CMake: Mark ELPA_DIR as deprecated (#7630)

* CMake: Find ELPA through pkg-config module

* Adjust document and toolchain scripts accordingly

* Adjust cmake/CollectBuildInfoVars.cmake

* Include pkg-config in GH workflow

* Keep ELPA_DIR but mark as deprecated

Author: Growl1234

.github/workflows/ase_plugin_test.yml

@@ -39,7 +39,7 @@ jobs:
 
       - name: Install external tools from toolchain
         run: |
-          sudo apt update && sudo apt install -y xz-utils ninja-build
+          sudo apt update && sudo apt install -y xz-utils ninja-build pkg-config
           cd toolchain
           ./install_abacus_toolchain_new.sh --with-dftd4=install --dry-run -j8
           ./scripts/stage4/install_stage4.sh

.github/workflows/build_test_cmake.yml

@@ -61,7 +61,7 @@ jobs:
 
       - name: Install external tools from toolchain
         run: |
-          sudo apt update && sudo apt install -y gfortran ninja-build xz-utils
+          sudo apt update && sudo apt install -y gfortran ninja-build pkg-config xz-utils
           cd toolchain
           ./install_abacus_toolchain_new.sh --with-dftd4=install --dry-run ${{matrix.external_toolchain_args}}
           ./scripts/stage4/install_stage4.sh

.github/workflows/coverage.yml

@@ -31,6 +31,7 @@ jobs:
           python3-pip \
           xz-utils \
           ninja-build \
+          pkg-config \
           lcov \
           perl-modules \
           libcapture-tiny-perl \

.github/workflows/cuda.yml

@@ -29,10 +29,10 @@ jobs:
         with:
           submodules: recursive
 
-      - name: Install Ccache
+      - name: Install CI tools
         run: |
           sudo apt-get update
-          sudo apt-get install -y ccache xz-utils ninja-build
+          sudo apt-get install -y ccache xz-utils ninja-build pkg-config
 
       - name: Install external tools from toolchain
         run: |

.github/workflows/dynamic.yml

@@ -20,7 +20,7 @@ jobs:
         uses: actions/checkout@v7
       - name: Install external tools from toolchain
         run: |
-          sudo apt update && sudo apt install -y xz-utils ninja-build
+          sudo apt update && sudo apt install -y xz-utils ninja-build pkg-config
           cd toolchain
           ./install_abacus_toolchain_new.sh --with-dftd4=install --dry-run -j8
           ./scripts/stage4/install_stage4.sh

.github/workflows/test.yml

@@ -40,6 +40,7 @@ jobs:
             gfortran \
             ccache \
             ca-certificates \
+            pkg-config \
             python-is-python3 \
             python3-pip \
             ninja-build \

cmake/CollectBuildInfoVars.cmake

@@ -146,21 +146,7 @@ endif()
 
 # Core Math Libraries
 if(ENABLE_LCAO AND ENABLE_ELPA)
-    set(ABACUS_ELPA_VERSION "yes (version unknown)")
-    if(ELPA_VERSION)
     set(ABACUS_ELPA_VERSION "yes (v${ELPA_VERSION})")
-    else()
-        find_program(ELPA_VERSION_EXE elpa2_print_version PATHS ${ELPA_DIR}/bin NO_DEFAULT_PATH)
-        if(ELPA_VERSION_EXE)
-            execute_process(COMMAND ${ELPA_VERSION_EXE} OUTPUT_VARIABLE ELPA_VER_RAW OUTPUT_STRIP_TRAILING_WHITESPACE ERROR_QUIET)
-            if(ELPA_VER_RAW)
-    set(ABACUS_ELPA_VERSION "yes (${ELPA_VER_RAW})")
-endif()
-        endif()
-    endif()
-    if(ABACUS_ELPA_VERSION STREQUAL "yes (version unknown)" AND ELPA_DIR)
-        set(ABACUS_ELPA_VERSION "yes (path: ${ELPA_DIR})")
-    endif()
 else()
     set(ABACUS_ELPA_VERSION "no")
 endif()

cmake/modules/FindELPA.cmake

@@ -1,15 +1,16 @@
 ###############################################################################
 # - Find ELPA
-# Find the native ELPA headers and libraries.
-#
-#  ELPA_FOUND        - True if libelpa is found.
-#  ELPA_LIBRARIES    - List of libraries when using libyaml
-#  ELPA_INCLUDE_DIR - Where to find ELPA headers.
+# Find the native ELPA headers and libraries through pkg-config.
 #
 
-find_package(PkgConfig)
+# ========================================================================
+# Deprecated (TODO: Remove this part)
+# ========================================================================
 
 # Compatible layer towards old manual routines
+if(DEFINED ELPA_DIR)
+  message(WARNING "ELPA_DIR is deprecated and will be removed in the future release.")
+endif()
 if(DEFINED ELPA_INCLUDE_DIR)
   set(ELPA_INCLUDE_DIRS ${ELPA_INCLUDE_DIR})
 endif()
@@ -31,34 +32,35 @@ if(ELPA_INCLUDE_DIRS MATCHES "^/usr/include/elpa/.*")
   endif()
 endif()
 if(ENABLE_OPENMP)
-    find_library(ELPA_LINK_LIBRARIES
+  find_library(ELPA_LINK_LIBRARIES
     NAMES elpa_openmp elpa
     HINTS ${ELPA_DIR}
     PATH_SUFFIXES "lib"
-    )
+  )
 else()
-    find_library(ELPA_LINK_LIBRARIES
+  find_library(ELPA_LINK_LIBRARIES
     NAMES elpa
     HINTS ${ELPA_DIR}
     PATH_SUFFIXES "lib"
-    )
+  )
 endif()
 
-# Incompatible with ELPA earlier than 2021.11.001
-# Before ELPA 2021.11.001, its pkg-config file
-# is named like "elpa-2021.05.002.pc".
-if(NOT ELPA_INCLUDE_DIRS AND PKG_CONFIG_FOUND)
-  if(DEFINED ELPA_DIR)
-    string(APPEND CMAKE_PREFIX_PATH ";${ELPA_DIR}")
+# ========================================================================
+
+if(NOT ELPA_INCLUDE_DIRS)
+  find_package(PkgConfig)
+  if(NOT PKG_CONFIG_FOUND)
+    message(FATAL_ERROR "Pkg-config is needed to get all information about the ELPA library")
   endif()
+  # Find preferred library corresponding with ABACUS configuration first
   if(ENABLE_OPENMP)
-    pkg_search_module(ELPA REQUIRED IMPORTED_TARGET GLOBAL elpa_openmp)
+    pkg_search_module(ELPA REQUIRED IMPORTED_TARGET GLOBAL elpa_openmp elpa)
   else()
     pkg_search_module(ELPA REQUIRED IMPORTED_TARGET GLOBAL elpa)
   endif()
-elseif(NOT PKG_CONFIG_FOUND)
-  message(STATUS
-    "ELPA : We need pkg-config to get all information about the elpa library")
+  if(${ELPA_VERSION} VERSION_LESS "2021.05.001")
+    message(FATAL_ERROR "ELPA version >= 2021.05.001 is required.")
+  endif()
 endif()
 
 # Handle the QUIET and REQUIRED arguments and
@@ -68,20 +70,21 @@ find_package_handle_standard_args(ELPA DEFAULT_MSG ELPA_LINK_LIBRARIES ELPA_INCL
 
 # Copy the results to the output variables and target.
 if(ELPA_FOUND)
-    list(GET ELPA_LINK_LIBRARIES 0 ELPA_LIBRARY)
-    set(ELPA_INCLUDE_DIR ${ELPA_INCLUDE_DIRS})
-
-    if(NOT TARGET ELPA::ELPA)
-        add_library(ELPA::ELPA UNKNOWN IMPORTED)
-        set_target_properties(ELPA::ELPA PROPERTIES
-           IMPORTED_LINK_INTERFACE_LANGUAGES "C"
-           IMPORTED_LOCATION "${ELPA_LIBRARY}"
-           INTERFACE_INCLUDE_DIRECTORIES "${ELPA_INCLUDE_DIR}")
-    endif()
+  list(GET ELPA_LINK_LIBRARIES 0 ELPA_LIBRARY)
+  set(ELPA_INCLUDE_DIR ${ELPA_INCLUDE_DIRS})
+  if(NOT TARGET ELPA::ELPA)
+    add_library(ELPA::ELPA UNKNOWN IMPORTED)
+    set_target_properties(ELPA::ELPA PROPERTIES
+      IMPORTED_LINK_INTERFACE_LANGUAGES "C"
+      IMPORTED_LOCATION "${ELPA_LIBRARY}"
+      INTERFACE_INCLUDE_DIRECTORIES "${ELPA_INCLUDE_DIR}")
+  endif()
 endif()
 
 set(CMAKE_REQUIRED_INCLUDES ${CMAKE_REQUIRED_INCLUDES} ${ELPA_INCLUDE_DIR})
 
+# Compability workaround for ELPA_DIR
+# TODO: Remove this check
 include(CheckCXXSourceCompiles)
 check_cxx_source_compiles("
 #include <elpa/elpa_version.h>
@@ -93,7 +96,7 @@ int main(){}
 ELPA_VERSION_SATISFIES
 )
 if(NOT ELPA_VERSION_SATISFIES)
-    message(FATAL_ERROR "ELPA version is too old. We support version 2021 or higher.")
+  message(FATAL_ERROR "ELPA version is too old. We support version 2021 or higher.")
 endif()
 
 mark_as_advanced(ELPA_INCLUDE_DIR ELPA_LIBRARY)

docs/quick_start/easy_install.md

@@ -158,9 +158,6 @@ Here, 'build' is the path for building ABACUS; and '-D' is used for setting up s
   - `MKLROOT`: If environment variable `MKLROOT` exists, `cmake` will take MKL as a preference, i.e. not using `LAPACK`, `ScaLAPACK` and `FFTW`. To disable MKL, unset environment variable `MKLROOT`, or pass `-DMKLROOT=OFF` to `cmake`.
   - `LAPACK_DIR`: Path to OpenBLAS library `libopenblas.so`(including BLAS and LAPACK)
   - `SCALAPACK_DIR`: Path to ScaLAPACK library `libscalapack.so`
-  - `ELPA_DIR`: Path to ELPA install directory; should be the folder containing 'include' and 'lib'.
-  > Note: In ABACUS v3.5.1 or earlier, if you install ELPA from source , please add a symlink to avoid the additional include file folder with version name: `ln -s elpa/include/elpa-2021.05.002/elpa elpa/include/elpa` to help the build system find ELPA headers.
-
   - `FFTW3_DIR`: Path to FFTW3.
   - `LIBRI_DIR`: (Optional) Path to LibRI.
   - `LIBCOMM_DIR`: (Optional) Path to LibComm when `ENABLE_LIBRI=ON`.
@@ -184,7 +181,12 @@ For some dependencies built with CMake, such as Libxc, dftd4, cereal, and RapidJ
 Here is an example:
 
 ```bash
-CXX=mpiicpx cmake -B build -DCMAKE_INSTALL_PREFIX=~/abacus -DELPA_DIR=~/elpa-2025.01.001/build
+CXX=mpiicpx cmake -B build \
+  -DCMAKE_INSTALL_PREFIX=~/abacus \
+  -DENABLE_MPI=ON \
+  -DENABLE_LCAO=ON \
+  -DENABLE_ELPA=ON \
+  -DENABLE_LIBXC=ON
 ```
 
 ### Build and Install

toolchain/build_abacus_aocc-aocl.sh

@@ -22,7 +22,6 @@ BUILD_DIR=build_abacus_aocc_aocl
 rm -rf $BUILD_DIR
 
 PREFIX=$ABACUS_DIR
-ELPA=${ELPA_ROOT}
 CEREAL=${CEREAL_ROOT}/include
 LAPACK=$AOCLhome/lib
 SCALAPACK=$AOCLhome/lib
@@ -67,7 +66,6 @@ cmake -B $BUILD_DIR -DCMAKE_INSTALL_PREFIX=$PREFIX \
         -DLAPACK_DIR=$LAPACK \
         -DSCALAPACK_DIR=$SCALAPACK \
         -DFFTW3_DIR=$FFTW3 \
-        -DELPA_DIR=$ELPA \
         -DCEREAL_INCLUDE_DIR=$CEREAL \
         -DENABLE_LCAO=ON \
         -DENABLE_LIBXC=ON \