Find MPI quietly on second pass

GROMACS expects package detection to be quiet upon repeat calls
to cmake, unless something has actually changed. It's fine to report
details thoroughly the first time through, however.

The previous code seemed to conflate verbosity with enforcing
requirements, which is now clearer.

diff --git a/cmake/gmxManageMPI.cmake b/cmake/gmxManageMPI.cmake
index 5c7df21e4ec7110c0460a66df014fe8d5f7b5f0d..4572a630c846dadc4ed6b56fd3bda7694aee27e0 100644 (file)
--- a/cmake/gmxManageMPI.cmake
+++ b/cmake/gmxManageMPI.cmake
@@ -58,10 +58,15 @@ endif ()
 if (GMX_LIB_MPI AND GMX_CP2K)
     list(APPEND GMX_REQUIRED_MPI_COMPONENTS "Fortran")
 endif ()
-# We can perform the find_package quietly because we report errors elsewhere
-# when we can't find a required component, but the MPI target is optional
+# We don't require MPI components here because we report errors elsewhere
+# when we can't find a required component, and the MPI target is optional
 # in some build configurations (e.g. thread-MPI gmxapi installations).
-find_package(MPI QUIET COMPONENTS ${GMX_REQUIRED_MPI_COMPONENTS})
+if (MPI_ALREADY_SEARCHED)
+    set(MPI_FIND_QUIETLY ON)
+endif()
+find_package(MPI COMPONENTS ${GMX_REQUIRED_MPI_COMPONENTS})
+set(MPI_ALREADY_SEARCHED TRUE CACHE BOOL "True if a search for MPI has already been done")
+mark_as_advanced(MPI_ALREADY_SEARCHED)
 
 if (GMX_LIB_MPI)
     if (NOT MPI_CXX_FOUND)
@@ -110,7 +115,9 @@ if (GMX_LIB_MPI AND OPENMPI_VERSION)
                 "This OpenMPI version is known to leak memory with GROMACS,"
                 "please update to a more recent version. ")
     endif ()
-    MESSAGE(STATUS "GROMACS library will use OpenMPI ${OPENMPI_VERSION}")
+    if (NOT MPI_FIND_QUIETLY)
+        MESSAGE(STATUS "GROMACS library will use OpenMPI ${OPENMPI_VERSION}")
+    endif ()
 endif ()
 
 # Test for and warn about unsuitable MPVAPICH2 versions
@@ -124,7 +131,9 @@ if (GMX_LIB_MPI AND MVAPICH2_VERSION)
                 "Please consider updating your MVAPICH2 if your MPI wrapper compilers "
                 "are using the above MVAPICH2 version.")
     endif ()
-    MESSAGE(STATUS "GROMACS library will use MVAPICH2 ${MVAPICH2_VERSION}")
+    if (NOT MPI_FIND_QUIETLY)
+        MESSAGE(STATUS "GROMACS library will use MVAPICH2 ${MVAPICH2_VERSION}")
+    endif ()
 endif ()
 
 # Look for MPI process launchers that may be missed, especially if we didn't