Add find module for LIBHQR (hierarchical householder tree)

Is this ok for you or do you want a more elaborated find module like the others. (Knowing that libhqr is a simple library without any third party dependency) @faverge

modules/find/FindHQR.cmake

+###
+#
+# @copyright (c) 2009-2014 The University of Tennessee and The University
+#                          of Tennessee Research Foundation.
+#                          All rights reserved.
+# @copyright (c) 2012-2017 Inria. All rights reserved.
+# @copyright (c) 2012-2014 Bordeaux INP, CNRS (LaBRI UMR 5800), Inria, Univ. Bordeaux. All rights reserved.
+#
+###
+#
+# - Find HQR include dirs and libraries
+# Use this module by invoking find_package with the form:
+#  find_package(HQR
+#               [REQUIRED]) # Fail with error if hqr is not found
+#
+# This module finds headers and hqr library.
+# Results are reported in variables:
+#  HQR_FOUND           - True if headers and requested libraries were found
+#  HQR_INCLUDE_DIRS    - hqr include directories
+#  HQR_LIBRARY_DIRS    - Link directories for hqr libraries
+#  HQR_LIBRARIES       - hqr component libraries to be linked
+#
+# The user can give specific paths where to find the libraries adding cmake
+# options at configure (ex: cmake path/to/project -DHQR_DIR=path/to/hqr):
+#  HQR_DIR             - Where to find the base directory of hqr
+#  HQR_INCDIR          - Where to find the header files
+#  HQR_LIBDIR          - Where to find the library files
+# The module can also look for the following environment variables if paths
+# are not given as cmake variable: HQR_DIR, HQR_INCDIR, HQR_LIBDIR
+
+#=============================================================================
+# Copyright 2012-2017 Inria
+# Copyright 2012-2013 Emmanuel Agullo
+# Copyright 2012-2013 Mathieu Faverge
+# Copyright 2012      Cedric Castagnede
+# Copyright 2013-2017 Florent Pruvost
+#
+# Distributed under the OSI-approved BSD License (the "License");
+# see accompanying file MORSE-Copyright.txt for details.
+#
+# This software is distributed WITHOUT ANY WARRANTY; without even the
+# implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+# See the License for more information.
+#=============================================================================
+# (To distribute this file outside of Morse, substitute the full
+#  License text for the above reference.)
+
+if (NOT HQR_FOUND)
+  set(HQR_DIR "" CACHE PATH "Installation directory of HQR library")
+  if (NOT HQR_FIND_QUIETLY)
+    message(STATUS "A cache variable, namely HQR_DIR, has been set to specify the install directory of HQR")
+  endif()
+endif()
+
+set(ENV_HQR_DIR "$ENV{HQR_DIR}")
+set(ENV_HQR_INCDIR "$ENV{HQR_INCDIR}")
+set(ENV_HQR_LIBDIR "$ENV{HQR_LIBDIR}")
+set(HQR_GIVEN_BY_USER "FALSE")
+if ( HQR_DIR OR ( HQR_INCDIR AND HQR_LIBDIR) OR ENV_HQR_DIR OR (ENV_HQR_INCDIR AND ENV_HQR_LIBDIR) )
+  set(HQR_GIVEN_BY_USER "TRUE")
+endif()
+
+# Optionally use pkg-config to detect include/library dirs (if pkg-config is available)
+# -------------------------------------------------------------------------------------
+include(FindPkgConfig)
+find_package(PkgConfig QUIET)
+if(PKG_CONFIG_EXECUTABLE AND NOT HQR_GIVEN_BY_USER)
+
+  pkg_search_module(HQR hqr)
+  if (NOT HQR_FIND_QUIETLY)
+    if (HQR_FOUND AND HQR_LIBRARIES)
+      message(STATUS "Looking for HQR - found using PkgConfig")
+      #if(NOT HQR_INCLUDE_DIRS)
+      #    message("${Magenta}HQR_INCLUDE_DIRS is empty using PkgConfig."
+      #        "Perhaps the path to hqr headers is already present in your"
+      #        "C(PLUS)_INCLUDE_PATH environment variable.${ColourReset}")
+      #endif()
+    else()
+      message(STATUS "${Magenta}Looking for HQR - not found using PkgConfig."
+	"\n   Perhaps you should add the directory containing hqr.pc to the"
+	"\n   PKG_CONFIG_PATH environment variable.${ColourReset}")
+    endif()
+  endif()
+
+endif(PKG_CONFIG_EXECUTABLE AND NOT HQR_GIVEN_BY_USER)
+
+if( (NOT PKG_CONFIG_EXECUTABLE) OR (PKG_CONFIG_EXECUTABLE AND NOT HQR_FOUND) OR (HQR_GIVEN_BY_USER) )
+
+  if (NOT HQR_FIND_QUIETLY)
+    message(STATUS "Looking for HQR - PkgConfig not used")
+  endif()
+
+  # Looking for include
+  # -------------------
+
+  # Add system include paths to search include
+  # ------------------------------------------
+  unset(_inc_env)
+  set(ENV_HQR_DIR "$ENV{HQR_DIR}")
+  set(ENV_HQR_INCDIR "$ENV{HQR_INCDIR}")
+  if(ENV_HQR_INCDIR)
+    list(APPEND _inc_env "${ENV_HQR_INCDIR}")
+  elseif(ENV_HQR_DIR)
+    list(APPEND _inc_env "${ENV_HQR_DIR}")
+    list(APPEND _inc_env "${ENV_HQR_DIR}/include")
+  else()
+    if(WIN32)
+      string(REPLACE ":" ";" _inc_env "$ENV{INCLUDE}")
+    else()
+      string(REPLACE ":" ";" _path_env "$ENV{INCLUDE}")
+      list(APPEND _inc_env "${_path_env}")
+      string(REPLACE ":" ";" _path_env "$ENV{C_INCLUDE_PATH}")
+      list(APPEND _inc_env "${_path_env}")
+      string(REPLACE ":" ";" _path_env "$ENV{CPATH}")
+      list(APPEND _inc_env "${_path_env}")
+      string(REPLACE ":" ";" _path_env "$ENV{INCLUDE_PATH}")
+      list(APPEND _inc_env "${_path_env}")
+    endif()
+  endif()
+  list(APPEND _inc_env "${CMAKE_PLATFORM_IMPLICIT_INCLUDE_DIRECTORIES}")
+  list(APPEND _inc_env "${CMAKE_C_IMPLICIT_INCLUDE_DIRECTORIES}")
+  list(REMOVE_DUPLICATES _inc_env)
+
+  # Try to find the hqr header in the given paths
+  # -------------------------------------------------
+  # call cmake macro to find the header path
+  if(HQR_INCDIR)
+    set(HQR_HQR.h_DIRS "HQR_libhqr.h_DIRS-NOTFOUND")
+    find_path(HQR_libhqr.h_DIRS
+      NAMES libhqr.h
+      HINTS ${HQR_INCDIR})
+  else()
+    if(HQR_DIR)
+      set(HQR_libhqr.h_DIRS "HQR_libhqr.h_DIRS-NOTFOUND")
+      find_path(HQR_libhqr.h_DIRS
+	NAMES libhqr.h
+	HINTS ${HQR_DIR}
+    else()
+      set(HQR_libhqr.h_DIRS "HQR_libhqr.h_DIRS-NOTFOUND")
+      find_path(HQR_libhqr.h_DIRS
+	NAMES libhqr.h
+	HINTS ${_inc_env}
+	PATH_SUFFIXES "hqr")
+    endif()
+  endif()
+  mark_as_advanced(HQR_libhqr.h_DIRS)
+
+  # Add path to cmake variable
+  # ------------------------------------
+  if (HQR_libhqr.h_DIRS)
+    set(HQR_INCLUDE_DIRS "${HQR_libhqr.h_DIRS}")
+  else ()
+    set(HQR_INCLUDE_DIRS "HQR_INCLUDE_DIRS-NOTFOUND")
+    if(NOT HQR_FIND_QUIETLY)
+      message(STATUS "Looking for hqr -- libhqr.h not found")
+    endif()
+  endif ()
+
+  if (HQR_INCLUDE_DIRS)
+    list(REMOVE_DUPLICATES HQR_INCLUDE_DIRS)
+  endif ()
+
+  # Looking for lib
+  # ---------------
+
+  # Add system library paths to search lib
+  # --------------------------------------
+  unset(_lib_env)
+  set(ENV_HQR_LIBDIR "$ENV{HQR_LIBDIR}")
+  if(ENV_HQR_LIBDIR)
+    list(APPEND _lib_env "${ENV_HQR_LIBDIR}")
+  elseif(ENV_HQR_DIR)
+    list(APPEND _lib_env "${ENV_HQR_DIR}")
+    list(APPEND _lib_env "${ENV_HQR_DIR}/lib")
+  else()
+    if(WIN32)
+      string(REPLACE ":" ";" _lib_env "$ENV{LIB}")
+    else()
+      if(APPLE)
+	string(REPLACE ":" ";" _lib_env "$ENV{DYLD_LIBRARY_PATH}")
+      else()
+	string(REPLACE ":" ";" _lib_env "$ENV{LD_LIBRARY_PATH}")
+      endif()
+      list(APPEND _lib_env "${CMAKE_PLATFORM_IMPLICIT_LINK_DIRECTORIES}")
+      list(APPEND _lib_env "${CMAKE_C_IMPLICIT_LINK_DIRECTORIES}")
+    endif()
+  endif()
+  list(REMOVE_DUPLICATES _lib_env)
+
+  # Try to find the hqr lib in the given paths
+  # ----------------------------------------------
+
+  # call cmake macro to find the lib path
+  if(HQR_LIBDIR)
+    set(HQR_hqr_LIBRARY "HQR_hqr_LIBRARY-NOTFOUND")
+    find_library(HQR_hqr_LIBRARY
+      NAMES hqr
+      HINTS ${HQR_LIBDIR})
+  else()
+    if(HQR_DIR)
+      set(HQR_hqr_LIBRARY "HQR_hqr_LIBRARY-NOTFOUND")
+      find_library(HQR_hqr_LIBRARY
+	NAMES hqr
+	HINTS ${HQR_DIR}
+	PATH_SUFFIXES lib lib32 lib64)
+    else()
+      set(HQR_hqr_LIBRARY "HQR_hqr_LIBRARY-NOTFOUND")
+      find_library(HQR_hqr_LIBRARY
+	NAMES hqr
+	HINTS ${_lib_env})
+    endif()
+  endif()
+  mark_as_advanced(HQR_hqr_LIBRARY)
+
+  # If found, add path to cmake variable
+  # ------------------------------------
+  if (HQR_hqr_LIBRARY)
+    get_filename_component(hqr_lib_path ${HQR_hqr_LIBRARY} PATH)
+    # set cmake variables (respects naming convention)
+    set(HQR_LIBRARIES    "${HQR_hqr_LIBRARY}")
+    set(HQR_LIBRARY_DIRS "${hqr_lib_path}")
+  else ()
+    set(HQR_LIBRARIES    "HQR_LIBRARIES-NOTFOUND")
+    set(HQR_LIBRARY_DIRS "HQR_LIBRARY_DIRS-NOTFOUND")
+    if(NOT HQR_FIND_QUIETLY)
+      message(STATUS "Looking for hqr -- lib hqr not found")
+    endif()
+  endif ()
+
+  if (HQR_LIBRARY_DIRS)
+    list(REMOVE_DUPLICATES HQR_LIBRARY_DIRS)
+  endif ()
+
+  # check a function to validate the find
+  if(HQR_LIBRARIES)
+
+    set(REQUIRED_INCDIRS)
+    set(REQUIRED_LIBDIRS)
+    set(REQUIRED_LIBS)
+
+    # HQR
+    if (HQR_INCLUDE_DIRS)
+      set(REQUIRED_INCDIRS "${HQR_INCLUDE_DIRS}")
+    endif()
+    if (HQR_LIBRARY_DIRS)
+      set(REQUIRED_LIBDIRS "${HQR_LIBRARY_DIRS}")
+    endif()
+    set(REQUIRED_LIBS "${HQR_LIBRARIES}")
+
+    # set required libraries for link
+    set(CMAKE_REQUIRED_INCLUDES "${REQUIRED_INCDIRS}")
+    set(CMAKE_REQUIRED_LIBRARIES)
+    foreach(lib_dir ${REQUIRED_LIBDIRS})
+      list(APPEND CMAKE_REQUIRED_LIBRARIES "-L${lib_dir}")
+    endforeach()
+    list(APPEND CMAKE_REQUIRED_LIBRARIES "${REQUIRED_LIBS}")
+    string(REGEX REPLACE "^ -" "-" CMAKE_REQUIRED_LIBRARIES "${CMAKE_REQUIRED_LIBRARIES}")
+
+    # test link
+    unset(HQR_WORKS CACHE)
+    include(CheckFunctionExists)
+    check_function_exists(libhqr_hqr_init HQR_WORKS)
+    mark_as_advanced(HQR_WORKS)
+
+    if(NOT HQR_WORKS)
+      if(NOT HQR_FIND_QUIETLY)
+	message(STATUS "Looking for hqr : test of libhqr_hqr_init with hqr library fails")
+	message(STATUS "CMAKE_REQUIRED_LIBRARIES: ${CMAKE_REQUIRED_LIBRARIES}")
+	message(STATUS "CMAKE_REQUIRED_INCLUDES: ${CMAKE_REQUIRED_INCLUDES}")
+	message(STATUS "Check in CMakeFiles/CMakeError.log to figure out why it fails")
+      endif()
+    endif()
+    set(CMAKE_REQUIRED_INCLUDES)
+    set(CMAKE_REQUIRED_FLAGS)
+    set(CMAKE_REQUIRED_LIBRARIES)
+  endif(HQR_LIBRARIES)
+
+endif( (NOT PKG_CONFIG_EXECUTABLE) OR (PKG_CONFIG_EXECUTABLE AND NOT HQR_FOUND) OR (HQR_GIVEN_BY_USER) )
+
+if (HQR_LIBRARIES)
+  if (HQR_LIBRARY_DIRS)
+    list(GET HQR_LIBRARY_DIRS 0 first_lib_path)
+  else()
+    list(GET HQR_LIBRARIES 0 first_lib)
+    get_filename_component(first_lib_path "${first_lib}" PATH)
+  endif()
+  if (${first_lib_path} MATCHES "/lib(32|64)?$")
+    string(REGEX REPLACE "/lib(32|64)?$" "" not_cached_dir "${first_lib_path}")
+    set(HQR_DIR_FOUND "${not_cached_dir}" CACHE PATH "Installation directory of HQR library" FORCE)
+  else()
+    set(HQR_DIR_FOUND "${first_lib_path}" CACHE PATH "Installation directory of HQR library" FORCE)
+  endif()
+endif()
+mark_as_advanced(HQR_DIR)
+mark_as_advanced(HQR_DIR_FOUND)
+
+# check that HQR has been found
+# -------------------------------
+include(FindPackageHandleStandardArgs)
+if (PKG_CONFIG_EXECUTABLE AND HQR_FOUND)
+  find_package_handle_standard_args(HQR DEFAULT_MSG
+    HQR_LIBRARIES)
+else()
+  find_package_handle_standard_args(HQR DEFAULT_MSG
+    HQR_LIBRARIES
+    HQR_WORKS)
+endif()