feat(semantic2): track symbol references

crates/oxc_semantic2/src/builder.rs

@@ -1,6 +1,7 @@
 use oxc_span::{Atom, SourceType, Span};
 
 use crate::{
+    reference::Reference,
     scope::{Scope, ScopeFlags, ScopeId, ScopeTree},
     symbol::{SymbolFlags, SymbolId, SymbolTable},
     Semantic,
@@ -79,9 +80,12 @@ impl SemanticBuilder {
     }
 
     fn resolve_reference(&mut self, name: &Atom) -> Option<SymbolId> {
-        self.scope_tree
+        let symbol_id = self
+            .scope_tree
             .ancestors(self.current_scope_id)
-            .find_map(|scope_id| self.scope_tree.get_scope(scope_id).get_binding(name))
+            .find_map(|scope_id| self.scope_tree.get_scope(scope_id).get_binding(name))?;
+        self.symbol_table.add_reference(Reference::new_read(symbol_id));
+        Some(symbol_id)
     }
 }
 

crates/oxc_semantic2/src/lib.rs

@@ -1,4 +1,5 @@
 mod builder;
+pub mod reference;
 pub mod scope;
 pub mod symbol;
 

crates/oxc_semantic2/src/reference.rs

@@ -0,0 +1,16 @@
+use crate::symbol::SymbolId;
+
+#[derive(Debug, Clone)]
+pub struct Reference {
+    symbol_id: SymbolId,
+}
+
+impl Reference {
+    pub fn new_read(symbol_id: SymbolId) -> Self {
+        Self { symbol_id }
+    }
+
+    pub fn symbol_id(&self) -> SymbolId {
+        self.symbol_id
+    }
+}

crates/oxc_semantic2/src/symbol.rs

@@ -4,6 +4,8 @@ use bitflags::bitflags;
 use oxc_index::{Idx, IndexVec};
 use oxc_span::{Atom, Span};
 
+use crate::reference::Reference;
+
 #[derive(Debug, Clone, Copy, Eq, PartialEq, Ord, PartialOrd, Hash)]
 pub struct SymbolId(usize);
 
@@ -62,11 +64,17 @@ pub struct SymbolTable {
     names: IndexVec<SymbolId, Atom>,
     spans: IndexVec<SymbolId, Span>,
     flags: IndexVec<SymbolId, SymbolFlags>,
+    references: IndexVec<SymbolId, Vec<Reference>>,
 }
 
 impl SymbolTable {
     pub fn new() -> Self {
-        Self { names: IndexVec::new(), spans: IndexVec::new(), flags: IndexVec::new() }
+        Self {
+            names: IndexVec::new(),
+            spans: IndexVec::new(),
+            flags: IndexVec::new(),
+            references: IndexVec::new(),
+        }
     }
 
     pub fn get_name(&self, symbol_id: SymbolId) -> &Atom {
@@ -76,9 +84,14 @@ impl SymbolTable {
     pub fn add_symbol(&mut self, name: Atom, span: Span, flag: SymbolFlags) -> SymbolId {
         let _ = self.names.push(name);
         let _ = self.spans.push(span);
+        let _ = self.references.push(vec![]);
         self.flags.push(flag)
     }
 
+    pub fn add_reference(&mut self, reference: Reference) {
+        self.references[reference.symbol_id()].push(reference);
+    }
+
     pub fn mangle(&mut self) {
         let mut offset = 0;
         for (symbol_id, flag) in self.flags.iter_enumerated() {