Author: ioeric Date: Fri Aug 24 01:59:54 2018 New Revision: 340598 URL: http://llvm.org/viewvc/llvm-project?rev=340598&view=rev Log: [FileManager] Do not call 'real_path' in getFile().
Summary: This partially rolls back the change in D48903: https://github.com/llvm-mirror/clang/commit/89aa7f45a1f728144935289d4ce69d8522999de0#diff-0025af005307891b5429b6a834823d5eR318 `real_path` can be very expensive on real file systems, and calling it on each opened file can slow down the compilation. This also slows down deserialized ASTs for which real paths need to be recalculated for each input files again. For clangd code completion latency (using preamble): Before {F7039629} After {F7039630} Reviewers: ilya-biryukov, simark Reviewed By: ilya-biryukov Subscribers: kadircet, cfe-commits Differential Revision: https://reviews.llvm.org/D51159 Modified: cfe/trunk/lib/Basic/FileManager.cpp Modified: cfe/trunk/lib/Basic/FileManager.cpp URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Basic/FileManager.cpp?rev=340598&r1=340597&r2=340598&view=diff ============================================================================== --- cfe/trunk/lib/Basic/FileManager.cpp (original) +++ cfe/trunk/lib/Basic/FileManager.cpp Fri Aug 24 01:59:54 2018 @@ -316,10 +316,14 @@ const FileEntry *FileManager::getFile(St UFE.File = std::move(F); UFE.IsValid = true; - SmallString<128> RealPathName; - if (!FS->getRealPath(InterndFileName, RealPathName)) - UFE.RealPathName = RealPathName.str(); - + llvm::SmallString<128> AbsPath(InterndFileName); + // This is not the same as `VFS::getRealPath()`, which resolves symlinks but + // can be very expensive on real file systems. + // FIXME: the semantic of RealPathName is unclear, and the name might be + // misleading. We need to clean up the interface here. + makeAbsolutePath(AbsPath); + llvm::sys::path::remove_dots(AbsPath, /*remove_dot_dot=*/true); + UFE.RealPathName = AbsPath.str(); return &UFE; } _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
