1 files changed, 106 insertions, 0 deletions
diff --git a/tests/run-make/long-linker-command-lines/foo.rs b/tests/run-make/long-linker-command-lines/foo.rs
new file mode 100644
index 000000000..db238c0cf
--- /dev/null
+++ b/tests/run-make/long-linker-command-lines/foo.rs
@@ -0,0 +1,106 @@
+// This is a test which attempts to blow out the system limit with how many
+// arguments can be passed to a process. This'll successively call rustc with
+// larger and larger argument lists in an attempt to find one that's way too
+// big for the system at hand. This file itself is then used as a "linker" to
+// detect when the process creation succeeds.
+//
+// Eventually we should see an argument that looks like `@` as we switch from
+// passing literal arguments to passing everything in the file.
+
+use std::collections::HashSet;
+use std::env;
+use std::fs::{self, File};
+use std::io::{BufWriter, Write};
+use std::path::{Path, PathBuf};
+use std::process::Command;
+
+fn write_test_case(file: &Path, n: usize) -> HashSet<String> {
+    let mut libs = HashSet::new();
+    let mut f = BufWriter::new(File::create(&file).unwrap());
+    let mut prefix = String::new();
+    for _ in 0..n {
+        prefix.push_str("foo");
+    }
+    for i in 0..n {
+        writeln!(f, "#[link(name = \"S{}{}S\")]", prefix, i).unwrap();
+        libs.insert(format!("{}{}", prefix, i));
+    }
+    writeln!(f, "extern \"C\" {{}}\nfn main() {{}}").unwrap();
+    f.into_inner().unwrap();
+
+    libs
+}
+
+fn read_linker_args(path: &Path) -> String {
+    let contents = fs::read(path).unwrap();
+    if cfg!(target_env = "msvc") {
+        let mut i = contents.chunks(2).map(|c| {
+            c[0] as u16 | ((c[1] as u16) << 8)
+        });
+        assert_eq!(i.next(), Some(0xfeff), "Expected UTF-16 BOM");
+        String::from_utf16(&i.collect::<Vec<u16>>()).unwrap()
+    } else {
+        String::from_utf8(contents).unwrap()
+    }
+}
+
+fn main() {
+    let tmpdir = PathBuf::from(env::var_os("TMPDIR").unwrap());
+    let ok = tmpdir.join("ok");
+    if env::var("YOU_ARE_A_LINKER").is_ok() {
+        if let Some(file) = env::args_os().find(|a| a.to_string_lossy().contains("@")) {
+            let file = file.to_str().expect("non-utf8 file argument");
+            fs::copy(&file[1..], &ok).unwrap();
+        }
+        return
+    }
+
+    let rustc = env::var_os("RUSTC").unwrap_or("rustc".into());
+    let me_as_linker = format!("linker={}", env::current_exe().unwrap().display());
+    for i in (1..).map(|i| i * 100) {
+        println!("attempt: {}", i);
+        let file = tmpdir.join("bar.rs");
+        let mut expected_libs = write_test_case(&file, i);
+
+        drop(fs::remove_file(&ok));
+        let output = Command::new(&rustc)
+            .arg(&file)
+            .arg("-C").arg(&me_as_linker)
+            .arg("--out-dir").arg(&tmpdir)
+            .env("YOU_ARE_A_LINKER", "1")
+            .output()
+            .unwrap();
+
+        if !output.status.success() {
+            let stderr = String::from_utf8_lossy(&output.stderr);
+            panic!("status: {}\nstdout:\n{}\nstderr:\n{}",
+                   output.status,
+                   String::from_utf8_lossy(&output.stdout),
+                   stderr.lines().map(|l| {
+                       if l.len() > 200 {
+                           format!("{}...\n", &l[..200])
+                       } else {
+                           format!("{}\n", l)
+                       }
+                   }).collect::<String>());
+        }
+
+        if !ok.exists() {
+            continue
+        }
+
+        let linker_args = read_linker_args(&ok);
+        for arg in linker_args.split('S') {
+            expected_libs.remove(arg);
+        }
+
+        assert!(
+            expected_libs.is_empty(),
+            "expected but missing libraries: {:#?}\nlinker arguments: \n{}",
+            expected_libs,
+            linker_args,
+        );
+
+        break
+    }
+}