Merge pull request #853 from gpospelov/develop

Simplify CMake search of fftw3

cmake/generic/modules/FindFFTW.cmake

 # Find the FFTW includes and library.
-# 
+#
 # This module defines
 # FFTW_INCLUDE_DIR, where to locate fftw3.h file
 # FFTW_LIBRARIES, the libraries to link against to use fftw3
-# FFTW_FOUND.  If false, you cannot build anything that requires fftw3.
 # FFTW_LIBRARY, where to find the libfftw3 library.
 
-set(FFTW_FOUND 0)
-if(FFTW_LIBRARY AND FFTW_INCLUDE_DIR)
-  set(FFTW_FIND_QUIETLY TRUE)
+# --- Looking for headers -----
+
+find_path(FFTW_INCLUDE_DIR fftw3.h)
+if(NOT FFTW_INCLUDE_DIR)
+    message(ERROR " Missed dependency. Can't find FFTW headers, please make sure that you've installed FFTW development version.")
 endif()
 
-if(NOT WIN32)
-    find_path(FFTW_INCLUDE_DIR fftw3.h
-        $ENV{FFTW_DIR}/include
-        $ENV{FFTW3} $ENV{FFTW3}/include $ENV{FFTW3}/api
-        /usr/local/include
-        /usr/include
-        /opt/fftw3/include
-        /opt/local/include
-        DOC "Specify the directory containing fftw3.h"
-    )
+# --- Looking for library -----
 
-    find_library(FFTW_LIBRARY NAMES fftw3 fftw3-3 PATHS
-        $ENV{FFTW_DIR}/lib
-        $ENV{FFTW3} $ENV{FFTW3}/lib $ENV{FFTW3}/.libs
-        /usr/local/lib
-        /usr/lib 
-        /opt/fftw3/lib
-        HINTS /opt/local/lib
-        DOC "Specify the fttw3 library here."
-    )
-else()
-    find_path(FFTW_INCLUDE_DIR fftw3.h
-        HINTS ENV PATH
-        PATHS "C:/opt/local_x64/include"  # if fftw cannot be found in env path
-        PATH_SUFFIXES ../include
-        NO_DEFAULT_PATH
-    )
-#    message("XXX ${FFTW_INCLUDE_DIR}")
+set(FFTW_NAMES ${FFTW_NAMES} fftw3 fftw3-3 libfftw3-3)
+set( ba_ORIG_CMAKE_FIND_LIBRARY_SUFFIXES ${CMAKE_FIND_LIBRARY_SUFFIXES})
 
-    find_library(FFTW_LIBRARY libfftw3-3
-        HINTS ENV PATH
-        PATHS "C:/opt/local_x64/lib"  # if fftw cannot be found in env path
-        NO_DEFAULT_PATH
-    )
+if (NOT APPLE AND NOT WIN32)
+    set(CMAKE_FIND_LIBRARY_SUFFIXES .so) # require shared version of library
+endif()
 
+find_library(FFTW_LIBRARY NAMES ${FFTW_NAMES} QUIET)
+set(CMAKE_FIND_LIBRARY_SUFFIXES ${ba_ORIG_CMAKE_FIND_LIBRARY_SUFFIXES})
+
+if (WIN31)
     string( REPLACE ".lib" ".dll" FFTW_LIBRARY_DLL "${FFTW_LIBRARY}" )
     if (NOT EXISTS ${FFTW_LIBRARY_DLL})
         message(FATAL_ERROR "File ${FFTW_LIBRARY_DLL} does not exist")
-    endif (NOT EXISTS ${FFTW_LIBRARY_DLL})
+    endif(NOT EXISTS ${FFTW_LIBRARY_DLL})
 endif()
 
-if(FFTW_INCLUDE_DIR AND FFTW_LIBRARY)
-  set(FFTW_FOUND 1 )
-  if(NOT FFTW_FIND_QUIETLY)
-     message(STATUS "Found fftw3 includes at ${FFTW_INCLUDE_DIR}")
-     message(STATUS "Found fftw3 library at ${FFTW_LIBRARY}")
-  endif()
-endif()
+# --- Processing variables -----
 
+include(FindPackageHandleStandardArgs)
+FIND_PACKAGE_HANDLE_STANDARD_ARGS(FFTW REQUIRED_VARS FFTW_LIBRARY FFTW_INCLUDE_DIR)
 
-if( NOT FFTW_FOUND )
-    if( FFTW_FIND_REQUIRED )
-        message( FATAL_ERROR "FindFFTW: can't find fftw3 header or library" )
-    endif()
+if(FFTW_FOUND)
+    set( FFTW_LIBRARIES ${FFTW_LIBRARY} )
 endif()
 
+if(FFTW_FOUND)
+    message(STATUS "Found FFTW: includes at ${FFTW_INCLUDE_DIR}, libraries at ${FFTW_LIBRARIES}")
+else()
+    message(STATUS "Cant'f find fftw3 library: ${FFTW_INCLUDE_DIR}, ${FFTW_LIBRARIES}.")
+    if (NOT WIN32 AND NOT APPLE)
+        message(STATUS "Please note, that shared version of FFTW library is required (use enable-shared during configuration phase).")
+    endif()
+endif()
 
-set(FFTW_LIBRARIES ${FFTW_LIBRARY})
-
-mark_as_advanced(FFTW_FOUND FFTW_LIBRARY FFTW_INCLUDE_DIR FFTW_LIBRARY_DLL)
+mark_as_advanced(FFTW_INCLUDE_DIR FFTW_LIBRARY FFTW_LIBRARY_DLL)