From 5e5bb91043eb598b39adf46410f97b9ae5dbcf03 Mon Sep 17 00:00:00 2001
From: Thomas Queiroz <thomasqueirozb@gmail.com>
Date: Sat, 23 Oct 2021 23:21:45 -0300
Subject: [PATCH 1/3] sort: remove unecessary implementation

---
 src/uu/sort/src/sort.rs | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/src/uu/sort/src/sort.rs b/src/uu/sort/src/sort.rs
index bd79a6811..84ded8ba9 100644
--- a/src/uu/sort/src/sort.rs
+++ b/src/uu/sort/src/sort.rs
@@ -171,10 +171,6 @@ impl UError for SortError {
             _ => 2,
         }
     }
-
-    fn usage(&self) -> bool {
-        false
-    }
 }
 
 impl Display for SortError {

From 21a2d0ce408166eac3850892e7ce2ed54488a20d Mon Sep 17 00:00:00 2001
From: Thomas Queiroz <thomasqueirozb@gmail.com>
Date: Sat, 23 Oct 2021 23:22:21 -0300
Subject: [PATCH 2/3] sort: use Range.is_empty

---
 src/uu/sort/src/sort.rs | 20 ++++++++------------
 1 file changed, 8 insertions(+), 12 deletions(-)

diff --git a/src/uu/sort/src/sort.rs b/src/uu/sort/src/sort.rs
index 84ded8ba9..ae1bcfa4c 100644
--- a/src/uu/sort/src/sort.rs
+++ b/src/uu/sort/src/sort.rs
@@ -659,18 +659,14 @@ impl<'a> Line<'a> {
                 " ".repeat(UnicodeWidthStr::width(&line[..selection.start]))
             )?;
 
-            // TODO: Once our minimum supported rust version is at least 1.47, use selection.is_empty() instead.
-            #[allow(clippy::len_zero)]
-            {
-                if selection.len() == 0 {
-                    writeln!(writer, "^ no match for key")?;
-                } else {
-                    writeln!(
-                        writer,
-                        "{}",
-                        "_".repeat(UnicodeWidthStr::width(&line[selection]))
-                    )?;
-                }
+            if selection.is_empty() {
+                writeln!(writer, "^ no match for key")?;
+            } else {
+                writeln!(
+                    writer,
+                    "{}",
+                    "_".repeat(UnicodeWidthStr::width(&line[selection]))
+                )?;
             }
         }
         if settings.mode != SortMode::Random

From 1f15b8fce4b30c805aec5ea46360134fda82bc04 Mon Sep 17 00:00:00 2001
From: Thomas Queiroz <thomasqueirozb@gmail.com>
Date: Sat, 23 Oct 2021 23:25:22 -0300
Subject: [PATCH 3/3] cksum: use while loops instead of unroll!

---
 src/uu/cksum/src/cksum.rs | 73 +++++----------------------------------
 1 file changed, 9 insertions(+), 64 deletions(-)

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
 }