Hello,
With the GCC 3.4 series, a front-end requesting a function to return
by invisible reference used to merely have to set TREE_ADDRESSABLE on
the proper types.
Current mainline now expects everything to be exposed explicitely, as
illustrated by cp_genericize for C++, for instance. Amongst other things,
the function result decl is marked DECL_BY_REFERENCE and the associated
type is made an explicit reference type.
The Ada front-end has not gone through this transition yet and relies on the
gimplifier for temporary creations in a number of circumstances.
One kind of observable effect is ICEs from attempts at creating temporaries of
TREE_ADDRESSABLE type, e.g. while compiling check_result_by_ref.adb in the
testcase below.
We are working at resolving this issue. Part of our current scheme consists
in unsetting the TREE_ADDRESSABLE flag on the function type, which prevents
part of the middle-end magic to work - in particular, the following bits from
expand_call:
/* Set up a place to return a structure. */
...
if (aggregate_value_p (exp, fndecl))
The attached patch is a simple helper for the aforementioned expand_call
issue, preriquisite for a larger change to come, hence part of a regression
fix.
Bootstrapped and successfully regression tested with languages=all,ada
on i686-pc-linux-gnu.
2006-06-24 Olivier Hainque <hainque@adacore.com>
* function.c (aggregate_value_p): Honor DECL_BY_REFERENCE on
a CALL_EXPR target function declaration.