Everywhere: Hoist the Libraries folder to the top-level

Author: https://github.com/trflynn89
Commit: 93712b24bf
Pull-request: https://github.com/LadybirdBrowser/ladybird/pull/2256
Reviewed-by: https://github.com/sideshowbarker

Libraries/LibJS/Runtime/Completion.cpp

@@ -0,0 +1,150 @@
+/*
+ * Copyright (c) 2021, Idan Horowitz <idan.horowitz@serenityos.org>
+ * Copyright (c) 2021-2023, Linus Groh <linusg@serenityos.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <AK/TypeCasts.h>
+#include <LibJS/Runtime/Completion.h>
+#include <LibJS/Runtime/NativeFunction.h>
+#include <LibJS/Runtime/Promise.h>
+#include <LibJS/Runtime/PromiseCapability.h>
+#include <LibJS/Runtime/PromiseConstructor.h>
+#include <LibJS/Runtime/VM.h>
+#include <LibJS/Runtime/Value.h>
+
+namespace JS {
+
+bool g_log_all_js_exceptions = false;
+
+Completion::Completion(ThrowCompletionOr<Value> const& throw_completion_or_value)
+{
+    if (throw_completion_or_value.is_throw_completion()) {
+        m_type = Type::Throw;
+        m_value = throw_completion_or_value.throw_completion().value();
+    } else {
+        m_type = Type::Normal;
+        m_value = throw_completion_or_value.value();
+    }
+}
+
+// 6.2.3.1 Await, https://tc39.es/ecma262/#await
+// FIXME: This no longer matches the spec!
+ThrowCompletionOr<Value> await(VM& vm, Value value)
+{
+    auto& realm = *vm.current_realm();
+
+    // 1. Let asyncContext be the running execution context.
+    // NOTE: This is not needed, as we don't suspend anything.
+
+    // 2. Let promise be ? PromiseResolve(%Promise%, value).
+    auto* promise_object = TRY(promise_resolve(vm, realm.intrinsics().promise_constructor(), value));
+
+    IGNORE_USE_IN_ESCAPING_LAMBDA Optional<bool> success;
+    IGNORE_USE_IN_ESCAPING_LAMBDA Value result;
+
+    // 3. Let fulfilledClosure be a new Abstract Closure with parameters (value) that captures asyncContext and performs the following steps when called:
+    auto fulfilled_closure = [&success, &result](VM& vm) -> ThrowCompletionOr<Value> {
+        // a. Let prevContext be the running execution context.
+        // b. Suspend prevContext.
+        // FIXME: We don't have this concept yet.
+
+        // NOTE: Since we don't support context suspension, we exfiltrate the result to await()'s scope instead
+        success = true;
+        result = vm.argument(0);
+
+        // c. Push asyncContext onto the execution context stack; asyncContext is now the running execution context.
+        // NOTE: This is not done, because we're not suspending anything (see above).
+
+        // d. Resume the suspended evaluation of asyncContext using NormalCompletion(value) as the result of the operation that suspended it.
+        // e. Assert: When we reach this step, asyncContext has already been removed from the execution context stack and prevContext is the currently running execution context.
+        // FIXME: We don't have this concept yet.
+
+        // f. Return undefined.
+        return js_undefined();
+    };
+
+    // 4. Let onFulfilled be CreateBuiltinFunction(fulfilledClosure, 1, "", « »).
+    auto on_fulfilled = NativeFunction::create(realm, move(fulfilled_closure), 1, "");
+
+    // 5. Let rejectedClosure be a new Abstract Closure with parameters (reason) that captures asyncContext and performs the following steps when called:
+    auto rejected_closure = [&success, &result](VM& vm) -> ThrowCompletionOr<Value> {
+        // a. Let prevContext be the running execution context.
+        // b. Suspend prevContext.
+        // FIXME: We don't have this concept yet.
+
+        // NOTE: Since we don't support context suspension, we exfiltrate the result to await()'s scope instead
+        success = false;
+        result = vm.argument(0);
+
+        // c. Push asyncContext onto the execution context stack; asyncContext is now the running execution context.
+        // NOTE: This is not done, because we're not suspending anything (see above).
+
+        // d. Resume the suspended evaluation of asyncContext using ThrowCompletion(reason) as the result of the operation that suspended it.
+        // e. Assert: When we reach this step, asyncContext has already been removed from the execution context stack and prevContext is the currently running execution context.
+        // FIXME: We don't have this concept yet.
+
+        // f. Return undefined.
+        return js_undefined();
+    };
+
+    // 6. Let onRejected be CreateBuiltinFunction(rejectedClosure, 1, "", « »).
+    auto on_rejected = NativeFunction::create(realm, move(rejected_closure), 1, "");
+
+    // 7. Perform PerformPromiseThen(promise, onFulfilled, onRejected).
+    auto promise = verify_cast<Promise>(promise_object);
+    promise->perform_then(on_fulfilled, on_rejected, {});
+
+    // FIXME: Since we don't support context suspension, we attempt to "wait" for the promise to resolve
+    //        by letting the event loop spin until our promise is no longer pending, and then synchronously
+    //        running all queued promise jobs.
+    // Note: This is not used by LibJS itself, and is performed for the embedder (i.e. LibWeb).
+    if (auto* custom_data = vm.custom_data()) {
+        custom_data->spin_event_loop_until(create_heap_function(vm.heap(), [success] {
+            return success.has_value();
+        }));
+    }
+
+    // 8. Remove asyncContext from the execution context stack and restore the execution context that is at the top of the execution context stack as the running execution context.
+    // NOTE: Since we don't push any EC, this step is not performed.
+
+    // 9. Set the code evaluation state of asyncContext such that when evaluation is resumed with a Completion Record completion, the following steps of the algorithm that invoked Await will be performed, with completion available.
+    // 10. Return NormalCompletion(unused).
+    // 11. NOTE: This returns to the evaluation of the operation that had most previously resumed evaluation of asyncContext.
+
+    vm.run_queued_promise_jobs();
+
+    // Make sure that the promise _actually_ resolved.
+    // Note that this is checked down the chain (result.is_empty()) anyway, but let's make the source of the issue more clear.
+    VERIFY(success.has_value());
+
+    if (success.value())
+        return result;
+    return throw_completion(result);
+}
+
+static void log_exception(Value value)
+{
+    if (!value.is_object()) {
+        dbgln("\033[31;1mTHROW!\033[0m {}", value);
+        return;
+    }
+
+    auto& object = value.as_object();
+    auto& vm = object.vm();
+    dbgln("\033[31;1mTHROW!\033[0m {}", object.get(vm.names.message).value());
+    vm.dump_backtrace();
+}
+
+// 6.2.4.2 ThrowCompletion ( value ), https://tc39.es/ecma262/#sec-throwcompletion
+Completion throw_completion(Value value)
+{
+    if (g_log_all_js_exceptions)
+        log_exception(value);
+
+    // 1. Return Completion Record { [[Type]]: throw, [[Value]]: value, [[Target]]: empty }.
+    return { Completion::Type::Throw, value };
+}
+
+}