Hi all,

I wonder where in the FPC compilation flow would be a good spot to dump the parsed syntax tree of a source?

Here's why I'm asking. For a while now, I've been struggling to adapt a bunch of Pascal code to various mobile platforms. It's been painful. The code itself is pretty conservative feature-wise, almost K&R C-like (except sets and ansistrings). I wonder if I could slap together a quick and dirty Pascal-to-C converter just for this codebase to work, but I'd rather reuse the existing parsing logic.

So if anyone could point me at a spot in the FPC source where the source tree is more or less ready, that's be nice. Thanks in advance.

The compiler already supports dumping the parse tree when you use the -vp option. But it's more intended for debugging the compiler - I don't know if it'll work for you.

Nikolay

Good point, thanks. From a brief look, tree.log retains enough information to rebuild the source. I'll see if I can work with that...

On second look, no, the -vp tree is not sufficient. It doesn't have datatype definitions, doesn't have interface definitions...

Vsevolod Alekseyev wrote

On second look, no, the -vp tree is not sufficient. It doesn't have datatype definitions, doesn't have interface definitions...

True. I guess, you can try to use ppudump in order to dump these definitions. It'll only work for units though, but I guess it shouldn't be too hard to make the compiler output ppu files for programs as well.

Nikolay

I don't see local variable definitions there, either...

Lazarus has a Pascal tokenizer unit under components\mpaslex\mpaslex.pp. It seems old and doesn't look like it supports the full FPC syntax, but it might be a starting point since most likely you can convert the code to C++ with GNU GCC extensions (nested functions, etc) straightforward.

You had better use the fcl-passrc units. They dump a complete syntax tree. It is used to generate (a currently limited version of) javascript, and used to create documentation.

so it should be usable to generate C code...

The test program re-dumps a pascal program.
Presumably you can adapt that to generate C.

Michael.

Kostas Michalopoulos wrote

Lazarus has a Pascal tokenizer unit under components\mpaslex\mpaslex.pp. It seems old and doesn't look like it supports the full FPC syntax, but it might be a starting point since most likely you can convert the code to C++ with GNU GCC extensions (nested functions, etc) straightforward.

What test program, please? Where?

See the FPC sources:

packages/fcl-passrc/examples/test_parser.pp

Michael.

I didn't knew about that! This can be very helpful for generating C compatible interfaces for DLLs.

On Thu, Oct 23, 2014 at 10:36 PM, Michael Van Canneyt <