Allow usage of relative install paths

Relative install paths is recommended(*) and required by some
cpack generators (e.g. NSIS). Using relative install paths should
always work, but to take no risks the absolute install paths are
still the default.

*) http://www.cmake.org/pipermail/cmake/2008-May/021663.html

Change-Id: Ie656d5fcfa62f9c7e0fee605c90251084a421a72

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 1c2f7838a166fdac59cf842c5afd4ac9d0ad0788..bd13be06febf400a4929362782800e0356eca8b8 100644 (file)
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -36,7 +36,7 @@ SET(CPACK_PACKAGE_VERSION_MINOR "6")
 # Cmake modules/macros are in a subdirectory to keep this file cleaner
 set(CMAKE_MODULE_PATH ${CMAKE_CURRENT_SOURCE_DIR}/cmake)
 
-if(CMAKE_INSTALL_PREFIX_INITIALIZED_TO_DEFAULT)
+if(CMAKE_INSTALL_PREFIX_INITIALIZED_TO_DEFAULT AND UNIX)
 set(CMAKE_INSTALL_PREFIX "/usr/local/gromacs" CACHE STRING "Installation prefix (installation will need write permissions here)" FORCE)
 endif()
 
@@ -46,10 +46,15 @@ endif(NOT CMAKE_BUILD_TYPE)
 
 enable_language(C)
 
+set(GMX_USE_RELATIVE_INSTALL_PATH OFF CACHE STRING "Use relative paths not absolute paths for cmake install. Has only an effect on cpack.")
+mark_as_advanced(GMX_USE_RELATIVE_INSTALL_PATH)
+
 set(CPACK_PACKAGE_VERSION ${PROJECT_VERSION})
 set(CPACK_PACKAGE_VENDOR "gromacs.org")
 set(CPACK_PACKAGE_DESCRIPTION_SUMMARY "Gromacs - a toolkit for high-performance molecular simulation")
-set(CPACK_SET_DESTDIR "ON")
+if (NOT GMX_USE_RELATIVE_INSTALL_PATH)
+    set(CPACK_SET_DESTDIR "ON")
+endif()
 set(CPACK_INCLUDE_TOPLEVEL_DIRECTORY 0)
 set(CPACK_RESOURCE_FILE_WELCOME "${CMAKE_SOURCE_DIR}/admin/InstallWelcome.txt")
 # Its GPL/LGPL, so they do not have to agree to a license for mere usage, but some installers require this...
@@ -978,15 +983,22 @@ endif()
 ########################################################################
 # Specify install locations and which subdirectories to process        #
 ########################################################################
+if (GMX_USE_RELATIVE_INSTALL_PATH)
+    set(GMX_INSTALL_PREFIX "" CACHE STRING "Prefix gets appended to CMAKE_INSTALL_PREFIX. For cpack it sets the root folder of the archive.")
+    mark_as_advanced(GMX_INSTALL_PREFIX)
+else()
+    set(GMX_INSTALL_PREFIX "${CMAKE_INSTALL_PREFIX}/")
+endif()
+
 if ( DEFINED GMXLIB )
-    set(LIB_INSTALL_DIR "${CMAKE_INSTALL_PREFIX}/${GMXLIB}")
+    set(LIB_INSTALL_DIR "${GMX_INSTALL_PREFIX}${GMXLIB}")
 else()
-    set(LIB_INSTALL_DIR  ${CMAKE_INSTALL_PREFIX}/lib)
+    set(LIB_INSTALL_DIR  ${GMX_INSTALL_PREFIX}lib)
 endif()
-set(BIN_INSTALL_DIR  ${CMAKE_INSTALL_PREFIX}/bin)
-set(DATA_INSTALL_DIR ${CMAKE_INSTALL_PREFIX}/share/gromacs)
-set(MAN_INSTALL_DIR  ${CMAKE_INSTALL_PREFIX}/share/man)
-set(INCL_INSTALL_DIR ${CMAKE_INSTALL_PREFIX}/include)
+set(BIN_INSTALL_DIR  ${GMX_INSTALL_PREFIX}bin)
+set(DATA_INSTALL_DIR ${GMX_INSTALL_PREFIX}share/gromacs)
+set(MAN_INSTALL_DIR  ${GMX_INSTALL_PREFIX}share/man)
+set(INCL_INSTALL_DIR ${GMX_INSTALL_PREFIX}include)
 
 set(GMXLIBDIR        ${DATA_INSTALL_DIR}/top)