feat(lsp): allow function rename (#4294)

# Description

## Problem\*

Resolves <!-- Link to GitHub Issue -->

Rename function Symbol with LSP #4192

## Summary\*

Allows to rename function symbol.

## Additional Context



## Documentation\*

Check one:
- [x] No documentation needed.
- [ ] Documentation included in this PR.
- [ ] **[Exceptional Case]** Documentation to be submitted in a separate
PR.

# PR Checklist\*

- [x] I have tested the changes locally.
- [x] I have formatted the changes with [Prettier](https://prettier.io/)
and/or `cargo fmt` on default settings.

---------

Co-authored-by: Jake Fecher <jfecher11@gmail.com>
Co-authored-by: jfecher <jake@aztecprotocol.com>
Co-authored-by: Tom French <15848336+TomAFrench@users.noreply.github.com>
Co-authored-by: Tom French <tom@tomfren.ch>
Co-authored-by: Ary Borenszweig <asterite@gmail.com>

compiler/noirc_frontend/Cargo.toml

@@ -29,6 +29,7 @@ regex = "1.9.1"
 cfg-if = "1.0.0"
 tracing.workspace = true
 petgraph = "0.6"
+rangemap = "1.4.0"
 lalrpop-util = { version = "0.20.2", features = ["lexer"] }
 
 

compiler/noirc_frontend/src/elaborator/patterns.rs

@@ -14,7 +14,7 @@ use crate::{
         stmt::HirPattern,
     },
     macros_api::{HirExpression, Ident, Path, Pattern},
-    node_interner::{DefinitionId, DefinitionKind, ExprId, GlobalId, TraitImplKind},
+    node_interner::{DefinitionId, DefinitionKind, DependencyId, ExprId, GlobalId, TraitImplKind},
     Shared, StructType, Type, TypeBindings,
 };
 
@@ -418,10 +418,14 @@ impl<'context> Elaborator<'context> {
 
             if hir_ident.id != DefinitionId::dummy_id() {
                 match self.interner.definition(hir_ident.id).kind {
-                    DefinitionKind::Function(id) => {
+                    DefinitionKind::Function(func_id) => {
                         if let Some(current_item) = self.current_item {
-                            self.interner.add_function_dependency(current_item, id);
+                            self.interner.add_function_dependency(current_item, func_id);
                         }
+
+                        let variable = DependencyId::Variable(hir_ident.location);
+                        let function = DependencyId::Function(func_id);
+                        self.interner.add_reference(function, variable);
                     }
                     DefinitionKind::Global(global_id) => {
                         if let Some(global) = self.unresolved_globals.remove(&global_id) {
@@ -430,6 +434,10 @@ impl<'context> Elaborator<'context> {
                         if let Some(current_item) = self.current_item {
                             self.interner.add_global_dependency(current_item, global_id);
                         }
+
+                        let variable = DependencyId::Variable(hir_ident.location);
+                        let global = DependencyId::Global(global_id);
+                        self.interner.add_reference(global, variable);
                     }
                     DefinitionKind::GenericType(_) => {
                         // Initialize numeric generics to a polymorphic integer type in case
@@ -575,7 +583,10 @@ impl<'context> Elaborator<'context> {
     }
 
     pub fn get_ident_from_path(&mut self, path: Path) -> (HirIdent, usize) {
-        let location = Location::new(path.span(), self.file);
+        let location = Location::new(
+            path.segments.last().expect("ice: path without segments").span(),
+            self.file,
+        );
 
         let error = match path.as_ident().map(|ident| self.use_variable(ident)) {
             Some(Ok(found)) => return found,

compiler/noirc_frontend/src/hir/def_collector/dc_crate.rs

@@ -20,17 +20,18 @@ use crate::hir::Context;
 
 use crate::macros_api::{MacroError, MacroProcessor};
 use crate::node_interner::{
-    FuncId, GlobalId, NodeInterner, StructId, TraitId, TraitImplId, TypeAliasId,
+    DependencyId, FuncId, GlobalId, NodeInterner, StructId, TraitId, TraitImplId, TypeAliasId,
 };
 
 use crate::ast::{
     ExpressionKind, Ident, LetStatement, Literal, NoirFunction, NoirStruct, NoirTrait,
     NoirTypeAlias, Path, PathKind, UnresolvedGenerics, UnresolvedTraitConstraint, UnresolvedType,
 };
+
 use crate::parser::{ParserError, SortedModule};
 use fm::FileId;
 use iter_extended::vecmap;
-use noirc_errors::{CustomDiagnostic, Span};
+use noirc_errors::{CustomDiagnostic, Location, Span};
 use rustc_hash::FxHashMap as HashMap;
 use std::collections::BTreeMap;
 
@@ -328,6 +329,7 @@ impl DefCollector {
 
         // Resolve unresolved imports collected from the crate, one by one.
         for collected_import in std::mem::take(&mut def_collector.imports) {
+            let module_id = collected_import.module_id;
             match resolve_import(crate_id, &collected_import, &context.def_maps) {
                 Ok(resolved_import) => {
                     if let Some(error) = resolved_import.error {
@@ -345,6 +347,9 @@ impl DefCollector {
                         let result = current_def_map.modules[resolved_import.module_scope.0]
                             .import(name.clone(), ns, resolved_import.is_prelude);
 
+                        let file_id = current_def_map.file_id(module_id);
+                        add_import_reference(ns, &name, &mut context.def_interner, file_id);
+
                         if let Err((first_def, second_def)) = result {
                             let err = DefCollectorErrorKind::Duplicate {
                                 typ: DuplicateType::Import,
@@ -468,6 +473,22 @@ impl DefCollector {
     }
 }
 
+fn add_import_reference(
+    def_id: crate::macros_api::ModuleDefId,
+    name: &Ident,
+    interner: &mut NodeInterner,
+    file_id: FileId,
+) {
+    if name.span() == Span::empty(0) {
+        // We ignore empty spans at 0 location, this must be Stdlib
+        return;
+    }
+    if let crate::macros_api::ModuleDefId::FunctionId(func_id) = def_id {
+        let variable = DependencyId::Variable(Location::new(name.span(), file_id));
+        interner.add_reference_for(DependencyId::Function(func_id), variable);
+    }
+}
+
 fn inject_prelude(
     crate_id: CrateId,
     context: &Context,

compiler/noirc_frontend/src/hir/def_collector/dc_mod.rs

@@ -415,6 +415,7 @@ impl<'a> ModCollector<'a> {
                         let func_id = context.def_interner.push_empty_fn();
                         method_ids.insert(name.to_string(), func_id);
 
+                        let location = Location::new(name.span(), self.file_id);
                         let modifiers = FunctionModifiers {
                             name: name.to_string(),
                             visibility: ItemVisibility::Public,
@@ -423,9 +424,9 @@ impl<'a> ModCollector<'a> {
                             is_unconstrained: false,
                             generic_count: generics.len(),
                             is_comptime: false,
+                            name_location: location,
                         };
 
-                        let location = Location::new(name.span(), self.file_id);
                         context
                             .def_interner
                             .push_function_definition(func_id, modifiers, trait_id.0, location);

compiler/noirc_frontend/src/hir/resolution/resolver.rs

@@ -1512,7 +1512,7 @@ impl<'a> Resolver<'a> {
                     // Otherwise, then it is referring to an Identifier
                     // This lookup allows support of such statements: let x = foo::bar::SOME_GLOBAL + 10;
                     // If the expression is a singular indent, we search the resolver's current scope as normal.
-                    let (hir_ident, var_scope_index) = self.get_ident_from_path(path);
+                    let (hir_ident, var_scope_index) = self.get_ident_from_path(path.clone());
 
                     if hir_ident.id != DefinitionId::dummy_id() {
                         match self.interner.definition(hir_ident.id).kind {

compiler/noirc_frontend/src/lib.rs

@@ -15,6 +15,7 @@ pub mod debug;
 pub mod elaborator;
 pub mod graph;
 pub mod lexer;
+pub mod locations;
 pub mod monomorphization;
 pub mod node_interner;
 pub mod parser;

compiler/noirc_frontend/src/locations.rs

@@ -0,0 +1,122 @@
+use fm::FileId;
+use noirc_errors::Location;
+use rangemap::RangeMap;
+use rustc_hash::FxHashMap;
+
+use crate::{macros_api::NodeInterner, node_interner::DependencyId};
+use petgraph::prelude::NodeIndex as PetGraphIndex;
+
+#[derive(Debug, Default)]
+pub(crate) struct LocationIndices {
+    map_file_to_range: FxHashMap<FileId, RangeMap<u32, PetGraphIndex>>,
+}
+
+impl LocationIndices {
+    pub(crate) fn add_location(&mut self, location: Location, node_index: PetGraphIndex) {
+        // Some location spans are empty: maybe they are from ficticious nodes?
+        if location.span.start() == location.span.end() {
+            return;
+        }
+
+        let range_map = self.map_file_to_range.entry(location.file).or_default();
+        range_map.insert(location.span.start()..location.span.end(), node_index);
+    }
+
+    pub(crate) fn get_node_from_location(&self, location: Location) -> Option<PetGraphIndex> {
+        let range_map = self.map_file_to_range.get(&location.file)?;
+        Some(*range_map.get(&location.span.start())?)
+    }
+}
+
+impl NodeInterner {
+    pub fn dependency_location(&self, dependency: DependencyId) -> Location {
+        match dependency {
+            DependencyId::Function(id) => self.function_modifiers(&id).name_location,
+            DependencyId::Struct(id) => self.get_struct(id).borrow().location,
+            DependencyId::Global(id) => self.get_global(id).location,
+            DependencyId::Alias(id) => self.get_type_alias(id).borrow().location,
+            DependencyId::Variable(location) => location,
+        }
+    }
+
+    pub(crate) fn add_reference(&mut self, referenced: DependencyId, reference: DependencyId) {
+        let referenced_index = self.get_or_insert_reference(referenced);
+        let reference_index = self.reference_graph.add_node(reference);
+
+        let referenced_location = self.dependency_location(referenced);
+        let reference_location = self.dependency_location(reference);
+
+        self.reference_graph.add_edge(referenced_index, reference_index, ());
+        self.location_indices.add_location(referenced_location, referenced_index);
+        self.location_indices.add_location(reference_location, reference_index);
+    }
+
+    pub(crate) fn add_reference_for(
+        &mut self,
+        referenced_id: DependencyId,
+        reference: DependencyId,
+    ) {
+        let Some(referenced_index) = self.reference_graph_indices.get(&referenced_id) else {
+            panic!("Compiler Error: Referenced index not found")
+        };
+
+        let reference_location = self.dependency_location(reference);
+        let reference_index = self.reference_graph.add_node(reference);
+        self.reference_graph.add_edge(*referenced_index, reference_index, ());
+        self.location_indices.add_location(reference_location, reference_index);
+    }
+
+    pub(crate) fn add_definition_location(&mut self, referenced: DependencyId) {
+        let referenced_index = self.get_or_insert_reference(referenced);
+        let referenced_location = self.dependency_location(referenced);
+        self.location_indices.add_location(referenced_location, referenced_index);
+    }
+
+    #[tracing::instrument(skip(self), ret)]
+    pub(crate) fn get_or_insert_reference(&mut self, id: DependencyId) -> PetGraphIndex {
+        if let Some(index) = self.reference_graph_indices.get(&id) {
+            return *index;
+        }
+
+        let index = self.reference_graph.add_node(id);
+        self.reference_graph_indices.insert(id, index);
+        index
+    }
+
+    pub fn check_rename_possible(&self, location: Location) -> bool {
+        self.location_indices.get_node_from_location(location).is_some()
+    }
+
+    pub fn find_rename_symbols_at(&self, location: Location) -> Option<Vec<Location>> {
+        let node_index = self.location_indices.get_node_from_location(location)?;
+
+        let reference_node = self.reference_graph[node_index];
+        let found_locations: Vec<Location> = match reference_node {
+            DependencyId::Alias(_) | DependencyId::Struct(_) | DependencyId::Global(_) => todo!(),
+            DependencyId::Function(_) => self.get_edit_locations(node_index),
+
+            DependencyId::Variable(_) => {
+                let referenced_node_index = self
+                    .reference_graph
+                    .neighbors_directed(node_index, petgraph::Direction::Incoming)
+                    .next()?;
+
+                self.get_edit_locations(referenced_node_index)
+            }
+        };
+        Some(found_locations)
+    }
+
+    fn get_edit_locations(&self, referenced_node_index: PetGraphIndex) -> Vec<Location> {
+        let id = self.reference_graph[referenced_node_index];
+        let mut edit_locations = vec![self.dependency_location(id)];
+
+        self.reference_graph
+            .neighbors_directed(referenced_node_index, petgraph::Direction::Outgoing)
+            .for_each(|reference_node_index| {
+                let id = self.reference_graph[reference_node_index];
+                edit_locations.push(self.dependency_location(id));
+            });
+        edit_locations
+    }
+}