BMain: Add utils to check if a Main is empty or not.

Mostly intended for debug code (asserts).

2 files changed, 13 insertions, 0 deletions

diff --git a/source/blender/blenkernel/BKE_main.h b/source/blender/blenkernel/BKE_main.h
index 93d5b5c5aa6..3108dfd5d8f 100644
--- a/source/blender/blenkernel/BKE_main.h
+++ b/source/blender/blenkernel/BKE_main.h
@@ -201,6 +201,8 @@ typedef struct Main {
 struct Main *BKE_main_new(void);
 void BKE_main_free(struct Main *mainvar);
 
+bool BKE_main_is_empty(struct Main *bmain);
+
 void BKE_main_lock(struct Main *bmain);
 void BKE_main_unlock(struct Main *bmain);
 
diff --git a/source/blender/blenkernel/intern/main.c b/source/blender/blenkernel/intern/main.c
index 9c3291edbcc..583feacc04b 100644
--- a/source/blender/blenkernel/intern/main.c
+++ b/source/blender/blenkernel/intern/main.c
@@ -205,6 +205,17 @@ void BKE_main_free(Main *mainvar)
   MEM_freeN(mainvar);
 }
 
+/* Check whether given `bmain` is empty or contains some IDs. */
+bool BKE_main_is_empty(struct Main *bmain)
+{
+  ID *id_iter;
+  FOREACH_MAIN_ID_BEGIN (bmain, id_iter) {
+    return false;
+  }
+  FOREACH_MAIN_ID_END;
+  return true;
+}
+
 void BKE_main_lock(struct Main *bmain)
 {
   BLI_spin_lock((SpinLock *)bmain->lock);