1 files changed, 36 insertions, 3 deletions

diff --git a/deps/v8/src/ast/scopes.cc b/deps/v8/src/ast/scopes.cc
index a66e4ea93f..cd8be1caec 100644
--- a/deps/v8/src/ast/scopes.cc
+++ b/deps/v8/src/ast/scopes.cc
@@ -632,7 +632,8 @@ void DeclarationScope::HoistSloppyBlockFunctions(AstNodeFactory* factory) {
     // scope and we terminate the iteration there anyway.
     do {
       Variable* var = query_scope->LookupInScopeOrScopeInfo(name, query_scope);
-      if (var != nullptr && IsLexicalVariableMode(var->mode())) {
+      if (var != nullptr && IsLexicalVariableMode(var->mode()) &&
+          !var->is_sloppy_block_function()) {
         should_hoist = false;
         break;
       }
@@ -649,6 +650,19 @@ void DeclarationScope::HoistSloppyBlockFunctions(AstNodeFactory* factory) {
       auto declaration = factory->NewVariableDeclaration(pos);
       // Based on the preceding checks, it doesn't matter what we pass as
       // sloppy_mode_block_scope_function_redefinition.
+      //
+      // This synthesized var for Annex B functions-in-block (FiB) may be
+      // declared multiple times for the same var scope, such as in the case of
+      // shadowed functions-in-block like the following:
+      //
+      // {
+      //    function f() {}
+      //    { function f() {} }
+      // }
+      //
+      // Redeclarations for vars do not create new bindings, but the
+      // redeclarations' initializers are still run. That is, shadowed FiB will
+      // result in multiple assignments to the same synthesized var.
       Variable* var = DeclareVariable(
           declaration, name, pos, VariableMode::kVar, NORMAL_VARIABLE,
           Variable::DefaultInitializationFlag(VariableMode::kVar), &was_added,
@@ -1263,8 +1277,9 @@ Declaration* DeclarationScope::CheckConflictingVarDeclarations(
     if (decl->IsVariableDeclaration() &&
         decl->AsVariableDeclaration()->AsNested() != nullptr) {
       Scope* current = decl->AsVariableDeclaration()->AsNested()->scope();
-      DCHECK(decl->var()->mode() == VariableMode::kVar ||
-             decl->var()->mode() == VariableMode::kDynamic);
+      if (decl->var()->mode() != VariableMode::kVar &&
+          decl->var()->mode() != VariableMode::kDynamic)
+        continue;
       // Iterate through all scopes until the declaration scope.
       do {
         // There is a conflict if there exists a non-VAR binding.
@@ -1796,6 +1811,8 @@ const char* Header(ScopeType scope_type, FunctionKind function_kind,
     case CLASS_SCOPE:
       return "class";
     case WITH_SCOPE: return "with";
+    case SHADOW_REALM_SCOPE:
+      return "shadowrealm";
   }
   UNREACHABLE();
 }
@@ -2058,6 +2075,15 @@ Variable* Scope::NonLocal(const AstRawString* name, VariableMode mode) {
   return var;
 }
 
+void Scope::ForceDynamicLookup(VariableProxy* proxy) {
+  // At the moment this is only used for looking up private names dynamically
+  // in debug-evaluate from top-level scope.
+  DCHECK(proxy->IsPrivateName());
+  DCHECK(is_script_scope() || is_module_scope() || is_eval_scope());
+  Variable* dynamic = NonLocal(proxy->raw_name(), VariableMode::kDynamic);
+  proxy->BindTo(dynamic);
+}
+
 // static
 template <Scope::ScopeLookupMode mode>
 Variable* Scope::Lookup(VariableProxy* proxy, Scope* scope,
@@ -3109,6 +3135,13 @@ void PrivateNameScopeIterator::AddUnresolvedPrivateName(VariableProxy* proxy) {
   // be new.
   DCHECK(!proxy->is_resolved());
   DCHECK(proxy->IsPrivateName());
+
+  // Use dynamic lookup for top-level scopes in debug-evaluate.
+  if (Done()) {
+    start_scope_->ForceDynamicLookup(proxy);
+    return;
+  }
+
   GetScope()->EnsureRareData()->unresolved_private_names.Add(proxy);
   // Any closure scope that contain uses of private names that skips over a
   // class scope due to heritage expressions need private name context chain