Shell completions for Cargo

README.md

@@ -67,7 +67,7 @@ but the gist is as simple as using one of the following:
 
 ```
 # Bash
-$ rustup completions bash > /etc/bash_completion.d/rustup.bash-completion
+$ rustup completions bash > ~/.local/share/bash_completion/completions/rustup
 
 # Bash (macOS/Homebrew)
 $ rustup completions bash > $(brew --prefix)/etc/bash_completion.d/rustup.bash-completion

src/cli/errors.rs

@@ -1,8 +1,11 @@
 #![allow(dead_code)]
 
+use crate::rustup_mode::CompletionCommand;
+
 use std::io;
 use std::path::PathBuf;
 
+use clap::Shell;
 use error_chain::error_chain;
 use error_chain::error_chain_processing;
 use error_chain::{impl_error_chain_kind, impl_error_chain_processed, impl_extract_backtrace};
@@ -46,5 +49,9 @@ error_chain! {
         WindowsUninstallMadness {
             description("failure during windows uninstall")
         }
+        UnsupportedCompletionShell(shell: Shell, cmd: CompletionCommand) {
+            description("completion script for shell not yet supported for tool")
+            display("{} does not currently support completions for {}", cmd, shell)
+        }
     }
 }

src/cli/help.rs

@@ -164,10 +164,12 @@ r"DISCUSSION:
 
     BASH:
 
-    Completion files are commonly stored in `/etc/bash_completion.d/`.
+    Completion files are commonly stored in `/etc/bash_completion.d/` for
+    system-wide commands, but can be stored in in
+    `~/.local/share/bash_completion/completions` for user-specific commands.
     Run the command:
 
-        $ rustup completions bash > /etc/bash_completion.d/rustup.bash-completion
+        $ rustup completions bash >> ~/.local/share/bash_completion/completions/rustup
 
     This installs the completion script. You may have to log out and
     log back in to your shell session for the changes to take affect.
@@ -249,7 +251,22 @@ r"DISCUSSION:
     into a separate file and source it inside our profile. To save the
     completions into our profile simply use
 
-        PS C:\> rustup completions powershell >> ${env:USERPROFILE}\Documents\WindowsPowerShell\Microsoft.PowerShell_profile.ps1";
+        PS C:\> rustup completions powershell >> ${env:USERPROFILE}\Documents\WindowsPowerShell\Microsoft.PowerShell_profile.ps1
+
+    CARGO:
+
+    Rustup can also generate a completion script for `cargo`. The script output
+    by `rustup` will source the completion script distributed with your default
+    toolchain. Not all shells are currently supported. Here are examples for
+    the currently supported shells.
+
+    BASH:
+
+        $ rustup completions bash cargo >> ~/.local/share/bash_completion/completions/cargo
+
+    ZSH:
+
+        $ rustup completions zsh cargo > ~/.zfunc/_cargo";
 
 pub static TOOLCHAIN_ARG_HELP: &'static str = "Toolchain name, such as 'stable', 'nightly', \
                                                or '1.8.0'. For more information see `rustup \

src/cli/rustup_mode.rs

@@ -9,10 +9,12 @@ use rustup::dist::manifest::Component;
 use rustup::utils::utils::{self, ExitCode};
 use rustup::{command, Cfg, Toolchain};
 use std::error::Error;
-use std::io::{self, Write};
+use std::fmt;
+use std::io::Write;
 use std::iter;
 use std::path::Path;
 use std::process::{self, Command};
+use std::str::FromStr;
 
 fn handle_epipe(res: Result<()>) -> Result<()> {
     match res {
@@ -85,11 +87,12 @@ pub fn main() -> Result<()> {
         },
         ("completions", Some(c)) => {
             if let Some(shell) = c.value_of("shell") {
-                cli().gen_completions_to(
-                    "rustup",
+                output_completion_script(
                     shell.parse::<Shell>().unwrap(),
-                    &mut io::stdout(),
-                );
+                    c.value_of("command")
+                        .and_then(|cmd| cmd.parse::<CompletionCommand>().ok())
+                        .unwrap_or(CompletionCommand::Rustup),
+                )?;
             }
         }
         (_, _) => unreachable!(),
@@ -442,40 +445,98 @@ pub fn cli() -> App<'static, 'static> {
         );
     }
 
+    app = app
+        .subcommand(
+            SubCommand::with_name("self")
+                .about("Modify the rustup installation")
+                .setting(AppSettings::VersionlessSubcommands)
+                .setting(AppSettings::DeriveDisplayOrder)
+                .setting(AppSettings::SubcommandRequiredElseHelp)
+                .subcommand(
+                    SubCommand::with_name("update").about("Download and install updates to rustup"),
+                )
+                .subcommand(
+                    SubCommand::with_name("uninstall")
+                        .about("Uninstall rustup.")
+                        .arg(Arg::with_name("no-prompt").short("y")),
+                )
+                .subcommand(
+                    SubCommand::with_name("upgrade-data")
+                        .about("Upgrade the internal data format."),
+                ),
+        )
+        .subcommand(
+            SubCommand::with_name("set")
+                .about("Alter rustup settings")
+                .setting(AppSettings::SubcommandRequiredElseHelp)
+                .subcommand(
+                    SubCommand::with_name("default-host")
+                        .about("The triple used to identify toolchains when not specified")
+                        .arg(Arg::with_name("host_triple").required(true)),
+                ),
+        )
+        .subcommand(
+            SubCommand::with_name("self")
+                .about("Modify the rustup installation")
+                .setting(AppSettings::VersionlessSubcommands)
+                .setting(AppSettings::DeriveDisplayOrder)
+                .setting(AppSettings::SubcommandRequiredElseHelp)
+                .subcommand(
+                    SubCommand::with_name("update").about("Download and install updates to rustup"),
+                )
+                .subcommand(
+                    SubCommand::with_name("uninstall")
+                        .about("Uninstall rustup.")
+                        .arg(Arg::with_name("no-prompt").short("y")),
+                )
+                .subcommand(
+                    SubCommand::with_name("upgrade-data")
+                        .about("Upgrade the internal data format."),
+                ),
+        )
+        .subcommand(
+            SubCommand::with_name("telemetry")
+                .about("rustup telemetry commands")
+                .setting(AppSettings::Hidden)
+                .setting(AppSettings::VersionlessSubcommands)
+                .setting(AppSettings::DeriveDisplayOrder)
+                .setting(AppSettings::SubcommandRequiredElseHelp)
+                .subcommand(SubCommand::with_name("enable").about("Enable rustup telemetry"))
+                .subcommand(SubCommand::with_name("disable").about("Disable rustup telemetry"))
+                .subcommand(SubCommand::with_name("analyze").about("Analyze stored telemetry")),
+        )
+        .subcommand(
+            SubCommand::with_name("set")
+                .about("Alter rustup settings")
+                .setting(AppSettings::SubcommandRequiredElseHelp)
+                .subcommand(
+                    SubCommand::with_name("default-host")
+                        .about("The triple used to identify toolchains when not specified")
+                        .arg(Arg::with_name("host_triple").required(true)),
+                ),
+        );
+
+    // Clap provides no good way to say that help should be printed in all
+    // cases where an argument without a default is not provided. The following
+    // creates lists out all the conditions where the "shell" argument are
+    // provided and give the default of "rustup". This way if "shell" is not
+    // provided then the help will still be printed.
+    let completion_defaults = Shell::variants()
+        .iter()
+        .map(|&shell| ("shell", Some(shell), "rustup"))
+        .collect::<Vec<_>>();
+
     app.subcommand(
-        SubCommand::with_name("self")
-            .about("Modify the rustup installation")
-            .setting(AppSettings::VersionlessSubcommands)
-            .setting(AppSettings::DeriveDisplayOrder)
-            .setting(AppSettings::SubcommandRequiredElseHelp)
-            .subcommand(
-                SubCommand::with_name("update").about("Download and install updates to rustup"),
-            )
-            .subcommand(
-                SubCommand::with_name("uninstall")
-                    .about("Uninstall rustup.")
-                    .arg(Arg::with_name("no-prompt").short("y")),
-            )
-            .subcommand(
-                SubCommand::with_name("upgrade-data").about("Upgrade the internal data format."),
-            ),
-    )
-    .subcommand(
-        SubCommand::with_name("set")
-            .about("Alter rustup settings")
-            .setting(AppSettings::SubcommandRequiredElseHelp)
-            .subcommand(
-                SubCommand::with_name("default-host")
-                    .about("The triple used to identify toolchains when not specified")
-                    .arg(Arg::with_name("host_triple").required(true)),
-            ),
-    )
-    .subcommand(
         SubCommand::with_name("completions")
             .about("Generate completion scripts for your shell")
             .after_help(COMPLETIONS_HELP)
             .setting(AppSettings::ArgRequiredElseHelp)
-            .arg(Arg::with_name("shell").possible_values(&Shell::variants())),
+            .arg(Arg::with_name("shell").possible_values(&Shell::variants()))
+            .arg(
+                Arg::with_name("command")
+                    .possible_values(&CompletionCommand::variants())
+                    .default_value_ifs(&completion_defaults[..]),
+            ),
     )
 }
 
@@ -1050,3 +1111,76 @@ fn set_default_host_triple(cfg: &Cfg, m: &ArgMatches<'_>) -> Result<()> {
     cfg.set_default_host_triple(m.value_of("host_triple").expect(""))?;
     Ok(())
 }
+
+#[derive(Copy, Clone, Debug, PartialEq)]
+pub enum CompletionCommand {
+    Rustup,
+    Cargo,
+}
+
+static COMPLETIONS: &[(&'static str, CompletionCommand)] = &[
+    ("rustup", CompletionCommand::Rustup),
+    ("cargo", CompletionCommand::Cargo),
+];
+
+impl CompletionCommand {
+    fn variants() -> Vec<&'static str> {
+        COMPLETIONS.iter().map(|&(s, _)| s).collect::<Vec<_>>()
+    }
+}
+
+impl FromStr for CompletionCommand {
+    type Err = String;
+
+    fn from_str(s: &str) -> std::result::Result<Self, Self::Err> {
+        match COMPLETIONS
+            .iter()
+            .filter(|&(val, _)| val.eq_ignore_ascii_case(s))
+            .next()
+        {
+            Some(&(_, cmd)) => Ok(cmd),
+            None => {
+                let completion_options = COMPLETIONS
+                    .iter()
+                    .map(|&(v, _)| v)
+                    .fold("".to_owned(), |s, v| format!("{}{}, ", s, v));
+                Err(format!(
+                    "[valid values: {}]",
+                    completion_options.trim_end_matches(", ")
+                ))
+            }
+        }
+    }
+}
+
+impl fmt::Display for CompletionCommand {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match COMPLETIONS.iter().filter(|&(_, cmd)| cmd == self).next() {
+            Some(&(val, _)) => write!(f, "{}", val),
+            None => unreachable!(),
+        }
+    }
+}
+
+fn output_completion_script(shell: Shell, command: CompletionCommand) -> Result<()> {
+    match command {
+        CompletionCommand::Rustup => {
+            cli().gen_completions_to("rustup", shell, &mut term2::stdout());
+        }
+        CompletionCommand::Cargo => {
+            let script = match shell {
+                Shell::Bash => "/etc/bash_completion.d/cargo",
+                Shell::Zsh => "/share/zsh/site-functions/_cargo",
+                _ => return Err(ErrorKind::UnsupportedCompletionShell(shell, command).into()),
+            };
+
+            writeln!(
+                &mut term2::stdout(),
+                "source $(rustc --print sysroot){}",
+                script,
+            )?;
+        }
+    }
+
+    Ok(())
+}

tests/cli-misc.rs

@@ -4,8 +4,8 @@
 pub mod mock;
 
 use crate::mock::clitools::{
-    self, expect_err, expect_ok, expect_ok_ex, expect_stderr_ok, expect_stdout_ok, run,
-    set_current_dist_date, this_host_triple, Config, Scenario,
+    self, expect_err, expect_ok, expect_ok_eq, expect_ok_ex, expect_stderr_ok, expect_stdout_ok,
+    run, set_current_dist_date, this_host_triple, Config, Scenario,
 };
 use rustup::dist::errors::TOOLSTATE_MSG;
 use rustup::utils::{raw, utils};
@@ -789,3 +789,66 @@ fn update_unavailable_rustc() {
         expect_stdout_ok(config, &["rustc", "--version"], "hash-n-1");
     });
 }
+
+#[test]
+fn completion_rustup() {
+    setup(&|config| {
+        expect_ok(config, &["rustup", "completions", "bash", "rustup"]);
+    });
+}
+
+#[test]
+fn completion_cargo() {
+    setup(&|config| {
+        expect_ok(config, &["rustup", "completions", "bash", "cargo"]);
+    });
+}
+
+#[test]
+fn completion_default() {
+    setup(&|config| {
+        expect_ok_eq(
+            config,
+            &["rustup", "completions", "bash"],
+            &["rustup", "completions", "bash", "rustup"],
+        );
+    });
+}
+
+#[test]
+fn completion_bad_shell() {
+    setup(&|config| {
+        expect_err(
+            config,
+            &["rustup", "completions", "fake"],
+            "error: 'fake' isn't a valid value for '<shell>'",
+        );
+        expect_err(
+            config,
+            &["rustup", "completions", "fake", "cargo"],
+            "error: 'fake' isn't a valid value for '<shell>'",
+        );
+    });
+}
+
+#[test]
+fn completion_bad_tool() {
+    setup(&|config| {
+        expect_err(
+            config,
+            &["rustup", "completions", "bash", "fake"],
+            "error: 'fake' isn't a valid value for '<command>'",
+        );
+    });
+}
+
+#[test]
+fn completion_cargo_unsupported_shell() {
+    setup(&|config| {
+        expect_err(
+            config,
+            &["rustup", "completions", "fish", "cargo"],
+            "error: cargo does not currently support completions for ",
+        );
+    });
+}