require jam 2.5

[supertux.git] / mk / jam / jamcompatibility.jam

#============================================================================
# Several hacks to make the build compatible with certain old/broken jam
# versions
#============================================================================

# boostjam is evil: It is compatible to jam 2.4 but has a version number 3.1, we# try to detect boostjam with the ARGV extension
if $(ARGV[0])
{
# boostjam hacks
  JAMVERSION = 2.4 ;
  rule FIncludes
  {
    return -I$(<) ;
  }
  rule FDefines
  {
    return -D$(<) ;
  }
}

# we can't use boostjam at the moment as it still has the bug from jam 2.4 where
# settings variables on header targets doesn't work
if $(JAMVERSION) <= 2.4
{
    EXIT "Error: This buildsystem requires jam version 2.5 or later." ;
}
# don't confuse users for now...
#if $(JAMVERSION) = 2.4 & $(JAM_DEBUG)
#{
#    echo "Warning: It is recommended to use jam2.5rc3 or later." ;
#}

# All scripts invoked by the build system expect a Bourne or compatible shell.
# Reject C-shell and its variants (such as tcsh).  Unfortunately, this is a bit
# of an ugly hack.  It would be nicer to perform this logic at the very end of
# this file as a last-minute assertion.  Unfortunately, however, it seems that
# references to $(SHELL) in any of the included files get bound at the point
# of reference, thus we need to perform this filtering as early as possible.
if [ Match (csh) : $(SHELL) ]
{
  SHELL = "/bin/sh" ;
}

# jam 2.4s SubDir rule had some problems and misses the usefull SUBDIRRULES
# extension. So we override it here with a better version (from jam 2.5rc3)
if $(JAMVERSION) = 2.4
{

rule SubDir
{
        #
        # SubDir TOP d1 d2 ... ;
        #
        # Support for a project tree spanning multiple directories.
        #
        # SubDir declares a Jamfile's location in a project tree, setting
        # Jambase variables (SEARCH_SOURCE, LOCATE_TARGET) so that source
        # files can be found.
        #
        # TOP is a user-select variable name for root of the tree, and
        # d1 d2 ...  are the directory elements that lead from the root
        # of the tree to the directory of the Jamfile.
        #
        # TOP can be set externally, but normally the first SubDir call
        # computes TOP as the path up from the current directory; the
        # path contains one ../ for each of d1 d2 ...
        #
        # SubDir reads once the project-specific rules file Jamrules 
        # in the TOP directory, if present.  This can be overridden
        # with the variable TOPRULES.
        #
        # SubDir supports multiple, overlaid project trees:  SubDir
        # invocations with different TOPs can appear in the same Jamfile.
        # The location established by the first SubDir call is used set
        # the TOPs for the subsequent SubDir calls.
        #
        # SubDir's public variables:
        #
        #       $(TOP) = path from CWD to root.
        #       $(SUBDIR) = path from CWD to the directory SubDir names.
        #       $(SUBDIR_TOKENS) = path from $(TOP) to $(SUBDIR) as dir names
        #       $(SEARCH_SOURCE) = $(SUBDIR)
        #       $(LOCATE_SOURCE) = $(ALL_LOCATE_TARGET) $(SUBDIR)
        #       $(LOCATE_TARGET) = $(ALL_LOCATE_TARGET) $(SUBDIR)
        #       $(SOURCE_GRIST) = $(SUBDIR_TOKENS) with !'s 
        #

        local _top = $(<[1]) ;
        local _tokens = $(<[2-]) ;

        #
        # First time through sets up relative root and includes Jamrules.
        #

        if ! $(_top)
        {
            Exit SubDir syntax error ;
        }

        if ! $($(_top)-SET)
        {
            $(_top)-SET = true ;

            # First time we've seen this TOP.
            # We'll initialize a number of internal variables:
            #
            #   $(TOP-UP) = directories from ROOT to a common point
            #   $(TOP-DOWN) = directories from common point to TOP
            #   $(TOP-ROOT) = root directory for UP/DOWN -- normally CWD
            #   $(SUBDIR_UP) = current value of $(TOP-UP)
            #   $(SUBDIR_DOWN) = current value of $(TOP-DOWN)
            #   $(SUBDIR_ROOT) = current value of $(TOP-ROOT)
            #

            if $($(_top))
            {
                # TOP externally set.
                # We'll ignore the relative (UP/DOWN) path that
                # got us here, and instead remember the hard ROOT.

                $(_top)-UP = ;
                $(_top)-DOWN = ;
                $(_top)-ROOT = $($(_top)) ;
            }
            else
            {
                # TOP not preset.

                # Establishing a new TOP.  In the simplest case,
                # (SUBDIR_UP/SUBDIR_DOWN/SUBDIR_ROOT unset), it's
                # merely a certain number of directories down from
                # the current directory, and FSubDirPath will set
                # TOP to a path consisting of ../ for each of the
                # elements of _tokens, because that represents how 
                # far below TOP the current directory sits.
                #
                # In the more complicated case, the starting directory
                # isn't the directory of jam's invocation but an 
                # location established by previous SubDir call.  The
                # starting directory is SUBDIR_UP directories up from
                # SUBDIR_ROOT, and then SUBDIR_DOWN directories down
                # from that.   If SUBDIR_ROOT is not set, that means
                # SUBDIR_DOWN and SUBDIR_UP represent the path from
                # the directory of jam's invocation.
                #
                # In the most complicated case, the _tokens also 
                # represents directories down, because TOP is being
                # estalished in a directory other than TOP's root.
                # Hopefully, _tokens and SUBDIR_DOWN represent the
                # same final directory, relative to the new TOP and
                # the previous SubDIr's TOP.  To find the new TOP,
                # we have to chop off any common directories from
                # then ends of _tokens and SUBDIR_DOWN.  To do so,
                # we reverse each of them, call FStripCommon to
                # remove the initial common elements, and then
                # reverse them again.  After this process, if
                # both _tokens and SUBDIR_DOWN have elements, it
                # means the directory names estalished by the two
                # SubDir calls don't match, and a warning is issued.
                # All hell will likely break loose at this point,
                # since the whole SubDir scheme relies on the SubDir
                # calls accurately naming the current directory.

                # Strip common trailing elements of _tokens and SUBDIR_DOWN.

                _tokens = [ FReverse $(_tokens) ] ;
                SUBDIR_DOWN = [ FReverse $(SUBDIR_DOWN) ] ;
                FStripCommon _tokens : SUBDIR_DOWN ;
                SUBDIR_DOWN = [ FReverse $(SUBDIR_DOWN) ] ;
                _tokens = [ FReverse $(_tokens) ] ;

                if $(SUBDIR_DOWN) && $(_tokens) 
                { 
                    Echo Warning: SubDir $(<) misplaced! ; 
                }

                # We'll remember the relative (UP/DOWN) path that
                # got us here, plus any hard ROOT starting point
                # for the UP/DOWN.  If TOP is never set externally,
                # ROOT will always be "" (directory of jam's invocation).

                $(_top)-UP = $(SUBDIR_UP) $(_tokens) ;
                $(_top)-DOWN = $(SUBDIR_DOWN) ;
                $(_top)-ROOT = $(SUBDIR_ROOT:E="") ;
                $(_top) = [ FSubDirPath $(_top) ] ;
            }

            # Set subdir vars for the inclusion of the Jamrules,
            # just in case they have SubDir rules of their own.
            # Note that SUBDIR_DOWN is empty: it's all the way
            # up where the Jamrules live.  These gets overrided
            # just after the inclusion.

            SUBDIR_UP = $($(_top)-UP) ;
            SUBDIR_DOWN = ;
            SUBDIR_ROOT = $($(_top)-ROOT) ;

            # Include $(TOPRULES) or $(TOP)/Jamrules.
            # Include $(TOPRULES) if set.
            # Otherwise include $(TOP)/Jamrules if present.

            if $($(_top)RULES) { 
                include $($(_top)RULES) ;
            } else { 
                NoCare $(JAMRULES:R=$($(_top)):G=$(_top)) ;
                include $(JAMRULES:R=$($(_top)):G=$(_top)) ;
            }
        }

        # Get path from $(TOP) to named directory.
        # Save dir tokens for other potential uses.

        SUBDIR_UP = $($(_top)-UP) ;
        SUBDIR_DOWN = $($(_top)-DOWN) $(_tokens) ;
        SUBDIR_ROOT = $($(_top)-ROOT) ;
        SUBDIR_TOKENS = $(SUBDIR_DOWN) ;

        SUBDIR = [ FSubDirPath $(<) ] ;

        # Now set up SEARCH_SOURCE, LOCATE_TARGET, SOURCE_GRIST
        # These can be reset if needed.  For example, if the source
        # directory should not hold object files, LOCATE_TARGET can
        # subsequently be redefined.

        SEARCH_SOURCE = $(SUBDIR) ;
        LOCATE_SOURCE = $(ALL_LOCATE_TARGET) $(SUBDIR) ;
        LOCATE_TARGET = $(ALL_LOCATE_TARGET) $(SUBDIR) ;
        SOURCE_GRIST = [ FGrist $(SUBDIR_TOKENS) ] ;

        # Reset per-directory ccflags, hdrs, etc,
        # listed in SUBDIRRESET.
        # Note use of variable expanded assignment var

        SUBDIR$(SUBDIRRESET) = ;

        # Invoke user-specific SubDir extensions,
        # rule names listed in SUBDIRRULES.
        # Note use of variable expanded rule invocation

        $(SUBDIRRULES) $(<) ;
}

rule FSubDirPath
{
        # FSubDirPath TOP d1 ... ;

        # Returns path to named directory.

        # If jam is invoked in a subdirectory of the TOP, then we
        # need to prepend a ../ for every level we must climb up
        # (TOP-UP), and then append the directory names we must 
        # climb down (TOP-DOWN), plus the named directories d1 ...
        # If TOP was set externally, or computed from another TOP 
        # that was, we'll have to reroot the whole thing at TOP-ROOT.

        local _r = [ FRelPath $($(<[1])-UP) : $($(<[1])-DOWN) $(<[2-]) ] ;

        return $(_r:R=$($(<[1])-ROOT)) ;
}

rule SubInclude
{
        # SubInclude TOP d1 ... ;
        #
        # Include a subdirectory's Jamfile.

        # We use SubDir to get there, in case the included Jamfile
        # either doesn't have its own SubDir (naughty) or is a subtree
        # with its own TOP.

        if ! $($(<[1]))
        {
            Exit SubInclude $(<[1]) without prior SubDir $(<[1]) ;
        }

        SubDir $(<) ;

        include $(JAMFILE:D=$(SUBDIR)) ;
}

rule SubRules
{
        # SubRules TOP d1 ... : Other-TOP ;
        #
        # Read another tree's Jamrules, by giving it's path according
        # to this tree and it's own name.

        if ! $($(<[1]))
        {
            Exit SubRules $(<[1]) without prior SubDir $(<[1]) ;
        }

        SubDir $(<) ;
        SubDir $(>) ;
}

## Now we try to fix up the already messed settings
## XXX We can only hope that jam2.4 users don't try starting jam from
## subdirectories
TOP-SET = true ;
TOP-UP = ;
TOP-DOWN = ;
TOP-ROOT = $(TOP) ;
SUBDIR_UP = $(TOP-UP) ;
SUBDIR_DOWN = ;
SUBDIR_ROOT = $(TOP-ROOT) ;

#SubDir TOP ;

} # end if $(JAMVERSION) = 2.4

# MakeLocate rule from jam 2.4 isn't optimal. Use improved version from jam
# 2.5
if $(JAMVERSION) = 2.4
{

rule MakeLocate
{
        # MakeLocate targets : directory ;

        # Sets special variable LOCATE on targets, and arranges    
        # with MkDir to create target directory.

        # Note we grist the directory name with 'dir',
        # so that directory path components and other
        # targets don't conflict.

        if $(>)
        {
            LOCATE on $(<) = $(>) ;
            Depends $(<) : $(>[1]:G=dir) ;
            MkDir $(>[1]:G=dir) ;
        }
}

}