pdl: Implement custom fields for rust generator (11a7eeb0) · Commits · e / os / android_packages_modules_Bluetooth

tools/pdl/Android.bp

+4 −0

Original line number	Diff line number	Diff line
		@@ -41,6 +41,8 @@ rust_binary_host {
		filegroup {
		name: "pdl_generated_files",
		srcs: [
		"tests/generated/custom_field_declaration_big_endian.rs",
		"tests/generated/custom_field_declaration_little_endian.rs",
		"tests/generated/enum_declaration_big_endian.rs",
		"tests/generated/enum_declaration_little_endian.rs",
		"tests/generated/packet_decl_8bit_enum_array_big_endian.rs",
		@@ -79,6 +81,8 @@ filegroup {
		"tests/generated/packet_decl_child_packets_little_endian.rs",
		"tests/generated/packet_decl_complex_scalars_big_endian.rs",
		"tests/generated/packet_decl_complex_scalars_little_endian.rs",
		"tests/generated/packet_decl_custom_field_big_endian.rs",
		"tests/generated/packet_decl_custom_field_little_endian.rs",
		"tests/generated/packet_decl_empty_big_endian.rs",
		"tests/generated/packet_decl_empty_little_endian.rs",
		"tests/generated/packet_decl_fixed_enum_field_big_endian.rs",

tools/pdl/src/backends/rust.rs

+91 −0

Original line number	Diff line number	Diff line
		@@ -899,6 +899,67 @@ fn generate_enum_decl(
		}
		}

		/// Generate the declaration for a custom field of static size.
		///
		/// * `id` - Enum identifier.
		/// * `width` - Width of the backing type of the enum, in bits.
		fn generate_custom_field_decl(id: &str, width: usize) -> proc_macro2::TokenStream {
		let id = format_ident!("{}", id);
		let backing_type = types::Integer::new(width);
		let backing_type_str = proc_macro2::Literal::string(&format!("u{}", backing_type.width));
		let max_value = mask_bits(width, "usize");
		let common = quote! {
		impl From<&#id> for #backing_type {
		fn from(value: &#id) -> #backing_type {
		value.0
		}
		}

		impl From<#id> for #backing_type {
		fn from(value: #id) -> #backing_type {
		value.0
		}
		}
		};

		if backing_type.width == width {
		quote! {
		#[derive(Debug, Clone, Copy, Hash, Eq, PartialEq)]
		#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
		#[cfg_attr(feature = "serde", serde(from = #backing_type_str, into = #backing_type_str))]
		pub struct #id(#backing_type);

		#common

		impl From<#backing_type> for #id {
		fn from(value: #backing_type) -> Self {
		#id(value)
		}
		}
		}
		} else {
		quote! {
		#[derive(Debug, Clone, Copy, Hash, Eq, PartialEq)]
		#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
		#[cfg_attr(feature = "serde", serde(try_from = #backing_type_str, into = #backing_type_str))]
		pub struct #id(#backing_type);

		#common

		impl TryFrom<#backing_type> for #id {
		type Error = #backing_type;
		fn try_from(value: #backing_type) -> std::result::Result<Self, Self::Error> {
		if value > #max_value {
		Err(value)
		} else {
		Ok(#id(value))
		}
		}
		}
		}
		}
		}

		fn generate_decl(
		scope: &lint::Scope<'_>,
		file: &analyzer_ast::File,
		@@ -919,6 +980,9 @@ fn generate_decl(
		ast::DeclDesc::Enum { id, tags, width } => {
		generate_enum_decl(id, tags, *width, false).to_string()
		}
		ast::DeclDesc::CustomField { id, width: Some(width), .. } => {
		generate_custom_field_decl(id, *width).to_string()
		}
		_ => todo!("unsupported Decl::{:?}", decl),
		}
		}
		@@ -1104,6 +1168,20 @@ mod tests {
		"#
		);

		test_pdl!(
		custom_field_declaration,
		r#"
		// Still unsupported.
		// custom_field Dynamic "dynamic"

		// Should generate a type with From<u32> implementation.
		custom_field ExactSize : 32 "exact_size"

		// Should generate a type with TryFrom<u32> implementation.
		custom_field TruncatedSize : 24 "truncated_size"
		"#
		);

		test_pdl!(
		packet_decl_simple_scalars,
		r#"
		@@ -1260,6 +1338,19 @@ mod tests {
		"
		);

		test_pdl!(
		packet_decl_custom_field,
		r#"
		custom_field Bar1 : 24 "exact"
		custom_field Bar2 : 32 "truncated"

		packet Foo {
		a: Bar1,
		b: Bar2,
		}
		"#
		);

		test_pdl!(
		packet_decl_fixed_scalar_field,
		"

tools/pdl/src/backends/rust/parser.rs

+28 −15

Original line number	Diff line number	Diff line
		@@ -459,27 +459,40 @@ impl<'a> FieldParser<'a> {
		let id = format_ident!("{id}");
		let type_id = format_ident!("{type_id}");

		match self.scope.get_decl_width(decl, true) {
		None => self.code.push(quote! {
		self.code.push(match self.scope.get_decl_width(decl, true) {
		None => quote! {
		let #id = #type_id::parse_inner(&mut #span)?;
		}),
		},
		Some(width) => {
		assert_eq!(width % 8, 0, "Typedef field type size is not a multiple of 8");
		let width = syn::Index::from(width / 8);
		self.code.push(if let ast::DeclDesc::Checksum { .. } = &decl.desc {
		// TODO: handle checksum fields.
		match &decl.desc {
		ast::DeclDesc::Checksum { .. } => todo!(),
		ast::DeclDesc::CustomField { .. } if [8, 16, 32, 64].contains(&width) => {
		let get_uint = types::get_uint(self.endianness, width, span);
		quote! {
		#span.get_mut().advance(#width);
		let #id = #get_uint.into();
		}
		} else {
		}
		ast::DeclDesc::CustomField { .. } => {
		let get_uint = types::get_uint(self.endianness, width, span);
		quote! {
		let #id = (#get_uint)
		.try_into()
		.unwrap(); // Value is masked and conversion must succeed.
		}
		}
		ast::DeclDesc::Struct { .. } => {
		let width = syn::Index::from(width / 8);
		quote! {
		let (head, tail) = #span.get().split_at(#width);
		#span.replace(tail);
		let #id = #type_id::parse(head)?;
		}
		});
		}
		_ => unreachable!(),
		}
		}
		});
		}

		/// Parse body and payload fields.

tools/pdl/src/backends/rust/serializer.rs

+19 −2

Original line number	Diff line number	Diff line
		@@ -302,8 +302,25 @@ impl<'a> FieldSerializer<'a> {

		let id = format_ident!("{id}");
		let span = format_ident!("{}", self.span);
		self.code.push(quote! {

		self.code.push(match &decl.desc {
		ast::DeclDesc::Checksum { .. } => todo!(),
		ast::DeclDesc::CustomField { width: Some(width), .. } => {
		let backing_type = types::Integer::new(*width);
		let put_uint = types::put_uint(
		self.endianness,
		&quote! { #backing_type::from(self.#id) },
		*width,
		self.span,
		);
		quote! {
		#put_uint;
		}
		}
		ast::DeclDesc::Struct { .. } => quote! {
		self.#id.write_to(#span);
		},
		_ => unreachable!(),
		});
		}

tools/pdl/src/backends/rust/types.rs

+1 −0

Original line number	Diff line number	Diff line
		@@ -90,6 +90,7 @@ pub fn rust_borrow(
		ast::FieldDesc::Typedef { type_id, .. } => match &scope.typedef[type_id].desc {
		ast::DeclDesc::Enum { .. } => quote!(),
		ast::DeclDesc::Struct { .. } => quote!(&),
		ast::DeclDesc::CustomField { .. } => quote!(&),
		desc => unreachable!("unexpected declaration: {desc:?}"),
		},
		ast::FieldDesc::Array { .. } => quote!(&),