From dc82989dd2747db0384cafb3b310f2e8792d5c24 Mon Sep 17 00:00:00 2001
From: Nathan Cutler <ncutler@suse.com>
Date: Sun, 28 Jan 2018 00:29:16 +0100
Subject: [PATCH] Makefile: try harder to use correct Python interpreter

In a Python 3-only system, there might not be an executable in the
PATH to satisfy "python". In configure we attempt to find the "right"
python command for the system we happen to be running in. With this
patch, we let configure save this command to a temporary file.

Subsequently, when make is run, it will find the command in that file
and use it (or fall back to "python" if the file doesn't exist for
whatever reason).

Change-Id: If65f2fc505a924b940b2054882504b8cbe1a53aa
Signed-off-by: Nathan Cutler <ncutler@suse.com>
Reviewed-on: https://review.gerrithub.io/397022
Tested-by: SPDK Automated Test System <sys_sgsw@intel.com>
Reviewed-by: Daniel Verkamp <daniel.verkamp@intel.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>
---
 .gitignore | 1 +
 Makefile   | 4 +++-
 configure  | 2 ++
 3 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/.gitignore b/.gitignore
index b7d5fe968..0a193fea7 100644
--- a/.gitignore
+++ b/.gitignore
@@ -26,3 +26,4 @@ CONFIG.local
 .cproject
 .settings
 mk/cc.mk
+PYTHON_COMMAND
diff --git a/Makefile b/Makefile
index 51810be89..24ac6ac2b 100644
--- a/Makefile
+++ b/Makefile
@@ -68,7 +68,9 @@ mk/cc.mk:
 	rm -f $@.tmp
 
 config.h: CONFIG CONFIG.local scripts/genconfig.py
-	$(Q)python scripts/genconfig.py $(MAKEFLAGS) > $@.tmp; \
+	$(Q)PYCMD=$$(cat PYTHON_COMMAND 2>/dev/null) ; \
+	test -z "$$PYCMD" && PYCMD=python ; \
+	$$PYCMD scripts/genconfig.py $(MAKEFLAGS) > $@.tmp; \
 	cmp -s $@.tmp $@ || mv $@.tmp $@ ; \
 	rm -f $@.tmp
 
diff --git a/configure b/configure
index 27309cf17..cfae6db8a 100755
--- a/configure
+++ b/configure
@@ -274,6 +274,8 @@ if [[ -z "$python_command" ]] ; then
 	exit 1
 fi
 
+rm -f PYTHON_COMMAND
+echo $python_command > PYTHON_COMMAND
 $python_command scripts/genconfig.py > config.h
 
 echo "done."