[Mesa-dev] [PATCH 1/2] configure: use AM_PATH_PYTHON to look for the python version

[Eric Engestrom]

On Saturday, 2018-08-18 12:21:04 +0100, Emil Velikov wrote:
> On 17 August 2018 at 18:36, Dylan Baker <dylan at pnwbakers.com> wrote:
> > Quoting Emil Velikov (2018-08-17 03:12:56)
> >> On 16 August 2018 at 21:28, Dylan Baker <dylan at pnwbakers.com> wrote:
> >> > Quoting Eric Engestrom (2018-08-16 09:52:05)
> >> >> On Thursday, 2018-08-16 17:18:56 +0100, Emil Velikov wrote:
> >> >> > From: Emil Velikov <emil.velikov at collabora.com>
> >> >> >
> >> >> > Currently we use AC_CHECK_PROGS looking for python2.7, python2 and
> >> >> > finally python. That is due to the varying names used across the
> >> >> > different OS.
> >> >> >
> >> >> > Use the handy AM_PATH_PYTHON which finds the correct name and checks for
> >> >> > the version.
> >> >> >
> >> >> > Note: python2.7 has been an unofficial requirement for quite some time.
> >> >> > Update the docs to reflect that.
> >> >> >
> >> >> > Cc: Dylan Baker <dylan at pnwbakers.com>
> >> >> > Signed-off-by: Emil Velikov <emil.velikov at collabora.com>
> >> >> > ---
> >> >> >  configure.ac      | 7 +++++--
> >> >> >  docs/install.html | 2 +-
> >> >> >  2 files changed, 6 insertions(+), 3 deletions(-)
> >> >> >
> >> >> > diff --git a/configure.ac b/configure.ac
> >> >> > index c2155a541b0..57fddb927ce 100644
> >> >> > --- a/configure.ac
> >> >> > +++ b/configure.ac
> >> >> > @@ -125,7 +125,10 @@ AC_PROG_GREP
> >> >> >  AC_PROG_NM
> >> >> >  AM_PROG_AS
> >> >> >  AX_CHECK_GNU_MAKE
> >> >> > -AC_CHECK_PROGS([PYTHON2], [python2.7 python2 python])
> >> >> > +AM_PATH_PYTHON([2.7],, [:])
> >> >> > +PYTHON2=$PYTHON
> >> >> > +AC_SUBST([PYTHON2])
> >> >> > +
> >> >> >  AC_PROG_SED
> >> >> >  AC_PROG_MKDIR_P
> >> >> >
> >> >> > @@ -157,7 +160,7 @@ fi
> >> >> >
> >> >> >  AX_CHECK_PYTHON_MAKO_MODULE($PYTHON_MAKO_REQUIRED)
> >> >> >
> >> >> > -if test -z "$PYTHON2"; then
> >> >> > +if test "$PYTHON2" = ":"; then
> >> >> >      if test ! -f "$srcdir/src/util/format_srgb.c"; then
> >> >> >          AC_MSG_ERROR([Python not found - unable to generate sources])
> >> >> >      fi
> >> >> > diff --git a/docs/install.html b/docs/install.html
> >> >> > index 08081944cfc..f6094671cf9 100644
> >> >> > --- a/docs/install.html
> >> >> > +++ b/docs/install.html
> >> >> > @@ -72,7 +72,7 @@ you think you've spotted a bug let developers know by filing a
> >> >> >
> >> >> >  <ul>
> >> >> >  <li><a href="https://www.python.org/">Python</a> - Python is required.
> >> >> > -Version 2.6.4 or later should work.
> >> >> > +Version 2.7 or later should work.
> >> >
> >> > Is this just the autotools build, or is this for all builds? For meson 3.4+ is
> >> > required.
> >> >
> >> With a 1-2 line change one could use python 2.7 there, not sure if
> >> that's a good idea though ;-)
> >
> > For meson I don't think it makes any sense to allow using python 2.7 for the
> > generators since meson itself requires 3.x; in the same way I don't think it's
> > worthwhile to allow python 3.x with the current scons build since it requires
> > 2.7
> >
> Agreed requiring both python 2 and 3 is very weird.
> 
> <random brain dump>
> Considering it's functionally possible, there is no obvious reason to ban.
> It's the weird setups that point out the no-so obvious bugs ;-)

Agreed with that argument, but python2 is dead. Adding py3 support in
a mixed py2 + py3 env like scons, sure, but adding py2 support is going
backwards imo.

> 
> That's my personal opinion, as a person who tends to do things differently.
> I'm not maintaining either scons nor meson so it's not my decision.
> </random brain dump>
> 
> -Emil