[VirtualFileSystem] InMemoryFileSystem::status: Return a Status with the requested name

Summary:
InMemoryFileSystem::status behaves differently than
RealFileSystem::status.  The Name contained in the Status returned by
RealFileSystem::status will be the path as requested by the caller,
whereas InMemoryFileSystem::status returns the normalized path.

For example, when requested the status for "../src/first.h",
RealFileSystem returns a Status with "../src/first.h" as the Name.
InMemoryFileSystem returns "/absolute/path/to/src/first.h".

The reason for this change is that I want to make a unit test in the
clangd testsuite (where we use an InMemoryFileSystem) to reproduce a
bug I get with the clangd program (where a RealFileSystem is used).
This difference in behavior "hides" the bug in the unit test version.

An indirect impact of this change is that a -Wnonportable-include-path
warning is now emitted in test PCH/case-insensitive-include.c.  This is
because the real path of the included file (with the wrong case) was not
available previously, whereas it is now.

Reviewers: malaperle, ilya-biryukov, bkramer

Reviewed By: ilya-biryukov

Subscribers: eric_niebler, malaperle, omtcyfz, hokein, bkramer, ilya-biryukov, ioeric, cfe-commits

Differential Revision: https://reviews.llvm.org/D48903

llvm-svn: 339063

clang/lib/Basic/FileManager.cpp

@@ -315,9 +315,11 @@ const FileEntry *FileManager::getFile(StringRef Filename, bool openFile,
   UFE.InPCH = Data.InPCH;
   UFE.File = std::move(F);
   UFE.IsValid = true;
-  if (UFE.File)
+
-    if (auto RealPathName = UFE.File->getName())
+  SmallString<128> RealPathName;
-      UFE.RealPathName = *RealPathName;
+  if (!FS->getRealPath(InterndFileName, RealPathName))
+    UFE.RealPathName = RealPathName.str();
+
   return &UFE;
 }
 

clang/lib/Basic/VirtualFileSystem.cpp

@@ -474,12 +474,28 @@ class InMemoryNode {
   Status Stat;
   InMemoryNodeKind Kind;
 
+protected:
+  /// Return Stat.  This should only be used for internal/debugging use.  When
+  /// clients wants the Status of this node, they should use
+  /// \p getStatus(StringRef).
+  const Status &getStatus() const { return Stat; }
+
 public:
   InMemoryNode(Status Stat, InMemoryNodeKind Kind)
       : Stat(std::move(Stat)), Kind(Kind) {}
   virtual ~InMemoryNode() = default;
 
-  const Status &getStatus() const { return Stat; }
+  /// Return the \p Status for this node. \p RequestedName should be the name
+  /// through which the caller referred to this node. It will override
+  /// \p Status::Name in the return value, to mimic the behavior of \p RealFile.
+  Status getStatus(StringRef RequestedName) const {
+    return Status::copyWithNewName(Stat, RequestedName);
+  }
+
+  /// Get the filename of this node (the name without the directory part).
+  StringRef getFileName() const {
+    return llvm::sys::path::filename(Stat.getName());
+  }
   InMemoryNodeKind getKind() const { return Kind; }
   virtual std::string toString(unsigned Indent) const = 0;
 };
@@ -504,14 +520,21 @@ public:
   }
 };
 
-/// Adapt a InMemoryFile for VFS' File interface.
+/// Adapt a InMemoryFile for VFS' File interface.  The goal is to make
+/// \p InMemoryFileAdaptor mimic as much as possible the behavior of
+/// \p RealFile.
 class InMemoryFileAdaptor : public File {
   InMemoryFile &Node;
+  /// The name to use when returning a Status for this file.
+  std::string RequestedName;
 
 public:
-  explicit InMemoryFileAdaptor(InMemoryFile &Node) : Node(Node) {}
+  explicit InMemoryFileAdaptor(InMemoryFile &Node, std::string RequestedName)
+      : Node(Node), RequestedName(std::move(RequestedName)) {}
 
-  llvm::ErrorOr<Status> status() override { return Node.getStatus(); }
+  llvm::ErrorOr<Status> status() override {
+    return Node.getStatus(RequestedName);
+  }
 
   llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>>
   getBuffer(const Twine &Name, int64_t FileSize, bool RequiresNullTerminator,
@@ -711,7 +734,7 @@ lookupInMemoryNode(const InMemoryFileSystem &FS, detail::InMemoryDirectory *Dir,
 llvm::ErrorOr<Status> InMemoryFileSystem::status(const Twine &Path) {
   auto Node = lookupInMemoryNode(*this, Root.get(), Path);
   if (Node)
-    return (*Node)->getStatus();
+    return (*Node)->getStatus(Path.str());
   return Node.getError();
 }
 
@@ -724,7 +747,8 @@ InMemoryFileSystem::openFileForRead(const Twine &Path) {
   // When we have a file provide a heap-allocated wrapper for the memory buffer
   // to match the ownership semantics for File.
   if (auto *F = dyn_cast<detail::InMemoryFile>(*Node))
-    return std::unique_ptr<File>(new detail::InMemoryFileAdaptor(*F));
+    return std::unique_ptr<File>(
+        new detail::InMemoryFileAdaptor(*F, Path.str()));
 
   // FIXME: errc::not_a_file?
   return make_error_code(llvm::errc::invalid_argument);
@@ -736,21 +760,33 @@ namespace {
 class InMemoryDirIterator : public clang::vfs::detail::DirIterImpl {
   detail::InMemoryDirectory::const_iterator I;
   detail::InMemoryDirectory::const_iterator E;
+  std::string RequestedDirName;
+
+  void setCurrentEntry() {
+    if (I != E) {
+      SmallString<256> Path(RequestedDirName);
+      llvm::sys::path::append(Path, I->second->getFileName());
+      CurrentEntry = I->second->getStatus(Path);
+    } else {
+      // When we're at the end, make CurrentEntry invalid and DirIterImpl will
+      // do the rest.
+      CurrentEntry = Status();
+    }
+  }
 
 public:
   InMemoryDirIterator() = default;
 
-  explicit InMemoryDirIterator(detail::InMemoryDirectory &Dir)
+  explicit InMemoryDirIterator(detail::InMemoryDirectory &Dir,
-      : I(Dir.begin()), E(Dir.end()) {
+                               std::string RequestedDirName)
-    if (I != E)
+      : I(Dir.begin()), E(Dir.end()),
-      CurrentEntry = I->second->getStatus();
+        RequestedDirName(std::move(RequestedDirName)) {
+    setCurrentEntry();
   }
 
   std::error_code increment() override {
     ++I;
-    // When we're at the end, make CurrentEntry invalid and DirIterImpl will do
+    setCurrentEntry();
-    // the rest.
-    CurrentEntry = I != E ? I->second->getStatus() : Status();
     return {};
   }
 };
@@ -766,7 +802,8 @@ directory_iterator InMemoryFileSystem::dir_begin(const Twine &Dir,
   }
 
   if (auto *DirNode = dyn_cast<detail::InMemoryDirectory>(*Node))
-    return directory_iterator(std::make_shared<InMemoryDirIterator>(*DirNode));
+    return directory_iterator(
+        std::make_shared<InMemoryDirIterator>(*DirNode, Dir.str()));
 
   EC = make_error_code(llvm::errc::not_a_directory);
   return directory_iterator(std::make_shared<InMemoryDirIterator>());

clang/test/PCH/case-insensitive-include.c

@@ -13,7 +13,7 @@
 // RUN: touch -r %t-dir/case-insensitive-include.h %t.copy
 // RUN: mv %t.copy %t-dir/case-insensitive-include.h
 
-// RUN: %clang_cc1 -fsyntax-only %s -include-pch %t.pch -I %t-dir -verify
+// RUN: %clang_cc1 -Wno-nonportable-include-path -fsyntax-only %s -include-pch %t.pch -I %t-dir -verify
 
 // expected-no-diagnostics
 

clang/unittests/Basic/VirtualFileSystemTest.cpp

@@ -13,6 +13,7 @@
 #include "llvm/Support/Errc.h"
 #include "llvm/Support/Host.h"
 #include "llvm/Support/MemoryBuffer.h"
+#include "llvm/Support/Path.h"
 #include "llvm/Support/SourceMgr.h"
 #include "gtest/gtest.h"
 #include <map>
@@ -151,6 +152,13 @@ public:
     addEntry(Path, S);
   }
 };
+
+/// Replace back-slashes by front-slashes.
+std::string getPosixPath(std::string S) {
+  SmallString<128> Result;
+  llvm::sys::path::native(S, Result, llvm::sys::path::Style::posix);
+  return Result.str();
+};
 } // end anonymous namespace
 
 TEST(VirtualFileSystemTest, StatusQueries) {
@@ -782,7 +790,9 @@ TEST_F(InMemoryFileSystemTest, DirectoryIteration) {
 
   I = FS.dir_begin("/b", EC);
   ASSERT_FALSE(EC);
-  ASSERT_EQ("/b/c", I->getName());
+  // When on Windows, we end up with "/b\\c" as the name.  Convert to Posix
+  // path for the sake of the comparison.
+  ASSERT_EQ("/b/c", getPosixPath(I->getName()));
   I.increment(EC);
   ASSERT_FALSE(EC);
   ASSERT_EQ(vfs::directory_iterator(), I);
@@ -794,23 +804,19 @@ TEST_F(InMemoryFileSystemTest, WorkingDirectory) {
 
   auto Stat = FS.status("/b/c");
   ASSERT_FALSE(Stat.getError()) << Stat.getError() << "\n" << FS.toString();
-  ASSERT_EQ("c", Stat->getName());
+  ASSERT_EQ("/b/c", Stat->getName());
   ASSERT_EQ("/b", *FS.getCurrentWorkingDirectory());
 
   Stat = FS.status("c");
   ASSERT_FALSE(Stat.getError()) << Stat.getError() << "\n" << FS.toString();
 
-  auto ReplaceBackslashes = [](std::string S) {
-    std::replace(S.begin(), S.end(), '\\', '/');
-    return S;
-  };
   NormalizedFS.setCurrentWorkingDirectory("/b/c");
   NormalizedFS.setCurrentWorkingDirectory(".");
-  ASSERT_EQ("/b/c", ReplaceBackslashes(
+  ASSERT_EQ("/b/c",
-                        NormalizedFS.getCurrentWorkingDirectory().get()));
+            getPosixPath(NormalizedFS.getCurrentWorkingDirectory().get()));
   NormalizedFS.setCurrentWorkingDirectory("..");
-  ASSERT_EQ("/b", ReplaceBackslashes(
+  ASSERT_EQ("/b",
-                      NormalizedFS.getCurrentWorkingDirectory().get()));
+            getPosixPath(NormalizedFS.getCurrentWorkingDirectory().get()));
 }
 
 #if !defined(_WIN32)
@@ -919,6 +925,39 @@ TEST_F(InMemoryFileSystemTest, AddDirectoryThenAddChild) {
   ASSERT_TRUE(Stat->isRegularFile());
 }
 
+// Test that the name returned by status() is in the same form as the path that
+// was requested (to match the behavior of RealFileSystem).
+TEST_F(InMemoryFileSystemTest, StatusName) {
+  NormalizedFS.addFile("/a/b/c", 0, MemoryBuffer::getMemBuffer("abc"),
+                       /*User=*/None,
+                       /*Group=*/None, sys::fs::file_type::regular_file);
+  NormalizedFS.setCurrentWorkingDirectory("/a/b");
+
+  // Access using InMemoryFileSystem::status.
+  auto Stat = NormalizedFS.status("../b/c");
+  ASSERT_FALSE(Stat.getError()) << Stat.getError() << "\n"
+                                << NormalizedFS.toString();
+  ASSERT_TRUE(Stat->isRegularFile());
+  ASSERT_EQ("../b/c", Stat->getName());
+
+  // Access using InMemoryFileAdaptor::status.
+  auto File = NormalizedFS.openFileForRead("../b/c");
+  ASSERT_FALSE(File.getError()) << File.getError() << "\n"
+                                << NormalizedFS.toString();
+  Stat = (*File)->status();
+  ASSERT_FALSE(Stat.getError()) << Stat.getError() << "\n"
+                                << NormalizedFS.toString();
+  ASSERT_TRUE(Stat->isRegularFile());
+  ASSERT_EQ("../b/c", Stat->getName());
+
+  // Access using a directory iterator.
+  std::error_code EC;
+  clang::vfs::directory_iterator It = NormalizedFS.dir_begin("../b", EC);
+  // When on Windows, we end up with "../b\\c" as the name.  Convert to Posix
+  // path for the sake of the comparison.
+  ASSERT_EQ("../b/c", getPosixPath(It->getName()));
+}
+
 // NOTE: in the tests below, we use '//root/' as our root directory, since it is
 // a legal *absolute* path on Windows as well as *nix.
 class VFSFromYAMLTest : public ::testing::Test {

clang/unittests/Driver/ToolChainTest.cpp

@@ -113,7 +113,7 @@ TEST(ToolChainTest, VFSGCCInstallationRelativeDir) {
   std::replace(S.begin(), S.end(), '\\', '/');
 #endif
   EXPECT_EQ("Found candidate GCC installation: "
-            "/home/test/lib/gcc/arm-linux-gnueabi/4.6.1\n"
+            "/home/test/bin/../lib/gcc/arm-linux-gnueabi/4.6.1\n"
             "Selected GCC installation: "
             "/home/test/bin/../lib/gcc/arm-linux-gnueabi/4.6.1\n"
             "Candidate multilib: .;@m32\n"