Function _parse_makefile

tools/python-3.11.9-amd64/Lib/sysconfig.py:315–440

Parse a Makefile-style file. A dictionary containing name/value pairs is returned. If an optional dictionary is passed in as the second argument, it is used instead of a new dictionary.

(filename, vars=None, keep_unresolved=True)

def _parse_makefile(filename, vars=None, keep_unresolved=True):
    """Parse a Makefile-style file.

    A dictionary containing name/value pairs is returned.  If an
    optional dictionary is passed in as the second argument, it is
    used instead of a new dictionary.
    """
    import re

    if vars is None:
        vars = {}
    done = {}
    notdone = {}

    with open(filename, encoding=sys.getfilesystemencoding(),
              errors="surrogateescape") as f:
        lines = f.readlines()

    for line in lines:
        if line.startswith('#') or line.strip() == '':
            continue
        m = re.match(_variable_rx, line)
        if m:
            n, v = m.group(1, 2)
            v = v.strip()
            # `$$' is a literal `$' in make
            tmpv = v.replace('$$', '')

            if "$" in tmpv:
                notdone[n] = v
            else:
                try:
                    if n in _ALWAYS_STR:
                        raise ValueError

                    v = int(v)
                except ValueError:
                    # insert literal `$'
                    done[n] = v.replace('$$', '$')
                else:
                    done[n] = v

    # do variable interpolation here
    variables = list(notdone.keys())

    # Variables with a 'PY_' prefix in the makefile. These need to
    # be made available without that prefix through sysconfig.
    # Special care is needed to ensure that variable expansion works, even
    # if the expansion uses the name without a prefix.
    renamed_variables = ('CFLAGS', 'LDFLAGS', 'CPPFLAGS')

    while len(variables) > 0:
        for name in tuple(variables):
            value = notdone[name]
            m1 = re.search(_findvar1_rx, value)
            m2 = re.search(_findvar2_rx, value)
            if m1 and m2:
                m = m1 if m1.start() < m2.start() else m2