456 lines
15 KiB
Python
456 lines
15 KiB
Python
|
"""Utility functions, node construction macros, etc."""
|
||
|
|
# Author: Collin Winter
|
||
|
|
|
||
|
|
from itertools import islice
|
||
|
|
|
||
|
|
# Local imports
|
||
|
|
from .pgen2 import token
|
||
|
|
from .pytree import Leaf, Node
|
||
|
|
from .pygram import python_symbols as syms
|
||
|
|
from . import patcomp
|
||
|
|
|
||
|
|
|
||
|
|
###########################################################
|
||
|
|
### Common node-construction "macros"
|
||
|
|
###########################################################
|
||
|
|
|
||
|
|
def KeywordArg(keyword, value):
|
||
|
|
return Node(syms.argument,
|
||
|
|
[keyword, Leaf(token.EQUAL, "="), value])
|
||
|
|
|
||
|
|
def LParen():
|
||
|
|
return Leaf(token.LPAR, "(")
|
||
|
|
|
||
|
|
def RParen():
|
||
|
|
return Leaf(token.RPAR, ")")
|
||
|
|
|
||
|
|
def Assign(target, source):
|
||
|
|
"""Build an assignment statement"""
|
||
|
|
if not isinstance(target, list):
|
||
|
|
target = [target]
|
||
|
|
if not isinstance(source, list):
|
||
|
|
source.prefix = " "
|
||
|
|
source = [source]
|
||
|
|
|
||
|
|
return Node(syms.atom,
|
||
|
|
target + [Leaf(token.EQUAL, "=", prefix=" ")] + source)
|
||
|
|
|
||
|
|
def Name(name, prefix=None):
|
||
|
|
"""Return a NAME leaf"""
|
||
|
|
return Leaf(token.NAME, name, prefix=prefix)
|
||
|
|
|
||
|
|
def Attr(obj, attr):
|
||
|
|
"""A node tuple for obj.attr"""
|
||
|
|
return [obj, Node(syms.trailer, [Dot(), attr])]
|
||
|
|
|
||
|
|
def Comma():
|
||
|
|
"""A comma leaf"""
|
||
|
|
return Leaf(token.COMMA, ",")
|
||
|
|
|
||
|
|
def Dot():
|
||
|
|
"""A period (.) leaf"""
|
||
|
|
return Leaf(token.DOT, ".")
|
||
|
|
|
||
|
|
def ArgList(args, lparen=LParen(), rparen=RParen()):
|
||
|
|
"""A parenthesised argument list, used by Call()"""
|
||
|
|
node = Node(syms.trailer, [lparen.clone(), rparen.clone()])
|
||
|
|
if args:
|
||
|
|
node.insert_child(1, Node(syms.arglist, args))
|
||
|
|
return node
|
||
|
|
|
||
|
|
def Call(func_name, args=None, prefix=None):
|
||
|
|
"""A function call"""
|
||
|
|
node = Node(syms.power, [func_name, ArgList(args)])
|
||
|
|
if prefix is not None:
|
||
|
|
node.prefix = prefix
|
||
|
|
return node
|
||
|
|
|
||
|
|
def Newline():
|
||
|
|
"""A newline literal"""
|
||
|
|
return Leaf(token.NEWLINE, "\n")
|
||
|
|
|
||
|
|
def BlankLine():
|
||
|
|
"""A blank line"""
|
||
|
|
return Leaf(token.NEWLINE, "")
|
||
|
|
|
||
|
|
def Number(n, prefix=None):
|
||
|
|
return Leaf(token.NUMBER, n, prefix=prefix)
|
||
|
|
|
||
|
|
def Subscript(index_node):
|
||
|
|
"""A numeric or string subscript"""
|
||
|
|
return Node(syms.trailer, [Leaf(token.LBRACE, "["),
|
||
|
|
index_node,
|
||
|
|
Leaf(token.RBRACE, "]")])
|
||
|
|
|
||
|
|
def String(string, prefix=None):
|
||
|
|
"""A string leaf"""
|
||
|
|
return Leaf(token.STRING, string, prefix=prefix)
|
||
|
|
|
||
|
|
def ListComp(xp, fp, it, test=None):
|
||
|
|
"""A list comprehension of the form [xp for fp in it if test].
|
||
|
|
|
||
|
|
If test is None, the "if test" part is omitted.
|
||
|
|
"""
|
||
|
|
xp.prefix = ""
|
||
|
|
fp.prefix = " "
|
||
|
|
it.prefix = " "
|
||
|
|
for_leaf = Leaf(token.NAME, "for")
|
||
|
|
for_leaf.prefix = " "
|
||
|
|
in_leaf = Leaf(token.NAME, "in")
|
||
|
|
in_leaf.prefix = " "
|
||
|
|
inner_args = [for_leaf, fp, in_leaf, it]
|
||
|
|
if test:
|
||
|
|
test.prefix = " "
|
||
|
|
if_leaf = Leaf(token.NAME, "if")
|
||
|
|
if_leaf.prefix = " "
|
||
|
|
inner_args.append(Node(syms.comp_if, [if_leaf, test]))
|
||
|
|
inner = Node(syms.listmaker, [xp, Node(syms.comp_for, inner_args)])
|
||
|
|
return Node(syms.atom,
|
||
|
|
[Leaf(token.LBRACE, "["),
|
||
|
|
inner,
|
||
|
|
Leaf(token.RBRACE, "]")])
|
||
|
|
|
||
|
|
def FromImport(package_name, name_leafs):
|
||
|
|
""" Return an import statement in the form:
|
||
|
|
from package import name_leafs"""
|
||
|
|
# XXX: May not handle dotted imports properly (eg, package_name='foo.bar')
|
||
|
|
#assert package_name == '.' or '.' not in package_name, "FromImport has "\
|
||
|
|
# "not been tested with dotted package names -- use at your own "\
|
||
|
|
# "peril!"
|
||
|
|
|
||
|
|
for leaf in name_leafs:
|
||
|
|
# Pull the leaves out of their old tree
|
||
|
|
leaf.remove()
|
||
|
|
|
||
|
|
children = [Leaf(token.NAME, "from"),
|
||
|
|
Leaf(token.NAME, package_name, prefix=" "),
|
||
|
|
Leaf(token.NAME, "import", prefix=" "),
|
||
|
|
Node(syms.import_as_names, name_leafs)]
|
||
|
|
imp = Node(syms.import_from, children)
|
||
|
|
return imp
|
||
|
|
|
||
|
|
def ImportAndCall(node, results, names):
|
||
|
|
"""Returns an import statement and calls a method
|
||
|
|
of the module:
|
||
|
|
|
||
|
|
import module
|
||
|
|
module.name()"""
|
||
|
|
obj = results["obj"].clone()
|
||
|
|
if obj.type == syms.arglist:
|
||
|
|
newarglist = obj.clone()
|
||
|
|
else:
|
||
|
|
newarglist = Node(syms.arglist, [obj.clone()])
|
||
|
|
after = results["after"]
|
||
|
|
if after:
|
||
|
|
after = [n.clone() for n in after]
|
||
|
|
new = Node(syms.power,
|
||
|
|
Attr(Name(names[0]), Name(names[1])) +
|
||
|
|
[Node(syms.trailer,
|
||
|
|
[results["lpar"].clone(),
|
||
|
|
newarglist,
|
||
|
|
results["rpar"].clone()])] + after)
|
||
|
|
new.prefix = node.prefix
|
||
|
|
return new
|
||
|
|
|
||
|
|
|
||
|
|
###########################################################
|
||
|
|
### Determine whether a node represents a given literal
|
||
|
|
###########################################################
|
||
|
|
|
||
|
|
def is_tuple(node):
|
||
|
|
"""Does the node represent a tuple literal?"""
|
||
|
|
if isinstance(node, Node) and node.children == [LParen(), RParen()]:
|
||
|
|
return True
|
||
|
|
return (isinstance(node, Node)
|
||
|
|
and len(node.children) == 3
|
||
|
|
and isinstance(node.children[0], Leaf)
|
||
|
|
and isinstance(node.children[1], Node)
|
||
|
|
and isinstance(node.children[2], Leaf)
|
||
|
|
and node.children[0].value == "("
|
||
|
|
and node.children[2].value == ")")
|
||
|
|
|
||
|
|
def is_list(node):
|
||
|
|
"""Does the node represent a list literal?"""
|
||
|
|
return (isinstance(node, Node)
|
||
|
|
and len(node.children) > 1
|
||
|
|
and isinstance(node.children[0], Leaf)
|
||
|
|
and isinstance(node.children[-1], Leaf)
|
||
|
|
and node.children[0].value == "["
|
||
|
|
and node.children[-1].value == "]")
|
||
|
|
|
||
|
|
|
||
|
|
###########################################################
|
||
|
|
### Misc
|
||
|
|
###########################################################
|
||
|
|
|
||
|
|
def parenthesize(node):
|
||
|
|
return Node(syms.atom, [LParen(), node, RParen()])
|
||
|
|
|
||
|
|
|
||
|
|
consuming_calls = {"sorted", "list", "set", "any", "all", "tuple", "sum",
|
||
|
|
"min", "max", "enumerate"}
|
||
|
|
|
||
|
|
def attr_chain(obj, attr):
|
||
|
|
"""Follow an attribute chain.
|
||
|
|
|
||
|
|
If you have a chain of objects where a.foo -> b, b.foo-> c, etc,
|
||
|
|
use this to iterate over all objects in the chain. Iteration is
|
||
|
|
terminated by getattr(x, attr) is None.
|
||
|
|
|
||
|
|
Args:
|
||
|
|
obj: the starting object
|
||
|
|
attr: the name of the chaining attribute
|
||
|
|
|
||
|
|
Yields:
|
||
|
|
Each successive object in the chain.
|
||
|
|
"""
|
||
|
|
next = getattr(obj, attr)
|
||
|
|
while next:
|
||
|
|
yield next
|
||
|
|
next = getattr(next, attr)
|
||
|
|
|
||
|
|
p0 = """for_stmt< 'for' any 'in' node=any ':' any* >
|
||
|
|
| comp_for< 'for' any 'in' node=any any* >
|
||
|
|
"""
|
||
|
|
p1 = """
|
||
|
|
power<
|
||
|
|
( 'iter' | 'list' | 'tuple' | 'sorted' | 'set' | 'sum' |
|
||
|
|
'any' | 'all' | 'enumerate' | (any* trailer< '.' 'join' >) )
|
||
|
|
trailer< '(' node=any ')' >
|
||
|
|
any*
|
||
|
|
>
|
||
|
|
"""
|
||
|
|
p2 = """
|
||
|
|
power<
|
||
|
|
( 'sorted' | 'enumerate' )
|
||
|
|
trailer< '(' arglist<node=any any*> ')' >
|
||
|
|
any*
|
||
|
|
>
|
||
|
|
"""
|
||
|
|
pats_built = False
|
||
|
|
def in_special_context(node):
|
||
|
|
""" Returns true if node is in an environment where all that is required
|
||
|
|
of it is being iterable (ie, it doesn't matter if it returns a list
|
||
|
|
or an iterator).
|
||
|
|
See test_map_nochange in test_fixers.py for some examples and tests.
|
||
|
|
"""
|
||
|
|
global p0, p1, p2, pats_built
|
||
|
|
if not pats_built:
|
||
|
|
p0 = patcomp.compile_pattern(p0)
|
||
|
|
p1 = patcomp.compile_pattern(p1)
|
||
|
|
p2 = patcomp.compile_pattern(p2)
|
||
|
|
pats_built = True
|
||
|
|
patterns = [p0, p1, p2]
|
||
|
|
for pattern, parent in zip(patterns, attr_chain(node, "parent")):
|
||
|
|
results = {}
|
||
|
|
if pattern.match(parent, results) and results["node"] is node:
|
||
|
|
return True
|
||
|
|
return False
|
||
|
|
|
||
|
|
def is_probably_builtin(node):
|
||
|
|
"""
|
||
|
|
Check that something isn't an attribute or function name etc.
|
||
|
|
"""
|
||
|
|
prev = node.prev_sibling
|
||
|
|
if prev is not None and prev.type == token.DOT:
|
||
|
|
# Attribute lookup.
|
||
|
|
return False
|
||
|
|
parent = node.parent
|
||
|
|
if parent.type in (syms.funcdef, syms.classdef):
|
||
|
|
return False
|
||
|
|
if parent.type == syms.expr_stmt and parent.children[0] is node:
|
||
|
|
# Assignment.
|
||
|
|
return False
|
||
|
|
if parent.type == syms.parameters or \
|
||
|
|
(parent.type == syms.typedargslist and (
|
||
|
|
(prev is not None and prev.type == token.COMMA) or
|
||
|
|
parent.children[0] is node
|
||
|
|
)):
|
||
|
|
# The name of an argument.
|
||
|
|
return False
|
||
|
|
return True
|
||
|
|
|
||
|
|
def find_indentation(node):
|
||
|
|
"""Find the indentation of *node*."""
|
||
|
|
while node is not None:
|
||
|
|
if node.type == syms.suite and len(node.children) > 2:
|
||
|
|
indent = node.children[1]
|
||
|
|
if indent.type == token.INDENT:
|
||
|
|
return indent.value
|
||
|
|
node = node.parent
|
||
|
|
return ""
|
||
|
|
|
||
|
|
###########################################################
|
||
|
|
### The following functions are to find bindings in a suite
|
||
|
|
###########################################################
|
||
|
|
|
||
|
|
def make_suite(node):
|
||
|
|
if node.type == syms.suite:
|
||
|
|
return node
|
||
|
|
node = node.clone()
|
||
|
|
parent, node.parent = node.parent, None
|
||
|
|
suite = Node(syms.suite, [node])
|
||
|
|
suite.parent = parent
|
||
|
|
return suite
|
||
|
|
|
||
|
|
def find_root(node):
|
||
|
|
"""Find the top level namespace."""
|
||
|
|
# Scamper up to the top level namespace
|
||
|
|
while node.type != syms.file_input:
|
||
|
|
node = node.parent
|
||
|
|
if not node:
|
||
|
|
raise ValueError("root found before file_input node was found.")
|
||
|
|
return node
|
||
|
|
|
||
|
|
def does_tree_import(package, name, node):
|
||
|
|
""" Returns true if name is imported from package at the
|
||
|
|
top level of the tree which node belongs to.
|
||
|
|
To cover the case of an import like 'import foo', use
|
||
|
|
None for the package and 'foo' for the name. """
|
||
|
|
binding = find_binding(name, find_root(node), package)
|
||
|
|
return bool(binding)
|
||
|
|
|
||
|
|
def is_import(node):
|
||
|
|
"""Returns true if the node is an import statement."""
|
||
|
|
return node.type in (syms.import_name, syms.import_from)
|
||
|
|
|
||
|
|
def touch_import(package, name, node):
|
||
|
|
""" Works like `does_tree_import` but adds an import statement
|
||
|
|
if it was not imported. """
|
||
|
|
def is_import_stmt(node):
|
||
|
|
return (node.type == syms.simple_stmt and node.children and
|
||
|
|
is_import(node.children[0]))
|
||
|
|
|
||
|
|
root = find_root(node)
|
||
|
|
|
||
|
|
if does_tree_import(package, name, root):
|
||
|
|
return
|
||
|
|
|
||
|
|
# figure out where to insert the new import. First try to find
|
||
|
|
# the first import and then skip to the last one.
|
||
|
|
insert_pos = offset = 0
|
||
|
|
for idx, node in enumerate(root.children):
|
||
|
|
if not is_import_stmt(node):
|
||
|
|
continue
|
||
|
|
for offset, node2 in enumerate(root.children[idx:]):
|
||
|
|
if not is_import_stmt(node2):
|
||
|
|
break
|
||
|
|
insert_pos = idx + offset
|
||
|
|
break
|
||
|
|
|
||
|
|
# if there are no imports where we can insert, find the docstring.
|
||
|
|
# if that also fails, we stick to the beginning of the file
|
||
|
|
if insert_pos == 0:
|
||
|
|
for idx, node in enumerate(root.children):
|
||
|
|
if (node.type == syms.simple_stmt and node.children and
|
||
|
|
node.children[0].type == token.STRING):
|
||
|
|
insert_pos = idx + 1
|
||
|
|
break
|
||
|
|
|
||
|
|
if package is None:
|
||
|
|
import_ = Node(syms.import_name, [
|
||
|
|
Leaf(token.NAME, "import"),
|
||
|
|
Leaf(token.NAME, name, prefix=" ")
|
||
|
|
])
|
||
|
|
else:
|
||
|
|
import_ = FromImport(package, [Leaf(token.NAME, name, prefix=" ")])
|
||
|
|
|
||
|
|
children = [import_, Newline()]
|
||
|
|
root.insert_child(insert_pos, Node(syms.simple_stmt, children))
|
||
|
|
|
||
|
|
|
||
|
|
_def_syms = {syms.classdef, syms.funcdef}
|
||
|
|
def find_binding(name, node, package=None):
|
||
|
|
""" Returns the node which binds variable name, otherwise None.
|
||
|
|
If optional argument package is supplied, only imports will
|
||
|
|
be returned.
|
||
|
|
See test cases for examples."""
|
||
|
|
for child in node.children:
|
||
|
|
ret = None
|
||
|
|
if child.type == syms.for_stmt:
|
||
|
|
if _find(name, child.children[1]):
|
||
|
|
return child
|
||
|
|
n = find_binding(name, make_suite(child.children[-1]), package)
|
||
|
|
if n: ret = n
|
||
|
|
elif child.type in (syms.if_stmt, syms.while_stmt):
|
||
|
|
n = find_binding(name, make_suite(child.children[-1]), package)
|
||
|
|
if n: ret = n
|
||
|
|
elif child.type == syms.try_stmt:
|
||
|
|
n = find_binding(name, make_suite(child.children[2]), package)
|
||
|
|
if n:
|
||
|
|
ret = n
|
||
|
|
else:
|
||
|
|
for i, kid in enumerate(child.children[3:]):
|
||
|
|
if kid.type == token.COLON and kid.value == ":":
|
||
|
|
# i+3 is the colon, i+4 is the suite
|
||
|
|
n = find_binding(name, make_suite(child.children[i+4]), package)
|
||
|
|
if n: ret = n
|
||
|
|
elif child.type in _def_syms and child.children[1].value == name:
|
||
|
|
ret = child
|
||
|
|
elif _is_import_binding(child, name, package):
|
||
|
|
ret = child
|
||
|
|
elif child.type == syms.simple_stmt:
|
||
|
|
ret = find_binding(name, child, package)
|
||
|
|
elif child.type == syms.expr_stmt:
|
||
|
|
if _find(name, child.children[0]):
|
||
|
|
ret = child
|
||
|
|
|
||
|
|
if ret:
|
||
|
|
if not package:
|
||
|
|
return ret
|
||
|
|
if is_import(ret):
|
||
|
|
return ret
|
||
|
|
return None
|
||
|
|
|
||
|
|
_block_syms = {syms.funcdef, syms.classdef, syms.trailer}
|
||
|
|
def _find(name, node):
|
||
|
|
nodes = [node]
|
||
|
|
while nodes:
|
||
|
|
node = nodes.pop()
|
||
|
|
if node.type > 256 and node.type not in _block_syms:
|
||
|
|
nodes.extend(node.children)
|
||
|
|
elif node.type == token.NAME and node.value == name:
|
||
|
|
return node
|
||
|
|
return None
|
||
|
|
|
||
|
|
def _is_import_binding(node, name, package=None):
|
||
|
|
""" Will reuturn node if node will import name, or node
|
||
|
|
will import * from package. None is returned otherwise.
|
||
|
|
See test cases for examples. """
|
||
|
|
|
||
|
|
if node.type == syms.import_name and not package:
|
||
|
|
imp = node.children[1]
|
||
|
|
if imp.type == syms.dotted_as_names:
|
||
|
|
for child in imp.children:
|
||
|
|
if child.type == syms.dotted_as_name:
|
||
|
|
if child.children[2].value == name:
|
||
|
|
return node
|
||
|
|
elif child.type == token.NAME and child.value == name:
|
||
|
|
return node
|
||
|
|
elif imp.type == syms.dotted_as_name:
|
||
|
|
last = imp.children[-1]
|
||
|
|
if last.type == token.NAME and last.value == name:
|
||
|
|
return node
|
||
|
|
elif imp.type == token.NAME and imp.value == name:
|
||
|
|
return node
|
||
|
|
elif node.type == syms.import_from:
|
||
|
|
# str(...) is used to make life easier here, because
|
||
|
|
# from a.b import parses to ['import', ['a', '.', 'b'], ...]
|
||
|
|
if package and str(node.children[1]).strip() != package:
|
||
|
|
return None
|
||
|
|
n = node.children[3]
|
||
|
|
if package and _find("as", n):
|
||
|
|
# See test_from_import_as for explanation
|
||
|
|
return None
|
||
|
|
elif n.type == syms.import_as_names and _find(name, n):
|
||
|
|
return node
|
||
|
|
elif n.type == syms.import_as_name:
|
||
|
|
child = n.children[2]
|
||
|
|
if child.type == token.NAME and child.value == name:
|
||
|
|
return node
|
||
|
|
elif n.type == token.NAME and n.value == name:
|
||
|
|
return node
|
||
|
|
elif package and n.type == token.STAR:
|
||
|
|
return node
|
||
|
|
return None
|