From 99c1bcfac500bc5bf1cc5992dca4f918540de556 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?R=C3=A9my=20Rakic?= <remy.rakic+github@gmail.com>
Date: Thu, 10 Aug 2023 20:35:48 +0000
Subject: [PATCH 1/2] Revert "make MCP510 behavior explicitly opt-in"

This reverts commit 2b61a5e17a6bcb552889966f8f932aa680826ab6.
---
 compiler/rustc_codegen_ssa/src/back/link.rs | 19 ++-----------------
 1 file changed, 2 insertions(+), 17 deletions(-)

diff --git a/compiler/rustc_codegen_ssa/src/back/link.rs b/compiler/rustc_codegen_ssa/src/back/link.rs
index cd6201648ee9b..53c56ee782e5d 100644
--- a/compiler/rustc_codegen_ssa/src/back/link.rs
+++ b/compiler/rustc_codegen_ssa/src/back/link.rs
@@ -2991,25 +2991,10 @@ fn add_lld_args(cmd: &mut dyn Linker, sess: &Session, flavor: LinkerFlavor) {
         return;
     }
 
-    let self_contained_linker = sess.opts.cg.link_self_contained.linker();
-
-    // FIXME: some targets default to using `lld`, but users can only override the linker on the CLI
-    // and cannot yet select the precise linker flavor to opt out of that. See for example issue
-    // #113597 for the `thumbv6m-none-eabi` target: a driver is used, and its default linker
-    // conflicts with the target's flavor, causing unexpected arguments being passed.
-    //
-    // Until the new `LinkerFlavor`-like CLI options are stabilized, we only adopt MCP510's behavior
-    // if its dedicated unstable CLI flags are used, to keep the current sub-optimal stable
-    // behavior.
-    let using_mcp510 =
-        self_contained_linker || sess.opts.cg.linker_flavor.is_some_and(|f| f.is_unstable());
-    if !using_mcp510 && !unstable_use_lld {
-        return;
-    }
-
     // 1. Implement the "self-contained" part of this feature by adding rustc distribution
     //    directories to the tool's search path.
-    if self_contained_linker || unstable_use_lld {
+    let self_contained_linker = sess.opts.cg.link_self_contained.linker() || unstable_use_lld;
+    if self_contained_linker {
         for path in sess.get_tools_search_paths(false) {
             cmd.arg({
                 let mut arg = OsString::from("-B");

From 498d6562c3fc4e9261efe2e8188fb45c64532eef Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?R=C3=A9my=20Rakic?= <remy.rakic+github@gmail.com>
Date: Thu, 10 Aug 2023 20:36:25 +0000
Subject: [PATCH 2/2] infer no use of lld when using a generic linker driver

---
 compiler/rustc_target/src/spec/mod.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/compiler/rustc_target/src/spec/mod.rs b/compiler/rustc_target/src/spec/mod.rs
index 1871239d7de70..4aa6f1f98a2ca 100644
--- a/compiler/rustc_target/src/spec/mod.rs
+++ b/compiler/rustc_target/src/spec/mod.rs
@@ -338,7 +338,7 @@ impl LinkerFlavor {
             || stem == "clang++"
             || stem.ends_with("-clang++")
         {
-            (Some(Cc::Yes), None)
+            (Some(Cc::Yes), Some(Lld::No))
         } else if stem == "wasm-ld"
             || stem.ends_with("-wasm-ld")
             || stem == "ld.lld"