[llvm] 3ef33e6 - [VirtualFileSystem] Support directory entries in the YAMLVFSWriter
Jonas Devlieghere via llvm-commits
llvm-commits at lists.llvm.org
Fri Mar 27 15:16:59 PDT 2020
Author: Jonas Devlieghere
Date: 2020-03-27T15:16:52-07:00
New Revision: 3ef33e69de085cb6bc028b4fc4dd39087631ac12
URL: https://github.com/llvm/llvm-project/commit/3ef33e69de085cb6bc028b4fc4dd39087631ac12
DIFF: https://github.com/llvm/llvm-project/commit/3ef33e69de085cb6bc028b4fc4dd39087631ac12.diff
LOG: [VirtualFileSystem] Support directory entries in the YAMLVFSWriter
The current implementation of the JSONWriter does not support writing
out directory entries. Earlier today I added a unit test to illustrate
the problem. When an entry is added to the YAMLVFSWriter and the path is
a directory, it will incorrectly emit the directory as a file, and any
files inside that directory will not be found by the VFS.
It's possible to partially work around the issue by only adding "leaf
nodes" (files) to the YAMLVFSWriter. However, this doesn't work for
representing empty directories. This is a problem for clients of the VFS
that want to iterate over a directory. The directory not being there is
not the same as the directory being empty.
This is not just a hypothetical problem. The FileCollector for example
does not differentiate between file and directory paths. I temporarily
worked around the issue for LLDB by ignoring directories, but I suspect
this will prove problematic sooner rather than later.
This patch fixes the issue by extending the JSONWriter to support
writing out directory entries. We store whether an entry should be
emitted as a file or directory.
Differential revision: https://reviews.llvm.org/D76670
Added:
Modified:
llvm/include/llvm/Support/VirtualFileSystem.h
llvm/lib/Support/VirtualFileSystem.cpp
llvm/unittests/Support/VirtualFileSystemTest.cpp
Removed:
################################################################################
diff --git a/llvm/include/llvm/Support/VirtualFileSystem.h b/llvm/include/llvm/Support/VirtualFileSystem.h
index 9b8d0574f008..f13140cd3448 100644
--- a/llvm/include/llvm/Support/VirtualFileSystem.h
+++ b/llvm/include/llvm/Support/VirtualFileSystem.h
@@ -506,10 +506,12 @@ getVFSFromYAML(std::unique_ptr<llvm::MemoryBuffer> Buffer,
struct YAMLVFSEntry {
template <typename T1, typename T2>
- YAMLVFSEntry(T1 &&VPath, T2 &&RPath)
- : VPath(std::forward<T1>(VPath)), RPath(std::forward<T2>(RPath)) {}
+ YAMLVFSEntry(T1 &&VPath, T2 &&RPath, bool IsDirectory = false)
+ : VPath(std::forward<T1>(VPath)), RPath(std::forward<T2>(RPath)),
+ IsDirectory(IsDirectory) {}
std::string VPath;
std::string RPath;
+ bool IsDirectory = false;
};
class VFSFromYamlDirIterImpl;
@@ -771,10 +773,13 @@ class YAMLVFSWriter {
Optional<bool> UseExternalNames;
std::string OverlayDir;
+ void addEntry(StringRef VirtualPath, StringRef RealPath, bool IsDirectory);
+
public:
YAMLVFSWriter() = default;
void addFileMapping(StringRef VirtualPath, StringRef RealPath);
+ void addDirectoryMapping(StringRef VirtualPath, StringRef RealPath);
void setCaseSensitivity(bool CaseSensitive) {
IsCaseSensitive = CaseSensitive;
diff --git a/llvm/lib/Support/VirtualFileSystem.cpp b/llvm/lib/Support/VirtualFileSystem.cpp
index 737116ce5ad2..22b4a08db9f7 100644
--- a/llvm/lib/Support/VirtualFileSystem.cpp
+++ b/llvm/lib/Support/VirtualFileSystem.cpp
@@ -1912,11 +1912,21 @@ UniqueID vfs::getNextVirtualUniqueID() {
return UniqueID(std::numeric_limits<uint64_t>::max(), ID);
}
-void YAMLVFSWriter::addFileMapping(StringRef VirtualPath, StringRef RealPath) {
+void YAMLVFSWriter::addEntry(StringRef VirtualPath, StringRef RealPath,
+ bool IsDirectory) {
assert(sys::path::is_absolute(VirtualPath) && "virtual path not absolute");
assert(sys::path::is_absolute(RealPath) && "real path not absolute");
assert(!pathHasTraversal(VirtualPath) && "path traversal is not supported");
- Mappings.emplace_back(VirtualPath, RealPath);
+ Mappings.emplace_back(VirtualPath, RealPath, IsDirectory);
+}
+
+void YAMLVFSWriter::addFileMapping(StringRef VirtualPath, StringRef RealPath) {
+ addEntry(VirtualPath, RealPath, /*IsDirectory=*/false);
+}
+
+void YAMLVFSWriter::addDirectoryMapping(StringRef VirtualPath,
+ StringRef RealPath) {
+ addEntry(VirtualPath, RealPath, /*IsDirectory=*/true);
}
namespace {
@@ -2017,7 +2027,10 @@ void JSONWriter::write(ArrayRef<YAMLVFSEntry> Entries,
if (!Entries.empty()) {
const YAMLVFSEntry &Entry = Entries.front();
- startDirectory(path::parent_path(Entry.VPath));
+ bool first_entry_is_directory = Entry.IsDirectory;
+ StringRef Dir =
+ first_entry_is_directory ? Entry.VPath : path::parent_path(Entry.VPath);
+ startDirectory(Dir);
StringRef RPath = Entry.RPath;
if (UseOverlayRelative) {
@@ -2027,13 +2040,18 @@ void JSONWriter::write(ArrayRef<YAMLVFSEntry> Entries,
RPath = RPath.slice(OverlayDirLen, RPath.size());
}
- writeEntry(path::filename(Entry.VPath), RPath);
+ if (!first_entry_is_directory)
+ writeEntry(path::filename(Entry.VPath), RPath);
for (const auto &Entry : Entries.slice(1)) {
- StringRef Dir = path::parent_path(Entry.VPath);
- if (Dir == DirStack.back())
- OS << ",\n";
- else {
+ StringRef Dir =
+ Entry.IsDirectory ? Entry.VPath : path::parent_path(Entry.VPath);
+ if (Dir == DirStack.back()) {
+ if (!first_entry_is_directory) {
+ OS << ",\n";
+ first_entry_is_directory = false;
+ }
+ } else {
while (!DirStack.empty() && !containedIn(DirStack.back(), Dir)) {
OS << "\n";
endDirectory();
diff --git a/llvm/unittests/Support/VirtualFileSystemTest.cpp b/llvm/unittests/Support/VirtualFileSystemTest.cpp
index 8ac454b511e8..f4e999dedd67 100644
--- a/llvm/unittests/Support/VirtualFileSystemTest.cpp
+++ b/llvm/unittests/Support/VirtualFileSystemTest.cpp
@@ -2200,20 +2200,14 @@ TEST_F(VFSFromYAMLTest, YAMLVFSWriterTest) {
ScopedDir _g(TestDirectory + "/g");
ScopedFile _h(TestDirectory + "/h", "");
- // This test exposes a bug/shortcoming in the YAMLVFSWriter. Below we call
- // addFileMapping for _a and _e, which causes _ab and _ef not to exists in
- // the deserialized file system, because _a and _e got emitted as regular
- // files. The counter example is _c, if we only call addFileMapping for _cd,
- // things work as expected.
-
vfs::YAMLVFSWriter VFSWriter;
- VFSWriter.addFileMapping(_a.Path, "//root/a");
+ VFSWriter.addDirectoryMapping(_a.Path, "//root/a");
VFSWriter.addFileMapping(_ab.Path, "//root/a/b");
VFSWriter.addFileMapping(_cd.Path, "//root/c/d");
- VFSWriter.addFileMapping(_e.Path, "//root/e");
- VFSWriter.addFileMapping(_ef.Path, "//root/e/f");
+ VFSWriter.addDirectoryMapping(_e.Path, "//root/e");
+ VFSWriter.addDirectoryMapping(_ef.Path, "//root/e/f");
VFSWriter.addFileMapping(_g.Path, "//root/g");
- VFSWriter.addFileMapping(_h.Path, "//root/h");
+ VFSWriter.addDirectoryMapping(_h.Path, "//root/h");
std::string Buffer;
raw_string_ostream OS(Buffer);
@@ -2236,11 +2230,11 @@ TEST_F(VFSFromYAMLTest, YAMLVFSWriterTest) {
ASSERT_TRUE(FS.get() != nullptr);
EXPECT_TRUE(FS->exists(_a.Path));
- EXPECT_FALSE(FS->exists(_ab.Path)); // FIXME: See explanation above.
+ EXPECT_TRUE(FS->exists(_ab.Path));
EXPECT_TRUE(FS->exists(_c.Path));
EXPECT_TRUE(FS->exists(_cd.Path));
EXPECT_TRUE(FS->exists(_e.Path));
- EXPECT_FALSE(FS->exists(_ef.Path)); // FIXME: See explanation above.
+ EXPECT_TRUE(FS->exists(_ef.Path));
EXPECT_TRUE(FS->exists(_g.Path));
EXPECT_TRUE(FS->exists(_h.Path));
}
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