Xcode Generator: Custom Project Name

Hi there.

I'd like to bring a small feature: custom name for a Xcode project.

Here is my motivation: on my machine I have few copies of LLVM, for each of them I have separate Xcode project.

The problem appears when I switch between different Xcode projects, or when I want to open another project: there is almost no way to determine which copy I'm working with. The only way to differentiate things now is to remember the target I worked with in each project.

But it's so annoying, error-prone, and counter-productive so I'd like CMake to generate me a project with a different, custom name.

i.e.:

cmake -G Xcode ~/Projects/LLVM/src
cmake -G Xcode -DCMAKE_XCODE_PROJECT_NAME=Mull ~/Projects/Mull/src
cmake -G Xcode -DCMAKE_XCODE_PROJECT_NAME=IRTests ~/Projects/Mull/Lab/src

where the commands will spit out xcode projects as the following: LLVM.xcodeproj, Mull.xcodeproj, IRTests.xcodeproj.

So far I looked into cmGlobalXCodeGenerator and found that this change can be done easily (see the patch below).

Now I have several questions:

1. Can such a feature be accepted into upstream?
2. What is the recommended way to write tests for this feature?
3. What else needs to be done to make this work besides the change below?

I will also appreciate any reference to more detailed contributing guidelines, if there are any.

P.S. the patch:

diff --git a/Source/cmGlobalXCodeGenerator.cxx b/Source/cmGlobalXCodeGenerator.cxx
index 736aa91..4fea196 100644
--- a/Source/cmGlobalXCodeGenerator.cxx
+++ b/Source/cmGlobalXCodeGenerator.cxx
@@ -3264,9 +3264,16 @@ void cmGlobalXCodeGenerator::OutputXCodeProject(
   if (!this->CreateXCodeObjects(root, generators)) {
     return;
   }
+
+  const char *customProjectName = this->CurrentMakefile->GetDefinition("CMAKE_XCODE_PROJECT_NAME");
+  std::string projectName = root->GetProjectName();
+  if (customProjectName) {
+    projectName = std::string(customProjectName);
+  }
+
   std::string xcodeDir = root->GetCurrentBinaryDirectory();
   xcodeDir += "/";
-  xcodeDir += root->GetProjectName();
+  xcodeDir += projectName;
   xcodeDir += ".xcode";
   if (this->XcodeVersion > 20) {
     xcodeDir += "proj";