Re: Mapping of TREE_CODE to tree_node

[Andrew Pinski <pinskia@gmail.com>]

On Sun, Jul 2, 2023 at 5:48 PM Aaron Lorey via Gcc <gcc@gcc.gnu.org> wrote:
>
> Am Mo., 26. Juni 2023 um 20:09 Uhr schrieb David Malcolm <dmalcolm@redhat.com>:
> >
> > On Mon, 2023-06-26 at 18:59 +0200, Aaron Lorey via Gcc wrote:
> > > Hello,
> > >
> > > this is the first time I am writing to a mailing list. I've tried
> > > researching the normal procedure but nothing special seems to be
> > > required.
> > >
> > > I'm currently trying to do a complete graph-discovery of GCC's symtab
> > > /
> > > tree_nodes to dump the full internal representation of the
> > > compilation
> > > unit. Gitlab: https://gitlab.com/graph-prog/code-database
> > >
> > > It is not exceptionally heavy but also not very easy to serialize the
> > > internal state to disk. I think this task was simply not considered
> > > in the
> > > design.
> > >
> > > Reason for writing to the mailing list are the troubles in connecting
> > > the
> > > TREE_CODE enumeration to the appropriate struct tree_node memory
> > > layout
> > > without guessing.
> > >
> > > Can you provide a mapping of TREE_CODE to tree_node memory layout?
> >
> > I don't know that such a mapping exists directly, but have a look at
> > the functions "tree_code_size" and "tree_size" defined in gcc/tree.cc.
> >
> > You might also find the LTO streaming code of interest; see gcc/lto-
> > streamer-{in,out}.cc
> >
> > Hope this is helpful
> > Dave
> >
> >
>
> Thank you for your reply.
>
> The tree_size() and tree_code_size() functions are useful, although incomplete.
>
> If I understand correctly, the link time optimization works on the
> GIMPLE representation. The original syntax tree and symbol table would
> be preferable.

You could also look into the module support in the C++ front-end,
`gcc/cp/module.cc ` which does store out the original trees and such.

Thanks,
Andrew

>
> Andrew's suggestion might be more what I'm looking for.