[LLVMdev] Do all user-written passes have to be run through a PassManager object (called from outside the LLVM infrastructure)?

[jiading]

Thanks John. Out of curiosity,  I wonder if it's possible to summarize 
the LLVMpass-specific design patterns. I.e., the software engineering 
techniques that were used to design/implement the LLVM Pass 
Infrastructure. Equivalently, this may also answer the question "Why is 
the code this way". This visibility can improve understanding and that 
is likely to improve quality as more developers are better informed.