Auto merge of #125436 - matthiaskrgr:rollup-uijo2ga, r=matthiaskrgr

Rollup of 8 pull requests

Successful merges:

 - #122665 (Add some tests for public-private dependencies.)
 - #123623 (Fix OutsideLoop's error suggestion: adding label `'block` for `if` block.)
 - #125054 (Handle `ReVar` in `note_and_explain_region`)
 - #125156 (Expand `for_loops_over_fallibles` lint to lint on fallibles behind references.)
 - #125222 (Migrate `run-make/issue-46239` to `rmake`)
 - #125316 (Tweak `Spacing` use)
 - #125392 (Wrap Context.ext in AssertUnwindSafe)
 - #125417 (self-contained linker: retry linking without `-fuse-ld=lld` on CCs that don't support it)

r? `@ghost`
`@rustbot` modify labels: rollup

1 files changed, 21 insertions, 0 deletions

diff --git a/compiler/rustc_codegen_ssa/src/back/link.rs b/compiler/rustc_codegen_ssa/src/back/link.rs
index 37b8f81ad94..c973bda1ef1 100644
--- a/compiler/rustc_codegen_ssa/src/back/link.rs
+++ b/compiler/rustc_codegen_ssa/src/back/link.rs
@@ -799,6 +799,27 @@ fn link_natively(
             continue;
         }
 
+        // Check if linking failed with an error message that indicates the driver didn't recognize
+        // the `-fuse-ld=lld` option. If so, re-perform the link step without it. This avoids having
+        // to spawn multiple instances on the happy path to do version checking, and ensures things
+        // keep working on the tier 1 baseline of GLIBC 2.17+. That is generally understood as GCCs
+        // circa RHEL/CentOS 7, 4.5 or so, whereas lld support was added in GCC 9.
+        if matches!(flavor, LinkerFlavor::Gnu(Cc::Yes, Lld::Yes))
+            && unknown_arg_regex.is_match(&out)
+            && out.contains("-fuse-ld=lld")
+            && cmd.get_args().iter().any(|e| e.to_string_lossy() == "-fuse-ld=lld")
+        {
+            info!("linker output: {:?}", out);
+            warn!("The linker driver does not support `-fuse-ld=lld`. Retrying without it.");
+            for arg in cmd.take_args() {
+                if arg.to_string_lossy() != "-fuse-ld=lld" {
+                    cmd.arg(arg);
+                }
+            }
+            info!("{:?}", &cmd);
+            continue;
+        }
+
         // Detect '-static-pie' used with an older version of gcc or clang not supporting it.
         // Fallback from '-static-pie' to '-static' in that case.
         if matches!(flavor, LinkerFlavor::Gnu(Cc::Yes, _))