此扩展默认为启用,编译时可通过下列选项禁用: --disable-simplexml
Note: Before PHP 5.1.2, --enable-simplexml is required to enable this extension.
alvaro at digdib dot com (2009-01-02 02:40:05)
Gentoo users: emerge does not compile dev-lang/php with simplexml by default. To enable this option, add the flag simplexml to your USE variable and recompile php.