From 8b18f41b98df5d82c3d4e1cfd7f3e9c73b2f22e5 Mon Sep 17 00:00:00 2001
From: "J. Ryan Stinnett" <jryans@gmail.com>
Date: Sat, 28 Nov 2020 15:07:51 +0000
Subject: [PATCH 1/2] Derive `Debug` for `DebugInfo`

This was useful during testing of `dsymutil` code paths.
---
 compiler/rustc_session/src/config.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/compiler/rustc_session/src/config.rs b/compiler/rustc_session/src/config.rs
index db16a90cc60fa..b648e14360c00 100644
--- a/compiler/rustc_session/src/config.rs
+++ b/compiler/rustc_session/src/config.rs
@@ -214,7 +214,7 @@ pub enum SymbolManglingVersion {
 
 impl_stable_hash_via_hash!(SymbolManglingVersion);
 
-#[derive(Clone, Copy, PartialEq, Hash)]
+#[derive(Clone, Copy, Debug, PartialEq, Hash)]
 pub enum DebugInfo {
     None,
     Limited,

From 4ed90835615f96f1260c633027bd673cd011ab36 Mon Sep 17 00:00:00 2001
From: "J. Ryan Stinnett" <jryans@gmail.com>
Date: Sat, 28 Nov 2020 15:09:18 +0000
Subject: [PATCH 2/2] Warn if `dsymutil` returns an error code

This checks the error code returned by `dsymutil` and warns if it failed. It
also provides the stdout and stderr logs from `dsymutil`, similar to the native
linker step.

Fixes https://github.com/rust-lang/rust/issues/78770
---
 compiler/rustc_codegen_ssa/src/back/link.rs | 32 +++++++++++++++------
 1 file changed, 23 insertions(+), 9 deletions(-)

diff --git a/compiler/rustc_codegen_ssa/src/back/link.rs b/compiler/rustc_codegen_ssa/src/back/link.rs
index 5a627a0efa364..f383be914cc19 100644
--- a/compiler/rustc_codegen_ssa/src/back/link.rs
+++ b/compiler/rustc_codegen_ssa/src/back/link.rs
@@ -643,15 +643,16 @@ fn link_natively<'a, B: ArchiveBuilder<'a>>(
         }
     }
 
+    fn escape_string(s: &[u8]) -> String {
+        str::from_utf8(s).map(|s| s.to_owned()).unwrap_or_else(|_| {
+            let mut x = "Non-UTF-8 output: ".to_string();
+            x.extend(s.iter().flat_map(|&b| ascii::escape_default(b)).map(char::from));
+            x
+        })
+    }
+
     match prog {
         Ok(prog) => {
-            fn escape_string(s: &[u8]) -> String {
-                str::from_utf8(s).map(|s| s.to_owned()).unwrap_or_else(|_| {
-                    let mut x = "Non-UTF-8 output: ".to_string();
-                    x.extend(s.iter().flat_map(|&b| ascii::escape_default(b)).map(char::from));
-                    x
-                })
-            }
             if !prog.status.success() {
                 let mut output = prog.stderr.clone();
                 output.extend_from_slice(&prog.stdout);
@@ -760,8 +761,21 @@ fn link_natively<'a, B: ArchiveBuilder<'a>>(
         && sess.opts.debuginfo != DebugInfo::None
         && !preserve_objects_for_their_debuginfo(sess)
     {
-        if let Err(e) = Command::new("dsymutil").arg(out_filename).output() {
-            sess.fatal(&format!("failed to run dsymutil: {}", e))
+        let prog = Command::new("dsymutil").arg(out_filename).output();
+        match prog {
+            Ok(prog) => {
+                if !prog.status.success() {
+                    let mut output = prog.stderr.clone();
+                    output.extend_from_slice(&prog.stdout);
+                    sess.struct_warn(&format!(
+                        "processing debug info with `dsymutil` failed: {}",
+                        prog.status
+                    ))
+                    .note(&escape_string(&output))
+                    .emit();
+                }
+            }
+            Err(e) => sess.fatal(&format!("unable to run `dsymutil`: {}", e)),
         }
     }
 }