Since commit 7d47c693 (Drop compatibility with CMake < 2.4, 2013-10-08)
we no longer need to use the configure_file IMMEDIATE option to support
compatibility modes less than 2.0.
This is necessary because custom commands and targets may create
custom files whose names are determined by generator expressions.
For example, clang should be using $<TARGET_FILE> and $<TARGET_FILE_DIR>
instead of reverse engineering the output file name:
http://thread.gmane.org/gmane.comp.compilers.clang.scm/80523
However, that can only be done when ADDITIONAL_MAKE_CLEAN_FILES
also accepts and evaluates generator expressions.
Similarly, KDE uses the LOCATION property where $<TARGET_FILE>
would also be better in KDE4_HANDLE_RPATH_FOR_EXECUTABLE but
also appends the result to ADDITIONAL_MAKE_CLEAN_FILES.
After this patch, both can be ported to generator expressions.
- Remove CMP_0001 (no slash in target name) and restore
old CMAKE_BACKWARDS_COMPATIBILITY check for it
- Replace all checks of CMAKE_BACKWARDS_COMPATIBILITY
with cmLocalGenerator::NeedBackwardsCompatibility calls
- Create new CMP_0001 to determine whether or not
CMAKE_BACKWARDS_COMPATIBILITY is used.
(old = use, new = ignore)
- Show CMAKE_BACKWARDS_COMPATIBILITY in cache only when
CMP_0001 is set to OLD or WARN
- Update documentation of cmake_policy and cmake_minimum_required
to indicate their relationship and the 2.4 version boundary
- When no cmake policy version is set in top level makefile
implicitly call cmake_policy(VERSION 2.4) which restores
CMAKE_BACKWARDS_COMPATIBILITY and other 2.4 compatibility
- Fix tests MakeClean and Preprocess to call
cmake_policy(VERSION 2.6) because they depend on new policies
Daniele E. Domenichelli
Stephen Kelly
Kitware Robot
Brad King
Ken Martin