[PATCH] Add an optional mapping from source paths to source contents.

[Dmitri Gribenko]

  I see.  It would be great if a comment about that was added to getAllCompileCommands().

  Also, you mentioned "this is for distributed build systems and generated files", so one should not expect to find everything there, and should fall back to the file system.  Please add a comment about this as well.

  LGTM with that, but I'm not an expert on this part of Clang.

http://llvm-reviews.chandlerc.com/D2121