From e9870c0c9145a2b261054348c7979333b8ed6655 Mon Sep 17 00:00:00 2001
From: Kadir Cetinkaya <kadircet@google.com>
Date: Fri, 30 Nov 2018 17:10:11 +0000
Subject: [PATCH] [clang] Fill RealPathName for virtual files.

Summary:
Absolute path information for virtual files were missing even if we
have already stat'd the files. This patch puts that information for virtual
files that can succesffully be stat'd.

Reviewers: ilya-biryukov

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D55054

llvm-svn: 348006
---
 clang/include/clang/Basic/FileManager.h   |  7 +++++++
 clang/lib/Basic/FileManager.cpp           | 24 +++++++++++++---------
 clang/unittests/Basic/FileManagerTest.cpp | 25 ++++++++++++++++-------
 3 files changed, 39 insertions(+), 17 deletions(-)

diff --git a/clang/include/clang/Basic/FileManager.h b/clang/include/clang/Basic/FileManager.h
index 66236c602f7a6..8e021f41c13da 100644
--- a/clang/include/clang/Basic/FileManager.h
+++ b/clang/include/clang/Basic/FileManager.h
@@ -104,6 +104,10 @@ class FileEntry {
   void closeFile() const {
     File.reset(); // rely on destructor to close File
   }
+
+  // Only for use in tests to see if deferred opens are happening, rather than
+  // relying on RealPathName being empty.
+  bool isOpenForTests() const { return File != nullptr; }
 };
 
 struct FileData;
@@ -173,6 +177,9 @@ class FileManager : public RefCountedBase<FileManager> {
   /// or a directory) as virtual directories.
   void addAncestorsAsVirtualDirs(StringRef Path);
 
+  /// Fills the RealPathName in file entry.
+  void fillRealPathName(FileEntry *UFE, llvm::StringRef FileName);
+
 public:
   FileManager(const FileSystemOptions &FileSystemOpts,
               IntrusiveRefCntPtr<llvm::vfs::FileSystem> FS = nullptr);
diff --git a/clang/lib/Basic/FileManager.cpp b/clang/lib/Basic/FileManager.cpp
index 21cb92d51c266..455d25c100a47 100644
--- a/clang/lib/Basic/FileManager.cpp
+++ b/clang/lib/Basic/FileManager.cpp
@@ -293,16 +293,8 @@ const FileEntry *FileManager::getFile(StringRef Filename, bool openFile,
   // If we opened the file for the first time, record the resulting info.
   // Do this even if the cache entry was valid, maybe we didn't previously open.
   if (F && !UFE.File) {
-    if (auto PathName = F->getName()) {
-      llvm::SmallString<128> AbsPath(*PathName);
-      // 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();
-    }
+    if (auto PathName = F->getName())
+      fillRealPathName(&UFE, *PathName);
     UFE.File = std::move(F);
     assert(!UFE.DeferredOpen && "we just opened it!");
   }
@@ -395,6 +387,7 @@ FileManager::getVirtualFile(StringRef Filename, off_t Size,
     UFE->UniqueID = Data.UniqueID;
     UFE->IsNamedPipe = Data.IsNamedPipe;
     UFE->InPCH = Data.InPCH;
+    fillRealPathName(UFE, Data.Name);
   }
 
   if (!UFE) {
@@ -438,6 +431,17 @@ bool FileManager::makeAbsolutePath(SmallVectorImpl<char> &Path) const {
   return Changed;
 }
 
+void FileManager::fillRealPathName(FileEntry *UFE, llvm::StringRef FileName) {
+  llvm::SmallString<128> AbsPath(FileName);
+  // 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();
+}
+
 llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>>
 FileManager::getBufferForFile(const FileEntry *Entry, bool isVolatile,
                               bool ShouldCloseOpenFile) {
diff --git a/clang/unittests/Basic/FileManagerTest.cpp b/clang/unittests/Basic/FileManagerTest.cpp
index 7e1e37f3c4c03..78c99909b7615 100644
--- a/clang/unittests/Basic/FileManagerTest.cpp
+++ b/clang/unittests/Basic/FileManagerTest.cpp
@@ -235,22 +235,18 @@ TEST_F(FileManagerTest, getFileDefersOpen) {
   ASSERT_TRUE(file != nullptr);
   ASSERT_TRUE(file->isValid());
   // "real path name" reveals whether the file was actually opened.
-  EXPECT_EQ("", file->tryGetRealPathName());
+  EXPECT_FALSE(file->isOpenForTests());
 
   file = manager.getFile("/tmp/test", /*OpenFile=*/true);
   ASSERT_TRUE(file != nullptr);
   ASSERT_TRUE(file->isValid());
-#ifdef _WIN32
-  EXPECT_EQ("/tmp\\test", file->tryGetRealPathName());
-#else
-  EXPECT_EQ("/tmp/test", file->tryGetRealPathName());
-#endif
+  EXPECT_TRUE(file->isOpenForTests());
 
   // However we should never try to open a file previously opened as virtual.
   ASSERT_TRUE(manager.getVirtualFile("/tmp/testv", 5, 0));
   ASSERT_TRUE(manager.getFile("/tmp/testv", /*OpenFile=*/false));
   file = manager.getFile("/tmp/testv", /*OpenFile=*/true);
-  EXPECT_EQ("", file->tryGetRealPathName());
+  EXPECT_FALSE(file->isOpenForTests());
 }
 
 // The following tests apply to Unix-like system only.
@@ -353,4 +349,19 @@ TEST_F(FileManagerTest, makeAbsoluteUsesVFS) {
   EXPECT_EQ(Path, ExpectedResult);
 }
 
+// getVirtualFile should always fill the real path.
+TEST_F(FileManagerTest, getVirtualFileFillsRealPathName) {
+  // Inject fake files into the file system.
+  auto statCache = llvm::make_unique<FakeStatCache>();
+  statCache->InjectDirectory("/tmp", 42);
+  statCache->InjectFile("/tmp/test", 43);
+  manager.addStatCache(std::move(statCache));
+
+  // Check for real path.
+  const FileEntry *file = manager.getVirtualFile("/tmp/test", 123, 1);
+  ASSERT_TRUE(file != nullptr);
+  ASSERT_TRUE(file->isValid());
+  EXPECT_EQ(file->tryGetRealPathName(), "/tmp/test");
+}
+
 } // anonymous namespace