From ac92973a6c5934377c6eca9906f3b7f17e220d4e Mon Sep 17 00:00:00 2001 From: Aleksey Kladov Date: Tue, 8 Jan 2019 20:11:13 +0300 Subject: move function to code_model_api --- .../ra_hir/src/code_model_impl/function/scope.rs | 481 +++++++++++++++++++++ 1 file changed, 481 insertions(+) create mode 100644 crates/ra_hir/src/code_model_impl/function/scope.rs (limited to 'crates/ra_hir/src/code_model_impl/function') diff --git a/crates/ra_hir/src/code_model_impl/function/scope.rs b/crates/ra_hir/src/code_model_impl/function/scope.rs new file mode 100644 index 000000000..699784f71 --- /dev/null +++ b/crates/ra_hir/src/code_model_impl/function/scope.rs @@ -0,0 +1,481 @@ +use std::sync::Arc; + +use rustc_hash::{FxHashMap, FxHashSet}; + +use ra_syntax::{ + AstNode, SyntaxNode, TextUnit, TextRange, + algo::generate, + ast, +}; +use ra_arena::{Arena, RawId, impl_arena_id}; +use ra_db::LocalSyntaxPtr; + +use crate::{Name, AsName, expr::{PatId, ExprId, Pat, Expr, Body, Statement, BodySyntaxMapping}}; + +#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)] +pub struct ScopeId(RawId); +impl_arena_id!(ScopeId); + +#[derive(Debug, PartialEq, Eq)] +pub struct FnScopes { + body: Arc, + scopes: Arena, + scope_for: FxHashMap, +} + +#[derive(Debug, PartialEq, Eq)] +pub struct ScopeEntry { + name: Name, + pat: PatId, +} + +#[derive(Debug, PartialEq, Eq)] +pub struct ScopeData { + parent: Option, + entries: Vec, +} + +impl FnScopes { + pub(crate) fn new(body: Arc) -> FnScopes { + let mut scopes = FnScopes { + body: body.clone(), + scopes: Arena::default(), + scope_for: FxHashMap::default(), + }; + let root = scopes.root_scope(); + scopes.add_params_bindings(root, body.args()); + compute_expr_scopes(body.body_expr(), &body, &mut scopes, root); + scopes + } + pub fn entries(&self, scope: ScopeId) -> &[ScopeEntry] { + &self.scopes[scope].entries + } + pub fn scope_chain_for<'a>(&'a self, expr: ExprId) -> impl Iterator + 'a { + generate(self.scope_for(expr), move |&scope| { + self.scopes[scope].parent + }) + } + + pub fn resolve_local_name<'a>( + &'a self, + context_expr: ExprId, + name: Name, + ) -> Option<&'a ScopeEntry> { + let mut shadowed = FxHashSet::default(); + let ret = self + .scope_chain_for(context_expr) + .flat_map(|scope| self.entries(scope).iter()) + .filter(|entry| shadowed.insert(entry.name())) + .find(|entry| entry.name() == &name); + ret + } + + 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 } => self.scopes[scope].entries.push(ScopeEntry { + name: name.clone(), + pat, + }), + 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 + .into_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); + } + fn scope_for(&self, expr: ExprId) -> Option { + self.scope_for.get(&expr).map(|&scope| scope) + } +} + +#[derive(Debug, Clone, PartialEq, Eq)] +pub struct ScopesWithSyntaxMapping { + pub syntax_mapping: Arc, + pub scopes: Arc, +} + +#[derive(Debug, Clone, PartialEq, Eq)] +pub struct ScopeEntryWithSyntax { + name: Name, + ptr: LocalSyntaxPtr, +} + +impl ScopeEntryWithSyntax { + pub fn name(&self) -> &Name { + &self.name + } + pub fn ptr(&self) -> LocalSyntaxPtr { + self.ptr + } +} + +impl ScopesWithSyntaxMapping { + pub fn scope_chain<'a>(&'a self, node: &SyntaxNode) -> impl Iterator + 'a { + generate(self.scope_for(node), move |&scope| { + self.scopes.scopes[scope].parent + }) + } + pub fn scope_chain_for_offset<'a>( + &'a self, + offset: TextUnit, + ) -> impl Iterator + 'a { + let scope = self + .scopes + .scope_for + .iter() + .filter_map(|(id, scope)| Some((self.syntax_mapping.expr_syntax(*id)?, scope))) + // find containing scope + .min_by_key(|(ptr, _scope)| { + ( + !(ptr.range().start() <= offset && offset <= ptr.range().end()), + ptr.range().len(), + ) + }) + .map(|(ptr, scope)| self.adjust(ptr, *scope, offset)); + + generate(scope, move |&scope| self.scopes.scopes[scope].parent) + } + // XXX: during completion, cursor might be outside of any particular + // expression. Try to figure out the correct scope... + fn adjust(&self, ptr: LocalSyntaxPtr, original_scope: ScopeId, offset: TextUnit) -> ScopeId { + let r = ptr.range(); + let child_scopes = self + .scopes + .scope_for + .iter() + .filter_map(|(id, scope)| Some((self.syntax_mapping.expr_syntax(*id)?, scope))) + .map(|(ptr, scope)| (ptr.range(), scope)) + .filter(|(range, _)| range.start() <= offset && range.is_subrange(&r) && *range != r); + + child_scopes + .max_by(|(r1, _), (r2, _)| { + if r2.is_subrange(&r1) { + std::cmp::Ordering::Greater + } else if r1.is_subrange(&r2) { + std::cmp::Ordering::Less + } else { + r1.start().cmp(&r2.start()) + } + }) + .map(|(_ptr, scope)| *scope) + .unwrap_or(original_scope) + } + + pub fn resolve_local_name(&self, name_ref: &ast::NameRef) -> Option { + let mut shadowed = FxHashSet::default(); + let name = name_ref.as_name(); + let ret = self + .scope_chain(name_ref.syntax()) + .flat_map(|scope| self.scopes.entries(scope).iter()) + .filter(|entry| shadowed.insert(entry.name())) + .filter(|entry| entry.name() == &name) + .nth(0); + ret.and_then(|entry| { + Some(ScopeEntryWithSyntax { + name: entry.name().clone(), + ptr: self.syntax_mapping.pat_syntax(entry.pat())?, + }) + }) + } + + pub fn find_all_refs(&self, pat: &ast::BindPat) -> Vec { + let fn_def = pat.syntax().ancestors().find_map(ast::FnDef::cast).unwrap(); + let name_ptr = LocalSyntaxPtr::new(pat.syntax()); + fn_def + .syntax() + .descendants() + .filter_map(ast::NameRef::cast) + .filter(|name_ref| match self.resolve_local_name(*name_ref) { + None => false, + Some(entry) => entry.ptr() == name_ptr, + }) + .map(|name_ref| ReferenceDescriptor { + name: name_ref.syntax().text().to_string(), + range: name_ref.syntax().range(), + }) + .collect() + } + + fn scope_for(&self, node: &SyntaxNode) -> Option { + node.ancestors() + .map(LocalSyntaxPtr::new) + .filter_map(|ptr| self.syntax_mapping.syntax_expr(ptr)) + .find_map(|it| self.scopes.scope_for(it)) + } +} + +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 FnScopes, + 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 FnScopes, 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_editor::find_node_at_offset; + use ra_syntax::SourceFile; + use test_utils::{extract_offset, assert_eq_text}; + + use crate::expr; + + 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 file = SourceFile::parse(&code); + let marker: &ast::PathExpr = find_node_at_offset(file.syntax(), off).unwrap(); + let fn_def: &ast::FnDef = find_node_at_offset(file.syntax(), off).unwrap(); + let body_hir = expr::collect_fn_body_syntax(fn_def); + let scopes = FnScopes::new(Arc::clone(body_hir.body())); + let scopes = ScopesWithSyntaxMapping { + scopes: Arc::new(scopes), + syntax_mapping: Arc::new(body_hir), + }; + let actual = scopes + .scope_chain(marker.syntax()) + .flat_map(|scope| scopes.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 file = SourceFile::parse(&code); + let fn_def: &ast::FnDef = find_node_at_offset(file.syntax(), off).unwrap(); + let name_ref: &ast::NameRef = find_node_at_offset(file.syntax(), off).unwrap(); + + let body_hir = expr::collect_fn_body_syntax(fn_def); + let scopes = FnScopes::new(Arc::clone(body_hir.body())); + let scopes = ScopesWithSyntaxMapping { + scopes: Arc::new(scopes), + syntax_mapping: Arc::new(body_hir), + }; + + let local_name_entry = scopes.resolve_local_name(name_ref).unwrap(); + let local_name = local_name_entry.ptr(); + let expected_name = + find_node_at_offset::(file.syntax(), expected_offset.into()).unwrap(); + 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<|> + }", + 46, + ); + } +} -- cgit v1.2.3