Create hinting stubs for Python IDEs

This implementation formats all signatures in a way
that is known as type hinting files (.pyi).

Usage
-----

The script is to be called by the same Python interpreter that
was used to build PySide. It works with Python 2 and 3.
On Python 3, it performs a self-test.

    python3  sources/pyside2/PySide2/support/generate_pyi.py run

will generate .pyi files for all compiled PySide modules
and places them into site packages to the binaries.
An optional outpath can be specified.

It is planned to call this script automatically after install.

o Local constants are not included, yet.
  Maybe they never will, unless requested.

o The keyword "from" appears 43 times in argument lists.
  It is fixed in Python, only which does not matter.

o When using Python 3.7 or above, it respects Pep 563 and
  avoids imports which are deferred to runtime.

Task-number: PYSIDE-735
Change-Id: I3bcd5d9284b853fe955376bf35c7897e3698da2b
Reviewed-by: Cristian Maureira-Fredes <cristian.maureira-fredes@qt.io>

1 files changed, 239 insertions, 0 deletions

diff --git a/sources/pyside2/PySide2/support/generate_pyi.py b/sources/pyside2/PySide2/support/generate_pyi.py
new file mode 100644
index 000000000..312b1418a
--- /dev/null
+++ b/sources/pyside2/PySide2/support/generate_pyi.py
@@ -0,0 +1,239 @@
+#############################################################################
+##
+## Copyright (C) 2018 The Qt Company Ltd.
+## Contact: https://www.qt.io/licensing/
+##
+## This file is part of Qt for Python.
+##
+## $QT_BEGIN_LICENSE:LGPL$
+## Commercial License Usage
+## Licensees holding valid commercial Qt licenses may use this file in
+## accordance with the commercial license agreement provided with the
+## Software or, alternatively, in accordance with the terms contained in
+## a written agreement between you and The Qt Company. For licensing terms
+## and conditions see https://www.qt.io/terms-conditions. For further
+## information use the contact form at https://www.qt.io/contact-us.
+##
+## GNU Lesser General Public License Usage
+## Alternatively, this file may be used under the terms of the GNU Lesser
+## General Public License version 3 as published by the Free Software
+## Foundation and appearing in the file LICENSE.LGPL3 included in the
+## packaging of this file. Please review the following information to
+## ensure the GNU Lesser General Public License version 3 requirements
+## will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+##
+## GNU General Public License Usage
+## Alternatively, this file may be used under the terms of the GNU
+## General Public License version 2.0 or (at your option) the GNU General
+## Public license version 3 or any later version approved by the KDE Free
+## Qt Foundation. The licenses are as published by the Free Software
+## Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+## included in the packaging of this file. Please review the following
+## information to ensure the GNU General Public License requirements will
+## be met: https://www.gnu.org/licenses/gpl-2.0.html and
+## https://www.gnu.org/licenses/gpl-3.0.html.
+##
+## $QT_END_LICENSE$
+##
+#############################################################################
+
+from __future__ import print_function, absolute_import, unicode_literals
+
+"""
+generate_pyi.py
+
+This script generates the .pyi files for all PySide modules.
+"""
+
+import sys
+import os
+import io
+import re
+import PySide2
+import subprocess
+import argparse
+from contextlib import contextmanager
+from textwrap import dedent
+
+from PySide2.support.signature import inspect
+from PySide2.support.signature.lib.enum_sig import HintingEnumerator
+from PySide2 import *  # all modules
+
+# Make sure not to get .pyc in Python2.
+sourcepath = os.path.splitext(__file__)[0] + ".py"
+
+# Can we use forward references?
+USE_PEP563 = sys.version_info[:2] >= (3, 7)
+
+indent = " " * 4
+
+class Writer(object):
+    def __init__(self, outfile):
+        self.outfile = outfile
+
+    def print(self, *args, **kw):
+        if self.outfile:
+            if args == ():
+                # This is a Python 2.7 glitch.
+                print("", file=self.outfile, **kw)
+            else:
+                print(*args, file=self.outfile, **kw)
+
+
+class Formatter(Writer):
+    """
+    Formatter is formatting the signature listing of an enumerator.
+
+    It is written as context managers in order to avoid many callbacks.
+    The separation in formatter and enumerator is done to keep the
+    unrelated tasks of enumeration and formatting apart.
+    """
+    @contextmanager
+    def module(self, mod_name):
+        self.mod_name = mod_name
+        self.print("# Module", mod_name)
+        self.print("import shiboken2 as Shiboken")
+        from PySide2.support.signature import typing
+        typing_str = "from PySide2.support.signature import typing"
+        self.print(typing_str)
+        self.print()
+        self.print("class Object(object): pass")
+        self.print()
+        self.print("Shiboken.Object = Object")
+        self.print()
+        # This line will be replaced by the missing imports.
+        self.print("IMPORTS")
+        yield
+
+    @contextmanager
+    def klass(self, class_name, class_str):
+        self.class_name = class_name
+        spaces = ""
+        while "." in class_name:
+            spaces += indent
+            class_name = class_name.split(".", 1)[-1]
+            class_str = class_str.split(".", 1)[-1]
+        self.print()
+        if not spaces:
+            self.print()
+        here = self.outfile.tell()
+        self.print("{spaces}class {class_str}:".format(**locals()))
+        self.print()
+        pos = self.outfile.tell()
+        self.spaces = spaces
+        yield
+        if pos == self.outfile.tell():
+            # we have not written any function
+            self.outfile.seek(here)
+            self.outfile.truncate()
+            # Note: we cannot use class_str when we have no body.
+            self.print("{spaces}class {class_name}: ...".format(**locals()))
+        if "<" in class_name:
+            # This is happening in QtQuick for some reason:
+            ## class QSharedPointer<QQuickItemGrabResult >:
+            # We simply skip over this class.
+            self.outfile.seek(here)
+            self.outfile.truncate()
+
+    @contextmanager
+    def function(self, func_name, signature):
+        key = func_name
+        spaces = indent + self.spaces if self.class_name else ""
+        if type(signature) == type([]):
+            for sig in signature:
+                self.print('{spaces}@typing.overload'.format(**locals()))
+                self._function(func_name, sig, spaces)
+        else:
+            self._function(func_name, signature, spaces)
+        yield key
+
+    def _function(self, func_name, signature, spaces):
+        # this would be nicer to get somehow together with the signature
+        is_meth = re.match("\((\w*)", str(signature)).group(1) == "self"
+        if self.class_name and not is_meth:
+            self.print('{spaces}@staticmethod'.format(**locals()))
+        self.print('{spaces}def {func_name}{signature}: ...'.format(**locals()))
+
+
+def get_license_text():
+    with io.open(sourcepath) as f:
+        lines = f.readlines()
+        license_line = next((lno for lno, line in enumerate(lines)
+                             if "$QT_END_LICENSE$" in line))
+    return "".join(lines[:license_line + 3])
+
+
+def find_imports(text):
+    return [imp for imp in PySide2.__all__ if imp + "." in text]
+
+
+def generate_pyi(mod_name, outpath):
+    module = sys.modules[mod_name]
+    mod_fullname = module.__file__
+    plainname = os.path.basename(mod_fullname).split(".")[0]
+    if not outpath:
+        outpath = os.path.dirname(mod_fullname)
+    outfilepath = os.path.join(outpath, plainname + ".pyi")
+    outfile = io.StringIO()
+    fmt = Formatter(outfile)
+    enu = HintingEnumerator(fmt)
+    fmt.print(get_license_text())
+    need_imports = not USE_PEP563
+    if USE_PEP563:
+        fmt.print("from __future__ import annotations")
+        fmt.print()
+    fmt.print(dedent('''\
+        """
+        This file contains the exact signatures for all functions in PySide
+        for module '{mod_fullname}',
+        except for defaults which are replaced by "...".
+        """
+        '''.format(**locals())))
+    enu.module(mod_name)
+    fmt.print("# eof")
+    with io.open(outfilepath, "w") as realfile:
+        wr = Writer(realfile)
+        outfile.seek(0)
+        while True:
+            line = outfile.readline()
+            if not line:
+                break
+            line = line.rstrip()
+            # we remove the IMPORTS marker and insert imports if needed
+            if line == "IMPORTS":
+                if need_imports:
+                    for imp in find_imports(outfile.getvalue()):
+                        imp = "PySide2." + imp
+                        if imp != mod_name:
+                            wr.print("import " + imp)
+                wr.print("import " + mod_name)
+                wr.print()
+                wr.print()
+            else:
+                wr.print(line)
+
+    print(outfilepath, file=sys.stderr)
+    if sys.version_info[0] == 3:
+        # Python 3: We can check the file directly if the syntax is ok.
+        subprocess.check_output([sys.executable, outfilepath])
+
+
+def generate_all_pyi(outpath=None):
+    for mod_name in PySide2.__all__:
+        generate_pyi("PySide2." + mod_name, outpath)
+
+
+if __name__ == "__main__":
+    parser = argparse.ArgumentParser(
+        description="This script generates the .pyi file for all PySide modules.")
+    subparsers = parser.add_subparsers(dest="command", metavar="", title="required argument")
+    # create the parser for the "run" command
+    parser_run = subparsers.add_parser("run", help="run the generation")
+    parser_run.add_argument("--outpath")
+    args = parser.parse_args()
+    outpath = args.outpath
+    if not outpath or os.path.exists(outpath):
+        generate_all_pyi(args.outpath)
+    else:
+        print("Please create the directory {outpath} before generating.".format(**locals()))
+