Exclude RedirectingFileSystem with null OverlayFileDir in VFSUsage #128267
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters. Learn more about bidirectional Unicode characters
| An assertion failure like the above was encountered in the swift toolchain in the context of this PR swiftlang/swift#78184 which uses a module map VFS overlay on top of the read-only Windows MSVC/ucrt include paths. |
hjyamauchi commented Feb 22, 2025
| return VFSUsage; | ||
| | ||
| llvm::vfs::FileSystem &RootFS = FileMgr.getVirtualFileSystem(); | ||
| // TODO: This only works if the `RedirectingFileSystem`s were all created by |
There was a problem hiding this comment.
Note: This PR partially addresses the limitation described by this comment.
llvmbot added clang 
| @llvm/pr-subscribers-clang Author: Hiroshi Yamauchi (hjyamauchi) ChangesThis is to avoid assertion failures like the following when RedirectingFileSystem's are created and used outside createVFSFromOverlayFiles. Full diff: https://github.com/llvm/llvm-project/pull/128267.diff 1 Files Affected:
diff --git a/clang/lib/Lex/HeaderSearch.cpp b/clang/lib/Lex/HeaderSearch.cpp index bf8fe44e4ca9c..f1e011627d499 100644 --- a/clang/lib/Lex/HeaderSearch.cpp +++ b/clang/lib/Lex/HeaderSearch.cpp @@ -149,11 +149,16 @@ std::vector<bool> HeaderSearch::collectVFSUsageAndClear() const { llvm::vfs::FileSystem &RootFS = FileMgr.getVirtualFileSystem(); // TODO: This only works if the `RedirectingFileSystem`s were all created by - // `createVFSFromOverlayFiles`. + // `createVFSFromOverlayFiles`. But at least exclude the ones with null + // OverlayFileDir. RootFS.visit([&](llvm::vfs::FileSystem &FS) { if (auto *RFS = dyn_cast<llvm::vfs::RedirectingFileSystem>(&FS)) { - VFSUsage.push_back(RFS->hasBeenUsed()); - RFS->clearHasBeenUsed(); + // Skip a `RedirectingFileSystem` with null OverlayFileDir which indicates + // that they aren't created by `createVFSFromOverlayFiles`. + if (!RFS->getOverlayFileDir().empty()) { + VFSUsage.push_back(RFS->hasBeenUsed()); + RFS->clearHasBeenUsed(); + } } }); assert(VFSUsage.size() == getHeaderSearchOpts().VFSOverlayFiles.size() && |
| CC: @Bigcheese |
Bigcheese approved these changes Feb 24, 2025
This is to avoid assertion failures like the following when RedirectingFileSystem's are created and used outside createVFSFromOverlayFiles. ``` Assertion failed: VFSUsage.size() == getHeaderSearchOpts().VFSOverlayFiles.size() && "A different number of RedirectingFileSystem's were present than " "-ivfsoverlay options passed to Clang!", file S:\SourceCache\llvm-project\clang\lib\Lex\HeaderSearch.cpp, line 162 ```
hjyamauchi added a commit to hjyamauchi/llvm-project that referenced this pull request Feb 25, 2025
This is to avoid assertion failures like the following when RedirectingFileSystem's are created and used outside createVFSFromOverlayFiles. ``` Assertion failed: VFSUsage.size() == getHeaderSearchOpts().VFSOverlayFiles.size() && "A different number of RedirectingFileSystem's were present than " "-ivfsoverlay options passed to Clang!", file S:\SourceCache\llvm-project\clang\lib\Lex\HeaderSearch.cpp, line 162 ``` Cherrypick commit llvm#128267
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
4 participants
Add this suggestion to a batch that can be applied as a single commit. This suggestion is invalid because no changes were made to the code. Suggestions cannot be applied while the pull request is closed. Suggestions cannot be applied while viewing a subset of changes. Only one suggestion per line can be applied in a batch. Add this suggestion to a batch that can be applied as a single commit. Applying suggestions on deleted lines is not supported. You must change the existing code in this line in order to create a valid suggestion. Outdated suggestions cannot be applied. This suggestion has been applied or marked resolved. Suggestions cannot be applied from pending reviews. Suggestions cannot be applied on multi-line comments. Suggestions cannot be applied while the pull request is queued to merge. Suggestion cannot be applied right now. Please check back later.
This is to avoid assertion failures like the following when RedirectingFileSystem's are created and used outside createVFSFromOverlayFiles.