Improving multi-backend support

README.md

@@ -30,9 +30,15 @@ source" style build to make it easy to clean up. We build in to a
 
 $ mkdir build
 $ cd build
-$ cmake ../src
+$ cmake [-DPLATFORM=<backend>] ../src
 $ make
 
+The PLATFORM argument to cmake specifies which backend source code should
+configured for the build and the value must correspond to a subdirectory
+in "gbtl/src/graphblas/system/" and that subdirectory must have a
+"backend_include.hpp" file.  If this argument is omitted it defaults to
+configuring the "sequential" backend.
+
 Using "make -i -j8" tries to build every test (ignoring all erros) and
 uses all eight the CPU's cores to speed up the build (use a number
 appropriate for your system).

src/CMakeLists.txt

@@ -14,16 +14,31 @@
 
 cmake_minimum_required(VERSION 2.8)
 
-project(SPIRALGRAPH)
-
-# https://stackoverflow.com/questions/14306642/adding-multiple-executables-in-cmake
+project(GRAPHBLAS_TEMPLATE_LIBRARY_2)
 
 # For debugging
-#message("CMake SRC: ${CMAKE_SOURCE_DIR}")
-#message("Project Name: ${PROJECT_NAME}")
-#message("Bin Directory: ${CMAKE_BINARY_DIR}")
-#message("Project Name: ${CMAKE_SOURCE_DIR}")
-#message("PProject Bin Directory: ${PROJECT_BINARY_DIR}")
+message("CMake SRC: ${CMAKE_SOURCE_DIR}")
+message("Project Name: ${PROJECT_NAME}")
+message("Bin Directory: ${CMAKE_BINARY_DIR}")
+message("Project Name: ${CMAKE_SOURCE_DIR}")
+message("Project Bin Directory: ${PROJECT_BINARY_DIR}")
+
+# Default platform is sequential
+if (NOT PLATFORM)
+  set(PLATFORM sequential)
+endif()
+
+message("Configuring platform: ${PLATFORM}")
+
+if (EXISTS ${CMAKE_SOURCE_DIR}/graphblas/system/${PLATFORM})
+    file(COPY ${CMAKE_SOURCE_DIR}/graphblas/system/${PLATFORM}/backend_include.hpp DESTINATION ${CMAKE_SOURCE_DIR}/graphblas)
+else()
+    message(FATAL_ERROR "Backend directory does not exist: ${PLATFORM}")
+endif()
+
+unset($PLATFORM)
+
+# https://stackoverflow.com/questions/14306642/adding-multiple-executables-in-cmake
 
 # This seems hokey that we need to include the root as our directory
 include_directories(${CMAKE_SOURCE_DIR})

src/graphblas/system/README_backend.txt

@@ -0,0 +1,18 @@
+Each subdirectory in this (system) directory, contains the backend code for
+one platform.  The name of the subdirectory is the name of the platform used
+when configuring the build.  Note that only one backend can be configured and
+compiled at a time.
+
+Each backend should copy backend_include_temp.hpp into the backend directory,
+rename it "backend_include.hpp", and modify the contents to point to a set of
+header files within the backend directory:
+  <backend name>.hpp  - that includes all of the other backend header files
+  Matrix.hpp
+  Vector.hpp
+  utility.hpp
+  TransposeView.hpp
+  ComplementView.hpp
+  operations.hpp
+
+This backend_include.hpp file is copied to the frontend during cmake build
+configuration.