[Mesa-dev] [RFC] configure.ac: Don't check for python mako module if python is not installed

[Emil Velikov]

On 27/02/15 17:42, Matt Turner wrote:
> On Fri, Feb 27, 2015 at 7:27 AM, Samuel Iglesias Gonsalvez
> <siglesias at igalia.com> wrote:
>> This could be the case of trying to compile a Mesa tarball (from 'make dist'
>> command) in a machine without Python interpreter installed. The autogenerated
>> files from mako templates were already created during tarball
>> generation.
>>
>> In case of building from git without Python it is going to fail anyway because
>> Python is not present when trying to autogenerate the files from mako
>> templates.
>>
>> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=89328
>>
>> Signed-off-by: Samuel Iglesias Gonsalvez <siglesias at igalia.com>
>> ---
>>  configure.ac | 7 ++++++-
>>  1 file changed, 6 insertions(+), 1 deletion(-)
>>
>> diff --git a/configure.ac b/configure.ac
>> index 22dc023..a4e6338 100644
>> --- a/configure.ac
>> +++ b/configure.ac
>> @@ -114,7 +114,12 @@ if test "x$INDENT" != "xcat"; then
>>      fi
>>  fi
>>
>> -AX_CHECK_PYTHON_MAKO_MODULE(0.3.4)
>> +if test -n "$PYTHON2"; then
>> +    AX_CHECK_PYTHON_MAKO_MODULE(0.3.4)
>> +else
>> +    AC_MSG_WARN([python not found - unable to check for python mako module])
>> +fi
>> +
> 
> For flex and bison, we check if a generated source file exists, which
> is probably a good idea. That way configure will fail in a git
> checkout if you don't have python.
> 
Checking for the presence of one auto-generated file does not sound like
a great idea imho. What happens if any of the other files is not present
- should we keep the whole list in configure.ac ? Keeping the list in
sync seems quite error prone.

A hacky alternative is to set the variable (BISON/LEX/PYTHON2) to
something like `echo "Missing XXX dependency" && return 1` when empty.
Yet that looks quite nasty, plus it shows rather late in the build
process :\

> I have in my todo list to add some remaining source files generated by
> python to the autotools distribution. After we commit some version of
> this patch, Emil or I should make sure that all the python-generated
> code is included in the tarball.
> 
I was under the impression that we already do, but I will double-check.


On a mildly related note:
For anyone that missed it Ken voiced concerns over shipping the
lex/bison generated files. Main idea is that as(if) security bugs are
found and fixed in those products, mesa has been released with such
vulnerable files.
I can see his point, and I tend to agree with him. How do others feel on
the topic ?


Thanks
Emil