From e3c15ff743f482cb869fa2fdf278a8371f4b7d17 Mon Sep 17 00:00:00 2001
From: kavoor <voork@fb.com>
Date: Wed, 13 Apr 2022 01:34:53 -0700
Subject: [PATCH] Support rename rule for union body members

---
 src/bindgen/config.rs         | 5 +++++
 src/bindgen/ir/enumeration.rs | 5 +++--
 2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/src/bindgen/config.rs b/src/bindgen/config.rs
index 3560bb2c9..d0dbf2205 100644
--- a/src/bindgen/config.rs
+++ b/src/bindgen/config.rs
@@ -559,6 +559,10 @@ impl StructConfig {
 pub struct EnumConfig {
     /// The rename rule to apply to the name of enum variants
     pub rename_variants: RenameRule,
+    /// The rename rule to apply to the names of the union fields in C/C++
+    /// generated from the Rust enum. Applied before rename_variants
+    /// rename rule. Defaults to SnakeCase.
+    pub rename_variant_name_fields: RenameRule,
     /// Whether to add a `Sentinel` value at the end of every enum
     /// This is useful in Gecko for IPC serialization
     pub add_sentinel: bool,
@@ -600,6 +604,7 @@ impl Default for EnumConfig {
     fn default() -> EnumConfig {
         EnumConfig {
             rename_variants: RenameRule::None,
+            rename_variant_name_fields: RenameRule::SnakeCase,
             add_sentinel: false,
             prefix_with_name: false,
             derive_helper_methods: false,
diff --git a/src/bindgen/ir/enumeration.rs b/src/bindgen/ir/enumeration.rs
index aa19bff7b..a9b1080b5 100644
--- a/src/bindgen/ir/enumeration.rs
+++ b/src/bindgen/ir/enumeration.rs
@@ -149,11 +149,12 @@ impl EnumVariant {
         if let Some(b) = enum_annotations.bool("derive-ostream") {
             annotations.add_default("derive-ostream", AnnotationValue::Bool(b));
         }
+        let body_rule = config.enumeration.rename_variant_name_fields;
         let body = match variant.fields {
             syn::Fields::Unit => VariantBody::Empty(annotations),
             syn::Fields::Named(ref fields) => {
                 let path = Path::new(format!("{}_Body", variant.ident));
-                let name = RenameRule::SnakeCase
+                let name = body_rule
                     .apply(
                         &variant.ident.unraw().to_string(),
                         IdentifierType::StructMember,
@@ -179,7 +180,7 @@ impl EnumVariant {
             }
             syn::Fields::Unnamed(ref fields) => {
                 let path = Path::new(format!("{}_Body", variant.ident));
-                let name = RenameRule::SnakeCase
+                let name = body_rule
                     .apply(
                         &variant.ident.unraw().to_string(),
                         IdentifierType::StructMember,