From 733768d7be42a5235c5d042401407eaa58dc32f9 Mon Sep 17 00:00:00 2001
From: Marijn Suijten <marijns95@gmail.com>
Date: Mon, 30 Nov 2020 21:15:16 +0100
Subject: [PATCH] codegen/flags: Add missing display trait generation

Analysis was copied from enums which adds an std::fmt when
generate_display_trait is true, but the codegen for it was missing.
Instead of removing the import, provide a simple Display trait that
forwards to bitflags' Debug implementation.
---
 src/codegen/flags.rs | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/src/codegen/flags.rs b/src/codegen/flags.rs
index b2f4df283..264cfab75 100644
--- a/src/codegen/flags.rs
+++ b/src/codegen/flags.rs
@@ -125,6 +125,20 @@ fn generate_flags(
 
     writeln!(w)?;
 
+    if config.generate_display_trait {
+        // Generate Display trait implementation.
+        version_condition(w, env, flags.version, false, 0)?;
+        writeln!(
+            w,
+            "impl fmt::Display for {0} {{\n\
+            \tfn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {{\n\
+            \t\t<Self as fmt::Debug>::fmt(self, f)\n\
+            \t}}\n\
+            }}\n",
+            flags.name
+        )?;
+    }
+
     version_condition(w, env, flags.version, false, 0)?;
     writeln!(
         w,