RubyVM on PHP

The RubyVM on PHP is implementation RubyVM written in PHP 100%. Completely documentation not exists how to implement RubyVM, and I was referred Ruby source code when contributing this project.

Notice: This project is very ultra super hyper maximum experimental implementation

Notice: I tested Ruby version 3.2 and 3.3 only

See also

• https://github.com/ruby/ruby/blob/master/compile.c
• https://github.com/ruby/ruby/blob/master/vm.c
• https://github.com/ruby/ruby/blob/master/vm_exec.c

DEMO

Requirement

• PHP 8.2+

Currently status

• Implemented general syntax (define local variables, global variables, classes, methods, booleans, hashes, arrays and so on)
• Implemented arithmetics (+, -, *, /), bit calculating (|, &, <<, >>), some operator (**, %) and available overwrite it
• Implemented the block syntax ([].each do | var | ... end) and non block syntax ([].push)
• Implemented keyword arguments when calling a method (keyword_argument(a: "Hello", c: "!", b: "World"))
• Implemented variadic arguments when using an array and calling a method ([*var1, *var2], keyword_argument(a, b, *c))
• Implemented partially ruby methods (to_s, to_i, [].push, foobar.nil?)
• Implemented case-when syntax
• Implemented regexp syntax (p /Hello/ =~ "Hello World")
• Implemented raise/rescue
• and anymore (see the tests' directory)

Quick start

1. Install via composer as following

$ composer require m3m0r7/rubyvm-on-php

2. Save the below code as HelloWorld.rb

puts RubyVM::InstructionSequence.compile("puts 'HelloWorld!\n'", "HelloWorld.rb").to_binary

3. Output .yarv file as following

$ ruby HelloWorld.rb > HelloWorld.yarv

3. Create PHP file with below code and save as HelloWorld.php

<?php
require __DIR__ . '/vendor/autoload.php';

// Instantiate RubyVM class
$rubyVM = new \RubyVM\VM\Core\Runtime\RubyVM(
    new \RubyVM\VM\Core\Runtime\Option(
        reader: new \RubyVM\Stream\BinaryStreamReader(
            streamHandler: new \RubyVM\Stream\FileStreamHandler(
                // Specify to want you to load YARV file
                __DIR__ . '/HelloWorld.yarv',
            ),
        ),

        // Choose Logger
        logger: new \Psr\Log\NullLogger(),
    ),
);

// Disassemble instruction sequence binary formatted and get executor
$executor = $rubyVM->disassemble();

// You can choose to run ruby version if you needed
// $executor = $rubyVM->disassemble(
//    useVersion: \RubyVM\RubyVersion::VERSION_3_2,
// );

// Execute disassembled instruction sequence
$executor->execute();

4. Run php HelloWorld.php and you will get outputted HelloWorld! from RubyVM.

Call defined ruby method on PHP

1. Create ruby code as below:

def callFromPHP
  puts "Hello World from Ruby!"
end

And then, save file as test.rb

2. Compile to YARV as below:

$ ruby -e "puts RubyVM::InstructionSequence.compile_file('test.rb').to_binary" > test.yarv

3. Call ruby method on PHP as below:

<?php
require __DIR__ . '/vendor/autoload.php';

// Instantiate RubyVM class
$rubyVM = new \RubyVM\VM\Core\Runtime\RubyVM(
    new \RubyVM\VM\Core\Runtime\Option(
        reader: new \RubyVM\Stream\BinaryStreamReader(
            streamHandler: new \RubyVM\Stream\FileStreamHandler(
                // Specify to want you to load YARV file
                __DIR__ . '/test.yarv',
            ),
        ),

        // Choose Logger
        logger: new \Psr\Log\NullLogger(),
    ),
);

// Disassemble instruction sequence binary formatted and get executor
$executor = $rubyVM->disassemble();

// Execute disassembled instruction sequence
$executed = $executor->execute();

// Call Ruby method as below code.
// In this case, you did define method name is `callFromPHP`.
$executed->context()->callFromPHP();

You will get to output Hello World from Ruby!. In addition case, maybe you want to pass arguments. of course, it is available on. First time, to modify previous code as below.

def callFromPHP(text)
  puts text
end

Second time, to modify PHP code $executed->context()->callFromPHP() as following:

$executed->context()->callFromPHP('Hello World! Here is passed an argument from PHP!')

You will get to output Hello World! Here is passed an argument from PHP.

Use an executor debugger

The RubyVM on PHP is provided an executor debugger that can display processed an INSN and anymore into a table as following:

+-----+--------------------------------+-------------------------------+--------------------------------+--------------+
| PC  | CALLEE                         | INSN                          | CURRENT STACKS                 | LOCAL TABLES |
+-----+--------------------------------+-------------------------------+--------------------------------+--------------+
| 0   | <main>                         | [0x12] putself                |                                |              |
+-----+--------------------------------+-------------------------------+--------------------------------+--------------+
| 1   | <main>                         | [0x15] putstring              | Main#0                         |              |
+-----+--------------------------------+-------------------------------+--------------------------------+--------------+
| 3   | <main>                         | [0x33] opt_send_without_block | Main#0, String(Hello World!)#1 |              |
|     |                                | (Main#puts(Hello World!))     |                                |              |
+-----+--------------------------------+-------------------------------+--------------------------------+--------------+
| 5   | <main>                         | [0x3c] leave                  | Nil(nil)#0                     |              |
+-----+--------------------------------+-------------------------------+--------------------------------+--------------+

If you want to display above table then add below code from the Quick start.

Notice: The executor debugger is using a lot of memories. We recommend to use disabling ordinarily. In depending on the case, may be using -d memory_limit=NEEDING_MEMORY_BYTES parameters to be working when calling php command

// You can display processed an INSN table when adding below code
$executor->context()->option()->debugger()->showExecutedOperations();

Step by step debugging

The RubyVM on PHP is providing step by step debugger. It is available to confirm to process a sequence step by step. Which collect previous stacks, registered local tables and so on. this is required debugging this project.

// Use breakpoint debugger with option

$rubyVM = new \RubyVM\VM\Core\Runtime\RubyVM(
    new \RubyVM\VM\Core\Runtime\Option(
        // excluded...

        debugger: new \RubyVM\VM\Core\Runtime\Executor\Debugger\StepByStepDebugger(),
    ),
);

When you enabled it, displays as below:

+-----+--------------------------------+-------------------------------+--------------------------------+--------------+
| PC  | CALLEE                         | INSN                          | CURRENT STACKS                 | LOCAL TABLES |
+-----+--------------------------------+-------------------------------+--------------------------------+--------------+
| 0   | <main>                         | [0x12] putself                |                                |              |
+-----+--------------------------------+-------------------------------+--------------------------------+--------------+
| 1   | <main>                         | [0x15] putstring              | Main#0                         |              |
+-----+--------------------------------+-------------------------------+--------------------------------+--------------+
Current INSN: putstring(0x15)
Previous Stacks: [total: 1, OperandEntry<Main>]#966
Previous Local Tables: []
Current Stacks: [total: 2, OperandEntry<Main>, OperandEntry<StringSymbol@HelloWorld!>]#561
Current Local Tables: []

Enter to next step (y/n/q): <INPUT_YOU_EXPECTING_NEXT_STEP>

Custom method

The RubyVM on PHP has custom method in the main context. Try to call phpinfo as below Ruby code on the RubyVM on PHP:

phpinfo

Then you got displayed PHP Version: 8.2.7

Test

$ ./vendor/bin/phpunit tests/

Linter

./vendor/bin/php-cs-fixer fix --allow-risky=yes

How to contribute

1. Build your ruby environment from source code with -DIBF_ISEQ_DEBUG flag

See: https://docs.ruby-lang.org/en/master/contributing/building_ruby_md.html

$ git clone git@github.com:ruby/ruby.git
$ mkdir build && cd build
$ ../configure cppflags="-DIBF_ISEQ_DEBUG=1"
$ make -j$(nproc)

2. When you built ruby environment, you will got vm.inc file which is wrote how to execute each INSN commands

3. You can get logging at ibf_load_** when running ruby code as following

...omitted

ibf_load_object: type=0x15 special=1 frozen=1 internal=1      // The type is a FIX_NUMBER (2)
ibf_load_object: index=0x3 obj=0x5
ibf_load_object: list=0xf0 offsets=0x12b80fcf0 offset=0xe1
ibf_load_object: type=0x15 special=1 frozen=1 internal=1      // The type is a FIX_NUMBER (3)
ibf_load_object: index=0x4 obj=0x7
ibf_load_object: list=0xf0 offsets=0x12b80fcf0 offset=0xcd
ibf_load_object: type=0x5 special=0 frozen=1 internal=0       // The type is a STRING SYMBOL (puts)

...omitted

The above logs is created below example code:

puts 1 + 2 + 3

4. Refer it and now you can contribute to implement INSN command in the RubyVM on PHP

Other my toys

• PHPJava - Implement a JVM written in PHP
• nfc-for-php - A NFC Reader (Control a NFC hardware) written in PHP
• PHPPython - Implement a PYC executor written in PHP