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.x and 3.x 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. One exception to this is scripts that are deliberately written to be source compatible with both Python 2.x and 3.x. Such scripts may continue to use python on their shebang line without affecting their portability. To meet this requirement, this commit adds new variables 'PYTHON2' and 'PYTHON3'. arch/ia64/scripts/unwcheck.py is the only script that has ever used $(PYTHON). Recent commit bd5edbe67794 ("ia64: convert unwcheck.py to python3") converted it to be compatible with both Python 2.x and 3.x, so this is the exceptional case where the use of 'python' is allowed. So, I did not touch arch/ia64/Makefile. tools/perf/Makefile.config sets PYTHON and PYTHON2 by itself, so it is not affected by this commit. Signed-off-by: Masahiro Yamada <yamada.masah...@socionext.com> --- Changes in v3: - Keep PYTHON as-is because ia64 recently converted its script compatible with Python 3.x Changes in v2: - Add backward compatibility for PYTHON Makefile | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/Makefile b/Makefile index e02d092..7a5f85e 100644 --- a/Makefile +++ b/Makefile @@ -385,6 +385,8 @@ INSTALLKERNEL := installkernel DEPMOD = /sbin/depmod PERL = perl PYTHON = python +PYTHON2 = python2 +PYTHON3 = python3 CHECK = sparse CHECKFLAGS := -D__linux__ -Dlinux -D__STDC__ -Dunix -D__unix__ \ @@ -430,7 +432,7 @@ 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 PYTHON PYTHON2 PYTHON3 UTS_MACHINE export HOSTCXX HOSTCXXFLAGS LDFLAGS_MODULE CHECK CHECKFLAGS export KBUILD_CPPFLAGS NOSTDINC_FLAGS LINUXINCLUDE OBJCOPYFLAGS LDFLAGS -- 2.7.4