djavu-asus/emacs/elpy/rpc-venv/lib/python3.11/site-packages/setuptools/depends.py

   1 import sys
   2 import marshal
   3 import contextlib
   4 import dis
   5
   6 from setuptools.extern.packaging import version
   7
   8 from ._imp import find_module, PY_COMPILED, PY_FROZEN, PY_SOURCE
   9 from . import _imp
  10
  11
  12 __all__ = [
  13     'Require', 'find_module', 'get_module_constant', 'extract_constant'
  14 ]
  15
  16
  17 class Require:
  18     """A prerequisite to building or installing a distribution"""
  19
  20     def __init__(
  21             self, name, requested_version, module, homepage='',
  22             attribute=None, format=None):
  23
  24         if format is None and requested_version is not None:
  25             format = version.Version
  26
  27         if format is not None:
  28             requested_version = format(requested_version)
  29             if attribute is None:
  30                 attribute = '__version__'
  31
  32         self.__dict__.update(locals())
  33         del self.self
  34
  35     def full_name(self):
  36         """Return full package/distribution name, w/version"""
  37         if self.requested_version is not None:
  38             return '%s-%s' % (self.name, self.requested_version)
  39         return self.name
  40
  41     def version_ok(self, version):
  42         """Is 'version' sufficiently up-to-date?"""
  43         return self.attribute is None or self.format is None or \
  44             str(version) != "unknown" and self.format(version) >= self.requested_version
  45
  46     def get_version(self, paths=None, default="unknown"):
  47         """Get version number of installed module, 'None', or 'default'
  48
  49         Search 'paths' for module.  If not found, return 'None'.  If found,
  50         return the extracted version attribute, or 'default' if no version
  51         attribute was specified, or the value cannot be determined without
  52         importing the module.  The version is formatted according to the
  53         requirement's version format (if any), unless it is 'None' or the
  54         supplied 'default'.
  55         """
  56
  57         if self.attribute is None:
  58             try:
  59                 f, p, i = find_module(self.module, paths)
  60                 if f:
  61                     f.close()
  62                 return default
  63             except ImportError:
  64                 return None
  65
  66         v = get_module_constant(self.module, self.attribute, default, paths)
  67
  68         if v is not None and v is not default and self.format is not None:
  69             return self.format(v)
  70
  71         return v
  72
  73     def is_present(self, paths=None):
  74         """Return true if dependency is present on 'paths'"""
  75         return self.get_version(paths) is not None
  76
  77     def is_current(self, paths=None):
  78         """Return true if dependency is present and up-to-date on 'paths'"""
  79         version = self.get_version(paths)
  80         if version is None:
  81             return False
  82         return self.version_ok(str(version))
  83
  84
  85 def maybe_close(f):
  86     @contextlib.contextmanager
  87     def empty():
  88         yield
  89         return
  90     if not f:
  91         return empty()
  92
  93     return contextlib.closing(f)
  94
  95
  96 def get_module_constant(module, symbol, default=-1, paths=None):
  97     """Find 'module' by searching 'paths', and extract 'symbol'
  98
  99     Return 'None' if 'module' does not exist on 'paths', or it does not define
 100     'symbol'.  If the module defines 'symbol' as a constant, return the
 101     constant.  Otherwise, return 'default'."""
 102
 103     try:
 104         f, path, (suffix, mode, kind) = info = find_module(module, paths)
 105     except ImportError:
 106         # Module doesn't exist
 107         return None
 108
 109     with maybe_close(f):
 110         if kind == PY_COMPILED:
 111             f.read(8)  # skip magic & date
 112             code = marshal.load(f)
 113         elif kind == PY_FROZEN:
 114             code = _imp.get_frozen_object(module, paths)
 115         elif kind == PY_SOURCE:
 116             code = compile(f.read(), path, 'exec')
 117         else:
 118             # Not something we can parse; we'll have to import it.  :(
 119             imported = _imp.get_module(module, paths, info)
 120             return getattr(imported, symbol, None)
 121
 122     return extract_constant(code, symbol, default)
 123
 124
 125 def extract_constant(code, symbol, default=-1):
 126     """Extract the constant value of 'symbol' from 'code'
 127
 128     If the name 'symbol' is bound to a constant value by the Python code
 129     object 'code', return that value.  If 'symbol' is bound to an expression,
 130     return 'default'.  Otherwise, return 'None'.
 131
 132     Return value is based on the first assignment to 'symbol'.  'symbol' must
 133     be a global, or at least a non-"fast" local in the code block.  That is,
 134     only 'STORE_NAME' and 'STORE_GLOBAL' opcodes are checked, and 'symbol'
 135     must be present in 'code.co_names'.
 136     """
 137     if symbol not in code.co_names:
 138         # name's not there, can't possibly be an assignment
 139         return None
 140
 141     name_idx = list(code.co_names).index(symbol)
 142
 143     STORE_NAME = 90
 144     STORE_GLOBAL = 97
 145     LOAD_CONST = 100
 146
 147     const = default
 148
 149     for byte_code in dis.Bytecode(code):
 150         op = byte_code.opcode
 151         arg = byte_code.arg
 152
 153         if op == LOAD_CONST:
 154             const = code.co_consts[arg]
 155         elif arg == name_idx and (op == STORE_NAME or op == STORE_GLOBAL):
 156             return const
 157         else:
 158             const = default
 159
 160
 161 def _update_globals():
 162     """
 163     Patch the globals to remove the objects not available on some platforms.
 164
 165     XXX it'd be better to test assertions about bytecode instead.
 166     """
 167
 168     if not sys.platform.startswith('java') and sys.platform != 'cli':
 169         return
 170     incompatible = 'extract_constant', 'get_module_constant'
 171     for name in incompatible:
 172         del globals()[name]
 173         __all__.remove(name)
 174
 175
 176 _update_globals()