cmake: add the possibility to force kind of mangling to use for BLAS/LAPACK

CMakeLists.txt

@@ -375,35 +375,53 @@ if (MORSE_DISTRIB_DIR OR EXISTS "${CMAKE_CURRENT_SOURCE_DIR}/CMakeModules/morse/
         list(APPEND CMAKE_INSTALL_RPATH "${LAPACK_LIBRARY_DIRS}")
       endif()
       message (STATUS "check BLAS Fortran mangling")
-      # check blas and lapack symbols naming
-      set(CMAKE_REQUIRED_LIBRARIES "${BLAS_LIBRARIES}")
-      check_function_exists(dgemv_ DGEMV_ADD_)
-      set (SCALFMM_BLAS_UPCASE OFF)
-      set (SCALFMM_BLAS_NOCHANGE OFF)
-      message (STATUS "BLAS dgemv_ " ${DGEMV_ADD_}   ${SCALFMM_BLAS_UPCASE})
-      if (DGEMV_ADD_)
-        set (SCALFMM_BLAS_ADD_ ON)
-        message (STATUS "BLAS dgemv_ symbol found, SCALFMM_BLAS_ADD_ is ON")
-      else (DGEMV_ADD_)
-        set (SCALFMM_BLAS_ADD_ OFF)
+      # add options to let the user be able to force a behavior
+      option( SCALFMM_BLAS_ADD_     "Set to ON to force calls to BLAS Fortran symbols with _ (ex: dgemm_)"        OFF )
+      option( SCALFMM_BLAS_UPCASE   "Set to ON to force calls to BLAS Fortran symbols in capital (ex: DGEMM)"     OFF )
+      option( SCALFMM_BLAS_NOCHANGE "Set to ON to force calls to BLAS Fortran symbols with no change (ex: dgemm)" OFF )
+      # if options not changed by user then auto-detection
+      if (NOT SCALFMM_BLAS_ADD_ AND NOT SCALFMM_BLAS_UPCASE AND NOT SCALFMM_BLAS_NOCHANGE)
+        # give blas libraries and check dgemm symbol
+        set(CMAKE_REQUIRED_LIBRARIES "${BLAS_LIBRARIES}")
+        check_function_exists(dgemv_ DGEMV_ADD_)
         check_function_exists(DGEMV  DGEMV_UPCASE)
-        if (DGEMV_UPCASE)
-          set (SCALFMM_BLAS_UPCASE ON)
-          message (STATUS "BLAS DGEMV symbol found, SCALFMM_BLAS_UPCASE is ON")
-        else (DGEMV_UPCASE)
-        #          set (SCALFMM_BLAS_UPCASE OFF)
-          check_function_exists(dgemv  DGEMV_NOCHANGE)
-          if (DGEMV_NOCHANGE) 
-            set (SCALFMM_BLAS_NOCHANGE ON)
-            message (STATUS "BLAS dgemv symbol found, SCALFMM_BLAS_NOCHANGE is ON")
-            #	  else   (DGEMV_NOCHANGE)
-            #            set (SCALFMM_BLAS_NOCHANGE OFF)
-          endif (DGEMV_NOCHANGE)
-        endif (DGEMV_UPCASE)
-      endif (DGEMV_ADD_)
-      if ( (NOT DGEMV_ADD_) AND (NOT DGEMV_UPCASE) AND (NOT DGEMV_NOCHANGE) )
-        message(FATAL_ERROR "BLAS Fortran mangling cannot be properly detected")
-      endif ()
+        check_function_exists(dgemv  DGEMV_NOCHANGE)
+        # here we consider that the first kind of symbol found will be the one used
+        # current order is: ADD_, UPCASE, NOCHANGE
+        if (DGEMV_ADD_)
+          set (SCALFMM_BLAS_ADD_     ON)
+          set (SCALFMM_BLAS_UPCASE   OFF)
+          set (SCALFMM_BLAS_NOCHANGE OFF)
+          message (STATUS "BLAS dgemv_ symbol found, SCALFMM_BLAS_ADD_ is ON")
+        else (DGEMV_ADD_)
+          if (DGEMV_UPCASE)
+            set (SCALFMM_BLAS_ADD_     OFF)
+            set (SCALFMM_BLAS_UPCASE   ON)
+            set (SCALFMM_BLAS_NOCHANGE OFF)
+            message (STATUS "BLAS DGEMV symbol found, SCALFMM_BLAS_UPCASE is ON")
+          else (DGEMV_UPCASE)
+            if (DGEMV_NOCHANGE)
+              set (SCALFMM_BLAS_ADD_     OFF)
+              set (SCALFMM_BLAS_UPCASE   OFF)
+              set (SCALFMM_BLAS_NOCHANGE ON)
+              message (STATUS "BLAS dgemv symbol found, SCALFMM_BLAS_NOCHANGE is ON")
+            endif (DGEMV_NOCHANGE)
+          endif (DGEMV_UPCASE)
+        endif (DGEMV_ADD_)
+        if ( (NOT DGEMV_ADD_) AND (NOT DGEMV_UPCASE) AND (NOT DGEMV_NOCHANGE) )
+          message(FATAL_ERROR "BLAS Fortran mangling is not properly detected - please check your BLAS libraries")
+        endif ()
+      else  (NOT SCALFMM_BLAS_ADD_ AND NOT SCALFMM_BLAS_UPCASE AND NOT SCALFMM_BLAS_NOCHANGE)
+        if (SCALFMM_BLAS_ADD_)
+          message (STATUS "SCALFMM_BLAS_ADD_ is set to ON")
+        endif()
+        if (SCALFMM_BLAS_UPCASE)
+          message (STATUS "SCALFMM_BLAS_UPCASE is set to ON")
+        endif()
+        if (SCALFMM_BLAS_NOCHANGE)
+          message (STATUS "SCALFMM_BLAS_NOCHANGE is set to ON")
+        endif()
+      endif (NOT SCALFMM_BLAS_ADD_ AND NOT SCALFMM_BLAS_UPCASE AND NOT SCALFMM_BLAS_NOCHANGE)
     else()
       message(WARNING "BLAS has not been found, SCALFMM will continue to compile but some applications will be disabled.")
       message(WARNING "If you have BLAS set BLAS_LIBDIR, BLAS_INCDIR or BLAS_DIR (CMake variables using -D or environment variables).")