Allow components in Config.cmake. (#396)

* Allow components in Config.cmake. * Add macro PROJECT_INSTALL_COMPONENT * Update doc. * Add missing include * Add optional argument NAMESPACE to PROJECT_INSTALL_COMPONENT
jrl-umi3218 · Jun 18, 2020 · 272d644 · 272d644
1 parent be594b8
commit 272d644
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Showing 4 changed files with 132 additions and 16 deletions.
diff --git a/.docs/pages/developers.rst b/.docs/pages/developers.rst
@@ -45,6 +45,18 @@ To document a macro or a variable in a ``.cmake`` file, use
   #   Variable details details (Mind the empty line before).
   #   Related to :cmake:command:`HOW_TO_DOCUMENT_A_COMMAND`.
   #
+  #   A code block::
+  #   
+  #     notice the double : and the indention
+  #
+  #   or the more verbose, but supports other language
+  #
+  #   .. code-block:: bash
+  #
+  #      make html
+  #      # Open build/html/index.html to see the doc
+  #      firefox build/html/index.html
+  #
   # .. command:: HOW_TO_DOCUMENT_A_COMMAND(argname)
   #
   #   Macro details (Mind the empty line before).
@@ -58,8 +70,20 @@ gives
 
 .. variable:: HOW_TO_DOCUMENT_A_VARIABLE
 
- Variable details (Mind the empty line before).
- Related to :cmake:command:`HOW_TO_DOCUMENT_A_COMMAND`.
+  Variable details (Mind the empty line before).
+  Related to :cmake:command:`HOW_TO_DOCUMENT_A_COMMAND`.
+
+  A cmake code block::
+  
+    set(foo "notice the double : and the indention")
+
+  or the more verbose, but supports other language
+
+  .. code-block:: bash
+
+     make html
+     # Open build/html/index.html to see the doc
+     firefox build/html/index.html
 
 .. command:: HOW_TO_DOCUMENT_A_COMMAND(argname)
 

diff --git a/Config.cmake.in b/Config.cmake.in
@@ -1,6 +1,17 @@
 @PACKAGE_INIT@
 
-if(@PROJECT_NAME@_FOUND)
+set(skip_this_file TRUE)
+if(NOT @PROJECT_NAME@_FOUND)
+  set(skip_this_file FALSE)
+endif()
+if(skip_this_file)
+  foreach(component ${@PROJECT_NAME@_FIND_COMPONENTS})
+    if(NOT "@PROJECT_NAME@_${component}_FOUND")
+      set(skip_this_file FALSE)
+    endif()
+  endforeach()
+endif()
+if(skip_this_file)
   return()
 endif()
 
@@ -82,9 +93,9 @@ set("@PROJECT_NAME_UPPER@_LIBRARIES" ${_PACKAGE_CONFIG_LIBRARIES})
 
 include(CMakeFindDependencyMacro)
 if(${CMAKE_VERSION} VERSION_LESS "3.15.0")
-@PACKAGE_DEPENDENCIES_FIND_PACKAGE@
+  @PACKAGE_DEPENDENCIES_FIND_PACKAGE@
 else()
-@PACKAGE_DEPENDENCIES_FIND_DEPENDENCY@
+  @PACKAGE_DEPENDENCIES_FIND_DEPENDENCY@
 endif()
 
 IF(COMMAND ADD_REQUIRED_DEPENDENCY)
@@ -98,6 +109,20 @@ IF(COMMAND ADD_REQUIRED_DEPENDENCY)
 ENDIF(COMMAND ADD_REQUIRED_DEPENDENCY)
 
 include("${CMAKE_CURRENT_LIST_DIR}/@[email protected]")
+
+foreach(component ${@PROJECT_NAME@_FIND_COMPONENTS})
+  set(comp_file "${CMAKE_CURRENT_LIST_DIR}/${component}Config.cmake")
+  if(EXISTS ${comp_file})
+    include(${comp_file})
+  else()
+    set("@PROJECT_NAME@_${component}_FOUND" FALSE)
+  endif()
+  if("@PROJECT_NAME@_${component}_FOUND")
+    message(STATUS "@PROJECT_NAME@: ${component} found.")
+  else()
+    message(STATUS "@PROJECT_NAME@: ${component} not found.")
+  endif()
+endforeach()
 check_required_components("@PROJECT_NAME@")
 
 @PACKAGE_EXTRA_MACROS@
diff --git a/componentConfig.cmake.in b/componentConfig.cmake.in
@@ -0,0 +1,23 @@
+@PACKAGE_INIT@
+
+if(NOT @PROJECT_NAME@_FOUND)
+  set(@PROJECT_NAME@_@COMPONENT@_FOUND FALSE)
+  return()
+endif()
+
+# At the moment, components only support targets
+#set("@PROJECT_NAME@_@COMPONENT@_INCLUDE_DIRS" "@CMAKE_INSTALL_FULL_INCLUDEDIR@")
+#set("@PROJECT_NAME@_@COMPONENT@_LIBRARIES" ${_PACKAGE_CONFIG_LIBRARIES})
+set(@PROJECT_NAME@_@COMPONENT@_DEPENDENCIES "@_PACKAGE_CONFIG_COMPONENT_DEPENDENCIES_PROJECTS@")
+
+include(CMakeFindDependencyMacro)
+if(${CMAKE_VERSION} VERSION_LESS "3.15.0")
+  @COMPONENT_FIND_PACKAGE@
+else()
+  @COMPONENT_FIND_DEPENDENCY@
+endif()
+
+include("${CMAKE_CURRENT_LIST_DIR}/@[email protected]")
+set(@PROJECT_NAME@_@COMPONENT@_FOUND TRUE)
+
+@COMPONENT_EXTRA_MACRO@
diff --git a/package-config.cmake b/package-config.cmake
@@ -53,7 +53,7 @@ set(PACKAGE_EXTRA_MACROS "" CACHE INTERNAL "")
 ENDMACRO(_SETUP_PROJECT_PACKAGE_INIT)
 
 #.rst:
-# .. command:: ADD_PROJECT_DEPENDENCY(ARGS [PKG_CONFIG_REQUIRES pkg])
+# .. command:: ADD_PROJECT_DEPENDENCY(ARGS [PKG_CONFIG_REQUIRES pkg] [FOR_COMPONENT component])
 #
 #   This is a wrapper around find_package to add correct find_dependency calls in
 #   the generated config script. All arguments are passed to find_package.
@@ -66,25 +66,27 @@ ENDMACRO(_SETUP_PROJECT_PACKAGE_INIT)
 #   section of the generated .pc file
 #
 MACRO(ADD_PROJECT_DEPENDENCY)
-  list(APPEND _PACKAGE_CONFIG_DEPENDENCIES_PROJECTS "${ARGV0}")
-
   # add dependency to the generated .pc
   # ref https://github.com/jrl-umi3218/jrl-cmakemodules/pull/335
-  cmake_parse_arguments(PARSED_ARGN "" "PKG_CONFIG_REQUIRES" "" ${ARGN})
+  cmake_parse_arguments(PARSED_ARGN "" "PKG_CONFIG_REQUIRES;FOR_COMPONENT" "" ${ARGN})
   IF(PARSED_ARGN_PKG_CONFIG_REQUIRES)
     _ADD_TO_LIST_IF_NOT_PRESENT(_PKG_CONFIG_REQUIRES "${PARSED_ARGN_PKG_CONFIG_REQUIRES}")
     _ADD_TO_LIST_IF_NOT_PRESENT(_PKG_CONFIG_DEP_NOT_FOR_CONFIG_CMAKE "${PARSED_ARGN_PKG_CONFIG_REQUIRES}")
   ENDIF()
+  if(PARSED_ARGN_FOR_COMPONENT)
+    set(component "_${PARSED_ARGN_FOR_COMPONENT}")
+  endif(PARSED_ARGN_FOR_COMPONENT)
+  _ADD_TO_LIST_IF_NOT_PRESENT(APPEND "_PACKAGE_CONFIG${component}_DEPENDENCIES_PROJECTS" "${ARGV0}")
 
   string(REPLACE ";" " " PACKAGE_ARGS "${PARSED_ARGN_UNPARSED_ARGUMENTS}")
-  list(APPEND _PACKAGE_CONFIG_DEPENDENCIES_FIND_PACKAGE "  find_package(${PACKAGE_ARGS})")
-  list(APPEND _PACKAGE_CONFIG_DEPENDENCIES_FIND_DEPENDENCY "  find_dependency(${PACKAGE_ARGS})")
+  _ADD_TO_LIST_IF_NOT_PRESENT("_PACKAGE_CONFIG${component}_DEPENDENCIES_FIND_PACKAGE" "find_package(${PACKAGE_ARGS})")
+  _ADD_TO_LIST_IF_NOT_PRESENT("_PACKAGE_CONFIG${component}_DEPENDENCIES_FIND_DEPENDENCY" "find_dependency(${PACKAGE_ARGS})")
   find_package(${PARSED_ARGN_UNPARSED_ARGUMENTS})
 
   # Propagate variables changes to the cached values
-  set(_PACKAGE_CONFIG_DEPENDENCIES_PROJECTS "${_PACKAGE_CONFIG_DEPENDENCIES_PROJECTS}" CACHE INTERNAL "")
-  set(_PACKAGE_CONFIG_DEPENDENCIES_FIND_PACKAGE "${_PACKAGE_CONFIG_DEPENDENCIES_FIND_PACKAGE}" CACHE INTERNAL "")
-  set(_PACKAGE_CONFIG_DEPENDENCIES_FIND_DEPENDENCY "${_PACKAGE_CONFIG_DEPENDENCIES_FIND_DEPENDENCY}" CACHE INTERNAL "")
+  set(_PACKAGE_CONFIG${component}_DEPENDENCIES_PROJECTS "${_PACKAGE_CONFIG${component}_DEPENDENCIES_PROJECTS}" CACHE INTERNAL "")
+  set(_PACKAGE_CONFIG${component}_DEPENDENCIES_FIND_PACKAGE "${_PACKAGE_CONFIG${component}_DEPENDENCIES_FIND_PACKAGE}" CACHE INTERNAL "")
+  set(_PACKAGE_CONFIG${component}_DEPENDENCIES_FIND_DEPENDENCY "${_PACKAGE_CONFIG${component}_DEPENDENCIES_FIND_DEPENDENCY}" CACHE INTERNAL "")
 ENDMACRO()
 
 
@@ -130,8 +132,8 @@ string(REGEX REPLACE "[^a-zA-Z0-9]" "_" PROJECT_NAME_UPPER "${PROJECT_NAME_UPPER
 # Include module with fuction 'write_basic_package_version_file'
 include(CMakePackageConfigHelpers)
 
-string(REPLACE ";" "\n" PACKAGE_DEPENDENCIES_FIND_PACKAGE "${_PACKAGE_CONFIG_DEPENDENCIES_FIND_PACKAGE}")
-string(REPLACE ";" "\n" PACKAGE_DEPENDENCIES_FIND_DEPENDENCY "${_PACKAGE_CONFIG_DEPENDENCIES_FIND_DEPENDENCY}")
+string(REPLACE ";" "\n  " PACKAGE_DEPENDENCIES_FIND_PACKAGE "${_PACKAGE_CONFIG_DEPENDENCIES_FIND_PACKAGE}")
+string(REPLACE ";" "\n  " PACKAGE_DEPENDENCIES_FIND_DEPENDENCY "${_PACKAGE_CONFIG_DEPENDENCIES_FIND_DEPENDENCY}")
 
 # Configure '<PROJECT-NAME>ConfigVersion.cmake'
 # Note: PROJECT_VERSION is used as a VERSION
@@ -174,3 +176,45 @@ install(
     DESTINATION "${CONFIG_INSTALL_DIR}"
 )
 ENDMACRO(SETUP_PROJECT_PACKAGE_FINALIZE)
+
+#.rst:
+# .. command:: PROJECT_INSTALL_COMPONENT(COMPONENT [EXTRA_MACRO cmake_code] [NAMESPACE namespace])
+#
+#   Generates CMake componentConfig.cmake and Targets files so users can call::
+#
+#     find_package(MyPackage COMPONENT component)
+#
+#   :param EXTRA_MACRO: optional argument. `cmake_code` will be appended to
+#          the generated *Config.cmake*.
+#   :param NAMESPACE: optional argument. Defaults to `${PROJECT_NAME}::`.
+#
+macro(PROJECT_INSTALL_COMPONENT COMPONENT)
+  cmake_parse_arguments(PARSED_ARGN "" "NAMESPACE;EXTRA_MACRO" "" ${ARGN})
+  if(PARSED_ARGN_NAMESPACE)
+    set(namespace "${PARSED_ARGN_NAMESPACE}")
+  else()
+    set(namespace "${PROJECT_NAME}::")
+  endif()
+
+  install(EXPORT ${COMPONENT}Targets
+    NAMESPACE "${namespace}"
+    DESTINATION "${CONFIG_INSTALL_DIR}")
+
+  set(COMPONENT ${COMPONENT})
+  set(_PACKAGE_CONFIG_COMPONENT_DEPENDENCIES_PROJECTS "${_PACKAGE_CONFIG_${COMPONENT}_DEPENDENCIES_PROJECTS}")
+  string(REPLACE ";" "\n  " COMPONENT_FIND_PACKAGE
+    "${_PACKAGE_CONFIG_${COMPONENT}_DEPENDENCIES_FIND_PACKAGE}")
+  string(REPLACE ";" "\n  " COMPONENT_FIND_DEPENDENCY
+    "${_PACKAGE_CONFIG_${COMPONENT}_DEPENDENCIES_FIND_DEPENDENCY}")
+  set(COMPONENT_CONFIG "${CMAKE_BINARY_DIR}/generated/${COMPONENT}Config.cmake")
+  set(COMPONENT_EXTRA_MACRO "${PARSED_ARGN_EXTRA_MACRO}")
+  include(CMakePackageConfigHelpers)
+  configure_package_config_file(
+      "${CMAKE_SOURCE_DIR}/cmake/componentConfig.cmake.in"
+      "${COMPONENT_CONFIG}"
+      INSTALL_DESTINATION "${CONFIG_INSTALL_DIR}"
+      NO_CHECK_REQUIRED_COMPONENTS_MACRO
+      NO_SET_AND_CHECK_MACRO)
+  install(FILES "${COMPONENT_CONFIG}"
+      DESTINATION "${CONFIG_INSTALL_DIR}")
+endmacro()