mirror of
https://github.com/zebrajr/ladybird.git
synced 2026-01-15 12:15:15 +00:00
9f822345bf
While we're in the bytecode compiler, we want to know which type of Operand we're dealing with, but once we've generated the bytecode stream, we only ever need its index. This patch simplifies Operand by removing the aarch64 bitfield hacks and makes it 32-bit on all platforms. We keep 3 type bits in the high bits of the index while compiling, and then zero them out when flattening the final bytecode stream. This makes bytecode more compact on x86_64, and avoids bit twiddling on aarch64. Everyone wins something! When stringifying bytecode for debugging output, we now have an API in Executable that can look at a raw operand index and tell you what type of operand it was, based on known quantities of each type in the stack frame.
130 lines
4.0 KiB
C++
130 lines
4.0 KiB
C++
/*
|
|
* Copyright (c) 2021-2025, Andreas Kling <andreas@ladybird.org>
|
|
*
|
|
* SPDX-License-Identifier: BSD-2-Clause
|
|
*/
|
|
|
|
#include <LibJS/Bytecode/BasicBlock.h>
|
|
#include <LibJS/Bytecode/Executable.h>
|
|
#include <LibJS/Bytecode/Instruction.h>
|
|
#include <LibJS/Bytecode/RegexTable.h>
|
|
#include <LibJS/Runtime/Value.h>
|
|
#include <LibJS/SourceCode.h>
|
|
|
|
namespace JS::Bytecode {
|
|
|
|
GC_DEFINE_ALLOCATOR(Executable);
|
|
|
|
Executable::Executable(
|
|
Vector<u8> bytecode,
|
|
NonnullOwnPtr<IdentifierTable> identifier_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_registers,
|
|
Strict strict)
|
|
: bytecode(move(bytecode))
|
|
, string_table(move(string_table))
|
|
, identifier_table(move(identifier_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);
|
|
}
|
|
|
|
Executable::~Executable() = default;
|
|
|
|
void Executable::dump() const
|
|
{
|
|
warnln("\033[37;1mJS bytecode executable\033[0m \"{}\"", name);
|
|
InstructionStreamIterator it(bytecode, this);
|
|
|
|
size_t basic_block_offset_index = 0;
|
|
|
|
while (!it.at_end()) {
|
|
bool print_basic_block_marker = false;
|
|
if (basic_block_offset_index < basic_block_start_offsets.size()
|
|
&& it.offset() == basic_block_start_offsets[basic_block_offset_index]) {
|
|
++basic_block_offset_index;
|
|
print_basic_block_marker = true;
|
|
}
|
|
|
|
StringBuilder builder;
|
|
builder.appendff("[{:4x}] ", it.offset());
|
|
if (print_basic_block_marker)
|
|
builder.appendff("{:4}: ", basic_block_offset_index - 1);
|
|
else
|
|
builder.append(" "sv);
|
|
builder.append((*it).to_byte_string(*this));
|
|
|
|
warnln("{}", builder.string_view());
|
|
|
|
++it;
|
|
}
|
|
|
|
if (!exception_handlers.is_empty()) {
|
|
warnln("");
|
|
warnln("Exception handlers:");
|
|
for (auto& handlers : exception_handlers) {
|
|
warnln(" from {:4x} to {:4x} handler {:4x} finalizer {:4x}",
|
|
handlers.start_offset,
|
|
handlers.end_offset,
|
|
handlers.handler_offset.value_or(0),
|
|
handlers.finalizer_offset.value_or(0));
|
|
}
|
|
}
|
|
|
|
warnln("");
|
|
}
|
|
|
|
void Executable::visit_edges(Visitor& visitor)
|
|
{
|
|
Base::visit_edges(visitor);
|
|
visitor.visit(constants);
|
|
}
|
|
|
|
Optional<Executable::ExceptionHandlers const&> Executable::exception_handlers_for_offset(size_t offset) const
|
|
{
|
|
for (auto& handlers : exception_handlers) {
|
|
if (handlers.start_offset <= offset && offset < handlers.end_offset)
|
|
return handlers;
|
|
}
|
|
return {};
|
|
}
|
|
|
|
UnrealizedSourceRange Executable::source_range_at(size_t offset) const
|
|
{
|
|
if (offset >= bytecode.size())
|
|
return {};
|
|
auto it = InstructionStreamIterator(bytecode.span().slice(offset), this);
|
|
VERIFY(!it.at_end());
|
|
auto mapping = source_map.get(offset);
|
|
if (!mapping.has_value())
|
|
return {};
|
|
return UnrealizedSourceRange {
|
|
.source_code = source_code,
|
|
.start_offset = mapping->source_start_offset,
|
|
.end_offset = mapping->source_end_offset,
|
|
};
|
|
}
|
|
|
|
Operand Executable::original_operand_from_raw(u32 raw) const
|
|
{
|
|
if (raw < number_of_registers)
|
|
return Operand { Operand::Type::Register, raw };
|
|
if (raw < local_index_base)
|
|
return Operand { Operand::Type::Constant, raw - static_cast<u32>(number_of_registers) };
|
|
if (raw < argument_index_base)
|
|
return Operand { Operand::Type::Local, raw - static_cast<u32>(local_index_base) };
|
|
return Operand { Operand::Type::Argument, raw - static_cast<u32>(argument_index_base) };
|
|
}
|
|
|
|
}
|