A question about java/lang.c:java_get_callee_fndecl.

[Steven Bosscher]

On Tuesday 22 March 2005 09:11, Andrew Haley wrote:
> Kazu Hirata writes:
>  > Hi,
>  >
>  > I see that the implementation of LANG_HOOKS_GET_CALLEE_FNDECL in Java
>  > always returns NULL (at least for the time being).
>  >
>  > static tree
>  > java_get_callee_fndecl (tree call_expr)
>  > {
>  >   tree method, table, element, atable_methods;
>  >
>  >   HOST_WIDE_INT index;
>  >
>  >   /* FIXME: This is disabled because we end up passing calls through
>  >      the PLT, and we do NOT want to do that.  */
>  >   return NULL;
>  >
>  >
>  >
>  >
>  > Is anybody planning to fix this?
>
> Yes.
>
> The problem is that I want to expose opportunities for inlining but I
> do not want calls to global functions to go through the PLT as
> required by C semantics.  To do that causes endless problems.

Ehm, inline how? We currently inline GIMPLE, but your langhook is
looking for FUNCTION_DECLs in something that is not GIMPLE.

The langhook currently looks inside ARRAY_REFs right now.  Apparently
Java has calls of the form CALL_EXPR<ARRAY_REF<array,index>, ....>,
which is very much *not* GIMPLE.  So if you enable the lang hook, you
are either going to need a GIMPLE extension (bad), or figure out some
different way to represent this kind of call such that the CALL_EXPR
is proper GIMPLE.

IMHO it is Bad Taste(tm) anyway if get_callee_fndecl must look in
language specific data structures even when it is call from language
independent parts of the compiler, like the tree optimizers.

Gr.
Steven