Add ByteRepr for enums

cpp2rust/converter/converter.cpp

@@ -3154,6 +3154,7 @@ bool Converter::VisitEnumDecl(clang::EnumDecl *decl) {
 
   AddFromImpl(decl);
   AddIncDecImpls(decl);
+  AddByteReprTrait(decl);
   return false;
 }
 
@@ -3936,6 +3937,8 @@ void Converter::EmitDefaultStructLiteral(const clang::RecordDecl *decl) {
 
 void Converter::AddByteReprTrait(const clang::RecordDecl *decl) {}
 
+void Converter::AddByteReprTrait(const clang::EnumDecl *decl) {}
+
 void Converter::ConvertUnsignedArithBinaryOperator(clang::BinaryOperator *op,
                                                    clang::Expr *expr) {
   StrCat(token::kDot);

cpp2rust/converter/converter.h

@@ -539,6 +539,8 @@ class Converter : public clang::RecursiveASTVisitor<Converter> {
 
   virtual void AddByteReprTrait(const clang::RecordDecl *decl);
 
+  virtual void AddByteReprTrait(const clang::EnumDecl *decl);
+
   virtual void
   ConvertUnsignedArithBinaryOperator(clang::BinaryOperator *binary_operator,
                                      clang::Expr *expr);

cpp2rust/converter/models/converter_refcount.cpp

@@ -510,10 +510,8 @@ static bool recordImplementsByteRepr(const clang::RecordDecl *decl) {
   // fields.
   for (auto *f : decl->fields()) {
     auto qt = f->getType();
-    if (qt->isEnumeralType()) {
-      return false;
-    }
-    if (!qt->isIntegerType() && !qt->isFloatingType()) {
+    if (!qt->isIntegerType() && !qt->isFloatingType() &&
+        !qt->isEnumeralType()) {
       return false;
     }
   }
@@ -567,6 +565,17 @@ void ConverterRefCount::AddByteReprTrait(const clang::RecordDecl *decl) {
   }
 }
 
+void ConverterRefCount::AddByteReprTrait(const clang::EnumDecl *decl) {
+  auto name = GetRecordName(decl);
+  StrCat(std::format("impl ByteRepr for {}", name));
+  PushBrace impl_brace(*this);
+  StrCat(
+      "fn to_bytes(&self, buf: &mut [u8]) { (*self as i32).to_bytes(buf); }");
+  StrCat(std::format("fn from_bytes(buf: &[u8]) -> Self {{ "
+                     "<{}>::from(i32::from_bytes(buf)) }}",
+                     name));
+}
+
 std::string
 ConverterRefCount::GetSelfMaybeWithMut(const clang::CXXMethodDecl *decl) {
   return "&self";

cpp2rust/converter/models/converter_refcount.h

@@ -39,6 +39,8 @@ class ConverterRefCount final : public Converter {
 
   void AddByteReprTrait(const clang::RecordDecl *decl) override;
 
+  void AddByteReprTrait(const clang::EnumDecl *decl) override;
+
   void AddDefaultTrait(const clang::RecordDecl *decl) override;
 
   void AddDefaultTraitForUnion(const clang::RecordDecl *decl) override;

tests/multi-file/cross_tu_anon_enum_collision/out/refcount/cross_tu_anon_enum_collision.rs

@@ -20,6 +20,14 @@ impl From<i32> for anon_0 {
     }
 }
 libcc2rs::impl_enum_inc_dec!(anon_0);
+impl ByteRepr for anon_0 {
+    fn to_bytes(&self, buf: &mut [u8]) {
+        (*self as i32).to_bytes(buf);
+    }
+    fn from_bytes(buf: &[u8]) -> Self {
+        <anon_0>::from(i32::from_bytes(buf))
+    }
+}
 pub fn a_value_1() -> i32 {
     let x: Value<i32> = Rc::new(RefCell::new(0));
     (*x.borrow_mut()) |= (anon_0::ALPHA as i32);
@@ -47,6 +55,14 @@ impl From<i32> for anon_3 {
     }
 }
 libcc2rs::impl_enum_inc_dec!(anon_3);
+impl ByteRepr for anon_3 {
+    fn to_bytes(&self, buf: &mut [u8]) {
+        (*self as i32).to_bytes(buf);
+    }
+    fn from_bytes(buf: &[u8]) -> Self {
+        <anon_3>::from(i32::from_bytes(buf))
+    }
+}
 pub fn b_value_2() -> i32 {
     let x: Value<i32> = Rc::new(RefCell::new(0));
     (*x.borrow_mut()) |= (anon_3::BETA as i32);

tests/multi-file/cross_tu_tag_collision/out/refcount/cross_tu_tag_collision.rs

@@ -51,6 +51,14 @@ impl From<i32> for widget_enum {
     }
 }
 libcc2rs::impl_enum_inc_dec!(widget_enum);
+impl ByteRepr for widget_enum {
+    fn to_bytes(&self, buf: &mut [u8]) {
+        (*self as i32).to_bytes(buf);
+    }
+    fn from_bytes(buf: &[u8]) -> Self {
+        <widget_enum>::from(i32::from_bytes(buf))
+    }
+}
 pub fn b_value_1() -> i32 {
     let w: Value<widget_enum> = Rc::new(RefCell::new(widget_enum::WIDGET_C));
     return ((*w.borrow()) as i32).clone();

tests/ub/out/refcount/enum_out_of_range_cast.rs

@@ -24,6 +24,14 @@ impl From<i32> for Color {
     }
 }
 libcc2rs::impl_enum_inc_dec!(Color);
+impl ByteRepr for Color {
+    fn to_bytes(&self, buf: &mut [u8]) {
+        (*self as i32).to_bytes(buf);
+    }
+    fn from_bytes(buf: &[u8]) -> Self {
+        <Color>::from(i32::from_bytes(buf))
+    }
+}
 pub fn main() {
     std::process::exit(main_0());
 }

tests/ub/out/refcount/enum_out_of_range_increment.rs

@@ -24,6 +24,14 @@ impl From<i32> for color {
     }
 }
 libcc2rs::impl_enum_inc_dec!(color);
+impl ByteRepr for color {
+    fn to_bytes(&self, buf: &mut [u8]) {
+        (*self as i32).to_bytes(buf);
+    }
+    fn from_bytes(buf: &[u8]) -> Self {
+        <color>::from(i32::from_bytes(buf))
+    }
+}
 pub fn main() {
     std::process::exit(main_0());
 }

tests/unit/out/refcount/anonymous_enum.rs

@@ -22,6 +22,14 @@ impl From<i32> for anon_0 {
     }
 }
 libcc2rs::impl_enum_inc_dec!(anon_0);
+impl ByteRepr for anon_0 {
+    fn to_bytes(&self, buf: &mut [u8]) {
+        (*self as i32).to_bytes(buf);
+    }
+    fn from_bytes(buf: &[u8]) -> Self {
+        <anon_0>::from(i32::from_bytes(buf))
+    }
+}
 #[derive(Clone, Copy, PartialEq, Debug, Default)]
 enum anon_1 {
     #[default]
@@ -38,6 +46,14 @@ impl From<i32> for anon_1 {
     }
 }
 libcc2rs::impl_enum_inc_dec!(anon_1);
+impl ByteRepr for anon_1 {
+    fn to_bytes(&self, buf: &mut [u8]) {
+        (*self as i32).to_bytes(buf);
+    }
+    fn from_bytes(buf: &[u8]) -> Self {
+        <anon_1>::from(i32::from_bytes(buf))
+    }
+}
 #[derive(Default)]
 pub struct S {
     pub a: Value<i32>,
@@ -76,6 +92,14 @@ impl From<i32> for TdEnum {
     }
 }
 libcc2rs::impl_enum_inc_dec!(TdEnum);
+impl ByteRepr for TdEnum {
+    fn to_bytes(&self, buf: &mut [u8]) {
+        (*self as i32).to_bytes(buf);
+    }
+    fn from_bytes(buf: &[u8]) -> Self {
+        <TdEnum>::from(i32::from_bytes(buf))
+    }
+}
 #[derive(Clone, Copy, PartialEq, Debug, Default)]
 enum anon_2 {
     #[default]
@@ -92,6 +116,14 @@ impl From<i32> for anon_2 {
     }
 }
 libcc2rs::impl_enum_inc_dec!(anon_2);
+impl ByteRepr for anon_2 {
+    fn to_bytes(&self, buf: &mut [u8]) {
+        (*self as i32).to_bytes(buf);
+    }
+    fn from_bytes(buf: &[u8]) -> Self {
+        <anon_2>::from(i32::from_bytes(buf))
+    }
+}
 #[derive(Default)]
 pub struct WithAnonField {
     pub a: Value<i32>,
@@ -106,7 +138,18 @@ impl Clone for WithAnonField {
         this
     }
 }
-impl ByteRepr for WithAnonField {}
+impl ByteRepr for WithAnonField {
+    fn to_bytes(&self, buf: &mut [u8]) {
+        (*self.a.borrow()).to_bytes(&mut buf[0..4]);
+        (*self.field.borrow()).to_bytes(&mut buf[4..8]);
+    }
+    fn from_bytes(buf: &[u8]) -> Self {
+        Self {
+            a: Rc::new(RefCell::new(<i32>::from_bytes(&buf[0..4]))),
+            field: Rc::new(RefCell::new(<anon_2>::from_bytes(&buf[4..8]))),
+        }
+    }
+}
 pub fn main() {
     std::process::exit(main_0());
 }
@@ -127,6 +170,14 @@ fn main_0() -> i32 {
         }
     }
     libcc2rs::impl_enum_inc_dec!(anon_3);
+    impl ByteRepr for anon_3 {
+        fn to_bytes(&self, buf: &mut [u8]) {
+            (*self as i32).to_bytes(buf);
+        }
+        fn from_bytes(buf: &[u8]) -> Self {
+            <anon_3>::from(i32::from_bytes(buf))
+        }
+    };
     assert!(((anon_0::FIRST_A as i32) != (anon_0::FIRST_B as i32)));
     assert!(((anon_1::SECOND_A as i32) != (anon_1::SECOND_B as i32)));
     assert!(((anon_3::THIRD_A as i32) != (anon_3::THIRD_B as i32)));

tests/unit/out/refcount/anonymous_enum_c.rs

@@ -22,6 +22,14 @@ impl From<i32> for anon_0 {
     }
 }
 libcc2rs::impl_enum_inc_dec!(anon_0);
+impl ByteRepr for anon_0 {
+    fn to_bytes(&self, buf: &mut [u8]) {
+        (*self as i32).to_bytes(buf);
+    }
+    fn from_bytes(buf: &[u8]) -> Self {
+        <anon_0>::from(i32::from_bytes(buf))
+    }
+}
 #[derive(Clone, Copy, PartialEq, Debug, Default)]
 enum anon_1 {
     #[default]
@@ -38,6 +46,14 @@ impl From<i32> for anon_1 {
     }
 }
 libcc2rs::impl_enum_inc_dec!(anon_1);
+impl ByteRepr for anon_1 {
+    fn to_bytes(&self, buf: &mut [u8]) {
+        (*self as i32).to_bytes(buf);
+    }
+    fn from_bytes(buf: &[u8]) -> Self {
+        <anon_1>::from(i32::from_bytes(buf))
+    }
+}
 #[derive(Default)]
 pub struct S {
     pub a: Value<i32>,
@@ -68,6 +84,14 @@ impl From<i32> for TdEnum_enum {
     }
 }
 libcc2rs::impl_enum_inc_dec!(TdEnum_enum);
+impl ByteRepr for TdEnum_enum {
+    fn to_bytes(&self, buf: &mut [u8]) {
+        (*self as i32).to_bytes(buf);
+    }
+    fn from_bytes(buf: &[u8]) -> Self {
+        <TdEnum_enum>::from(i32::from_bytes(buf))
+    }
+}
 #[derive(Clone, Copy, PartialEq, Debug, Default)]
 enum anon_2 {
     #[default]
@@ -84,12 +108,31 @@ impl From<i32> for anon_2 {
     }
 }
 libcc2rs::impl_enum_inc_dec!(anon_2);
+impl ByteRepr for anon_2 {
+    fn to_bytes(&self, buf: &mut [u8]) {
+        (*self as i32).to_bytes(buf);
+    }
+    fn from_bytes(buf: &[u8]) -> Self {
+        <anon_2>::from(i32::from_bytes(buf))
+    }
+}
 #[derive(Default)]
 pub struct WithAnonField {
     pub a: Value<i32>,
     pub field: Value<anon_2>,
 }
-impl ByteRepr for WithAnonField {}
+impl ByteRepr for WithAnonField {
+    fn to_bytes(&self, buf: &mut [u8]) {
+        (*self.a.borrow()).to_bytes(&mut buf[0..4]);
+        (*self.field.borrow()).to_bytes(&mut buf[4..8]);
+    }
+    fn from_bytes(buf: &[u8]) -> Self {
+        Self {
+            a: Rc::new(RefCell::new(<i32>::from_bytes(&buf[0..4]))),
+            field: Rc::new(RefCell::new(<anon_2>::from_bytes(&buf[4..8]))),
+        }
+    }
+}
 pub fn main() {
     std::process::exit(main_0());
 }
@@ -110,6 +153,14 @@ fn main_0() -> i32 {
         }
     }
     libcc2rs::impl_enum_inc_dec!(anon_3);
+    impl ByteRepr for anon_3 {
+        fn to_bytes(&self, buf: &mut [u8]) {
+            (*self as i32).to_bytes(buf);
+        }
+        fn from_bytes(buf: &[u8]) -> Self {
+            <anon_3>::from(i32::from_bytes(buf))
+        }
+    };
     assert!(((((anon_0::FIRST_A as i32) != (anon_0::FIRST_B as i32)) as i32) != 0));
     assert!(((((anon_1::SECOND_A as i32) != (anon_1::SECOND_B as i32)) as i32) != 0));
     assert!(((((anon_3::THIRD_A as i32) != (anon_3::THIRD_B as i32)) as i32) != 0));

tests/unit/out/refcount/bool_condition_enum.rs

@@ -24,6 +24,14 @@ impl From<i32> for Code {
     }
 }
 libcc2rs::impl_enum_inc_dec!(Code);
+impl ByteRepr for Code {
+    fn to_bytes(&self, buf: &mut [u8]) {
+        (*self as i32).to_bytes(buf);
+    }
+    fn from_bytes(buf: &[u8]) -> Self {
+        <Code>::from(i32::from_bytes(buf))
+    }
+}
 pub fn main() {
     std::process::exit(main_0());
 }

tests/unit/out/refcount/bool_condition_enum_c.rs

@@ -24,6 +24,14 @@ impl From<i32> for Code {
     }
 }
 libcc2rs::impl_enum_inc_dec!(Code);
+impl ByteRepr for Code {
+    fn to_bytes(&self, buf: &mut [u8]) {
+        (*self as i32).to_bytes(buf);
+    }
+    fn from_bytes(buf: &[u8]) -> Self {
+        <Code>::from(i32::from_bytes(buf))
+    }
+}
 pub fn main() {
     std::process::exit(main_0());
 }

tests/unit/out/refcount/bool_condition_logical.rs

@@ -24,6 +24,14 @@ impl From<i32> for Code {
     }
 }
 libcc2rs::impl_enum_inc_dec!(Code);
+impl ByteRepr for Code {
+    fn to_bytes(&self, buf: &mut [u8]) {
+        (*self as i32).to_bytes(buf);
+    }
+    fn from_bytes(buf: &[u8]) -> Self {
+        <Code>::from(i32::from_bytes(buf))
+    }
+}
 thread_local!(
     pub static side_effect_0: Value<i32> = Rc::new(RefCell::new(0));
 );

tests/unit/out/refcount/bool_condition_logical_c.rs

@@ -24,6 +24,14 @@ impl From<i32> for Code {
     }
 }
 libcc2rs::impl_enum_inc_dec!(Code);
+impl ByteRepr for Code {
+    fn to_bytes(&self, buf: &mut [u8]) {
+        (*self as i32).to_bytes(buf);
+    }
+    fn from_bytes(buf: &[u8]) -> Self {
+        <Code>::from(i32::from_bytes(buf))
+    }
+}
 thread_local!(
     pub static side_effect_0: Value<i32> = Rc::new(RefCell::new(0));
 );