Re: [Help] Reason on when to declare and protect ZEND_API function

On Thu, Jan 20, 2022 at 1:56 AM Su, Tao <tao.su@intel.com> wrote: > > Hello internals, > > I am trying to read Zend header files to understand its functional interfaces, > but have got confusion and anybody knows why zend_startup_system_id() and > zend_finalize_system_id() > do not have to be protected by BEGIN_EXTERN_C()/END_EXTERN_C() enclosure, > but zend_add_system_entropy() has to. > > Is the following code intentional for any reason? > And also, these two functions do not have ZEND_API attribute. Thanks. > > Zend/zend_system_id.h > BEGIN_EXTERN_C() > /* True global; Write-only during MINIT/startup */ > extern ZEND_API char zend_system_id[32]; > > ZEND_API ZEND_RESULT_CODE zend_add_system_entropy(const char *module_name, const char > *hook_name, const void *data, size_t size); > END_EXTERN_C() > > void zend_startup_system_id(void); > void zend_finalize_system_id(void); > > > ======================================= > Tony Su (Su, Tao) > make a 'lazy' programmer diligently with efficiency > I haven't looked at the details of these specific functions recently, but in general functions which are marked ZEND_API are capable of being called from extensions and modules. These same ZEND_API functions need to be in extern "C" sections for that to happen if the extension or module is using C++. I would guess that zend_startup_system_id and zend_finalize_system_id do not need to be used outside of the engine but needed to have a forward declaration for code organization reasons.