Hi Stefan
> Am 28.10.20 um 13:02 schrieb Julian H. Stacey:
> > man calendar states:
> > "The calendar internal cpp does not correctly do #ifndef and will discard
> > the rest of the file if a #ifndef is triggered."
> > That is wrong, as proved by test file:
> > ---
> > // Test data for ~/.calendar/calendar
> > * bla0
> > #ifdef DEBUG1
> > * 28 bla1
> > #endif
> > #ifdef DEBUG2
> > * 28 bla2
> > #endif
> > #ifndef DEBUG3
> > * 28 bla3
> > #endif
> > #define DEBUG4 TRUE
> > #ifndef DEBUG4
> > * 28 bla4
> > #endif
> > * 28 bla5
> > ---
> > Produces:
> > ---
> > Oct 28 bla5
> > Oct 28 bla4
> > Oct 28 bla3
> > Oct 28 bla2
> > Oct 28 bla1
> > ---
> > Correction:
> > The calendar internal cpp ignores directives #ifdef , #ifndef and #endif
> > ,
> > and simply including intervening text regardless.
>
> Hi Julian,
>
> no, the calendar program worked as documented, see the BUGS section of
> the man-page:
>
> .Sh BUGS
> The
> .Nm
> internal cpp does not correctly do #ifndef and will discard the rest-of
> the file if a #ifndef is triggered.-It also has a maximum of 50 include
> file and/or 100 #defines and only recognises #include, #define and
> #ifndef.
Ah OK, here's 2 test cases
---Ex 1
* 29 bla1
#ifndef RAINEY
* 29 bla4
#endif
* 29 bla5
--- Ex 2
* 29 bla1
#define RAINEY YES
#ifndef RAINEY
* 29 bla4
#endif
* 29 bla5
---
They both produce:
---
Oct 29 bla5
Oct 29 bla4
Oct 29 bla1
---
Where manual misleads with:
"internal cpp ... will discard the rest-of the file if a
#ifndef is triggered"
Triggered or not, that #ifndef to cpp seems not discard rest of file.
> There is no mention of #ifdef being supported ...
OK, I just assumed that would be supported if #ifndef was.
> And your "#ifndef DEBUG4" did not trigger, since the whole line after
> #define is used as the identifier, in your case "DEBUG4 TRUE".
There lies the problem, Thanks !
Nasty, I dont recall anything called cpp aka C Pre Processor ever being
that limited, back to 1983 on a C compiler that ran on CP/M,
where masses of other C things were broken. Best that calendar
not call it cpp at all, as name misleads.
OK, tested with
---
* 29 bla1
#define RAINEY
#ifndef RAINEY
* 29 bla4
#endif
* 29 bla5
---
& got
---
Oct 29 bla5
Oct 29 bla1
---
& finaly in this special case current manual correctly reports a bug.
> This is not obvious from reading the man-page and it might be more
> intuitive, if the identifier was only the word up to the first blank,
Yes
> but the code in the calendar program does just strip off leading and
> trailing white-space. It might be too late to change this behavior.
Hopefully not too late.
Either way, Ameliorations:
- Do a global edit in manual from "cpp" to "pre-processor"
to remove expectation of similarity to cpp.
- Define in manual exactly how the pre-processor handles defines.
> I have updated the code in -CURRENT to support #ifdef (MFC in 3 days)
Nice
> and I plan to add supported for nested conditions in -CURRENT
Nice
> (not
> sure whether that should be merged to -STABLE, though).
Probably yes ?
> I could change the #define and #if/ifndef to only consider the first
> following word, but do not plan to do that at this time.
Would be good if you did, silently swallowing space seperated text
as extended name of a define instead of value of define, is not
intuitive, At least document if you have no time to change it please ?
Fixing documenting & extanding a pp in calendar could become like
re-inventing the wheel ? As a cpp is in src/ & not ports, can't
calendar use popen(/usr/bin/cpp) & save work ? Looks like there's
enough work to do in main calendar without extra work of a custom
pre processor ?
Thanks for copy of your reply to Greg Balfour's off list mail, ref
https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=205580
which notes:
"This patch is against 11.4-RELEASE. Note that it requires
the installation of the devel/tradcpp port/package."
I agree your policy point, FreeBSD can't use a port as dependency
to build calendar, while calendar is still build by src/ world. (&
not just for Free, but Net & Open BSD etc will have similiar views
I presume)
I don't know which cpp's from where might have been looked at in the past,
> Regards, STefan
Thanks !
Cheers,
--
Julian Stacey, Consultant Sys. Eng. BSD Linux Unix, http://berklix.com/jhs/cv/
Crash Brexit profits financial speculators in cabinet damaging Britain.
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