[PATCH] D21157: [pdb] Improve StreamInterface to support writing

[Rui Ueyama via llvm-commits]

ruiu added a comment.

Although I agree with you that this is good for testing and completeness is generally good, but how about runtime performance? Updating read buffers incurs runtime cost and hence slows down PDB file generation. The most important thing for the linker is performance, and the current good number comes from the fact that we just do less instead of doing everything efficiently. If we add too much to the PDB reader/writer library beforehand, we risk the usability of the library for the linker. Aiming completeness is not always a win.

Being said that, the most difficult point of PDB reading/writing is to understand the format, so once we get a complete picture, it should be much easier to speed it up (by eliminating features or whatever) or write another one. So I think it's your call. If this helps creating PDB and help us understand the PDB as a file format (I guess it is), it's probably a good change.


http://reviews.llvm.org/D21157