meson: port python bindings to build natively via meson and meson-python

We get full build parallelism and fewer confusing ancient distutils
paths. The python wheels build fully standalone, including linking
libfdt as a static library.

For convenience, when running pip install a meson option is passed that
prevents building tools or installing headers/pkgconfig files.
meson-python would otherwise include them in the wheel itself, in case
they are needed, but this is essentially a bit useless so don't bother.

The old setuptools-based build is now redundant and goes away.

Signed-off-by: Eli Schwartz <eschwartz@gentoo.org>
Message-ID: <20250430152601.43554-3-eschwartz@gentoo.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

Makefile

@@ -31,7 +31,6 @@ BISON = bison
 LEX = flex
 SWIG = swig
 PKG_CONFIG ?= pkg-config
-PYTHON ?= python3
 
 INSTALL = install
 INSTALL_PROGRAM = $(INSTALL)
@@ -47,8 +46,6 @@ INCLUDEDIR = $(PREFIX)/include
 HOSTOS := $(shell uname -s | tr '[:upper:]' '[:lower:]' | \
 	    sed -e 's/\(cygwin\|msys\).*/\1/')
 
-NO_PYTHON ?= 0
-
 NO_VALGRIND := $(shell $(PKG_CONFIG) --exists valgrind; echo $$?)
 ifeq ($(NO_VALGRIND),1)
 	CPPFLAGS += -DNO_VALGRIND
@@ -158,29 +155,6 @@ SCRIPTS = dtdiff
 
 all: $(BIN) libfdt
 
-# We need both Python and swig to build/install pylibfdt.
-# This builds the given make ${target} if those deps are found.
-check_python_deps = \
-	if $(PKG_CONFIG) --cflags $(PYTHON) >/dev/null 2>&1; then \
-		if which swig >/dev/null 2>&1; then \
-			can_build=yes; \
-		fi; \
-	fi; \
-	if [ "$${can_build}" = "yes" ]; then \
-		$(MAKE) $${target}; \
-	else \
-		echo "\#\# Skipping pylibfdt (install python dev and swig to build)"; \
-	fi ;
-
-.PHONY: maybe_pylibfdt
-maybe_pylibfdt: FORCE
-	target=pylibfdt; $(check_python_deps)
-
-ifeq ($(NO_PYTHON),0)
-all: maybe_pylibfdt
-endif
-
-
 ifneq ($(DEPTARGETS),)
 ifneq ($(MAKECMDGOALS),libfdt)
 -include $(DTC_OBJS:%.o=%.d)
@@ -254,14 +228,6 @@ install-includes:
 
 install: install-bin install-lib install-includes
 
-.PHONY: maybe_install_pylibfdt
-maybe_install_pylibfdt: FORCE
-	target=install_pylibfdt; $(check_python_deps)
-
-ifeq ($(NO_PYTHON),0)
-install: maybe_install_pylibfdt
-endif
-
 $(VERSION_FILE): Makefile FORCE
 	$(call filechk,version)
 
@@ -287,16 +253,6 @@ dist:
 		gzip -9 > ../dtc-$(dtc_version).tar.gz
 
 
-#
-# Rules for pylibfdt
-#
-PYLIBFDT_dir = pylibfdt
-
-include $(PYLIBFDT_dir)/Makefile.pylibfdt
-
-.PHONY: pylibfdt
-pylibfdt: $(PYLIBFDT_dir)/_libfdt.so
-
 #
 # Release signing and uploading
 # This is for maintainer convenience, don't try this at home.
@@ -330,9 +286,6 @@ TESTS_BIN += fdtput
 TESTS_BIN += fdtget
 TESTS_BIN += fdtdump
 TESTS_BIN += fdtoverlay
-ifeq ($(NO_PYTHON),0)
-TESTS_PYLIBFDT += maybe_pylibfdt
-endif
 
 ifneq ($(MAKECMDGOALS),libfdt)
 include tests/Makefile.tests
@@ -344,7 +297,7 @@ endif
 STD_CLEANFILES = *~ *.o *.$(SHAREDLIB_EXT) *.d *.a *.i *.s core a.out vgcore.* \
 	*.tab.[ch] *.lex.c *.output
 
-clean: libfdt_clean pylibfdt_clean tests_clean
+clean: libfdt_clean tests_clean
 	@$(VECHO) CLEAN
 	rm -f $(STD_CLEANFILES)
 	rm -f $(VERSION_FILE)