From 7ce8274c1f5638df490c64cdef2e351437a03c25 Mon Sep 17 00:00:00 2001
From: Adrien Cotte <adrien@cotte.com>
Date: Sat, 30 Apr 2022 09:19:00 +0200
Subject: [PATCH] Remove Open MPI dependency

Testing still requires OPENMPI_ROOT, add a note.
Slightly modify user guide to document this new behaviour,
and other <MPI_STACK>_ROOT variables.
---
 CMakeLists.txt            | 26 --------------------------
 README.md                 |  1 -
 Testing/etc/mpivars.sh.in |  6 ++++++
 docs/Users_guide          | 16 +++++++++++-----
 etc/wi4mpi.cfg.in         |  8 ++++----
 5 files changed, 21 insertions(+), 36 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 1a91854..ce60e01 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -124,31 +124,6 @@ endif()
 
 set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -fcommon")
 
-find_package(MPI REQUIRED) 
-if(MPI_C_FOUND AND MPI_Fortran_FOUND) #Need to be OpenMPI
-  if(NOT DEFINED OPENMPI_ROOT)
-    execute_process(COMMAND "${MPI_C_COMPILER}" --showme:version
-                    OUTPUT_VARIABLE ERR_VAR1
-                    OUTPUT_FILE "compiler_version"
-                    ERROR_QUIET)
-    execute_process(COMMAND "grep" -i "Open MPI"
-                    INPUT_FILE "compiler_version"
-                    OUTPUT_VARIABLE ERR_VAR2
-                    RESULT_VARIABLE COMMAND_RESULT1
-                    ERROR_QUIET)
-    message(STATUS "res command : ${ERR_VAR2}")
-    if(NOT ERR_VAR2)
-      message(FATAL_ERROR "Be sure to have an OpenMPI librarie in your PATH or set -DOPENMPI_ROOT=...")
-    endif()
-    foreach(p ${MPI_C_INCLUDE_PATH})
-      get_filename_component(OPENMPI_ROOT_TEST ${p} DIRECTORY)
-      if(EXISTS "${OPENMPI_ROOT_TEST}/lib")
-        set(OPENMPI_ROOT ${OPENMPI_ROOT_TEST})
-      endif ()
-    endforeach(p) 
-  endif()
-endif()
-
 find_package(Threads)
 if(NOT CMAKE_THREAD_LIBS_INIT)
     message(FATAL_ERROR "Be sure to have Pthread available on you system")
@@ -157,7 +132,6 @@ endif()
 #Setting wi4mpi.cfg
 CONFIGURE_FILE(${CMAKE_CURRENT_SOURCE_DIR}/etc/wi4mpi.cfg.in ${CMAKE_CURRENT_BINARY_DIR}/wi4mpi.cfg)
 
-
 #Source subdirectory
 add_subdirectory(src)
 enable_testing ()
diff --git a/README.md b/README.md
index afcc287..2c705dc 100644
--- a/README.md
+++ b/README.md
@@ -15,7 +15,6 @@ Interface :
 ### Prerequisites
 
 * C and Fortran compiler
-* [OpenMPI](https://www.open-mpi.org/)
 
 WI4MPI has been tested on GNU/Linux only
 
diff --git a/Testing/etc/mpivars.sh.in b/Testing/etc/mpivars.sh.in
index 2c2d2be..fbf2810 100644
--- a/Testing/etc/mpivars.sh.in
+++ b/Testing/etc/mpivars.sh.in
@@ -1,3 +1,9 @@
+# For now, testing requires cmake -DOPENMPI_ROOT=/path/to/ompi/
+if [[ ! -n "@OPENMPI_ROOT@" ]]; then
+    echo "Error: tests require 'cmake -DOPENMPI_ROOT=/path/to/ompi/' option!"
+    exit 1
+fi
+
 # Batch scheduler configuration to running tests
 export WI4MPI_MPRUN=@WI4MPI_MPRUN@
 export WI4MPI_PARTITION=@WI4MPI_PARTITION@
diff --git a/docs/Users_guide b/docs/Users_guide
index 791272e..83f827e 100644
--- a/docs/Users_guide
+++ b/docs/Users_guide
@@ -83,11 +83,17 @@ WI4MPI specific variables
     Possible options: INTEL(default), GNU, PGI, LLVM, ARMCLANG, FUJITSU
 
 - OPENMPI_ROOT
-    If CMAKE is not able to find OPENMPI_ROOT, one must add -DOPENMPI_ROOT=/path/to/openmpi option.
-    ```
-    CMake Error at CMakeLists.txt:xxx (message):
-    Be sure to have an OpenMPI librarie in your PATH or set -DOPENMPI_ROOT=...
-    ```
+    Open MPI root dir, put in wi4mpi.cfg, could be added manually, optionnal value.
+    This variable is required for Testing, one must add -DOPENMPI_ROOT=/path/to/openmpi option.
+
+- INTELMPI_ROOT
+    Intel MPI root dir, put in wi4mpi.cfg, could be added manually, optionnal value.
+
+- MPC_ROOT
+    MPC root dir, put in wi4mpi.cfg, could be added manually, optionnal value.
+
+- MPICH_ROOT
+    MPICH root dir, put in wi4mpi.cfg, could be added manually, optionnal value.
 
 - WI4MPI_REALEASE
 
diff --git a/etc/wi4mpi.cfg.in b/etc/wi4mpi.cfg.in
index fb00913..1892b8c 100644
--- a/etc/wi4mpi.cfg.in
+++ b/etc/wi4mpi.cfg.in
@@ -1,7 +1,7 @@
 #This part is handled by cmake
 WI4MPI_VERSION="@WI4MPI_VERSION@"
-OPENMPI_DEFAULT_ROOT="@OPENMPI_ROOT@"
 #Please provide the following variables to use the launcher
-INTELMPI_DEFAULT_ROOT=""
-MPC_DEFAULT_ROOT=""
-MPICH_DEFAULT_ROOT=""
+OPENMPI_DEFAULT_ROOT="@OPENMPI_ROOT@"
+INTELMPI_DEFAULT_ROOT="@INTELMPI_ROOT@"
+MPC_DEFAULT_ROOT="@MPC_ROOT@"
+MPICH_DEFAULT_ROOT="@MPICH_ROOT@"