From fcf4c5a809f49bf6c26b3654c6602de5c9e37760 Mon Sep 17 00:00:00 2001
From: Robert Underwood <rr.underwood94@gmail.com>
Date: Mon, 18 Nov 2019 10:17:22 -0600
Subject: [PATCH] use gnuinstalldirs

---
 CMakeLists.txt   | 11 +++++------
 ffts.pc.cmake.in |  7 +++----
 2 files changed, 8 insertions(+), 10 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index a02f11a13c7..296c32874cd 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -18,8 +18,7 @@ if(NOT CMAKE_BUILD_TYPE)
 endif(NOT CMAKE_BUILD_TYPE)
 
 # installation parameters
-set(INCLUDE_INSTALL_DIR ${CMAKE_INSTALL_PREFIX}/include/ffts)
-set(LIB_INSTALL_DIR ${CMAKE_INSTALL_PREFIX}/lib)
+include(GNUInstallDirs)
 
 # common options
 option(ENABLE_NEON
@@ -497,7 +496,7 @@ if(ENABLE_SHARED)
     VERSION ${FFTS_MAJOR}.${FFTS_MINOR}.${FFTS_MICRO}
   )
 
-  install( TARGETS ffts_shared DESTINATION ${LIB_INSTALL_DIR} )
+install( TARGETS ffts_shared DESTINATION ${CMAKE_INSTALL_LIBDIR} )
 endif(ENABLE_SHARED)
 
 if(ENABLE_STATIC)
@@ -511,7 +510,7 @@ if(ENABLE_STATIC)
     set_target_properties(ffts_static PROPERTIES OUTPUT_NAME ffts)
   endif(UNIX)
 
-  install( TARGETS ffts_static DESTINATION ${LIB_INSTALL_DIR} )
+  install( TARGETS ffts_static DESTINATION ${CMAKE_INSTALL_LIBDIR} )
 endif(ENABLE_STATIC)
 
 if(ENABLE_STATIC OR ENABLE_SHARED)
@@ -543,10 +542,10 @@ if(UNIX)
       # Produce a pkg-config file for linking against the shared lib
       configure_file("ffts.pc.cmake.in" "ffts.pc" @ONLY)
       install(FILES       "${CMAKE_CURRENT_BINARY_DIR}/ffts.pc"
-              DESTINATION "${CMAKE_INSTALL_PREFIX}/lib/pkgconfig")
+        DESTINATION "${CMAKE_INSTALL_DATAROOTDIR}/pkgconfig/")
   endif(PKG_CONFIG_FOUND)
 endif(UNIX)
 
 install( FILES
     ${FFTS_HEADERS}
-  DESTINATION ${INCLUDE_INSTALL_DIR} )
+    DESTINATION ${CMAKE_INSTALL_INCLUDEDIR} )
diff --git a/ffts.pc.cmake.in b/ffts.pc.cmake.in
index 43f38e9c114..953785f7f52 100644
--- a/ffts.pc.cmake.in
+++ b/ffts.pc.cmake.in
@@ -1,10 +1,9 @@
 prefix=@CMAKE_INSTALL_PREFIX@
-exec_prefix=${exec_prefix}
-libdir=${libdir}
-includedir=${includedir}
+libdir=${prefix}/@CMAKE_INSTALL_LIBDIR@
+includedir=${prefix}/@CMAKE_INSTALL_INCLUDEDIR@
 
 Name: @CMAKE_PROJECT_NAME@
 Description: fast Fourier transform library
 Version: @FFTS_VERSION@
 Libs: -L${libdir} -lffts -lm
-Cflags: -I${includedir}/ffts
+Cflags: -I${includedir}