Improved handing of external rabbitmq-codegen

- By default look in the CMAKE_SOURCE_DIR/rabbitmq-codegen, then CMAKE_SOURCE_DIR/../rabbitmq-codegen unless RABBITMQ_CODEGEN_DIR is set - If FETCH_CODEGEN_FROM_GIT use the CMake ExternalProject to do it

Author: alanxz

CMakeLists.txt

@@ -19,23 +19,47 @@ if (CHECK_PYTHON_JSON_FAILED)
  endif (CHECK_PYTHON_SIMPLEJSON_FAILED)
 endif (CHECK_PYTHON_JSON_FAILED)
 
-
 set(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} ${CMAKE_CURRENT_SOURCE_DIR})
 include(TestCInline)
 
-include(ExternalProject)
-ExternalProject_Add(
-amqp_codegen
-GIT_REPOSITORY https://github.com/rabbitmq/rabbitmq-codegen.git
-GIT_TAG rabbitmq_v2_5_1
-SOURCE_DIR amqp_codegen
-CONFIGURE_COMMAND ""
-BUILD_COMMAND ""
-INSTALL_COMMAND ""
-TEST_COMMAND "")
-
-ExternalProject_Get_Property(amqp_codegen SOURCE_DIR)
-set(AMQP_CODEGEN_DIR ${SOURCE_DIR})
+option(FETCH_CODEGEN_FROM_GIT "Fetch codegen directly from the git repository" OFF)
+
+set(CODEGEN_GIT_TAG rabbitmq_v2_5_1 CACHE STRING "Git tag in rabbitmq-codegen to fetch with FETCH_CODEGEN_FROM_GIT")
+if (FETCH_CODEGEN_FROM_GIT)
+ include(ExternalProject)
+ ExternalProject_Add(
+ amqp_codegen
+ GIT_REPOSITORY https://github.com/rabbitmq/rabbitmq-codegen.git
+ GIT_TAG ${CODEGEN_GIT_TAG}
+ SOURCE_DIR amqp_codegen
+ CONFIGURE_COMMAND ""
+ BUILD_COMMAND ""
+ INSTALL_COMMAND ""
+ TEST_COMMAND "")
+
+ ExternalProject_Get_Property(amqp_codegen SOURCE_DIR)
+ set(AMQP_CODEGEN_DIR ${SOURCE_DIR} CACHE PATH "Path to rabbitmq-codegen" FORCE)
+ message(STATUS "Using amqp_codegen.py in ${AMQP_CODEGEN_DIR}")
+else (FETCH_CODEGEN_FROM_GIT)
+ find_path(RABBITMQ_CODEGEN_DIR
+ amqp_codegen.py
+ PATHS ${CMAKE_SOURCE_DIR}/rabbitmq-codegen 
+ ${CMAKE_SOURCE_DIR}/../rabbitmq-codegen
+ DOC "Path to directory containing amqp_codegen.py (rabbitmq-codegen)"
+ NO_DEFAULT_PATH
+ )
+
+ if (RABBITMQ_CODEGEN_DIR STREQUAL "RABBITMQ_CODEGEN_DIR-NOTFOUND")
+ message(SEND_ERROR "Cannot find rabbitmq-codegen, set RABBITMQ_CODEGEN_DIR to a rabbitmq-codegen checkout, or set FETCH_CODEGEN_FROM_GIT to download it from git automatically")
+ else ()
+ message(STATUS "Using amqp_codegen.py in ${RABBITMQ_CODEGEN_DIR}")
+ endif()
+
+ set(AMQP_CODEGEN_DIR ${RABBITMQ_CODEGEN_DIR} CACHE PATH "Path to rabbitmq-codegen" FORCE)
+endif (FETCH_CODEGEN_FROM_GIT)
+
+mark_as_advanced(AMQP_CODEGEN_DIR)
+
 
 add_subdirectory(librabbitmq)
 add_subdirectory(examples)