[OCCA] Add OCCA as git submodule (#72)

* [OCCA] Add OCCA as a git submodule

* [OCCA] Revert to slightly older OCCA for now

* [Make] Hook internal OCCA into build system

* Update README

* [CI] Update github CI workflow

* [CI] Need to tell github actions to checkout submodules

.github/workflows/build.yml

@@ -13,26 +13,18 @@ jobs:
 
     steps:
     - uses: actions/checkout@v2
+      with:
+        submodules: true
     - name: Install Dependencies
       run: |
           sudo apt install -y libopenmpi-dev openmpi-bin libblas-dev liblapack-dev
-          git clone https://github.com/libocca/occa
-          cd occa
-          make -j `nproc`
-          cd ..
     - name: Build
       run: make -j `nproc` verbose=true
       env:
-        OCCA_DIR: /home/runner/work/libparanumal/libparanumal/occa/
-        LD_LIBRARY_PATH: /home/runner/work/libparanumal/libparanumal/occa/lib
         LIBP_COVERAGE: 1
     - name: Test
       run: |
-        echo ${LD_LIBRARY_PATH}
-        ls ${OCCA_DIR}/lib
-        make test  LIBP_COVERAGE=1
+        make test
         bash <(curl --no-buffer -s https://codecov.io/bash) -x gcov
       env:
-        OCCA_DIR: /home/runner/work/libparanumal/libparanumal/occa/
-        LD_LIBRARY_PATH: /home/runner/work/libparanumal/libparanumal/occa/lib
         LIBP_COVERAGE: 1

.gitmodules

@@ -0,0 +1,3 @@
+[submodule "occa"]
+	path = occa
+	url = https://github.com/libocca/occa

README.md

@@ -93,13 +93,9 @@ G. Dependencies:
 
 ---
 ### 5. OCCA dependency
-`git clone https://github.com/libocca/occa`
-
-#### 5-1. Build OCCA
-`cd occa`
-`export OCCA_DIR=${PWD}`
-```make -j `nproc` ```
-`cd ../  `
+OCCA is held as a git submodule inside libParanumal. If you did not clone with `--recursive` then run the following command before building.
+`git submodule init`
+`git submodule update`
 
 ---
 ### 6. Required Libraries
@@ -127,7 +123,7 @@ Each solver resides in its respective sub-directory in `solvers/`. Each solver s
 #### 8-1. Build libParanumal elliptic solver
 
 `cd libparanumal/solvers/elliptic`
-`make -j  `
+```make -j `nproc` ```
 
 #### 8-2. Run elliptic example with provided quadrilateral set up file on a single device:
 

libs/makefile

@@ -231,8 +231,11 @@ silentUpdate-parAlmond:
 silentUpdate-timeStepper:
 	@true
 
+${OCCA_DIR}/lib/libocca.so:
+	${MAKE} -C ${OCCA_DIR}
+
 # rule for .cpp files
-core/%.o: core/%.cpp $(LIB_DEPS)
+core/%.o: core/%.cpp $(LIB_DEPS) ${OCCA_DIR}/lib/libocca.so
 ifneq (,${verbose})
 	$(LIBP_MPICXX) -o $@ -c $< ${LIBCORE_DEFINES} $(LIB_CXXFLAGS)
 else

make.top

@@ -42,9 +42,7 @@ export LIBP_BLAS_LIB  =-L${LIBP_BLAS_DIR} -lblas
 export LIBP_LAPACK_LIB=-L${LIBP_LAPACK_DIR} -llapack
 
 #include OCCA
-ifndef OCCA_DIR
-  $(error environment variable [OCCA_DIR] is not set)
-endif
+export OCCA_DIR=${LIBP_DIR}/occa
 
 #compilers to use for C/C++
 export LIBP_MPICC = mpicc