Improve build process

- search for libmpich if libmpi isn't found
- run gen_consts under mpi launcher

Author: simonbyrne

deps/.gitignore

@@ -1,4 +1,5 @@
 deps.jl
+consts.jl
 build.log
 gen_consts.c
 gen_consts

deps/build.jl

@@ -15,18 +15,34 @@ mpicc = get(ENV, "JULIA_MPICC") do
     end
 end
 
-mpiexec = get(ENV, "JULIA_MPIEXEC") do
-    if MPI_PATH !== nothing
+const mpiexec = get(ENV, "JULIA_MPIEXEC") do
+    if MPI_PATH !== nothing && Sys.isexecutable(joinpath(MPI_PATH,"bin","mpiexec"))
         joinpath(MPI_PATH,"bin","mpiexec")
     else
-        "mpiexec"
+        Sys.which("mpiexec")
+    end
+end
+
+const libmpi = get(ENV, "JULIA_MPI_LIBRARY") do
+    libmpi = find_library(["libmpi", "msmpi", "libmpich"],
+                 MPI_LIBRARY_PATH !== nothing ? [MPI_LIBRARY_PATH] : [])
+    try
+        # expand paths
+        dlpath(libmpi)
+    catch e
+        error("No MPI library found.\nEnsure an MPI implementation is loaded, or set the `JULIA_MPI_PATH` variable.")
     end
 end
 
+
 if haskey(ENV, "JULIA_MPI_CFLAGS")
     CFLAGS = split(ENV["JULIA_MPI_CFLAGS"])
 else
-    CFLAGS = ["-lmpi"]
+    lname, = split(basename(libmpi),'.')
+    if startswith(lname, "lib")
+        lname = lname[4:end]
+    end
+    CFLAGS = ["-l$lname"]
     if MPI_LIBRARY_PATH !== nothing
         push!(CFLAGS, "-L$(MPI_LIBRARY_PATH)")
     end
@@ -35,19 +51,8 @@ else
     end
 end
 
-const libmpi = find_library(Sys.iswindows() ? "msmpi.dll" : "libmpi",
-                            MPI_LIBRARY_PATH !== nothing ? [MPI_LIBRARY_PATH] : [])
-
-if libmpi == ""
-    error("No MPI library found.\nEnsure an MPI implementation is loaded, or set the `JULIA_MPI_PATH` variable.")
-end
-
-# expand paths
-libmpi = dlpath(libmpi)
 libsize = filesize(libmpi)
 
-mpiexec = Sys.which(mpiexec)
-
 @info "Using MPI library $libmpi"
 
 function Get_version()
@@ -74,18 +79,15 @@ open("deps.jl","w") do f
     println(f, :(const libmpi_size = $libsize))
     println(f, :(const MPI_VERSION = $MPI_VERSION))
     println(f, :(const mpiexec = $mpiexec))
-end
 
-if Sys.iswindows()
-    open("deps.jl","a") do f
+    if Sys.iswindows()
         println(f, :(include("consts_msmpi.jl")))
-    end
-else
-    include("gen_consts.jl")
+    else
+        include("gen_consts.jl")
 
-    run(`$mpicc gen_consts.c -o gen_consts $CFLAGS`)
+        run(`$mpicc gen_consts.c -o gen_consts $CFLAGS`)
+        run(`$mpiexec -n 1 ./gen_consts`)
 
-    open("deps.jl","a") do f
-        run(pipeline(`./gen_consts`, stdout = f))
+        println(f, :(include("consts.jl")))
     end
 end

deps/gen_consts.jl

@@ -117,44 +117,50 @@ open("gen_consts.c","w") do f
 int main(int argc, char *argv[]) {
     MPI_Init(&argc, &argv);
 
+    FILE *fptr;
+    fptr = fopen("consts.jl", "w");
+
+    fprintf(fptr, "# This file is automatically generated\\n");
+    fprintf(fptr, "# Do not edit\\n");
 """)
 
-    println(f,"  printf(\"const MPI_Status_size = %d\\n\", (int)sizeof(MPI_Status));")
-    println(f,"  printf(\"const MPI_Status_Source_offset = %d\\n\", (int)offsetof(MPI_Status, MPI_SOURCE));")
-    println(f,"  printf(\"const MPI_Status_Tag_offset = %d\\n\", (int)offsetof(MPI_Status, MPI_TAG));")
-    println(f,"  printf(\"const MPI_Status_Error_offset = %d\\n\", (int)offsetof(MPI_Status, MPI_ERROR));")
+    println(f,"  fprintf(fptr, \"const MPI_Status_size = %d\\n\", (int)sizeof(MPI_Status));")
+    println(f,"  fprintf(fptr, \"const MPI_Status_Source_offset = %d\\n\", (int)offsetof(MPI_Status, MPI_SOURCE));")
+    println(f,"  fprintf(fptr, \"const MPI_Status_Tag_offset = %d\\n\", (int)offsetof(MPI_Status, MPI_TAG));")
+    println(f,"  fprintf(fptr, \"const MPI_Status_Error_offset = %d\\n\", (int)offsetof(MPI_Status, MPI_ERROR));")
 
     for (T,constants) in MPI_handle
-        println(f,"  printf(\"primitive type $T %d end\\n\", (int)(sizeof($T) * 8));")
+        println(f,"  fprintf(fptr, \"primitive type $T %d end\\n\", (int)(sizeof($T) * 8));")
 
         T_f2c = T == :MPI_Datatype ? :MPI_Type_f2c : Symbol(T, :_f2c)
         T_c2f = T == :MPI_Datatype ? :MPI_Type_c2f : Symbol(T, :_c2f)
         if Libdl.dlsym_e(libptr, T_f2c) == C_NULL
-            println(f,"  printf(\"$T(c::Cint) = reinterpret($T,c)\\n\");")
+            println(f,"  fprintf(fptr, \"$T(c::Cint) = reinterpret($T,c)\\n\");")
             for constant in constants
-                println(f,"  printf(\"const $constant = Cint(%i)\\n\", $constant);")
+                println(f,"  fprintf(fptr, \"const $constant = Cint(%i)\\n\", $constant);")
             end
         else
-            println(f,"  printf(\"$T(c::Cint) = ccall((:$T_f2c,libmpi),$T,(Cint,),c)\\n\");")
+            println(f,"  fprintf(fptr, \"$T(c::Cint) = ccall((:$T_f2c,libmpi),$T,(Cint,),c)\\n\");")
             for constant in constants
-                println(f,"  printf(\"const $constant = Cint(%i)\\n\", $T_c2f($constant));")
+                println(f,"  fprintf(fptr, \"const $constant = Cint(%i)\\n\", $T_c2f($constant));")
             end
         end
     end
 
     for constant in MPI_Cints
-        println(f,"  printf(\"const $constant = Cint(%i)\\n\", (int)($constant));")
+        println(f,"  fprintf(fptr, \"const $constant = Cint(%i)\\n\", (int)($constant));")
     end
 
     for constant in MPI_pointers
         if Sys.WORD_SIZE == 32
-            println(f,"  printf(\"const $constant = reinterpret(SentinelPtr, 0x%08\" PRIx32 \")\\n\", (uint32_t)($constant));")
+            println(f,"  fprintf(fptr, \"const $constant = reinterpret(SentinelPtr, 0x%08\" PRIx32 \")\\n\", (uint32_t)($constant));")
         else
-            println(f,"  printf(\"const $constant = reinterpret(SentinelPtr, 0x%016\" PRIx64 \")\\n\", (uint64_t)($constant));")
+            println(f,"  fprintf(fptr, \"const $constant = reinterpret(SentinelPtr, 0x%016\" PRIx64 \")\\n\", (uint64_t)($constant));")
         end
     end
 
     print(f,"""
+  fclose(fptr);
   MPI_Finalize();
   return 0;
 }

docs/src/installation.md

@@ -27,6 +27,7 @@ The build script will attempt to find the shared library and constants: this can
 controlled with the optional environment variables:
 
 - `JULIA_MPI_PATH`: the top-level installation directory of MPI.
+- `JULIA_MPI_LIBRARY`: the path of the MPI shared library.
 - `JULIA_MPI_LIBRARY_PATH`: the directory containing the MPI library files.
 - `JULIA_MPI_INCLUDE_PATH`: the directory containing the MPI header files.
 - `JULIA_MPI_CFLAGS`: C flags passed to the constant generation build (default: `-lmpi`)