uucore: Cache args_os(), util_name(), execution_phrase()

And remove args() because there's no valid use for it, invalid unicode
handling is specified in a different way.

Cargo.lock

@@ -3276,6 +3276,7 @@ dependencies = [
  "getopts",
  "lazy_static",
  "libc",
+ "once_cell",
  "termion",
  "thiserror",
  "time",

src/uu/base32/src/base32.rs

@@ -38,7 +38,7 @@ pub fn uumain(args: impl uucore::Args) -> i32 {
     let name = uucore::util_name();
 
     let config_result: Result<base_common::Config, String> =
-        base_common::parse_base_cmd_args(args, &name, VERSION, ABOUT, &usage);
+        base_common::parse_base_cmd_args(args, name, VERSION, ABOUT, &usage);
     let config = config_result.unwrap_or_else(|s| crash!(BASE_CMD_PARSE_ERROR, "{}", s));
 
     // Create a reference to stdin so we can return a locked stdin from
@@ -52,12 +52,12 @@ pub fn uumain(args: impl uucore::Args) -> i32 {
         config.wrap_cols,
         config.ignore_garbage,
         config.decode,
-        &name,
+        name,
     );
 
     0
 }
 
 pub fn uu_app() -> App<'static, 'static> {
-    base_common::base_app(&uucore::util_name(), VERSION, ABOUT)
+    base_common::base_app(uucore::util_name(), VERSION, ABOUT)
 }

src/uu/base64/src/base64.rs

@@ -38,7 +38,7 @@ pub fn uumain(args: impl uucore::Args) -> i32 {
     let usage = usage();
     let name = uucore::util_name();
     let config_result: Result<base_common::Config, String> =
-        base_common::parse_base_cmd_args(args, &name, VERSION, ABOUT, &usage);
+        base_common::parse_base_cmd_args(args, name, VERSION, ABOUT, &usage);
     let config = config_result.unwrap_or_else(|s| crash!(BASE_CMD_PARSE_ERROR, "{}", s));
 
     // Create a reference to stdin so we can return a locked stdin from
@@ -52,7 +52,7 @@ pub fn uumain(args: impl uucore::Args) -> i32 {
         config.wrap_cols,
         config.ignore_garbage,
         config.decode,
-        &name,
+        name,
     );
 
     0

src/uu/basenc/src/basenc.rs

@@ -47,7 +47,7 @@ fn usage() -> String {
 }
 
 pub fn uu_app() -> App<'static, 'static> {
-    let mut app = base_common::base_app(&uucore::util_name(), crate_version!(), ABOUT);
+    let mut app = base_common::base_app(uucore::util_name(), crate_version!(), ABOUT);
     for encoding in ENCODINGS {
         app = app.arg(Arg::with_name(encoding.0).long(encoding.0));
     }
@@ -88,7 +88,7 @@ pub fn uumain(args: impl uucore::Args) -> i32 {
         config.wrap_cols,
         config.ignore_garbage,
         config.decode,
-        &name,
+        name,
     );
 
     0

src/uu/du/src/du.rs

@@ -466,7 +466,7 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
 
     let options = Options {
         all: matches.is_present(options::ALL),
-        util_name: uucore::util_name(),
+        util_name: uucore::util_name().to_owned(),
         max_depth,
         total: matches.is_present(options::TOTAL),
         separate_dirs: matches.is_present(options::SEPARATE_DIRS),

src/uu/logname/src/logname.rs

@@ -35,7 +35,7 @@ fn get_userlogin() -> Option<String> {
 
 static SUMMARY: &str = "Print user's login name";
 
-fn usage() -> String {
+fn usage() -> &'static str {
     uucore::execution_phrase()
 }
 
@@ -44,8 +44,7 @@ pub fn uumain(args: impl uucore::Args) -> i32 {
         .collect_str(InvalidEncodingHandling::Ignore)
         .accept_any();
 
-    let usage = usage();
-    let _ = uu_app().usage(&usage[..]).get_matches_from(args);
+    let _ = uu_app().usage(usage()).get_matches_from(args);
 
     match get_userlogin() {
         Some(userlogin) => println!("{}", userlogin),

src/uucore/Cargo.toml

@@ -30,6 +30,7 @@ data-encoding = { version="2.1", optional=true }
 data-encoding-macro = { version="0.1.12", optional=true }
 z85 = { version="3.0.3", optional=true }
 libc = { version="0.2.15", optional=true }
+once_cell = "1.8.0"
 
 [dev-dependencies]
 clap = "2.33.3"

src/uucore/src/lib/lib.rs

@@ -70,6 +70,8 @@ pub use crate::features::wide;
 use std::ffi::OsString;
 use std::sync::atomic::Ordering;
 
+use once_cell::sync::Lazy;
+
 pub fn get_utility_is_second_arg() -> bool {
     crate::macros::UTILITY_IS_SECOND_ARG.load(Ordering::SeqCst)
 }
@@ -78,36 +80,40 @@ pub fn set_utility_is_second_arg() {
     crate::macros::UTILITY_IS_SECOND_ARG.store(true, Ordering::SeqCst)
 }
 
-/// Get the executable path (as `OsString`).
-fn executable_os() -> OsString {
-    args_os().next().unwrap()
-}
+// args_os() can be expensive to call, it copies all of argv before iterating.
+// So if we want only the first arg or so it's overkill. We cache it.
+static ARGV: Lazy<Vec<OsString>> = Lazy::new(|| wild::args_os().collect());
 
-/// Get the executable path (as `String`).
-fn executable() -> String {
-    executable_os().to_string_lossy().into_owned()
-}
+static UTIL_NAME: Lazy<String> = Lazy::new(|| {
+    if get_utility_is_second_arg() {
+        &ARGV[1]
+    } else {
+        &ARGV[0]
+    }
+    .to_string_lossy()
+    .into_owned()
+});
 
 /// Derive the utility name.
-pub fn util_name() -> String {
-    if get_utility_is_second_arg() {
-        args_os().nth(1).unwrap().to_string_lossy().into_owned()
-    } else {
-        executable()
-    }
+pub fn util_name() -> &'static str {
+    &UTIL_NAME
 }
 
-/// Derive the complete execution phrase for "usage".
-pub fn execution_phrase() -> String {
+static EXECUTION_PHRASE: Lazy<String> = Lazy::new(|| {
     if get_utility_is_second_arg() {
-        args_os()
+        ARGV.iter()
             .take(2)
             .map(|os_str| os_str.to_string_lossy().into_owned())
             .collect::<Vec<_>>()
             .join(" ")
     } else {
-        executable()
+        ARGV[0].to_string_lossy().into_owned()
     }
+});
+
+/// Derive the complete execution phrase for "usage".
+pub fn execution_phrase() -> &'static str {
+    &EXECUTION_PHRASE
 }
 
 pub enum InvalidEncodingHandling {
@@ -204,13 +210,8 @@ pub trait Args: Iterator<Item = OsString> + Sized {
 
 impl<T: Iterator<Item = OsString> + Sized> Args for T {}
 
-// args() ...
-pub fn args() -> impl Iterator<Item = String> {
-    wild::args()
-}
-
 pub fn args_os() -> impl Iterator<Item = OsString> {
-    wild::args_os()
+    ARGV.iter().cloned()
 }
 
 #[cfg(test)]