[cmake-developers] FindMPI with intel MPI wrappers

[Dominic Meiser]

Hi,

I've been having trouble with the detection of the MPI libraries
when using intel's MPI compiler wrappers.  The issue is that

- The wrappers use /LIBPATH: instead of -L to specify the library
  search path
- The wrappers link against static versions of the mpi libraries
  without using -l.

I'm attaching a couple of patches to deal with this.  Are patches
to the mailing list still the recommended way to submit changes?
Or are pull requests on github preferred?

Cheers,
Dominic


-- 
Dominic Meiser
Tech-X Corporation - 5621 Arapahoe Avenue - Boulder, CO 80303
-------------- next part --------------
>From 879532ce66d87d9733e0edca9d54d95823880dff Mon Sep 17 00:00:00 2001
From: Dominic Meiser <dmeiser79 at gmail.com>
Date: Thu, 14 Apr 2016 11:01:43 -0600
Subject: [PATCH 1/2] Accept /LIBPATH for  specification of linker paths.

The intel MPI wrappers use this form of -L to specify library locations.
---
 Modules/FindMPI.cmake | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/Modules/FindMPI.cmake b/Modules/FindMPI.cmake
index 0e406e0..0bf5549 100644
--- a/Modules/FindMPI.cmake
+++ b/Modules/FindMPI.cmake
@@ -357,10 +357,11 @@ function (interrogate_mpi_compiler lang try_libs)
         endif()
 
         # Extract linker paths from the link command line
-        string(REGEX MATCHALL "(^| |-Wl,)-L([^\" ]+|\"[^\"]+\")" MPI_ALL_LINK_PATHS "${MPI_LINK_CMDLINE}")
+        string(REGEX MATCHALL "(^| |-Wl,)(-L|/LIBPATH:)([^\" ]+|\"[^\"]+\")" MPI_ALL_LINK_PATHS "${MPI_LINK_CMDLINE}")
         set(MPI_LINK_PATH)
         foreach(LPATH ${MPI_ALL_LINK_PATHS})
           string(REGEX REPLACE "^(| |-Wl,)-L" "" LPATH ${LPATH})
+          string(REGEX REPLACE "/LIBPATH:" "" LPATH ${LPATH})
           string(REPLACE "//" "/" LPATH ${LPATH})
           list(APPEND MPI_LINK_PATH ${LPATH})
         endforeach()
-- 
2.6.2.450.g259b5e6

-------------- next part --------------
>From 62a9bf47f07b5853a7c857545f243844ab3b5ca6 Mon Sep 17 00:00:00 2001
From: Dominic Meiser <dmeiser79 at gmail.com>
Date: Thu, 14 Apr 2016 11:03:21 -0600
Subject: [PATCH 2/2] Fix for static MPI libraries.

The intel MPI compiler wrappers link against static MPI libraries simply
by listing the libraries (no `-l`).
---
 Modules/FindMPI.cmake | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/Modules/FindMPI.cmake b/Modules/FindMPI.cmake
index 0bf5549..fd9cc19 100644
--- a/Modules/FindMPI.cmake
+++ b/Modules/FindMPI.cmake
@@ -386,6 +386,13 @@ function (interrogate_mpi_compiler lang try_libs)
         # Extract the set of libraries to link against from the link command
         # line
         string(REGEX MATCHALL "(^| )-l([^\" ]+|\"[^\"]+\")" MPI_LIBNAMES "${MPI_LINK_CMDLINE}")
+        if(WIN32)
+          # The intel wrappers on windows link against static versions of the MPI libraries.
+          # The static libraries are simply listed on the command line without -l.
+          # For instance: " icl ... impi.lib "
+          string(REGEX MATCHALL "(^| )([^\" ]+)\\.lib" tmp "${MPI_LINK_CMDLINE}")
+          list(APPEND MPI_LIBNAMES ${tmp})
+        endif()
 
         # add the compiler implicit directories because some compilers
         # such as the intel compiler have libraries that show up
@@ -400,6 +407,10 @@ function (interrogate_mpi_compiler lang try_libs)
         # to link against in an MPI program
         foreach(LIB ${MPI_LIBNAMES})
           string(REGEX REPLACE "^ ?-l" "" LIB ${LIB})
+          if(WIN32)
+            string(REGEX REPLACE "\\.lib$" "" LIB ${LIB})
+          endif()
+          string(STRIP ${LIB} LIB)
           # MPI_LIB is cached by find_library, but we don't want that.  Clear it first.
           set(MPI_LIB "MPI_LIB-NOTFOUND" CACHE FILEPATH "Cleared" FORCE)
           find_library(MPI_LIB NAMES ${LIB} HINTS ${MPI_LINK_PATH})
-- 
2.6.2.450.g259b5e6