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

From: Peter Schueller (schueller.p_at_[hidden])
Date: 2008-04-05 03:36:26

Hello!

I am using two standard generators to create a client and a server
version of gsoap code. I have to distinguish between server and client
and so I use  a property as requirement. If I forget to add this
property to the Jamfile, both of the generators will be pruned and I
will only get the message "target could not be constructed".

The generators are registered the following way:

12 generators.register-standard gsoap.soapcpp2 :
13 WSDL_H : H(%SoapStub) H(%SoapH) CPP(%SoapC) CPP(%SoapClient) :
14 <gsoap.usage>client ;
15
16 generators.register-standard gsoap.soapcpp2 :
17 WSDL_H : H(%SoapStub) H(%SoapH) CPP(%SoapC) CPP(%SoapServer) :
18 <gsoap.usage>server ;

Is it possible to do something like
>generators.register-standard gsoap.error.usage : WSDL_H : CPP :
<gsoap.usage>"" ;
which only applies the rule gsoap.error.usage if the property
gsoap.usage is not given and a CPP needs to be created from a WSDL_H?

If I do as above I get a generator ambiguity for targets which have
the property set correctly to either server or client.

The custom generator soap sample in examles/generators/soap always
creates a client source and sometimes additional server sources. So
not given properties are not an issue in the example.

Kind regards,
Peter