--- a/OrthancFramework/Resources/CMake/OrthancFrameworkParameters.cmake	Sun Mar 26 11:59:03 2023 +0200
+++ b/OrthancFramework/Resources/CMake/OrthancFrameworkParameters.cmake	Sun Mar 26 21:09:13 2023 +0200
@@ -124,7 +124,8 @@
 set(ENABLE_LOCALE OFF CACHE INTERNAL "Enable support for locales (notably in Boost)")
 set(ENABLE_LUA OFF CACHE INTERNAL "Enable support of Lua scripting")
 set(ENABLE_PNG OFF CACHE INTERNAL "Enable support of PNG")
-set(ENABLE_PROTOBUF OFF CACHE INTERNAL "Enable support for Google Protocol Buffers")
+set(ENABLE_PROTOBUF OFF CACHE INTERNAL "Enable support for Google Protocol Buffers' library")
+set(ENABLE_PROTOBUF_COMPILER OFF CACHE INTERNAL "Enable support for Google Protocol Buffers' compiler")
 set(ENABLE_PUGIXML OFF CACHE INTERNAL "Enable support of XML through Pugixml")
 set(ENABLE_SQLITE OFF CACHE INTERNAL "Enable support of SQLite databases")
 set(ENABLE_ZLIB OFF CACHE INTERNAL "Enable support of zlib")

--- a/OrthancFramework/Resources/CMake/ProtobufConfiguration.cmake	Sun Mar 26 11:59:03 2023 +0200
+++ b/OrthancFramework/Resources/CMake/ProtobufConfiguration.cmake	Sun Mar 26 21:09:13 2023 +0200
@@ -20,13 +20,35 @@
 
 
 if (STATIC_BUILD OR NOT USE_SYSTEM_PROTOBUF)
+  if (ENABLE_PROTOBUF_COMPILER)
+    include(ExternalProject)
+    externalproject_add(ProtobufCompiler
+      SOURCE_DIR "${CMAKE_SOURCE_DIR}/../OrthancFramework/Resources/ProtocolBuffers"
+      BINARY_DIR "${CMAKE_CURRENT_BINARY_DIR}/ProtobufCompiler-build"
+      # this helps triggering build when changing the external project
+      BUILD_ALWAYS 1
+      CMAKE_ARGS
+      -DCMAKE_BUILD_TYPE:STRING=${CMAKE_BUILD_TYPE}
+      -DCMAKE_INSTALL_PREFIX=${CMAKE_CURRENT_BINARY_DIR}
+      INSTALL_COMMAND ""
+      )
+    set(PROTOC_EXECUTABLE ${CMAKE_CURRENT_BINARY_DIR}/ProtobufCompiler-build/protoc)
+  endif()
+
   include(${CMAKE_CURRENT_LIST_DIR}/../ProtocolBuffers/ProtobufLibrary.cmake)  
   source_group(ThirdParty\\Protobuf REGULAR_EXPRESSION ${PROTOBUF_SOURCE_DIR}/.*)
 
 else()
-  find_program(PROTOC_EXECUTABLE protoc)
-  if (${PROTOC_EXECUTABLE} MATCHES "PROTOC_EXECUTABLE-NOTFOUND")
-    message(FATAL_ERROR "Please install the 'protoc' compiler for Protocol Buffers (package 'protobuf-compiler' on Debian/Ubuntu)")
+  if (CMAKE_CROSSCOMPILING)
+    message(FATAL_ERROR "If cross-compiling, the static version of Protocol Buffers should be used to avoid version mismatch")
+  endif()
+  
+  if (ENABLE_PROTOBUF_COMPILER)
+    find_program(PROTOC_EXECUTABLE protoc)
+    if (${PROTOC_EXECUTABLE} MATCHES "PROTOC_EXECUTABLE-NOTFOUND")
+      message(FATAL_ERROR "Please install the 'protoc' compiler for Protocol Buffers (package 'protobuf-compiler' on Debian/Ubuntu)")
+    endif()
+    add_custom_target(ProtobufCompiler)
   endif()
   
   check_include_file_cxx(google/protobuf/any.h HAVE_PROTOBUF_H)

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/OrthancFramework/Resources/Patches/protobuf-3.5.1.patch	Sun Mar 26 21:09:13 2023 +0200
@@ -0,0 +1,17 @@
+diff -urEb protobuf-3.5.1.orig/src/google/protobuf/stubs/io_win32.cc protobuf-3.5.1/src/google/protobuf/stubs/io_win32.cc
+--- protobuf-3.5.1.orig/src/google/protobuf/stubs/io_win32.cc	2023-03-26 20:13:45.095021011 +0200
++++ protobuf-3.5.1/src/google/protobuf/stubs/io_win32.cc	2023-03-26 20:19:19.932920102 +0200
+@@ -91,7 +91,12 @@
+ 
+ template <typename char_type>
+ bool null_or_empty(const char_type* s) {
+-  return s == nullptr || *s == 0;
++  /**
++   * "nullptr" is not known to Visual Studio 2008, because this is a
++   * C++11 construction, which shouldn't be present in protobuf 3.5.1
++   * that is supposed to comply with C++98.
++   **/
++  return s == NULL || *s == 0;
+ }
+ 
+ // Returns true if the path starts with a drive letter, e.g. "c:".

--- a/OrthancFramework/Resources/ProtocolBuffers/ProtobufLibrary.cmake	Sun Mar 26 11:59:03 2023 +0200
+++ b/OrthancFramework/Resources/ProtocolBuffers/ProtobufLibrary.cmake	Sun Mar 26 21:09:13 2023 +0200
@@ -19,12 +19,32 @@
 # <http://www.gnu.org/licenses/>.
 
 
+set(PROTOBUF_SOURCE_DIR ${CMAKE_CURRENT_BINARY_DIR}/protobuf-3.5.1)
+
+if (IS_DIRECTORY "${PROTOBUF_SOURCE_DIR}")
+  set(FirstRun OFF)
+else()
+  set(FirstRun ON)
+endif()
+
 DownloadPackage(
   "ca0d9b243e649d398a6b419acd35103a"
   "http://orthanc.uclouvain.be/third-party-downloads/protobuf-cpp-3.5.1.tar.gz"
   "${CMAKE_CURRENT_BINARY_DIR}/protobuf-3.5.1")
 
-set(PROTOBUF_SOURCE_DIR ${CMAKE_CURRENT_BINARY_DIR}/protobuf-3.5.1)
+if (FirstRun)
+  # Apply the patches
+  execute_process(
+    COMMAND ${PATCH_EXECUTABLE} -p0 -N -i
+    ${CMAKE_CURRENT_LIST_DIR}/../Patches/protobuf-3.5.1.patch
+    WORKING_DIRECTORY ${CMAKE_BINARY_DIR}
+    RESULT_VARIABLE Failure
+    )
+
+  if (Failure)
+    message(FATAL_ERROR "Error while patching a file")
+  endif()
+endif()
 
 include_directories(
   ${PROTOBUF_SOURCE_DIR}/src

--- a/OrthancServer/CMakeLists.txt	Sun Mar 26 11:59:03 2023 +0200
+++ b/OrthancServer/CMakeLists.txt	Sun Mar 26 21:09:13 2023 +0200
@@ -42,6 +42,7 @@
 set(ENABLE_OPENSSL_ENGINES ON)  # OpenSSL engines are necessary for PKCS11
 set(ENABLE_PNG ON)
 set(ENABLE_PROTOBUF ON)
+set(ENABLE_PROTOBUF_COMPILER ON)
 set(ENABLE_PUGIXML ON)
 set(ENABLE_SQLITE ON)
 set(ENABLE_WEB_CLIENT ON)
@@ -362,8 +363,13 @@
 ## Build the core of Orthanc
 #####################################################################
 
+add_custom_target(AutogeneratedTarget
+  DEPENDS
+  ${AUTOGENERATED_SOURCES}
+  )
+
 # "CoreLibrary" contains all the third-party dependencies and the
-# content of the "Core" folder
+# content of the "OrthancFramework" folder
 add_library(CoreLibrary
   STATIC
   ${ORTHANC_CORE_PCH}
@@ -372,6 +378,8 @@
   ${AUTOGENERATED_SOURCES}
   )
 
+add_dependencies(CoreLibrary AutogeneratedTarget)
+
 if (LIBICU_LIBRARIES)
   target_link_libraries(CoreLibrary ${LIBICU_LIBRARIES})
 endif()
@@ -381,6 +389,30 @@
 ## Build the Orthanc server
 #####################################################################
 
+if (ENABLE_PLUGINS)
+  add_custom_command(
+    COMMAND
+    ${PROTOC_EXECUTABLE} ${CMAKE_SOURCE_DIR}/Plugins/Include/orthanc/OrthancDatabasePlugin.proto --cpp_out=${AUTOGENERATED_DIR} -I${CMAKE_SOURCE_DIR}/Plugins/Include/orthanc
+    DEPENDS
+    ProtobufCompiler
+    ${CMAKE_SOURCE_DIR}/Plugins/Include/orthanc/OrthancDatabasePlugin.proto
+    OUTPUT
+    ${AUTOGENERATED_DIR}/OrthancDatabasePlugin.pb.cc
+    ${AUTOGENERATED_DIR}/OrthancDatabasePlugin.pb.h
+    )
+  
+  add_custom_target(OrthancDatabaseProtobuf
+    DEPENDS
+    ${AUTOGENERATED_DIR}/OrthancDatabasePlugin.pb.h
+    )
+
+  list(APPEND ORTHANC_SERVER_SOURCES
+    ${AUTOGENERATED_DIR}/OrthancDatabasePlugin.pb.cc
+    )
+else()
+  add_custom_target(OrthancDatabaseProtobuf)
+endif()
+
 add_library(ServerLibrary
   STATIC
   ${ORTHANC_SERVER_PCH}
@@ -388,7 +420,7 @@
   )
 
 # Ensure autogenerated code is built before building ServerLibrary
-add_dependencies(ServerLibrary CoreLibrary)
+add_dependencies(ServerLibrary CoreLibrary OrthancDatabaseProtobuf)
 
 add_executable(Orthanc
   ${CMAKE_SOURCE_DIR}/Sources/main.cpp
@@ -547,7 +579,6 @@
 
 if (ENABLE_PLUGINS AND (BUILD_DELAYED_DELETION OR BUILD_CONNECTIVITY_CHECKS))
   include(ExternalProject)
-
 endif()
 
 

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/OrthancServer/Plugins/Include/orthanc/OrthancDatabasePlugin.proto	Sun Mar 26 21:09:13 2023 +0200
@@ -0,0 +1,7 @@
+syntax = "proto2";
+
+message Point {
+  required int32 x = 1;
+  required int32 y = 2;
+  optional string label = 3;
+}