From c955add18c88427eaf09ec2086e3f8a9ccd30021 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Tomasz=20Mi=C4=85sko?= <tomasz.miasko@gmail.com>
Date: Fri, 2 Dec 2022 00:00:00 +0000
Subject: [PATCH] Disable coverage instrumentation for naked functions

---
 compiler/rustc_hir_analysis/src/collect.rs |  4 ++++
 src/test/codegen/naked-nocoverage.rs       | 19 +++++++++++++++++++
 2 files changed, 23 insertions(+)
 create mode 100644 src/test/codegen/naked-nocoverage.rs

diff --git a/compiler/rustc_hir_analysis/src/collect.rs b/compiler/rustc_hir_analysis/src/collect.rs
index d623e726139..3b602a6561f 100644
--- a/compiler/rustc_hir_analysis/src/collect.rs
+++ b/compiler/rustc_hir_analysis/src/collect.rs
@@ -2073,6 +2073,10 @@ fn codegen_fn_attrs(tcx: TyCtxt<'_>, did: DefId) -> CodegenFnAttrs {
         }
     }
 
+    if codegen_fn_attrs.flags.contains(CodegenFnAttrFlags::NAKED) {
+        codegen_fn_attrs.flags |= CodegenFnAttrFlags::NO_COVERAGE;
+    }
+
     // Weak lang items have the same semantics as "std internal" symbols in the
     // sense that they're preserved through all our LTO passes and only
     // strippable by the linker.
diff --git a/src/test/codegen/naked-nocoverage.rs b/src/test/codegen/naked-nocoverage.rs
new file mode 100644
index 00000000000..91a6260bf2a
--- /dev/null
+++ b/src/test/codegen/naked-nocoverage.rs
@@ -0,0 +1,19 @@
+// Checks that naked functions are not instrumented by -Cinstrument-coverage.
+// Regression test for issue #105170.
+//
+// needs-asm-support
+// needs-profiler-support
+// compile-flags: -Cinstrument-coverage
+#![crate_type = "lib"]
+#![feature(naked_functions)]
+use std::arch::asm;
+
+#[naked]
+#[no_mangle]
+pub unsafe extern "C" fn f() {
+    // CHECK:       define void @f()
+    // CHECK-NEXT:  start:
+    // CHECK-NEXT:    call void asm
+    // CHECK-NEXT:    unreachable
+    asm!("", options(noreturn));
+}