[CMake] Introduce cmake_policy(CMP0022) for target_link_libraries(INTERFACE|PRIVATE).

For now, use both keywords, INTERFACE and PRIVATE via the variable,
  - ${cmake_2_8_12_INTERFACE}
  - ${cmake_2_8_12_PRIVATE}

They could be cleaned up when we introduce 2.8.12.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@202239 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 5662d1bf4b25da6b6058f192bcafc15766aed613..8190203dc6aee73b7f3457593ccb5aab53557042 100644 (file)
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,5 +1,19 @@
 cmake_minimum_required(VERSION 2.8.8)
 
+# FIXME: It may be removed when we use 2.8.12.
+if(CMAKE_VERSION VERSION_LESS 2.8.12)
+  # Invalidate a couple of keywords.
+  set(cmake_2_8_12_INTERFACE)
+  set(cmake_2_8_12_PRIVATE)
+else()
+  # Use ${cmake_2_8_12_KEYWORD} intead of KEYWORD in target_link_libraries().
+  set(cmake_2_8_12_INTERFACE INTERFACE)
+  set(cmake_2_8_12_PRIVATE PRIVATE)
+  if(POLICY CMP0022)
+    cmake_policy(SET CMP0022 NEW) # automatic when 2.8.12 is required
+  endif()
+endif()
+
 # If we are not building as a part of LLVM, build Clang as an
 # standalone project, using LLVM as an external library:
 if( CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR )