Re: bison and downwards compatibility

[Joerg Hoffmann]

Hi Bob,

thanks for the quick answer.

Well, now you mention it: right now I got for the first time an error 
for which I have absolutely no clue what to do, and which I could not 
resove after some (random) guessing.

I just downloaded bison version 1.875 because that is what I used on a 
previous system and there the code compiled. However, what I get is this:

flex -Pfct_pddl lex-fct_pddl.l
bison -pfct_pddl -bscan-fct_pddl scan-fct_pddl.y
scan-fct_pddl.y: warning: 1 useless nonterminal and 2 useless rules
scan-fct_pddl.y:115.17-33: warning: useless nonterminal: literal_name_plus
scan-fct_pddl.y:793.1-796.1: warning: useless rule: literal_name_plus: 
literal_name
scan-fct_pddl.y:798.1-802.1: warning: useless rule: literal_name_plus: 
literal_name literal_name_plus
scan-fct_pddl.y: conflicts: 1 shift/reduce
gcc -c -O6 -Wall -g -ansi scan-fct_pddl.tab.c
scan-fct_pddl.tab.c: In function ‘fct_pddlparse’:
scan-fct_pddl.tab.c:1213: warning: implicit declaration of function 
‘fct_pddllex’
scan-fct_pddl.tab.c:2038: warning: implicit declaration of function 
‘fct_pddlerror’
In file included from scan-fct_pddl.y:845:
lex.fct_pddl.c:615:31: error: macro "fct_pddlwrap" passed 1 arguments, 
but takes just 0
In file included from scan-fct_pddl.y:845:
lex.fct_pddl.c: In function ‘fct_pddl_init_buffer’:
lex.fct_pddl.c:1642: warning: implicit declaration of function ‘fileno’
scan-fct_pddl.y: In function ‘load_fct_file’:
scan-fct_pddl.y:910: error: ‘yyin’ undeclared (first use in this function)
scan-fct_pddl.y:910: error: (Each undeclared identifier is reported only 
once
scan-fct_pddl.y:910: error: for each function it appears in.)
make: *** [scan-fct_pddl.tab.o] Error 1


I of course have absolutely no clue about the error reported in 
lex.fct_pddl.c. As for "yyin" apparently that's another one of these 
downwards compatibility issues? Yes I can see that yyin is decleared 
nowhere; but that has been the case since 12 years, and I have no idea 
how to declare it because i don;t know the required type.

thanks,
joerg



Bob Rossi wrote:
> On Tue, Oct 24, 2006 at 05:38:27PM +0200, Joerg Hoffmann wrote:
>   
> > Dear Bison makers,
> >
> > First, thanks for your very useful tool. However, I have to say I'm 
> > frustrated by the utter lack of downwards compatibility. Why is this 
> > necessary?
> >
> > I'm working with code that originated in 1998. It has in the meantime 
> > been copied so often that it is impossible to revise all instances. 
> > Every time I get a new bison update I get new errors and complaints that 
> > are totally cryptic and un-understandable, whereas with the older 
> > versions everything worked. Just as a simple example, some old versions 
> > allowed to ommit the ";" at the end of a rule. Newer versions don't. In 
> > effect, I have spent countless hours in the last 5 years inserting ";" 
> > at the points where some programmer in 1998 happened to leave them away.
> >
> > It would be so much more convenient if the bison development obeyed some 
> > form of downwards compatibility.
> >
> > best regards,
> > Joerg Hoffmann
> >     
>
> Hi Joerg,
>
> It probably would have been a good idea to not hold this in for so long.
> If you have a problem with bison, report early, report often.
>
> Anyways, as you see problems, and report them, they can be fixed if they
> are bugs. Others will benefit from your frustrations.
>
> Bob Rossi
>