Introduced DUNE-2.8 compatible imported targets where needed.

I.e. in the find_package files for PTScotch ParMETIS, Quadmath,
SuiteSparse, and SuperLU.

cmake/Modules/FindPTScotch.cmake

@@ -70,6 +70,20 @@ if(PTSCOTCH_FOUND)
   set(PTSCOCH_LINK_FLAGS "${DUNE_MPI_LINK_FLAGS}"
     CACHE STRING "PT-Scotch link flags")
   set(HAVE_PTSCOTCH 1)
+  if(NOT TARGET PTScotch::Scotch)
+    add_library(PTScotch::Scotch UNKNOWN IMPORTED GLOBAL)
+    set_target_properties(PTScotch::Scotch PROPERTIES
+      IMPORTED_LOCATION "${SCOTCH_LIBRARY}"
+      INCLUDE_DIRECTORIES "${PTSCOTCH_INCLUDE_DIRS}"
+      INTERFACE_LINK_LIBRARIES "${PTSCOTCHERR_LIBRARY}")
+  endif()
+  if(NOT TARGET PTScotch::PTScotch)
+    add_library(PTScotch::PTScotch UNKNOWN IMPORTED GLOBAL)
+    set_target_properties(PTScotch::PTScotch PROPERTIES
+      IMPORTED_LOCATION "${PTSCOTCH_LIBRARY}"
+      INCLUDE_DIRECTORIES "${PTSCOTCH_INCLUDE_DIRS}"
+      INTERFACE_LINK_LIBRARIES "PTScotch::Scotch;${MPI_DUNE_LIBRARIES}")
+  endif()
   # log result
   file(APPEND ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeOutput.log
     "Determing location of PT-Scotch succeded:\n"

cmake/Modules/FindParMETIS.cmake

@@ -102,6 +102,13 @@ if(PARMETIS_FOUND)
     "Include directory: ${PARMETIS_INCLUDE_DIRS}\n"
     "Library directory: ${PARMETIS_LIBRARIES}\n\n")
 
+  if(NOT TARGET ParMETIS::ParMETIS)
+    add_library(ParMETIS::ParMETIS UNKNOWN IMPORTED GLOBAL)
+    set_target_properties(ParMETIS::ParMETIS PROPERTIES
+      IMPORTED_LOCATION ${PARMETIS_LIBRARY}
+      INCLUDE_DIRECTORIES "${PARMETIS_INCLUDE_DIRS}"
+      INTERFACE_LINK_LIBRARIES "${METIS_LIBRARIES};${MPI_C_LIBRARIES}")
+  endif()
 endif(PARMETIS_FOUND)
 
 mark_as_advanced(PARMETIS_INCLUDE_DIRS PARMETIS_LIBRARIES HAVE_PARMETIS)

cmake/Modules/FindQuadmath.cmake

@@ -34,6 +34,11 @@ int main(void){
   if (QUADMATH_FOUND)
     set(QUADMATH_LIBRARIES "quadmath")
     set(HAVE_QUAD "${QUADMATH_FOUND}")
+    add_library(QuadMath::QuadMath INTERFACE IMPORTED)
+    set_target_properties(QuadMath::QuadMath PROPERTIES
+      INTERFACE_LINK_LIBRARIES quadmath
+      INTERFACE_COMPILE_DEFINITIONS _GLIBCXX_USE_FLOAT128
+      INTERFACE_COMPILE_OPTIONS $<$<CXX_COMPILER_ID:GNU>:-fext-numeric-literals>)
   endif()
 endif()
 

cmake/Modules/FindSuiteSparse.cmake

@@ -280,6 +280,32 @@ if (SuiteSparse_LIBRARIES)
   list (REVERSE SuiteSparse_LIBRARIES)
 endif (SuiteSparse_LIBRARIES)
 
+if(SuiteSparse_FOUND)
+  if(NOT TARGET SuiteSparse::SuiteSparse)
+    add_library(SuiteSparse::SuiteSparse INTERFACE IMPORTED GLOBAL)
+    set_property(TARGET SuiteSparse::SuiteSparse PROPERTY
+      INTERFACE_INCLUDE_DIRECTORIES ${SuiteSparse_INCLUDE_DIRS})
+    if(config_LIBRARY)
+      set_property(TARGET SuiteSparse::SuiteSparse PROPERTY
+	INTERFACE_LINK_LIBRARIES ${config_LIBRARY})
+    endif()
+  endif()
+  foreach(_module ${SuiteSparse_MODULES})
+    string (TOUPPER ${_module} _MODULE)
+    if(SuiteSparse_${_MODULE}_FOUND)
+      if(NOT TARGET SuiteSparse::${_module})
+	message(STATUS "Creating target SuitSparse::${_module}")
+	add_library(SuiteSparse::${_module} UNKNOWN IMPORTED GLOBAL)
+	set_target_properties(SuiteSparse::${_module} PROPERTIES
+	  IMPORTED_LOCATION ${${_MODULE}_LIBRARY}
+	  INCLUDE_DIRECTORIES ${${_MODULE}_INCLUDE_DIRS}
+	  INTERFACE_LINK_LIBRARIES "${config_LIBRARY}")
+	target_link_libraries(SuiteSparse::SuiteSparse
+          INTERFACE SuiteSparse::${_module})
+      endif()
+    endif()
+  endforeach(_module)
+endif()
 # print a message to indicate status of this package
 include (FindPackageHandleStandardArgs)
 find_package_handle_standard_args (SuiteSparse

cmake/Modules/FindSuperLU.cmake

@@ -180,6 +180,16 @@ if(SUPERLU_FOUND)
   if (SUPERLU_BLAS_LIBRARY)
     list(APPEND SUPERLU_LIBRARIES ${SUPERLU_BLAS_LIBRARY})
   endif()
+  if(NOT TARGET SuperLU::SuperLU)
+    add_library(SuperLU::SuperLU UNKNOWN IMPORTED GLOBAL)
+    set_target_properties(SuperLU::SuperLU PROPERTIES
+      IMPORTED_LOCATION ${SUPERLU_LIBRARY}
+      INCLUDE_DIRECTORIES ${SUPERLU_INCLUDE_DIRS})
+    if(SUPERLU_BLAS_LIBRARY)
+      set_property(TARGET SuperLU::SuperLU PROPERTY
+	INTERFACE_LINK_LIBRARIES ${SUPERLU_BLAS_LIBRARY})
+    endif()
+  endif()
 endif()
 
 cmake_pop_check_state()