[ceph.git] / ceph / src / boost / tools / build / src / util / path.jam

# Copyright 2002-2006. Vladimir Prus
# Copyright 2003-2004. Dave Abrahams
# Copyright 2003-2006. Rene Rivera
# Distributed under the Boost Software License, Version 1.0.
# (See accompanying file LICENSE.txt or copy at
# https://www.bfgroup.xyz/b2/LICENSE.txt)

# Performs various path manipulations. Paths are always in a 'normalized'
# representation. In it, a path may be either:
#
#     - '.', or
#
#     - ['/'] [ ( '..' '/' )* (token '/')* token ]
#
# In plain english, path can be rooted, '..' elements are allowed only at the
# beginning, and it never ends in slash, except for path consisting of slash
# only.

import modules ;
import regex ;
import sequence ;
import set ;


os = [ modules.peek : OS ] ;
if [ modules.peek : UNIX ]
{
    local uname = [ modules.peek : JAMUNAME ] ;
    switch $(uname)
    {
        case CYGWIN* : os = CYGWIN ;
        case *       : os = UNIX ;
    }
}


# Converts the native path into normalized form.
#
rule make ( native )
{
    return [ make-$(os) $(native) ] ;
}


# Builds native representation of the path.
#
rule native ( path )
{
    return [ native-$(os) $(path) ] ;
}


# Tests if a path is rooted.
#
rule is-rooted ( path )
{
    return [ MATCH "^(/)" : $(path) ] ;
}


# Tests if a path has a parent.
#
rule has-parent ( path )
{
    if $(path) != /
    {
        return 1 ;
    }
    else
    {
        return ;
    }
}


# Returns the path without any directory components.
#
rule basename ( path )
{
    return [ MATCH "([^/]+)$" : $(path) ] ;
}


# Returns parent directory of the path. If no parent exists, error is issued.
#
rule parent ( path )
{
    if [ has-parent $(path) ]
    {
        if $(path) = .
        {
            return .. ;
        }
        else
        {
            # Strip everything at the end of path up to and including the last
            # slash.
            local result = [ regex.match "((.*)/)?([^/]+)" : $(path) : 2 3 ] ;

            # Did we strip what we shouldn't?
            if $(result[2]) = ".."
            {
                return $(path)/.. ;
            }
            else
            {
                if ! $(result[1])
                {
                    if [ is-rooted $(path) ]
                    {
                        result = / ;
                    }
                    else
                    {
                        result = . ;
                    }
                }
                return $(result[1]) ;
            }
        }
    }
    else
    {
        import errors ;
        errors.error "Path '$(path)' has no parent" ;
    }
}


# Returns path2 such that "[ join path path2 ] = .". The path may not contain
# ".." element or be rooted.
#
rule reverse ( path )
{
    if $(path) = .
    {
        return $(path) ;
    }
    else
    {
        local tokens = [ regex.split $(path) / ] ;
        local tokens2 ;
        for local i in $(tokens)
        {
            tokens2 += .. ;
        }
        return [ sequence.join $(tokens2) : / ] ;
    }
}


# Concatenates the passed path elements. Generates an error if any element other
# than the first one is rooted. Skips any empty or undefined path elements.
#
rule join ( elements + )
{
    if ! $(elements[2-])
    {
        return $(elements[1]) ;
    }
    else
    {
        for local e in $(elements[2-])
        {
            if [ is-rooted $(e) ]
            {
                import errors ;
                errors.error only the first element may be rooted ;
            }
        }
        return [ NORMALIZE_PATH "$(elements)" ] ;
    }
}


# If 'path' is relative, it is rooted at 'root'. Otherwise, it is unchanged.
#
rule root ( path root )
{
    if [ is-rooted $(path) ]
    {
        return $(path) ;
    }
    else
    {
        return [ join $(root) $(path) ] ;
    }
}


# Returns the current working directory.
#
rule pwd ( )
{
    if ! $(.pwd)
    {
        .pwd = [ make [ PWD ] ] ;
    }
    return $(.pwd) ;
}


# Returns the list of files matching the given pattern in the specified
# directory. Both directories and patterns are supplied as portable paths. Each
# pattern should be non-absolute path, and can't contain "." or ".." elements.
# Each slash separated element of pattern can contain the following special
# characters:
#   - '?', which match any character
#   - '*', which matches arbitrary number of characters.
# A file $(d)/e1/e2/e3 (where 'd' is in $(dirs)) matches pattern p1/p2/p3 if and
# only if e1 matches p1, e2 matches p2 and so on.
#
# For example:
#   [ glob . : *.cpp ]
#   [ glob . : */build/Jamfile ]
#
rule glob ( dirs * : patterns + : exclude-patterns * )
{
    local result ;
    local real-patterns ;
    local real-exclude-patterns ;
    for local d in $(dirs)
    {
        for local p in $(patterns)
        {
            local pattern = [ path.root $(p) $(d) ] ;
            real-patterns += [ path.native $(pattern) ] ;
        }

        for local p in $(exclude-patterns)
        {
            local pattern = [ path.root $(p) $(d) ] ;
            real-exclude-patterns += [ path.native $(pattern) ] ;
        }
    }

    local inc = [ GLOB-RECURSIVELY $(real-patterns) ] ;
    inc = [ sequence.transform NORMALIZE_PATH : $(inc) ] ;
    local exc = [ GLOB-RECURSIVELY $(real-exclude-patterns) ] ;
    exc = [ sequence.transform NORMALIZE_PATH : $(exc) ] ;

    return [ sequence.transform path.make : [ set.difference $(inc) : $(exc) ] ]
        ;
}


# Recursive version of GLOB. Builds the glob of files while also searching in
# the subdirectories of the given roots. An optional set of exclusion patterns
# will filter out the matching entries from the result. The exclusions also
# apply to the subdirectory scanning, such that directories that match the
# exclusion patterns will not be searched.
#
rule glob-tree ( roots * : patterns + : exclude-patterns * )
{
    return [ sequence.transform path.make : [ .glob-tree [ sequence.transform
        path.native : $(roots) ] : $(patterns) : $(exclude-patterns) ] ] ;
}


local rule .glob-tree ( roots * : patterns * : exclude-patterns * )
{
    local excluded ;
    if $(exclude-patterns)
    {
        excluded = [ GLOB $(roots) : $(exclude-patterns) ] ;
    }
    local result = [ set.difference [ GLOB $(roots) : $(patterns) ] :
        $(excluded) ] ;
    local subdirs ;
    for local d in [ set.difference [ GLOB $(roots) : * ] : $(excluded) ]
    {
        if ! ( $(d:D=) in . .. ) && ! [ CHECK_IF_FILE $(d) ]
        {
            subdirs += $(d) ;
        }
    }
    if $(subdirs)
    {
        result += [ .glob-tree $(subdirs) : $(patterns) : $(exclude-patterns) ]
            ;
    }
    return $(result) ;
}


# Returns true is the specified file exists.
#
rule exists ( file )
{
    return [ path.glob $(file:D) : $(file:D=) ] ;
}
NATIVE_RULE path : exists ;


# Find out the absolute name of path and returns the list of all the parents,
# starting with the immediate one. Parents are returned as relative names. If
# 'upper_limit' is specified, directories above it will be pruned.
#
rule all-parents ( path : upper_limit ? : cwd ? )
{
    cwd ?= [ pwd ] ;
    local path_ele = [ regex.split [ root $(path) $(cwd) ] / ] ;

    if ! $(upper_limit)
    {
        upper_limit = / ;
    }
    local upper_ele = [ regex.split [ root $(upper_limit) $(cwd) ] / ] ;

    # Leave only elements in 'path_ele' below 'upper_ele'.
    while $(path_ele) && ( $(upper_ele[1]) = $(path_ele[1]) )
    {
        upper_ele = $(upper_ele[2-]) ;
        path_ele = $(path_ele[2-]) ;
    }

    # Have all upper elements been removed ?
    if $(upper_ele)
    {
        import errors ;
        errors.error "$(upper_limit) is not prefix of $(path)" ;
    }

    # Create the relative paths to parents, number of elements in 'path_ele'.
    local result ;
    for local i in $(path_ele)
    {
        path = [ parent $(path) ] ;
        result += $(path) ;
    }
    return $(result) ;
}


# Search for 'pattern' in parent directories of 'dir', up to and including
# 'upper_limit', if it is specified, or up to the filesystem root otherwise.
#
rule glob-in-parents ( dir : patterns + : upper-limit ? )
{
    local result ;
    local parent-dirs = [ all-parents $(dir) : $(upper-limit) ] ;

    while $(parent-dirs) && ! $(result)
    {
        result = [ glob $(parent-dirs[1]) : $(patterns) ] ;
        parent-dirs = $(parent-dirs[2-]) ;
    }
    return $(result) ;
}


# Assuming 'child' is a subdirectory of 'parent', return the relative path from
# 'parent' to 'child'.
#
rule relative ( child parent : no-error ? )
{
    local not-a-child ;
    if $(parent) = "."
    {
        return $(child) ;
    }
    else
    {
        local split1 = [ regex.split $(parent) / ] ;
        local split2 = [ regex.split $(child) / ] ;

        while $(split1)
        {
            if $(split1[1]) = $(split2[1])
            {
                split1 = $(split1[2-]) ;
                split2 = $(split2[2-]) ;
            }
            else
            {
                not-a-child = true ;
                split1 = ;
            }
        }
        if $(split2)
        {
            if $(not-a-child)
            {
                if $(no-error)
                {
                    return not-a-child ;
                }
                else
                {
                    import errors ;
                    errors.error $(child) is not a subdir of $(parent) ;
                }
            }
            else
            {
                return [ join $(split2) ] ;
            }
        }
        else
        {
            return "." ;
        }
    }
}


# Returns the minimal path to path2 that is relative to path1.
# If no such path exists and path2 is rooted, return it unchanged.
#
rule relative-to ( path1 path2 )
{
    local root_1 = [ regex.split [ reverse $(path1) ] / ] ;
    local split1 = [ regex.split $(path1) / ] ;
    local split2 = [ regex.split $(path2) / ] ;
    local is-rooted ;

    if $(split1[1]) = "" && $(split2[1]) = ""
    {
        is-rooted = true ;
    }
    else if $(split1[1]) != "" && $(split2[1]) = ""
    {
        # Second path is rooted
        return $(path2) ;
    }
    else if $(split1[1]) = "" && $(split2[1]) != ""
    {
        import errors ;
        errors.error Cannot find relative path from $(path1) to $(path2) ;
    }

    # For windows paths on different drives, return an
    # absolute path
    if $(os) = NT && $(split1[1]) = "" &&
        [ MATCH "^(.:)$" : $(split1[2]) ] &&
        $(split1[2]) != $(split2[2])
    {
        return $(path2) ;
    }

    while $(split1) && $(root_1)
    {
        if $(split1[1]) = $(split2[1])
        {
            root_1 = $(root_1[2-]) ;
            split1 = $(split1[2-]) ;
            split2 = $(split2[2-]) ;
        }
        else if $(split1[1]) = ..
        {
            if $(is-rooted)
            {
                return $(path2) ;
            }
            else
            {
                import errors ;
                errors.error Cannot find relative path from $(path1) to $(path2) ;
                return ;
            }
        }
        else
        {
            split1 = ;
        }
    }
    return [ join . $(root_1) $(split2) ] ;
}


# Returns the list of paths used by the operating system for looking up
# programs.
#
rule programs-path ( )
{
    local result ;
    local raw = [ modules.peek : PATH Path path ] ;
    for local p in $(raw)
    {
        if $(p)
        {
            result += [ path.make $(p) ] ;
        }
    }
    return $(result) ;
}


rule makedirs ( path )
{
    local result = true ;
    local native = [ native $(path) ] ;
    if ! [ exists $(native) ]
    {
        if [ makedirs [ parent $(path) ] ]
        {
            if ! [ MAKEDIR $(native) ]
            {
                import errors ;
                errors.error "Could not create directory '$(path)'" ;
                result = ;
            }
        }
    }
    return $(result) ;
}


# Converts native Windows paths into our internal canonic path representation.
# Supports 'invalid' paths containing multiple successive path separator
# characters.
#
# TODO: Check and if needed add support for Windows 'X:file' path format where
# the file is located in the current folder on drive X.
#
rule make-NT ( native )
{
    local result = [ NORMALIZE_PATH $(native) ] ;

    # We need to add an extra '/' in front in case this is a rooted Windows path
    # starting with a drive letter and not a path separator character since the
    # builtin NORMALIZE_PATH rule has no knowledge of this leading drive letter
    # and treats it as a regular folder name.
    if [ regex.match "(^.:)" : $(native) ]
    {
        result = /$(result) ;
    }

    return $(result) ;
}


rule native-NT ( path )
{
    local remove-slash = [ MATCH "^/(.:.*)" : $(path) ] ;
    if $(remove-slash)
    {
        path = $(remove-slash) ;
    }
    return [ regex.replace $(path) / \\ ] ;
}


rule make-UNIX ( native )
{
    # VP: I have no idea now 'native' can be empty here! But it can!
    if ! $(native)
    {
        import errors ;
        errors.error "Empty path passed to 'make-UNIX'" ;
    }
    else
    {
        return [ NORMALIZE_PATH $(native:T) ] ;
    }
}


rule native-UNIX ( path )
{
    return $(path) ;
}


rule make-CYGWIN ( path )
{
    return [ make-NT $(path) ] ;
}


rule native-CYGWIN ( path )
{
    local result = $(path) ;
    if [ regex.match "(^/.:)" : $(path)  ]  # Windows absolute path.
    {
        result = [ MATCH "^/?(.*)" : $(path) ] ;  # Remove leading '/'.
    }
    return [ native-UNIX $(result) ] ;
}


# split-path-VMS: splits input native path into device dir file (each part is
# optional).
#
# example:
#
# dev:[dir]file.c => dev: [dir] file.c
#
rule split-path-VMS ( native )
{
    local matches = [ MATCH "([a-zA-Z0-9_-]+:)?(\\[[^\]]*\\])?(.*)?$" : $(native)
        ] ;
    local device = $(matches[1]) ;
    local dir = $(matches[2]) ;
    local file = $(matches[3]) ;

    return $(device) $(dir) $(file) ;
}


# Converts a native VMS path into a portable path spec.
#
# Does not handle current-device absolute paths such as "[dir]File.c" as it is
# not clear how to represent them in the portable path notation.
#
# Adds a trailing dot (".") to the file part if no extension is present (helps
# when converting it back into native path).
#
rule make-VMS ( native )
{
    ## Use POSIX-style path (keep previous code commented out - real magic!).
    ## VMS CRTL supports POSIX path, JAM is retrofitted to pass it to VMS CRTL.

    local portable = [ make-UNIX $(native) ] ;

    #if [ MATCH ^(\\[[a-zA-Z0-9]) : $(native) ]
    #{
    #    import errors ;
    #    errors.error "Can't handle default-device absolute paths: " $(native) ;
    #}
    #
    #local parts = [ split-path-VMS $(native) ] ;
    #local device = $(parts[1]) ;
    #local dir = $(parts[2]) ;
    #local file = $(parts[3]) ;
    #local elems ;
    #
    #if $(device)
    #{
    #    #
    #    # rooted
    #    #
    #    elems = /$(device) ;
    #}
    #
    #if $(dir) = "[]"
    #{
    #    #
    #    # Special case: current directory
    #    #
    #    elems = $(elems) "." ;
    #}
    #else if $(dir)
    #{
    #    dir = [ regex.replace $(dir) "\\[|\\]" "" ] ;
    #    local dir_parts = [ regex.split $(dir) \\. ]  ;
    #
    #    if $(dir_parts[1]) = ""
    #    {
    #        #
    #        # Relative path
    #        #
    #        dir_parts = $(dir_parts[2--1]) ;
    #    }
    #
    #    #
    #    # replace "parent-directory" parts (- => ..)
    #    #
    #    dir_parts = [ regex.replace-list $(dir_parts) : - : .. ] ;
    #
    #    elems = $(elems) $(dir_parts) ;
    #}
    #
    #if $(file)
    #{
    #    if ! [ MATCH (\\.) : $(file) ]
    #    {
    #        #
    #        # Always add "." to end of non-extension file.
    #        #
    #        file = $(file). ;
    #    }
    #    elems = $(elems) $(file) ;
    #}
    #
    #portable = [ path.join $(elems) ] ;

    return $(portable) ;
}


# Converts a portable path spec into a native VMS path.
#
# Relies on having at least one dot (".") included in the file name to be able
# to differentiate it from the directory part.
#
rule native-VMS ( path )
{
    ## Use POSIX-style path (keep previous code commented out - real magic!).
    ## VMS CRTL supports POSIX path, JAM is retrofitted to pass it to VMS CRTL.
    ## NOTE: While translation to VMS-style is implemented with $(:W) modifier,
    ##       Here we retain POSIX-style path, so it can be portably manipulated
    ##       in B2 rules, and only in actions it's translated with $(:W).

    local native = [ native-UNIX $(path) ] ;

    #local device = "" ;
    #local dir = $(path) ;
    #local file = "" ;
    #local split ;
    #
    ##
    ## Has device ?
    ##
    #if [ is-rooted $(dir) ]
    #{
    #    split = [ MATCH ^/([^:]+:)/?(.*) : $(dir) ] ;
    #    device = $(split[1]) ;
    #    dir = $(split[2]) ;
    #}
    #
    ##
    ## Has file ?
    ##
    ## This is no exact science, just guess work:
    ##
    ## If the last part of the current path spec includes some chars, followed by
    ## a dot, optionally followed by more chars - then it is a file (keep your
    ## fingers crossed).
    ##
    #split = [ regex.split $(dir) / ] ;
    #local maybe_file = $(split[-1]) ;
    #
    #if [ MATCH ^([^.]+\\..*) : $(maybe_file) ]
    #{
    #    file = $(maybe_file) ;
    #    dir = [ sequence.join $(split[1--2]) : / ] ;
    #}
    #
    ##
    ## Has dir spec ?
    ##
    #if $(dir) = "."
    #{
    #    dir = "[]" ;
    #}
    #else if $(dir)
    #{
    #    dir = [ regex.replace $(dir) \\.\\. - ] ;
    #    dir = [ regex.replace $(dir) / . ] ;
    #
    #    if $(device) = ""
    #    {
    #        #
    #        # Relative directory
    #        #
    #        dir = "."$(dir) ;
    #    }
    #    dir = "["$(dir)"]" ;
    #}
    #
    #native = [ sequence.join $(device) $(dir) $(file) ] ;

    return $(native) ;
}


if $(os) = VMS
{
    # Translates POSIX-style path to VMS-style path
    #
    # This results in actual VMS path, unlike 'native-VMS' rule which is meant
    # to return POSIX-style in order to mask VMS specificity and help portability.

    rule to-VMS ( path )
    {
        return $(path:W) ;
    }

    EXPORT $(__name__) : to-$(os) ;
}

# Remove one level of indirection
IMPORT $(__name__) : make-$(os) native-$(os) : $(__name__) : make native ;
EXPORT $(__name__) : make native ;

rule __test__ ( )
{
    import assert ;
    import errors : try catch ;

    assert.true is-rooted "/" ;
    assert.true is-rooted "/foo" ;
    assert.true is-rooted "/foo/bar" ;
    assert.result : is-rooted "." ;
    assert.result : is-rooted "foo" ;
    assert.result : is-rooted "foo/bar" ;

    assert.true has-parent "foo" ;
    assert.true has-parent "foo/bar" ;
    assert.true has-parent "." ;
    assert.result : has-parent "/" ;

    assert.result "." : basename "." ;
    assert.result ".." : basename ".." ;
    assert.result "foo" : basename "foo" ;
    assert.result "foo" : basename "bar/foo" ;
    assert.result "foo" : basename "gaz/bar/foo" ;
    assert.result "foo" : basename "/gaz/bar/foo" ;

    assert.result "." : parent "foo" ;
    assert.result "/" : parent "/foo" ;
    assert.result "foo/bar" : parent "foo/bar/giz" ;
    assert.result ".." : parent "." ;
    assert.result ".." : parent "../foo" ;
    assert.result "../../foo" : parent "../../foo/bar" ;

    assert.result "." : reverse "." ;
    assert.result ".." : reverse "foo" ;
    assert.result "../../.." : reverse "foo/bar/giz" ;

    assert.result "foo" : join "foo" ;
    assert.result "/foo" : join "/" "foo" ;
    assert.result "foo/bar" : join "foo" "bar" ;
    assert.result "foo/bar" : join "foo/giz" "../bar" ;
    assert.result "foo/giz" : join "foo/bar/baz" "../../giz" ;
    assert.result ".." : join "." ".." ;
    assert.result ".." : join "foo" "../.." ;
    assert.result "../.." : join "../foo" "../.." ;
    assert.result "/foo" : join "/bar" "../foo" ;
    assert.result "foo/giz" : join "foo/giz" "." ;
    assert.result "." : join lib2 ".." ;
    assert.result "/" : join "/a" ".." ;

    assert.result /a/b : join /a/b/c .. ;

    assert.result "foo/bar/giz" : join "foo" "bar" "giz" ;
    assert.result "giz" : join "foo" ".." "giz" ;
    assert.result "foo/giz" : join "foo" "." "giz" ;

    try ;
    {
        join "a" "/b" ;
    }
    catch only first element may be rooted ;

    local CWD = "/home/ghost/build" ;
    assert.result : all-parents . : . : $(CWD) ;
    assert.result . .. ../.. ../../..  : all-parents "Jamfile" : "" : $(CWD) ;
    assert.result foo . .. ../.. ../../.. : all-parents "foo/Jamfile" : "" :
        $(CWD) ;
    assert.result ../Work .. ../.. ../../.. : all-parents "../Work/Jamfile" : ""
        : $(CWD) ;

    local CWD = "/home/ghost" ;
    assert.result . .. : all-parents "Jamfile" : "/home" : $(CWD) ;
    assert.result . : all-parents "Jamfile" : "/home/ghost" : $(CWD) ;

    assert.result "c/d" : relative "a/b/c/d" "a/b" ;
    assert.result "foo" : relative "foo" "." ;

    assert.result "c/d" : relative-to "a/b" "a/b/c/d" ;
    assert.result "foo" : relative-to "." "foo" ;
    assert.result "../d" : relative-to "/a/b" "/a/d" ;
    assert.result "x" : relative-to .. ../x ;
    assert.result "/x" : relative-to x /x ;
    try ;
    {
        relative-to "../x" "a" ;
    }
    catch Cannot find relative path from ../x to a ;
    try ;
    {
        relative-to "../../x" "../a" ;
    }
    catch Cannot find relative path from ../../x to ../a ;
    try ;
    {
        relative-to "/x/y" "a/b" ;
    }
    catch Cannot find relative path from /x/y to a/b ;

    local save-os = [ modules.peek path : os ] ;
    modules.poke path : os : NT ;

    assert.result "foo/bar/giz" : make-NT "foo/bar/giz" ;
    assert.result "foo/bar/giz" : make-NT "foo\\bar\\giz" ;
    assert.result "foo" : make-NT "foo/" ;
    assert.result "foo" : make-NT "foo\\" ;
    assert.result "foo" : make-NT "foo/." ;
    assert.result "foo" : make-NT "foo/bar/.." ;
    assert.result "foo" : make-NT "foo/bar/../" ;
    assert.result "foo" : make-NT "foo/bar/..\\" ;
    assert.result "foo/bar" : make-NT "foo/././././bar" ;
    assert.result "/foo" : make-NT "\\foo" ;
    assert.result "/D:/My Documents" : make-NT "D:\\My Documents" ;
    assert.result "/c:/boost/tools/build/new/project.jam" : make-NT
        "c:\\boost\\tools\\build\\test\\..\\new\\project.jam" ;

    # Test processing 'invalid' paths containing multiple successive path
    # separators.
    assert.result "foo" : make-NT "foo//" ;
    assert.result "foo" : make-NT "foo///" ;
    assert.result "foo" : make-NT "foo\\\\" ;
    assert.result "foo" : make-NT "foo\\\\\\" ;
    assert.result "/foo" : make-NT "//foo" ;
    assert.result "/foo" : make-NT "///foo" ;
    assert.result "/foo" : make-NT "\\\\foo" ;
    assert.result "/foo" : make-NT "\\\\\\foo" ;
    assert.result "/foo" : make-NT "\\/\\/foo" ;
    assert.result "foo/bar" : make-NT "foo//\\//\\\\bar//\\//\\\\\\//\\//\\\\" ;
    assert.result "foo" : make-NT "foo/bar//.." ;
    assert.result "foo/bar" : make-NT "foo/bar/giz//.." ;
    assert.result "foo/giz" : make-NT
        "foo//\\//\\\\bar///\\\\//\\\\////\\/..///giz\\//\\\\\\//\\//\\\\" ;
    assert.result "../../../foo" : make-NT "..///.//..///.//..////foo///" ;

    # Test processing 'invalid' rooted paths with too many '..' path elements
    # that would place them before the root.
    assert.result : make-NT "/.." ;
    assert.result : make-NT "/../" ;
    assert.result : make-NT "/../." ;
    assert.result : make-NT "/.././" ;
    assert.result : make-NT "/foo/../bar/giz/.././././../../." ;
    assert.result : make-NT "/foo/../bar/giz/.././././../.././" ;
    assert.result : make-NT "//foo/../bar/giz/.././././../../." ;
    assert.result : make-NT "//foo/../bar/giz/.././././../.././" ;
    assert.result : make-NT "\\\\foo/../bar/giz/.././././../../." ;
    assert.result : make-NT "\\\\foo/../bar/giz/.././././../.././" ;
    assert.result : make-NT "/..///.//..///.//..////foo///" ;

    assert.result "foo\\bar\\giz" : native-NT "foo/bar/giz" ;
    assert.result "foo" : native-NT "foo" ;
    assert.result "\\foo" : native-NT "/foo" ;
    assert.result "D:\\My Documents\\Work" : native-NT "/D:/My Documents/Work" ;

    assert.result "../y" : relative-to "/C:/x" "/C:/y" ;
    assert.result "/D:/test" : relative-to "/C:/test" "/D:/test" ;
    try ;
    {
        relative-to "/C:/y" "a/b" ;
    }
    catch Cannot find relative path from "/C:/y" to a/b ;

    modules.poke path : os : UNIX ;

    assert.result "foo/bar/giz" : make-UNIX "foo/bar/giz" ;
    assert.result "/sub1" : make-UNIX "/sub1/." ;
    assert.result "/sub1" : make-UNIX "/sub1/sub2/.." ;
    assert.result "sub1" : make-UNIX "sub1/." ;
    assert.result "sub1" : make-UNIX "sub1/sub2/.." ;
    assert.result "/foo/bar" : native-UNIX "/foo/bar" ;

    modules.poke path : os : VMS ;

    ## On VMS use POSIX-style path (keep previous tests commented out).

    assert.result "foo/bar/giz" : make-VMS "foo/bar/giz" ;
    assert.result "/sub1" : make-VMS "/sub1/." ;
    assert.result "/sub1" : make-VMS "/sub1/sub2/.." ;
    assert.result "sub1" : make-VMS "sub1/." ;
    assert.result "sub1" : make-VMS "sub1/sub2/.." ;
    assert.result "/foo/bar" : native-VMS "/foo/bar" ;

    ##
    ## Do not really need to poke os before these
    ##
    #assert.result "disk:" "[dir]"  "file" : split-path-VMS "disk:[dir]file" ;
    #assert.result "disk:" "[dir]"  ""     : split-path-VMS "disk:[dir]" ;
    #assert.result "disk:" ""       ""     : split-path-VMS "disk:" ;
    #assert.result "disk:" ""       "file" : split-path-VMS "disk:file" ;
    #assert.result ""      "[dir]"  "file" : split-path-VMS "[dir]file" ;
    #assert.result ""      "[dir]"  ""     : split-path-VMS "[dir]" ;
    #assert.result ""      ""       "file" : split-path-VMS "file" ;
    #assert.result ""      ""       ""     : split-path-VMS "" ;
    #
    ##
    ## Special case: current directory
    ##
    #assert.result ""      "[]"     ""     : split-path-VMS "[]" ;
    #assert.result "disk:" "[]"     ""     : split-path-VMS "disk:[]" ;
    #assert.result ""      "[]"     "file" : split-path-VMS "[]file" ;
    #assert.result "disk:" "[]"     "file" : split-path-VMS "disk:[]file" ;
    #
    ##
    ## Make portable paths
    ##
    #assert.result "/disk:" : make-VMS "disk:" ;
    #assert.result "foo/bar/giz" : make-VMS "[.foo.bar.giz]" ;
    #assert.result "foo" : make-VMS "[.foo]" ;
    #assert.result "foo" : make-VMS "[.foo.bar.-]" ;
    #assert.result ".." : make-VMS "[.-]" ;
    #assert.result ".." : make-VMS "[-]" ;
    #assert.result "." : make-VMS "[]" ;
    #assert.result "giz.h" : make-VMS "giz.h" ;
    #assert.result "foo/bar/giz.h" : make-VMS "[.foo.bar]giz.h" ;
    #assert.result "/disk:/my_docs" : make-VMS "disk:[my_docs]" ;
    #assert.result "/disk:/boost/tools/build/new/project.jam" : make-VMS
    #    "disk:[boost.tools.build.test.-.new]project.jam" ;
    #
    ##
    ## Special case (adds '.' to end of file w/o extension to disambiguate from
    ## directory in portable path spec)
    ##
    #assert.result "Jamfile." : make-VMS "Jamfile" ;
    #assert.result "dir/Jamfile." : make-VMS "[.dir]Jamfile" ;
    #assert.result "/disk:/dir/Jamfile." : make-VMS "disk:[dir]Jamfile" ;
    #
    ##
    ## Make native paths
    ##
    #assert.result "disk:" : native-VMS "/disk:" ;
    #assert.result "[.foo.bar.giz]" : native-VMS "foo/bar/giz" ;
    #assert.result "[.foo]" : native-VMS "foo" ;
    #assert.result "[.-]" : native-VMS ".." ;
    #assert.result "[.foo.-]" : native-VMS "foo/.." ;
    #assert.result "[]" : native-VMS "." ;
    #assert.result "disk:[my_docs.work]" : native-VMS "/disk:/my_docs/work" ;
    #assert.result "giz.h" : native-VMS "giz.h" ;
    #assert.result "disk:Jamfile." : native-VMS "/disk:Jamfile." ;
    #assert.result "disk:[my_docs.work]Jamfile." : native-VMS
    #    "/disk:/my_docs/work/Jamfile." ;

    modules.poke path : os : $(save-os) ;
}