pdl: apply zero-padding correctly on the MSB side of the payload am: 6c1556eec7 (d1fbfe0c) · Commits · e / os / android_packages_modules_Bluetooth

tools/pdl/src/generator.rs

+99 −3

Original line number	Original line	Diff line number	Diff line
	@@ -152,9 +152,17 @@ fn generate_field_parser(
	ast::EndiannessValue::LittleEndian => format_ident!("from_le_bytes"),		ast::EndiannessValue::LittleEndian => format_ident!("from_le_bytes"),
	};		};

			// We need the padding on the MSB side of the payload, so
			// for big-endian, we need to padding on the left, for
			// little-endian we need it on the right.
			let padding = vec![syn::Index::from(0); (type_width - width) / 8];
			let (padding_before, padding_after) = match endianness_value {
			ast::EndiannessValue::BigEndian => (padding, vec![]),
			ast::EndiannessValue::LittleEndian => (vec![], padding),
			};

	let wanted_len = syn::Index::from(offset + width / 8);		let wanted_len = syn::Index::from(offset + width / 8);
	let indices = (offset..offset + width / 8).map(syn::Index::from);		let indices = (offset..offset + width / 8).map(syn::Index::from);
	let padding = vec![syn::Index::from(0); (type_width - width) / 8];
	let mask = if *width != type_width {		let mask = if *width != type_width {
	Some(quote! {		Some(quote! {
	let #field_name = #field_name & 0xfff;		let #field_name = #field_name & 0xfff;
	@@ -174,7 +182,9 @@ fn generate_field_parser(
	got: bytes.len(),		got: bytes.len(),
	});		});
	}		}
	let #field_name = #field_type::#getter([#(bytes[#indices]),* #(, #padding)*]);		let #field_name = #field_type::#getter([
			#(#padding_before,)* #(bytes[#indices]),* #(, #padding_after)*
			]);
	#mask		#mask
	}		}
	}		}
	@@ -528,7 +538,7 @@ mod tests {
	use super::*;		use super::*;
	use crate::ast;		use crate::ast;
	use crate::parser::parse_inline;		use crate::parser::parse_inline;
	use crate::test_utils::{assert_snapshot_eq, rustfmt};		use crate::test_utils::{assert_eq_with_diff, assert_snapshot_eq, rustfmt};

	/// Parse a string fragment as a PDL file.		/// Parse a string fragment as a PDL file.
	///		///
	@@ -604,4 +614,90 @@ mod tests {
	&rustfmt(&actual_code),		&rustfmt(&actual_code),
	);		);
	}		}

			// Assert that an expression equals the given expression.
			//
			// Both expressions are wrapped in a `main` function (so we can
			// format it with `rustfmt`) and a diff is be shown if they
			// differ.
			#[track_caller]
			fn assert_expr_eq(left: proc_macro2::TokenStream, right: proc_macro2::TokenStream) {
			let left = quote! {
			fn main() { #left }
			};
			let right = quote! {
			fn main() { #right }
			};
			assert_eq_with_diff(
			"left",
			&rustfmt(&left.to_string()),
			"right",
			&rustfmt(&right.to_string()),
			);
			}

			#[test]
			fn test_generate_field_parser_no_padding() {
			let loc = ast::SourceRange::default();
			let field = ast::Field::Scalar { loc, id: String::from("a"), width: 8 };

			assert_expr_eq(
			generate_field_parser(&ast::EndiannessValue::BigEndian, "Foo", &field, 10),
			quote! {
			if bytes.len() < 11 {
			return Err(Error::InvalidLengthError {
			obj: "Foo".to_string(),
			field: "a".to_string(),
			wanted: 11,
			got: bytes.len(),
			});
			}
			let a = u8::from_be_bytes([bytes[10]]);
			},
			);
			}

			#[test]
			fn test_generate_field_parser_little_endian_padding() {
			// Test with width != type width.
			let loc = ast::SourceRange::default();
			let field = ast::Field::Scalar { loc, id: String::from("a"), width: 24 };
			assert_expr_eq(
			generate_field_parser(&ast::EndiannessValue::LittleEndian, "Foo", &field, 10),
			quote! {
			if bytes.len() < 13 {
			return Err(Error::InvalidLengthError {
			obj: "Foo".to_string(),
			field: "a".to_string(),
			wanted: 13,
			got: bytes.len(),
			});
			}
			let a = u32::from_le_bytes([bytes[10], bytes[11], bytes[12], 0]);
			let a = a & 0xfff;
			},
			);
			}

			#[test]
			fn test_generate_field_parser_big_endian_padding() {
			// Test with width != type width.
			let loc = ast::SourceRange::default();
			let field = ast::Field::Scalar { loc, id: String::from("a"), width: 24 };
			assert_expr_eq(
			generate_field_parser(&ast::EndiannessValue::BigEndian, "Foo", &field, 10),
			quote! {
			if bytes.len() < 13 {
			return Err(Error::InvalidLengthError {
			obj: "Foo".to_string(),
			field: "a".to_string(),
			wanted: 13,
			got: bytes.len(),
			});
			}
			let a = u32::from_be_bytes([0, bytes[10], bytes[11], bytes[12]]);
			let a = a & 0xfff;
			},
			);
			}
	}		}