fix(es/renamer): Don't use symbols used by declarations if eval exists

crates/swc/tests/fixture/issues-6xxx/6871/input/.swcrc

@@ -0,0 +1,19 @@
+{
+    "jsc": {
+        "parser": {
+            "syntax": "ecmascript",
+            "jsx": false
+        },
+        "target": "es2015",
+        "loose": true,
+        "minify": {
+            "compress": false,
+            "mangle": false
+        }
+    },
+    "module": {
+        "type": "es6"
+    },
+    "minify": false,
+    "isModule": true
+}

crates/swc/tests/fixture/issues-6xxx/6871/input/index.js

@@ -0,0 +1,3 @@
+async function fromTokenizer() { }
+async function _fromTokenizer() { }
+eval()

crates/swc/tests/fixture/issues-6xxx/6871/output/index.js

@@ -0,0 +1,16 @@
+import _async_to_generator from "@swc/helpers/src/_async_to_generator.mjs";
+function fromTokenizer() {
+    return _fromTokenizer1.apply(this, arguments);
+}
+function _fromTokenizer1() {
+    _fromTokenizer1 = _async_to_generator(function*() {});
+    return _fromTokenizer1.apply(this, arguments);
+}
+function _fromTokenizer() {
+    return __fromTokenizer.apply(this, arguments);
+}
+function __fromTokenizer() {
+    __fromTokenizer = _async_to_generator(function*() {});
+    return __fromTokenizer.apply(this, arguments);
+}
+eval();

crates/swc_ecma_minifier/tests/full/issues/7094/input.js

@@ -0,0 +1,5 @@
+export function useSyncExternalStore$2(e, n, t) {
+    let a = n(); // any variable expect `e` 
+    return a;
+}
+eval();

crates/swc_ecma_minifier/tests/full/issues/7094/output.js

@@ -0,0 +1 @@
+export function useSyncExternalStore$2(r,o,u){return o()}eval();

crates/swc_ecma_transforms_base/src/rename/collector.rs

@@ -1,7 +1,7 @@
 use std::hash::Hash;
 
 use rustc_hash::FxHashSet;
-use swc_common::SyntaxContext;
+use swc_common::{Mark, SyntaxContext};
 use swc_ecma_ast::*;
 use swc_ecma_utils::ident::IdentLike;
 use swc_ecma_visit::{noop_visit_type, visit_obj_and_computed, Visit, VisitWith};
@@ -47,14 +47,25 @@ where
     I: IdentLike + Eq + Hash + Send + Sync,
 {
     bindings: FxHashSet<I>,
+    preserved: FxHashSet<I>,
     is_pat_decl: bool,
+
+    /// [None] if there's no `eval`.
+    pub top_level_mark_for_eval: Option<Mark>,
 }
 
 impl<I> CustomBindingCollector<I>
 where
     I: IdentLike + Eq + Hash + Send + Sync,
 {
     fn add(&mut self, i: &Ident) {
+        if let Some(top_level_mark) = self.top_level_mark_for_eval {
+            if i.span.ctxt.outer().is_descendant_of(top_level_mark) {
+                self.preserved.insert(I::from_ident(i));
+                return;
+            }
+        }
+
         self.bindings.insert(I::from_ident(i));
     }
 }
@@ -177,15 +188,21 @@ where
     }
 }
 
-pub(super) fn collect_decls<I, N>(n: &N) -> FxHashSet<I>
+/// Returns `(bindings, preserved)`.
+pub(super) fn collect_decls<I, N>(
+    n: &N,
+    top_level_mark_for_eval: Option<Mark>,
+) -> (FxHashSet<I>, FxHashSet<I>)
 where
     I: IdentLike + Eq + Hash + Send + Sync,
     N: VisitWith<CustomBindingCollector<I>>,
 {
     let mut v = CustomBindingCollector {
         bindings: Default::default(),
+        preserved: Default::default(),
         is_pat_decl: false,
+        top_level_mark_for_eval,
     };
     n.visit_with(&mut v);
-    v.bindings
+    (v.bindings, v.preserved)
 }

crates/swc_ecma_transforms_base/src/rename/mod.rs

@@ -82,7 +82,7 @@ impl<R> RenamePass<R>
 where
     R: Renamer,
 {
-    fn get_unresolved<N>(&self, n: &N) -> FxHashSet<JsWord>
+    fn get_unresolved<N>(&self, n: &N, has_eval: bool) -> FxHashSet<JsWord>
     where
         N: VisitWith<IdCollector> + VisitWith<CustomBindingCollector<Id>>,
     {
@@ -93,11 +93,19 @@ where
             n.visit_with(&mut v);
             v.ids
         };
-        let decls = collect_decls(n);
+        let (decls, preserved) = collect_decls(
+            n,
+            if has_eval {
+                Some(self.config.top_level_mark)
+            } else {
+                None
+            },
+        );
         usages
             .into_iter()
             .filter(|used_id| !decls.contains(used_id))
             .map(|v| v.0)
+            .chain(preserved.into_iter().map(|v| v.0))
             .collect()
     }
 
@@ -133,7 +141,7 @@ where
 
         let mut unresolved = if !is_module_or_script {
             let mut unresolved = self.unresolved.clone();
-            unresolved.extend(self.get_unresolved(node));
+            unresolved.extend(self.get_unresolved(node, has_eval));
             Cow::Owned(unresolved)
         } else {
             Cow::Borrowed(&self.unresolved)
@@ -230,10 +238,11 @@ where
 
     fn visit_mut_module(&mut self, m: &mut Module) {
         self.preserved = self.renamer.preserved_ids_for_module(m);
-        self.unresolved = self.get_unresolved(m);
 
         let has_eval = contains_eval(m, true);
 
+        self.unresolved = self.get_unresolved(m, has_eval);
+
         {
             let map = self.get_map(m, false, true, has_eval);
 
@@ -247,10 +256,11 @@ where
 
     fn visit_mut_script(&mut self, m: &mut Script) {
         self.preserved = self.renamer.preserved_ids_for_script(m);
-        self.unresolved = self.get_unresolved(m);
 
         let has_eval = contains_eval(m, true);
 
+        self.unresolved = self.get_unresolved(m, has_eval);
+
         {
             let map = self.get_map(m, false, true, has_eval);