Re: [PATCH] ada-lang, possible_user_operator_p, null pointer

[Joel Brobecker <brobecker@adacore.com>]

> 2007-08-11  Michael Snyder  <msnyder@access-company.com>
> 
> 	* ada-lang.c (possible_user_operator_p): Guard against NULL.

This is another case where I'd prefer to have the check for a NULL
type moved to the top of the function. But I'm having a tough time
determining how this might actually happen. So I'd like to sit on it
for a little longer before we proceed.

> Also, I'm not sure what the CONCAT operator is, but is it
> possible that the OR at the beginning of the same line
> should be an AND?  Just checking...

The BINOP_CONCAT operator corresponds to the "&" binop operator, which
allows us to concatenate two arrays into one. For instance, you may
have some code like this:

        Hello : constant String := "Hello";
        There : constant String := "there";
        Hello_There : constant String := Hello & " " & There;

In terms of the condition, it's kind of confusing, since the logic is
sort of backwards as far as my brain seems to work. But I think the
condition is actually correct: If you have an array on each side,
then use the pre-defined operator. So if you negate this condition,
if either lhs *or* rhs are not arrays, then...

> Index: ada-lang.c
> ===================================================================
> RCS file: /cvs/src/src/gdb/ada-lang.c,v
> retrieving revision 1.100
> diff -p -r1.100 ada-lang.c
> *** ada-lang.c	6 Aug 2007 20:07:44 -0000	1.100
> --- ada-lang.c	11 Aug 2007 20:39:20 -0000
> *************** possible_user_operator_p (enum exp_opcod
> *** 3536,3542 ****
>           ((TYPE_CODE (type0) != TYPE_CODE_ARRAY
>             && (TYPE_CODE (type0) != TYPE_CODE_PTR
>                 || TYPE_CODE (TYPE_TARGET_TYPE (type0)) != TYPE_CODE_ARRAY))
> !          || (TYPE_CODE (type1) != TYPE_CODE_ARRAY
>                && (TYPE_CODE (type1) != TYPE_CODE_PTR
>                    || (TYPE_CODE (TYPE_TARGET_TYPE (type1)) 
>   		     != TYPE_CODE_ARRAY))));
> --- 3536,3542 ----
>           ((TYPE_CODE (type0) != TYPE_CODE_ARRAY
>             && (TYPE_CODE (type0) != TYPE_CODE_PTR
>                 || TYPE_CODE (TYPE_TARGET_TYPE (type0)) != TYPE_CODE_ARRAY))
> !          || (type1 != NULL && TYPE_CODE (type1) != TYPE_CODE_ARRAY
>                && (TYPE_CODE (type1) != TYPE_CODE_PTR
>                    || (TYPE_CODE (TYPE_TARGET_TYPE (type1)) 
>   		     != TYPE_CODE_ARRAY))));

-- 
Joel