Re: Need help: Is a VAR_DECL type builtin or not?

[Richard Biener <richard dot guenther at gmail dot com>]

On Mon, Feb 17, 2014 at 1:15 PM, Dominik Vogt <vogt@linux.vnet.ibm.com> wrote:
> On Fri, Feb 14, 2014 at 02:40:44PM +0100, Richard Biener wrote:
>> On Fri, Feb 14, 2014 at 9:59 AM, Dominik Vogt <vogt@linux.vnet.ibm.com> wrote:
>> > Given a specific VAR_DECL tree node, I need to find out whether
>> > its type is built in or not.  Up to now I have
>> >
>> >   tree tn = TYPE_NAME (TREE_TYPE (var_decl));
>> >   if (tn != NULL_TREE && TREE_CODE (tn) == TYPE_DECL && DECL_NAME (tn))
>> >     {
>> >       ...
>> >     }
>> >
>> > This if-condition is true for both,
>> >
>> >   int x;
>> >   const int x;
>> >   ...
>> >
>> > and
>> >
>> >   typedef int i_t;
>> >   i_t x;
>> >   const i_t x;
>> >   ...
>> >
>> > I need to weed out the class of VAR_DECLs that directly use built
>> > in types.
>>
>> Try DECL_IS_BUILTIN.  But I question how you define "builtin" here?
>
> Well, actually I'm working on the variable output function in
> godump.c.  At the moment, if the code comes across
>
>   typedef char c_t
>   chat c1;
>   c_t c2;
>
> it emits
>
>   type _c_t byte
>   var c1 byte
>   var c2 byte
>
> This is fine for c1, but for c2 it should really use the type:
>
>   var c2 _c_t
>
> So the rule I'm trying to implement is:
>
>   Given a Tree node that is a VAR_DECL, if its type is an "alias"
>   (defined with typedef/union/struct/class etc.), use the name of
>   the alias, otherwise resolve the type recursively until only
>   types built into the language are left.
>
> It's really only about the underlying data types (int, float,
> _Complex etc.), not about storage classes, pointers, attributes,
> qualifiers etc.
>
> Well, since godump.c already caches all declarations it has come
> across, I could assume that these declarations are not built-in
> and use that in the "rule" above.

Not sure what GO presents us as location info, but DECL_IS_BUILTIN
looks if the line the type was declared is sth "impossible" (reserved
and supposed to be used for all types that do not have to be declared).

Richard.

> Ciao
>
> Dominik ^_^  ^_^
>
> --
>
> Dominik Vogt
> IBM Germany
>