pdl: Generate just a single length check per chunk (3aee419e) · Commits · e / os / android_packages_modules_Bluetooth

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

+13 −45

Original line number	Diff line number	Diff line
		@@ -35,37 +35,22 @@ impl Chunk<'_> {
		}

		/// Generate length checks for this chunk.
		pub fn generate_length_checks(
		pub fn generate_length_check(
		&self,
		packet_name: &str,
		offset: usize,
		) -> Vec<proc_macro2::TokenStream> {
		let mut field_offset = offset;
		let mut last_field_range_end = 0;
		let mut length_checks = Vec::new();
		for field in self.fields {
		let id = field.get_id();
		let width = field.get_width();
		let field_range = get_field_range(field_offset, width);
		field_offset += width;
		if field_range.end == last_field_range_end {
		continue;
		}

		last_field_range_end = field_range.end;
		let range_end = syn::Index::from(field_range.end);
		length_checks.push(quote! {
		if bytes.len() < #range_end {
		) -> proc_macro2::TokenStream {
		let range = get_field_range(offset, self.get_width());
		let wanted_length = syn::Index::from(range.end);
		quote! {
		if bytes.len() < #wanted_length {
		return Err(Error::InvalidLengthError {
		obj: #packet_name.to_string(),
		field: #id.to_string(),
		wanted: #range_end,
		wanted: #wanted_length,
		got: bytes.len(),
		});
		}
		});
		}
		length_checks
		}

		/// Read data for a chunk.
		@@ -88,10 +73,7 @@ impl Chunk<'_> {

		let range = get_field_range(offset, chunk_width);
		let indices = range.map(syn::Index::from).collect::<Vec<_>>();

		// TODO(mgeisler): emit just a single length check per chunk. We
		// could even emit a single length check per packet.
		let length_checks = self.generate_length_checks(packet_name, offset);
		let length_check = self.generate_length_check(packet_name, offset);

		// When the chunk_type.width is larger than chunk_width (e.g.
		// chunk_width is 24 but chunk_type.width is 32), then we need
		@@ -112,7 +94,7 @@ impl Chunk<'_> {
		let read_adjustments = self.generate_read_adjustments();

		quote! {
		#(#length_checks)*
		#length_check
		let #chunk_name = #chunk_type::#getter([
		#(#zero_padding_before,)* #(bytes[#indices]),* #(, #zero_padding_after)*
		]);
		@@ -211,7 +193,6 @@ mod tests {
		if bytes.len() < 11 {
		return Err(Error::InvalidLengthError {
		obj: "Foo".to_string(),
		field: "a".to_string(),
		wanted: 11,
		got: bytes.len(),
		});
		@@ -231,7 +212,6 @@ mod tests {
		if bytes.len() < 12 {
		return Err(Error::InvalidLengthError {
		obj: "Foo".to_string(),
		field: "a".to_string(),
		wanted: 12,
		got: bytes.len(),
		});
		@@ -251,7 +231,6 @@ mod tests {
		if bytes.len() < 12 {
		return Err(Error::InvalidLengthError {
		obj: "Foo".to_string(),
		field: "a".to_string(),
		wanted: 12,
		got: bytes.len(),
		});
		@@ -271,7 +250,6 @@ mod tests {
		if bytes.len() < 13 {
		return Err(Error::InvalidLengthError {
		obj: "Foo".to_string(),
		field: "a".to_string(),
		wanted: 13,
		got: bytes.len(),
		});
		@@ -291,7 +269,6 @@ mod tests {
		if bytes.len() < 13 {
		return Err(Error::InvalidLengthError {
		obj: "Foo".to_string(),
		field: "a".to_string(),
		wanted: 13,
		got: bytes.len(),
		});
		@@ -311,18 +288,9 @@ mod tests {
		assert_expr_eq(
		chunk.generate_read("Foo", ast::EndiannessValue::BigEndian, 80),
		quote! {
		if bytes.len() < 12 {
		return Err(Error::InvalidLengthError {
		obj: "Foo".to_string(),
		field: "a".to_string(),
		wanted: 12,
		got: bytes.len(),
		});
		}
		if bytes.len() < 15 {
		return Err(Error::InvalidLengthError {
		obj: "Foo".to_string(),
		field: "b".to_string(),
		wanted: 15,
		got: bytes.len(),
		});

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

+0 −10

Original line number	Diff line number	Diff line
		@@ -20,10 +20,6 @@ impl ScalarField {
		self.width
		}

		fn get_id(&self) -> &str {
		&self.id
		}

		fn get_ident(&self) -> proc_macro2::Ident {
		format_ident!("{}", self.id)
		}
		@@ -149,12 +145,6 @@ impl Field {
		}
		}

		pub fn get_id(&self) -> &str {
		match self {
		Field::Scalar(field) => field.get_id(),
		}
		}

		pub fn get_ident(&self) -> proc_macro2::Ident {
		match self {
		Field::Scalar(field) => field.get_ident(),

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

+2 −2

Original line number	Diff line number	Diff line
		@@ -29,8 +29,8 @@ pub fn generate(path: &Path) -> String {
		InvalidPacketError,
		#[error("{field} was {value:x}, which is not known")]
		ConstraintOutOfBounds { field: String, value: u64 },
		#[error("when parsing {obj}.{field} needed length of {wanted} but got {got}")]
		InvalidLengthError { obj: String, field: String, wanted: usize, got: usize },
		#[error("when parsing {obj} needed length of {wanted} but got {got}")]
		InvalidLengthError { obj: String, wanted: usize, got: usize },
		#[error("Due to size restrictions a struct could not be parsed.")]
		ImpossibleStructError,
		#[error("when parsing field {obj}.{field}, {value} is not a valid {type_} value")]

tools/pdl/tests/generated/packet_decl_complex_big_endian.rs

+0 −11

Original line number	Diff line number	Diff line
		@@ -31,18 +31,9 @@ impl FooData {
		true
		}
		fn parse(bytes: &[u8]) -> Result<Self> {
		if bytes.len() < 1 {
		return Err(Error::InvalidLengthError {
		obj: "Foo".to_string(),
		field: "a".to_string(),
		wanted: 1,
		got: bytes.len(),
		});
		}
		if bytes.len() < 2 {
		return Err(Error::InvalidLengthError {
		obj: "Foo".to_string(),
		field: "b".to_string(),
		wanted: 2,
		got: bytes.len(),
		});
		@@ -54,7 +45,6 @@ impl FooData {
		if bytes.len() < 5 {
		return Err(Error::InvalidLengthError {
		obj: "Foo".to_string(),
		field: "d".to_string(),
		wanted: 5,
		got: bytes.len(),
		});
		@@ -63,7 +53,6 @@ impl FooData {
		if bytes.len() < 7 {
		return Err(Error::InvalidLengthError {
		obj: "Foo".to_string(),
		field: "e".to_string(),
		wanted: 7,
		got: bytes.len(),
		});

tools/pdl/tests/generated/packet_decl_complex_little_endian.rs

+0 −11

Original line number	Diff line number	Diff line
		@@ -31,18 +31,9 @@ impl FooData {
		true
		}
		fn parse(bytes: &[u8]) -> Result<Self> {
		if bytes.len() < 1 {
		return Err(Error::InvalidLengthError {
		obj: "Foo".to_string(),
		field: "a".to_string(),
		wanted: 1,
		got: bytes.len(),
		});
		}
		if bytes.len() < 2 {
		return Err(Error::InvalidLengthError {
		obj: "Foo".to_string(),
		field: "b".to_string(),
		wanted: 2,
		got: bytes.len(),
		});
		@@ -54,7 +45,6 @@ impl FooData {
		if bytes.len() < 5 {
		return Err(Error::InvalidLengthError {
		obj: "Foo".to_string(),
		field: "d".to_string(),
		wanted: 5,
		got: bytes.len(),
		});
		@@ -63,7 +53,6 @@ impl FooData {
		if bytes.len() < 7 {
		return Err(Error::InvalidLengthError {
		obj: "Foo".to_string(),
		field: "e".to_string(),
		wanted: 7,
		got: bytes.len(),
		});