build: gate utilities by target support

Author: xtqqczze

build.rs

@@ -37,6 +37,9 @@ pub fn main() {
 
     let out_dir = env::var("OUT_DIR").unwrap();
 
+    let target_os = env::var_os("CARGO_CFG_TARGET_OS").unwrap();
+    let is_unix = env::var_os("CARGO_CFG_UNIX").is_some();
+
     let mut crates = Vec::new();
     for (key, val) in env::vars() {
         if val == "1" && key.starts_with(ENV_FEATURE_PREFIX) {
@@ -48,6 +51,12 @@ pub fn main() {
                 "chcon" | "runcon" => {
                     continue;
                 }
+                "nohup" | "stdbuf" if !is_unix => {
+                    continue;
+                }
+                "who" if !(is_unix && target_os != "redox") => {
+                    continue;
+                }
                 "default" | "macos" | "unix" | "windows" | "selinux" | "zip" | "clap_complete"
                 | "clap_mangen" | "fluent_syntax" => continue, // common/standard feature names
                 "nightly" | "test_unimplemented" | "expensive_tests" | "test_risky_names" => {

src/uu/nohup/Cargo.toml

@@ -19,7 +19,7 @@ path = "src/nohup.rs"
 test = false
 doctest = false
 
-[dependencies]
+[target.'cfg(unix)'.dependencies]
 clap = { workspace = true }
 libc = { workspace = true }
 rustix = { workspace = true, features = ["process", "stdio"] }
@@ -30,3 +30,4 @@ fluent = { workspace = true }
 [[bin]]
 name = "nohup"
 path = "src/main.rs"
+required-features = ["uucore/default"]

src/uu/nohup/src/nohup.rs

@@ -4,8 +4,8 @@
 // file that was distributed with this source code.
 
 // spell-checker:ignore (ToDO) SIGHUP cproc vprocmgr homeout
-#[cfg(not(unix))]
-compile_error!("nohup is not supported on the target");
+
+#![cfg(unix)]
 
 use clap::{Arg, ArgAction, Command};
 use rustix::stdio::{dup2_stderr, dup2_stdin, dup2_stdout, stdout};

src/uu/who/Cargo.toml

@@ -25,7 +25,7 @@ path = "src/who.rs"
 test = false
 doctest = false
 
-[dependencies]
+[target.'cfg(all(unix, not(target_os = "redox")))'.dependencies]
 clap = { workspace = true }
 rustix = { workspace = true }
 uucore = { workspace = true, features = ["utmpx"] }
@@ -34,3 +34,4 @@ fluent = { workspace = true }
 [[bin]]
 name = "who"
 path = "src/main.rs"
+required-features = ["uucore/utmpx"]

src/uu/who/src/who.rs

@@ -5,6 +5,8 @@
 
 // spell-checker:ignore (ToDO) runlevel mesg
 
+#![cfg(all(unix, not(target_os = "redox")))]
+
 use clap::{Arg, ArgAction, Command};
 use uucore::format_usage;
 use uucore::translate;