ladybird/Userland/Libraries/LibJS/Bytecode/BasicBlock.h
Andreas Kling 0f70ff9a67 LibJS/Bytecode: Only emit ResolveThisBinding once per basic block
Once executed, this instruction will always produce the same result
in subsequent executions, so it's okay to cache it.

Unfortunately it may throw, so we can't just hoist it to the top of
every executable, since that would break observable execution order.
2024-05-09 09:12:13 +02:00

73 lines
2 KiB
C++

/*
* Copyright (c) 2021, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
#include <AK/Badge.h>
#include <AK/String.h>
#include <LibJS/Bytecode/Executable.h>
#include <LibJS/Bytecode/Operand.h>
#include <LibJS/Forward.h>
#include <LibJS/Heap/Handle.h>
namespace JS::Bytecode {
struct UnwindInfo {
JS::GCPtr<Executable const> executable;
JS::GCPtr<Environment> lexical_environment;
bool handler_called { false };
};
class BasicBlock {
AK_MAKE_NONCOPYABLE(BasicBlock);
public:
static NonnullOwnPtr<BasicBlock> create(u32 index, String name);
~BasicBlock();
u32 index() const { return m_index; }
ReadonlyBytes instruction_stream() const { return m_buffer.span(); }
u8* data() { return m_buffer.data(); }
u8 const* data() const { return m_buffer.data(); }
size_t size() const { return m_buffer.size(); }
void grow(size_t additional_size);
void terminate(Badge<Generator>) { m_terminated = true; }
bool is_terminated() const { return m_terminated; }
String const& name() const { return m_name; }
void set_handler(BasicBlock const& handler) { m_handler = &handler; }
void set_finalizer(BasicBlock const& finalizer) { m_finalizer = &finalizer; }
BasicBlock const* handler() const { return m_handler; }
BasicBlock const* finalizer() const { return m_finalizer; }
auto const& source_map() const { return m_source_map; }
void add_source_map_entry(size_t bytecode_offset, SourceRecord const& source_record) { m_source_map.set(bytecode_offset, source_record); }
auto const& this_() const { return m_this; }
void set_this(Operand operand) { m_this = operand; }
private:
explicit BasicBlock(u32 index, String name);
u32 m_index { 0 };
Vector<u8> m_buffer;
BasicBlock const* m_handler { nullptr };
BasicBlock const* m_finalizer { nullptr };
String m_name;
bool m_terminated { false };
HashMap<size_t, SourceRecord> m_source_map;
Optional<Operand> m_this;
};
}