CMake: Adopt find_package2

* Adds support for Boost 1.70

Resolves #14

CMakeLists.txt

@@ -28,7 +28,13 @@ option(USE_BOOST_PRETTY_FUNCTION "Use Boost BOOST_PRETTY_FUNCTION macro" OFF)
 
 # Dependency ###################################################################
 if(USE_BOOST_PRETTY_FUNCTION)
-  find_package(Boost REQUIRED)
+  if(NOT DEFINED Boost_NO_BOOST_CMAKE AND CMAKE_VERSION VERSION_LESS 3.15)
+    # Since Boost 1.70 a CMake package is shipped by default. Unfortunately, it has a number
+    # of problems that are only fixed in Boost 1.71 or CMake 3.15. By default we skip the
+    # BoostConfig lookup. This can be overridden on the command line via -DBoost_NO_BOOST_CMAKE=OFF
+    set(Boost_NO_BOOST_CMAKE ON)
+  endif()
+  find_package2(PUBLIC Boost REQUIRED)
 endif()
 ################################################################################
 

cmake/FairLoggerLib.cmake

@@ -212,3 +212,98 @@ macro(install_cmake_package)
     DESTINATION ${PACKAGE_INSTALL_DESTINATION}
   )
 endmacro()
+
+#
+# find_package2(PRIVATE|PUBLIC|INTERFACE <pkgname>
+#               [VERSION <version>]
+#               [COMPONENTS <list of components>]
+#               [ADD_REQUIREMENTS_OF <list of dep_pgkname>]
+#               [any other option the native find_package supports]...)
+#
+# Wrapper around CMake's native find_package command to add some features and bookkeeping.
+#
+# The qualifier (PRIVATE|PUBLIC|INTERFACE) to the package to populate
+# the variables PROJECT_[INTERFACE]_<pkgname>_([VERSION]|[COMPONENTS]|PACKAGE_DEPENDENCIES)
+# accordingly. This bookkeeping information is used to print our dependency found summary
+# table and to generate a part of our CMake package.
+#
+# When a dependending package is listed with ADD_REQUIREMENTS_OF the variables
+# <dep_pkgname>_<pkgname>_VERSION|COMPONENTS are looked up to and added to the native
+# VERSION (selected highest version) and COMPONENTS (deduplicated) args.
+#
+# COMPONENTS and VERSION args are then just passed to the native find_package.
+#
+macro(find_package2 qualifier pkgname)
+  cmake_parse_arguments(ARGS "" "VERSION" "COMPONENTS;ADD_REQUIREMENTS_OF" ${ARGN})
+
+  string(TOUPPER ${pkgname} pkgname_upper)
+  set(__old_cpp__ ${CMAKE_PREFIX_PATH})
+  set(CMAKE_PREFIX_PATH ${${pkgname_upper}_ROOT} $ENV{${pkgname_upper}_ROOT} ${CMAKE_PREFIX_PATH})
+
+  # build lists of required versions and components
+  unset(__required_versions__)
+  unset(__components__)
+  if(ARGS_VERSION)
+    list(APPEND __required_versions__ ${ARGS_VERSION})
+  endif()
+  if(ARGS_COMPONENTS)
+    list(APPEND __components__ ${ARGS_COMPONENTS})
+  endif()
+  if(ARGS_ADD_REQUIREMENTS_OF)
+    foreach(dep_pkgname IN LISTS ARGS_ADD_REQUIREMENTS_OF)
+      if(${dep_pkgname}_${pkgname}_VERSION)
+        list(APPEND __required_versions__ ${${dep_pkgname}_${pkgname}_VERSION})
+      endif()
+      if(${dep_pkgname}_${pkgname}_COMPONENTS)
+        list(APPEND __components__ ${${dep_pkgname}_${pkgname}_COMPONENTS})
+      endif()
+    endforeach()
+  endif()
+
+  # select highest required version
+  unset(__version__)
+  if(__required_versions__)
+    list(GET __required_versions__ 0 __version__)
+    foreach(v IN LISTS __required_versions__)
+      if(${v} VERSION_GREATER ${__version__})
+        set(__version__ ${v})
+      endif()
+    endforeach()
+  endif()
+  # deduplicate required component list
+  if(__components__)
+    list(REMOVE_DUPLICATES ARGS_COMPONENTS)
+  endif()
+
+  # call native find_package
+  if(__components__)
+    find_package(${pkgname} ${__version__} QUIET COMPONENTS ${__components__} ${ARGS_UNPARSED_ARGUMENTS})
+  else()
+    find_package(${pkgname} ${__version__} QUIET ${ARGS_UNPARSED_ARGUMENTS})
+  endif()
+
+  if(${pkgname}_FOUND)
+    if(${qualifier} STREQUAL PRIVATE)
+      set(PROJECT_${pkgname}_VERSION ${__version__})
+      set(PROJECT_${pkgname}_COMPONENTS ${ARGS_COMPONENTS})
+      set(PROJECT_PACKAGE_DEPENDENCIES ${PROJECT_PACKAGE_DEPENDENCIES} ${pkgname})
+    elseif(${qualifier} STREQUAL PUBLIC)
+      set(PROJECT_${pkgname}_VERSION ${__version__})
+      set(PROJECT_${pkgname}_COMPONENTS ${ARGS_COMPONENTS})
+      set(PROJECT_PACKAGE_DEPENDENCIES ${PROJECT_PACKAGE_DEPENDENCIES} ${pkgname})
+      set(PROJECT_INTERFACE_${pkgname}_VERSION ${__version__})
+      set(PROJECT_INTERFACE_${pkgname}_COMPONENTS ${ARGS_COMPONENTS})
+      set(PROJECT_INTERFACE_PACKAGE_DEPENDENCIES ${PROJECT_INTERFACE_PACKAGE_DEPENDENCIES} ${pkgname})
+    elseif(${qualifier} STREQUAL INTERFACE)
+      set(PROJECT_INTERFACE_${pkgname}_VERSION ${__version__})
+      set(PROJECT_INTERFACE_${pkgname}_COMPONENTS ${ARGS_COMPONENTS})
+      set(PROJECT_INTERFACE_PACKAGE_DEPENDENCIES ${PROJECT_INTERFACE_PACKAGE_DEPENDENCIES} ${pkgname})
+    endif()
+  endif()
+
+  unset(__version__)
+  unset(__components__)
+  unset(__required_versions__)
+  set(CMAKE_PREFIX_PATH ${__old_cpp__})
+  unset(__old_cpp__)
+endmacro()