"""distutils.util

Miscellaneous utility functions -- anything that doesn't fit into

one of the other *util.py modules.

"""

__revision__ = "$Id: util.py 59116 2007-11-22 10:14:26Z ronald.oussoren $"

import sys, os, string, re

from distutils.errors import DistutilsPlatformError

from distutils.dep_util import newer

from distutils.spawn import spawn

from distutils import log

def get_platform ():

    """Return a string that identifies the current platform.  This is used

    mainly to distinguish platform-specific build directories and

    platform-specific built distributions.  Typically includes the OS name

    and version and the architecture (as supplied by 'os.uname()'),

    although the exact information included depends on the OS; eg. for IRIX

    the architecture isn't particularly important (IRIX only runs on SGI

    hardware), but for Linux the kernel version isn't particularly

    important.

    Examples of returned values:

       linux-i586

       linux-alpha (?)

       solaris-2.6-sun4u

       irix-5.3

       irix64-6.2

    For non-POSIX platforms, currently just returns 'sys.platform'.

    """

    if os.name != "posix" or not hasattr(os, 'uname'):

        # XXX what about the architecture? NT is Intel or Alpha,

        # Mac OS is M68k or PPC, etc.

        return sys.platform

    # Try to distinguish various flavours of Unix

    (osname, host, release, version, machine) = os.uname()

    # Convert the OS name to lowercase, remove '/' characters

    # (to accommodate BSD/OS), and translate spaces (for "Power Macintosh")

    osname = string.lower(osname)

    osname = string.replace(osname, '/', '')

    machine = string.replace(machine, ' ', '_')

    machine = string.replace(machine, '/', '-')

    if osname[:5] == "linux":

        # At least on Linux/Intel, 'machine' is the processor --

        # i386, etc.

        # XXX what about Alpha, SPARC, etc?

        return  "%s-%s" % (osname, machine)

    elif osname[:5] == "sunos":

        if release[0] >= "5":           # SunOS 5 == Solaris 2

            osname = "solaris"

            release = "%d.%s" % (int(release[0]) - 3, release[2:])

        # fall through to standard osname-release-machine representation

    elif osname[:4] == "irix":              # could be "irix64"!

        return "%s-%s" % (osname, release)

    elif osname[:3] == "aix":

        return "%s-%s.%s" % (osname, version, release)

    elif osname[:6] == "cygwin":

        osname = "cygwin"

        rel_re = re.compile (r'[\d.]+')

        m = rel_re.match(release)

        if m:

            release = m.group()

    elif osname[:6] == "darwin":

        #

        # For our purposes, we'll assume that the system version from

        # distutils' perspective is what MACOSX_DEPLOYMENT_TARGET is set

        # to. This makes the compatibility story a bit more sane because the

        # machine is going to compile and link as if it were

        # MACOSX_DEPLOYMENT_TARGET.

        from distutils.sysconfig import get_config_vars

        cfgvars = get_config_vars()

        macver = os.environ.get('MACOSX_DEPLOYMENT_TARGET')

        if not macver:

            macver = cfgvars.get('MACOSX_DEPLOYMENT_TARGET')

        if not macver:

            # Get the system version. Reading this plist is a documented

            # way to get the system version (see the documentation for

            # the Gestalt Manager)

            try:

                f = open('/System/Library/CoreServices/SystemVersion.plist')

            except IOError:

                # We're on a plain darwin box, fall back to the default

                # behaviour.

                pass

            else:

                m = re.search(

                        r'<key>ProductUserVisibleVersion</key>\s*' +

                        r'<string>(.*?)</string>', f.read())

                f.close()

                if m is not None:

                    macver = '.'.join(m.group(1).split('.')[:2])

                # else: fall back to the default behaviour

        if macver:

            from distutils.sysconfig import get_config_vars

            release = macver

            osname = "macosx"

            if (release + '.') >= '10.4.' and \

                    get_config_vars().get('UNIVERSALSDK', '').strip():

                # The universal build will build fat binaries, but not on

                # systems before 10.4

                machine = 'fat'

            elif machine in ('PowerPC', 'Power_Macintosh'):

                # Pick a sane name for the PPC architecture.

                machine = 'ppc'

    return "%s-%s-%s" % (osname, release, machine)

# get_platform ()

def convert_path (pathname):

    """Return 'pathname' as a name that will work on the native filesystem,

    i.e. split it on '/' and put it back together again using the current

    directory separator.  Needed because filenames in the setup script are

    always supplied in Unix style, and have to be converted to the local

    convention before we can actually use them in the filesystem.  Raises

    ValueError on non-Unix-ish systems if 'pathname' either starts or

    ends with a slash.

    """

    if os.sep == '/':

        return pathname

    if not pathname:

        return pathname

    if pathname[0] == '/':

        raise ValueError, "path '%s' cannot be absolute" % pathname

    if pathname[-1] == '/':

        raise ValueError, "path '%s' cannot end with '/'" % pathname

    paths = string.split(pathname, '/')

    while '.' in paths:

        paths.remove('.')

    if not paths:

        return os.curdir

    return apply(os.path.join, paths)

# convert_path ()

def change_root (new_root, pathname):

    """Return 'pathname' with 'new_root' prepended.  If 'pathname' is

    relative, this is equivalent to "os.path.join(new_root,pathname)".

    Otherwise, it requires making 'pathname' relative and then joining the

    two, which is tricky on DOS/Windows and Mac OS.

    """

    if os.name == 'posix':

        if not os.path.isabs(pathname):

            return os.path.join(new_root, pathname)

        else:

            return os.path.join(new_root, pathname[1:])

    elif os.name == 'nt':

        (drive, path) = os.path.splitdrive(pathname)

        if path[0] == '\\':

            path = path[1:]

        return os.path.join(new_root, path)

    elif os.name == 'os2':

        (drive, path) = os.path.splitdrive(pathname)

        if path[0] == os.sep:

            path = path[1:]

        return os.path.join(new_root, path)

    elif os.name == 'mac':

        if not os.path.isabs(pathname):

            return os.path.join(new_root, pathname)

        else:

            # Chop off volume name from start of path

            elements = string.split(pathname, ":", 1)

            pathname = ":" + elements[1]

            return os.path.join(new_root, pathname)

    else:

        raise DistutilsPlatformError, \

              "nothing known about platform '%s'" % os.name

_environ_checked = 0

def check_environ ():

    """Ensure that 'os.environ' has all the environment variables we

    guarantee that users can use in config files, command-line options,

    etc.  Currently this includes:

      HOME - user's home directory (Unix only)

      PLAT - description of the current platform, including hardware

             and OS (see 'get_platform()')

    """

    global _environ_checked

    if _environ_checked:

        return

    if os.name == 'posix' and not os.environ.has_key('HOME'):

        import pwd

        os.environ['HOME'] = pwd.getpwuid(os.getuid())[5]

    if not os.environ.has_key('PLAT'):

        os.environ['PLAT'] = get_platform()

    _environ_checked = 1

def subst_vars (s, local_vars):

    """Perform shell/Perl-style variable substitution on 'string'.  Every

    occurrence of '$' followed by a name is considered a variable, and

    variable is substituted by the value found in the 'local_vars'

    dictionary, or in 'os.environ' if it's not in 'local_vars'.

    'os.environ' is first checked/augmented to guarantee that it contains

    certain values: see 'check_environ()'.  Raise ValueError for any

    variables not found in either 'local_vars' or 'os.environ'.

    """

    check_environ()

    def _subst (match, local_vars=local_vars):

        var_name = match.group(1)

        if local_vars.has_key(var_name):

            return str(local_vars[var_name])

        else:

            return os.environ[var_name]

    try:

        return re.sub(r'\$([a-zA-Z_][a-zA-Z_0-9]*)', _subst, s)

    except KeyError, var:

        raise ValueError, "invalid variable '$%s'" % var

# subst_vars ()

def grok_environment_error (exc, prefix="error: "):

    """Generate a useful error message from an EnvironmentError (IOError or

    OSError) exception object.  Handles Python 1.5.1 and 1.5.2 styles, and

    does what it can to deal with exception objects that don't have a

    filename (which happens when the error is due to a two-file operation,

    such as 'rename()' or 'link()'.  Returns the error message as a string

    prefixed with 'prefix'.

    """

    # check for Python 1.5.2-style {IO,OS}Error exception objects

    if hasattr(exc, 'filename') and hasattr(exc, 'strerror'):

        if exc.filename:

            error = prefix + "%s: %s" % (exc.filename, exc.strerror)

        else:

            # two-argument functions in posix module don't

            # include the filename in the exception object!

            error = prefix + "%s" % exc.strerror

    else:

        error = prefix + str(exc[-1])

    return error

# Needed by 'split_quoted()'

_wordchars_re = _squote_re = _dquote_re = None

def _init_regex():

    global _wordchars_re, _squote_re, _dquote_re

    _wordchars_re = re.compile(r'[^\\\'\"%s ]*' % string.whitespace)

    _squote_re = re.compile(r"'(?:[^'\\]|\\.)*'")

    _dquote_re = re.compile(r'"(?:[^"\\]|\\.)*"')

def split_quoted (s):

    """Split a string up according to Unix shell-like rules for quotes and

    backslashes.  In short: words are delimited by spaces, as long as those

    spaces are not escaped by a backslash, or inside a quoted string.

    Single and double quotes are equivalent, and the quote characters can

    be backslash-escaped.  The backslash is stripped from any two-character

    escape sequence, leaving only the escaped character.  The quote

    characters are stripped from any quoted string.  Returns a list of

    words.

    """

    # This is a nice algorithm for splitting up a single string, since it

    # doesn't require character-by-character examination.  It was a little

    # bit of a brain-bender to get it working right, though...

    if _wordchars_re is None: _init_regex()

    s = string.strip(s)

    words = []

    pos = 0

    while s:

        m = _wordchars_re.match(s, pos)

        end = m.end()

        if end == len(s):

            words.append(s[:end])

            break

        if s[end] in string.whitespace: # unescaped, unquoted whitespace: now

            words.append(s[:end])       # we definitely have a word delimiter

            s = string.lstrip(s[end:])

            pos = 0

        elif s[end] == '\\':            # preserve whatever is being escaped;

                                        # will become part of the current word

            s = s[:end] + s[end+1:]

            pos = end+1

        else:

            if s[end] == "'":           # slurp singly-quoted string

                m = _squote_re.match(s, end)

            elif s[end] == '"':         # slurp doubly-quoted string

                m = _dquote_re.match(s, end)

            else:

                raise RuntimeError, \

                      "this can't happen (bad char '%c')" % s[end]

            if m is None:

                raise ValueError, \

                      "bad string (mismatched %s quotes?)" % s[end]

            (beg, end) = m.span()

            s = s[:beg] + s[beg+1:end-1] + s[end:]

            pos = m.end() - 2

        if pos >= len(s):

            words.append(s)

            break

    return words

# split_quoted ()

def execute (func, args, msg=None, verbose=0, dry_run=0):

    """Perform some action that affects the outside world (eg.  by

    writing to the filesystem).  Such actions are special because they

    are disabled by the 'dry_run' flag.  This method takes care of all

    that bureaucracy for you; all you have to do is supply the

    function to call and an argument tuple for it (to embody the

    "external action" being performed), and an optional message to

    print.

    """

    if msg is None:

        msg = "%s%r" % (func.__name__, args)

        if msg[-2:] == ',)':        # correct for singleton tuple

            msg = msg[0:-2] + ')'

    log.info(msg)

    if not dry_run:

        apply(func, args)

def strtobool (val):

    """Convert a string representation of truth to true (1) or false (0).

    True values are 'y', 'yes', 't', 'true', 'on', and '1'; false values

    are 'n', 'no', 'f', 'false', 'off', and '0'.  Raises ValueError if

    'val' is anything else.

    """

    val = string.lower(val)

    if val in ('y', 'yes', 't', 'true', 'on', '1'):

        return 1

    elif val in ('n', 'no', 'f', 'false', 'off', '0'):

        return 0

    else:

        raise ValueError, "invalid truth value %r" % (val,)

def byte_compile (py_files,

                  optimize=0, force=0,

                  prefix=None, base_dir=None,

                  verbose=1, dry_run=0,

                  direct=None):

    """Byte-compile a collection of Python source files to either .pyc

    or .pyo files in the same directory.  'py_files' is a list of files

    to compile; any files that don't end in ".py" are silently skipped.

    'optimize' must be one of the following:

      0 - don't optimize (generate .pyc)

      1 - normal optimization (like "python -O")

      2 - extra optimization (like "python -OO")

    If 'force' is true, all files are recompiled regardless of

    timestamps.

    The source filename encoded in each bytecode file defaults to the

    filenames listed in 'py_files'; you can modify these with 'prefix' and

    'basedir'.  'prefix' is a string that will be stripped off of each

    source filename, and 'base_dir' is a directory name that will be

    prepended (after 'prefix' is stripped).  You can supply either or both

    (or neither) of 'prefix' and 'base_dir', as you wish.

    If 'dry_run' is true, doesn't actually do anything that would

    affect the filesystem.

    Byte-compilation is either done directly in this interpreter process

    with the standard py_compile module, or indirectly by writing a

    temporary script and executing it.  Normally, you should let

    'byte_compile()' figure out to use direct compilation or not (see

    the source for details).  The 'direct' flag is used by the script

    generated in indirect mode; unless you know what you're doing, leave

    it set to None.

    """

    # First, if the caller didn't force us into direct or indirect mode,

    # figure out which mode we should be in.  We take a conservative

    # approach: choose direct mode *only* if the current interpreter is

    # in debug mode and optimize is 0.  If we're not in debug mode (-O

    # or -OO), we don't know which level of optimization this

    # interpreter is running with, so we can't do direct

    # byte-compilation and be certain that it's the right thing.  Thus,

    # always compile indirectly if the current interpreter is in either

    # optimize mode, or if either optimization level was requested by

    # the caller.

    if direct is None:

        direct = (__debug__ and optimize == 0)

    # "Indirect" byte-compilation: write a temporary script and then

    # run it with the appropriate flags.

    if not direct:

        try:

            from tempfile import mkstemp

            (script_fd, script_name) = mkstemp(".py")

        except ImportError:

            from tempfile import mktemp

            (script_fd, script_name) = None, mktemp(".py")

        log.info("writing byte-compilation script '%s'", script_name)

        if not dry_run:

            if script_fd is not None:

                script = os.fdopen(script_fd, "w")

            else:

                script = open(script_name, "w")

            script.write("""\

from distutils.util import byte_compile

files = [

""")

            # XXX would be nice to write absolute filenames, just for

            # safety's sake (script should be more robust in the face of

            # chdir'ing before running it).  But this requires abspath'ing

            # 'prefix' as well, and that breaks the hack in build_lib's

            # 'byte_compile()' method that carefully tacks on a trailing

            # slash (os.sep really) to make sure the prefix here is "just

            # right".  This whole prefix business is rather delicate -- the

            # problem is that it's really a directory, but I'm treating it

            # as a dumb string, so trailing slashes and so forth matter.

            #py_files = map(os.path.abspath, py_files)

            #if prefix:

            #    prefix = os.path.abspath(prefix)

            script.write(string.join(map(repr, py_files), ",\n") + "]\n")

            script.write("""

byte_compile(files, optimize=%r, force=%r,

             prefix=%r, base_dir=%r,

             verbose=%r, dry_run=0,

             direct=1)

""" % (optimize, force, prefix, base_dir, verbose))

            script.close()

        cmd = [sys.executable, script_name]

        if optimize == 1:

            cmd.insert(1, "-O")

        elif optimize == 2:

            cmd.insert(1, "-OO")

        spawn(cmd, dry_run=dry_run)

        execute(os.remove, (script_name,), "removing %s" % script_name,

                dry_run=dry_run)

    # "Direct" byte-compilation: use the py_compile module to compile

    # right here, right now.  Note that the script generated in indirect

    # mode simply calls 'byte_compile()' in direct mode, a weird sort of

    # cross-process recursion.  Hey, it works!

    else:

        from py_compile import compile

        for file in py_files:

            if file[-3:] != ".py":

                # This lets us be lazy and not filter filenames in

                # the "install_lib" command.

                continue

            # Terminology from the py_compile module:

            #   cfile - byte-compiled file

            #   dfile - purported source filename (same as 'file' by default)

            cfile = file + (__debug__ and "c" or "o")

            dfile = file

            if prefix:

                if file[:len(prefix)] != prefix:

                    raise ValueError, \

                          ("invalid prefix: filename %r doesn't start with %r"

                           % (file, prefix))

                dfile = dfile[len(prefix):]

            if base_dir:

                dfile = os.path.join(base_dir, dfile)

            cfile_base = os.path.basename(cfile)

            if direct:

                if force or newer(file, cfile):

                    log.info("byte-compiling %s to %s", file, cfile_base)

                    if not dry_run:

                        compile(file, cfile, dfile)

                else:

                    log.debug("skipping byte-compilation of %s to %s",

                              file, cfile_base)

# byte_compile ()

def rfc822_escape (header):

    """Return a version of the string escaped for inclusion in an

    RFC-822 header, by ensuring there are 8 spaces space after each newline.

    """

    lines = string.split(header, '\n')

    lines = map(string.strip, lines)

    header = string.join(lines, '\n' + 8*' ')

    return header