test: check attribute/derive ordering

Cargo.toml

@@ -42,6 +42,7 @@ quickcheck = "1.0"
 quote = { version = "1", default-features = false }
 regex = { version = "1.5.3", default-features = false }
 rustc-hash = "2.1.0"
+serde = { version = "1", features = ["derive"] }
 shlex = "1"
 similar = "2.2.1"
 syn = "2.0"

bindgen-tests/tests/expectations/Cargo.toml

@@ -15,6 +15,7 @@ edition.workspace = true
 block.workspace = true
 libloading.workspace = true
 objc.workspace = true
+serde.workspace = true
 
 # Both of these sections need to be copied here from the workspace because
 # Cargo currently does not allow overriding workspace settings in a member

bindgen-tests/tests/headers/derive-and-attribute-order.h

@@ -0,0 +1,8 @@
+// bindgen-flags: --no-layout-tests
+// bindgen-parse-callbacks: derive-uppercase-serialize=color
+// bindgen-skip-formatting
+typedef struct {
+    int red;
+    int green;
+    int blue;
+} color;

bindgen-tests/tests/parse_callbacks/mod.rs

@@ -146,6 +146,27 @@ impl ParseCallbacks for WrapAsVariadicFn {
     }
 }
 
+#[derive(Debug)]
+struct DeriveTransparentSerialize(String);
+
+impl ParseCallbacks for DeriveTransparentSerialize {
+    fn add_derives(&self, info: &DeriveInfo<'_>) -> Vec<String> {
+        if info.name == &self.0 {
+            vec!["serde::Serialize".to_owned()]
+        } else {
+            vec![]
+        }
+    }
+
+    fn add_attributes(&self, info: &AttributeInfo<'_>) -> Vec<String> {
+        if info.name == &self.0 {
+            vec!["#[serde(rename_all = \"UPPERCASE\")]".to_owned()]
+        } else {
+            vec![]
+        }
+    }
+}
+
 pub fn lookup(cb: &str) -> Box<dyn ParseCallbacks> {
     match cb {
         "enum-variant-rename" => Box::new(EnumVariantRename),
@@ -155,7 +176,11 @@ pub fn lookup(cb: &str) -> Box<dyn ParseCallbacks> {
         "wrap-as-variadic-fn" => Box::new(WrapAsVariadicFn),
         "type-visibility" => Box::new(TypeVisibility),
         call_back => {
-            if let Some(prefix) =
+            if let Some(name) =
+                call_back.strip_prefix("derive-uppercase-serialize=")
+            {
+                Box::new(DeriveTransparentSerialize(name.to_owned()))
+            } else if let Some(prefix) =
                 call_back.strip_prefix("remove-function-prefix-")
             {
                 let lnopc = RemovePrefixParseCallback::new(prefix);

bindgen-tests/tests/tests.rs

@@ -187,17 +187,23 @@ fn compare_generated_header(
             looked_at,
         ),
     };
-
+    let do_formatting = builder.do_formatting;
     let (builder, roundtrip_builder) = builder.into_builder(check_roundtrip)?;
 
     // We skip the generate() error here so we get a full diff below
     let actual = match builder.generate() {
-        Ok(bindings) => format_code(bindings.to_string()).map_err(|err| {
-            Error::new(
-                ErrorKind::Other,
-                format!("Cannot parse the generated bindings: {err}"),
-            )
-        })?,
+        Ok(bindings) => {
+            if do_formatting {
+                format_code(bindings.to_string()).map_err(|err| {
+                    Error::new(
+                        ErrorKind::Other,
+                        format!("Cannot parse the generated bindings: {err}"),
+                    )
+                })?
+            } else {
+                bindings.to_string()
+            }
+        }
         Err(_) => "/* error generating bindings */\n".into(),
     };
 
@@ -237,6 +243,7 @@ fn builder() -> Builder {
 struct BuilderState {
     builder: Builder,
     parse_callbacks: Option<String>,
+    do_formatting: bool,
 }
 
 impl BuilderState {
@@ -255,6 +262,7 @@ impl BuilderState {
             Some(BuilderState {
                 builder,
                 parse_callbacks: self.parse_callbacks,
+                do_formatting: self.do_formatting,
             })
         } else {
             None
@@ -273,6 +281,7 @@ fn create_bindgen_builder(header: &Path) -> Result<BuilderState, Error> {
     // Scoop up bindgen-flags from test header
     let mut flags = Vec::with_capacity(2);
     let mut parse_callbacks = None;
+    let mut do_formatting = true;
 
     for line in reader.lines() {
         let line = line?;
@@ -298,6 +307,8 @@ fn create_bindgen_builder(header: &Path) -> Result<BuilderState, Error> {
             let parse_cb =
                 line.split("bindgen-parse-callbacks: ").last().unwrap();
             parse_callbacks = Some(parse_cb.to_owned());
+        } else if line.contains("bindgen-skip-formatting") {
+            do_formatting = false;
         }
     }
 
@@ -345,6 +356,7 @@ fn create_bindgen_builder(header: &Path) -> Result<BuilderState, Error> {
     Ok(BuilderState {
         builder,
         parse_callbacks,
+        do_formatting,
     })
 }