[v3,42/50] qapi: add a -u/--unit option to specify which unit to visit

Allow to filter expressions based on unit name.

By default, only default units are processed (unspecified pragma).

'all' will include all units. Anything else will filter by unit name.

(add a FIXME to make implicit array types use the element type unit,
not the unit of the first expression using that array type. This isn't
necessary for now, and I am not sure how to best do it yet)

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
---
 scripts/qapi.py      | 14 ++++++++++++--
 scripts/qapi2texi.py |  1 +
 2 files changed, 13 insertions(+), 2 deletions(-)

Marc-André Lureau <marcandre.lureau@redhat.com> writes:

> Allow to filter expressions based on unit name.
>
> By default, only default units are processed (unspecified pragma).
>
> 'all' will include all units. Anything else will filter by unit name.

You therefore can't have a unit called 'all'.  Hardly a loss, but I
suspect documenting and guarding against it is more trouble than the
feature's worth.

If we want to keep it, the previous patch needs to reject { 'pragma': {
'unit': 'all' } }.

> (add a FIXME to make implicit array types use the element type unit,
> not the unit of the first expression using that array type. This isn't
> necessary for now, and I am not sure how to best do it yet)
>
> Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
> ---
>  scripts/qapi.py      | 14 ++++++++++++--
>  scripts/qapi2texi.py |  1 +
>  2 files changed, 13 insertions(+), 2 deletions(-)
>
> diff --git a/scripts/qapi.py b/scripts/qapi.py
> index 1d0defd638..7778585819 100644
> --- a/scripts/qapi.py
> +++ b/scripts/qapi.py
> @@ -47,6 +47,9 @@ returns_whitelist = []
>  # Whitelist of entities allowed to violate case conventions
>  name_case_whitelist = []
>  
> +# Unit to consider for the visit, 'all' for all units
> +visit_unit = None
> +
>  enum_types = {}
>  struct_types = {}
>  union_types = {}
> @@ -1796,6 +1799,10 @@ class QAPISchema(object):
>      def visit(self, visitor):
>          visitor.visit_begin(self)
>          for (name, entity) in sorted(self._entity_dict.items()):
> +            # FIXME: implicit array types should use element type unit
> +            unit = entity.info and entity.info.get('unit')

@unit is str, ensured by QAPISchemaParser.

> +            if visit_unit != 'all' and visit_unit != unit:
> +                continue

If visit_unit is still None, we don't visit anything.

>              if visitor.visit_needed(entity):
>                  entity.visit(visitor)
>          visitor.visit_end()
> @@ -2103,13 +2110,14 @@ def parse_command_line(extra_options='', extra_long_options=[]):
>  
>      try:
>          opts, args = getopt.gnu_getopt(sys.argv[1:],
> -            'chp:o:i:' + extra_options,
> +            'chp:o:u:i:' + extra_options,
>              ['source', 'header', 'prefix=', 'output-dir=',
> -             'include='] + extra_long_options)
> +             'unit=', 'include='] + extra_long_options)
>      except getopt.GetoptError as err:
>          print >>sys.stderr, "%s: %s" % (sys.argv[0], str(err))
>          sys.exit(1)
>  
> +    global visit_unit
>      output_dir = ''
>      prefix = ''
>      do_c = False
> @@ -2129,6 +2137,8 @@ def parse_command_line(extra_options='', extra_long_options=[]):
>              prefix = a
>          elif o in ('-o', '--output-dir'):
>              output_dir = a + '/'
> +        elif o in ('-u', '--unit'):
> +            visit_unit = a
>          elif o in ('-c', '--source'):
>              do_c = True
>          elif o in ('-h', '--header'):

If the user doesn't give -u, @visit_unit remains None, and
QAPISchema.visit() won't visit anything.

I recommend to dumb this down as follows.  No special unit name 'all'.
If you want all, don't specify -u.  @visit_unit remains None then.

> diff --git a/scripts/qapi2texi.py b/scripts/qapi2texi.py
> index 4e7b1cda87..6c856d4cb7 100755
> --- a/scripts/qapi2texi.py
> +++ b/scripts/qapi2texi.py
> @@ -293,6 +293,7 @@ def main(argv):
>          print >>sys.stderr, "%s: need exactly 1 argument: SCHEMA" % argv[0]
>          sys.exit(1)
>  
> +    qapi.visit_unit = 'all'
>      schema = qapi.QAPISchema(argv[1])
>      if not qapi.doc_required:
>          print >>sys.stderr, ("%s: need pragma 'doc-required' "

Bonus: this hunk won't be needed then, because the default value just
works.