pylibfdt: Use setuptools_scm for the version

The DTC version in version_gen.h causes a warning with setuptools:

setuptools/dist.py:501: UserWarning: The version specified ('1.6.1-g5454474d') \
is an invalid version, this may not work as expected with newer versions of \
setuptools, pip, and PyPI. Please see PEP 440 for more details.

It also creates an unnecessary dependency on the rest of the build
system(s). Switch to use setuptools_scm instead to get the version for
pylibfdt.

Signed-off-by: Rob Herring <robh@kernel.org>
Message-Id: <20211111011135.2386773-3-robh@kernel.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

pylibfdt/Makefile.pylibfdt

@@ -16,7 +16,7 @@ ifndef V
 SETUPFLAGS += --quiet
 endif
 
-$(PYMODULE): $(PYLIBFDT_srcs) $(LIBFDT_archive) $(SETUP) $(VERSION_FILE)
+$(PYMODULE): $(PYLIBFDT_srcs) $(LIBFDT_archive) $(SETUP)
 	@$(VECHO) PYMOD $@
 	$(PYTHON) $(SETUP) $(SETUPFLAGS) build_ext --build-lib=$(PYLIBFDT_dir)
 

pylibfdt/meson.build

@@ -5,7 +5,6 @@ custom_target(
   'pylibfdt',
   input: 'libfdt.i',
   output: '_libfdt.so',
-  depends: version_gen_h,
   command: [setup_py, 'build_ext', '--build-lib=' + meson.current_build_dir()],
   build_by_default: true,
 )

pylibfdt/setup.py

@@ -15,10 +15,6 @@ import os
 import re
 import sys
 
-
-VERSION_PATTERN = '^#define DTC_VERSION "DTC ([^"]*)"$'
-
-
 def get_top_builddir():
     if '--top-builddir' in sys.argv:
         index = sys.argv.index('--top-builddir')
@@ -27,18 +23,9 @@ def get_top_builddir():
     else:
         return os.getcwd()
 
-
 srcdir = os.path.dirname(os.path.abspath(sys.argv[0]))
 top_builddir = get_top_builddir()
 
-
-def get_version():
-    version_file = os.path.join(top_builddir, 'version_gen.h')
-    f = open(version_file, 'rt')
-    m = re.match(VERSION_PATTERN, f.readline())
-    return m.group(1)
-
-
 libfdt_module = Extension(
     '_libfdt',
     sources=[os.path.join(srcdir, 'libfdt.i')],
@@ -50,7 +37,10 @@ libfdt_module = Extension(
 
 setup(
     name='libfdt',
-    version=get_version(),
+    use_scm_version={
+        "root": os.path.join(srcdir, '..'),
+    },
+    setup_requires = ['setuptools_scm'],
     author='Simon Glass <sjg@chromium.org>',
     description='Python binding for libfdt',
     ext_modules=[libfdt_module],