FindMPI: Add error logging

Modules/FindMPI.cmake

@@ -1155,7 +1155,7 @@ macro(_MPI_create_imported_target LANG)
   set_property(TARGET MPI::MPI_${LANG} PROPERTY INTERFACE_INCLUDE_DIRECTORIES "${MPI_${LANG}_INCLUDE_DIRS}")
 endmacro()
 
-function(_MPI_try_staged_settings LANG MPI_TEST_FILE_NAME MODE RUN_BINARY)
+function(_MPI_try_staged_settings LANG MPI_TEST_FILE_NAME MODE RUN_BINARY SUPPRESS_ERRORS)
   set(WORK_DIR "${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/FindMPI")
   set(SRC_DIR "${CMAKE_ROOT}/Modules/FindMPI")
   set(BIN_FILE "${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/FindMPI/${MPI_TEST_FILE_NAME}_${LANG}.bin")
@@ -1184,18 +1184,29 @@ function(_MPI_try_staged_settings LANG MPI_TEST_FILE_NAME MODE RUN_BINARY)
      "${CMAKE_BINARY_DIR}" SOURCES "${MPI_TEST_SOURCE_FILE}"
       COMPILE_DEFINITIONS ${MPI_TEST_COMPILE_DEFINITIONS}
       LINK_LIBRARIES MPI::MPI_${LANG}
-      RUN_OUTPUT_VARIABLE MPI_RUN_OUTPUT_${LANG}_${MPI_TEST_FILE_NAME}_${MODE})
+      RUN_OUTPUT_VARIABLE MPI_RUN_OUTPUT_${LANG}_${MPI_TEST_FILE_NAME}_${MODE}
+      COMPILE_OUTPUT_VARIABLE _MPI_TRY_${MPI_TEST_FILE_NAME}_${MODE}_OUTPUT)
     set(MPI_RUN_OUTPUT_${LANG}_${MPI_TEST_FILE_NAME}_${MODE} "${MPI_RUN_OUTPUT_${LANG}_${MPI_TEST_FILE_NAME}_${MODE}}" PARENT_SCOPE)
   else()
     try_compile(MPI_RESULT_${LANG}_${MPI_TEST_FILE_NAME}_${MODE}
       "${CMAKE_BINARY_DIR}" SOURCES "${MPI_TEST_SOURCE_FILE}"
       COMPILE_DEFINITIONS ${MPI_TEST_COMPILE_DEFINITIONS}
       LINK_LIBRARIES MPI::MPI_${LANG}
-      COPY_FILE "${BIN_FILE}")
+      COPY_FILE "${BIN_FILE}"
+      OUTPUT_VARIABLE _MPI_TRY_${MPI_TEST_FILE_NAME}_${MODE}_OUTPUT)
+  endif()
+  if(NOT SUPPRESS_ERRORS)
+    if(NOT MPI_RESULT_${LANG}_${MPI_TEST_FILE_NAME}_${MODE})
+      file(APPEND ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeError.log
+          "The MPI test ${MPI_TEST_FILE_NAME} for ${LANG} in mode ${MODE} failed to compile with the following output:\n${_MPI_TRY_${MPI_TEST_FILE_NAME}_${MODE}_OUTPUT}\n\n")
+    elseif(DEFINED MPI_RUN_RESULT_${LANG}_${MPI_TEST_FILE_NAME}_${MODE} AND MPI_RUN_RESULT_${LANG}_${MPI_TEST_FILE_NAME}_${MODE})
+        file(APPEND ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeError.log
+          "The MPI test ${MPI_TEST_FILE_NAME} for ${LANG} in mode ${MODE} failed to run with the following output:\n${MPI_RUN_OUTPUT_${LANG}_${MPI_TEST_FILE_NAME}_${MODE}}\n\n")
+    endif()
   endif()
 endfunction()
 
-macro(_MPI_check_lang_works LANG)
+macro(_MPI_check_lang_works LANG SUPPRESS_ERRORS)
   # For Fortran we may have by the MPI-3 standard an implementation that provides:
   #   - the mpi_f08 module
   #   - *both*, the mpi module and 'mpif.h'
@@ -1203,9 +1214,9 @@ macro(_MPI_check_lang_works LANG)
   if( NOT MPI_${LANG}_WORKS )
     if("${LANG}" STREQUAL "Fortran")
       set(MPI_Fortran_INTEGER_LINE "(kind=MPI_INTEGER_KIND)")
-      _MPI_try_staged_settings(${LANG} test_mpi F77_HEADER FALSE)
-      _MPI_try_staged_settings(${LANG} test_mpi F90_MODULE FALSE)
-      _MPI_try_staged_settings(${LANG} test_mpi F08_MODULE FALSE)
+      _MPI_try_staged_settings(${LANG} test_mpi F77_HEADER FALSE ${SUPPRESS_ERRORS})
+      _MPI_try_staged_settings(${LANG} test_mpi F90_MODULE FALSE ${SUPPRESS_ERRORS})
+      _MPI_try_staged_settings(${LANG} test_mpi F08_MODULE FALSE ${SUPPRESS_ERRORS})
 
       set(MPI_${LANG}_WORKS FALSE)
 
@@ -1221,14 +1232,14 @@ macro(_MPI_check_lang_works LANG)
       # However, MPI-1 also did not define the Fortran 90 and 08 modules, so we only try the F77 header.
       unset(MPI_Fortran_INTEGER_LINE)
       if(NOT MPI_${LANG}_WORKS)
-        _MPI_try_staged_settings(${LANG} test_mpi F77_HEADER_NOKIND FALSE)
+        _MPI_try_staged_settings(${LANG} test_mpi F77_HEADER_NOKIND FALSE ${SUPPRESS_ERRORS})
         if(MPI_RESULT_${LANG}_test_mpi_F77_HEADER_NOKIND)
           set(MPI_${LANG}_WORKS TRUE)
           set(MPI_${LANG}_HAVE_F77_HEADER TRUE)
         endif()
       endif()
     else()
-      _MPI_try_staged_settings(${LANG} test_mpi normal FALSE)
+      _MPI_try_staged_settings(${LANG} test_mpi normal FALSE ${SUPPRESS_ERRORS})
       # If 'test_mpi' built correctly, we've found valid MPI settings. There might not be MPI-2 C++ support, but there can't
       # be MPI-2 C++ support without the C bindings being present, so checking for them is sufficient.
       set(MPI_${LANG}_WORKS "${MPI_RESULT_${LANG}_test_mpi_normal}")
@@ -1390,7 +1401,7 @@ foreach(LANG IN ITEMS C CXX Fortran)
         # 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.
         _MPI_create_imported_target(${LANG})
-        _MPI_check_lang_works(${LANG})
+        _MPI_check_lang_works(${LANG} TRUE)
 
         # 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_${LANG}_WORKS)
@@ -1442,7 +1453,7 @@ foreach(LANG IN ITEMS C CXX Fortran)
             # If we haven't made the implicit compiler test yet, perform it now.
             if(NOT MPI_${LANG}_TRIED_IMPLICIT)
               _MPI_create_imported_target(${LANG})
-              _MPI_check_lang_works(${LANG})
+              _MPI_check_lang_works(${LANG} TRUE)
             endif()
 
             # Should the MPI compiler not work implicitly for MPI, still interrogate it.
@@ -1488,7 +1499,7 @@ foreach(LANG IN ITEMS C CXX Fortran)
     _MPI_create_imported_target(${LANG})
 
     if(NOT MPI_${LANG}_WORKS)
-      _MPI_check_lang_works(${LANG})
+      _MPI_check_lang_works(${LANG} FALSE)
     endif()
 
     # Next, we'll initialize the MPI variables that have not been previously set.
@@ -1507,7 +1518,7 @@ foreach(LANG IN ITEMS C CXX Fortran)
     if(MPI_${LANG}_WORKS)
       if("${LANG}" STREQUAL "CXX" AND NOT DEFINED MPI_MPICXX_FOUND)
         if(NOT MPI_CXX_SKIP_MPICXX AND NOT MPI_CXX_VALIDATE_SKIP_MPICXX)
-          _MPI_try_staged_settings(${LANG} test_mpi MPICXX FALSE)
+          _MPI_try_staged_settings(${LANG} test_mpi MPICXX FALSE FALSE)
           if(MPI_RESULT_${LANG}_test_mpi_MPICXX)
             set(MPI_MPICXX_FOUND TRUE)
           else()
@@ -1542,7 +1553,7 @@ foreach(LANG IN ITEMS C CXX Fortran)
         # and MPI_SUBVERSION are provided. These defines did not exist in MPI 1.0 and 1.1 and therefore might not
         # exist. For C/C++, test_mpi.c will handle the MPI_VERSION extraction, but for Fortran, we need mpiver.f90.
         if(NOT DEFINED MPI_${LANG}_VERSION)
-          _MPI_try_staged_settings(${LANG} mpiver ${MPI_${LANG}_HIGHEST_METHOD} FALSE)
+          _MPI_try_staged_settings(${LANG} mpiver ${MPI_${LANG}_HIGHEST_METHOD} FALSE FALSE)
           if(MPI_RESULT_${LANG}_mpiver_${MPI_${LANG}_HIGHEST_METHOD})
             file(STRINGS ${MPI_BIN_FOLDER}/mpiver_${LANG}.bin _MPI_VERSION_STRING LIMIT_COUNT 1 REGEX "INFO:MPI-VER")
             if("${_MPI_VERSION_STRING}" MATCHES ".*INFO:MPI-VER\\[([0-9]+)\\.([0-9]+)\\].*")
@@ -1561,7 +1572,7 @@ foreach(LANG IN ITEMS C CXX Fortran)
             if(MPI_${LANG}_HAVE_${mpimethod})
               set(MPI_${LANG}_${mpimethod}_SUBARRAYS FALSE)
               set(MPI_${LANG}_${mpimethod}_ASYNCPROT FALSE)
-              _MPI_try_staged_settings(${LANG} fortranparam_mpi ${mpimethod} TRUE)
+              _MPI_try_staged_settings(${LANG} fortranparam_mpi ${mpimethod} TRUE FALSE)
               if(MPI_RESULT_${LANG}_fortranparam_mpi_${mpimethod} AND
                 NOT "${MPI_RUN_RESULT_${LANG}_fortranparam_mpi_${mpimethod}}" STREQUAL "FAILED_TO_RUN")
                 if("${MPI_RUN_OUTPUT_${LANG}_fortranparam_mpi_${mpimethod}}" MATCHES
@@ -1602,7 +1613,7 @@ foreach(LANG IN ITEMS C CXX Fortran)
       # It's also worth noting that the installed version string can depend on the language, or on the system the binary
       # runs on if MPI is not statically linked.
       if(MPI_DETERMINE_LIBRARY_VERSION AND NOT MPI_${LANG}_LIBRARY_VERSION_STRING)
-        _MPI_try_staged_settings(${LANG} libver_mpi ${MPI_${LANG}_HIGHEST_METHOD} TRUE)
+        _MPI_try_staged_settings(${LANG} libver_mpi ${MPI_${LANG}_HIGHEST_METHOD} TRUE FALSE)
         if(MPI_RESULT_${LANG}_libver_mpi_${MPI_${LANG}_HIGHEST_METHOD} AND
           "${MPI_RUN_RESULT_${LANG}_libver_mpi_${MPI_${LANG}_HIGHEST_METHOD}}" EQUAL "0")
           string(STRIP "${MPI_RUN_OUTPUT_${LANG}_libver_mpi_${MPI_${LANG}_HIGHEST_METHOD}}"