From 5586dda17823fae0695d3eded69b46ebe7bc3455 Mon Sep 17 00:00:00 2001
From: Christian Heimes <christian@python.org>
Date: Sat, 23 Oct 2021 13:40:48 +0200
Subject: [PATCH 1/2] bpo-45548: Put Modules/Setup extensions into builddir

Modules/Setup used to put shared extensions into ``./Modules/``
directory. Now it puts the shared extensions in the same directory
library directory ``./build/lib.$plat-$ver`` as distutils.

The change makes the shared modules importable and fixes build issues.

Signed-off-by: Christian Heimes <christian@python.org>
---
 Makefile.pre.in   |  1 +
 Modules/makesetup | 18 +++++++++++++++---
 setup.py          |  5 +++++
 3 files changed, 21 insertions(+), 3 deletions(-)

diff --git a/Makefile.pre.in b/Makefile.pre.in
index 7d403663cec0b8d..6cd8af128015e6b 100644
--- a/Makefile.pre.in
+++ b/Makefile.pre.in
@@ -21,6 +21,7 @@
 # === Variables set by makesetup ===
 
 MODBUILT_NAMES=    _MODBUILT_NAMES_
+MODBUILT_SHARED_NAMES=    _MODBUILT_SHARED_NAMES_
 MODDISABLED_NAMES= _MODDISABLED_NAMES_
 MODOBJS=           _MODOBJS_
 MODLIBS=           _MODLIBS_
diff --git a/Modules/makesetup b/Modules/makesetup
index 849f15fddaab0aa..085ed47ff5c61e3 100755
--- a/Modules/makesetup
+++ b/Modules/makesetup
@@ -111,9 +111,11 @@ sed -e 's/[ 	]*#.*//' -e '/^[ 	]*$/d' |
 	trap 'rm -f $rulesf' 0 1 2 3
 	echo "
 # Rules appended by makesetup
+\$(SHAREDMODS): pybuilddir.txt
 " >$rulesf
 	DEFS=
 	BUILT=
+	BUILT_SHARED=
 	DISABLED=
 	MODS=
 	SHAREDMODS=
@@ -244,9 +246,15 @@ sed -e 's/[ 	]*#.*//' -e '/^[ 	]*$/d' |
 		esac
 		for mod in $mods
 		do
-			file="$srcdir/$mod\$(EXT_SUFFIX)"
 			case $doconfig in
-			no)	SHAREDMODS="$SHAREDMODS $file";;
+			no)
+				file="\$(PYBUILDDIR)/$mod\$(EXT_SUFFIX)"
+				SHAREDMODS="$SHAREDMODS $file"
+				BUILT_SHARED="$BUILT_SHARED $mod"
+				;;
+			*)
+				file="\$(srcdir)/$mod\$(EXT_SUFFIX)"
+				;;
 			esac
 			rule="$file: $objs"
 			rule="$rule; \$(BLDSHARED) $objs $libs $ExtraLibs -o \$@"
@@ -256,7 +264,10 @@ sed -e 's/[ 	]*#.*//' -e '/^[ 	]*$/d' |
 
 	case $SHAREDMODS in
 	'')	;;
-	*)	DEFS="SHAREDMODS=$SHAREDMODS$NL$DEFS";;
+	*)
+		DEFS="PYBUILDDIR=\$(file < pybuilddir.txt)$NL$DEFS"
+		DEFS="SHAREDMODS=$SHAREDMODS$NL$DEFS"
+		;;
 	esac
 
 	case $noobjects in
@@ -296,6 +307,7 @@ sed -e 's/[ 	]*#.*//' -e '/^[ 	]*$/d' |
 		str="# Generated automatically from $makepre by makesetup."
 		echo "$str" >>$sedf
 		echo "s%_MODBUILT_NAMES_%$BUILT%" >>$sedf
+		echo "s%_MODBUILT_SHARED_NAMES_%$BUILT_SHARED%" >>$sedf
 		echo "s%_MODDISABLED_NAMES_%$DISABLED%" >>$sedf
 		echo "s%_MODOBJS_%$OBJS%" >>$sedf
 		echo "s%_MODLIBS_%$LIBS%" >>$sedf
diff --git a/setup.py b/setup.py
index f32dd4c6e5e1455..84155ff88b44fef 100644
--- a/setup.py
+++ b/setup.py
@@ -431,6 +431,7 @@ def remove_configured_extensions(self):
         # built modules and the disabled modules as configured by the Setup
         # files.
         sysconf_built = sysconfig.get_config_var('MODBUILT_NAMES').split()
+        sysconf_built_shared = sysconfig.get_config_var('MODBUILT_SHARED_NAMES').split()
         sysconf_dis = sysconfig.get_config_var('MODDISABLED_NAMES').split()
 
         mods_built = []
@@ -449,6 +450,10 @@ def remove_configured_extensions(self):
                                mods_configured]
             # Remove the shared libraries built by a previous build.
             for ext in mods_configured:
+                # don't remove shared extensions that have been
+                # declared in Modules/Setup and built by Makefile
+                if ext.name in sysconf_built_shared:
+                    continue
                 fullpath = self.get_ext_fullpath(ext.name)
                 if os.path.exists(fullpath):
                     os.unlink(fullpath)

From 632bb41059e841f19115d3b143c7684810e7e096 Mon Sep 17 00:00:00 2001
From: Christian Heimes <christian@python.org>
Date: Mon, 25 Oct 2021 13:48:36 +0200
Subject: [PATCH 2/2] blurb

---
 .../NEWS.d/next/Build/2021-10-25-13-48-27.bpo-45548.kSFSrQ.rst | 3 +++
 1 file changed, 3 insertions(+)
 create mode 100644 Misc/NEWS.d/next/Build/2021-10-25-13-48-27.bpo-45548.kSFSrQ.rst

diff --git a/Misc/NEWS.d/next/Build/2021-10-25-13-48-27.bpo-45548.kSFSrQ.rst b/Misc/NEWS.d/next/Build/2021-10-25-13-48-27.bpo-45548.kSFSrQ.rst
new file mode 100644
index 000000000000000..18d7c405fe70ee5
--- /dev/null
+++ b/Misc/NEWS.d/next/Build/2021-10-25-13-48-27.bpo-45548.kSFSrQ.rst
@@ -0,0 +1,3 @@
+``Modules/Setup`` now puts shared extensions in the same directory as
+distutils. Before the change, ``makesetup`` created shared libraries in
+``Modules/`` directory, which is not on the import path.