Proper way to check bit fields

Author: kornilova203

bindgen/ir/IR.cpp

@@ -34,9 +34,10 @@ void IR::addEnum(std::string name, const std::string &type,
 
 void IR::addStruct(std::string name, std::vector<std::shared_ptr<Field>> fields,
                    uint64_t typeSize, std::shared_ptr<Location> location,
-                   bool isPacked) {
-    std::shared_ptr<Struct> s = std::make_shared<Struct>(
-        name, std::move(fields), typeSize, std::move(location), isPacked);
+                   bool isPacked, bool isBitField) {
+    std::shared_ptr<Struct> s =
+        std::make_shared<Struct>(name, std::move(fields), typeSize,
+                                 std::move(location), isPacked, isBitField);
     structs.push_back(s);
     std::shared_ptr<TypeDef> typeDef = getTypeDefWithName("struct_" + name);
     if (typeDef) {

bindgen/ir/IR.h

@@ -36,7 +36,7 @@ class IR {
 
     void addStruct(std::string name, std::vector<std::shared_ptr<Field>> fields,
                    uint64_t typeSize, std::shared_ptr<Location> location,
-                   bool isPacked);
+                   bool isPacked, bool isBitField);
 
     void addUnion(std::string name, std::vector<std::shared_ptr<Field>> fields,
                   uint64_t maxSize, std::shared_ptr<Location> location);

bindgen/ir/Struct.cpp

@@ -31,9 +31,9 @@ bool StructOrUnion::hasHelperMethods() const { return !fields.empty(); }
 
 Struct::Struct(std::string name, std::vector<std::shared_ptr<Field>> fields,
                uint64_t typeSize, std::shared_ptr<Location> location,
-               bool isPacked)
+               bool isPacked, bool isBitField)
     : StructOrUnion(std::move(name), std::move(fields), std::move(location)),
-      typeSize(typeSize), isPacked(isPacked) {}
+      typeSize(typeSize), isPacked(isPacked), isBitField(isBitField) {}
 
 std::shared_ptr<TypeDef> Struct::generateTypeDef() {
     if (isRepresentedAsStruct()) {
@@ -74,7 +74,7 @@ std::string Struct::generateHelperClass() const {
 }
 
 bool Struct::hasHelperMethods() const {
-    if (isBitField()) {
+    if (isBitField) {
         return false;
     }
     if (!isRepresentedAsStruct()) {
@@ -181,7 +181,7 @@ Struct::generateGetterForStructRepresentation(unsigned fieldIndex) const {
 }
 
 bool Struct::isRepresentedAsStruct() const {
-    return fields.size() <= SCALA_NATIVE_MAX_STRUCT_FIELDS && !isBitField();
+    return fields.size() <= SCALA_NATIVE_MAX_STRUCT_FIELDS && !isBitField;
 }
 
 std::string
@@ -242,16 +242,6 @@ Struct::generateGetterForArrayRepresentation(unsigned fieldIndex) const {
     return s.str();
 }
 
-bool Struct::isBitField() const {
-    // TODO: find proper way to check it
-    for (const auto &field : fields) {
-        if (field->getOffsetInBits() % 8 != 0) {
-            return true;
-        }
-    }
-    return false;
-}
-
 Union::Union(std::string name, std::vector<std::shared_ptr<Field>> fields,
              uint64_t maxSize, std::shared_ptr<Location> location)
     : StructOrUnion(std::move(name), std::move(fields), std::move(location)),

bindgen/ir/Struct.h

@@ -52,8 +52,8 @@ class Struct : public StructOrUnion,
                public std::enable_shared_from_this<Struct> {
   public:
     Struct(std::string name, std::vector<std::shared_ptr<Field>> fields,
-           uint64_t typeSize, std::shared_ptr<Location> location,
-           bool isPacked);
+           uint64_t typeSize, std::shared_ptr<Location> location, bool isPacked,
+           bool isBitField);
 
     std::shared_ptr<TypeDef> generateTypeDef() override;
 
@@ -74,9 +74,11 @@ class Struct : public StructOrUnion,
     bool operator==(const Type &other) const override;
 
   private:
-    /* type size is needed if number of fields is bigger than 22 */
+    /** type size is needed if number of fields is bigger than 22 */
     uint64_t typeSize;
     bool isPacked;
+    /** true if at least one field is bit field */
+    bool isBitField;
 
     bool isRepresentedAsStruct() const;
 
@@ -99,8 +101,6 @@ class Struct : public StructOrUnion,
     std::string generateSetterForArrayRepresentation(unsigned fieldIndex) const;
 
     std::string generateGetterForArrayRepresentation(unsigned fieldIndex) const;
-
-    bool isBitField() const;
 };
 
 class Union : public StructOrUnion,

bindgen/visitor/TreeVisitor.cpp

@@ -130,7 +130,11 @@ void TreeVisitor::handleStruct(clang::RecordDecl *record, std::string name) {
     const clang::ASTRecordLayout &recordLayout =
         astContext->getASTRecordLayout(record);
 
+    bool isBitFieldStruct = false;
     for (const clang::FieldDecl *field : record->fields()) {
+        if (field->isBitField()) {
+            isBitFieldStruct = true;
+        }
         std::shared_ptr<Type> ftype =
             typeTranslator.translate(field->getType(), &name);
         uint64_t recordOffsetInBits =
@@ -155,7 +159,7 @@ void TreeVisitor::handleStruct(clang::RecordDecl *record, std::string name) {
     assert(sizeInBits % 8 == 0);
 
     ir.addStruct(name, std::move(fields), sizeInBits / 8, getLocation(record),
-                 record->hasAttr<clang::PackedAttr>());
+                 record->hasAttr<clang::PackedAttr>(), isBitFieldStruct);
 }
 
 bool TreeVisitor::VisitVarDecl(clang::VarDecl *varDecl) {

tests/samples/Struct.h

@@ -67,6 +67,12 @@ struct bitFieldStruct { // no helper methods
     unsigned char b3 : 2;
 };
 
+struct bitFieldOffsetDivByEight { // no helper methods
+    unsigned b1 : 8;
+    unsigned b2 : 8;
+    unsigned char b3 : 8;
+};
+
 char getCharFromAnonymousStruct(struct structWithAnonymousStruct *s);
 
 char getIntFromAnonymousStruct(struct structWithAnonymousStruct *s);

tests/samples/Struct.scala

@@ -15,6 +15,7 @@ object Struct {
   type struct_structWithAnonymousStruct = native.CStruct2[native.CInt, native.CArray[Byte, native.Nat._8]]
   type struct_packedStruct = native.CStruct1[native.CChar]
   type struct_bitFieldStruct = native.CArray[Byte, native.Nat._2]
+  type struct_bitFieldOffsetDivByEight = native.CArray[Byte, native.Nat._4]
   type enum_struct_op = native.CUnsignedInt
   def setPoints(points: native.Ptr[struct_points], x1: native.CInt, y1: native.CInt, x2: native.CInt, y2: native.CInt): Unit = native.extern
   def getPoint(points: native.Ptr[struct_points], pointIndex: enum_pointIndex): native.CInt = native.extern