Re: Mapping of TREE_CODE to tree_node

[Aaron Lorey <lorey.bewerbung@gmail.com>]

Am Mo., 3. Juli 2023 um 02:50 Uhr schrieb 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.

I've now managed to dump the syntax tree of the compilation unit
(tree_function_decl.saved_tree -> tree_exp.operands ->
tree_statement_list.nodes). Thank you very much for the help!

In order to print out the original code, I need to know which program
code was translated to the individual nodes. Is there a chance to get
the original tokens (or the offsets in the program code file) per
tree_node without modifying the parser?