SCons/Node/Alias.py

   1 # MIT License
   2 #
   3 # Copyright The SCons Foundation
   4 #
   5 # Permission is hereby granted, free of charge, to any person obtaining
   6 # a copy of this software and associated documentation files (the
   7 # "Software"), to deal in the Software without restriction, including
   8 # without limitation the rights to use, copy, modify, merge, publish,
   9 # distribute, sublicense, and/or sell copies of the Software, and to
  10 # permit persons to whom the Software is furnished to do so, subject to
  11 # the following conditions:
  12 #
  13 # The above copyright notice and this permission notice shall be included
  14 # in all copies or substantial portions of the Software.
  15 #
  16 # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
  17 # KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
  18 # WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  19 # NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  20 # LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  21 # OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  22 # WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  23
  24 """Alias nodes.
  25
  26 This creates a hash of global Aliases (dummy targets).
  27 """
  28
  29 import collections
  30
  31 import SCons.Errors
  32 import SCons.Node
  33 import SCons.Util
  34 from SCons.Util import hash_signature
  35
  36 class AliasNameSpace(collections.UserDict):
  37     def Alias(self, name, **kw):
  38         if isinstance(name, SCons.Node.Alias.Alias):
  39             return name
  40         try:
  41             a = self[name]
  42         except KeyError:
  43             a = SCons.Node.Alias.Alias(name, **kw)
  44             self[name] = a
  45         return a
  46
  47     def lookup(self, name, **kw):
  48         try:
  49             return self[name]
  50         except KeyError:
  51             return None
  52
  53 class AliasNodeInfo(SCons.Node.NodeInfoBase):
  54     __slots__ = ('csig',)
  55     current_version_id = 2
  56     field_list = ['csig']
  57     def str_to_node(self, s):
  58         return default_ans.Alias(s)
  59
  60 class AliasBuildInfo(SCons.Node.BuildInfoBase):
  61     __slots__ = ()
  62     current_version_id = 2
  63
  64 class Alias(SCons.Node.Node):
  65
  66     NodeInfo = AliasNodeInfo
  67     BuildInfo = AliasBuildInfo
  68
  69     def __init__(self, name) -> None:
  70         super().__init__()
  71         self.name = name
  72         self.changed_since_last_build = 1
  73         self.store_info = 0
  74
  75     def str_for_display(self):
  76         return '"' + self.__str__() + '"'
  77
  78     def __str__(self) -> str:
  79         return self.name
  80
  81     def make_ready(self) -> None:
  82         self.get_csig()
  83
  84     really_build = SCons.Node.Node.build
  85     is_up_to_date = SCons.Node.Node.children_are_up_to_date
  86
  87     def is_under(self, dir) -> bool:
  88         # Make Alias nodes get built regardless of
  89         # what directory scons was run from. Alias nodes
  90         # are outside the filesystem:
  91         return True
  92
  93     def get_contents(self):
  94         """The contents of an alias is the concatenation
  95         of the content signatures of all its sources."""
  96         childsigs = [n.get_csig() for n in self.children()]
  97         return ''.join(childsigs)
  98
  99     def sconsign(self) -> None:
 100         """An Alias is not recorded in .sconsign files"""
 101         pass
 102
 103     #
 104     #
 105     #
 106
 107     def build(self) -> None:
 108         """A "builder" for aliases."""
 109         pass
 110
 111     def convert(self) -> None:
 112         try: del self.builder
 113         except AttributeError: pass
 114         self.reset_executor()
 115         self.build = self.really_build
 116
 117     def get_csig(self):
 118         """
 119         Generate a node's content signature, the digested signature
 120         of its content.
 121
 122         node - the node
 123         cache - alternate node to use for the signature cache
 124         returns - the content signature
 125         """
 126         try:
 127             return self.ninfo.csig
 128         except AttributeError:
 129             pass
 130
 131         contents = self.get_contents()
 132         csig = hash_signature(contents)
 133         self.get_ninfo().csig = csig
 134         return csig
 135
 136 default_ans = AliasNameSpace()
 137
 138 SCons.Node.arg2nodes_lookups.append(default_ans.lookup)
 139
 140 # Local Variables:
 141 # tab-width:4
 142 # indent-tabs-mode:nil
 143 # End:
 144 # vim: set expandtab tabstop=4 shiftwidth=4: