Gfortran internal tree structure

[Paul Richard Thomas]

Daniel,


>  What do you think about writing a (maybe just quite summarizing)
> documentation about how gfc_code statements and gfc_expr expressions have to
> be structured for IF, DO, things like "a+5" or "ALLOCATED(arr)" and whatever
> comes to mind?  Or is there already such documentation and I missed it?

Don't think, just do!  yes, yes!

>
> If you want and I find time, I volunteer to start this in parallel to my
> coding; but I think for that I need at least a good reviewer as I'm not
> myself a guru on this topic :)  Additionally, if you think that's a good
> idea, I could write builder-functions (maybe in a new code file
> build-tree.c); for instance, given a code-block and a condition, build a
> complete (resolved?) IF-gfc_code block; and similar for other constructs and
> expressions (build a less-than expression given two operands or a
> function-call given the list of actual argument expressions and the
> symbl/symtree/name.  These could serve both as a secondary documentation on
> how such an expression really looks like and be used to combine this logic
> where it's used in the code (during parsing and at places like my
> finalization routines during resolution).

This is done, of course, in the parser.  Whether it would be
worthwhile to extract builder functions from the parser, both for
maintainability and clarity, I do not know.  This is effictively done
in array.c and arith.c.

Incidentally, dump-parse-tree.c could do with updating and, I have no
doubt, could always stand some improvement in the format.

Cheers

Paul