[Cobolforgcc-devel] Re: [open-cobol-list] GCC front end for COBOL

[Bernard G. <bg...@fr...>]

Keisuke Nishida a écrit :

> Hi,
>
> I am a developer of a COBOL compiler called OpenCOBOL,
> and I would like to make it a GCC front end.
>
> I have experimentally implemented a GCC front end by
> modifying OpenCOBOL, and it now compiles basic COBOL
> programs as much as OpenCOBOL can do.
>
>

A whole lot of thanks for the excellent work you've
done so far, Keisuke !!

I would just suggest changing the external name
gcb (and the project name) to something like
gcob: quicker to pronounce, and better imaging
against GNU (like gcc, g77, ...).

> So, what should I do next?  Could I contribute the
> code to the GCC team, or should I continue development
> by myself until it becomes more useful and stable?

I wonder how much easy it would be to continue
to work with OpenCOBOL modified to have
a structure more compatible to GCC, so that minimal
modifications could be applied back to gcc-cobol ?

>
> I have implemented the front end from scratch by
> myself and I am ready to send a copyright assignment
> (with my employer's disclaimer).

Better sending now your copyright assignment request,
by experience, it takes time to proceed !

>
> The current status of my compiler is that it is
> partially compliant to the COBOL 85 standard.  It
> can compile some useful COBOL programs, but still
> there is lots of work to be done.
>
> At this time, I implemented the front end based on
> the gcc-3_3-branch.  I am aware of the tree-ssa
> branch, and probably I had better rewrite the front
> end using the new internal representation, but I am
> not sure when and how I should do that.
>
> The current implementation of my front end is more
> like a quick hack; it works, but is not so elegant.
> I am going to rewrite it to make it cleaner and
> more efficient.
>
> Before further going on, I would like to hear what
> people think about my project.  Would GCC accept
> my front end for the COBOL language?  With what
> version (branch) of GCC I should work?
>
> The source code of my COBOL front end is available
> at the following page:
>
>   http://www.open-cobol.org/gcc.html
>

A few technical hints when making the compiler:

- on a RH8.0, I had to rename all malloc in cob-tree.c
  into xmalloc, following a error message about
  "poisonous malloc".
- contrary to your instructions, you need OpenCOBOL 0.12.
  If 0.11, cob_get_environment and cob_put_environment
  are missing. If 0.20, then cob_decimal_get, cob_decimal_get_r
  and cob_error_code are missing.

Also where should cobc1 be installed to make it work ?

>
> Thanks,
> Keisuke Nishida

--
Bernard Giroud
TinyCOBOL Developer