Stdlib: assert() failure warns E_USER_WARNING "Assertion failed" — Zend E_WARNING "assert(): … failed" (ext/standard/assert.c) #23731

Category

Stdlib · php-src-strict · assert · pillar 4

Problem

With assertions active and assert.exception=0, a failing assert() on this VM emits E_USER_WARNING (512) with message Assertion failed: x. Zend emits E_WARNING (2) with assert(): x failed.

Verified 2026-07-27 against php:8.4-cli 8.4.23 (zend.assertions=1 at runtime). Pinned image Zend 8.2 cannot flip zend.assertions via ini_set (php.ini-only) — use 8.4 reference for this slice.

(assert.exception=1 → AssertionError already matches Zend.)

php-src reference

• php/php-src ext/standard/assert.c — assert_handle_failure / warning channel + message format
• php.net assert

PHP implementation target

• ext/standard/ assert implementation (PHP-in-PHP) — emit E_WARNING and message assert(): {description} failed (or Zend's exact format for the description form used)
• Mirror JIT/AOT assert helpers; no new C assert paths in runtime/

Repro

# Zend 8.4 reference (pinned CI Zend 8.2 cannot enable zend.assertions at runtime):
docker run --rm -i \$HARNESS_DOCKER_RUN_OPTS --entrypoint php php:8.4-cli /dev/stdin <<'PHP'
<?php
ini_set("zend.assertions", "1");
ini_set("assert.exception", "0");
error_reporting(E_ALL);
function handler($no, $str) { echo "W:$no:$str\n"; return true; }
set_error_handler("handler");
assert(false, "x");
echo "after\n";
PHP

./script/docker-exec.sh -- bash -lc 'cat > /tmp/assert_w.php <<'"'"'PHP'"'"'
<?php
ini_set("zend.assertions", "1");
ini_set("assert.exception", "0");
error_reporting(E_ALL);
function handler($no, $str) { echo "W:$no:$str\n"; return true; }
set_error_handler("handler");
assert(false, "x");
echo "after\n";
PHP
php bin/vm.php /tmp/assert_w.php'

Done when

• Failing assert (exception off) reports level 2 (E_WARNING) and Zend message shape assert(): … failed
• assert.exception=1 still throws AssertionError (unchanged)
• Compliance .phpt under test/compliance/cases/
• php-src-strict; no php-compiler-strict shortcut