Merge pull request #94 from jfrimmel/support-running-msrv

Follow-up to #77: make sure, that everything works with current MSRV

.github/workflows/msrv.yaml

@@ -5,10 +5,13 @@ env:
   CARGO_TERM_COLOR: always
   MSRV: "1.51"
 jobs:
-  # build but don't test the crate with the Minimum Supported Rust Version
+  # Build and test the tool with the Minimum Supported Rust Version
   msrv:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
+      - name: Install valgrind
+        run: sudo apt install valgrind
       - run: rustup update $MSRV && rustup default $MSRV
-      - run: cargo check
+      - name: Run tests
+        run: cargo test

src/driver.rs

@@ -3,6 +3,7 @@
 use std::env;
 use std::ffi::OsString;
 use std::io;
+use std::path::Path;
 use std::process::Command;
 
 /// The prefix line for the target host output.
@@ -18,16 +19,23 @@ const HOST_PREFIX: &[u8] = b"host: ";
 /// executed.
 pub fn driver() -> io::Result<bool> {
     let cargo = env::var_os("CARGO").expect("CARGO environment variable is not set");
+    let rustc = Path::new(&cargo).with_file_name("rustc");
 
     /* get the output of `cargo version -v` */
-    let rustc_info = Command::new(&cargo).args(&["version", "-v"]).output()?.stdout;
+    let cargo_info = Command::new(&cargo)
+        .args(&["version", "-v"])
+        .output()?
+        .stdout;
+    /* old cargo versions don't include the host-field, so fall back to rustc */
+    let rustc_info = Command::new(rustc).arg("-vV").output()?.stdout;
+    let info = [cargo_info, rustc_info].concat();
 
     /* get the host information (all after the "host: ..." line) */
-    let host = rustc_info
+    let host = info
         .windows(HOST_PREFIX.len())
         .position(|window| window == HOST_PREFIX)
-        .expect("Host information not present in `cargo version -v`");
-    let host: String = rustc_info
+        .expect("Host information not present in `cargo version -v` or `rustc -vV");
+    let host: String = info
         .into_iter()
         .skip(host)
         .skip(HOST_PREFIX.len())
@@ -36,7 +44,7 @@ pub fn driver() -> io::Result<bool> {
         .collect();
 
     /* convert to runner env variable */
-    let host = host.replace(&['-', '.'], "_").to_uppercase();
+    let host = host.replace('-', "_").replace('.', "_").to_uppercase();
     let runner = format!("CARGO_TARGET_{}_RUNNER", host);
 
     /* cargo run with a custom runner */

tests/corpus/issue-74.rs

@@ -29,9 +29,9 @@ fn ex4() {
   let (a, b)
       = split_at_mut(r, 4);
 
-  println!("a={a:?} (should be [1, 2, 3, 4]");
+  println!("a={:?} (should be [1, 2, 3, 4]", a);
   drop(a);
-  println!("b={b:?} (should be [5, 6])");
+  println!("b={:?} (should be [5, 6])", b);
   // assert_eq!(a, &mut[1, 2, 3, 4]);
   // assert_eq!(b, &mut[5, 6]);
 }