Re: [PATCH v5 17/36] qapi/common.py: move build_params into gen.py

[Eduardo Habkost]

On Wed, Oct 07, 2020 at 11:21:51AM +0200, Markus Armbruster wrote:
> John Snow <jsnow@redhat.com> writes:
> 
> > Including it in common.py creates a circular import dependency; schema
> > relies on common, but common.build_params requires a type annotation
> > from schema. To type this properly, it needs to be moved outside the
> > cycle.
> >
> > Signed-off-by: John Snow <jsnow@redhat.com>
> > Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>
> > Reviewed-by: Cleber Rosa <crosa@redhat.com>
> > ---
> >  scripts/qapi/commands.py |  9 +++++++--
> >  scripts/qapi/common.py   | 23 -----------------------
> >  scripts/qapi/events.py   |  9 ++-------
> >  scripts/qapi/gen.py      | 31 +++++++++++++++++++++++++++++--
> >  4 files changed, 38 insertions(+), 34 deletions(-)
> >
> > diff --git a/scripts/qapi/commands.py b/scripts/qapi/commands.py
> > index 5dc2f5a9fa8..f67393f8713 100644
> > --- a/scripts/qapi/commands.py
> > +++ b/scripts/qapi/commands.py
> > @@ -13,8 +13,13 @@
> >  See the COPYING file in the top-level directory.
> >  """
> >  
> > -from .common import build_params, c_name, mcgen
> > -from .gen import QAPIGenCCode, QAPISchemaModularCVisitor, ifcontext
> > +from .common import c_name, mcgen
> > +from .gen import (
> > +    QAPIGenCCode,
> > +    QAPISchemaModularCVisitor,
> > +    build_params,
> > +    ifcontext,
> > +)
> >  
> >  
> >  def gen_command_decl(name, arg_type, boxed, ret_type):
> > diff --git a/scripts/qapi/common.py b/scripts/qapi/common.py
> > index 0ef38ea5fe0..9ab0685cc51 100644
> > --- a/scripts/qapi/common.py
> > +++ b/scripts/qapi/common.py
> > @@ -209,26 +209,3 @@ def gen_endif(ifcond: Sequence[str]) -> str:
> >  #endif /* %(cond)s */
> >  ''', cond=ifc)
> >      return ret
> > -
> > -
> > -def build_params(arg_type,
> > -                 boxed: bool,
> > -                 extra: Optional[str] = None) -> str:
> > -    ret = ''
> > -    sep = ''
> > -    if boxed:
> > -        assert arg_type
> > -        ret += '%s arg' % arg_type.c_param_type()
> > -        sep = ', '
> > -    elif arg_type:
> > -        assert not arg_type.variants
> > -        for memb in arg_type.members:
> > -            ret += sep
> > -            sep = ', '
> > -            if memb.optional:
> > -                ret += 'bool has_%s, ' % c_name(memb.name)
> > -            ret += '%s %s' % (memb.type.c_param_type(),
> > -                              c_name(memb.name))
> > -    if extra:
> > -        ret += sep + extra
> > -    return ret if ret else 'void'
> > diff --git a/scripts/qapi/events.py b/scripts/qapi/events.py
> > index 6b3afa14d72..f840a62ed92 100644
> > --- a/scripts/qapi/events.py
> > +++ b/scripts/qapi/events.py
> > @@ -12,13 +12,8 @@
> >  See the COPYING file in the top-level directory.
> >  """
> >  
> > -from .common import (
> > -    build_params,
> > -    c_enum_const,
> > -    c_name,
> > -    mcgen,
> > -)
> > -from .gen import QAPISchemaModularCVisitor, ifcontext
> > +from .common import c_enum_const, c_name, mcgen
> > +from .gen import QAPISchemaModularCVisitor, build_params, ifcontext
> >  from .schema import QAPISchemaEnumMember
> >  from .types import gen_enum, gen_enum_lookup
> >  
> > diff --git a/scripts/qapi/gen.py b/scripts/qapi/gen.py
> > index 1fed712b43b..f2e2746fea5 100644
> > --- a/scripts/qapi/gen.py
> > +++ b/scripts/qapi/gen.py
> > @@ -2,9 +2,11 @@
> >  #
> >  # QAPI code generation
> >  #
> > -# Copyright (c) 2018-2019 Red Hat Inc.
> > +# Copyright IBM, Corp. 2011
> > +# Copyright (c) 2013-2019 Red Hat Inc.
> >  #
> >  # Authors:
> > +#  Anthony Liguori <aliguori@us.ibm.com>
> >  #  Markus Armbruster <armbru@redhat.com>
> >  #  Marc-André Lureau <marcandre.lureau@redhat.com>
> >  #
> 
> The code you move into this file is actually Red Hat's:
> 
> $ git-log -L174,193:scripts/qapi/common.py master| egrep 'Author|Date'
> Author: Markus Armbruster <armbru@redhat.com>
> Date:   Wed Aug 15 21:37:36 2018 +0800
> Author: Marc-André Lureau <marcandre.lureau@redhat.com>
> Date:   Thu Jun 1 16:41:41 2017 +0400
> Author: Eric Blake <eblake@redhat.com>
> Date:   Wed Jul 13 21:50:20 2016 -0600
> Author: Eric Blake <eblake@redhat.com>
> Date:   Wed Jul 13 21:50:19 2016 -0600
> Author: Eric Blake <eblake@redhat.com>
> Date:   Thu Mar 17 16:48:28 2016 -0600
> Author: Markus Armbruster <armbru@redhat.com>
> Date:   Wed Sep 16 13:06:20 2015 +0200
> 
> So the correct update is simply
> 
>    #
>    # QAPI code generation
>    #
>   -# Copyright (c) 2018-2019 Red Hat Inc.
>   +# Copyright (c) 2015-2019 Red Hat Inc.
>    #
>    # Authors:
>    #  Markus Armbruster <armbru@redhat.com>
>    #  Marc-André Lureau <marcandre.lureau@redhat.com>
>    #

I am pretty sure build_params() below is a derivative work of
generate_command_decl(), added in commit c17d9908a942 ("qapi: add
qapi-commands.py code generator"), copyright IBM Corp.  I'm not a
lawyer, though.

Because figuring that out is complicated, when I move or copy
code between files, I either:
(a) copy no copyright notices from the other file, or
(b) copy all copyright notices from the other files.

(The above is a description of what I do, but it is not a
suggestion on how to proceed on this case.)

> 
> > @@ -15,16 +17,18 @@
> >  import errno
> >  import os
> >  import re
> > +from typing import Optional
> >  
> >  from .common import (
> >      c_fname,
> > +    c_name,
> >      gen_endif,
> >      gen_if,
> >      guardend,
> >      guardstart,
> >      mcgen,
> >  )
> > -from .schema import QAPISchemaVisitor
> > +from .schema import QAPISchemaObjectType, QAPISchemaVisitor
> >  
> >  
> >  class QAPIGen:
> > @@ -90,6 +94,29 @@ def _wrap_ifcond(ifcond, before, after):
> >      return out
> >  
> >  
> > +def build_params(arg_type: Optional[QAPISchemaObjectType],
> > +                 boxed: bool,
> > +                 extra: Optional[str] = None) -> str:
> > +    ret = ''
> > +    sep = ''
> > +    if boxed:
> > +        assert arg_type
> > +        ret += '%s arg' % arg_type.c_param_type()
> > +        sep = ', '
> > +    elif arg_type:
> > +        assert not arg_type.variants
> > +        for memb in arg_type.members:
> > +            ret += sep
> > +            sep = ', '
> > +            if memb.optional:
> > +                ret += 'bool has_%s, ' % c_name(memb.name)
> > +            ret += '%s %s' % (memb.type.c_param_type(),
> > +                              c_name(memb.name))
> > +    if extra:
> > +        ret += sep + extra
> > +    return ret if ret else 'void'
> > +
> > +
> >  class QAPIGenCCode(QAPIGen):
> >  
> >      def __init__(self, fname):

-- 
Eduardo