use ccache correctly

.github/workflows/ci.yml

@@ -64,20 +64,10 @@ jobs:
         sudo ln -s /usr/lib/x86_64-linux-gnu/libscalapack-openmpi.so /usr/lib/x86_64-linux-gnu/libscalapack.so
         echo "MPIEXEC=/usr/bin/mpiexec" >> $GITHUB_ENV
 
-    - name: Prepare ccache timestamp
-      id: ccache_cache_timestamp
-      shell: cmake -P {0}
-      run: |
-        string(TIMESTAMP current_date "%Y-%m-%d-%H;%M;%S" UTC)
-        message("::set-output name=timestamp::${current_date}")
-
-    - name: Setup ccache cache files
-      uses: actions/cache@v1.1.0
+    - name: Setup ccache
+      uses: hendrikmuhs/ccache-action@v1.2
       with:
-        path: ${{github.workspace}}/build/.ccache
-        key: ${{ matrix.config.name }}-ccache-${{ steps.ccache_cache_timestamp.outputs.timestamp }}
-        restore-keys: |
-          ${{ matrix.config.name }}-ccache-
+        key: ccache-${{ matrix.os }}-${{ matrix.build_type }}-${{ matrix.task_backend }}
 
     - name: "Configure build: ${{ env.BUILD_CONFIG }}"
       shell: bash

CMakeLists.txt

@@ -299,6 +299,16 @@ include_directories(${PROJECT_SOURCE_DIR}/src ${PROJECT_BINARY_DIR}/src)
 ##########################
 add_custom_target(External-tiledarray)
 
+# ccache is an optional dep but must be found first so that the rest of dependencies can use it
+find_program(CCACHE ccache)
+if(CCACHE)
+  mark_as_advanced(CCACHE)
+  message (STATUS "Found ccache: ${CCACHE}")
+  set(CMAKE_CXX_COMPILER_LAUNCHER "${CCACHE}" CACHE STRING "Compiler launcher to use for compiling C++")
+  set(CMAKE_C_COMPILER_LAUNCHER "${CCACHE}" CACHE STRING "Compiler launcher to use for compiling C")
+  set(CMAKE_CUDA_COMPILER_LAUNCHER "${CCACHE}" CACHE STRING "Compiler launcher to use for compiling CUDA")
+endif(CCACHE)
+
 # required deps:
 # 1. derive runtime (CUDA/HIP/...) first since others may depend on it
 if(ENABLE_CUDA)
@@ -336,15 +346,7 @@ if(ENABLE_SCALAPACK)
   include(external/scalapackpp.cmake)
 endif()
 
-# optional deps:
-# 1. ccache
-find_program(CCACHE ccache)
-if(CCACHE)
-    mark_as_advanced(CCACHE)
-    message (STATUS "Found ccache: ${CCACHE}")
-    set(CMAKE_CXX_COMPILER_LAUNCHER "${CCACHE}" CACHE STRING "Compiler launcher to use for compiling C++")
-    set(CMAKE_C_COMPILER_LAUNCHER "${CCACHE}" CACHE STRING "Compiler launcher to use for compiling C")
-endif(CCACHE)
+# other optional deps:
 # 2. TTG
 # N.B. make sure TA configures MADNESS correctly
 #if (TA_TTG)

external/librett.cmake

@@ -98,6 +98,13 @@ else()
             "-DCMAKE_TOOLCHAIN_FILE=${CMAKE_TOOLCHAIN_FILE}")
     endif(CMAKE_TOOLCHAIN_FILE)
 
+    foreach(lang C CXX CUDA)
+        if (DEFINED CMAKE_${lang}_COMPILER_LAUNCHER)
+            list(APPEND LIBRETT_CMAKE_ARGS
+                    "-DCMAKE_${lang}_COMPILER_LAUNCHER=${CMAKE_${lang}_COMPILER_LAUNCHER}")
+        endif()
+    endforeach()
+
     if (BUILD_SHARED_LIBS)
         set(LIBRETT_DEFAULT_LIBRARY_SUFFIX ${CMAKE_SHARED_LIBRARY_SUFFIX})
     else(BUILD_SHARED_LIBS)

external/umpire.cmake

@@ -152,6 +152,13 @@ else()
             )
     endif(CMAKE_TOOLCHAIN_FILE)
 
+    foreach(lang C CXX CUDA)
+        if (DEFINED CMAKE_${lang}_COMPILER_LAUNCHER)
+            list(APPEND UMPIRE_CMAKE_ARGS
+                    "-DCMAKE_${lang}_COMPILER_LAUNCHER=${CMAKE_${lang}_COMPILER_LAUNCHER}")
+        endif()
+    endforeach()
+
     if (BUILD_SHARED_LIBS)
         set(UMPIRE_DEFAULT_LIBRARY_SUFFIX ${CMAKE_SHARED_LIBRARY_SUFFIX})
     else(BUILD_SHARED_LIBS)