LibJS: Ref-counted execution context

kalenikaliaksandr · May 16, 2024 · e398220 · e398220
1 parent ed50eb0
commit e398220
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Showing 17 changed files with 46 additions and 37 deletions.
diff --git a/Userland/Libraries/LibJS/Bytecode/Executable.h b/Userland/Libraries/LibJS/Bytecode/Executable.h
@@ -9,6 +9,7 @@
 #include <AK/DeprecatedFlyString.h>
 #include <AK/HashMap.h>
 #include <AK/NonnullOwnPtr.h>
+#include <AK/NonnullRefPtr.h>
 #include <AK/OwnPtr.h>
 #include <AK/WeakPtr.h>
 #include <LibJS/Bytecode/IdentifierTable.h>

diff --git a/Userland/Libraries/LibJS/Forward.h b/Userland/Libraries/LibJS/Forward.h
@@ -323,6 +323,11 @@ class Interpreter;
 class Operand;
 class RegexTable;
 class Register;
+
+namespace Op {
+class Call;
+};
+
 }
 
 }
diff --git a/Userland/Libraries/LibJS/Runtime/AsyncFunctionDriverWrapper.h b/Userland/Libraries/LibJS/Runtime/AsyncFunctionDriverWrapper.h
@@ -39,7 +39,7 @@ class AsyncFunctionDriverWrapper final : public Promise {
     NonnullGCPtr<Promise> m_top_level_promise;
     GCPtr<Promise> m_current_promise { nullptr };
     Handle<AsyncFunctionDriverWrapper> m_self_handle;
-    OwnPtr<ExecutionContext> m_suspended_execution_context;
+    RefPtr<ExecutionContext> m_suspended_execution_context;
 };
 
 }
diff --git a/Userland/Libraries/LibJS/Runtime/AsyncGenerator.cpp b/Userland/Libraries/LibJS/Runtime/AsyncGenerator.cpp
@@ -16,7 +16,7 @@ namespace JS {
 
 JS_DEFINE_ALLOCATOR(AsyncGenerator);
 
-ThrowCompletionOr<NonnullGCPtr<AsyncGenerator>> AsyncGenerator::create(Realm& realm, Value initial_value, ECMAScriptFunctionObject* generating_function, NonnullOwnPtr<ExecutionContext> execution_context)
+ThrowCompletionOr<NonnullGCPtr<AsyncGenerator>> AsyncGenerator::create(Realm& realm, Value initial_value, ECMAScriptFunctionObject* generating_function, NonnullRefPtr<ExecutionContext> execution_context)
 {
     auto& vm = realm.vm();
     // This is "g1.prototype" in figure-2 (https://tc39.es/ecma262/img/figure-2.png)
@@ -28,7 +28,7 @@ ThrowCompletionOr<NonnullGCPtr<AsyncGenerator>> AsyncGenerator::create(Realm& re
     return object;
 }
 
-AsyncGenerator::AsyncGenerator(Realm&, Object& prototype, NonnullOwnPtr<ExecutionContext> context)
+AsyncGenerator::AsyncGenerator(Realm&, Object& prototype, NonnullRefPtr<ExecutionContext> context)
     : Object(ConstructWithPrototypeTag::Tag, prototype)
     , m_async_generator_context(move(context))
 {

diff --git a/Userland/Libraries/LibJS/Runtime/AsyncGenerator.h b/Userland/Libraries/LibJS/Runtime/AsyncGenerator.h
@@ -28,7 +28,7 @@ class AsyncGenerator final : public Object {
         Completed,
     };
 
-    static ThrowCompletionOr<NonnullGCPtr<AsyncGenerator>> create(Realm&, Value, ECMAScriptFunctionObject*, NonnullOwnPtr<ExecutionContext>);
+    static ThrowCompletionOr<NonnullGCPtr<AsyncGenerator>> create(Realm&, Value, ECMAScriptFunctionObject*, NonnullRefPtr<ExecutionContext>);
 
     virtual ~AsyncGenerator() override = default;
 
@@ -44,7 +44,7 @@ class AsyncGenerator final : public Object {
     Optional<String> const& generator_brand() const { return m_generator_brand; }
 
 private:
-    AsyncGenerator(Realm&, Object& prototype, NonnullOwnPtr<ExecutionContext>);
+    AsyncGenerator(Realm&, Object& prototype, NonnullRefPtr<ExecutionContext>);
 
     virtual void visit_edges(Cell::Visitor&) override;
 
@@ -54,7 +54,7 @@ class AsyncGenerator final : public Object {
     // At the time of constructing an AsyncGenerator, we still need to point to an
     // execution context on the stack, but later need to 'adopt' it.
     State m_async_generator_state { State::SuspendedStart };   // [[AsyncGeneratorState]]
-    NonnullOwnPtr<ExecutionContext> m_async_generator_context; // [[AsyncGeneratorContext]]
+    NonnullRefPtr<ExecutionContext> m_async_generator_context; // [[AsyncGeneratorContext]]
     Vector<AsyncGeneratorRequest> m_async_generator_queue;     // [[AsyncGeneratorQueue]]
     Optional<String> m_generator_brand;                        // [[GeneratorBrand]]
 

diff --git a/Userland/Libraries/LibJS/Runtime/ExecutionContext.cpp b/Userland/Libraries/LibJS/Runtime/ExecutionContext.cpp
@@ -13,9 +13,9 @@
 
 namespace JS {
 
-NonnullOwnPtr<ExecutionContext> ExecutionContext::create(Heap& heap)
+NonnullRefPtr<ExecutionContext> ExecutionContext::create(Heap& heap)
 {
-    return adopt_own(*new ExecutionContext(heap));
+    return adopt_ref(*new ExecutionContext(heap));
 }
 
 ExecutionContext::ExecutionContext(Heap& heap)
@@ -27,7 +27,7 @@ ExecutionContext::~ExecutionContext()
 {
 }
 
-NonnullOwnPtr<ExecutionContext> ExecutionContext::copy() const
+NonnullRefPtr<ExecutionContext> ExecutionContext::copy() const
 {
     auto copy = create(m_heap);
     copy->function = function;

diff --git a/Userland/Libraries/LibJS/Runtime/ExecutionContext.h b/Userland/Libraries/LibJS/Runtime/ExecutionContext.h
@@ -22,9 +22,9 @@ namespace JS {
 using ScriptOrModule = Variant<Empty, NonnullGCPtr<Script>, NonnullGCPtr<Module>>;
 
 // 9.4 Execution Contexts, https://tc39.es/ecma262/#sec-execution-contexts
-struct ExecutionContext {
-    static NonnullOwnPtr<ExecutionContext> create(Heap&);
-    [[nodiscard]] NonnullOwnPtr<ExecutionContext> copy() const;
+struct ExecutionContext : RefCounted<ExecutionContext> {
+    static NonnullRefPtr<ExecutionContext> create(Heap&);
+    [[nodiscard]] NonnullRefPtr<ExecutionContext> copy() const;
 
     ~ExecutionContext();
 
@@ -80,6 +80,9 @@ struct ExecutionContext {
     Vector<Bytecode::UnwindInfo> unwind_contexts;
     Vector<Optional<size_t>> previously_scheduled_jumps;
     Vector<GCPtr<Environment>> saved_lexical_environments;
+
+    Optional<Bytecode::Operand> result_dst;
+    Function<ThrowCompletionOr<Value>(Value)> return_steps;
 };
 
 struct StackTraceElement {

diff --git a/Userland/Libraries/LibJS/Runtime/GeneratorObject.cpp b/Userland/Libraries/LibJS/Runtime/GeneratorObject.cpp
@@ -16,7 +16,7 @@ namespace JS {
 
 JS_DEFINE_ALLOCATOR(GeneratorObject);
 
-ThrowCompletionOr<NonnullGCPtr<GeneratorObject>> GeneratorObject::create(Realm& realm, Value initial_value, ECMAScriptFunctionObject* generating_function, NonnullOwnPtr<ExecutionContext> execution_context)
+ThrowCompletionOr<NonnullGCPtr<GeneratorObject>> GeneratorObject::create(Realm& realm, Value initial_value, ECMAScriptFunctionObject* generating_function, NonnullRefPtr<ExecutionContext> execution_context)
 {
     auto& vm = realm.vm();
     // This is "g1.prototype" in figure-2 (https://tc39.es/ecma262/img/figure-2.png)
@@ -36,7 +36,7 @@ ThrowCompletionOr<NonnullGCPtr<GeneratorObject>> GeneratorObject::create(Realm&
     return object;
 }
 
-GeneratorObject::GeneratorObject(Realm&, Object& prototype, NonnullOwnPtr<ExecutionContext> context, Optional<StringView> generator_brand)
+GeneratorObject::GeneratorObject(Realm&, Object& prototype, NonnullRefPtr<ExecutionContext> context, Optional<StringView> generator_brand)
     : Object(ConstructWithPrototypeTag::Tag, prototype)
     , m_execution_context(move(context))
     , m_generator_brand(move(generator_brand))

diff --git a/Userland/Libraries/LibJS/Runtime/GeneratorObject.h b/Userland/Libraries/LibJS/Runtime/GeneratorObject.h
@@ -17,7 +17,7 @@ class GeneratorObject : public Object {
     JS_DECLARE_ALLOCATOR(GeneratorObject);
 
 public:
-    static ThrowCompletionOr<NonnullGCPtr<GeneratorObject>> create(Realm&, Value, ECMAScriptFunctionObject*, NonnullOwnPtr<ExecutionContext>);
+    static ThrowCompletionOr<NonnullGCPtr<GeneratorObject>> create(Realm&, Value, ECMAScriptFunctionObject*, NonnullRefPtr<ExecutionContext>);
     virtual ~GeneratorObject() override = default;
     void visit_edges(Cell::Visitor&) override;
 
@@ -34,13 +34,13 @@ class GeneratorObject : public Object {
     void set_generator_state(GeneratorState generator_state) { m_generator_state = generator_state; }
 
 protected:
-    GeneratorObject(Realm&, Object& prototype, NonnullOwnPtr<ExecutionContext>, Optional<StringView> generator_brand = {});
+    GeneratorObject(Realm&, Object& prototype, NonnullRefPtr<ExecutionContext>, Optional<StringView> generator_brand = {});
 
     ThrowCompletionOr<GeneratorState> validate(VM&, Optional<StringView> const& generator_brand);
     virtual ThrowCompletionOr<Value> execute(VM&, JS::Completion const& completion);
 
 private:
-    NonnullOwnPtr<ExecutionContext> m_execution_context;
+    NonnullRefPtr<ExecutionContext> m_execution_context;
     GCPtr<ECMAScriptFunctionObject> m_generating_function;
     Value m_previous_value;
     GeneratorState m_generator_state { GeneratorState::SuspendedStart };

diff --git a/Userland/Libraries/LibJS/Runtime/Realm.cpp b/Userland/Libraries/LibJS/Runtime/Realm.cpp
@@ -34,7 +34,7 @@ ThrowCompletionOr<NonnullGCPtr<Realm>> Realm::create(VM& vm)
 }
 
 // 9.6 InitializeHostDefinedRealm ( ), https://tc39.es/ecma262/#sec-initializehostdefinedrealm
-ThrowCompletionOr<NonnullOwnPtr<ExecutionContext>> Realm::initialize_host_defined_realm(VM& vm, Function<Object*(Realm&)> create_global_object, Function<Object*(Realm&)> create_global_this_value)
+ThrowCompletionOr<NonnullRefPtr<ExecutionContext>> Realm::initialize_host_defined_realm(VM& vm, Function<Object*(Realm&)> create_global_object, Function<Object*(Realm&)> create_global_this_value)
 {
     DeferGC defer_gc(vm.heap());
 

diff --git a/Userland/Libraries/LibJS/Runtime/Realm.h b/Userland/Libraries/LibJS/Runtime/Realm.h
@@ -32,7 +32,7 @@ class Realm final : public Cell {
     };
 
     static ThrowCompletionOr<NonnullGCPtr<Realm>> create(VM&);
-    static ThrowCompletionOr<NonnullOwnPtr<ExecutionContext>> initialize_host_defined_realm(VM&, NOESCAPE Function<Object*(Realm&)> create_global_object, NOESCAPE Function<Object*(Realm&)> create_global_this_value);
+    static ThrowCompletionOr<NonnullRefPtr<ExecutionContext>> initialize_host_defined_realm(VM&, NOESCAPE Function<Object*(Realm&)> create_global_object, NOESCAPE Function<Object*(Realm&)> create_global_this_value);
 
     void set_global_object(Object* global_object, Object* this_value);
 

diff --git a/Userland/Libraries/LibJS/Runtime/ShadowRealm.cpp b/Userland/Libraries/LibJS/Runtime/ShadowRealm.cpp
@@ -22,7 +22,7 @@ namespace JS {
 
 JS_DEFINE_ALLOCATOR(ShadowRealm);
 
-ShadowRealm::ShadowRealm(Realm& shadow_realm, NonnullOwnPtr<ExecutionContext> execution_context, Object& prototype)
+ShadowRealm::ShadowRealm(Realm& shadow_realm, NonnullRefPtr<ExecutionContext> execution_context, Object& prototype)
     : Object(ConstructWithPrototypeTag::Tag, prototype)
     , m_shadow_realm(shadow_realm)
     , m_execution_context(move(execution_context))

diff --git a/Userland/Libraries/LibJS/Runtime/ShadowRealm.h b/Userland/Libraries/LibJS/Runtime/ShadowRealm.h
@@ -26,13 +26,13 @@ class ShadowRealm final : public Object {
     [[nodiscard]] ExecutionContext& execution_context() { return *m_execution_context; }
 
 private:
-    ShadowRealm(Realm&, NonnullOwnPtr<ExecutionContext>, Object& prototype);
+    ShadowRealm(Realm&, NonnullRefPtr<ExecutionContext>, Object& prototype);
 
     virtual void visit_edges(Visitor&) override;
 
     // 3.5 Properties of ShadowRealm Instances, https://tc39.es/proposal-shadowrealm/#sec-properties-of-shadowrealm-instances
     NonnullGCPtr<Realm> m_shadow_realm;                  // [[ShadowRealm]]
-    NonnullOwnPtr<ExecutionContext> m_execution_context; // [[ExecutionContext]]
+    NonnullRefPtr<ExecutionContext> m_execution_context; // [[ExecutionContext]]
 };
 
 ThrowCompletionOr<void> copy_name_and_length(VM&, FunctionObject& function, FunctionObject& target, Optional<StringView> prefix = {}, Optional<unsigned> arg_count = {});

diff --git a/Userland/Libraries/LibJS/Runtime/VM.cpp b/Userland/Libraries/LibJS/Runtime/VM.cpp
@@ -203,7 +203,7 @@ void VM::gather_roots(HashMap<Cell*, HeapRoot>& roots)
     for (auto finalization_registry : m_finalization_registry_cleanup_jobs)
         roots.set(finalization_registry, HeapRoot { .type = HeapRoot::Type::VM });
 
-    auto gather_roots_from_execution_context_stack = [&roots](Vector<ExecutionContext*> const& stack) {
+    auto gather_roots_from_execution_context_stack = [&roots](Vector<NonnullRefPtr<ExecutionContext>> const& stack) {
         for (auto const& execution_context : stack) {
             ExecutionContextRootsCollector visitor;
             execution_context->visit_edges(visitor);
@@ -686,16 +686,16 @@ void VM::load_imported_module(ImportedModuleReferrer referrer, ModuleRequest con
     finish_loading_imported_module(referrer, module_request, payload, module);
 }
 
-void VM::push_execution_context(ExecutionContext& context)
+void VM::push_execution_context(NonnullRefPtr<ExecutionContext> context)
 {
     if (!m_execution_context_stack.is_empty())
         m_execution_context_stack.last()->program_counter = bytecode_interpreter().program_counter();
-    m_execution_context_stack.append(&context);
+    m_execution_context_stack.append(move(context));
 }
 
 void VM::pop_execution_context()
 {
-    m_execution_context_stack.take_last();
+    (void)m_execution_context_stack.take_last();
     if (m_execution_context_stack.is_empty() && on_call_stack_emptied)
         on_call_stack_emptied();
 }
@@ -723,7 +723,7 @@ Vector<StackTraceElement> VM::stack_trace() const
 {
     Vector<StackTraceElement> stack_trace;
     for (ssize_t i = m_execution_context_stack.size() - 1; i >= 0; i--) {
-        auto* context = m_execution_context_stack[i];
+        auto context = m_execution_context_stack[i];
         stack_trace.append({
             .execution_context = context,
             .source_range = get_source_range(context).value_or({}),

diff --git a/Userland/Libraries/LibJS/Runtime/VM.h b/Userland/Libraries/LibJS/Runtime/VM.h
@@ -107,16 +107,16 @@ class VM : public RefCounted<VM> {
     // TODO: Rename this function instead of providing a second argument, now that the global object is no longer passed in.
     struct CheckStackSpaceLimitTag { };
 
-    ThrowCompletionOr<void> push_execution_context(ExecutionContext& context, CheckStackSpaceLimitTag)
+    ThrowCompletionOr<void> push_execution_context(NonnullRefPtr<ExecutionContext> context, CheckStackSpaceLimitTag)
     {
         // Ensure we got some stack space left, so the next function call doesn't kill us.
         if (did_reach_stack_space_limit())
             return throw_completion<InternalError>(ErrorType::CallStackSizeExceeded);
-        push_execution_context(context);
+        push_execution_context(move(context));
         return {};
     }
 
-    void push_execution_context(ExecutionContext&);
+    void push_execution_context(NonnullRefPtr<ExecutionContext>);
     void pop_execution_context();
 
     // https://tc39.es/ecma262/#running-execution-context
@@ -135,8 +135,8 @@ class VM : public RefCounted<VM> {
 
     // https://tc39.es/ecma262/#execution-context-stack
     // The execution context stack is used to track execution contexts.
-    Vector<ExecutionContext*> const& execution_context_stack() const { return m_execution_context_stack; }
-    Vector<ExecutionContext*>& execution_context_stack() { return m_execution_context_stack; }
+    Vector<NonnullRefPtr<ExecutionContext>> const& execution_context_stack() const { return m_execution_context_stack; }
+    Vector<NonnullRefPtr<ExecutionContext>>& execution_context_stack() { return m_execution_context_stack; }
 
     Environment const* lexical_environment() const { return running_execution_context().lexical_environment; }
     Environment* lexical_environment() { return running_execution_context().lexical_environment; }
@@ -282,9 +282,9 @@ class VM : public RefCounted<VM> {
 
     Heap m_heap;
 
-    Vector<ExecutionContext*> m_execution_context_stack;
+    Vector<NonnullRefPtr<ExecutionContext>> m_execution_context_stack;
 
-    Vector<Vector<ExecutionContext*>> m_saved_execution_context_stacks;
+    Vector<Vector<NonnullRefPtr<ExecutionContext>>> m_saved_execution_context_stacks;
 
     StackInfo m_stack_info;
 
@@ -323,7 +323,7 @@ class VM : public RefCounted<VM> {
 };
 
 template<typename GlobalObjectType, typename... Args>
-[[nodiscard]] static NonnullOwnPtr<ExecutionContext> create_simple_execution_context(VM& vm, Args&&... args)
+[[nodiscard]] static NonnullRefPtr<ExecutionContext> create_simple_execution_context(VM& vm, Args&&... args)
 {
     auto root_execution_context = MUST(Realm::initialize_host_defined_realm(
         vm,

diff --git a/Userland/Libraries/LibJS/SourceTextModule.h b/Userland/Libraries/LibJS/SourceTextModule.h
@@ -42,7 +42,7 @@ class SourceTextModule final : public CyclicModule {
     virtual void visit_edges(Cell::Visitor&) override;
 
     NonnullRefPtr<Program> m_ecmascript_code;            // [[ECMAScriptCode]]
-    NonnullOwnPtr<ExecutionContext> m_execution_context; // [[Context]]
+    NonnullRefPtr<ExecutionContext> m_execution_context; // [[Context]]
     GCPtr<Object> m_import_meta;                         // [[ImportMeta]]
     Vector<ImportEntry> m_import_entries;                // [[ImportEntries]]
     Vector<ExportEntry> m_local_export_entries;          // [[LocalExportEntries]]

diff --git a/Userland/Utilities/js.cpp b/Userland/Utilities/js.cpp
@@ -795,7 +795,7 @@ ErrorOr<int> serenity_main(Main::Arguments arguments)
         TRY(repl(realm));
         s_editor->save_history(s_history_path.to_byte_string());
     } else {
-        OwnPtr<JS::ExecutionContext> root_execution_context;
+        RefPtr<JS::ExecutionContext> root_execution_context;
         if (use_test262_global)
             root_execution_context = JS::create_simple_execution_context<JS::Test262::GlobalObject>(*g_vm);
         else