[llvm-dev] [RFC] Embedded bitcode and related upstream (Part II)

[Duncan P. N. Exon Smith via llvm-dev]

>>> 3. Bitcode symbol hiding:

[...] 

>>> 4. Debug info strip to line-tables pass:
>>> As the name suggested, this pass strip down the full debug info to line-tables only. This is also one of the steps we took to prevent the leak of source code information in bitcode.
>>> 
>>> I'm very curious about what's going on here. Could you elaborate? :)
>> 
>> Cc Adrian
>> He would know more about it. I would only know that it can reconstruct -gline-tables-only debug info from full debug info. We use it as a part of the bitcode pipeline because we don't want the bitcode file to be exceedingly large but I can see this pass to be useful in other circumstances.
> 
> :)

IIRC, removing the type information and flattening the scope tree also helps to prevent leaking information about the source file, as part of (3) above.