CMake/Tests/RunCMake/CMP0019/CMakeLists.txt

cmake_minimum_required(VERSION 2.8.4)
project(${RunCMake_TEST} NONE)
include(${RunCMake_TEST}.cmake)
Cygwin: Avoid legacy warnings in RunCMake.* tests Set the minimum required version of CMake high enough to avoid the warning for CMAKE_LEGACY_CYGWIN_WIN32. The warning appears on stderr and breaks the expected output matching. 2013-08-13 17:46:14 +04:00			`cmake_minimum_required(VERSION 2.8.4)`
Add policy CMP0019 to skip include/link variable re-expansion Historically CMake has always expanded ${} variable references in the values given to include_directories(), link_directories(), and link_libraries(). This has been unnecessary since general ${} evaluation syntax was added to the language a LONG time ago, but has remained for compatibility with VERY early CMake versions. For a long time the re-expansion was a lightweight operation because it was only processed once at the directory level and the fast-path of cmMakefile::ExpandVariablesInString was usually taken because values did not have any '$' in them. Then commit d899eb71 (Call ExpandVariablesInString for each target's INCLUDE_DIRECTORIES, 2012-02-22) made the operation a bit heavier because the expansion is now needed on a per-target basis. In the future we will support generator expressions in INCLUDE_DIRECTORIES with $<> syntax, so the fast-path in cmMakefile::ExpandVariablesInString will no longer be taken and re-expansion will be very expensive. Add policy CMP0019 to skip the re-expansion altogether in NEW behavior. In OLD behavior perform the expansion but improve the fast-path heuristic to match ${} but not $<>. If the policy is not set then warn if expansion actually does anything. We expect this to be encountered very rarely in practice. 2012-12-06 18:59:18 +04:00			`project(${RunCMake_TEST} NONE)`
			`include(${RunCMake_TEST}.cmake)`