package/python-flit-core: new package/infrastructure

This adds pep517(needed for flit-core to build itself) and flit python
package types.

We need to add an installer script and pass it appropriate options for
installing pep517 wheels generated by python-pypa-build during the
build stage. Unfortunately it seems pep517 does not support builds
without using the wheel format.

We also need to add a patch fixing the version parser in flit-core.

Signed-off-by: James Hilliard <james.hilliard1@gmail.com>
[Arnout:
 - fix indentation in pkg-python.mk (tabs, not spaces);
 - use the new _CMD variables instead of duplicating the entire _CMDS
   definitions;
 - no need to filter dependencies (they're not self-referencing);
 - _NEEDS_HOST_PYTHON no longer exists;
 - host-python-pypa-build gets added to DEPENDENCIES automatically.
]
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>

package/pkg-python.mk

@@ -103,6 +103,47 @@ HOST_PKG_PYTHON_SETUPTOOLS_INSTALL_OPTS = \
 	--root=/ \
 	--single-version-externally-managed
 
+# Target pep517-based packages
+PKG_PYTHON_PEP517_ENV = \
+	_PYTHON_SYSCONFIGDATA_NAME="$(PKG_PYTHON_SYSCONFIGDATA_NAME)" \
+	PATH=$(BR_PATH) \
+	$(TARGET_CONFIGURE_OPTS) \
+	PYTHONPATH="$(PYTHON3_PATH)" \
+	PYTHONNOUSERSITE=1 \
+	_python_sysroot=$(STAGING_DIR) \
+	_python_prefix=/usr \
+	_python_exec_prefix=/usr
+
+PKG_PYTHON_PEP517_INSTALL_TARGET_OPTS = \
+	--interpreter=/usr/bin/python \
+	--script-kind=posix \
+	--purelib=$(TARGET_DIR)/lib/python$(PYTHON3_VERSION_MAJOR)/site-packages \
+	--headers=$(TARGET_DIR)/usr/include/python$(PYTHON3_VERSION_MAJOR)  \
+	--scripts=$(TARGET_DIR)/usr/bin \
+	--data=$(TARGET_DIR)/usr
+
+PKG_PYTHON_PEP517_INSTALL_STAGING_OPTS = \
+	--interpreter=/usr/bin/python \
+	--script-kind=posix \
+	--purelib=$(STAGING_DIR)/lib/python$(PYTHON3_VERSION_MAJOR)/site-packages \
+	--headers=$(STAGING_DIR)/usr/include/python$(PYTHON3_VERSION_MAJOR)  \
+	--scripts=$(STAGING_DIR)/usr/bin \
+	--data=$(STAGING_DIR)/usr
+
+# Host pep517-based packages
+HOST_PKG_PYTHON_PEP517_ENV = \
+	PATH=$(BR_PATH) \
+	PYTHONNOUSERSITE=1 \
+	$(HOST_CONFIGURE_OPTS)
+
+HOST_PKG_PYTHON_PEP517_INSTALL_OPTS = \
+	--interpreter=/usr/bin/python \
+	--script-kind=posix \
+	--purelib=$(HOST_DIR)/lib/python$(PYTHON3_VERSION_MAJOR)/site-packages \
+	--headers=$(HOST_DIR)/usr/include/python$(PYTHON3_VERSION_MAJOR)  \
+	--scripts=$(HOST_DIR)/usr/bin \
+	--data=$(HOST_DIR)/usr
+
 ################################################################################
 # inner-python-package -- defines how the configuration, compilation
 # and installation of a Python package should be done, implements a
@@ -152,8 +193,19 @@ $(2)_BASE_ENV = $$(HOST_PKG_PYTHON_SETUPTOOLS_ENV)
 $(2)_BASE_BUILD_CMD = setup.py build
 $(2)_BASE_INSTALL_CMD = setup.py install $$(HOST_PKG_PYTHON_SETUPTOOLS_INSTALL_OPTS)
 endif
+else ifneq ($$(filter flit pep517,$$($(2)_SETUP_TYPE)),)
+ifeq ($(4),target)
+$(2)_BASE_ENV = $$(PKG_PYTHON_PEP517_ENV)
+$(2)_BASE_BUILD_CMD = -m build -n -w
+$(2)_BASE_INSTALL_TARGET_CMD = $(TOPDIR)/support/scripts/pyinstaller.py dist/* $$(PKG_PYTHON_PEP517_INSTALL_TARGET_OPTS)
+$(2)_BASE_INSTALL_STAGING_CMD = $(TOPDIR)/support/scripts/pyinstaller.py dist/* $$(PKG_PYTHON_PEP517_INSTALL_STAGING_OPTS)
 else
-$$(error "Invalid $(2)_SETUP_TYPE. Valid options are 'distutils' or 'setuptools'")
+$(2)_BASE_ENV = $$(HOST_PKG_PYTHON_PEP517_ENV)
+$(2)_BASE_BUILD_CMD = -m build -n -w
+$(2)_BASE_INSTALL_CMD = $(TOPDIR)/support/scripts/pyinstaller.py dist/* $$(HOST_PKG_PYTHON_PEP517_INSTALL_OPTS)
+endif
+else
+$$(error "Invalid $(2)_SETUP_TYPE. Valid options are 'distutils', 'setuptools', 'pep517' or 'flit'.")
 endif
 
 # Target packages need both the python interpreter on the target (for
@@ -172,6 +224,11 @@ endif # ($(4),target)
 #
 ifeq ($$($(2)_SETUP_TYPE),setuptools)
 $(2)_DEPENDENCIES += $$(if $$(filter host-python-setuptools,$(1)),,host-python-setuptools)
+else ifneq ($$(filter flit pep517,$$($(2)_SETUP_TYPE)),)
+$(2)_DEPENDENCIES += host-python-pypa-build host-python-installer
+ifeq ($$($(2)_SETUP_TYPE),flit)
+$(2)_DEPENDENCIES += host-python-flit-core
+endif
 endif # SETUP_TYPE
 
 # Python interpreter to use for building the package.

package/python-flit-core/0001-Fix-ast-version-parser-for-multiple-assignments.patch

@@ -0,0 +1,80 @@
+From 2cd8b5708be88b90ea2fa0fb35407a5ec2038c8e Mon Sep 17 00:00:00 2001
+From: James Hilliard <james.hilliard1@gmail.com>
+Date: Sat, 27 Nov 2021 02:36:15 -0700
+Subject: [PATCH] Fix ast version parser for multiple assignments
+
+Signed-off-by: James Hilliard <james.hilliard1@gmail.com>
+[Upstream status:
+https://github.com/takluyver/flit/pull/474]
+---
+ flit_core/common.py                 | 21 +++++++++++--------
+ .../tests/samples/moduleunimportabledouble.py |  8 +++++++
+ flit_core/tests/test_common.py      |  5 +++++
+ 3 files changed, 25 insertions(+), 9 deletions(-)
+ create mode 100644 flit_core/tests/samples/moduleunimportabledouble.py
+
+diff --git a/flit_core/common.py b/flit_core/common.py
+index f1f378f..86bcf4b 100644
+--- a/flit_core/common.py
++++ b/flit_core/common.py
+@@ -132,15 +132,18 @@ def get_docstring_and_version_via_ast(target):
+     for child in node.body:
+         # Only use the version from the given module if it's a simple
+         # string assignment to __version__
+-        is_version_str = (
+-                isinstance(child, ast.Assign)
+-                and len(child.targets) == 1
+-                and isinstance(child.targets[0], ast.Name)
+-                and child.targets[0].id == "__version__"
+-                and isinstance(child.value, ast.Str)
+-        )
+-        if is_version_str:
+-            version = child.value.s
++        if isinstance(child, ast.Assign):
++            for target in child.targets:
++                is_version_str = (
++                    isinstance(target, ast.Name)
++                    and target.id == "__version__"
++                    and isinstance(child.value, ast.Str)
++                )
++                if is_version_str:
++                    version = child.value.s
++                    break
++            else:
++                continue
+             break
+     else:
+         version = None
+diff --git a/flit_core/tests/samples/moduleunimportabledouble.py b/flit_core/tests/samples/moduleunimportabledouble.py
+new file mode 100644
+index 0000000..42d51f3
+--- /dev/null
++++ b/flit_core/tests/samples/moduleunimportabledouble.py
+@@ -0,0 +1,8 @@
++
++"""
++A sample unimportable module with double assignment
++"""
++
++raise ImportError()
++
++VERSION = __version__ = "0.1"
+diff --git a/flit_core/tests/test_common.py b/flit_core/tests/test_common.py
+index 02cfab7..42e230b 100644
+--- a/flit_core/tests/test_common.py
++++ b/flit_core/tests/test_common.py
+@@ -70,6 +70,11 @@ class ModuleTests(TestCase):
+                                 'version': '0.1'}
+                          )
+ 
++        info = get_info_from_module(Module('moduleunimportabledouble', samples_dir))
++        self.assertEqual(info, {'summary': 'A sample unimportable module with double assignment',
++                                'version': '0.1'}
++                         )
++
+         info = get_info_from_module(Module('module1', samples_dir / 'constructed_version'))
+         self.assertEqual(info, {'summary': 'This module has a __version__ that requires runtime interpretation',
+                                 'version': '1.2.3'}
+-- 
+2.33.1
+

package/python-flit-core/python-flit-core.hash

@@ -0,0 +1,3 @@
+# md5, sha256 from https://pypi.org/pypi/flit_core/json
+md5  82143536b81f148851a0213305838e53  flit_core-3.6.0.tar.gz
+sha256  5892962ab8b8ea945835b3a288fe9dd69316f1903d5288c3f5cafdcdd04756ad  flit_core-3.6.0.tar.gz

package/python-flit-core/python-flit-core.mk

@@ -0,0 +1,13 @@
+################################################################################
+#
+# python-flit-core
+#
+################################################################################
+
+PYTHON_FLIT_CORE_VERSION = 3.6.0
+PYTHON_FLIT_CORE_SOURCE = flit_core-$(PYTHON_FLIT_CORE_VERSION).tar.gz
+PYTHON_FLIT_CORE_SITE = https://files.pythonhosted.org/packages/08/e9/0653f7783ba2ec2f954f19442878427f1d5bfccb01842d354453c2809b22
+PYTHON_FLIT_CORE_LICENSE = BSD-3-Clause
+PYTHON_FLIT_CORE_SETUP_TYPE = pep517
+
+$(eval $(host-python-package))

support/scripts/pyinstaller.py

@@ -0,0 +1,69 @@
+#!/usr/bin/env python3
+
+import argparse
+import glob
+
+from installer import install
+from installer.destinations import SchemeDictionaryDestination
+from installer.sources import WheelFile
+
+
+def main():
+    """Entry point for CLI."""
+    ap = argparse.ArgumentParser("python pyinstaller.py")
+    ap.add_argument("wheel_file", help="Path to a .whl file to install")
+
+    ap.add_argument(
+        "--interpreter", required=True, help="Interpreter path to be used in scripts"
+    )
+    ap.add_argument(
+        "--script-kind",
+        required=True,
+        choices=["posix", "win-ia32", "win-amd64", "win-arm", "win-arm64"],
+        help="Kind of launcher to create for each script",
+    )
+
+    dest_args = ap.add_argument_group("Destination directories")
+    dest_args.add_argument(
+        "--purelib",
+        required=True,
+        help="Directory for platform-independent Python modules",
+    )
+    dest_args.add_argument(
+        "--platlib",
+        help="Directory for platform-dependent Python modules (same as purelib "
+        "if not specified)",
+    )
+    dest_args.add_argument(
+        "--headers", required=True, help="Directory for C header files"
+    )
+    dest_args.add_argument(
+        "--scripts", required=True, help="Directory for executable scripts"
+    )
+    dest_args.add_argument(
+        "--data", required=True, help="Directory for external data files"
+    )
+    args = ap.parse_args()
+
+    destination = SchemeDictionaryDestination(
+        {
+            "purelib": args.purelib,
+            "platlib": args.platlib if args.platlib is not None else args.purelib,
+            "headers": args.headers,
+            "scripts": args.scripts,
+            "data": args.data,
+        },
+        interpreter=args.interpreter,
+        script_kind=args.script_kind,
+    )
+
+    with WheelFile.open(glob.glob(args.wheel_file)[0]) as source:
+        install(
+            source=source,
+            destination=destination,
+            additional_metadata={},
+        )
+
+
+if __name__ == "__main__":
+    main()