Support --verbose for rustup show

Which prints rustc info for each installed toolchain. See added test for
example output.

Author: Enselic

src/cli/rustup_mode.rs

@@ -142,7 +142,7 @@ pub fn main() -> Result<utils::ExitCode> {
             ("home", Some(_)) => handle_epipe(show_rustup_home(cfg))?,
             ("profile", Some(_)) => handle_epipe(show_profile(cfg))?,
             ("keys", Some(_)) => handle_epipe(show_keys(cfg))?,
-            (_, _) => handle_epipe(show(cfg))?,
+            (_, _) => handle_epipe(show(cfg, c))?,
         },
         ("install", Some(m)) => deprecated("toolchain install", cfg, m, update)?,
         ("update", Some(m)) => update(cfg, m)?,
@@ -243,6 +243,9 @@ pub(crate) fn cli() -> App<'static, 'static> {
             SubCommand::with_name("show")
                 .about("Show the active and installed toolchains or profiles")
                 .after_help(SHOW_HELP)
+                .arg(
+                    verbose_arg("Enable verbose output with rustc information for all installed toolchains"),
+                )
                 .setting(AppSettings::VersionlessSubcommands)
                 .setting(AppSettings::DeriveDisplayOrder)
                 .subcommand(
@@ -1056,7 +1059,9 @@ fn which(cfg: &Cfg, m: &ArgMatches<'_>) -> Result<utils::ExitCode> {
     Ok(utils::ExitCode(0))
 }
 
-fn show(cfg: &Cfg) -> Result<utils::ExitCode> {
+fn show(cfg: &Cfg, m: &ArgMatches<'_>) -> Result<utils::ExitCode> {
+    let verbose = m.is_present("verbose");
+
     // Print host triple
     {
         let mut t = term2::stdout();
@@ -1130,6 +1135,14 @@ fn show(cfg: &Cfg) -> Result<utils::ExitCode> {
             } else {
                 writeln!(t, "{}", it)?;
             }
+            if verbose {
+                if let Ok(toolchain) = cfg.get_toolchain(&it, false) {
+                    writeln!(process().stdout(), "{}", toolchain.rustc_version())?;
+                }
+                // To make it easy to see what rustc that belongs to what
+                // toolchain we separate each pair with an extra newline
+                writeln!(process().stdout())?;
+            }
         }
         if show_headers {
             writeln!(t)?

tests/cli-rustup.rs

@@ -1067,6 +1067,42 @@ fn show_active_toolchain() {
     });
 }
 
+#[test]
+fn show_with_verbose() {
+    setup(&|config| {
+        expect_ok(config, &["rustup", "default", "nightly"]);
+        expect_ok(config, &["rustup", "update", "nightly-2015-01-01"]);
+        expect_ok_ex(
+            config,
+            &["rustup", "show", "--verbose"],
+            for_host_and_home!(
+                config,
+                r"Default host: {0}
+rustup home:  {1}
+
+installed toolchains
+--------------------
+
+nightly-2015-01-01-{0}
+1.2.0 (hash-nightly-1)
+
+nightly-{0} (default)
+1.3.0 (hash-nightly-2)
+
+
+active toolchain
+----------------
+
+nightly-{0} (default)
+1.3.0 (hash-nightly-2)
+
+"
+            ),
+            r"",
+        );
+    });
+}
+
 #[test]
 fn show_active_toolchain_with_verbose() {
     setup(&|config| {