Re: [jamboost] Re: [Boost-build] CVS: boost/tools/build/new sequence.jam,1.10,1.11 property.jam,1.22,1.23 gcc.jam,1.17,1.18 feature.jam,1.25,1.26 build-request.jam,1.14,1.15

From: David Abrahams (dave_at_[hidden])
Date: 2003-01-15 06:13:09

Vladimir Prus <ghost_at_[hidden]> writes:

> David Abrahams wrote:
>> @@ -148,10 +168,13 @@
>> # return the implicit feature associated with the given implicit value.
>> rule implied-feature ( implicit-value )
>> {
>> - local feature = $($(implicit-value).implicit-feature) ;
>> + local components = [ regex.split $(implicit-value) "-" ] ;
>> + 
>> + local feature = $($(components[1]).implicit-feature) ;
>> if ! $(feature)
>> {
>> error \"$(implicit-value)\" is not a value of an implicit feature ;
>> + feature = "" ;
>
> Why is this assignment necessary?

During testing, try; {...} turns errors off. If this doesn't return a
value, its empty result gets passed on to a following rule which has
an argument list, and causes a hard argument error. Ultimately the
right fix would be to have a built-in which allowed us to turn arg
checking on/off, but I didn't want to make a core change for this
purpose.

-- 
David Abrahams
dave_at_[hidden] * http://www.boost-consulting.com
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