Add FOLDER target property, for IDEs (#3796)

This work was started from a patch by Thomas Schiffer.
Thanks, Thomas!

See the newly added documentation of the FOLDER target
property for details.

Also added global properties, USE_FOLDERS and
PREDEFINED_TARGETS_FOLDER. See new docs here, too.

By default, the FOLDER target property is used to organize
targets into folders in IDEs that have support for such
organization.

This commit adds "solution folder" support to the Visual
Studio generators. Currently works with versions 7 through
10.

Also, use the new FOLDER property in the ExternalProject
test and in the CMake project itself.

1 files changed, 10 insertions, 1 deletions

diff --git a/Source/cmTarget.cxx b/Source/cmTarget.cxx
index 45ba358..9611912 100644
--- a/Source/cmTarget.cxx
+++ b/Source/cmTarget.cxx
@@ -854,10 +854,19 @@ void cmTarget::DefineProperties(cmake *cm)
      "set_source_files_properties command.");
 
   cm->DefineProperty
+    ("FOLDER", cmProperty::TARGET,
+     "Set the folder name. Use to organize targets in an IDE.",
+     "Targets with no FOLDER property will appear as top level "
+     "entities in IDEs like Visual Studio. Targets with the same "
+     "FOLDER property value will appear next to each other in a "
+     "folder of that name. To nest folders, use FOLDER values such "
+     "as 'GUI/Dialogs' with '/' characters separating folder levels.");
+
+  cm->DefineProperty
     ("PROJECT_LABEL", cmProperty::TARGET,
      "Change the name of a target in an IDE.",
      "Can be used to change the name of the target in an IDE "
-     "like visual stuido. ");
+     "like Visual Studio. ");
   cm->DefineProperty
     ("VS_KEYWORD", cmProperty::TARGET,
      "Visual Studio project keyword.",