From e8317bd5380fcc502539ca8481773d201555b771 Mon Sep 17 00:00:00 2001
From: Fangrui Song <i@maskray.me>
Date: Wed, 10 Oct 2018 09:52:41 -0700
Subject: [PATCH] Add namespace alias clang::vfs = llvm::vfs to adapt D52783

---
 src/clang_complete.cc | 8 ++++----
 src/clang_complete.hh | 4 ++--
 src/clang_tu.cc       | 2 +-
 src/clang_tu.hh       | 9 ++++++++-
 src/indexer.cc        | 2 +-
 5 files changed, 16 insertions(+), 9 deletions(-)

diff --git a/src/clang_complete.cc b/src/clang_complete.cc
index 32ef2ef7..3e206387 100644
--- a/src/clang_complete.cc
+++ b/src/clang_complete.cc
@@ -114,11 +114,11 @@ struct PreambleStatCache {
     return new VFS(std::move(FS), *this);
   }
 
-  IntrusiveRefCntPtr<vfs::FileSystem>
-  Consumer(IntrusiveRefCntPtr<vfs::FileSystem> FS) {
-    struct VFS : vfs::ProxyFileSystem {
+  IntrusiveRefCntPtr<llvm::vfs::FileSystem>
+  Consumer(IntrusiveRefCntPtr<llvm::vfs::FileSystem> FS) {
+    struct VFS : llvm::vfs::ProxyFileSystem {
       const PreambleStatCache &Cache;
-      VFS(IntrusiveRefCntPtr<vfs::FileSystem> FS,
+      VFS(IntrusiveRefCntPtr<llvm::vfs::FileSystem> FS,
           const PreambleStatCache &Cache)
           : ProxyFileSystem(std::move(FS)), Cache(Cache) {}
       llvm::ErrorOr<vfs::Status> status(const Twine &Path) override {
diff --git a/src/clang_complete.hh b/src/clang_complete.hh
index 7d610d2d..822ea6ca 100644
--- a/src/clang_complete.hh
+++ b/src/clang_complete.hh
@@ -63,8 +63,8 @@ struct CompletionSession
   bool inferred = false;
 
   // TODO share
-  llvm::IntrusiveRefCntPtr<clang::vfs::FileSystem> FS =
-      clang::vfs::getRealFileSystem();
+  llvm::IntrusiveRefCntPtr<llvm::vfs::FileSystem> FS =
+      llvm::vfs::getRealFileSystem();
   std::shared_ptr<clang::PCHContainerOperations> PCH;
 
   CompletionSession(const Project::Entry &file, WorkingFiles *wfiles,
diff --git a/src/clang_tu.cc b/src/clang_tu.cc
index d1dd3f02..5392ee52 100644
--- a/src/clang_tu.cc
+++ b/src/clang_tu.cc
@@ -83,7 +83,7 @@ Range FromTokenRange(const SourceManager &SM, const LangOptions &LangOpts,
 
 std::unique_ptr<CompilerInvocation>
 BuildCompilerInvocation(std::vector<const char *> args,
-                        IntrusiveRefCntPtr<vfs::FileSystem> VFS) {
+                        IntrusiveRefCntPtr<llvm::vfs::FileSystem> VFS) {
   std::string save = "-resource-dir=" + g_config->clang.resourceDir;
   args.push_back(save.c_str());
   IntrusiveRefCntPtr<DiagnosticsEngine> Diags(
diff --git a/src/clang_tu.hh b/src/clang_tu.hh
index 96325466..30d0f464 100644
--- a/src/clang_tu.hh
+++ b/src/clang_tu.hh
@@ -22,6 +22,13 @@ limitations under the License.
 #include <clang/Basic/SourceManager.h>
 #include <clang/Frontend/CompilerInstance.h>
 
+#if LLVM_VERSION_MAJOR < 8
+// D52783 Lift VFS from clang to llvm
+namespace llvm {
+namespace vfs = clang::vfs;
+}
+#endif
+
 std::string PathFromFileEntry(const clang::FileEntry &file);
 
 Range FromCharSourceRange(const clang::SourceManager &SM,
@@ -39,6 +46,6 @@ Range FromTokenRange(const clang::SourceManager &SM,
 
 std::unique_ptr<clang::CompilerInvocation>
 BuildCompilerInvocation(std::vector<const char *> args,
-                        llvm::IntrusiveRefCntPtr<clang::vfs::FileSystem> VFS);
+                        llvm::IntrusiveRefCntPtr<llvm::vfs::FileSystem> VFS);
 
 const char *ClangBuiltinTypeName(int);
diff --git a/src/indexer.cc b/src/indexer.cc
index 34137630..1b9aaac1 100644
--- a/src/indexer.cc
+++ b/src/indexer.cc
@@ -1225,7 +1225,7 @@ Index(CompletionManager *completion, WorkingFiles *wfiles, VFS *vfs,
       const std::vector<std::pair<std::string, std::string>> &remapped, bool &ok) {
   ok = true;
   auto PCH = std::make_shared<PCHContainerOperations>();
-  llvm::IntrusiveRefCntPtr<vfs::FileSystem> FS = vfs::getRealFileSystem();
+  llvm::IntrusiveRefCntPtr<llvm::vfs::FileSystem> FS = llvm::vfs::getRealFileSystem();
   std::shared_ptr<CompilerInvocation> CI = BuildCompilerInvocation(args, FS);
   // e.g. .s
   if (!CI)