From a24ab56da8b0382c4cc58d196fc9eab3bec485d9 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Daniel=20P=2E=20Berrang=C3=A9?= <berrange@redhat.com>
Date: Wed, 1 Feb 2023 11:19:16 -0500
Subject: [PATCH] build-aux: introduce 'black' tool for python formatting
MIME-Version: 1.0
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The 'black' tool is intended to be an opinionated formatting
tool for python code. It is complementary to flake8 which
validates coding bad practices, but (mostly) ignores code
layout issues.

Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
---
 build-aux/Makefile.in     |  1 +
 build-aux/meson.build     |  5 +++++
 build-aux/syntax-check.mk | 18 ++++++++++++++++++
 meson.build               |  1 +
 4 files changed, 25 insertions(+)

diff --git a/build-aux/Makefile.in b/build-aux/Makefile.in
index 7ee4680847..db44ee36a4 100644
--- a/build-aux/Makefile.in
+++ b/build-aux/Makefile.in
@@ -3,6 +3,7 @@
 top_srcdir = @top_srcdir@
 top_builddir = @top_builddir@
 FLAKE8 = @flake8_path@
+BLACK = @black_path@
 RUNUTF8 = @runutf8@
 PYTHON = @PYTHON3@
 GREP = @GREP@
diff --git a/build-aux/meson.build b/build-aux/meson.build
index f96d46c445..06be6ab6c8 100644
--- a/build-aux/meson.build
+++ b/build-aux/meson.build
@@ -5,6 +5,10 @@ if git and tests_enabled[0]
   if flake8_prog.found()
     flake8_path = flake8_prog.full_path()
   endif
+  black_path = ''
+  if black_prog.found()
+    black_path = black_prog.full_path()
+  endif
 
   if host_machine.system() == 'freebsd' or host_machine.system() == 'darwin'
     make_prog = find_program('gmake')
@@ -35,6 +39,7 @@ if git and tests_enabled[0]
     'top_srcdir': meson.project_source_root(),
     'top_builddir': meson.project_build_root(),
     'flake8_path': flake8_path,
+    'black_path': black_path,
     'runutf8': ' '.join(runutf8),
     'PYTHON3': python3_prog.full_path(),
     'GREP': grep_prog.full_path(),
diff --git a/build-aux/syntax-check.mk b/build-aux/syntax-check.mk
index 070737842e..721e82f49a 100644
--- a/build-aux/syntax-check.mk
+++ b/build-aux/syntax-check.mk
@@ -608,6 +608,16 @@ sc_flake8:
 		echo 'skipping test $@: flake8 not installed' 1>&2; \
 	fi
 
+sc_black:
+	if [ -n "$(BLACK)" ]; then \
+		DOT_PY=$$($(VC_LIST_EXCEPT) | $(GREP) '\.py$$'); \
+		BANG_PY=$$($(VC_LIST_EXCEPT) | xargs grep -l '^#!/usr/bin/env python3$$'); \
+		ALL_PY=$$(printf "%s\n%s" "$$DOT_PY" "$$BANG_PY" | sort -u); \
+		echo "$$ALL_PY" | xargs --no-run-if-empty $(BLACK) --check; \
+	else \
+		echo 'skipping test $@: black not installed' 1>&2; \
+	fi
+
 # mymain() in test files should use return, not exit, for nicer output
 sc_prohibit_exit_in_tests:
 	@prohibit='\<exit *\(' \
@@ -1307,6 +1317,11 @@ syntax-check: sc_spacing-check \
 		echo "* flake8 not installed, sc_flake8 has been skipped  *" >&2; \
 		echo "*****************************************************" >&2; \
 	fi
+	if [ -z "$(BLACK)" ]; then \
+		echo "*****************************************************" >&2; \
+		echo "* black not installed, sc_black has been skipped    *" >&2; \
+		echo "*****************************************************" >&2; \
+	fi
 endif
 
 # Don't include duplicate header in the source (either *.c or *.h)
@@ -1486,6 +1501,9 @@ exclude_file_name_regexp--sc_prohibit_select = \
   ^build-aux/syntax-check\.mk|src/util/vireventglibwatch\.c|tests/meson\.build$$
 
 
+exclude_file_name_regexp--sc_black = \
+  ^tools/|src/|tests/|ci/|run\.in|scripts/[^/]*\.py
+
 ## -------------- ##
 ## Implementation ##
 ## -------------- ##
diff --git a/meson.build b/meson.build
index dc0969abcc..5b095bb809 100644
--- a/meson.build
+++ b/meson.build
@@ -809,6 +809,7 @@ endforeach
 
 optional_programs = [
   'augparse',
+  'black',
   'dmidecode',
   'ebtables',
   'flake8',