diff options
| -rw-r--r-- | clang-tools-extra/clangd/FSProvider.cpp | 17 | ||||
| -rw-r--r-- | clang-tools-extra/clangd/FSProvider.h | 1 |
2 files changed, 8 insertions, 10 deletions
diff --git a/clang-tools-extra/clangd/FSProvider.cpp b/clang-tools-extra/clangd/FSProvider.cpp index 5d1434bf6f0..80d6be005cc 100644 --- a/clang-tools-extra/clangd/FSProvider.cpp +++ b/clang-tools-extra/clangd/FSProvider.cpp @@ -19,7 +19,10 @@ namespace clangd { namespace { /// Always opens files in the underlying filesystem as "volatile", meaning they -/// won't be memory-mapped. This avoid locking the files on Windows. +/// won't be memory-mapped. Memory-mapping isn't desirable for clangd: +/// - edits to the underlying files change contents MemoryBuffers owned by +// SourceManager, breaking its invariants and leading to crashes +/// - it locks files on windows, preventing edits class VolatileFileSystem : public llvm::vfs::ProxyFileSystem { public: explicit VolatileFileSystem(llvm::IntrusiveRefCntPtr<FileSystem> FS) @@ -34,7 +37,7 @@ public: if (!File) return File; // Try to guess preamble files, they can be memory-mapped even on Windows as - // clangd has exclusive access to those. + // clangd has exclusive access to those and nothing else should touch them. llvm::StringRef FileName = llvm::sys::path::filename(Path); if (FileName.startswith("preamble-") && FileName.endswith(".pch")) return File; @@ -70,15 +73,11 @@ private: llvm::IntrusiveRefCntPtr<llvm::vfs::FileSystem> clang::clangd::RealFileSystemProvider::getFileSystem() const { -// Avoid using memory-mapped files on Windows, they cause file locking issues. -// FIXME: Try to use a similar approach in Sema instead of relying on -// propagation of the 'isVolatile' flag through all layers. -#ifdef _WIN32 + // Avoid using memory-mapped files. + // FIXME: Try to use a similar approach in Sema instead of relying on + // propagation of the 'isVolatile' flag through all layers. return new VolatileFileSystem( llvm::vfs::createPhysicalFileSystem().release()); -#else - return llvm::vfs::createPhysicalFileSystem().release(); -#endif } } // namespace clangd } // namespace clang diff --git a/clang-tools-extra/clangd/FSProvider.h b/clang-tools-extra/clangd/FSProvider.h index 22957892506..1fe3ba864a3 100644 --- a/clang-tools-extra/clangd/FSProvider.h +++ b/clang-tools-extra/clangd/FSProvider.h @@ -30,7 +30,6 @@ public: class RealFileSystemProvider : public FileSystemProvider { public: - // FIXME: returns the single real FS instance, which is not threadsafe. llvm::IntrusiveRefCntPtr<llvm::vfs::FileSystem> getFileSystem() const override; }; |
