New USE_FOLDERS property OFF by default. (#3796)

Visual Studio Express editions do not support solution folders,
so default behavior should be as if USE_FOLDERS global property
is OFF.

Also, allow folder names to be the same as target names: internally,
use a prefix to distinguish folder GUIDs from target GUIDs. Add
a target and folder with the same name in the ExternalProject
test to exercise this code.

For CMake itself, provide a new option CMAKE_USE_FOLDERS that
defaults to ON so that Visual Studio users get a nicely organized
CMake project. Express edition users will have to turn off the
CMAKE_USE_FOLDERS option in order to build CMake in the VS Express
IDE.

3 files changed, 14 insertions, 5 deletions

diff --git a/Source/cmGlobalGenerator.cxx b/Source/cmGlobalGenerator.cxx
index 8e77294..b9deaef 100644
--- a/Source/cmGlobalGenerator.cxx
+++ b/Source/cmGlobalGenerator.cxx
@@ -1863,9 +1863,10 @@ bool cmGlobalGenerator::UseFolderProperty()
     return cmSystemTools::IsOn(prop);
     }
 
-  // By default, this feature is ON:
+  // By default, this feature is OFF, since it is not supported in the
+  // Visual Studio Express editions:
   //
-  return true;
+  return false;
 }
 
 //----------------------------------------------------------------------------
diff --git a/Source/cmGlobalVisualStudio7Generator.cxx b/Source/cmGlobalVisualStudio7Generator.cxx
index f455810..e08b1ef 100644
--- a/Source/cmGlobalVisualStudio7Generator.cxx
+++ b/Source/cmGlobalVisualStudio7Generator.cxx
@@ -323,7 +323,7 @@ void cmGlobalVisualStudio7Generator::WriteTargetsToSolution(
 
               if (cumulativePath.empty())
                 {
-                cumulativePath = *iter;
+                cumulativePath = "CMAKE_FOLDER_GUID_" + *iter;
                 }
               else
                 {
@@ -431,14 +431,22 @@ void cmGlobalVisualStudio7Generator
 //----------------------------------------------------------------------------
 void cmGlobalVisualStudio7Generator::WriteFolders(std::ostream& fout)
 {
+  const char *prefix = "CMAKE_FOLDER_GUID_";
+  const std::string::size_type skip_prefix = strlen(prefix);
   std::string guidProjectTypeFolder = "2150E333-8FDC-42A3-9474-1A3956D46DE8";
   for(std::map<std::string,std::set<std::string> >::iterator iter =
     VisualStudioFolders.begin(); iter != VisualStudioFolders.end(); ++iter)
     {
     std::string fullName = iter->first;
     std::string guid = this->GetGUID(fullName.c_str());
-    std::string nameOnly = cmSystemTools::GetFilenameName(fullName);
+
     cmSystemTools::ReplaceString(fullName, "/", "\\");
+    if (cmSystemTools::StringStartsWith(fullName.c_str(), prefix))
+      {
+      fullName = fullName.substr(skip_prefix);
+      }
+
+    std::string nameOnly = cmSystemTools::GetFilenameName(fullName);
 
     fout << "Project(\"{" <<
       guidProjectTypeFolder << "}\") = \"" <<
diff --git a/Source/cmake.cxx b/Source/cmake.cxx
index 37ff7c5..db26b73 100644
--- a/Source/cmake.cxx
+++ b/Source/cmake.cxx
@@ -3486,7 +3486,7 @@ void cmake::DefineProperties(cmake *cm)
   cm->DefineProperty
     ("USE_FOLDERS", cmProperty::GLOBAL,
      "Use the FOLDER target property to organize targets into folders.",
-     "If not set, CMake treats this property as ON by default. "
+     "If not set, CMake treats this property as OFF by default. "
      "CMake generators that are capable of organizing into a "
      "hierarchy of folders use the values of the FOLDER target "
      "property to name those folders. See also the documentation "