Nodes: store socket declaration reference in socket

Previously, to get the declaration of a socket, one had to go
through `node->declaration`. Now this indirection is not necessary
anymore. This makes it easier to add more per-socket information
into the declaration and accessing it in various places.

Currently, this system is used by socket descriptions and node warnings
for unsupported geometry component types.

1 files changed, 19 insertions, 10 deletions

diff --git a/source/blender/makesdna/DNA_node_types.h b/source/blender/makesdna/DNA_node_types.h
index 94e4cc1323a..79287885dec 100644
--- a/source/blender/makesdna/DNA_node_types.h
+++ b/source/blender/makesdna/DNA_node_types.h
@@ -81,6 +81,19 @@ typedef struct bNodeStack {
 #define NS_CR_FIT 4
 #define NS_CR_STRETCH 5
 
+/** Workaround to forward-declare C++ type in C header. */
+#ifdef __cplusplus
+namespace blender::nodes {
+class NodeDeclaration;
+class SocketDeclaration;
+}  // namespace blender::nodes
+using NodeDeclarationHandle = blender::nodes::NodeDeclaration;
+using SocketDeclarationHandle = blender::nodes::SocketDeclaration;
+#else
+typedef struct NodeDeclarationHandle NodeDeclarationHandle;
+typedef struct SocketDeclarationHandle SocketDeclarationHandle;
+#endif
+
 typedef struct bNodeSocket {
   struct bNodeSocket *next, *prev, *new_sock;
 
@@ -153,6 +166,12 @@ typedef struct bNodeSocket {
    * kept for forward compatibility */
   /** Custom data for inputs, only UI writes in this. */
   bNodeStack ns DNA_DEPRECATED;
+
+  /**
+   * References a socket declaration that is owned by `node->declaration`. This is only runtime
+   * data. It has to be updated when the node declaration changes.
+   */
+  const SocketDeclarationHandle *declaration;
 } bNodeSocket;
 
 /* sock->type */
@@ -220,16 +239,6 @@ typedef enum eNodeSocketFlag {
   SOCK_HIDE_LABEL = (1 << 12),
 } eNodeSocketFlag;
 
-/** Workaround to forward-declare C++ type in C header. */
-#ifdef __cplusplus
-namespace blender::nodes {
-class NodeDeclaration;
-}
-using NodeDeclarationHandle = blender::nodes::NodeDeclaration;
-#else
-typedef struct NodeDeclarationHandle NodeDeclarationHandle;
-#endif
-
 /* TODO: Limit data in bNode to what we want to see saved. */
 typedef struct bNode {
   struct bNode *next, *prev, *new_node;