fix cmake issues: always build static heFFTe libs, fixup git hash, cmake output

cmake/CMakeLists.txt

@@ -971,14 +971,15 @@ if(PKG_KOKKOS)
   endif()
 endif()
 if(PKG_KSPACE)
-  if (LMP_HEFFTE)
+  if (FFT_USE_HEFFTE)
     message(STATUS "<<< FFT settings >>>
 -- Primary FFT lib:  heFFTe")
-    if (HEFFTE_BACKEND)
+    if (FFT_HEFFTE_BACKEND)
-      message(STATUS "heFFTe backend:  ${HEFFTE_BACKEND}")
+      message(STATUS "heFFTe backend:  ${FFT_HEFFTE_BACKEND}")
     else()
       message(STATUS "heFFTe backend:  stock (builtin FFT implementation, tested for corrected but not optimized for production)")
     endif()
+    message(STATUS "Using distributed FFT algorithms from heFTTe")
     if(FFT_SINGLE)
       message(STATUS "Using single precision FFTs")
     else()
@@ -997,14 +998,10 @@ if(PKG_KSPACE)
     else()
       message(STATUS "Using non-threaded FFTs")
     endif()
-    if (FFT_HEFFTE)
+    message(STATUS "Using builtin distributed FFT algorithms")
-      message(STATUS "Using distributed algorithms from heFTTe")
+  endif()
-    else()
+  if(PKG_KOKKOS)
-      message(STATUS "Using builtin distributed algorithms")
+    message(STATUS "Kokkos FFT: ${FFT_KOKKOS}")
-    endif()
-    if(PKG_KOKKOS)
-      message(STATUS "Kokkos FFT: ${FFT_KOKKOS}")
-    endif()
   endif()
 endif()
 if(BUILD_DOC)

cmake/Modules/Packages/KSPACE.cmake

@@ -50,7 +50,7 @@ option(FFT_USE_HEFFTE  "Use heFFTe as the distributed FFT engine, overrides the
 if(FFT_USE_HEFFTE)
   # if FFT_HEFFTE is enabled, switch the builtin FFT engine with Heffte
   set(FFT_HEFFTE_BACKEND_VALUES FFTW MKL)
-  set(FFT_HEFFTE_BACKEND "" CACHE STRING "Select heFFTe backend, e.g., FFTW or MKL")
+  set(FFT_HEFFTE_BACKEND "${FFT}" CACHE STRING "Select heFFTe backend, e.g., FFTW or MKL")
   set_property(CACHE FFT_HEFFTE_BACKEND PROPERTY STRINGS ${FFT_HEFFTE_BACKEND_VALUES})
 
   if(FFT_HEFFTE_BACKEND STREQUAL "FFTW") # respect the backend choice, FFTW or MKL
@@ -60,24 +60,36 @@ if(FFT_USE_HEFFTE)
     set(HEFFTE_COMPONENTS "MKL")
     set(Heffte_ENABLE_MKL "ON" CACHE BOOL "Enables MKL backend for heFFTe")
   else()
+    set(HEFFTE_COMPONENTS "BUILTIN")
     message(WARNING "FFT_HEFFTE_BACKEND not selected, defaulting to the builtin 'stock' backend, which is intended for testing and is not optimized for production runs")
   endif()
 
   find_package(Heffte 2.4.0 QUIET COMPONENTS ${HEFFTE_COMPONENTS})
   if (NOT Heffte_FOUND) # download and build
+    if(BUILD_SHARED_LIBS)
+      set(BUILD_SHARED_LIBS_WAS_ON YES)
+      set(BUILD_SHARED_LIBS OFF)
+    endif()
+    if(CMAKE_REQUEST_PIC)
+      set(CMAKE_POSITION_INDEPENDENT_CODE ON)
+    endif()
     include(FetchContent)
     FetchContent_Declare(HEFFTE_PROJECT # using v2.4.0
       URL  "https://github.com/icl-utk-edu/heffte/archive/refs/tags/v2.4.0.tar.gz"
       URL_HASH SHA256=02310fb4f9688df02f7181667e61c3adb7e38baf79611d80919d47452ff7881d
       )
     FetchContent_Populate(HEFFTE_PROJECT)
+    # fixup git hash to show "(unknown)" to avoid compilation failures. It cannot derive the HeFFTe hash anyway.
+    file(READ ${heffte_project_SOURCE_DIR}/include/heffte_config.cmake.h HEFFTE_CFG_FILE_TEXT)
+    string(REPLACE "@Heffte_GIT_HASH@" "(unknown)" HEFFTE_CFG_FILE_TEXT "${HEFFTE_CFG_FILE_TEXT}")
+    file(WRITE ${heffte_project_SOURCE_DIR}/include/heffte_config.cmake.h "${HEFFTE_CFG_FILE_TEXT}")
     add_subdirectory(${heffte_project_SOURCE_DIR} ${heffte_project_BINARY_DIR})
-    set_target_properties(lmp PROPERTIES INSTALL_RPATH "${CMAKE_INSTALL_PREFIX}/lib")
-    set_target_properties(lammps PROPERTIES INSTALL_RPATH "${CMAKE_INSTALL_PREFIX}/lib")
     add_library(Heffte::Heffte INTERFACE IMPORTED GLOBAL)
     target_link_libraries(Heffte::Heffte INTERFACE Heffte)
+    if(BUILD_SHARED_LIBS_WAS_ON)
+      set(BUILD_SHARED_LIBS ON)
+    endif()
   endif()
-
   target_compile_definitions(lammps PRIVATE -DFFT_HEFFTE "-DFFT_HEFFTE_${FFT_HEFFTE_BACKEND}")
   target_link_libraries(lammps PRIVATE Heffte::Heffte)
 endif()

src/lmpfftsettings.h

@@ -34,7 +34,15 @@
 
 // set strings for library info output
 
-#if defined(FFT_FFTW3)
+#if defined(FFT_HEFFTE)
+#if defined(FFT_HEFFTE_FFTW)
+#define LMP_FFT_LIB "HeFFTe(FFTW3)"
+#elif defined(FFT_HEFFTE_MKL)
+#define LMP_FFT_LIB "HeFFTe(MKL)"
+#else
+#define LMP_FFT_LIB "HeFFTe(native)"
+#endif
+#elif defined(FFT_FFTW3)
 #define LMP_FFT_LIB "FFTW3"
 #elif defined(FFT_MKL)
 #define LMP_FFT_LIB "MKL FFT"
@@ -42,14 +50,6 @@
 #define LMP_FFT_LIB "cuFFT"
 #elif defined(FFT_HIPFFT)
 #define LMP_FFT_LIB "hipFFT"
-#elif defined(FFT_HEFFT)
-#if defined(FFT_HEFFTE_FFTW)
-#define LMP_FFT_LIB "HeFFTe (FFTW3)"
-#elif defined(FFT_HEFFTE_MKL)
-#define LMP_FFT_LIB "HeFFTe (MKL)"
-#else
-#define LMP_FFT_LIB "HeFFTe (native)"
-#endif
 #else
 #define LMP_FFT_LIB "KISS FFT"
 #endif