217 lines
8.3 KiB
Python
217 lines
8.3 KiB
Python
|
# MIT License
|
||
|
|
#
|
||
|
|
# Copyright The SCons Foundation
|
||
|
|
#
|
||
|
|
# Permission is hereby granted, free of charge, to any person obtaining
|
||
|
|
# a copy of this software and associated documentation files (the
|
||
|
|
# "Software"), to deal in the Software without restriction, including
|
||
|
|
# without limitation the rights to use, copy, modify, merge, publish,
|
||
|
|
# distribute, sublicense, and/or sell copies of the Software, and to
|
||
|
|
# permit persons to whom the Software is furnished to do so, subject to
|
||
|
|
# the following conditions:
|
||
|
|
#
|
||
|
|
# The above copyright notice and this permission notice shall be included
|
||
|
|
# in all copies or substantial portions of the Software.
|
||
|
|
#
|
||
|
|
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
|
||
|
|
# KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
|
||
|
|
# WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
|
||
|
|
# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
|
||
|
|
# LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
|
||
|
|
# OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
|
||
|
|
# WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
|
||
|
|
|
||
|
|
"""Dependency scanner for Python code.
|
||
|
|
|
||
|
|
One important note about the design is that this does not take any dependencies
|
||
|
|
upon packages or binaries in the Python installation unless they are listed in
|
||
|
|
PYTHONPATH. To do otherwise would have required code to determine where the
|
||
|
|
Python installation is, which is outside of the scope of a scanner like this.
|
||
|
|
If consumers want to pick up dependencies upon these packages, they must put
|
||
|
|
those directories in PYTHONPATH.
|
||
|
|
|
||
|
|
"""
|
||
|
|
|
||
|
|
import itertools
|
||
|
|
import os
|
||
|
|
import re
|
||
|
|
|
||
|
|
import SCons.Node.FS
|
||
|
|
import SCons.Util
|
||
|
|
from . import ScannerBase
|
||
|
|
|
||
|
|
# Capture python "from a import b" and "import a" statements.
|
||
|
|
from_cre = re.compile(r'^\s*from\s+([^\s]+)\s+import\s+(.*)', re.M)
|
||
|
|
import_cre = re.compile(r'^\s*import\s+([^\s]+)', re.M)
|
||
|
|
|
||
|
|
|
||
|
|
def path_function(env, dir=None, target=None, source=None, argument=None):
|
||
|
|
"""Retrieves a tuple with all search paths."""
|
||
|
|
paths = env['ENV'].get('PYTHONPATH', '').split(os.pathsep)
|
||
|
|
if source:
|
||
|
|
paths.append(source[0].dir.abspath)
|
||
|
|
return tuple(paths)
|
||
|
|
|
||
|
|
|
||
|
|
def find_include_names(node):
|
||
|
|
"""Scans the node for all imports.
|
||
|
|
|
||
|
|
Returns a list of tuples. Each tuple has two elements:
|
||
|
|
1. The main import (e.g. module, module.file, module.module2)
|
||
|
|
2. Additional optional imports that could be functions or files
|
||
|
|
in the case of a "from X import Y" statement. In the case of a
|
||
|
|
normal "import" statement, this is None.
|
||
|
|
"""
|
||
|
|
text = node.get_text_contents()
|
||
|
|
all_matches = []
|
||
|
|
matches = from_cre.findall(text)
|
||
|
|
if matches:
|
||
|
|
for match in matches:
|
||
|
|
imports = [i.strip() for i in match[1].split(',')]
|
||
|
|
|
||
|
|
# Add some custom logic to strip out "as" because the regex
|
||
|
|
# includes it.
|
||
|
|
last_import_split = imports[-1].split()
|
||
|
|
if len(last_import_split) > 1:
|
||
|
|
imports[-1] = last_import_split[0]
|
||
|
|
|
||
|
|
all_matches.append((match[0], imports))
|
||
|
|
|
||
|
|
matches = import_cre.findall(text)
|
||
|
|
if matches:
|
||
|
|
for match in matches:
|
||
|
|
all_matches.append((match, None))
|
||
|
|
|
||
|
|
return all_matches
|
||
|
|
|
||
|
|
|
||
|
|
def find_import(import_path, search_paths):
|
||
|
|
"""
|
||
|
|
Finds the specified import in the various search paths.
|
||
|
|
For an import of "p", it could either result in a file named p.py or
|
||
|
|
p/__init__.py. We can't do two consecutive searches for p then p.py
|
||
|
|
because the first search could return a result that is lower in the
|
||
|
|
search_paths precedence order. As a result, it is safest to iterate over
|
||
|
|
search_paths and check whether p or p.py exists in each path. This allows
|
||
|
|
us to cleanly respect the precedence order.
|
||
|
|
|
||
|
|
If the import is found, returns a tuple containing:
|
||
|
|
1. Discovered dependency node (e.g. p/__init__.py or p.py)
|
||
|
|
2. True if the import was a package, False if the import was a module.
|
||
|
|
3. The Dir node in search_paths that the import is relative to.
|
||
|
|
If the import is not found, returns a tuple containing (None, False, None).
|
||
|
|
Callers should check for failure by checking whether the first entry in the
|
||
|
|
tuple is not None.
|
||
|
|
"""
|
||
|
|
for search_path in search_paths:
|
||
|
|
paths = [search_path]
|
||
|
|
# Note: if the same import is present as a package and a module, Python
|
||
|
|
# prefers the package. As a result, we always look for x/__init__.py
|
||
|
|
# before looking for x.py.
|
||
|
|
node = SCons.Node.FS.find_file(import_path + '/__init__.py', paths)
|
||
|
|
if node:
|
||
|
|
return node, True, search_path
|
||
|
|
else:
|
||
|
|
node = SCons.Node.FS.find_file(import_path + '.py', paths)
|
||
|
|
if node:
|
||
|
|
return node, False, search_path
|
||
|
|
|
||
|
|
return None, False, None
|
||
|
|
|
||
|
|
|
||
|
|
def scan(node, env, path=()):
|
||
|
|
# cache the includes list in node so we only scan it once:
|
||
|
|
if node.includes is not None:
|
||
|
|
includes = node.includes
|
||
|
|
else:
|
||
|
|
includes = find_include_names(node)
|
||
|
|
# Intern the names of the include files. Saves some memory
|
||
|
|
# if the same header is included many times.
|
||
|
|
node.includes = list(map(SCons.Util.silent_intern, includes))
|
||
|
|
|
||
|
|
nodes = []
|
||
|
|
if callable(path):
|
||
|
|
path = path()
|
||
|
|
|
||
|
|
for module, imports in includes:
|
||
|
|
is_relative = module.startswith('.')
|
||
|
|
if is_relative:
|
||
|
|
# This is a relative include, so we must ignore PYTHONPATH.
|
||
|
|
module_lstripped = module.lstrip('.')
|
||
|
|
# One dot is current directory, two is parent, three is
|
||
|
|
# grandparent, etc.
|
||
|
|
num_parents = len(module) - len(module_lstripped) - 1
|
||
|
|
current_dir = node.get_dir()
|
||
|
|
for i in itertools.repeat(None, num_parents):
|
||
|
|
current_dir = current_dir.up()
|
||
|
|
|
||
|
|
search_paths = [current_dir]
|
||
|
|
search_string = module_lstripped
|
||
|
|
else:
|
||
|
|
search_paths = [env.Dir(p) for p in path]
|
||
|
|
search_string = module
|
||
|
|
|
||
|
|
# If there are no paths, there is no point in parsing includes for this
|
||
|
|
# iteration of the loop.
|
||
|
|
if not search_paths:
|
||
|
|
continue
|
||
|
|
|
||
|
|
module_components = [x for x in search_string.split('.') if x]
|
||
|
|
package_dir = None
|
||
|
|
hit_dir = None
|
||
|
|
if not module_components:
|
||
|
|
# This is just a "from . import x".
|
||
|
|
package_dir = search_paths[0]
|
||
|
|
else:
|
||
|
|
# Translate something like "import x.y" to a call to find_import
|
||
|
|
# with 'x/y' as the path. find_import will then determine whether
|
||
|
|
# we can find 'x/y/__init__.py' or 'x/y.py'.
|
||
|
|
import_node, is_dir, hit_dir = find_import(
|
||
|
|
'/'.join(module_components), search_paths)
|
||
|
|
if import_node:
|
||
|
|
nodes.append(import_node)
|
||
|
|
if is_dir:
|
||
|
|
package_dir = import_node.dir
|
||
|
|
|
||
|
|
# If the statement was something like "from x import y, z", whether we
|
||
|
|
# iterate over imports depends on whether x was a package or module.
|
||
|
|
# If it was a module, y and z are just functions so we don't need to
|
||
|
|
# search for them. If it was a package, y and z are either packages or
|
||
|
|
# modules and we do need to search for them.
|
||
|
|
if package_dir and imports:
|
||
|
|
for i in imports:
|
||
|
|
import_node, _, _ = find_import(i, [package_dir])
|
||
|
|
if import_node:
|
||
|
|
nodes.append(import_node)
|
||
|
|
|
||
|
|
# Take a dependency on all __init__.py files from all imported
|
||
|
|
# packages unless it's a relative import. If it's a relative
|
||
|
|
# import, we don't need to take the dependency because Python
|
||
|
|
# requires that all referenced packages have already been imported,
|
||
|
|
# which means that the dependency has already been established.
|
||
|
|
if hit_dir and not is_relative:
|
||
|
|
import_dirs = module_components
|
||
|
|
for i in range(len(import_dirs)):
|
||
|
|
init_path = '/'.join(import_dirs[:i+1] + ['__init__.py'])
|
||
|
|
init_node = SCons.Node.FS.find_file(init_path, [hit_dir])
|
||
|
|
if init_node and init_node not in nodes:
|
||
|
|
nodes.append(init_node)
|
||
|
|
|
||
|
|
return sorted(nodes)
|
||
|
|
|
||
|
|
|
||
|
|
PythonSuffixes = ['.py']
|
||
|
|
PythonScanner = ScannerBase(
|
||
|
|
scan,
|
||
|
|
name='PythonScanner',
|
||
|
|
skeys=PythonSuffixes,
|
||
|
|
path_function=path_function,
|
||
|
|
recursive=True,
|
||
|
|
)
|
||
|
|
|
||
|
|
# Local Variables:
|
||
|
|
# tab-width:4
|
||
|
|
# indent-tabs-mode:nil
|
||
|
|
# End:
|
||
|
|
# vim: set expandtab tabstop=4 shiftwidth=4:
|