Merge pull request #826 in HDFFV/hdf5 from ~BYRN/hdf5_adb:develop to develop

* commit 'e94ed99c5bf7c4ae5df56f75606ef1b486e16bb2':
  Add HD prefix
  HDFFV-9724 Remove VDS file cache functionality
  Removed incorrect MPI text
  Par example needs to link with mpi libs
  Because of MPI requirements in library ALWAYS add include path
  Cleanup comments and if() in TRY blocks
  Skip test if 1.6 API
  HDFFV-9724 Add ENV VAR to vds test
  HDFFV-9724 Copy efc_open search from Lextern_traverse
  Add prefix dir to the clear command
  HDFFV-9724 Add H5LS prefix test with ${ORIGIN}
  Add h5dump VDS prefix tests
  HDFFV-9724 combine efc and vds into one function
  Correct var name
  Fix VDS file cache var names
  Remove return from void functions
  Added java wrappers and tests
  HDFFV-9724 Initial changes and test
  Changed reference from dl to CMake variable
  H5detect and H5make_libsettings need include folder

1 files changed, 170 insertions, 117 deletions

diff --git a/config/cmake_ext_mod/FindMPI.cmake b/config/cmake_ext_mod/FindMPI.cmake
index 8084472..d01dd35 100644
--- a/config/cmake_ext_mod/FindMPI.cmake
+++ b/config/cmake_ext_mod/FindMPI.cmake
@@ -347,7 +347,7 @@ function (_MPI_check_compiler LANG QUERY_FLAG OUTPUT_VARIABLE RESULT_VARIABLE)
   # library that has invalid or missing version information there would be warning
   # messages emitted by ld.so in the compiler output. In either case, we'll treat
   # the output as invalid.
-  if("${WRAPPER_OUTPUT}" MATCHES "undefined reference|unrecognized|need to set|no version information available")
+  if("${WRAPPER_OUTPUT}" MATCHES "undefined reference|unrecognized|need to set|no version information available|command not found")
     set(WRAPPER_RETURN 255)
   endif()
   # Ensure that no error output might be passed upwards.
@@ -615,6 +615,16 @@ function (_MPI_interrogate_compiler lang)
     endif()
   endif()
 
+  if(MPI_${LANG}_EXTRA_COMPILE_DEFINITIONS)
+    list(APPEND MPI_COMPILE_DEFINITIONS_WORK "${MPI_${LANG}_EXTRA_COMPILE_DEFINITIONS}")
+  endif()
+  if(MPI_${LANG}_EXTRA_COMPILE_OPTIONS)
+    list(APPEND MPI_COMPILE_OPTIONS_WORK "${MPI_${LANG}_EXTRA_COMPILE_OPTIONS}")
+  endif()
+  if(MPI_${LANG}_EXTRA_LIB_NAMES)
+    list(APPEND MPI_PLAIN_LIB_NAMES_WORK "${MPI_${LANG}_EXTRA_LIB_NAMES}")
+  endif()
+
   # If we found MPI, set up all of the appropriate cache entries
   if(NOT MPI_${LANG}_COMPILE_OPTIONS)
     set(MPI_${LANG}_COMPILE_OPTIONS          ${MPI_COMPILE_OPTIONS_WORK}     CACHE STRING "MPI ${LANG} compilation options"            FORCE)
@@ -823,33 +833,43 @@ endfunction()
 
 macro(_MPI_assemble_libraries LANG)
   set(MPI_${LANG}_LIBRARIES "")
-  foreach(mpilib IN LISTS MPI_${LANG}_LIB_NAMES)
-    list(APPEND MPI_${LANG}_LIBRARIES ${MPI_${mpilib}_LIBRARY})
-  endforeach()
+  # Only for libraries do we need to check whether the compiler's linking stage is separate.
+  if(NOT "${MPI_${LANG}_COMPILER}" STREQUAL "${CMAKE_${LANG}_COMPILER}" OR NOT MPI_${LANG}_WORKS_IMPLICIT)
+    foreach(mpilib IN LISTS MPI_${LANG}_LIB_NAMES)
+      list(APPEND MPI_${LANG}_LIBRARIES ${MPI_${mpilib}_LIBRARY})
+    endforeach()
+  endif()
 endmacro()
 
 macro(_MPI_assemble_include_dirs LANG)
-  set(MPI_${LANG}_INCLUDE_DIRS "${MPI_${LANG}_ADDITIONAL_INCLUDE_DIRS}")
-  if("${LANG}" MATCHES "(C|CXX)")
-    if(MPI_${LANG}_HEADER_DIR)
-      list(APPEND MPI_${LANG}_INCLUDE_DIRS "${MPI_${LANG}_HEADER_DIR}")
-    endif()
-  else() # Fortran
-    if(MPI_${LANG}_F77_HEADER_DIR)
-      list(APPEND MPI_${LANG}_INCLUDE_DIRS "${MPI_${LANG}_F77_HEADER_DIR}")
+  if("${MPI_${LANG}_COMPILER}" STREQUAL "${CMAKE_${LANG}_COMPILER}")
+    set(MPI_${LANG}_INCLUDE_DIRS "")
+  else()
+    set(MPI_${LANG}_INCLUDE_DIRS "${MPI_${LANG}_ADDITIONAL_INCLUDE_DIRS}")
+    if("${LANG}" MATCHES "(C|CXX)")
+      if(MPI_${LANG}_HEADER_DIR)
+        list(APPEND MPI_${LANG}_INCLUDE_DIRS "${MPI_${LANG}_HEADER_DIR}")
+      endif()
+    else() # Fortran
+      if(MPI_${LANG}_F77_HEADER_DIR)
+        list(APPEND MPI_${LANG}_INCLUDE_DIRS "${MPI_${LANG}_F77_HEADER_DIR}")
+      endif()
+      if(MPI_${LANG}_MODULE_DIR AND NOT "${MPI_${LANG}_MODULE_DIR}" IN_LIST MPI_${LANG}_INCLUDE_DIRS)
+        list(APPEND MPI_${LANG}_INCLUDE_DIRS "${MPI_${LANG}_MODULE_DIR}")
+      endif()
     endif()
-    if(MPI_${LANG}_MODULE_DIR AND NOT "${MPI_${LANG}_MODULE_DIR}" IN_LIST MPI_${LANG}_INCLUDE_DIRS)
-      list(APPEND MPI_${LANG}_INCLUDE_DIRS "${MPI_${LANG}_MODULE_DIR}")
+    if(MPI_${LANG}_ADDITIONAL_INCLUDE_VARS)
+      foreach(MPI_ADDITIONAL_INC_DIR IN LISTS MPI_${LANG}_ADDITIONAL_INCLUDE_VARS)
+        list(APPEND MPI_${LANG}_INCLUDE_DIRS "${MPI_${MPI_ADDITIONAL_INC_DIR}_INCLUDE_DIR}")
+      endforeach()
     endif()
   endif()
-  if(MPI_${LANG}_ADDITIONAL_INCLUDE_VARS)
-    foreach(mpiadditionalinclude IN LISTS MPI_${LANG}_ADDITIONAL_INCLUDE_VARS)
-      list(APPEND MPI_${LANG}_INCLUDE_DIRS "${MPI_${mpiadditionalinclude}_INCLUDE_DIR}")
-    endforeach()
-  endif()
 endmacro()
 
 function(_MPI_split_include_dirs LANG)
+  if("${MPI_${LANG}_COMPILER}" STREQUAL "${CMAKE_${LANG}_COMPILER}")
+    return()
+  endif()
   # Backwards compatibility: Search INCLUDE_PATH if given.
   if(MPI_${LANG}_INCLUDE_PATH)
     list(APPEND MPI_${LANG}_ADDITIONAL_INCLUDE_DIRS "${MPI_${LANG}_INCLUDE_PATH}")
@@ -885,6 +905,13 @@ function(_MPI_split_include_dirs LANG)
     endif()
     mark_as_advanced(MPI_${LANG}_F77_HEADER_DIR MPI_${LANG}_MODULE_DIR)
   endif()
+  # Remove duplicates and default system directories from the list.
+  if(MPI_${LANG}_ADDITIONAL_INCLUDE_DIRS)
+    list(REMOVE_DUPLICATES MPI_${LANG}_ADDITIONAL_INCLUDE_DIRS)
+    foreach(MPI_IMPLICIT_INC_DIR IN LISTS CMAKE_${LANG}_IMPLICIT_LINK_DIRECTORIES)
+      list(REMOVE_ITEM MPI_${LANG}_ADDITIONAL_INCLUDE_DIRS ${MPI_IMPLICIT_INC_DIR})
+    endforeach()
+  endif()
   set(MPI_${LANG}_ADDITIONAL_INCLUDE_DIRS ${MPI_${LANG}_ADDITIONAL_INCLUDE_DIRS} CACHE STRING "MPI ${LANG} additional include directories" FORCE)
 endfunction()
 
@@ -1014,7 +1041,7 @@ elseif("${CMAKE_HOST_SYSTEM_NAME}" STREQUAL "Windows")
 elseif("${CMAKE_HOST_SYSTEM_NAME}" STREQUAL "FreeBSD")
   # FreeBSD ships mpich under the normal system paths - but available openmpi implementations
   # will be found in /usr/local/mpi/<name>
-  MPI_search_mpi_prefix_folder("/usr/local/mpi/")
+  MPI_search_mpi_prefix_folder("/usr/local/mpi")
 endif()
 
 # Most MPI distributions have some form of mpiexec or mpirun which gives us something we can look for.
@@ -1050,48 +1077,54 @@ mark_as_advanced(MPIEXEC_EXECUTABLE MPIEXEC_NUMPROC_FLAG MPIEXEC_PREFLAGS MPIEXE
 #
 # Once we find the new variables, we translate them back into their old
 # equivalents below.
-foreach (LANG IN ITEMS C CXX)
-  # Old input variables.
-  set(_MPI_OLD_INPUT_VARS COMPILER COMPILE_FLAGS INCLUDE_PATH LINK_FLAGS)
-
-  # Set new vars based on their old equivalents, if the new versions are not already set.
-  foreach (var ${_MPI_OLD_INPUT_VARS})
-    if (NOT MPI_${LANG}_${var} AND MPI_${var})
-      set(MPI_${LANG}_${var} "${MPI_${var}}")
-    endif()
-  endforeach()
-
-  # Chop the old compile flags into options and definitions
-  if(MPI_${LANG}_COMPILE_FLAGS)
-    unset(MPI_${LANG}_COMPILE_OPTIONS)
-    unset(MPI_${LANG}_COMPILE_DEFINITIONS)
-    separate_arguments(MPI_SEPARATE_FLAGS NATIVE_COMMAND "${MPI_${LANG}_COMPILE_FLAGS}")
-    foreach(_MPI_FLAG IN LISTS MPI_SEPARATE_FLAGS)
-      if("${_MPI_FLAG}" MATCHES "^ *[-/D]([^ ]+)")
-        list(APPEND MPI_${LANG}_COMPILE_DEFINITIONS "${CMAKE_MATCH_1}")
-      else()
-        list(APPEND MPI_${LANG}_COMPILE_FLAGS "${_MPI_FLAG}")
+if(NOT MPI_IGNORE_LEGACY_VARIABLES)
+  foreach (LANG IN ITEMS C CXX)
+    # Old input variables.
+    set(_MPI_OLD_INPUT_VARS COMPILER COMPILE_FLAGS INCLUDE_PATH LINK_FLAGS)
+
+    # Set new vars based on their old equivalents, if the new versions are not already set.
+    foreach (var ${_MPI_OLD_INPUT_VARS})
+      if (NOT MPI_${LANG}_${var} AND MPI_${var})
+        set(MPI_${LANG}_${var} "${MPI_${var}}")
       endif()
     endforeach()
-    unset(MPI_SEPARATE_FLAGS)
-  endif()
 
-  # If a list of libraries was given, we'll split it into new-style cache variables
-  if(NOT MPI_${LANG}_LIB_NAMES)
-    foreach(_MPI_LIB IN LISTS MPI_${LANG}_LIBRARIES MPI_LIBRARY MPI_EXTRA_LIBRARY)
-      get_filename_component(_MPI_PLAIN_LIB_NAME "${_MPI_LIB}" NAME_WE)
-      get_filename_component(_MPI_LIB_NAME "${_MPI_LIB}" NAME)
-      get_filename_component(_MPI_LIB_DIR "${_MPI_LIB}" DIRECTORY)
-      list(APPEND MPI_PLAIN_LIB_NAMES_WORK "${_MPI_PLAIN_LIB_NAME}")
-      find_library(MPI_${_MPI_PLAIN_LIB_NAME}_LIBRARY
-        NAMES "${_MPI_LIB_NAME}" "lib${_MPI_LIB_NAME}"
-        HINTS ${_MPI_LIB_DIR} $ENV{MPI_LIB}
-        DOC "Location of the ${_MPI_PLAIN_LIB_NAME} library for MPI"
-      )
-      mark_as_advanced(MPI_${_MPI_PLAIN_LIB_NAME}_LIBRARY)
-    endforeach()
-  endif()
-endforeach()
+    # Chop the old compile flags into options and definitions
+
+    unset(MPI_${LANG}_EXTRA_COMPILE_DEFINITIONS)
+    unset(MPI_${LANG}_EXTRA_COMPILE_OPTIONS)
+    if(MPI_${LANG}_COMPILE_FLAGS)
+      separate_arguments(MPI_SEPARATE_FLAGS NATIVE_COMMAND "${MPI_${LANG}_COMPILE_FLAGS}")
+      foreach(_MPI_FLAG IN LISTS MPI_SEPARATE_FLAGS)
+        if("${_MPI_FLAG}" MATCHES "^ *[-/D]([^ ]+)")
+          list(APPEND MPI_${LANG}_EXTRA_COMPILE_DEFINITIONS "${CMAKE_MATCH_1}")
+        else()
+          list(APPEND MPI_${LANG}_EXTRA_COMPILE_OPTIONS "${_MPI_FLAG}")
+        endif()
+      endforeach()
+      unset(MPI_SEPARATE_FLAGS)
+    endif()
+
+    # If a list of libraries was given, we'll split it into new-style cache variables
+    unset(MPI_${LANG}_EXTRA_LIB_NAMES)
+    if(NOT MPI_${LANG}_LIB_NAMES)
+      foreach(_MPI_LIB IN LISTS MPI_${LANG}_LIBRARIES MPI_LIBRARY MPI_EXTRA_LIBRARY)
+        if(_MPI_LIB)
+          get_filename_component(_MPI_PLAIN_LIB_NAME "${_MPI_LIB}" NAME_WE)
+          get_filename_component(_MPI_LIB_NAME "${_MPI_LIB}" NAME)
+          get_filename_component(_MPI_LIB_DIR "${_MPI_LIB}" DIRECTORY)
+          list(APPEND MPI_${LANG}_EXTRA_LIB_NAMES "${_MPI_PLAIN_LIB_NAME}")
+          find_library(MPI_${_MPI_PLAIN_LIB_NAME}_LIBRARY
+            NAMES "${_MPI_LIB_NAME}" "lib${_MPI_LIB_NAME}"
+            HINTS ${_MPI_LIB_DIR} $ENV{MPI_LIB}
+            DOC "Location of the ${_MPI_PLAIN_LIB_NAME} library for MPI"
+          )
+          mark_as_advanced(MPI_${_MPI_PLAIN_LIB_NAME}_LIBRARY)
+        endif()
+      endforeach()
+    endif()
+  endforeach()
+endif()
 #=============================================================================
 
 unset(MPI_VERSION)
@@ -1100,6 +1133,11 @@ unset(MPI_VERSION_MINOR)
 
 unset(_MPI_MIN_VERSION)
 
+# If the user specified a library name we assume they prefer that library over a wrapper. If not, they can disable skipping manually.
+if(NOT DEFINED MPI_SKIP_COMPILER_WRAPPER AND MPI_GUESS_LIBRARY_NAME)
+  set(MPI_SKIP_COMPILER_WRAPPER TRUE)
+endif()
+
 # This loop finds the compilers and sends them off for interrogation.
 foreach(LANG IN ITEMS C CXX Fortran)
   if(CMAKE_${LANG}_COMPILER_LOADED)
@@ -1121,6 +1159,8 @@ foreach(LANG IN ITEMS C CXX Fortran)
       mark_as_advanced(MPI_CXX_SKIP_MPICXX)
     endif()
     if(NOT (MPI_${LANG}_LIB_NAMES AND (MPI_${LANG}_INCLUDE_PATH OR MPI_${LANG}_INCLUDE_DIRS OR MPI_${LANG}_ADDITIONAL_INCLUDE_DIRS)))
+      set(MPI_${LANG}_TRIED_IMPLICIT FALSE)
+      set(MPI_${LANG}_WORKS_IMPLICIT FALSE)
       if(NOT MPI_${LANG}_COMPILER AND NOT MPI_ASSUME_NO_BUILTIN_MPI)
         # Should the imported targets be empty, we effectively try whether the compiler supports MPI on its own, which is the case on e.g.
         # Cray PrgEnv.
@@ -1130,80 +1170,90 @@ foreach(LANG IN ITEMS C CXX Fortran)
         # If the compiler can build MPI code on its own, it functions as an MPI compiler and we'll set the variable to point to it.
         if(MPI_${LANG}_WORKS)
           set(MPI_${LANG}_COMPILER "${CMAKE_${LANG}_COMPILER}" CACHE FILEPATH "MPI compiler for ${LANG}" FORCE)
+          set(MPI_${LANG}_WORKS_IMPLICIT TRUE)
         endif()
+        set(MPI_${LANG}_TRIED_IMPLICIT TRUE)
       endif()
 
-      # If the user specified a library name we assume they prefer that library over a wrapper. If not, they can disable skipping manually.
-      if(NOT DEFINED MPI_SKIP_COMPILER_WRAPPER AND MPI_GUESS_LIBRARY_NAME)
-        set(MPI_SKIP_COMPILER_WRAPPER TRUE)
-      endif()
-      if(NOT MPI_SKIP_COMPILER_WRAPPER)
-        if(MPI_${LANG}_COMPILER)
-          # If the user supplies a compiler *name* instead of an absolute path, assume that we need to find THAT compiler.
-          if (NOT IS_ABSOLUTE "${MPI_${LANG}_COMPILER}")
-            # Get rid of our default list of names and just search for the name the user wants.
-            set(_MPI_${LANG}_COMPILER_NAMES "${MPI_${LANG}_COMPILER}")
-            unset(MPI_${LANG}_COMPILER CACHE)
+      if(NOT "${MPI_${LANG}_COMPILER}" STREQUAL "${CMAKE_${LANG}_COMPILER}" OR NOT MPI_${LANG}_WORKS)
+        set(MPI_${LANG}_WRAPPER_FOUND FALSE)
+        set(MPI_PINNED_COMPILER FALSE)
+
+        if(NOT MPI_SKIP_COMPILER_WRAPPER)
+          if(MPI_${LANG}_COMPILER)
+            # If the user supplies a compiler *name* instead of an absolute path, assume that we need to find THAT compiler.
+            if (NOT IS_ABSOLUTE "${MPI_${LANG}_COMPILER}")
+              # Get rid of our default list of names and just search for the name the user wants.
+              set(_MPI_${LANG}_COMPILER_NAMES "${MPI_${LANG}_COMPILER}")
+              unset(MPI_${LANG}_COMPILER CACHE)
+            endif()
+            # If the user specifies a compiler, we don't want to try to search libraries either.
+            set(MPI_PINNED_COMPILER TRUE)
+          endif()
+
+          # If we have an MPI base directory, we'll try all compiler names in that one first.
+          # This should prevent mixing different MPI environments
+          if(_MPI_BASE_DIR)
+            find_program(MPI_${LANG}_COMPILER
+              NAMES  ${_MPI_${LANG}_COMPILER_NAMES}
+              PATH_SUFFIXES bin sbin
+              HINTS  ${_MPI_BASE_DIR}
+              NO_DEFAULT_PATH
+              DOC    "MPI compiler for ${LANG}"
+            )
           endif()
-          # If the user specifies a compiler, we don't want to try to search libraries either.
-          set(MPI_PINNED_COMPILER TRUE)
-        else()
-          set(MPI_PINNED_COMPILER FALSE)
-        endif()
 
-        # If we have an MPI base directory, we'll try all compiler names in that one first.
-        # This should prevent mixing different MPI environments
-        if(_MPI_BASE_DIR)
+          # If the base directory did not help (for example because the mpiexec isn't in the same directory as the compilers),
+          # we shall try searching in the default paths.
           find_program(MPI_${LANG}_COMPILER
             NAMES  ${_MPI_${LANG}_COMPILER_NAMES}
             PATH_SUFFIXES bin sbin
-            HINTS  ${_MPI_BASE_DIR}
-            NO_DEFAULT_PATH
             DOC    "MPI compiler for ${LANG}"
           )
-        endif()
 
-        # If the base directory did not help (for example because the mpiexec isn't in the same directory as the compilers),
-        # we shall try searching in the default paths.
-        find_program(MPI_${LANG}_COMPILER
-          NAMES  ${_MPI_${LANG}_COMPILER_NAMES}
-          PATH_SUFFIXES bin sbin
-          DOC    "MPI compiler for ${LANG}"
-        )
-
-        if(MPI_${LANG}_COMPILER STREQUAL CMAKE_${LANG}_COMPILER)
-          set(MPI_SKIP_GUESSING TRUE)
-        elseif(MPI_${LANG}_COMPILER)
-          _MPI_interrogate_compiler(${LANG})
-        else()
-          set(MPI_${LANG}_WRAPPER_FOUND FALSE)
+          if("${MPI_${LANG}_COMPILER}" STREQUAL "${CMAKE_${LANG}_COMPILER}")
+            set(MPI_PINNED_COMPILER TRUE)
+
+            # If we haven't made the implicit compiler test yet, perform it now.
+            if(NOT MPI_${LANG}_TRIED_IMPLICIT)
+              _MPI_create_imported_target(${LANG})
+              _MPI_check_lang_works(${LANG})
+            endif()
+
+            # Should the MPI compiler not work implicitly for MPI, still interrogate it.
+            # Otherwise, MPI compilers for which CMake has separate linking stages, e.g. Intel MPI on Windows where link.exe is being used
+            # directly during linkage instead of CMAKE_<LANG>_COMPILER will not work.
+            if(NOT MPI_${LANG}_WORKS)
+              set(MPI_${LANG}_WORKS_IMPLICIT FALSE)
+              _MPI_interrogate_compiler(${LANG})
+            else()
+              set(MPI_${LANG}_WORKS_IMPLICIT TRUE)
+            endif()
+          elseif(MPI_${LANG}_COMPILER)
+            _MPI_interrogate_compiler(${LANG})
+          endif()
         endif()
-      else()
-        set(MPI_${LANG}_WRAPPER_FOUND FALSE)
-        set(MPI_PINNED_COMPILER FALSE)
-      endif()
 
-      if(NOT MPI_${LANG}_WRAPPER_FOUND AND NOT MPI_PINNED_COMPILER)
-        # For C++, we may use the settings for C. Should a given compiler wrapper for C++ not exist, but one for C does, we copy over the
-        # settings for C. An MPI distribution that is in this situation would be IBM Platform MPI.
-        if("${LANG}" STREQUAL "CXX" AND MPI_C_WRAPPER_FOUND)
-          set(MPI_${LANG}_COMPILE_OPTIONS          ${MPI_C_COMPILE_OPTIONS}     CACHE STRING "MPI ${LANG} compilation options"           )
-          set(MPI_${LANG}_COMPILE_DEFINITIONS      ${MPI_C_COMPILE_DEFINITIONS} CACHE STRING "MPI ${LANG} compilation definitions"       )
-          set(MPI_${LANG}_ADDITIONAL_INCLUDE_DIRS  ${MPI_C_INCLUDE_DIRS}        CACHE STRING "MPI ${LANG} additional include directories")
-          set(MPI_${LANG}_LINK_FLAGS               ${MPI_C_LINK_FLAGS}          CACHE STRING "MPI ${LANG} linker flags"                  )
-          set(MPI_${LANG}_LIB_NAMES                ${MPI_C_LIB_NAMES}           CACHE STRING "MPI ${LANG} libraries to link against"     )
-          set(MPI_${LANG}_WRAPPER_FOUND TRUE)
-        elseif(NOT MPI_SKIP_GUESSING)
-          _MPI_guess_settings(${LANG})
+        if(NOT MPI_SKIP_GUESSING AND NOT MPI_${LANG}_WRAPPER_FOUND AND NOT MPI_PINNED_COMPILER)
+          # For C++, we may use the settings for C. Should a given compiler wrapper for C++ not exist, but one for C does, we copy over the
+          # settings for C. An MPI distribution that is in this situation would be IBM Platform MPI.
+          if("${LANG}" STREQUAL "CXX" AND MPI_C_WRAPPER_FOUND)
+            set(MPI_${LANG}_COMPILE_OPTIONS          ${MPI_C_COMPILE_OPTIONS}     CACHE STRING "MPI ${LANG} compilation options"           )
+            set(MPI_${LANG}_COMPILE_DEFINITIONS      ${MPI_C_COMPILE_DEFINITIONS} CACHE STRING "MPI ${LANG} compilation definitions"       )
+            set(MPI_${LANG}_ADDITIONAL_INCLUDE_DIRS  ${MPI_C_INCLUDE_DIRS}        CACHE STRING "MPI ${LANG} additional include directories")
+            set(MPI_${LANG}_LINK_FLAGS               ${MPI_C_LINK_FLAGS}          CACHE STRING "MPI ${LANG} linker flags"                  )
+            set(MPI_${LANG}_LIB_NAMES                ${MPI_C_LIB_NAMES}           CACHE STRING "MPI ${LANG} libraries to link against"     )
+          else()
+            _MPI_guess_settings(${LANG})
+          endif()
         endif()
       endif()
     endif()
 
     _MPI_split_include_dirs(${LANG})
-    if(NOT MPI_${LANG}_COMPILER STREQUAL CMAKE_${LANG}_COMPILER)
-      _MPI_assemble_include_dirs(${LANG})
-      _MPI_assemble_libraries(${LANG})
-    endif()
+    _MPI_assemble_include_dirs(${LANG})
+    _MPI_assemble_libraries(${LANG})
+
     _MPI_adjust_compile_definitions(${LANG})
     # We always create imported targets even if they're empty
     _MPI_create_imported_target(${LANG})
@@ -1217,7 +1267,9 @@ foreach(LANG IN ITEMS C CXX Fortran)
     set(MPI_${LANG}_COMPILE_DEFINITIONS      "" CACHE STRING "MPI ${LANG} compilation definitions"       )
     set(MPI_${LANG}_ADDITIONAL_INCLUDE_DIRS  "" CACHE STRING "MPI ${LANG} additional include directories")
     set(MPI_${LANG}_LINK_FLAGS               "" CACHE STRING "MPI ${LANG} linker flags"                  )
-    set(MPI_${LANG}_LIB_NAMES                "" CACHE STRING "MPI ${LANG} libraries to link against"     )
+    if(NOT MPI_${LANG}_COMPILER STREQUAL CMAKE_${LANG}_COMPILER)
+      set(MPI_${LANG}_LIB_NAMES                "" CACHE STRING "MPI ${LANG} libraries to link against"   )
+    endif()
     mark_as_advanced(MPI_${LANG}_COMPILE_OPTIONS MPI_${LANG}_COMPILE_DEFINITIONS MPI_${LANG}_LINK_FLAGS
       MPI_${LANG}_LIB_NAMES MPI_${LANG}_ADDITIONAL_INCLUDE_DIRS MPI_${LANG}_COMPILER)
 
@@ -1337,7 +1389,7 @@ foreach(LANG IN ITEMS C CXX Fortran)
     set(MPI_${LANG}_FIND_VERSION_EXACT ${MPI_FIND_VERSION_EXACT})
 
     unset(MPI_${LANG}_REQUIRED_VARS)
-    if (MPI_${LANG}_WRAPPER_FOUND OR MPI_${LANG}_GUESS_FOUND)
+    if (NOT "${MPI_${LANG}_COMPILER}" STREQUAL "${CMAKE_${LANG}_COMPILER}")
       foreach(mpilibname IN LISTS MPI_${LANG}_LIB_NAMES)
         list(APPEND MPI_${LANG}_REQUIRED_VARS "MPI_${mpilibname}_LIBRARY")
       endforeach()
@@ -1448,6 +1500,7 @@ if (MPI_NUMLIBS GREATER 1)
 else()
   set(MPI_EXTRA_LIBRARY "MPI_EXTRA_LIBRARY-NOTFOUND")
 endif()
+set(MPI_IGNORE_LEGACY_VARIABLES TRUE)
 #=============================================================================
 
 # unset these vars to cleanup namespace