Cleanup: Improve usage of extern "C"

source/blender/blenkernel/BKE_deform.h

@@ -20,6 +20,10 @@
 #ifndef __BKE_DEFORM_H__
 #define __BKE_DEFORM_H__
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 /** \file
  * \ingroup bke
  * \brief support for deformation groups and hooks.
@@ -142,4 +146,8 @@ void BKE_defvert_extract_vgroup_to_polyweights(struct MDeformVert *dvert,
 
 void BKE_defvert_weight_to_rgb(float r_rgb[3], const float weight);
 
+#ifdef __cplusplus
+}
+#endif
+
 #endif /* __BKE_DEFORM_H__ */

source/blender/blenkernel/BKE_modifier.h

@@ -20,14 +20,14 @@
  * \ingroup bke
  */
 
-#ifdef __cplusplus
-extern "C" {
-#endif
-
 #include "DNA_modifier_types.h" /* needed for all enum typdefs */
 #include "BLI_compiler_attrs.h"
 #include "BKE_customdata.h"
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 struct BMEditMesh;
 struct CustomData_MeshMasks;
 struct DepsNodeHandle;

source/blender/makesdna/DNA_modifier_types.h

@@ -24,6 +24,10 @@
 #include "DNA_defs.h"
 #include "DNA_listBase.h"
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 /* WARNING ALERT! TYPEDEF VALUES ARE WRITTEN IN FILES! SO DO NOT CHANGE!
  * (ONLY ADD NEW ITEMS AT THE END)
  */
@@ -2042,4 +2046,8 @@ enum {
 #define MOD_MESHSEQ_READ_ALL \
   (MOD_MESHSEQ_READ_VERT | MOD_MESHSEQ_READ_POLY | MOD_MESHSEQ_READ_UV | MOD_MESHSEQ_READ_COLOR)
 
+#ifdef __cplusplus
+}
+#endif
+
 #endif /* __DNA_MODIFIER_TYPES_H__ */