use std::sync::Arc;
use rustc_hash::{FxHashMap};
use ra_syntax::{
TextRange, AstPtr,
ast,
};
use ra_arena::{Arena, RawId, impl_arena_id};
use crate::{
Name, DefWithBody, Either,
expr::{PatId, ExprId, Pat, Expr, Body, Statement},
HirDatabase,
};
#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
pub struct ScopeId(RawId);
impl_arena_id!(ScopeId);
#[derive(Debug, PartialEq, Eq)]
pub struct ExprScopes {
body: Arc
,
scopes: Arena,
pub(crate) scope_for: FxHashMap,
}
#[derive(Debug, PartialEq, Eq)]
pub(crate) struct ScopeEntry {
name: Name,
pat: PatId,
}
#[derive(Debug, PartialEq, Eq)]
pub(crate) struct ScopeData {
parent: Option,
entries: Vec,
}
impl ExprScopes {
pub(crate) fn expr_scopes_query(db: &impl HirDatabase, def: DefWithBody) -> Arc {
let body = db.body_hir(def);
let res = ExprScopes::new(body);
Arc::new(res)
}
fn new(body: Arc) -> ExprScopes {
let mut scopes = ExprScopes {
body: body.clone(),
scopes: Arena::default(),
scope_for: FxHashMap::default(),
};
let root = scopes.root_scope();
scopes.add_params_bindings(root, body.params());
compute_expr_scopes(body.body_expr(), &body, &mut scopes, root);
scopes
}
pub(crate) fn entries(&self, scope: ScopeId) -> &[ScopeEntry] {
&self.scopes[scope].entries
}
pub(crate) fn scope_chain<'a>(
&'a self,
scope: Option,
) -> impl Iterator- + 'a {
std::iter::successors(scope, move |&scope| self.scopes[scope].parent)
}
fn root_scope(&mut self) -> ScopeId {
self.scopes.alloc(ScopeData { parent: None, entries: vec![] })
}
fn new_scope(&mut self, parent: ScopeId) -> ScopeId {
self.scopes.alloc(ScopeData { parent: Some(parent), entries: vec![] })
}
fn add_bindings(&mut self, body: &Body, scope: ScopeId, pat: PatId) {
match &body[pat] {
Pat::Bind { name, .. } => {
// bind can have a sub pattern, but it's actually not allowed
// to bind to things in there
let entry = ScopeEntry { name: name.clone(), pat };
self.scopes[scope].entries.push(entry)
}
p => p.walk_child_pats(|pat| self.add_bindings(body, scope, pat)),
}
}
fn add_params_bindings(&mut self, scope: ScopeId, params: &[PatId]) {
let body = Arc::clone(&self.body);
params.iter().for_each(|pat| self.add_bindings(&body, scope, *pat));
}
fn set_scope(&mut self, node: ExprId, scope: ScopeId) {
self.scope_for.insert(node, scope);
}
pub(crate) fn scope_for(&self, expr: ExprId) -> Option {
self.scope_for.get(&expr).map(|&scope| scope)
}
}
#[derive(Debug, Clone, PartialEq, Eq)]
pub struct ScopeEntryWithSyntax {
pub(crate) name: Name,
pub(crate) ptr: Either, AstPtr>,
}
impl ScopeEntryWithSyntax {
pub fn name(&self) -> &Name {
&self.name
}
pub fn ptr(&self) -> Either, AstPtr> {
self.ptr
}
}
impl ScopeEntry {
pub fn name(&self) -> &Name {
&self.name
}
pub fn pat(&self) -> PatId {
self.pat
}
}
fn compute_block_scopes(
statements: &[Statement],
tail: Option,
body: &Body,
scopes: &mut ExprScopes,
mut scope: ScopeId,
) {
for stmt in statements {
match stmt {
Statement::Let { pat, initializer, .. } => {
if let Some(expr) = initializer {
scopes.set_scope(*expr, scope);
compute_expr_scopes(*expr, body, scopes, scope);
}
scope = scopes.new_scope(scope);
scopes.add_bindings(body, scope, *pat);
}
Statement::Expr(expr) => {
scopes.set_scope(*expr, scope);
compute_expr_scopes(*expr, body, scopes, scope);
}
}
}
if let Some(expr) = tail {
compute_expr_scopes(expr, body, scopes, scope);
}
}
fn compute_expr_scopes(expr: ExprId, body: &Body, scopes: &mut ExprScopes, scope: ScopeId) {
scopes.set_scope(expr, scope);
match &body[expr] {
Expr::Block { statements, tail } => {
compute_block_scopes(&statements, *tail, body, scopes, scope);
}
Expr::For { iterable, pat, body: body_expr } => {
compute_expr_scopes(*iterable, body, scopes, scope);
let scope = scopes.new_scope(scope);
scopes.add_bindings(body, scope, *pat);
compute_expr_scopes(*body_expr, body, scopes, scope);
}
Expr::Lambda { args, body: body_expr, .. } => {
let scope = scopes.new_scope(scope);
scopes.add_params_bindings(scope, &args);
compute_expr_scopes(*body_expr, body, scopes, scope);
}
Expr::Match { expr, arms } => {
compute_expr_scopes(*expr, body, scopes, scope);
for arm in arms {
let scope = scopes.new_scope(scope);
for pat in &arm.pats {
scopes.add_bindings(body, scope, *pat);
}
scopes.set_scope(arm.expr, scope);
compute_expr_scopes(arm.expr, body, scopes, scope);
}
}
e => e.walk_child_exprs(|e| compute_expr_scopes(e, body, scopes, scope)),
};
}
#[derive(Debug)]
pub struct ReferenceDescriptor {
pub range: TextRange,
pub name: String,
}
#[cfg(test)]
mod tests {
use ra_db::SourceDatabase;
use ra_syntax::{algo::find_node_at_offset, AstNode, SyntaxNodePtr};
use test_utils::{extract_offset, assert_eq_text};
use crate::{source_binder::SourceAnalyzer, mock::MockDatabase};
use super::*;
fn do_check(code: &str, expected: &[&str]) {
let (off, code) = extract_offset(code);
let code = {
let mut buf = String::new();
let off = u32::from(off) as usize;
buf.push_str(&code[..off]);
buf.push_str("marker");
buf.push_str(&code[off..]);
buf
};
let (db, _source_root, file_id) = MockDatabase::with_single_file(&code);
let file = db.parse(file_id);
let marker: &ast::PathExpr = find_node_at_offset(file.syntax(), off).unwrap();
let analyzer = SourceAnalyzer::new(&db, file_id, marker.syntax(), None);
let scopes = analyzer.scopes();
let expr_id =
analyzer.body_source_map().syntax_expr(SyntaxNodePtr::new(marker.syntax())).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_string())
.collect::>()
.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| {
<|>
};
}",
&["bar", "baz", "foo"],
);
}
#[test]
fn test_call_scope() {
do_check(
r"
fn quux() {
f(|x| <|> );
}",
&["x"],
);
}
#[test]
fn test_method_call_scope() {
do_check(
r"
fn quux() {
z.f(|x| <|> );
}",
&["x"],
);
}
#[test]
fn test_loop_scope() {
do_check(
r"
fn quux() {
loop {
let x = ();
<|>
};
}",
&["x"],
);
}
#[test]
fn test_match() {
do_check(
r"
fn quux() {
match () {
Some(x) => {
<|>
}
};
}",
&["x"],
);
}
#[test]
fn test_shadow_variable() {
do_check(
r"
fn foo(x: String) {
let x : &str = &x<|>;
}",
&["x"],
);
}
fn do_check_local_name(code: &str, expected_offset: u32) {
let (off, code) = extract_offset(code);
let (db, _source_root, file_id) = MockDatabase::with_single_file(&code);
let file = db.parse(file_id);
let expected_name = find_node_at_offset::(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(), off).unwrap();
let analyzer = SourceAnalyzer::new(&db, file_id, name_ref.syntax(), None);
let local_name_entry = analyzer.resolve_local_name(name_ref).unwrap();
let local_name =
local_name_entry.ptr().either(|it| it.syntax_node_ptr(), |it| it.syntax_node_ptr());
assert_eq!(local_name.range(), expected_name.syntax().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<|> * 3;
}
}"#,
21,
);
}
#[test]
fn test_resolve_local_name_declaration() {
do_check_local_name(
r#"
fn foo(x: String) {
let x : &str = &x<|>;
}"#,
21,
);
}
#[test]
fn test_resolve_local_name_shadow() {
do_check_local_name(
r"
fn foo(x: String) {
let x : &str = &x;
x<|>
}
",
53,
);
}
#[test]
fn ref_patterns_contribute_bindings() {
do_check_local_name(
r"
fn foo() {
if let Some(&from) = bar() {
from<|>;
}
}
",
53,
);
}
}