Add preinstall-toolchains binary and run it in CI

.github/workflows/ci.yml

@@ -157,6 +157,9 @@ jobs:
           sudo rm -rf /usr/share/swift
           # du -sh /usr/*/* 2>/dev/null | sort -h || true
 
+      - name: Preinstall toolchains
+        run: cargo run -p dylint_internal --bin preinstall-toolchains
+
       - name: Test
         run: |
           if [[ '${{ matrix.package }}' =~ ^cargo-dylint ]]; then

internal/Cargo.toml

@@ -9,6 +9,8 @@ repository = "https://github.com/trailofbits/dylint"
 
 [dependencies]
 anyhow = "1.0"
+assert_cmd = "2.0"
+regex = "1.10"
 
 ansi_term = { version = "0.12", optional = true }
 bitflags = { version = "2.6", optional = true }
@@ -22,7 +24,6 @@ if_chain = { version = "1.0", optional = true }
 is-terminal = { version = "0.4", optional = true }
 log = { version = "0.4", optional = true }
 once_cell = { version = "1.19", optional = true }
-regex = { version = "1.10", optional = true }
 rust-embed = { version = "8.5", features = [
     "include-exclude",
 ], optional = true }
@@ -53,7 +54,7 @@ examples = ["cargo", "cargo-util", "rustup", "walkdir"]
 git = ["command", "git2", "if_chain"]
 packaging = ["cargo", "rust-embed"]
 rustup = ["command"]
-sed = ["regex"]
+sed = []
 testing = ["ctor", "env_logger", "packaging"]
 
 [lints]

internal/src/bin/preinstall-toolchains.rs

@@ -0,0 +1,62 @@
+use anyhow::{Context, Result};
+use assert_cmd::output::OutputError;
+use regex::Regex;
+use std::{
+    fs::read_to_string,
+    io::{BufRead, BufReader},
+    process::{Child, Command, Stdio},
+};
+
+fn main() -> Result<()> {
+    let re = Regex::new(r"\<nightly-[0-9]{4}-[0-9]{2}-[0-9]{2}\>")?;
+
+    let mut ls_files_child = Command::new("git")
+        .arg("ls-files")
+        .stdout(Stdio::piped())
+        .spawn()
+        .with_context(|| "Could not spawn `git ls-files`")?;
+
+    let ls_files_stdout = ls_files_child.stdout.take().unwrap();
+    let mut toolchains = BufReader::new(ls_files_stdout).lines().try_fold(
+        Vec::new(),
+        |mut toolchains, result| -> Result<Vec<_>> {
+            let path = result.with_context(|| "Could not read from `git ls-files`")?;
+            if let Ok(contents) = read_to_string(&path) {
+                toolchains.extend(re.find_iter(&contents).map(|m| m.as_str().to_owned()));
+            } else {
+                eprintln!("Could not read `{path}`");
+            }
+            Ok(toolchains)
+        },
+    )?;
+
+    ensure_child_success(ls_files_child)?;
+
+    toolchains.sort();
+    toolchains.dedup();
+
+    let rustup_children = toolchains
+        .into_iter()
+        .map(|toolchain| -> Result<Child> {
+            Command::new("rustup")
+                .args(["toolchain", "install", &toolchain, "--no-self-update"])
+                .spawn()
+                .map_err(Into::into)
+        })
+        .collect::<Result<Vec<_>>>()
+        .with_context(|| "Could not spawn `rustup`")?;
+
+    for rustup_child in rustup_children {
+        ensure_child_success(rustup_child)?;
+    }
+
+    Ok(())
+}
+
+fn ensure_child_success(child: Child) -> Result<()> {
+    let output = child.wait_with_output()?;
+    if !output.status.success() {
+        eprintln!("child failed: {}", OutputError::new(output));
+    }
+    Ok(())
+}