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Commit 68efe3a9 authored by Martin Geisler's avatar Martin Geisler
Browse files

pdl: correctly apply mask in ‘write_to’ as well 

Before we only applied a mask in ‘parse’, and we always used a
hard-coded mask of the wrong size.

Test: atest pdl_inline_tests
Change-Id: Id499e009d2d83e9eb5e4aaffc375e527a1995864
parent 2bb6e84a

tools/pdl/src/generator.rs

+39 −12
Original line number Diff line number Diff line
@@ -122,6 +122,26 @@ fn generate_field_getter(packet_name: &syn::Ident, field: &ast::Field) -> proc_m 
    }

}



/// Mask and rebind the field value (if necessary).

fn mask_field_value(field: &ast::Field) -> Option<proc_macro2::TokenStream> {

    match field {

        ast::Field::Scalar { id, width, .. } => {

            let field_name = format_ident!("{id}");

            let type_width = round_bit_width(*width);

            if *width != type_width {

                let mask =

                    syn::parse_str::<syn::LitInt>(&format!("{:#x}", (1u64 << *width) - 1)).unwrap();

                Some(quote! {

                    let #field_name = #field_name & #mask;

                })

            } else {

                None

            }

        }

        _ => todo!("unsupported field: {:?}", field),

    }

}



fn generate_field_parser(

    endianness_value: &ast::EndiannessValue,

    packet_name: &str,
@@ -150,13 +170,7 @@ fn generate_field_parser( 


            let wanted_len = syn::Index::from(offset + width / 8);

            let indices = (offset..offset + width / 8).map(syn::Index::from);

            let mask = if *width != type_width {

                Some(quote! {

                    let #field_name = #field_name & 0xfff;

                })

            } else {

                None

            };

            let mask = mask_field_value(field);



            quote! {

                // TODO(mgeisler): call a function instead to avoid
@@ -187,16 +201,17 @@ fn generate_field_writer( 
    match field {

        ast::Field::Scalar { id, width, .. } => {

            let field_name = format_ident!("{id}");

            let bit_width = round_bit_width(*width);

            let start = syn::Index::from(offset);

            let end = syn::Index::from(offset + bit_width / 8);

            let byte_width = syn::Index::from(bit_width / 8);

            let end = syn::Index::from(offset + width / 8);

            let byte_width = syn::Index::from(width / 8);

            let mask = mask_field_value(field);

            let writer = match file.endianness.value {

                ast::EndiannessValue::BigEndian => format_ident!("to_be_bytes"),

                ast::EndiannessValue::LittleEndian => format_ident!("to_le_bytes"),

            };

            quote! {

                let #field_name = self.#field_name;

                #mask

                buffer[#start..#end].copy_from_slice(&#field_name.#writer()[0..#byte_width]);

            }

        }
@@ -535,6 +550,7 @@ mod tests { 
              packet Foo {

                x: 8,

                y: 16,

                z: 24,

              }

            "#,

        );
@@ -557,6 +573,7 @@ mod tests { 
              packet Foo {

                x: 8,

                y: 16,

                z: 24,

              }

            "#,

        );
@@ -591,6 +608,16 @@ mod tests { 
        );

    }



    #[test]

    fn test_mask_field_value() {

        let loc = ast::SourceRange::default();

        let field = ast::Field::Scalar { loc: loc.clone(), id: String::from("a"), width: 8 };

        assert_eq!(mask_field_value(&field).map(|m| m.to_string()), None);



        let field = ast::Field::Scalar { loc, id: String::from("a"), width: 24 };

        assert_expr_eq(mask_field_value(&field).unwrap(), quote! { let a = a & 0xffffff; });

    }



    #[test]

    fn test_generate_field_parser_no_padding() {

        let loc = ast::SourceRange::default();
@@ -629,7 +656,7 @@ mod tests { 
                    });

                }

                let a = u32::from_le_bytes([bytes[10], bytes[11], bytes[12], 0]);

                let a = a & 0xfff;

                let a = a & 0xffffff;

            },

        );

    }
@@ -651,7 +678,7 @@ mod tests { 
                    });

                }

                let a = u32::from_be_bytes([0, bytes[10], bytes[11], bytes[12]]);

                let a = a & 0xfff;

                let a = a & 0xffffff;

            },

        );

    }

tools/pdl/tests/generated/packet_decl_simple_big_endian.rs

+22 −4
Original line number Diff line number Diff line
@@ -2,6 +2,7 @@ 
struct FooData {

    x: u8,

    y: u16,

    z: u32,

}



#[derive(Debug, Clone)]
@@ -13,11 +14,12 @@ pub struct FooPacket { 
pub struct FooBuilder {

    pub x: u8,

    pub y: u16,

    pub z: u32,

}



impl FooData {

    fn conforms(bytes: &[u8]) -> bool {

        if bytes.len() < 3 {

        if bytes.len() < 6 {

            return false;

        }

        true
@@ -41,20 +43,33 @@ impl FooData { 
            });

        }

        let y = u16::from_be_bytes([bytes[1], bytes[2]]);

        Ok(Self { x, y })

        if bytes.len() < 6 {

            return Err(Error::InvalidLengthError {

                obj: "Foo".to_string(),

                field: "z".to_string(),

                wanted: 6,

                got: bytes.len(),

            });

        }

        let z = u32::from_be_bytes([0, bytes[3], bytes[4], bytes[5]]);

        let z = z & 0xffffff;

        Ok(Self { x, y, z })

    }

    fn write_to(&self, buffer: &mut BytesMut) {

        let x = self.x;

        buffer[0..1].copy_from_slice(&x.to_be_bytes()[0..1]);

        let y = self.y;

        buffer[1..3].copy_from_slice(&y.to_be_bytes()[0..2]);

        let z = self.z;

        let z = z & 0xffffff;

        buffer[3..6].copy_from_slice(&z.to_be_bytes()[0..3]);

    }

    fn get_total_size(&self) -> usize {

        self.get_size()

    }

    fn get_size(&self) -> usize {

        let ret = 0;

        let ret = ret + 3;

        let ret = ret + 6;

        ret

    }

}
@@ -95,11 +110,14 @@ impl FooPacket { 
    pub fn get_y(&self) -> u16 {

        self.foo.as_ref().y

    }

    pub fn get_z(&self) -> u32 {

        self.foo.as_ref().z

    }

}



impl FooBuilder {

    pub fn build(self) -> FooPacket {

        let foo = Arc::new(FooData { x: self.x, y: self.y });

        let foo = Arc::new(FooData { x: self.x, y: self.y, z: self.z });

        FooPacket::new(foo).unwrap()

    }

}

tools/pdl/tests/generated/packet_decl_simple_little_endian.rs

+22 −4
Original line number Diff line number Diff line
@@ -2,6 +2,7 @@ 
struct FooData {

    x: u8,

    y: u16,

    z: u32,

}



#[derive(Debug, Clone)]
@@ -13,11 +14,12 @@ pub struct FooPacket { 
pub struct FooBuilder {

    pub x: u8,

    pub y: u16,

    pub z: u32,

}



impl FooData {

    fn conforms(bytes: &[u8]) -> bool {

        if bytes.len() < 3 {

        if bytes.len() < 6 {

            return false;

        }

        true
@@ -41,20 +43,33 @@ impl FooData { 
            });

        }

        let y = u16::from_le_bytes([bytes[1], bytes[2]]);

        Ok(Self { x, y })

        if bytes.len() < 6 {

            return Err(Error::InvalidLengthError {

                obj: "Foo".to_string(),

                field: "z".to_string(),

                wanted: 6,

                got: bytes.len(),

            });

        }

        let z = u32::from_le_bytes([bytes[3], bytes[4], bytes[5], 0]);

        let z = z & 0xffffff;

        Ok(Self { x, y, z })

    }

    fn write_to(&self, buffer: &mut BytesMut) {

        let x = self.x;

        buffer[0..1].copy_from_slice(&x.to_le_bytes()[0..1]);

        let y = self.y;

        buffer[1..3].copy_from_slice(&y.to_le_bytes()[0..2]);

        let z = self.z;

        let z = z & 0xffffff;

        buffer[3..6].copy_from_slice(&z.to_le_bytes()[0..3]);

    }

    fn get_total_size(&self) -> usize {

        self.get_size()

    }

    fn get_size(&self) -> usize {

        let ret = 0;

        let ret = ret + 3;

        let ret = ret + 6;

        ret

    }

}
@@ -95,11 +110,14 @@ impl FooPacket { 
    pub fn get_y(&self) -> u16 {

        self.foo.as_ref().y

    }

    pub fn get_z(&self) -> u32 {

        self.foo.as_ref().z

    }

}



impl FooBuilder {

    pub fn build(self) -> FooPacket {

        let foo = Arc::new(FooData { x: self.x, y: self.y });

        let foo = Arc::new(FooData { x: self.x, y: self.y, z: self.z });

        FooPacket::new(foo).unwrap()

    }

}