6ae9346cd3
This introduces two new instructions: Jump and JumpIfFalse. Jumps are made to a Bytecode::Label, which is a simple object that represents a location in the bytecode stream. Note that you may not always know the target of a jump when adding the jump instruction itself, but we can just update the instruction later on during codegen once we know where the jump target is. The Bytecode::Interpreter now implements jumping via a jump slot that gets checked after each instruction to see if a jump is pending. If not, we just increment the PC as usual.
50 lines
1 KiB
C++
50 lines
1 KiB
C++
/*
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* Copyright (c) 2021, Andreas Kling <kling@serenityos.org>
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*
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* SPDX-License-Identifier: BSD-2-Clause
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*/
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#include <AK/OwnPtr.h>
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#include <LibJS/AST.h>
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#include <LibJS/Bytecode/Block.h>
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#include <LibJS/Bytecode/Generator.h>
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#include <LibJS/Bytecode/Instruction.h>
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#include <LibJS/Bytecode/Register.h>
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#include <LibJS/Forward.h>
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namespace JS::Bytecode {
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Generator::Generator()
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{
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m_block = Block::create();
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}
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Generator::~Generator()
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{
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}
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OwnPtr<Block> Generator::generate(ASTNode const& node)
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{
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Generator generator;
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[[maybe_unused]] auto dummy = node.generate_bytecode(generator);
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generator.m_block->set_register_count({}, generator.m_next_register);
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return move(generator.m_block);
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}
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void Generator::append(NonnullOwnPtr<Instruction> instruction)
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{
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m_block->append({}, move(instruction));
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}
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Register Generator::allocate_register()
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{
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VERIFY(m_next_register != NumericLimits<u32>::max());
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return Register { m_next_register++ };
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}
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Label Generator::make_label() const
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{
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return Label { m_block->instructions().size() };
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}
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}
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