ziqingluo-90 wrote: > I'm very happy that this is going somewhere! Everything makes sense to me but > I also don't know a lot about this stuff. > > > During serialization, it only serializes regions of the current translation > > unit. Regions from loaded files are not serialized. > > Hmm how does this work? When a precompiled header includes another > precompiled header, do they both get loaded independently and then you get to > combine the maps?
For loading multiple PCHs, it is a chain. Suppose `TU` includes pch `B` and `B` includes pch `C`. So one would compile and emit PCHs starting from `C`, then do it for `B` with `C` being loaded. When compile `A`, it includes pch `B` from the command line and clang actually loads `C` and `B` separately. It is the same story for modules, except that modules form a DAG instead of a chain. Clang will load each module file in an order with respect to the DAG. So for each module/PCH emitted by clang, only their own opt-out regions need to be serialized. https://github.com/llvm/llvm-project/pull/92031 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
