bpo-45573: Introduce extension module flags in Makefile (GH-29594)

``configure`` now uses a standardized format to forward state, compiler
flags, and linker flags to ``Makefile``, ``setup.py``, and
``Modules/Setup``. ``makesetup`` use the new variables by default if a
module line does not contain any compiler or linker flags. ``setup.py``
has a new function ``addext()``.

For a module ``egg``, configure adds:

* ``MODULE_EGG`` with value yes, missing, disabled, or n/a
* ``MODULE_EGG_CFLAGS``
* ``MODULE_EGG_LDFLAGS``

``Makefile.pre.in`` may also provide ``MODULE_EGG_DEPS`` that lists
dependencies such as header files and static libs.

Signed-off-by: Christian Heimes <christian@python.org>

2 files changed, 20 insertions, 5 deletions

diff --git a/Modules/Setup b/Modules/Setup
index 608866d..414c6af 100644
--- a/Modules/Setup
+++ b/Modules/Setup
@@ -42,6 +42,15 @@
 # You can also use any Make variable that is detected by configure and
 # defined in Makefile.pre.in, e.g. OpenSSL flags $(OPENSSL_INCLUDES).
 #
+# Rules generated by makesetup use additional variables:
+#
+# - All source file rules have a dependency on $(PYTHON_HEADERS) and on
+#   optional variable $(MODULES_{mod_upper}_DEPS).
+# - If no <cpparg> and no <library> arguments are given, then makesetup
+#   defaults to $(MODULES_{mod_upper}_CFLAGS) cppargs and
+#   $(MODULES_{mod_upper}_LDFLAGS) libraries. The variables are typically
+#   defined by configure.
+#
 # The build process works like this:
 #
 # 1. Build all modules that are declared as static in Modules/Setup,
@@ -149,7 +158,7 @@ time timemodule.c
 #_contextvars _contextvarsmodule.c
 #_csv _csv.c
 #_datetime _datetimemodule.c
-#_decimal _decimal/_decimal.c $(DECIMAL_CFLAGS) $(DECIMAL_LDFLAGS)
+#_decimal _decimal/_decimal.c
 #_heapq _heapqmodule.c
 #_json _json.c
 #_lsprof _lsprof.c rotatingtree.c
@@ -172,8 +181,8 @@ time timemodule.c
 #select selectmodule.c
 
 # XML
-#_elementtree _elementtree.c $(EXPAT_CFLAGS)
-#pyexpat pyexpat.c $(EXPAT_CFLAGS) $(EXPAT_LDFLAGS)
+#_elementtree _elementtree.c
+#pyexpat pyexpat.c
 
 # hashing builtins
 #_blake2 _blake2/blake2module.c _blake2/blake2b_impl.c _blake2/blake2s_impl.c
diff --git a/Modules/makesetup b/Modules/makesetup
index a8817ff..2335724 100755
--- a/Modules/makesetup
+++ b/Modules/makesetup
@@ -154,6 +154,7 @@ sed -e 's/[ 	]*#.*//' -e '/^[ 	]*$/d' |
 		cpps=
 		libs=
 		mods=
+		mods_upper=
 		skip=
 		for arg in $line
 		do
@@ -194,11 +195,17 @@ sed -e 's/[ 	]*#.*//' -e '/^[ 	]*$/d' |
 			*.*)		echo 1>&2 "bad word $arg in $line"
 					exit 1;;
 			-u)		skip=libs; libs="$libs -u";;
-			[a-zA-Z_]*)	mods="$mods $arg";;
+			[a-zA-Z_]*)
+					mods="$mods $arg"
+					mods_upper=$(echo $mods | tr '[a-z]' '[A-Z]');;
 			*)		echo 1>&2 "bad word $arg in $line"
 					exit 1;;
 			esac
 		done
+		if test -z "$cpps" -a -z "$libs"; then
+			cpps="\$(MODULE_${mods_upper}_CFLAGS)"
+			libs="\$(MODULE_${mods_upper}_LDFLAGS)"
+		fi
 		case $doconfig in
 		yes)
 			LIBS="$LIBS $libs"
@@ -245,7 +252,6 @@ sed -e 's/[ 	]*#.*//' -e '/^[ 	]*$/d' |
 			*)
 				cc="$cc \$(PY_BUILTIN_MODULE_CFLAGS)";;
 			esac
-			mods_upper=$(echo $mods | tr '[a-z]' '[A-Z]')
 			# force rebuild when header file or module build flavor (static/shared) is changed
 			rule="$obj: $src \$(MODULE_${mods_upper}_DEPS) \$(PYTHON_HEADERS) Modules/config.c; $cc $cpps -c $src -o $obj"
 			echo "$rule" >>$rulesf