From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: "Jan Alexander Steffens (heftig)" <heftig@archlinux.org>
Date: Fri, 12 Mar 2021 17:31:56 +0100
Subject: [PATCH] compiler: Change LLVM targets

 - Change x86_64-unknown-linux-gnu to use x86_64-pc-linux-gnu
 - Change i686-unknown-linux-gnu to use i686-pc-linux-gnu

Reintroduce the aliasing that was removed in 1.52.0 and alias the -pc-
triples to the -unknown- triples. This avoids defining proper -pc-
targets, as things break when this is done:

 - The crate ecosystem expects the -unknown- targets. Making -pc-
   rustc's host triple (and thus default target) would break various
   crates.
 - Firefox's build breaks when the host triple (from
   `rustc --version --verbose`) is different from the target triple
   (from `rustc --print target-list`) that best matches autoconf.
---
 compiler/rustc_session/src/config.rs                        | 6 ++++++
 .../rustc_target/src/spec/targets/i686_unknown_linux_gnu.rs | 2 +-
 .../src/spec/targets/x86_64_unknown_linux_gnu.rs            | 2 +-
 3 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/compiler/rustc_session/src/config.rs b/compiler/rustc_session/src/config.rs
index 5e47559847e0..bd7965540560 100644
--- a/compiler/rustc_session/src/config.rs
+++ b/compiler/rustc_session/src/config.rs
@@ -2374,6 +2374,12 @@ pub fn parse_target_triple(early_dcx: &EarlyDiagCtxt, matches: &getopts::Matches
                 early_dcx.early_fatal(format!("target file {path:?} does not exist"))
             })
         }
+        Some(target) if &target == "x86_64-pc-linux-gnu" => {
+            TargetTuple::from_tuple("x86_64-unknown-linux-gnu")
+        }
+        Some(target) if &target == "i686-pc-linux-gnu" => {
+            TargetTuple::from_tuple("i686-unknown-linux-gnu")
+        }
         Some(target) => TargetTuple::TargetTuple(target),
         _ => TargetTuple::from_tuple(host_tuple()),
     }
diff --git a/compiler/rustc_target/src/spec/targets/i686_unknown_linux_gnu.rs b/compiler/rustc_target/src/spec/targets/i686_unknown_linux_gnu.rs
index c70c026f9f71..5ffa2eb8eddb 100644
--- a/compiler/rustc_target/src/spec/targets/i686_unknown_linux_gnu.rs
+++ b/compiler/rustc_target/src/spec/targets/i686_unknown_linux_gnu.rs
@@ -23,7 +23,7 @@ pub(crate) fn target() -> Target {
     base.stack_probes = StackProbeType::Inline;
 
     Target {
-        llvm_target: "i686-unknown-linux-gnu".into(),
+        llvm_target: "i686-pc-linux-gnu".into(),
         metadata: TargetMetadata {
             description: Some("32-bit Linux (kernel 3.2, glibc 2.17+)".into()),
             tier: Some(1),
diff --git a/compiler/rustc_target/src/spec/targets/x86_64_unknown_linux_gnu.rs b/compiler/rustc_target/src/spec/targets/x86_64_unknown_linux_gnu.rs
index 0c8353fad182..d2b414766d4d 100644
--- a/compiler/rustc_target/src/spec/targets/x86_64_unknown_linux_gnu.rs
+++ b/compiler/rustc_target/src/spec/targets/x86_64_unknown_linux_gnu.rs
@@ -28,7 +28,7 @@ pub(crate) fn target() -> Target {
     }
 
     Target {
-        llvm_target: "x86_64-unknown-linux-gnu".into(),
+        llvm_target: "x86_64-pc-linux-gnu".into(),
         metadata: TargetMetadata {
             description: Some("64-bit Linux (kernel 3.2+, glibc 2.17+)".into()),
             tier: Some(1),