forked from VimPlug/jedi
91 lines
3.0 KiB
Python
91 lines
3.0 KiB
Python
from jedi.parser import tree
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class Status(object):
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lookup_table = {}
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def __init__(self, value, name):
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self._value = value
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self._name = name
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Status.lookup_table[value] = self
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def invert(self):
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if self is REACHABLE:
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return UNREACHABLE
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elif self is UNREACHABLE:
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return REACHABLE
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else:
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return UNSURE
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def __and__(self, other):
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if UNSURE in (self, other):
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return UNSURE
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else:
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return REACHABLE if self._value and other._value else UNREACHABLE
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def __repr__(self):
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return '<%s: %s>' % (type(self).__name__, self._name)
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REACHABLE = Status(True, 'reachable')
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UNREACHABLE = Status(False, 'unreachable')
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UNSURE = Status(None, 'unsure')
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def reachability_check(context, context_scope, node, origin_scope=None):
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flow_scope = node.get_parent_scope(include_flows=True)
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# Direct parents get resolved, we filter scopes that are separate branches.
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# This makes sense for autocompletion and static analysis. For actual
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# Python it doesn't matter, because we're talking about potentially
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# unreachable code.
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# e.g. `if 0:` would cause all name lookup within the flow make
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# unaccessible. This is not a "problem" in Python, because the code is
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# never called. In Jedi though, we still want to infer types.
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#while origin_scope is not None:
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#if flow_scope == origin_scope:
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#return REACHABLE
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#origin_scope = origin_scope.parent
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return _break_check(context, context_scope, flow_scope, node)
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def _break_check(context, context_scope, flow_scope, node):
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reachable = REACHABLE
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if flow_scope.type == 'if_stmt':
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if flow_scope.node_after_else(node):
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for check_node in flow_scope.check_nodes():
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reachable = _check_if(context, check_node)
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if reachable in (REACHABLE, UNSURE):
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break
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reachable = reachable.invert()
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else:
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node = flow_scope.node_in_which_check_node(node)
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if node is not None:
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reachable = _check_if(context, node)
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elif flow_scope.type in ('try_stmt', 'while_stmt'):
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return UNSURE
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# Only reachable branches need to be examined further.
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if reachable in (UNREACHABLE, UNSURE):
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return reachable
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# TODO REMOVE WTF
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#if element_scope.type == 'file_input':
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# The definition is in another module and therefore just return what we
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# have generated.
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# return reachable
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if context_scope != flow_scope and context_scope != flow_scope.parent:
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flow_scope = flow_scope.get_parent_scope(include_flows=True)
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return reachable & _break_check(context, context_scope, flow_scope, node)
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else:
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return reachable
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def _check_if(context, node):
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types = context.eval_node(node)
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values = set(x.py__bool__() for x in types)
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if len(values) == 1:
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return Status.lookup_table[values.pop()]
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else:
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return UNSURE
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