It should just contain a vector of libraries, and clients that manipulate it should ensure that duplicates do not get entered.
Fixed with these patches: http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20070129/043837.html http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20070129/043838.html http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20070129/043839.html http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20070129/043840.html http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20070129/043841.html