Merge pull request #190 from remicollet/issue-gnuinstalldirs

restore GNUInstallDirs
diff --git a/CMakeLists.txt b/CMakeLists.txt
index b730318..3af9e81 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -32,6 +32,7 @@
 include(CheckCSourceCompiles)
 include(CheckStructHasMember)
 include(TestBigEndian)
+include(GNUInstallDirs)
 if(ENABLE_COMMONCRYPTO)
   check_include_files(CommonCrypto/CommonCrypto.h COMMONCRYPTO_FOUND)
 else()
@@ -237,7 +238,7 @@
 
 # rpath handling: use rpath in installed binaries
 if(NOT CMAKE_SYSTEM_NAME MATCHES Linux)
-  set(CMAKE_INSTALL_RPATH ${CMAKE_INSTALL_PREFIX}/lib)
+  set(CMAKE_INSTALL_RPATH ${CMAKE_INSTALL_PREFIX}/${CMAKE_INSTALL_LIBDIR})
   set(CMAKE_INSTALL_RPATH_USE_LINK_PATH TRUE)
 endif()
 
@@ -282,9 +283,9 @@
 # pkgconfig file
 set(prefix ${CMAKE_INSTALL_PREFIX})
 set(exec_prefix \${prefix})
-set(bindir \${exec_prefix}/bin)
-set(libdir \${exec_prefix}/lib)
-set(includedir \${prefix}/include)
+SET(bindir \${exec_prefix}/${CMAKE_INSTALL_BINDIR})
+SET(libdir \${exec_prefix}/${CMAKE_INSTALL_LIBDIR})
+SET(includedir \${prefix}/${CMAKE_INSTALL_INCLUDEDIR})
 if(CMAKE_SYSTEM_NAME MATCHES BSD)
   set(PKG_CONFIG_RPATH "-Wl,-R\${libdir}")
 endif(CMAKE_SYSTEM_NAME MATCHES BSD)
@@ -304,7 +305,7 @@
 string(REGEX REPLACE "-lNettle::Nettle" "-lnettle" LIBS ${LIBS})
 configure_file(libzip.pc.in libzip.pc @ONLY)
 if(LIBZIP_DO_INSTALL)
-  install(FILES ${PROJECT_BINARY_DIR}/libzip.pc DESTINATION lib/pkgconfig)
+  install(FILES ${PROJECT_BINARY_DIR}/libzip.pc DESTINATION ${CMAKE_INSTALL_LIBDIR}/pkgconfig)
 endif()
 
 # fixed size integral types
@@ -426,7 +427,7 @@
   COMPATIBILITY AnyNewerVersion)
 
 configure_package_config_file("${PROJECT_NAME}-config.cmake.in" "${PROJECT_BINARY_DIR}/${PROJECT_NAME}-config.cmake"
-  INSTALL_DESTINATION lib/cmake/libzip)
+  INSTALL_DESTINATION ${CMAKE_INSTALL_LIBDIR}/cmake/libzip)
 
 # Add targets to the build-tree export set
 export(TARGETS zip
@@ -436,10 +437,10 @@
 if(LIBZIP_DO_INSTALL)
   install(FILES ${PROJECT_BINARY_DIR}/zipconf.h DESTINATION include)
   install(FILES ${PROJECT_BINARY_DIR}/${PROJECT_NAME}-config.cmake ${PROJECT_BINARY_DIR}/${PROJECT_NAME}-config-version.cmake
-    DESTINATION lib/cmake/${PROJECT_NAME}
+    DESTINATION ${CMAKE_INSTALL_LIBDIR}/cmake/${PROJECT_NAME}
     )
   install(EXPORT ${PROJECT_NAME}-targets NAMESPACE libzip:: FILE ${PROJECT_NAME}-targets.cmake
-    DESTINATION lib/cmake/${PROJECT_NAME}
+    DESTINATION ${CMAKE_INSTALL_LIBDIR}/cmake/${PROJECT_NAME}
     )
 endif()
 
diff --git a/lib/CMakeLists.txt b/lib/CMakeLists.txt
index 5a6f171..082203d 100644
--- a/lib/CMakeLists.txt
+++ b/lib/CMakeLists.txt
@@ -181,11 +181,11 @@
 if(LIBZIP_DO_INSTALL)
   install(TARGETS zip
     EXPORT ${PROJECT_NAME}-targets
-    RUNTIME DESTINATION bin
-    ARCHIVE DESTINATION lib
-    INCLUDES DESTINATION include
-    LIBRARY DESTINATION lib)
-  install(FILES zip.h DESTINATION include)
+    RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR}
+    ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}
+    INCLUDES DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}
+    LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR})
+  install(FILES zip.h DESTINATION ${CMAKE_INSTALL_INCLUDEDIR})
 endif()
 
 # create zip_err_str.h from zip.h
diff --git a/man/CMakeLists.txt b/man/CMakeLists.txt
index ce714ec..90d462a 100644
--- a/man/CMakeLists.txt
+++ b/man/CMakeLists.txt
@@ -104,10 +104,10 @@
   string(REGEX REPLACE "[1-9]$" "${DOCUMENTATION_FORMAT}" SOURCE_FILE ${MAN_PAGE})
   if(LIBZIP_DO_INSTALL)
     if (DOCUMENTATION_FORMAT MATCHES "html")
-      install(FILES ${PROJECT_BINARY_DIR}/man/${MAN_PAGE} DESTINATION share/doc/${PROJECT_NAME} RENAME ${SOURCE_FILE})
+      install(FILES ${PROJECT_BINARY_DIR}/man/${MAN_PAGE} DESTINATION ${CMAKE_INSTALL_DOCDIR}/${PROJECT_NAME} RENAME ${SOURCE_FILE})
     else()
       string(REGEX REPLACE ".*(.)$" "man\\1" SUBDIR ${MAN_PAGE})
-      install(FILES ${PROJECT_BINARY_DIR}/man/${MAN_PAGE} DESTINATION man/${SUBDIR})
+      install(FILES ${PROJECT_BINARY_DIR}/man/${MAN_PAGE} DESTINATION ${CMAKE_INSTALL_MANDIR}/${SUBDIR})
     endif()
   endif()
   # configure_file does not find out about updates to the sources, and it does not provide a target
@@ -147,9 +147,9 @@
     set(TARGET ${CMAKE_MATCH_2})
     if(LIBZIP_DO_INSTALL)
       if (DOCUMENTATION_FORMAT MATCHES "html")
-	INSTALL(FILES ${PROJECT_BINARY_DIR}/man/${SOURCE}.3 DESTINATION share/doc/${PROJECT_NAME} RENAME ${TARGET}.html)
+	INSTALL(FILES ${PROJECT_BINARY_DIR}/man/${SOURCE}.3 DESTINATION ${CMAKE_INSTALL_DOCDIR}/${PROJECT_NAME} RENAME ${TARGET}.html)
       else()
-	INSTALL(FILES ${PROJECT_BINARY_DIR}/man/${SOURCE}.3 DESTINATION man/man3 RENAME ${TARGET}.3)
+	INSTALL(FILES ${PROJECT_BINARY_DIR}/man/${SOURCE}.3 DESTINATION ${CMAKE_INSTALL_MANDIR}/man3 RENAME ${TARGET}.3)
       endif()
     endif()
   endif()