#
# CWM.
#
# There are a number of modifications made to Jam which you can either
# accept or reject as you wish.
#
# 
# To turn on one of these features, either alter the default below or
# set it on the Jam command line, like:
#     jam -sHeaderCache=1
#

DynamicCommandSize  default = True ;
ImprovedWarnings    default = True ;
SerialOutput        default = "" ;
SlashModifiers      default = True ;
HeaderCache         default = "" ;
OptionalHeaders     default = "" ;
GraphDebugDump      default = True ;
LargeBuildOutput    default = "" ;
TimeStamps          default = "" ;
DebugOutputMods     default = True ;
NocareNodes         default = True ;
NTBatchFileFix      default = True ;


# ----------------------------------------------------------------------
# A rule that checks a variable, if its set, it adds the define to the
# list of defines

OPT_DEFINES = ;

rule config
{
    if $($(<))
    {
        OPT_DEFINES += $(2) ;
        ECHO "Config:" $(<) is on ;
    }
    else {
        ECHO "Config:" $(<) is off ;
    }
}

# ----------------------------------------------------------------------
# A note on the names of the defines.  
# 
# An optional part of Jam is initially an extension, following the OpenGL
# model.  If an extension is accepted into to the mainline, its define
# is changed to drop the extension.  For example, if the header cache
# code is accepted into the mainline but as a continuing option to the build,
# the define would be OPT_HEADER_CACHE, not OPT_HEADER_CACHE_EXT.
#
# Or something like that.


# When creating the actions command buffer, dynamically grow the buffer 
# to as large as needed.  Even though some shells are not able to accept
# very large buffers - some OSs support amazingly large commands.  Multi
# mega-byte commands are ok on Solaris, HPUX, Linux, etc
config DynamicCommandSize : OPT_DYNAMIC_COMMAND_SIZE_EXT ;


# Try to associate a filename and line number with errors and warnings
config ImprovedWarnings : OPT_IMPROVED_WARNINGS_EXT ;


# Actions write their output into temporary files.  When an action
# completes, the files contents are displayed along with the associated
# jam action line.  This serializes the output from Jam - however it 
# introduces a latency in that you don't see what Jam is doing as it
# works on an action, you only see the results afterwards
config SerialOutput : OPT_SERIAL_OUTPUT_EXT ;


# Add support for the variable expansion modifiers:
#    $(foo:/)  - which converts all \ characters to /, and
#    $(foo:\)  - which converts all / characters to \
# These are useful mainly on NT to get the pathname syntax you want
config SlashModifiers : OPT_SLASH_MODIFIERS_EXT ;


# The header cache is used to cache the results from the scan of each
# file to find headers.  Pretty much as it sounds.
#
# When Jam is started, the header cache is read into a hash table.  Then
# as each file is about to be scanned for headers, it is looked up in 
# the cache, and if its there and the files timestamp agrees with the 
# cache then the cache's results are used.  This is really useful for large
# builds.
config HeaderCache : OPT_HEADER_CACHE_EXT ;


# This option allows you to ignore header dependencies when building with
# Jam.  If you are working with a large system, and you have modified a 
# low level header, you may want to delay the full build Jam would do 
# when it sees the dependencies that are out of date.  By building with
# this option, you can specify a command line argument to have include 
# file dependencies ignored for a build.
config OptionalHeaders : OPT_HEADER_OPTION_EXT ;


# This option enables a new debugging level, which outputs a more
# readable form of the dependency graph, debug level 10.  This may be
# useful for people trying to understand a problem with the dependency
# graph
config GraphDebugDump : OPT_GRAPH_DEBUG_EXT ;


# This option controls a variety of minor mods to the output of Jam which
# I found more suitable when working with large systems.  YMMV.
config LargeBuildOutput : OPT_LARGE_BUILD_EXT ;


# This option places time stamps on various output messages in jam.  I
# found this useful to guage the performance of long builds, to find 
# where most of the time was spent.
config TimeStamps : OPT_TIME_STAMP_OUTPUT_EXT ;


# Various minor mods to the output
config DebugOutputMods : OPT_OUTPUT_MOD_EXT ;


# This option allows you to mark an intermediate node as being 
# NOCARE.  If an action related to the building of this node fails,
# any dependencies on this NOCARE node continue anyway.  This is useful
# when partial results from the build are useful.
config NocareNodes : OPT_NOCARE_NODES_EXT ;


# This option fixes a problem with the naming of batch files on NT.
# If more than one instance of Jam was run, there was a naming conflict
# and the files would clobber each other
config NTBatchFileFix : OPT_FIX_NT_BATCH_EXT ;


# ----------------------------------------------------------------------
# Propogate the defines into the compiler flags

if $(UNIX)
{
    CCFLAGS += -D$(OPT_DEFINES) ;
}
else if $(NT)
{
    CCFLAGS += /D$(OPT_DEFINES) ;
}
else {
    ECHO The build options are not supported on this platform. ;
}