Cleanup: replace Main ID's foreach functions by macros.

Am really no a big fan of using macros for that kind of things, but
meh... C solution to do that with functions (using callbacks) is
even worse. :(

3 files changed, 68 insertions, 93 deletions

diff --git a/source/blender/blenkernel/BKE_main.h b/source/blender/blenkernel/BKE_main.h
index a96c1399979..08b6d47877e 100644
--- a/source/blender/blenkernel/BKE_main.h
+++ b/source/blender/blenkernel/BKE_main.h
@@ -140,14 +140,39 @@ void BKE_main_relations_free(struct Main *bmain);
 struct GSet *BKE_main_gset_create(struct Main *bmain, struct GSet *gset);
 
 /* *** Generic utils to loop over whole Main database. *** */
-/** \return false to stop iteration, true to keep going. */
-typedef bool (*MainForeachIDCallback) (struct Main *bmain, struct ID *id, void *user_data);
-bool BKE_main_listbase_foreach_id(
-        struct Main *bmain, struct ListBase *lb,
-        MainForeachIDCallback callback, void *user_data);
-bool BKE_main_foreach_id(
-        struct Main *bmain, const bool reverse_type_order,
-        MainForeachIDCallback callback, void *user_data);
+
+#define FOREACH_MAIN_LISTBASE_ID_BEGIN(_lb, _id)                          \
+	for (_id = _lb->first; _id != NULL; _id = _id->next) {                \
+
+#define FOREACH_MAIN_LISTBASE_ID_END                                      \
+	} ((void)0)
+
+
+#define FOREACH_MAIN_ID_BEGIN(_bmain, _id)                                \
+	{                                                                     \
+		ListBase *_lbarray[MAX_LIBARRAY];                                 \
+		int i = set_listbasepointers(_bmain, _lbarray);                   \
+		while (i--) {                                                     \
+			FOREACH_MAIN_LISTBASE_ID_BEGIN(_lbarray[i], _id)              \
+
+#define FOREACH_MAIN_ID_END                                               \
+			FOREACH_MAIN_LISTBASE_ID_END;                                 \
+		}                                                                 \
+	} ((void)0)
+
+/** \param _do_break A boolean, to allow breaking iteration (only used to break by type,
+ *                   you must also use an explicit `break;` operation if you want to
+ *                   immediately break from inner by-ID loop).
+ */
+#define FOREACH_MAIN_ID_BREAKABLE_BEGIN(_bmain, _id, _do_break)           \
+	{                                                                     \
+		ListBase *_lbarray[MAX_LIBARRAY];                                 \
+		int i = set_listbasepointers(_bmain, _lbarray);                   \
+		while (i-- && !_do_break) {                                       \
+			FOREACH_MAIN_LISTBASE_ID_BEGIN(_lbarray[i], _id)              \
+
+#define FOREACH_MAIN_ID_BREAKABLE_END FOREACH_MAIN_ID_END
+
 
 struct BlendThumbnail *BKE_main_thumbnail_from_imbuf(struct Main *bmain, struct ImBuf *img);
 struct ImBuf *BKE_main_thumbnail_to_imbuf(struct Main *bmain, struct BlendThumbnail *data);
diff --git a/source/blender/blenkernel/intern/library_query.c b/source/blender/blenkernel/intern/library_query.c
index cfda7ab2682..29e0ee0715d 100644
--- a/source/blender/blenkernel/intern/library_query.c
+++ b/source/blender/blenkernel/intern/library_query.c
@@ -1328,27 +1328,6 @@ static int foreach_libblock_used_linked_data_tag_clear_cb(
 	return IDWALK_RET_NOP;
 }
 
-static bool unused_linked_data_tag_init_cb(Main *UNUSED(bmain), ID *id, void *UNUSED(user_data))
-{
-	if (id->lib && (id->tag & LIB_TAG_INDIRECT) != 0) {
-		id->tag |= LIB_TAG_DOIT;
-	}
-	else {
-		id->tag &= ~LIB_TAG_DOIT;
-	}
-	return true;
-}
-
-static bool unused_linked_data_check_cb(Main *bmain, ID *id, void *user_data)
-{
-	if ((id->tag & LIB_TAG_DOIT) == 0) {
-		BKE_library_foreach_ID_link(
-		            bmain, id, foreach_libblock_used_linked_data_tag_clear_cb, user_data, IDWALK_READONLY);
-	}
-	/* Else it is an unused ID (so far), no need to check it further. */
-	return true;
-}
-
 /**
  * Detect orphaned linked data blocks (i.e. linked data not used (directly or indirectly) in any way by any local data),
  * including complex cases like 'linked archipelagoes', i.e. linked datablocks that use each other in loops,
@@ -1359,13 +1338,35 @@ static bool unused_linked_data_check_cb(Main *bmain, ID *id, void *user_data)
  */
 void BKE_library_unused_linked_data_set_tag(Main *bmain, const bool do_init_tag)
 {
+	ID *id;
+
 	if (do_init_tag) {
-		BKE_main_foreach_id(bmain, true, unused_linked_data_tag_init_cb, NULL);
+		FOREACH_MAIN_ID_BEGIN(bmain, id)
+		{
+			if (id->lib && (id->tag & LIB_TAG_INDIRECT) != 0) {
+				id->tag |= LIB_TAG_DOIT;
+			}
+			else {
+				id->tag &= ~LIB_TAG_DOIT;
+			}
+		}
+		FOREACH_MAIN_ID_END;
 	}
 
 	for (bool do_loop = true; do_loop; ) {
+		bool do_break = false;
 		do_loop = false;
-		BKE_main_foreach_id(bmain, true, unused_linked_data_check_cb, &do_loop);
+		FOREACH_MAIN_ID_BREAKABLE_BEGIN(bmain, id, do_break)
+		{
+			if ((id->tag & LIB_TAG_DOIT) == 0) {
+				BKE_library_foreach_ID_link(
+				            bmain, id, foreach_libblock_used_linked_data_tag_clear_cb, &do_loop, IDWALK_READONLY);
+			}
+			/* Else it is an unused ID (so far), no need to check it further. */
+			do_break = true;
+			break;
+		}
+		FOREACH_MAIN_ID_BREAKABLE_END;
 	}
 }
 
diff --git a/source/blender/blenkernel/intern/main.c b/source/blender/blenkernel/intern/main.c
index 11150f827e2..a4500e6616d 100644
--- a/source/blender/blenkernel/intern/main.c
+++ b/source/blender/blenkernel/intern/main.c
@@ -173,12 +173,6 @@ static int main_relations_create_idlink_cb(void *user_data, ID *id_self, ID **id
 	return IDWALK_RET_NOP;
 }
 
-static bool main_relations_create_id_cb(Main *bmain, ID *id, void *UNUSED(user_data))
-{
-	BKE_library_foreach_ID_link(NULL, id, main_relations_create_idlink_cb, bmain->relations, IDWALK_READONLY);
-	return true;
-}
-
 /** Generate the mappings between used IDs and their users, and vice-versa. */
 void BKE_main_relations_create(Main *bmain)
 {
@@ -191,7 +185,12 @@ void BKE_main_relations_create(Main *bmain)
 	bmain->relations->id_user_to_used = BLI_ghash_new(BLI_ghashutil_ptrhash, BLI_ghashutil_ptrcmp, __func__);
 	bmain->relations->entry_pool = BLI_mempool_create(sizeof(MainIDRelationsEntry), 128, 128, BLI_MEMPOOL_NOP);
 
-	BKE_main_foreach_id(bmain, false, main_relations_create_id_cb, NULL);
+	ID *id;
+	FOREACH_MAIN_ID_BEGIN(bmain, id)
+	{
+		BKE_library_foreach_ID_link(NULL, id, main_relations_create_idlink_cb, bmain->relations, IDWALK_READONLY);
+	}
+	FOREACH_MAIN_ID_END;
 }
 
 void BKE_main_relations_free(Main *bmain)
@@ -209,13 +208,6 @@ void BKE_main_relations_free(Main *bmain)
 	}
 }
 
-static bool main_gset_create(Main *UNUSED(bmain), ID *id, void *user_data)
-{
-	GSet *gset = user_data;
-	BLI_gset_add(gset, id);
-	return true;
-}
-
 /**
  * Create a GSet storing all IDs present in given \a bmain, by their pointers.
  *
@@ -226,57 +218,14 @@ GSet *BKE_main_gset_create(Main *bmain, GSet *gset)
 	if (gset == NULL) {
 		gset = BLI_gset_new(BLI_ghashutil_ptrhash, BLI_ghashutil_ptrcmp, __func__);
 	}
-	BKE_main_foreach_id(bmain, false, main_gset_create, gset);
-	return gset;
-}
-
-/**
- * Call given callback over every IDs of given \a lb listbase (assumed to be part of given \a bmain).
- *
- * \return false if the iteration was iterrupted by the callback.
- *
- * \warning \a callback may affect the ID, but DO NOT change the listbase or Main database (add/remove/reorder its IDs).
- */
-bool BKE_main_listbase_foreach_id(
-        Main *bmain, ListBase *lb,
-        MainForeachIDCallback callback, void *user_data)
-{
-	bool keep_looping = true;
-	for (ID *id = lb->first; id; id = id->next) {
-		if (!(keep_looping = callback(bmain, id, user_data))) {
-			return keep_looping;
-		}
-	}
-	return keep_looping;
-}
-
-/**
- * Call given callback over every IDs of given \a bmain Main database.
- *
- * \param reverse_type_order: Allow to reverse order in which ID *types* are handled
- * (i.e. does not reverse the order in which IDs themselves are handled whithin a give listbase).
- * Note that in most cases, you want to set that parameter to true.
- * \return false if the iteration was iterrupted by the callback.
- *
- * \warning \a callback may affect the ID, but DO NOT change the Main database (add/remove/reorder its IDs).
- */
-bool BKE_main_foreach_id(
-        Main *bmain, const bool reverse_type_order,
-        MainForeachIDCallback callback, void *user_data)
-{
-	ListBase *lbarray[MAX_LIBARRAY];
-	const int nbr_types = set_listbasepointers(bmain, lbarray);
 
-	bool keep_looping = true;
-	for (int i = reverse_type_order ? nbr_types - 1 : 0;
-	     reverse_type_order ? i >= 0 : i < nbr_types;
-	     reverse_type_order ? i-- : i++)
+	ID *id;
+	FOREACH_MAIN_ID_BEGIN(bmain, id)
 	{
-		if (!(keep_looping = BKE_main_listbase_foreach_id(bmain, lbarray[i], callback, user_data))) {
-			return keep_looping;
-		}
+		BLI_gset_add(gset, id);
 	}
-	return keep_looping;
+	FOREACH_MAIN_ID_END;
+	return gset;
 }
 
 /**