Use CMake's FetchContent module to (optionally) download and build FM…

…ILibrary (#23)

Download FMILibrary using FetchContent if not found

CMakeLists.txt

@@ -1,6 +1,6 @@
 # Copyright (C) 2018 Fondazione Istituto Italiano di Tecnologia
-# 
-# Licensed under either the GNU Lesser General Public License v3.0 : 
+#
+# Licensed under either the GNU Lesser General Public License v3.0 :
 # https://www.gnu.org/licenses/lgpl-3.0.html
 # or the GNU Lesser General Public License v2.1 :
 # https://www.gnu.org/licenses/old-licenses/lgpl-2.1.html
@@ -24,6 +24,9 @@ set(CMAKE_LIBRARY_OUTPUT_DIRECTORY "${CMAKE_BINARY_DIR}/${CMAKE_INSTALL_LIBDIR}"
 set(CMAKE_ARCHIVE_OUTPUT_DIRECTORY "${CMAKE_BINARY_DIR}/${CMAKE_INSTALL_LIBDIR}")
 
 list(APPEND CMAKE_MODULE_PATH ${CMAKE_CURRENT_SOURCE_DIR}/cmake)
+if (CMAKE_VERSION VERSION_LESS 3.11)
+  list(APPEND CMAKE_MODULE_PATH ${CMAKE_CURRENT_SOURCE_DIR}/cmake/cmake-3.11)
+endif() 
 
 option(BUILD_SHARED_LIBS "Build libraries as shared as opposed to static" ON)
 
@@ -33,6 +36,7 @@ if(BUILD_TESTING)
     enable_testing()
 endif()
 
+
 # Encourage user to specify a build type (e.g. Release, Debug, etc.), otherwise set it to Release.
 if(NOT CMAKE_CONFIGURATION_TYPES)
     if(NOT CMAKE_BUILD_TYPE)
@@ -48,14 +52,20 @@ if (gazebo_VERSION_MAJOR LESS 7.0)
     message(FATAL_ERROR "Your Gazebo version is older than Gazebo 7.0. Gazebo Yarp plugins are supported with gazebo versions >= 7.0. Please update to a newer version")
 endif()
 
-find_package(FMILibrary REQUIRED)
+find_package(FMILibrary QUIET)
+option(USE_SYSTEM_FMILIBRARY "If TRUE/ON use system FMILibrary, otherwise download and compile using FetchContent" ${FMILibrary_FOUND})
+if (USE_SYSTEM_FMILIBRARY)
+    find_package(FMILibrary REQUIRED)
+else()
+    include(FetchFMILibrary)
+endif()
 
 # Add extern libraries vendored (only used for the tests)
 if(BUILD_TESTING)
-  add_subdirectory(extern)
+    add_subdirectory(extern)
 endif()
 
-# Add plugins 
+# Add plugins
 add_subdirectory(plugins)
 
 include(InstallBasicPackageFiles)
@@ -70,4 +80,3 @@ install_basic_package_files(${PROJECT_NAME}
 # Add the uninstall target
 include(AddUninstallTarget)
 
-

README.md

@@ -12,7 +12,7 @@
 
 
 # About versioning
-The project is undergoing _heavy_ development: APIs may still be subject to changes, and some functionalities may be broken. 
+The project is undergoing _heavy_ development: APIs may still be subject to changes, and some functionalities may be broken.
 
 
 # Background
@@ -28,10 +28,12 @@ gazebo-fmi depends on
 - [Gazebo](http://gazebosim.org/) - `version >= 7`
 - [FMILibrary](https://jmodelica.org/) (see https://github.com/svn2github/FMILibrary for an updated GitHub mirror) - `version >= 2.0.3`
 
-We recommend to install Gazebo as described  in [official documentation](http://gazebosim.org/tutorials?cat=install),
-while for FMILibrary the easiest option is to compile it as any CMake project and then add its installation prefix to [`CMAKE_PREFIX_PATH`](https://cmake.org/cmake/help/v3.10/variable/CMAKE_PREFIX_PATH.html).
+We recommend to install Gazebo as described  in [official documentation](http://gazebosim.org/tutorials?cat=install).
+For FMILibrary, one option is to compile it as any CMake project and then add its installation prefix to [`CMAKE_PREFIX_PATH`](https://cmake.org/cmake/help/v3.10/variable/CMAKE_PREFIX_PATH.html).
 See [CGold guide](https://cgold.readthedocs.io/en/latest/first-step.html) if you need some details on how to build a CMake project.
 
+An easier option is provided by the gazebo-fmi repository which downloads and compiles the FMILibrary internally within its build folder using CMake's FetchContent module. This is performed when FMILibrary package is not already existing in the system or if the FMILibrary related environment variable (`FMILibrary_ROOT`) is not set, making gazebo-fmi unable to find FMILibrary package. To use this option, the CMake option `USE_SYSTEM_FMILIBRARY` should be set to `OFF`.
+
 # Build the plugins
 Use the following commands to build and install the plugin.
 
@@ -66,7 +68,8 @@ See plugin-specific documentation on how to use each plugin:
 # Test the plugins 
 For running the automatic tests of the plugins contained in this repo, you need the additional dependency of the [OpenModelica](https://openmodelica.org/) compiler. The OpenModelica compiler is used to generate test FMUs from [Modelica](https://www.modelica.org/) models. We recommend to use OpenModelica at least version 1.13 (the `nightly` version as of August 2018) as OpenModelica 1.12 has several bugs related to FMU generation (see https://github.com/robotology/gazebo-fmi/issues/5 and https://trac.openmodelica.org/OpenModelica/ticket/4135 ). 
 
-Once you  installed OpenModelica on your system, you can regenerated the project with the `BUILD_TESTING` CMake option set to `ON` to compile the tests. Once test are compiled, you can run them using [ctest](https://cmake.org/cmake/help/latest/manual/ctest.1.html), for example run: 
+
+Once you  installed OpenModelica on your system, you can regenerated the project with the `BUILD_TESTING` CMake option set to `ON` to compile the tests. Once test are compiled, you can run them using [ctest](https://cmake.org/cmake/help/latest/manual/ctest.1.html), for example run:
 ```cmake
 $ ctest [-VV]
 ```

cmake/FetchFMILibrary.cmake

@@ -0,0 +1,34 @@
+# Copyright (C) 2018 Fondazione Istituto Italiano di Tecnologia
+#
+# Licensed under either the GNU Lesser General Public License v3.0 :
+# https://www.gnu.org/licenses/lgpl-3.0.html
+# or the GNU Lesser General Public License v2.1 :
+# https://www.gnu.org/licenses/old-licenses/lgpl-2.1.html
+# at your option.
+
+# Fetch FMI library for downloading and installing
+include(FetchContent)
+FetchContent_Declare(FMILibrary
+                     GIT_REPOSITORY https://github.com/svn2github/FMILibrary.git)
+
+FetchContent_GetProperties(FMILibrary)
+if(NOT FMILibrary_POPULATED)
+        FetchContent_Populate(FMILibrary)
+        set(BUILD_SHARED_LIBS OFF)
+        option (FMILIB_BUILD_TESTS "Build tests" OFF)
+        add_subdirectory(${fmilibrary_SOURCE_DIR} ${fmilibrary_BINARY_DIR})
+        set(BUILD_SHARED_LIBS ON)
+endif()
+
+add_library(FMILibrary_FMILibrary INTERFACE)
+target_include_directories(FMILibrary_FMILibrary INTERFACE ${fmilibrary_SOURCE_DIR}/src/CAPI/include
+                                                           ${fmilibrary_SOURCE_DIR}/src/Import/include
+                                                           ${fmilibrary_SOURCE_DIR}/src/Util/include
+                                                           ${fmilibrary_SOURCE_DIR}/src/XML/include
+                                                           ${fmilibrary_SOURCE_DIR}/src/ZIP/include
+                                                           ${fmilibrary_SOURCE_DIR}/ThirdParty/FMI/default
+                                                           ${fmilibrary_SOURCE_DIR}/Config.cmake
+                                                           ${fmilibrary_BINARY_DIR})
+target_link_libraries(FMILibrary_FMILibrary INTERFACE fmilib)
+add_library(FMILibrary::FMILibrary ALIAS FMILibrary_FMILibrary)
+

cmake/FindFMILibrary.cmake

@@ -50,23 +50,23 @@ mark_as_advanced(FMILibrary_INCLUDE_DIR
                  FMILibrary_LIBRARY)
 
 if(FMILibrary_LIBRARY AND FMILibrary_INCLUDE_DIR AND NOT TARGET FMILibrary::FMILibrary)
-  add_library(FMILibrary::FMILibrary UNKNOWN IMPORTED)
-  set_target_properties(FMILibrary::FMILibrary PROPERTIES
-            INTERFACE_INCLUDE_DIRECTORIES "${FMILibrary_INCLUDE_DIR}"
-            IMPORTED_LOCATION "${FMILibrary_LIBRARY}")
-
-  set(FMILibrary_LIBRARIES FMILibrary::FMILibrary)
-  set(FMILibrary_INCLUDE_DIRS "${FMILibrary_INCLUDE_DIR}")
-endif()
+    add_library(FMILibrary::FMILibrary UNKNOWN IMPORTED)
+    set_target_properties(FMILibrary::FMILibrary PROPERTIES
+                          INTERFACE_INCLUDE_DIRECTORIES "${FMILibrary_INCLUDE_DIR}"
+                          IMPORTED_LOCATION "${FMILibrary_LIBRARY}")
 
+    set(FMILibrary_LIBRARIES FMILibrary::FMILibrary)
+    set(FMILibrary_INCLUDE_DIRS "${FMILibrary_INCLUDE_DIR}")
 
-include(FindPackageHandleStandardArgs)
-find_package_handle_standard_args(FMILibrary
-                                  FOUND_VAR FMILibrary_FOUND
-                                  REQUIRED_VARS FMILibrary_LIBRARIES FMILibrary_INCLUDE_DIRS)
+    include(FindPackageHandleStandardArgs)
+    find_package_handle_standard_args(FMILibrary
+                                      FOUND_VAR FMILibrary_FOUND
+                                      REQUIRED_VARS FMILibrary_LIBRARIES FMILibrary_INCLUDE_DIRS)
 
-# Set package properties if FeatureSummary was included
-if(COMMAND set_package_properties)
-  set_package_properties(FMILibrary PROPERTIES DESCRIPTION "FMILibrary"
-                                          URL "http://www.jmodelica.org/FMILibrary")
+    # Set package properties if FeatureSummary was included
+    if(COMMAND set_package_properties)
+        set_package_properties(FMILibrary PROPERTIES DESCRIPTION "FMILibrary"
+                                                     URL "http://www.jmodelica.org/FMILibrary")
+    endif()
 endif()
+