69dddd4ef5
This patch begins the work of implementing JavaScript execution in a bytecode VM instead of an AST tree-walk interpreter. It's probably quite naive, but we have to start somewhere. The basic idea is that you call Bytecode::Generator::generate() on an AST node and it hands you back a Bytecode::Block filled with instructions that can then be interpreted by a Bytecode::Interpreter. This first version only implements two instructions: Load and Add. :^) Each bytecode block has infinity registers, and the interpreter resizes its register file to fit the block being executed. Two new `js` options are added in this patch as well: `-d` will dump the generated bytecode `-b` will execute the generated bytecode Note that unless `-d` and/or `-b` are specified, none of the bytecode related stuff in LibJS runs at all. This is implemented in parallel with the existing AST interpreter. :^)
42 lines
1,006 B
C++
42 lines
1,006 B
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 <LibJS/Bytecode/Block.h>
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#include <LibJS/Bytecode/Instruction.h>
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#include <LibJS/Bytecode/Interpreter.h>
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namespace JS::Bytecode {
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Interpreter::Interpreter(GlobalObject& global_object)
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: m_global_object(global_object)
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{
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}
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Interpreter::~Interpreter()
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{
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}
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void Interpreter::run(Bytecode::Block const& block)
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{
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dbgln("Bytecode::Interpreter will run block {:p}", &block);
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m_registers.resize(block.register_count());
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for (auto& instruction : block.instructions())
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instruction.execute(*this);
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dbgln("Bytecode::Interpreter did run block {:p}", &block);
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for (size_t i = 0; i < m_registers.size(); ++i) {
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String value_string;
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if (m_registers[i].is_empty())
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value_string = "(empty)";
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else
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value_string = m_registers[i].to_string_without_side_effects();
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dbgln("[{:3}] {}", i, value_string);
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}
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}
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}
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