[Bf-blender-cvs] [bb7747e7cae] master: Fix undefined behavior in dependency graph tagging

[Sergey Sharybin]

Commit: bb7747e7caee59a8c98cd7d9abc9cd1e9b0e0762
Author: Sergey Sharybin
Date:   Tue Aug 2 11:10:40 2022 +0200
Branches: master
https://developer.blender.org/rBbb7747e7caee59a8c98cd7d9abc9cd1e9b0e0762

Fix undefined behavior in dependency graph tagging

The tagging code was iterating over bits set in the ID_RECALC_ALL and
was casting the flag to IDRecalcFlag. This was triggering an undefined
behavior warning in Clang since the bit might not have a corresponding
value in the enumerator.

The solution is to pre-define all reacalc flags for all bits. While
this seems a bit annoying this seems to be the least fragile solution
from all suggested ones.

Differential Revision: https://developer.blender.org/D15602

===================================================================

M	source/blender/depsgraph/intern/depsgraph_tag.cc
M	source/blender/makesdna/DNA_ID.h

===================================================================

diff --git a/source/blender/depsgraph/intern/depsgraph_tag.cc b/source/blender/depsgraph/intern/depsgraph_tag.cc
index 7a2904e3766..d95e871d6c7 100644
--- a/source/blender/depsgraph/intern/depsgraph_tag.cc
+++ b/source/blender/depsgraph/intern/depsgraph_tag.cc
@@ -220,6 +220,15 @@ void depsgraph_tag_to_component_opcode(const ID *id,
       *component_type = NodeType::NTREE_OUTPUT;
       *operation_code = OperationCode::NTREE_OUTPUT;
       break;
+
+    case ID_RECALC_PROVISION_26:
+    case ID_RECALC_PROVISION_27:
+    case ID_RECALC_PROVISION_28:
+    case ID_RECALC_PROVISION_29:
+    case ID_RECALC_PROVISION_30:
+    case ID_RECALC_PROVISION_31:
+      BLI_assert_msg(0, "Should not happen");
+      break;
   }
 }
 
@@ -741,6 +750,15 @@ const char *DEG_update_tag_as_string(IDRecalcFlag flag)
       return "TAG_FOR_UNDO";
     case ID_RECALC_NTREE_OUTPUT:
       return "ID_RECALC_NTREE_OUTPUT";
+
+    case ID_RECALC_PROVISION_26:
+    case ID_RECALC_PROVISION_27:
+    case ID_RECALC_PROVISION_28:
+    case ID_RECALC_PROVISION_29:
+    case ID_RECALC_PROVISION_30:
+    case ID_RECALC_PROVISION_31:
+      BLI_assert_msg(0, "Should not happen");
+      return nullptr;
   }
   return nullptr;
 }
diff --git a/source/blender/makesdna/DNA_ID.h b/source/blender/makesdna/DNA_ID.h
index 8b99345e237..7ba2b426fcf 100644
--- a/source/blender/makesdna/DNA_ID.h
+++ b/source/blender/makesdna/DNA_ID.h
@@ -870,6 +870,17 @@ typedef enum IDRecalcFlag : unsigned int {
   /* The node tree has changed in a way that affects its output nodes. */
   ID_RECALC_NTREE_OUTPUT = (1 << 25),
 
+  /* Provisioned flags.
+   *
+   * Not for actual use. The idea of them is to have all bits of the `IDRecalcFlag` defined to a
+   * known value, silencing sanitizer warnings when checkign bits of the ID_RECALC_ALL. */
+  ID_RECALC_PROVISION_26 = (1 << 26),
+  ID_RECALC_PROVISION_27 = (1 << 27),
+  ID_RECALC_PROVISION_28 = (1 << 28),
+  ID_RECALC_PROVISION_29 = (1 << 29),
+  ID_RECALC_PROVISION_30 = (1 << 30),
+  ID_RECALC_PROVISION_31 = (1u << 31),
+
   /***************************************************************************
    * Pseudonyms, to have more semantic meaning in the actual code without
    * using too much low-level and implementation specific tags. */