Auto merge of rust-lang#138645 - Kobzol:stabilize-lld-test, r=<try>

[do not merge] Preparation for LLD stabilization

This PR serves for testing test changes for stabilizing LLD.

CC `@lqd`

r? `@ghost`

try-job: dist-x86_64-linux

Author: bors

src/bootstrap/src/core/build_steps/compile.rs

@@ -1328,9 +1328,7 @@ pub fn rustc_cargo_env(
     }
 
     // Enable rustc's env var for `rust-lld` when requested.
-    if builder.config.lld_enabled
-        && (builder.config.channel == "dev" || builder.config.channel == "nightly")
-    {
+    if builder.config.lld_enabled {
         cargo.env("CFG_USE_SELF_CONTAINED_LINKER", "1");
     }
 

src/bootstrap/src/core/config/config.rs

@@ -2334,10 +2334,7 @@ impl Config {
         //   thus, disabled
         // - similarly, lld will not be built nor used by default when explicitly asked not to, e.g.
         //   when the config sets `rust.lld = false`
-        if config.build.triple == "x86_64-unknown-linux-gnu"
-            && config.hosts == [config.build]
-            && (config.channel == "dev" || config.channel == "nightly")
-        {
+        if config.build.triple == "x86_64-unknown-linux-gnu" && config.hosts == [config.build] {
             let no_llvm_config = config
                 .target_config
                 .get(&config.build)

src/tools/opt-dist/src/tests.rs

@@ -104,7 +104,10 @@ llvm-config = "{llvm_config}"
             "tests/incremental",
             "tests/mir-opt",
             "tests/pretty",
+            // Make sure that we don't use too new GLIBC symbols on x64
             "tests/run-make/glibc-symbols-x86_64-unknown-linux-gnu",
+            // Make sure that we use LLD by default on x64
+            "tests/run-make/rust-lld-x86_64-unknown-linux-gnu-dist",
             "tests/ui",
             "tests/crashes",
         ];

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

@@ -17,6 +17,7 @@ pub mod assertion_helpers;
 pub mod diff;
 pub mod env;
 pub mod external_deps;
+pub mod linker;
 pub mod path_helpers;
 pub mod run;
 pub mod scoped_run;

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

@@ -0,0 +1,36 @@
+use regex::Regex;
+
+use crate::{Rustc, is_msvc};
+
+/// Asserts that `rustc` uses LLD for linking when executed.
+pub fn assert_rustc_uses_lld(rustc: &mut Rustc) {
+    let stderr = get_stderr_with_linker_messages(rustc);
+    assert!(
+        has_lld_version_in_logs(&stderr),
+        "LLD version should be present in rustc stderr:\n{stderr}"
+    );
+}
+
+/// Asserts that `rustc` doesn't use LLD for linking when executed.
+pub fn assert_rustc_doesnt_use_lld(rustc: &mut Rustc) {
+    let stderr = get_stderr_with_linker_messages(rustc);
+    assert!(
+        !has_lld_version_in_logs(&stderr),
+        "LLD version should NOT be present in rustc stderr:\n{stderr}"
+    );
+}
+
+fn get_stderr_with_linker_messages(rustc: &mut Rustc) -> String {
+    // lld-link is used if msvc, otherwise a gnu-compatible lld is used.
+    let linker_version_flag = if is_msvc() { "--version" } else { "-Wl,-v" };
+
+    let output = rustc.arg("-Wlinker-messages").link_arg(linker_version_flag).run();
+    output.stderr_utf8()
+}
+
+fn has_lld_version_in_logs(stderr: &str) -> bool {
+    // Strip the `-Wlinker-messages` wrappers prefixing the linker output.
+    let stderr = Regex::new(r"warning: linker std(out|err):").unwrap().replace_all(&stderr, "");
+    let lld_version_re = Regex::new(r"^LLD [0-9]+\.[0-9]+\.[0-9]+").unwrap();
+    stderr.lines().any(|line| lld_version_re.is_match(line.trim()))
+}

tests/run-make/rust-lld-by-default-beta-stable/main.rs

@@ -8,43 +8,22 @@
 //@ needs-rust-lld
 //@ only-x86_64-unknown-linux-gnu
 
-use run_make_support::regex::Regex;
+use run_make_support::linker::{assert_rustc_doesnt_use_lld, assert_rustc_uses_lld};
 use run_make_support::rustc;
 
 fn main() {
     // Compile to a custom target spec with rust-lld enabled by default. We'll check that by asking
     // the linker to display its version number with a link-arg.
-    let output = rustc()
-        .crate_type("cdylib")
-        .arg("-Wlinker-messages")
-        .target("custom-target.json")
-        .link_arg("-Wl,-v")
-        .input("lib.rs")
-        .run();
-    assert!(
-        find_lld_version_in_logs(output.stderr_utf8()),
-        "the LLD version string should be present in the output logs:\n{}",
-        output.stderr_utf8()
+    assert_rustc_uses_lld(
+        rustc().crate_type("cdylib").target("custom-target.json").input("lib.rs"),
     );
 
     // But it can also be disabled via linker features.
-    let output = rustc()
-        .crate_type("cdylib")
-        .arg("-Wlinker-messages")
-        .target("custom-target.json")
-        .arg("-Zlinker-features=-lld")
-        .link_arg("-Wl,-v")
-        .input("lib.rs")
-        .run();
-    assert!(
-        !find_lld_version_in_logs(output.stderr_utf8()),
-        "the LLD version string should not be present in the output logs:\n{}",
-        output.stderr_utf8()
+    assert_rustc_doesnt_use_lld(
+        rustc()
+            .crate_type("cdylib")
+            .target("custom-target.json")
+            .arg("-Zlinker-features=-lld")
+            .input("lib.rs"),
     );
 }
-
-fn find_lld_version_in_logs(stderr: String) -> bool {
-    let lld_version_re =
-        Regex::new(r"^warning: linker stdout: LLD [0-9]+\.[0-9]+\.[0-9]+").unwrap();
-    stderr.lines().any(|line| lld_version_re.is_match(line.trim()))
-}