Re: [Boost-build] Enforcing missing properties to cause warning or error messages

From: Peter Schueller (schueller.p_at_[hidden])
Date: 2008-04-06 10:38:09

On Sun, Apr 6, 2008 at 11:59 AM, Vladimir Prus <ghost_at_[hidden]> wrote:
> On Sun, 6 Apr 2008 11:45:06 +0200
>  "Peter Schueller" <schueller.p_at_[hidden]> wrote:
>  > On Sun, Apr 6, 2008 at 6:56 AM, Vladimir Prus <ghost_at_[hidden]> wrote:
>  > >  2. If you know for sure that CPP files created with different
>  > > value of the feature are identical, and always will be, you have to
>  > > remove the feature from the property set associate with the CPP
>  > > file.
>  > >
>  > >  The example generator has this code:
>  > >
>  > >                 # Produce one output, using just copy.
>  > >                 local a = [ new action $(sources[1])
>  > >                   : common.copy : $(property-set) ] ;
>  > >                 local t = [ new file-target $(name) : CPP :
>  > > $(project) : $(a) ] ;
>  > >
>  > >  which can be modifier as follows:
>  > >
>  > >         local raw = [ $(property-set).raw ] ;
>  > >         local stripped = [ property.change $(raw) :
>  > > <gsoap.usage> ] ; local a = [ new actions $(sources[1]) :
>  > > common.copy : [ property-set.create $(stripped) ] ;
>  > >         local t = [ new file-target $(name) : CPP : $(project)
>  > >                   : $(a) ] ;
>  > >
>  > >
>  > >  In this case, the gsoap.usage property won't be associated with the
>  > >  target and the call to virtual-target.register will no longer
>  > > complain that two different targets are associated with the same
>  > > filename.
>  > >
>  > >  Note: the above is untested, so some *details* might be wrong. It
>  > > should work overall.
>  >
>  > I only use the property to pass some information to the generator so
>  > that the generator can decide which CPP files from the action are
>  > passed to the target, i.e. which CPP files get linked into the final
>  > LIB or EXE. Therefore I could use the method from above.
>  >
>  > But this does not work, and I think the reason is the following fact
>  > stated in property-set.jam:
>  >
>  >  13 # - there's 1<->1 correspondence between identity and value. No
>  > two instances of
>  >  14 #   the class are equal. To maintain this property, the
>  > 'property-set.create'
>  >  15 #   rule should be used to create new instances. Instances are
>  > immutable.
>  >
>  > With your method I create two content-wise equal property-sets but
>  > virtual-target still gets no instance equality
>
>  This should not happen. property-set.create is exactly the method that
>  ensured the 1-1 correspondence between identity and value.
>
>
>  > and complains about a
>  > duplicate target (see attached output.txt)
>  >
>  > This seems similar to this problem
>  > http://lists.boost.org/boost-build/2005/11/12089.php which was fixed
>  > in http://svn.boost.org/trac/boost/changeset/31830 but I do not
>  > understand how this changeset fixed it and if it applies to my
>  > problem.
>
>  Just in case -- are you sure all targets you create get passed via
>  virtual-target.register?
>
>  If yes, then please send me a minimal complete project that reproduces
>  the problem, and I will take a look.

I am quite sure that I don't miss to register a target as virtual
target, perhaps the problem is my usage of generators.construct?

I am sending the complete gsoap.jam and a minimal Jamroot file. To get
my error messages, you need to do "touch foo.wsdl server.cpp
client.cpp ; bjam".

If the <gsoap.usage> is both set to server or both to client there
will be no error messages.

Thanks for your help,
Peter