Add test

Author: jansvoboda11

clang/unittests/Tooling/CMakeLists.txt

@@ -13,7 +13,6 @@ add_clang_unittest(ToolingTests
   CastExprTest.cpp
   CommentHandlerTest.cpp
   CompilationDatabaseTest.cpp
-  DependencyScannerTest.cpp
   DiagnosticsYamlTest.cpp
   ExecutionTest.cpp
   FixItTest.cpp
@@ -24,6 +23,8 @@ add_clang_unittest(ToolingTests
   LookupTest.cpp
   QualTypeNamesTest.cpp
   RangeSelectorTest.cpp
+  DependencyScanning/DependencyScannerTest.cpp
+  DependencyScanning/DependencyScanningFilesystemTest.cpp
   RecursiveASTVisitorTests/Attr.cpp
   RecursiveASTVisitorTests/BitfieldInitializer.cpp
   RecursiveASTVisitorTests/CallbacksLeaf.cpp

clang/unittests/Tooling/DependencyScannerTest.cpp renamed to clang/unittests/Tooling/DependencyScanning/DependencyScannerTest.cpp

@@ -1,4 +1,4 @@
-//===- unittest/Tooling/ToolingTest.cpp - Tooling unit tests --------------===//
+//===- DependencyScannerTest.cpp ------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.

clang/unittests/Tooling/DependencyScanning/DependencyScanningFilesystemTest.cpp

@@ -0,0 +1,64 @@
+//===- DependencyScanningFilesystemTest.cpp -------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Tooling/DependencyScanning/DependencyScanningFilesystem.h"
+#include "llvm/ADT/SmallString.h"
+#include "llvm/Support/VirtualFileSystem.h"
+#include "gtest/gtest.h"
+
+using namespace clang::tooling::dependencies;
+
+namespace {
+struct InstrumentingFilesystem
+    : llvm::RTTIExtends<InstrumentingFilesystem, llvm::vfs::ProxyFileSystem> {
+  unsigned NumGetRealPathCalls = 0;
+
+  using llvm::RTTIExtends<InstrumentingFilesystem,
+                          llvm::vfs::ProxyFileSystem>::RTTIExtends;
+
+  std::error_code getRealPath(const llvm::Twine &Path,
+                              llvm::SmallVectorImpl<char> &Output) override {
+    ++NumGetRealPathCalls;
+    return ProxyFileSystem::getRealPath(Path, Output);
+  }
+};
+} // namespace
+
+TEST(DependencyScanningFilesystem, CacheGetRealPath) {
+  auto InMemoryFS = llvm::makeIntrusiveRefCnt<llvm::vfs::InMemoryFileSystem>();
+  InMemoryFS->setCurrentWorkingDirectory("/");
+  InMemoryFS->addFile("/foo", 0, llvm::MemoryBuffer::getMemBuffer(""));
+  InMemoryFS->addFile("/bar", 0, llvm::MemoryBuffer::getMemBuffer(""));
+
+  auto InstrumentingFS =
+      llvm::makeIntrusiveRefCnt<InstrumentingFilesystem>(InMemoryFS);
+
+  DependencyScanningFilesystemSharedCache SharedCache;
+  DependencyScanningWorkerFilesystem DepFS(SharedCache, InstrumentingFS);
+
+  {
+    llvm::SmallString<128> Result;
+    DepFS.getRealPath("/foo", Result);
+    EXPECT_EQ(Result, "/foo");
+    EXPECT_EQ(InstrumentingFS->NumGetRealPathCalls, 1u);
+  }
+
+  {
+    llvm::SmallString<128> Result;
+    DepFS.getRealPath("/foo", Result);
+    EXPECT_EQ(Result, "/foo");
+    EXPECT_EQ(InstrumentingFS->NumGetRealPathCalls, 1u); // Cached, no increase.
+  }
+
+  {
+    llvm::SmallString<128> Result;
+    DepFS.getRealPath("/bar", Result);
+    EXPECT_EQ(Result, "/bar");
+    EXPECT_EQ(InstrumentingFS->NumGetRealPathCalls, 2u);
+  }
+}