LibJS+Everywhere: Remove VM::exception() and most related functions

This commit removes all exception related code:
Remove VM::exception(), VM::throw_exception() etc. Any leftover
throw_exception calls are moved to throw_completion.
The one method left is clear_exception() which is now a no-op. Most of
these calls are just to clear whatever exception might have been thrown
when handling a Completion. So to have a cleaner commit this will be
removed in a next commit.

It also removes the actual Exception and TemporaryClearException classes
since these are no longer used.

In any spot where the exception was actually used an attempt was made to
preserve that behavior. However since it is no longer tracked by the VM
we cannot access exceptions which were thrown in previous calls.
There are two such cases which might have different behavior:
- In Web::DOM::Document::interpreter() the on_call_stack_emptied hook
  used to print any uncaught exception but this is now no longer
  possible as the VM does not store uncaught exceptions.
- In js the code used to be interruptable by throwing an exception on
  the VM. This is no longer possible but was already somewhat fragile
  before as you could happen to throw an exception just before a VERIFY.

Tests/LibJS/test-bytecode-js.cpp

@@ -25,8 +25,7 @@
 #define EXPECT_NO_EXCEPTION(executable)                           \
     auto executable = JS::Bytecode::Generator::generate(program); \
     auto result = bytecode_interpreter.run(*executable);          \
-    EXPECT(!result.is_error());                                   \
-    EXPECT(!vm->exception());
+    EXPECT(!result.is_error());
 
 #define EXPECT_NO_EXCEPTION_WITH_OPTIMIZATIONS(executable)                  \
     auto& passes = JS::Bytecode::Interpreter::optimization_pipeline();      \
@@ -34,8 +33,7 @@
                                                                             \
     auto result_with_optimizations = bytecode_interpreter.run(*executable); \
                                                                             \
-    EXPECT(!result_with_optimizations.is_error());                          \
-    EXPECT(!vm->exception())
+    EXPECT(!result_with_optimizations.is_error());
 
 #define EXPECT_NO_EXCEPTION_ALL(source) \
     SETUP_AND_PARSE(source)             \
@@ -117,7 +115,6 @@ TEST_CASE(loading_multiple_files)
         auto executable = JS::Bytecode::Generator::generate(test_file_program);
         auto result = bytecode_interpreter.run(*executable);
         EXPECT(!result.is_error());
-        EXPECT(!vm->exception());
     }
 }
 

Tests/LibWeb/test-web.cpp

@@ -22,8 +22,8 @@ TEST_ROOT("Userland/Libraries/LibWeb/Tests");
 RefPtr<Web::InProcessWebView> g_page_view;
 RefPtr<GUI::Application> g_app;
 Optional<URL> next_page_to_load;
-Vector<Function<void(JS::Object&)>> after_initial_load_hooks;
-Vector<Function<void(JS::Object&)>> before_initial_load_hooks;
+Vector<Function<JS::ThrowCompletionOr<void>(JS::Object&)>> after_initial_load_hooks;
+Vector<Function<JS::ThrowCompletionOr<void>(JS::Object&)>> before_initial_load_hooks;
 
 TESTJS_MAIN_HOOK()
 {
@@ -62,8 +62,9 @@ TESTJS_GLOBAL_FUNCTION(after_initial_page_load, afterInitialPageLoad)
         return vm.throw_completion<JS::TypeError>(global_object, JS::ErrorType::NotAnObjectOfType, "Function");
     }
 
-    after_initial_load_hooks.append([fn = JS::make_handle(&function.as_function()), &global_object](auto& page_object) {
-        [[maybe_unused]] auto unused = JS::call(global_object, const_cast<JS::FunctionObject&>(*fn.cell()), JS::js_undefined(), &page_object);
+    after_initial_load_hooks.append([fn = JS::make_handle(&function.as_function()), &global_object](auto& page_object) -> JS::ThrowCompletionOr<void> {
+        TRY(JS::call(global_object, const_cast<JS::FunctionObject&>(*fn.cell()), JS::js_undefined(), &page_object));
+        return {};
     });
     return JS::js_undefined();
 }
@@ -76,8 +77,9 @@ TESTJS_GLOBAL_FUNCTION(before_initial_page_load, beforeInitialPageLoad)
         return vm.throw_completion<JS::TypeError>(global_object, JS::ErrorType::NotAnObjectOfType, "Function");
     }
 
-    before_initial_load_hooks.append([fn = JS::make_handle(&function.as_function()), &global_object](auto& page_object) {
-        [[maybe_unused]] auto unused = JS::call(global_object, const_cast<JS::FunctionObject&>(*fn.cell()), JS::js_undefined(), &page_object);
+    before_initial_load_hooks.append([fn = JS::make_handle(&function.as_function()), &global_object](auto& page_object) -> JS::ThrowCompletionOr<void> {
+        TRY(JS::call(global_object, const_cast<JS::FunctionObject&>(*fn.cell()), JS::js_undefined(), &page_object));
+        return {};
     });
     return JS::js_undefined();
 }
@@ -89,12 +91,14 @@ TESTJS_GLOBAL_FUNCTION(wait_for_page_to_load, waitForPageToLoad)
 
     // Run the "before" hooks
     for (auto& entry : before_initial_load_hooks)
-        entry(document->interpreter().global_object());
+        TRY(entry(document->interpreter().global_object()));
 
     // Set the load hook
     Web::LoadRequest request;
     request.set_url(next_page_to_load.value());
 
+    JS::ThrowCompletionOr<void> result = {};
+
     auto& loader = Web::ResourceLoader::the();
     loader.load_sync(
         request,
@@ -103,22 +107,23 @@ TESTJS_GLOBAL_FUNCTION(wait_for_page_to_load, waitForPageToLoad)
             // Now parse the HTML page.
             parser.run(next_page_to_load.value());
             g_page_view->set_document(&parser.document());
-            if (vm.exception()) {
-                // FIXME: Should we do something about this? the document itself threw unhandled exceptions...
-                vm.clear_exception();
-            }
+            // Note: Unhandled exceptions are just dropped here.
 
             // Run the "after" hooks
             for (auto& entry : after_initial_load_hooks) {
-                entry(document->interpreter().global_object());
-                if (vm.exception())
+                auto ran_or_error = entry(document->interpreter().global_object());
+                if (ran_or_error.is_error()) {
+                    result = ran_or_error.release_error();
                     break;
+                }
             }
         },
         [&](auto&, auto) {
             dbgln("Load of resource {} failed", next_page_to_load.value());
-            vm.throw_exception<JS::TypeError>(global_object, "Resource load failed");
+            result = vm.template throw_completion<JS::TypeError>(global_object, "Resource load failed");
         });
 
+    if (result.is_error())
+        return result.release_error();
     return JS::js_undefined();
 }

Userland/Libraries/LibJS/AST.cpp

@@ -456,7 +456,6 @@ Completion SuperCall::execute(Interpreter& interpreter, GlobalObject& global_obj
 
     // 3. Let func be ! GetSuperConstructor().
     auto* func = get_super_constructor(interpreter.vm());
-    VERIFY(!vm.exception());
 
     // 4. Let argList be ? ArgumentListEvaluation of Arguments.
     MarkedValueList arg_list(vm.heap());
@@ -3686,7 +3685,6 @@ Completion TryStatement::execute(Interpreter& interpreter, GlobalObject& global_
     // TryStatement : try Block Catch
     // TryStatement : try Block Catch Finally
     if (m_handler) {
-        vm.clear_exception();
         // 2. If B.[[Type]] is throw, let C be CatchClauseEvaluation of Catch with argument B.[[Value]].
         if (block_result.type() == Completion::Type::Throw)
             result = catch_clause_evaluation(*block_result.value());
@@ -3702,12 +3700,6 @@ Completion TryStatement::execute(Interpreter& interpreter, GlobalObject& global_
     // TryStatement : try Block Finally
     // TryStatement : try Block Catch Finally
     if (m_finalizer) {
-        // NOTE: Temporary until VM::exception() is removed
-        // Keep, if any, and then clear the current exception so we can
-        // execute() the finalizer without an exception in our way.
-        auto* previous_exception = vm.exception();
-        vm.clear_exception();
-
         // 4. Let F be the result of evaluating Finally.
         auto finalizer_result = m_finalizer->execute(interpreter, global_object);
 
@@ -3715,12 +3707,6 @@ Completion TryStatement::execute(Interpreter& interpreter, GlobalObject& global_
         if (finalizer_result.type() == Completion::Type::Normal)
             finalizer_result = move(result);
 
-        // NOTE: Temporary until VM::exception() is removed
-        // If we previously had an exception and we're carrying over
-        // the catch block completion, restore it.
-        if (finalizer_result.type() == Completion::Type::Normal && previous_exception)
-            vm.set_exception(*previous_exception);
-
         // 6. Return Completion(UpdateEmpty(F, undefined)).
         return finalizer_result.update_empty(js_undefined());
     }
@@ -3748,8 +3734,6 @@ Completion ThrowStatement::execute(Interpreter& interpreter, GlobalObject& globa
     auto value = TRY(m_argument->execute(interpreter, global_object)).release_value();
 
     // 3. Return ThrowCompletion(exprValue).
-    // TODO: Remove this once we get rid of VM::exception()
-    interpreter.vm().throw_exception(global_object, value);
     return throw_completion(value);
 }
 

Userland/Libraries/LibJS/Bytecode/Interpreter.cpp

@@ -80,13 +80,6 @@ Interpreter::ValueAndFrame Interpreter::run_and_return_frame(Executable const& e
         while (!pc.at_end()) {
             auto& instruction = *pc;
             auto ran_or_error = instruction.execute(*this);
-            if (vm().exception()) {
-                if (!ran_or_error.is_error()) {
-                    // FIXME: Until exception is removed use this to make sure we always get the error if there is one.
-                    ran_or_error = throw_completion(vm().exception()->value());
-                }
-                vm().clear_exception();
-            }
             if (ran_or_error.is_error()) {
                 auto exception_value = *ran_or_error.throw_completion().value();
                 m_saved_exception = make_handle(exception_value);

Userland/Libraries/LibJS/CMakeLists.txt

@@ -72,7 +72,6 @@ set(SOURCES
     Runtime/ErrorConstructor.cpp
     Runtime/ErrorPrototype.cpp
     Runtime/ErrorTypes.cpp
-    Runtime/Exception.cpp
     Runtime/FinalizationRegistry.cpp
     Runtime/FinalizationRegistryConstructor.cpp
     Runtime/FinalizationRegistryPrototype.cpp

Userland/Libraries/LibJS/CyclicModule.cpp

@@ -207,8 +207,6 @@ ThrowCompletionOr<Promise*> CyclicModule::evaluate(VM& vm)
     // 8. Let result be InnerModuleEvaluation(module, stack, 0).
     auto result = inner_module_evaluation(vm, stack, 0);
 
-    VERIFY(!vm.exception());
-
     // 9. If result is an abrupt completion, then
     if (result.is_throw_completion()) {
         VERIFY(!m_evaluation_error.is_error());
@@ -238,8 +236,6 @@ ThrowCompletionOr<Promise*> CyclicModule::evaluate(VM& vm)
 
         // d. Perform ! Call(capability.[[Reject]], undefined, « result.[[Value]] »).
         MUST(call(global_object, m_top_level_capability->reject, js_undefined(), *result.throw_completion().value()));
-
-        VERIFY(!vm.exception());
     }
     // 10. Else,
     else {

Userland/Libraries/LibJS/Forward.h

@@ -147,7 +147,6 @@ class ECMAScriptFunctionObject;
 class Environment;
 class Error;
 class ErrorType;
-class Exception;
 class Expression;
 class FunctionEnvironment;
 class FunctionNode;

Userland/Libraries/LibJS/Interpreter.cpp

@@ -44,7 +44,6 @@ Interpreter::~Interpreter()
 ThrowCompletionOr<Value> Interpreter::run(Script& script_record)
 {
     auto& vm = this->vm();
-    VERIFY(!vm.exception());
 
     VM::InterpreterExecutionScope scope(*this);
 
@@ -136,24 +135,15 @@ ThrowCompletionOr<Value> Interpreter::run(SourceTextModule& module)
     //        To avoid work we use link_and_eval_module however that can already be
     //        dangerous if the vm loaded other modules.
     auto& vm = this->vm();
-    VERIFY(!vm.exception());
 
     VM::InterpreterExecutionScope scope(*this);
 
-    auto evaluated_or_error = vm.link_and_eval_module({}, module);
-    // This error does not set vm.exception so we set that here for the stuff that needs it
-    if (evaluated_or_error.is_throw_completion()) {
-        auto* error = vm.heap().allocate<Exception>(global_object(), *(evaluated_or_error.throw_completion().value()));
-        vm.set_exception(*error);
-        return evaluated_or_error.throw_completion();
-    }
-    VERIFY(!vm.exception());
+    TRY(vm.link_and_eval_module({}, module));
 
     vm.run_queued_promise_jobs();
 
     vm.run_queued_finalization_registry_cleanup_jobs();
 
-    VERIFY(!vm.exception());
     return js_undefined();
 }
 

Userland/Libraries/LibJS/Interpreter.h

@@ -18,7 +18,6 @@
 #include <LibJS/Runtime/Completion.h>
 #include <LibJS/Runtime/DeclarativeEnvironment.h>
 #include <LibJS/Runtime/ErrorTypes.h>
-#include <LibJS/Runtime/Exception.h>
 #include <LibJS/Runtime/GlobalEnvironment.h>
 #include <LibJS/Runtime/GlobalObject.h>
 #include <LibJS/Runtime/MarkedValueList.h>
@@ -116,7 +115,6 @@ public:
     ALWAYS_INLINE VM& vm() { return *m_vm; }
     ALWAYS_INLINE const VM& vm() const { return *m_vm; }
     ALWAYS_INLINE Heap& heap() { return vm().heap(); }
-    ALWAYS_INLINE Exception* exception() { return vm().exception(); }
 
     Environment* lexical_environment() { return vm().lexical_environment(); }
 

Userland/Libraries/LibJS/Runtime/AbstractOperations.cpp

@@ -964,7 +964,6 @@ Object* create_mapped_arguments_object(GlobalObject& global_object, FunctionObje
     // 8. Set obj.[[Delete]] as specified in 10.4.4.5.
     // 9. Set obj.[[Prototype]] to %Object.prototype%.
     auto* object = vm.heap().allocate<ArgumentsObject>(global_object, global_object, environment);
-    VERIFY(!vm.exception());
 
     // 14. Let index be 0.
     // 15. Repeat, while index < len,

Userland/Libraries/LibJS/Runtime/Array.h

@@ -26,13 +26,11 @@ public:
     template<typename T>
     static Array* create_from(GlobalObject& global_object, Span<T const> elements, Function<Value(T const&)> map_fn)
     {
-        auto& vm = global_object.vm();
         auto values = MarkedValueList { global_object.heap() };
         values.ensure_capacity(elements.size());
-        for (auto const& element : elements) {
+        for (auto const& element : elements)
             values.append(map_fn(element));
-            VERIFY(!vm.exception());
-        }
+
         return Array::create_from(global_object, values);
     }
 

Userland/Libraries/LibJS/Runtime/Completion.cpp

@@ -115,10 +115,6 @@ ThrowCompletionOr<Value> await(GlobalObject& global_object, Value value)
 
     if (success.value())
         return result;
-    // NOTE: This is temporary until we remove VM::exception(). It's required as callers of
-    //       AwaitExpression still need to check for an exception rather than a completion
-    //       type as long as ASTNode::execute() returns a plain Value.
-    vm.throw_exception(global_object, result);
     return throw_completion(result);
 }
 

Userland/Libraries/LibJS/Runtime/ECMAScriptFunctionObject.cpp

@@ -551,7 +551,6 @@ ThrowCompletionOr<void> ECMAScriptFunctionObject::function_declaration_instantia
         });
     });
 
-    VERIFY(!vm.exception());
     auto* private_environment = callee_context.private_environment;
     for (auto& declaration : functions_to_initialize) {
         auto* function = ECMAScriptFunctionObject::create(global_object(), declaration.name(), declaration.source_text(), declaration.body(), declaration.parameters(), declaration.function_length(), lex_environment, private_environment, declaration.kind(), declaration.is_strict_mode(), declaration.might_need_arguments_object(), declaration.contains_direct_call_to_eval());
@@ -731,7 +730,6 @@ void async_block_start(VM& vm, NonnullRefPtr<Statement> const& async_body, Promi
             VERIFY(result.type() == Completion::Type::Throw);
 
             // ii. Perform ! Call(promiseCapability.[[Reject]], undefined, « result.[[Value]] »).
-            vm.clear_exception();
             MUST(call(global_object, promise_capability.reject, js_undefined(), *result.value()));
         }
         // g. Return.
@@ -781,14 +779,11 @@ Completion ECMAScriptFunctionObject::ordinary_call_evaluate_body()
                 m_bytecode_executable->dump();
         }
         auto result_and_frame = bytecode_interpreter->run_and_return_frame(*m_bytecode_executable, nullptr);
-        if (auto* exception = vm.exception())
-            return throw_completion(exception->value());
 
         VERIFY(result_and_frame.frame != nullptr);
-        if (result_and_frame.value.is_error()) {
-            vm.throw_exception(bytecode_interpreter->global_object(), *result_and_frame.value.release_error().value());
-            return throw_completion(vm.exception()->value());
-        }
+        if (result_and_frame.value.is_error())
+            return result_and_frame.value.release_error();
+
         auto result = result_and_frame.value.release_value();
 
         // NOTE: Running the bytecode should eventually return a completion.

Userland/Libraries/LibJS/Runtime/Exception.cpp

@@ -1,42 +0,0 @@
-/*
- * Copyright (c) 2020, Andreas Kling <kling@serenityos.org>
- * Copyright (c) 2021, Linus Groh <linusg@serenityos.org>
- *
- * SPDX-License-Identifier: BSD-2-Clause
- */
-
-#include <AK/String.h>
-#include <LibJS/AST.h>
-#include <LibJS/Interpreter.h>
-#include <LibJS/Runtime/Exception.h>
-#include <LibJS/Runtime/VM.h>
-
-namespace JS {
-
-Exception::Exception(Value value)
-    : m_value(value)
-{
-    auto& vm = this->vm();
-    m_traceback.ensure_capacity(vm.execution_context_stack().size());
-    for (ssize_t i = vm.execution_context_stack().size() - 1; i >= 0; i--) {
-        auto* context = vm.execution_context_stack()[i];
-        auto function_name = context->function_name;
-        if (function_name.is_empty())
-            function_name = "<anonymous>";
-        m_traceback.empend(
-            move(function_name),
-            // We might not have an AST node associated with the execution context, e.g. in promise
-            // reaction jobs (which aren't called anywhere from the source code).
-            // They're not going to generate any _unhandled_ exceptions though, so a meaningless
-            // source range is fine.
-            context->current_node ? context->current_node->source_range() : SourceRange {});
-    }
-}
-
-void Exception::visit_edges(Visitor& visitor)
-{
-    Cell::visit_edges(visitor);
-    visitor.visit(m_value);
-}
-
-}

Userland/Libraries/LibJS/Runtime/Exception.h

@@ -1,35 +0,0 @@
-/*
- * Copyright (c) 2020, Andreas Kling <kling@serenityos.org>
- * Copyright (c) 2021, Linus Groh <linusg@serenityos.org>
- *
- * SPDX-License-Identifier: BSD-2-Clause
- */
-
-#pragma once
-
-#include <AK/FlyString.h>
-#include <AK/Vector.h>
-#include <LibJS/Heap/Cell.h>
-#include <LibJS/Runtime/Error.h>
-#include <LibJS/Runtime/Value.h>
-#include <LibJS/SourceRange.h>
-
-namespace JS {
-
-class Exception : public Cell {
-public:
-    explicit Exception(Value);
-    virtual ~Exception() override = default;
-
-    Value value() const { return m_value; }
-    const Vector<TracebackFrame, 32>& traceback() const { return m_traceback; }
-
-private:
-    virtual const char* class_name() const override { return "Exception"; }
-    virtual void visit_edges(Visitor&) override;
-
-    Value m_value;
-    Vector<TracebackFrame, 32> m_traceback;
-};
-
-}

Userland/Libraries/LibJS/Runtime/GeneratorObject.cpp

@@ -104,8 +104,8 @@ ThrowCompletionOr<Value> GeneratorObject::next_impl(VM& vm, GlobalObject& global
 
     // Pretend that 'yield' returned the passed value, or threw
     if (value_to_throw.has_value()) {
-        vm.throw_exception(global_object, value_to_throw.release_value());
         bytecode_interpreter->accumulator() = js_undefined();
+        return throw_completion(value_to_throw.release_value());
     } else {
         bytecode_interpreter->accumulator() = next_argument.value_or(js_undefined());
     }

Userland/Libraries/LibJS/Runtime/IteratorOperations.cpp

@@ -11,7 +11,6 @@
 #include <LibJS/Runtime/FunctionObject.h>
 #include <LibJS/Runtime/GlobalObject.h>
 #include <LibJS/Runtime/IteratorOperations.h>
-#include <LibJS/Runtime/TemporaryClearException.h>
 
 namespace JS {
 
@@ -141,10 +140,6 @@ static Completion iterator_close_impl(GlobalObject& global_object, Iterator cons
     // 2. Let iterator be iteratorRecord.[[Iterator]].
     auto* iterator = iterator_record.iterator;
 
-    // The callers of iterator_close() are often in an exceptional state.
-    // Temporarily clear that exception for invocation(s) to Call.
-    TemporaryClearException clear_exception(vm);
-
     // 3. Let innerResult be GetMethod(iterator, "return").
     auto inner_result = ThrowCompletionOr<Value> { js_undefined() };
     auto get_method_result = Value(iterator).get_method(global_object, vm.names.return_);

Userland/Libraries/LibJS/Runtime/Object.cpp

@@ -18,7 +18,6 @@
 #include <LibJS/Runtime/PropertyDescriptor.h>
 #include <LibJS/Runtime/ProxyObject.h>
 #include <LibJS/Runtime/Shape.h>
-#include <LibJS/Runtime/TemporaryClearException.h>
 #include <LibJS/Runtime/Value.h>
 
 namespace JS {

Userland/Libraries/LibJS/Runtime/PromiseConstructor.cpp

@@ -17,7 +17,6 @@
 #include <LibJS/Runtime/PromiseConstructor.h>
 #include <LibJS/Runtime/PromiseReaction.h>
 #include <LibJS/Runtime/PromiseResolvingElementFunctions.h>
-#include <LibJS/Runtime/TemporaryClearException.h>
 
 namespace JS {
 
@@ -209,7 +208,6 @@ static ThrowCompletionOr<Value> perform_promise_any(GlobalObject& global_object,
             MUST(error->define_property_or_throw(vm.names.errors, { .value = errors_array, .writable = true, .enumerable = false, .configurable = true }));
 
             // 3. Return ThrowCompletion(error).
-            vm.throw_exception(global_object, error);
             return throw_completion(error);
         },
         [&](PromiseValueList& errors, RemainingElements& remaining_elements_count, Value next_promise, size_t index) {
@@ -304,14 +302,12 @@ ThrowCompletionOr<Object*> PromiseConstructor::construct(FunctionObject& new_tar
     auto [resolve_function, reject_function] = promise->create_resolving_functions();
 
     // 9. Let completion be Call(executor, undefined, « resolvingFunctions.[[Resolve]], resolvingFunctions.[[Reject]] »).
-    (void)JS::call(global_object, executor.as_function(), js_undefined(), &resolve_function, &reject_function);
+    auto completion = JS::call(global_object, executor.as_function(), js_undefined(), &resolve_function, &reject_function);
 
     // 10. If completion is an abrupt completion, then
-    if (auto* exception = vm.exception()) {
-        vm.clear_exception();
-
+    if (completion.is_error()) {
         // a. Perform ? Call(resolvingFunctions.[[Reject]], undefined, « completion.[[Value]] »).
-        TRY(JS::call(global_object, reject_function, js_undefined(), exception->value()));
+        TRY(JS::call(global_object, reject_function, js_undefined(), *completion.release_error().value()));
     }
 
     // 11. Return promise.

Userland/Libraries/LibJS/Runtime/PromiseJobs.cpp

@@ -70,7 +70,7 @@ ThrowCompletionOr<Value> PromiseReactionJob::call()
     // f. If promiseCapability is undefined, then
     if (!promise_capability.has_value()) {
         // i. Assert: handlerResult is not an abrupt completion.
-        VERIFY(!vm.exception());
+        VERIFY(!handler_result.is_abrupt());
 
         // ii. Return NormalCompletion(empty).
         dbgln_if(PROMISE_DEBUG, "[PromiseReactionJob @ {}]: Reaction has no PromiseCapability, returning empty value", this);

Userland/Libraries/LibJS/Runtime/PromisePrototype.cpp

@@ -138,9 +138,8 @@ JS_DEFINE_NATIVE_FUNCTION(PromisePrototype::finally)
             auto* promise = TRY(promise_resolve(global_object, constructor, result));
 
             // iv. Let thrower be ! CreateBuiltinFunction(throwReason, 0, "", « »).
-            auto* thrower = NativeFunction::create(global_object, "", [reason](auto& vm, auto& global_object) -> ThrowCompletionOr<Value> {
+            auto* thrower = NativeFunction::create(global_object, "", [reason](auto&, auto&) -> ThrowCompletionOr<Value> {
                 // 1. Return ThrowCompletion(reason).
-                vm.throw_exception(global_object, reason);
                 return throw_completion(reason);
             });
 

Userland/Libraries/LibJS/Runtime/TemporaryClearException.h

@@ -1,34 +0,0 @@
-/*
- * Copyright (c) 2021, Linus Groh <linusg@serenityos.org>
- *
- * SPDX-License-Identifier: BSD-2-Clause
- */
-
-#pragma once
-
-#include <LibJS/Runtime/Exception.h>
-#include <LibJS/Runtime/VM.h>
-
-namespace JS {
-
-class TemporaryClearException {
-public:
-    explicit TemporaryClearException(VM& vm)
-        : m_vm(vm)
-        , m_previous_exception(vm.exception())
-    {
-        m_vm.clear_exception();
-    }
-
-    ~TemporaryClearException()
-    {
-        if (m_previous_exception)
-            m_vm.set_exception(*m_previous_exception);
-    }
-
-private:
-    VM& m_vm;
-    Exception* m_previous_exception;
-};
-
-}

Userland/Libraries/LibJS/Runtime/VM.cpp

@@ -26,7 +26,6 @@
 #include <LibJS/Runtime/PromiseReaction.h>
 #include <LibJS/Runtime/Reference.h>
 #include <LibJS/Runtime/Symbol.h>
-#include <LibJS/Runtime/TemporaryClearException.h>
 #include <LibJS/Runtime/VM.h>
 #include <LibJS/SourceTextModule.h>
 #include <LibJS/SyntheticModule.h>
@@ -152,8 +151,6 @@ void VM::gather_roots(HashTable<Cell*>& roots)
     for (auto* string : m_single_ascii_character_strings)
         roots.set(string);
 
-    roots.set(m_exception);
-
     auto gather_roots_from_execution_context_stack = [&roots](Vector<ExecutionContext*> const& stack) {
         for (auto& execution_context : stack) {
             if (execution_context->this_value.is_cell())
@@ -564,11 +561,6 @@ ThrowCompletionOr<void> VM::initialize_instance_elements(Object& object, ECMAScr
     return {};
 }
 
-void VM::throw_exception(Exception& exception)
-{
-    set_exception(exception);
-}
-
 // 9.4.4 ResolveThisBinding ( ), https://tc39.es/ecma262/#sec-resolvethisbinding
 ThrowCompletionOr<Value> VM::resolve_this_binding(GlobalObject& global_object)
 {
@@ -610,9 +602,7 @@ bool VM::in_strict_mode() const
 void VM::run_queued_promise_jobs()
 {
     dbgln_if(PROMISE_DEBUG, "Running queued promise jobs");
-    // Temporarily get rid of the exception, if any - job functions must be called
-    // either way, and that can't happen if we already have an exception stored.
-    TemporaryClearException temporary_clear_exception(*this);
+
     while (!m_promise_jobs.is_empty()) {
         auto* job = m_promise_jobs.take_first();
         dbgln_if(PROMISE_DEBUG, "Calling promise job function @ {}", job);
@@ -633,15 +623,11 @@ void VM::run_queued_promise_jobs()
         // This doesn't match the spec, it actually defines that Job Abstract Closures must return
         // a normal completion. In reality that's not the case however, and all major engines clear
         // exceptions when running Promise jobs. See the commit where these two lines were initially
-        // added for a much more detailed explanation.
-        clear_exception();
+        // added for a much more detailed explanation. (Hash: a53542e0a3fbd7bf22b685d87f0473e489e1cf42)
 
         if (pushed_execution_context)
             pop_execution_context();
     }
-    // Ensure no job has created a new exception, they must clean up after themselves.
-    // If they don't, we help a little (see above) so that this assumption remains valid.
-    VERIFY(!m_exception);
 }
 
 // 9.5.4 HostEnqueuePromiseJob ( job, realm ), https://tc39.es/ecma262/#sec-hostenqueuepromisejob
@@ -654,7 +640,8 @@ void VM::run_queued_finalization_registry_cleanup_jobs()
 {
     while (!m_finalization_registry_cleanup_jobs.is_empty()) {
         auto* registry = m_finalization_registry_cleanup_jobs.take_first();
-        registry->cleanup();
+        // FIXME: Handle any uncatched exceptions here.
+        (void)registry->cleanup();
     }
 }
 
@@ -793,8 +780,6 @@ ThrowCompletionOr<void> VM::link_and_eval_module(Module& module)
     dbgln_if(JS_MODULE_DEBUG, "[JS MODULE] Linking passed, now evaluating module {}", filepath);
     auto evaluated_or_error = module.evaluate(*this);
 
-    VERIFY(!exception());
-
     if (evaluated_or_error.is_error())
         return evaluated_or_error.throw_completion();
 
@@ -806,10 +791,8 @@ ThrowCompletionOr<void> VM::link_and_eval_module(Module& module)
     // FIXME: This will break if we start doing promises actually asynchronously.
     VERIFY(evaluated_value->state() != Promise::State::Pending);
 
-    if (evaluated_value->state() == Promise::State::Rejected) {
-        VERIFY(!exception());
+    if (evaluated_value->state() == Promise::State::Rejected)
         return JS::throw_completion(evaluated_value->result());
-    }
 
     dbgln_if(JS_MODULE_DEBUG, "[JS MODULE] Evaluating passed for module {}", module.filename());
     return {};
@@ -954,13 +937,10 @@ void VM::import_module_dynamically(ScriptOrModule referencing_script_or_module,
         }
     }
 
-    VERIFY(!exception());
     // Note: If host_resolve_imported_module returns a module it has been loaded successfully and the next call in finish_dynamic_import will retrieve it again.
     auto module_or_error = host_resolve_imported_module(referencing_script_or_module, module_request);
     dbgln_if(JS_MODULE_DEBUG, "[JS MODULE] HostImportModuleDynamically(..., {}) -> {}", module_request.module_specifier, module_or_error.is_error() ? "failed" : "passed");
     if (module_or_error.is_throw_completion()) {
-        // Note: We should not leak the exception thrown in host_resolve_imported_module.
-        clear_exception();
         promise->reject(*module_or_error.throw_completion().value());
     } else {
         auto module = module_or_error.release_value();
@@ -969,11 +949,8 @@ void VM::import_module_dynamically(ScriptOrModule referencing_script_or_module,
         auto evaluated_or_error = link_and_eval_module(source_text_module);
 
         if (evaluated_or_error.is_throw_completion()) {
-            // Note: Again we don't want to leak the exception from link_and_eval_module.
-            clear_exception();
             promise->reject(*evaluated_or_error.throw_completion().value());
         } else {
-            VERIFY(!exception());
             promise->fulfill(js_undefined());
         }
     }
@@ -1001,7 +978,6 @@ void VM::finish_dynamic_import(ScriptOrModule referencing_script_or_module, Modu
         // d. Let namespace be GetModuleNamespace(moduleRecord).
         auto namespace_ = module_record->get_module_namespace(vm);
 
-        VERIFY(!vm.exception());
         // e. If namespace is an abrupt completion, then
         if (namespace_.is_throw_completion()) {
             // i. Perform ! Call(promiseCapability.[[Reject]], undefined, « namespace.[[Value]] »).
@@ -1033,8 +1009,6 @@ void VM::finish_dynamic_import(ScriptOrModule referencing_script_or_module, Modu
 
     // 5. Perform ! PerformPromiseThen(innerPromise, onFulfilled, onRejected).
     inner_promise->perform_then(on_fulfilled, on_rejected, {});
-
-    VERIFY(!exception());
 }
 
 }

Userland/Libraries/LibJS/Runtime/VM.h

@@ -19,7 +19,6 @@
 #include <LibJS/Runtime/Completion.h>
 #include <LibJS/Runtime/Error.h>
 #include <LibJS/Runtime/ErrorTypes.h>
-#include <LibJS/Runtime/Exception.h>
 #include <LibJS/Runtime/ExecutionContext.h>
 #include <LibJS/Runtime/Iterator.h>
 #include <LibJS/Runtime/MarkedValueList.h>
@@ -49,10 +48,7 @@ public:
     void push_interpreter(Interpreter&);
     void pop_interpreter(Interpreter&);
 
-    Exception* exception() { return m_exception; }
-    void set_exception(Exception& exception) { m_exception = &exception; }
-    void clear_exception() { m_exception = nullptr; }
-
+    void clear_exception() { }
     void dump_backtrace() const;
 
     class InterpreterExecutionScope {
@@ -90,7 +86,6 @@ public:
 
     ThrowCompletionOr<void> push_execution_context(ExecutionContext& context, GlobalObject& global_object)
     {
-        VERIFY(!exception());
         // 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>(global_object, ErrorType::CallStackSizeExceeded);
@@ -160,32 +155,11 @@ public:
     ThrowCompletionOr<Reference> resolve_binding(FlyString const&, Environment* = nullptr);
     ThrowCompletionOr<Reference> get_identifier_reference(Environment*, FlyString, bool strict, size_t hops = 0);
 
-    template<typename T, typename... Args>
-    void throw_exception(GlobalObject& global_object, Args&&... args)
-    {
-        return throw_exception(global_object, T::create(global_object, forward<Args>(args)...));
-    }
-
-    void throw_exception(Exception&);
-    void throw_exception(GlobalObject& global_object, Value value)
-    {
-        return throw_exception(*heap().allocate<Exception>(global_object, value));
-    }
-
-    template<typename T, typename... Args>
-    void throw_exception(GlobalObject& global_object, ErrorType type, Args&&... args)
-    {
-        return throw_exception(global_object, T::create(global_object, String::formatted(type.message(), forward<Args>(args)...)));
-    }
-
     // 5.2.3.2 Throw an Exception, https://tc39.es/ecma262/#sec-throw-an-exception
     template<typename T, typename... Args>
     Completion throw_completion(GlobalObject& global_object, Args&&... args)
     {
-        auto* error = T::create(global_object, forward<Args>(args)...);
-        // NOTE: This is temporary until we remove VM::exception().
-        throw_exception(global_object, error);
-        return JS::throw_completion(error);
+        return JS::throw_completion(T::create(global_object, forward<Args>(args)...));
     }
 
     template<typename T, typename... Args>
@@ -255,8 +229,6 @@ private:
     void import_module_dynamically(ScriptOrModule referencing_script_or_module, ModuleRequest module_request, PromiseCapability promise_capability);
     void finish_dynamic_import(ScriptOrModule referencing_script_or_module, ModuleRequest module_request, PromiseCapability promise_capability, Promise* inner_promise);
 
-    Exception* m_exception { nullptr };
-
     HashMap<String, PrimitiveString*> m_string_cache;
 
     Heap m_heap;

Userland/Libraries/LibJS/SourceTextModule.cpp

@@ -664,7 +664,6 @@ Completion SourceTextModule::execute_module(VM& vm, Optional<PromiseCapability>
 
         // d. Suspend moduleContext and remove it from the execution context stack.
         vm.pop_execution_context();
-        vm.clear_exception();
 
         // e. Resume the context that is now on the top of the execution context stack as the running execution context.
         // FIXME: We don't have resume yet.

Userland/Libraries/LibTest/JavaScriptTestRunner.h

@@ -363,9 +363,6 @@ inline JSFileResult TestRunner::run_file_test(const String& test_path)
         g_vm->pop_execution_context();
     }
 
-    if (g_vm->exception())
-        g_vm->clear_exception();
-
     auto test_json = get_test_results(*interpreter);
     if (test_json.is_error()) {
         warnln("Received malformed JSON from test \"{}\"", test_path);

Userland/Libraries/LibWeb/CMakeLists.txt

@@ -194,6 +194,7 @@ set(SOURCES
     HTML/Parser/ListOfActiveFormattingElements.cpp
     HTML/Parser/StackOfOpenElements.cpp
     HTML/Scripting/ClassicScript.cpp
+    HTML/Scripting/ExceptionReporter.cpp
     HTML/Scripting/Script.cpp
     HTML/SyntaxHighlighter/SyntaxHighlighter.cpp
     HTML/TagNames.cpp

Userland/Libraries/LibWeb/DOM/AbortSignal.cpp

@@ -76,16 +76,10 @@ HTML::EventHandler AbortSignal::onabort()
 // https://dom.spec.whatwg.org/#dom-abortsignal-throwifaborted
 JS::ThrowCompletionOr<void> AbortSignal::throw_if_aborted() const
 {
-    auto& global_object = wrapper()->global_object();
-    auto& vm = global_object.vm();
-
     // The throwIfAborted() method steps are to throw this’s abort reason, if this is aborted.
     if (!aborted())
         return {};
 
-    // FIXME: Remove this once VM::exception() has been removed.
-    vm.throw_exception(global_object, m_abort_reason);
-
     return JS::throw_completion(m_abort_reason);
 }
 

Userland/Libraries/LibWeb/DOM/Document.cpp

@@ -53,6 +53,7 @@
 #include <LibWeb/HTML/HTMLScriptElement.h>
 #include <LibWeb/HTML/HTMLTitleElement.h>
 #include <LibWeb/HTML/MessageEvent.h>
+#include <LibWeb/HTML/Scripting/ExceptionReporter.h>
 #include <LibWeb/Layout/BlockFormattingContext.h>
 #include <LibWeb/Layout/InitialContainingBlock.h>
 #include <LibWeb/Layout/TreeBuilder.h>
@@ -641,32 +642,6 @@ JS::Interpreter& Document::interpreter()
             // FIXME: This isn't exactly the right place for this.
             HTML::main_thread_event_loop().perform_a_microtask_checkpoint();
 
-            // Note: This is not an exception check for the promise jobs, they will just leave any
-            // exception that already exists intact and never throw a new one (without cleaning it
-            // up, that is). Taking care of any previous unhandled exception just happens to be the
-            // very last thing we want to do, even after running promise jobs.
-            if (auto* exception = vm.exception()) {
-                auto value = exception->value();
-                if (value.is_object()) {
-                    auto& object = value.as_object();
-                    auto name = object.get_without_side_effects(vm.names.name).value_or(JS::js_undefined());
-                    auto message = object.get_without_side_effects(vm.names.message).value_or(JS::js_undefined());
-                    if (name.is_accessor() || message.is_accessor()) {
-                        // The result is not going to be useful, let's just print the value. This affects DOMExceptions, for example.
-                        dbgln("\033[31;1mUnhandled JavaScript exception:\033[0m {}", value);
-                    } else {
-                        dbgln("\033[31;1mUnhandled JavaScript exception:\033[0m [{}] {}", name, message);
-                    }
-                } else {
-                    dbgln("\033[31;1mUnhandled JavaScript exception:\033[0m {}", value);
-                }
-                for (auto& traceback_frame : exception->traceback()) {
-                    auto& function_name = traceback_frame.function_name;
-                    auto& source_range = traceback_frame.source_range;
-                    dbgln("  {} at {}:{}:{}", function_name, source_range.filename, source_range.start.line, source_range.start.column);
-                }
-            }
-
             vm.finish_execution_generation();
         };
     }
@@ -685,10 +660,10 @@ JS::Value Document::run_javascript(StringView source, StringView filename)
 
     auto result = interpreter.run(script_or_error.value());
 
-    auto& vm = interpreter.vm();
     if (result.is_error()) {
         // FIXME: I'm sure the spec could tell us something about error propagation here!
-        vm.clear_exception();
+        HTML::report_exception(result);
+
         return {};
     }
     return result.value();

Userland/Libraries/LibWeb/DOM/EventDispatcher.cpp

@@ -23,6 +23,7 @@
 #include <LibWeb/DOM/ShadowRoot.h>
 #include <LibWeb/DOM/Window.h>
 #include <LibWeb/HTML/EventNames.h>
+#include <LibWeb/HTML/Scripting/ExceptionReporter.h>
 #include <LibWeb/UIEvents/MouseEvent.h>
 
 namespace Web::DOM {
@@ -89,11 +90,17 @@ bool EventDispatcher::inner_invoke(Event& event, Vector<EventTarget::EventListen
 
         auto* this_value = Bindings::wrap(global, *event.current_target());
         auto* wrapped_event = Bindings::wrap(global, event);
-        auto& vm = global.vm();
-        [[maybe_unused]] auto rc = JS::call(global, function, this_value, wrapped_event);
-        if (vm.exception()) {
-            vm.clear_exception();
-            // FIXME: Set legacyOutputDidListenersThrowFlag if given. (Only used by IndexedDB currently)
+
+        // 10. Call a user object’s operation with listener’s callback, "handleEvent", « event », and event’s currentTarget attribute value.
+        auto result = JS::call(global, function, this_value, wrapped_event);
+
+        // If this throws an exception, then:
+        if (result.is_error()) {
+            // 1. Report the exception.
+            VERIFY(result.throw_completion().value().has_value());
+            HTML::report_exception(*result.throw_completion().value());
+
+            // FIXME: 2. Set legacyOutputDidListenersThrowFlag if given. (Only used by IndexedDB currently)
         }
 
         event.set_in_passive_listener(false);

Userland/Libraries/LibWeb/DOM/Window.cpp

@@ -19,6 +19,7 @@
 #include <LibWeb/HTML/BrowsingContext.h>
 #include <LibWeb/HTML/EventLoop/EventLoop.h>
 #include <LibWeb/HTML/PageTransitionEvent.h>
+#include <LibWeb/HTML/Scripting/ExceptionReporter.h>
 #include <LibWeb/HighResolutionTime/Performance.h>
 #include <LibWeb/Layout/InitialContainingBlock.h>
 #include <LibWeb/Page/Page.h>
@@ -170,11 +171,9 @@ void Window::timer_did_fire(Badge<Timer>, Timer& timer)
     HTML::queue_global_task(HTML::Task::Source::TimerTask, associated_document(), [this, strong_this = NonnullRefPtr(*this), strong_timer = NonnullRefPtr(timer)]() mutable {
         // We should not be here if there's no JS wrapper for the Window object.
         VERIFY(wrapper());
-        auto& vm = wrapper()->vm();
-
-        [[maybe_unused]] auto rc = JS::call(wrapper()->global_object(), strong_timer->callback(), wrapper());
-        if (vm.exception())
-            vm.clear_exception();
+        auto result = JS::call(wrapper()->global_object(), strong_timer->callback(), wrapper());
+        if (result.is_error())
+            HTML::report_exception(result);
     });
 }
 
@@ -198,14 +197,18 @@ void Window::clear_interval(i32 timer_id)
     m_timers.remove(timer_id);
 }
 
+// https://html.spec.whatwg.org/multipage/imagebitmap-and-animations.html#run-the-animation-frame-callbacks
 i32 Window::request_animation_frame(JS::FunctionObject& js_callback)
 {
     auto callback = request_animation_frame_driver().add([this, handle = JS::make_handle(&js_callback)](i32 id) mutable {
         auto& function = *handle.cell();
-        auto& vm = function.vm();
-        (void)JS::call(function.global_object(), function, JS::js_undefined(), JS::Value(performance().now()));
-        if (vm.exception())
-            vm.clear_exception();
+        // 3. Invoke callback, passing now as the only argument,
+        auto result = JS::call(function.global_object(), function, JS::js_undefined(), JS::Value(performance().now()));
+
+        // and if an exception is thrown, report the exception.
+        if (result.is_error())
+            HTML::report_exception(result);
+
         m_request_animation_frame_callbacks.remove(id);
     });
     m_request_animation_frame_callbacks.set(callback->id(), callback);
@@ -399,11 +402,10 @@ void Window::queue_microtask(JS::FunctionObject& callback)
 {
     // The queueMicrotask(callback) method must queue a microtask to invoke callback,
     HTML::queue_a_microtask(associated_document(), [&callback, handle = JS::make_handle(&callback)]() {
-        auto& vm = callback.vm();
-        [[maybe_unused]] auto rc = JS::call(callback.global_object(), callback, JS::js_null());
-        // FIXME: ...and if callback throws an exception, report the exception.
-        if (vm.exception())
-            vm.clear_exception();
+        auto result = JS::call(callback.global_object(), callback, JS::js_null());
+        // and if callback throws an exception, report the exception.
+        if (result.is_error())
+            HTML::report_exception(result);
     });
 }
 

Userland/Libraries/LibWeb/HTML/Scripting/ClassicScript.cpp

@@ -8,6 +8,7 @@
 #include <LibCore/ElapsedTimer.h>
 #include <LibJS/Interpreter.h>
 #include <LibWeb/HTML/Scripting/ClassicScript.h>
+#include <LibWeb/HTML/Scripting/ExceptionReporter.h>
 
 namespace Web::HTML {
 
@@ -81,7 +82,7 @@ JS::Value ClassicScript::run(RethrowErrors rethrow_errors)
     dbgln_if(HTML_SCRIPT_DEBUG, "ClassicScript: Finished running script {}, Duration: {}ms", filename(), timer.elapsed());
     if (evaluation_status.is_error()) {
         // FIXME: Propagate error according to the spec.
-        interpreter->vm().clear_exception();
+        report_exception(evaluation_status);
         return {};
     }
     return evaluation_status.value();

Userland/Libraries/LibWeb/HTML/Scripting/ExceptionReporter.cpp

@@ -0,0 +1,45 @@
+/*
+ * Copyright (c) 2022, David Tuin <davidot@serenityos.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <AK/TypeCasts.h>
+#include <LibJS/Runtime/VM.h>
+#include <LibJS/Runtime/Value.h>
+#include <LibWeb/HTML/Scripting/ExceptionReporter.h>
+
+namespace Web::HTML {
+
+// https://html.spec.whatwg.org/#report-the-exception
+void report_exception(JS::ThrowCompletionOr<JS::Value> const& result)
+{
+    // FIXME: This is just old code, and does not strictly follow the spec of report an exception.
+    // FIXME: We should probably also report these exceptions to the JS console.
+    VERIFY(result.throw_completion().value().has_value());
+    auto thrown_value = *result.throw_completion().value();
+    if (thrown_value.is_object()) {
+        auto& object = thrown_value.as_object();
+        auto& vm = object.vm();
+        auto name = object.get_without_side_effects(vm.names.name).value_or(JS::js_undefined());
+        auto message = object.get_without_side_effects(vm.names.message).value_or(JS::js_undefined());
+        if (name.is_accessor() || message.is_accessor()) {
+            // The result is not going to be useful, let's just print the value. This affects DOMExceptions, for example.
+            dbgln("\033[31;1mUnhandled JavaScript exception:\033[0m {}", thrown_value);
+        } else {
+            dbgln("\033[31;1mUnhandled JavaScript exception:\033[0m [{}] {}", name, message);
+        }
+        if (is<JS::Error>(object)) {
+            auto const& error_value = static_cast<JS::Error const&>(object);
+            for (auto const& traceback_frame : error_value.traceback()) {
+                auto const& function_name = traceback_frame.function_name;
+                auto const& source_range = traceback_frame.source_range;
+                dbgln("  {} at {}:{}:{}", function_name, source_range.filename, source_range.start.line, source_range.start.column);
+            }
+        }
+    } else {
+        dbgln("\033[31;1mUnhandled JavaScript exception:\033[0m {}", thrown_value);
+    }
+}
+
+}

Userland/Libraries/LibWeb/HTML/Scripting/ExceptionReporter.h

@@ -0,0 +1,15 @@
+/*
+ * Copyright (c) 2022, David Tuin <davidot@serenityos.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <LibJS/Forward.h>
+
+namespace Web::HTML {
+
+void report_exception(JS::ThrowCompletionOr<JS::Value> const& value);
+
+}

Userland/Utilities/js.cpp

@@ -891,7 +891,6 @@ static void print_value(JS::Value value, HashTable<JS::Object*>& seen_objects)
         auto prototype_or_error = object.internal_get_prototype_of();
         if (prototype_or_error.has_value() && prototype_or_error.value() == object.global_object().error_prototype())
             return print_error(object, seen_objects);
-        vm->clear_exception();
 
         if (is<JS::RegExpObject>(object))
             return print_regexp_object(object, seen_objects);
@@ -1059,7 +1058,7 @@ static bool parse_and_run(JS::Interpreter& interpreter, StringView source, Strin
             if (!hint.is_empty())
                 outln("{}", hint);
             outln(error.to_string());
-            vm->throw_exception<JS::SyntaxError>(interpreter.global_object(), error.to_string());
+            result = JS::SyntaxError::create(interpreter.global_object(), error.to_string());
         } else {
             auto return_early = run_script_or_module(script_or_error.value());
             if (return_early == ReturnEarly::Yes)
@@ -1073,7 +1072,7 @@ static bool parse_and_run(JS::Interpreter& interpreter, StringView source, Strin
             if (!hint.is_empty())
                 outln("{}", hint);
             outln(error.to_string());
-            vm->throw_exception<JS::SyntaxError>(interpreter.global_object(), error.to_string());
+            result = JS::SyntaxError::create(interpreter.global_object(), error.to_string());
         } else {
             auto return_early = run_script_or_module(module_or_error.value());
             if (return_early == ReturnEarly::Yes)
@@ -1081,12 +1080,13 @@ static bool parse_and_run(JS::Interpreter& interpreter, StringView source, Strin
         }
     }
 
-    auto handle_exception = [&] {
-        auto* exception = vm->exception();
-        vm->clear_exception();
+    auto handle_exception = [&](JS::Value thrown_value) {
         js_out("Uncaught exception: ");
-        print(exception->value());
-        auto& traceback = exception->traceback();
+        print(thrown_value);
+
+        if (!thrown_value.is_object() || !is<JS::Error>(thrown_value.as_object()))
+            return;
+        auto& traceback = static_cast<JS::Error const&>(thrown_value.as_object()).traceback();
         if (traceback.size() > 1) {
             unsigned repetitions = 0;
             for (size_t i = 0; i < traceback.size(); ++i) {
@@ -1117,21 +1117,11 @@ static bool parse_and_run(JS::Interpreter& interpreter, StringView source, Strin
         last_value = JS::make_handle(result.value());
 
     if (result.is_error()) {
-        if (!vm->exception()) {
-            // Until js no longer relies on vm->exception() we have to set it in case the exception was cleared
-            VERIFY(result.throw_completion().value().has_value());
-            auto throw_value = result.release_error().release_value().release_value();
-            auto* exception = interpreter.heap().allocate<JS::Exception>(interpreter.global_object(), throw_value);
-            vm->set_exception(*exception);
-        }
-        handle_exception();
+        VERIFY(result.throw_completion().value().has_value());
+        handle_exception(*result.release_error().value());
         return false;
     } else if (s_print_last_result) {
         print(result.value());
-        if (vm->exception()) {
-            handle_exception();
-            return false;
-        }
     }
     return true;
 }
@@ -1401,10 +1391,7 @@ ErrorOr<int> serenity_main(Main::Arguments arguments)
     };
     OwnPtr<JS::Interpreter> interpreter;
 
-    interrupt_interpreter = [&] {
-        auto error = JS::Error::create(interpreter->global_object(), "Received SIGINT");
-        vm->throw_exception(interpreter->global_object(), error);
-    };
+    // FIXME: Figure out some way to interrupt the interpreter now that vm.exception() is gone.
 
     if (script_paths.is_empty()) {
         s_print_last_result = true;