[libcamera-devel] [PATCH v2 2/5] generate fixed- and variable-sized Span Controls

[Laurent Pinchart]

Hi Christian,

Thank you for the patch.

On Tue, Apr 05, 2022 at 01:42:12AM +0100, Christian Rauch via libcamera-devel wrote:
> This defines Controls with a 'size' as either variable-sized Span<T> or as
> fixed-sized Span<T,N>.
> 
> Signed-off-by: Christian Rauch <Rauch.Christian at gmx.de>
> ---
>  utils/gen-controls.py | 33 +++++++++++++++++++++++----------
>  1 file changed, 23 insertions(+), 10 deletions(-)
> 
> diff --git a/utils/gen-controls.py b/utils/gen-controls.py
> index 3f99b5e2..4cadf160 100755
> --- a/utils/gen-controls.py
> +++ b/utils/gen-controls.py
> @@ -7,6 +7,7 @@
>  # gen-controls.py - Generate control definitions from YAML
> 
>  import argparse
> +from math import prod

I'd prefer

import math

and math.prod() below, to avoid future namespace clashes.

>  import string
>  import sys
>  import yaml
> @@ -22,6 +23,26 @@ def format_description(description):
>      return '\n'.join([(line and ' * ' or ' *') + line for line in description])
> 
> 
> +def get_ctrl_type_format(ctrl):

This should be named get_ctrl_type() as it returns the control type.

> +    ctrl_type = ctrl['type']
> +    ctrl_size_arr = ctrl.get('size')
> +    ctrl_is_span = ctrl_size_arr is not None
> +    if ctrl_is_span:
> +        ctrl_span_size = prod(ctrl_size_arr) if len(ctrl_size_arr) > 0 else None

You can move this to the "elif ctrl_is_span" below.

> +
> +    if ctrl_type == 'string':
> +        return 'std::string'
> +    elif ctrl_is_span:
> +        if ctrl_span_size:
> +            # fixed-sized Span
> +            return 'Span<const {}, {}>'.format(ctrl_type, ctrl_span_size)

We're increasingly standardizing on the f'...' string formatting method,
which here would be

            return f'Span<const {ctrl_type}, {ctrl_span_size}>'

> +        else:
> +            # variable-sized Span
> +            return 'Span<const {}>'.format(ctrl_type)

Same here.

> +    else:
> +        return ctrl_type
> +
> +
>  def generate_cpp(controls):
>      enum_doc_start_template = string.Template('''/**
>   * \\enum ${name}Enum
> @@ -50,11 +71,7 @@ ${description}
>          name, ctrl = ctrl.popitem()
>          id_name = snake_case(name).upper()
> 
> -        ctrl_type = ctrl['type']
> -        if ctrl_type == 'string':
> -            ctrl_type = 'std::string'
> -        elif ctrl.get('size'):
> -            ctrl_type = 'Span<const %s>' % ctrl_type
> +        ctrl_type = get_ctrl_type_format(ctrl)
> 
>          info = {
>              'name': name,
> @@ -135,11 +152,7 @@ def generate_h(controls):
> 
>          ids.append('\t' + id_name + ' = ' + str(id_value) + ',')
> 
> -        ctrl_type = ctrl['type']
> -        if ctrl_type == 'string':
> -            ctrl_type = 'std::string'
> -        elif ctrl.get('size'):
> -            ctrl_type = 'Span<const %s>' % ctrl_type
> +        ctrl_type = get_ctrl_type_format(ctrl)

Nice change overall :-)

> 
>          info = {
>              'name': name,

-- 
Regards,

Laurent Pinchart