Remove active-toolchain-version and add help for show active-toolchain

Author: segevfiner

src/rustup-cli/help.rs

@@ -17,6 +17,15 @@ pub static SHOW_HELP: &'static str = r"DISCUSSION:
     If there are multiple toolchains installed then all installed
     toolchains are listed as well.";
 
+pub static SHOW_ACTIVE_TOOLCHAIN_HELP: &'static str = r"DISCUSSION:
+    Shows the name of the active toolchain.
+
+    This is useful for figuring out the active tool chain from
+    scripts.
+
+    You should use `rustc --print sysroot` to get the sysroot, or
+    `rustc --version` to get the toolchain version.";
+
 pub static UPDATE_HELP: &'static str = r"DISCUSSION:
     With no toolchain specified, the `update` command updates each of
     the installed toolchains from the official release channels, then

src/rustup-cli/rustup_mode.rs

@@ -31,7 +31,6 @@ pub fn main() -> Result<()> {
     match matches.subcommand() {
         ("show", Some(c)) => match c.subcommand() {
             ("active-toolchain", Some(_)) => show_active_toolchain(cfg)?,
-            ("active-toolchain-version", Some(_)) => show_active_toolchain_version(cfg)?,
             (_, _) => show(cfg)?
         },
         ("install", Some(m)) => update(cfg, m)?,
@@ -119,9 +118,7 @@ pub fn cli() -> App<'static, 'static> {
                 .setting(AppSettings::DeriveDisplayOrder)
                 .subcommand(SubCommand::with_name("active-toolchain")
                     .about("Show the active toolchain")
-                )
-                .subcommand(SubCommand::with_name("active-toolchain-version")
-                    .about("Show the active toolchain version")
+                    .after_help(SHOW_ACTIVE_TOOLCHAIN_HELP)
                 ),
         )
         .subcommand(
@@ -758,19 +755,6 @@ fn show_active_toolchain(cfg: &Cfg) -> Result<()> {
     Ok(())
 }
 
-fn show_active_toolchain_version(cfg: &Cfg) -> Result<()> {
-    let ref cwd = utils::current_dir()?;
-    match cfg.find_override_toolchain_or_default(cwd)? {
-        Some((ref toolchain, _)) => {
-            println!("{}", common::rustc_version(toolchain));
-        },
-        None => {
-            // Print nothing
-        }
-    }
-    Ok(())
-}
-
 fn target_list(cfg: &Cfg, m: &ArgMatches) -> Result<()> {
     let toolchain = explicit_or_dir_toolchain(cfg, m)?;
 

tests/cli-rustup.rs

@@ -873,32 +873,6 @@ fn show_active_toolchain_none() {
     });
 }
 
-#[test]
-fn show_active_toolchain_version() {
-    setup(&|config| {
-        expect_ok(config, &["rustup", "default", "nightly"]);
-        expect_ok_ex(
-            config,
-            &["rustup", "show", "active-toolchain-version"],
-            r"1.3.0 (hash-n-2)
-",
-            r"",
-        );
-    });
-}
-
-#[test]
-fn show_active_toolchain_version_none() {
-    setup(&|config| {
-        expect_ok_ex(
-            config,
-            &["rustup", "show", "active-toolchain-version"],
-            r"",
-            r"",
-        );
-    });
-}
-
 // #846
 #[test]
 fn set_default_host() {