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ZEND_ARG_VARIADIC_TYPE_INFO(0, str, IS_STRING, 0) does not enforce strings #18826

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Description

@divinity76

Description

When doing

function str_starts_with(string $haystack, string ...$needle): bool {}
(...)
ZEND_BEGIN_ARG_WITH_RETURN_TYPE_INFO_EX(arginfo_str_starts_with, 0, 1, _IS_BOOL, 0)
	ZEND_ARG_TYPE_INFO(0, haystack, IS_STRING, 0)
	ZEND_ARG_VARIADIC_TYPE_INFO(0, needle, IS_STRING, 0)
ZEND_END_ARG_INFO()

You would think that the string type would be enforced with strict_types=1

but it doesn't! If you do

function str_starts_with(string $haystack, string ...$needle): bool {}
(...)
ZEND_BEGIN_ARG_WITH_RETURN_TYPE_INFO_EX(arginfo_str_starts_with, 0, 1, _IS_BOOL, 0)
	ZEND_ARG_TYPE_INFO(0, haystack, IS_STRING, 0)
	ZEND_ARG_VARIADIC_TYPE_INFO(0, needle, IS_STRING, 0)
ZEND_END_ARG_INFO()
(...)
    zval *needles;
    size_t num_needles;
    ZEND_PARSE_PARAMETERS_START(2, -1)
        Z_PARAM_STR(haystack)
        Z_PARAM_VARIADIC('+', needles, num_needles)
    ZEND_PARSE_PARAMETERS_END();
    for (size_t i = 0; i < num_needles; ++i) {
        Z_STR(needles[i]); // << segfault on int
    }

and 1 of the needles is an int, you get a segfault!

PHP Version

current git master, 3399235bec275516f6b87714087526d36d6f6976

Operating System

Ubuntu 24.04

Activity

  1. ndossche commented on Jun 10, 2025

    @ndossche
    Member

    Arginfo never enforces anything. It's just metadata. The enforcement of the argument types happens via the ZPP functions or macros.
    In this case you have to do it yourself.

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