603 lines
17 KiB
Rust
603 lines
17 KiB
Rust
//! Name resolution for expressions.
|
|
use hir_expand::name::Name;
|
|
use la_arena::{Arena, ArenaMap, Idx, IdxRange, RawIdx};
|
|
use triomphe::Arc;
|
|
|
|
use crate::{
|
|
body::Body,
|
|
db::DefDatabase,
|
|
hir::{Binding, BindingId, Expr, ExprId, LabelId, Pat, PatId, Statement},
|
|
BlockId, DefWithBodyId,
|
|
};
|
|
|
|
pub type ScopeId = Idx<ScopeData>;
|
|
|
|
#[derive(Debug, PartialEq, Eq)]
|
|
pub struct ExprScopes {
|
|
scopes: Arena<ScopeData>,
|
|
scope_entries: Arena<ScopeEntry>,
|
|
scope_by_expr: ArenaMap<ExprId, ScopeId>,
|
|
}
|
|
|
|
#[derive(Debug, PartialEq, Eq)]
|
|
pub struct ScopeEntry {
|
|
name: Name,
|
|
binding: BindingId,
|
|
}
|
|
|
|
impl ScopeEntry {
|
|
pub fn name(&self) -> &Name {
|
|
&self.name
|
|
}
|
|
|
|
pub fn binding(&self) -> BindingId {
|
|
self.binding
|
|
}
|
|
}
|
|
|
|
#[derive(Debug, PartialEq, Eq)]
|
|
pub struct ScopeData {
|
|
parent: Option<ScopeId>,
|
|
block: Option<BlockId>,
|
|
label: Option<(LabelId, Name)>,
|
|
entries: IdxRange<ScopeEntry>,
|
|
}
|
|
|
|
impl ExprScopes {
|
|
pub(crate) fn expr_scopes_query(db: &dyn DefDatabase, def: DefWithBodyId) -> Arc<ExprScopes> {
|
|
let body = db.body(def);
|
|
let mut scopes = ExprScopes::new(&body);
|
|
scopes.shrink_to_fit();
|
|
Arc::new(scopes)
|
|
}
|
|
|
|
pub fn entries(&self, scope: ScopeId) -> &[ScopeEntry] {
|
|
&self.scope_entries[self.scopes[scope].entries.clone()]
|
|
}
|
|
|
|
/// If `scope` refers to a block expression scope, returns the corresponding `BlockId`.
|
|
pub fn block(&self, scope: ScopeId) -> Option<BlockId> {
|
|
self.scopes[scope].block
|
|
}
|
|
|
|
/// If `scope` refers to a labeled expression scope, returns the corresponding `Label`.
|
|
pub fn label(&self, scope: ScopeId) -> Option<(LabelId, Name)> {
|
|
self.scopes[scope].label.clone()
|
|
}
|
|
|
|
/// Returns the scopes in ascending order.
|
|
pub fn scope_chain(&self, scope: Option<ScopeId>) -> impl Iterator<Item = ScopeId> + '_ {
|
|
std::iter::successors(scope, move |&scope| self.scopes[scope].parent)
|
|
}
|
|
|
|
pub fn resolve_name_in_scope(&self, scope: ScopeId, name: &Name) -> Option<&ScopeEntry> {
|
|
self.scope_chain(Some(scope))
|
|
.find_map(|scope| self.entries(scope).iter().find(|it| it.name == *name))
|
|
}
|
|
|
|
pub fn scope_for(&self, expr: ExprId) -> Option<ScopeId> {
|
|
self.scope_by_expr.get(expr).copied()
|
|
}
|
|
|
|
pub fn scope_by_expr(&self) -> &ArenaMap<ExprId, ScopeId> {
|
|
&self.scope_by_expr
|
|
}
|
|
}
|
|
|
|
fn empty_entries(idx: usize) -> IdxRange<ScopeEntry> {
|
|
IdxRange::new(Idx::from_raw(RawIdx::from(idx as u32))..Idx::from_raw(RawIdx::from(idx as u32)))
|
|
}
|
|
|
|
impl ExprScopes {
|
|
fn new(body: &Body) -> ExprScopes {
|
|
let mut scopes = ExprScopes {
|
|
scopes: Arena::default(),
|
|
scope_entries: Arena::default(),
|
|
scope_by_expr: ArenaMap::with_capacity(body.exprs.len()),
|
|
};
|
|
let mut root = scopes.root_scope();
|
|
scopes.add_params_bindings(body, root, &body.params);
|
|
compute_expr_scopes(body.body_expr, body, &mut scopes, &mut root);
|
|
scopes
|
|
}
|
|
|
|
fn root_scope(&mut self) -> ScopeId {
|
|
self.scopes.alloc(ScopeData {
|
|
parent: None,
|
|
block: None,
|
|
label: None,
|
|
entries: empty_entries(self.scope_entries.len()),
|
|
})
|
|
}
|
|
|
|
fn new_scope(&mut self, parent: ScopeId) -> ScopeId {
|
|
self.scopes.alloc(ScopeData {
|
|
parent: Some(parent),
|
|
block: None,
|
|
label: None,
|
|
entries: empty_entries(self.scope_entries.len()),
|
|
})
|
|
}
|
|
|
|
fn new_labeled_scope(&mut self, parent: ScopeId, label: Option<(LabelId, Name)>) -> ScopeId {
|
|
self.scopes.alloc(ScopeData {
|
|
parent: Some(parent),
|
|
block: None,
|
|
label,
|
|
entries: empty_entries(self.scope_entries.len()),
|
|
})
|
|
}
|
|
|
|
fn new_block_scope(
|
|
&mut self,
|
|
parent: ScopeId,
|
|
block: Option<BlockId>,
|
|
label: Option<(LabelId, Name)>,
|
|
) -> ScopeId {
|
|
self.scopes.alloc(ScopeData {
|
|
parent: Some(parent),
|
|
block,
|
|
label,
|
|
entries: empty_entries(self.scope_entries.len()),
|
|
})
|
|
}
|
|
|
|
fn add_bindings(&mut self, body: &Body, scope: ScopeId, binding: BindingId) {
|
|
let Binding { name, .. } = &body.bindings[binding];
|
|
let entry = self.scope_entries.alloc(ScopeEntry { name: name.clone(), binding });
|
|
self.scopes[scope].entries =
|
|
IdxRange::new_inclusive(self.scopes[scope].entries.start()..=entry);
|
|
}
|
|
|
|
fn add_pat_bindings(&mut self, body: &Body, scope: ScopeId, pat: PatId) {
|
|
let pattern = &body[pat];
|
|
if let Pat::Bind { id, .. } = pattern {
|
|
self.add_bindings(body, scope, *id);
|
|
}
|
|
|
|
pattern.walk_child_pats(|pat| self.add_pat_bindings(body, scope, pat));
|
|
}
|
|
|
|
fn add_params_bindings(&mut self, body: &Body, scope: ScopeId, params: &[PatId]) {
|
|
params.iter().for_each(|pat| self.add_pat_bindings(body, scope, *pat));
|
|
}
|
|
|
|
fn set_scope(&mut self, node: ExprId, scope: ScopeId) {
|
|
self.scope_by_expr.insert(node, scope);
|
|
}
|
|
|
|
fn shrink_to_fit(&mut self) {
|
|
let ExprScopes { scopes, scope_entries, scope_by_expr } = self;
|
|
scopes.shrink_to_fit();
|
|
scope_entries.shrink_to_fit();
|
|
scope_by_expr.shrink_to_fit();
|
|
}
|
|
}
|
|
|
|
fn compute_block_scopes(
|
|
statements: &[Statement],
|
|
tail: Option<ExprId>,
|
|
body: &Body,
|
|
scopes: &mut ExprScopes,
|
|
scope: &mut ScopeId,
|
|
) {
|
|
for stmt in statements {
|
|
match stmt {
|
|
Statement::Let { pat, initializer, else_branch, .. } => {
|
|
if let Some(expr) = initializer {
|
|
compute_expr_scopes(*expr, body, scopes, scope);
|
|
}
|
|
if let Some(expr) = else_branch {
|
|
compute_expr_scopes(*expr, body, scopes, scope);
|
|
}
|
|
|
|
*scope = scopes.new_scope(*scope);
|
|
scopes.add_pat_bindings(body, *scope, *pat);
|
|
}
|
|
Statement::Expr { expr, .. } => {
|
|
compute_expr_scopes(*expr, body, scopes, scope);
|
|
}
|
|
Statement::Item => (),
|
|
}
|
|
}
|
|
if let Some(expr) = tail {
|
|
compute_expr_scopes(expr, body, scopes, scope);
|
|
}
|
|
}
|
|
|
|
fn compute_expr_scopes(expr: ExprId, body: &Body, scopes: &mut ExprScopes, scope: &mut ScopeId) {
|
|
let make_label =
|
|
|label: &Option<LabelId>| label.map(|label| (label, body.labels[label].name.clone()));
|
|
|
|
scopes.set_scope(expr, *scope);
|
|
match &body[expr] {
|
|
Expr::Block { statements, tail, id, label } => {
|
|
let mut scope = scopes.new_block_scope(*scope, *id, make_label(label));
|
|
// Overwrite the old scope for the block expr, so that every block scope can be found
|
|
// via the block itself (important for blocks that only contain items, no expressions).
|
|
scopes.set_scope(expr, scope);
|
|
compute_block_scopes(statements, *tail, body, scopes, &mut scope);
|
|
}
|
|
Expr::Const(_) => {
|
|
// FIXME: This is broken.
|
|
}
|
|
Expr::Unsafe { id, statements, tail } | Expr::Async { id, statements, tail } => {
|
|
let mut scope = scopes.new_block_scope(*scope, *id, None);
|
|
// Overwrite the old scope for the block expr, so that every block scope can be found
|
|
// via the block itself (important for blocks that only contain items, no expressions).
|
|
scopes.set_scope(expr, scope);
|
|
compute_block_scopes(statements, *tail, body, scopes, &mut scope);
|
|
}
|
|
Expr::Loop { body: body_expr, label } => {
|
|
let mut scope = scopes.new_labeled_scope(*scope, make_label(label));
|
|
compute_expr_scopes(*body_expr, body, scopes, &mut scope);
|
|
}
|
|
Expr::Closure { args, body: body_expr, .. } => {
|
|
let mut scope = scopes.new_scope(*scope);
|
|
scopes.add_params_bindings(body, scope, args);
|
|
compute_expr_scopes(*body_expr, body, scopes, &mut scope);
|
|
}
|
|
Expr::Match { expr, arms } => {
|
|
compute_expr_scopes(*expr, body, scopes, scope);
|
|
for arm in arms.iter() {
|
|
let mut scope = scopes.new_scope(*scope);
|
|
scopes.add_pat_bindings(body, scope, arm.pat);
|
|
if let Some(guard) = arm.guard {
|
|
scope = scopes.new_scope(scope);
|
|
compute_expr_scopes(guard, body, scopes, &mut scope);
|
|
}
|
|
compute_expr_scopes(arm.expr, body, scopes, &mut scope);
|
|
}
|
|
}
|
|
&Expr::If { condition, then_branch, else_branch } => {
|
|
let mut then_branch_scope = scopes.new_scope(*scope);
|
|
compute_expr_scopes(condition, body, scopes, &mut then_branch_scope);
|
|
compute_expr_scopes(then_branch, body, scopes, &mut then_branch_scope);
|
|
if let Some(else_branch) = else_branch {
|
|
compute_expr_scopes(else_branch, body, scopes, scope);
|
|
}
|
|
}
|
|
&Expr::Let { pat, expr } => {
|
|
compute_expr_scopes(expr, body, scopes, scope);
|
|
*scope = scopes.new_scope(*scope);
|
|
scopes.add_pat_bindings(body, *scope, pat);
|
|
}
|
|
e => e.walk_child_exprs(|e| compute_expr_scopes(e, body, scopes, scope)),
|
|
};
|
|
}
|
|
|
|
#[cfg(test)]
|
|
mod tests {
|
|
use base_db::{FileId, SourceDatabase};
|
|
use hir_expand::{name::AsName, InFile};
|
|
use syntax::{algo::find_node_at_offset, ast, AstNode};
|
|
use test_fixture::WithFixture;
|
|
use test_utils::{assert_eq_text, extract_offset};
|
|
|
|
use crate::{db::DefDatabase, test_db::TestDB, FunctionId, ModuleDefId};
|
|
|
|
fn find_function(db: &TestDB, file_id: FileId) -> FunctionId {
|
|
let krate = db.test_crate();
|
|
let crate_def_map = db.crate_def_map(krate);
|
|
|
|
let module = crate_def_map.modules_for_file(file_id).next().unwrap();
|
|
let (_, def) = crate_def_map[module].scope.entries().next().unwrap();
|
|
match def.take_values().unwrap() {
|
|
ModuleDefId::FunctionId(it) => it,
|
|
_ => panic!(),
|
|
}
|
|
}
|
|
|
|
fn do_check(ra_fixture: &str, expected: &[&str]) {
|
|
let (offset, code) = extract_offset(ra_fixture);
|
|
let code = {
|
|
let mut buf = String::new();
|
|
let off: usize = offset.into();
|
|
buf.push_str(&code[..off]);
|
|
buf.push_str("$0marker");
|
|
buf.push_str(&code[off..]);
|
|
buf
|
|
};
|
|
|
|
let (db, position) = TestDB::with_position(&code);
|
|
let file_id = position.file_id;
|
|
let offset = position.offset;
|
|
|
|
let file_syntax = db.parse(file_id).syntax_node();
|
|
let marker: ast::PathExpr = find_node_at_offset(&file_syntax, offset).unwrap();
|
|
let function = find_function(&db, file_id);
|
|
|
|
let scopes = db.expr_scopes(function.into());
|
|
let (_body, source_map) = db.body_with_source_map(function.into());
|
|
|
|
let expr_id = source_map
|
|
.node_expr(InFile { file_id: file_id.into(), value: &marker.into() })
|
|
.unwrap();
|
|
let scope = scopes.scope_for(expr_id);
|
|
|
|
let actual = scopes
|
|
.scope_chain(scope)
|
|
.flat_map(|scope| scopes.entries(scope))
|
|
.map(|it| it.name().to_smol_str())
|
|
.collect::<Vec<_>>()
|
|
.join("\n");
|
|
let expected = expected.join("\n");
|
|
assert_eq_text!(&expected, &actual);
|
|
}
|
|
|
|
#[test]
|
|
fn test_lambda_scope() {
|
|
do_check(
|
|
r"
|
|
fn quux(foo: i32) {
|
|
let f = |bar, baz: i32| {
|
|
$0
|
|
};
|
|
}",
|
|
&["bar", "baz", "foo"],
|
|
);
|
|
}
|
|
|
|
#[test]
|
|
fn test_call_scope() {
|
|
do_check(
|
|
r"
|
|
fn quux() {
|
|
f(|x| $0 );
|
|
}",
|
|
&["x"],
|
|
);
|
|
}
|
|
|
|
#[test]
|
|
fn test_method_call_scope() {
|
|
do_check(
|
|
r"
|
|
fn quux() {
|
|
z.f(|x| $0 );
|
|
}",
|
|
&["x"],
|
|
);
|
|
}
|
|
|
|
#[test]
|
|
fn test_loop_scope() {
|
|
do_check(
|
|
r"
|
|
fn quux() {
|
|
loop {
|
|
let x = ();
|
|
$0
|
|
};
|
|
}",
|
|
&["x"],
|
|
);
|
|
}
|
|
|
|
#[test]
|
|
fn test_match() {
|
|
do_check(
|
|
r"
|
|
fn quux() {
|
|
match () {
|
|
Some(x) => {
|
|
$0
|
|
}
|
|
};
|
|
}",
|
|
&["x"],
|
|
);
|
|
}
|
|
|
|
#[test]
|
|
fn test_shadow_variable() {
|
|
do_check(
|
|
r"
|
|
fn foo(x: String) {
|
|
let x : &str = &x$0;
|
|
}",
|
|
&["x"],
|
|
);
|
|
}
|
|
|
|
#[test]
|
|
fn test_bindings_after_at() {
|
|
do_check(
|
|
r"
|
|
fn foo() {
|
|
match Some(()) {
|
|
opt @ Some(unit) => {
|
|
$0
|
|
}
|
|
_ => {}
|
|
}
|
|
}
|
|
",
|
|
&["opt", "unit"],
|
|
);
|
|
}
|
|
|
|
#[test]
|
|
fn macro_inner_item() {
|
|
do_check(
|
|
r"
|
|
macro_rules! mac {
|
|
() => {{
|
|
fn inner() {}
|
|
inner();
|
|
}};
|
|
}
|
|
|
|
fn foo() {
|
|
mac!();
|
|
$0
|
|
}
|
|
",
|
|
&[],
|
|
);
|
|
}
|
|
|
|
#[test]
|
|
fn broken_inner_item() {
|
|
do_check(
|
|
r"
|
|
fn foo() {
|
|
trait {}
|
|
$0
|
|
}
|
|
",
|
|
&[],
|
|
);
|
|
}
|
|
|
|
fn do_check_local_name(ra_fixture: &str, expected_offset: u32) {
|
|
let (db, position) = TestDB::with_position(ra_fixture);
|
|
let file_id = position.file_id;
|
|
let offset = position.offset;
|
|
|
|
let file = db.parse(file_id).ok().unwrap();
|
|
let expected_name = find_node_at_offset::<ast::Name>(file.syntax(), expected_offset.into())
|
|
.expect("failed to find a name at the target offset");
|
|
let name_ref: ast::NameRef = find_node_at_offset(file.syntax(), offset).unwrap();
|
|
|
|
let function = find_function(&db, file_id);
|
|
|
|
let scopes = db.expr_scopes(function.into());
|
|
let (body, source_map) = db.body_with_source_map(function.into());
|
|
|
|
let expr_scope = {
|
|
let expr_ast = name_ref.syntax().ancestors().find_map(ast::Expr::cast).unwrap();
|
|
let expr_id =
|
|
source_map.node_expr(InFile { file_id: file_id.into(), value: &expr_ast }).unwrap();
|
|
scopes.scope_for(expr_id).unwrap()
|
|
};
|
|
|
|
let resolved = scopes.resolve_name_in_scope(expr_scope, &name_ref.as_name()).unwrap();
|
|
let pat_src = source_map
|
|
.pat_syntax(*body.bindings[resolved.binding()].definitions.first().unwrap())
|
|
.unwrap();
|
|
|
|
let local_name = pat_src.value.syntax_node_ptr().to_node(file.syntax());
|
|
assert_eq!(local_name.text_range(), expected_name.syntax().text_range());
|
|
}
|
|
|
|
#[test]
|
|
fn test_resolve_local_name() {
|
|
do_check_local_name(
|
|
r#"
|
|
fn foo(x: i32, y: u32) {
|
|
{
|
|
let z = x * 2;
|
|
}
|
|
{
|
|
let t = x$0 * 3;
|
|
}
|
|
}
|
|
"#,
|
|
7,
|
|
);
|
|
}
|
|
|
|
#[test]
|
|
fn test_resolve_local_name_declaration() {
|
|
do_check_local_name(
|
|
r#"
|
|
fn foo(x: String) {
|
|
let x : &str = &x$0;
|
|
}
|
|
"#,
|
|
7,
|
|
);
|
|
}
|
|
|
|
#[test]
|
|
fn test_resolve_local_name_shadow() {
|
|
do_check_local_name(
|
|
r"
|
|
fn foo(x: String) {
|
|
let x : &str = &x;
|
|
x$0
|
|
}
|
|
",
|
|
28,
|
|
);
|
|
}
|
|
|
|
#[test]
|
|
fn ref_patterns_contribute_bindings() {
|
|
do_check_local_name(
|
|
r"
|
|
fn foo() {
|
|
if let Some(&from) = bar() {
|
|
from$0;
|
|
}
|
|
}
|
|
",
|
|
28,
|
|
);
|
|
}
|
|
|
|
#[test]
|
|
fn while_let_adds_binding() {
|
|
do_check_local_name(
|
|
r#"
|
|
fn test() {
|
|
let foo: Option<f32> = None;
|
|
while let Option::Some(spam) = foo {
|
|
spam$0
|
|
}
|
|
}
|
|
"#,
|
|
75,
|
|
);
|
|
do_check_local_name(
|
|
r#"
|
|
fn test() {
|
|
let foo: Option<f32> = None;
|
|
while (((let Option::Some(_) = foo))) && let Option::Some(spam) = foo {
|
|
spam$0
|
|
}
|
|
}
|
|
"#,
|
|
107,
|
|
);
|
|
}
|
|
|
|
#[test]
|
|
fn match_guard_if_let() {
|
|
do_check_local_name(
|
|
r#"
|
|
fn test() {
|
|
let foo: Option<f32> = None;
|
|
match foo {
|
|
_ if let Option::Some(spam) = foo => spam$0,
|
|
}
|
|
}
|
|
"#,
|
|
93,
|
|
);
|
|
}
|
|
|
|
#[test]
|
|
fn let_chains_can_reference_previous_lets() {
|
|
do_check_local_name(
|
|
r#"
|
|
fn test() {
|
|
let foo: Option<i32> = None;
|
|
if let Some(spam) = foo && spa$0m > 1 && let Some(spam) = foo && spam > 1 {}
|
|
}
|
|
"#,
|
|
61,
|
|
);
|
|
do_check_local_name(
|
|
r#"
|
|
fn test() {
|
|
let foo: Option<i32> = None;
|
|
if let Some(spam) = foo && spam > 1 && let Some(spam) = foo && sp$0am > 1 {}
|
|
}
|
|
"#,
|
|
100,
|
|
);
|
|
}
|
|
}
|