where are variables such as SYMROOT or DSTROOT defined in Xcode?

Question

I'd like to change DSTROOT(or any other variables that Xcode use for build settings) to somewhere else but can't to locate where it's defined.

I'm using Xcode 4.

Answer 1

Looking at the Xcode Build Settings Reference, it looks like $DSTROOT is only affected by $PROJECT_NAME and $SYMROOT is only affected by $SRCROOT, so I'm not sure you can easily change them at all.