[PATCH 1/3] dtoc: Rename is_wider_than() to reduce confusion

[Simon Glass]

Hi Walter,

On Sun, 1 Aug 2021 at 20:45, Walter Lozano <wlozano at collabora.com> wrote:
>
> Hi Simon,
>
> Thanks for checking this bug, I'm glad that you were able to come with
> fix quickly. I have some questions, I hope that you find some time to
> help me understand.
>
> On 7/28/21 10:23 PM, Simon Glass wrote:
> > The current name is confusing because the logic is actually backwards from
> > what you might expect. Rename it to needs_widening() and update the
> > comments.
> >
> > Signed-off-by: Simon Glass <sjg at chromium.org>
> > ---
> >
> >   tools/dtoc/fdt.py | 15 +++++++++------
> >   1 file changed, 9 insertions(+), 6 deletions(-)
> >
> > diff --git a/tools/dtoc/fdt.py b/tools/dtoc/fdt.py
> > index 3996971e39c..9749966d5fb 100644
> > --- a/tools/dtoc/fdt.py
> > +++ b/tools/dtoc/fdt.py
> > @@ -24,16 +24,19 @@ from patman import tools
> >
> >   # A list of types we support
> >   class Type(IntEnum):
> > +    # Types in order from widest to narrowest
> >       (BYTE, INT, STRING, BOOL, INT64) = range(5)
>
> Sorry but I don't understand why BYTE is wider than INT (or INT64)

I think perhaps we need a better name. A wider type is one that can
hold the values of a narrower one, plus more.

In this case a 'bytes' type can hold anything (bytes, int, int64,
bool) so is the 'widest' there is. It is the lowest common denominator
in the devicetree.


>
> >
> > -    def is_wider_than(self, other):
> > -        """Check if another type is 'wider' than this one
> > +    def needs_widening(self, other):
> > +        """Check if this type needs widening to hold a value from another type
> >
> > -        A wider type is one that holds more information than an earlier one,
> > -        similar to the concept of type-widening in C.
> > +        A wider type is one that can hold a wider array of information than
> > +        another one, or is less restrictive, so it can hold the information of
> > +        another type as well as its own. This is similar to the concept of
> > +        type-widening in C.
> >
> >           This uses a simple arithmetic comparison, since type values are in order
> > -        from narrowest (BYTE) to widest (INT64).
> > +        from widest (BYTE) to narrowest (INT64).
> >
> >           Args:
> >               other: Other type to compare against
> > @@ -149,7 +152,7 @@ class Prop:
> >           update the current property to be like the second, since it is less
> >           specific.
> >           """
> > -        if self.type.is_wider_than(newprop.type):
> > +        if self.type.needs_widening(newprop.type):
> >               if self.type == Type.INT and newprop.type == Type.BYTE:
> >                   if type(self.value) == list:
> >                       new_value = []
>

Regards,
Simon