Swift 5 Compatibility + Small Example App

Package.swift

@@ -1,3 +1,5 @@
+// swift-tools-version:5.0
+
 /*
  * This file is part of COpenMPI.
  *
@@ -18,9 +20,30 @@
 import PackageDescription
 
 let package = Package(
-    name: "COpenMPI",
-    pkgConfig: "ompi-c",
-    providers: [
-    	.Brew("open-mpi")
-    ]
+  name: "COpenMPI",
+  products: [
+    .library(
+      name: "COpenMPI",
+      targets: ["CMPI"]
+    ),
+    .executable(
+      name: "COpenMPI-Example",
+      targets: ["COpenMPI-Example"]
+    )
+  ],
+  targets: [
+    .systemLibrary(
+      name: "CMPI",
+      pkgConfig: "ompi-c",
+      providers: [
+        .brew(["open-mpi"])
+      ]
+    ),
+    .target(
+      name: "COpenMPI-Example",
+      dependencies: [
+        "CMPI"
+      ]
+    )
+  ]
 )

README.md

@@ -6,3 +6,12 @@ The package exports a single module, `CMPI`.
 Due to the use of function-like macros in `mpi.h`, a shim header that wraps these is required. `shim.h` creates inline functions for the constants and maps them to read-only global computed properties.
 
 A simple MPI program (à la '[Hello World](http://mpitutorial.com/tutorials/mpi-hello-world/)') appears to work correctly, but this has not been extensively tested. Feedback is requested!
+
+## Example
+
+An example of using the library is included. To clone and run the example run the following commands in Terminal.
+
+1. `git clone https://github.com/omor1/COpenMPI.git`
+2. `cd COpenMPI`
+3. `swift build -c release`
+4. `mpirun -c 2 .build/*/release/COpenMPI-Example`

Sources/COpenMPI-Example/main.swift

@@ -0,0 +1,62 @@
+/*
+ * This file is part of COpenMPI.
+ *
+ * COpenMPI is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * COpenMPI is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with COpenMPI.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+import CMPI
+
+var argc = CommandLine.argc
+var argv: UnsafeMutablePointer<UnsafeMutablePointer<Int8>?>? = CommandLine.unsafeArgv
+
+MPI_Init(&argc, &argv)
+
+var worldSize = Int32()
+MPI_Comm_size(MPI_COMM_WORLD, &worldSize)
+
+var worldRank = Int32()
+MPI_Comm_rank(MPI_COMM_WORLD, &worldRank)
+
+if (worldRank == 0) {
+  var majorVersion = Int32()
+  var minorVersion = Int32()
+
+  MPI_Get_version(&majorVersion, &minorVersion)
+
+  var cLibraryVersion = [CChar](repeating: 0, count: Int(MPI_MAX_LIBRARY_VERSION_STRING))
+  var libraryVersionResultLen = Int32()
+
+  MPI_Get_library_version(&cLibraryVersion, &libraryVersionResultLen)
+
+  let libraryVersion = withUnsafePointer(to: &cLibraryVersion[0]) {
+    return String(cString: $0)
+  }
+
+  print("MPI Version: \(majorVersion).\(minorVersion), \(libraryVersion)\n")
+}
+
+MPI_Barrier(MPI_COMM_WORLD)
+
+var cProcessorName = [CChar](repeating: 0, count: Int(MPI_MAX_PROCESSOR_NAME))
+var processorNameResultLen = Int32()
+
+MPI_Get_processor_name(&cProcessorName, &processorNameResultLen)
+
+let processorName = withUnsafePointer(to: &cProcessorName[0]) {
+  return String(cString: $0)
+}
+
+print("👋🗺  World Rank: \(worldRank), World Size: \(worldSize), Processor Name: \(processorName)")
+
+MPI_Finalize()