ladybird/Libraries/LibJS/Bytecode/Executable.cpp
Andreas Kling 164ed80244 Meta: Enable exit-time destructor warnings for libraries
Enable -Wexit-time-destructors for all in-tree library targets and
update process-lifetime library statics so they no longer register
exit-time destructors. Long-lived caches, lookup tables, singleton
registries, and generated constants now use NeverDestroyed or leaked
references where the data is intended to live until process exit.

Update LibWeb, LibLine, and the binding generators so regenerated
sources follow the same rule instead of reintroducing destructed
statics.
2026-06-04 19:20:49 +02:00

753 lines
27 KiB
C++

/*
* Copyright (c) 2021-2025, Andreas Kling <andreas@ladybird.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <AK/BinarySearch.h>
#include <AK/NeverDestroyed.h>
#include <AK/NumericLimits.h>
#include <AK/QuickSort.h>
#include <AK/StdLibExtras.h>
#include <LibGC/Heap.h>
#include <LibGC/HeapBlock.h>
#include <LibJS/Bytecode/BasicBlock.h>
#include <LibJS/Bytecode/Executable.h>
#include <LibJS/Bytecode/FormatOperand.h>
#include <LibJS/Bytecode/Instruction.h>
#include <LibJS/Bytecode/Op.h>
#include <LibJS/Bytecode/RegexTable.h>
#include <LibJS/Runtime/Array.h>
#include <LibJS/Runtime/ExternalMemory.h>
#include <LibJS/Runtime/SharedFunctionInstanceData.h>
#include <LibJS/Runtime/Value.h>
#include <LibJS/SourceCode.h>
namespace JS::Bytecode {
GC_DEFINE_ALLOCATOR(Executable);
GC_DEFINE_ALLOCATOR(TemplateObjectCache);
GC_DEFINE_ALLOCATOR(ObjectPropertyIteratorCacheData);
InstructionStream::InstructionStream(Vector<u8> bytecode)
: m_storage(move(bytecode))
{
update_view_from_storage();
}
InstructionStream::InstructionStream(Core::ImmutableBytes bytecode, size_t offset, size_t size)
: m_storage(move(bytecode))
{
update_view_from_storage(offset, size);
}
void InstructionStream::update_view_from_storage(size_t offset, Optional<size_t> size)
{
auto bytes = m_storage.visit(
[](Vector<u8> const& bytecode) -> ReadonlyBytes {
return bytecode.span();
},
[](Core::ImmutableBytes const& bytecode) -> ReadonlyBytes {
return bytecode.bytes();
});
VERIFY(offset <= bytes.size());
m_size = size.value_or(bytes.size() - offset);
VERIFY(m_size <= bytes.size() - offset);
m_data = bytes.is_empty() ? nullptr : bytes.data() + offset;
}
size_t InstructionStream::external_memory_size() const
{
return m_storage.visit(
[](Vector<u8> const& bytecode) -> size_t {
return vector_external_memory_size(bytecode);
},
[](Core::ImmutableBytes const& bytecode) -> size_t {
if (bytecode.is_file_backed())
return 0;
return bytecode.size();
});
}
static_assert(alignof(PropertyLookupCache::MonomorphicData) > PropertyLookupCache::polymorphic_data_tag);
static_assert(alignof(PropertyLookupCache::PolymorphicData) > PropertyLookupCache::polymorphic_data_tag);
static_assert(offsetof(PropertyLookupCache::MonomorphicData, entry) == 0);
static_assert(offsetof(PropertyLookupCache::PolymorphicData, entries) == 0);
PropertyLookupCache::PropertyLookupCache(PropertyLookupCache&& other)
: m_data(exchange(other.m_data, 0))
{
}
PropertyLookupCache& PropertyLookupCache::operator=(PropertyLookupCache&& other)
{
if (this != &other) {
clear();
m_data = exchange(other.m_data, 0);
}
return *this;
}
PropertyLookupCache::~PropertyLookupCache()
{
clear();
}
PropertyLookupCache::MonomorphicData* PropertyLookupCache::monomorphic_data()
{
if (!m_data || (m_data & polymorphic_data_tag))
return nullptr;
return reinterpret_cast<MonomorphicData*>(m_data);
}
PropertyLookupCache::MonomorphicData const* PropertyLookupCache::monomorphic_data() const
{
if (!m_data || (m_data & polymorphic_data_tag))
return nullptr;
return reinterpret_cast<MonomorphicData const*>(m_data);
}
PropertyLookupCache::PolymorphicData* PropertyLookupCache::polymorphic_data()
{
if (!(m_data & polymorphic_data_tag))
return nullptr;
return reinterpret_cast<PolymorphicData*>(m_data & ~polymorphic_data_tag);
}
PropertyLookupCache::PolymorphicData const* PropertyLookupCache::polymorphic_data() const
{
if (!(m_data & polymorphic_data_tag))
return nullptr;
return reinterpret_cast<PolymorphicData const*>(m_data & ~polymorphic_data_tag);
}
void PropertyLookupCache::set_monomorphic_data(MonomorphicData* data)
{
VERIFY(data);
VERIFY(!(reinterpret_cast<FlatPtr>(data) & polymorphic_data_tag));
m_data = reinterpret_cast<FlatPtr>(data);
}
void PropertyLookupCache::set_polymorphic_data(PolymorphicData* data)
{
VERIFY(data);
VERIFY(!(reinterpret_cast<FlatPtr>(data) & polymorphic_data_tag));
m_data = reinterpret_cast<FlatPtr>(data) | polymorphic_data_tag;
}
PropertyLookupCache::Entry* PropertyLookupCache::first_entry()
{
if (auto* data = monomorphic_data())
return &data->entry;
if (auto* data = polymorphic_data())
return &data->entries[0];
return nullptr;
}
PropertyLookupCache::Entry const* PropertyLookupCache::first_entry() const
{
if (auto* data = monomorphic_data())
return &data->entry;
if (auto* data = polymorphic_data())
return &data->entries[0];
return nullptr;
}
Span<PropertyLookupCache::Entry> PropertyLookupCache::entries()
{
if (auto* data = monomorphic_data())
return { &data->entry, 1 };
if (auto* data = polymorphic_data())
return data->entries.span();
return {};
}
ReadonlySpan<PropertyLookupCache::Entry> PropertyLookupCache::entries() const
{
if (auto* data = monomorphic_data())
return { &data->entry, 1 };
if (auto* data = polymorphic_data())
return data->entries.span();
return {};
}
size_t PropertyLookupCache::external_memory_size() const
{
if (monomorphic_data())
return sizeof(MonomorphicData);
if (polymorphic_data())
return sizeof(PolymorphicData);
return 0;
}
void PropertyLookupCache::copy_from(PropertyLookupCache const& other)
{
clear();
if (auto* data = other.monomorphic_data()) {
set_monomorphic_data(new MonomorphicData(*data));
return;
}
if (auto* data = other.polymorphic_data())
set_polymorphic_data(new PolymorphicData(*data));
}
void PropertyLookupCache::clear()
{
if (auto* data = monomorphic_data()) {
delete data;
m_data = 0;
return;
}
if (auto* data = polymorphic_data()) {
delete data;
m_data = 0;
}
}
bool PropertyLookupCache::entries_have_same_cache_key(Entry const& a, Entry const& b)
{
if (a.type == Entry::Type::Empty || b.type == Entry::Type::Empty)
return false;
if (a.type != b.type)
return false;
switch (a.type) {
case Entry::Type::AddOwnProperty:
return a.from_shape == b.from_shape && a.shape == b.shape;
case Entry::Type::ChangeOwnProperty:
case Entry::Type::GetOwnProperty:
return a.shape == b.shape;
case Entry::Type::ChangePropertyInPrototypeChain:
case Entry::Type::GetPropertyInPrototypeChain:
return a.shape == b.shape && a.prototype == b.prototype;
case Entry::Type::Empty:
VERIFY_NOT_REACHED();
}
VERIFY_NOT_REACHED();
}
ObjectPropertyIteratorCacheData::ObjectPropertyIteratorCacheData(VM& vm, Vector<PropertyKey> properties, ObjectPropertyIteratorFastPath fast_path, u32 indexed_property_count, bool receiver_has_magical_length_property, GC::Ref<Shape> shape, GC::Ptr<PrototypeChainValidity> prototype_chain_validity)
: m_properties(move(properties))
, m_shape(shape)
, m_prototype_chain_validity(prototype_chain_validity)
, m_indexed_property_count(indexed_property_count)
, m_receiver_has_magical_length_property(receiver_has_magical_length_property)
, m_fast_path(fast_path)
{
// The iterator fast path returns JS Values directly, so materialize the
// cached key list once up front instead of converting PropertyKeys during
// every ObjectPropertyIteratorNext.
m_property_values.ensure_capacity(indexed_property_count + m_properties.size());
for (u32 i = 0; i < indexed_property_count; ++i)
m_property_values.append(PropertyKey { i }.to_value(vm));
for (auto const& key : m_properties)
m_property_values.append(key.to_value(vm));
if (m_shape->is_dictionary())
m_shape_dictionary_generation = m_shape->dictionary_generation();
}
void ObjectPropertyIteratorCacheData::visit_edges(Visitor& visitor)
{
Base::visit_edges(visitor);
visitor.visit(m_shape);
visitor.visit(m_prototype_chain_validity);
visitor.visit(m_property_values.span());
for (auto& key : m_properties)
key.visit_edges(visitor);
}
size_t ObjectPropertyIteratorCacheData::external_memory_size() const
{
auto size = vector_external_memory_size(m_properties);
size = saturating_add_external_memory_size(size, vector_external_memory_size(m_property_values));
return size;
}
void TemplateObjectCache::visit_edges(Visitor& visitor)
{
Base::visit_edges(visitor);
visitor.visit(cached_template_object);
}
Executable::Executable(
InstructionStream bytecode,
NonnullOwnPtr<IdentifierTable> identifier_table,
NonnullOwnPtr<PropertyKeyTable> property_key_table,
NonnullOwnPtr<StringTable> string_table,
NonnullOwnPtr<RegexTable> regex_table,
Vector<Value> constants,
NonnullRefPtr<SourceCode const> source_code,
size_t number_of_property_lookup_caches,
size_t number_of_global_variable_caches,
size_t number_of_environment_coordinate_caches,
size_t number_of_template_object_caches,
size_t number_of_object_shape_caches,
size_t number_of_object_property_iterator_caches,
size_t number_of_registers,
Strict strict)
: GC::WeakContainer(heap())
, bytecode(move(bytecode))
, string_table(move(string_table))
, identifier_table(move(identifier_table))
, property_key_table(move(property_key_table))
, regex_table(move(regex_table))
, constants(move(constants))
, source_code(move(source_code))
, number_of_registers(number_of_registers)
, is_strict_mode(strict == Strict::Yes)
{
property_lookup_caches.resize(number_of_property_lookup_caches);
global_variable_caches.resize(number_of_global_variable_caches);
environment_coordinate_caches.resize(number_of_environment_coordinate_caches);
template_object_caches.ensure_capacity(number_of_template_object_caches);
for (size_t i = 0; i < number_of_template_object_caches; ++i)
template_object_caches.append(heap().allocate<TemplateObjectCache>());
object_shape_caches.resize(number_of_object_shape_caches);
object_property_iterator_caches.resize(number_of_object_property_iterator_caches);
asm_constants_size = this->constants.size();
asm_constants_data = this->constants.data();
}
Executable::~Executable() = default;
static SourceMapEntry const* first_real_source_map_entry(Executable const& executable)
{
SourceMapEntry const* first_entry = nullptr;
for (auto const& entry : executable.source_map) {
if (entry.line == 0 && entry.column == 0)
continue;
if (!first_entry || entry.line < first_entry->line || (entry.line == first_entry->line && entry.column < first_entry->column))
first_entry = &entry;
}
return first_entry;
}
static void dump_header(StringBuilder& output, Executable const& executable, bool use_color)
{
auto const white_bold = use_color ? "\033[37;1m"sv : ""sv;
auto const reset = use_color ? "\033[0m"sv : ""sv;
auto const* first_source_map_entry = first_real_source_map_entry(executable);
u32 hash = 2166136261u; // FNV-1a offset basis
auto update_hash = [&](u32 value) {
for (size_t i = 0; i < sizeof(value); ++i) {
hash ^= (value >> (i * 8)) & 0xFF;
hash *= 16777619u;
}
};
auto update_hash_with_code_unit = [&](u16 code_unit) {
hash ^= code_unit & 0xFF;
hash *= 16777619u;
hash ^= (code_unit >> 8) & 0xFF;
hash *= 16777619u;
};
auto name_view = executable.name.view();
for (size_t i = 0; i < name_view.length_in_code_units(); ++i)
update_hash_with_code_unit(name_view.code_unit_at(i));
if (first_source_map_entry) {
update_hash(first_source_map_entry->line);
update_hash(first_source_map_entry->column);
}
update_hash(static_cast<u32>(min(executable.bytecode.size(), static_cast<size_t>(NumericLimits<u32>::max()))));
if (executable.name.is_empty())
output.appendff("{}${:08x}{}", white_bold, hash, reset);
else
output.appendff("{}{}${:08x}{}", white_bold, executable.name, hash, reset);
// Show source location if available.
if (first_source_map_entry) {
auto filename = executable.source_code->filename();
if (!filename.is_empty()) {
// Show just the basename to keep output portable across machines.
auto last_slash = filename.bytes_as_string_view().find_last('/');
if (last_slash.has_value())
filename = MUST(filename.substring_from_byte_offset(last_slash.value() + 1));
output.appendff(" {}:{}:{}", filename, first_source_map_entry->line, first_source_map_entry->column);
} else {
output.appendff(" line {}, column {}", first_source_map_entry->line, first_source_map_entry->column);
}
}
output.append('\n');
}
static bool instruction_is_terminator(Instruction const& instruction)
{
#define __BYTECODE_OP(op) \
case Instruction::Type::op: \
return Op::op::IsTerminator;
switch (instruction.type()) {
ENUMERATE_BYTECODE_OPS(__BYTECODE_OP)
default:
VERIFY_NOT_REACHED();
}
#undef __BYTECODE_OP
}
static Vector<u32> collect_basic_block_start_offsets(Executable const& executable)
{
Vector<u32> offsets;
auto append_offset = [&](size_t offset) {
VERIFY(offset <= NumericLimits<u32>::max());
auto offset32 = static_cast<u32>(offset);
if (!offsets.contains_slow(offset32))
offsets.append(offset32);
};
auto append_instruction_offset = [&](size_t offset) {
if (offset < executable.bytecode.size())
append_offset(offset);
};
append_offset(0);
for (InstructionStreamIterator it(executable.bytecode, &executable); !it.at_end(); ++it) {
auto const& instruction = *it;
auto next_offset = it.offset() + instruction.length();
const_cast<Instruction&>(instruction).visit_labels([&](Label& label) {
append_offset(label.address());
});
if (instruction_is_terminator(instruction) && next_offset < executable.bytecode.size())
append_offset(next_offset);
}
for (auto const& handler : executable.exception_handlers) {
append_instruction_offset(handler.start_offset);
append_instruction_offset(handler.end_offset);
append_instruction_offset(handler.handler_offset);
}
quick_sort(offsets);
return offsets;
}
Optional<size_t> Executable::basic_block_index_for_offset(size_t offset) const
{
VERIFY(offset <= NumericLimits<u32>::max());
auto basic_block_start_offsets = collect_basic_block_start_offsets(*this);
size_t index = 0;
if (binary_search(basic_block_start_offsets, static_cast<u32>(offset), &index))
return index;
return {};
}
static void dump_metadata(StringBuilder& output, Executable const& executable, bool use_color)
{
auto const green = use_color ? "\033[32m"sv : ""sv;
auto const yellow = use_color ? "\033[33m"sv : ""sv;
auto const blue = use_color ? "\033[34m"sv : ""sv;
auto const cyan = use_color ? "\033[36m"sv : ""sv;
auto const reset = use_color ? "\033[0m"sv : ""sv;
output.appendff(" {}Registers{}: {}\n", green, reset, executable.number_of_registers);
output.appendff(" {}Blocks{}: {}\n", green, reset, collect_basic_block_start_offsets(executable).size());
if (!executable.local_variable_names.is_empty()) {
output.appendff(" {}Locals{}: ", green, reset);
for (size_t i = 0; i < executable.local_variable_names.size(); ++i) {
if (i != 0)
output.append(", "sv);
output.appendff("{}{}~{}{}", blue, executable.local_variable_names[i].name, i, reset);
}
output.append('\n');
}
if (!executable.constants.is_empty()) {
output.appendff(" {}Constants{}:\n", green, reset);
for (size_t i = 0; i < executable.constants.size(); ++i) {
auto value = executable.constants[i];
output.append(" "sv);
output.appendff("{}[{}]{} = ", yellow, i, reset);
output.append(cyan);
if (value.is_special_empty_value())
output.append("<Empty>"sv);
else if (value.is_boolean())
output.appendff("Bool({})", value.as_bool() ? "true"sv : "false"sv);
else if (value.is_int32())
output.appendff("Int32({})", value.as_i32());
else if (value.is_double())
output.appendff("Double({})", value.as_double());
else if (value.is_bigint())
output.appendff("BigInt({})", MUST(value.as_bigint().to_string()));
else if (value.is_string())
output.appendff("String(\"{}\")", value.as_string().utf8_string_view());
else if (value.is_undefined())
output.append("Undefined"sv);
else if (value.is_null())
output.append("Null"sv);
else
output.appendff("Value({})", value);
output.append(reset);
output.append('\n');
}
}
}
static void dump_bytecode(StringBuilder& output, Executable const& executable, bool use_color)
{
auto const magenta = use_color ? "\033[35;1m"sv : ""sv;
auto const reset = use_color ? "\033[0m"sv : ""sv;
InstructionStreamIterator it(executable.bytecode, &executable);
auto basic_block_start_offsets = collect_basic_block_start_offsets(executable);
size_t basic_block_offset_index = 0;
while (!it.at_end()) {
if (basic_block_offset_index < basic_block_start_offsets.size()
&& it.offset() == basic_block_start_offsets[basic_block_offset_index]) {
if (basic_block_offset_index > 0)
output.append('\n');
output.appendff("{}block{}{}:\n", magenta, basic_block_offset_index, reset);
++basic_block_offset_index;
}
output.appendff(" [{:4x}] {}\n", it.offset(), (*it).to_byte_string(executable));
++it;
}
}
void Executable::dump() const
{
StringBuilder output;
dump_header(output, *this, true);
dump_metadata(output, *this, true);
output.append('\n');
dump_bytecode(output, *this, true);
if (!exception_handlers.is_empty()) {
output.append("\nException handlers:\n"sv);
for (auto const& handler : exception_handlers) {
output.appendff(" [{:4x} .. {:4x}] => handler ", handler.start_offset, handler.end_offset);
Label handler_label(static_cast<u32>(handler.handler_offset));
output.appendff("{}\n", format_label(""sv, handler_label, *this));
}
}
output.append('\n');
warnln("{}", output.string_view());
}
String Executable::dump_to_string() const
{
StringBuilder output;
dump_header(output, *this, false);
dump_metadata(output, *this, false);
output.append('\n');
dump_bytecode(output, *this, false);
if (!exception_handlers.is_empty()) {
output.append("\nException handlers:\n"sv);
for (auto const& handler : exception_handlers) {
output.appendff(" [{:4x} .. {:4x}] => handler ", handler.start_offset, handler.end_offset);
Label handler_label(static_cast<u32>(handler.handler_offset));
output.appendff("{}\n", format_label(""sv, handler_label, *this));
}
}
return output.to_string_without_validation();
}
void Executable::visit_edges(Visitor& visitor)
{
Base::visit_edges(visitor);
visitor.visit(constants);
visitor.visit(template_object_caches);
for (auto& cache : object_property_iterator_caches)
visitor.visit(cache.data);
for (auto& cache : object_property_iterator_caches)
visitor.visit(cache.reusable_property_name_iterator);
for (auto& data : shared_function_data)
visitor.visit(data);
for (auto& blueprint : class_blueprints) {
for (auto& element : blueprint.elements) {
if (element.literal_value.has_value() && element.literal_value->is_cell())
visitor.visit(element.literal_value->as_cell());
}
}
property_key_table->visit_edges(visitor);
}
void Executable::copy_runtime_caches_from(Executable const& other)
{
if (this == &other)
return;
if (property_lookup_caches.size() == other.property_lookup_caches.size()) {
for (size_t i = 0; i < property_lookup_caches.size(); ++i)
property_lookup_caches[i].copy_from(other.property_lookup_caches[i]);
}
if (global_variable_caches.size() == other.global_variable_caches.size())
global_variable_caches = other.global_variable_caches;
if (environment_coordinate_caches.size() == other.environment_coordinate_caches.size())
environment_coordinate_caches = other.environment_coordinate_caches;
if (template_object_caches.size() == other.template_object_caches.size())
template_object_caches = other.template_object_caches;
if (object_shape_caches.size() == other.object_shape_caches.size())
object_shape_caches = other.object_shape_caches;
if (object_property_iterator_caches.size() == other.object_property_iterator_caches.size()) {
for (size_t i = 0; i < object_property_iterator_caches.size(); ++i)
object_property_iterator_caches[i].data = other.object_property_iterator_caches[i].data;
}
}
size_t Executable::external_memory_size() const
{
size_t size = bytecode.external_memory_size();
size = saturating_add_external_memory_size(size, vector_external_memory_size(property_lookup_caches));
for (auto const& cache : property_lookup_caches)
size = saturating_add_external_memory_size(size, cache.external_memory_size());
size = saturating_add_external_memory_size(size, vector_external_memory_size(global_variable_caches));
size = saturating_add_external_memory_size(size, vector_external_memory_size(environment_coordinate_caches));
size = saturating_add_external_memory_size(size, vector_external_memory_size(template_object_caches));
size = saturating_add_external_memory_size(size, vector_external_memory_size(object_shape_caches));
for (auto const& cache : object_shape_caches)
size = saturating_add_external_memory_size(size, vector_external_memory_size(cache.property_offsets));
size = saturating_add_external_memory_size(size, vector_external_memory_size(object_property_iterator_caches));
size = saturating_add_external_memory_size(size, string_table->external_memory_size());
size = saturating_add_external_memory_size(size, identifier_table->external_memory_size());
size = saturating_add_external_memory_size(size, property_key_table->external_memory_size());
size = saturating_add_external_memory_size(size, regex_table->external_memory_size());
size = saturating_add_external_memory_size(size, vector_external_memory_size(constants));
size = saturating_add_external_memory_size(size, vector_external_memory_size(shared_function_data));
size = saturating_add_external_memory_size(size, vector_external_memory_size(class_blueprints));
for (auto const& blueprint : class_blueprints)
size = saturating_add_external_memory_size(size, vector_external_memory_size(blueprint.elements));
size = saturating_add_external_memory_size(size, vector_external_memory_size(exception_handlers));
size = saturating_add_external_memory_size(size, vector_external_memory_size(source_map));
size = saturating_add_external_memory_size(size, vector_external_memory_size(local_variable_names));
size = saturating_add_external_memory_size(size, hash_map_external_memory_size(m_source_range_cache));
return size;
}
static Vector<PropertyLookupCache*>& static_property_lookup_caches()
{
static NeverDestroyed<Vector<PropertyLookupCache*>> caches;
return *caches;
}
StaticPropertyLookupCache::StaticPropertyLookupCache()
{
static_property_lookup_caches().append(this);
}
static bool cell_is_dead(Cell const* cell)
{
auto* block = GC::HeapBlock::from_cell(cell);
if (!GC::Heap::the().is_live_heap_block(block))
return true;
return cell->state() != Cell::State::Live || !cell->is_marked();
}
static void clear_cache_entry_if_dead(PropertyLookupCache::Entry& entry)
{
if (entry.from_shape && cell_is_dead(entry.from_shape))
entry.from_shape = nullptr;
if (entry.shape && cell_is_dead(entry.shape))
entry.shape = nullptr;
if (entry.prototype && cell_is_dead(entry.prototype))
entry.prototype = nullptr;
if (entry.prototype_chain_validity && cell_is_dead(entry.prototype_chain_validity))
entry.prototype_chain_validity = nullptr;
}
void StaticPropertyLookupCache::sweep_all()
{
for (auto* cache : static_property_lookup_caches()) {
for (auto& entry : cache->entries())
clear_cache_entry_if_dead(entry);
}
}
void Executable::remove_dead_cells(Badge<GC::Heap>)
{
for (auto& cache : property_lookup_caches) {
for (auto& entry : cache.entries())
clear_cache_entry_if_dead(entry);
}
for (auto& cache : global_variable_caches)
clear_cache_entry_if_dead(cache.entry);
for (auto& cache : object_shape_caches) {
auto* shape = cache.shape.ptr();
if (shape && cell_is_dead(shape))
cache.shape = nullptr;
}
}
Optional<Executable::ExceptionHandlers const&> Executable::exception_handlers_for_offset(size_t offset) const
{
// NB: exception_handlers is sorted by start_offset.
auto* entry = binary_search(exception_handlers, offset, nullptr, [](size_t needle, ExceptionHandlers const& entry) -> int {
if (needle < entry.start_offset)
return -1;
if (needle >= entry.end_offset)
return 1;
return 0;
});
if (!entry)
return {};
return *entry;
}
Optional<SourceRange> Executable::source_range_at(size_t offset) const
{
if (offset >= bytecode.size())
return {};
if (source_map.is_empty())
return {};
size_t low = 0;
size_t high = source_map.size();
while (low < high) {
auto middle = low + (high - low) / 2;
if (source_map[middle].bytecode_offset <= offset)
low = middle + 1;
else
high = middle;
}
if (low == 0)
return {};
auto& entry = source_map[low - 1];
return SourceRange {
.code = source_code,
.start = { .line = entry.line, .column = entry.column },
};
}
SourceRange const& Executable::get_source_range(u32 program_counter)
{
return m_source_range_cache.ensure(program_counter, [&] {
if (auto source_range = source_range_at(program_counter); source_range.has_value())
return *source_range;
static NeverDestroyed<SourceRange> dummy { SourceRange { SourceCode::create({}, Utf16String {}), {} } };
return *dummy;
});
}
Operand Executable::original_operand_from_raw(u32 raw) const
{
// NB: Layout is [registers | locals | constants | arguments]
if (raw < number_of_registers)
return Operand { Operand::Type::Register, raw };
if (raw < registers_and_locals_count)
return Operand { Operand::Type::Local, raw - local_index_base };
if (raw < argument_index_base)
return Operand { Operand::Type::Constant, raw - registers_and_locals_count };
return Operand { Operand::Type::Argument, raw - argument_index_base };
}
}