ExternalModule: Improve target export to allow build against external…

… module This commit backports the ITK external module infrastructure to allow building against a collection of VTK module externally built. In a nutshell, config files [1] associated with external modules are now configured into the VTK module directory found in the VTK binary directory and they have to be explicitly listed as components when using `find_package(VTK COMPONENTS NameOfExternalModule REQUIRED)`. More specifically, it implements the following changes: * List of enabled VTK module is now configured into `VTKConfig.cmake` instead of being set based on the list of `*.cmake` found in the VTK module directory. This allows to only consider VTK modules enabled in the original VTK build directory when using signature `find_package(VTK REQUIRED)` in user code or VTK remote module. * Each external module is now associated with its own target file independent of `VTKTargets.cmake` [1] module config files: ``` lib/cmake/vtk-8.1/Modules/vtkNameOfExternalModule-Headers.cmake lib/cmake/vtk-8.1/Modules/vtkNameOfExternalModule.cmake lib/cmake/vtk-8.1/Modules/vtkNameOfExternalModuleHierarchy.txt ```
leftwillow · Oct 17, 2017 · 2062959 · 2062959
1 parent 074d321
commit 2062959
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Showing 5 changed files with 56 additions and 13 deletions.
diff --git a/CMake/VTKConfig.cmake.in b/CMake/VTKConfig.cmake.in
@@ -98,16 +98,7 @@ endif()
 # Load requested modules.
 
 # List of available VTK modules.
-set(VTK_MODULES_ENABLED)
-
-# Determine list of available VTK-modules by scanning the VTK_MODULES_DIR.
-file(GLOB config_files RELATIVE "${VTK_MODULES_DIR}" "${VTK_MODULES_DIR}/*.cmake")
-foreach (_file ${config_files})
-  if (NOT "${_file}" MATCHES "[^\\-]+-[a-zA-Z]+\\.cmake")
-    string(REGEX REPLACE "\\.cmake$" "" _module "${_file}")
-    list(APPEND VTK_MODULES_ENABLED "${_module}")
-  endif()
-endforeach()
+set(VTK_MODULES_ENABLED "@VTK_CONFIG_MODULES_ENABLED@")
 
 # Import VTK targets.
 set(VTK_CONFIG_TARGETS_FILE "@VTK_CONFIG_TARGETS_FILE@")

diff --git a/CMake/vtkExternalModuleMacros.cmake b/CMake/vtkExternalModuleMacros.cmake
@@ -61,6 +61,17 @@ endif()
 if(VTK_MODULES_DIR)
   set(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} ${VTK_MODULES_DIR})
 endif()
-set(VTK_MODULES_DIR "${CMAKE_BINARY_DIR}/${VTK_INSTALL_PACKAGE_DIR}/Modules")
+set(VTK_MODULES_DIR "${VTK_DIR}/${VTK_INSTALL_PACKAGE_DIR}/Modules")
 
 include(vtkModuleMacros)
+include(module.cmake OPTIONAL RESULT_VARIABLE _found)
+if(_found)
+  set(${vtk-module}-targets ${vtk-module}Targets)
+  set(${vtk-module}-targets-install "\${VTK_INSTALL_PREFIX}/${VTK_INSTALL_PACKAGE_DIR}/Modules/Targets/${vtk-module}Targets.cmake")
+  set(${vtk-module}_TARGETS_FILE_INSTALL "${${vtk-module}-targets-install}")
+  set(${vtk-module}-targets-build-directory "${VTK_DIR}/${VTK_INSTALL_PACKAGE_DIR}/Modules/Targets")
+  file(MAKE_DIRECTORY ${${vtk-module}-targets-build-directory})
+  set(${vtk-module}-targets-build "${${vtk-module}-targets-build-directory}/${vtk-module}Targets.cmake")
+  set(${vtk-module}_TARGETS_FILE_BUILD "${${vtk-module}-targets-build}")
+  file(WRITE "${${vtk-module}_TARGETS_FILE_BUILD}" "") # Clear targets
+endif()
diff --git a/CMake/vtkModuleAPI.cmake b/CMake/vtkModuleAPI.cmake
@@ -52,6 +52,13 @@ macro(vtk_module_load mod)
     if(NOT ${mod}_LOADED)
       message(FATAL_ERROR "No such module: \"${mod}\"")
     endif()
+    # Include the targets file if it has been defined. Targets files other
+    # than VTKTargets.cmake are created when modules are built externally. Do not
+    # include the targets file inside the module itself -- which occurs in a module's
+    # test configuration.
+    if(EXISTS "${${mod}_TARGETS_FILE}" AND NOT vtk-module STREQUAL mod)
+      include("${${mod}_TARGETS_FILE}")
+    endif()
   endif()
 endmacro()
 
@@ -108,9 +115,20 @@ endmacro()
 #
 # Do not name a module as the namespace.
 macro(vtk_module_config ns)
+
+  # Determine list of available VTK-modules by scanning the VTK_MODULES_DIR.
+  set(VTK_MODULES_AVAILABLE)
+  file(GLOB config_files RELATIVE "${VTK_MODULES_DIR}" "${VTK_MODULES_DIR}/*.cmake")
+  foreach (_file ${config_files})
+    if (NOT "${_file}" MATCHES "[^\\-]+-[a-zA-Z]+\\.cmake")
+      string(REGEX REPLACE "\\.cmake$" "" _module "${_file}")
+      list(APPEND VTK_MODULES_AVAILABLE "${_module}")
+    endif()
+  endforeach()
+
   set(_${ns}_MISSING ${ARGN})
   if(_${ns}_MISSING)
-    list(REMOVE_ITEM _${ns}_MISSING ${VTK_MODULES_ENABLED})
+    list(REMOVE_ITEM _${ns}_MISSING ${VTK_MODULES_AVAILABLE})
   endif()
   if(_${ns}_MISSING)
     set(msg "")

diff --git a/CMake/vtkModuleInfo.cmake.in b/CMake/vtkModuleInfo.cmake.in
@@ -6,4 +6,5 @@ set(@vtk-module@_LIBRARY_DIRS "@vtk-module-LIBRARY_DIRS@")
 set(@vtk-module@_RUNTIME_LIBRARY_DIRS "@vtk-module-RUNTIME_LIBRARY_DIRS@")
 set(@vtk-module@_WRAP_HIERARCHY_FILE "@vtk-module-WRAP_HIERARCHY_FILE@")
 set(@vtk-module@_KIT "@vtk-module-KIT@")
+set(@vtk-module@_TARGETS_FILE "@vtk-module-TARGETS_FILE@")
 @vtk-module-EXPORT_CODE@
diff --git a/CMake/vtkModuleMacros.cmake b/CMake/vtkModuleMacros.cmake
@@ -309,6 +309,14 @@ macro(vtk_module_export_info)
   endif()
   set(vtk-module-EXPORT_CODE-build "${_code}${${vtk-module}_EXPORT_CODE_BUILD}\n")
   set(vtk-module-EXPORT_CODE-install "${_code}${${vtk-module}_EXPORT_CODE_INSTALL}\n")
+  if(VTK_SOURCE_DIR)
+    # Uses VTKTargets.cmake
+    set(vtk-module-TARGETS_FILE-build "")
+    set(vtk-module-TARGETS_FILE-install "")
+  else()
+    set(vtk-module-TARGETS_FILE-build "${${vtk-module}_TARGETS_FILE_BUILD}")
+    set(vtk-module-TARGETS_FILE-install "${${vtk-module}_TARGETS_FILE_INSTALL}")
+  endif()
 
   if(${vtk-module}_WRAP_HINTS)
     set(vtk-module-EXPORT_CODE-build
@@ -336,13 +344,15 @@ macro(vtk_module_export_info)
   set(vtk-module-RUNTIME_LIBRARY_DIRS "${vtk-module-RUNTIME_LIBRARY_DIRS-build}")
   set(vtk-module-INCLUDE_DIRS "${vtk-module-INCLUDE_DIRS-build}")
   set(vtk-module-EXPORT_CODE "${vtk-module-EXPORT_CODE-build}")
+  set(vtk-module-TARGETS_FILE "${vtk-module-TARGETS_FILE-build}")
   set(vtk-module-WRAP_HIERARCHY_FILE "${${vtk-module}_WRAP_HIERARCHY_FILE}")
   set(vtk-module-KIT "${${vtk-module}_KIT}")
   configure_file(${_VTKModuleMacros_DIR}/vtkModuleInfo.cmake.in
     ${VTK_MODULES_DIR}/${vtk-module}.cmake @ONLY)
   set(vtk-module-INCLUDE_DIRS "${vtk-module-INCLUDE_DIRS-install}")
   set(vtk-module-RUNTIME_LIBRARY_DIRS "${vtk-module-RUNTIME_LIBRARY_DIRS-install}")
   set(vtk-module-EXPORT_CODE "${vtk-module-EXPORT_CODE-install}")
+  set(vtk-module-TARGETS_FILE "${vtk-module-TARGETS_FILE-install}")
   set(vtk-module-WRAP_HIERARCHY_FILE
     "\${CMAKE_CURRENT_LIST_DIR}/${vtk-module}Hierarchy.txt")
   configure_file(${_VTKModuleMacros_DIR}/vtkModuleInfo.cmake.in
@@ -481,7 +491,19 @@ function(vtk_target_name _name)
 endfunction()
 
 function(vtk_target_export _name)
-  set_property(GLOBAL APPEND PROPERTY VTK_TARGETS ${_name})
+  set(is_insource_module 0)
+  if(VTK_SOURCE_DIR)
+    set(is_insource_module 1)
+  endif()
+  set(is_local_project 0)
+  if("${${vtk-module}-targets-build}" STREQUAL "")
+    set(is_local_project 1) # E.g Examples/Build/vtkMy or Examples/Build/vtkLocal
+  endif()
+  if(is_insource_module OR is_local_module )
+    set_property(GLOBAL APPEND PROPERTY VTK_TARGETS ${_name})
+  else()
+    export(TARGETS ${_name} APPEND FILE ${${vtk-module}-targets-build}) # External VTK module
+  endif()
 endfunction()
 
 function(vtk_target_install _name)