ian-twilightcoder wrote: > > Once a file has been `#import`'ed, it gets stamped as if it was `#pragma > > once` and will not be re-entered, even on #include. > > Can you explain how this is happening? The only place where > `HeaderFileInfo::isPragmaOnce` is set to `true` is in > `HeaderSearch::MarkFileIncludeOnce()`, only called from > `Preprocessor::HandlePragmaOnce()`, which seems correct.
It gets `HeaderFileInfo::isImport` which causes it to be treated the same as `#pragma once` from then on. > > The problem arises when a submodule includes a multiple-include header. The > > "already included" state is global across all modules (which is necessary > > so that non-modular headers don't get compiled into multiple translation > > units and cause redeclaration errors). If another module or the main file > > #import's the same header, it becomes invisible from then on. If the > > original submodule is not imported, the include of the header will > > effectively do nothing and the header will be invisible. The only way to > > actually get the header's declarations is to somehow figure out which > > submodule consumed the header, and import that instead. That's basically > > impossible since it depends on exactly which modules were built in which > > order. > > Could this be also solved by tracking the "already included" state [per > submodule](https://github.com/llvm/llvm-project/pull/71117)? That would fix headers that can be included multiple times (which is what I'm trying to fix here). But I think that would break headers that can only be included once and are not part of a module, since their declarations would go into multiple pcms. https://github.com/llvm/llvm-project/pull/83660 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
