Re: a questiong about the return value type "CORBA_char *"

[Michael Meeks <michael ximian com>]

Hi Folke,

On Tue, 2002-12-17 at 09:24, folke@sina.com.cn wrote:
>   i am a new comer of this community.
> i want to make some questions clear :)

	These are rather basic C questions - it'd be more appropriate to ask
these on the 'gnome-love' list I think.

> CORBA_char *
> BasicServer__get_foo(PortableServer_Servant servant,
>       CORBA_Environment *ev) {
>   return CORBA_string_dup(constants_STRING_RETN);  
> }
...
>   CORBA_string_dup() will allocate a new memory block,
> which will be freed by the system after the 
> BasicServer__get_foo() returns, is that it?

	Quite correct.

> if so how about the following procedure:
> 
> static
> CORBA_char *
> BasicServer__get_foo(PortableServer_Servant servant,
>       CORBA_Environment *ev) {
> 
>   CORBA_char *retval;
> 
>   retval = CORBA_string_dup(constants_STRING_RETN);  
>   /* do something interesting here */
>   return retval;  
> }

	Compile this without any debugging symbols with -O2 and do a binary
diff on the output.

> the only modification is i defined a temporary variable
> "retval", i wonder whether this procedure is quite the 
> same as the first one ? That is , whether the memory 
> block pointed by the retval will be freed automatically
> by the system after the BasicServer__get_foo() returns?

	C is a low level language - what you see is what you get; an assignment
of a pointer, just copies the pointer into another bit of stack - there
is no magic.

	Regards,

		Michael.

-- 
 mmeeks@gnu.org  <><, Pseudo Engineer, itinerant idiot