Current File : //lib/python3/dist-packages/pythran/unparse.py
"""
This code is extracted from the python source tree, and thus under the PSF
License.
Usage: unparse.py <path to source file>
"""
import pythran.metadata as metadata
import pythran.openmp as openmp
from pythran.utils import isnum
import gast as ast
import os
import sys
import io
# Large float and imaginary literals get turned into infinities in the AST.
# We unparse those infinities to INFSTR.
INFSTR = "(1e1000 ** 2)"
def interleave(inter, f, seq):
"""Call f on each item in seq, calling inter() in between.
"""
seq = iter(seq)
try:
f(next(seq))
except StopIteration:
pass
else:
for x in seq:
inter()
f(x)
class Unparser:
"""Methods in this class recursively traverse an AST and
output source code for the abstract syntax; original formatting
is disregarded. """
def __init__(self, tree, file=sys.stdout):
"""Unparser(tree, file=sys.stdout) -> None.
Print the source for tree to file."""
self.f = file
self.future_imports = []
self._indent = 0
self.line_marker = ""
self.dispatch(tree)
self.f.write("")
self.f.flush()
def fill(self, text=""):
"Indent a piece of text, according to the current indentation level"
self.f.write(self.line_marker + " " * self._indent + text)
self.line_marker = "\n"
def write(self, text):
"Append a piece of text to the current line."
self.f.write(text)
def enter(self):
"Print ':', and increase the indentation."
self.write(":")
self._indent += 1
def leave(self):
"""Decrease the indentation level."""
self._indent -= 1
def dispatch(self, tree):
"""Dispatcher function, dispatching tree type T to method _T."""
# display omp directive in python dump
for omp in metadata.get(tree, openmp.OMPDirective):
deps = list()
for dep in omp.deps:
old_file = self.f
self.f = io.StringIO()
self.dispatch(dep)
deps.append(self.f.getvalue())
self.f = old_file
directive = omp.s.format(*deps)
self._Expr(ast.Expr(ast.Constant(directive, None)))
if isinstance(tree, list):
for t in tree:
self.dispatch(t)
return
meth = getattr(self, "_" + tree.__class__.__name__)
meth(tree)
# ############# Unparsing methods ######################
# There should be one method per concrete grammar type #
# Constructors should be grouped by sum type. Ideally, #
# this would follow the order in the grammar, but #
# currently doesn't. #
# ######################################################
def _Module(self, tree):
# Goes through each top-level statement. If the special __init__()
# function is found, add a call to it because it's a special Pythran
# feature.
has_init = False
for stmt in tree.body:
self.dispatch(stmt)
if (type(stmt) is ast.FunctionDef and
stmt.name == '__init__'):
has_init = True
# Call __init__() in which top statements are moved.
if has_init:
self.fill("__init__()")
# pythran specific
def _ContainerOf(self, co):
if co.index == co.index: # always valid except for UnknownIndex
self.write('|[{}]='.format(co.index))
self.dispatch(co.containee)
self.write('|')
else:
self.write('|')
self.dispatch(co.containee)
self.write('|')
def _UnboundValueType(self, ui):
self.write('<unbound-value>')
# stmt
def _Expr(self, tree):
self.fill()
self.dispatch(tree.value)
def _Import(self, t):
self.fill("import ")
interleave(lambda: self.write(", "), self.dispatch, t.names)
def _ImportFrom(self, t):
# A from __future__ import may affect unparsing, so record it.
if t.module and t.module == '__future__':
self.future_imports.extend(n.name for n in t.names)
self.fill("from ")
self.write("." * t.level)
if t.module:
self.write(t.module)
self.write(" import ")
interleave(lambda: self.write(", "), self.dispatch, t.names)
def _Assign(self, t):
self.fill()
for target in t.targets:
self.dispatch(target)
self.write(" = ")
self.dispatch(t.value)
def _AugAssign(self, t):
self.fill()
self.dispatch(t.target)
self.write(" " + self.binop[t.op.__class__.__name__] + "= ")
self.dispatch(t.value)
def _Return(self, t):
self.fill("return")
if t.value:
self.write(" ")
self.dispatch(t.value)
def _Pass(self, t):
self.fill("pass")
def _Break(self, t):
self.fill("break")
def _Continue(self, t):
self.fill("continue")
def _Delete(self, t):
self.fill("del ")
interleave(lambda: self.write(", "), self.dispatch, t.targets)
def _Assert(self, t):
self.fill("assert ")
self.dispatch(t.test)
if t.msg:
self.write(", ")
self.dispatch(t.msg)
def _Exec(self, t):
self.fill("exec ")
self.dispatch(t.body)
if t.globals:
self.write(" in ")
self.dispatch(t.globals)
if t.locals:
self.write(", ")
self.dispatch(t.locals)
def _NameConstant(self, t):
self.write('{}'.format(t.value))
def _Print(self, t):
# Assume from __future__ import print_function
self.fill("print")
do_comma = False
self.write("(")
for e in t.values:
if do_comma:
self.write(", ")
else:
do_comma = True
self.dispatch(e)
if t.dest:
self.write(", file=")
self.dispatch(t.dest)
if not t.nl:
self.write(", end=''")
self.write(")")
def _Global(self, t):
self.fill("global ")
interleave(lambda: self.write(", "), self.write, t.names)
def _Yield(self, t):
self.write("(")
self.write("yield")
if t.value:
self.write(" ")
self.dispatch(t.value)
self.write(")")
def _Raise(self, t):
self.fill('raise ')
if t.exc:
self.dispatch(t.exc)
if t.cause:
self.write("from ")
self.dispatch(t.cause)
def _Try(self, t):
self.fill("try")
self.enter()
self.dispatch(t.body)
self.leave()
for ex in t.handlers:
self.dispatch(ex)
if t.orelse:
self.fill("else")
self.enter()
self.dispatch(t.orelse)
self.leave()
def _ExceptHandler(self, t):
self.fill("except")
if t.type:
self.write(" ")
self.dispatch(t.type)
if t.name:
self.write(" as ")
self.dispatch(t.name)
self.enter()
self.dispatch(t.body)
self.leave()
def _ClassDef(self, t):
for deco in t.decorator_list:
self.fill("@")
self.dispatch(deco)
self.fill("class " + t.name)
if t.bases:
self.write("(")
for a in t.bases:
self.dispatch(a)
self.write(", ")
self.write(")")
self.enter()
self.dispatch(t.body)
self.leave()
def _FunctionDef(self, t):
for deco in t.decorator_list:
self.fill("@")
self.dispatch(deco)
self.fill("def " + t.name + "(")
self.dispatch(t.args)
self.write(")")
self.enter()
self.dispatch(t.body)
self.leave()
def _For(self, t):
self.fill("for ")
self.dispatch(t.target)
self.write(" in ")
self.dispatch(t.iter)
self.enter()
self.dispatch(t.body)
self.leave()
if t.orelse:
self.fill("else")
self.enter()
self.dispatch(t.orelse)
self.leave()
def _If(self, t):
self.fill("if ")
self.dispatch(t.test)
self.enter()
self.dispatch(t.body)
self.leave()
# collapse nested ifs into equivalent elifs.
while (t.orelse and len(t.orelse) == 1 and
isinstance(t.orelse[0], ast.If)):
t = t.orelse[0]
self.fill("elif ")
self.dispatch(t.test)
self.enter()
self.dispatch(t.body)
self.leave()
# final else
if t.orelse:
self.fill("else")
self.enter()
self.dispatch(t.orelse)
self.leave()
def _While(self, t):
self.fill("while ")
self.dispatch(t.test)
self.enter()
self.dispatch(t.body)
self.leave()
if t.orelse:
self.fill("else")
self.enter()
self.dispatch(t.orelse)
self.leave()
def _With(self, t):
self.fill("with ")
self.dispatch(t.context_expr)
if t.optional_vars:
self.write(" as ")
self.dispatch(t.optional_vars)
self.enter()
self.dispatch(t.body)
self.leave()
# expr
def _Str(self, tree):
# if from __future__ import unicode_literals is in effect,
# then we want to output string literals using a 'b' prefix
# and unicode literals with no prefix.
if "unicode_literals" not in self.future_imports:
self.write(repr(tree.value))
elif isinstance(tree.value, str):
self.write("b" + repr(tree.value))
else:
assert False, "shouldn't get here"
def _Name(self, t):
self.write(t.id)
def _Repr(self, t):
self.write("`")
self.dispatch(t.value)
self.write("`")
def _Num(self, t):
repr_n = repr(t.value)
# Parenthesize negative numbers, to avoid turning (-1)**2 into -1**2.
if repr_n.startswith("-"):
self.write("(")
# Substitute overflowing decimal literal for AST infinities.
self.write(repr_n.replace("inf", INFSTR))
if repr_n.startswith("-"):
self.write(")")
def _Constant(self, t):
if isinstance(t, str):
return self._Str(t)
elif t is None or isinstance(t, bool):
return self._NameConstant(t)
else:
return self._Num(t)
def _List(self, t):
self.write("[")
interleave(lambda: self.write(", "), self.dispatch, t.elts)
self.write("]")
def _ListComp(self, t):
self.write("[")
self.dispatch(t.elt)
for gen in t.generators:
self.dispatch(gen)
self.write("]")
def _GeneratorExp(self, t):
self.write("(")
self.dispatch(t.elt)
for gen in t.generators:
self.dispatch(gen)
self.write(")")
def _SetComp(self, t):
self.write("{")
self.dispatch(t.elt)
for gen in t.generators:
self.dispatch(gen)
self.write("}")
def _DictComp(self, t):
self.write("{")
self.dispatch(t.key)
self.write(": ")
self.dispatch(t.value)
for gen in t.generators:
self.dispatch(gen)
self.write("}")
def _comprehension(self, t):
self.write(" for ")
self.dispatch(t.target)
self.write(" in ")
self.dispatch(t.iter)
for if_clause in t.ifs:
self.write(" if ")
self.dispatch(if_clause)
def _IfExp(self, t):
self.write("(")
self.dispatch(t.body)
self.write(" if ")
self.dispatch(t.test)
self.write(" else ")
self.dispatch(t.orelse)
self.write(")")
def _Set(self, t):
assert(t.elts) # should be at least one element
self.write("{")
interleave(lambda: self.write(", "), self.dispatch, t.elts)
self.write("}")
def _Dict(self, t):
self.write("{")
def write_pair(pair):
k, v = pair
self.dispatch(k)
self.write(": ")
self.dispatch(v)
interleave(lambda: self.write(", "), write_pair, zip(t.keys, t.values))
self.write("}")
def _Tuple(self, t):
self.write("(")
if len(t.elts) == 1:
(elt,) = t.elts
self.dispatch(elt)
self.write(",")
else:
interleave(lambda: self.write(", "), self.dispatch, t.elts)
self.write(")")
unop = {"Invert": "~", "Not": "not", "UAdd": "+", "USub": "-"}
def _UnaryOp(self, t):
self.write("(")
self.write(self.unop[t.op.__class__.__name__])
self.write(" ")
# If we're applying unary minus to a number, parenthesize the number.
# This is necessary: -2147483648 is different from -(2147483648) on
# a 32-bit machine (the first is an int, the second a long), and
# -7j is different from -(7j). (The first has real part 0.0, the
# second has real part -0.0.)
if isinstance(t.op, ast.USub) and isnum(t.operand):
self.write("(")
self.dispatch(t.operand)
self.write(")")
else:
self.dispatch(t.operand)
self.write(")")
binop = {"Add": "+", "Sub": "-", "Mult": "*", "Div": "/", "Mod": "%",
"LShift": "<<", "RShift": ">>", "BitOr": "|", "BitXor": "^",
"BitAnd": "&", "FloorDiv": "//", "Pow": "**", "MatMult": "@"}
def _BinOp(self, t):
self.write("(")
self.dispatch(t.left)
self.write(" " + self.binop[t.op.__class__.__name__] + " ")
self.dispatch(t.right)
self.write(")")
cmpops = {"Eq": "==", "NotEq": "!=", "Lt": "<", "LtE": "<=", "Gt": ">",
"GtE": ">=", "Is": "is", "IsNot": "is not", "In": "in",
"NotIn": "not in"}
def _Compare(self, t):
self.write("(")
self.dispatch(t.left)
for o, e in zip(t.ops, t.comparators):
self.write(" " + self.cmpops[o.__class__.__name__] + " ")
self.dispatch(e)
self.write(")")
boolops = {ast.And: 'and', ast.Or: 'or'}
def _BoolOp(self, t):
self.write("(")
s = " %s " % self.boolops[t.op.__class__]
interleave(lambda: self.write(s), self.dispatch, t.values)
self.write(")")
def _Attribute(self, t):
self.dispatch(t.value)
# Special case: 3.__abs__() is a syntax error, so if t.value
# is an integer literal then we need to either parenthesize
# it or add an extra space to get 3 .__abs__().
if isnum(t.value) and isinstance(t.value.value, int):
self.write(" ")
self.write(".")
self.write(t.attr)
def _Call(self, t):
self.dispatch(t.func)
self.write("(")
comma = False
for e in t.args:
if comma:
self.write(", ")
else:
comma = True
self.dispatch(e)
for e in t.keywords:
if comma:
self.write(", ")
else:
comma = True
self.dispatch(e)
self.write(")")
def _Starred(self, t):
self.write('*')
self.dispatch(self.value)
def _Subscript(self, t):
self.dispatch(t.value)
self.write("[")
self.dispatch(t.slice)
self.write("]")
# slice
def _Ellipsis(self, t):
self.write("...")
def _Index(self, t):
self.dispatch(t.value)
def _Slice(self, t):
if t.lower:
self.dispatch(t.lower)
self.write(":")
if t.upper:
self.dispatch(t.upper)
if t.step:
self.write(":")
self.dispatch(t.step)
def _ExtSlice(self, t):
interleave(lambda: self.write(', '), self.dispatch, t.dims)
# others
def _arguments(self, t):
first = True
# normal arguments
defaults = [None] * (len(t.args) - len(t.defaults)) + t.defaults
for a, d in zip(t.args, defaults):
if first:
first = False
else:
self.write(", ")
self.dispatch(a),
if d:
self.write("=")
self.dispatch(d)
# varargs
if t.vararg:
if first:
first = False
else:
self.write(", ")
self.write("*")
self.write(t.vararg)
# kwargs
if t.kwarg:
if first:
first = False
else:
self.write(", ")
self.write("**" + t.kwarg)
def _keyword(self, t):
if t.arg:
self.write(t.arg)
else:
self.write('**')
self.write("=")
self.dispatch(t.value)
def _Lambda(self, t):
self.write("(")
self.write("lambda ")
self.dispatch(t.args)
self.write(": ")
self.dispatch(t.body)
self.write(")")
def _alias(self, t):
self.write(t.name)
if t.asname:
self.write(" as " + t.asname)
def roundtrip(filename, output=sys.stdout):
with open(filename, "r") as pyfile:
source = pyfile.read()
tree = compile(source, filename, "exec", ast.PyCF_ONLY_AST)
Unparser(tree, output)
def testdir(a):
try:
names = [n for n in os.listdir(a) if n.endswith('.py')]
except OSError:
sys.stderr.write("Directory not readable: %s" % a)
else:
for n in names:
fullname = os.path.join(a, n)
if os.path.isfile(fullname):
output = io.StringIO()
print('Testing %s' % fullname)
try:
roundtrip(fullname, output)
except Exception as e:
print(' Failed to compile, exception is %s' % repr(e))
elif os.path.isdir(fullname):
testdir(fullname)
def main(args):
if args[0] == '--testdir':
for a in args[1:]:
testdir(a)
else:
for a in args:
roundtrip(a)
if __name__ == '__main__':
main(sys.argv[1:])
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