ENH: Allow policy CMP0000 to be set explicitly

  - Message for missing cmake_minimum_required is not issued
    until the end of processing the top CMakeLists.txt file
  - During processing a cmake_policy command may set behavior
  - OLD behavior is to silently ignore the problem
  - NEW behavior is to issue an error instead of a warning

1 files changed, 9 insertions, 1 deletions

diff --git a/Source/cmPolicies.cxx b/Source/cmPolicies.cxx
index b37171b..b69a719 100644
--- a/Source/cmPolicies.cxx
+++ b/Source/cmPolicies.cxx
@@ -101,7 +101,15 @@ cmPolicies::cmPolicies()
     "(such as \"2.6\").  "
     "The command will ensure that at least the given version of CMake is "
     "running and help newer versions be compatible with the project.  "
-    "See documentation of cmake_minimum_required for details.",
+    "See documentation of cmake_minimum_required for details.\n"
+    "Note that the command invocation must appear in the CMakeLists.txt "
+    "file itself; a call in an included file is not sufficient.  "
+    "However, the cmake_policy command may be called to set policy "
+    "CMP0000 to OLD or NEW behavior explicitly.  "
+    "The OLD behavior is to silently ignore the missing invocation.  "
+    "The NEW behavior is to issue an error instead of a warning.  "
+    "An included file may set CMP0000 explicitly to affect how this "
+    "policy is enforced for the main CMakeLists.txt file.",
     2,6,0, cmPolicies::WARN
     );