[FileManager] getFile(open=true) after getFile(open=false) should open the file.

Summary:
Old behavior is to just return the cached entry regardless of opened-ness.
That feels buggy (though I guess nobody ever actually needed this).

This came up in the context of clangd+clang-tidy integration: we're
going to getFile(open=false) to replay preprocessor actions obscured by
the preamble, but the compilation may subsequently getFile(open=true)
for non-preamble includes.

Reviewers: ilya-biryukov

Subscribers: ioeric, kadircet, cfe-commits

Differential Revision: https://reviews.llvm.org/D54691

llvm-svn: 347205

1 files changed, 27 insertions, 0 deletions

diff --git a/clang/unittests/Basic/FileManagerTest.cpp b/clang/unittests/Basic/FileManagerTest.cpp
index 309de479499..b5855eeff7e 100644
--- a/clang/unittests/Basic/FileManagerTest.cpp
+++ b/clang/unittests/Basic/FileManagerTest.cpp
@@ -222,6 +222,33 @@ TEST_F(FileManagerTest, getFileReturnsNULLForNonexistentFile) {
   EXPECT_EQ(nullptr, file);
 }
 
+// When calling getFile(OpenFile=false); getFile(OpenFile=true) the file is
+// opened for the second call.
+TEST_F(FileManagerTest, getFileDefersOpen) {
+  llvm::IntrusiveRefCntPtr<llvm::vfs::InMemoryFileSystem> FS(
+      new llvm::vfs::InMemoryFileSystem());
+  FS->addFile("/tmp/test", 0, llvm::MemoryBuffer::getMemBufferCopy("test"));
+  FS->addFile("/tmp/testv", 0, llvm::MemoryBuffer::getMemBufferCopy("testv"));
+  FileManager manager(options, FS);
+
+  const FileEntry *file = manager.getFile("/tmp/test", /*OpenFile=*/false);
+  ASSERT_TRUE(file != nullptr);
+  ASSERT_TRUE(file->isValid());
+  // "real path name" reveals whether the file was actually opened.
+  EXPECT_EQ("", file->tryGetRealPathName());
+
+  file = manager.getFile("/tmp/test", /*OpenFile=*/true);
+  ASSERT_TRUE(file != nullptr);
+  ASSERT_TRUE(file->isValid());
+  EXPECT_EQ("/tmp/test", file->tryGetRealPathName());
+
+  // 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());
+}
+
 // The following tests apply to Unix-like system only.
 
 #ifndef _WIN32