ide_db/
path_transform.rs

1//! See [`PathTransform`].
2
3use crate::helpers::mod_path_to_ast;
4use either::Either;
5use hir::{
6    AsAssocItem, FindPathConfig, HirDisplay, HirFileId, ModuleDef, SemanticsScope,
7    prettify_macro_expansion,
8};
9use itertools::Itertools;
10use rustc_hash::FxHashMap;
11use span::Edition;
12use syntax::{
13    NodeOrToken, SyntaxNode,
14    ast::{self, AstNode, HasGenericArgs, HasName, make},
15    syntax_editor::{self, SyntaxEditor},
16};
17
18#[derive(Default, Debug)]
19struct AstSubsts {
20    types_and_consts: Vec<TypeOrConst>,
21    lifetimes: Vec<ast::LifetimeArg>,
22}
23
24#[derive(Debug)]
25enum TypeOrConst {
26    Either(ast::TypeArg), // indistinguishable type or const param
27    Const(ast::ConstArg),
28}
29
30type LifetimeName = String;
31type DefaultedParam = Either<hir::TypeParam, hir::ConstParam>;
32
33/// `PathTransform` substitutes path in SyntaxNodes in bulk.
34///
35/// This is mostly useful for IDE code generation. If you paste some existing
36/// code into a new context (for example, to add method overrides to an `impl`
37/// block), you generally want to appropriately qualify the names, and sometimes
38/// you might want to substitute generic parameters as well:
39///
40/// ```ignore
41/// mod x {
42///   pub struct A<V>;
43///   pub trait T<U> { fn foo(&self, _: U) -> A<U>; }
44/// }
45///
46/// mod y {
47///   use x::T;
48///
49///   impl T<()> for () {
50///      // If we invoke **Add Missing Members** here, we want to copy-paste `foo`.
51///      // But we want a slightly-modified version of it:
52///      fn foo(&self, _: ()) -> x::A<()> {}
53///   }
54/// }
55/// ```
56pub struct PathTransform<'a> {
57    generic_def: Option<hir::GenericDef>,
58    substs: AstSubsts,
59    target_scope: &'a SemanticsScope<'a>,
60    source_scope: &'a SemanticsScope<'a>,
61}
62
63impl<'a> PathTransform<'a> {
64    pub fn trait_impl(
65        target_scope: &'a SemanticsScope<'a>,
66        source_scope: &'a SemanticsScope<'a>,
67        trait_: hir::Trait,
68        impl_: ast::Impl,
69    ) -> PathTransform<'a> {
70        PathTransform {
71            source_scope,
72            target_scope,
73            generic_def: Some(trait_.into()),
74            substs: get_syntactic_substs(impl_).unwrap_or_default(),
75        }
76    }
77
78    pub fn function_call(
79        target_scope: &'a SemanticsScope<'a>,
80        source_scope: &'a SemanticsScope<'a>,
81        function: hir::Function,
82        generic_arg_list: ast::GenericArgList,
83    ) -> PathTransform<'a> {
84        PathTransform {
85            source_scope,
86            target_scope,
87            generic_def: Some(function.into()),
88            substs: get_type_args_from_arg_list(generic_arg_list).unwrap_or_default(),
89        }
90    }
91
92    pub fn impl_transformation(
93        target_scope: &'a SemanticsScope<'a>,
94        source_scope: &'a SemanticsScope<'a>,
95        impl_: hir::Impl,
96        generic_arg_list: ast::GenericArgList,
97    ) -> PathTransform<'a> {
98        PathTransform {
99            source_scope,
100            target_scope,
101            generic_def: Some(impl_.into()),
102            substs: get_type_args_from_arg_list(generic_arg_list).unwrap_or_default(),
103        }
104    }
105
106    pub fn adt_transformation(
107        target_scope: &'a SemanticsScope<'a>,
108        source_scope: &'a SemanticsScope<'a>,
109        adt: hir::Adt,
110        generic_arg_list: ast::GenericArgList,
111    ) -> PathTransform<'a> {
112        PathTransform {
113            source_scope,
114            target_scope,
115            generic_def: Some(adt.into()),
116            substs: get_type_args_from_arg_list(generic_arg_list).unwrap_or_default(),
117        }
118    }
119
120    pub fn generic_transformation(
121        target_scope: &'a SemanticsScope<'a>,
122        source_scope: &'a SemanticsScope<'a>,
123    ) -> PathTransform<'a> {
124        PathTransform {
125            source_scope,
126            target_scope,
127            generic_def: None,
128            substs: AstSubsts::default(),
129        }
130    }
131
132    #[must_use]
133    pub fn apply(&self, syntax: &SyntaxNode) -> SyntaxNode {
134        self.build_ctx().apply(syntax)
135    }
136
137    #[must_use]
138    pub fn apply_all<'b>(
139        &self,
140        nodes: impl IntoIterator<Item = &'b SyntaxNode>,
141    ) -> Vec<SyntaxNode> {
142        let ctx = self.build_ctx();
143        nodes.into_iter().map(|node| ctx.apply(&node.clone())).collect()
144    }
145
146    fn prettify_target_node(&self, node: SyntaxNode) -> SyntaxNode {
147        match self.target_scope.file_id() {
148            HirFileId::FileId(_) => node,
149            HirFileId::MacroFile(file_id) => {
150                let db = self.target_scope.db;
151                prettify_macro_expansion(
152                    db,
153                    node,
154                    &db.expansion_span_map(file_id),
155                    self.target_scope.module().krate(db).into(),
156                )
157            }
158        }
159    }
160
161    fn prettify_target_ast<N: AstNode>(&self, node: N) -> N {
162        N::cast(self.prettify_target_node(node.syntax().clone())).unwrap()
163    }
164
165    fn build_ctx(&self) -> Ctx<'a> {
166        let db = self.source_scope.db;
167        let target_module = self.target_scope.module();
168        let source_module = self.source_scope.module();
169        let skip = match self.generic_def {
170            // this is a trait impl, so we need to skip the first type parameter (i.e. Self) -- this is a bit hacky
171            Some(hir::GenericDef::Trait(_)) => 1,
172            _ => 0,
173        };
174        let mut type_substs: FxHashMap<hir::TypeParam, ast::Type> = Default::default();
175        let mut const_substs: FxHashMap<hir::ConstParam, SyntaxNode> = Default::default();
176        let mut defaulted_params: Vec<DefaultedParam> = Default::default();
177        let target_edition = target_module.krate(db).edition(self.source_scope.db);
178        self.generic_def
179            .into_iter()
180            .flat_map(|it| it.type_or_const_params(db))
181            .skip(skip)
182            // The actual list of trait type parameters may be longer than the one
183            // used in the `impl` block due to trailing default type parameters.
184            // For that case we extend the `substs` with an empty iterator so we
185            // can still hit those trailing values and check if they actually have
186            // a default type. If they do, go for that type from `hir` to `ast` so
187            // the resulting change can be applied correctly.
188            .zip(self.substs.types_and_consts.iter().map(Some).chain(std::iter::repeat(None)))
189            .for_each(|(k, v)| match (k.split(db), v) {
190                (Either::Right(k), Some(TypeOrConst::Either(v))) => {
191                    if let Some(ty) = v.ty() {
192                        type_substs.insert(k, self.prettify_target_ast(ty));
193                    }
194                }
195                (Either::Right(k), None) => {
196                    if let Some(default) = k.default(db)
197                        && let Some(default) =
198                            &default.display_source_code(db, source_module.into(), false).ok()
199                    {
200                        type_substs.insert(k, make::ty(default));
201                        defaulted_params.push(Either::Left(k));
202                    }
203                }
204                (Either::Left(k), Some(TypeOrConst::Either(v))) => {
205                    if let Some(ty) = v.ty() {
206                        const_substs.insert(k, self.prettify_target_node(ty.syntax().clone()));
207                    }
208                }
209                (Either::Left(k), Some(TypeOrConst::Const(v))) => {
210                    if let Some(expr) = v.expr() {
211                        // FIXME: expressions in curly brackets can cause ambiguity after insertion
212                        // (e.g. `N * 2` -> `{1 + 1} * 2`; it's unclear whether `{1 + 1}`
213                        // is a standalone statement or a part of another expression)
214                        // and sometimes require slight modifications; see
215                        // https://doc.rust-lang.org/reference/statements.html#expression-statements
216                        // (default values in curly brackets can cause the same problem)
217                        const_substs.insert(k, self.prettify_target_node(expr.syntax().clone()));
218                    }
219                }
220                (Either::Left(k), None) => {
221                    if let Some(default) =
222                        k.default(db, target_module.krate(db).to_display_target(db))
223                        && let Some(default) = default.expr()
224                    {
225                        const_substs.insert(k, default.syntax().clone());
226                        defaulted_params.push(Either::Right(k));
227                    }
228                }
229                _ => (), // ignore mismatching params
230            });
231        // No need to prettify lifetimes, there's nothing to prettify.
232        let lifetime_substs: FxHashMap<_, _> = self
233            .generic_def
234            .into_iter()
235            .flat_map(|it| it.lifetime_params(db))
236            .zip(self.substs.lifetimes.clone())
237            .filter_map(|(k, v)| {
238                Some((k.name(db).display(db, target_edition).to_string(), v.lifetime()?))
239            })
240            .collect();
241        let mut ctx = Ctx {
242            type_substs,
243            const_substs,
244            lifetime_substs,
245            target_module,
246            source_scope: self.source_scope,
247            same_self_type: self.target_scope.has_same_self_type(self.source_scope),
248            target_edition,
249        };
250        ctx.transform_default_values(defaulted_params);
251        ctx
252    }
253}
254
255struct Ctx<'a> {
256    type_substs: FxHashMap<hir::TypeParam, ast::Type>,
257    const_substs: FxHashMap<hir::ConstParam, SyntaxNode>,
258    lifetime_substs: FxHashMap<LifetimeName, ast::Lifetime>,
259    target_module: hir::Module,
260    source_scope: &'a SemanticsScope<'a>,
261    same_self_type: bool,
262    target_edition: Edition,
263}
264
265fn preorder_rev(item: &SyntaxNode) -> impl Iterator<Item = SyntaxNode> {
266    let x = item
267        .preorder()
268        .filter_map(|event| match event {
269            syntax::WalkEvent::Enter(node) => Some(node),
270            syntax::WalkEvent::Leave(_) => None,
271        })
272        .collect_vec();
273    x.into_iter().rev()
274}
275
276impl Ctx<'_> {
277    fn apply(&self, item: &SyntaxNode) -> SyntaxNode {
278        // `transform_path` may update a node's parent and that would break the
279        // tree traversal. Thus all paths in the tree are collected into a vec
280        // so that such operation is safe.
281        let (editor, item) = SyntaxEditor::new(self.transform_path(item));
282        preorder_rev(&item).filter_map(ast::Lifetime::cast).for_each(|lifetime| {
283            if let Some(subst) = self.lifetime_substs.get(&lifetime.syntax().text().to_string()) {
284                editor.replace(lifetime.syntax(), subst.clone().syntax());
285            }
286        });
287
288        editor.finish().new_root().clone()
289    }
290
291    fn transform_default_values(&mut self, defaulted_params: Vec<DefaultedParam>) {
292        // By now the default values are simply copied from where they are declared
293        // and should be transformed. As any value is allowed to refer to previous
294        // generic (both type and const) parameters, they should be all iterated left-to-right.
295        for param in defaulted_params {
296            let value = match &param {
297                Either::Left(k) => self.type_substs.get(k).unwrap().syntax(),
298                Either::Right(k) => self.const_substs.get(k).unwrap(),
299            };
300            // `transform_path` may update a node's parent and that would break the
301            // tree traversal. Thus all paths in the tree are collected into a vec
302            // so that such operation is safe.
303            let new_value = self.transform_path(value);
304            match param {
305                Either::Left(k) => {
306                    self.type_substs.insert(k, ast::Type::cast(new_value.clone()).unwrap());
307                }
308                Either::Right(k) => {
309                    self.const_substs.insert(k, new_value.clone());
310                }
311            }
312        }
313    }
314
315    fn transform_path(&self, path: &SyntaxNode) -> SyntaxNode {
316        fn find_child_paths_and_ident_pats(
317            root_path: &SyntaxNode,
318        ) -> Vec<Either<ast::Path, ast::IdentPat>> {
319            let mut result: Vec<Either<ast::Path, ast::IdentPat>> = Vec::new();
320            for child in root_path.children() {
321                if let Some(child_path) = ast::Path::cast(child.clone()) {
322                    result.push(either::Left(child_path));
323                } else if let Some(child_ident_pat) = ast::IdentPat::cast(child.clone()) {
324                    result.push(either::Right(child_ident_pat));
325                } else {
326                    result.extend(find_child_paths_and_ident_pats(&child));
327                }
328            }
329            result
330        }
331
332        let (editor, root_path) = SyntaxEditor::new(path.clone());
333        let result = find_child_paths_and_ident_pats(&root_path);
334        for sub_path in result {
335            let new = self.transform_path(sub_path.syntax());
336            editor.replace(sub_path.syntax(), new);
337        }
338        let (editor, update_sub_item) = SyntaxEditor::new(editor.finish().new_root().clone());
339        let item = find_child_paths_and_ident_pats(&update_sub_item);
340        for sub_path in item {
341            self.transform_path_or_ident_pat(&editor, &sub_path);
342        }
343        editor.finish().new_root().clone()
344    }
345    fn transform_path_or_ident_pat(
346        &self,
347        editor: &SyntaxEditor,
348        item: &Either<ast::Path, ast::IdentPat>,
349    ) -> Option<()> {
350        match item {
351            Either::Left(path) => self.transform_path_(editor, path),
352            Either::Right(ident_pat) => self.transform_ident_pat(editor, ident_pat),
353        }
354    }
355
356    fn transform_path_(&self, editor: &SyntaxEditor, path: &ast::Path) -> Option<()> {
357        if path.qualifier().is_some() {
358            return None;
359        }
360        if path.segment().is_some_and(|s| {
361            s.parenthesized_arg_list().is_some()
362                || (s.self_token().is_some() && path.parent_path().is_none())
363        }) {
364            // don't try to qualify `Fn(Foo) -> Bar` paths, they are in prelude anyway
365            // don't try to qualify sole `self` either, they are usually locals, but are returned as modules due to namespace clashing
366            return None;
367        }
368        let resolution = self.source_scope.speculative_resolve(path)?;
369
370        match resolution {
371            hir::PathResolution::TypeParam(tp) => {
372                if let Some(subst) = self.type_substs.get(&tp) {
373                    let parent = path.syntax().parent()?;
374                    if let Some(parent) = ast::Path::cast(parent.clone()) {
375                        // Path inside path means that there is an associated
376                        // type/constant on the type parameter. It is necessary
377                        // to fully qualify the type with `as Trait`. Even
378                        // though it might be unnecessary if `subst` is generic
379                        // type, always fully qualifying the path is safer
380                        // because of potential clash of associated types from
381                        // multiple traits
382
383                        let trait_ref = find_trait_for_assoc_item(
384                            self.source_scope,
385                            tp,
386                            parent.segment()?.name_ref()?,
387                        )
388                        .and_then(|trait_ref| {
389                            let cfg = FindPathConfig {
390                                prefer_no_std: false,
391                                prefer_prelude: true,
392                                prefer_absolute: false,
393                                allow_unstable: true,
394                            };
395                            let found_path = self.target_module.find_path(
396                                self.source_scope.db,
397                                hir::ModuleDef::Trait(trait_ref),
398                                cfg,
399                            )?;
400                            match make::ty_path(mod_path_to_ast(&found_path, self.target_edition)) {
401                                ast::Type::PathType(path_ty) => Some(path_ty),
402                                _ => None,
403                            }
404                        });
405
406                        let segment = make::path_segment_ty(subst.clone(), trait_ref);
407                        let qualified = make::path_from_segments(std::iter::once(segment), false);
408                        editor.replace(path.syntax(), qualified.clone().syntax());
409                    } else if let Some(path_ty) = ast::PathType::cast(parent) {
410                        let old = path_ty.syntax();
411
412                        if old.parent().is_some() {
413                            editor.replace(old, subst.clone().syntax());
414                        } else {
415                            let start = path_ty.syntax().first_child().map(NodeOrToken::Node)?;
416                            let end = path_ty.syntax().last_child().map(NodeOrToken::Node)?;
417                            editor.replace_all(
418                                start..=end,
419                                subst
420                                    .clone()
421                                    .syntax()
422                                    .children()
423                                    .map(NodeOrToken::Node)
424                                    .collect::<Vec<_>>(),
425                            );
426                        }
427                    } else {
428                        editor.replace(path.syntax(), subst.clone().syntax());
429                    }
430                }
431            }
432            hir::PathResolution::Def(def) if def.as_assoc_item(self.source_scope.db).is_none() => {
433                if let hir::ModuleDef::Trait(_) = def
434                    && matches!(path.segment()?.kind()?, ast::PathSegmentKind::Type { .. })
435                {
436                    // `speculative_resolve` resolves segments like `<T as
437                    // Trait>` into `Trait`, but just the trait name should
438                    // not be used as the replacement of the original
439                    // segment.
440                    return None;
441                }
442
443                let cfg = FindPathConfig {
444                    prefer_no_std: false,
445                    prefer_prelude: true,
446                    prefer_absolute: false,
447                    allow_unstable: true,
448                };
449                let found_path = self.target_module.find_path(self.source_scope.db, def, cfg)?;
450                let res = mod_path_to_ast(&found_path, self.target_edition);
451                let (res_editor, res) = SyntaxEditor::with_ast_node(&res);
452                if let Some(args) = path.segment().and_then(|it| it.generic_arg_list())
453                    && let Some(segment) = res.segment()
454                {
455                    if let Some(old) = segment.generic_arg_list() {
456                        res_editor.replace(old.syntax(), args.syntax().clone())
457                    } else {
458                        res_editor.insert(
459                            syntax_editor::Position::last_child_of(segment.syntax()),
460                            args.syntax().clone(),
461                        );
462                    }
463                }
464                let res = res_editor.finish().new_root().clone();
465                editor.replace(path.syntax().clone(), res);
466            }
467            hir::PathResolution::ConstParam(cp) => {
468                if let Some(subst) = self.const_substs.get(&cp) {
469                    editor.replace(path.syntax(), subst.clone());
470                }
471            }
472            hir::PathResolution::SelfType(imp) => {
473                // keep Self type if it does not need to be replaced
474                if self.same_self_type {
475                    return None;
476                }
477
478                let ty = imp.self_ty(self.source_scope.db);
479                let ty_str = &ty
480                    .display_source_code(
481                        self.source_scope.db,
482                        self.source_scope.module().into(),
483                        true,
484                    )
485                    .ok()?;
486                let ast_ty = make::ty(ty_str);
487
488                if let Some(adt) = ty.as_adt()
489                    && let ast::Type::PathType(path_ty) = &ast_ty
490                {
491                    let cfg = FindPathConfig {
492                        prefer_no_std: false,
493                        prefer_prelude: true,
494                        prefer_absolute: false,
495                        allow_unstable: true,
496                    };
497                    let found_path = self.target_module.find_path(
498                        self.source_scope.db,
499                        ModuleDef::from(adt),
500                        cfg,
501                    )?;
502
503                    if let Some(qual) =
504                        mod_path_to_ast(&found_path, self.target_edition).qualifier()
505                    {
506                        editor.replace(
507                            path.syntax(),
508                            make::path_concat(qual, path_ty.path()?).syntax(),
509                        );
510                        return Some(());
511                    }
512                }
513
514                editor.replace(path.syntax(), ast_ty.syntax());
515            }
516            hir::PathResolution::Local(_)
517            | hir::PathResolution::Def(_)
518            | hir::PathResolution::BuiltinAttr(_)
519            | hir::PathResolution::ToolModule(_)
520            | hir::PathResolution::DeriveHelper(_) => (),
521        }
522        Some(())
523    }
524
525    fn transform_ident_pat(&self, editor: &SyntaxEditor, ident_pat: &ast::IdentPat) -> Option<()> {
526        let name = ident_pat.name()?;
527
528        let temp_path = make::path_from_text(&name.text());
529
530        let resolution = self.source_scope.speculative_resolve(&temp_path)?;
531
532        match resolution {
533            hir::PathResolution::Def(def) if def.as_assoc_item(self.source_scope.db).is_none() => {
534                // Macros cannot be used in pattern position, and identifiers that happen
535                // to have the same name as macros (like parameter names `vec`, `format`, etc.)
536                // are bindings, not references. Don't qualify them.
537                if matches!(def, hir::ModuleDef::Macro(_)) {
538                    return None;
539                }
540
541                // Similarly, modules cannot be used in pattern position.
542                if matches!(def, hir::ModuleDef::Module(_)) {
543                    return None;
544                }
545
546                if matches!(
547                    def,
548                    hir::ModuleDef::Function(_)
549                        | hir::ModuleDef::Trait(_)
550                        | hir::ModuleDef::TypeAlias(_)
551                ) {
552                    return None;
553                }
554
555                if let hir::ModuleDef::Adt(adt) = def {
556                    match adt {
557                        hir::Adt::Struct(s)
558                            if s.kind(self.source_scope.db) != hir::StructKind::Unit =>
559                        {
560                            return None;
561                        }
562                        hir::Adt::Union(_) => return None,
563                        hir::Adt::Enum(_) => return None,
564                        _ => (),
565                    }
566                }
567
568                if let hir::ModuleDef::EnumVariant(v) = def
569                    && v.kind(self.source_scope.db) != hir::StructKind::Unit
570                {
571                    return None;
572                }
573
574                let cfg = FindPathConfig {
575                    prefer_no_std: false,
576                    prefer_prelude: true,
577                    prefer_absolute: false,
578                    allow_unstable: true,
579                };
580                let found_path = self.target_module.find_path(self.source_scope.db, def, cfg)?;
581                editor.replace(
582                    ident_pat.syntax(),
583                    mod_path_to_ast(&found_path, self.target_edition).syntax(),
584                );
585                Some(())
586            }
587            _ => None,
588        }
589    }
590}
591
592// FIXME: It would probably be nicer if we could get this via HIR (i.e. get the
593// trait ref, and then go from the types in the substs back to the syntax).
594fn get_syntactic_substs(impl_def: ast::Impl) -> Option<AstSubsts> {
595    let target_trait = impl_def.trait_()?;
596    let path_type = match target_trait {
597        ast::Type::PathType(path) => path,
598        _ => return None,
599    };
600    let generic_arg_list = path_type.path()?.segment()?.generic_arg_list()?;
601
602    get_type_args_from_arg_list(generic_arg_list)
603}
604
605fn get_type_args_from_arg_list(generic_arg_list: ast::GenericArgList) -> Option<AstSubsts> {
606    let mut result = AstSubsts::default();
607    generic_arg_list.generic_args().for_each(|generic_arg| match generic_arg {
608        // Const params are marked as consts on definition only,
609        // being passed to the trait they are indistguishable from type params;
610        // anyway, we don't really need to distinguish them here.
611        ast::GenericArg::TypeArg(type_arg) => {
612            result.types_and_consts.push(TypeOrConst::Either(type_arg))
613        }
614        // Some const values are recognized correctly.
615        ast::GenericArg::ConstArg(const_arg) => {
616            result.types_and_consts.push(TypeOrConst::Const(const_arg));
617        }
618        ast::GenericArg::LifetimeArg(l_arg) => result.lifetimes.push(l_arg),
619        _ => (),
620    });
621
622    Some(result)
623}
624
625fn find_trait_for_assoc_item(
626    scope: &SemanticsScope<'_>,
627    type_param: hir::TypeParam,
628    assoc_item: ast::NameRef,
629) -> Option<hir::Trait> {
630    let db = scope.db;
631    let trait_bounds = type_param.trait_bounds(db);
632
633    let assoc_item_name = assoc_item.text();
634
635    for trait_ in trait_bounds {
636        let names = trait_.items(db).into_iter().filter_map(|item| match item {
637            hir::AssocItem::TypeAlias(ta) => Some(ta.name(db)),
638            hir::AssocItem::Const(cst) => cst.name(db),
639            _ => None,
640        });
641
642        for name in names {
643            if assoc_item_name.as_str() == name.as_str() {
644                // It is fine to return the first match because in case of
645                // multiple possibilities, the exact trait must be disambiguated
646                // in the definition of trait being implemented, so this search
647                // should not be needed.
648                return Some(trait_);
649            }
650        }
651    }
652
653    None
654}
655
656#[cfg(test)]
657mod tests {
658    use crate::RootDatabase;
659    use crate::path_transform::PathTransform;
660    use hir::Semantics;
661    use syntax::{AstNode, ast::HasName};
662    use test_fixture::WithFixture;
663    use test_utils::assert_eq_text;
664
665    #[test]
666    fn test_transform_ident_pat() {
667        let (db, file_id) = RootDatabase::with_single_file(
668            r#"
669mod foo {
670    pub struct UnitStruct;
671    pub struct RecordStruct {}
672    pub enum Enum { UnitVariant, RecordVariant {} }
673    pub fn function() {}
674    pub const CONST: i32 = 0;
675    pub static STATIC: i32 = 0;
676    pub type Alias = i32;
677    pub union Union { f: i32 }
678}
679
680mod bar {
681    fn anchor() {}
682}
683
684fn main() {
685    use foo::*;
686    use foo::Enum::*;
687    let UnitStruct = ();
688    let RecordStruct = ();
689    let Enum = ();
690    let UnitVariant = ();
691    let RecordVariant = ();
692    let function = ();
693    let CONST = ();
694    let STATIC = ();
695    let Alias = ();
696    let Union = ();
697}
698"#,
699        );
700        let sema = Semantics::new(&db);
701        let source_file = sema.parse(file_id);
702
703        let function = source_file
704            .syntax()
705            .descendants()
706            .filter_map(syntax::ast::Fn::cast)
707            .find(|it| it.name().unwrap().text() == "main")
708            .unwrap();
709        let source_scope = sema.scope(function.body().unwrap().syntax()).unwrap();
710
711        let anchor = source_file
712            .syntax()
713            .descendants()
714            .filter_map(syntax::ast::Fn::cast)
715            .find(|it| it.name().unwrap().text() == "anchor")
716            .unwrap();
717        let target_scope = sema.scope(anchor.body().unwrap().syntax()).unwrap();
718
719        let transform = PathTransform::generic_transformation(&target_scope, &source_scope);
720        let transformed = transform.apply(function.body().unwrap().syntax());
721
722        let expected = r#"{
723    use crate::foo::*;
724    use crate::foo::Enum::*;
725    let crate::foo::UnitStruct = ();
726    let RecordStruct = ();
727    let Enum = ();
728    let crate::foo::Enum::UnitVariant = ();
729    let RecordVariant = ();
730    let function = ();
731    let crate::foo::CONST = ();
732    let crate::foo::STATIC = ();
733    let Alias = ();
734    let Union = ();
735}"#;
736        assert_eq_text!(expected, &transformed.to_string());
737    }
738}
ide_db/path_transform.rs

ide_db/
path_transform.rs
