From 1fe7cc5595a7ae458cd63cd503ebd9f00171036b Mon Sep 17 00:00:00 2001
From: Roy Ivy III <rivy.dev@gmail.com>
Date: Thu, 21 May 2020 17:10:28 -0500
Subject: [PATCH] build/fix ~ (build.rs) fix 'feature => sub-crate/util'
 translation logic + improved output formatting

---
 build.rs | 85 +++++++++++++++++++++++++++++++-------------------------
 1 file changed, 47 insertions(+), 38 deletions(-)

diff --git a/build.rs b/build.rs
index 3e969ab32..34c62d210 100644
--- a/build.rs
+++ b/build.rs
@@ -11,18 +11,22 @@ pub fn main() {
         println!("cargo:rustc-cfg=build={:?}", profile);
     }
 
-    let feature_prefix = "CARGO_FEATURE_";
+    let env_feature_prefix: &str = "CARGO_FEATURE_";
+    let feature_prefix: &str = "feat_";
+    let override_prefix: &str = "uu_";
+
     let out_dir = env::var("OUT_DIR").unwrap();
 
     let mut crates = Vec::new();
     for (key, val) in env::vars() {
-        if val == "1" && key.starts_with(feature_prefix) {
-            let krate = key[feature_prefix.len()..].to_lowercase();
+        if val == "1" && key.starts_with(env_feature_prefix) {
+            let krate = key[env_feature_prefix.len()..].to_lowercase();
             match krate.as_ref() {
-                "default" | "macos" | "unix" | "windows" => continue,
-                "nightly" | "test_unimplemented" => continue,
-                s if s.starts_with("feat_") => continue,
-                _ => {}
+                "default" | "macos" | "unix" | "windows" => continue, // common/standard feature names
+                "nightly" | "test_unimplemented" => continue,         // crate-local custom features
+                "test" => continue, // over-ridden with 'uu_test' to avoid collision with rust core crate 'test'
+                s if s.starts_with(feature_prefix) => continue, // crate feature sets
+                _ => {}             // util feature name
             }
             crates.push(krate.to_string());
         }
@@ -32,50 +36,55 @@ pub fn main() {
     let mut mf = File::create(Path::new(&out_dir).join("uutils_map.rs")).unwrap();
 
     mf.write_all(
+        "type UtilityMap = HashMap<&'static str, fn(Vec<String>) -> i32>;\n\
+        \n\
+        fn util_map() -> UtilityMap {\n\
+        \tlet mut map: UtilityMap = HashMap::new();\n\
         "
-    type UtilityMap = HashMap<&'static str, fn(Vec<String>) -> i32>;
-
-    fn util_map() -> UtilityMap {
-    let mut map: UtilityMap = HashMap::new();\n"
-            .as_bytes(),
+        .as_bytes(),
     )
     .unwrap();
 
     for krate in crates {
         match krate.as_ref() {
-            // ToDO: add another bypass method for publishing name collisions requiring a non-`uu_` prefix for a util
-            // * use "uu_" prefix as bypass method to avoid name collisions with imported crates, when necessary (eg, 'test')
-            k if k.starts_with("uu_")
-                => mf
-                    .write_all(
-                        format!("map.insert(\"{k}\", {krate}::uumain);\n", k = krate.clone().remove("uu_".len()), krate = krate)
-                            .as_bytes(),
+            k if k.starts_with(override_prefix) => mf
+                .write_all(
+                    format!(
+                        "\tmap.insert(\"{k}\", {krate}::uumain);\n",
+                        k = krate[override_prefix.len()..].to_string(),
+                        krate = krate
                     )
-                    .unwrap(),
+                    .as_bytes(),
+                )
+                .unwrap(),
             "false" | "true" => mf
                 .write_all(
-                    format!("map.insert(\"{krate}\", r#{krate}::uumain);\n", krate = krate)
-                        .as_bytes(),
+                    format!(
+                        "\tmap.insert(\"{krate}\", r#{krate}::uumain);\n",
+                        krate = krate
+                    )
+                    .as_bytes(),
                 )
                 .unwrap(),
             "hashsum" => mf
                 .write_all(
                     format!(
-                        "
-                        map.insert(\"{krate}\", {krate}::uumain);
-                            map.insert(\"md5sum\", {krate}::uumain);
-                            map.insert(\"sha1sum\", {krate}::uumain);
-                            map.insert(\"sha224sum\", {krate}::uumain);
-                            map.insert(\"sha256sum\", {krate}::uumain);
-                            map.insert(\"sha384sum\", {krate}::uumain);
-                            map.insert(\"sha512sum\", {krate}::uumain);
-                            map.insert(\"sha3sum\", {krate}::uumain);
-                            map.insert(\"sha3-224sum\", {krate}::uumain);
-                            map.insert(\"sha3-256sum\", {krate}::uumain);
-                            map.insert(\"sha3-384sum\", {krate}::uumain);
-                            map.insert(\"sha3-512sum\", {krate}::uumain);
-                            map.insert(\"shake128sum\", {krate}::uumain);
-                            map.insert(\"shake256sum\", {krate}::uumain);\n",
+                        "\
+                        \tmap.insert(\"{krate}\", {krate}::uumain);\n\
+                        \t\tmap.insert(\"md5sum\", {krate}::uumain);\n\
+                        \t\tmap.insert(\"sha1sum\", {krate}::uumain);\n\
+                        \t\tmap.insert(\"sha224sum\", {krate}::uumain);\n\
+                        \t\tmap.insert(\"sha256sum\", {krate}::uumain);\n\
+                        \t\tmap.insert(\"sha384sum\", {krate}::uumain);\n\
+                        \t\tmap.insert(\"sha512sum\", {krate}::uumain);\n\
+                        \t\tmap.insert(\"sha3sum\", {krate}::uumain);\n\
+                        \t\tmap.insert(\"sha3-224sum\", {krate}::uumain);\n\
+                        \t\tmap.insert(\"sha3-256sum\", {krate}::uumain);\n\
+                        \t\tmap.insert(\"sha3-384sum\", {krate}::uumain);\n\
+                        \t\tmap.insert(\"sha3-512sum\", {krate}::uumain);\n\
+                        \t\tmap.insert(\"shake128sum\", {krate}::uumain);\n\
+                        \t\tmap.insert(\"shake256sum\", {krate}::uumain);\n\
+                        ",
                         krate = krate
                     )
                     .as_bytes(),
@@ -84,7 +93,7 @@ pub fn main() {
             _ => mf
                 .write_all(
                     format!(
-                        "map.insert(\"{krate}\", {krate}::uumain);\n",
+                        "\tmap.insert(\"{krate}\", {krate}::uumain);\n",
                         krate = krate
                     )
                     .as_bytes(),