egpbos/findfftw

CMake module for finding FFTW 3 using find_package

CMake module for finding FFTW 3 using find_package

Usage

Once added to your project, this module allows you to find FFTW libraries and headers using the CMake find_package command:

find_package(FFTW [REQUIRED] [QUIET] [COMPONENTS component1 ... componentX] )

This module sets the following variables:

• FFTW_FOUND ... true if fftw is found on the system
• FFTW_[component]_LIB_FOUND ... true if the component is found on the system (see components below)
• FFTW_LIBRARIES ... full paths to all found fftw libraries
• FFTW_[component]_LIB ... full path to one of the components (see below)
• FFTW_INCLUDE_DIRS ... fftw include directory paths

The following variables will be checked by the module:

• FFTW_USE_STATIC_LIBS ... if true, only static libraries are found, otherwise both static and shared.
• FFTW_ROOT ... if set, the libraries are exclusively searched under this path.

This package supports the following components:

• FLOAT_LIB
• DOUBLE_LIB
• LONGDOUBLE_LIB
• FLOAT_THREADS_LIB
• DOUBLE_THREADS_LIB
• LONGDOUBLE_THREADS_LIB
• FLOAT_OPENMP_LIB
• DOUBLE_OPENMP_LIB
• LONGDOUBLE_OPENMP_LIB
• FLOAT_MPI_LIB
• DOUBLE_MPI_LIB
• LONGDOUBLE_MPI_LIB

and the following linking targets

• FFTW::Float
• FFTW::Double
• FFTW::LongDouble
• FFTW::FloatThreads
• FFTW::DoubleThreads
• FFTW::LongDoubleThreads
• FFTW::FloatOpenMP
• FFTW::DoubleOpenMP
• FFTW::LongDoubleOpenMP
• FFTW::FloatMPI
• FFTW::DoubleMPI
• FFTW::LongDoubleMPI

Adding to your project

Automatic download from CMake project

Copy the following into the CMakeLists.txt file of the project you want to use FindFFTW in:

configure_file(downloadFindFFTW.cmake.in findFFTW-download/CMakeLists.txt)
execute_process(COMMAND ${CMAKE_COMMAND} -G "${CMAKE_GENERATOR}" .
        RESULT_VARIABLE result
        WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}/findFFTW-download )
if(result)
    message(FATAL_ERROR "CMake step for findFFTW failed: ${result}")
    else()
    message("CMake step for findFFTW completed (${result}).")
endif()
execute_process(COMMAND ${CMAKE_COMMAND} --build .
        RESULT_VARIABLE result
        WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}/findFFTW-download )
if(result)
    message(FATAL_ERROR "Build step for findFFTW failed: ${result}")
endif()

set(findFFTW_DIR ${CMAKE_CURRENT_BINARY_DIR}/findFFTW-src)

set(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} "${findFFTW_DIR}")

And add a file called downloadFindFFTW.cmake.in to your project containing the following:

cmake_minimum_required(VERSION 2.8.2)

project(findFFTW-download NONE)

include(ExternalProject)

ExternalProject_Add(findFFTW_download
    GIT_REPOSITORY    "https://github.com/egpbos/findfftw.git"
    CONFIGURE_COMMAND ""
    BUILD_COMMAND     ""
    INSTALL_COMMAND   ""
    TEST_COMMAND      ""
    SOURCE_DIR        "${CMAKE_CURRENT_BINARY_DIR}/findFFTW-src"
    BINARY_DIR        ""
    INSTALL_DIR       ""
)

After this, find_package(FFTW) can be used in the CMakeLists.txt file.

Manual

Clone the repository into directory PREFIX/findFFTW:

git clone https://github.com/egpbos/findfftw.git PREFIX/findFFTW

Then add the following to your CMakeLists.txt to allow CMake to find the module:

set(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} "PREFIX/findFFTW")

findfftw's Issues

Add test suite and CI

I want to add a test suite on which FFTW is installed/compiled with all the possible options and FindFFTW tries to find them from CMakeLists.txt files. This suite should then run on CI, I think GitHub Actions would be best.

As mentioned in #3 (comment), I think this will make adding new features like #3 a lot easier.

fftw not found when installed in non standard place

Hello,
i compiled and installed fftw3 in ~/LIBS/fftw-3.3.10. I'm using cmake as noted in your README, but i got the message:

cmake -DFFTW_ROOT=~/LIBS/fftw-3.3.10 .. 
...

-- Build files have been written to: /home/me/AMUbox/projets/modelisation-simujura/build/findFFTW-download
CMake step for findFFTW completed (0).
[ 11%] Performing update step for 'findFFTW_download'
Current branch master is up to date.
[ 22%] No configure step for 'findFFTW_download'
[ 33%] No build step for 'findFFTW_download'
[ 44%] No install step for 'findFFTW_download'
[ 55%] No test step for 'findFFTW_download'
[ 66%] Completed 'findFFTW_download'
[100%] Built target findFFTW_download
-- Could NOT find FFTW (missing: FLOAT_LIB FLOAT_OPENMP_LIB) 
FFTW not found

i notice that fftw3 comes with pkg-config file, is it possible to use it to find FFTW with cmake? it seems necessary to set PKG_CONFIG_PATH to dir given by FFTW_ROOT and the reult will be:

$ pkg-config --libs fftw3
-L/home/me/LIBS/fftw-3.3.10/lib -lfftw3

Thanks for help

Gérard