diff --git a/src/uu/cksum/src/cksum.rs b/src/uu/cksum/src/cksum.rs index 55c4f980f..92853a3e8 100644 --- a/src/uu/cksum/src/cksum.rs +++ b/src/uu/cksum/src/cksum.rs @@ -25,60 +25,15 @@ const NAME: &str = "cksum"; const SYNTAX: &str = "[OPTIONS] [FILE]..."; const SUMMARY: &str = "Print CRC and size for each file"; -// this is basically a hack to get "loops" to work on Rust 1.33. Once we update to Rust 1.46 or -// greater, we can just use while loops -macro_rules! unroll { - (256, |$i:ident| $s:expr) => {{ - unroll!(@ 32, 0 * 32, $i, $s); - unroll!(@ 32, 1 * 32, $i, $s); - unroll!(@ 32, 2 * 32, $i, $s); - unroll!(@ 32, 3 * 32, $i, $s); - unroll!(@ 32, 4 * 32, $i, $s); - unroll!(@ 32, 5 * 32, $i, $s); - unroll!(@ 32, 6 * 32, $i, $s); - unroll!(@ 32, 7 * 32, $i, $s); - }}; - (8, |$i:ident| $s:expr) => {{ - unroll!(@ 8, 0, $i, $s); - }}; - - (@ 32, $start:expr, $i:ident, $s:expr) => {{ - unroll!(@ 8, $start + 0 * 8, $i, $s); - unroll!(@ 8, $start + 1 * 8, $i, $s); - unroll!(@ 8, $start + 2 * 8, $i, $s); - unroll!(@ 8, $start + 3 * 8, $i, $s); - }}; - (@ 8, $start:expr, $i:ident, $s:expr) => {{ - unroll!(@ 4, $start, $i, $s); - unroll!(@ 4, $start + 4, $i, $s); - }}; - (@ 4, $start:expr, $i:ident, $s:expr) => {{ - unroll!(@ 2, $start, $i, $s); - unroll!(@ 2, $start + 2, $i, $s); - }}; - (@ 2, $start:expr, $i:ident, $s:expr) => {{ - unroll!(@ 1, $start, $i, $s); - unroll!(@ 1, $start + 1, $i, $s); - }}; - (@ 1, $start:expr, $i:ident, $s:expr) => {{ - let $i = $start; - let _ = $s; - }}; -} - const fn generate_crc_table() -> [u32; CRC_TABLE_LEN] { let mut table = [0; CRC_TABLE_LEN]; - // NOTE: works on Rust 1.46 - //let mut i = 0; - //while i < CRC_TABLE_LEN { - // table[i] = crc_entry(i as u8) as u32; - // - // i += 1; - //} - unroll!(256, |i| { + let mut i = 0; + while i < CRC_TABLE_LEN { table[i] = crc_entry(i as u8) as u32; - }); + + i += 1; + } table } @@ -86,19 +41,8 @@ const fn generate_crc_table() -> [u32; CRC_TABLE_LEN] { const fn crc_entry(input: u8) -> u32 { let mut crc = (input as u32) << 24; - // NOTE: this does not work on Rust 1.33, but *does* on 1.46 - //let mut i = 0; - //while i < 8 { - // if crc & 0x8000_0000 != 0 { - // crc <<= 1; - // crc ^= 0x04c1_1db7; - // } else { - // crc <<= 1; - // } - // - // i += 1; - //} - unroll!(8, |_i| { + let mut i = 0; + while i < 8 { let if_condition = crc & 0x8000_0000; let if_body = (crc << 1) ^ 0x04c1_1db7; let else_body = crc << 1; @@ -108,7 +52,8 @@ const fn crc_entry(input: u8) -> u32 { let condition_table = [else_body, if_body]; crc = condition_table[(if_condition != 0) as usize]; - }); + i += 1; + } crc }