RE: [PATCH for-4.14] golang/xenlight: sort cases in switch statement

[Paul Durrant <xadimgnik@xxxxxxxxx>]

> -----Original Message-----
> From: Ian Jackson <ian.jackson@xxxxxxxxxx>
> Sent: 15 June 2020 16:43
> To: Nick Rosbrook <rosbrookn@xxxxxxxxx>
> Cc: xen-devel@xxxxxxxxxxxxxxxxxxxx; paul@xxxxxxx; Andrew Cooper 
> <Andrew.Cooper3@xxxxxxxxxx>; Nick
> Rosbrook <rosbrookn@xxxxxxxxxxxx>; George Dunlap <George.Dunlap@xxxxxxxxxx>; 
> Wei Liu <wl@xxxxxxx>
> Subject: Re: [PATCH for-4.14] golang/xenlight: sort cases in switch statement
> 
> Nick Rosbrook writes ("[PATCH for-4.14] golang/xenlight: sort cases in switch 
> statement"):
> > The xenlight_golang_union_from_C function iterates over a dict to
> > construct a switch statement that marshals a C keyed union into a Go
> > type. Because python does not guarantee dict ordering across all
> > versions, this can result in the switch statement being generated in a
> > different order depending on the version of python used. For example,
> > running gengotypes.py with python2.7 and python3.6 will yield different
> > orderings.
> >
> > Iterate over sorted(cases.items()) rather than cases.items() to fix
> > this.
> >
> > This patch changes the ordering from what was previously checked-in, but
> > running gengotypes.py with different versions of python will now yield
> > the same result.
> >
> > Signed-off-by: Nick Rosbrook <rosbrookn@xxxxxxxxxxxx>
> > ---
> > Andrew reported this in [1], so I intend this as a build fix for 4.14.
> >
> > [1] 
> > https://lists.xenproject.org/archives/html/xen-devel/2020-06/msg00881.html
> > ---
> >  tools/golang/xenlight/gengotypes.py  |  2 +-
> >  tools/golang/xenlight/helpers.gen.go | 32 ++++++++++++++--------------
> >  2 files changed, 17 insertions(+), 17 deletions(-)
> >
> > diff --git a/tools/golang/xenlight/gengotypes.py 
> > b/tools/golang/xenlight/gengotypes.py
> > index ecca59745f..557fecd07b 100644
> > --- a/tools/golang/xenlight/gengotypes.py
> > +++ b/tools/golang/xenlight/gengotypes.py
> > @@ -379,7 +379,7 @@ def xenlight_golang_union_from_C(ty = None, union_name 
> > = '', struct_name = ''):
> >
> >      # Create switch statement to determine which 'union element'
> >      # to populate in the Go struct.
> > -    for case_name, case_tuple in cases.items():
> > +    for case_name, case_tuple in sorted(cases.items()):
> >          (case_val, case_type) = case_tuple
> 
> This part
> 
> Acked-by: Ian Jackson <ian.jackson@xxxxxxxxxxxxx>
> 
> But I don't think I have the right golang tools to verify the
> autogenerated code.  George, can you check that this patch is right,
> and/or do the commit and rerun the generation ?
> 
> Obviously that needs to wait for a release ack.
> 

Assuming George is happy...

Release-acked-by: Paul Durrant <paul@xxxxxxx>

> Ian.