RGBCube/serenity
1
Fork 0
mirror of https://github.com/RGBCube/serenity synced 2025-05-20 14:55:08 +00:00
Code Issues Activity Actions

LibJS/Bytecode: Leave GlobalDeclarationInstantiation in C++

Browse source 
Don't try to implement this AO in bytecode. Instead, the bytecode
Interpreter class now has a run() API with the same inputs as the AST
interpreter. It sets up the necessary environments etc, including
invoking the GlobalDeclarationInstantiation AO.
This commit is contained in:
Andreas Kling 2023-06-15 12:36:57 +02:00
parent 32d9c8e3ca
commit d063f35afd
12 changed files with 172 additions and 284 deletions
Download patch file Download diff file Expand all files Collapse all files

177
Userland/Libraries/LibJS/Bytecode/ASTCodegen.cpp
View file

@ -70,182 +70,7 @@ Bytecode::CodeGenerationErrorOr<void> ScopeNode::generate_bytecode(Bytecode::Gen
return {};
} else if (is<Program>(*this)) {
// Perform the steps of GlobalDeclarationInstantiation.
generator.begin_variable_scope(Bytecode::Generator::BindingMode::Global, Bytecode::Generator::SurroundingScopeKind::Global);
pushed_scope_count++;
// 1. Let lexNames be the LexicallyDeclaredNames of script.
// 2. Let varNames be the VarDeclaredNames of script.
// 3. For each element name of lexNames, do
(void)for_each_lexically_declared_name([&](auto const& name) -> ThrowCompletionOr<void> {
auto identifier = generator.intern_identifier(name);
// a. If env.HasVarDeclaration(name) is true, throw a SyntaxError exception.
// b. If env.HasLexicalDeclaration(name) is true, throw a SyntaxError exception.
if (generator.has_binding(identifier)) {
// FIXME: Throw an actual SyntaxError instance.
generator.emit<Bytecode::Op::NewString>(generator.intern_string(DeprecatedString::formatted("SyntaxError: toplevel variable already declared: {}", name)));
generator.emit<Bytecode::Op::Throw>();
return {};
}
// FIXME: c. If hasRestrictedGlobalProperty is true, throw a SyntaxError exception.
// d. If hasRestrictedGlobal is true, throw a SyntaxError exception.
return {};
});
// 4. For each element name of varNames, do
(void)for_each_var_declared_name([&](auto const& name) -> ThrowCompletionOr<void> {
auto identifier = generator.intern_identifier(name);
// a. If env.HasLexicalDeclaration(name) is true, throw a SyntaxError exception.
if (generator.has_binding(identifier)) {
// FIXME: Throw an actual SyntaxError instance.
generator.emit<Bytecode::Op::NewString>(generator.intern_string(DeprecatedString::formatted("SyntaxError: toplevel variable already declared: {}", name)));
generator.emit<Bytecode::Op::Throw>();
}
return {};
});
// 5. Let varDeclarations be the VarScopedDeclarations of script.
// 6. Let functionsToInitialize be a new empty List.
Vector<FunctionDeclaration const&> functions_to_initialize;
// 7. Let declaredFunctionNames be a new empty List.
HashTable<DeprecatedFlyString> declared_function_names;
// 8. For each element d of varDeclarations, in reverse List order, do
(void)for_each_var_function_declaration_in_reverse_order([&](FunctionDeclaration const& function) -> ThrowCompletionOr<void> {
// a. If d is neither a VariableDeclaration nor a ForBinding nor a BindingIdentifier, then
// i. Assert: d is either a FunctionDeclaration, a GeneratorDeclaration, an AsyncFunctionDeclaration, or an AsyncGeneratorDeclaration.
// Note: This is checked in for_each_var_function_declaration_in_reverse_order.
// ii. NOTE: If there are multiple function declarations for the same name, the last declaration is used.
// iii. Let fn be the sole element of the BoundNames of d.
// iv. If fn is not an element of declaredFunctionNames, then
if (declared_function_names.set(function.name()) != AK::HashSetResult::InsertedNewEntry)
return {};
// FIXME: 1. Let fnDefinable be ? env.CanDeclareGlobalFunction(fn).
// FIXME: 2. If fnDefinable is false, throw a TypeError exception.
// 3. Append fn to declaredFunctionNames.
// Note: Already done in step iv. above.
// 4. Insert d as the first element of functionsToInitialize.
functions_to_initialize.prepend(function);
return {};
});
// 9. Let declaredVarNames be a new empty List.
HashTable<DeprecatedFlyString> declared_var_names;
// 10. For each element d of varDeclarations, do
(void)for_each_var_scoped_variable_declaration([&](Declaration const& declaration) {
// a. If d is a VariableDeclaration, a ForBinding, or a BindingIdentifier, then
// Note: This is done in for_each_var_scoped_variable_declaration.
// i. For each String vn of the BoundNames of d, do
return declaration.for_each_bound_name([&](auto const& name) -> ThrowCompletionOr<void> {
// 1. If vn is not an element of declaredFunctionNames, then
if (declared_function_names.contains(name))
return {};
// FIXME: a. Let vnDefinable be ? env.CanDeclareGlobalVar(vn).
// FIXME: b. If vnDefinable is false, throw a TypeError exception.
// c. If vn is not an element of declaredVarNames, then
// i. Append vn to declaredVarNames.
declared_var_names.set(name);
return {};
});
});
// 11. NOTE: No abnormal terminations occur after this algorithm step if the global object is an ordinary object. However, if the global object is a Proxy exotic object it may exhibit behaviours that cause abnormal terminations in some of the following steps.
// 12. NOTE: Annex B.3.2.2 adds additional steps at this point.
// 12. Let strict be IsStrict of script.
// 13. If strict is false, then
if (!verify_cast<Program>(*this).is_strict_mode()) {
// a. Let declaredFunctionOrVarNames be the list-concatenation of declaredFunctionNames and declaredVarNames.
// b. For each FunctionDeclaration f that is directly contained in the StatementList of a Block, CaseClause, or DefaultClause Contained within script, do
(void)for_each_function_hoistable_with_annexB_extension([&](FunctionDeclaration& function_declaration) {
// i. Let F be StringValue of the BindingIdentifier of f.
auto& function_name = function_declaration.name();
// ii. If replacing the FunctionDeclaration f with a VariableStatement that has F as a BindingIdentifier would not produce any Early Errors for script, then
// Note: This step is already performed during parsing and for_each_function_hoistable_with_annexB_extension so this always passes here.
// 1. If env.HasLexicalDeclaration(F) is false, then
auto index = generator.intern_identifier(function_name);
if (generator.has_binding(index, Bytecode::Generator::BindingMode::Lexical))
return;
// FIXME: a. Let fnDefinable be ? env.CanDeclareGlobalVar(F).
// b. If fnDefinable is true, then
// i. NOTE: A var binding for F is only instantiated here if it is neither a VarDeclaredName nor the name of another FunctionDeclaration.
// ii. If declaredFunctionOrVarNames does not contain F, then
if (!declared_function_names.contains(function_name) && !declared_var_names.contains(function_name)) {
// i. Perform ? env.CreateGlobalVarBinding(F, false).
generator.emit<Bytecode::Op::CreateVariable>(index, Bytecode::Op::EnvironmentMode::Var, false, true);
// ii. Append F to declaredFunctionOrVarNames.
declared_function_names.set(function_name);
}
// iii. When the FunctionDeclaration f is evaluated, perform the following steps in place of the FunctionDeclaration Evaluation algorithm provided in 15.2.6:
// i. Let genv be the running execution context's VariableEnvironment.
// ii. Let benv be the running execution context's LexicalEnvironment.
// iii. Let fobj be ! benv.GetBindingValue(F, false).
// iv. Perform ? genv.SetMutableBinding(F, fobj, false).
// v. Return unused.
function_declaration.set_should_do_additional_annexB_steps();
});
}
// 15. For each element d of lexDeclarations, do
(void)for_each_lexically_scoped_declaration([&](Declaration const& declaration) -> ThrowCompletionOr<void> {
// a. NOTE: Lexically declared names are only instantiated here but not initialized.
// b. For each element dn of the BoundNames of d, do
return declaration.for_each_bound_name([&](auto const& name) -> ThrowCompletionOr<void> {
auto identifier = generator.intern_identifier(name);
// i. If IsConstantDeclaration of d is true, then
generator.register_binding(identifier);
if (declaration.is_constant_declaration()) {
// 1. Perform ? env.CreateImmutableBinding(dn, true).
generator.emit<Bytecode::Op::CreateVariable>(identifier, Bytecode::Op::EnvironmentMode::Lexical, true);
} else {
// ii. Else,
// 1. Perform ? env.CreateMutableBinding(dn, false).
generator.emit<Bytecode::Op::CreateVariable>(identifier, Bytecode::Op::EnvironmentMode::Lexical, false);
}
return {};
});
});
// 16. For each Parse Node f of functionsToInitialize, do
for (auto& function_declaration : functions_to_initialize) {
// FIXME: Do this more correctly.
// a. Let fn be the sole element of the BoundNames of f.
// b. Let fo be InstantiateFunctionObject of f with arguments env and privateEnv.
generator.emit<Bytecode::Op::NewFunction>(function_declaration);
// c. Perform ? env.CreateGlobalFunctionBinding(fn, fo, false).
auto const& name = function_declaration.name();
auto index = generator.intern_identifier(name);
if (!generator.has_binding(index)) {
generator.register_binding(index, Bytecode::Generator::BindingMode::Var);
generator.emit<Bytecode::Op::CreateVariable>(index, Bytecode::Op::EnvironmentMode::Lexical, false);
}
generator.emit<Bytecode::Op::SetVariable>(index, Bytecode::Op::SetVariable::InitializationMode::Initialize);
}
// 17. For each String vn of declaredVarNames, do
for (auto& var_name : declared_var_names) {
// a. Perform ? env.CreateGlobalVarBinding(vn, false).
auto index = generator.intern_identifier(var_name);
generator.register_binding(index, Bytecode::Generator::BindingMode::Var);
generator.emit<Bytecode::Op::CreateVariable>(index, Bytecode::Op::EnvironmentMode::Var, false, true);
}
// GlobalDeclarationInstantiation is handled by the C++ AO.
} else {
// FunctionDeclarationInstantiation is handled by the C++ AO.
}

3
Userland/Libraries/LibJS/Bytecode/Generator.cpp
View file

@ -60,7 +60,8 @@ CodeGenerationErrorOr<NonnullOwnPtr<Executable>> Generator::generate(ASTNode con
.string_table = move(generator.m_string_table),
.identifier_table = move(generator.m_identifier_table),
.number_of_registers = generator.m_next_register,
.is_strict_mode = is_strict_mode });
.is_strict_mode = is_strict_mode,
});
}
void Generator::grow(size_t additional_size)

136
Userland/Libraries/LibJS/Bytecode/Interpreter.cpp
View file

@ -6,6 +6,7 @@
#include <AK/Debug.h>
#include <AK/TemporaryChange.h>
#include <LibJS/AST.h>
#include <LibJS/Bytecode/BasicBlock.h>
#include <LibJS/Bytecode/Instruction.h>
#include <LibJS/Bytecode/Interpreter.h>
@ -39,6 +40,141 @@ Interpreter::~Interpreter()
s_current = nullptr;
}
// 16.1.6 ScriptEvaluation ( scriptRecord ), https://tc39.es/ecma262/#sec-runtime-semantics-scriptevaluation
ThrowCompletionOr<Value> Interpreter::run(Script& script_record, JS::GCPtr<Environment> lexical_environment_override)
{
auto& vm = this->vm();
// 1. Let globalEnv be scriptRecord.[[Realm]].[[GlobalEnv]].
auto& global_environment = script_record.realm().global_environment();
// 2. Let scriptContext be a new ECMAScript code execution context.
ExecutionContext script_context(vm.heap());
// 3. Set the Function of scriptContext to null.
// NOTE: This was done during execution context construction.
// 4. Set the Realm of scriptContext to scriptRecord.[[Realm]].
script_context.realm = &script_record.realm();
// 5. Set the ScriptOrModule of scriptContext to scriptRecord.
script_context.script_or_module = NonnullGCPtr<Script>(script_record);
// 6. Set the VariableEnvironment of scriptContext to globalEnv.
script_context.variable_environment = &global_environment;
// 7. Set the LexicalEnvironment of scriptContext to globalEnv.
script_context.lexical_environment = &global_environment;
// Non-standard: Override the lexical environment if requested.
if (lexical_environment_override)
script_context.lexical_environment = lexical_environment_override;
// 8. Set the PrivateEnvironment of scriptContext to null.
// NOTE: This isn't in the spec, but we require it.
script_context.is_strict_mode = script_record.parse_node().is_strict_mode();
// FIXME: 9. Suspend the currently running execution context.
// 10. Push scriptContext onto the execution context stack; scriptContext is now the running execution context.
TRY(vm.push_execution_context(script_context, {}));
// 11. Let script be scriptRecord.[[ECMAScriptCode]].
auto& script = script_record.parse_node();
// 12. Let result be Completion(GlobalDeclarationInstantiation(script, globalEnv)).
auto instantiation_result = script.global_declaration_instantiation(vm, global_environment);
Completion result = instantiation_result.is_throw_completion() ? instantiation_result.throw_completion() : normal_completion({});
// 13. If result.[[Type]] is normal, then
if (result.type() == Completion::Type::Normal) {
auto executable_result = JS::Bytecode::Generator::generate(script);
if (executable_result.is_error()) {
if (auto error_string = executable_result.error().to_string(); error_string.is_error())
result = vm.template throw_completion<JS::InternalError>(vm.error_message(JS::VM::ErrorMessage::OutOfMemory));
else if (error_string = String::formatted("TODO({})", error_string.value()); error_string.is_error())
result = vm.template throw_completion<JS::InternalError>(vm.error_message(JS::VM::ErrorMessage::OutOfMemory));
else
result = JS::throw_completion(JS::InternalError::create(realm(), error_string.release_value()));
} else {
auto executable = executable_result.release_value();
if (m_optimizations_enabled) {
auto& passes = optimization_pipeline();
passes.perform(*executable);
}
if (g_dump_bytecode)
executable->dump();
// a. Set result to the result of evaluating script.
auto result_or_error = run_and_return_frame(*executable, nullptr);
if (result_or_error.value.is_error())
result = result_or_error.value.release_error();
else
result = result_or_error.frame->registers[0];
}
}
// 14. If result.[[Type]] is normal and result.[[Value]] is empty, then
if (result.type() == Completion::Type::Normal && !result.value().has_value()) {
// a. Set result to NormalCompletion(undefined).
result = normal_completion(js_undefined());
}
// FIXME: 15. Suspend scriptContext and remove it from the execution context stack.
vm.pop_execution_context();
// 16. Assert: The execution context stack is not empty.
VERIFY(!vm.execution_context_stack().is_empty());
// FIXME: 17. Resume the context that is now on the top of the execution context stack as the running execution context.
// At this point we may have already run any queued promise jobs via on_call_stack_emptied,
// in which case this is a no-op.
// FIXME: These three should be moved out of Interpreter::run and give the host an option to run these, as it's up to the host when these get run.
// https://tc39.es/ecma262/#sec-jobs for jobs and https://tc39.es/ecma262/#_ref_3508 for ClearKeptObjects
// finish_execution_generation is particularly an issue for LibWeb, as the HTML spec wants to run it specifically after performing a microtask checkpoint.
// The promise and registry cleanup queues don't cause LibWeb an issue, as LibWeb overrides the hooks that push onto these queues.
vm.run_queued_promise_jobs();
vm.run_queued_finalization_registry_cleanup_jobs();
vm.finish_execution_generation();
// 18. Return ? result.
if (result.is_abrupt()) {
VERIFY(result.type() == Completion::Type::Throw);
return result.release_error();
}
VERIFY(result.value().has_value());
return *result.value();
}
ThrowCompletionOr<Value> Interpreter::run(SourceTextModule& module)
{
// FIXME: This is not a entry point as defined in the spec, but is convenient.
// 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();
TRY(vm.link_and_eval_module(Badge<Bytecode::Interpreter> {}, module));
vm.run_queued_promise_jobs();
vm.run_queued_finalization_registry_cleanup_jobs();
return js_undefined();
}
void Interpreter::set_optimizations_enabled(bool enabled)
{
m_optimizations_enabled = enabled;
}
Interpreter::ValueAndFrame Interpreter::run_and_return_frame(Executable const& executable, BasicBlock const* entry_point, RegisterWindow* in_frame)
{
dbgln_if(JS_BYTECODE_DEBUG, "Bytecode::Interpreter will run unit {:p}", &executable);

6
Userland/Libraries/LibJS/Bytecode/Interpreter.h
View file

@ -36,6 +36,11 @@ public:
Realm& realm() { return m_realm; }
VM& vm() { return m_vm; }
void set_optimizations_enabled(bool);
ThrowCompletionOr<Value> run(Script&, JS::GCPtr<Environment> lexical_environment_override = nullptr);
ThrowCompletionOr<Value> run(SourceTextModule&);
ThrowCompletionOr<Value> run(Bytecode::Executable const& executable, Bytecode::BasicBlock const* entry_point = nullptr)
{
auto value_and_frame = run_and_return_frame(executable, entry_point);
@ -120,6 +125,7 @@ private:
OwnPtr<JS::Interpreter> m_ast_interpreter;
BasicBlock const* m_current_block { nullptr };
InstructionStreamIterator* m_pc { nullptr };
bool m_optimizations_enabled { false };
};
extern bool g_dump_bytecode;