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From André Pang <>
Subject Re: Bug with __stdcall modules on Windows
Date Wed, 05 Jan 2005 04:42:17 GMT
On 05/01/2005, at 1:17 PM, William A. Rowe, Jr. wrote:

> At 06:06 PM 1/4/2005, Andre Pang wrote:
>> [...]
>> This doesn't quite work however, because foo_handler is declared to be
>> of the ap_HOOK_handler_t type.  Since the ap_HOOK_handler_t typedef is
>> declared in the Apache headers files without __cdecl, the compiler
>> type-checks ap_HOOK_handler_t as __stdcall (because the header files
>> are included by the module, and since the module is compiled with
>> __stdcall, any header declarations are also presumed to be __stdcall).
> Let me make sure I understand; you build your module forcing
> the /Gz option?

That's exactly right.

> I'll consider the minimal semantics to force this to behave
> (we have a set of macros, AP[...]_DECLARE_NONSTD) which should
> actually handle this nicely, with the addition of __cdecl.

That sounds perfect to me.  I mentioned this in my original message, 

>>   * Add an AP_MODULE_ENTRY_POINT macro to declare direct function 
>> entry points into a module, similar to how AP_MODULE_DECLARE_DATA is 
>> needed for module declarations.  Or, change the 
>> AP_MODULE_DECLARE_NONSTD macro so that it contains __cdecl on 
>> Windows.

... so it looks like we're in sync there.  Adding __cdecl to 

> It's up to you to correctly declare your registered hook
> entry points as __cdecl if you insist on the nonstandard /Gz
> compiler option.

I do correctly declare my hook entry points as __cdecl, but this isn't 
quite enough.

The problem is that when the Apache header files are #included by the 
module's source code, the ap_HOOK_handler_t and module typedefs expect 
__stdcall function pointers (because I'm compiling with /Gz).  
Specifically, I mean these parameters:

   static void __cdecl foo_register_hooks(apr_pool_t *p)
       ap_hook_handler(foo_handler /* <-- this function pointer
                                          needs to be typedef'ed as
                                          __cdecl */,
   		            NULL, NULL, APR_HOOK_MIDDLE);


   module AP_MODULE_DECLARE_DATA foo_module = {
       NULL,                  /* create per-dir    config structures */
       NULL,                  /* merge  per-dir    config structures */
       NULL,                  /* create per-server config structures */
       NULL,                  /* merge  per-server config structures */
       NULL,                  /* table of config file commands       */
       foo_register_hooks     /* <-- this function pointer needs to be
                                 typedef'ed as __cdecl (register hooks) 

I'd send a patch for the Apache/APR headers myself, but I looked hard 
for the typedefs for ap_hook_handler and the function pointer for the 
module struct and couldn't find them in any of the .h files, sorry.  
I'm hoping you can help me out with that.

% Andre Pang :

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