api/msgpack-rpc: Parse type information from api/private/defs.h

Enhance msgpack-gen.lua to extract custom api type codes from the ObjectType
enum in api/private/defs.h. The type information is made available from the api
metadata and clients can use to correctly serialize/deserialize these types
using msgpack EXT type.

src/nvim/CMakeLists.txt

@@ -3,6 +3,7 @@ include(CheckLibraryExists)
 set(GENERATED_DIR ${PROJECT_BINARY_DIR}/src/nvim/auto)
 set(DISPATCH_GENERATOR ${PROJECT_SOURCE_DIR}/scripts/msgpack-gen.lua)
 file(GLOB API_HEADERS api/*.h)
+file(GLOB API_DEFS api/private/defs.h)
 set(MSGPACK_RPC_HEADER ${PROJECT_SOURCE_DIR}/src/nvim/os/msgpack_rpc.h)
 set(MSGPACK_DISPATCH ${GENERATED_DIR}/msgpack_dispatch.c)
 set(HEADER_GENERATOR ${PROJECT_SOURCE_DIR}/scripts/gendeclarations.lua)
@@ -123,9 +124,10 @@ foreach(sfile ${NEOVIM_SOURCES}
 endforeach()
 
 add_custom_command(OUTPUT ${MSGPACK_DISPATCH}
-  COMMAND ${LUA_PRG} ${DISPATCH_GENERATOR} ${API_HEADERS} ${MSGPACK_DISPATCH}
+  COMMAND ${LUA_PRG} ${DISPATCH_GENERATOR} ${API_DEFS} ${API_HEADERS} ${MSGPACK_DISPATCH}
   DEPENDS
     ${API_HEADERS}
+    ${API_DEFS}
     ${MSGPACK_RPC_HEADER}
     ${DISPATCH_GENERATOR}
 )

src/nvim/api/private/defs.h

@@ -49,32 +49,36 @@ typedef struct {
 } Dictionary;
 
 typedef enum {
+// The following comments are markers that msgpack-gen.lua uses to extract
+// types, don't remove!
+// start custom types
+  kObjectTypePosition,
+  kObjectTypeBuffer,
+  kObjectTypeWindow,
+  kObjectTypeTabpage,
+// end custom types
   kObjectTypeNil,
   kObjectTypeBoolean,
   kObjectTypeInteger,
   kObjectTypeFloat,
   kObjectTypeString,
-  kObjectTypeBuffer,
-  kObjectTypeWindow,
-  kObjectTypeTabpage,
   kObjectTypeArray,
   kObjectTypeDictionary,
-  kObjectTypePosition,
 } ObjectType;
 
 struct object {
   ObjectType type;
   union {
+    Position position;
+    Buffer buffer;
+    Window window;
+    Tabpage tabpage;
     Boolean boolean;
     Integer integer;
     Float floating;
     String string;
-    Buffer buffer;
-    Window window;
-    Tabpage tabpage;
     Array array;
     Dictionary dictionary;
-    Position position;
   } data;
 };