nikic/PHP-Parser

php composer.phar require nikic/php-parser

<?php
use PhpParser\Error;
use PhpParser\NodeDumper;
use PhpParser\ParserFactory;

$code = <<<'CODE'
<?php

function test($foo)
{
    var_dump($foo);
}
CODE;

$parser = (new ParserFactory())->createForNewestSupportedVersion();
try {
    $ast = $parser->parse($code);
} catch (Error $error) {
    echo "Parse error: {$error->getMessage()}\n";
    return;
}

$dumper = new NodeDumper;
echo $dumper->dump($ast) . "\n";

array(
    0: Stmt_Function(
        attrGroups: array(
        )
        byRef: false
        name: Identifier(
            name: test
        )
        params: array(
            0: Param(
                attrGroups: array(
                )
                flags: 0
                type: null
                byRef: false
                variadic: false
                var: Expr_Variable(
                    name: foo
                )
                default: null
            )
        )
        returnType: null
        stmts: array(
            0: Stmt_Expression(
                expr: Expr_FuncCall(
                    name: Name(
                        name: var_dump
                    )
                    args: array(
                        0: Arg(
                            name: null
                            value: Expr_Variable(
                                name: foo
                            )
                            byRef: false
                            unpack: false
                        )
                    )
                )
            )
        )
    )
)

use PhpParser\Node;
use PhpParser\Node\Stmt\Function_;
use PhpParser\NodeTraverser;
use PhpParser\NodeVisitorAbstract;

$traverser = new NodeTraverser();
$traverser->addVisitor(new class extends NodeVisitorAbstract {
    public function enterNode(Node $node) {
        if ($node instanceof Function_) {
            // Clean out the function body
            $node->stmts = [];
        }
    }
});

$ast = $traverser->traverse($ast);
echo $dumper->dump($ast) . "\n";

array(
    0: Stmt_Function(
        attrGroups: array(
        )
        byRef: false
        name: Identifier(
            name: test
        )
        params: array(
            0: Param(
                attrGroups: array(
                )
                type: null
                byRef: false
                variadic: false
                var: Expr_Variable(
                    name: foo
                )
                default: null
            )
        )
        returnType: null
        stmts: array(
        )
    )
)

use PhpParser\PrettyPrinter;

$prettyPrinter = new PrettyPrinter\Standard;
echo $prettyPrinter->prettyPrintFile($ast);

<?php

function test($foo)
{
}