rust/crates/ide-completion/src/context.rs

763 lines
23 KiB
Rust

//! See [`CompletionContext`] structure.
mod analysis;
#[cfg(test)]
mod tests;
use std::iter;
use hir::{
HasAttrs, Local, Name, PathResolution, ScopeDef, Semantics, SemanticsScope, Type, TypeInfo,
};
use ide_db::{
base_db::{FilePosition, SourceDatabase},
famous_defs::FamousDefs,
helpers::is_editable_crate,
FxHashMap, FxHashSet, RootDatabase,
};
use syntax::{
ast::{self, AttrKind, NameOrNameRef},
AstNode, SmolStr,
SyntaxKind::{self, *},
SyntaxToken, TextRange, TextSize, T,
};
use text_edit::Indel;
use crate::{
context::analysis::{expand_and_analyze, AnalysisResult},
CompletionConfig,
};
const COMPLETION_MARKER: &str = "intellijRulezz";
#[derive(Copy, Clone, Debug, PartialEq, Eq)]
pub(crate) enum PatternRefutability {
Refutable,
Irrefutable,
}
#[derive(Debug)]
pub(crate) enum Visible {
Yes,
Editable,
No,
}
/// Existing qualifiers for the thing we are currently completing.
#[derive(Debug, Default)]
pub(super) struct QualifierCtx {
pub(super) unsafe_tok: Option<SyntaxToken>,
pub(super) vis_node: Option<ast::Visibility>,
}
impl QualifierCtx {
pub(super) fn none(&self) -> bool {
self.unsafe_tok.is_none() && self.vis_node.is_none()
}
}
/// The state of the path we are currently completing.
#[derive(Debug)]
pub(crate) struct PathCompletionCtx {
/// If this is a call with () already there (or {} in case of record patterns)
pub(super) has_call_parens: bool,
/// If this has a macro call bang !
pub(super) has_macro_bang: bool,
/// The qualifier of the current path.
pub(super) qualified: Qualified,
/// The parent of the path we are completing.
pub(super) parent: Option<ast::Path>,
#[allow(dead_code)]
/// The path of which we are completing the segment
pub(super) path: ast::Path,
/// The path of which we are completing the segment in the original file
pub(crate) original_path: Option<ast::Path>,
pub(super) kind: PathKind,
/// Whether the path segment has type args or not.
pub(super) has_type_args: bool,
/// Whether the qualifier comes from a use tree parent or not
pub(crate) use_tree_parent: bool,
}
impl PathCompletionCtx {
pub(super) fn is_trivial_path(&self) -> bool {
matches!(
self,
PathCompletionCtx {
has_call_parens: false,
has_macro_bang: false,
qualified: Qualified::No,
parent: None,
has_type_args: false,
..
}
)
}
}
/// The kind of path we are completing right now.
#[derive(Debug, PartialEq, Eq)]
pub(super) enum PathKind {
Expr {
expr_ctx: ExprCtx,
},
Type {
location: TypeLocation,
},
Attr {
attr_ctx: AttrCtx,
},
Derive {
existing_derives: ExistingDerives,
},
/// Path in item position, that is inside an (Assoc)ItemList
Item {
kind: ItemListKind,
},
Pat {
pat_ctx: PatternContext,
},
Vis {
has_in_token: bool,
},
Use,
}
pub(crate) type ExistingDerives = FxHashSet<hir::Macro>;
#[derive(Debug, PartialEq, Eq)]
pub(crate) struct AttrCtx {
pub(crate) kind: AttrKind,
pub(crate) annotated_item_kind: Option<SyntaxKind>,
}
#[derive(Debug, PartialEq, Eq)]
pub(crate) struct ExprCtx {
pub(crate) in_block_expr: bool,
pub(crate) in_loop_body: bool,
pub(crate) after_if_expr: bool,
/// Whether this expression is the direct condition of an if or while expression
pub(crate) in_condition: bool,
pub(crate) incomplete_let: bool,
pub(crate) ref_expr_parent: Option<ast::RefExpr>,
/// The surrounding RecordExpression we are completing a functional update
pub(crate) is_func_update: Option<ast::RecordExpr>,
pub(crate) self_param: Option<hir::SelfParam>,
pub(crate) innermost_ret_ty: Option<hir::Type>,
pub(crate) impl_: Option<ast::Impl>,
/// Whether this expression occurs in match arm guard position: before the
/// fat arrow token
pub(crate) in_match_guard: bool,
}
/// Original file ast nodes
#[derive(Clone, Debug, PartialEq, Eq)]
pub(crate) enum TypeLocation {
TupleField,
TypeAscription(TypeAscriptionTarget),
/// Generic argument position e.g. `Foo<$0>`
GenericArg {
/// The generic argument list containing the generic arg
args: Option<ast::GenericArgList>,
/// `Some(trait_)` if `trait_` is being instantiated with `args`
of_trait: Option<hir::Trait>,
/// The generic parameter being filled in by the generic arg
corresponding_param: Option<ast::GenericParam>,
},
/// Associated type equality constraint e.g. `Foo<Bar = $0>`
AssocTypeEq,
/// Associated constant equality constraint e.g. `Foo<X = $0>`
AssocConstEq,
TypeBound,
ImplTarget,
ImplTrait,
Other,
}
impl TypeLocation {
pub(crate) fn complete_lifetimes(&self) -> bool {
matches!(
self,
TypeLocation::GenericArg {
corresponding_param: Some(ast::GenericParam::LifetimeParam(_)),
..
}
)
}
pub(crate) fn complete_consts(&self) -> bool {
match self {
TypeLocation::GenericArg {
corresponding_param: Some(ast::GenericParam::ConstParam(_)),
..
} => true,
TypeLocation::AssocConstEq => true,
_ => false,
}
}
pub(crate) fn complete_types(&self) -> bool {
match self {
TypeLocation::GenericArg { corresponding_param: Some(param), .. } => {
matches!(param, ast::GenericParam::TypeParam(_))
}
TypeLocation::AssocConstEq => false,
TypeLocation::AssocTypeEq => true,
_ => true,
}
}
pub(crate) fn complete_self_type(&self) -> bool {
self.complete_types() && !matches!(self, TypeLocation::ImplTarget | TypeLocation::ImplTrait)
}
}
#[derive(Clone, Debug, PartialEq, Eq)]
pub(crate) enum TypeAscriptionTarget {
Let(Option<ast::Pat>),
FnParam(Option<ast::Pat>),
RetType(Option<ast::Expr>),
Const(Option<ast::Expr>),
}
/// The kind of item list a [`PathKind::Item`] belongs to.
#[derive(Debug, PartialEq, Eq)]
pub(super) enum ItemListKind {
SourceFile,
Module,
Impl,
TraitImpl(Option<ast::Impl>),
Trait,
ExternBlock,
}
#[derive(Debug)]
pub(super) enum Qualified {
No,
With {
path: ast::Path,
resolution: Option<PathResolution>,
/// How many `super` segments are present in the path
///
/// This would be None, if path is not solely made of
/// `super` segments, e.g.
///
/// ```rust
/// use super::foo;
/// ```
///
/// Otherwise it should be Some(count of `super`)
super_chain_len: Option<usize>,
},
/// <_>::
TypeAnchor {
ty: Option<hir::Type>,
trait_: Option<hir::Trait>,
},
/// Whether the path is an absolute path
Absolute,
}
/// The state of the pattern we are completing.
#[derive(Debug, Clone, PartialEq, Eq)]
pub(super) struct PatternContext {
pub(super) refutability: PatternRefutability,
pub(super) param_ctx: Option<ParamContext>,
pub(super) has_type_ascription: bool,
pub(super) parent_pat: Option<ast::Pat>,
pub(super) ref_token: Option<SyntaxToken>,
pub(super) mut_token: Option<SyntaxToken>,
/// The record pattern this name or ref is a field of
pub(super) record_pat: Option<ast::RecordPat>,
pub(super) impl_: Option<ast::Impl>,
/// List of missing variants in a match expr
pub(super) missing_variants: Vec<hir::Variant>,
}
#[derive(Debug, Clone, PartialEq, Eq)]
pub(super) struct ParamContext {
pub(super) param_list: ast::ParamList,
pub(super) param: ast::Param,
pub(super) kind: ParamKind,
}
/// The state of the lifetime we are completing.
#[derive(Debug)]
pub(super) struct LifetimeContext {
pub(super) lifetime: Option<ast::Lifetime>,
pub(super) kind: LifetimeKind,
}
/// The kind of lifetime we are completing.
#[derive(Debug)]
pub(super) enum LifetimeKind {
LifetimeParam { is_decl: bool, param: ast::LifetimeParam },
Lifetime,
LabelRef,
LabelDef,
}
/// The state of the name we are completing.
#[derive(Debug)]
pub(super) struct NameContext {
#[allow(dead_code)]
pub(super) name: Option<ast::Name>,
pub(super) kind: NameKind,
}
/// The kind of the name we are completing.
#[derive(Debug)]
#[allow(dead_code)]
pub(super) enum NameKind {
Const,
ConstParam,
Enum,
Function,
IdentPat(PatternContext),
MacroDef,
MacroRules,
/// Fake node
Module(ast::Module),
RecordField,
Rename,
SelfParam,
Static,
Struct,
Trait,
TypeAlias,
TypeParam,
Union,
Variant,
}
/// The state of the NameRef we are completing.
#[derive(Debug)]
pub(super) struct NameRefContext {
/// NameRef syntax in the original file
pub(super) nameref: Option<ast::NameRef>,
pub(super) kind: NameRefKind,
}
/// The kind of the NameRef we are completing.
#[derive(Debug)]
pub(super) enum NameRefKind {
Path(PathCompletionCtx),
DotAccess(DotAccess),
/// Position where we are only interested in keyword completions
Keyword(ast::Item),
/// The record expression this nameref is a field of and whether a dot precedes the completion identifier.
RecordExpr {
dot_prefix: bool,
expr: ast::RecordExpr,
},
Pattern(PatternContext),
ExternCrate,
}
/// The identifier we are currently completing.
#[derive(Debug)]
pub(super) enum CompletionAnalysis {
Name(NameContext),
NameRef(NameRefContext),
Lifetime(LifetimeContext),
/// The string the cursor is currently inside
String {
/// original token
original: ast::String,
/// fake token
expanded: Option<ast::String>,
},
/// Set if we are currently completing in an unexpanded attribute, this usually implies a builtin attribute like `allow($0)`
UnexpandedAttrTT {
colon_prefix: bool,
fake_attribute_under_caret: Option<ast::Attr>,
},
}
/// Information about the field or method access we are completing.
#[derive(Debug)]
pub(super) struct DotAccess {
pub(super) receiver: Option<ast::Expr>,
pub(super) receiver_ty: Option<TypeInfo>,
pub(super) kind: DotAccessKind,
}
#[derive(Debug)]
pub(super) enum DotAccessKind {
Field {
/// True if the receiver is an integer and there is no ident in the original file after it yet
/// like `0.$0`
receiver_is_ambiguous_float_literal: bool,
},
Method {
has_parens: bool,
},
}
#[derive(Clone, Debug, PartialEq, Eq)]
pub(crate) enum ParamKind {
Function(ast::Fn),
Closure(ast::ClosureExpr),
}
/// `CompletionContext` is created early during completion to figure out, where
/// exactly is the cursor, syntax-wise.
#[derive(Debug)]
pub(crate) struct CompletionContext<'a> {
pub(super) sema: Semantics<'a, RootDatabase>,
pub(super) scope: SemanticsScope<'a>,
pub(super) db: &'a RootDatabase,
pub(super) config: &'a CompletionConfig,
pub(super) position: FilePosition,
/// The token before the cursor, in the original file.
pub(super) original_token: SyntaxToken,
/// The token before the cursor, in the macro-expanded file.
pub(super) token: SyntaxToken,
/// The crate of the current file.
pub(super) krate: hir::Crate,
/// The module of the `scope`.
pub(super) module: hir::Module,
/// Whether nightly toolchain is used. Cached since this is looked up a lot.
is_nightly: bool,
/// The expected name of what we are completing.
/// This is usually the parameter name of the function argument we are completing.
pub(super) expected_name: Option<NameOrNameRef>,
/// The expected type of what we are completing.
pub(super) expected_type: Option<Type>,
pub(super) qualifier_ctx: QualifierCtx,
pub(super) locals: FxHashMap<Name, Local>,
/// The module depth of the current module of the cursor position.
/// - crate-root
/// - mod foo
/// - mod bar
/// Here depth will be 2
pub(super) depth_from_crate_root: usize,
}
impl CompletionContext<'_> {
/// The range of the identifier that is being completed.
pub(crate) fn source_range(&self) -> TextRange {
let kind = self.original_token.kind();
match kind {
CHAR => {
// assume we are completing a lifetime but the user has only typed the '
cov_mark::hit!(completes_if_lifetime_without_idents);
TextRange::at(self.original_token.text_range().start(), TextSize::from(1))
}
IDENT | LIFETIME_IDENT | UNDERSCORE => self.original_token.text_range(),
_ if kind.is_keyword() => self.original_token.text_range(),
_ => TextRange::empty(self.position.offset),
}
}
pub(crate) fn famous_defs(&self) -> FamousDefs<'_, '_> {
FamousDefs(&self.sema, self.krate)
}
/// Checks if an item is visible and not `doc(hidden)` at the completion site.
pub(crate) fn def_is_visible(&self, item: &ScopeDef) -> Visible {
match item {
ScopeDef::ModuleDef(def) => match def {
hir::ModuleDef::Module(it) => self.is_visible(it),
hir::ModuleDef::Function(it) => self.is_visible(it),
hir::ModuleDef::Adt(it) => self.is_visible(it),
hir::ModuleDef::Variant(it) => self.is_visible(it),
hir::ModuleDef::Const(it) => self.is_visible(it),
hir::ModuleDef::Static(it) => self.is_visible(it),
hir::ModuleDef::Trait(it) => self.is_visible(it),
hir::ModuleDef::TraitAlias(it) => self.is_visible(it),
hir::ModuleDef::TypeAlias(it) => self.is_visible(it),
hir::ModuleDef::Macro(it) => self.is_visible(it),
hir::ModuleDef::BuiltinType(_) => Visible::Yes,
},
ScopeDef::GenericParam(_)
| ScopeDef::ImplSelfType(_)
| ScopeDef::AdtSelfType(_)
| ScopeDef::Local(_)
| ScopeDef::Label(_)
| ScopeDef::Unknown => Visible::Yes,
}
}
/// Checks if an item is visible and not `doc(hidden)` at the completion site.
pub(crate) fn is_visible<I>(&self, item: &I) -> Visible
where
I: hir::HasVisibility + hir::HasAttrs + hir::HasCrate + Copy,
{
let vis = item.visibility(self.db);
let attrs = item.attrs(self.db);
self.is_visible_impl(&vis, &attrs, item.krate(self.db))
}
pub(crate) fn doc_aliases<I>(&self, item: &I) -> Vec<SmolStr>
where
I: hir::HasAttrs + Copy,
{
let attrs = item.attrs(self.db);
attrs.doc_aliases().collect()
}
/// Check if an item is `#[doc(hidden)]`.
pub(crate) fn is_item_hidden(&self, item: &hir::ItemInNs) -> bool {
let attrs = item.attrs(self.db);
let krate = item.krate(self.db);
match (attrs, krate) {
(Some(attrs), Some(krate)) => self.is_doc_hidden(&attrs, krate),
_ => false,
}
}
/// Checks whether this item should be listed in regards to stability. Returns `true` if we should.
pub(crate) fn check_stability(&self, attrs: Option<&hir::Attrs>) -> bool {
let Some(attrs) = attrs else {
return true;
};
!attrs.is_unstable() || self.is_nightly
}
/// Whether the given trait is an operator trait or not.
pub(crate) fn is_ops_trait(&self, trait_: hir::Trait) -> bool {
match trait_.attrs(self.db).lang() {
Some(lang) => OP_TRAIT_LANG_NAMES.contains(&lang.as_str()),
None => false,
}
}
/// Returns the traits in scope, with the [`Drop`] trait removed.
pub(crate) fn traits_in_scope(&self) -> hir::VisibleTraits {
let mut traits_in_scope = self.scope.visible_traits();
if let Some(drop) = self.famous_defs().core_ops_Drop() {
traits_in_scope.0.remove(&drop.into());
}
traits_in_scope
}
pub(crate) fn iterate_path_candidates(
&self,
ty: &hir::Type,
mut cb: impl FnMut(hir::AssocItem),
) {
let mut seen = FxHashSet::default();
ty.iterate_path_candidates(
self.db,
&self.scope,
&self.traits_in_scope(),
Some(self.module),
None,
|item| {
// We might iterate candidates of a trait multiple times here, so deduplicate
// them.
if seen.insert(item) {
cb(item)
}
None::<()>
},
);
}
/// A version of [`SemanticsScope::process_all_names`] that filters out `#[doc(hidden)]` items and
/// passes all doc-aliases along, to funnel it into [`Completions::add_path_resolution`].
pub(crate) fn process_all_names(&self, f: &mut dyn FnMut(Name, ScopeDef, Vec<SmolStr>)) {
let _p = profile::span("CompletionContext::process_all_names");
self.scope.process_all_names(&mut |name, def| {
if self.is_scope_def_hidden(def) {
return;
}
let doc_aliases = self.doc_aliases_in_scope(def);
f(name, def, doc_aliases);
});
}
pub(crate) fn process_all_names_raw(&self, f: &mut dyn FnMut(Name, ScopeDef)) {
let _p = profile::span("CompletionContext::process_all_names_raw");
self.scope.process_all_names(f);
}
fn is_scope_def_hidden(&self, scope_def: ScopeDef) -> bool {
if let (Some(attrs), Some(krate)) = (scope_def.attrs(self.db), scope_def.krate(self.db)) {
return self.is_doc_hidden(&attrs, krate);
}
false
}
fn is_visible_impl(
&self,
vis: &hir::Visibility,
attrs: &hir::Attrs,
defining_crate: hir::Crate,
) -> Visible {
if !vis.is_visible_from(self.db, self.module.into()) {
if !self.config.enable_private_editable {
return Visible::No;
}
// If the definition location is editable, also show private items
return if is_editable_crate(defining_crate, self.db) {
Visible::Editable
} else {
Visible::No
};
}
if self.is_doc_hidden(attrs, defining_crate) {
Visible::No
} else {
Visible::Yes
}
}
fn is_doc_hidden(&self, attrs: &hir::Attrs, defining_crate: hir::Crate) -> bool {
// `doc(hidden)` items are only completed within the defining crate.
self.krate != defining_crate && attrs.has_doc_hidden()
}
pub(crate) fn doc_aliases_in_scope(&self, scope_def: ScopeDef) -> Vec<SmolStr> {
if let Some(attrs) = scope_def.attrs(self.db) {
attrs.doc_aliases().collect()
} else {
vec![]
}
}
}
// CompletionContext construction
impl<'a> CompletionContext<'a> {
pub(super) fn new(
db: &'a RootDatabase,
position @ FilePosition { file_id, offset }: FilePosition,
config: &'a CompletionConfig,
) -> Option<(CompletionContext<'a>, CompletionAnalysis)> {
let _p = profile::span("CompletionContext::new");
let sema = Semantics::new(db);
let original_file = sema.parse(file_id);
// Insert a fake ident to get a valid parse tree. We will use this file
// to determine context, though the original_file will be used for
// actual completion.
let file_with_fake_ident = {
let parse = db.parse(file_id);
let edit = Indel::insert(offset, COMPLETION_MARKER.to_string());
parse.reparse(&edit).tree()
};
// always pick the token to the immediate left of the cursor, as that is what we are actually
// completing on
let original_token = original_file.syntax().token_at_offset(offset).left_biased()?;
// try to skip completions on path with invalid colons
// this approach works in normal path and inside token tree
if original_token.kind() == T![:] {
// return if no prev token before colon
let prev_token = original_token.prev_token()?;
// only has a single colon
if prev_token.kind() != T![:] {
return None;
}
// has 3 colon or 2 coloncolon in a row
// special casing this as per discussion in https://github.com/rust-lang/rust-analyzer/pull/13611#discussion_r1031845205
// and https://github.com/rust-lang/rust-analyzer/pull/13611#discussion_r1032812751
if prev_token
.prev_token()
.map(|t| t.kind() == T![:] || t.kind() == T![::])
.unwrap_or(false)
{
return None;
}
}
let AnalysisResult {
analysis,
expected: (expected_type, expected_name),
qualifier_ctx,
token,
offset,
} = expand_and_analyze(
&sema,
original_file.syntax().clone(),
file_with_fake_ident.syntax().clone(),
offset,
&original_token,
)?;
// adjust for macro input, this still fails if there is no token written yet
let scope = sema.scope_at_offset(&token.parent()?, offset)?;
let krate = scope.krate();
let module = scope.module();
let toolchain = db.crate_graph()[krate.into()].channel;
// `toolchain == None` means we're in some detached files. Since we have no information on
// the toolchain being used, let's just allow unstable items to be listed.
let is_nightly = matches!(toolchain, Some(base_db::ReleaseChannel::Nightly) | None);
let mut locals = FxHashMap::default();
scope.process_all_names(&mut |name, scope| {
if let ScopeDef::Local(local) = scope {
locals.insert(name, local);
}
});
let depth_from_crate_root = iter::successors(module.parent(db), |m| m.parent(db)).count();
let ctx = CompletionContext {
sema,
scope,
db,
config,
position,
original_token,
token,
krate,
module,
is_nightly,
expected_name,
expected_type,
qualifier_ctx,
locals,
depth_from_crate_root,
};
Some((ctx, analysis))
}
}
const OP_TRAIT_LANG_NAMES: &[&str] = &[
"add_assign",
"add",
"bitand_assign",
"bitand",
"bitor_assign",
"bitor",
"bitxor_assign",
"bitxor",
"deref_mut",
"deref",
"div_assign",
"div",
"eq",
"fn_mut",
"fn_once",
"fn",
"index_mut",
"index",
"mul_assign",
"mul",
"neg",
"not",
"partial_ord",
"rem_assign",
"rem",
"shl_assign",
"shl",
"shr_assign",
"shr",
"sub",
];