From af3721e8132a8d5268a1e263f7058cdb65fbbac2 Mon Sep 17 00:00:00 2001
From: bjorn3 <17426603+bjorn3@users.noreply.github.com>
Date: Fri, 13 Dec 2024 16:39:11 +0100
Subject: [PATCH] Document the symbol Visibility enum

---
 compiler/rustc_middle/src/mir/mono.rs | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/compiler/rustc_middle/src/mir/mono.rs b/compiler/rustc_middle/src/mir/mono.rs
index 1f50b67cb50d5..266dc7ad2b3b2 100644
--- a/compiler/rustc_middle/src/mir/mono.rs
+++ b/compiler/rustc_middle/src/mir/mono.rs
@@ -294,10 +294,22 @@ pub enum Linkage {
     Common,
 }
 
+/// Specifies the symbol visibility with regards to dynamic linking.
+///
+/// Visibility doesn't have any effect when linkage is internal.
+///
+/// DSO means dynamic shared object, that is a dynamically linked executable or dylib.
 #[derive(Copy, Clone, PartialEq, Debug, HashStable)]
 pub enum Visibility {
+    /// Export the symbol from the DSO and apply overrides of the symbol by outside DSOs to within
+    /// the DSO if the object file format supports this.
     Default,
+    /// Hide the symbol outside of the defining DSO even when external linkage is used to export it
+    /// from the object file.
     Hidden,
+    /// Export the symbol from the DSO, but don't apply overrides of the symbol by outside DSOs to
+    /// within the DSO. Equivalent to default visibility with object file formats that don't support
+    /// overriding exported symbols by another DSO.
     Protected,
 }