From 8817ba6d397143c5983c4f1be8f52028aed84f02 Mon Sep 17 00:00:00 2001
From: Ashley Ruglys <ashley.ruglys@gmail.com>
Date: Sat, 13 May 2023 20:47:19 +1200
Subject: [PATCH 1/3] Add ParseCallbacks::process_field_name

---
 bindgen/callbacks.rs   |  9 +++++++++
 bindgen/codegen/mod.rs | 19 +++++++++++++++++--
 bindgen/lib.rs         | 10 ++++++++++
 3 files changed, 36 insertions(+), 2 deletions(-)

diff --git a/bindgen/callbacks.rs b/bindgen/callbacks.rs
index 582446687c..21ac9af691 100644
--- a/bindgen/callbacks.rs
+++ b/bindgen/callbacks.rs
@@ -135,6 +135,15 @@ pub trait ParseCallbacks: fmt::Debug {
     fn process_comment(&self, _comment: &str) -> Option<String> {
         None
     }
+
+    /// .
+    fn process_field_name(
+        &self,
+        _parent_name: &str,
+        _name: &str,
+    ) -> Option<String> {
+        None
+    }
 }
 
 /// Relevant information about a type to which new derive attributes will be added using
diff --git a/bindgen/codegen/mod.rs b/bindgen/codegen/mod.rs
index 47f23193cb..2626ebbe5f 100644
--- a/bindgen/codegen/mod.rs
+++ b/bindgen/codegen/mod.rs
@@ -1296,6 +1296,7 @@ trait FieldCodegen<'a> {
         fields: &mut F,
         methods: &mut M,
         extra: Self::Extra,
+        parent_name: &str,
     ) where
         F: Extend<proc_macro2::TokenStream>,
         M: Extend<proc_macro2::TokenStream>;
@@ -1315,6 +1316,7 @@ impl<'a> FieldCodegen<'a> for Field {
         fields: &mut F,
         methods: &mut M,
         _: (),
+        parent_name: &str,
     ) where
         F: Extend<proc_macro2::TokenStream>,
         M: Extend<proc_macro2::TokenStream>,
@@ -1331,6 +1333,7 @@ impl<'a> FieldCodegen<'a> for Field {
                     fields,
                     methods,
                     (),
+                    parent_name,
                 );
             }
             Field::Bitfields(ref unit) => {
@@ -1344,6 +1347,7 @@ impl<'a> FieldCodegen<'a> for Field {
                     fields,
                     methods,
                     (),
+                    parent_name,
                 );
             }
         }
@@ -1393,6 +1397,7 @@ impl<'a> FieldCodegen<'a> for FieldData {
         fields: &mut F,
         methods: &mut M,
         _: (),
+        parent_name: &str,
     ) where
         F: Extend<proc_macro2::TokenStream>,
         M: Extend<proc_macro2::TokenStream>,
@@ -1438,9 +1443,15 @@ impl<'a> FieldCodegen<'a> for FieldData {
 
         let field_name = self
             .name()
-            .map(|name| ctx.rust_mangle(name).into_owned())
+            .map(|name| {
+                let name = ctx.rust_mangle(name);
+                ctx.options()
+                    .process_field_name(&parent_name, &name)
+                    .map(|name| Cow::Owned(name))
+                    .unwrap_or(name.to_owned())
+            })
             .expect("Each field should have a name in codegen!");
-        let field_ident = ctx.rust_ident_raw(field_name.as_str());
+        let field_ident = ctx.rust_ident_raw(&field_name);
 
         if let Some(padding_field) =
             struct_layout.saw_field(&field_name, field_ty, self.offset())
@@ -1641,6 +1652,7 @@ impl<'a> FieldCodegen<'a> for BitfieldUnit {
         fields: &mut F,
         methods: &mut M,
         _: (),
+        parent_name: &str,
     ) where
         F: Extend<proc_macro2::TokenStream>,
         M: Extend<proc_macro2::TokenStream>,
@@ -1720,6 +1732,7 @@ impl<'a> FieldCodegen<'a> for BitfieldUnit {
                 fields,
                 methods,
                 (&unit_field_name, &mut bitfield_representable_as_int),
+                parent_name,
             );
 
             // Generating a constructor requires the bitfield to be representable as an integer.
@@ -1800,6 +1813,7 @@ impl<'a> FieldCodegen<'a> for Bitfield {
         _fields: &mut F,
         methods: &mut M,
         (unit_field_name, bitfield_representable_as_int): (&'a str, &mut bool),
+        parent_name: &str,
     ) where
         F: Extend<proc_macro2::TokenStream>,
         M: Extend<proc_macro2::TokenStream>,
@@ -2002,6 +2016,7 @@ impl CodeGenerator for CompInfo {
                     &mut fields,
                     &mut methods,
                     (),
+                    &canonical_name,
                 );
             }
             // Check whether an explicit padding field is needed
diff --git a/bindgen/lib.rs b/bindgen/lib.rs
index e4b71b0496..459f5ec541 100644
--- a/bindgen/lib.rs
+++ b/bindgen/lib.rs
@@ -562,6 +562,16 @@ impl BindgenOptions {
             .and_then(|cb| cb.process_comment(&comment))
             .unwrap_or(comment)
     }
+
+    fn process_field_name(
+        &self,
+        parent_name: &str,
+        name: &str,
+    ) -> Option<String> {
+        self.parse_callbacks
+            .last()
+            .and_then(|cb| cb.process_field_name(parent_name, name))
+    }
 }
 
 fn deprecated_target_diagnostic(target: RustTarget, _options: &BindgenOptions) {

From f988b27d4c055a69236dde2eef50a9a2ecafd55d Mon Sep 17 00:00:00 2001
From: Ashley Ruglys <ashley.ruglys@gmail.com>
Date: Sat, 13 May 2023 20:50:39 +1200
Subject: [PATCH 2/3] Add doc comment

---
 bindgen/callbacks.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/bindgen/callbacks.rs b/bindgen/callbacks.rs
index 21ac9af691..36e03e5ae8 100644
--- a/bindgen/callbacks.rs
+++ b/bindgen/callbacks.rs
@@ -136,7 +136,7 @@ pub trait ParseCallbacks: fmt::Debug {
         None
     }
 
-    /// .
+    /// Allows renaming the name of a field, replacing `_name`.
     fn process_field_name(
         &self,
         _parent_name: &str,

From cdf53b2956ba6eaf213c52af48a2ccc24bb55708 Mon Sep 17 00:00:00 2001
From: Ashley Ruglys <ashley.ruglys@gmail.com>
Date: Sat, 13 May 2023 21:10:40 +1200
Subject: [PATCH 3/3] unused parent_name -> _parent_name

---
 bindgen/codegen/mod.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/bindgen/codegen/mod.rs b/bindgen/codegen/mod.rs
index 2626ebbe5f..7c5fb5e516 100644
--- a/bindgen/codegen/mod.rs
+++ b/bindgen/codegen/mod.rs
@@ -1813,7 +1813,7 @@ impl<'a> FieldCodegen<'a> for Bitfield {
         _fields: &mut F,
         methods: &mut M,
         (unit_field_name, bitfield_representable_as_int): (&'a str, &mut bool),
-        parent_name: &str,
+        _parent_name: &str,
     ) where
         F: Extend<proc_macro2::TokenStream>,
         M: Extend<proc_macro2::TokenStream>,