/*
* Copyright (c) 2020, Andreas Kling <andreas@ladybird.org>
* Copyright (c) 2021-2023, Linus Groh <linusg@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <AK/StringBuilder.h>
#include <LibJS/AST.h>
#include <LibJS/Runtime/Completion.h>
#include <LibJS/Runtime/Error.h>
#include <LibJS/Runtime/ExecutionContext.h>
#include <LibJS/Runtime/GlobalObject.h>
#include <LibJS/SourceRange.h>
namespace JS {
GC_DEFINE_ALLOCATOR(Error);
static SourceRange dummy_source_range { SourceCode::create(String {}, String {}), {}, {} };
SourceRange const& TracebackFrame::source_range() const
{
if (!cached_source_range)
return dummy_source_range;
if (auto* unrealized = cached_source_range->source_range.get_pointer<UnrealizedSourceRange>()) {
auto source_range = [&] {
if (!unrealized->source_code)
return dummy_source_range;
return unrealized->realize();
}();
cached_source_range->source_range = move(source_range);
}
return cached_source_range->source_range.get<SourceRange>();
}
GC::Ref<Error> Error::create(Realm& realm)
{
return realm.create<Error>(realm.intrinsics().error_prototype());
}
GC::Ref<Error> Error::create(Realm& realm, String message)
{
auto& vm = realm.vm();
auto error = Error::create(realm);
u8 attr = Attribute::Writable | Attribute::Configurable;
error->define_direct_property(vm.names.message, PrimitiveString::create(vm, move(message)), attr);
return error;
}
GC::Ref<Error> Error::create(Realm& realm, StringView message)
{
return create(realm, MUST(String::from_utf8(message)));
}
Error::Error(Object& prototype)
: Object(ConstructWithPrototypeTag::Tag, prototype)
{
populate_stack();
}
// 20.5.8.1 InstallErrorCause ( O, options ), https://tc39.es/ecma262/#sec-installerrorcause
ThrowCompletionOr<void> Error::install_error_cause(Value options)
{
auto& vm = this->vm();
// 1. If Type(options) is Object and ? HasProperty(options, "cause") is true, then
if (options.is_object() && TRY(options.as_object().has_property(vm.names.cause))) {
// a. Let cause be ? Get(options, "cause").
auto cause = TRY(options.as_object().get(vm.names.cause));
// b. Perform CreateNonEnumerableDataPropertyOrThrow(O, "cause", cause).
create_non_enumerable_data_property_or_throw(vm.names.cause, cause);
}
// 2. Return unused.
return {};
}
void Error::populate_stack()
{
auto stack_trace = vm().stack_trace();
m_traceback.ensure_capacity(stack_trace.size());
for (auto& element : stack_trace) {
auto* context = element.execution_context;
TracebackFrame frame {
.function_name = context->function_name ? context->function_name->byte_string() : "",
.cached_source_range = element.source_range,
};
m_traceback.append(move(frame));
}
}
String Error::stack_string(CompactTraceback compact) const
{
if (m_traceback.is_empty())
return {};
StringBuilder stack_string_builder;
// Note: We roughly follow V8's formatting
auto append_frame = [&](TracebackFrame const& frame) {
auto function_name = frame.function_name;
auto source_range = frame.source_range();
// Note: Since we don't know whether we have a valid SourceRange here we just check for some default values.
if (!source_range.filename().is_empty() || source_range.start.offset != 0 || source_range.end.offset != 0) {
if (function_name.is_empty())
stack_string_builder.appendff(" at {}:{}:{}\n", source_range.filename(), source_range.start.line, source_range.start.column);
else
stack_string_builder.appendff(" at {} ({}:{}:{})\n", function_name, source_range.filename(), source_range.start.line, source_range.start.column);
} else {
stack_string_builder.appendff(" at {}\n", function_name.is_empty() ? "<unknown>"sv : function_name.view());
}
};
auto is_same_frame = [](TracebackFrame const& a, TracebackFrame const& b) {
if (a.function_name.is_empty() && b.function_name.is_empty()) {
auto source_range_a = a.source_range();
auto source_range_b = b.source_range();
return source_range_a.filename() == source_range_b.filename() && source_range_a.start.line == source_range_b.start.line;
}
return a.function_name == b.function_name;
};
// Note: We don't want to capture the global execution context, so we omit the last frame
// Note: The error's name and message get prepended by ErrorPrototype::stack
// FIXME: We generate a stack-frame for the Errors constructor, other engines do not
unsigned repetitions = 0;
size_t used_frames = m_traceback.size() - 1;
for (size_t i = 0; i < used_frames; ++i) {
auto const& frame = m_traceback[i];
if (compact == CompactTraceback::Yes && i + 1 < used_frames) {
auto const& next_traceback_frame = m_traceback[i + 1];
if (is_same_frame(frame, next_traceback_frame)) {
repetitions++;
continue;
}
}
if (repetitions > 4) {
// If more than 5 (1 + >4) consecutive function calls with the same name, print
// the name only once and show the number of repetitions instead. This prevents
// printing ridiculously large call stacks of recursive functions.
append_frame(frame);
stack_string_builder.appendff(" {} more calls\n", repetitions);
} else {
for (size_t j = 0; j < repetitions + 1; j++)
append_frame(frame);
}
repetitions = 0;
}
for (size_t j = 0; j < repetitions; j++)
append_frame(m_traceback[used_frames - 1]);
return MUST(stack_string_builder.to_string());
}
#define __JS_ENUMERATE(ClassName, snake_name, PrototypeName, ConstructorName, ArrayType) \
GC_DEFINE_ALLOCATOR(ClassName); \
GC::Ref<ClassName> ClassName::create(Realm& realm) \
{ \
return realm.create<ClassName>(realm.intrinsics().snake_name##_prototype()); \
} \
\
GC::Ref<ClassName> ClassName::create(Realm& realm, String message) \
{ \
auto& vm = realm.vm(); \
auto error = ClassName::create(realm); \
u8 attr = Attribute::Writable | Attribute::Configurable; \
error->define_direct_property(vm.names.message, PrimitiveString::create(vm, move(message)), attr); \
return error; \
} \
\
GC::Ref<ClassName> ClassName::create(Realm& realm, StringView message) \
{ \
return create(realm, MUST(String::from_utf8(message))); \
} \
\
ClassName::ClassName(Object& prototype) \
: Error(prototype) \
{ \
}
JS_ENUMERATE_NATIVE_ERRORS
#undef __JS_ENUMERATE
}