Allow selecting toolchains to uninstall with glob pattern

src/cli/rustup_mode.rs

@@ -7,6 +7,7 @@ use std::process::Command;
 use std::str::FromStr;
 
 use clap::{App, AppSettings, Arg, ArgGroup, ArgMatches, Shell, SubCommand};
+use regex::Regex;
 
 use super::common;
 use super::errors::*;
@@ -404,6 +405,12 @@ pub fn cli() -> App<'static, 'static> {
                     SubCommand::with_name("uninstall")
                         .about("Uninstall a toolchain")
                         .alias("remove")
+                        .arg(
+                            Arg::with_name("regex")
+                                .help("Use a regular expression to select the toolchains to uninstall")
+                                .long("regex")
+                                .takes_value(false),
+                        )
                         .arg(
                             Arg::with_name("toolchain")
                                 .help(TOOLCHAIN_ARG_HELP)
@@ -1312,10 +1319,25 @@ fn toolchain_link(cfg: &Cfg, m: &ArgMatches<'_>) -> Result<utils::ExitCode> {
 }
 
 fn toolchain_remove(cfg: &mut Cfg, m: &ArgMatches<'_>) -> Result<utils::ExitCode> {
-    for toolchain in m.values_of("toolchain").unwrap() {
-        let toolchain = cfg.get_toolchain(toolchain, false)?;
-        toolchain.remove()?;
+    if m.is_present("regex") {
+        assert!(
+            m.values_of("toolchain").unwrap().len() == 1,
+            "exactly one regex filter must be supplied"
+        );
+
+        let regex = Regex::from_str(m.values_of("toolchain").unwrap().next().unwrap())
+            .expect("invalid regex");
+
+        for toolchain in cfg.get_toolchains_from_regex(regex)? {
+            toolchain.remove()?;
+        }
+    } else {
+        for toolchain in m.values_of("toolchain").unwrap() {
+            let toolchain = cfg.get_toolchain(toolchain, false)?;
+            toolchain.remove()?;
+        }
     }
+
     Ok(utils::ExitCode(0))
 }
 

src/config.rs

@@ -1,12 +1,14 @@
 use std::borrow::Cow;
 use std::fmt::{self, Display};
 use std::io;
+use std::iter;
 use std::path::{Path, PathBuf};
 use std::process::Command;
 use std::str::FromStr;
 use std::sync::Arc;
 
 use pgp::{Deserializable, SignedPublicKey};
+use regex::Regex;
 use serde::Deserialize;
 
 use crate::dist::download::DownloadCfg;
@@ -362,6 +364,14 @@ impl Cfg {
         Toolchain::from(self, name)
     }
 
+    pub fn get_toolchains_from_regex(&self, regex: Regex) -> Result<Vec<Toolchain<'_>>> {
+        Ok(self
+            .list_toolchains_iter()?
+            .filter(|toolchain| regex.is_match(toolchain))
+            .map(|toolchain| Toolchain::from(self, &toolchain).unwrap())
+            .collect())
+    }
+
     pub fn verify_toolchain(&self, name: &str) -> Result<Toolchain<'_>> {
         let toolchain = self.get_toolchain(name, false)?;
         toolchain.verify()?;
@@ -694,18 +704,21 @@ impl Cfg {
     }
 
     pub fn list_toolchains(&self) -> Result<Vec<String>> {
-        if utils::is_directory(&self.toolchains_dir) {
-            let mut toolchains: Vec<_> = utils::read_dir("toolchains", &self.toolchains_dir)?
-                .filter_map(io::Result::ok)
-                .filter(|e| e.file_type().map(|f| !f.is_file()).unwrap_or(false))
-                .filter_map(|e| e.file_name().into_string().ok())
-                .collect();
-
-            utils::toolchain_sort(&mut toolchains);
+        let mut toolchains: Vec<_> = self.list_toolchains_iter()?.collect();
+        utils::toolchain_sort(&mut toolchains);
+        Ok(toolchains)
+    }
 
-            Ok(toolchains)
+    fn list_toolchains_iter(&self) -> Result<Box<dyn Iterator<Item = String>>> {
+        if utils::is_directory(&self.toolchains_dir) {
+            Ok(Box::new(
+                utils::read_dir("toolchains", &self.toolchains_dir)?
+                    .filter_map(io::Result::ok)
+                    .filter(|e| e.file_type().map(|f| !f.is_file()).unwrap_or(false))
+                    .filter_map(|e| e.file_name().into_string().ok()),
+            ))
         } else {
-            Ok(Vec::new())
+            Ok(Box::new(iter::empty()))
         }
     }