fn load()

in src/bindgen/ir/enumeration.rs [98:231]
121 lines of code
9 McCabe index (conditional complexity)

    fn load(
        inline_tag_field: bool,
        variant: &syn::Variant,
        generic_params: GenericParams,
        mod_cfg: Option<&Cfg>,
        self_path: &Path,
        enum_annotations: &AnnotationSet,
        config: &Config,
    ) -> Result<Self, String> {
        let discriminant = match variant.discriminant {
            Some((_, ref expr)) => Some(Literal::load(expr)?),
            None => None,
        };

        fn parse_fields(
            inline_tag_field: bool,
            fields: &syn::punctuated::Punctuated<syn::Field, syn::token::Comma>,
            self_path: &Path,
            inline_name: Option<&str>,
        ) -> Result<Vec<Field>, String> {
            let mut res = Vec::new();

            if inline_tag_field {
                res.push(Field::from_name_and_type(
                    inline_name.map_or_else(|| "tag".to_string(), |name| format!("{}_tag", name)),
                    Type::Path(GenericPath::new(Path::new("Tag"), vec![])),
                ));
            }

            for (i, field) in fields.iter().enumerate() {
                if let Some(mut ty) = Type::load(&field.ty)? {
                    ty.replace_self_with(self_path);
                    res.push(Field {
                        name: inline_name.map_or_else(
                            || match field.ident {
                                Some(ref ident) => ident.unraw().to_string(),
                                None => i.to_string(),
                            },
                            |name| name.to_string(),
                        ),
                        ty,
                        cfg: Cfg::load(&field.attrs),
                        annotations: AnnotationSet::load(&field.attrs)?,
                        documentation: Documentation::load(&field.attrs),
                    });
                }
            }

            Ok(res)
        }

        let variant_cfg = Cfg::append(mod_cfg, Cfg::load(&variant.attrs));
        let mut annotations = AnnotationSet::load(&variant.attrs)?;
        if let Some(b) = enum_annotations.bool("derive-ostream") {
            annotations.add_default("derive-ostream", AnnotationValue::Bool(b));
        }

        let body_rule = enum_annotations.parse_atom::<RenameRule>("rename-variant-name-fields");
        let body_rule = body_rule
            .as_ref()
            .unwrap_or(&config.enumeration.rename_variant_name_fields);

        let body = match variant.fields {
            syn::Fields::Unit => VariantBody::Empty(annotations),
            syn::Fields::Named(ref fields) => {
                let path = Path::new(format!("{}_Body", variant.ident));
                let name = body_rule
                    .apply(
                        &variant.ident.unraw().to_string(),
                        IdentifierType::StructMember,
                    )
                    .into_owned();
                VariantBody::Body {
                    body: Struct::new(
                        path,
                        generic_params,
                        parse_fields(inline_tag_field, &fields.named, self_path, None)?,
                        inline_tag_field,
                        true,
                        None,
                        false,
                        None,
                        annotations,
                        Documentation::none(),
                    ),
                    name,
                    inline: false,
                    inline_casts: false,
                }
            }
            syn::Fields::Unnamed(ref fields) => {
                let path = Path::new(format!("{}_Body", variant.ident));
                let name = body_rule
                    .apply(
                        &variant.ident.unraw().to_string(),
                        IdentifierType::StructMember,
                    )
                    .into_owned();
                let inline_casts = fields.unnamed.len() == 1;
                // In C++ types with destructors cannot be put into unnamed structs like the
                // inlining requires, and it's hard to detect such types.
                // Besides that for C++ we generate casts/getters that can be used instead of
                // direct field accesses and also have a benefit of being checked.
                // As a result we don't currently inline variant definitions in C++ mode at all.
                let inline = inline_casts && config.language != Language::Cxx;
                let inline_name = if inline { Some(&*name) } else { None };
                VariantBody::Body {
                    body: Struct::new(
                        path,
                        generic_params,
                        parse_fields(inline_tag_field, &fields.unnamed, self_path, inline_name)?,
                        inline_tag_field,
                        true,
                        None,
                        false,
                        None,
                        annotations,
                        Documentation::none(),
                    ),
                    name,
                    inline,
                    inline_casts,
                }
            }
        };

        Ok(EnumVariant::new(
            variant.ident.unraw().to_string(),
            discriminant,
            body,
            variant_cfg,
            Documentation::load(&variant.attrs),
        ))
    }