Also implement div-style must_use_type annotation.

Author: KarelPeeters

src/codegen/mod.rs

@@ -2023,7 +2023,7 @@ impl CodeGenerator for CompInfo {
             attributes.push(attributes::derives(&derives))
         }
 
-        if ctx.must_use_type_by_name(item) {
+        if item.annotations().must_use_type() || ctx.must_use_type_by_name(item) {
             attributes.push(attributes::must_use());
         }
 

src/ir/annotations.rs

@@ -42,6 +42,8 @@ pub struct Annotations {
     disallow_debug: bool,
     /// Manually disable deriving/implement default on this type.
     disallow_default: bool,
+    /// Whether to add a #[must_use] annotation to this type.
+    must_use_type: bool,
     /// Whether fields should be marked as private or not. You can set this on
     /// structs (it will apply to all the fields), or individual fields.
     private_fields: Option<bool>,
@@ -84,6 +86,7 @@ impl Default for Annotations {
             disallow_copy: false,
             disallow_debug: false,
             disallow_default: false,
+            must_use_type: false,
             private_fields: None,
             accessor_kind: None,
             constify_enum_variant: false,
@@ -163,6 +166,11 @@ impl Annotations {
         self.disallow_default
     }
 
+    /// Should this type get a `#[must_use]` annotation?
+    pub fn must_use_type(&self) -> bool {
+        self.must_use_type
+    }
+
     /// Should the fields be private?
     pub fn private_fields(&self) -> Option<bool> {
         self.private_fields
@@ -190,6 +198,7 @@ impl Annotations {
                     "nocopy" => self.disallow_copy = true,
                     "nodebug" => self.disallow_debug = true,
                     "nodefault" => self.disallow_default = true,
+                    "mustusetype" => self.must_use_type = true,
                     "replaces" => {
                         self.use_instead_of = Some(
                             attr.value.split("::").map(Into::into).collect(),

tests/expectations/tests/issue-710-must-use-type.rs

@@ -8,11 +8,18 @@
 #[repr(C)]
 #[derive(Debug, Copy, Clone)]
 #[must_use]
-pub struct MyType {
+pub struct A {
     _unused: [u8; 0],
 }
+/// <div rustbindgen mustusetype></div>
 #[repr(C)]
 #[derive(Debug, Copy, Clone)]
-pub struct OtherType {
+#[must_use]
+pub struct B {
+    _unused: [u8; 0],
+}
+#[repr(C)]
+#[derive(Debug, Copy, Clone)]
+pub struct C {
     _unused: [u8; 0],
 }

tests/headers/issue-710-must-use-type.h

@@ -1,5 +1,8 @@
-// bindgen-flags: --must-use-type MyType
+// bindgen-flags: --must-use-type A
 
-struct MyType;
+struct A;
 
-struct OtherType;
+/** <div rustbindgen mustusetype></div> */
+struct B;
+
+struct C;