[boost] [build system] Documentation error for Variant Descriptions

From: Michael Stevens (Michael.Stevens_at_[hidden])
Date: 2003-03-24 01:47:15

  Firstly my thanks to everyone who worked so hard on boost 1_30_0. 
Particularly all the that regression testing that went on.

On to the next release... One quick fix for the documentation for 
"Variant descriptions" used in the build system
The syntax for defining parents (see features.jam) is missing. At the 
moment the syntax descirbed in build_system.htm reads

    variant name : [<toolset-name>]<feature>value... ;

The corrected syntax description (see boost-base.jam:757) is:

    variant name : [parent-name : ] [<toolset-name>]<feature>value... ;

The descriptive text looks to be correct. It may be worth adding an 
additional simple example so it reads:
  Properties may be optionally qualified with a toolset name, which 
specifies that the property applies only to that toolset.
        variant my-debug-pedantic-gxx : debug : <gcc><cxxflags>"-pedantic"
  One or .....

At the moment I am also test driving Boost.build version 2. The design 
is very attractive! I not sure were the best place to discuss issues 
with v2 are? However just one quick pointer to a problem I am working on 
but don't have a solution to as yet.

Problem: Build.v2 fails if any parent directory (above build point) 
contains regex special charaters.
Reason: The directory path is itself used as a regex's template.
Location: rule all-parents (path.jam)

    # Leave only directory names below 'upper_limits'
    # Assure pruned_path[2] will have no leading '/'
    local pruned_path = [ regex.match "($(upper_limit))/*(.*)" :  
$(rpath) : 1 2 ] ;
    if ! $(pruned_path) {

I don't have a fix as am unsure of the Jam syntax for a simple (non 
regex) match to do this job.

Any ideas of best solution?

Michael Stevens