Generate AST of a PHP source file

Question

I want to parse a PHP source file, into an AST (preferably as a nested array of instructions).

I basically want to convert things like

f($a, $b + 1)

into something like

array( 'function_call',
    array(
        array( 'var', '$a' ),
        array( 'expression',
            array(
                array( 'binary_operation',
                    '+',
                    array ('var', '$b'),
                    array( 'int', '1' )
                )
            )
        )
    )
)

Are there any inbuilt PHP library or third party libraries (preferably in PHP) that would let me do this?

Answer 1

I have implemented a PHP Parser after I figured out that there was no existing parser. It parses the PHP code into a node tree.

Answer 2

HipHop

You can use Facebook's HHVM to dump the AST.

apt-get install hhvm

# parse specified file and dump the AST
hhvm --parse arg  

This worked for HipHop (the old PHP to C++ compiler) - back in the days of 2013!

---

HHVM

Update 2015

--parse is not supported.

You will get an error: HHVM The 'parse' command line option is not supported.

See https://github.com/facebook/hhvm/blob/c494c3a145008f65d349611eb2d09d0c33f1ab23/hphp/runtime/base/program_functions.cpp#L1111

Feature Request to support the CLI option again: https://github.com/facebook/hhvm/issues/4615

---

PHP 7

PHP 7 will have an AST, see the related RFC.

There are two extensions, which provide access and expose the AST generated by PHP 7:

• https://github.com/nikic/php-ast
• https://github.com/sgolemon/astkit