[fpc-devel] Troubles with FPDOC in 2.5.1 and 2.4.1

[Mattias Gaertner]

On Fri, 14 May 2010 14:33:57 +0200
Graeme Geldenhuys <graemeg.lists at gmail.com> wrote:

> Marco van de Voort het geskryf:
> > 
> > 1) I would particularly be interested if there is a difference between 2.4.1
> > (say a week old maximally) and 2.5.1 (likewise). Before my holiday I
> > committed a fix or two.
> 
> Marco, you are off the hook. :-)
> 
> 
> Damn I love the 'git bisect' command. ;-)  Anyway the problem is
> sub-divided. The errors for 'label' and 'xxx of byte' syntax is introduced
> in r14938. Sorry Michael, that the big patch from Mattias. Now you will
> understand why I *hate* such big single commits. Where do you start looking
> for the problem??   You should ask Mattias for a refund. ;-)

I can send you my 49 smaller patches. But I doubt that would help.
AFAIK deprecated and label were not supported, so I did not break
that.
As I wrote on the fpc mailing list:
I extended the fcl parser to parse the FCL code, which does
not use all the FPC features (tons of modifiers, special compiler directives, nested classes) and not all the Delphi "bugs" like ommitting semicolons.
It took some effort to extend the fcl parser without breaking
compatibility and having extendable code. 
Pre- and post-modifiers make parsers ugly and complicated, because
there is no single start/terminal token anymore and because some
modifiers can be identifiers, requiring bigger lookaheads. The fcl
parser design requires to know the node type before start parsing the
node. This makes implementing lookahead somewhat more difficult
(compared to the codetools). That's why I added some more context
information. But its parser design is still not the best for
pre/postmodifiers. OTOH you get a nice class hierarchy: When the parser
is changed affected code is spotted easier than with the codetools.

In short:
It is difficult to add pre/postmodifiers to the fcl parser, because of
its design. But its design is good for tools like fpdoc. (Note: the fcl parser was designed by Sebastian Guenther).


Mattias