From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1165078AbeCBEe5 (ORCPT ); Thu, 1 Mar 2018 23:34:57 -0500 Received: from conuserg-08.nifty.com ([210.131.2.75]:53203 "EHLO conuserg-08.nifty.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1164993AbeCBEds (ORCPT ); Thu, 1 Mar 2018 23:33:48 -0500 DKIM-Filter: OpenDKIM Filter v2.10.3 conuserg-08.nifty.com w224WURC022085 X-Nifty-SrcIP: [153.142.97.92] From: Masahiro Yamada To: linux-kbuild@vger.kernel.org Cc: Sam Ravnborg , Michal Marek , Ulf Magnusson , Randy Dunlap , "Luis R . Rodriguez" , Masahiro Yamada , Tony Luck , linux-ia64@vger.kernel.org, linux-kernel@vger.kernel.org, Fenghua Yu Subject: [PATCH v2 01/11] kbuild: define PYTHON2 and PYTHON3 variables instead of PYTHON Date: Fri, 2 Mar 2018 13:31:51 +0900 Message-Id: <1519965121-12017-2-git-send-email-yamada.masahiro@socionext.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1519965121-12017-1-git-send-email-yamada.masahiro@socionext.com> References: <1519965121-12017-1-git-send-email-yamada.masahiro@socionext.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The variable 'PYTHON' allows users to specify a proper executable name in case the default 'python' does not work. However, this does not address the case where both Python 2 and Python 3 scripts are used in one source tree. PEP 394 (https://www.python.org/dev/peps/pep-0394/) provides a convention for Python scripts portability. Here is a quotation: In order to tolerate differences across platforms, all new code that needs to invoke the Python interpreter should not specify 'python', but rather should specify either 'python2' or 'python3'. This distinction should be made in shebangs, when invoking from a shell script, when invoking via the system() call, or when invoking in any other context. arch/ia64/scripts/unwcheck.py is apparently written in Python 2, so it should be invoked by 'python2'. It is legitimate to use 'python' for scripts compatible with both Python 2 and Python 3, but this is rare (at least I do not see the case in kernel tree). You do not need to make efforts to write your scripts in that way. Anyway, Python 2 will retire in 2020. This commit is needed for new scripts written in Python 3. For the backward compatibility for ia64, if 'PYTHON' is specified, it is propagated to 'PYTHON2'. Signed-off-by: Masahiro Yamada --- Changes in v2: - Add backward compatibility for PYTHON Makefile | 5 +++-- arch/ia64/Makefile | 2 +- 2 files changed, 4 insertions(+), 3 deletions(-) diff --git a/Makefile b/Makefile index 4fb97e9..ea23d9b 100644 --- a/Makefile +++ b/Makefile @@ -393,7 +393,8 @@ GENKSYMS = scripts/genksyms/genksyms INSTALLKERNEL := installkernel DEPMOD = /sbin/depmod PERL = perl -PYTHON = python +PYTHON2 := $(if $(PYTHON), $(PYTHON), python2) +PYTHON3 := python3 CHECK = sparse CHECKFLAGS := -D__linux__ -Dlinux -D__STDC__ -Dunix -D__unix__ \ @@ -439,7 +440,7 @@ GCC_PLUGINS_CFLAGS := export ARCH SRCARCH CONFIG_SHELL HOSTCC HOSTCFLAGS CROSS_COMPILE AS LD CC export CPP AR NM STRIP OBJCOPY OBJDUMP HOSTLDFLAGS HOST_LOADLIBES -export MAKE LEX YACC AWK GENKSYMS INSTALLKERNEL PERL PYTHON UTS_MACHINE +export MAKE LEX YACC AWK GENKSYMS INSTALLKERNEL PERL PYTHON2 PYTHON3 UTS_MACHINE export HOSTCXX HOSTCXXFLAGS LDFLAGS_MODULE CHECK CHECKFLAGS export KBUILD_CPPFLAGS NOSTDINC_FLAGS LINUXINCLUDE OBJCOPYFLAGS LDFLAGS diff --git a/arch/ia64/Makefile b/arch/ia64/Makefile index 2dd7f51..862a2ba 100644 --- a/arch/ia64/Makefile +++ b/arch/ia64/Makefile @@ -75,7 +75,7 @@ vmlinux.gz: vmlinux $(Q)$(MAKE) $(build)=$(boot) $@ unwcheck: vmlinux - -$(Q)READELF=$(READELF) $(PYTHON) $(srctree)/arch/ia64/scripts/unwcheck.py $< + -$(Q)READELF=$(READELF) $(PYTHON2) $(srctree)/arch/ia64/scripts/unwcheck.py $< archclean: $(Q)$(MAKE) $(clean)=$(boot) -- 2.7.4