1 //! A module with ide helpers for high-level ide features.
3 pub mod generated_lints;
7 pub mod insert_whitespace_into_node;
11 use std::{collections::VecDeque, iter};
14 use hir::{ItemInNs, MacroDef, ModuleDef, Name, PathResolution, Semantics};
15 use itertools::Itertools;
17 ast::{self, make, HasLoopBody},
18 AstNode, AstToken, Direction, SyntaxElement, SyntaxKind, SyntaxToken, TokenAtOffset, WalkEvent,
22 use crate::{defs::Definition, RootDatabase};
24 pub use self::famous_defs::FamousDefs;
26 pub fn item_name(db: &RootDatabase, item: ItemInNs) -> Option<Name> {
28 ItemInNs::Types(module_def_id) => ModuleDef::from(module_def_id).name(db),
29 ItemInNs::Values(module_def_id) => ModuleDef::from(module_def_id).name(db),
30 ItemInNs::Macros(macro_def_id) => MacroDef::from(macro_def_id).name(db),
34 /// Parses and returns the derive path at the cursor position in the given attribute, if it is a derive.
35 /// This special case is required because the derive macro is a compiler builtin that discards the input derives.
37 /// The returned path is synthesized from TokenTree tokens and as such cannot be used with the [`Semantics`].
38 pub fn get_path_in_derive_attr(
39 sema: &hir::Semantics<RootDatabase>,
42 ) -> Option<ast::Path> {
43 let path = attr.path()?;
44 let tt = attr.token_tree()?;
45 if !tt.syntax().text_range().contains_range(cursor.syntax().text_range()) {
48 let scope = sema.scope(attr.syntax());
49 let resolved_attr = sema.resolve_path(&path)?;
50 let derive = FamousDefs(sema, scope.krate()).core_macros_builtin_derive()?;
51 if PathResolution::Macro(derive) != resolved_attr {
54 get_path_at_cursor_in_tt(cursor)
57 /// Parses the path the identifier is part of inside a token tree.
58 pub fn get_path_at_cursor_in_tt(cursor: &ast::Ident) -> Option<ast::Path> {
59 let cursor = cursor.syntax();
61 .siblings_with_tokens(Direction::Prev)
62 .filter_map(SyntaxElement::into_token)
63 .take_while(|tok| tok.kind() != T!['('] && tok.kind() != T![,])
65 let path_tokens = first
66 .siblings_with_tokens(Direction::Next)
67 .filter_map(SyntaxElement::into_token)
68 .take_while(|tok| tok != cursor);
70 syntax::hacks::parse_expr_from_str(&path_tokens.chain(iter::once(cursor.clone())).join(""))
71 .and_then(|expr| match expr {
72 ast::Expr::PathExpr(it) => it.path(),
77 /// Parses and resolves the path at the cursor position in the given attribute, if it is a derive.
78 /// This special case is required because the derive macro is a compiler builtin that discards the input derives.
79 pub fn try_resolve_derive_input(
80 sema: &hir::Semantics<RootDatabase>,
83 ) -> Option<PathResolution> {
84 let path = get_path_in_derive_attr(sema, attr, cursor)?;
85 let scope = sema.scope(attr.syntax());
86 // FIXME: This double resolve shouldn't be necessary
87 // It's only here so we prefer macros over other namespaces
88 match scope.speculative_resolve_as_mac(&path) {
89 Some(mac) if mac.kind() == hir::MacroKind::Derive => Some(PathResolution::Macro(mac)),
90 Some(_) => return None,
92 .speculative_resolve(&path)
93 .filter(|res| matches!(res, PathResolution::Def(ModuleDef::Module(_)))),
97 /// Picks the token with the highest rank returned by the passed in function.
98 pub fn pick_best_token(
99 tokens: TokenAtOffset<SyntaxToken>,
100 f: impl Fn(SyntaxKind) -> usize,
101 ) -> Option<SyntaxToken> {
102 tokens.max_by_key(move |t| f(t.kind()))
105 /// Converts the mod path struct into its ast representation.
106 pub fn mod_path_to_ast(path: &hir::ModPath) -> ast::Path {
107 let _p = profile::span("mod_path_to_ast");
109 let mut segments = Vec::new();
110 let mut is_abs = false;
112 hir::PathKind::Plain => {}
113 hir::PathKind::Super(0) => segments.push(make::path_segment_self()),
114 hir::PathKind::Super(n) => segments.extend((0..n).map(|_| make::path_segment_super())),
115 hir::PathKind::DollarCrate(_) | hir::PathKind::Crate => {
116 segments.push(make::path_segment_crate())
118 hir::PathKind::Abs => is_abs = true,
124 .map(|segment| make::path_segment(make::name_ref(&segment.to_smol_str()))),
126 make::path_from_segments(segments, is_abs)
129 /// Iterates all `ModuleDef`s and `Impl` blocks of the given file.
130 pub fn visit_file_defs(
131 sema: &Semantics<RootDatabase>,
133 cb: &mut dyn FnMut(Definition),
136 let module = match sema.to_module_def(file_id) {
140 let mut defs: VecDeque<_> = module.declarations(db).into();
141 while let Some(def) = defs.pop_front() {
142 if let ModuleDef::Module(submodule) = def {
143 if let hir::ModuleSource::Module(_) = submodule.definition_source(db).value {
144 defs.extend(submodule.declarations(db));
145 submodule.impl_defs(db).into_iter().for_each(|impl_| cb(impl_.into()));
150 module.impl_defs(db).into_iter().for_each(|impl_| cb(impl_.into()));
153 #[derive(Clone, Copy, Debug, PartialEq, Eq)]
154 pub struct SnippetCap {
159 pub const fn new(allow_snippets: bool) -> Option<SnippetCap> {
161 Some(SnippetCap { _private: () })
168 /// Calls `cb` on each expression inside `expr` that is at "tail position".
169 /// Does not walk into `break` or `return` expressions.
170 /// Note that modifying the tree while iterating it will cause undefined iteration which might
171 /// potentially results in an out of bounds panic.
172 pub fn for_each_tail_expr(expr: &ast::Expr, cb: &mut dyn FnMut(&ast::Expr)) {
174 ast::Expr::BlockExpr(b) => {
177 ast::BlockModifier::Async(_)
178 | ast::BlockModifier::Try(_)
179 | ast::BlockModifier::Const(_),
180 ) => return cb(expr),
182 Some(ast::BlockModifier::Label(label)) => {
183 for_each_break_expr(Some(label), b.stmt_list(), &mut |b| {
184 cb(&ast::Expr::BreakExpr(b))
187 Some(ast::BlockModifier::Unsafe(_)) => (),
190 if let Some(stmt_list) = b.stmt_list() {
191 if let Some(e) = stmt_list.tail_expr() {
192 for_each_tail_expr(&e, cb);
196 ast::Expr::IfExpr(if_) => {
197 let mut if_ = if_.clone();
199 if let Some(block) = if_.then_branch() {
200 for_each_tail_expr(&ast::Expr::BlockExpr(block), cb);
202 match if_.else_branch() {
203 Some(ast::ElseBranch::IfExpr(it)) => if_ = it,
204 Some(ast::ElseBranch::Block(block)) => {
205 for_each_tail_expr(&ast::Expr::BlockExpr(block), cb);
212 ast::Expr::LoopExpr(l) => {
213 for_each_break_expr(l.label(), l.loop_body().and_then(|it| it.stmt_list()), &mut |b| {
214 cb(&ast::Expr::BreakExpr(b))
217 ast::Expr::MatchExpr(m) => {
218 if let Some(arms) = m.match_arm_list() {
219 arms.arms().filter_map(|arm| arm.expr()).for_each(|e| for_each_tail_expr(&e, cb));
222 ast::Expr::ArrayExpr(_)
223 | ast::Expr::AwaitExpr(_)
224 | ast::Expr::BinExpr(_)
225 | ast::Expr::BoxExpr(_)
226 | ast::Expr::BreakExpr(_)
227 | ast::Expr::CallExpr(_)
228 | ast::Expr::CastExpr(_)
229 | ast::Expr::ClosureExpr(_)
230 | ast::Expr::ContinueExpr(_)
231 | ast::Expr::FieldExpr(_)
232 | ast::Expr::ForExpr(_)
233 | ast::Expr::IndexExpr(_)
234 | ast::Expr::Literal(_)
235 | ast::Expr::MacroCall(_)
236 | ast::Expr::MacroStmts(_)
237 | ast::Expr::MethodCallExpr(_)
238 | ast::Expr::ParenExpr(_)
239 | ast::Expr::PathExpr(_)
240 | ast::Expr::PrefixExpr(_)
241 | ast::Expr::RangeExpr(_)
242 | ast::Expr::RecordExpr(_)
243 | ast::Expr::RefExpr(_)
244 | ast::Expr::ReturnExpr(_)
245 | ast::Expr::TryExpr(_)
246 | ast::Expr::TupleExpr(_)
247 | ast::Expr::WhileExpr(_)
248 | ast::Expr::YieldExpr(_) => cb(expr),
252 /// Calls `cb` on each break expr inside of `body` that is applicable for the given label.
253 pub fn for_each_break_expr(
254 label: Option<ast::Label>,
255 body: Option<ast::StmtList>,
256 cb: &mut dyn FnMut(ast::BreakExpr),
258 let label = label.and_then(|lbl| lbl.lifetime());
260 if let Some(b) = body {
261 let preorder = &mut b.syntax().preorder();
262 let ev_as_expr = |ev| match ev {
263 WalkEvent::Enter(it) => Some(WalkEvent::Enter(ast::Expr::cast(it)?)),
264 WalkEvent::Leave(it) => Some(WalkEvent::Leave(ast::Expr::cast(it)?)),
266 let eq_label = |lt: Option<ast::Lifetime>| {
267 lt.zip(label.as_ref()).map_or(false, |(lt, lbl)| lt.text() == lbl.text())
269 while let Some(node) = preorder.find_map(ev_as_expr) {
271 WalkEvent::Enter(expr) => match expr {
272 ast::Expr::LoopExpr(_) | ast::Expr::WhileExpr(_) | ast::Expr::ForExpr(_) => {
275 ast::Expr::BlockExpr(e) if e.label().is_some() => depth += 1,
276 ast::Expr::BreakExpr(b)
277 if (depth == 0 && b.lifetime().is_none()) || eq_label(b.lifetime()) =>
283 WalkEvent::Leave(expr) => match expr {
284 ast::Expr::LoopExpr(_) | ast::Expr::WhileExpr(_) | ast::Expr::ForExpr(_) => {
287 ast::Expr::BlockExpr(e) if e.label().is_some() => depth -= 1,
295 /// Checks if the given lint is equal or is contained by the other lint which may or may not be a group.
296 pub fn lint_eq_or_in_group(lint: &str, lint_is: &str) -> bool {
301 if let Some(group) = generated_lints::DEFAULT_LINT_GROUPS
303 .chain(generated_lints::CLIPPY_LINT_GROUPS.iter())
304 .chain(generated_lints::RUSTDOC_LINT_GROUPS.iter())
305 .find(|&check| check.lint.label == lint_is)
307 group.children.contains(&lint)
313 /// Parses the input token tree as comma separated plain paths.
314 pub fn parse_tt_as_comma_sep_paths(input: ast::TokenTree) -> Option<Vec<ast::Path>> {
315 let r_paren = input.r_paren_token();
317 input.syntax().children_with_tokens().skip(1).map_while(|it| match it.into_token() {
318 // seeing a keyword means the attribute is unclosed so stop parsing here
319 Some(tok) if tok.kind().is_keyword() => None,
320 // don't include the right token tree parenthesis if it exists
321 tok @ Some(_) if tok == r_paren => None,
322 // only nodes that we can find are other TokenTrees, those are unexpected in this parse though
324 Some(tok) => Some(tok),
326 let input_expressions = tokens.into_iter().group_by(|tok| tok.kind() == T![,]);
327 let paths = input_expressions
329 .filter_map(|(is_sep, group)| (!is_sep).then(|| group))
330 .filter_map(|mut tokens| {
331 syntax::hacks::parse_expr_from_str(&tokens.join("")).and_then(|expr| match expr {
332 ast::Expr::PathExpr(it) => it.path(),