Auto merge of #141856 - folkertdev:run-make-forward-compiletest-runner, r=jieyouxu

forward the bootstrap `runner` to `run-make`

The runner was already forwarded to `compiletest`, this just passes it on to `run-make` and uses it in the `run` functions.

The configuration can look like this

```toml
# in bootstrap.toml
[target.s390x-unknown-linux-gnu]
runner = "qemu-s390x -L /usr/s390x-linux-gnu"
```

Any C compilation automatically sets the correct target. Calls to rustc must use `.target(target())`. Then, a command like below will work by cross-compiling to the given target, and using the given runner for that target to execute the binary:

```
./x test tests/run-make/c-link-to-rust-va-list-fn --target s390x-unknown-linux-gnu
```

The runner can also be used for e.g. running with `valgrind`.

This PR also enables its use in the test case that I care about, hopefully that actually does work on the platforms that CI uses. We should probably run some try jobs to be sure?

r? `@jieyouxu`

try-job: test-various
try-job: armhf-gnu

Author: bors

src/tools/compiletest/src/runtest/run_make.rs

@@ -221,6 +221,10 @@ impl TestCx<'_> {
             cmd.env("REMOTE_TEST_CLIENT", remote_test_client);
         }
 
+        if let Some(runner) = &self.config.runner {
+            cmd.env("RUNNER", runner);
+        }
+
         // We don't want RUSTFLAGS set from the outside to interfere with
         // compiler flags set in the test cases:
         cmd.env_remove("RUSTFLAGS");

src/tools/run-make-support/src/run.rs

@@ -1,4 +1,4 @@
-use std::ffi::OsStr;
+use std::ffi::{OsStr, OsString};
 use std::path::PathBuf;
 use std::{env, panic};
 
@@ -21,6 +21,20 @@ fn run_common(name: &str, args: Option<&[&str]>) -> Command {
         // will have to be changed (and the support files will have to be uploaded).
         cmd.arg("0");
         cmd.arg(bin_path);
+        cmd
+    } else if let Ok(runner) = std::env::var("RUNNER") {
+        let mut args = split_maybe_args(&runner);
+
+        let prog = args.remove(0);
+        let mut cmd = Command::new(prog);
+
+        for arg in args {
+            cmd.arg(arg);
+        }
+
+        cmd.arg("--");
+        cmd.arg(bin_path);
+
         cmd
     } else {
         Command::new(bin_path)
@@ -92,3 +106,12 @@ pub fn cmd<S: AsRef<OsStr>>(program: S) -> Command {
     command.env("LC_ALL", "C"); // force english locale
     command
 }
+
+fn split_maybe_args(s: &str) -> Vec<OsString> {
+    // FIXME(132599): implement proper env var/shell argument splitting.
+    s.split(' ')
+        .filter_map(|s| {
+            if s.chars().all(|c| c.is_whitespace()) { None } else { Some(OsString::from(s)) }
+        })
+        .collect()
+}

tests/run-make/c-link-to-rust-va-list-fn/rmake.rs

@@ -3,7 +3,8 @@
 // prevent the creation of a functional binary.
 // See https://github.com/rust-lang/rust/pull/49878
 
-//@ ignore-cross-compile
+//@ needs-target-std
+//@ ignore-android: FIXME(#142855)
 
 use run_make_support::{cc, extra_c_flags, run, rustc, static_lib_name};