HHVM 4.86 is released! This release marks the end of support for 4.79; HHVM 4.80–4.84 remain supported (4.85 was skipped), as does the 4.56 LTS release.

Breaking Changes

• The built-in function \preg_last_error may now return a new value, \PREG_BAD_REGEX_ERROR. Various \preg_... functions use this error code when called with an invalid regular expression (previously, they would return false without setting an error code).
• If an async function is declared with a non-Awaitable return type, the typechecker now raises an error at the position of the return type (previously, it would raise an error at the position of the function name). This doesn’t introduce any new errors but may require some HH_FIXMEs to be moved.

Future Changes

• Calling a function or method “dynamically” (e.g. calling a function/method whose name is stored in a variable) will become more restricted in the future.
  • The function/method must have the <<__DynamicallyCallable>> attribute.
  • The reference to the function/method to be called must be created using \HH\dynamic_fun($function_name) or \HH\dynamic_class_meth($class_name, $method_name) (a way to dynamically call non-static methods is in the works).
  • To enable the future behavior now, set the INI options hhvm.forbid_dynamic_calls_to_func, hhvm.forbid_dynamic_calls_to_cls_meth and/or hhvm.forbid_dynamic_calls_to_inst_meth to:
    • 0 – Do nothing
    • 1 – Warn if target is not annotated
    • 2 – Throw exception if target is not annotated; warn if dynamic callsite is using a raw string or array
    • 3 – Throw exception