Category

stdlib

Problem

Debug output builtins are incomplete: print_r() is missing entirely; var_dump() exists in ext/standard/var_dump.php but is not registered in Module.php and only formats a tiny type subset.

Verified May 2026:

./script/docker-exec.sh -- bash -lc 'source script/php-env.sh && php bin/vm.php -r "print_r([1]);"'
# Call to undefined function print_r()

./script/docker-exec.sh -- bash -lc 'source script/php-env.sh && php bin/vm.php -r "var_dump([1]);"'
# Call to undefined function var_dump()  (not registered)

php-src reference

• php/php-src ext/standard/basic_functions.c — PHP_FUNCTION(print_r), PHP_FUNCTION(var_dump)
• php/php-src ext/standard/var.c — shared pretty-print helpers

Repro

<?php
$a = ['k' => 1, 'nested' => ['x' => 2]];
print_r($a, true);
var_dump($a);

./script/docker-exec.sh -- bash -lc 'source script/php-env.sh && php bin/vm.php repro.php'
php repro.php

Scope (this repo)

JIT/AOT may remain VM-only v1; document in matrix notes.

Done when

• print_r($var, $return=false) echoes; $return=true returns string
• var_dump(...$vars) registered and dumps arrays with keys/types
• Repro produces Zend-like structure (exact whitespace optional; structure required)
• ./script/ci-fast.sh --filter "print_r|var_dump" green
• No duplicate registration with var_export (Stdlib: var_export() — arrays, scalars, and objects (ext/standard/var.c parity) #3594)

Related

• Stdlib: var_export() — arrays, scalars, and objects (ext/standard/var.c parity) #3594 — var_export() full parity
• Stdlib: preg_last_error_msg() — human-readable PCRE error (PHP 8.0) #3110 — preg JIT area (separate)