| # Copyright 2017 The TensorFlow Authors. All Rights Reserved. |
| # |
| # Licensed under the Apache License, Version 2.0 (the "License"); |
| # you may not use this file except in compliance with the License. |
| # You may obtain a copy of the License at |
| # |
| # http://www.apache.org/licenses/LICENSE-2.0 |
| # |
| # Unless required by applicable law or agreed to in writing, software |
| # distributed under the License is distributed on an "AS IS" BASIS, |
| # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| # See the License for the specific language governing permissions and |
| # limitations under the License. |
| # ============================================================================== |
| """Converting code to AST. |
| |
| Adapted from Tangent. |
| """ |
| |
| from __future__ import absolute_import |
| from __future__ import division |
| from __future__ import print_function |
| |
| import textwrap |
| |
| import gast |
| |
| from tensorflow.python.util import tf_inspect |
| |
| |
| def parse_entity(entity): |
| """Returns the AST of given entity.""" |
| source = tf_inspect.getsource(entity) |
| # Comments and multiline strings can appear at arbitrary indentation levels, |
| # causing textwrap.dedent to not correctly dedent source code. |
| # TODO(b/115884650): Automatic handling of comments/multiline strings. |
| source = textwrap.dedent(source) |
| try: |
| return parse_str(source), source |
| except IndentationError: |
| # Because we are parsing the source code of entities that have already |
| # successfully parsed once, any IndentationErrors are guaranteed to be |
| # caused by insufficient dedenting. |
| raise ValueError( |
| 'Failed to dedent prior to parsing source code. If you have comments ' |
| 'or multiline strings in your code, try indenting them. ' |
| 'Multiline strings can be rewritten using textwrap.dedent.\n' |
| 'Offending source code: \n %s' % source) |
| |
| |
| def parse_str(src): |
| """Returns the AST of given piece of code.""" |
| # TODO(mdan): This should exclude the module things are autowrapped in. |
| return gast.parse(src) |
| |
| |
| def parse_expression(src): |
| """Returns the AST of given identifier. |
| |
| Args: |
| src: A piece of code that represents a single Python expression |
| Returns: |
| A gast.AST object. |
| Raises: |
| ValueError: if src does not consist of a single Expression. |
| """ |
| node = parse_str(src) |
| assert isinstance(node, gast.Module) |
| if len(node.body) != 1 and not isinstance(node.body[0], gast.Expr): |
| raise ValueError( |
| 'Expected a single expression, found instead %s' % node.body) |
| return node.body[0].value |