax.as_ref() {
if name_ref.syntax().text() == name.to_smol_str().as_str() {
// for `use self::foo$0`, don't suggest `foo` as a completion
cov_mark::hit!(dont_complete_current_use);
continue;
}
}
}
}
let add_resolution = match def {
// Don't suggest attribute macros and derives.
ScopeDef::MacroDef(mac) => mac.is_fn_like(),
// no values in type places
ScopeDef::ModuleDef(
hir::ModuleDef::Function(_)
| hir::ModuleDef::Variant(_)
| hir::ModuleDef::Static(_),
)
| ScopeDef::Local(_) => !ctx.expects_type(),
// unless its a constant in a generic arg list position
ScopeDef::ModuleDef(hir::ModuleDef::Const(_)) => {
!ctx.expects_type() || ctx.expects_generic_arg()
}
_ => true,
};
if add_resolution {
acc.add_resolution(ctx, name, def);
}
}
}
hir::PathResolution::Def(
def @ (hir::ModuleDef::Adt(_)
| hir::ModuleDef::TypeAlias(_)
| hir::ModuleDef::BuiltinType(_)),
) => {
if let hir::ModuleDef::Adt(hir::Adt::Enum(e)) = def {
add_enum_variants(acc, ctx, e);
}
let ty = match def {
hir::ModuleDef::Adt(adt) => adt.ty(ctx.db),
hir::ModuleDef::TypeAlias(a) => {
let ty = a.ty(ctx.db);
if let Some(hir::Adt::Enum(e)) = ty.as_adt() {
cov_mark::hit!(completes_variant_through_alias);
add_enum_variants(acc, ctx, e);
}
ty
}
hir::ModuleDef::BuiltinType(builtin) => {
let module = match ctx.module {
Some(it) => it,
None => return,
};
cov_mark::hit!(completes_primitive_assoc_const);
builtin.ty(ctx.db, module)
}
_ => unreachable!(),
};
// XXX: For parity with Rust bug #22519, this does not complete Ty::AssocType.
// (where AssocType is defined on a trait, not an inherent impl)
let krate = ctx.krate;
if let Some(krate) = krate {
let traits_in_scope = ctx.scope.visible_traits();
ty.iterate_path_candidates(
ctx.db,
krate,
&traits_in_scope,
ctx.module,
None,
|_ty, item| {
add_assoc_item(acc, ctx, item);
None::<()>
},
);
// Iterate assoc types separately
ty.iterate_assoc_items(ctx.db, krate, |item| {
if let hir::AssocItem::TypeAlias(ty) = item {
acc.add_type_alias(ctx, ty)
}
None::<()>
});
}
}
hir::PathResolution::Def(hir::ModuleDef::Trait(t)) => {
// Handles `Trait::assoc` as well as `<Ty as Trait>::assoc`.
for item in t.items(ctx.db) {
add_assoc_item(acc, ctx, item);
}
}
hir::PathResolution::TypeParam(_) | hir::PathResolution::SelfType(_) => {
if let Some(krate) = ctx.krate {
let ty = match resolution {
hir::PathResolution::TypeParam(param) => param.ty(ctx.db),
hir::PathResolution::SelfType(impl_def) => impl_def.self_ty(ctx.db),
_ => return,
};
if let Some(hir::Adt::Enum(e)) = ty.as_adt() {
add_enum_variants(acc, ctx, e);
}
let traits_in_scope = ctx.scope.visible_traits();
let mut seen = FxHashSet::default();
ty.iterate_path_candidates(
ctx.db,
krate,
&traits_in_scope,
ctx.module,
None,
|_ty, item| {
// We might iterate candidates of a trait multiple times here, so deduplicate
// them.
if seen.insert(item) {
add_assoc_item(acc, ctx, item);
}
None::<()>
},
);
}
}
hir::PathResolution::Macro(mac) => acc.add_macro(ctx, None, mac),
_ => {}
}
}
fn add_assoc_item(acc: &mut Completions, ctx: &CompletionContext, item: hir::AssocItem) {
match item {
hir::AssocItem::Function(func) if !ctx.expects_type() => acc.add_function(ctx, func, None),
hir::AssocItem::Const(ct) if !ctx.expects_type() || ctx.expects_generic_arg() => {
acc.add_const(ctx, ct)
}
hir::AssocItem::TypeAlias(ty) => acc.add_type_alias(ctx, ty),
_ => (),
}
}
fn add_enum_variants(acc: &mut Completions, ctx: &CompletionContext, e: hir::Enum) {
if ctx.expects_type() {
return;
}
e.variants(ctx.db).into_iter().for_each(|variant| acc.add_enum_variant(ctx, variant, None));
}
#[cfg(test)]
mod tests {
use expect_test::{expect, Expect};
use crate::tests::{check_edit, completion_list_no_kw};
fn check(ra_fixture: &str, expect: Expect) {
let actual = completion_list_no_kw(ra_fixture);
expect.assert_eq(&actual);
}
#[test]
fn associated_item_visibility() {
check(
r#"
//- /lib.rs crate:lib new_source_root:library
pub struct S;
impl S {
pub fn public_method() { }
fn private_method() { }
pub type PublicType = u32;
type PrivateType = u32;
pub const PUBLIC_CONST: u32 = 1;
const PRIVATE_CONST: u32 = 1;
}
//- /main.rs crate:main deps:lib new_source_root:local
fn foo() { let _ = lib::S::$0 }
"#,
expect![[r#"
fn public_method() fn()
ct PUBLIC_CONST pub const PUBLIC_CONST: u32
ta PublicType pub type PublicType = u32
"#]],
);
}
#[test]
fn completes_union_associated_method() {
check(
r#"
union U {};
impl U { fn m() { } }
fn foo() { let _ = U::$0 }
"#,
expect![[r#"
fn m() fn()
"#]],
);
}
#[test]
fn completes_trait_associated_method_1() {
check(
r#"
trait Trait { fn m(); }
fn foo() { let _ = Trait::$0 }
"#,
expect![[r#"
fn m() (as Trait) fn()
"#]],
);
}
#[test]
fn completes_trait_associated_method_2() {
check(
r#"
trait Trait { fn m(); }
struct S;
impl Trait for S {}
fn foo() { let _ = S::$0 }
"#,
expect![[r#"
fn m() (as Trait) fn()
"#]],
);
}
#[test]
fn completes_trait_associated_method_3() {
check(
r#"
trait Trait { fn m(); }
struct S;
impl Trait for S {}
fn foo() { let _ = <S as Trait>::$0 }
"#,
expect![[r#"
fn m() (as Trait) fn()
"#]],
);
}
#[test]
fn completes_ty_param_assoc_ty() {
check(
r#"
trait Super {
type Ty;
const CONST: u8;
fn func() {}
fn method(&self) {}
}
trait Sub: Super {
type SubTy;
const C2: ();
fn subfunc() {}
fn submethod(&self) {}
}
fn foo<T: Sub>() { T::$0 }
"#,
expect![[r#"
ta SubTy (as Sub) type SubTy
ta Ty (as Super) type Ty
ct C2 (as Sub) const C2: ()
fn subfunc() (as Sub) fn()
me submethod(…) (as Sub) fn(&self)
ct CONST (as Super) const CONST: u8
fn func() (as Super) fn()
me method(…) (as Super) fn(&self)
"#]],
);
}
#[test]
fn completes_self_param_assoc_ty() {
check(
r#"
trait Super {
type Ty;
const CONST: u8 = 0;
fn func() {}
fn method(&self) {}
}
trait Sub: Super {
type SubTy;
const C2: () = ();
fn subfunc() {}
fn submethod(&self) {}
}
struct Wrap<T>(T);
impl<T> Super for Wrap<T> {}
impl<T> Sub for Wrap<T> {
fn subfunc() {
// Should be able to assume `Self: Sub + Super`
Self::$0
}
}
"#,
expect![[r#"
ta SubTy (as Sub) type SubTy
ta Ty (as Super) type Ty
ct CONST (as Super) const CONST: u8
fn func() (as Super) fn()
me method(…) (as Super) fn(&self)
ct C2 (as Sub) const C2: ()
fn subfunc() (as Sub) fn()
me submethod(…) (as Sub) fn(&self)
"#]],
);
}
#[test]
fn completes_type_alias() {
check(
r#"
struct S;
impl S { fn foo() {} }
type T = S;
impl T { fn bar() {} }
fn main() { T::$0; }
"#,
expect![[r#"
fn foo() fn()
fn bar() fn()
"#]],
);
}
#[test]
fn completes_qualified_macros() {
check(
r#"
#[macro_export]
macro_rules! foo { () => {} }
fn main() { let _ = crate::$0 }
"#,
expect![[r##"
fn main() fn()
ma foo!(…) #[macro_export] macro_rules! foo
"##]],
);
}
#[test]
fn does_not_complete_non_fn_macros() {
check(
r#"
mod m {
#[rustc_builtin_macro]
pub macro Clone {}
}
fn f() {m::$0}
"#,
expect![[r#""#]],
);
check(
r#"
mod m {
#[rustc_builtin_macro]
pub macro bench {}
}
fn f() {m::$0}
"#,
expect![[r#""#]],
);
}
#[test]
fn completes_reexported_items_under_correct_name() {
check(
r#"
fn foo() { self::m::$0 }
mod m {
pub use super::p::wrong_fn as right_fn;
pub use super::p::WRONG_CONST as RIGHT_CONST;
pub use super::p::WrongType as RightType;
}
mod p {
fn wrong_fn() {}
const WRONG_CONST: u32 = 1;
struct WrongType {};
}
"#,
expect![[r#"
ct RIGHT_CONST
fn right_fn() fn()
st RightType
"#]],
);
check_edit(
"RightType",
r#"
fn foo() { self::m::$0 }
mod m {
pub use super::p::wrong_fn as right_fn;
pub use super::p::WRONG_CONST as RIGHT_CONST;
pub use super::p::WrongType as RightType;
}
mod p {
fn wrong_fn() {}
const WRONG_CONST: u32 = 1;
struct WrongType {};
}
"#,
r#"
fn foo() { self::m::RightType }
mod m {
pub use super::p::wrong_fn as right_fn;
pub use super::p::WRONG_CONST as RIGHT_CONST;
pub use super::p::WrongType as RightType;
}
mod p {
fn wrong_fn() {}
const WRONG_CONST: u32 = 1;
struct WrongType {};
}
"#,
);
}
#[test]
fn completes_in_simple_macro_call() {
check(
r#"
macro_rules! m { ($e:expr) => { $e } }
fn main() { m!(self::f$0); }
fn foo() {}
"#,
expect![[r#"
fn main() fn()
fn foo() fn()
"#]],
);
}
#[test]
fn function_mod_share_name() {
check(
r#"
fn foo() { self::m::$0 }
mod m {
pub mod z {}
pub fn z() {}
}
"#,
expect![[r#"
md z
fn z() fn()
"#]],
);
}
#[test]
fn completes_hashmap_new() {
check(
r#"
struct RandomState;
struct HashMap<K, V, S = RandomState> {}
impl<K, V> HashMap<K, V, RandomState> {
pub fn new() -> HashMap<K, V, RandomState> { }
}
fn foo() {
HashMap::$0
}
"#,
expect![[r#"
fn new() fn() -> HashMap<K, V, RandomState>
"#]],
);
}
#[test]
fn dont_complete_attr() {
check(
r#"
mod foo { pub struct Foo; }
#[foo::$0]
fn f() {}
"#,
expect![[""]],
);
}
#[test]
fn completes_variant_through_self() {
check(
r#"
enum Foo {
Bar,
Baz,
}
impl Foo {
fn foo(self) {
Self::$0
}
}
"#,
expect![[r#"
ev Bar ()
ev Baz ()
me foo(…) fn(self)
"#]],
);
}
#[test]
fn completes_primitive_assoc_const() {
cov_mark::check!(completes_primitive_assoc_const);
check(
r#"
//- /lib.rs crate:lib deps:core
fn f() {
u8::$0
}
//- /core.rs crate:core
#[lang = "u8"]
impl u8 {
pub const MAX: Self = 255;
pub fn func(self) {}
}
"#,
expect![[r#"
ct MAX pub const MAX: Self
me func(…) fn(self)
"#]],
);
}
#[test]
fn completes_variant_through_alias() {
cov_mark::check!(completes_variant_through_alias);
check(
r#"
enum Foo {
Bar
}
type Foo2 = Foo;
fn main() {
Foo2::$0
}
"#,
expect![[r#"
ev Bar ()
"#]],
);
}
#[test]
fn respects_doc_hidden() {
cov_mark::check!(qualified_path_doc_hidden);
check(
r#"
//- /lib.rs crate:lib deps:dep
fn f() {
dep::$0
}
//- /dep.rs crate:dep
#[doc(hidden)]
#[macro_export]
macro_rules! m {
() => {}
}
#[doc(hidden)]
pub fn f() {}
#[doc(hidden)]
pub struct S;
#[doc(hidden)]
pub mod m {}
"#,
expect![[r#""#]],
)
}
#[test]
fn type_anchor_empty() {
cov_mark::check!(completion_type_anchor_empty);
check(
r#"
trait Foo {
fn foo() -> Self;
}
struct Bar;
impl Foo for Bar {
fn foo() -> {
Bar
}
}
fn bar() -> Bar {
<_>::$0
}
"#,
expect![[r#"
fn foo() (as Foo) fn() -> Self
"#]],
)
}
}