From 4d280de47c4c0021f55bb1a9c7d6e5293a4670ab Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?R=C3=A9my=20Rakic?= <remy.rakic+github@gmail.com>
Date: Sat, 13 Apr 2024 22:09:50 +0000
Subject: [PATCH] test rust-lld is on by default on the x64 linux target

---
 tests/run-make/rust-lld-by-default/main.rs  |  5 +++
 tests/run-make/rust-lld-by-default/rmake.rs | 43 +++++++++++++++++++++
 2 files changed, 48 insertions(+)
 create mode 100644 tests/run-make/rust-lld-by-default/main.rs
 create mode 100644 tests/run-make/rust-lld-by-default/rmake.rs

diff --git a/tests/run-make/rust-lld-by-default/main.rs b/tests/run-make/rust-lld-by-default/main.rs
new file mode 100644
index 000000000000..e9f655fc09e4
--- /dev/null
+++ b/tests/run-make/rust-lld-by-default/main.rs
@@ -0,0 +1,5 @@
+// Test linking using `cc` with `rust-lld`, which is on by default on the x86_64-unknown-linux-gnu
+// target.
+// See https://github.com/rust-lang/compiler-team/issues/510 for more info
+
+fn main() {}
diff --git a/tests/run-make/rust-lld-by-default/rmake.rs b/tests/run-make/rust-lld-by-default/rmake.rs
new file mode 100644
index 000000000000..876968727f3c
--- /dev/null
+++ b/tests/run-make/rust-lld-by-default/rmake.rs
@@ -0,0 +1,43 @@
+// Ensure that rust-lld is used as the default linker on `x86_64-unknown-linux-gnu`, and that it can
+// also be turned off with a CLI flag.
+
+//@ needs-rust-lld
+//@ only-x86_64-unknown-linux-gnu
+
+extern crate run_make_support;
+
+use run_make_support::regex::Regex;
+use run_make_support::rustc;
+use std::process::Output;
+
+fn main() {
+    // A regular compilation should use rust-lld by default. We'll check that by asking the linker
+    // to display its version number with a link-arg.
+    let output = rustc()
+        .env("RUSTC_LOG", "rustc_codegen_ssa::back::link=info")
+        .link_arg("-Wl,-v")
+        .input("main.rs")
+        .run();
+    assert!(
+        find_lld_version_in_logs(output),
+        "the LLD version string should be present in the output logs"
+    );
+
+    // But it can still be disabled by turning the linker feature off.
+    let output = rustc()
+        .env("RUSTC_LOG", "rustc_codegen_ssa::back::link=info")
+        .link_arg("-Wl,-v")
+        .arg("-Zlinker-features=-lld")
+        .input("main.rs")
+        .run();
+    assert!(
+        !find_lld_version_in_logs(output),
+        "the LLD version string should not be present in the output logs"
+    );
+}
+
+fn find_lld_version_in_logs(output: Output) -> bool {
+    let lld_version_re = Regex::new(r"^LLD [0-9]+\.[0-9]+\.[0-9]+").unwrap();
+    let stderr = std::str::from_utf8(&output.stderr).unwrap();
+    stderr.lines().any(|line| lld_version_re.is_match(line))
+}