Re: Overriding default feature behaviour

From: David Abrahams (dave_at_[hidden])
Date: 2003-11-30 07:54:25

> Is it possible for a toolset that inherits from another, to override the
> default behaviour of some feature - specifically I want to inherit from
> msvc-stlport-tools.jam, but have the default for <stlport-iostream> to be
> "on" rather than "off".

Sure; here's an example toolset I use for compiling with Intel's 8.0
compiler on windows.

 --=-=-= Content-Disposition: attachment; filename=intel8-tools.jam

# Copyright David Abrahams 2003. Permission to copy, use,
# modify, sell and distribute this software is granted provided this
# copyright notice appears in all copies. This software is provided
# "as is" without express or implied warranty, and with no claim as
# to its suitability for any purpose.

{
# Handle defaults
INTEL8_BASE_MSVC_TOOLSET ?= vc7.1 ; # replicate no microsoft bugs
INTEL8_PATH ?= "c:/tools/intel/compiler80/ia32" ;
INTEL8_TOOL_PATH ?= $(INTEL8_PATH)/bin/ ; 

# Spoof defaults for the underlying intel toolset
local INTEL_BASE_MSVC_TOOLSET = $(INTEL8_BASE_MSVC_TOOLSET) ;
local INTEL_PATH = $(INTEL8_PATH) ;
local INTEL_TOOL_PATH = $(INTEL8_TOOL_PATH) ;

extends-toolset intel-win32 ;
C++FLAGS = [ difference $(C++FLAGS) : /Q$(INTEL8_BASE_MSVC_TOOLSET) ] /Qms0 ;
VC_SETUP = "CALL \"$(INTEL8_TOOL_PATH)ICLVARS.BAT\" > nul" ; 
}
 --=-=-= 

Note the use of the difference rule.

HTH,
-- 
Dave Abrahams
Boost Consulting
www.boost-consulting.com
 --=-=-=--