Cleanup: Avoid some void pointer freeing for type safety

Essentially add some API to properly free non-public data, instead of directly calling `MEM_freeN` on them.

Based on @brecht code from
https://projects.blender.org/mont29/blender/compare/tmp-guardedalloc-api...brecht:free-void

Co-authored-by: Brecht Van Lommel <brecht@blender.org>
Pull Request: https://projects.blender.org/blender/blender/pulls/134765

source/blender/blenkernel/intern/screen.cc

@@ -54,6 +54,8 @@
 #  include "BPY_extern.hh"
 #endif
 
+#include "WM_types.hh"
+
 using blender::Span;
 using blender::Vector;
 

source/blender/blenlib/BLI_dial_2d.h

@@ -29,12 +29,13 @@
  *
  * angle = BLI_dial_angle(dial, current_position);
  *
- * MEM_freeN(dial);
+ * BLI_dial_free(dial);
  * \endcode
  */
 
 typedef struct Dial Dial;
 
 Dial *BLI_dial_init(const float start_position[2], float threshold);
+void BLI_dial_free(Dial *dial);
 
 float BLI_dial_angle(Dial *dial, const float current_position[2]);

source/blender/blenlib/BLI_uvproject.h

@@ -45,4 +45,8 @@ void BLI_uvproject_from_view_ortho(float target[2], float source[3], const float
 /**
  * So we can adjust scale with keeping the struct private.
  */
-void BLI_uvproject_camera_info_scale(struct ProjCameraInfo *uci, float scale_x, float scale_y);
+void BLI_uvproject_camera_info_scale(ProjCameraInfo *uci, float scale_x, float scale_y);
+
+/*
+ * Free info. */
+void BLI_uvproject_camera_info_free(ProjCameraInfo *uci);

source/blender/blenlib/intern/BLI_dial_2d.cc

@@ -44,6 +44,11 @@ Dial *BLI_dial_init(const float start_position[2], float threshold)
   return dial;
 }
 
+void BLI_dial_free(Dial *dial)
+{
+  MEM_freeN(dial);
+}
+
 float BLI_dial_angle(Dial *dial, const float current_position[2])
 {
   float current_direction[2];

source/blender/blenlib/intern/uvproject.cc

@@ -173,6 +173,11 @@ ProjCameraInfo *BLI_uvproject_camera_info(const Object *ob,
   return nullptr;
 }
 
+void BLI_uvproject_camera_info_free(ProjCameraInfo *uci)
+{
+  MEM_freeN(uci);
+}
+
 void BLI_uvproject_from_view_ortho(float target[2], float source[3], const float rotmat[4][4])
 {
   float pv[3];

source/blender/editors/asset/intern/asset_list.cc

@@ -57,7 +57,6 @@ class FileListWrapper {
   static void filelist_free_fn(FileList *list)
   {
     filelist_free(list);
-    MEM_freeN(static_cast<void *>(list));
   }
 
   std::unique_ptr<FileList, decltype(&filelist_free_fn)> file_list_;

source/blender/editors/gizmo_library/gizmo_types/cage2d_gizmo.cc

@@ -1290,9 +1290,8 @@ static void gizmo_cage2d_exit(bContext *C, wmGizmo *gz, const bool cancel)
 {
   RectTransformInteraction *data = static_cast<RectTransformInteraction *>(gz->interaction_data);
 
-  /* Cannot use MEM_SAFE_FREE, as #Dial type is only forward-declared in `BLI_dial_2d.h` */
   if (data->dial) {
-    MEM_freeN(static_cast<void *>(data->dial));
+    BLI_dial_free(data->dial);
     data->dial = nullptr;
   }
 

source/blender/editors/grease_pencil/intern/grease_pencil_image_render.cc

@@ -71,7 +71,7 @@ void region_reset(ARegion &region, const RegionViewData &data)
   region.winrct = data.winrct;
 
   ED_view3d_mats_rv3d_restore(&rv3d, data.rv3d_store);
-  MEM_freeN(static_cast<void *>(data.rv3d_store));
+  ED_view3D_mats_rv3d_free(data.rv3d_store);
 }
 
 GPUOffScreen *image_render_begin(const int2 &win_size)

source/blender/editors/include/ED_info.hh

@@ -25,6 +25,8 @@ const char *ED_info_statusbar_string(Main *bmain, Scene *scene, ViewLayer *view_
 
 const char *ED_info_statistics_string(Main *bmain, Scene *scene, ViewLayer *view_layer);
 
+void ED_view3d_local_stats_free(View3D *v3d);
+
 /**
  * \param v3d_local: Pass this argument to calculate view-port local statistics.
  * Note that this must only be used for local-view, otherwise report specific statistics

source/blender/editors/include/ED_view3d.hh

@@ -1065,6 +1065,7 @@ void ED_view3d_check_mats_rv3d(RegionView3D *rv3d);
 
 RV3DMatrixStore *ED_view3d_mats_rv3d_backup(RegionView3D *rv3d);
 void ED_view3d_mats_rv3d_restore(RegionView3D *rv3d, RV3DMatrixStore *rv3dmat);
+void ED_view3D_mats_rv3d_free(RV3DMatrixStore *rv3d_mat);
 
 RenderEngineType *ED_view3d_engine_type(const Scene *scene, int drawtype);
 

source/blender/editors/sculpt_paint/sculpt.cc

@@ -3905,10 +3905,8 @@ namespace blender::ed::sculpt_paint {
 
 StrokeCache::~StrokeCache()
 {
-  /* Cannot use MEM_SAFE_FREE, as #Dial type is only forward-declared in `BLI_dial_2d.h` */
   if (this->dial) {
-    MEM_freeN(static_cast<void *>(this->dial));
-    this->dial = nullptr;
+    BLI_dial_free(this->dial);
   }
 }
 

source/blender/editors/space_file/filelist.cc

@@ -1975,6 +1975,8 @@ void filelist_free(FileList *filelist)
   memset(&filelist->filter_data, 0, sizeof(filelist->filter_data));
 
   filelist->flags &= ~(FL_NEED_SORTING | FL_NEED_FILTERING);
+
+  MEM_freeN(filelist);
 }
 
 blender::asset_system::AssetLibrary *filelist_asset_library(FileList *filelist)
@@ -4196,7 +4198,6 @@ static void filelist_readjob_free(void *flrjv)
 
     filelist_freelib(flrj->tmp_filelist);
     filelist_free(flrj->tmp_filelist);
-    MEM_freeN(flrj->tmp_filelist);
   }
 
   BLI_mutex_end(&flrj->lock);

source/blender/editors/space_file/filesel.cc

@@ -1329,7 +1329,6 @@ void ED_fileselect_exit(wmWindowManager *wm, SpaceFile *sfile)
   if (sfile->files) {
     ED_fileselect_clear(wm, sfile);
     filelist_free(sfile->files);
-    MEM_freeN(static_cast<void *>(sfile->files));
     sfile->files = nullptr;
   }
 }

source/blender/editors/space_file/space_file.cc

@@ -117,7 +117,6 @@ static void file_free(SpaceLink *sl)
     /* XXX would need to do thumbnails_stop here, but no context available */
     filelist_freelib(sfile->files);
     filelist_free(sfile->files);
-    MEM_freeN(static_cast<void *>(sfile->files));
     sfile->files = nullptr;
   }
 

source/blender/editors/space_info/info_stats.cc

@@ -450,13 +450,18 @@ void ED_info_stats_clear(wmWindowManager *wm, ViewLayer *view_layer)
       if (area->spacetype == SPACE_VIEW3D) {
         View3D *v3d = (View3D *)area->spacedata.first;
         if (v3d->localvd) {
-          MEM_SAFE_FREE(v3d->runtime.local_stats);
+          ED_view3d_local_stats_free(v3d);
         }
       }
     }
   }
 }
 
+void ED_view3d_local_stats_free(View3D *v3d)
+{
+  MEM_SAFE_FREE(v3d->runtime.local_stats);
+}
+
 static bool format_stats(
     Main *bmain, Scene *scene, ViewLayer *view_layer, View3D *v3d_local, SceneStatsFmt *stats_fmt)
 {

source/blender/editors/space_view3d/space_view3d.cc

@@ -50,6 +50,7 @@
 
 #include "ED_asset_shelf.hh"
 #include "ED_geometry.hh"
+#include "ED_info.hh"
 #include "ED_object.hh"
 #include "ED_outliner.hh"
 #include "ED_render.hh"
@@ -277,12 +278,7 @@ static void view3d_free(SpaceLink *sl)
     MEM_freeN(vd->localvd);
   }
 
-  /* Cannot use MEM_SAFE_FREE, as #SceneStats type is only forward-declared in `DNA_layer_types.h`
-   */
-  if (vd->runtime.local_stats) {
-    MEM_freeN(static_cast<void *>(vd->runtime.local_stats));
-    vd->runtime.local_stats = nullptr;
-  }
+  ED_view3d_local_stats_free(vd);
 
   if (vd->runtime.properties_storage_free) {
     vd->runtime.properties_storage_free(vd->runtime.properties_storage);
@@ -304,12 +300,7 @@ static void view3d_exit(wmWindowManager * /*wm*/, ScrArea *area)
 {
   BLI_assert(area->spacetype == SPACE_VIEW3D);
   View3D *v3d = static_cast<View3D *>(area->spacedata.first);
-  /* Cannot use MEM_SAFE_FREE, as #SceneStats type is only forward-declared in `DNA_layer_types.h`
-   */
-  if (v3d->runtime.local_stats) {
-    MEM_freeN(static_cast<void *>(v3d->runtime.local_stats));
-    v3d->runtime.local_stats = nullptr;
-  }
+  ED_view3d_local_stats_free(v3d);
 }
 
 static SpaceLink *view3d_duplicate(SpaceLink *sl)
@@ -2016,12 +2007,7 @@ static void space_view3d_listener(const wmSpaceTypeListenerParams *params)
 static void space_view3d_refresh(const bContext *C, ScrArea *area)
 {
   View3D *v3d = (View3D *)area->spacedata.first;
-  /* Cannot use MEM_SAFE_FREE, as #SceneStats type is only forward-declared in `DNA_layer_types.h`
-   */
-  if (v3d->runtime.local_stats) {
-    MEM_freeN(static_cast<void *>(v3d->runtime.local_stats));
-    v3d->runtime.local_stats = nullptr;
-  }
+  ED_view3d_local_stats_free(v3d);
 
   if (v3d->localvd && v3d->localvd->runtime.flag & V3D_RUNTIME_LOCAL_MAYBE_EMPTY) {
     ED_localview_exit_if_empty(CTX_data_ensure_evaluated_depsgraph(C),

source/blender/editors/space_view3d/view3d_draw.cc

@@ -2715,6 +2715,11 @@ void ED_view3d_mats_rv3d_restore(RegionView3D *rv3d, RV3DMatrixStore *rv3dmat_pt
   rv3d->pixsize = rv3dmat->pixsize;
 }
 
+void ED_view3D_mats_rv3d_free(RV3DMatrixStore *rv3d_mat)
+{
+  MEM_freeN(rv3d_mat);
+}
+
 /** \} */
 
 /* -------------------------------------------------------------------- */

source/blender/editors/space_view3d/view3d_navigate.cc

@@ -8,6 +8,7 @@
 
 #include "DNA_curve_types.h"
 
+#include "BLI_dial_2d.h"
 #include "BLI_listbase.h"
 #include "BLI_math_geom.h"
 #include "BLI_math_matrix.hh"
@@ -385,9 +386,8 @@ void ViewOpsData::end_navigation(bContext *C)
     WM_event_timer_remove(CTX_wm_manager(C), this->timer->win, this->timer);
   }
 
-  /* Cannot use MEM_SAFE_FREE, as #Dial type is only forward-declared in `BLI_dial_2d.h` */
   if (this->init.dial) {
-    MEM_freeN(static_cast<void *>(this->init.dial));
+    BLI_dial_free(this->init.dial);
     this->init.dial = nullptr;
   }
 

source/blender/editors/space_view3d/view3d_view.cc

@@ -39,6 +39,7 @@
 
 #include "WM_api.hh"
 
+#include "ED_info.hh"
 #include "ED_object.hh"
 #include "ED_screen.hh"
 
@@ -985,12 +986,7 @@ static bool view3d_localview_exit(const Depsgraph *depsgraph,
 
   MEM_freeN(v3d->localvd);
   v3d->localvd = nullptr;
-  /* Cannot use MEM_SAFE_FREE, as #SceneStats type is only forward-declared in `DNA_layer_types.h`
-   */
-  if (v3d->runtime.local_stats) {
-    MEM_freeN(static_cast<void *>(v3d->runtime.local_stats));
-    v3d->runtime.local_stats = nullptr;
-  }
+  ED_view3d_local_stats_free(v3d);
 
   LISTBASE_FOREACH (ARegion *, region, &area->regionbase) {
     if (region->regiontype == RGN_TYPE_WINDOW) {

source/blender/editors/uvedit/uvedit_unwrap_ops.cc

@@ -3507,7 +3507,7 @@ static int uv_from_view_exec(bContext *C, wmOperator *op)
           changed = true;
         }
 
-        MEM_freeN(static_cast<void *>(uci));
+        BLI_uvproject_camera_info_free(uci);
       }
     }
     else {

source/blender/windowmanager/intern/wm_operators.cc

@@ -3208,9 +3208,8 @@ static void radial_control_cancel(bContext *C, wmOperator *op)
   wmWindowManager *wm = CTX_wm_manager(C);
   ScrArea *area = CTX_wm_area(C);
 
-  /* Cannot use MEM_SAFE_FREE, as #Dial type is only forward-declared in `BLI_dial_2d.h` */
   if (rc->dial) {
-    MEM_freeN(static_cast<void *>(rc->dial));
+    BLI_dial_free(rc->dial);
     rc->dial = nullptr;
   }
 
@@ -3405,9 +3404,8 @@ static int radial_control_modal(bContext *C, wmOperator *op, const wmEvent *even
       if (event->val == KM_RELEASE) {
         rc->slow_mode = false;
         handled = true;
-        /* Cannot use MEM_SAFE_FREE, as #Dial type is only forward-declared in `BLI_dial_2d.h` */
         if (rc->dial) {
-          MEM_freeN(static_cast<void *>(rc->dial));
+          BLI_dial_free(rc->dial);
           rc->dial = nullptr;
         }
       }