svn commit: r366962 - in head: include usr.bin/calendar

[Scott Long]

> On Oct 26, 2020, at 1:50 AM, Baptiste Daroussin <bapt at FreeBSD.org> wrote:
> 
> On Mon, Oct 26, 2020 at 12:11:56AM -0600, Warner Losh wrote:
>> On Mon, Oct 26, 2020 at 12:01 AM Alex Kozlov <ak at freebsd.org> wrote:
>> 
>>> On Sun, Oct 25, 2020 at 11:37:34AM +0100, Stefan Esser wrote:
>>>> Am 25.10.20 um 06:56 schrieb Alex Kozlov:
>>>>> On Sat, Oct 24, 2020 at 04:37:45PM +0200, Stefan Esser wrote:
>>>>>> Am 24.10.20 um 09:48 schrieb Alex Kozlov:
>>>> [...]
>>>>>>> You are hardcoding assumption that LOCALBASE = /usr/local. Please
>>> make it
>>>>>>> overridable with LOCALBASE environment variable.
>>>>>> This was a trivial change to get us going with calendars provided by
>>>>>> a port (which has not been committed, yet - therefore there are no
>>>>>> port-provided calendars, neither under /usr/local nor under any other
>>>>>> PREFIX, as of now).
>>>>> 
>>>>>> I understand what you are asking for, but in such a case I'd rather
>>>>>> think you want to rebuild FreeBSD with _PATH_LOCALBASE modified in
>>>>>> paths.h.
>>>>> The PREFIX != LOCALBASE and both != /usr/local configurations
>>>>> are supported in the ports tree and the base for a long time, please
>>> see
>>>>> 
>>> https://www.freebsd.org/doc/en_US.ISO8859-1/books/porters-handbook/porting-prefix.html
>>>> 
>>>> Yes, and I do not need to look that up in the handbook, having been
>>>> a ports committer for 2 decades by now.
>>>> 
>>>>> If after this commit you need to rebuild base to use non-default
>>> LOCALBASE/PREFIX
>>>>> it is pretty big regression and POLA.
>>>> 
>>>> How is that any different than before?
>>>> 
>>>> What I did is make the PATH easier to change when you rebuild base.
>>>> 
>>>> There are numerous programs in base that contain the literal string
>>>> /usr/local - and what I did was implement a mechanism that allows
>>>> to replace this literal reference with a simple change in paths.h.
>>>> 
>>>> If you do not modify paths.h for a different LOCALBASE, then you'll
>>>> get a wrong _PATH_DEFPATH compiled into your binaries, for example.
>>>> 
>>>>>> And I have made this a single instance that needs to be changed.
>>>>>> Before my change there were 2 instances of /usr/local hard-coded
>>>>>> in _PATH_DEFPATH - now you have to only change the definition of
>>>>>> _PATH_LOCALBASE to adjust all 3 locations that use it.
>>>>> I think you made situation worse, there were two stray hardcoded
>>>>> string and now there is official LOCALBASE define which likely will be
>>>>> used by other people in the future.
>>>> 
>>>> I'd hope so to get rid of many of the 1713 literal uses of /usr/local
>>>> in our source tree.
>>>> 
>>>>>> If you can show me precedence of a LOCALBASE environment variable
>>>>>> being used in the way you suggest, I'd be willing to make calendar
>>>>>> use it.
>>>>> Just an analogy from LOCALBASE make variable, perhaps CALENDAR_HOME
>>>>> is a better name.
>>>> 
>>>> Yes, I already suggested CALENDAR_HOME, but as an environment variable
>>>> to check, if you want to be able to path an additional directory (or
>>>> search path) to the calendar program at run-time. But why introduce
>>>> a CALENDAR_HOME macro in the sources, if the port supplied calendar
>>>> files are known to be found at LOCALBASE/share/calendar (for some value
>>>> of LOCALBASE).
>>>> 
>>>> I want to make more programs that currently hard-code /usr/local use
>>>> _PATH_LOCALBASE instead. This C macro can then be default to /usr/local
>>>> but can be overridden by passing LOCALBASE to the compiler (from the
>>>> build infrastructure) when paths.h is included.
>>>> 
>>>> Instead of referring to _PATH_LOCALBASE these files could directly use
>>>> LOCALBASE, but since other paths are defined as _PATH_xxx in paths.h I
>>>> think it is best to follow this precedent.
>>>> 
>>>>>> But then I think a CALENDAR_HOME variable would be even more useful,
>>>>>> since it would allow to search an additional user selected directory
>>>>>> (and not just share/calendar within what you provide as LOCALBASE).
>>>> 
>>>> My change did not add any dependency on LOCALBASE to any previously
>>>> existing functionality. It added support for calendar files provided
>>>> by a port (a feature that did not exist before) at a location that is
>>>> correct for the big majority of users (who do not modify LOCALBASE).
>>>> 
>>>> As I said: I'm going to make it easier to build the base system with
>>>> a different LOCALBASE, but not by run-time checking an environment
>>>> variable that specifies LOCALBASE in each affected program.
>>> It seems that you intend to follow through no matter what. So, just for
>>> the record, I think that hardcoding LOCALBASE and requiring base rebuild
>>> to change it is a very wrong approach.
>>> 
>> 
>> So, first off, it's already hard coded. Stefan's changes change the hard
>> coding from 'impossible to change' to 'changeable with a recompile' which
>> is an improvement. It might even wind up as a build variable (or not, doing
>> that has some really ugly, nasty dependencies).
>> 
>> But even in ports-land, it's a compile time constant. Quite a large number
>> of ports will allow you to change it at compile / build time, but not
>> after. You have to rebuild if you want to change PREFIX...
>> 
>> So I'm a bit puzzled what makes this the wrong approach?
>> 
> 
> I think what Alex revents to is the following:
> 
> Some utilities in base base either have a configurable way to look for things in
> localbase (via configuration entries for instances):
> - syslog
> - periodic
> - rc
> - man
> Some have hardcoded LOCALBASE but only after looking first at the LOCALBASE env
> var:
> - usr.sbin/pkg
> - mailwrapper
> 
> which means with a prebuilt base I can still rebuild all my packages with a
> different localbase and it will work with only a few configurations changes.
> which imho is a good target.
> 
> The list of tools which hardcodes /usr/local
> - calendar
> - fortune
> - cron
> - bsnmp
> - nvmecontrol
> - cpucontrol (at least can be workaround via -d option)
> 
> 

It would be pretty trivial to add a new libc function, something like getlocaldir.2,
that took care of searching the environment and the invoking a fallback to the
compile-time default from path.h.  I’ll see if I can come up with something for
review before I fall asleep.

Scott