Revert "Implement C++ methods for DNA structures"

This reverts commit 8c44793228750537c08ea7b19fc18df0138f9501.

Apparently, this generated a lot of warnings in GCC.

Didn't find a quick solution and is it not something I want to be
trading between (more quiet Clang in an expense of less quiet GCC).

Will re-iterate on the patch are re-commit it.

9 files changed, 7 insertions, 116 deletions

diff --git a/source/blender/blenkernel/intern/mesh_convert.cc b/source/blender/blenkernel/intern/mesh_convert.cc
index 1be2d06ce61..40c6fbcf67e 100644
--- a/source/blender/blenkernel/intern/mesh_convert.cc
+++ b/source/blender/blenkernel/intern/mesh_convert.cc
@@ -910,8 +910,7 @@ static void curve_to_mesh_eval_ensure(Object &object)
    *
    * So we create temporary copy of the object which will use same data as the original bevel, but
    * will have no modifiers. */
-  Object bevel_object;
-  memset(&bevel_object, 0, sizeof(bevel_object));
+  Object bevel_object = {{nullptr}};
   if (curve.bevobj != nullptr) {
     memcpy(&bevel_object, curve.bevobj, sizeof(bevel_object));
     BLI_listbase_clear(&bevel_object.modifiers);
@@ -920,8 +919,7 @@ static void curve_to_mesh_eval_ensure(Object &object)
   }
 
   /* Same thing for taper. */
-  Object taper_object;
-  memset(&taper_object, 0, sizeof(taper_object));
+  Object taper_object = {{nullptr}};
   if (curve.taperobj != nullptr) {
     memcpy(&taper_object, curve.taperobj, sizeof(taper_object));
     BLI_listbase_clear(&taper_object.modifiers);
diff --git a/source/blender/blenkernel/intern/object.cc b/source/blender/blenkernel/intern/object.cc
index 6d1eac5af49..1e3b5d77fa7 100644
--- a/source/blender/blenkernel/intern/object.cc
+++ b/source/blender/blenkernel/intern/object.cc
@@ -3946,7 +3946,7 @@ bool BKE_object_minmax_dupli(Depsgraph *depsgraph,
       /* pass */
     }
     else {
-      Object temp_ob = blender::dna::shallow_copy(*dob->ob);
+      Object temp_ob = *dob->ob;
       /* Do not modify the original boundbox. */
       temp_ob.runtime.bb = nullptr;
       BKE_object_replace_data_on_shallow_copy(&temp_ob, dob->ob_data);
diff --git a/source/blender/depsgraph/intern/depsgraph_query_iter.cc b/source/blender/depsgraph/intern/depsgraph_query_iter.cc
index d5566e4be98..5788e8efa07 100644
--- a/source/blender/depsgraph/intern/depsgraph_query_iter.cc
+++ b/source/blender/depsgraph/intern/depsgraph_query_iter.cc
@@ -167,7 +167,7 @@ bool deg_iterator_duplis_step(DEGObjectIterData *data)
     /* Temporary object to evaluate. */
     Object *dupli_parent = data->dupli_parent;
     Object *temp_dupli_object = &data->temp_dupli_object;
-    *temp_dupli_object = blender::dna::shallow_copy(*dob->ob);
+    *temp_dupli_object = *dob->ob;
     temp_dupli_object->base_flag = dupli_parent->base_flag | BASE_FROM_DUPLI;
     temp_dupli_object->base_local_view_bits = dupli_parent->base_local_view_bits;
     temp_dupli_object->runtime.local_collections_bits =
diff --git a/source/blender/editors/object/object_transform.cc b/source/blender/editors/object/object_transform.cc
index afd2c048379..24425b5a991 100644
--- a/source/blender/editors/object/object_transform.cc
+++ b/source/blender/editors/object/object_transform.cc
@@ -1695,13 +1695,13 @@ static void object_apply_rotation(Object *ob, const float rmat[3][3])
 static void object_apply_location(Object *ob, const float loc[3])
 {
   /* quick but weak */
-  Object ob_prev = blender::dna::shallow_copy(*ob);
+  Object ob_prev = *ob;
   float mat[4][4];
   copy_m4_m4(mat, ob->obmat);
   copy_v3_v3(mat[3], loc);
   BKE_object_apply_mat4(ob, mat, true, true);
   copy_v3_v3(mat[3], ob->loc);
-  *ob = blender::dna::shallow_copy(ob_prev);
+  *ob = ob_prev;
   copy_v3_v3(ob->loc, mat[3]);
 }
 
diff --git a/source/blender/io/wavefront_obj/exporter/obj_export_mesh.cc b/source/blender/io/wavefront_obj/exporter/obj_export_mesh.cc
index 8c9b04a5ac3..aa63e65b1e8 100644
--- a/source/blender/io/wavefront_obj/exporter/obj_export_mesh.cc
+++ b/source/blender/io/wavefront_obj/exporter/obj_export_mesh.cc
@@ -33,7 +33,7 @@ OBJMesh::OBJMesh(Depsgraph *depsgraph, const OBJExportParams &export_params, Obj
 {
   /* We need to copy the object because it may be in temporary space. */
   Object *obj_eval = DEG_get_evaluated_object(depsgraph, mesh_object);
-  export_object_eval_ = dna::shallow_copy(*obj_eval);
+  export_object_eval_ = *obj_eval;
   export_mesh_eval_ = export_params.apply_modifiers ?
                           BKE_object_get_evaluated_mesh(&export_object_eval_) :
                           BKE_object_get_pre_modified_mesh(&export_object_eval_);
diff --git a/source/blender/makesdna/DNA_defs.h b/source/blender/makesdna/DNA_defs.h
index 283eacf1a16..b4230209dd5 100644
--- a/source/blender/makesdna/DNA_defs.h
+++ b/source/blender/makesdna/DNA_defs.h
@@ -46,84 +46,3 @@
 
 /* non-id name variables should use this length */
 #define MAX_NAME 64
-
-/* #DNA_DEFINE_CXX_METHODS is used to define C++ methods which are needed for proper/safe resource
- * management, making unsafe (from an ownership perspective: i.e. pointers which sometimes needs to
- * be set to nullptr on copy, sometimes needs to be dupalloc-ed) operations explicit, and taking
- * care of compiler specific warnings when dealing with members marked with DNA_DEPRECATED.
- *
- * The `class_name` argument is to match the structure name the macro is used from.
- *
- * Typical usage example:
- *
- *   typedef struct Object {
- *     DNA_DEFINE_CXX_METHODS(Object)
- *   } Object;
- */
-#ifndef __cplusplus
-#  define DNA_DEFINE_CXX_METHODS(class_name)
-#else
-
-/* Forward-declared here since there is no simple header file to be pulled for this functionality.
- * Avoids pulling `string.h` from this header to get access to #memcpy. */
-extern "C" void _DNA_internal_memcpy(void *dst, const void *src, size_t size);
-
-namespace blender::dna::internal {
-
-template<class T> class ShallowDataConstRef {
- public:
-  constexpr explicit ShallowDataConstRef(const T &ref) : ref_(ref)
-  {
-  }
-
-  inline const T *get_pointer() const
-  {
-    return &ref_;
-  }
-
- private:
-  const T &ref_;
-};
-
-}  // namespace blender::dna::internal
-
-#  define DNA_DEFINE_CXX_METHODS(class_name) \
-    class_name() = default; \
-    ~class_name() = default; \
-    /* Delete copy and assignment, which are not safe for resource ownership. */ \
-    class_name(const class_name &other) = delete; \
-    class_name(class_name &&other) noexcept = delete; \
-    class_name &operator=(const class_name &other) = delete; \
-    class_name &operator=(class_name &&other) = delete; \
-    /* Support for shallow copy. */ \
-    class_name(const blender::dna::internal::ShallowDataConstRef<class_name> ref) \
-    { \
-      _DNA_internal_memcpy(this, ref.get_pointer(), sizeof(class_name)); \
-    } \
-    class_name &operator=(const blender::dna::internal::ShallowDataConstRef<class_name> ref) \
-    { \
-      if (this != ref.get_pointer()) { \
-        _DNA_internal_memcpy(this, ref.get_pointer(), sizeof(class_name)); \
-      } \
-      return *this; \
-    }
-
-namespace blender::dna {
-
-/* Creates shallow copy of the given object.
- * The entire object is copied as-is using memory copy.
- *
- * Typical usage:
- *   Object temp_object = blender::dna::shallow_copy(*input_object);
- *
- * From the implementation detail go via copy constructor/assign operator defined in the structure.
- */
-template<class T>
-[[nodiscard]] inline internal::ShallowDataConstRef<T> shallow_copy(const T &other)
-{
-  return internal::ShallowDataConstRef(other);
-}
-
-}  // namespace blender::dna
-
-#endif
diff --git a/source/blender/makesdna/DNA_object_types.h b/source/blender/makesdna/DNA_object_types.h
index c3708e25ee7..9e0bf7dcc5a 100644
--- a/source/blender/makesdna/DNA_object_types.h
+++ b/source/blender/makesdna/DNA_object_types.h
@@ -233,8 +233,6 @@ enum eObjectLineArt_Flags {
 };
 
 typedef struct Object {
-  DNA_DEFINE_CXX_METHODS(Object)
-
   ID id;
   /** Animation data (must be immediately after id for utilities to use it). */
   struct AnimData *adt;
diff --git a/source/blender/makesdna/intern/dna_utils.c b/source/blender/makesdna/intern/dna_utils.c
index 560b91b925e..8c86ef69ebd 100644
--- a/source/blender/makesdna/intern/dna_utils.c
+++ b/source/blender/makesdna/intern/dna_utils.c
@@ -308,15 +308,3 @@ const char *DNA_struct_rename_legacy_hack_alias_from_static(const char *name)
 }
 
 /** \} */
-
-/* -------------------------------------------------------------------- */
-/** \name Internal helpers for C++
- * \{ */
-
-void _DNA_internal_memcpy(void *dst, const void *src, size_t size);
-void _DNA_internal_memcpy(void *dst, const void *src, const size_t size)
-{
-  memcpy(dst, src, size);
-}
-
-/** \} */
diff --git a/source/blender/makesdna/intern/makesdna.c b/source/blender/makesdna/intern/makesdna.c
index 12ec7262906..0d2f265a9b5 100644
--- a/source/blender/makesdna/intern/makesdna.c
+++ b/source/blender/makesdna/intern/makesdna.c
@@ -620,7 +620,6 @@ static int preprocess_include(char *maindata, const int maindata_len)
   int newlen = 0;
   comment = 0;
   a = maindata_len;
-  bool skip_until_closing_brace = false;
   while (a--) {
 
     if (cp[0] == '/' && cp[1] == '*') {
@@ -647,17 +646,6 @@ static int preprocess_include(char *maindata, const int maindata_len)
       a -= 13;
       cp += 13;
     }
-    else if (match_identifier(cp, "DNA_DEFINE_CXX_METHODS")) {
-      /* single values are skipped already, so decrement 1 less */
-      a -= 21;
-      cp += 21;
-      skip_until_closing_brace = true;
-    }
-    else if (skip_until_closing_brace) {
-      if (cp[0] == ')') {
-        skip_until_closing_brace = false;
-      }
-    }
     else {
       md[0] = cp[0];
       md++;